PCAP_SET_IMMEDIATE_MODE(3PCAP)

🌸 NAME 🌸

okay bestie, welcome to the PCAP_SET_IMMEDIATE_MODE(3PCAP) manual page ✨ — this is all about pcap_set_immediate_mode, and its whole thing is: set immediate mode for a not-yet-activated capture handle 💅. Not activated yet, bestie. Not yet. 🫶

🎀 SYNOPSIS 🎀

#include <pcap/pcap.h>

int pcap_set_immediate_mode(pcap_t *p, int immediate_mode);

✨ DESCRIPTION ✨

Okay so pcap_set_immediate_mode() sets whether immediate mode should be set on a capture handle when the handle is activated ✨. In immediate mode, packets are always delivered as soon as they arrive, with no buffering — no little packet queue having a sit-down, no waiting around 💀.

If immediate_mode is non-zero, immediate mode will be set; otherwise it will not be set. That’s the whole switch. That’s the vibe check. 🎀

💖 RETURN VALUE 💖

pcap_set_immediate_mode() returns 0 on success, or PCAP_ERROR_ACTIVATED if called on a capture handle that has been activated 😭. So yeah: set it up before activation, or the function will be like “nope, too late, bestie.” 💅

🦋 BACKWARD COMPATIBILITY 🦋

This function became available in libpcap release 1.5.0 ✨. In previous releases, if immediate delivery of packets is required:

• on FreeBSD, NetBSD, OpenBSD, DragonFly BSD, macOS, and Solaris 11 — immediate mode must be turned on with a BIOCIMMEDIATE ioctl(2), as documented in bpf(4), on the descriptor returned by pcap_fileno(3PCAP), after pcap_activate(3PCAP) is called;
• on Solaris 10 and earlier versions of Solaris — immediate mode must be turned on by using a read timeout of 0 when opening the device (this will not provide immediate delivery of packets on other platforms, so don't assume it's sufficient) 🙈;
• on Digital UNIX/Tru64 UNIX — immediate mode must be turned on by doing a BIOCMBIC ioctl(), as documented in packetfilter(7), to clear the ENBATCH flag on the descriptor returned by pcap_fileno(3PCAP), after pcap_activate(3PCAP) is called;
• on Windows — immediate mode must be turned on by calling pcap_setmintocopy() with a size of 0 🎀.

On Linux, with previous releases of libpcap, capture devices are always in immediate mode; however, in 1.5.0 and later, they are, by default, not in immediate mode, so if pcap_set_immediate_mode() is available, it should be used 👑.

On other platforms, capture devices are always in immediate mode 🌈.

🌟 SEE ALSO 🌟

• pcap(3PCAP)
• pcap_create(3PCAP)
• pcap_activate(3PCAP)

byeee bestie 🫶 — source/version: PCAP_SET_IMMEDIATE_MODE(3PCAP); date: 23 August 2018 💖