| 1 | #include <stdio.h> |
| 2 | #include <stdint.h> |
| 3 | #include <signal.h> |
| 4 | #include <sys/types.h> |
| 5 | #include <sys/socket.h> |
| 6 | #include <sys/un.h> |
| 7 | #include <sched.h> |
| 8 | |
| 9 | #include "marker.h" |
| 10 | |
| 11 | #define UNIX_PATH_MAX 108 |
| 12 | |
| 13 | //#define SOCKETDIR "/var/run/ust/socks" |
| 14 | #define SOCKETDIR "/tmp/socks" |
| 15 | #define SOCKETDIRLEN sizeof(SOCKETDIR) |
| 16 | #define USTSIGNAL SIGIO |
| 17 | |
| 18 | #define DBG(fmt, args...) fprintf(stderr, fmt "\n", ## args) |
| 19 | #define WARN(fmt, args...) fprintf(stderr, "usertrace: WARNING: " fmt "\n", ## args) |
| 20 | #define ERR(fmt, args...) fprintf(stderr, "usertrace: ERROR: " fmt "\n", ## args) |
| 21 | #define PERROR(call) perror("usertrace: ERROR: " call) |
| 22 | |
| 23 | #define MAX_MSG_SIZE (100) |
| 24 | #define MSG_NOTIF 1 |
| 25 | #define MSG_REGISTER_NOTIF 2 |
| 26 | |
| 27 | struct tracecmd { /* no padding */ |
| 28 | uint32_t size; |
| 29 | uint16_t command; |
| 30 | }; |
| 31 | |
| 32 | //struct listener_arg { |
| 33 | // int pipe_fd; |
| 34 | //}; |
| 35 | |
| 36 | struct trctl_msg { |
| 37 | /* size: the size of all the fields except size itself */ |
| 38 | uint32_t size; |
| 39 | uint16_t type; |
| 40 | /* Only the necessary part of the payload is transferred. It |
| 41 | * may even be none of it. |
| 42 | */ |
| 43 | char payload[94]; |
| 44 | }; |
| 45 | |
| 46 | pid_t mypid; |
| 47 | char mysocketfile[UNIX_PATH_MAX] = ""; |
| 48 | int pfd = -1; |
| 49 | |
| 50 | |
| 51 | static void print_markers(void) |
| 52 | { |
| 53 | struct marker_iter iter; |
| 54 | |
| 55 | marker_iter_reset(&iter); |
| 56 | marker_iter_start(&iter); |
| 57 | |
| 58 | while(iter.marker) { |
| 59 | fprintf(stderr, "marker: %s_%s \"%s\"\n", iter.marker->channel, iter.marker->name, iter.marker->format); |
| 60 | marker_iter_next(&iter); |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | void do_command(struct tracecmd *cmd) |
| 65 | { |
| 66 | } |
| 67 | |
| 68 | void receive_commands() |
| 69 | { |
| 70 | } |
| 71 | |
| 72 | int fd_notif = -1; |
| 73 | void notif_cb(void) |
| 74 | { |
| 75 | int result; |
| 76 | struct trctl_msg msg; |
| 77 | |
| 78 | /* FIXME: fd_notif should probably be protected by a spinlock */ |
| 79 | |
| 80 | if(fd_notif == -1) |
| 81 | return; |
| 82 | |
| 83 | msg.type = MSG_NOTIF; |
| 84 | msg.size = sizeof(msg.type); |
| 85 | |
| 86 | /* FIXME: don't block here */ |
| 87 | result = write(fd_notif, &msg, msg.size+sizeof(msg.size)); |
| 88 | if(result == -1) { |
| 89 | PERROR("write"); |
| 90 | return; |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | char recvbuf[10000]; |
| 95 | |
| 96 | int listener_main(void *p) |
| 97 | { |
| 98 | int result; |
| 99 | |
| 100 | for(;;) { |
| 101 | uint32_t size; |
| 102 | struct sockaddr_un addr; |
| 103 | socklen_t addrlen = sizeof(addr); |
| 104 | char trace_name[] = "auto"; |
| 105 | char trace_type[] = "ustrelay"; |
| 106 | |
| 107 | for(;;) { |
| 108 | struct trctl_msg msg; |
| 109 | int len; |
| 110 | |
| 111 | result = len = recvfrom(pfd, recvbuf, sizeof(recvbuf), 0, &addr, &addrlen); |
| 112 | if(result == -1) { |
| 113 | PERROR("recvfrom"); |
| 114 | continue; |
| 115 | } |
| 116 | |
| 117 | if(recvbuf[len-1] == '\n') |
| 118 | recvbuf[len-1] = '\0'; |
| 119 | |
| 120 | fprintf(stderr, "received a message! it's: %s\n", recvbuf); |
| 121 | |
| 122 | |
| 123 | if(!strcmp(recvbuf, "print_markers")) { |
| 124 | print_markers(); |
| 125 | } |
| 126 | else if(!strcmp(recvbuf, "trace_setup")) { |
| 127 | DBG("trace setup"); |
