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 (at) email.it> 32 * Modifications: Kris Katterjohn <katterjohn (at) 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 /* 65 * We might need <linux/compiler.h> to define __user for 66 * <linux/usbdevice_fs.h>. 67 */ 68 #ifdef HAVE_LINUX_COMPILER_H 69 #include <linux/compiler.h> 70 #endif /* HAVE_LINUX_COMPILER_H */ 71 #include <linux/usbdevice_fs.h> 72 #endif /* HAVE_LINUX_USBDEVICE_FS_H */ 73 74 #define USB_IFACE "usbmon" 75 #define USB_TEXT_DIR_OLD "/sys/kernel/debug/usbmon" 76 #define USB_TEXT_DIR "/sys/kernel/debug/usb/usbmon" 77 #define SYS_USB_BUS_DIR "/sys/bus/usb/devices" 78 #define PROC_USB_BUS_DIR "/proc/bus/usb" 79 #define USB_LINE_LEN 4096 80 81 #if __BYTE_ORDER == __LITTLE_ENDIAN 82 #define htols(s) s 83 #define htoll(l) l 84 #define htol64(ll) ll 85 #else 86 #define htols(s) bswap_16(s) 87 #define htoll(l) bswap_32(l) 88 #define htol64(ll) bswap_64(ll) 89 #endif 90 91 struct mon_bin_stats { 92 u_int32_t queued; 93 u_int32_t dropped; 94 }; 95 96 struct mon_bin_get { 97 pcap_usb_header *hdr; 98 void *data; 99 size_t data_len; /* Length of data (can be zero) */ 100 }; 101 102 struct mon_bin_mfetch { 103 int32_t *offvec; /* Vector of events fetched */ 104 int32_t nfetch; /* Number of events to fetch (out: fetched) */ 105 int32_t nflush; /* Number of events to flush */ 106 }; 107 108 #define MON_IOC_MAGIC 0x92 109 110 #define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1) 111 #define MON_IOCX_URB _IOWR(MON_IOC_MAGIC, 2, struct mon_bin_hdr) 112 #define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats) 113 #define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4) 114 #define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5) 115 #define MON_IOCX_GET _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get) 116 #define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch) 117 #define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8) 118 119 #define MON_BIN_SETUP 0x1 /* setup hdr is present*/ 120 #define MON_BIN_SETUP_ZERO 0x2 /* setup buffer is not available */ 121 #define MON_BIN_DATA_ZERO 0x4 /* data buffer is not available */ 122 #define MON_BIN_ERROR 0x8 123 124 /* 125 * Private data for capturing on Linux USB. 126 */ 127 struct pcap_usb_linux { 128 u_char *mmapbuf; /* memory-mapped region pointer */ 129 size_t mmapbuflen; /* size of region */ 130 int bus_index; 131 u_int packets_read; 132 }; 133 134 /* forward declaration */ 135 static int usb_activate(pcap_t *); 136 static int usb_stats_linux(pcap_t *, struct pcap_stat *); 137 static int usb_stats_linux_bin(pcap_t *, struct pcap_stat *); 138 static int usb_read_linux(pcap_t *, int , pcap_handler , u_char *); 139 static int usb_read_linux_bin(pcap_t *, int , pcap_handler , u_char *); 140 static int usb_read_linux_mmap(pcap_t *, int , pcap_handler , u_char *); 141 static int usb_inject_linux(pcap_t *, const void *, size_t); 142 static int usb_setdirection_linux(pcap_t *, pcap_direction_t); 143 static void usb_cleanup_linux_mmap(pcap_t *); 144 145 /* facility to add an USB device to the device list*/ 146 static int 147 usb_dev_add(pcap_if_t** alldevsp, int n, char *err_str) 148 { 149 char dev_name[10]; 150 char dev_descr[30]; 151 snprintf(dev_name, 10, USB_IFACE"%d", n); 152 snprintf(dev_descr, 30, "USB bus number %d", n); 153 154 if (pcap_add_if(alldevsp, dev_name, 0, 155 dev_descr, err_str) < 0) 156 return -1; 157 return 0; 158 } 159 160 int 161 usb_findalldevs(pcap_if_t **alldevsp, char *err_str) 162 { 163 struct dirent* data; 164 int ret = 0; 165 