| 1 | /* |
| 2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | #define _GNU_SOURCE |
| 18 | #include <assert.h> |
| 19 | |
| 20 | #include <common/common.h> |
| 21 | #include "ust-registry.h" |
| 22 | |
| 23 | /* |
| 24 | * Hash table match function for event in the registry. |
| 25 | */ |
| 26 | static int ht_match_event(struct cds_lfht_node *node, const void *_key) |
| 27 | { |
| 28 | struct ust_registry_event *event; |
| 29 | const struct ust_registry_event *key; |
| 30 | |
| 31 | assert(node); |
| 32 | assert(_key); |
| 33 | |
| 34 | event = caa_container_of(node, struct ust_registry_event, node.node); |
| 35 | assert(event); |
| 36 | key = _key; |
| 37 | |
| 38 | /* It has to be a perfect match. */ |
| 39 | if (strncmp(event->name, key->name, sizeof(event->name)) != 0) { |
| 40 | goto no_match; |
| 41 | } |
| 42 | |
| 43 | /* It has to be a perfect match. */ |
| 44 | if (strncmp(event->signature, key->signature, |
| 45 | strlen(event->signature) != 0)) { |
| 46 | goto no_match; |
| 47 | } |
| 48 | |
| 49 | /* Match */ |
| 50 | return 1; |
| 51 | |
| 52 | no_match: |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | /* |
| 57 | * Allocate event and initialize it. This does NOT set a valid event id from a |
| 58 | * registry. |
| 59 | */ |
| 60 | static struct ust_registry_event *alloc_event(int session_objd, |
| 61 | int channel_objd, char *name, char *sig, size_t nr_fields, |
| 62 | struct ustctl_field *fields, int loglevel, char *model_emf_uri) |
| 63 | { |
| 64 | struct ust_registry_event *event = NULL; |
| 65 | |
| 66 | event = zmalloc(sizeof(*event)); |
| 67 | if (!event) { |
| 68 | PERROR("zmalloc ust registry event"); |
| 69 | goto error; |
| 70 | } |
| 71 | |
| 72 | event->session_objd = session_objd; |
| 73 | event->channel_objd = channel_objd; |
| 74 | /* Allocated by ustctl. */ |
| 75 | event->signature = sig; |
| 76 | event->nr_fields = nr_fields; |
| 77 | event->fields = fields; |
| 78 | event->loglevel = loglevel; |
| 79 | event->model_emf_uri = model_emf_uri; |
| 80 | if (name) { |
| 81 | /* Copy event name and force NULL byte. */ |
| 82 | strncpy(event->name, name, sizeof(event->name)); |
| 83 | event->name[sizeof(event->name) - 1] = '\0'; |
| 84 | } |
| 85 | lttng_ht_node_init_str(&event->node, event->name); |
| 86 | |
| 87 | error: |
| 88 | return event; |
| 89 | } |
| 90 | |
| 91 | /* |
| 92 | * Free event data structure. This does NOT delete it from any hash table. It's |
| 93 | * safe to pass a NULL pointer. This shoudl be called inside a call RCU if the |
| 94 | * event is previously deleted from a rcu hash table. |
| 95 | */ |
| 96 | static void destroy_event(struct ust_registry_event *event) |
| 97 | { |
| 98 | if (!event) { |
| 99 | return; |
| 100 | } |
| 101 | |
| 102 | free(event->fields); |
| 103 | free(event->model_emf_uri); |
| 104 | free(event->signature); |
| 105 | free(event); |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * Destroy event function call of the call RCU. |
| 110 | */ |
| 111 | static void destroy_event_rcu(struct rcu_head *head) |
| 112 | { |
| 113 | struct lttng_ht_node_str *node = |
| 114 | caa_container_of(head, struct lttng_ht_node_str, head); |
| 115 | struct ust_registry_event *event = |
| 116 | caa_container_of(node, struct ust_registry_event, node); |
| 117 | |
| 118 | destroy_event(event); |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Find an event using the name and signature in the given registry. RCU read |
| 123 | * side lock MUST be acquired before calling this function and as long as the |
| 124 | * event reference is kept by the caller. |
| 125 | * |
| 126 | * On success, the event pointer is returned else NULL. |
| 127 | */ |
| 128 | struct ust_registry_event *ust_registry_find_event( |
| 129 | struct ust_registry_channel *chan, char *name, char *sig) |
| 130 | { |
| 131 | struct lttng_ht_node_str *node; |
| 132 | struct lttng_ht_iter iter; |
| 133 | struct ust_registry_event *event = NULL; |
| 134 | struct ust_registry_event key; |
| 135 | |
| 136 | assert(chan); |
| 137 | assert(name); |
| 138 | assert(sig); |
| 139 | |
