external/bsd/libpcap/dist/pcap-dbus.c

   1 /*      $NetBSD: pcap-dbus.c,v 1.3 2015/03/31 21:39:42 christos Exp $   */
   2
   3 /*
   4  * Copyright (c) 2012 Jakub Zawadzki
   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
  33 #include <sys/cdefs.h>
  34 __RCSID("$NetBSD: pcap-dbus.c,v 1.3 2015/03/31 21:39:42 christos Exp $");
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include "config.h"
  38 #endif
  39
  40 #include <string.h>
  41
  42 #include <time.h>
  43 #include <sys/time.h>
  44
  45 #include <dbus/dbus.h>
  46
  47 #include "pcap-int.h"
  48 #include "pcap-dbus.h"
  49
  50 /*
  51  * Private data for capturing on D-Bus.
  52  */
  53 struct pcap_dbus {
  54         DBusConnection *conn;
  55         u_int   packets_read;   /* count of packets read */
  56 };
  57
  58 static int
  59 dbus_read(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
  60 {
  61         struct pcap_dbus *handlep = handle->priv;
  62
  63         struct pcap_pkthdr pkth;
  64         DBusMessage *message;
  65
  66         char *raw_msg;
  67         int raw_msg_len;
  68
  69         int count = 0;
  70
  71         message = dbus_connection_pop_message(handlep->conn);
  72
  73         while (!message) {
  74                 // XXX handle->opt.timeout = timeout_ms;
  75                 if (!dbus_connection_read_write(handlep->conn, 100)) {
  76                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Connection closed");
  77                         return -1;
  78                 }
  79
  80                 if (handle->break_loop) {
  81                         handle->break_loop = 0;
  82                         return -2;
  83                 }
  84
  85                 message = dbus_connection_pop_message(handlep->conn);
  86         }
  87
  88         if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
  89                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Disconnected");
  90                 return -1;
  91         }
  92
  93         if (dbus_message_marshal(message, &raw_msg, &raw_msg_len)) {
  94                 pkth.caplen = pkth.len = raw_msg_len;
  95                 /* pkth.caplen = min (payload_len, handle->snapshot); */
  96
  97                 gettimeofday(&pkth.ts, NULL);
  98                 if (handle->fcode.bf_insns == NULL ||
  99                     bpf_filter(handle->fcode.bf_insns, (u_char *)raw_msg, pkth.len, pkth.caplen)) {
 100                         handlep->packets_read++;
 101                         callback(user, &pkth, (u_char *)raw_msg);
 102                         count++;
 103                 }
 104
 105                 dbus_free(raw_msg);
 106         }
 107         return count;
 108 }
 109
 110 static int
 111 dbus_write(pcap_t *handle, const void *buf, size_t size)
 112 {
 113         /* XXX, not tested */
 114         struct pcap_dbus *handlep = handle->priv;
 115
 116         DBusError error = DBUS_ERROR_INIT;
 117         DBusMessage *msg;
 118
 119         if (!(msg = dbus_message_demarshal(buf, size, &error))) {
 120                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dbus_message_demarshal() failed: %s", error.message);
 121                 dbus_error_free(&error);
 122                 return -1;
 123         }
 124
 125         dbus_connection_send(handlep->conn, msg, NULL);
 126         dbus_connection_flush(handlep->conn);
 127
 128         dbus_message_unref(msg);
 129         return 0;
 130 }
 131
 132 static int
 133 dbus_stats(pcap_t *handle, struct pcap_stat *stats)
 134 {
 135         struct pcap_dbus *handlep = handle->priv;
 136
 137         stats->ps_recv = handlep->packets_read;
 138         stats->ps_drop = 0;
 139         stats->ps_ifdrop = 0;
 140         return 0;
 141 }
 142
 143 static void
 144 dbus_cleanup(pcap_t *handle)
 145 {
 146         struct pcap_dbus *handlep = handle->priv;
 147
 148         dbus_connection_unref(handlep->conn);
 149
 150         pcap_cleanup_live_common(handle);
 151 }
 152
 153 static int
 154 dbus_activate(pcap_t *handle)
 155 {
 156 #define EAVESDROPPING_RULE "eavesdrop=true,"
 157
 158         static const char *rules[] = {
 159                 EAVESDROPPING_RULE "type='signal'",
 160                 EAVESDROPPING_RULE "type='method_call'",
 161                 EAVESDROPPING_RULE "type='method_return'",
 162                 EAVESDROPPING_RULE "type='error'",
 163         };
 164
 165         #define N_RULES sizeof(rules)/sizeof(rules[0])
 166
 167         struct pcap_dbus *handlep = handle->priv;
 168         const char *dev = handle->opt.source;
 169
 170         DBusError error = DBUS_ERROR_INIT;
 171         int i;
 172
 173         if (strcmp(dev, "dbus-system") == 0) {
 174                 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) {
