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authorhannes <hannes>2006-10-04 15:50:26 +0000
committerhannes <hannes>2006-10-04 15:50:26 +0000
commitdc03d28d88aabb976f1fe4fb407fa773996f9a84 (patch)
tree66abef2aaf6cf3c854608091da904063bee2ac75 /pcap-usb-linux.c
parent788c73d4bd3463f4e6720ab95f5a0a60409381df (diff)
from Paolo Abeni <paolo.abeni@email.com>: USB capturing support on linux
Diffstat (limited to 'pcap-usb-linux.c')
-rw-r--r--pcap-usb-linux.c444
1 files changed, 444 insertions, 0 deletions
diff --git a/pcap-usb-linux.c b/pcap-usb-linux.c
new file mode 100644
index 0000000..942bb0a
--- /dev/null
+++ b/pcap-usb-linux.c
@@ -0,0 +1,444 @@
+/*
+ * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy)
+ * Copyright (c) 2005 - 2006 CACE Technologies, Davis (California)
+ * 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. Neither the name of the Politecnico di Torino, CACE Technologies
+ * nor the names of its contributors may 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 sniffig API implementation for linux platform
+ * By Paolo Abeni <paolo.abeni@email.com>
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcap-int.h"
+#include "sll.h"
+
+#ifdef NEED_STRERROR_H
+#include "strerror.h"
+#endif
+
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <dirent.h>
+#include <netinet/in.h>
+
+#define USB_IFACE "usb"
+#define USB_DIR "/sys/kernel/debug/usbmon"
+#define USB_LINE_LEN 4096
+
+/* forward declaration */
+static int usb_read_linux(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 int usb_stats_linux(pcap_t *, struct pcap_stat *);
+static void usb_close_linux(pcap_t *);
+
+int
+usb_platform_finddevs(pcap_if_t **alldevsp, char *err_str)
+{
+ pcap_if_t *devlist = *alldevsp;
+ struct dirent* data;
+ DIR* dir = opendir(USB_DIR);
+ if (!dir) {
+ /* it's not fatal, but it would be useful to give a message
+ about debugfs:
+ modprobe usbmon
+ mount -t debugfs none_debugs /sys/kernel/debug
+ */
+ return 0;
+ }
+
+ /* scan usbmon directory */
+ int ret = 0;
+ while ((data = readdir(dir)) != 0)
+ {
+ char* name = data->d_name;
+ int len = strlen(name);
+
+ if ((len >= 2) && name[len -1]== 't')
+ {
+ int n = name[0] - '0';
+ char dev_name[10], dev_descr[30];
+ snprintf(dev_name, 10, USB_IFACE"%d", n);
+ snprintf(dev_descr, 30, "usb bus number %d", n);
+
+ if (pcap_add_if(&devlist, dev_name, 0,
+ dev_descr, err_str) < 0)
+ {
+ ret = -1;
+ break;
+ }
+ }
+ }
+ closedir(dir);
+
+ *alldevsp = devlist;
+ return ret;
+}
+
+pcap_t*
+usb_open_live(const char* bus, int snaplen, int promisc , int to_ms, char* errmsg)
+{
+ char full_path[USB_LINE_LEN];
+ pcap_t *handle;
+
+ /* Allocate a handle for this session. */
+ handle = malloc(sizeof(*handle));
+ if (handle == NULL) {
+ snprintf(errmsg, PCAP_ERRBUF_SIZE, "malloc: %s",
+ pcap_strerror(errno));
+ return NULL;
+ }
+
+ /* Initialize some components of the pcap structure. */
+ memset(handle, 0, sizeof(*handle));
+ handle->snapshot = snaplen;
+ handle->md.timeout = to_ms;
+ handle->bufsize = USB_LINE_LEN;
+ handle->offset = 0;
+ handle->linktype = DLT_USB;
+
+ /* get usb bus index from device name */
+ if (sscanf(bus, USB_IFACE"%d", &handle->md.ifindex) != 1)
+ {
+ snprintf(errmsg, PCAP_ERRBUF_SIZE,
+ "Can't get usb bus index from %s", bus);
+ free(handle);
+ return NULL;
+ }
+
+ /* open text output file*/
+ snprintf(full_path, USB_LINE_LEN, USB_DIR"/%dt", handle->md.ifindex);
+ handle->fd = open(full_path, O_RDONLY, 0);
+ if (handle->fd < 0)
+ {
+ snprintf(errmsg, PCAP_ERRBUF_SIZE,
+ "Can't open usb bus file %s: %s", full_path, strerror(errno));
+ free(handle);
+ return NULL;
+ }
+
+ handle->buffer = malloc(handle->bufsize + handle->offset);
+ if (!handle->buffer) {
+ snprintf(errmsg, PCAP_ERRBUF_SIZE,
+ "malloc: %s", pcap_strerror(errno));
+ usb_close_linux(handle);
+ return NULL;
+ }
+
+ /*
+ * "handle->fd" is a real file , so "select()" and "poll()"
+ * work on it.
