1 /* 2 * Copyright (c) 2006 Paolo Abeni (Italy) 3 * 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 * 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 * 3. The name of the author may not be used to endorse or promote 15 * products derived from this software without specific prior written 16 * permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * USB sniffing API implementation for Linux platform 31 * By Paolo Abeni <paolo.abeni@email.it> 32 * Modifications: Kris Katterjohn <katterjohn@gmail.com> 33 * 34 */ 35 #ifndef lint 36 static const char rcsid[] _U_ = 37 "@(#) Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.33 2008-12-23 21:38:50 guy Exp (LBL)"; 38 #endif 39 40 #ifdef HAVE_CONFIG_H 41 #include "config.h" 42 #endif 43 44 #include "pcap-int.h" 45 #include "pcap-usb-linux.h" 46 #include "pcap/usb.h" 47 48 #ifdef NEED_STRERROR_H 49 #include "strerror.h" 50 #endif 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <stdlib.h> 55 #include <unistd.h> 56 #include <fcntl.h> 57 #include <string.h> 58 #include <dirent.h> 59 #include <byteswap.h> 60 #include <netinet/in.h> 61 #include <sys/ioctl.h> 62 #include <sys/mman.h> 63 #ifdef HAVE_LINUX_USBDEVICE_FS_H 64 #include <linux/usbdevice_fs.h> 65 #endif 66 67 #define USB_IFACE "usbmon" 68 #define USB_TEXT_DIR_OLD "/sys/kernel/debug/usbmon" 69 #define USB_TEXT_DIR "/sys/kernel/debug/usb/usbmon" 70 #define SYS_USB_BUS_DIR "/sys/bus/usb/devices" 71 #define PROC_USB_BUS_DIR "/proc/bus/usb" 72 #define USB_LINE_LEN 4096 73 74 #if __BYTE_ORDER == __LITTLE_ENDIAN 75 #define htols(s) s 76 #define htoll(l) l 77 #define htol64(ll) ll 78 #else 79 #define htols(s) bswap_16(s) 80 #define htoll(l) bswap_32(l) 81 #define htol64(ll) bswap_64(ll) 82 #endif 83 84 struct mon_bin_stats { 85 u_int32_t queued; 86 u_int32_t dropped; 87 }; 88 89 struct mon_bin_get { 90 pcap_usb_header *hdr; 91 void *data; 92 size_t data_len; /* Length of data (can be zero) */ 93 }; 94 95 struct mon_bin_mfetch { 96 int32_t *offvec; /* Vector of events fetched */ 97 int32_t nfetch; /* Number of events to fetch (out: fetched) */ 98 int32_t nflush; /* Number of events to flush */ 99 }; 100 101 #define MON_IOC_MAGIC 0x92 102 103 #define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1) 104 #define MON_IOCX_URB _IOWR(MON_IOC_MAGIC, 2, struct mon_bin_hdr) 105 #define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats) 106 #define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4) 107 #define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5) 108 #define MON_IOCX_GET _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get) 109 #define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch) 110 #define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8) 111 112 #define MON_BIN_SETUP 0x1 /* setup hdr is present*/ 113 #define MON_BIN_SETUP_ZERO 0x2 /* setup buffer is not available */ 114 #define MON_BIN_DATA_ZERO 0x4 /* data buffer is not available */ 115 #define MON_BIN_ERROR 0x8 116 117 /* forward declaration */ 118 static int usb_activate(pcap_t *); 119 static int usb_stats_linux(pcap_t *, struct pcap_stat *); 120 static int usb_stats_linux_bin(pcap_t *, struct pcap_stat *); 121 static int usb_read_linux(pcap_t *, int , pcap_handler , u_char *); 122 static int usb_read_linux_bin(pcap_t *, int , pcap_handler , u_char *); 123 static int usb_read_linux_mmap(pcap_t *, int , pcap_handler , u_char *); 124 static int