/* * Copyright (c) 2006 Paolo Abeni (Italy) * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * USB sniffing API implementation for Linux platform * By Paolo Abeni * Modifications: Kris Katterjohn * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "pcap-int.h" #include "pcap-usb-linux.h" #include "pcap/usb.h" #ifdef NEED_STRERROR_H #include "strerror.h" #endif #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_LINUX_USBDEVICE_FS_H /* * We might need to define __user for * . */ #ifdef HAVE_LINUX_COMPILER_H #include #endif /* HAVE_LINUX_COMPILER_H */ #include #endif /* HAVE_LINUX_USBDEVICE_FS_H */ #define USB_IFACE "usbmon" #define USB_TEXT_DIR_OLD "/sys/kernel/debug/usbmon" #define USB_TEXT_DIR "/sys/kernel/debug/usb/usbmon" #define SYS_USB_BUS_DIR "/sys/bus/usb/devices" #define PROC_USB_BUS_DIR "/proc/bus/usb" #define USB_LINE_LEN 4096 #if __BYTE_ORDER == __LITTLE_ENDIAN #define htols(s) s #define htoll(l) l #define htol64(ll) ll #else #define htols(s) bswap_16(s) #define htoll(l) bswap_32(l) #define htol64(ll) bswap_64(ll) #endif struct mon_bin_stats { u_int32_t queued; u_int32_t dropped; }; struct mon_bin_get { pcap_usb_header *hdr; void *data; size_t data_len; /* Length of data (can be zero) */ }; struct mon_bin_mfetch { int32_t *offvec; /* Vector of events fetched */ int32_t nfetch; /* Number of events to fetch (out: fetched) */ int32_t nflush; /* Number of events to flush */ }; #define MON_IOC_MAGIC 0x92 #define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1) #define MON_IOCX_URB _IOWR(MON_IOC_MAGIC, 2, struct mon_bin_hdr) #define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats) #define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4) #define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5) #define MON_IOCX_GET _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get) #define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch) #define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8) #define MON_BIN_SETUP 0x1 /* setup hdr is present*/ #define MON_BIN_SETUP_ZERO 0x2 /* setup buffer is not available */ #define MON_BIN_DATA_ZERO 0x4 /* data buffer is not available */ #define MON_BIN_ERROR 0x8 /* * Private data for capturing on Linux USB. */ struct pcap_usb_linux { u_char *mmapbuf; /* memory-mapped region pointer */ size_t mmapbuflen; /* size of region */ int bus_index; u_int packets_read; }; /* forward declaration */ static int usb_activate(pcap_t *); static int usb_stats_linux(pcap_t *, struct pcap_stat *); static int usb_stats_linux_bin(pcap_t *, struct pcap_stat *); static int usb_read_linux(pcap_t *, int , pcap_handler , u_char *); static int usb_read_linux_bin(pcap_t *, int , pcap_handler , u_char *); static int usb_read_linux_mmap(pcap_t *, int , pcap_handler , u_char *); static int usb_inject_linux(pcap_t *, const void *, size_t); static int usb_setdirection_linux(pcap_t *, pcap_direction_t); static void usb_cleanup_linux_mmap(pcap_t *); /* facility to add an USB device to the device list*/ static int usb_dev_add(pcap_if_t** alldevsp, int n, char *err_str) { char dev_name[10]; char dev_descr[30]; snprintf(dev_name, 10, USB_IFACE"%d", n); snprintf(dev_descr, 30, "USB bus number %d", n); if (pcap_add_if(alldevsp, dev_name, 0, dev_descr, err_str) < 0) return -1; return 0; } int usb_findalldevs(pcap_if_t **alldevsp, char *err_str) { struct dirent* data; int ret = 0; DIR* dir; int n; char* name; size_t len; /* try scanning sysfs usb bus directory */ dir = opendir(SYS_USB_BUS_DIR); if (dir != NULL) { while ((ret == 0) && ((data = readdir(dir)) != 0)) { name = data->d_name; if (strncmp(name, "usb", 3) != 0) continue; if (sscanf(&name[3], "%d", &n) == 0) continue; ret = usb_dev_add(alldevsp, n, err_str); } closedir(dir); return ret; } /* that didn't work; try scanning procfs usb bus directory */ dir = opendir(PROC_USB_BUS_DIR); if (dir != NULL) { while ((ret == 0) && ((data = readdir(dir)) != 0)) { name = data->d_name; len = strlen(name); /* if this file name does not end with a number it's not of our interest */ if ((len < 1) || !isdigit(name[--len])) continue; while (isdigit(name[--len])); if (sscanf(&name[len+1], "%d", &n) != 1) continue; ret = usb_dev_add(alldevsp, n, err_str); } closedir(dir); return ret; } /* neither of them worked */ return 0; } static int usb_mmap(pcap_t* handle) { struct pcap_usb_linux *handlep = handle->priv; int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE); if (len < 0) return 0; handlep->mmapbuflen = len; handlep->mmapbuf = mmap(0, handlep->mmapbuflen, PROT_READ, MAP_SHARED, handle->fd, 0); return handlep->mmapbuf != MAP_FAILED; } #ifdef HAVE_LINUX_USBDEVICE_FS_H #define CTRL_TIMEOUT (5*1000) /* milliseconds */ #define USB_DIR_IN 0x80 #define USB_TYPE_STANDARD 0x00 #define USB_RECIP_DEVICE 0x00 #define USB_REQ_GET_DESCRIPTOR 6 #define USB_DT_DEVICE 1 /* probe the descriptors of the devices attached to the bus */ /* the descriptors will end up in the captured packet stream */ /* and be decoded by external apps like wireshark */ /* without these identifying probes packet data can't be fully decoded */ static void probe_devices(int bus) { struct usbdevfs_ctrltransfer ctrl; struct dirent* data; int ret = 0; char buf[40]; DIR* dir; /* scan usb bus directories for device nodes */ snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d", bus); dir = opendir(buf); if (!dir) return; while ((ret >= 0) && ((data = readdir(dir)) != 0)) { int fd; char* name = data->d_name; if (name[0] == '.') continue; snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d/%s", bus, data->d_name); fd = open(buf, O_RDWR); if (fd == -1) continue; /* * Sigh. Different kernels have different member names * for this structure. */ #ifdef HAVE_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE ctrl.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; ctrl.wValue = USB_DT_DEVICE << 8; ctrl.wIndex = 0; ctrl.wLength = sizeof(buf); #else ctrl.requesttype = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; ctrl.request = USB_REQ_GET_DESCRIPTOR; ctrl.value = USB_DT_DEVICE << 8; ctrl.index = 0; ctrl.length = sizeof(buf); #endif ctrl.data = buf; ctrl.timeout = CTRL_TIMEOUT; ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl); close(fd); } closedir(dir); } #endif /* HAVE_LINUX_USBDEVICE_FS_H */ pcap_t * usb_create(const char *device, char *ebuf, int *is_ours) { const char *cp; char *cpend; long devnum; pcap_t *p; /* Does this look like a USB monitoring device? */ cp = strrchr(device, '/'); if (cp == NULL) cp = device; /* Does it begin with USB_IFACE? */ if (strncmp(cp, USB_IFACE, sizeof USB_IFACE - 1) != 0) { /* Nope, doesn't begin with USB_IFACE */ *is_ours = 0; return NULL; } /* Yes - is USB_IFACE followed by a number? */ cp += sizeof USB_IFACE - 1; devnum = strtol(cp, &cpend, 10); if (cpend == cp || *cpend != '\0') { /* Not followed by a number. */ *is_ours = 0; return NULL; } if (devnum < 0) { /* Followed by a non-valid number. */ *is_ours = 0; return NULL; } /* OK, it's probably ours. */ *is_ours = 1; p = pcap_create_common(device, ebuf, sizeof (struct pcap_usb_linux)); if (p == NULL) return (NULL); p->activate_op = usb_activate; return (p); } static int usb_activate(pcap_t* handle) { struct