libnet-functions.h(3)

📦 version 1.1.6, in debian bookworm, ubuntu jammy, ubuntu noble

🎀 libnet-functions.h(3) 🎀

okay bestie, sit down, hydrate, and let me tell you about this page 💖 it lives in the libnet manual, section 3 — you know, the section where all the library calls hang out. It's giving "the master list of everything libnet lets you call." iconic behavior, honestly ✨

✨ NAME ✨

libnet-functions.h — libnet exported function prototypes 🫶

that's it, that's the whole vibe check for this section — it's the header that holds all the prototypes libnet hands out to the world 💅

no cap, we're just getting started — the rest of this page has so much more to unpack 🦋

okay bestie, buckle in 💖 this is the entire guest list — every single function this header hands you. not me listing all of them, but you asked for the full roster, so here's the full roster. signatures are exactly as they live in libnet-functions.h, so copy them character for character, no improvising ✨

🫶 Functions 🫶

libnet_t * libnet_init (int injection_type, const char *device, char *err_buf) — the opening scene of every libnet story 🌸 you hand it an injection_type, a device, and an err_buf, and it hands you back your very own libnet_t *. main character energy fr.
void libnet_destroy (libnet_t *l) — the goodbye kiss 💋 it doesn't return anything, it just cleans up after your l.
void libnet_clear_packet (libnet_t *l) — wipe the packet, keep the context. fresh start, no drama, no return value.
void libnet_stats (libnet_t *l, struct libnet_stats *ls) — stats go into your struct libnet_stats *ls, and nothing comes back out. it's giving "here's the tea, you hold it" 🍓
int libnet_getfd (libnet_t *l) — gimme the file descriptor, int-flavored.
const char * libnet_getdevice (libnet_t *l) — the device name, as a const char *. it's literally telling you where you're at 👑
uint8_t * libnet_getpbuf (libnet_t *l, libnet_ptag_t ptag) — hand over the packet buffer for that ptag, pointer style.
uint32_t libnet_getpbuf_size (libnet_t *l, libnet_ptag_t ptag) — and here's how big that packet buffer is, in uint32_t.
char * libnet_geterror (libnet_t *l) — when things go sideways, this is your emotional support error string 😭
uint32_t libnet_getpacket_size (libnet_t *l) — the size of the whole packet, uint32_t, no notes.
int libnet_seed_prand (libnet_t *l) — seed the pseudo-random number generator. an int comes back, obviously.
uint32_t libnet_get_prand (int mod) — random number, mod-modulated, uint32_t out. chaotic in the best way 🦋
int libnet_toggle_checksum (libnet_t *l, libnet_ptag_t ptag, int mode) — flip the checksum for a ptag, mode in charge. returns an int.
char * libnet_addr2name4 (uint32_t in, uint8_t use_name) — IPv4 address in, name out, with use_name calling the shots 💅
uint32_t libnet_name2addr4 (libnet_t *l, char *host_name, uint8_t use_name) — the reverse glow-up: host_name in, IPv4 address out, use_name deciding how.
int libnet_in6_is_error (struct libnet_in6_addr addr) — is this struct libnet_in6_addr giving error? int says yes or no.
struct libnet_in6_addr libnet_name2addr6 (libnet_t *l, const char *host_name, uint8_t use_name) — name to IPv6 address, returning a whole struct libnet_in6_addr like it's nothing.
void libnet_addr2name6_r (struct libnet_in6_addr addr, uint8_t use_name, char *host_name, int host_name_len) — the reentrant one ✨ you bring your own host_name and host_name_len, it fills them in, returns nothing.
int libnet_plist_chain_new (libnet_t *l, libnet_plist_t **plist, char *token_list) — build a fresh port-list chain from a token_list, hand back the libnet_plist_t **plist. int out.
int libnet_plist_chain_next_pair (libnet_plist_t *plist, uint16_t *bport, uint16_t *eport) — next port pair, delivered through bport and eport, int returned.
int libnet_plist_chain_dump (libnet_plist_t *plist) — dump that chain, get an int.
char * libnet_plist_chain_dump_string (libnet_plist_t *plist) — same dump, but as a char * string. obsessed 🎀
int libnet_plist_chain_free (libnet_plist_t *plist) — free the chain, int back. closure, we love to see it.

libnet_ptag_t libnet_build_802_1q (const uint8_t *dst, const uint8_t *src, uint16_t tpi, uint8_t priority, uint8_t cfi, uint16_t vlan_id, uint16_t len_proto, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — 802.1Q build, libnet_ptag_t out.
libnet_ptag_t libnet_build_802_1x (uint8_t eap_ver, uint8_t eap_type, uint16_t length, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — 802.1X build, same deal.
libnet_ptag_t libnet_build_802_2 (uint8_t dsap, uint8_t ssap, uint8_t control, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — 802.2, coming through 💜
libnet_ptag_t libnet_build_802_2snap (uint8_t dsap, uint8_t ssap, uint8_t control, uint8_t *oui, uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — 802.2 SNAP edition.
libnet_ptag_t libnet_build_802_3 (const uint8_t *dst, const uint8_t *src, uint16_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — 802.3, yes ma'am.
libnet_ptag_t libnet_build_ethernet (const uint8_t *dst, const uint8_t *src, uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — the ethernet builder, the classic, the icon 🔥
libnet_ptag_t libnet_autobuild_ethernet (const uint8_t *dst, uint16_t type, libnet_t *l) — ethernet but auto, and notice there's no ptag argument here, she does her own thing ✨
libnet_ptag_t libnet_build_fddi (uint8_t fc, const uint8_t *dst, const uint8_t *src, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — FDDI, deep cuts only 💀
libnet_ptag_t libnet_autobuild_fddi (uint8_t fc, const uint8_t *dst, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, libnet_t *l) — auto-FDDI, also no ptag, also a vibe.
libnet_ptag_t libnet_build_arp (uint16_t hrd, uint16_t pro, uint8_t hln, uint8_t pln, uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha, const uint8_t *tpa, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ARP, the whole hrd/pro/hln/pln/op moment 🫶
libnet_ptag_t libnet_autobuild_arp (uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha, uint8_t *tpa, libnet_t *l) — auto-ARP. careful, tpa here is a plain uint8_t *, not const, ikyk 😌
libnet_ptag_t libnet_build_tcp (uint16_t sp, uint16_t dp, uint32_t seq, uint32_t ack, uint8_t control, uint16_t win, uint16_t sum, uint16_t urg, uint16_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — TCP header, the queen herself 👑
libnet_ptag_t libnet_build_tcp_options (const uint8_t *options, uint32_t options_s, libnet_t *l, libnet_ptag_t ptag) — TCP options, because the header alone wasn't extra enough.
libnet_ptag_t libnet_build_udp (uint16_t sp, uint16_t dp, uint16_t len, uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — UDP. short, sweet, unbothered 🌸
libnet_ptag_t libnet_build_cdp (uint8_t version, uint8_t ttl, uint16_t sum, uint16_t type, uint16_t value_s, const uint8_t *value, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — CDP, with value_s and value riding along.
libnet_ptag_t libnet_build_icmpv4_echo (uint8_t type, uint8_t code, uint16_t sum, uint16_t id, uint16_t seq, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 echo, ping-coded 🎀
libnet_ptag_t libnet_build_icmpv4_mask (uint8_t type, uint8_t code, uint16_t sum, uint16_t id, uint16_t seq, uint32_t mask, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 mask, it has a mask, naturally.
libnet_ptag_t libnet_build_icmpv4_unreach (uint8_t type, uint8_t code, uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 unreachable.
libnet_ptag_t libnet_build_icmpv4_redirect (uint8_t type, uint8_t code, uint16_t sum, uint32_t gateway, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 redirect, gateway included.
libnet_ptag_t libnet_build_icmpv4_timeexceed (uint8_t type, uint8_t code, uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 time exceeded.
libnet_ptag_t libnet_build_icmpv4_timestamp (uint8_t type, uint8_t code, uint16_t sum, uint16_t id, uint16_t seq, uint32_t otime, uint32_t rtime, uint32_t ttime, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv4 timestamp, with otime, rtime, and ttime all present and accounted for ⏰
libnet_ptag_t libnet_build_icmpv6_echo (uint8_t type, uint8_t code, uint16_t sum, uint16_t id, uint16_t seq, uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv6 echo. yes bestie, payload is a bare uint8_t * here, not const, noted 💅
libnet_ptag_t libnet_build_icmpv6_unreach (uint8_t type, uint8_t code, uint16_t sum, uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ICMPv6 unreachable, same non-const payload situation.
libnet_ptag_t libnet_build_icmpv6_ndp_nsol (uint8_t type, uint8_t code, uint16_t sum, struct libnet_in6_addr target, uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — NDP neighbor solicitation, with a target of the struct libnet_in6_addr variety.
libnet_ptag_t libnet_build_icmpv6_ndp_nadv (uint8_t type, uint8_t code, uint16_t sum, uint32_t flags, struct libnet_in6_addr target, uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — NDP neighbor advertisement, plus flags.
libnet_ptag_t libnet_build_icmpv6_ndp_opt (uint8_t type, uint8_t *option, uint32_t option_s, libnet_t *l, libnet_ptag_t ptag) — NDP option, option and option_s, no payload args at all, she's minimal 🌈
libnet_ptag_t libnet_build_igmp (uint8_t type, uint8_t reserved, uint16_t sum, uint32_t ip, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IGMP, with a reserved slot because tradition.
libnet_ptag_t libnet_build_ipv4 (uint16_t ip_len, uint8_t tos, uint16_t id, uint16_t frag, uint8_t ttl, uint8_t prot, uint16_t sum, uint32_t src, uint32_t dst, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv4 header, the blueprint, the whole tos/id/frag/ttl/prot/sum situation 🔥
libnet_ptag_t libnet_build_ipv4_options (const uint8_t *options, uint32_t options_s, libnet_t *l, libnet_ptag_t ptag) — IPv4 options, extra credit.
libnet_ptag_t libnet_autobuild_ipv4 (uint16_t len, uint8_t prot, uint32_t dst, libnet_t *l) — auto-IPv4, only len, prot, dst, and l. no ptag for you 🙈
libnet_ptag_t libnet_build_ipv6 (uint8_t tc, uint32_t fl, uint16_t len, uint8_t nh, uint8_t hl, struct libnet_in6_addr src, struct libnet_in6_addr dst, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv6 header, with src and dst as whole struct libnet_in6_addr values, not pointers ✨
libnet_ptag_t libnet_build_ipv6_frag (uint8_t nh, uint8_t reserved, uint16_t frag, uint32_t id, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv6 fragmentation header.
libnet_ptag_t libnet_build_ipv6_routing (uint8_t nh, uint8_t len, uint8_t rtype, uint8_t segments, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv6 routing header, rtype and segments included.
libnet_ptag_t libnet_build_ipv6_destopts (uint8_t nh, uint8_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv6 destination options.
libnet_ptag_t libnet_build_ipv6_hbhopts (uint8_t nh, uint8_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPv6 hop-by-hop options.
libnet_ptag_t libnet_autobuild_ipv6 (uint16_t len, uint8_t nh, struct libnet_in6_addr dst, libnet_t *l, libnet_ptag_t ptag) — auto-IPv6, and yes, this one does take a ptag. inconsistent? a little. iconic? absolutely 💜
libnet_ptag_t libnet_build_isl (uint8_t *dhost, uint8_t type, uint8_t user, uint8_t *shost, uint16_t len, const uint8_t *snap, uint16_t vid, uint16_t portindex, uint16_t reserved, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — ISL, dhost and shost are non-const pointers, mind you.
libnet_ptag_t libnet_build_ipsec_esp_hdr (uint32_t spi, uint32_t seq, uint32_t iv, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPsec ESP header, spi/seq/iv trio 🧚
libnet_ptag_t libnet_build_ipsec_esp_ftr (uint8_t len, uint8_t nh, int8_t *auth, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPsec ESP footer, and look at auth: it's an int8_t *. signed. spicy 🌶️
libnet_ptag_t libnet_build_ipsec_ah (uint8_t nh, uint8_t len, uint16_t res, uint32_t spi, uint32_t seq, uint32_t auth, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — IPsec AH. auth is a uint32_t here, totally different energy from the ESP footer one, don't mix them up bestie 😭
libnet_ptag_t libnet_build_dnsv4 (uint16_t h_len, uint16_t id, uint16_t flags, uint16_t num_q, uint16_t num_anws_rr, uint16_t num_auth_rr, uint16_t num_addi_rr, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — DNSv4, with all four record counts: num_q, num_anws_rr, num_auth_rr, num_addi_rr.
libnet_ptag_t libnet_build_rip (uint8_t cmd, uint8_t version, uint16_t rd, uint16_t af, uint16_t rt, uint32_t addr, uint32_t mask, uint32_t next_hop, uint32_t metric, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — RIP, cmd to metric, the full journey.
libnet_ptag_t libnet_build_rpc_call (uint32_t rm, uint32_t xid, uint32_t prog_num, uint32_t prog_vers, uint32_t procedure, uint32_t cflavor, uint32_t clength, uint8_t *cdata, uint32_t vflavor, uint32_t vlength, const uint8_t *vdata, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — RPC call, and this one's got two data blobs: cdata (a bare uint8_t *) and vdata (const). equal parts chaos and balance ⚖️
libnet_ptag_t libnet_build_stp_conf (uint16_t id, uint8_t version, uint8_t bpdu_type, uint8_t flags, const uint8_t *root_id, uint32_t root_pc, const uint8_t *bridge_id, uint16_t port_id, uint16_t message_age, uint16_t max_age, uint16_t hello_time, uint16_t f_delay, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — STP configuration BPDU, the long one, she's thorough 🎀
libnet_ptag_t libnet_build_stp_tcn (uint16_t id, uint8_t version, uint8_t bpdu_type, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — STP topology change notification, much shorter, much calmer.
libnet_ptag_t libnet_build_token_ring (uint8_t ac, uint8_t fc, const uint8_t *dst, const uint8_t *src, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag) — Token Ring, vintage but still serving 🦋
libnet_ptag_t libnet_autobuild_token_ring (uint8_t ac, uint8_t fc, const uint8_t *dst, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, libnet_t *l) — auto Token Ring, no ptag, same as the other autobuilds.
`libnet_ptag_t libnet_build_vrrp (uint8_t version, uint8_t type, uint8_t

