formats/lttng-live/lttng-live-plugin.c

   1 /*
   2  * BabelTrace - LTTng live Output
   3  *
   4  * Copyright 2013 Julien Desfossez <jdesfossez@efficios.com>
   5  *                Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <babeltrace/ctf-text/types.h>
  27 #include <babeltrace/format.h>
  28 #include <babeltrace/babeltrace-internal.h>
  29 #include <inttypes.h>
  30 #include <sys/mman.h>
  31 #include <errno.h>
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <fcntl.h>
  35 #include <dirent.h>
  36 #include <glib.h>
  37 #include <unistd.h>
  38 #include <stdlib.h>
  39 #include <signal.h>
  40 #include "lttng-live.h"
  41
  42 static volatile int should_quit;
  43
  44 void bt_lttng_live_hook(void)
  45 {
  46         /*
  47          * Dummy function to prevent the linker from discarding this format as
  48          * "unused" in static builds.
  49          */
  50 }
  51
  52 int lttng_live_should_quit(void)
  53 {
  54         return should_quit;
  55 }
  56
  57 static
  58 void sighandler(int sig)
  59 {
  60         switch (sig) {
  61         case SIGTERM:
  62         case SIGINT:
  63                 should_quit = 1;
  64                 break;
  65         default:
  66                 break;
  67         }
  68 }
  69
  70 /*
  71  * TODO: Eventually, this signal handler setup should be done at the
  72  * plugin manager level, rather than within this plugin. Beware, we are
  73  * not cleaning up the signal handler after plugin execution.
  74  */
  75 static
  76 int setup_sighandler(void)
  77 {
  78         struct sigaction sa;
  79         sigset_t sigset;
  80         int ret;
  81
  82         if ((ret = sigemptyset(&sigset)) < 0) {
  83                 perror("sigemptyset");
  84                 return ret;
  85         }
  86         sa.sa_handler = sighandler;
  87         sa.sa_mask = sigset;
  88         sa.sa_flags = 0;
  89         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
  90                 perror("sigaction");
  91                 return ret;
  92         }
  93         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
  94                 perror("sigaction");
  95                 return ret;
  96         }
  97         return 0;
  98 }
  99
 100 /*
 101  * hostname parameter needs to hold MAXNAMLEN chars.
 102  */
 103 static
 104 int parse_url(const char *path, struct lttng_live_ctx *ctx)
 105 {
 106         char remain[3][MAXNAMLEN] = { { 0 } };
 107         int ret = -1, proto, proto_offset = 0;
 108         size_t path_len = strlen(path); /* not accounting \0 */
 109
 110         /*
 111          * Since sscanf API does not allow easily checking string length
 112          * against a size defined by a macro. Test it beforehand on the
 113          * input. We know the output is always <= than the input length.
 114          */
 115         if (path_len >= MAXNAMLEN) {
 116                 goto end;
 117         }
 118         ret = sscanf(path, "net%d://", &proto);
 119         if (ret < 1) {
 120                 proto = 4;
 121                 /* net:// */
 122                 proto_offset = strlen("net://");
 123         } else {
 124                 /* net4:// or net6:// */
 125                 proto_offset = strlen("netX://");
 126         }
 127         if (proto_offset > path_len) {
 128                 goto end;
 129         }
 130         if (proto == 6) {
 131                 fprintf(stderr, "[error] IPv6 is currently unsupported by lttng-live\n");
 132                 goto end;
 133         }
 134         /* TODO : parse for IPv6 as well */
 135         /* Parse the hostname or IP */
 136         ret = sscanf(&path[proto_offset], "%[a-zA-Z.0-9%-]%s",
 137                 ctx->relay_hostname, remain[0]);
 138         if (ret == 2) {
 139                 /* Optional port number */
 140                 switch (remain[0][0]) {