pcap_usb_linux *handlep = handle->priv; char full_path[USB_LINE_LEN]; /* Initialize some components of the pcap structure. */ handle->bufsize = handle->snapshot; handle->offset = 0; handle->linktype = DLT_USB_LINUX; handle->inject_op = usb_inject_linux; handle->setfilter_op = install_bpf_program; /* no kernel filtering */ handle->setdirection_op = usb_setdirection_linux; handle->set_datalink_op = NULL; /* can't change data link type */ handle->getnonblock_op = pcap_getnonblock_fd; handle->setnonblock_op = pcap_setnonblock_fd; /*get usb bus index from device name */ if (sscanf(handle->opt.source, USB_IFACE"%d", &handlep->bus_index) != 1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get USB bus index from %s", handle->opt.source); return PCAP_ERROR; } /*now select the read method: try to open binary interface */ snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handlep->bus_index); handle->fd = open(full_path, O_RDONLY, 0); if (handle->fd >= 0) { if (handle->opt.rfmon) { /* * Monitor mode doesn't apply to USB devices. */ close(handle->fd); return PCAP_ERROR_RFMON_NOTSUP; } /* binary api is available, try to use fast mmap access */ if (usb_mmap(handle)) { handle->linktype = DLT_USB_LINUX_MMAPPED; handle->stats_op = usb_stats_linux_bin; handle->read_op = usb_read_linux_mmap; handle->cleanup_op = usb_cleanup_linux_mmap; #ifdef HAVE_LINUX_USBDEVICE_FS_H probe_devices(handlep->bus_index); #endif /* * "handle->fd" is a real file, so "select()" and * "poll()" work on it. */ handle->selectable_fd = handle->fd; return 0; } /* can't mmap, use plain binary interface access */ handle->stats_op = usb_stats_linux_bin; handle->read_op = usb_read_linux_bin; #ifdef HAVE_LINUX_USBDEVICE_FS_H probe_devices(handlep->bus_index); #endif } else { /*Binary interface not available, try open text interface */ snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handlep->bus_index); handle->fd = open(full_path, O_RDONLY, 0); if (handle->fd < 0) { if (errno == ENOENT) { /* * Not found at the new location; try * the old location. */ snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%dt", handlep->bus_index); handle->fd = open(full_path, O_RDONLY, 0); } if (handle->fd < 0) { /* no more fallback, give it up*/ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't open USB bus file %s: %s", full_path, strerror(errno)); return PCAP_ERROR; } } if (handle->opt.rfmon) { /* * Monitor mode doesn't apply to USB devices. */ close(handle->fd); return PCAP_ERROR_RFMON_NOTSUP; } handle->stats_op = usb_stats_linux; handle->read_op = usb_read_linux; } /* * "handle->fd" is a real file, so "select()" and "poll()" * work on it. */ handle->selectable_fd = handle->fd; /* for plain binary access and text access we need to allocate the read * buffer */ handle->buffer = malloc(handle->bufsize); if (!handle->buffer) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); close(handle->fd); return PCAP_ERROR; } return 0; } static inline int ascii_to_int(char c) { return c < 'A' ? c- '0': ((c<'a') ? c - 'A' + 10: c-'a'+10); } /* * see /Documentation/usb/usbmon.txt and * /drivers/usb/mon/mon_text.c for urb string * format description */ static int usb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) { /* see: * /usr/src/linux/Documentation/usb/usbmon.txt * for message format */ struct pcap_usb_linux *handlep = handle->priv; unsigned timestamp; int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len; char etype, pipeid1, pipeid2, status[16], urb_tag, line[USB_LINE_LEN]; char *string = line; u_char * rawdata = handle->buffer; struct pcap_pkthdr pkth; pcap_usb_header* uhdr = (pcap_usb_header*)handle->buffer; u_char urb_transfer=0; int incoming=0; /* ignore interrupt system call errors */ do { ret = read(handle->fd, line, USB_LINE_LEN - 1); if (handle->break_loop) { handle->break_loop = 0; return -2; } } while ((ret == -1) && (errno == EINTR)); if (ret < 0) { if (errno == EAGAIN) return 0; /* no data there */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't read from fd %d: %s", handle->fd, strerror(errno)); return -1; } /* read urb header; %n argument may increment return value, but it's * not mandatory, so does not count on it*/ string[ret] = 0; ret = sscanf(string, "%x %d %c %c%c:%d:%d %s%n", &tag, ×tamp, &etype, &pipeid1, &pipeid2, &dev_addr, &ep_num, status, &cnt); if (ret < 8) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)", string, ret); return -1; } uhdr->id = tag; uhdr->device_address = dev_addr; uhdr->bus_id = handlep->bus_index; uhdr->status = 0; string += cnt; /* don't use usbmon provided timestamp, since it have low precision*/ if (gettimeofday(&pkth.ts, NULL) < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get timestamp for message '%s' %d:%s", string, errno, strerror(errno)); return -1; } uhdr->ts_sec = pkth.ts.tv_sec; uhdr->ts_usec = pkth.ts.tv_usec; /* parse endpoint information */ if (pipeid1 == 'C') urb_transfer = URB_CONTROL; else if (pipeid1 == 'Z') urb_transfer = URB_ISOCHRONOUS; else if (pipeid1 == 'I') urb_transfer = URB_INTERRUPT; else if (pipeid1 == 'B') urb_transfer = URB_BULK; if (pipeid2 == 'i') { ep_num |= URB_TRANSFER_IN; incoming = 1; } if (etype == 'C') incoming = !incoming; /* direction check*/ if (incoming) { if (handle->direction == PCAP_D_OUT) return 0; } else if (handle->direction == PCAP_D_IN) return 0; uhdr->event_type = etype; uhdr->transfer_type = urb_transfer; uhdr->endpoint_number = ep_num; pkth.caplen = sizeof(pcap_usb_header); rawdata += sizeof(pcap_usb_header); /* check if this is a setup packet */ ret = sscanf(status, "%d", &dummy); if (ret != 1) { /* this a setup packet, setup data can be filled with underscore if * usbmon has not been able to read them, so we must parse this fields as * strings */ pcap_usb_setup* shdr; char str1[3], str2[3], str3[5], str4[5], str5[5]; ret = sscanf(string, "%s %s %s %s %s%n", str1, str2, str3, str4, str5, &cnt); if (ret < 5) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't parse USB bus message '%s', too few tokens (expected 5 got %d)", string, ret); return -1; } string += cnt; /* try to convert to corresponding integer */ shdr = &uhdr->setup; shdr->bmRequestType = strtoul(str1, 0, 16); shdr->bRequest = strtoul(str2, 0, 16); shdr->wValue = htols(strtoul(str3, 0, 16)); shdr->wIndex = htols(strtoul(str4, 0, 16)); shdr->wLength = htols(strtoul(str5, 0, 16)); uhdr->setup_flag = 0; } else uhdr->setup_flag = 1; /* read urb data */ ret = sscanf(string, " %d%n", &urb_len, &cnt); if (ret < 1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't parse urb length from '%s'", string); return -1; } string += cnt; /* urb tag is not present if urb length is 0, so we can stop here * text parsing */ pkth.len = urb_len+pkth.caplen; uhdr->urb_len = urb_len; uhdr->data_flag = 1; data_len = 0; if (uhdr->urb_len == 0) goto got; /* check for data presence; data is present if and only if urb tag is '=' */ if (sscanf(string, " %c", &urb_tag) != 1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't parse urb tag from '%s'", string); return -1; } if (urb_tag != '=') goto got; /* skip urb tag and following space */ string += 3; /* if we reach this point we got some urb data*/ uhdr->data_flag = 0; /* read all urb