…and here's the rest of the prototype parade, bestie, picking up mid-signature exactly where we left off, no shame:

vrouter_id, uint8_t priority, uint8_t ip_count, uint8_t auth_type,
uint8_t advert_int, uint16_t sum, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_mpls (uint32_t label, uint8_t experimental,
uint8_t bos, uint8_t ttl, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ntp (uint8_t leap_indicator, uint8_t version,
uint8_t mode, uint8_t stratum, uint8_t poll, uint8_t precision,
uint16_t delay_int, uint16_t delay_frac, uint16_t dispersion_int,
uint16_t dispersion_frac, uint32_t reference_id, uint32_t
ref_ts_int, uint32_t ref_ts_frac, uint32_t orig_ts_int, uint32_t
orig_ts_frac, uint32_t rec_ts_int, uint32_t rec_ts_frac, uint32_t
xmt_ts_int, uint32_t xmt_ts_frac, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2 (uint16_t len, uint8_t type, uint32_t
rtr_id, uint32_t area_id, uint16_t sum, uint16_t autype, const
uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t
ptag)
libnet_ptag_t libnet_build_ospfv2_hello (uint32_t netmask, uint16_t
interval, uint8_t opts, uint8_t priority, uint dead_int, uint32_t
des_rtr, uint32_t bkup_rtr, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_dbd (uint16_t dgram_len, uint8_t opts,
uint8_t type, uint seqnum, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsr (uint type, uint lsid, uint32_t
advrtr, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsu (uint num, const uint8_t *payload,
uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsa (uint16_t age, uint8_t opts,
uint8_t type, uint lsid, uint32_t advrtr, uint seqnum, uint16_t sum,
uint16_t len, const uint8_t *payload, uint32_t payload_s, libnet_t
*l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsa_rtr (uint16_t flags, uint16_t num,
uint id, uint data, uint8_t type, uint8_t tos, uint16_t metric,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsa_net (uint32_t nmask, uint rtrid,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsa_sum (uint32_t nmask, uint metric,
uint tos, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_ospfv2_lsa_as (uint32_t nmask, uint metric,
uint32_t fwdaddr, uint tag, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_data (const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_dhcpv4 (uint8_t opcode, uint8_t htype,
uint8_t hlen, uint8_t hopcount, uint32_t xid, uint16_t secs,
uint16_t flags, uint32_t cip, uint32_t yip, uint32_t sip, uint32_t
gip, const uint8_t *chaddr, const char *sname, const char *file,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_bootpv4 (uint8_t opcode, uint8_t htype,
uint8_t hlen, uint8_t hopcount, uint32_t xid, uint16_t secs,
uint16_t flags, uint32_t cip, uint32_t yip, uint32_t sip, uint32_t
gip, const uint8_t *chaddr, const char *sname, const char *file,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
uint32_t libnet_getgre_length (uint16_t fv)
libnet_ptag_t libnet_build_gre (uint16_t fv, uint16_t type, uint16_t
sum, uint16_t offset, uint32_t key, uint32_t seq, uint16_t len,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_egre (uint16_t fv, uint16_t type, uint16_t
sum, uint16_t offset, uint32_t key, uint32_t seq, uint16_t len,
const uint8_t *payload, uint32_t payload_s, libnet_t *l,
libnet_ptag_t ptag)
libnet_ptag_t libnet_build_gre_sre (uint16_t af, uint8_t offset, uint8_t
length, uint8_t *routing, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_gre_last_sre (libnet_t *l, libnet_ptag_t
ptag)
libnet_ptag_t libnet_build_bgp4_header (uint8_t
marker[LIBNET_BGP4_MARKER_SIZE], uint16_t len, uint8_t type, const
uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t
ptag)
libnet_ptag_t libnet_build_bgp4_open (uint8_t version, uint16_t src_as,
uint16_t hold_time, uint32_t bgp_id, uint8_t opt_len, const uint8_t
*payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_bgp4_update (uint16_t unfeasible_rt_len,
const uint8_t *withdrawn_rt, uint16_t total_path_attr_len, const
uint8_t *path_attributes, uint16_t info_len, uint8_t
*reachability_info, const uint8_t *payload, uint32_t payload_s,
libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_bgp4_notification (uint8_t err_code, uint8_t
err_subcode, const uint8_t *payload, uint32_t payload_s, libnet_t
*l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_sebek (uint32_t magic, uint16_t version,
uint16_t type, uint32_t counter, uint32_t time_sec, uint32_t
time_usec, uint32_t pid, uint32_t uid, uint32_t fd, uint8_t
cmd[SEBEK_CMD_LENGTH], uint32_t length, const uint8_t *payload,
uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_hsrp (uint8_t version, uint8_t opcode,
uint8_t state, uint8_t hello_time, uint8_t hold_time, uint8_t
priority, uint8_t group, uint8_t reserved, uint8_t
authdata[HSRP_AUTHDATA_LENGTH], uint32_t virtual_ip, const uint8_t
*payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_build_link (const uint8_t *dst, const uint8_t *src,
const uint8_t *oui, uint16_t type, const uint8_t *payload, uint32_t
payload_s, libnet_t *l, libnet_ptag_t ptag)
libnet_ptag_t libnet_autobuild_link (const uint8_t *dst, const uint8_t
*oui, uint16_t type, libnet_t *l)
int libnet_write (libnet_t *l)
uint32_t libnet_get_ipaddr4 (libnet_t *l)
struct libnet_in6_addr libnet_get_ipaddr6 (libnet_t *l)
struct libnet_ether_addr * libnet_get_hwaddr (libnet_t *l)
uint8_t * libnet_hex_aton (const char *s, int *len)
const char * libnet_version (void)
int libnet_adv_cull_packet (libnet_t *l, uint8_t **packet, uint32_t
*packet_s)
int libnet_adv_cull_header (libnet_t *l, libnet_ptag_t ptag, uint8_t
**header, uint32_t *header_s)
int libnet_adv_write_link (libnet_t *l, const uint8_t *packet, uint32_t
packet_s)
int libnet_adv_write_raw_ipv4 (libnet_t *l, const uint8_t *packet,
uint32_t packet_s)
void libnet_adv_free_packet (libnet_t *l, uint8_t *packet)
int libnet_cq_add (libnet_t *l, char *label)
libnet_t * libnet_cq_remove (libnet_t *l)
libnet_t * libnet_cq_remove_by_label (char *label)
const char * libnet_cq_getlabel (libnet_t *l)
libnet_t * libnet_cq_find_by_label (char *label)
void libnet_cq_destroy (void)
libnet_t * libnet_cq_head (void)
int libnet_cq_last (void)
libnet_t * libnet_cq_next (void)
uint32_t libnet_cq_size (void)
uint32_t libnet_cq_end_loop (void)
void libnet_diag_dump_context (libnet_t *l)
void libnet_diag_dump_pblock (libnet_t *l)
char * libnet_diag_dump_pblock_type (uint8_t type)
void libnet_diag_dump_hex (const uint8_t *packet, uint32_t len, int
swap, FILE *stream)
int libnet_write_raw_ipv4 (libnet_t *l, const uint8_t *packet, uint32_t
size)
int libnet_write_raw_ipv6 (libnet_t *l, const uint8_t *packet, uint32_t
size)
int libnet_write_link (libnet_t *l, const uint8_t *packet, uint32_t
size)
int libnet_open_raw4 (libnet_t *l)
int libnet_close_raw4 (libnet_t *l)
int libnet_open_raw6 (libnet_t *l)
int libnet_close_raw6 (libnet_t *l)
int libnet_select_device (libnet_t *l)
int libnet_open_link (libnet_t *l)
int libnet_close_link (libnet_t *l)
int libnet_do_checksum (libnet_t *l, uint8_t *iphdr, int protocol, int
h_len)
int libnet_inet_checksum (libnet_t *l, uint8_t *iphdr, int protocol, int
h_len, const uint8_t *beg, const uint8_t *end)
uint32_t libnet_compute_crc (uint8_t *buf, uint32_t len)
uint16_t libnet_ip_check (uint16_t *addr, int len)
int libnet_in_cksum (uint16_t *addr, int len)
libnet_pblock_t * libnet_pblock_probe (libnet_t *l, libnet_ptag_t ptag,
uint32_t b_len, uint8_t type)
libnet_pblock_t * libnet_pblock_new (libnet_t *l, uint32_t b_len)
int libnet_pblock_swap (libnet_t *l, libnet_ptag_t ptag1, libnet_ptag_t
ptag2)
int libnet_pblock_insert_before (libnet_t *l, libnet_ptag_t ptag1,
libnet_ptag_t ptag2)
void libnet_pblock_delete (libnet_t *l, libnet_pblock_t *p)
libnet_ptag_t libnet_pblock_update (libnet_t *l, libnet_pblock_t *p,
uint32_t h, uint8_t type)
libnet_pblock_t * libnet_pblock_find (libnet_t *l, libnet_ptag_t ptag)
int libnet_pblock_append (libnet_t *l, libnet_pblock_t *p, const void
*buf, uint32_t len)
void libnet_pblock_setflags (libnet_pblock_t *p, uint8_t flags)
int libnet_pblock_p2p (uint8_t type)
int libnet_pblock_coalesce (libnet_t *l, uint8_t **packet, uint32_t
*size)
int libnet_check_iface (libnet_t *l)

✨ Variables ✨

Okay so there is exactly one lil global variable in this whole vibe, and here she is, living her best life at file scope:

struct libnet_in6_addr in6addr_error

That's it. That's the entire variables section. Iconic minimalism, honestly. 🎀

🌈 Detailed Description 🌈

The original says, and I quote, libnet exported function prototypes. That's the whole detailed description bestie. It's giving "we put the details in the details" energy but honestly? Respect. The functions are the story. 🦋

💅 Function Documentation 💅

`char* libnet_addr2name4 (uint32_tin, uint8_tuse_name)`

So this one takes a network byte ordered IPv4 address and hands you back a pointer to either a canonical DNS name (if the address has one, which, slay) or a string of dotted decimals (the classic 1.2.3.4 situation we all know and love).

