1 /* $NetBSD: pcap-usb-linux.c,v 1.1.1.4 2013/12/31 16:57:24 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Paolo Abeni (Italy) 5 * 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 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote 17 * products derived from this software without specific prior written 18 * permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 * USB sniffing API implementation for Linux platform 33 * By Paolo Abeni <paolo.abeni@email.it> 34 * Modifications: Kris Katterjohn <katterjohn@gmail.com> 35 * 36 */ 37 #ifndef lint 38 static const char rcsid[] _U_ = 39 "@(#) Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.33 2008-12-23 21:38:50 guy Exp (LBL)"; 40 #endif 41 42 #ifdef HAVE_CONFIG_H 43 #include "config.h" 44 #endif 45 46 #include "pcap-int.h" 47 #include "pcap-usb-linux.h" 48 #include "pcap/usb.h" 49 50 #ifdef NEED_STRERROR_H 51 #include "strerror.h" 52 #endif 53 54 #include <ctype.h> 55 #include <errno.h> 56 #include <stdlib.h> 57 #include <unistd.h> 58 #include <fcntl.h> 59 #include <string.h> 60 #include <dirent.h> 61 #include <byteswap.h> 62 #include <netinet/in.h> 63 #include <sys/ioctl.h> 64 #include <sys/mman.h> 65 #ifdef HAVE_LINUX_USBDEVICE_FS_H 66 /* 67 * We might need <linux/compiler.h> to define __user for 68 * <linux/usbdevice_fs.h>. 69 */ 70 #ifdef HAVE_LINUX_COMPILER_H 71 #include <linux/compiler.h> 72 #endif /* HAVE_LINUX_COMPILER_H */ 73 #include <linux/usbdevice_fs.h> 74 #endif /* HAVE_LINUX_USBDEVICE_FS_H */ 75 76 #define USB_IFACE "usbmon" 77 #define USB_TEXT_DIR_OLD "/sys/kernel/debug/usbmon" 78 #define USB_TEXT_DIR "/sys/kernel/debug/usb/usbmon" 79 #define SYS_USB_BUS_DIR "/sys/bus/usb/devices" 80 #define PROC_USB_BUS_DIR "/proc/bus/usb" 81 #define USB_LINE_LEN 4096 82 83 #if __BYTE_ORDER == __LITTLE_ENDIAN 84 #define htols(s) s 85 #define htoll(l) l 86 #define htol64(ll) ll 87 #else 88 #define htols(s) bswap_16(s) 89 #define htoll(l) bswap_32(l) 90 #define htol64(ll) bswap_64(ll) 91 #endif 92 93 struct mon_bin_stats { 94 u_int32_t queued; 95 u_int32_t dropped; 96 }; 97 98 struct mon_bin_get { 99 pcap_usb_header *hdr; 100 void *data; 101 size_t data_len; /* Length of data (can be zero) */ 102 }; 103 104 struct mon_bin_mfetch { 105 int32_t *offvec; /* Vector of events fetched */ 106 int32_t nfetch; /* Number of events to fetch (out: fetched) */ 107 int32_t nflush; /* Number of events to flush */ 108 }; 109 110 #define MON_IOC_MAGIC 0x92 111 112 #define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1) 113 #define MON_IOCX_URB _IOWR(MON_IOC_MAGIC, 2, struct mon_bin_hdr) 114 #define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats) 115 #define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4) 116 #define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5) 117 #define MON_IOCX_GET _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get) 118 #define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch) 119 #define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8) 120 121 #define MON_BIN_SETUP 0x1 /* setup hdr is present*/ 122 #define MON_BIN_SETUP_ZERO 0x2 /* setup buffer is not available */ 123 #define MON_BIN_DATA_ZERO 0x4 /* data buffer is not available */ 124 #define MON_BIN_ERROR 0x8 125 126 /* 127 * Private data for capturing on Linux USB. 128 */ 129 struct pcap_usb_linux { 130 u_char *mmapbuf; /* memory-mapped region pointer */ 131 size_t mmapbuflen; /* size of region */ 132 int bus_index; 133 u_int packets_read; 134 }; 135 136 /* forward declaration */ 137 static int usb_activate(pcap_t *); 138 static int usb_stats_linux(pcap_t *, struct pcap_stat *); 139 static int usb_stats_linux_bin(pcap_t *, struct pcap_stat *); 140 static int usb_read_linux(pcap_t *, int , pcap_handler , u_char *); 141 static int usb_read_linux_bin(pcap_t *, int , pcap_handler , u_char *); 142 static int usb_read_linux_mmap(pcap_t *, int , pcap_handler , u_char *); 143 static int usb_inject_linux(pcap_t *, const void *, size_t); 144 static int usb_setdirection_linux(pcap_t *, pcap_direction_t); 145 static void usb_cleanup_linux_mmap(pcap_t *); 146 147 /* facility to add an USB device to the device list*/ 148 static int 149 usb_dev_add(pcap_if_t** alldevsp, int n, char *err_str) 150 { 151 char dev_name[10]; 152 char dev_descr[30]; 153 snprintf(dev_name, 10, USB_IFACE"%d", n); 154 snprintf(dev_descr, 30, "USB bus number %d", n); 155 156 if (pcap_add_if(alldevsp, dev_name, 0, 157 dev_descr, err_str) < 0) 158 return -1; 159 return 0; 160 } 161 162 int 163 usb_findalldevs(pcap_if_t **alldevsp, char *err_str) 164 { 165 struct dirent* data; 166 int ret = 0; 167 DIR* dir; 168 int n; 169 char* name; 170 size_t len; 171 172 /* try scanning sysfs usb bus directory */ 173 dir = opendir(SYS_USB_BUS_DIR); 174 if (dir != NULL) { 175 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 176 name = data->d_name; 177 178 if (strncmp(name, "usb", 3) != 0) 179 continue; 180 181 if (sscanf(&name[3], "%d", &n) == 0) 182 continue; 183 184 ret = usb_dev_add(alldevsp, n, err_str); 185 } 186 187 closedir(dir); 188 return ret; 189 } 190 191 /* that didn't work; try scanning procfs usb bus directory */ 192 dir = opendir(PROC_USB_BUS_DIR); 193 if (dir != NULL) { 194 while ((ret == 0) && ((data = readdir(dir)) != 0)) { 195 name = data->d_name; 196 len = strlen(name); 197 198 /* if this file name does not end with a number it's not of our interest */ 199 if ((len < 1) || !isdigit(name[--len])) 200 continue; 201 while (isdigit(name[--len])); 202 if (sscanf(&name[len+1], "%d", &n) != 1) 203 continue; 204 205 ret = usb_dev_add(alldevsp, n, err_str); 206 } 207 208 closedir(dir); 209 return ret; 210 } 211 212 /* neither of them worked */ 213 return 0; 214 } 215 216 static 217 int usb_mmap(pcap_t* handle) 218 { 219 struct pcap_usb_linux *handlep = handle->priv; 220 int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE); 221 if (len < 0) 222 return 0; 223 224 handlep->mmapbuflen = len; 225 handlep->mmapbuf = mmap(0, handlep->mmapbuflen, PROT_READ, 226 MAP_SHARED, handle->fd, 0); 227 return handlep->mmapbuf != MAP_FAILED; 228 } 229 230 #define CTRL_TIMEOUT (5*1000) /* milliseconds */ 231 232 #define USB_DIR_IN 0x80 233 #define USB_TYPE_STANDARD 0x00 234 #define USB_RECIP_DEVICE 0x00 235 236 #define USB_REQ_GET_DESCRIPTOR 6 237 238 #define USB_DT_DEVICE 1 239 240 /* probe the descriptors of the devices attached to the bus */ 241 /* the descriptors will end up in the captured packet stream */ 242 /* and be decoded by external apps like wireshark */ 243 /* without these identifying probes packet data can't be fully decoded */ 244 static void 245 probe_devices(int bus) 246 { 247 struct usbdevfs_ctrltransfer ctrl; 248 struct dirent* data; 249 int ret = 0; 250 char buf[40]; 251 DIR* dir; 252 253 /* scan usb bus directories for device nodes */ 254 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d", bus); 255 dir = opendir(buf); 256 if (!dir) 257 return; 258 259 while ((ret >= 0) && ((data = readdir(dir)) != 0)) { 260 int fd; 261 char* name = data->d_name; 262 263 if (name[0] == '.') 264 continue; 265 266 snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d/%s", bus, data->d_name); 267 268 fd = open(buf, O_RDWR); 269 if (fd == -1) 270 continue; 271 272 /* 273 * Sigh. Different kernels have different member names 274 * for this structure. 275 */ 276 #ifdef HAVE_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE 277 ctrl.