diff options
Diffstat (limited to 'contrib/libpcap/pcap-usb-linux.c')
| -rw-r--r-- | contrib/libpcap/pcap-usb-linux.c | 730 |
1 files changed, 730 insertions, 0 deletions
diff --git a/contrib/libpcap/pcap-usb-linux.c b/contrib/libpcap/pcap-usb-linux.c new file mode 100644 index 0000000..830abc7 --- /dev/null +++ b/contrib/libpcap/pcap-usb-linux.c @@ -0,0 +1,730 @@ +/* + * 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 <paolo.abeni@email.it> + * Modifications: Kris Katterjohn <katterjohn@gmail.com> + * + */ +#ifndef lint +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.16.2.8 2008-04-14 21:06:29 guy Exp $ (LBL)"; +#endif + +#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 <ctype.h> +#include <errno.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <string.h> +#include <dirent.h> +#include <byteswap.h> +#include <netinet/in.h> +#include <sys/ioctl.h> +#include <sys/mman.h> + +#define USB_IFACE "usb" +#define USB_TEXT_DIR "/sys/kernel/debug/usbmon" +#define USB_BUS_DIR "/proc/bus/usb" +#define USB_LINE_LEN 4096 + + +#define PIPE_IN 0x80 +#define PIPE_ISOCHRONOUS 0 +#define PIPE_INTERRUPT 1 +#define PIPE_CONTROL 2 +#define PIPE_BULK 3 + +#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 + +/* 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_setfilter_linux(pcap_t *, struct bpf_program *); +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_platform_finddevs(pcap_if_t **alldevsp, char *err_str) +{ + struct dirent* data; + int ret = 0; + DIR* dir; + + /* scan procfs usb bus directory */ + dir = opendir(USB_BUS_DIR); + if (!dir) return 0; + while ((ret == 0) && ((data = readdir(dir)) != 0)) { + int n; + char* name = data->d_name; + int 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; +} + +static +int usb_mmap(pcap_t* handle) +{ + int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE); + if (len < 0) + return 0; + + handle->buffer = mmap(0, len, PROT_READ, MAP_SHARED, handle->fd, 0); + return handle->buffer != MAP_FAILED; +} + +pcap_t * +usb_create(const char *device, char *ebuf) +{ + pcap_t *p; + + p = pcap_create_common(device, ebuf); + if (p == NULL) + return (NULL); + + p->activate_op = usb_activate; + return (p); +} + +static int +usb_activate(pcap_t* handle) +{ + 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 = usb_setfilter_linux; + 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", &handle->md.ifindex) != 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", handle->md.ifindex); + handle->fd = open(full_path, O_RDONLY, 0); + if (handle->fd >= 0) + { + if (handle->opt.rfmon) { + /* + * Monitor mode doesn't apply to USB devices. + */ + return PCAP_ERROR_RFMON_NOTSUP; + } + + /* binary api is available, try to use fast mmap access */ + if (usb_mmap(handle)) { + handle->stats_op = usb_stats_linux_bin; + handle->read_op = usb_read_linux_mmap; + handle->cleanup_op = usb_cleanup_linux_mmap; + + /* + * "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; + } + else { + /*Binary interface not available, try open text interface */ + snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handle->md.ifindex); + 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; + } + handle->stats_op = usb_stats_linux; + handle->read_op = usb_read_linux; + } + + if (handle->opt.rfmon) { + /* + * Monitor mode doesn't apply to USB devices. + */ + return PCAP_ERROR_RFMON_NOTSUP; + } + + /* + * "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)); + 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 <linux-kernel-source>/Documentation/usb/usbmon.txt and + * <linux-kernel-source>/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 + */ + 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->endpoint_number = ep_num; + uhdr->device_address = dev_addr; + uhdr->bus_id = handle->md.ifindex; + 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') { + urb_transfer |= 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; + 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 == pkth.caplen) + 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; + handle->md.packets_read++; + if (pkth.caplen > handle->snapshot) + pkth.caplen = handle->snapshot; + + callback(user, &pkth, handle->buffer); + return 1; +} + +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) +{ + int dummy, ret, consumed, cnt; + char string[USB_LINE_LEN]; + char token[USB_LINE_LEN]; + char * ptr = string; + snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handle->md.ifindex); + + int 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*/ + cnt = -1; + int 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 = handle->md.packets_read; + stats->ps_ifdrop = 0; + return 0; +} + +static int +usb_setfilter_linux(pcap_t *p, struct bpf_program *fp) +{ + 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) +{ + 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 = handle->md.packets_read + st.queued; + stats->ps_ifdrop = st.dropped; + return 0; +} + +/* + * see <linux-kernel-source>/Documentation/usb/usbmon.txt and + * <linux-kernel-source>/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 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->urb_len + sizeof(pcap_usb_header); + pkth.ts.tv_sec = info.hdr->ts_sec; + pkth.ts.tv_usec = info.hdr->ts_usec; + + handle->md.packets_read++; + callback(user, &pkth, handle->buffer); + return 1; +} + +/* + * see <linux-kernel-source>/Documentation/usb/usbmon.txt and + * <linux-kernel-source>/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 mon_bin_mfetch fetch; + int32_t vec[VEC_SIZE]; + struct pcap_pkthdr pkth; + pcap_usb_header* hdr; + int nflush = 0; + int packets = 0; + + 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; i<fetch.nfetch; ++i) { + /* discard filler */ + hdr = (pcap_usb_header*) &handle->buffer[vec[i]]; + if (hdr->event_type == '@') + continue; + + /* get packet info from header*/ + pkth.caplen = hdr->data_len + sizeof(pcap_usb_header); + pkth.len = hdr->urb_len + sizeof(pcap_usb_header); + pkth.ts.tv_sec = hdr->ts_sec; + pkth.ts.tv_usec = hdr->ts_usec; + + handle->md.packets_read++; + callback(user, &pkth, (u_char*) hdr); + packets++; + } + + /* with max_packets <= 0 we stop afer the first chunk*/ + if ((max_packets <= 0) || (packets == max_packets)) + break; + } + + /* flush pending events*/ + ioctl(handle->fd, MON_IOCH_MFLUSH, nflush); + return packets; +} + +static void +usb_cleanup_linux_mmap(pcap_t* handle) +{ + /* buffer must not be freed because it's memory mapped */ + /* XXX - does it need to be unmapped? */ + handle->buffer = NULL; + pcap_cleanup_live_common(handle); +} |