usb_inject_linux(pcap_t *, const void *, size_t); 125 static int usb_setfilter_linux(pcap_t *, struct bpf_program *); 126 static int usb_setdirection_linux(pcap_t *, pcap_direction_t); 127 static void usb_cleanup_linux_mmap(pcap_t *); 128 129 /* facility to add an USB device to the device list*/ 130 static int 131 usb_dev_add(pcap_if_t** alldevsp, int n, char *err_str) 132 { 133 char dev_name[10]; 134 char dev_descr[30]; 135 snprintf(dev_name, 10, USB_IFACE"%d", n); 136 snprintf(dev_descr, 30, "USB bus number %d", n); 137 138 if (pcap_add_if(alldevsp, dev_name, 0, 139 dev_descr, err_str) < 0) 140 return -1; 141 return 0; 142 } 143 144 int 145 usb_platform_finddevs(pcap_if_t **alldevsp, char *err_str) 146 { 147 struct dirent* data; 148 int ret = 0; 149 DIR* dir; 150 int n; 151 char* name; 152 size_t len; 153 154 /* try scanning sysfs usb bus directory */ 155 dir = opendir(SYS_USB_BUS_DIR); 156 if (dir != NULL) { 157 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 158 name = data->d_name; 159 160 if (strncmp(name, "usb", 3) != 0) 161 continue; 162 163 if (sscanf(&name[3], "%d", &n) == 0) 164 continue; 165 166 ret = usb_dev_add(alldevsp, n, err_str); 167 } 168 169 closedir(dir); 170 return ret; 171 } 172 173 /* that didn't work; try scanning procfs usb bus directory */ 174 dir = opendir(PROC_USB_BUS_DIR); 175 if (dir != NULL) { 176 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 177 name = data->d_name; 178 len = strlen(name); 179 180 /* if this file name does not end with a number it's not of our interest */ 181 if ((len < 1) || !isdigit(name[--len])) 182 continue; 183 while (isdigit(name[--len])); 184 if (sscanf(&name[len+1], "%d", &n) != 1) 185 continue; 186 187 ret = usb_dev_add(alldevsp, n, err_str); 188 } 189 190 closedir(dir); 191 return ret; 192 } 193 194 /* neither of them worked */ 195 return 0; 196 } 197 198 static 199 int usb_mmap(pcap_t* handle) 200 { 201 int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE); 202 if (len < 0) 203 return 0; 204 205 handle->md.mmapbuflen = len; 206 handle->md.mmapbuf = mmap(0, handle->md.mmapbuflen, PROT_READ, 207 MAP_SHARED, handle->fd, 0); 208 return handle->md.mmapbuf != MAP_FAILED; 209 } 210 211 #define CTRL_TIMEOUT (5*1000) /* milliseconds */ 212 213 #define USB_DIR_IN 0x80 214 #define USB_TYPE_STANDARD 0x00 215 #define USB_RECIP_DEVICE 0x00 216 217 #define USB_REQ_GET_DESCRIPTOR 6 218 219 #define USB_DT_DEVICE 1 220 221 /* probe the descriptors of the devices attached to the bus */ 222 /* the descriptors will end up in the captured packet stream */ 223 /* and be decoded by external apps like wireshark */ 224 /* without these identifying probes packet data can't be fully decoded */ 225 static void 226 probe_devices(int bus) 227 { 228 struct usbdevfs_ctrltransfer ctrl; 229 struct dirent* data; 230 int ret = 0; 231 char buf[40]; 232 DIR* dir; 233 234 /* scan usb bus directories for device nodes */ 235 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d", bus); 236 dir = opendir(buf); 237 if (!dir) 238 return; 239 240 while ((ret >= 0) && ((data = readdir(dir)) != 0)) { 241 int fd; 242 char* name = data->d_name; 243 244 if (name[0] == '.') 245 continue; 246 247 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d/%s", bus, data->d_name); 248 249 fd = open(buf, O_RDWR); 250 if (fd == -1) 251 continue; 252 253 /* 254 * Sigh. Different kernels have different member names 255 * for this structure. 