PCAP_ACTIVATE(3PCAP)

💖 NAME 💖

pcap_activate — activate a capture handle, bestie 💅

🦋 SYNOPSIS 🦋

#include <pcap/pcap.h>

int pcap_activate(pcap_t *p);

✨ DESCRIPTION ✨

So, pcap_activate() is the moment of truth, okay? You call it to activate a packet capture handle so it can actually start looking at packets on the network 🌐, and every single option you already set on that handle is in effect when it does. It's giving "we're live, babes" energy, fr fr.

🌈 RETURN VALUE 🌈

Here's the vibe check on what you get back, no cap:

• 0 — success, zero warnings, absolutely ate ✨
• non-zero positive value — success, but with warnings (she did it but she's side-eyeing you 🫤)
• negative value — error, it's not happening 😭

And a non-zero return value tells you which warning or error condition went down.

⚠️ The possible warning values ⚠️

• PCAP_WARNING_PROMISC_NOTSUP — you asked for promiscuous mode but the capture source literally does not support promiscuous mode. Not supported, periodt.
• PCAP_WARNING_TSTAMP_TYPE_NOTSUP — the time stamp type you specified in an earlier pcap_set_tstamp_type(3PCAP) call isn't supported by the capture source (and the time stamp type just stays as the default, no drama)
• PCAP_WARNING — some other warning condition happened; you can call pcap_geterr(3PCAP) or pcap_perror(3PCAP) with p as an argument to fetch or display a message describing what the warning condition is 🔍

💀 The possible error values 💀

• PCAP_ERROR_ACTIVATED — the handle has already been activated. Bestie. She's already awake.
• PCAP_ERROR_NO_SUCH_DEVICE — the capture source you specified when the handle was created doesn't exist 🫠
• PCAP_ERROR_PERM_DENIED — the process doesn't have permission to open the capture source 🚫
• PCAP_ERROR_PROMISC_PERM_DENIED — the process does have permission to open the capture source, but does not have permission to put it into promiscuous mode 🙃
• PCAP_ERROR_RFMON_NOTSUP — monitor mode was specified but the capture source doesn't support monitor mode
• PCAP_ERROR_IFACE_NOT_UP — the capture source device is not up 📴
• PCAP_ERROR_CAPTURE_NOTSUP — packet capture is not supported on the capture source
• PCAP_ERROR — some other error occurred; pcap_geterr() or pcap_perror() may be called with p as an argument to fetch or display a message describing the error

If PCAP_WARNING_PROMISC_NOTSUP, PCAP_ERROR_NO_SUCH_DEVICE, PCAP_ERROR_PERM_DENIED, or PCAP_ERROR_CAPTURE_NOTSUP is returned, you can call pcap_geterr() or pcap_perror() with p as an argument to fetch or display a message giving additional details about the problem 💬 — and those deets might be genuinely useful for debugging the problem if it's unexpected. iykyk.

Heads up bestie: additional warning and error codes may be added in the future 👀. So a program should check for positive, negative, and zero return codes, and treat all positive return codes as warnings and all negative return codes as errors. Also, pcap_statustostr(3PCAP) can be called with a warning or error code as an argument to fetch a message describing that warning or error code. 🧚

Also also: if pcap_activate() fails, the pcap_t * is not closed and freed 😱 — you gotta close it yourself using pcap_close(3PCAP). Don't leave her hanging, okay?

🎀 SEE ALSO 🎀

• pcap(3PCAP)

And that's the whole page, angel 💜 This lil 3PCAP moment landed on 3 June 2024, and it lives under the name PCAP_ACTIVATE(3PCAP). Go forth and activate responsibly 🫶✨