src/bin/lttng-sessiond/ust-registry.h

   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
  18 #ifndef LTTNG_UST_REGISTRY_H
  19 #define LTTNG_UST_REGISTRY_H
  20
  21 #include <pthread.h>
  22 #include <stdint.h>
  23
  24 #include <common/hashtable/hashtable.h>
  25 #include <common/compat/uuid.h>
  26
  27 #include "ust-ctl.h"
  28
  29 #define CTF_SPEC_MAJOR  1
  30 #define CTF_SPEC_MINOR  8
  31
  32 struct ust_app;
  33
  34 struct ust_registry_session {
  35         /*
  36          * With multiple writers and readers, use this lock to access
  37          * the registry. Can nest within the ust app session lock.
  38          * Also acts as a registry serialization lock. Used by registry
  39          * readers to serialize the registry information sent from the
  40          * sessiond to the consumerd.
  41          * The consumer socket lock nests within this lock.
  42          */
  43         pthread_mutex_t lock;
  44         /* Next channel ID available for a newly registered channel. */
  45         uint32_t next_channel_id;
  46         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
  47         uint32_t used_channel_id;
  48         /* Next enumeration ID available. */
  49         uint64_t next_enum_id;
  50         /* Universal unique identifier used by the tracer. */
  51         unsigned char uuid[UUID_LEN];
  52
  53         /* session ABI description */
  54
  55         /* Size of long, in bits */
  56         unsigned int bits_per_long;
  57         /* Alignment, in bits */
  58         unsigned int uint8_t_alignment,
  59                 uint16_t_alignment,
  60                 uint32_t_alignment,
  61                 uint64_t_alignment,
  62                 long_alignment;
  63         /* endianness */
  64         int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */
  65
  66         /* Generated metadata. */
  67         char *metadata;         /* NOT null-terminated ! Use memcpy. */
  68         size_t metadata_len, metadata_alloc_len;
  69         /* Length of bytes sent to the consumer. */
  70         size_t metadata_len_sent;
  71
  72         char root_shm_path[PATH_MAX];
  73         char shm_path[PATH_MAX];
  74         char metadata_path[PATH_MAX];
  75         int metadata_fd;        /* file-backed metadata FD */
  76
  77         /*
  78          * Hash table containing channels sent by the UST tracer. MUST
  79          * be accessed with a RCU read side lock acquired.
  80          */
  81         struct lttng_ht *channels;
  82         /*
  83          * Unique key to identify the metadata on the consumer side.
  84          */
  85         uint64_t metadata_key;
  86         /*
  87          * Indicates if the metadata is closed on the consumer side. This is to
  88          * avoid double close of metadata when an application unregisters AND
  89          * deletes its sessions.
  90          */
  91         unsigned int metadata_closed;
  92
  93         /* User and group owning the session. */
  94         uid_t uid;
  95         gid_t gid;
  96
  97         /* Enumerations table. */
  98         struct lttng_ht *enums;
  99 };
 100
 101 struct ust_registry_channel {
 102         uint64_t key;
 103         /* Id set when replying to a register channel. */
 104         uint32_t chan_id;
 105         enum ustctl_channel_header header_type;
 106
 107         /*
 108          * Flag for this channel if the metadata was dumped once during
 109          * registration. 0 means no, 1 yes.
 110          */
 111         unsigned int metadata_dumped;
 112         /* Indicates if this channel registry has already been registered. */
 113         unsigned int register_done;
 114
 115         /*
 116          * Hash table containing events sent by the UST tracer. MUST be accessed
 117          * with a RCU read side lock acquired.
 118          */
 119         struct lttng_ht *ht;
 120         /* Next event ID available for a newly registered event. */
 121         uint32_t next_event_id;
 122         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 123         uint32_t used_event_id;
 124         /*
 125          * Context fields of the registry. Context are per channel. Allocated by a
 126          * register channel notification from the UST tracer.
 127          */
 128         size_t nr_ctx_fields;
 129         struct ustctl_field *ctx_fields;
 130         struct lttng_ht_node_u64 node;
 131         /* For delayed reclaim */
 132         struct rcu_head rcu_head;
 133 };
 134
 135 /*
 136  * Event registered from a UST tracer sent to the session daemon. This is
 137  * indexed and matched by <event_name/signature>.