| 128 | |
| 129 | result = ltt_trace_setup(trace_name); |
| 130 | if(result < 0) { |
| 131 | ERR("ltt_trace_setup failed"); |
| 132 | return; |
| 133 | } |
| 134 | |
| 135 | result = ltt_trace_set_type(trace_name, trace_type); |
| 136 | if(result < 0) { |
| 137 | ERR("ltt_trace_set_type failed"); |
| 138 | return; |
| 139 | } |
| 140 | } |
| 141 | else if(!strcmp(recvbuf, "trace_alloc")) { |
| 142 | DBG("trace alloc"); |
| 143 | |
| 144 | result = ltt_trace_alloc(trace_name); |
| 145 | if(result < 0) { |
| 146 | ERR("ltt_trace_alloc failed"); |
| 147 | return; |
| 148 | } |
| 149 | } |
| 150 | else if(!strcmp(recvbuf, "trace_start")) { |
| 151 | DBG("trace start"); |
| 152 | |
| 153 | result = ltt_trace_start(trace_name); |
| 154 | if(result < 0) { |
| 155 | ERR("ltt_trace_start failed"); |
| 156 | return; |
| 157 | } |
| 158 | } |
| 159 | else if(!strcmp(recvbuf, "trace_stop")) { |
| 160 | DBG("trace stop"); |
| 161 | |
| 162 | result = ltt_trace_stop(trace_name); |
| 163 | if(result < 0) { |
| 164 | ERR("ltt_trace_stop failed"); |
| 165 | return; |
| 166 | } |
| 167 | } |
| 168 | else if(!strcmp(recvbuf, "trace_destroy")) { |
| 169 | |
| 170 | DBG("trace destroy"); |
| 171 | |
| 172 | result = ltt_trace_destroy(trace_name); |
| 173 | if(result < 0) { |
| 174 | ERR("ltt_trace_destroy failed"); |
| 175 | return; |
| 176 | } |
| 177 | } |
| 178 | } |
| 179 | next_conn:; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | void create_listener(void) |
| 184 | { |
| 185 | int result; |
| 186 | static char listener_stack[16384]; |
| 187 | |
| 188 | result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL); |
| 189 | if(result == -1) { |
| 190 | perror("clone"); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | /* The signal handler itself. */ |
| 195 | |
| 196 | void sighandler(int sig) |
| 197 | { |
| 198 | DBG("sighandler"); |
| 199 | create_listener(); |
| 200 | } |
| 201 | |
| 202 | /* Called by the app signal handler to chain it to us. */ |
| 203 | |
| 204 | void chain_signal(void) |
| 205 | { |
| 206 | sighandler(USTSIGNAL); |
| 207 | } |
| 208 | |
| 209 | static int init_socket(void) |
| 210 | { |
| 211 | int result; |
| 212 | int fd; |
| 213 | char pidstr[6]; |
| 214 | int pidlen; |
| 215 | |
| 216 | struct sockaddr_un addr; |
| 217 | |
| 218 | result = fd = socket(PF_UNIX, SOCK_DGRAM, 0); |
| 219 | if(result == -1) { |
| 220 | PERROR("socket"); |
| 221 | return -1; |
| 222 | } |
| 223 | |
| 224 | addr.sun_family = AF_UNIX; |
| 225 | |
| 226 | result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s/%d", SOCKETDIR, mypid); |
| 227 | if(result >= UNIX_PATH_MAX) { |
| 228 | ERR("string overflow allocating socket name"); |
| 229 | goto close_sock; |
| 230 | } |
| 231 | //DBG("opening socket at %s", addr.sun_path); |
| 232 | |
| 233 | result = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); |
| 234 | if(result == -1) { |
| 235 | PERROR("bind"); |
| 236 | goto close_sock; |
| 237 | } |
| 238 | |
| 239 | strcpy(mysocketfile, addr.sun_path); |
| 240 | |
| 241 | pfd = fd; |
| 242 | return 0; |
| 243 | |
| 244 | close_sock: |
| 245 | close(fd); |
| 246 | |
| 247 | return -1; |
| 248 | } |
| 249 | |
| 250 | static void destroy_socket(void) |
| 251 | { |
| 252 | int result; |
| 253 | |
| 254 | if(mysocketfile[0] == '\0') |
| 255 | return; |
| 256 | |
| 257 | result = unlink(mysocketfile); |
| 258 | if(result == -1) { |
| 259 | PERROR("unlink"); |
| 260 | } |
| 261 | } |
| 262 | |
| 263 | static int init_signal_handler(void) |
| 264 | { |
| 265 | /* Attempt to handler SIGIO. If the main program wants to |