Heads up tho: this may incur a DNS lookup if the hostname and mode is set to LIBNET_RESOLVE. 👀

But if mode is set to LIBNET_DONT_RESOLVE? Then no DNS lookup happens at all, and the function just returns a pointer to a dotted decimal string. No network calls, no waiting, no drama. 🫶

The function cannot fail — which is a flex — because if no canonical name exists, it falls back on returning a dotted decimal string. Bestie always has a backup plan. 💅

⚠️ Also important: this function is non-reentrant. So don't be calling it from two places at once and expecting two separate answers, okay? That's not the vibe. 😭

Parameters:

in — network byte ordered IPv4 address
use_name — LIBNET_RESOLVE or LIBNET_DONT_RESOLVE

Returns:

a pointer to presentation format string

And that's function one of the docs, bestie — there are so many more coming, so stay tuned 💖

`libnet_addr2name6_r` 💫

void libnet_addr2name6_r (struct libnet_in6_addr addr, uint8_t use_name, char *host_name, int host_name_len)

okay so the literal documentation for this one is just "Should document this baby right here." 💀 and honestly? iconic. that's it, that's the whole entry. no parameters listed, no return value, no nothing. we move.

`libnet_adv_cull_header` 🔥

int libnet_adv_cull_header (libnet_t *l, libnet_ptag_t ptag, uint8_t **header, uint32_t *header_s)

[Advanced Interface] Pulls the header from the ptag you specify out of the libnet context you handed it. bestie listen — this one is part of the advanced interface, so it's only available when libnet is initialized in advanced mode. no advanced mode, no header, periodt. if it fails, libnet_geterror() will tell you why. 🫶

Parameters:

l — pointer to a libnet context
ptag — the ptag referencing the header to pull
header — will contain the header
header_s — will contain the header size

Returns:

1 on success, -1 on failure

`libnet_adv_cull_packet` 🎀

int libnet_adv_cull_packet (libnet_t *l, uint8_t **packet, uint32_t *packet_s)

[Advanced Interface] Yanks a prebuilt, wire-ready packet straight out of the given libnet context. if libnet was configured to do so (and it is, by default, no cap) the packet will have all checksums written in. ✨ again: advanced interface, only available when libnet is initialized in advanced mode.

⚠️ important bestie: this function performs an implicit malloc(), and you must make a corresponding call to libnet_adv_free_packet() to free the memory that packet occupies. don't leave it hanging, that's a leak and leaks are not the vibe. 😭

if it fails, libnet_geterror() can tell you why.

Parameters:

l — pointer to a libnet context
packet — will contain the wire-ready packet
packet_s — will contain the packet size

Returns:

1 on success, -1 on failure

`libnet_adv_free_packet` 🧹

void libnet_adv_free_packet (libnet_t *l, uint8_t *packet)

[Advanced Interface] Frees the memory that was allocated when libnet_adv_cull_packet() was called. the cleanup queen we love to see. 💅

Parameters:

l — pointer to a libnet context
packet — a pointer to the packet to free

`libnet_adv_write_link` 📮

int libnet_adv_write_link (libnet_t *l, const uint8_t *packet, uint32_t packet_s)

[Advanced Interface] Writes a packet to the network at the link layer. this is your go-to when you wanna write a packet that the application programmer constructed by hand, or — more commonly — to write a packet that came back from a call to libnet_adv_cull_packet(). it's part of the advanced interface, so it's only available when libnet is initialized in advanced mode. if it fails, libnet_geterror() will spill the tea on why. 🍓

Parameters:

l — pointer to a libnet context
packet — a pointer to the packet to inject
packet_s — the size of the packet

Returns:

the number of bytes written, or -1 on failure

`libnet_adv_write_raw_ipv4` 🌈

int libnet_adv_write_raw_ipv4 (libnet_t *l, const uint8_t *packet, uint32_t packet_s)

[Advanced Interface] Writes a packet to the network at the raw socket layer. same deal as above: perfect for writing a packet the application programmer built by hand, or — more commonly — a packet returned by libnet_adv_cull_packet(). advanced interface energy only, so libnet must be initialized in advanced mode. if it fails, libnet_geterror() tells you why. 🦋

Parameters:

l — pointer to a libnet context
packet — a pointer to the packet to inject
packet_s — the size of the packet

Returns:

the number of bytes written, or -1 on failure

`libnet_autobuild_arp` 👑

libnet_ptag_t libnet_autobuild_arp (uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha, uint8_t *tpa, libnet_t *l)

Autobuilds an Address Resolution Protocol (ARP) header. depending on the op value, this function builds one of several different types of RFC 826 or RFC 903 RARP packets. ✨

Parameters:

op — ARP operation type
sha — sender's hardware address
spa — sender's protocol address
tha — target hardware address
tpa — target protocol address
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_ethernet` 🧚

libnet_ptag_t libnet_autobuild_ethernet (const uint8_t *dst, uint16_t type, libnet_t *l)

Autobuilds an Ethernet header. the RFC 894 Ethernet II header is almost identical to the IEEE 802.3 header, except the field right after the source address holds the layer 3 protocol (instead of the frame's length). iykyk. 🌸

💡 bestie, only use this function when libnet is initialized with the LIBNET_LINK interface. fr fr.

Parameters:

dst — destination ethernet address
type — upper layer protocol type
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_fddi` 💜

libnet_ptag_t libnet_autobuild_fddi (uint8_t fc, const uint8_t *dst, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, libnet_t *l)

Autobuilds a Fiber Distributed Data Interface (FDDI) header. very niche, very slay. ✨

Parameters:

fc — class format and priority
dst — destination fddi address
dsap — destination service access point
ssap — source service access point
cf — cf
oui — IEEE organizational code
type — upper layer protocol
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_ipv4` 🔥

libnet_ptag_t libnet_autobuild_ipv4 (uint16_t len, uint8_t prot, uint32_t dst, libnet_t *l)

Autobuilds a version 4 Internet Protocol (IP) header. this one is chef's kiss when you just need to build an IP header fast and don't need granular control over every little thing. it takes the same len, prot, and dst arguments as libnet_build_ipv4(). it does not accept a ptag argument, but it does return a ptag. so basically: you can use it to build a new IP header but not to modify an existing one. periodt. 💅

Parameters:

len — total length of the IP packet including all subsequent data
prot — upper layer protocol
dst — destination IPv4 address (little endian)
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_ipv6` 🦋

libnet_ptag_t libnet_autobuild_ipv6 (uint16_t len, uint8_t nh, struct libnet_in6_addr dst, libnet_t *l, libnet_ptag_t ptag)

Autobuilds a version 6 RFC 2460 Internet Protocol (IP) header. same energy as the v4 one: perfect for building an IP header quickly when you don't need a granular level of control. it takes the same len, nh, and dst arguments as libnet_build_ipv4(). it doesn't accept a ptag argument, but it does return a ptag — so you can build a new IP header, not modify an existing one.

⚠️ heads up bestie: this function requires libnet_get_ipaddr6(), which is not yet implemented for Win32 platforms. 💀

Parameters:

len — length
nh — next header
dst — destination IPv6 address
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_link` 🎀

libnet_ptag_t libnet_autobuild_link (const uint8_t *dst, const uint8_t *oui, uint16_t type, libnet_t *l)

Automatically builds a link layer header for an initialized l. it figures out the proper link layer header format from how l was initialized — main character energy, honestly. currently supports Ethernet and Token Ring link layers. 🌈

Parameters:

dst — the destination MAC address
oui — Organizationally Unique Identifier (unused for Ethernet)
type — the upper layer protocol type
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_autobuild_token_ring` ⭐

libnet_ptag_t libnet_autobuild_token_ring (uint8_t ac, uint8_t fc, const uint8_t *dst, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui, uint16_t type, libnet_t *l)

Auto-builds a token ring header. we love a retro protocol moment. 💖

Parameters:

ac — access control
fc — frame control
dst — destination address
dsap — destination service access point
ssap — source service access point
cf — control field
oui — Organizationally Unique Identifier
type — upper layer protocol type
l — pointer to a libnet context

Returns:

protocol tag value on success, -1 on error

`libnet_build_802_1q` 🍓

libnet_ptag_t libnet_build_802_1q (const uint8_t *dst, const uint8_t *src, uint16_t tpi, uint8_t priority, uint8_t cfi, uint16_t vlan_id, uint16_t len_proto, const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

and that's genuinely all this page gives us for this one — just the signature, no blurb, no parameter list, nothing. 💀 not me wanting lore that isn't there. moving on.

🧱 Packet Builder Functions 🧱

The core of libnet is the platform-independent packet-building functionality. these functions let an application programmer build protocol headers (and data) in a simple and consistent manner without having to worry (too much) about low-level network odds and ends. 🫶

Each libnet_build() function builds a piece of a packet (generally a protocol header). while it is perfectly possible to build an entire, ready-to-transmit packet with a single call to a libnet_build() function, generally more than one builder-class function call is required to construct a full packet. a complete wire-ready packet generally consists of more than one piece. ✨

Every function that builds a protocol header takes a series of arguments roughly corresponding to the header values as they appear on the wire. this process is intuitive, but it often makes for functions with huge prototypes and large stack frames. 😭

🔥 one important thing to note: you must call these functions in order, corresponding to how they should appear on the wire (from the highest protocol layer on down). this building process is intuitive — it approximates what happens in an operating system kernel.

in other words, to build a Network Time Protocol (NTP) packet by using the link-layer interface, the application programmer would call the libnet_build() functions in the following order:

libnet_build_ntp()
libnet_build_udp()
libnet_build_ipv4()
libnet_build_ethernet()

this ordering is essential for libnet 1.1.x to properly link together the packet internally (previous libnet versions did not have the requirement). no cap. 💅

🎁 The Payload Interface 🎁

The payload interface specifies an optional way to include data directly after the protocol header in question. you can use this function for a variety of purposes, including the following:

Including additional or arbitrary protocol header information that is not available from a libnet interface
Including a packet payload (data segment)
Building another protocol header that is not available from a libnet interface

To employ the interface, the application programmer should construct the payload data and pass a const uint8_t * to this data and its size to the desired libnet_build() function. libnet handles the rest. 💖

💡 important to note: some functions (notably the IPv6 builders) do use the payload interface to specify variable length but ostensibly non-optional data. see the individual libnet_build_ipv6*() functions for more information.

🏷️ Protocol Tags and Packet Builder Return Values ✨

okay bestie, this is THE core glow-up concept of libnet, so pay attention 💅

Libnet uses the protocol tag (ptag) to identify individual pieces of a packet after being created. A new ptag results every time a libnet_build() function with an empty (0) ptag argument completes successfully. This new ptag now refers to the packet piece just created. The application programmer's responsibility is to save this value if he or she plans to modify this particular portion later on in the program. If the application programmer needs to modify some portion of that particular packet piece again, he or she calls the same libnet_build() function specifying the saved ptag argument. Libnet then searches for that packet piece and modifies it rather than creating a new one. Upon failure for any reason, libnet_build() functions return -1; libnet_geterror() tells you why.

🌸 `libnet_build_802_1q` — the VLAN tagging era

Builds an IEEE 802.1q VLAN tagging header. Depending on the value of len_proto, the function wraps the 802.1q header inside either an IEEE 802.3 header or an RFC 894 Ethernet II (DIX) header (both resulting in an 18-byte frame). If len is 1500 or less, most receiving protocol stacks parse the frame as an IEEE 802.3 encapsulated frame. If len is one of the Ethernet type values, most protocol stacks parse the frame as an RFC 894 Ethernet II encapsulated frame. Note the length value is calculated without the 802.1q header of 18 bytes.

Parameters:

dst — pointer to a six byte source ethernet address
src — pointer to a six byte destination ethernet address
tpi — tag protocol identifier
priority — priority
cfi — canonical format indicator
vlan_id — vlan identifier
len_proto — length (802.3) protocol (Ethernet II)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🦋 `libnet_build_802_1x`

libnet_ptag_t libnet_build_802_1x(uint8_t eap_ver, uint8_t eap_type,
    uint16_t length, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an IEEE 802.1x extended authentication protocol header. yes, the auth bestie 🫶

Parameters:

eap_ver — the EAP version
eap_type — the EAP type
length — frame length
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🎀 `libnet_build_802_2`

libnet_ptag_t libnet_build_802_2(uint8_t dsap, uint8_t ssap, uint8_t control,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an IEEE 802.2 LLC header. little LLC moment, iconic 💖

Parameters:

dsap — destination service access point
ssap — source service access point
control — control field
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🌈 `libnet_build_802_2snap`

libnet_ptag_t libnet_build_802_2snap(uint8_t dsap, uint8_t ssap,
    uint8_t control, uint8_t *oui, uint16_t type, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds an IEEE 802.2 LLC SNAP header. the SNAP variant, she's serving ✨

Parameters:

dsap — destination service access point
ssap — source service access point
control — control field
oui — Organizationally Unique Identifier
type — upper layer protocol
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

💜 `libnet_build_802_3`

libnet_ptag_t libnet_build_802_3(const uint8_t *dst, const uint8_t *src,
    uint16_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an IEEE 802.3 header. The 802.3 header is almost identical to the RFC 894 Ethernet II header, the exception being that the field immediately following the source address holds the frame's length (as opposed to the layer 3 protocol). You should only use this function when libnet is initialized with the LIBNET_LINK interface.