256 */ 257 #ifdef HAVE_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE 258 ctrl.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 259 ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; 260 ctrl.wValue = USB_DT_DEVICE << 8; 261 ctrl.wIndex = 0; 262 ctrl.wLength = sizeof(buf); 263 #else 264 ctrl.requesttype = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 265 ctrl.request = USB_REQ_GET_DESCRIPTOR; 266 ctrl.value = USB_DT_DEVICE << 8; 267 ctrl.index = 0; 268 ctrl.length = sizeof(buf); 269 #endif 270 ctrl.data = buf; 271 ctrl.timeout = CTRL_TIMEOUT; 272 273 ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl); 274 275 close(fd); 276 } 277 closedir(dir); 278 } 279 280 pcap_t * 281 usb_create(const char *device, char *ebuf) 282 { 283 pcap_t *p; 284 285 p = pcap_create_common(device, ebuf); 286 if (p == NULL) 287 return (NULL); 288 289 p->activate_op = usb_activate; 290 return (p); 291 } 292 293 static int 294 usb_activate(pcap_t* handle) 295 { 296 char full_path[USB_LINE_LEN]; 297 298 /* Initialize some components of the pcap structure. */ 299 handle->bufsize = handle->snapshot; 300 handle->offset = 0; 301 handle->linktype = DLT_USB_LINUX; 302 303 handle->inject_op = usb_inject_linux; 304 handle->setfilter_op = usb_setfilter_linux; 305 handle->setdirection_op = usb_setdirection_linux; 306 handle->set_datalink_op = NULL; /* can't change data link type */ 307 handle->getnonblock_op = pcap_getnonblock_fd; 308 handle->setnonblock_op = pcap_setnonblock_fd; 309 310 /*get usb bus index from device name */ 311 if (sscanf(handle->opt.source, USB_IFACE"%d", &handle->md.ifindex) != 1) 312 { 313 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 314 "Can't get USB bus index from %s", handle->opt.source); 315 return PCAP_ERROR; 316 } 317 318 /*now select the read method: try to open binary interface */ 319 snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handle->md.ifindex); 320 handle->fd = open(full_path, O_RDONLY, 0); 321 if (handle->fd >= 0) 322 { 323 if (handle->opt.rfmon) { 324 /* 325 * Monitor mode doesn't apply to USB devices. 326 */ 327 close(handle->fd); 328 return PCAP_ERROR_RFMON_NOTSUP; 329 } 330 331 /* binary api is available, try to use fast mmap access */ 332 if (usb_mmap(handle)) { 333 handle->linktype = DLT_USB_LINUX_MMAPPED; 334 handle->stats_op = usb_stats_linux_bin; 335 handle->read_op = usb_read_linux_mmap; 336 handle->cleanup_op = usb_cleanup_linux_mmap; 337 probe_devices(handle->md.ifindex); 338 339 /* 340 * "handle->fd" is a real file, so "select()" and 341 * "poll()" work on it. 342 */ 343 handle->selectable_fd = handle->fd; 344 return 0; 345 } 346 347 /* can't mmap, use plain binary interface access */ 348 handle->stats_op = usb_stats_linux_bin; 349 handle->read_op = usb_read_linux_bin; 350 probe_devices(handle->md.ifindex); 351 } 352 else { 353 /*Binary interface not available, try open text interface */ 354 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handle->md.ifindex); 355 handle->fd = open(full_path, O_RDONLY, 0); 356 if (handle->fd < 0) 357 { 358 if (errno == ENOENT) 359 { 360 /* 361 * Not found at the new location; try 362 * the old location. 363 */ 364 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%dt", handle->md.ifindex); 365 handle->fd = open(full_path, O_RDONLY, 0); 366 } 367 if (handle->fd < 0) { 368 /* no more fallback, give it up*/ 369 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 370 "Can't open USB bus file %s: %s", full_path, strerror(errno)); 371 return PCAP_ERROR; 372 } 373 } 374 375 if (handle->opt.rfmon) { 376 /* 377 * Monitor mode doesn't apply to USB devices. 