DIR* dir; 166 int n; 167 char* name; 168 size_t len; 169 170 /* try scanning sysfs usb bus directory */ 171 dir = opendir(SYS_USB_BUS_DIR); 172 if (dir != NULL) { 173 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 174 name = data->d_name; 175 176 if (strncmp(name, "usb", 3) != 0) 177 continue; 178 179 if (sscanf(&name[3], "%d", &n) == 0) 180 continue; 181 182 ret = usb_dev_add(alldevsp, n, err_str); 183 } 184 185 closedir(dir); 186 return ret; 187 } 188 189 /* that didn't work; try scanning procfs usb bus directory */ 190 dir = opendir(PROC_USB_BUS_DIR); 191 if (dir != NULL) { 192 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 193 name = data->d_name; 194 len = strlen(name); 195 196 /* if this file name does not end with a number it's not of our interest */ 197 if ((len < 1) || !isdigit(name[--len])) 198 continue; 199 while (isdigit(name[--len])); 200 if (sscanf(&name[len+1], "%d", &n) != 1) 201 continue; 202 203 ret = usb_dev_add(alldevsp, n, err_str); 204 } 205 206 closedir(dir); 207 return ret; 208 } 209 210 /* neither of them worked */ 211 return 0; 212 } 213 214 static 215 int usb_mmap(pcap_t* handle) 216 { 217 struct pcap_usb_linux *handlep = handle->priv; 218 int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE); 219 if (len < 0) 220 return 0; 221 222 handlep->mmapbuflen = len; 223 handlep->mmapbuf = mmap(0, handlep->mmapbuflen, PROT_READ, 224 MAP_SHARED, handle->fd, 0); 225 return handlep->mmapbuf != MAP_FAILED; 226 } 227 228 #define CTRL_TIMEOUT (5*1000) /* milliseconds */ 229 230 #define USB_DIR_IN 0x80 231 #define USB_TYPE_STANDARD 0x00 232 #define USB_RECIP_DEVICE 0x00 233 234 #define USB_REQ_GET_DESCRIPTOR 6 235 236 #define USB_DT_DEVICE 1 237 238 /* probe the descriptors of the devices attached to the bus */ 239 /* the descriptors will end up in the captured packet stream */ 240 /* and be decoded by external apps like wireshark */ 241 /* without these identifying probes packet data can't be fully decoded */ 242 static void 243 probe_devices(int bus) 244 { 245 struct usbdevfs_ctrltransfer ctrl; 246 struct dirent* data; 247 int ret = 0; 248 char buf[40]; 249 DIR* dir; 250 251 /* scan usb bus directories for device nodes */ 252 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d", bus); 253 dir = opendir(buf); 254 if (!dir) 255 return; 256 257 while ((ret >= 0) && ((data = readdir(dir)) != 0)) { 258 int fd; 259 char* name = data->d_name; 260 261 if (name[0] == '.') 262 continue; 263 264 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d/%s", bus, data->d_name); 265 266 fd = open(buf, O_RDWR); 267 if (fd == -1) 268 continue; 269 270 /* 271 * Sigh. Different kernels have different member names 272 * for this structure. 273 */ 274 #ifdef HAVE_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE 275 ctrl.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 276 ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; 277 ctrl.wValue = USB_DT_DEVICE << 8; 278 ctrl.wIndex = 0; 279 ctrl.wLength = sizeof(buf); 280 #else 281 ctrl.requesttype = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 282 ctrl.request = USB_REQ_GET_DESCRIPTOR; 283 ctrl.value = USB_DT_DEVICE << 8; 284 ctrl.index = 0; 285 ctrl.length = sizeof(buf); 286 #endif 287 ctrl.data = buf; 288 ctrl.timeout = CTRL_TIMEOUT; 289 290 ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl); 291 292 close(fd); 293 } 294 closedir(dir); 295 } 296 297 pcap_t * 298 usb_create(const char *device, char *ebuf, int *is_ours) 299 { 300 const char *cp; 301 char *cpend; 302 long devnum; 303 pcap_t *p; 304 305 /* Does this