1 /* 2 * This code is derived from code formerly in pcap-dlpi.c, originally 3 * contributed by Atanu Ghosh (atanu (at) cs.ucl.ac.uk), University College 4 * London, and subsequently modified by Guy Harris (guy (at) alum.mit.edu), 5 * Mark Pizzolato <List-tcpdump-workers (at) subscriptions.pizzolato.net>, 6 * Mark C. Brown (mbrown (at) hp.com), and Sagun Shakya <Sagun.Shakya (at) Sun.COM>. 7 */ 8 9 /* 10 * This file contains dlpi/libdlpi related common functions used 11 * by pcap-[dlpi,libdlpi].c. 12 */ 13 14 #ifdef HAVE_CONFIG_H 15 #include "config.h" 16 #endif 17 18 #ifndef DL_IPATM 19 #define DL_IPATM 0x12 /* ATM Classical IP interface */ 20 #endif 21 22 #ifdef HAVE_SYS_BUFMOD_H 23 /* 24 * Size of a bufmod chunk to pass upstream; that appears to be the 25 * biggest value to which you can set it, and setting it to that value 26 * (which is bigger than what appears to be the Solaris default of 8192) 27 * reduces the number of packet drops. 28 */ 29 #define CHUNKSIZE 65536 30 31 /* 32 * Size of the buffer to allocate for packet data we read; it must be 33 * large enough to hold a chunk. 34 */ 35 #define PKTBUFSIZE CHUNKSIZE 36 37 #else /* HAVE_SYS_BUFMOD_H */ 38 39 /* 40 * Size of the buffer to allocate for packet data we read; this is 41 * what the value used to be - there's no particular reason why it 42 * should be tied to MAXDLBUF, but we'll leave it as this for now. 43 */ 44 #define MAXDLBUF 8192 45 #define PKTBUFSIZE (MAXDLBUF * sizeof(bpf_u_int32)) 46 47 #endif 48 49 #include <sys/types.h> 50 #include <sys/time.h> 51 #ifdef HAVE_SYS_BUFMOD_H 52 #include <sys/bufmod.h> 53 #endif 54 #include <sys/dlpi.h> 55 #include <sys/stream.h> 56 57 #include <errno.h> 58 #include <memory.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <stropts.h> 63 #include <unistd.h> 64 65 #ifdef HAVE_LIBDLPI 66 #include <libdlpi.h> 67 #endif 68 69 #include "pcap-int.h" 70 #include "dlpisubs.h" 71 72 #ifdef HAVE_SYS_BUFMOD_H 73 static void pcap_stream_err(const char *, int, char *); 74 #endif 75 76 /* 77 * Get the packet statistics. 78 */ 79 int 80 pcap_stats_dlpi(pcap_t *p, struct pcap_stat *ps) 81 { 82 struct pcap_dlpi *pd = p->priv; 83 84 /* 85 * "ps_recv" counts packets handed to the filter, not packets 86 * that passed the filter. As filtering is done in userland, 87 * this would not include packets dropped because we ran out 88 * of buffer space; in order to make this more like other 89 * platforms (Linux 2.4 and later, BSDs with BPF), where the 90 * "packets received" count includes packets received but dropped 91 * due to running out of buffer space, and to keep from confusing 92 * applications that, for example, compute packet drop percentages, 93 * we also make it count packets dropped by "bufmod" (otherwise we 94 * might run the risk of the packet drop count being bigger than 95 * the received-packet count). 96 * 97 * "ps_drop" counts packets dropped by "bufmod" because of 98 * flow control requirements or resource exhaustion; it doesn't 99 * count packets dropped by the interface driver, or packets 100 * dropped upstream. As filtering is done in userland, it counts 101 * packets regardless of whether they would've passed the filter. 102 * 103 * These statistics don't include packets not yet read from 104 * the kernel by libpcap, but they may include packets not 105 * yet read from libpcap by the application. 