 141                 case ':':
 142                         ret = sscanf(remain[0], ":%d%s", &ctx->port, remain[1]);
 143                         /* Optional session ID with port number */
 144                         if (ret == 2) {
 145                                 ret = sscanf(remain[1], "/%s", remain[2]);
 146                                 /* Accept 0 or 1 (optional) */
 147                                 if (ret < 0) {
 148                                         goto end;
 149                                 }
 150                         } else if (ret == 0) {
 151                                 fprintf(stderr, "[error] Missing port number after delimitor ':'\n");
 152                                 ret = -1;
 153                                 goto end;
 154                         }
 155                         break;
 156                 case '/':
 157                         /* Optional session ID */
 158                         ret = sscanf(remain[0], "/%s", remain[2]);
 159                         /* Accept 0 or 1 (optional) */
 160                         if (ret < 0) {
 161                                 goto end;
 162                         }
 163                         break;
 164                 default:
 165                         fprintf(stderr, "[error] wrong delimitor : %c\n",
 166                                 remain[0][0]);
 167                         ret = -1;
 168                         goto end;
 169                 }
 170         }
 171
 172         if (ctx->port < 0) {
 173                 ctx->port = LTTNG_DEFAULT_NETWORK_VIEWER_PORT;
 174         }
 175
 176         if (strlen(remain[2]) == 0) {
 177                 printf_verbose("Connecting to hostname : %s, port : %d, "
 178                                 "proto : IPv%d\n",
 179                                 ctx->relay_hostname, ctx->port, proto);
 180                 ret = 0;
 181                 goto end;
 182         }
 183         ret = sscanf(remain[2], "host/%[a-zA-Z.0-9%-]/%s",
 184                         ctx->traced_hostname, ctx->session_name);
 185         if (ret != 2) {
 186                 fprintf(stderr, "[error] Format : "
 187                         "net://<hostname>/host/<traced_hostname>/<session_name>\n");
 188                 ret = -1;
 189                 goto end;
 190         }
 191
 192         printf_verbose("Connecting to hostname : %s, port : %d, "
 193                         "traced hostname : %s, session name : %s, "
 194                         "proto : IPv%d\n",
 195                         ctx->relay_hostname, ctx->port, ctx->traced_hostname,
 196                         ctx->session_name, proto);
 197         ret = 0;
 198
 199 end:
 200         return ret;
 201 }
 202
 203 static
 204 guint g_uint64p_hash(gconstpointer key)
 205 {
 206         uint64_t v = *(uint64_t *) key;
 207
 208         if (sizeof(gconstpointer) == sizeof(uint64_t)) {
 209                 return g_direct_hash((gconstpointer) (unsigned long) v);
 210         } else {
 211                 return g_direct_hash((gconstpointer) (unsigned long) (v >> 32))
 212                         ^ g_direct_hash((gconstpointer) (unsigned long) v);
 213         }
 214 }
 215
 216 static
 217 gboolean g_uint64p_equal(gconstpointer a, gconstpointer b)
 218 {
 219         uint64_t va = *(uint64_t *) a;
 220         uint64_t vb = *(uint64_t *) b;
 221
 222         if (va != vb)
 223                 return FALSE;
 224         return TRUE;
 225 }
 226
 227 static void free_session_streams(struct lttng_live_session *lsession)
 228 {
 229         struct lttng_live_viewer_stream *lvstream, *tmp;
 230
 231         bt_list_for_each_entry_safe(lvstream, tmp, &lsession->stream_list,
 232                         session_stream_node) {
 233                 /*
 234                  * The stream should not be in trace anymore.
