1 /* $NetBSD: pcap-dbus.c,v 1.1.1.1 2013/12/31 16:57:18 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 #ifdef HAVE_CONFIG_H 34 #include "config.h" 35 #endif 36 37 #include <string.h> 38 39 #include <time.h> 40 #include <sys/time.h> 41 42 #include <dbus/dbus.h> 43 44 #include "pcap-int.h" 45 #include "pcap-dbus.h" 46 47 /* 48 * Private data for capturing on D-Bus. 49 */ 50 struct pcap_dbus { 51 DBusConnection *conn; 52 u_int packets_read; /* count of packets read */ 53 }; 54 55 static int 56 dbus_read(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 57 { 58 struct pcap_dbus *handlep = handle->priv; 59 60 struct pcap_pkthdr pkth; 61 DBusMessage *message; 62 63 char *raw_msg; 64 int raw_msg_len; 65 66 int count = 0; 67 68 message = dbus_connection_pop_message(handlep->conn); 69 70 while (!message) { 71 // XXX handle->opt.timeout = timeout_ms; 72 if (!dbus_connection_read_write(handlep->conn, 100)) { 73 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Connection closed"); 74 return -1; 75 } 76 77 if (handle->break_loop) { 78 handle->break_loop = 0; 79 return -2; 80 } 81 82 message = dbus_connection_pop_message(handlep->conn); 83 } 84 85 if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) { 86 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Disconnected"); 87 return -1; 88 } 89 90 if (dbus_message_marshal(message, &raw_msg, &raw_msg_len)) { 91 pkth.caplen = pkth.len = raw_msg_len; 92 /* pkth.caplen = min (payload_len, handle->snapshot); */ 93 94 gettimeofday(&pkth.ts, NULL); 95 if (handle->fcode.bf_insns == NULL || 96 bpf_filter(handle->fcode.bf_insns, (u_char *)raw_msg, pkth.len, pkth.caplen)) { 97 handlep->packets_read++; 98 callback(user, &pkth, (u_char *)raw_msg); 99 count++; 100 } 101 102 dbus_free(raw_msg); 103 } 104 return count; 105 } 106 107 static int 108 dbus_write(pcap_t *handle, const void *buf, size_t size) 109 { 110 /* XXX, not tested */ 111 struct pcap_dbus *handlep = handle->priv; 112 113 DBusError error = DBUS_ERROR_INIT; 114 DBusMessage *msg; 115 116 if (!(msg = dbus_message_demarshal(buf, size, &error))) { 117 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dbus_message_demarshal() failed: %s", error.message); 118 dbus_error_free(&error); 119 return -1; 120 } 121 122 dbus_connection_send(handlep->conn, msg, NULL); 123 dbus_connection_flush(handlep->conn); 124 125 dbus_message_unref(msg); 126 return 0; 127 } 128 129 static int 130 dbus_stats(pcap_t *handle, struct pcap_stat *stats) 131 { 132 struct pcap_dbus *handlep = handle->priv; 133 134 stats->ps_recv = handlep->packets_read; 135 stats->ps_drop = 0; 136 stats->ps_ifdrop = 0; 137 return 0; 138 } 139 140 static void 141 dbus_cleanup(pcap_t *handle) 142 { 143 struct pcap_dbus *handlep = handle->priv; 144 145 dbus_connection_unref(handlep->conn); 146 147 pcap_cleanup_live_common(handle); 148 } 149 150 static int 151 dbus_activate(pcap_t *handle) 152 { 153 #define EAVESDROPPING_RULE "eavesdrop=true," 154 155 static const char *rules[] = { 156 EAVESDROPPING_RULE "type='signal'", 157 EAVESDROPPING_RULE "type='method_call'", 158 EAVESDROPPING_RULE "type='method_return'", 159 EAVESDROPPING_RULE "type='error'", 160 }; 161 162 #define N_RULES sizeof(rules)/sizeof(rules[0]) 163 164 struct pcap_dbus *handlep = handle->priv; 165 const char *dev = handle->opt.source; 166 167 DBusError error = DBUS_ERROR_INIT; 168 int i; 169 170 if (strcmp(dev, "dbus-system") == 0) { 171 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) { 172 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get system bus: %s", error.message); 173 dbus_error_free(&error); 174 return PCAP_ERROR; 175 } 176 177 } else if (strcmp(dev, "dbus-session") == 0) { 178 if (!