data; if urb length is greater then the usbmon internal * buffer length used by the kernel to spool the URB, we get only * a partial information. * At least until linux 2.6.17 there is no way to set usbmon intenal buffer * length and default value is 130. */ while ((string[0] != 0) && (string[1] != 0) && (pkth.caplen < handle->snapshot)) { rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]); rawdata++; string+=2; if (string[0] == ' ') string++; pkth.caplen++; data_len++; } got: uhdr->data_len = data_len; if (pkth.caplen > handle->snapshot) pkth.caplen = handle->snapshot; if (handle->fcode.bf_insns == NULL || bpf_filter(handle->fcode.bf_insns, handle->buffer, pkth.len, pkth.caplen)) { handlep->packets_read++; callback(user, &pkth, handle->buffer); return 1; } return 0; /* didn't pass filter */ } static int usb_inject_linux(pcap_t *handle, const void *buf, size_t size) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " "USB devices"); return (-1); } static int usb_stats_linux(pcap_t *handle, struct pcap_stat *stats) { struct pcap_usb_linux *handlep = handle->priv; int dummy, ret, consumed, cnt; char string[USB_LINE_LEN]; char token[USB_LINE_LEN]; char * ptr = string; int fd; snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handlep->bus_index); fd = open(string, O_RDONLY, 0); if (fd < 0) { if (errno == ENOENT) { /* * Not found at the new location; try the old * location. */ snprintf(string, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%ds", handlep->bus_index); fd = open(string, O_RDONLY, 0); } if (fd < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't open USB stats file %s: %s", string, strerror(errno)); return -1; } } /* read stats line */ do { ret = read(fd, string, USB_LINE_LEN-1); } while ((ret == -1) && (errno == EINTR)); close(fd); if (ret < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't read stats from fd %d ", fd); return -1; } string[ret] = 0; /* extract info on dropped urbs */ for (consumed=0; consumed < ret; ) { /* from the sscanf man page: * The C standard says: "Execution of a %n directive does * not increment the assignment count returned at the completion * of execution" but the Corrigendum seems to contradict this. * Do not make any assumptions on the effect of %n conversions * on the return value and explicitly check for cnt assignmet*/ int ntok; cnt = -1; ntok = sscanf(ptr, "%s%n", token, &cnt); if ((ntok < 1) || (cnt < 0)) break; consumed += cnt; ptr += cnt; if (strcmp(token, "nreaders") == 0) ret = sscanf(ptr, "%d", &stats->ps_drop); else ret = sscanf(ptr, "%d", &dummy); if (ntok != 1) break; consumed += cnt; ptr += cnt; } stats->ps_recv = handlep->packets_read; stats->ps_ifdrop = 0; return 0; } static int usb_setdirection_linux(pcap_t *p, pcap_direction_t d) { p->direction = d; return 0; } static int usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats) { struct pcap_usb_linux *handlep = handle->priv; int ret; struct mon_bin_stats st; ret = ioctl(handle->fd, MON_IOCG_STATS, &st); if (ret < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't read stats from fd %d:%s ", handle->fd, strerror(errno)); return -1; } stats->ps_recv = handlep->packets_read + st.queued; stats->ps_drop = st.dropped; stats->ps_ifdrop = 0; return 0; } /* * see /Documentation/usb/usbmon.txt and * /drivers/usb/mon/mon_bin.c binary ABI */ static int usb_read_linux_bin(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) { struct pcap_usb_linux *handlep = handle->priv; struct mon_bin_get info; int ret; struct pcap_pkthdr pkth; int clen = handle->snapshot - sizeof(pcap_usb_header); /* the usb header