JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 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 | |