(handlep->conn = dbus_bus_get(DBUS_BUS_SESSION, &error))) { 179 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get session bus: %s", error.message); 180 dbus_error_free(&error); 181 return PCAP_ERROR; 182 } 183 184 } else if (strncmp(dev, "dbus://", 7) == 0) { 185 const char *addr = dev + 7; 186 187 if (!(handlep->conn = dbus_connection_open(addr, &error))) { 188 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to open connection to: %s: %s", addr, error.message); 189 dbus_error_free(&error); 190 return PCAP_ERROR; 191 } 192 193 if (!dbus_bus_register(handlep->conn, &error)) { 194 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to register bus %s: %s\n", addr, error.message); 195 dbus_error_free(&error); 196 return PCAP_ERROR; 197 } 198 199 } else { 200 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get bus address from %s", handle->opt.source); 201 return PCAP_ERROR; 202 } 203 204 /* Initialize some components of the pcap structure. */ 205 handle->bufsize = 0; 206 handle->offset = 0; 207 handle->linktype = DLT_DBUS; 208 handle->read_op = dbus_read; 209 handle->inject_op = dbus_write; 210 handle->setfilter_op = install_bpf_program; /* XXX, later add support for dbus_bus_add_match() */ 211 handle->setdirection_op = NULL; 212 handle->set_datalink_op = NULL; /* can't change data link type */ 213 handle->getnonblock_op = pcap_getnonblock_fd; 214 handle->setnonblock_op = pcap_setnonblock_fd; 215 handle->stats_op = dbus_stats; 216 217 handle->selectable_fd = handle->fd = -1; 218 219 if (handle->opt.rfmon) { 220 /* 221 * Monitor mode doesn't apply to dbus connections. 222 */ 223 dbus_cleanup(handle); 224 return PCAP_ERROR_RFMON_NOTSUP; 225 } 226 227 /* dbus_connection_set_max_message_size(handlep->conn, handle->snapshot); */ 228 if (handle->opt.buffer_size != 0) 229 dbus_connection_set_max_received_size(handlep->conn, handle->opt.buffer_size); 230 231 for (i = 0; i < N_RULES; i++) { 232 dbus_bus_add_match(handlep->conn, rules[i], &error); 233 if (dbus_error_is_set(&error)) { 234 dbus_error_free(&error); 235 236 /* try without eavesdrop */ 237 dbus_bus_add_match(handlep->conn, rules[i] + strlen(EAVESDROPPING_RULE), &error); 238 if (dbus_error_is_set(&error)) { 239 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to add bus match: %s\n", error.message); 240 dbus_error_free(&error); 241 dbus_cleanup(handle); 242 return PCAP_ERROR; 243 } 244 } 245 } 246 247 return 0; 248 } 249 250 pcap_t * 251 dbus_create(const char *device, char *ebuf, int *is_ours) 252 { 253 pcap_t *p; 254 255 if (strcmp(device, "dbus-system") && 256 strcmp(device, "dbus-session") && 257 strncmp(device, "dbus://", 7)) 258 { 259 *is_ours = 0; 260 return NULL; 261 } 262 263 *is_ours = 1; 264 p = pcap_create_common(device, ebuf, sizeof (struct pcap_dbus)); 265 if (p == NULL) 266 return (NULL); 267 268 p->activate_op = dbus_activate; 269 return (p); 270 } 271 272 int 273 dbus_findalldevs(pcap_if_t **alldevsp, char *err_str) 274 { 275 if (pcap_add_if(alldevsp, "dbus-system", 0, "D-Bus system bus", err_str) < 0) 276 return -1; 277 if (pcap_add_if(alldevsp, "dbus-session", 0, "D-Bus session bus", err_str) < 0) 278 return -1; 279 return 0; 280 } 281 282