look like a USB monitoring device? */ 306 cp = strrchr(device, '/'); 307 if (cp == NULL) 308 cp = device; 309 /* Does it begin with USB_IFACE? */ 310 if (strncmp(cp, USB_IFACE, sizeof USB_IFACE - 1) != 0) { 311 /* Nope, doesn't begin with USB_IFACE */ 312 *is_ours = 0; 313 return NULL; 314 } 315 /* Yes - is USB_IFACE followed by a number? */ 316 cp += sizeof USB_IFACE - 1; 317 devnum = strtol(cp, &cpend, 10); 318 if (cpend == cp || *cpend != '\0') { 319 /* Not followed by a number. */ 320 *is_ours = 0; 321 return NULL; 322 } 323 if (devnum < 0) { 324 /* Followed by a non-valid number. */ 325 *is_ours = 0; 326 return NULL; 327 } 328 329 /* OK, it's probably ours. */ 330 *is_ours = 1; 331 332 p = pcap_create_common(device, ebuf, sizeof (struct pcap_usb_linux)); 333 if (p == NULL) 334 return (NULL); 335 336 p->activate_op = usb_activate; 337 return (p); 338 } 339 340 static int 341 usb_activate(pcap_t* handle) 342 { 343 struct pcap_usb_linux *handlep = handle->priv; 344 char full_path[USB_LINE_LEN]; 345 346 /* Initialize some components of the pcap structure. */ 347 handle->bufsize = handle->snapshot; 348 handle->offset = 0; 349 handle->linktype = DLT_USB_LINUX; 350 351 handle->inject_op = usb_inject_linux; 352 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 353 handle->setdirection_op = usb_setdirection_linux; 354 handle->set_datalink_op = NULL; /* can't change data link type */ 355 handle->getnonblock_op = pcap_getnonblock_fd; 356 handle->setnonblock_op = pcap_setnonblock_fd; 357 358 /*get usb bus index from device name */ 359 if (sscanf(handle->opt.source, USB_IFACE"%d", &handlep->bus_index) != 1) 360 { 361 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 362 "Can't get USB bus index from %s", handle->opt.source); 363 return PCAP_ERROR; 364 } 365 366 /*now select the read method: try to open binary interface */ 367 snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handlep->bus_index); 368 handle->fd = open(full_path, O_RDONLY, 0); 369 if (handle->fd >= 0) 370 { 371 if (handle->opt.rfmon) { 372 /* 373 * Monitor mode doesn't apply to USB devices. 374 */ 375 close(handle->fd); 376 return PCAP_ERROR_RFMON_NOTSUP; 377 } 378 379 /* binary api is available, try to use fast mmap access */ 380 if (usb_mmap(handle)) { 381 handle->linktype = DLT_USB_LINUX_MMAPPED; 382 handle->stats_op = usb_stats_linux_bin; 383 handle->read_op = usb_read_linux_mmap; 384 handle->cleanup_op = usb_cleanup_linux_mmap; 385 probe_devices(handlep->bus_index); 386 387 /* 388 * "handle->fd" is a real file, so "select()" and 389 * "poll()" work on it. 390 */ 391 handle->selectable_fd = handle->fd; 392 return 0; 393 } 394 395 /* can't mmap, use plain binary interface access */ 396 handle->stats_op = usb_stats_linux_bin; 397 handle->read_op = usb_read_linux_bin; 398 probe_devices(handlep->bus_index); 399 } 400 else { 401 /*Binary interface not available, try open text interface */ 402 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handlep->bus_index); 403 handle->fd = open(full_path, O_RDONLY, 0); 404 if (handle->fd < 0) 405 { 406 if (errno == ENOENT) 407 { 408 /* 409 * Not found at the new location; try 410 * the old location. 411 */ 412 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%dt", handlep->bus_index); 413 handle->fd = open(full_path, O_RDONLY, 0); 414 } 415 if (handle->fd < 0) { 416 /* no more fallback, give it up*/ 417 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 418 "Can't open USB bus file %s: %s", full_path, strerror(errno)); 419 return PCAP_ERROR; 420 } 421 } 422 423 if (handle->opt.rfmon) { 424 /* 425 * Monitor mode doesn't apply to USB devices. 