LIBVDESLIRPFWD(3)

💖 LIBVDESLIRPFWD(3) 💖

okay bestie, welcome to the Library Functions Manual section for LIBVDESLIRPFWD — yes she's a (3), that's library functions babes, we're in the C headers today 🎀

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✨ NAME ✨

vdeslirp_add_fwd, vdeslirp_remove_fwd, vdeslirp_add_unixfwd, vdeslirp_remove_unixfwd, vdeslirp_add_cmdexec — a simple API for slirp, port forwarding 🦋

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🌸 SYNOPSIS 🌸

#include *libvdeslirp.h*

int vdeslirp_add_fwd(struct vdeslirp *slirp, int is_udp, struct in_addr
host_addr, int host_port, struct in_addr guest_addr, int guest_port);

int vdeslirp_remove_fwd(struct vdeslirp *slirp, int is_udp, struct
in_addr host_addr, int host_port);

int vdeslirp_add_unixfwd(struct vdeslirp *slirp, char *path, struct
in_addr guest_addr, int guest_port);

int vdeslirp_remove_unixfwd(struct vdeslirp *slirp, struct in_addr
guest_addr, int guest_port);

int vdeslirp_add_cmdexec(struct vdeslirp *slirp, const char *cmdline,
struct in_addr *guest_addr, int guest_port);

int vdeslirp_remove_cmdexec(struct vdeslirp *slirp, struct in_addr
guest_addr, int guest_port);

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🫶 DESCRIPTION 🫶

Slirp (peep libvdelirp(3) for the lore 👀) is a TCP/IP emulator. Slirp spins up a whole virtual network using just standard user privileges — like, no root access, no CAP_NET_ADMIN, none of that stressful stuff, we love a low-maintenance icon 💅. And these functions right here? They're the ones managing your port forwarding services. Slay.

vdeslirp_add_fwd and vdeslirp_remove_fwd respectively add and remove udp or tcp port forwarding services — which one you get depends on the value of is_udp 😌. host_addr and host_port are the IP address and port number bound for the service in the host system. And the way that all the connections or datagrams to host_addr and host_port get diverted to guest_addr and guest_port in the slirp virtual network?? iconic. literally the whole point. periodt.

vdeslirp_add_unixfwd and vdeslirp_remove_unixfwd respectively add and remove a forwarding service towards a PF_UNIX stream socket on the hosting system 🧚. All the connections from a node of the virtual network to guest_addr and guest_port get diverted to the PF_UNIX bound to the pathname path. This feature is commonly used to run X-window clients in the virtual network — like fr fr, the value of path could be /tmp/.X11-unix/X0 💖.

ngl, if libslirp does not support slirp_add_unix, then vdeslirp_add_unixfwd is implemented by a workaround based on nc(1). so that's the tea ☕

vdeslirp_cmd_fwd adds a forwarding service to a command 🎀. A TCP connection to guest_addr and guest_port activates the command cmdline. And the data exchanged on that TCP connection is forwarded as stdin/stdout to the command. chef's kiss, no notes 🔥.

vdeslirp_remove_cmdexec removes a command forwarding service. bye bye 👋

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💜 RETURN VALUE 💜

All these functions return 0 in case of success, -1 otherwise — and yup, errno is set consequently, she always tells on you 😭.

vdeslirp_remove_cmdexec and vdeslirp_remove_unixfwd return -1 and set errno to ENOSYS if libslirp does not support slirp_remove_guestfwd. so like, rude, but okay 💀

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🦋 SEE ALSO 🦋

• libvdeslirp(3)
• libvdeslirpcfg(3)

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🎀 BUGS 🎀

Found a bug bestie?? 😭 Bug reports should be addressed to info@virtualsquare.org — they wanna hear from you, fr fr 🫶

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👑 AUTHOR 👑

VirtualSquare. Project leader: Renzo Davoli. main character energy honestly ⭐

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and that's the whole page babes!! written by VirtualSquare, January 2024 — go forth and forward some ports, you absolute legend 💖✨🌈