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 NAME_MAX chars.
  94  */
  95 static
  96 int parse_url(const char *path, struct lttng_live_ctx *ctx)
  97 {
  98         char remain[3][NAME_MAX];
  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 >= NAME_MAX) {
 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                         }
 139                         break;
 140                 case '/':
 141                         /* Optional session ID */
 142                         ret = sscanf(remain[0], "/%s", remain[2]);
 143                         /* Accept 0 or 1 (optional) */
 144                         if (ret < 0) {
 145                                 goto end;
 146                         }
 147                         break;
 148                 default:
 149                         fprintf(stderr, "[error] wrong delimitor : %c\n",
 150                                 remain[0][0]);
 151                         ret = -1;
 152                         goto end;
 153                 }
 154         }
 155
 156         if (ctx->port < 0) {
 157                 ctx->port = LTTNG_DEFAULT_NETWORK_VIEWER_PORT;
 158         }
 159
 160         if (strlen(remain[2]) == 0) {
 161                 printf_verbose("Connecting to hostname : %s, port : %d, "
 162                                 "proto : IPv%d\n",
 163                                 ctx->relay_hostname, ctx->port, proto);
 164                 ret = 0;
 165                 goto end;
 166         }
 167         ret = sscanf(remain[2], "host/%[a-zA-Z.0-9%-]/%s",
 168                         ctx->traced_hostname, ctx->session_name);
 169         if (ret != 2) {
 170                 fprintf(stderr, "[error] Format : "
 171                         "net://<hostname>/host/<traced_hostname>/<session_name>\n");
 172                 goto end;
 173         }
 174
 175         printf_verbose("Connecting to hostname : %s, port : %d, "
 176                         "traced hostname : %s, session name : %s, "
 177                         "proto : IPv%d\n",
 178                         ctx->relay_hostname, ctx->port, ctx->traced_hostname,
 179                         ctx->session_name, proto);
 180         ret = 0;
 181
 182 end:
 183         return ret;
 184 }
 185
 186 static int lttng_live_open_trace_read(const char *path)
 187 {
 188         int ret = 0;
 189         struct lttng_live_ctx *ctx;
 190
 191         ctx = g_new0(struct lttng_live_ctx, 1);
 192         ctx->session = g_new0(struct lttng_live_session, 1);
 193
 194         /* We need a pointer to the context from the packet_seek function. */
 195         ctx->session->ctx = ctx;
 196
 197         /* HT to store the CTF traces. */
 198         ctx->session->ctf_traces = g_hash_table_new(g_direct_hash,
 199                         g_direct_equal);
 200         ctx->port = -1;
 201         ctx->session_ids = g_array_new(FALSE, TRUE, sizeof(uint64_t));
 202
 203         ret = parse_url(path, ctx);
 204         if (ret < 0) {
 205                 goto end_free;
 206         }
 207         ret = setup_sighandler();
 208         if (ret < 0) {
 209                 goto end_free;
 210         }
 211         ret = lttng_live_connect_viewer(ctx);
 212         if (ret < 0) {
 213                 goto end_free;
 214         }
 215         printf_verbose("LTTng-live connected to relayd\n");
 216
 217         ret = lttng_live_establish_connection(ctx);
 218         if (ret < 0) {
 219                 goto end_free;
 220         }
 221
 222         printf_verbose("Listing sessions\n");
 223         ret = lttng_live_list_sessions(ctx, path);
 224         if (ret < 0) {
 225                 goto end_free;
 226         }
 227
 228         if (ctx->session_ids->len > 0) {
 229                 lttng_live_read(ctx);
 230         }
 231
 232 end_free:
 233         g_hash_table_destroy(ctx->session->ctf_traces);
 234         g_free(ctx->session);
 235         g_free(ctx->session->streams);
 236         g_free(ctx);
 237
 238         if (lttng_live_should_quit()) {
 239                 ret = 0;
 240         }
 241         return ret;
 242 }
 243
 244 static
 245 struct bt_trace_descriptor *lttng_live_open_trace(const char *path, int flags,
 246                 void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
 247                         int whence), FILE *metadata_fp)
 248 {
 249         struct ctf_text_stream_pos *pos;
 250
 251         switch (flags & O_ACCMODE) {
 252         case O_RDONLY:
 253                 /* OK */
 254                 break;
 255         case O_RDWR:
 256                 fprintf(stderr, "[error] lttng live plugin cannot be used as output plugin.\n");
 257                 goto error;
 258         default:
 259                 fprintf(stderr, "[error] Incorrect open flags.\n");
 260                 goto error;
 261         }
 262
 263         pos = g_new0(struct ctf_text_stream_pos, 1);
 264         pos->parent.rw_table = NULL;
 265         pos->parent.event_cb = NULL;
 266         pos->parent.trace = &pos->trace_descriptor;
 267         lttng_live_open_trace_read(path);
 268         return &pos->trace_descriptor;
 269
 270 error:
 271         return NULL;
 272 }
 273
 274 static
 275 int lttng_live_close_trace(struct bt_trace_descriptor *td)
 276 {
 277         struct ctf_text_stream_pos *pos =
 278                 container_of(td, struct ctf_text_stream_pos,
 279                         trace_descriptor);
 280         free(pos);
 281         return 0;
 282 }
 283
 284 static
 285 struct bt_format lttng_live_format = {
 286         .open_trace = lttng_live_open_trace,
 287         .close_trace = lttng_live_close_trace,
 288 };
 289
 290 static
 291 void __attribute__((constructor)) lttng_live_init(void)
 292 {
 293         int ret;
 294
 295         lttng_live_format.name = g_quark_from_static_string("lttng-live");
 296         ret = bt_register_format(&lttng_live_format);
 297         assert(!ret);
 298 }
 299
 300 static
 301 void __attribute__((destructor)) lttng_live_exit(void)
 302 {
 303         bt_unregister_format(&lttng_live_format);
 304 }