426 */ 427 close(handle->fd); 428 return PCAP_ERROR_RFMON_NOTSUP; 429 } 430 431 handle->stats_op = usb_stats_linux; 432 handle->read_op = usb_read_linux; 433 } 434 435 /* 436 * "handle->fd" is a real file, so "select()" and "poll()" 437 * work on it. 438 */ 439 handle->selectable_fd = handle->fd; 440 441 /* for plain binary access and text access we need to allocate the read 442 * buffer */ 443 handle->buffer = malloc(handle->bufsize); 444 if (!handle->buffer) { 445 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 446 "malloc: %s", pcap_strerror(errno)); 447 close(handle->fd); 448 return PCAP_ERROR; 449 } 450 return 0; 451 } 452 453 static inline int 454 ascii_to_int(char c) 455 { 456 return c < 'A' ? c- '0': ((c<'a') ? c - 'A' + 10: c-'a'+10); 457 } 458 459 /* 460 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 461 * <linux-kernel-source>/drivers/usb/mon/mon_text.c for urb string 462 * format description 463 */ 464 static int 465 usb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 466 { 467 /* see: 468 * /usr/src/linux/Documentation/usb/usbmon.txt 469 * for message format 470 */ 471 struct pcap_usb_linux *handlep = handle->priv; 472 unsigned timestamp; 473 int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len; 474 char etype, pipeid1, pipeid2, status[16], urb_tag, line[USB_LINE_LEN]; 475 char *string = line; 476 u_char * rawdata = handle->buffer; 477 struct pcap_pkthdr pkth; 478 pcap_usb_header* uhdr = (pcap_usb_header*)handle->buffer; 479 u_char urb_transfer=0; 480 int incoming=0; 481 482 /* ignore interrupt system call errors */ 483 do { 484 ret = read(handle->fd, line, USB_LINE_LEN - 1); 485 if (handle->break_loop) 486 { 487 handle->break_loop = 0; 488 return -2; 489 } 490 } while ((ret == -1) && (errno == EINTR)); 491 if (ret < 0) 492 { 493 if (errno == EAGAIN) 494 return 0; /* no data there */ 495 496 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 497 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 498 return -1; 499 } 500 501 /* read urb header; %n argument may increment return value, but it's 502 * not mandatory, so does not count on it*/ 503 string[ret] = 0; 504 ret = sscanf(string, "%x %d %c %c%c:%d:%d %s%n", &tag, ×tamp, &etype, 505 &pipeid1, &pipeid2, &dev_addr, &ep_num, status, 506 &cnt); 507 if (ret < 8) 508 { 509 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 510 "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)", 511 string, ret); 512 return -1; 513 } 514 uhdr->id = tag; 515 uhdr->device_address = dev_addr; 516 uhdr->bus_id = handlep->bus_index; 517 uhdr->status = 0; 518 string += cnt; 519 520 /* don't use usbmon provided timestamp, since it have low precision*/ 521 if (gettimeofday(&pkth.ts, NULL) < 0) 522 { 523 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 524 "Can't get timestamp for message '%s' %d:%s", 525 string, errno, strerror(errno)); 526 return -1; 527 } 528 uhdr->ts_sec = pkth.ts.tv_sec; 529 uhdr->ts_usec = pkth.ts.tv_usec; 530 531 /* parse endpoint information */ 532 if (pipeid1 == 'C') 533 urb_transfer = URB_CONTROL; 534 else if (pipeid1 == 'Z') 535 urb_transfer = URB_ISOCHRONOUS; 536 else if (pipeid1 == 'I') 537 urb_transfer = URB_INTERRUPT; 538 else if (pipeid1 == 'B') 539 urb_transfer = URB_BULK; 540 if (pipeid2 == 'i') { 541 ep_num |= URB_TRANSFER_IN; 542 incoming = 1; 543 } 544 if (etype == 'C') 545 incoming = !incoming; 546 547 /* direction check*/ 548 if (incoming) 549 { 550 if (handle->direction == PCAP_D_OUT) 551 return 0; 552 } 553 else 554 