 235                  */
 236                 assert(!lvstream->in_trace);
 237                 bt_list_del(&lvstream->session_stream_node);
 238                 g_free(lvstream);
 239         }
 240 }
 241
 242 static int lttng_live_open_trace_read(const char *path)
 243 {
 244         int ret = 0;
 245         struct lttng_live_ctx *ctx;
 246
 247         ctx = g_new0(struct lttng_live_ctx, 1);
 248         ctx->session = g_new0(struct lttng_live_session, 1);
 249
 250         BT_INIT_LIST_HEAD(&ctx->session->stream_list);
 251
 252         /* We need a pointer to the context from the packet_seek function. */
 253         ctx->session->ctx = ctx;
 254
 255         /* HT to store the CTF traces. */
 256         ctx->session->ctf_traces = g_hash_table_new(g_uint64p_hash,
 257                         g_uint64p_equal);
 258         ctx->port = -1;
 259         ctx->session_ids = g_array_new(FALSE, TRUE, sizeof(uint64_t));
 260
 261         ret = parse_url(path, ctx);
 262         if (ret < 0) {
 263                 goto end_free;
 264         }
 265         ret = setup_sighandler();
 266         if (ret < 0) {
 267                 goto end_free;
 268         }
 269         ret = lttng_live_connect_viewer(ctx);
 270         if (ret < 0) {
 271                 goto end_free;
 272         }
 273         printf_verbose("LTTng-live connected to relayd\n");
 274
 275         ret = lttng_live_establish_connection(ctx);
 276         if (ret < 0) {
 277                 goto end_free;
 278         }
 279
 280         printf_verbose("Listing sessions\n");
 281         ret = lttng_live_list_sessions(ctx, path);
 282         if (ret < 0) {
 283                 goto end_free;
 284         }
 285
 286         if (ctx->session_ids->len > 0) {
 287                 ret = lttng_live_read(ctx);
 288         }
 289
 290 end_free:
 291         g_array_free(ctx->session_ids, TRUE);
 292         g_hash_table_destroy(ctx->session->ctf_traces);
 293         free_session_streams(ctx->session);
 294         g_free(ctx->session);
 295         g_free(ctx);
 296
 297         if (lttng_live_should_quit()) {
 298                 ret = 0;
 299         }
 300         return ret;
 301 }
 302
 303 static
 304 struct bt_trace_descriptor *lttng_live_open_trace(const char *path, int flags,
 305                 void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
 306                         int whence), FILE *metadata_fp)
 307 {
 308         struct ctf_text_stream_pos *pos;
 309
 310         switch (flags & O_ACCMODE) {
 311         case O_RDONLY:
 312                 /* OK */
 313                 break;
 314         case O_RDWR:
 315                 fprintf(stderr, "[error] lttng live plugin cannot be used as output plugin.\n");
 316                 goto error;
 317         default:
 318                 fprintf(stderr, "[error] Incorrect open flags.\n");
 319                 goto error;
 320         }
 321
 322         pos = g_new0(struct ctf_text_stream_pos, 1);
 323         pos->parent.rw_table = NULL;
 324         pos->parent.event_cb = NULL;
 325         pos->parent.trace = &pos->trace_descriptor;
 326         /*
 327          * Since we do *everything* in this function, we are skipping
 328          * the output plugin handling that is part of Babeltrace 1.x.
 329          * Therefore, don't expect the --output cmd line option to work.
 330          * This limits the output of lttng-live to stderr and stdout.
 331          */
 332         if (lttng_live_open_trace_read(path) < 0) {
 333                 goto error;
 334         }
 335         return &pos->trace_descriptor;
 336
 337 error:
 338         return NULL;
 339 }
 340
 341 static
 342 int lttng_live_close_trace(struct bt_trace_descriptor *td)
 343 {
 344         struct ctf_text_stream_pos *pos =
 345                 container_of(td, struct ctf_text_stream_pos,
 346                         trace_descriptor);
 347         g_free(pos);
 348         return 0;
 349 }
 350
 351 static
 352 struct bt_format lttng_live_format = {
 353         .open_trace = lttng_live_open_trace,
 354         .close_trace = lttng_live_close_trace,
 355 };
 356
 357 static
 358 void __attribute__((constructor)) lttng_live_init(void)
 359 {
 360         int ret;
 361
 362         lttng_live_format.name = g_quark_from_static_string("lttng-live");
 363         ret = bt_register_format(&lttng_live_format);
 364         assert(!ret);
 365 }
 366
 367 static
 368 void __attribute__((destructor)) lttng_live_exit(void)
 369 {
 370         bt_unregister_format(&lttng_live_format);
 371 }