| 266 | * handle it, fine, it'll override us. They it'll have to |
| 267 | * use the chaining function. |
| 268 | */ |
| 269 | |
| 270 | int result; |
| 271 | struct sigaction act; |
| 272 | |
| 273 | result = sigemptyset(&act.sa_mask); |
| 274 | if(result == -1) { |
| 275 | PERROR("sigemptyset"); |
| 276 | return -1; |
| 277 | } |
| 278 | |
| 279 | act.sa_handler = sighandler; |
| 280 | act.sa_flags = SA_RESTART; |
| 281 | |
| 282 | /* Only defer ourselves. Also, try to restart interrupted |
| 283 | * syscalls to disturb the traced program as little as possible. |
| 284 | */ |
| 285 | result = sigaction(SIGIO, &act, NULL); |
| 286 | if(result == -1) { |
| 287 | PERROR("sigaction"); |
| 288 | return -1; |
| 289 | } |
| 290 | |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | static void auto_probe_connect(struct marker *m) |
| 295 | { |
| 296 | int result; |
| 297 | |
| 298 | result = ltt_marker_connect(m->channel, m->name, "default"); |
| 299 | if(result) |
| 300 | ERR("ltt_marker_connect"); |
| 301 | |
| 302 | DBG("just auto connected marker %s %s to probe default", m->channel, m->name); |
| 303 | } |
| 304 | |
| 305 | static void __attribute__((constructor(101))) init0() |
| 306 | { |
| 307 | DBG("UST_AUTOPROBE constructor"); |
| 308 | if(getenv("UST_AUTOPROBE")) { |
| 309 | marker_set_new_marker_cb(auto_probe_connect); |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | static void __attribute__((constructor(1000))) init() |
| 314 | { |
| 315 | int result; |
| 316 | |
| 317 | DBG("UST_TRACE constructor"); |
| 318 | |
| 319 | mypid = getpid(); |
| 320 | |
| 321 | if(getenv("UST_TRACE")) { |
| 322 | char trace_name[] = "auto"; |
| 323 | char trace_type[] = "ustrelay"; |
| 324 | |
| 325 | DBG("starting early tracing"); |
| 326 | |
| 327 | /* Ensure marker control is initialized */ |
| 328 | init_marker_control(); |
| 329 | |
| 330 | /* Ensure relay is initialized */ |
| 331 | init_ustrelay_transport(); |
| 332 | |
| 333 | /* Ensure markers are initialized */ |
| 334 | init_markers(); |
| 335 | |
| 336 | /* In case. */ |
| 337 | ltt_channels_register("ust"); |
| 338 | |
| 339 | result = ltt_trace_setup(trace_name); |
| 340 | if(result < 0) { |
| 341 | ERR("ltt_trace_setup failed"); |
| 342 | return; |
| 343 | } |
| 344 | |
| 345 | result = ltt_trace_set_type(trace_name, trace_type); |
| 346 | if(result < 0) { |
| 347 | ERR("ltt_trace_set_type failed"); |
| 348 | return; |
| 349 | } |
| 350 | |
| 351 | result = ltt_trace_alloc(trace_name); |
| 352 | if(result < 0) { |
| 353 | ERR("ltt_trace_alloc failed"); |
| 354 | return; |
| 355 | } |
| 356 | |
| 357 | result = ltt_trace_start(trace_name); |
| 358 | if(result < 0) { |
| 359 | ERR("ltt_trace_start failed"); |
| 360 | return; |
| 361 | } |
| 362 | } |
| 363 | |
| 364 | /* Must create socket before signal handler to prevent races |
| 365 | * on pfd variable. |
| 366 | */ |
| 367 | result = init_socket(); |
| 368 | if(result == -1) { |
| 369 | ERR("init_socket error"); |
| 370 | return; |
| 371 | } |
| 372 | result = init_signal_handler(); |
| 373 | if(result == -1) { |
| 374 | ERR("init_signal_handler error"); |
| 375 | return; |
| 376 | } |
| 377 | |
| 378 | return; |
| 379 | |
| 380 | /* should decrementally destroy stuff if error */ |
| 381 | |
| 382 | } |
| 383 | |
| 384 | /* This is only called if we terminate normally, not with an unhandled signal, |
| 385 | * so we cannot rely on it. */ |
| 386 | |
| 387 | static void __attribute__((destructor)) fini() |
| 388 | { |
| 389 | destroy_socket(); |
| 390 | } |