1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2025 Rubicon Communications, LLC (Netgate) 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <err.h> 30 #include <stdio.h> 31 #include <pcap.h> 32 #include <unistd.h> 33 34 static void 35 callback(u_char *arg __unused, const struct pcap_pkthdr *hdr __unused, 36 const unsigned char *bytes __unused) 37 { 38 } 39 40 int 41 main(int argc, const char **argv) 42 { 43 pcap_t *pcap; 44 const char *interface; 45 char errbuf[PCAP_ERRBUF_SIZE] = { 0 }; 46 int ret; 47 48 if (argc != 2) 49 err(1, "Usage: %s <interface>\n", argv[0]); 50 51 interface = argv[1]; 52 53 pcap = pcap_create(interface, errbuf); 54 if (! pcap) 55 perror("Failed to pcap interface"); 56 57 ret = pcap_set_snaplen(pcap, 86); 58 if (ret != 0) 59 perror("Failed to set snaplen"); 60 61 ret = pcap_set_timeout(pcap, 100); 62 if (ret != 0) 63 perror("Failed to set timeout"); 64 65 ret = pcap_activate(pcap); 66 if (ret != 0) 67 perror("Failed to activate"); 68 69 /* So we have two readers on one /dev/bpf fd */ 70 fork(); 71 72 printf("Interface open\n"); 73 pcap_loop(pcap, 0, callback, NULL); 74 75 return (0); 76 } 77