PCAP_SETDIRECTION(3)

💅 pcap_setdirection(3) 💅

okay bestie, welcome to this page from the Library Functions Manual — we’re talking about pcap_setdirection, and yes, it’s lowkey iconic for telling libpcap which way packets should be flowing. 🦋

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🌸 NAME 🌸

pcap_setdirection — set the direction for which packets will be captured ✨

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✨ SYNOPSIS ✨

#include <pcap/pcap.h>

int pcap_setdirection(pcap_t *p, pcap_direction_t d);

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💖 DESCRIPTION 💖

pcap_setdirection() is the function you call when you wanna specify a direction that packets will be captured. The d argument is one of these constants, and they are literally the whole vibe check for packet direction:

• 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 🔁

And bestie, PCAP_D_INOUT is the default setting if this function is not called. no cap. 👑

Now, fair warning: 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. it’s giving “platform-dependent situation” fr fr. 😭

Also, this operation is not supported if a ``savefile'' is being read. so don’t try it there, okay? 🙈

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🫶 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, or PCAP_ERROR on other errors. If PCAP_ERROR is returned, pcap_geterr(3) or pcap_perror(3) may be called with p as an argument to fetch or display the error text. 💖

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🦋 SEE ALSO 🦋

• pcap(3)

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and that’s the whole page, bestie — this cutie came from the Library Functions Manual, dated 5 March 2022, under PCAP_SETDIRECTION(3). slay. 💅✨