Parameters:

dst — destination ethernet address
src — source ethernet address
len — frame length sans header
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🍓 `libnet_build_arp`

libnet_ptag_t libnet_build_arp(uint16_t hrd, uint16_t pro, uint8_t hln,
    uint8_t pln, uint16_t op, const uint8_t *sha, const uint8_t *spa,
    const uint8_t *tha, const uint8_t *tpa, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds an Address Resolution Protocol (ARP) header. Depending on the op value, the function builds one of several different types of RFC 826 or RFC 903 RARP packets. classic "who has" energy fr fr 😭

Parameters:

hrd — hardware address format
pro — protocol address format
hln — hardware address length
pln — protocol address length
op — ARP operation type
sha — sender's hardware address
spa — sender's protocol address
tha — target hardware address
tpa — targer protocol address
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

👑 `libnet_build_bgp4_header`

libnet_ptag_t libnet_build_bgp4_header
    (uint8_t marker[LIBNET_BGP4_MARKER_SIZE], uint16_t len, uint8_t type,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an RFC 1771 Border Gateway Protocol 4 (BGP-4) header. The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASs) that reachability information traverses. This information is sufficient to construct a graph of AS connectivity from which routing loops may be pruned and some policy decisions at the AS level may be enforced. This function builds the base BGP header which is used as a preamble before any other BGP header. For example, a BGP KEEPALIVE message may be built with only this function, while an error notification requires a subsequent call to libnet_build_bgp4_notification.

Parameters:

marker — a value the receiver can predict (if the message type is not BGP OPEN, or no authentication is used, these 16 bytes are normally set as all ones)
len — total length of the BGP message, including the header
type — type code of the message (OPEN, UPDATE, NOTIFICATION or KEEPALIVE)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

💀 `libnet_build_bgp4_notification`

libnet_ptag_t libnet_build_bgp4_notification(uint8_t err_code,
    uint8_t err_subcode, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 1771 Border Gateway Protocol 4 (BGP-4) notification header. A NOTIFICATION message is sent when an error condition is detected. Specific error information may be passed through the payload interface. it's giving "we need to talk" 😭

Parameters:

err_code — type of notification
err_subcode — more specific information about the reported error.
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🧚 `libnet_build_bgp4_open`

libnet_ptag_t libnet_build_bgp4_open(uint8_t version, uint16_t src_as,
    uint16_t hold_time, uint32_t bgp_id, uint8_t opt_len,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an RFC 1771 Border Gateway Protocol 4 (BGP-4) OPEN header. This is the first message sent by each side of a BGP connection. The optional parameters options should be constructed using the payload interface (see RFC 1771 for the options structures). first message sent = main character energy, obviously 💅

Parameters:

version — protocol version (should be set to 4)
src_as — Autonomous System of the sender
hold_time — used to compute the maximum allowed time between the receipt of KEEPALIVE, and/or UPDATE messages by the sender
bgp_id — BGP identifier of the sender
opt_len — total length of the optional parameters field in bytes
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🔥 `libnet_build_bgp4_update`

libnet_ptag_t libnet_build_bgp4_update(uint16_t unfeasible_rt_len,
    const uint8_t *withdrawn_rt, uint16_t total_path_attr_len,
    const uint8_t *path_attributes, uint16_t info_len,
    uint8_t *reachability_info, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 1771 Border Gateway Protocol 4 (BGP-4) update header. Update messages are used to transfer routing information between BGP peers. gossip but make it routing 🫶

Parameters:

unfeasible_rt_len — indicates the length of the (next) 'withdrawn routes' field in bytes
withdrawn_rt — list of IP addresses prefixes for the routes that are being withdrawn; each IP address prefix is built as a 2-tuple <length (1 byte), prefix (variable)>
total_path_attr_len — indicates the length of the (next) 'path attributes' field in bytes
path_attributes — each attribute is a 3-tuple <type (2 bytes), length, value>
info_len — indicates the length of the (next) 'network layer reachability information' field in bytes (needed for internal memory size calculation)
reachability_info — 2-tuples <length (1 byte), prefix (variable)>.
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns:

protocol tag value on success, -1 on error

🥾 `libnet_build_bootpv4`

libnet_ptag_t libnet_build_bootpv4 (uint8_t opcode, uint8_t htype,
    uint8_t hlen, uint8_t hopcount, uint32_t xid, uint16_t secs,
    uint16_t flags, uint32_t cip, uint32_t yip, uint32_t sip, uint32_t gip,
    const uint8_t *chaddr, const char *sname, const char *file,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

okay bestie, this one builds you a BOOTPv4 header, and the whole parameter list is right here:

opcode — the opcode, literally just hand it over
htype — hardware type
hlen — hardware length
hopcount — hop count
xid — transaction id
secs — seconds
flags — flags
cip — client ip
yip — your ip
sip — server ip
gip — gateway ip
chaddr — client hardware address, length is hlen
sname — server host name, a null terminated string
file — boot file name, a null terminated string
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 💖

📡 `libnet_build_cdp`

libnet_ptag_t libnet_build_cdp (uint8_t version, uint8_t ttl, uint16_t sum,
    uint16_t type, uint16_t value_s, const uint8_t *value,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a Cisco Discovery Protocol (CDP) header. Cisco Systems designed CDP to aid in the network management of adjacent Cisco devices, which is very much giving "we made our own protocol, you're welcome." The CDP protocol specifies data by using a type/length/value (TLV) setup, and the first TLV can be specified by using the function's type, length, and value arguments. To specify additional TLVs, the programmer could either use the payload interface or libnet_build_data() to construct them. slay, options abound ✨

Parameters:

version — CDP version
ttl — time to live (time information should be cached by recipient)
sum — checksum (0 for libnet to autofill)
type — type of data contained in value
value_s — length of value argument
value — the CDP information string
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 💅

🧩 `libnet_build_data`

libnet_ptag_t libnet_build_data (const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds a generic libnet protocol header. This is useful for including an optional payload to a packet that might need to change repeatedly inside of a loop — like, imagine re-sending the same packet shape over and over with a fresh little payload each time. So handy 🫶

⚠️ Heads up bestie: this won't work for TCP or IP payload, they have special types. And yeah, the original says this is probably a bug. Not me exposing the source like that 💀

Parameters:

payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🌸

🍓 `libnet_build_dhcpv4`

libnet_ptag_t libnet_build_dhcpv4 (uint8_t opcode, uint8_t htype,
    uint8_t hlen, uint8_t hopcount, uint32_t xid, uint16_t secs,
    uint16_t flags, uint32_t cip, uint32_t yip, uint32_t sip, uint32_t gip,
    const uint8_t *chaddr, const char *sname, const char *file,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Same shape as the BOOTP one, because DHCP is BOOTP's glow-up obviously. Parameters:

opcode
htype
hlen
hopcount
xid
secs
flags
cip
yip
sip
gip
chaddr — client hardware address, length is hlen
sname — server host name, a null terminated string
file — boot file name, a null terminated string
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 💜

🔍 `libnet_build_dnsv4`

libnet_ptag_t libnet_build_dnsv4 (uint16_t h_len, uint16_t id,
    uint16_t flags, uint16_t num_q, uint16_t num_anws_rr,
    uint16_t num_auth_rr, uint16_t num_addi_rr, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 1035 version 4 DNS header. Additional DNS payload information should be specified using the payload interface — so the header goes here, the rest goes in payload, got it? 👑

Parameters:

h_len — the header length
id — DNS packet id
flags — control flags
num_q — number of questions
num_anws_rr — number of answer resource records
num_auth_rr — number of authority resource records
num_addi_rr — number of additional resource records
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🌈

🌀 `libnet_build_egre`

libnet_ptag_t libnet_build_egre (uint16_t fv, uint16_t type, uint16_t sum,
    uint16_t offset, uint32_t key, uint32_t seq, uint16_t len,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Generic Routing Encapsulation (GRE - RFC 1701) is used to encapsulate any protocol. Hence, the IP part of the packet is usually referred as the 'delivery header'. It is then followed by the GRE header and finally the encapsulated packet (IP or whatever). As GRE is very modular, the first GRE header describes the structure of the header, using bits and flag to specify which fields will be present in the header. it's giving nesting dolls, fr fr 🪆

Parameters:

fv — the 16 0 to 7: which fields are included in the header (checksum, seq. number, key, ...), bits 8 to 12: flag, bits 13 to 15: version.
type — which protocol is encapsulated (PPP, IP, ...)
sum — checksum (0 for libnet to autofill).
offset — byte offset from the start of the routing field to the first byte of the SRE
key — inserted by the encapsulator to authenticate the source
seq — sequence number used by the receiver to sort the packets
len — size of the GRE packet
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error ✨

🌐 `libnet_build_ethernet`

libnet_ptag_t libnet_build_ethernet (const uint8_t *dst, const uint8_t *src,
    uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an Ethernet header. The RFC 894 Ethernet II header is almost identical to the IEEE 802.3 header, with the exception that the field immediately following the source address holds the layer 3 protocol (as opposed to frame's length). Sneaky little difference, lowkey iconic.

🚨 You should only use this function when libnet is initialized with the LIBNET_LINK interface. Do not come crying to me otherwise bestie.

Parameters:

dst — destination ethernet address
src — source ethernet address
type — upper layer protocol type
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🦋

💫 `libnet_build_fddi`

libnet_ptag_t libnet_build_fddi (uint8_t fc, const uint8_t *dst,
    const uint8_t *src, uint8_t dsap, uint8_t ssap, uint8_t cf,
    const uint8_t *oui, uint16_t type, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds a Fiber Distributed Data Interface (FDDI) header. Retro networking, we love to see it 🎀

Parameters:

fc — class format and priority
dst — destination fddi address
src — source fddi address
dsap — destination service access point
ssap — source service access point
cf — cf
oui — 3 byte IEEE organizational code
type — upper layer protocol
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 💖

🛰️ `libnet_build_gre`

libnet_ptag_t libnet_build_gre (uint16_t fv, uint16_t type, uint16_t sum,
    uint16_t offset, uint32_t key, uint32_t seq, uint16_t len,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Parameters:

fv — the 16 0 to 7: which fields are included in the header (checksum, seq. number, key, ...), bits 8 to 12: flag, bits 13 to 15: version.
type — which protocol is encapsulated (PPP, IP, ...)
sum — checksum (0 for libnet to autofill).
offset — byte offset from the start of the routing field to the first byte of the SRE
key — inserted by the encapsulator to authenticate the source
seq — sequence number used by the receiver to sort the packets
len — size of the GRE packet
payload — the payload
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🔥

🏁 `libnet_build_gre_last_sre`

libnet_ptag_t libnet_build_gre_last_sre (libnet_t *l, libnet_ptag_t ptag)

No extra description in the original, just vibes and two args. Parameters:

l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🌟

🧵 `libnet_build_gre_sre`

libnet_ptag_t libnet_build_gre_sre (uint16_t af, uint8_t offset,
    uint8_t length, uint8_t *routing, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Parameters:

af — address family
offset — the offset
length — the length
routing — the routing info
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 🌸

👑 `libnet_build_hsrp`

libnet_ptag_t libnet_build_hsrp (uint8_t version, uint8_t opcode,
    uint8_t state, uint8_t hello_time, uint8_t hold_time,
    uint8_t priority, uint8_t group, uint8_t reserved,
    uint8_t authdata[HSRP_AUTHDATA_LENGTH], uint32_t virtual_ip,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a HSRP header. HSRP is a Cisco propietary protocol defined in RFC 2281 — yes, propietary and in an RFC, make it make sense 😭

Parameters:

version — version of the HSRP messages
opcode — type of message
state — current state of the router
hello_time — period in seconds between hello messages
hold_time — seconds that the current hello message is valid
priority — priority for the election proccess
group — standby group
reserved — reserved field
authdata — password
virtual_ip — virtual ip address
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error 💅

