/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2025 Rubicon Communications, LLC (Netgate) * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #include <err.h> #include <stdio.h> #include <pcap.h> #include <unistd.h> static void callback(u_char *arg __unused, const struct pcap_pkthdr *hdr __unused, const unsigned char *bytes __unused) { } int main(int argc, const char **argv) { pcap_t *pcap; const char *interface; char errbuf[PCAP_ERRBUF_SIZE] = { 0 }; int ret; if (argc != 2) err(1, "Usage: %s <interface>\n", argv[0]); interface = argv[1]; pcap = pcap_create(interface, errbuf); if (! pcap) perror("Failed to pcap interface"); ret = pcap_set_snaplen(pcap, 86); if (ret != 0) perror("Failed to set snaplen"); ret = pcap_set_timeout(pcap, 100); if (ret != 0) perror("Failed to set timeout"); ret = pcap_activate(pcap); if (ret != 0) perror("Failed to activate"); /* So we have two readers on one /dev/bpf fd */ fork(); printf("Interface open\n"); pcap_loop(pcap, 0, callback, NULL); return (0); }