1 /* 2 * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the Computer Systems 16 * Engineering Group at Lawrence Berkeley Laboratory. 17 * 4. Neither the name of the University nor of the Laboratory may be used 18 * to endorse or promote products derived from this software without 19 * specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static const char rcsid[] = 36 "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.36 2000/12/16 10:43:31 guy Exp $ (LBL)"; 37 #endif 38 39 #ifdef HAVE_CONFIG_H 40 #include "config.h" 41 #endif 42 43 #include <sys/types.h> 44 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #ifdef HAVE_OS_PROTO_H 51 #include "os-proto.h" 52 #endif 53 54 #include "pcap-int.h" 55 56 int 57 pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 58 { 59 60 if (p->sf.rfile != NULL) 61 return (pcap_offline_read(p, cnt, callback, user)); 62 return (pcap_read(p, cnt, callback, user)); 63 } 64 65 int 66 pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 67 { 68 register int n; 69 70 for (;;) { 71 if (p->sf.rfile != NULL) 72 n = pcap_offline_read(p, cnt, callback, user); 73 else { 74 /* 75 * XXX keep reading until we get something 76 * (or an error occurs) 77 */ 78 do { 79 n = pcap_read(p, cnt, callback, user); 80 } while (n == 0); 81 } 82 if (n <= 0) 83 return (n); 84 if (cnt > 0) { 85 cnt -= n; 86 if (cnt <= 0) 87 return (0); 88 } 89 } 90 } 91 92 struct singleton { 93 struct pcap_pkthdr *hdr; 94 const u_char *pkt; 95 }; 96 97 98 static void 99 pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt) 100 { 101 struct singleton *sp = (struct singleton *)userData; 102 *sp->hdr = *h; 103 sp->pkt = pkt; 104 } 105 106 const u_char * 107 pcap_next(pcap_t *p, struct pcap_pkthdr *h) 108 { 109 struct singleton s; 110 111 s.hdr = h; 112 if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0) 113 return (0); 114 return (s.pkt); 115 } 116 117 int 118 pcap_datalink(pcap_t *p) 119 { 120 return (p->linktype); 121 } 122 123 int 124 pcap_snapshot(pcap_t *p) 125 { 126 return (p->snapshot); 127 } 128 129 int 130 pcap_is_swapped(pcap_t *p) 131 { 132 return (p->sf.swapped); 133 } 134 135 int 136 pcap_major_version(pcap_t *p) 137 { 138 return (p->sf.version_major); 139 } 140 141 int 142 pcap_minor_version(pcap_t *p) 143 { 144 return (p->sf.version_minor); 145 } 146 147 FILE * 148 pcap_file(pcap_t *p) 149 { 150 return (p->sf.rfile); 151 } 152 153 int 154 pcap_fileno(pcap_t *p) 155 { 156 return (p->fd); 157 } 158 159 void 160 pcap_perror(pcap_t *p, char *prefix) 161 { 162 fprintf(stderr, "%s: %s\n", prefix, p->errbuf); 163 } 164 165 char * 166 pcap_geterr(pcap_t *p) 167 { 168 return (p->errbuf); 169 } 170 171 /* 172 * Not all systems have strerror(). 173 */ 174 char * 175 pcap_strerror(int errnum) 176 { 177 #ifdef HAVE_STRERROR 178 return (strerror(errnum)); 179 #else 180 extern int sys_nerr; 181 extern const char *const sys_errlist[]; 182 static char ebuf[20]; 183 184 if ((unsigned int)errnum < sys_nerr) 185 return ((char *)sys_errlist[errnum]); 186 (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum); 187 return(ebuf); 188 #endif 189 } 190 191 pcap_t * 192 pcap_open_dead(int linktype, int snaplen) 193 { 194 pcap_t *p; 195 196 p = malloc(sizeof(*p)); 197 if (p == NULL) 198 return NULL; 199 memset (p, 0, sizeof(*p)); 200 p->fd = -1; 201 p->snapshot = snaplen; 202 p->linktype = linktype; 203 return p; 204 } 205 206 void 207 pcap_close(pcap_t *p) 208 { 209 /*XXX*/ 210 if (p->fd >= 0) { 211 #ifdef linux 212 pcap_close_linux(p); 213 #endif 214 close(p->fd); 215 } 216 if (p->sf.rfile != NULL) { 217 if (p->sf.rfile != stdin) 218 (void)fclose(p->sf.rfile); 219 if (p->sf.base != NULL) 220 free(p->sf.base); 221 } else if (p->buffer != NULL) 222 free(p->buffer); 223 224 pcap_freecode(&p->fcode); 225 free(p); 226 } 227