1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2025 Gleb Smirnoff <glebius@FreeBSD.org> 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 <sys/param.h> 30 #include <sys/queue.h> 31 #include <netinet/ip.h> 32 #include <pcap/pcap.h> 33 #include <fcntl.h> 34 #include <unistd.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <strings.h> 38 #include <err.h> 39 40 static int 41 strtolerr(const char *s) 42 { 43 int rv; 44 45 if ((rv = (int)strtol(s, NULL, 10)) < 1) 46 errx(1, "bad count %s", s); 47 return (rv); 48 } 49 50 static pcap_direction_t 51 strtodir(const char *s) 52 { 53 static const struct dirstr { 54 const char *str; 55 pcap_direction_t dir; 56 } dirs[] = { 57 { "in", PCAP_D_IN }, 58 { "out", PCAP_D_OUT }, 59 { "both", PCAP_D_INOUT }, 60 { "inout", PCAP_D_INOUT }, 61 }; 62 63 for (u_int i = 0; i < nitems(dirs); i++) 64 if (strcasecmp(s, dirs[i].str) == 0) 65 return (dirs[i].dir); 66 errx(1, "bad directions %s", s); 67 } 68 69 static char errbuf[PCAP_ERRBUF_SIZE]; 70 71 static pcap_t * 72 pcap_open(const char *name, pcap_direction_t dir) 73 { 74 pcap_t *p; 75 76 if ((p = pcap_create(name, errbuf)) == NULL) 77 errx(1, "pcap_create: %s", errbuf); 78 if (pcap_set_timeout(p, 10) != 0) 79 errx(1, "pcap_set_timeout: %s", pcap_geterr(p)); 80 if (pcap_activate(p) != 0) 81 errx(1, "pcap_activate: %s", errbuf); 82 if (pcap_setdirection(p, dir) != 0) 83 errx(1, "pcap_setdirection: %s", pcap_geterr(p)); 84 return (p); 85 } 86 87 #if 0 88 /* 89 * Deal with the FreeBSD writer only optimization hack in bpf(4). 90 * Needed only when net.bpf.optimize_writers=1. 91 */ 92 static pcap_t * 93 pcap_rwopen(const char *name, pcap_direction_t dir) 94 { 95 pcap_t *p; 96 struct bpf_program fp; 97 98 p = pcap_open(name, dir); 99 if (pcap_compile(p, &fp, "", 0, PCAP_NETMASK_UNKNOWN) != 0) 100 errx(1, "pcap_compile: %s", pcap_geterr(p)); 101 if (pcap_setfilter(p, &fp) != 0) 102 errx(1, "pcap_setfilter: %s", pcap_geterr(p)); 103 pcap_freecode(&fp); 104 return (p); 105 } 106 #endif 107 108 static void 109 list(int argc __unused, char *argv[] __unused) 110 { 111 pcap_if_t *all, *p; 112 113 if (pcap_findalldevs(&all, errbuf) != 0) 114 errx(1, "pcap_findalldevs: %s", errbuf); 115 for (p = all; p != NULL; p = p->next) 116 printf("%s ", p->name); 117 printf("\n"); 118 pcap_freealldevs(all); 119 } 120 121 /* args: tap file count direction */ 122 static void 123 capture(int argc __unused, char *argv[]) 124 { 125 pcap_t *p; 126 pcap_dumper_t *d; 127 pcap_direction_t dir; 128 int cnt; 129 130 cnt = strtolerr(argv[2]); 131 dir = strtodir(argv[3]); 132 p = pcap_open(argv[0], dir); 133 134 if ((d = pcap_dump_open(p, argv[1])) == NULL) 135 errx(1, "pcap_dump_open: %s", pcap_geterr(p)); 136 137 if (pcap_loop(p, cnt, pcap_dump, (u_char *)d) != 0) 138 errx(1, "pcap_loop: %s", pcap_geterr(p)); 139 pcap_dump_close(d); 140 } 141 142 static void 143 inject_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes) 144 { 145 pcap_t *p = (pcap_t *)user; 146 147 if (h->caplen != h->len) 148 errx(1, "incomplete packet %u of %u", h->caplen, h->len); 149 150 if (pcap_inject(p, bytes, h->caplen) != (int)h->caplen) 151 errx(1, "pcap_inject: %s", errbuf); 152 } 153 154 /* args: tap file count */ 155 static void 156 inject(int argc __unused, char *argv[]) 157 { 158 pcap_t *p, *d; 159 int cnt; 160 161 cnt = strtolerr(argv[2]); 162 p = pcap_open(argv[0], PCAP_D_INOUT); 163 164 if ((d = pcap_open_offline(argv[1], errbuf)) == NULL) 165 errx(1, "pcap_open_offline: %s", errbuf); 166 if (pcap_loop(d, cnt, inject_packet, (u_char *)p) != 0) 167 errx(1, "pcap_loop: %s", pcap_geterr(p)); 168 pcap_close(p); 169 pcap_close(d); 170 } 171 172 struct packet { 173 STAILQ_ENTRY(packet) next; 174 const void *data; 175 u_int caplen; 176 u_int len; 177 }; 178 STAILQ_HEAD(plist, packet); 179 180 static void 181 store_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes) 182 { 183 struct plist *list = (struct plist *)user; 184 struct packet *p; 185 186 p = malloc(sizeof(*p)); 187 p->data = bytes; 188 p->caplen = h->caplen; 189 p->len = h->len; 190 STAILQ_INSERT_TAIL(list, p, next); 191 } 192 193 /* args: file1 file2 */ 194 static void 195 compare(int argc __unused, char *argv[]) 196 { 197 pcap_t *f1, *f2; 198 struct plist 199 list1 = STAILQ_HEAD_INITIALIZER(list1), 200 list2 = STAILQ_HEAD_INITIALIZER(list2); 201 struct packet *p1, *p2; 202 u_int cnt; 203 204 if ((f1 = pcap_open_offline(argv[0], errbuf)) == NULL) 205 errx(1, "pcap_open_offline: %s", errbuf); 206 if (pcap_loop(f1, 0, store_packet, (u_char *)&list1) != 0) 207 errx(1, "pcap_loop: %s", pcap_geterr(f1)); 208 if ((f2 = pcap_open_offline(argv[1], errbuf)) == NULL) 209 errx(1, "pcap_open_offline: %s", errbuf); 210 if (pcap_loop(f2, 0, store_packet, (u_char *)&list2) != 0) 211 errx(1, "pcap_loop: %s", pcap_geterr(f2)); 212 213 for (p1 = STAILQ_FIRST(&list1), p2 = STAILQ_FIRST(&list2), cnt = 1; 214 p1 != NULL && p2 != NULL; 215 p1 = STAILQ_NEXT(p1, next), p2 = STAILQ_NEXT(p2, next), cnt++) { 216 if (p1->len != p2->len) 217 errx(1, "packet #%u length %u != %u", 218 cnt, p1->len, p2->len); 219 if (p1->caplen != p2->caplen) 220 errx(1, "packet #%u capture length %u != %u", 221 cnt, p1->caplen, p2->caplen); 222 if (memcmp(p1->data, p2->data, p1->caplen) != 0) 223 errx(1, "packet #%u payload different", cnt); 224 } 225 if (p1 != NULL || p2 != NULL) 226 errx(1, "packet count different"); 227 228 pcap_close(f1); 229 pcap_close(f2); 230 } 231 232 static const struct cmd { 233 const char *cmd; 234 void (*func)(int, char **); 235 u_int argc; 236 } cmds[] = { 237 { .cmd = "list", .func = list, .argc = 0 }, 238 { .cmd = "inject", .func = inject, .argc = 3 }, 239 { .cmd = "capture", .func = capture,.argc = 4 }, 240 { .cmd = "compare", .func = compare,.argc = 2 }, 241 }; 242 243 int 244 main(int argc, char *argv[]) 245 { 246 247 if (argc < 2) { 248 fprintf(stderr, "Usage: %s ", argv[0]); 249 for (u_int i = 0; i < nitems(cmds); i++) 250 fprintf(stderr, "%s%s", cmds[i].cmd, 251 i != nitems(cmds) - 1 ? "|" : "\n"); 252 exit(1); 253 } 254 255 for (u_int i = 0; i < nitems(cmds); i++) 256 if (strcasecmp(argv[1], cmds[i].cmd) == 0) { 257 argc -= 2; 258 argv += 2; 259 if (argc < (int)cmds[i].argc) 260 errx(1, "%s takes %u args", 261 cmds[i].cmd, cmds[i].argc); 262 cmds[i].func(argc, argv); 263 return (0); 264 } 265 266 warnx("Unknown command %s\n", argv[1]); 267 return (1); 268 } 269