378 */ 379 close(handle->fd); 380 return PCAP_ERROR_RFMON_NOTSUP; 381 } 382 383 handle->stats_op = usb_stats_linux; 384 handle->read_op = usb_read_linux; 385 } 386 387 /* 388 * "handle->fd" is a real file, so "select()" and "poll()" 389 * work on it. 390 */ 391 handle->selectable_fd = handle->fd; 392 393 /* for plain binary access and text access we need to allocate the read 394 * buffer */ 395 handle->buffer = malloc(handle->bufsize); 396 if (!handle->buffer) { 397 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 398 "malloc: %s", pcap_strerror(errno)); 399 close(handle->fd); 400 return PCAP_ERROR; 401 } 402 return 0; 403 } 404 405 static inline int 406 ascii_to_int(char c) 407 { 408 return c < 'A' ? c- '0': ((c<'a') ? c - 'A' + 10: c-'a'+10); 409 } 410 411 /* 412 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 413 * <linux-kernel-source>/drivers/usb/mon/mon_text.c for urb string 414 * format description 415 */ 416 static int 417 usb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 418 { 419 /* see: 420 * /usr/src/linux/Documentation/usb/usbmon.txt 421 * for message format 422 */ 423 unsigned timestamp; 424 int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len; 425 char etype, pipeid1, pipeid2, status[16], urb_tag, line[USB_LINE_LEN]; 426 char *string = line; 427 u_char * rawdata = handle->buffer; 428 struct pcap_pkthdr pkth; 429 pcap_usb_header* uhdr = (pcap_usb_header*)handle->buffer; 430 u_char urb_transfer=0; 431 int incoming=0; 432 433 /* ignore interrupt system call errors */ 434 do { 435 ret = read(handle->fd, line, USB_LINE_LEN - 1); 436 if (handle->break_loop) 437 { 438 handle->break_loop = 0; 439 return -2; 440 } 441 } while ((ret == -1) && (errno == EINTR)); 442 if (ret < 0) 443 { 444 if (errno == EAGAIN) 445 return 0; /* no data there */ 446 447 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 448 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 449 return -1; 450 } 451 452 /* read urb header; %n argument may increment return value, but it's 453 * not mandatory, so does not count on it*/ 454 string[ret] = 0; 455 ret = sscanf(string, "%x %d %c %c%c:%d:%d %s%n", &tag, ×tamp, &etype, 456 &pipeid1, &pipeid2, &dev_addr, &ep_num, status, 457 &cnt); 458 if (ret < 8) 459 { 460 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 461 "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)", 462 string, ret); 463 return -1; 464 } 465 uhdr->id = tag; 466 uhdr->device_address = dev_addr; 467 uhdr->bus_id = handle->md.ifindex; 468 uhdr->status = 0; 469 string += cnt; 470 471 /* don't use usbmon provided timestamp, since it have low precision*/ 472 if (gettimeofday(&pkth.ts, NULL) < 0) 473 { 474 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 475 "Can't get timestamp for message '%s' %d:%s", 476 string, errno, strerror(errno)); 477 return -1; 478 } 479 uhdr->ts_sec = pkth.ts.tv_sec; 480 uhdr->ts_usec = pkth.ts.tv_usec; 481 482 /* parse endpoint information */ 483 if (pipeid1 == 'C') 484 urb_transfer = URB_CONTROL; 485 else if (pipeid1 == 'Z') 486 urb_transfer = URB_ISOCHRONOUS; 487 else if (pipeid1 == 'I') 488 urb_transfer = URB_INTERRUPT; 489 else if (pipeid1 == 'B') 490 urb_transfer = URB_BULK; 491 if (pipeid2 == 'i') { 492 ep_num |= URB_TRANSFER_IN; 493 incoming = 1; 494 } 495 if (etype == 'C') 496 incoming = !incoming; 497 498 /* direction check*/ 499 if (incoming) 500 { 501 if (handle->direction == PCAP_D_OUT) 502 return 0; 503 } 504 else 505 if (handle->direction == PCAP_D_IN) 506 return 0; 507 uhdr->event_type = etype; 508 uhdr->transfer_type = urb_transfer; 509 uhdr->endpoint_number = ep_num; 510 pkth.caplen = sizeof(pcap_usb_header); 511 rawdata += sizeof(pcap_usb_header); 512 513 /* check if this is a setup packet */ 514 ret = sscanf(status, "%d", &dummy); 515 if (ret != 1) 516 { 517 /* this a setup packet, setup data can be filled with underscore if 518 * usbmon has not been able to read them, so we must parse this fields as 519 * strings */ 520 pcap_usb_setup* shdr; 521 char str1[3], str2[3], str3[5], str4[5], str5[5]; 522 ret = sscanf(string, "%s %s %s %s %s%n", str1, str2, str3, str4, 523 str5, &cnt); 524 if (ret < 5) 525 { 526 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 527 "Can't parse USB bus message '%s', too few tokens (expected 5 got %d)", 528 string, ret); 529 return -1; 530 } 531 string += cnt; 532 533 /* try to convert to corresponding integer */ 534 shdr = &uhdr->setup; 535 shdr->bmRequestType = strtoul(str1, 0, 16); 536 shdr->bRequest = strtoul(str2, 0, 16); 537 shdr->wValue = htols(strtoul(str3, 0, 16)); 538 shdr->wIndex = htols(strtoul(str4, 0, 16)); 539 shdr->wLength = htols(strtoul(str5, 0, 16)); 540 541 uhdr->setup_flag = 0; 542 } 543 else 544 uhdr->setup_flag = 1; 545 546 /* read urb data */ 547 ret = sscanf(string, " %d%n", &urb_len, &cnt); 548 if (ret < 1) 549 { 550 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 551 "Can't parse urb length from '%s'", string); 552 return -1; 553 } 554 string += cnt; 555 556 /* urb tag is not present if urb length is 0, so we can stop here 557 * text parsing */ 558 pkth.len = urb_len+pkth.caplen; 559 uhdr->urb_len = urb_len; 560 uhdr->data_flag = 1; 561 data_len = 0; 562 if (uhdr->urb_len == 0) 563 goto got; 564 565 /* check for data presence; data is present if and only if urb tag is '=' */ 566 if (sscanf(string, " %c", &urb_tag) != 1) 567 { 568 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 569 "Can't parse urb tag from '%s'", string); 570 return -1; 571 } 572 573 if (urb_tag != '=') 574 goto got; 575 576 /* skip urb tag and following space */ 577 string += 3; 578 579 /* if we reach this point we got some urb data*/ 580 uhdr->data_flag = 0; 581 582 /* read all urb data; if urb length is greater then the usbmon internal 583 * buffer length used by the kernel to spool the URB, we get only 584 * a partial information. 585 * At least until linux 2.6.17 there is no way to set usbmon intenal buffer 586 * length and default value is 130. */ 587 while ((string[0] != 0) && (string[1] != 0) && (pkth.caplen < handle->snapshot)) 588 { 589 rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]); 590 rawdata++; 591 string+=2; 592 if (string[0] == ' ') 593 string++; 594 pkth.caplen++; 595 data_len++; 596 } 597 598 got: 599 uhdr->data_len = data_len; 600 handle->md.packets_read++; 601 if (pkth.caplen > handle->snapshot) 602 pkth.caplen = handle->snapshot; 603 604 callback(user, &pkth, handle->buffer); 605 return 1; 606 } 607 608 static int 609 usb_inject_linux(pcap_t *handle, const void *buf, size_t size) 610 { 611 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 612 "USB devices"); 613 return (-1); 614 } 615 616 static int 617 usb_stats_linux(pcap_t *handle, struct pcap_stat *stats) 618 { 619 int dummy, ret, consumed, cnt; 620 char string[USB_LINE_LEN]; 621 char token[USB_LINE_LEN]; 622 char * ptr = string; 623 int fd; 624 625 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handle->md.ifindex); 626 fd = open(string, O_RDONLY, 0); 627 if (fd < 0) 628 { 629 if (errno == ENOENT) 630 { 631 /* 632 * Not found at the new location; try the old 633 * location. 