if (handle->direction == PCAP_D_IN) 555 return 0; 556 uhdr->event_type = etype; 557 uhdr->transfer_type = urb_transfer; 558 uhdr->endpoint_number = ep_num; 559 pkth.caplen = sizeof(pcap_usb_header); 560 rawdata += sizeof(pcap_usb_header); 561 562 /* check if this is a setup packet */ 563 ret = sscanf(status, "%d", &dummy); 564 if (ret != 1) 565 { 566 /* this a setup packet, setup data can be filled with underscore if 567 * usbmon has not been able to read them, so we must parse this fields as 568 * strings */ 569 pcap_usb_setup* shdr; 570 char str1[3], str2[3], str3[5], str4[5], str5[5]; 571 ret = sscanf(string, "%s %s %s %s %s%n", str1, str2, str3, str4, 572 str5, &cnt); 573 if (ret < 5) 574 { 575 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 576 "Can't parse USB bus message '%s', too few tokens (expected 5 got %d)", 577 string, ret); 578 return -1; 579 } 580 string += cnt; 581 582 /* try to convert to corresponding integer */ 583 shdr = &uhdr->setup; 584 shdr->bmRequestType = strtoul(str1, 0, 16); 585 shdr->bRequest = strtoul(str2, 0, 16); 586 shdr->wValue = htols(strtoul(str3, 0, 16)); 587 shdr->wIndex = htols(strtoul(str4, 0, 16)); 588 shdr->wLength = htols(strtoul(str5, 0, 16)); 589 590 uhdr->setup_flag = 0; 591 } 592 else 593 uhdr->setup_flag = 1; 594 595 /* read urb data */ 596 ret = sscanf(string, " %d%n", &urb_len, &cnt); 597 if (ret < 1) 598 { 599 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 600 "Can't parse urb length from '%s'", string); 601 return -1; 602 } 603 string += cnt; 604 605 /* urb tag is not present if urb length is 0, so we can stop here 606 * text parsing */ 607 pkth.len = urb_len+pkth.caplen; 608 uhdr->urb_len = urb_len; 609 uhdr->data_flag = 1; 610 data_len = 0; 611 if (uhdr->urb_len == 0) 612 goto got; 613 614 /* check for data presence; data is present if and only if urb tag is '=' */ 615 if (sscanf(string, " %c", &urb_tag) != 1) 616 { 617 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 618 "Can't parse urb tag from '%s'", string); 619 return -1; 620 } 621 622 if (urb_tag != '=') 623 goto got; 624 625 /* skip urb tag and following space */ 626 string += 3; 627 628 /* if we reach this point we got some urb data*/ 629 uhdr->data_flag = 0; 630 631 /* read all urb data; if urb length is greater then the usbmon internal 632 * buffer length used by the kernel to spool the URB, we get only 633 * a partial information. 634 * At least until linux 2.6.17 there is no way to set usbmon intenal buffer 635 * length and default value is 130. */ 636 while ((string[0] != 0) && (string[1] != 0) && (pkth.caplen < handle->snapshot)) 637 { 638 rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]); 639 rawdata++; 640 string+=2; 641 if (string[0] == ' ') 642 string++; 643 pkth.caplen++; 644 data_len++; 645 } 646 647 got: 648 uhdr->data_len = data_len; 649 if (pkth.caplen > handle->snapshot) 650 pkth.caplen = handle->snapshot; 651 652 if (handle->fcode.bf_insns == NULL || 653 bpf_filter(handle->fcode.bf_insns, handle->buffer, 654 pkth.len, pkth.caplen)) { 655 handlep->packets_read++; 656 callback(user, &pkth, handle->buffer); 657 return 1; 658 } 659 return 0; /* didn't pass filter */ 660 } 661 662 static int 663 usb_inject_linux(pcap_t *handle, const void *buf, size_t size) 664 { 665 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 666 "USB devices"); 667 return (-1); 668 } 669 670 static int 671 usb_stats_linux(pcap_t *handle, struct pcap_stat *stats) 672 { 673 struct pcap_usb_linux *handlep = handle->priv; 674 int dummy, ret, consumed, cnt; 675 char string[USB_LINE_LEN]; 676 char token[USB_LINE_LEN]; 677 char * ptr = string; 678 int fd; 679 680 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handlep->bus_index); 681 fd = open(string, O_RDONLY, 0); 682 if (fd < 0) 683 { 684 if (errno == ENOENT) 685 { 686 /* 687 * Not found at the new location; try the old 688 * location. 