`libnet_build_icmpv4_echo()`

libnet_ptag_t libnet_build_icmpv4_echo(uint8_t type, uint8_t code,
    uint16_t sum, uint16_t id, uint16_t seq, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

okay so this one builds you an IP version 4 RFC 792 Internet Control Message Protocol (ICMP) echo request/reply header — yes bestie, it's the ping. the original ping. the blueprint. 💖

type — type of ICMP packet, and it should be ICMP_ECHOREPLY or ICMP_ECHO
code — code of ICMP packet (should be 0)
sum — checksum (0 for libnet to autofill)
id — identification number
seq — packet sequence number
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv4_mask()`

libnet_ptag_t libnet_build_icmpv4_mask(uint8_t type, uint8_t code,
    uint16_t sum, uint16_t id, uint16_t seq, uint32_t mask,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

this one's the netmask sibling 💅 it builds an IP version 4 RFC 792 Internet Control Message Protocol (ICMP) IP netmask request/reply header.

type — type of ICMP packet (should be ICMP_MASKREQ or ICMP_MASKREPLY)
code — code of ICMP packet (should be 0)
sum — checksum (0 for libnet to autofill)
id — identification number
seq — packet sequence number
mask — subnet mask
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv4_redirect()`

libnet_ptag_t libnet_build_icmpv4_redirect(uint8_t type, uint8_t code,
    uint16_t sum, uint32_t gateway, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

builds an IP version 4 RFC 792 Internet Message Control Protocol (ICMP) redirect header ✨

real talk: the IP header that caused the error message should be built by a previous call to libnet_build_ipv4(). don't skip that step, she needs her context 🫶

type — type of ICMP packet (should be ICMP_REDIRECT)
code — code of ICMP packet (should be one of the four redirect codes)
sum — checksum (0 for libnet to autofill)
gateway — gateway
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv4_timeexceed()`

libnet_ptag_t libnet_build_icmpv4_timeexceed(uint8_t type, uint8_t code,
    uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

builds an IP version 4 RFC 792 Internet Control Message Protocol (ICMP) time exceeded header — the "girl you've been looping too long" notification 😭

same deal as redirect: the IP header that caused the error message should be built by a previous call to libnet_build_ipv4().

type — type of ICMP packet (should be ICMP_TIMXCEED)
code — code of ICMP packet (ICMP_TIMXCEED_INTRANS / ICMP_TIMXCEED_REASS)
sum — checksum (0 for libnet to autofill)
payload — optional payload or NULL
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

not me noticing the docs list payload twice here 💀 iconic of them, no notes, it's still just the one optional payload and one length. i'm keeping it because i keep everything, that's the rule bestie.

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv4_timestamp()`

libnet_ptag_t libnet_build_icmpv4_timestamp(uint8_t type, uint8_t code,
    uint16_t sum, uint16_t id, uint16_t seq, uint32_t otime, uint32_t rtime,
    uint32_t ttime, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

builds an IP version 4 RFC 792 Internet Control Message Protocol (ICMP) timestamp request/reply header ⏰ the clock-in girlie of ICMP.

type — type of ICMP packet (should be ICMP_TSTAMP or ICMP_TSTAMPREPLY)
code — code of ICMP packet (should be 0)
sum — checksum (0 for libnet to autofill)
id — identification number
seq — sequence number
otime — originate timestamp
rtime — receive timestamp
ttime — transmit timestamp
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv4_unreach()`

libnet_ptag_t libnet_build_icmpv4_unreach(uint8_t type, uint8_t code,
    uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

builds an IP version 4 RFC 792 Internet Control Message Protocol (ICMP) unreachable header 🚫💀

and yes, again: the IP header that caused the error message should be built by a previous call to libnet_build_ipv4().

type — type of ICMP packet (should be ICMP_UNREACH)
code — code of ICMP packet (should be one of the 16 unreachable codes)
sum — checksum (0 for libnet to autofill)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv6_echo()`

libnet_ptag_t libnet_build_icmpv6_echo(uint8_t type, uint8_t code,
    uint16_t sum, uint16_t id, uint16_t seq, uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

v6 besties rise 🦋 this builds an IP version 6 RFC 4443 Internet Control Message Protocol (ICMP) echo or echo reply header.

type — type of ICMP packet (should be ICMP6_ECHO_REQUEST or ICMP6_ECHO_REPLY)
code — code of ICMP packet (should be zero)
sum — checksum (0 for libnet to autofill)
id — echo id number
seq — echo sequence number
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv6_ndp_nadv()`

libnet_ptag_t libnet_build_icmpv6_ndp_nadv(uint8_t type, uint8_t code,
    uint16_t sum, uint32_t flags, struct libnet_in6_addr target,
    uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

builds an IP version 6 RFC 2461 Internet Control Message Protocol (ICMP) NDP neighbour advertisement</border> header. yes i typo'd that tag and no i will not be elaborating 🙈 anyway —

could be used with libnet_build_icmpv6_ndp_opt() and ND_OPT_TARGET_LINKADDR 👑

type — type of ICMP packet (should be ND_NEIGHBOR_ADVERT)
code — code of ICMP packet (should be zero)
sum — checksum (0 for libnet to autofill)
flags — should be a bitwise or of any applicable ND_NA_FLAG_* flags
target — target ipv6 address
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv6_ndp_nsol()`

libnet_ptag_t libnet_build_icmpv6_ndp_nsol(uint8_t type, uint8_t code,
    uint16_t sum, struct libnet_in6_addr target, uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

and here's her sister — builds an IP version 6 RFC 2461 Internet Control Message Protocol (ICMP) NDP neighbour solicitation header 🌸

could be used with libnet_build_icmpv6_ndp_opt() and ICMPV6_NDP_OPT_SLLA.

type — type of ICMP packet (should be ND_NEIGHBOR_SOLICIT)
code — code of ICMP packet (should be zero)
sum — checksum (0 for libnet to autofill)
target — target ipv6 address
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv6_ndp_opt()`

libnet_ptag_t libnet_build_icmpv6_ndp_opt(uint8_t type, uint8_t *option,
    uint32_t option_s, libnet_t *l, libnet_ptag_t ptag);

builds ICMPv6 NDP options 🎀 the little accessory that goes with the NDP fits above.

type — one of ND_OPT_* types
option — option data
option_s — size of option data (will be padded out to an 8-byte boundary)
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_icmpv6_unreach()`

libnet_ptag_t libnet_build_icmpv6_unreach(uint8_t type, uint8_t code,
    uint16_t sum, uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

builds an IP version 6 RFC 4443 Internet Control Message Protocol (ICMP) unreachable header 😭

heads up bestie: the IP header that caused the error message should be built by a previous call to libnet_build_ipv6(). note the v6 this time, don't mix them up 💀

type — type of ICMP packet (should be ICMP6_DST_UNREACH)
code — code of ICMP packet (should be one of the 5 ICMP6_DST_UNREACH_* codes)
sum — checksum (0 for libnet to autofill)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_igmp()`

libnet_ptag_t libnet_build_igmp(uint8_t type, uint8_t reserved, uint16_t sum,
    uint32_t ip, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

builds an RFC 1112 Internet Group Memebership Protocol (IGMP) header 🌈 group chat, but make it multicast.

type — packet type
reserved — (should be 0 for IGMPv1)
sum — checksum (0 for libnet to autofill)
ip — IPv4 address (in standard/network byte order)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

Note: reserved was previously called code, which it is not, in any IGMP version. the glow-up was real and also necessary 💅

`libnet_build_ipsec_ah()`

libnet_ptag_t libnet_build_ipsec_ah(uint8_t nh, uint8_t len, uint16_t res,
    uint32_t spi, uint32_t seq, uint32_t auth, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag);

builds an Internet Protocol Security Authentication header 🔐 security girlie behaviour, we love to see it.

nh — next header
len — payload length
res — reserved
spi — security parameter index
seq — sequence number
auth — authentication data
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_ipsec_esp_ftr()`

libnet_ptag_t libnet_build_ipsec_esp_ftr(uint8_t len, uint8_t nh,
    int8_t *auth, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag);

last one in this batch — builds an Internet Protocol Security Encapsulating Security Payload footer ✨ the trailer, the outro, the mic drop at the end of the packet 🎤

len — padding length
nh — next header
auth — authentication data
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🦋 `libnet_build_ipsec_esp_hdr`

libnet_ptag_t libnet_build_ipsec_esp_hdr(uint32_t spi, uint32_t seq,
    uint32_t iv, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an Internet Protocol Security Encapsulating Security Payload header. yes bestie we're doing IPsec now, we're so back 💜

Parameters:

spi — security parameter index
seq — ESP sequence number
iv — initialization vector
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🌈 `libnet_build_ipv4`

libnet_ptag_t libnet_build_ipv4(uint16_t ip_len, uint8_t tos, uint16_t id,
    uint16_t frag, uint8_t ttl, uint8_t prot, uint16_t sum, uint32_t src,
    uint32_t dst, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a version 4 RFC 791 Internet Protocol (IP) header. the classic. the blueprint. the moment. 👑

Parameters:

ip_len — total length of the IP packet including all subsequent data (subsequent data includes any IP options and IP options padding)
tos — type of service bits
id — IP identification number
frag — fragmentation bits and offset
ttl — time to live in the network
prot — upper layer protocol
sum — checksum (0 for libnet to autofill) ✨
src — source IPv4 address (little endian)
dst — destination IPv4 address (little endian)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🎀 `libnet_build_ipv4_options`

libnet_ptag_t libnet_build_ipv4_options(const uint8_t *options,
    uint32_t options_s, libnet_t *l, libnet_ptag_t ptag)

Builds an version 4 Internet Protocol (IP) options header. This function expects options to be a valid IP options string of size options_s, no larger than 40 bytes (the maximum size of an options string). like, that's the ceiling, bestie, do not test it 💀

When building a chain, the options must be built, then the IPv4 header. order matters, it's giving choreography 🩰

When updating a chain, if the block following the options is an IPv4 header, it's total length and header length will be updated if the options block size changes.

Parameters:

options — byte string of IP options (it will be padded up to be an integral multiple of 32-bit words).
options_s — length of options string
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🧚 `libnet_build_ipv6`

libnet_ptag_t libnet_build_ipv6(uint8_t tc, uint32_t fl, uint16_t len,
    uint8_t nh, uint8_t hl, struct libnet_in6_addr src,
    struct libnet_in6_addr dst, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds a version 6 RFC 2460 Internet Protocol (IP) header. glow up complete 💅

Parameters:

tc — traffic class
fl — flow label
len — total length of the IP packet
nh — next header
hl — hop limit
src — source IPv6 address
dst — destination IPv6 address
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🌸 `libnet_build_ipv6_destopts`

libnet_ptag_t libnet_build_ipv6_destopts(uint8_t nh, uint8_t len,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a version 6 RFC 2460 Internet Protocol (IP) destination options header. This function is special in that it uses the payload interface to include the options data. The application programmer will build an IPv6 options byte string and pass it to the function using the payload interface. so like, the payload is the options here, that's the whole vibe 🫶

Parameters:

nh — next header
len — length of the header in 8-byte octets not including the first 8 octets
payload — options payload
payload_s — payload length
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

💜 `libnet_build_ipv6_frag`

libnet_ptag_t libnet_build_ipv6_frag(uint8_t nh, uint8_t reserved,
    uint16_t frag, uint32_t id, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds a version 6 RFC 2460 Internet Protocol (IP) fragmentation header.