is going to be part of 'packet' data*/ info.hdr = (pcap_usb_header*) handle->buffer; info.data = handle->buffer + sizeof(pcap_usb_header); info.data_len = clen; /* ignore interrupt system call errors */ do { ret = ioctl(handle->fd, MON_IOCX_GET, &info); if (handle->break_loop) { handle->break_loop = 0; return -2; } } while ((ret == -1) && (errno == EINTR)); if (ret < 0) { if (errno == EAGAIN) return 0; /* no data there */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't read from fd %d: %s", handle->fd, strerror(errno)); return -1; } /* we can get less that than really captured from kernel, depending on * snaplen, so adjust header accordingly */ if (info.hdr->data_len < clen) clen = info.hdr->data_len; info.hdr->data_len = clen; pkth.caplen = clen + sizeof(pcap_usb_header); pkth.len = info.hdr->data_len + sizeof(pcap_usb_header); pkth.ts.tv_sec = info.hdr->ts_sec; pkth.ts.tv_usec = info.hdr->ts_usec; if (handle->fcode.bf_insns == NULL || bpf_filter(handle->fcode.bf_insns, handle->buffer, pkth.len, pkth.caplen)) { handlep->packets_read++; callback(user, &pkth, handle->buffer); return 1; } return 0; /* didn't pass filter */ } /* * see /Documentation/usb/usbmon.txt and * /drivers/usb/mon/mon_bin.c binary ABI */ #define VEC_SIZE 32 static int usb_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) { struct pcap_usb_linux *handlep = handle->priv; struct mon_bin_mfetch fetch; int32_t vec[VEC_SIZE]; struct pcap_pkthdr pkth; pcap_usb_header* hdr; int nflush = 0; int packets = 0; int clen, max_clen; max_clen = handle->snapshot - sizeof(pcap_usb_header); for (;;) { int i, ret; int limit = max_packets - packets; if (limit <= 0) limit = VEC_SIZE; if (limit > VEC_SIZE) limit = VEC_SIZE; /* try to fetch as many events as possible*/ fetch.offvec = vec; fetch.nfetch = limit; fetch.nflush = nflush; /* ignore interrupt system call errors */ do { ret = ioctl(handle->fd, MON_IOCX_MFETCH, &fetch); if (handle->break_loop) { handle->break_loop = 0; return -2; } } while ((ret == -1) && (errno == EINTR)); if (ret < 0) { if (errno == EAGAIN) return 0; /* no data there */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't mfetch fd %d: %s", handle->fd, strerror(errno)); return -1; } /* keep track of processed events, we will flush them later */ nflush = fetch.nfetch; for (i=0; immapbuf[vec[i]]; if (hdr->event_type == '@') continue; /* we can get less that than really captured from kernel, depending on * snaplen, so adjust header accordingly */ clen = max_clen; if (hdr->data_len < clen) clen = hdr->data_len; /* get packet info from header*/ pkth.caplen = clen + sizeof(pcap_usb_header_mmapped); pkth.len = hdr->data_len + sizeof(pcap_usb_header_mmapped); pkth.ts.tv_sec = hdr->ts_sec; pkth.ts.tv_usec = hdr->ts_usec; if (handle->fcode.bf_insns == NULL || bpf_filter(handle->fcode.bf_insns, (u_char*) hdr, pkth.len, pkth.caplen)) { handlep->packets_read++; callback(user, &pkth, (u_char*) hdr); packets++; } } /* with max_packets specifying "unlimited" we stop afer the first chunk*/ if (PACKET_COUNT_IS_UNLIMITED(max_packets) || (packets == max_packets)) break; } /* flush pending events*/ if (ioctl(handle->fd, MON_IOCH_MFLUSH, nflush) == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't mflush fd %d: %s", handle->fd, strerror(errno)); return -1; } return packets; } static void usb_cleanup_linux_mmap(pcap_t* handle) { struct pcap_usb_linux *handlep = handle->priv; /* if we have a memory-mapped buffer, unmap it */ if (handlep->mmapbuf != NULL) { munmap(handlep->mmapbuf, handlep->mmapbuflen); handlep->mmapbuf = NULL; } pcap_cleanup_live_common(handle); }