634 */ 635 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%ds", handle->md.ifindex); 636 fd = open(string, O_RDONLY, 0); 637 } 638 if (fd < 0) { 639 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 640 "Can't open USB stats file %s: %s", 641 string, strerror(errno)); 642 return -1; 643 } 644 } 645 646 /* read stats line */ 647 do { 648 ret = read(fd, string, USB_LINE_LEN-1); 649 } while ((ret == -1) && (errno == EINTR)); 650 close(fd); 651 652 if (ret < 0) 653 { 654 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 655 "Can't read stats from fd %d ", fd); 656 return -1; 657 } 658 string[ret] = 0; 659 660 /* extract info on dropped urbs */ 661 for (consumed=0; consumed < ret; ) { 662 /* from the sscanf man page: 663 * The C standard says: "Execution of a %n directive does 664 * not increment the assignment count returned at the completion 665 * of execution" but the Corrigendum seems to contradict this. 666 * Do not make any assumptions on the effect of %n conversions 667 * on the return value and explicitly check for cnt assignmet*/ 668 int ntok; 669 670 cnt = -1; 671 ntok = sscanf(ptr, "%s%n", token, &cnt); 672 if ((ntok < 1) || (cnt < 0)) 673 break; 674 consumed += cnt; 675 ptr += cnt; 676 if (strcmp(token, "nreaders") == 0) 677 ret = sscanf(ptr, "%d", &stats->ps_drop); 678 else 679 ret = sscanf(ptr, "%d", &dummy); 680 if (ntok != 1) 681 break; 682 consumed += cnt; 683 ptr += cnt; 684 } 685 686 stats->ps_recv = handle->md.packets_read; 687 stats->ps_ifdrop = 0; 688 return 0; 689 } 690 691 static int 692 usb_setfilter_linux(pcap_t *p, struct bpf_program *fp) 693 { 694 return 0; 695 } 696 697 static int 698 usb_setdirection_linux(pcap_t *p, pcap_direction_t d) 699 { 700 p->direction = d; 701 return 0; 702 } 703 704 705 static int 706 usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats) 707 { 708 int ret; 709 struct mon_bin_stats st; 710 ret = ioctl(handle->fd, MON_IOCG_STATS, &st); 711 if (ret < 0) 712 { 713 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 714 "Can't read stats from fd %d:%s ", handle->fd, strerror(errno)); 715 return -1; 716 } 717 718 stats->ps_recv = handle->md.packets_read + st.queued; 719 stats->ps_drop = st.dropped; 720 stats->ps_ifdrop = 0; 721 return 0; 722 } 723 724 /* 725 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 726 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 727 */ 728 static int 729 usb_read_linux_bin(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 730 { 731 struct mon_bin_get info; 732 int ret; 733 struct pcap_pkthdr pkth; 734 int clen = handle->snapshot - sizeof(pcap_usb_header); 735 736 /* the usb header is going to be part of 'packet' data*/ 737 info.hdr = (pcap_usb_header*) handle->buffer; 738 info.data = handle->buffer + sizeof(pcap_usb_header); 739 info.data_len = clen; 740 741 /* ignore interrupt system call errors */ 742 do { 743 ret = ioctl(handle->fd, MON_IOCX_GET, &info); 744 if (handle->break_loop) 745 { 746 handle->break_loop = 0; 747 return -2; 748 } 749 } while ((ret == -1) && (errno == EINTR)); 750 if (ret < 0) 751 { 752 if (errno == EAGAIN) 753 return 0; /* no data there */ 754 755 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 756 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 757 return -1; 758 } 759 760 /* we can get less that than really captured from kernel, depending on 761 * snaplen, so adjust header accordingly */ 762 if (info.hdr->data_len < clen) 763 clen = info.hdr->data_len; 764 info.hdr->data_len = clen; 765 pkth.caplen = clen + sizeof(pcap_usb_header); 766 pkth.len = info.hdr->data_len + sizeof(pcap_usb_header); 767 pkth.ts.tv_sec = info.hdr->ts_sec; 768 pkth.ts.tv_usec = info.hdr->ts_usec; 769 770 handle->md.packets_read++; 771 callback(user, &pkth, handle->buffer); 772 return 1; 773 } 774 775 /* 776 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 777 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 778 */ 779 #define VEC_SIZE 32 780 static int 781 usb_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 782 { 783 struct mon_bin_mfetch fetch; 784 int32_t vec[VEC_SIZE]; 785 struct pcap_pkthdr pkth; 786 pcap_usb_header* hdr; 787 int nflush = 0; 788 int packets = 0; 789 int clen, max_clen; 790 791 max_clen = handle->snapshot - sizeof(pcap_usb_header); 792 793 for (;;) { 794 int i, ret; 795 int limit = max_packets - packets; 796 if (limit <= 0) 797 limit = VEC_SIZE; 798 if (limit > VEC_SIZE) 799 limit = VEC_SIZE; 800 801 /* try to fetch as many events as possible*/ 802 fetch.offvec = vec; 803 fetch.nfetch = limit; 804 fetch.nflush = nflush; 805 /* ignore interrupt system call errors */ 806 do { 807 ret = ioctl(handle->fd, MON_IOCX_MFETCH, &fetch); 808 if (handle->break_loop) 809 { 810 handle->break_loop = 0; 811 return -2; 812 } 813 } while ((ret == -1) && (errno == EINTR)); 814 if (ret < 0) 815 { 816 if (errno == EAGAIN) 817 return 0; /* no data there */ 818 819 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 820 "Can't mfetch fd %d: %s", handle->fd, strerror(errno)); 821 return -1; 822 } 823 824 /* keep track of processed events, we will flush them later */ 825 nflush = fetch.nfetch; 826 for (i=0; i<fetch.nfetch; ++i) { 827 /* discard filler */ 828 hdr = (pcap_usb_header*) &handle->md.mmapbuf[vec[i]]; 829 if (hdr->event_type == '@') 830 continue; 831 832 /* we can get less that than really captured from kernel, depending on 833 * snaplen, so adjust header accordingly */ 834 clen = max_clen; 835 if (hdr->data_len < clen) 836 clen = hdr->data_len; 837 838 /* get packet info from header*/ 839 pkth.caplen = clen + sizeof(pcap_usb_header_mmapped); 840 pkth.len = hdr->data_len + sizeof(pcap_usb_header_mmapped); 841 pkth.ts.tv_sec = hdr->ts_sec; 842 pkth.ts.tv_usec = hdr->ts_usec; 843 844 handle->md.packets_read++; 845 callback(user, &pkth, (u_char*) hdr); 846 packets++; 847 } 848 849 /* with max_packets <= 0 we stop afer the first chunk*/ 850 if ((max_packets <= 0) || (packets == max_packets)) 851 break; 852 } 853 854 /* flush pending events*/ 855 ioctl(handle->fd, MON_IOCH_MFLUSH, nflush); 856 return packets; 857 } 858 859 static void 860 usb_cleanup_linux_mmap(pcap_t* handle) 861 { 862 /* if we have a memory-mapped buffer, unmap it */ 863 if (handle->md.mmapbuf != NULL) { 864 munmap(handle->md.mmapbuf, handle->md.mmapbuflen); 865 handle->md.mmapbuf = NULL; 866 } 867 pcap_cleanup_live_common(handle); 868 } 869