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 278 ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; 279 ctrl.wValue = USB_DT_DEVICE << 8; 280 ctrl.wIndex = 0; 281 ctrl.wLength = sizeof(buf); 282 #else 283 ctrl.requesttype = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; 284 ctrl.request = USB_REQ_GET_DESCRIPTOR; 285 ctrl.value = USB_DT_DEVICE << 8; 286 ctrl.index = 0; 287 ctrl.length = sizeof(buf); 288 #endif 289 ctrl.data = buf; 290 ctrl.timeout = CTRL_TIMEOUT; 291 292 ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl); 293 294 close(fd); 295 } 296 closedir(dir); 297 } 298 299 pcap_t * 300 usb_create(const char *device, char *ebuf, int *is_ours) 301 { 302 const char *cp; 303 char *cpend; 304 long devnum; 305 pcap_t *p; 306 307 /* Does this look like a USB monitoring device? */ 308 cp = strrchr(device, '/'); 309 if (cp == NULL) 310 cp = device; 311 /* Does it begin with USB_IFACE? */ 312 if (strncmp(cp, USB_IFACE, sizeof USB_IFACE - 1) != 0) { 313 /* Nope, doesn't begin with USB_IFACE */ 314 *is_ours = 0; 315 return NULL; 316 } 317 /* Yes - is USB_IFACE followed by a number? */ 318 cp += sizeof USB_IFACE - 1; 319 devnum = strtol(cp, &cpend, 10); 320 if (cpend == cp || *cpend != '\0') { 321 /* Not followed by a number. */ 322 *is_ours = 0; 323 return NULL; 324 } 325 if (devnum < 0) { 326 /* Followed by a non-valid number. */ 327 *is_ours = 0; 328 return NULL; 329 } 330 331 /* OK, it's probably ours. */ 332 *is_ours = 1; 333 334 p = pcap_create_common(device, ebuf, sizeof (struct pcap_usb_linux)); 335 if (p == NULL) 336 return (NULL); 337 338 p->activate_op = usb_activate; 339 return (p); 340 } 341 342 static int 343 usb_activate(pcap_t* handle) 344 { 345 struct pcap_usb_linux *handlep = handle->priv; 346 char full_path[USB_LINE_LEN]; 347 348 /* Initialize some components of the pcap structure. */ 349 handle->bufsize = handle->snapshot; 350 handle->offset = 0; 351 handle->linktype = DLT_USB_LINUX; 352 353 handle->inject_op = usb_inject_linux; 354 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 355 handle->setdirection_op = usb_setdirection_linux; 356 handle->set_datalink_op = NULL; /* can't change data link type */ 357 handle->getnonblock_op = pcap_getnonblock_fd; 358 handle->setnonblock_op = pcap_setnonblock_fd; 359 360 /*get usb bus index from device name */ 361 if (sscanf(handle->opt.source, USB_IFACE"%d", &handlep->bus_index) != 1) 362 { 363 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 364 "Can't get USB bus index from %s", handle->opt.source); 365 return PCAP_ERROR; 366 } 367 368 /*now select the read method: try to open binary interface */ 369 snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handlep->bus_index); 370 handle->fd = open(full_path, O_RDONLY, 0); 371 if (handle->fd >= 0) 372 { 373 if (handle->opt.rfmon) { 374 /* 375 * Monitor mode doesn't apply to USB devices. 376 */ 377 close(handle->fd); 378 return PCAP_ERROR_RFMON_NOTSUP; 379 } 380 381 /* binary api is available, try to use fast mmap access */ 382 if (usb_mmap(handle)) { 383 handle->linktype = DLT_USB_LINUX_MMAPPED; 384 handle->stats_op = usb_stats_linux_bin; 385 handle->read_op = usb_read_linux_mmap; 386 handle->cleanup_op = usb_cleanup_linux_mmap; 387 probe_devices(handlep->bus_index); 388 389 /* 390 * "handle->fd" is a real file, so "select()" and 391 * "poll()" work on it. 392 */ 393 handle->selectable_fd = handle->fd; 394 return 0; 395 } 396 397 /* can't mmap, use plain binary interface access */ 398 handle->stats_op = usb_stats_linux_bin; 399 handle->read_op = usb_read_linux_bin; 400 probe_devices(handlep->bus_index); 401 } 402 else { 403 /*Binary interface not available, try open text interface */ 404 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handlep->bus_index); 405 handle->fd = open(full_path, O_RDONLY, 0); 406 if (handle->fd < 0) 407 { 408 if (errno == ENOENT) 409 { 410 /* 411 * Not found at the new location; try 412 * the old location. 