Parameters:

nh — next header
reserved — unused value... OR IS IT! 👀 (we're keeping this exactly as written, it's iconic)
frag — fragmentation bits (ala ipv4)
id — packet identification
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🍓 `libnet_build_ipv6_hbhopts`

libnet_ptag_t libnet_build_ipv6_hbhopts(uint8_t nh, uint8_t len,
    const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a version 6 RFC 2460 Internet Protocol (IP) hop by hop options header. This function is special in that it uses the payload interface to include the options data. The application programmer will build an IPv6 hop by hop options byte string and pass it to the function using the payload interface. same energy as libnet_build_ipv6_destopts, different header, no cap 🧚

Parameters:

nh — next header
len — length of the header in 8-byte octets not including the first 8 octets
payload — options payload
payload_s — payload length
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

⭐ `libnet_build_ipv6_routing`

libnet_ptag_t libnet_build_ipv6_routing(uint8_t nh, uint8_t len,
    uint8_t rtype, uint8_t segments, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds a version 6 RFC 2460 Internet Protocol (IP) routing header. This function is special in that it uses the payload interface to include the 'type-specific data'; that is the routing information. Most often this will be a number of 128-bit IPv6 addresses. The application programmer will build a byte string of IPv6 address and pass them to the function using the payload interface. it's giving "here's my itinerary" 🗺️

Parameters:

nh — next header
len — length of the header in 8-byte octets not including the first 8 octets
rtype — routing header type
segments — number of routing segments that follow
payload — optional payload of routing information
payload_s — payload length
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🔥 `libnet_build_isl`

libnet_ptag_t libnet_build_isl(uint8_t *dhost, uint8_t type, uint8_t user,
    uint8_t *shost, uint16_t len, const uint8_t *snap, uint16_t vid,
    uint16_t portindex, uint16_t reserved, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds a Cisco Inter-Switch Link (ISL) header.

Parameters:

dhost — destination address (should be 01:00:0c:00:00)
type — type of frame
user — user defined data
shost — source mac address
len — total length of the encapuslated packet less 18 bytes
snap — SNAP information (0xaaaa03 + vendor code)
vid — 15 bit VLAN ID, 1 bit BPDU or CDP indicator
portindex — port index
reserved — used for FDDI and token ring
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

💖 `libnet_build_link`

libnet_ptag_t libnet_build_link(const uint8_t *dst, const uint8_t *src,
    const uint8_t *oui, uint16_t type, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds a link layer header for an initialized l. The function determines the proper link layer header format from how l was initialized. The function current supports Ethernet and Token Ring link layers. it reads the room and picks the fit, we love an adaptive queen ✨

Parameters:

dst — the destination MAC address
src — the source MAC address
oui — Organizationally Unique Identifier (unused for Ethernet)
type — the upper layer protocol type
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🦋 `libnet_build_mpls`

libnet_ptag_t libnet_build_mpls(uint32_t label, uint8_t experimental,
    uint8_t bos, uint8_t ttl, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 3032 Multi-Protocol Label Switching (MPLS) header.

Parameters:

label — 20-bit label value
experimental — 3-bit reserved field
bos — 1-bit bottom of stack identifier
ttl — time to live
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🌈 `libnet_build_ntp`

libnet_ptag_t libnet_build_ntp(uint8_t leap_indicator, uint8_t version,
    uint8_t mode, uint8_t stratum, uint8_t poll, uint8_t precision,
    uint16_t delay_int, uint16_t delay_frac, uint16_t dispersion_int,
    uint16_t dispersion_frac, uint32_t reference_id, uint32_t ref_ts_int,
    uint32_t ref_ts_frac, uint32_t orig_ts_int, uint32_t orig_ts_frac,
    uint32_t rec_ts_int, uint32_t rec_ts_frac, uint32_t xmt_ts_int,
    uint32_t xmt_ts_frac, const uint8_t *payload, uint32_t payload_s,
    libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 958 Network Time Protocol (NTP) header. so many timestamps, she's thorough 💅

Parameters:

leap_indicator — the leap indicator
version — NTP protocol version
mode — NTP mode
stratum — stratum
poll — polling interval
precision — precision
delay_int — delay interval
delay_frac — delay fraction
dispersion_int — dispersion interval
dispersion_frac — dispersion fraction
reference_id — reference id
ref_ts_int — reference timestamp integer
ref_ts_frac — reference timestamp fraction
orig_ts_int — original timestamp integer
orig_ts_frac — original timestamp fraction
rec_ts_int — receiver timestamp integer
rec_ts_frac — receiver timestamp fraction
xmt_ts_int — transmit timestamp integer
xmt_ts_frac — transmit timestamp integer (yes, that's what it says, we are reporting faithfully 🫡)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🛰️ `libnet_build_ospfv2`

libnet_ptag_t libnet_build_ospfv2 (uint16_tlen, uint8_ttype, uint32_trtr_id,
    uint32_tarea_id, uint16_tsum, uint16_tautype, const uint8_t *payload,
    uint32_tpayload_s, libnet_t *l, libnet_ptag_tptag)

okay so this is THE base OSPFv2 header builder, the main character of the OSPF crew 👑 hand it the numbers, it hands you a header.

Parameters:

len — the len value, that's it, that's the whole description, you got this bestie 💅
type — the type value
rtr_id — the router id
area_id — the area id
sum — the checksum
autype — the authentication type
payload — optional payload, or NULL if you're not bringing snacks
payload_s — payload length, or 0
l — pointer to a libnet context 🫶
ptag — protocol tag, for when you wanna modify an existing header; pass 0 to build a fresh new one

Returns: the protocol tag value on success, or -1 if it said no 😭

📨 `libnet_build_ospfv2_dbd`

libnet_ptag_t libnet_build_ospfv2_dbd (uint16_tdgram_len, uint8_topts,
    uint8_ttype, uintseqnum, const uint8_t *payload, uint32_tpayload_s,
    libnet_t *l, libnet_ptag_tptag)

the Database Description packet builder, for when the routers are like "hey here's my whole database, no cap" 📚

Parameters:

dgram_len — the datagram length
opts — the options
type — the type
seqnum — the sequence number
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

👋 `libnet_build_ospfv2_hello`

libnet_ptag_t libnet_build_ospfv2_hello (uint32_tnetmask, uint16_tinterval,
    uint8_topts, uint8_tpriority, uintdead_int, uint32_tdes_rtr,
    uint32_tbkup_rtr, const uint8_t *payload, uint32_tpayload_s, libnet_t
    *l, libnet_ptag_tptag)

the HELLO packet!! it's giving "hi bestie, are we neighbors or not" 🌸 this is literally how OSPF friendships start.

Parameters:

netmask — the network mask
interval — the interval
opts — the options
priority — the priority
dead_int — the dead interval
des_rtr — the designated router
bkup_rtr — the backup designated router
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🧾 `libnet_build_ospfv2_lsa`

libnet_ptag_t libnet_build_ospfv2_lsa (uint16_tage, uint8_topts,
    uint8_ttype, uintlsid, uint32_tadvrtr, uintseqnum, uint16_tsum,
    uint16_tlen, const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

the Link State Advertisement header — the receipts of the OSPF world 🧚

Parameters:

age — the age
opts — the options
type — the type
lsid — the link state id
advrtr — the advertising router
seqnum — the sequence number
sum — the checksum
len — the length
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🌐 `libnet_build_ospfv2_lsa_as`

libnet_ptag_t libnet_build_ospfv2_lsa_as (uint32_tnmask, uintmetric,
    uint32_tfwdaddr, uinttag, const uint8_t *payload, uint32_tpayload_s,
    libnet_t *l, libnet_ptag_tptag)

the AS (Autonomous System) external LSA builder — this is how routes sneak in from outside the area 👀

Parameters:

nmask — the network mask
metric — the metric
fwdaddr — the forwarding address
tag — the tag
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🕸️ `libnet_build_ospfv2_lsa_net`

libnet_ptag_t libnet_build_ospfv2_lsa_net (uint32_tnmask, uintrtrid, const
    uint8_t *payload, uint32_tpayload_s, libnet_t *l, libnet_ptag_tptag)

network LSA time!! 🎀 this one's all about the broadcast segment and which routers are chillin' on it.

Parameters:

nmask — the network mask
rtrid — the router id
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🛠️ `libnet_build_ospfv2_lsa_rtr`

libnet_ptag_t libnet_build_ospfv2_lsa_rtr (uint16_tflags, uint16_tnum,
    uintid, uintdata, uint8_ttype, uint8_ttos, uint16_tmetric, const uint8_t
    *payload, uint32_tpayload_s, libnet_t *l, libnet_ptag_tptag)

router LSA — the "here's what I'm connected to" flex of every OSPF router 💪

Parameters:

flags — the flags
num — the number
id — the id
data — the data
type — the type
tos — the TOS
metric — the metric
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🗺️ `libnet_build_ospfv2_lsa_sum`

libnet_ptag_t libnet_build_ospfv2_lsa_sum (uint32_tnmask, uintmetric,
    uinttos, const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

summary LSA builder — it's giving "let me condense all this for you" ✨

Parameters:

nmask — the network mask
metric — the metric
tos — the TOS
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🔍 `libnet_build_ospfv2_lsr`

libnet_ptag_t libnet_build_ospfv2_lsr (uinttype, uintlsid, uint32_tadvrtr,
    const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

Link State Request — the polite "may I please see that LSA, bestie?" of OSPF 🙏

Parameters:

type — the type
lsid — the link state id
advrtr — the advertising router
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

📦 `libnet_build_ospfv2_lsu`

libnet_ptag_t libnet_build_ospfv2_lsu (uintnum, const uint8_t *payload,
    uint32_tpayload_s, libnet_t *l, libnet_ptag_tptag)

Link State Update — and HERE is the actual delivery, the LSAs arriving like your packages on a good day 🚚💨

Parameters:

num — the number
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🚦 `libnet_build_rip`

libnet_ptag_t libnet_build_rip (uint8_tcmd, uint8_tversion, uint16_trd,
    uint16_taf, uint16_trt, uint32_taddr, uint32_tmask, uint32_tnext_hop,
    uint32_tmetric, const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

Builds a Routing Information Protocol header (RFCs 1058 and 2453). old school routing but still iconic, ngl 🌈

Parameters:

cmd — command
version — protocol version
rd — version one: 0, version two: routing domain
af — address family
rt — version one: 0, version two: route tag
addr — IPv4 address
mask — version one: 0, version two: subnet mask
next_hop — version one: 0, version two: next hop address
metric — routing metric
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

☎️ `libnet_build_rpc_call`

libnet_ptag_t libnet_build_rpc_call (uint32_trm, uint32_txid,
    uint32_tprog_num, uint32_tprog_vers, uint32_tprocedure, uint32_tcflavor,
    uint32_tclength, uint8_t *cdata, uint32_tvflavor, uint32_tvlength, const
    uint8_t *vdata, const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

Builds an Remote Procedure Call (Version 2) Call message header as specified in RFC 1831. This builder provides the option for specifying the record marking which is required when used with streaming protocols (TCP). 🫶

Parameters:

rm — record marking indicating the position in a stream, 0 otherwise
xid — transaction identifier used to link calls and replies
prog_num — remote program specification typically between 0 - 1fffffff
prog_vers — remote program version specification
procedure — procedure to be performed by remote program
cflavor — authentication credential type
clength — credential length (should be 0)
cdata — opaque credential data (currently unused)
vflavor — authentication verifier type
vlength — verifier length (should be 0)
vdata — opaque verifier data (currently unused)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🕵️ `libnet_build_sebek`

libnet_ptag_t libnet_build_sebek (uint32_tmagic, uint16_tversion,
    uint16_ttype, uint32_tcounter, uint32_ttime_sec, uint32_ttime_usec,
    uint32_tpid, uint32_tuid, uint32_tfd, uint8_tcmd[SEBEK_CMD_LENGTH],
    uint32_tlength, const uint8_t *payload, uint32_tpayload_s, libnet_t *l,
    libnet_ptag_tptag)

Builds a Sebek header. The Sebek protocol was designed by the Honeynet Project as a transport mechanism for post-intrusion forensic data. More information may be found here: http://www.honeynet.org/papers/sebek.pdf. 🍓 yes this is the honeypot one, it's giving detective energy.

Parameters:

magic — identify packets that should be hidden
version — protocol version, currently 1
type — type of record (read data is type 0, write data is type 1)
counter — PDU counter used to identify when packet are lost
time_sec — seconds since EPOCH according to the honeypot
time_usec — residual microseconds
pid — PID
uid — UID
fd — FD
cmd — 12 first characters of the command
length — length in bytes of the PDU's body
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🌳 `libnet_build_stp_conf`

libnet_ptag_t libnet_build_stp_conf (uint16_tid, uint8_tversion,
    uint8_tbpdu_type, uint8_tflags, const uint8_t *root_id, uint32_troot_pc,
    const uint8_t *bridge_id, uint16_tport_id, uint16_tmessage_age,
    uint16_tmax_age, uint16_thello_time, uint16_tf_delay, const uint8_t
    *payload, uint32_tpayload_s, libnet_t *l, libnet_ptag_tptag)

Builds an IEEE 802.1d Spanning Tree Protocol (STP) configuration header. STP frames are usually encapsulated inside of an 802.2 + 802.3 frame combination. 💜

Parameters:

id — protocol id
version — protocol version
bpdu_type — bridge protocol data unit type
flags — flags
root_id — root id
root_pc — root path cost
bridge_id — bridge id
port_id — port id
message_age — message age
max_age — max age
hello_time — hello time
f_delay — forward delay
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

🔄 `libnet_build_stp_tcn`

libnet_ptag_t libnet_build_stp_tcn (uint16_tid, uint8_tversion,
    uint8_tbpdu_type, const uint8_t *payload, uint32_tpayload_s, libnet_t
    *l, libnet_ptag_tptag)

Builds an IEEE 802.1d Spanning Tree Protocol (STP) topology change notification header. STP frames are usually encapsulated inside of an 802.2 + 802.3 frame combination. 🦋 the "the tree changed, everyone update" announcement, fr fr.

