1 /* 2 * Copyright (c) 2012 Jakub Zawadzki 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote 15 * products derived from this software without specific prior written 16 * permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifdef HAVE_CONFIG_H 32 #include "config.h" 33 #endif 34 35 #include <string.h> 36 37 #include <time.h> 38 #include <sys/time.h> 39 40 #include <dbus/dbus.h> 41 42 #include "pcap-int.h" 43 #include "pcap-dbus.h" 44 45 /* 46 * Private data for capturing on D-Bus. 47 */ 48 struct pcap_dbus { 49 DBusConnection *conn; 50 u_int packets_read; /* count of packets read */ 51 }; 52 53 static int 54 dbus_read(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 55 { 56 struct pcap_dbus *handlep = handle->priv; 57 58 struct pcap_pkthdr pkth; 59 DBusMessage *message; 60 61 char *raw_msg; 62 int raw_msg_len; 63 64 int count = 0; 65 66 message = dbus_connection_pop_message(handlep->conn); 67 68 while (!message) { 69 // XXX handle->opt.timeout = timeout_ms; 70 if (!dbus_connection_read_write(handlep->conn, 100)) { 71 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Connection closed"); 72 return -1; 73 } 74 75 if (handle->break_loop) { 76 handle->break_loop = 0; 77 return -2; 78 } 79 80 message = dbus_connection_pop_message(handlep->conn); 81 } 82 83 if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) { 84 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Disconnected"); 85 return -1; 86 } 87 88 if (dbus_message_marshal(message, &raw_msg, &raw_msg_len)) { 89 pkth.caplen = pkth.len = raw_msg_len; 90 /* pkth.caplen = min (payload_len, handle->snapshot); */ 91 92 gettimeofday(&pkth.ts, NULL); 93 if (handle->fcode.bf_insns == NULL || 94 bpf_filter(handle->fcode.bf_insns, (u_char *)raw_msg, pkth.len, pkth.caplen)) { 95 handlep->packets_read++; 96 callback(user, &pkth, (u_char *)raw_msg); 97 count++; 98 } 99 100 dbus_free(raw_msg); 101 } 102 return count; 103 } 104 105 static int 106 dbus_write(pcap_t *handle, const void *buf, size_t size) 107 { 108 /* XXX, not tested */ 109 struct pcap_dbus *handlep = handle->priv; 110 111 DBusError error = DBUS_ERROR_INIT; 112 DBusMessage *msg; 113 114 if (!(msg = dbus_message_demarshal(buf, size, &error))) { 115 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dbus_message_demarshal() failed: %s", error.message); 116 dbus_error_free(&error); 117 return -1; 118 } 119 120 dbus_connection_send(handlep->conn, msg, NULL); 121 dbus_connection_flush(handlep->conn); 122 123 dbus_message_unref(msg); 124 return 0; 125 } 126 127 static int 128 dbus_stats(pcap_t *handle, struct pcap_stat *stats) 129 { 130 struct pcap_dbus *handlep = handle->priv; 131 132 stats->ps_recv = handlep->packets_read; 133 stats->ps_drop = 0; 134 stats->ps_ifdrop = 0; 135 return 0; 136 } 137 138 static void 139 dbus_cleanup(pcap_t *handle) 140 { 141 struct pcap_dbus *handlep = handle->priv; 142 143 dbus_connection_unref(handlep->conn); 144 145 pcap_cleanup_live_common(handle); 146 } 147 148 static int 149 dbus_activate(pcap_t *handle) 150 { 151 #define EAVESDROPPING_RULE "eavesdrop=true," 152 153 static const char *rules[] = { 154 EAVESDROPPING_RULE "type='signal'", 155 EAVESDROPPING_RULE "type='method_call'", 156 EAVESDROPPING_RULE "type='method_return'", 157 EAVESDROPPING_RULE "type='error'", 158 }; 159 160 #define N_RULES sizeof(rules)/sizeof(rules[0]) 161 162 struct pcap_dbus *handlep = handle->priv; 163 const char *dev = handle->opt.source; 164 165 DBusError error = DBUS_ERROR_INIT; 166 int i; 167 168 if (strcmp(dev, "dbus-system") == 0) { 169 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) { 170 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get system bus: %s", error.message); 171 dbus_error_free(&error); 172 return PCAP_ERROR; 173 } 174 175 } else if (strcmp(dev, "dbus-session") == 0) { 176 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SESSION, &error))) { 177 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get session bus: %s", error.message); 178 dbus_error_free(&error); 179 return PCAP_ERROR; 180 } 181 182 } else if (strncmp(dev, "dbus://", 7) == 0) { 183 const char *addr = dev + 7; 184 185 if (!(handlep->conn = dbus_connection_open(addr, &error))) { 186 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to open connection to: %s: %s", addr, error.message); 187 dbus_error_free(&error); 188 return PCAP_ERROR; 189 } 190 191 if (!dbus_bus_register(handlep->conn, &error)) { 192 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to register bus %s: %s\n", addr, error.message); 193 dbus_error_free(&error); 194 return PCAP_ERROR; 195 } 196 197 } else { 198 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get bus address from %s", handle->opt.source); 199 return PCAP_ERROR; 200 } 201 202 /* Initialize some components of the pcap structure. */ 203 handle->bufsize = 0; 204 handle->offset = 0; 205 handle->linktype = DLT_DBUS; 206 handle->read_op = dbus_read; 207 handle->inject_op = dbus_write; 208 handle->setfilter_op = install_bpf_program; /* XXX, later add support for dbus_bus_add_match() */ 209 handle->setdirection_op = NULL; 210 handle->set_datalink_op = NULL; /* can't change data link type */ 211 handle->getnonblock_op = pcap_getnonblock_fd; 212 handle->setnonblock_op = pcap_setnonblock_fd; 213 handle->stats_op = dbus_stats; 214 215 handle->selectable_fd = handle->fd = -1; 216 217 if (handle->opt.rfmon) { 218 /* 219 * Monitor mode doesn't apply to dbus connections. 220 */ 221 dbus_cleanup(handle); 222 return PCAP_ERROR_RFMON_NOTSUP; 223 } 224 225 /* dbus_connection_set_max_message_size(handlep->conn, handle->snapshot); */ 226 if (handle->opt.buffer_size != 0) 227 dbus_connection_set_max_received_size(handlep->conn, handle->opt.buffer_size); 228 229 for (i = 0; i < N_RULES; i++) { 230 dbus_bus_add_match(handlep->conn, rules[i], &error); 231 if (dbus_error_is_set(&error)) { 232 dbus_error_free(&error); 233 234 /* try without eavesdrop */ 235 dbus_bus_add_match(handlep->conn, rules[i] + strlen(EAVESDROPPING_RULE), &error); 236 if (dbus_error_is_set(&error)) { 237 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to add bus match: %s\n", error.message); 238 dbus_error_free(&error); 239 dbus_cleanup(handle); 240 return PCAP_ERROR; 241 } 242 } 243 } 244 245 return 0; 246 } 247 248 pcap_t * 249 dbus_create(const char *device, char *ebuf, int *is_ours) 250 { 251 pcap_t *p; 252 253 if (strcmp(device, "dbus-system") && 254 strcmp(device, "dbus-session") && 255 strncmp(device, "dbus://", 7)) 256 { 257 *is_ours = 0; 258 return NULL; 259 } 260 261 *is_ours = 1; 262 p = pcap_create_common(device, ebuf, sizeof (struct pcap_dbus)); 263 if (p == NULL) 264 return (NULL); 265 266 p->activate_op = dbus_activate; 267 return (p); 268 } 269 270 int 271 dbus_findalldevs(pcap_if_t **alldevsp, char *err_str) 272 { 273 if (pcap_add_if(alldevsp, "dbus-system", 0, "D-Bus system bus", err_str) < 0) 274 return -1; 275 if (pcap_add_if(alldevsp, "dbus-session", 0, "D-Bus session bus", err_str) < 0) 276 return -1; 277 return 0; 278 } 279 280