413 */ 414 snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%dt", handlep->bus_index); 415 handle->fd = open(full_path, O_RDONLY, 0); 416 } 417 if (handle->fd < 0) { 418 /* no more fallback, give it up*/ 419 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 420 "Can't open USB bus file %s: %s", full_path, strerror(errno)); 421 return PCAP_ERROR; 422 } 423 } 424 425 if (handle->opt.rfmon) { 426 /* 427 * Monitor mode doesn't apply to USB devices. 428 */ 429 close(handle->fd); 430 return PCAP_ERROR_RFMON_NOTSUP; 431 } 432 433 handle->stats_op = usb_stats_linux; 434 handle->read_op = usb_read_linux; 435 } 436 437 /* 438 * "handle->fd" is a real file, so "select()" and "poll()" 439 * work on it. 440 */ 441 handle->selectable_fd = handle->fd; 442 443 /* for plain binary access and text access we need to allocate the read 444 * buffer */ 445 handle->buffer = malloc(handle->bufsize); 446 if (!handle->buffer) { 447 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 448 "malloc: %s", pcap_strerror(errno)); 449 close(handle->fd); 450 return PCAP_ERROR; 451 } 452 return 0; 453 } 454 455 static inline int 456 ascii_to_int(char c) 457 { 458 return c < 'A' ? c- '0': ((c<'a') ? c - 'A' + 10: c-'a'+10); 459 } 460 461 /* 462 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 463 * <linux-kernel-source>/drivers/usb/mon/mon_text.c for urb string 464 * format description 465 */ 466 static int 467 usb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 468 { 469 /* see: 470 * /usr/src/linux/Documentation/usb/usbmon.txt 471 * for message format 472 */ 473 struct pcap_usb_linux *handlep = handle->priv; 474 unsigned timestamp; 475 int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len; 476 char etype, pipeid1, pipeid2, status[16], urb_tag, line[USB_LINE_LEN]; 477 char *string = line; 478 u_char * rawdata = handle->buffer; 479 struct pcap_pkthdr pkth; 480 pcap_usb_header* uhdr = (pcap_usb_header*)handle->buffer; 481 u_char urb_transfer=0; 482 int incoming=0; 483 484 /* ignore interrupt system call errors */ 485 do { 486 ret = read(handle->fd, line, USB_LINE_LEN - 1); 487 if (handle->break_loop) 488 { 489 handle->break_loop = 0; 490 return -2; 491 } 492 } while ((ret == -1) && (errno == EINTR)); 493 if (ret < 0) 494 { 495 if (errno == EAGAIN) 496 return 0; /* no data there */ 497 498 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 499 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 500 return -1; 501 } 502 503 /* read urb header; %n argument may increment return value, but it's 504 * not mandatory, so does not count on it*/ 505 string[ret] = 0; 506 ret = sscanf(string, "%x %d %c %c%c:%d:%d %s%n", &tag, ×tamp, &etype, 507 &pipeid1, &pipeid2, &dev_addr, &ep_num, status, 508 &cnt); 509 if (ret < 8) 510 { 511 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 512 "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)", 513 string, ret); 514 return -1; 515 } 516 uhdr->id = tag; 517 uhdr->device_address = dev_addr; 518 uhdr->bus_id = handlep->bus_index; 519 uhdr->status = 0; 520 string += cnt; 521 522 /* don't use usbmon provided timestamp, since it have low precision*/ 523 if (gettimeofday(&pkth.ts, NULL) < 0) 524 { 525 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 526 "Can't get timestamp for message '%s' %d:%s", 527 string, errno, strerror(errno)); 528 return -1; 529 } 530 uhdr->ts_sec = pkth.ts.tv_sec; 531 uhdr->ts_usec = pkth.ts.tv_usec; 532 533 /* parse endpoint information */ 534 if (pipeid1 == 'C') 535 urb_transfer = URB_CONTROL; 536 else if (pipeid1 == 'Z') 537 urb_transfer = URB_ISOCHRONOUS; 538 else if (pipeid1 == 'I') 539 urb_transfer = URB_INTERRUPT; 540 else if (pipeid1 == 'B') 541 urb_transfer = URB_BULK; 542 if (pipeid2 == 'i') { 543 ep_num |= URB_TRANSFER_IN; 544 incoming = 1; 545 } 546 if (etype == 'C') 547 incoming = !incoming; 548 549 /* direction check*/ 550 if (incoming) 551 { 552 if (handle->direction == PCAP_D_OUT) 553 return 0; 554 } 555 else 556 if (handle->direction == PCAP_D_IN) 557 return 0; 558 uhdr->event_type = etype; 559 uhdr->transfer_type = urb_transfer; 560 uhdr->endpoint_number = ep_num; 561 pkth.caplen = sizeof(pcap_usb_header); 562 rawdata += sizeof(pcap_usb_header); 563 564 /* check if this is a setup packet */ 565 ret = sscanf(status, "%d", &dummy); 566 if (ret != 1) 567 { 568 /* this a setup packet, setup data can be filled with underscore if 569 * usbmon has not been able to read them, so we must parse this fields as 570 * strings */ 571 pcap_usb_setup* shdr; 572 char str1[3], str2[3], str3[5], str4[5], str5[5]; 573 ret = sscanf(string, "%s %s %s %s %s%n", str1, str2, str3, str4, 574 str5, &cnt); 575 if (ret < 5) 576 { 577 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 578 "Can't parse USB bus message '%s', too few tokens (expected 5 got %d)", 579 string, ret); 580 return -1; 581 } 582 string += cnt; 583 584 /* try to convert to corresponding integer */ 585 shdr = &uhdr->setup; 586 shdr->bmRequestType = strtoul(str1, 0, 16); 587 shdr->bRequest = strtoul(str2, 0, 16); 588 shdr->wValue = htols(strtoul(str3, 0, 16)); 589 shdr->wIndex = htols(strtoul(str4, 0, 16)); 590 shdr->wLength = htols(strtoul(str5, 0, 16)); 591 592 uhdr->setup_flag = 0; 593 } 594 else 595 uhdr->setup_flag = 1; 596 597 /* read urb data */ 598 ret = sscanf(string, " %d%n", &urb_len, &cnt); 599 if (ret < 1) 600 { 601 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 602 "Can't parse urb length from '%s'", string); 603 return -1; 604 } 605 string += cnt; 606 607 /* urb tag is not present if urb length is 0, so we can stop here 608 * text parsing */ 609 pkth.len = urb_len+pkth.caplen; 610 uhdr->urb_len = urb_len; 611 uhdr->data_flag = 1; 612 data_len = 0; 613 if (uhdr->urb_len == 0) 614 goto got; 615 616 /* check for data presence; data is present if and only if urb tag is '=' */ 617 if (sscanf(string, " %c", &urb_tag) != 1) 618 { 619 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 620 "Can't parse urb tag from '%s'", string); 621 return -1; 622 } 623 624 if (urb_tag != '=') 625 goto got; 626 627 /* skip urb tag and following space */ 628 string += 3; 629 630 /* if we reach this point we got some urb data*/ 631 uhdr->data_flag = 0; 632 633 /* read all urb data; if urb length is greater then the usbmon internal 634 * buffer length used by the kernel to spool the URB, we get only 635 * a partial information. 636 * At least until linux 2.6.17 there is no way to set usbmon intenal buffer 637 * length and default value is 130. */ 638 while ((string[0] != 0) && (string[1] != 0) && (pkth.caplen < handle->snapshot)) 639 { 640 rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]); 641 rawdata++; 642 string+=2; 643 if (string[0] == ' ') 644 string++; 645 pkth.caplen++; 646 data_len++; 647 } 648 649 got: 650 uhdr->data_len = data_len; 651 if (pkth.caplen > handle->snapshot) 652 pkth.caplen = handle->snapshot; 653 654 if (handle->fcode.bf_insns == NULL || 655 bpf_filter(handle->fcode.bf_insns, handle->buffer, 656 pkth.len, pkth.caplen)) { 657 handlep->packets_read++; 658 callback(user, &pkth, handle->buffer); 659 return 1; 660 } 661 return 0; /* didn't pass filter */ 662 } 663 664 static int 665 usb_inject_linux(pcap_t *handle, const void *buf, size_t size) 666 { 667 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 668 "USB devices"); 669 return (-1); 670 } 671 672 static int 673 usb_stats_linux(pcap_t *handle, struct pcap_stat *stats) 674 { 675 struct pcap_usb_linux *handlep = handle->priv; 676 int dummy, ret, consumed, cnt; 677 char string[USB_LINE_LEN]; 678 char token[USB_LINE_LEN]; 679 char * ptr = string; 680 int fd; 681 682 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handlep->bus_index); 683 fd = open(string, O_RDONLY, 0); 684 if (fd < 0) 685 { 686 if (errno == ENOENT) 687 { 688 /* 689 * Not found at the new location; try the old 690 * location. 691 */ 692 snprintf(string, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%ds", handlep->bus_index); 693 fd = open(string, O_RDONLY, 0); 694 } 695 if (fd < 0) { 696 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 697 "Can't open USB stats file %s: %s", 698 string, strerror(errno)); 699 return -1; 700 } 701 } 702 703 /* read stats line */ 704 do { 705 ret = read(fd, string, USB_LINE_LEN-1); 706 } while ((ret == -1) && (errno == EINTR)); 707 close(fd); 708 709 if (ret < 0) 710 { 711 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 712 "Can't read stats from fd %d ", fd); 713 return -1; 714 } 715 string[ret] = 0; 716 717 /* extract info on dropped urbs */ 718 for (consumed=0; consumed < ret; ) { 719 /* from the sscanf man page: 720 * The C standard says: "Execution of a %n directive does 721 * not increment the assignment count returned at the completion 722 * of execution" but the Corrigendum seems to contradict this. 723 * Do not make any assumptions on the effect of %n conversions 724 * on the return value and explicitly check for cnt assignmet*/ 725 int ntok; 726 727 cnt = -1; 728 ntok = sscanf(ptr, "%s%n", token, &cnt); 729 if ((ntok < 1) || (cnt < 0)) 730 break; 731 consumed += cnt; 732 ptr += cnt; 733 if (strcmp(token, "nreaders") == 0) 734 ret = sscanf(ptr, "%d", &stats->ps_drop); 735 else 736 ret = sscanf(ptr, "%d", &dummy); 737 if (ntok != 1) 738 break; 739 consumed += cnt; 740 ptr += cnt; 741 } 742 743 stats->ps_recv = handlep->packets_read; 744 stats->ps_ifdrop = 0; 745 return 0; 746 } 747 748 static int 749 usb_setdirection_linux(pcap_t *p, pcap_direction_t d) 750 { 751 p->direction = d; 752 return 0; 753 } 754 755 756 static int 757 usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats) 758 { 759 struct pcap_usb_linux *handlep = handle->priv; 760 int ret; 761 struct mon_bin_stats st; 762 ret = ioctl(handle->fd, MON_IOCG_STATS, &st); 763 if (ret < 0) 764 { 765 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 766 "Can't read stats from fd %d:%s ", handle->fd, strerror(errno)); 767 return -1; 768 } 769 770 stats->ps_recv = handlep->packets_read + st.queued; 771 stats->ps_drop = st.dropped; 772 stats->ps_ifdrop = 0; 773 return 0; 774 } 775 776 /* 777 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 778 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 779 */ 780 static int 781 usb_read_linux_bin(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 782 { 783 struct pcap_usb_linux *handlep = handle->priv; 784 struct mon_bin_get info; 785 int ret; 786 struct pcap_pkthdr pkth; 787 int clen = handle->snapshot - sizeof(pcap_usb_header); 788 789 /* the usb header is going to be part of 'packet' data*/ 790 info.hdr = (pcap_usb_header*) handle->buffer; 791 info.data = handle->buffer + sizeof(pcap_usb_header); 792 info.data_len = clen; 793 794 /* ignore interrupt system call errors */ 795 do { 796 ret = ioctl(handle->fd, MON_IOCX_GET, &info); 797 if (handle->break_loop) 798 { 799 handle->break_loop = 0; 800 return -2; 801 } 802 } while ((ret == -1) && (errno == EINTR)); 803 if (ret < 0) 