689 */ 690 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%ds", handlep->bus_index); 691 fd = open(string, O_RDONLY, 0); 692 } 693 if (fd < 0) { 694 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 695 "Can't open USB stats file %s: %s", 696 string, strerror(errno)); 697 return -1; 698 } 699 } 700 701 /* read stats line */ 702 do { 703 ret = read(fd, string, USB_LINE_LEN-1); 704 } while ((ret == -1) && (errno == EINTR)); 705 close(fd); 706 707 if (ret < 0) 708 { 709 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 710 "Can't read stats from fd %d ", fd); 711 return -1; 712 } 713 string[ret] = 0; 714 715 /* extract info on dropped urbs */ 716 for (consumed=0; consumed < ret; ) { 717 /* from the sscanf man page: 718 * The C standard says: "Execution of a %n directive does 719 * not increment the assignment count returned at the completion 720 * of execution" but the Corrigendum seems to contradict this. 721 * Do not make any assumptions on the effect of %n conversions 722 * on the return value and explicitly check for cnt assignmet*/ 723 int ntok; 724 725 cnt = -1; 726 ntok = sscanf(ptr, "%s%n", token, &cnt); 727 if ((ntok < 1) || (cnt < 0)) 728 break; 729 consumed += cnt; 730 ptr += cnt; 731 if (strcmp(token, "nreaders") == 0) 732 ret = sscanf(ptr, "%d", &stats->ps_drop); 733 else 734 ret = sscanf(ptr, "%d", &dummy); 735 if (ntok != 1) 736 break; 737 consumed += cnt; 738 ptr += cnt; 739 } 740 741 stats->ps_recv = handlep->packets_read; 742 stats->ps_ifdrop = 0; 743 return 0; 744 } 745 746 static int 747 usb_setdirection_linux(pcap_t *p, pcap_direction_t d) 748 { 749 p->direction = d; 750 return 0; 751 } 752 753 754 static int 755 usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats) 756 { 757 struct pcap_usb_linux *handlep = handle->priv; 758 int ret; 759 struct mon_bin_stats st; 760 ret = ioctl(handle->fd, MON_IOCG_STATS, &st); 761 if (ret < 0) 762 { 763 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 764 "Can't read stats from fd %d:%s ", handle->fd, strerror(errno)); 765 return -1; 766 } 767 768 stats->ps_recv = handlep->packets_read + st.queued; 769 stats->ps_drop = st.dropped; 770 stats->ps_ifdrop = 0; 771 return 0; 772 } 773 774 /* 775 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 776 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 777 */ 778 static int 779 usb_read_linux_bin(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 780 { 781 struct pcap_usb_linux *handlep = handle->priv; 782 struct mon_bin_get info; 783 int ret; 784 struct pcap_pkthdr pkth; 785 int clen = handle->snapshot - sizeof(pcap_usb_header); 786 787 /* the usb header is going to be part of 'packet' data*/ 788 info.hdr = (pcap_usb_header*) handle->buffer; 789 info.data = handle->buffer + sizeof(pcap_usb_header); 790 info.data_len = clen; 791 792 /* ignore interrupt system call errors */ 793 do { 794 ret = ioctl(handle->fd, MON_IOCX_GET, &info); 795 if (handle->break_loop) 796 { 797 handle->break_loop = 0; 798 return -2; 799 } 800 } while ((ret == -1) && (errno == EINTR)); 801 if (ret < 0) 802 { 803 if (errno == EAGAIN) 804 return 0; /* no data there */ 805 806 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 807 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 