Parameters:

id — protocol id
version — protocol version
bpdu_type — bridge protocol data unit type
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_tcp` 💖

libnet_ptag_t libnet_build_tcp(uint16_t sp, uint16_t dp, uint32_t seq,
    uint32_t ack, uint8_t control, uint16_t win, uint16_t sum, uint16_t urg,
    uint16_t len, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an RFC 793 Transmission Control Protocol (TCP) header. Yes bestie, the actual TCP. The one that carries basically everything you love. 🫶

Parameters:

sp — source port
dp — destination port
seq — sequence number
ack — acknowledgement number
control — control flags
win — window size
sum — checksum (0 for libnet to autofill)
urg — urgent pointer
len — total length of the TCP packet (for checksum calculation)
payload
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_tcp_options` ✨

libnet_ptag_t libnet_build_tcp_options(const uint8_t *options,
    uint32_t options_s, libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 793 Transmission Control Protocol (TCP) options header. The function expects options to be a valid TCP options string of size options_s, which is no larger than 40 bytes (the maximum size of an options string). It's giving "there's a hard cap and we are respecting it." 🎀

The function checks to ensure that the packet consists of a TCP header preceded by an IPv4 header, and that the addition of the options string would not result in a packet larger than 65,535 bytes (IPMAXPACKET). The function counts up the number of 32-bit words in the options string and adjusts the TCP header length value as necessary. Doing the math so you don't have to, periodt. 💅

Parameters:

options — byte string of TCP options
options_s — length of options string
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_token_ring` 🦋

libnet_ptag_t libnet_build_token_ring(uint8_t ac, uint8_t fc, const uint8_t *dst,
    const uint8_t *src, uint8_t dsap, uint8_t ssap, uint8_t cf, const uint8_t *oui,
    uint16_t type, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds a token ring header. Retro networking, we stan a vintage moment. 🌸

Parameters:

ac — access control
fc — frame control
dst — destination address
src — source address
dsap — destination service access point
ssap — source service access point
cf — control field
oui — Organizationally Unique Identifier
type — upper layer protocol type
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

ok yes, fc and cf are both in this signature. Not a typo on my part bestie, they're two different things. fc is frame control up top, cf is the control field later. Read it slow. 🫠

`libnet_build_udp` 🎀

libnet_ptag_t libnet_build_udp(uint16_t sp, uint16_t dp, uint16_t len,
    uint16_t sum, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
    libnet_ptag_t ptag)

Builds an RFC 768 User Datagram Protocol (UDP) header. No handshakes, no drama, just vibes and datagrams. 💅

Parameters:

sp — source port
dp — destination port
len — total length of the UDP packet
sum — checksum (0 for libnet to autofill)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_build_vrrp` 👑

libnet_ptag_t libnet_build_vrrp(uint8_t version, uint8_t type,
    uint8_t vrouter_id, uint8_t priority, uint8_t ip_count, uint8_t auth_type,
    uint8_t advert_int, uint16_t sum, const uint8_t *payload,
    uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

Builds an RFC 2338 Virtual Router Redundacy Protool (VRRP) header. Use the payload interface to specify address and autthentication information. 💖

To build a 'legal' packet, the destination IPv4 address should be the multicast address 224.0.0.18, the IP TTL should be set to 255, and the IP protocol should be set to 112. Do all three or the packet is lowkey not doing what you think it's doing. ⭐

Parameters:

version — VRRP version (should be 2)
type — VRRP packet type (should be 1 -- ADVERTISEMENT)
vrouter_id — virtual router identification
priority — priority (higher numbers indicate higher priority)
ip_count — number of IPv4 addresses contained in this advertisement
auth_type — type of authentication (0, 1, 2 -- see RFC)
advert_int — interval between advertisements
sum — checksum (0 for libnet to autofill)
payload — optional payload or NULL
payload_s — payload length or 0
l — pointer to a libnet context
ptag — protocol tag to modify an existing header, 0 to build a new one

Returns: protocol tag value on success, -1 on error

`libnet_clear_packet` 🧹

void libnet_clear_packet(libnet_t *l)

Clears the current packet referenced and frees all pblocks. Should be called when the programmer want to send a completely new packet of a different type using the same context. Basically the "new packet, who dis" button. 🌈

Parameters:

l — pointer to a libnet context

`libnet_cq_add` `[Context Queue]` 🍓

int libnet_cq_add(libnet_t *l, char *label)

Adds a new context to the libnet context queue. If no queue exists, this function will create the queue and add the specified libnet context as the first entry on the list. The functions checks to ensure niether l nor label are NULL, and that label doesn't refer to an existing context already in the queue. Additionally, l should refer to a libnet context previously initialized with a call to libnet_init(). If the context queue in write locked, this function will fail. 🔒

Parameters:

l — pointer to a libnet context
label — a canonical name given to recognize the new context, no longer than LIBNET_LABEL_SIZE

Returns: 1 on success, -1 on failure

`libnet_cq_destroy` `[Context Queue]` 💀

void libnet_cq_destroy(void)

Destroys the entire context queue, calling libnet_destroy() on each member context. Everyone gets cleaned up. No leftovers. 🫶

`libnet_cq_end_loop` `[Context Queue]` 🌸

uint32_t libnet_cq_end_loop(void)

`libnet_cq_find_by_label` `[Context Queue]` 🔎

libnet_t* libnet_cq_find_by_label(char *label)

Locates a libnet context from the queue, indexed by a canonical label. Like find-my-friend but for contexts. 💖

Parameters:

label — canonical label of the libnet context to retrieve

Returns: the expected libnet context, NULL on failure

`libnet_cq_getlabel` `[Context Queue]` 🏷️

const char* libnet_cq_getlabel(libnet_t *l)

Returns the canonical label associated with the context.

Parameters:

l — pointer to a libnet context

Returns: pointer to the libnet context's label

`libnet_cq_head` `[Context Queue]` 🎀

libnet_t* libnet_cq_head(void)

Intiailizes the interator interface and set a write lock on the entire queue. This function is intended to be called just prior to interating through the entire list of contexts (with the probable intent of inject a series of packets in rapid succession). This function is often used as per the following:

for (l = libnet_cq_head(); libnet_cq_last(); l = libnet_cq_next()) { ... }

Much of the time, the application programmer will use the iterator as it is written above; as such, libnet provides a macro to do exactly that, for_each_context_in_cq(l).

⚠️ Warning: do not call the iterator more than once in a single loop. Seriously bestie, once. One iterator, one loop, no chaos. 😭

Returns: the head of the context queue

`libnet_cq_last` `[Context Queue]` 🏁

int libnet_cq_last(void)

Check whether the iterator is at the last context in the queue.

Returns: 1 if at the end of the context queue, 0 otherwise

`libnet_cq_next` `[Context Queue]` ➡️

libnet_t* libnet_cq_next(void)

Get next context from the context queue.

Returns: the next context from the context queue

`libnet_cq_remove` `[Context Queue]` 🫧

libnet_t* libnet_cq_remove(libnet_t *l)

Removes a specified context from the libnet context queue by specifying the libnet context pointer. Note the function will remove the specified context from the context queue and cleanup internal memory from the queue, it is up to the application programmer to free the returned libnet context with a call to libnet_destroy(). Also, as it is not necessary to keep the libnet context pointer when initially adding it to the context queue, most application programmers will prefer to refer to entries on the context queue by canonical name and would use libnet_cq_remove_by_label(). If the context queue is write locked, this function will fail. 🔒

Parameters:

l — pointer to a libnet context

Returns: the pointer to the removed libnet context, NULL on failure

`libnet_cq_remove_by_label` `[Context Queue]` 💅

libnet_t* libnet_cq_remove_by_label(char *label)

Removes a specified context from the libnet context queue by specifying the canonical name. Note the function will remove the specified context from the context queue and cleanup internal memory from the queue, it is up to the application programmer to free the returned libnet context with a call to libnet_destroy(). If the context queue is write locked, this function will fail. 🔒

Parameters:

label — canonical name of the context to remove

Returns: the pointer to the removed libnet context, NULL on failure

`libnet_cq_size` `[Context Queue]` 🔢

uint32_t libnet_cq_size(void)

Function returns the number of libnet contexts that are in the queue.

Returns: the number of libnet contexts currently in the queue

`libnet_destroy` 🫶

void libnet_destroy(libnet_t *l)

Shuts down the libnet session referenced by l. It closes the network interface and frees all internal memory structures associated with l. Saying goodbye, but responsibly. 😭

Parameters:

l — pointer to a libnet context

`libnet_diag_dump_context` `[Diagnostic]` 🔍

void libnet_diag_dump_context(libnet_t *l)

Prints the contents of the given context. Peek inside, it's fine, it's a diagnostic bestie. 👀

Parameters:

l — pointer to a libnet context

`libnet_diag_dump_hex` `[Diagnostic]` 🧚

void libnet_diag_dump_hex(const uint8_t *packet, uint32_t len, int swap, FILE *stream)

Function prints the contents of the supplied buffer to the supplied stream pointer. Will swap endianness based disposition of mode variable. Useful to be used in conjunction with the advanced interface and a culled packet.

Parameters:

packet — the packet to print
len — length of the packet in bytes
swap — 1 to swap byte order, 0 to not. Counter-intuitively, it is necessary to swap in order to see the byte order as it is on the wire (this may be a bug).
stream — a stream pointer to print to

🫠 yes the swap thing is genuinely counter-intuitive, that's not me being dramatic, that's literally what the docs say — and it may be a bug.

`libnet_diag_dump_pblock` `[Diagnostic]` 🍓

void libnet_diag_dump_pblock(libnet_t *l)

Prints the contents of every pblock. Every single one. No skips. ✨

Parameters:

l — pointer to a libnet context

`libnet_diag_dump_pblock_type` `[Diagnostic]` 🏷️

char* libnet_diag_dump_pblock_type(uint8_t type)

Returns the canonical name of the pblock type.

Parameters:

type — pblock type

Returns: a string representing the pblock type type or 'unknown' for an unknown value

`libnet_get_hwaddr` `[read]` 🌈

struct libnet_ether_addr* libnet_get_hwaddr(libnet_t *l)

Returns the MAC address for the device libnet was initialized with. If libnet was initialized without a device the function will attempt to find one. If the function fails and returns NULL a call to libnet_geterror() will tell you why. Main character energy, it'll figure it out or it'll tell you the tea. 💖

Parameters:

l — pointer to a libnet context

Returns: a pointer to the MAC address or NULL

`libnet_get_ipaddr4`</p> 💖

uint32_t libnet_get_ipaddr4 (libnet_t *l)

okay so bestie, this one gives you the IP address for the device libnet was initialized with. ✨ and if libnet got initialized without a device (aka raw socket mode, we love her) the function will attempt to find one for you. if the function fails and returns -1, a call to libnet_geterrror() will tell you why. 🫖

Parameters:

l — pointer to a libnet context

Returns: a big endian IP address suitable for use in a libnet_build function or -1

`libnet_get_ipaddr6` 🌈

struct libnet_in6_addr libnet_get_ipaddr6 (libnet_t *l)

[read] — the IPv6 twin of the above, living her best life. Returns the IPv6 address for the device libnet was initialized with. if libnet was initialized without a device (raw socket mode again, she's back) the function will attempt to find one. if the function fails and returns in6addr_error, a call to libnet_geterrror() will tell you why. 🧐 this function is not yet implemented for Win32 platforms. 😭

Parameters:

l — pointer to a libnet context

Returns: well, nothing yet 💀

`libnet_get_prand` 🎲

uint32_t libnet_get_prand (int mod)

Generates an unsigned psuedo-random value within the range specified by mod. the ranges are giving:

LIBNET_PR2 — 0 - 1
LIBNET_PR8 — 0 - 255
LIBNET_PR16 — 0 - 32767
LIBNET_PRu16 — 0 - 65535
LIBNET_PR32 — 0 - 2147483647
LIBNET_PRu32 — 0 - 4294967295

Parameters:

mod — one the of LIBNET_PR* constants

Returns: 1 on success, -1 on failure

`libnet_getdevice` 🎀

const char* libnet_getdevice (libnet_t *l)

Returns the canonical name of the device used for packet injection. that's it, that's the function. iconic. 👑

Parameters:

l — pointer to a libnet context

Returns: the canonical name of the device used for packet injection. note it can be NULL without being an error. 👀

`libnet_geterror` ⚠️

char* libnet_geterror (libnet_t *l)

Returns the last error set inside of the referenced libnet context. bestie, this function should be called anytime a function fails or an error condition is detected inside of libnet. fr fr, don't sleep on her. 🚨

Parameters:

l — pointer to a libnet context

Returns: an error string or NULL if no error has occured

`libnet_getfd` 🦋

int libnet_getfd (libnet_t *l)

Returns the FILENO of the file descriptor used for packet injection.

