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 int lttng_live_should_quit(void)
  45 {
  46         return should_quit;
  47 }
  48
  49 static
  50 void sighandler(int sig)
  51 {
  52         switch (sig) {
  53         case SIGTERM:
  54         case SIGINT:
  55                 should_quit = 1;
  56                 break;
  57         default:
  58                 break;
  59         }
  60 }
  61
  62 /*
  63  * TODO: Eventually, this signal handler setup should be done at the
  64  * plugin manager level, rather than within this plugin. Beware, we are
  65  * not cleaning up the signal handler after plugin execution.
  66  */
  67 static
  68 int setup_sighandler(void)
  69 {
  70         struct sigaction sa;
  71         sigset_t sigset;
  72         int ret;
  73
  74         if ((ret = sigemptyset(&sigset)) < 0) {
  75                 perror("sigemptyset");
  76                 return ret;
  77         }
  78         sa.sa_handler = sighandler;
  79         sa.sa_mask = sigset;
  80         sa.sa_flags = 0;
  81         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
  82                 perror("sigaction");
  83                 return ret;
  84         }
  85         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
  86                 perror("sigaction");
  87                 return ret;
  88         }
  89         return 0;
  90 }
  91
  92 /*
  93  * hostname parameter needs to hold MAXNAMLEN chars.
  94  */
  95 static
  96 int parse_url(const char *path, struct lttng_live_ctx *ctx)
  97 {
  98         char remain[3][MAXNAMLEN];
  99         int ret = -1, proto, proto_offset = 0;
 100         size_t path_len = strlen(path); /* not accounting \0 */
 101
 102         /*
 103          * Since sscanf API does not allow easily checking string length
 104          * against a size defined by a macro. Test it beforehand on the
 105          * input. We know the output is always <= than the input length.
 106          */
 107         if (path_len >= MAXNAMLEN) {
 108                 goto end;
 109         }
 110         ret = sscanf(path, "net%d://", &proto);
 111         if (ret < 1) {
 112                 proto = 4;
 113                 /* net:// */
 114                 proto_offset = strlen("net://");
 115         } else {
 116                 /* net4:// or net6:// */
 117                 proto_offset = strlen("netX://");
 118         }
 119         if (proto_offset > path_len) {
 120                 goto end;
 121         }
 122         /* TODO : parse for IPv6 as well */
 123         /* Parse the hostname or IP */
 124         ret = sscanf(&path[proto_offset], "%[a-zA-Z.0-9%-]%s",
 125                 ctx->relay_hostname, remain[0]);
 126         if (ret == 2) {
 127                 /* Optional port number */
 128                 switch (remain[0][0]) {
 129                 case ':':
 130                         ret = sscanf(remain[0], ":%d%s", &ctx->port, remain[1]);
 131                         /* Optional session ID with port number */
 132                         if (ret == 2) {
 133                                 ret = sscanf(remain[1], "/%s", remain[2]);
 134                                 /* Accept 0 or 1 (optional) */
 135                                 if (ret < 0) {
 136                                         goto end;
 137                                 }
 138                         } else if (ret == 0) {
 139                                 fprintf(stderr, "[error] Missing port number after delimitor ':'\n");
 140                                 ret = -1;
 141                                 goto end;
 142                         }
 143                         break;
 144                 case '/':
 145                         /* Optional session ID */
 146                         ret = sscanf(remain[0], "/%s", remain[2]);
 147                         /* Accept 0 or 1 (optional) */
 148                         if (ret < 0) {
 149                                 goto end;
 150                         }
 151                         break;
 152                 default:
 153                         fprintf(stderr, "[error] wrong delimitor : %c\n",
 154                                 remain[0][0]);
 155                         ret = -1;
 156                         goto end;
 157                 }
 158         }
 159
 160         if (ctx->port < 0) {
 161                 ctx->port = LTTNG_DEFAULT_NETWORK_VIEWER_PORT;
 162         }
 163
 164         if (strlen(remain[2]) == 0) {
 165                 printf_verbose("Connecting to hostname : %s, port : %d, "
 166                                 "proto : IPv%d\n",
 167                                 ctx->relay_hostname, ctx->port, proto);
 168                 ret = 0;
 169                 goto end;
 170         }
 171         ret = sscanf(remain[2], "host/%[a-zA-Z.0-9%-]/%s",
 172                         ctx->traced_hostname, ctx->session_name);
 173         if (ret != 2) {
 174                 fprintf(stderr, "[error] Format : "
 175                         "net://<hostname>/host/<traced_hostname>/<session_name>\n");
 176                 goto end;
 177         }
 178
 179         printf_verbose("Connecting to hostname : %s, port : %d, "
 180                         "traced hostname : %s, session name : %s, "
