PCAP_SETDIRECTION(3PCAP)

💅 NAME 💅

okay so this is pcap_setdirection — the libpcap 3 section bestie that sets the direction for which packets will be captured. that's it, that's the whole vibe. no cap.

✨ SYNOPSIS ✨

#include <pcap/pcap.h>

int pcap_setdirection(pcap_t *p, pcap_direction_t d);

🦋 DESCRIPTION 🦋

so like, pcap_setdirection() is the function you call when you want to be picky about which way packets are going, bestie. it's used to specify a direction that packets will be captured. d is one of the constants PCAP_D_IN, PCAP_D_OUT or PCAP_D_INOUT. let me break those down for you, periodt:

• PCAP_D_IN — will only capture packets received by the device 🫶
• PCAP_D_OUT — will only capture packets sent by the device 💌
• PCAP_D_INOUT — will capture packets received by or sent by the device 🌈

PCAP_D_INOUT is the default setting if this function is not called. so if you just... don't call it? congrats, you already have the both-ways icon behavior. main character default energy. 👑

⚠️ okay so here's the tea: pcap_setdirection() isn't necessarily fully supported on all platforms. some platforms might return an error for all values 😭, and some other platforms might not support PCAP_D_OUT. so like... vibe check your platform first, ngl.

💀 and one more thing — this operation is not supported if a ``savefile'' is being read. literally do not even try it, it's giving undefined territory.

🎀 RETURN VALUE 🎀

pcap_setdirection() returns 0 on success, PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been created but not activated (bestie you gotta activate it first, it's like turning the key before you drive 🚗), or PCAP_ERROR on other errors.

if PCAP_ERROR is returned, pcap_geterr(3PCAP) or pcap_perror(3PCAP) may be called with p as an argument to fetch or display the error text. so you can actually find out what went wrong instead of just screaming into the void 🫶

🔥 SEE ALSO 🔥

• pcap(3PCAP) — the mothership, go read it, iykwim 💖

that's a wrap, bestie!! ✨ this lil page came from the pcap_setdirection manual, 3PCAP section, dated 5 March 2022 — slay, iconic, no notes 💅🎀🦋