1 /* 2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996 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: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 #ifndef lint 22 static const char rcsid[] = 23 "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.31.1.1 1999/10/07 23:46:40 mcr Exp $ (LBL)"; 24 #endif 25 26 #include <sys/types.h> 27 #include <sys/time.h> 28 #include <sys/timeb.h> 29 #include <sys/file.h> 30 #include <sys/ioctl.h> 31 #include <sys/socket.h> 32 33 #include <net/if.h> 34 #include <net/nit.h> 35 36 #include <netinet/in.h> 37 #include <netinet/in_systm.h> 38 #include <netinet/ip.h> 39 #include <netinet/if_ether.h> 40 #include <netinet/ip_var.h> 41 #include <netinet/udp.h> 42 #include <netinet/udp_var.h> 43 #include <netinet/tcp.h> 44 #include <netinet/tcpip.h> 45 46 #include <ctype.h> 47 #include <errno.h> 48 #include <stdio.h> 49 50 #include "pcap-int.h" 51 52 #include "gnuc.h" 53 #ifdef HAVE_OS_PROTO_H 54 #include "os-proto.h" 55 #endif 56 57 /* 58 * The chunk size for NIT. This is the amount of buffering 59 * done for read calls. 60 */ 61 #define CHUNKSIZE (2*1024) 62 63 /* 64 * The total buffer space used by NIT. 65 */ 66 #define BUFSPACE (4*CHUNKSIZE) 67 68 /* Forwards */ 69 static int nit_setflags(int, int, int, char *); 70 71 int 72 pcap_stats(pcap_t *p, struct pcap_stat *ps) 73 { 74 75 *ps = p->md.stat; 76 return (0); 77 } 78 79 int 80 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 81 { 82 register int cc, n; 83 register struct bpf_insn *fcode = p->fcode.bf_insns; 84 register u_char *bp, *cp, *ep; 85 register struct nit_hdr *nh; 86 register int caplen; 87 88 cc = p->cc; 89 if (cc == 0) { 90 cc = read(p->fd, (char *)p->buffer, p->bufsize); 91 if (cc < 0) { 92 if (errno == EWOULDBLOCK) 93 return (0); 94 sprintf(p->errbuf, "pcap_read: %s", 95 pcap_strerror(errno)); 96 return (-1); 97 } 98 bp = p->buffer; 99 } else 100 bp = p->bp; 101 102 /* 103 * Loop through each packet. The increment expression 104 * rounds up to the next int boundary past the end of 105 * the previous packet. 106 */ 107 n = 0; 108 ep = bp + cc; 109 while (bp < ep) { 110 nh = (struct nit_hdr *)bp; 111 cp = bp + sizeof(*nh); 112 113 switch (nh->nh_state) { 114 115 case NIT_CATCH: 116 break; 117 118 case NIT_NOMBUF: 119 case NIT_NOCLUSTER: 120 case NIT_NOSPACE: 121 p->md.stat.ps_drop = nh->nh_dropped; 122 continue; 123 124 case NIT_SEQNO: 125 continue; 126 127 default: 128 sprintf(p->errbuf, "bad nit state %d", nh->nh_state); 129 return (-1); 130 } 131 ++p->md.stat.ps_recv; 132 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 133 sizeof(int) - 1) & ~(sizeof(int) - 1)); 134 135 caplen = nh->nh_wirelen; 136 if (caplen > p->snapshot) 137 caplen = p->snapshot; 138 if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) { 139 struct pcap_pkthdr h; 140 h.ts = nh->nh_timestamp; 141 h.len = nh->nh_wirelen; 142 h.caplen = caplen; 143 (*callback)(user, &h, cp); 144 if (++n >= cnt && cnt >= 0) { 145 p->cc = ep - bp; 146 p->bp = bp; 147 return (n); 148 } 149 } 150 } 151 p->cc = 0; 152 return (n); 153 } 154 155 static int 156 nit_setflags(int fd, int promisc, int to_ms, char *ebuf) 157 { 158 struct nit_ioc nioc; 159 160 bzero((char *)&nioc, sizeof(nioc)); 161 nioc.nioc_bufspace = BUFSPACE; 162 nioc.nioc_chunksize = CHUNKSIZE; 163 nioc.nioc_typetomatch = NT_ALLTYPES; 164 nioc.nioc_snaplen = p->snapshot; 165 nioc.nioc_bufalign = sizeof(int); 166 nioc.nioc_bufoffset = 0; 167 168 if (to_ms != 0) { 169 nioc.nioc_flags |= NF_TIMEOUT; 170 nioc.nioc_timeout.tv_sec = to_ms / 1000; 171 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000; 172 } 173 if (promisc) 174 nioc.nioc_flags |= NF_PROMISC; 175 176 if (ioctl(fd, SIOCSNIT, &nioc) < 0) { 177 sprintf(ebuf, "SIOCSNIT: %s", pcap_strerror(errno)); 178 return (-1); 179 } 180 return (0); 181 } 182 183 pcap_t * 184 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) 185 { 186 int fd; 187 struct sockaddr_nit snit; 188 register pcap_t *p; 189 190 p = (pcap_t *)malloc(sizeof(*p)); 191 if (p == NULL) { 192 strcpy(ebuf, pcap_strerror(errno)); 193 return (NULL); 194 } 195 196 if (snaplen < 96) 197 /* 198 * NIT requires a snapshot length of at least 96. 199 */ 200 snaplen = 96; 201 202 bzero(p, sizeof(*p)); 203 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 204 if (fd < 0) { 205 sprintf(ebuf, "socket: %s", pcap_strerror(errno)); 206 goto bad; 207 } 208 snit.snit_family = AF_NIT; 209 (void)strncpy(snit.snit_ifname, device, NITIFSIZ); 210 211 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 212 sprintf(ebuf, "bind: %s: %s", snit.snit_ifname, 213 pcap_strerror(errno)); 214 goto bad; 215 } 216 p->snapshot = snaplen; 217 nit_setflags(p->fd, promisc, to_ms, ebuf); 218 219 /* 220 * NIT supports only ethernets. 221 */ 222 p->linktype = DLT_EN10MB; 223 224 p->bufsize = BUFSPACE; 225 p->buffer = (u_char *)malloc(p->bufsize); 226 if (p->buffer == NULL) { 227 strcpy(ebuf, pcap_strerror(errno)); 228 goto bad; 229 } 230 return (p); 231 bad: 232 if (fd >= 0) 233 close(fd); 234 free(p); 235 return (NULL); 236 } 237 238 int 239 pcap_setfilter(pcap_t *p, struct bpf_program *fp) 240 { 241 242 p->fcode = *fp; 243 return (0); 244 } 245