 175                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get system bus: %s", error.message);
 176                         dbus_error_free(&error);
 177                         return PCAP_ERROR;
 178                 }
 179
 180         } else if (strcmp(dev, "dbus-session") == 0) {
 181                 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SESSION, &error))) {
 182                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get session bus: %s", error.message);
 183                         dbus_error_free(&error);
 184                         return PCAP_ERROR;
 185                 }
 186
 187         } else if (strncmp(dev, "dbus://", 7) == 0) {
 188                 const char *addr = dev + 7;
 189
 190                 if (!(handlep->conn = dbus_connection_open(addr, &error))) {
 191                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to open connection to: %s: %s", addr, error.message);
 192                         dbus_error_free(&error);
 193                         return PCAP_ERROR;
 194                 }
 195
 196                 if (!dbus_bus_register(handlep->conn, &error)) {
 197                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to register bus %s: %s\n", addr, error.message);
 198                         dbus_error_free(&error);
 199                         return PCAP_ERROR;
 200                 }
 201
 202         } else {
 203                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get bus address from %s", handle->opt.source);
 204                 return PCAP_ERROR;
 205         }
 206
 207         /* Initialize some components of the pcap structure. */
 208         handle->bufsize = 0;
 209         handle->offset = 0;
 210         handle->linktype = DLT_DBUS;
 211         handle->read_op = dbus_read;
 212         handle->inject_op = dbus_write;
 213         handle->setfilter_op = install_bpf_program; /* XXX, later add support for dbus_bus_add_match() */
 214         handle->setdirection_op = NULL;
 215         handle->set_datalink_op = NULL;      /* can't change data link type */
 216         handle->getnonblock_op = pcap_getnonblock_fd;
 217         handle->setnonblock_op = pcap_setnonblock_fd;
 218         handle->stats_op = dbus_stats;
 219
 220         handle->selectable_fd = handle->fd = -1;
 221
 222         if (handle->opt.rfmon) {
 223                 /*
 224                  * Monitor mode doesn't apply to dbus connections.
 225                  */
 226                 dbus_cleanup(handle);
 227                 return PCAP_ERROR_RFMON_NOTSUP;
 228         }
 229
 230         /* dbus_connection_set_max_message_size(handlep->conn, handle->snapshot); */
 231         if (handle->opt.buffer_size != 0)
 232                 dbus_connection_set_max_received_size(handlep->conn, handle->opt.buffer_size);
 233
 234         for (i = 0; i < N_RULES; i++) {
 235                 dbus_bus_add_match(handlep->conn, rules[i], &error);
 236                 if (dbus_error_is_set(&error)) {
 237                         dbus_error_free(&error);
 238
 239                         /* try without eavesdrop */
 240                         dbus_bus_add_match(handlep->conn, rules[i] + strlen(EAVESDROPPING_RULE), &error);
 241                         if (dbus_error_is_set(&error)) {
 242                                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to add bus match: %s\n", error.message);
 243                                 dbus_error_free(&error);
 244                                 dbus_cleanup(handle);
 245                                 return PCAP_ERROR;
 246                         }
 247                 }
 248         }
 249
 250         return 0;
 251 }
 252
 253 pcap_t *
 254 dbus_create(const char *device, char *ebuf, int *is_ours)
 255 {
 256         pcap_t *p;
 257
 258         if (strcmp(device, "dbus-system") &&
 259                 strcmp(device, "dbus-session") &&
 260                 strncmp(device, "dbus://", 7))
 261         {
 262                 *is_ours = 0;
 263                 return NULL;
 264         }
 265
 266         *is_ours = 1;
 267         p = pcap_create_common(device, ebuf, sizeof (struct pcap_dbus));
 268         if (p == NULL)
 269                 return (NULL);
 270
 271         p->activate_op = dbus_activate;
 272         return (p);
 273 }
 274
 275 int
 276 dbus_findalldevs(pcap_if_t **alldevsp, char *err_str)
 277 {
 278         if (pcap_add_if(alldevsp, "dbus-system", 0, "D-Bus system bus", err_str) < 0)
 279                 return -1;
 280         if (pcap_add_if(alldevsp, "dbus-session", 0, "D-Bus session bus", err_str) < 0)
 281                 return -1;
 282         return 0;
 283 }
 284