808 return -1; 809 } 810 811 /* we can get less that than really captured from kernel, depending on 812 * snaplen, so adjust header accordingly */ 813 if (info.hdr->data_len < clen) 814 clen = info.hdr->data_len; 815 info.hdr->data_len = clen; 816 pkth.caplen = clen + sizeof(pcap_usb_header); 817 pkth.len = info.hdr->data_len + sizeof(pcap_usb_header); 818 pkth.ts.tv_sec = info.hdr->ts_sec; 819 pkth.ts.tv_usec = info.hdr->ts_usec; 820 821 if (handle->fcode.bf_insns == NULL || 822 bpf_filter(handle->fcode.bf_insns, handle->buffer, 823 pkth.len, pkth.caplen)) { 824 handlep->packets_read++; 825 callback(user, &pkth, handle->buffer); 826 return 1; 827 } 828 829 return 0; /* didn't pass filter */ 830 } 831 832 /* 833 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 834 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 835 */ 836 #define VEC_SIZE 32 837 static int 838 usb_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 839 { 840 struct pcap_usb_linux *handlep = handle->priv; 841 struct mon_bin_mfetch fetch; 842 int32_t vec[VEC_SIZE]; 843 struct pcap_pkthdr pkth; 844 pcap_usb_header* hdr; 845 int nflush = 0; 846 int packets = 0; 847 int clen, max_clen; 848 849 max_clen = handle->snapshot - sizeof(pcap_usb_header); 850 851 for (;;) { 852 int i, ret; 853 int limit = max_packets - packets; 854 if (limit <= 0) 855 limit = VEC_SIZE; 856 if (limit > VEC_SIZE) 857 limit = VEC_SIZE; 858 859 /* try to fetch as many events as possible*/ 860 fetch.offvec = vec; 861 fetch.nfetch = limit; 862 fetch.nflush = nflush; 863 /* ignore interrupt system call errors */ 864 do { 865 ret = ioctl(handle->fd, MON_IOCX_MFETCH, &fetch); 866 if (handle->break_loop) 867 { 868 handle->break_loop = 0; 869 return -2; 870 } 871 } while ((ret == -1) && (errno == EINTR)); 872 if (ret < 0) 873 { 874 if (errno == EAGAIN) 875 return 0; /* no data there */ 876 877 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 878 "Can't mfetch fd %d: %s", handle->fd, strerror(errno)); 879 return -1; 880 } 881 882 /* keep track of processed events, we will flush them later */ 883 nflush = fetch.nfetch; 884 for (i=0; i<fetch.nfetch; ++i) { 885 /* discard filler */ 886 hdr = (pcap_usb_header*) &handlep->mmapbuf[vec[i]]; 887 if (hdr->event_type == '@') 888 continue; 889 890 /* we can get less that than really captured from kernel, depending on 891 * snaplen, so adjust header accordingly */ 892 clen = max_clen; 893 if (hdr->data_len < clen) 894 clen = hdr->data_len; 895 896 /* get packet info from header*/ 897 pkth.caplen = clen + sizeof(pcap_usb_header_mmapped); 898 pkth.len = hdr->data_len + sizeof(pcap_usb_header_mmapped); 899 pkth.ts.tv_sec = hdr->ts_sec; 900 pkth.ts.tv_usec = hdr->ts_usec; 901 902 if (handle->fcode.bf_insns == NULL || 903 bpf_filter(handle->fcode.bf_insns, (u_char*) hdr, 904 pkth.len, pkth.caplen)) { 905 handlep->packets_read++; 906 callback(user, &pkth, (u_char*) hdr); 907 packets++; 908 } 909 } 910 911 /* with max_packets specifying "unlimited" we stop afer the first chunk*/ 912 if (PACKET_COUNT_IS_UNLIMITED(max_packets) || (packets == max_packets)) 913 break; 914 } 915 916 /* flush pending events*/ 917 ioctl(handle->fd, MON_IOCH_MFLUSH, nflush); 918 return packets; 919 } 920 921 static void 922 usb_cleanup_linux_mmap(pcap_t* handle) 923 { 924 struct pcap_usb_linux *handlep = handle->priv; 925 926 /* if we have a memory-mapped buffer, unmap it */ 927 if (handlep->mmapbuf != NULL) { 928 munmap(handlep->mmapbuf, handlep->mmapbuflen); 929 handlep->mmapbuf = NULL; 930 } 931 pcap_cleanup_live_common(handle); 932 } 933