106 */ 107 *ps = pd->stat; 108 109 /* 110 * Add in the drop count, as per the above comment. 111 */ 112 ps->ps_recv += ps->ps_drop; 113 return (0); 114 } 115 116 /* 117 * Loop through the packets and call the callback for each packet. 118 * Return the number of packets read. 119 */ 120 int 121 pcap_process_pkts(pcap_t *p, pcap_handler callback, u_char *user, 122 int count, u_char *bufp, int len) 123 { 124 struct pcap_dlpi *pd = p->priv; 125 int n, caplen, origlen; 126 u_char *ep, *pk; 127 struct pcap_pkthdr pkthdr; 128 #ifdef HAVE_SYS_BUFMOD_H 129 struct sb_hdr *sbp; 130 #ifdef LBL_ALIGN 131 struct sb_hdr sbhdr; 132 #endif 133 #endif 134 135 /* Loop through packets */ 136 ep = bufp + len; 137 n = 0; 138 139 #ifdef HAVE_SYS_BUFMOD_H 140 while (bufp < ep) { 141 /* 142 * Has "pcap_breakloop()" been called? 143 * If so, return immediately - if we haven't read any 144 * packets, clear the flag and return -2 to indicate 145 * that we were told to break out of the loop, otherwise 146 * leave the flag set, so that the *next* call will break 147 * out of the loop without having read any packets, and 148 * return the number of packets we've processed so far. 149 */ 150 if (p->break_loop) { 151 if (n == 0) { 152 p->break_loop = 0; 153 return (-2); 154 } else { 155 p->bp = bufp; 156 p->cc = ep - bufp; 157 return (n); 158 } 159 } 160 #ifdef LBL_ALIGN 161 if ((long)bufp & 3) { 162 sbp = &sbhdr; 163 memcpy(sbp, bufp, sizeof(*sbp)); 164 } else 165 #endif 166 sbp = (struct sb_hdr *)bufp; 167 pd->stat.ps_drop = sbp->sbh_drops; 168 pk = bufp + sizeof(*sbp); 169 bufp += sbp->sbh_totlen; 170 origlen = sbp->sbh_origlen; 171 caplen = sbp->sbh_msglen; 172 #else 173 origlen = len; 174 caplen = min(p->snapshot, len); 175 pk = bufp; 176 bufp += caplen; 177 #endif 178 ++pd->stat.ps_recv; 179 if (bpf_filter(p->fcode.bf_insns, pk, origlen, caplen)) { 180 #ifdef HAVE_SYS_BUFMOD_H 181 pkthdr.ts.tv_sec = sbp->sbh_timestamp.tv_sec; 182 pkthdr.ts.tv_usec = sbp->sbh_timestamp.tv_usec; 183 #else 184 (void) gettimeofday(&pkthdr.ts, NULL); 185 #endif 186 pkthdr.len = origlen; 187 pkthdr.caplen = caplen; 188 /* Insure caplen does not exceed snapshot */ 189 if (pkthdr.caplen > p->snapshot) 190 pkthdr.caplen = p->snapshot; 191 (*callback)(user, &pkthdr, pk); 192 if (++n >= count && !PACKET_COUNT_IS_UNLIMITED(count)) { 193 p->cc = ep - bufp; 194 p->bp = bufp; 195 return (n); 196 } 197 } 198 #ifdef HAVE_SYS_BUFMOD_H 199 } 200 #endif 201 p->cc = 0; 202 return (n); 203 } 204 205 /* 206 * Process the mac type. Returns -1 if no matching mac type found, otherwise 0. 207 */ 208 int 209 pcap_process_mactype(pcap_t *p, u_int mactype) 210 { 211 int retv = 0; 212 213 switch (mactype) { 214 215 case DL_CSMACD: 216 case DL_ETHER: 217 p->linktype = DLT_EN10MB; 218 p->offset = 2; 219 /* 220 * This is (presumably) a real Ethernet capture; give it a 221 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 222 * that an application can let you choose it, in case you're 223 * capturing DOCSIS traffic that a Cisco Cable Modem 224 * Termination System is putting out onto an Ethernet (it 225 * doesn't put an Ethernet header onto the wire, it puts raw 226 * DOCSIS frames out on the wire inside the low-level 227 * Ethernet framing). 