| 140 | /* Setup key for the match function. */ |
| 141 | strncpy(key.name, name, sizeof(key.name)); |
| 142 | key.name[sizeof(key.name) - 1] = '\0'; |
| 143 | key.signature = sig; |
| 144 | |
| 145 | cds_lfht_lookup(chan->ht->ht, chan->ht->hash_fct(name, lttng_ht_seed), |
| 146 | chan->ht->match_fct, &key, &iter.iter); |
| 147 | node = lttng_ht_iter_get_node_str(&iter); |
| 148 | if (!node) { |
| 149 | goto end; |
| 150 | } |
| 151 | event = caa_container_of(node, struct ust_registry_event, node); |
| 152 | |
| 153 | end: |
| 154 | return event; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * Create a ust_registry_event from the given parameters and add it to the |
| 159 | * registry hash table. If event_id is valid, it is set with the newly created |
| 160 | * event id. |
| 161 | * |
| 162 | * On success, return 0 else a negative value. The created event MUST be unique |
| 163 | * so on duplicate entry -EINVAL is returned. On error, event_id is untouched. |
| 164 | * |
| 165 | * Should be called with session registry mutex held. |
| 166 | */ |
| 167 | int ust_registry_create_event(struct ust_registry_session *session, |
| 168 | struct ust_registry_channel *chan, |
| 169 | int session_objd, int channel_objd, char *name, char *sig, |
| 170 | size_t nr_fields, struct ustctl_field *fields, int loglevel, |
| 171 | char *model_emf_uri, uint32_t *event_id) |
| 172 | { |
| 173 | int ret; |
| 174 | struct cds_lfht_node *nptr; |
| 175 | struct ust_registry_event *event = NULL; |
| 176 | |
| 177 | assert(session); |
| 178 | assert(chan); |
| 179 | assert(name); |
| 180 | assert(sig); |
| 181 | |
| 182 | /* |
| 183 | * This should not happen but since it comes from the UST tracer, an |
| 184 | * external party, don't assert and simply validate values. |
| 185 | */ |
| 186 | if (session_objd < 0 || channel_objd < 0) { |
| 187 | ret = -EINVAL; |
| 188 | goto error; |
| 189 | } |
| 190 | |
| 191 | /* Check if we've reached the maximum possible id. */ |
| 192 | if (ust_registry_is_max_id(chan->used_event_id)) { |
| 193 | ret = -ENOENT; |
| 194 | goto error; |
| 195 | } |
| 196 | |
| 197 | event = alloc_event(session_objd, channel_objd, name, sig, nr_fields, |
| 198 | fields, loglevel, model_emf_uri); |
| 199 | if (!event) { |
| 200 | ret = -ENOMEM; |
| 201 | goto error; |
| 202 | } |
| 203 | |
| 204 | event->id = ust_registry_get_next_event_id(chan); |
| 205 | |
| 206 | DBG3("UST registry creating event with event: %s, sig: %s, id: %u, " |
| 207 | "chan_objd: %u, sess_objd: %u", event->name, event->signature, |
| 208 | event->id, event->channel_objd, event->session_objd); |
| 209 | |
| 210 | rcu_read_lock(); |
| 211 | /* |
| 212 | * This is an add unique with a custom match function for event. The node |
| 213 | * are matched using the event name and signature. |
| 214 | */ |
| 215 | nptr = cds_lfht_add_unique(chan->ht->ht, chan->ht->hash_fct(event->node.key, |
| 216 | lttng_ht_seed), chan->ht->match_fct, event, &event->node.node); |
| 217 | if (nptr != &event->node.node) { |
| 218 | ERR("UST registry create event add unique failed for event: %s, " |
| 219 | "sig: %s, id: %u, chan_objd: %u, sess_objd: %u", event->name, |
| 220 | event->signature, event->id, event->channel_objd, |
| 221 | event->session_objd); |
| 222 | ret = -EINVAL; |
| 223 | goto error_unlock; |
| 224 | } |
| 225 | |
| 226 | /* Set event id if user wants it. */ |
| 227 | if (event_id) { |
| 228 | *event_id = event->id; |
| 229 | } |
| 230 | rcu_read_unlock(); |
| 231 | |
| 232 | /* Append to metadata */ |
| 233 | ret = ust_metadata_event_statedump(session, chan, event); |
| 234 | if (ret) { |
| 235 | ERR("Error appending event metadata (errno = %d)", ret); |
| 236 | return ret; |
| 237 | } |
| 238 | |
| 239 | return 0; |
| 240 | |
| 241 | error_unlock: |
| 242 | rcu_read_unlock(); |
| 243 | error: |
| 244 | destroy_event(event); |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * For a given event in a registry, delete the entry and destroy the event. |
| 250 | * This MUST be called within a RCU read side lock section. |
| 251 | */ |