804 { 805 if (errno == EAGAIN) 806 return 0; /* no data there */ 807 808 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 809 "Can't read from fd %d: %s", handle->fd, strerror(errno)); 810 return -1; 811 } 812 813 /* we can get less that than really captured from kernel, depending on 814 * snaplen, so adjust header accordingly */ 815 if (info.hdr->data_len < clen) 816 clen = info.hdr->data_len; 817 info.hdr->data_len = clen; 818 pkth.caplen = clen + sizeof(pcap_usb_header); 819 pkth.len = info.hdr->data_len + sizeof(pcap_usb_header); 820 pkth.ts.tv_sec = info.hdr->ts_sec; 821 pkth.ts.tv_usec = info.hdr->ts_usec; 822 823 if (handle->fcode.bf_insns == NULL || 824 bpf_filter(handle->fcode.bf_insns, handle->buffer, 825 pkth.len, pkth.caplen)) { 826 handlep->packets_read++; 827 callback(user, &pkth, handle->buffer); 828 return 1; 829 } 830 831 return 0; /* didn't pass filter */ 832 } 833 834 /* 835 * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 836 * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI 837 */ 838 #define VEC_SIZE 32 839 static int 840 usb_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 841 { 842 struct pcap_usb_linux *handlep = handle->priv; 843 struct mon_bin_mfetch fetch; 844 int32_t vec[VEC_SIZE]; 845 struct pcap_pkthdr pkth; 846 pcap_usb_header* hdr; 847 int nflush = 0; 848 int packets = 0; 849 int clen, max_clen; 850 851 max_clen = handle->snapshot - sizeof(pcap_usb_header); 852 853 for (;;) { 854 int i, ret; 855 int limit = max_packets - packets; 856 if (limit <= 0) 857 limit = VEC_SIZE; 858 if (limit > VEC_SIZE) 859 limit = VEC_SIZE; 860 861 /* try to fetch as many events as possible*/ 862 fetch.offvec = vec; 863 fetch.nfetch = limit; 864 fetch.nflush = nflush; 865 /* ignore interrupt system call errors */ 866 do { 867 ret = ioctl(handle->fd, MON_IOCX_MFETCH, &fetch); 868 if (handle->break_loop) 869 { 870 handle->break_loop = 0; 871 return -2; 872 } 873 } while ((ret == -1) && (errno == EINTR)); 874 if (ret < 0) 875 { 876 if (errno == EAGAIN) 877 return 0; /* no data there */ 878 879 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 880 "Can't mfetch fd %d: %s", handle->fd, strerror(errno)); 881 return -1; 882 } 883 884 /* keep track of processed events, we will flush them later */ 885 nflush = fetch.nfetch; 886 for (i=0; i<fetch.nfetch; ++i) { 887 /* discard filler */ 888 hdr = (pcap_usb_header*) &handlep->mmapbuf[vec[i]]; 889 if (hdr->event_type == '@') 890 continue; 891 892 /* we can get less that than really captured from kernel, depending on 893 * snaplen, so adjust header accordingly */ 894 clen = max_clen; 895 if (hdr->data_len < clen) 896 clen = hdr->data_len; 897 898 /* get packet info from header*/ 899 pkth.caplen = clen + sizeof(pcap_usb_header_mmapped); 900 pkth.len = hdr->data_len + sizeof(pcap_usb_header_mmapped); 901 pkth.ts.tv_sec = hdr->ts_sec; 902 pkth.ts.tv_usec = hdr->ts_usec; 903 904 if (handle->fcode.bf_insns == NULL || 905 bpf_filter(handle->fcode.bf_insns, (u_char*) hdr, 906 pkth.len, pkth.caplen)) { 907 handlep->packets_read++; 908 callback(user, &pkth, (u_char*) hdr); 909 packets++; 910 } 911 } 912 913 /* with max_packets <= 0 we stop afer the first chunk*/ 914 if ((max_packets <= 0) || (packets == max_packets)) 915 break; 916 } 917 918 /* flush pending events*/ 919 ioctl(handle->fd, MON_IOCH_MFLUSH, nflush); 920 return packets; 921 } 922 923 static void 924 usb_cleanup_linux_mmap(pcap_t* handle) 925 { 926 struct pcap_usb_linux *handlep = handle->priv; 927 928 /* if we have a memory-mapped buffer, unmap it */ 929 if (handlep->mmapbuf != NULL) { 930 munmap(handlep->mmapbuf, handlep->mmapbuflen); 931 handlep->mmapbuf = NULL; 932 } 933 pcap_cleanup_live_common(handle); 934 } 935