228 */ 229 p->dlt_list = (u_int *)malloc(sizeof(u_int) * 2); 230 /* 231 * If that fails, just leave the list empty. 232 */ 233 if (p->dlt_list != NULL) { 234 p->dlt_list[0] = DLT_EN10MB; 235 p->dlt_list[1] = DLT_DOCSIS; 236 p->dlt_count = 2; 237 } 238 break; 239 240 case DL_FDDI: 241 p->linktype = DLT_FDDI; 242 p->offset = 3; 243 break; 244 245 case DL_TPR: 246 /* XXX - what about DL_TPB? Is that Token Bus? */ 247 p->linktype = DLT_IEEE802; 248 p->offset = 2; 249 break; 250 251 #ifdef HAVE_SOLARIS 252 case DL_IPATM: 253 p->linktype = DLT_SUNATM; 254 p->offset = 0; /* works for LANE and LLC encapsulation */ 255 break; 256 #endif 257 258 default: 259 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown mactype %u", 260 mactype); 261 retv = -1; 262 } 263 264 return (retv); 265 } 266 267 #ifdef HAVE_SYS_BUFMOD_H 268 /* 269 * Push and configure the buffer module. Returns -1 for error, otherwise 0. 270 */ 271 int 272 pcap_conf_bufmod(pcap_t *p, int snaplen) 273 { 274 struct timeval to; 275 bpf_u_int32 ss, chunksize; 276 277 /* Non-standard call to get the data nicely buffered. */ 278 if (ioctl(p->fd, I_PUSH, "bufmod") != 0) { 279 pcap_stream_err("I_PUSH bufmod", errno, p->errbuf); 280 return (-1); 281 } 282 283 ss = snaplen; 284 if (ss > 0 && 285 strioctl(p->fd, SBIOCSSNAP, sizeof(ss), (char *)&ss) != 0) { 286 pcap_stream_err("SBIOCSSNAP", errno, p->errbuf); 287 return (-1); 288 } 289 290 if (p->opt.immediate) { 291 /* Set the timeout to zero, for immediate delivery. */ 292 to.tv_sec = 0; 293 to.tv_usec = 0; 294 if (strioctl(p->fd, SBIOCSTIME, sizeof(to), (char *)&to) != 0) { 295 pcap_stream_err("SBIOCSTIME", errno, p->errbuf); 296 return (-1); 297 } 298 } else { 299 /* Set up the bufmod timeout. */ 300 if (p->opt.timeout != 0) { 301 to.tv_sec = p->opt.timeout / 1000; 302 to.tv_usec = (p->opt.timeout * 1000) % 1000000; 303 if (strioctl(p->fd, SBIOCSTIME, sizeof(to), (char *)&to) != 0) { 304 pcap_stream_err("SBIOCSTIME", errno, p->errbuf); 305 return (-1); 306 } 307 } 308 309 /* Set the chunk length. */ 310 chunksize = CHUNKSIZE; 311 if (strioctl(p->fd, SBIOCSCHUNK, sizeof(chunksize), (char *)&chunksize) 312 != 0) { 313 pcap_stream_err("SBIOCSCHUNKP", errno, p->errbuf); 314 return (-1); 315 } 316 } 317 318 return (0); 319 } 320 #endif /* HAVE_SYS_BUFMOD_H */ 321 322 /* 323 * Allocate data buffer. Returns -1 if memory allocation fails, else 0. 324 */ 325 int 326 pcap_alloc_databuf(pcap_t *p) 327 { 328 p->bufsize = PKTBUFSIZE; 329 p->buffer = (u_char *)malloc(p->bufsize + p->offset); 330 if (p->buffer == NULL) { 331 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE); 332 return (-1); 333 } 334 335 return (0); 336 } 337 338 /* 339 * Issue a STREAMS I_STR ioctl. Returns -1 on error, otherwise 340 * length of returned data on success. 341 */ 342 int 343 strioctl(int fd, int cmd, int len, char *dp) 344 { 345 struct strioctl str; 346 int retv; 347 348 str.ic_cmd = cmd; 349 str.ic_timout = -1; 350 str.ic_len = len; 351 str.ic_dp = dp; 352 if ((retv = ioctl(fd, I_STR, &str)) < 0) 353 return (retv); 354 355 return (str.ic_len); 356 } 357 358 #ifdef HAVE_SYS_BUFMOD_H 359 /* 360 * Write stream error message to errbuf. 361 */ 362 static void 363 pcap_stream_err(const char *func, int err, char *errbuf) 364 { 365 snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", func, pcap_strerror(err)); 366 } 367 #endif 368