 181                         "proto : IPv%d\n",
 182                         ctx->relay_hostname, ctx->port, ctx->traced_hostname,
 183                         ctx->session_name, proto);
 184         ret = 0;
 185
 186 end:
 187         return ret;
 188 }
 189
 190 static
 191 guint g_uint64p_hash(gconstpointer key)
 192 {
 193         uint64_t v = *(uint64_t *) key;
 194
 195         if (sizeof(gconstpointer) == sizeof(uint64_t)) {
 196                 return g_direct_hash((gconstpointer) (unsigned long) v);
 197         } else {
 198                 return g_direct_hash((gconstpointer) (unsigned long) (v >> 32))
 199                         ^ g_direct_hash((gconstpointer) (unsigned long) v);
 200         }
 201 }
 202
 203 static
 204 gboolean g_uint64p_equal(gconstpointer a, gconstpointer b)
 205 {
 206         uint64_t va = *(uint64_t *) a;
 207         uint64_t vb = *(uint64_t *) b;
 208
 209         if (va != vb)
 210                 return FALSE;
 211         return TRUE;
 212 }
 213
 214 static int lttng_live_open_trace_read(const char *path)
 215 {
 216         int ret = 0;
 217         struct lttng_live_ctx *ctx;
 218
 219         ctx = g_new0(struct lttng_live_ctx, 1);
 220         ctx->session = g_new0(struct lttng_live_session, 1);
 221
 222         /* We need a pointer to the context from the packet_seek function. */
 223         ctx->session->ctx = ctx;
 224
 225         /* HT to store the CTF traces. */
 226         ctx->session->ctf_traces = g_hash_table_new(g_uint64p_hash,
 227                         g_uint64p_equal);
 228         ctx->port = -1;
 229         ctx->session_ids = g_array_new(FALSE, TRUE, sizeof(uint64_t));
 230
 231         ret = parse_url(path, ctx);
 232         if (ret < 0) {
 233                 goto end_free;
 234         }
 235         ret = setup_sighandler();
 236         if (ret < 0) {
 237                 goto end_free;
 238         }
 239         ret = lttng_live_connect_viewer(ctx);
 240         if (ret < 0) {
 241                 goto end_free;
 242         }
 243         printf_verbose("LTTng-live connected to relayd\n");
 244
 245         ret = lttng_live_establish_connection(ctx);
 246         if (ret < 0) {
 247                 goto end_free;
 248         }
 249
 250         printf_verbose("Listing sessions\n");
 251         ret = lttng_live_list_sessions(ctx, path);
 252         if (ret < 0) {
 253                 goto end_free;
 254         }
 255
 256         if (ctx->session_ids->len > 0) {
 257                 ret = lttng_live_read(ctx);
 258         }
 259
 260 end_free:
 261         g_hash_table_destroy(ctx->session->ctf_traces);
 262         g_free(ctx->session);
 263         g_free(ctx->session->streams);
 264         g_free(ctx);
 265
 266         if (lttng_live_should_quit()) {
 267                 ret = 0;
 268         }
 269         return ret;
 270 }
 271
 272 static
 273 struct bt_trace_descriptor *lttng_live_open_trace(const char *path, int flags,
 274                 void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
 275                         int whence), FILE *metadata_fp)
 276 {
 277         struct ctf_text_stream_pos *pos;
 278
 279         switch (flags & O_ACCMODE) {
 280         case O_RDONLY:
 281                 /* OK */
 282                 break;
 283         case O_RDWR:
 284                 fprintf(stderr, "[error] lttng live plugin cannot be used as output plugin.\n");
 285                 goto error;
 286         default:
 287                 fprintf(stderr, "[error] Incorrect open flags.\n");
 288                 goto error;
 289         }
 290
 291         pos = g_new0(struct ctf_text_stream_pos, 1);
 292         pos->parent.rw_table = NULL;
 293         pos->parent.event_cb = NULL;
 294         pos->parent.trace = &pos->trace_descriptor;
 295         /*
 296          * Since we do *everything* in this function, we are skipping
 297          * the output plugin handling that is part of Babeltrace 1.x.
 298          * Therefore, don't expect the --output cmd line option to work.
 299          * This limits the output of lttng-live to stderr and stdout.
 300          */
 301         if (lttng_live_open_trace_read(path) < 0) {
 302                 goto error;
 303         }
 304         return &pos->trace_descriptor;
 305
 306 error:
 307         return NULL;
 308 }
 309
 310 static
 311 int lttng_live_close_trace(struct bt_trace_descriptor *td)
 312 {
 313         struct ctf_text_stream_pos *pos =
 314                 container_of(td, struct ctf_text_stream_pos,
 315                         trace_descriptor);
 316         g_free(pos);
 317         return 0;
 318 }
 319
 320 static
 321 struct bt_format lttng_live_format = {
 322         .open_trace = lttng_live_open_trace,
 323         .close_trace = lttng_live_close_trace,
 324 };
 325
 326 static
 327 void __attribute__((constructor)) lttng_live_init(void)
 328 {
 329         int ret;
 330
 331         lttng_live_format.name = g_quark_from_static_string("lttng-live");
 332         ret = bt_register_format(&lttng_live_format);
 333         assert(!ret);
 334 }
 335
 336 static
 337 void __attribute__((destructor)) lttng_live_exit(void)
 338 {
 339         bt_unregister_format(&lttng_live_format);
 340 }