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];
 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                 goto end;
 189         }
 190
 191         printf_verbose("Connecting to hostname : %s, port : %d, "
 192                         "traced hostname : %s, session name : %s, "
 193                         "proto : IPv%d\n",
 194                         ctx->relay_hostname, ctx->port, ctx->traced_hostname,
 195                         ctx->session_name, proto);
 196         ret = 0;
 197
 198 end:
 199         return ret;
 200 }
 201
 202 static
 203 guint g_uint64p_hash(gconstpointer key)
 204 {
 205         uint64_t v = *(uint64_t *) key;
 206
 207         if (sizeof(gconstpointer) == sizeof(uint64_t)) {
 208                 return g_direct_hash((gconstpointer) (unsigned long) v);
 209         } else {
 210                 return g_direct_hash((gconstpointer) (unsigned long) (v >> 32))
 211                         ^ g_direct_hash((gconstpointer) (unsigned long) v);
 212         }
 213 }
 214
 215 static
 216 gboolean g_uint64p_equal(gconstpointer a, gconstpointer b)
 217 {
 218         uint64_t va = *(uint64_t *) a;
 219         uint64_t vb = *(uint64_t *) b;
 220
 221         if (va != vb)
 222                 return FALSE;
 223         return TRUE;
 224 }
 225
 226 static int lttng_live_open_trace_read(const char *path)
 227 {
 228         int ret = 0;
 229         struct lttng_live_ctx *ctx;
 230
 231         ctx = g_new0(struct lttng_live_ctx, 1);
 232         ctx->session = g_new0(struct lttng_live_session, 1);
 233
 234         /* We need a pointer to the context from the packet_seek function. */
 235         ctx->session->ctx = ctx;
 236
 237         /* HT to store the CTF traces. */
 238         ctx->session->ctf_traces = g_hash_table_new(g_uint64p_hash,
 239                         g_uint64p_equal);
 240         ctx->port = -1;
 241         ctx->session_ids = g_array_new(FALSE, TRUE, sizeof(uint64_t));
 242
 243         ret = parse_url(path, ctx);
 244         if (ret < 0) {
 245                 goto end_free;
 246         }
 247         ret = setup_sighandler();
 248         if (ret < 0) {
 249                 goto end_free;
 250         }
 251         ret = lttng_live_connect_viewer(ctx);
 252         if (ret < 0) {
 253                 goto end_free;
 254         }
 255         printf_verbose("LTTng-live connected to relayd\n");
 256
 257         ret = lttng_live_establish_connection(ctx);
 258         if (ret < 0) {
 259                 goto end_free;
 260         }
 261
 262         printf_verbose("Listing sessions\n");
 263         ret = lttng_live_list_sessions(ctx, path);
 264         if (ret < 0) {
 265                 goto end_free;
 266         }
 267
 268         if (ctx->session_ids->len > 0) {
 269                 ret = lttng_live_read(ctx);
 270         }
 271
 272 end_free:
 273         g_hash_table_destroy(ctx->session->ctf_traces);
 274         g_free(ctx->session);
 275         g_free(ctx->session->streams);
 276         g_free(ctx);
 277
 278         if (lttng_live_should_quit()) {
 279                 ret = 0;
 280         }
 281         return ret;
 282 }
 283
 284 static
 285 struct bt_trace_descriptor *lttng_live_open_trace(const char *path, int flags,
 286                 void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
 287                         int whence), FILE *metadata_fp)
 288 {
 289         struct ctf_text_stream_pos *pos;
 290
 291         switch (flags & O_ACCMODE) {
 292         case O_RDONLY:
 293                 /* OK */
 294                 break;
 295         case O_RDWR:
 296                 fprintf(stderr, "[error] lttng live plugin cannot be used as output plugin.\n");
 297                 goto error;
 298         default:
 299                 fprintf(stderr, "[error] Incorrect open flags.\n");
 300                 goto error;
 301         }
 302
 303         pos = g_new0(struct ctf_text_stream_pos, 1);
 304         pos->parent.rw_table = NULL;
 305         pos->parent.event_cb = NULL;
 306         pos->parent.trace = &pos->trace_descriptor;
 307         /*
 308          * Since we do *everything* in this function, we are skipping
 309          * the output plugin handling that is part of Babeltrace 1.x.
 310          * Therefore, don't expect the --output cmd line option to work.
 311          * This limits the output of lttng-live to stderr and stdout.
 312          */
 313         if (lttng_live_open_trace_read(path) < 0) {
 314                 goto error;
 315         }
 316         return &pos->trace_descriptor;
 317
 318 error:
 319         return NULL;
 320 }
 321
 322 static
 323 int lttng_live_close_trace(struct bt_trace_descriptor *td)
 324 {
 325         struct ctf_text_stream_pos *pos =
 326                 container_of(td, struct ctf_text_stream_pos,
 327                         trace_descriptor);
 328         g_free(pos);
 329         return 0;
 330 }
 331
 332 static
 333 struct bt_format lttng_live_format = {
 334         .open_trace = lttng_live_open_trace,
 335         .close_trace = lttng_live_close_trace,
 336 };
 337
 338 static
 339 void __attribute__((constructor)) lttng_live_init(void)
 340 {
 341         int ret;
 342
 343         lttng_live_format.name = g_quark_from_string("lttng-live");
 344         ret = bt_register_format(&lttng_live_format);
 345         assert(!ret);
 346 }
 347
 348 static
 349 void __attribute__((destructor)) lttng_live_exit(void)
 350 {
 351         bt_unregister_format(&lttng_live_format);
 352 }