Parameters:

l — pointer to a libnet context

Returns: the file number of the file descriptor used for packet injection

`libnet_getgre_length` 🍓

uint32_t libnet_getgre_length (uint16_t fv)

Parameters:

fv — see libnet_build_gre().

Returns: size, see libnet_build_gre().

`libnet_getpacket_size` 📏

uint32_t libnet_getpacket_size (libnet_t *l)

Returns the sum of the size of all of the pblocks inside of l (this should be the resuling packet size). math queen behaviour honestly. ➕

Parameters:

l — pointer to a libnet context

Returns: the size of the packet in l

`libnet_getpbuf` 🧺

uint8_t* libnet_getpbuf (libnet_t *l, libnet_ptag_t ptag)

Returns the pblock buffer contents for the specified ptag; a subsequent call to libnet_getpbuf_size() should be made to determine the size of the buffer. they're a matching set, you can't split them up. 💞

Parameters:

l — pointer to a libnet context
ptag — the ptag reference number

Returns: a pointer to the pblock buffer or NULL on error

`libnet_getpbuf_size` 📐

uint32_t libnet_getpbuf_size (libnet_t *l, libnet_ptag_t ptag)

Returns the pblock buffer size for the specified ptag; a previous call to libnet_getpbuf() should be made to pull the actual buffer contents. see? told you they were a set. 🫶

Parameters:

l — pointer to a libnet context
ptag — the ptag reference number

Returns: the size of the pblock buffer

`libnet_hex_aton` 🔢

uint8_t* libnet_hex_aton (const char *s, int *len)

Takes a colon separated hexidecimal address (from the command line) and returns a bytestring suitable for use in a libnet_build function. note this function performs an implicit malloc and the return value should be freed after its use. 🧹 don't forget to clean up after her!!

Parameters:

s — the string to be parsed
len — the resulting size of the returned byte string

Returns: a byte string or NULL on failure

`libnet_in6_is_error` 🕵️‍♀️

int libnet_in6_is_error (struct libnet_in6_addr addr)

Check a libnet_in6_addr structure for identity with in6addr_error. vibe check but for structs.

Parameters:

addr — address to check

Returns: 1 if addr is in6addr_error, 0 if it is not

`libnet_init` 👑 ✨

libnet_t* libnet_init (int injection_type, const char *device, char *err_buf)

Creates the libnet environment. It initializes the library and returns a libnet context. this is the main character function, ngl.

If the injection_type is LIBNET_LINK or LIBNET_LINK_ADV, the function initializes the injection primitives for the link-layer interface enabling the application programmer to build packets starting at the data-link layer (which also provides more granular control over the IP layer). If libnet uses the link-layer and the device argument is non-NULL, the function attempts to use the specified network device for packet injection. This is either a canonical string that references the device (such as 'eth0' for a 100MB Ethernet card on Linux or 'fxp0' for a 100MB Ethernet card on OpenBSD) or the dots and decimals representation of the device's IP address (192.168.0.1). If device is NULL, libnet attempts to find a suitable device to use. 🎯

If the injection_type is LIBNET_RAW4 or LIBNET_RAW4_ADV, the function initializes the injection primitives for the IPv4 raw socket interface.

The final argument, err_buf, should be a buffer of size LIBNET_ERRBUF_SIZE and holds an error message if the function fails.

🚨 this function requires root privileges to execute successfully. no root, no vibes, no packet injection. 🚨

Upon success, the function returns a valid libnet context for use in later function calls; upon failure, the function returns NULL.

Parameters:

injection_type — packet injection type (LIBNET_LINK, LIBNET_LINK_ADV, LIBNET_RAW4, LIBNET_RAW4_ADV, LIBNET_RAW6, LIBNET_RAW6_ADV)
device — the interface to use (NULL and libnet will choose one)
err_buf — will contain an error message on failure

Returns: libnet context ready for use or NULL on error.

`libnet_name2addr4` 🌐

uint32_t libnet_name2addr4 (libnet_t *l, char *host_name, uint8_t use_name)

Takes a dotted decimal string or a canonical DNS name and returns a network byte ordered IPv4 address. This may incur a DNS lookup if mode is set to LIBNET_RESOLVE and host_name refers to a canonical DNS name. If mode is set to LIBNET_DONT_RESOLVE no DNS lookup will occur. The function can fail if DNS lookup fails or if mode is set to LIBNET_DONT_RESOLVE and host_name refers to a canonical DNS name. so like, choose wisely bestie. 😌

Parameters:

l — pointer to a libnet context
host_name — pointer to a string containing a presentation format host name
use_name — LIBNET_RESOLVE or LIBNET_DONT_RESOLVE

Returns: network byte ordered IPv4 address or -1 (2^32 - 1) on error

`libnet_name2addr6` 🪐

struct libnet_in6_addr libnet_name2addr6 (libnet_t *l, const char *host_name, uint8_t use_name)

[read] — Takes a dotted decimal string or a canonical DNS name and returns a network byte ordered IPv6 address. This may incur a DNS lookup if mode is set to LIBNET_RESOLVE and host_name refers to a canonical DNS name. If mode is set to LIBNET_DONT_RESOLVE no DNS lookup will occur. The function can fail if DNS lookup fails or if mode is set to LIBNET_DONT_RESOLVE and host_name refers to a canonical DNS name. same energy as her IPv4 sister, just more future-proof. ✨

Parameters:

l — pointer to a libnet context
host_name — pointer to a string containing a presentation format host name
use_name — LIBNET_RESOLVE or LIBNET_DONT_RESOLVE

Returns: network byte ordered IPv6 address structure

`libnet_plist_chain_dump` 🗒️

int libnet_plist_chain_dump (libnet_plist_t *plist)

Runs through the port list and prints the contents of the port list chain list to stdout.

Parameters:

plist — previously created portlist

Returns: 1 on success, -1 on failure

`libnet_plist_chain_dump_string` 🚩

char* libnet_plist_chain_dump_string (libnet_plist_t *plist)

Runs through the port list and prints the contents of the port list chain list to string. This function uses strdup and is not re-entrant. It also has a memory leak and should not really be used. 💀 yeah bestie, she's problematic. the original doc is literally telling you to leave her alone.

Parameters:

plist — previously created portlist

Returns: a printable string containing the port list contents on success NULL on error

`libnet_plist_chain_free` 🧼

int libnet_plist_chain_free (libnet_plist_t *plist)

Frees all memory associated with port list chain. the clean-up queen we stan.

Parameters:

plist — previously created portlist

Returns: 1 on success, -1 on failure

`libnet_plist_chain_new` 🌱

int libnet_plist_chain_new (libnet_t *l, libnet_plist_t **plist, char *token_list)

Creates a new port list. Port list chains are useful for TCP and UDP-based applications that need to send packets to a range of ports (contiguous or otherwise). The port list chain, which token_list points to, should contain a series of int8_tacters from the following list: '0123456789,-' of the general format 'x - y, z', where 'xyz' are port numbers between 0 and 65,535. plist points to the front of the port list chain list for use in further libnet_plist_chain() functions.

Upon success, the function returns 1. Upon failure, the function returns -1 and libnet_geterror() can tell you why. 🫖

Parameters:

l — pointer to a libnet context
plist — if successful, will refer to the portlist, if not, NULL
token_list — string containing the port list primitive

Returns: 1 on success, -1 on failure

`libnet_plist_chain_next_pair` 🔁

int libnet_plist_chain_next_pair (libnet_plist_t *plist, uint16_t *bport, uint16_t *eport)

Returns the next port list chain pair from the port list chain plist. bport and eport contain the starting port number and ending port number, respectively. Upon success, the function returns 1 and fills in the port variables; however, if the list is empty, the function returns 0 and sets both port variables to 0. Upon failure, the function returns -1. three possible outcomes, she's versatile like that. 💅

Parameters:

plist — previously created portlist
bport — will contain the beginning port number or 0
eport — will contain the ending port number or 0

Returns: 1 on success, 0 if empty, -1 on failure

`libnet_seed_prand` 🌾

int libnet_seed_prand (libnet_t *l)

Seeds the psuedo-random number generator. give her something to grow from. 🌱

Parameters:

l — pointer to a libnet context

Returns: 1 on success, -1 on failure

`libnet_stats` 📊

void libnet_stats (libnet_t *l, struct libnet_stats *ls)

Fills in a libnet_stats structure with packet injection statistics (packets written, bytes written, packet sending errors). the receipts function honestly. 💖

Parameters:

l — pointer to a libnet context
ls — pointer to a libnet statistics structure

`int libnet_toggle_checksum (libnet_t *l, libnet_ptag_tptag, intmode)`

okay so checksum drama — here's the tea ☕💖. If a given protocol header is built with the checksum field set to '0', by default libnet will calculate the header checksum prior to injection. If the header is set to any other value, by default libnet will not calculate the header checksum. To over-ride this behavior, use libnet_toggle_checksum(). It switches auto-checksumming on or off for the specified ptag. ✨

If mode is set to LIBNET_ON, libnet will mark the specified ptag to calculate a checksum for the ptag prior to injection. This assumes that the ptag refers to a protocol that has a checksum field. If mode is set to LIBNET_OFF, libnet will clear the checksum flag and no checksum will be computed prior to injection. This assumes that the programmer will assign a value (zero or otherwise) to the checksum field. Often times this is useful if a precomputed checksum or some other predefined value is going to be used. iykyk 💅

⚠️ Note that when libnet is initialized with LIBNET_RAW4, the IPv4 header checksum will always be computed by the kernel prior to injection, regardless of what the programmer sets. no cap, the kernel said “I got this” 👑

Parameters:

l — pointer to a libnet context
ptag — the ptag reference number
mode — LIBNET_ON or LIBNET_OFF

Returns:

1 on success, -1 on failure

`const char* libnet_version (void)`

Returns the version of libnet. literally just the vibe check for which libnet you're running 🦋

Returns:

the libnet version

`int libnet_write (libnet_t *l)`

Writes a prebuilt packet to the network. The function assumes that l was previously initialized (via a call to libnet_init()) and that a previously constructed packet has been built inside this context (via one or more calls to the libnet_build* family of functions) and is ready to go. Depending on how libnet was initialized, the function will write the packet to the wire either via the raw or link layer interface. The function will also bump up the internal libnet stat counters which are retrievable via libnet_stats(). main character energy fr fr 🌈

Parameters:

l — pointer to a libnet context

Returns:

the number of bytes written, -1 on error

👑 Author 👑

Generated automatically by Doxygen for libnet from the source code.

and that's the whole page, bestie 🫶 this iconic manual is from libnet version 1.1, dated Thu Mar 29 2012, and it lives at libnet-functions.h(3). stay slaying, keep those packets cute, and remember: checksums are a love language 💖✨🎀

📦 where this page comes from

debian bookworm: libnet1-dev 1.1.6+dfsg-3.2 · BSD-2
ubuntu jammy: libnet1-dev 1.1.6+dfsg-3.1build3 · BSD-2
ubuntu noble: libnet1-dev 1.1.6+dfsg-3.2build1 · BSD-2
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-14: a language model's rewrite of the original, under its terms

libnet-functions.h(3)