| 252 | void ust_registry_destroy_event(struct ust_registry_channel *chan, |
| 253 | struct ust_registry_event *event) |
| 254 | { |
| 255 | int ret; |
| 256 | struct lttng_ht_iter iter; |
| 257 | |
| 258 | assert(chan); |
| 259 | assert(event); |
| 260 | |
| 261 | /* Delete the node first. */ |
| 262 | iter.iter.node = &event->node.node; |
| 263 | ret = lttng_ht_del(chan->ht, &iter); |
| 264 | assert(!ret); |
| 265 | |
| 266 | call_rcu(&event->node.head, destroy_event_rcu); |
| 267 | |
| 268 | return; |
| 269 | } |
| 270 | |
| 271 | /* |
| 272 | * Initialize registry with default values. |
| 273 | */ |
| 274 | void ust_registry_channel_init(struct ust_registry_session *session, |
| 275 | struct ust_registry_channel *chan) |
| 276 | { |
| 277 | assert(chan); |
| 278 | |
| 279 | memset(chan, 0, sizeof(struct ust_registry_channel)); |
| 280 | |
| 281 | chan->ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING); |
| 282 | assert(chan->ht); |
| 283 | |
| 284 | /* Set custom match function. */ |
| 285 | chan->ht->match_fct = ht_match_event; |
| 286 | } |
| 287 | |
| 288 | /* |
| 289 | * Destroy every element of the registry and free the memory. This does NOT |
| 290 | * free the registry pointer since it might not have been allocated before so |
| 291 | * it's the caller responsability. |
| 292 | * |
| 293 | * This MUST be called within a RCU read side lock section. |
| 294 | */ |
| 295 | void ust_registry_channel_destroy(struct ust_registry_session *session, |
| 296 | struct ust_registry_channel *chan) |
| 297 | { |
| 298 | struct lttng_ht_iter iter; |
| 299 | struct ust_registry_event *event; |
| 300 | |
| 301 | assert(chan); |
| 302 | |
| 303 | /* Destroy all event associated with this registry. */ |
| 304 | cds_lfht_for_each_entry(chan->ht->ht, &iter.iter, event, node.node) { |
| 305 | /* Delete the node from the ht and free it. */ |
| 306 | ust_registry_destroy_event(chan, event); |
| 307 | } |
| 308 | lttng_ht_destroy(chan->ht); |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Initialize registry with default values. |
| 313 | */ |
| 314 | int ust_registry_session_init(struct ust_registry_session *session, |
| 315 | struct ust_app *app, |
| 316 | uint32_t bits_per_long, |
| 317 | uint32_t uint8_t_alignment, |
| 318 | uint32_t uint16_t_alignment, |
| 319 | uint32_t uint32_t_alignment, |
| 320 | uint32_t uint64_t_alignment, |
| 321 | uint32_t long_alignment, |
| 322 | int byte_order) |
| 323 | { |
| 324 | int ret; |
| 325 | |
| 326 | assert(session); |
| 327 | |
| 328 | memset(session, 0, sizeof(struct ust_registry_session)); |
| 329 | |
| 330 | pthread_mutex_init(&session->lock, NULL); |
| 331 | session->bits_per_long = bits_per_long; |
| 332 | session->uint8_t_alignment = uint8_t_alignment; |
| 333 | session->uint16_t_alignment = uint16_t_alignment; |
| 334 | session->uint32_t_alignment = uint32_t_alignment; |
| 335 | session->uint64_t_alignment = uint64_t_alignment; |
| 336 | session->long_alignment = long_alignment; |
| 337 | session->byte_order = byte_order; |
| 338 | |
| 339 | ret = lttng_uuid_generate(session->uuid); |
| 340 | if (ret) { |
| 341 | ERR("Failed to generate UST uuid (errno = %d)", ret); |
| 342 | goto error; |
| 343 | } |
| 344 | |
| 345 | pthread_mutex_lock(&session->lock); |
| 346 | ret = ust_metadata_session_statedump(session, app); |
| 347 | pthread_mutex_unlock(&session->lock); |
| 348 | if (ret) { |
| 349 | ERR("Failed to generate session metadata (errno = %d)", ret); |
| 350 | goto error; |
| 351 | } |
| 352 | |
| 353 | return 0; |
| 354 | |
| 355 | error: |
| 356 | return -1; |
| 357 | } |
| 358 | |
| 359 | /* |
| 360 | * Destroy session registry. This does NOT free the given pointer since it |
| 361 | * might get passed as a reference. The registry lock should NOT be acquired. |
| 362 | */ |
| 363 | void ust_registry_session_destroy(struct ust_registry_session *reg) |
| 364 | { |
| 365 | int ret; |
| 366 | |
| 367 | /* On error, EBUSY can be returned if lock. Code flow error. */ |
| 368 | ret = pthread_mutex_destroy(®->lock); |
| 369 | assert(!ret); |
| 370 | |
| 371 | free(reg->metadata); |
| 372 | } |