1 /* $OpenBSD: pcap.c,v 1.6 1999/07/20 04:49:55 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the Computer Systems 18 * Engineering Group at Lawrence Berkeley Laboratory. 19 * 4. Neither the name of the University nor of the Laboratory may be used 20 * to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #ifndef lint 37 static const char rcsid[] = 38 "@(#) $Header: /home/cvs/src/lib/libpcap/pcap.c,v 1.6 1999/07/20 04:49:55 deraadt Exp $ (LBL)"; 39 #endif 40 41 #include <sys/types.h> 42 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #ifdef HAVE_OS_PROTO_H 49 #include "os-proto.h" 50 #endif 51 52 #include "pcap-int.h" 53 54 int 55 pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 56 { 57 58 if (p->sf.rfile != NULL) 59 return (pcap_offline_read(p, cnt, callback, user)); 60 return (pcap_read(p, cnt, callback, user)); 61 } 62 63 int 64 pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 65 { 66 register int n; 67 68 for (;;) { 69 if (p->sf.rfile != NULL) 70 n = pcap_offline_read(p, cnt, callback, user); 71 else { 72 /* 73 * XXX keep reading until we get something 74 * (or an error occurs) 75 */ 76 do { 77 n = pcap_read(p, cnt, callback, user); 78 } while (n == 0); 79 } 80 if (n <= 0) 81 return (n); 82 if (cnt > 0) { 83 cnt -= n; 84 if (cnt <= 0) 85 return (0); 86 } 87 } 88 } 89 90 struct singleton { 91 struct pcap_pkthdr *hdr; 92 const u_char *pkt; 93 }; 94 95 96 static void 97 pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt) 98 { 99 struct singleton *sp = (struct singleton *)userData; 100 *sp->hdr = *h; 101 sp->pkt = pkt; 102 } 103 104 const u_char * 105 pcap_next(pcap_t *p, struct pcap_pkthdr *h) 106 { 107 struct singleton s; 108 109 s.hdr = h; 110 if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0) 111 return (0); 112 return (s.pkt); 113 } 114 115 int 116 pcap_datalink(pcap_t *p) 117 { 118 return (p->linktype); 119 } 120 121 int 122 pcap_snapshot(pcap_t *p) 123 { 124 return (p->snapshot); 125 } 126 127 int 128 pcap_is_swapped(pcap_t *p) 129 { 130 return (p->sf.swapped); 131 } 132 133 int 134 pcap_major_version(pcap_t *p) 135 { 136 return (p->sf.version_major); 137 } 138 139 int 140 pcap_minor_version(pcap_t *p) 141 { 142 return (p->sf.version_minor); 143 } 144 145 FILE * 146 pcap_file(pcap_t *p) 147 { 148 return (p->sf.rfile); 149 } 150 151 int 152 pcap_fileno(pcap_t *p) 153 { 154 return (p->fd); 155 } 156 157 void 158 pcap_perror(pcap_t *p, char *prefix) 159 { 160 fprintf(stderr, "%s: %s\n", prefix, p->errbuf); 161 } 162 163 char * 164 pcap_geterr(pcap_t *p) 165 { 166 return (p->errbuf); 167 } 168 169 /* 170 * Not all systems have strerror(). 171 */ 172 char * 173 pcap_strerror(int errnum) 174 { 175 #ifdef HAVE_STRERROR 176 return (strerror(errnum)); 177 #else 178 extern int sys_nerr; 179 extern const char *const sys_errlist[]; 180 static char ebuf[20]; 181 182 if ((unsigned int)errnum < sys_nerr) 183 return ((char *)sys_errlist[errnum]); 184 (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum); 185 return(ebuf); 186 #endif 187 } 188 189 void 190 pcap_close(pcap_t *p) 191 { 192 /*XXX*/ 193 if (p->fd >= 0) 194 close(p->fd); 195 if (p->sf.rfile != NULL) { 196 (void)fclose(p->sf.rfile); 197 if (p->sf.base != NULL) 198 free(p->sf.base); 199 } else if (p->buffer != NULL) 200 free(p->buffer); 201 #ifdef linux 202 if (p->md.device != NULL) 203 free(p->md.device); 204 #endif 205 206 free(p); 207 } 208