+ */
+ handle->selectable_fd = handle->fd;
+
+ handle->read_op = usb_read_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;
+ handle->stats_op = usb_stats_linux;
+ handle->close_op = usb_close_linux;
+
+ return handle;
+
+}
+
+static inline int
+ascii_to_int(char c)
+{
+ return c < 'A' ? c- '0': ((c<'a') ? c- 'A': c-'a');
+}
+
+/*
+ * 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;
+ char etype, pipeid1, pipeid2, status[16], urb_tag, line[4096];
+ char *string = line;
+ u_char * rawdata = handle->buffer;
+ struct pcap_pkthdr pkth;
+ pcap_usb_header* uhdr = (pcap_usb_header*)rawdata;
+ pcap_urb_type_t urb_type = URB_UNKNOWN;
+
+ /* 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, &timestamp, &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 token (expected 8 got %d)",
+ string, ret);
+ return -1;
+ }
+ uhdr->endpoint_number = htonl(ep_num);
+ uhdr->device_address = htonl(dev_addr);
+ string += cnt;
+ pkth.ts.tv_sec = timestamp / 1000000;
+ pkth.ts.tv_usec = timestamp % 1000000;
+
+ /* parse endpoint information */
+ if (pipeid1 == 'C')
+ {
+ if (pipeid2 =='i')
+ urb_type = URB_CONTROL_INPUT;
+ else
+ urb_type = URB_CONTROL_OUTPUT;
+ }
+ else if (pipeid1 == 'Z')
+ {
+ if (pipeid2 == 'i')
+ urb_type = URB_ISOCHRONOUS_INPUT;
+ else
+ urb_type = URB_ISOCHRONOUS_OUTPUT;
+ }
+ else if (pipeid1 == 'I')
+ {
+ if (pipeid2 == 'i')
+ urb_type = URB_INTERRUPT_INPUT;
+ else
+ urb_type = URB_INTERRUPT_OUTPUT;
+ }
+ else if (pipeid1 == 'B')
+ {
+ if (pipeid2 == 'i')
+ urb_type = URB_BULK_INPUT;
+ else
+ urb_type = URB_BULK_OUTPUT;
+ }
+
+ /* direction check*/
+ if ((urb_type == URB_BULK_INPUT) || (urb_type == URB_INTERRUPT_INPUT) ||
+ (urb_type == URB_ISOCHRONOUS_INPUT) || (urb_type == URB_CONTROL_INPUT))
+ {
+ if (handle->direction == PCAP_D_OUT)
+ return 0;
+ }
+ else
+ if (handle->direction == PCAP_D_IN)
+ return 0;
+
+ uhdr->urb_type = htonl(urb_type);
+ 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 == 0)
+ {
+ /* 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 token (expected 5 got %d)",
+ string, ret);
+ return -1;
+ }
+ string += cnt;
+
+ /* try to convert to corresponding integer */
+ shdr = (pcap_usb_setup*)rawdata;
+ shdr->bmRequestType = htonl(strtol(str1, 0, 16));
+ shdr->bRequest = htonl(strtol(str2, 0, 16));
+ shdr->wValue = htonl(strtol(str3, 0, 16));
+ shdr->wIndex = htonl(strtol(str4, 0, 16));
+ shdr->wLength = htonl(strtol(str5, 0, 16));
+
+ pkth.caplen = sizeof(pcap_usb_setup);
+ rawdata += sizeof(pcap_usb_setup);
+ }
+
+ /* read urb data */
+ ret = sscanf(string, " %d%n", &pkth.len, &cnt);
+ if (ret < 1)
+ {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "Can't parse urb length from '%s'", string);
+ return -1;
+ }
+ string += cnt;
+ handle->md.packets_read++;
+
+ /* urb tag is not present if urb length is 0 */
+ pkth.len += pkth.caplen;
+ if (pkth.len == pkth.caplen)
+ return 1;
+
+ /* check for data presence */
+ 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;
+
+ /* read all urb data; if urb length is less then our string we get only
+ * a partial information */
+ while ((string[0] != 0) && (string[1] != 0))
+ {
+ rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]);
+ rawdata++;
+ string+=2;
+ if (string[0] == ' ')
+ string++;
+ pkth.caplen++;
+ }
+
+got:
+ 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 void
+usb_close_linux(pcap_t* handle)
+{
+ /* handle fill be freed in pcap_close() 'common' code */
+ close(handle->fd);
+ free(handle->buffer);
+}
+
+
+static int
+usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
+{
+ int dummy, ret;
+ char string[USB_LINE_LEN];
+ snprintf(string, USB_LINE_LEN, USB_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 */
+ ret = sscanf(string, "nreaders %d text_lost %d", &dummy, &stats->ps_drop);
+ if (ret != 2)
+ {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "Can't parse stat line '%s' expected 2 token got %d", string, ret);
+ return -1;
+ }
+
+ 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;
+}