 138  */
 139 struct ust_registry_event {
 140         int id;
 141         /* Both objd are set by the tracer. */
 142         int session_objd;
 143         int channel_objd;
 144         /* Name of the event returned by the tracer. */
 145         char name[LTTNG_UST_SYM_NAME_LEN];
 146         char *signature;
 147         int loglevel_value;
 148         size_t nr_fields;
 149         struct ustctl_field *fields;
 150         char *model_emf_uri;
 151         /*
 152          * Flag for this channel if the metadata was dumped once during
 153          * registration. 0 means no, 1 yes.
 154          */
 155         unsigned int metadata_dumped;
 156         /*
 157          * Node in the ust-registry hash table. The event name is used to
 158          * initialize the node and the event_name/signature for the match function.
 159          */
 160         struct lttng_ht_node_u64 node;
 161 };
 162
 163 struct ust_registry_enum {
 164         char name[LTTNG_UST_SYM_NAME_LEN];
 165         struct ustctl_enum_entry *entries;
 166         size_t nr_entries;
 167         uint64_t id;    /* enum id in session */
 168         /* Enumeration node in session hash table. */
 169         struct lttng_ht_node_str node;
 170         /* For delayed reclaim. */
 171         struct rcu_head rcu_head;
 172 };
 173
 174 /*
 175  * Validate that the id has reached the maximum allowed or not.
 176  *
 177  * Return 0 if NOT else 1.
 178  */
 179 static inline int ust_registry_is_max_id(uint32_t id)
 180 {
 181         return (id == UINT32_MAX) ? 1 : 0;
 182 }
 183
 184 /*
 185  * Return next available event id and increment the used counter. The
 186  * ust_registry_is_max_id function MUST be called before in order to validate
 187  * if the maximum number of IDs have been reached. If not, it is safe to call
 188  * this function.
 189  *
 190  * Return a unique channel ID. If max is reached, the used_event_id counter is
 191  * returned.
 192  */
 193 static inline uint32_t ust_registry_get_next_event_id(
 194                 struct ust_registry_channel *r)
 195 {
 196         if (ust_registry_is_max_id(r->used_event_id)) {
 197                 return r->used_event_id;
 198         }
 199
 200         r->used_event_id++;
 201         return r->next_event_id++;
 202 }
 203
 204 /*
 205  * Return next available channel id and increment the used counter. The
 206  * ust_registry_is_max_id function MUST be called before in order to validate
 207  * if the maximum number of IDs have been reached. If not, it is safe to call
 208  * this function.
 209  *
 210  * Return a unique channel ID. If max is reached, the used_channel_id counter
 211  * is returned.
 212  */
 213 static inline uint32_t ust_registry_get_next_chan_id(
 214                 struct ust_registry_session *r)
 215 {
 216         if (ust_registry_is_max_id(r->used_channel_id)) {
 217                 return r->used_channel_id;
 218         }
 219
 220         r->used_channel_id++;
 221         return r->next_channel_id++;
 222 }
 223
 224 /*
 225  * Return registry event count. This is read atomically.
 226  */
 227 static inline uint32_t ust_registry_get_event_count(
 228                 struct ust_registry_channel *r)
 229 {
 230         return (uint32_t) uatomic_read(&r->used_event_id);
 231 }
 232
 233 #ifdef HAVE_LIBLTTNG_UST_CTL
 234
 235 void ust_registry_channel_destroy(struct ust_registry_session *session,
 236                 struct ust_registry_channel *chan);
 237 struct ust_registry_channel *ust_registry_channel_find(
 238                 struct ust_registry_session *session, uint64_t key);
 239 int ust_registry_channel_add(struct ust_registry_session *session,
 240                 uint64_t key);
 241 void ust_registry_channel_del_free(struct ust_registry_session *session,
 242                 uint64_t key);
 243
 244 int ust_registry_session_init(struct ust_registry_session **sessionp,
 245                 struct ust_app *app,
 246                 uint32_t bits_per_long,
 247                 uint32_t uint8_t_alignment,
 248                 uint32_t uint16_t_alignment,
 249                 uint32_t uint32_t_alignment,
 250                 uint32_t uint64_t_alignment,
 251                 uint32_t long_alignment,
 252                 int byte_order,
 253                 uint32_t major,
 254                 uint32_t minor,
 255                 const char *root_shm_path,
 256                 const char *shm_path,
 257                 uid_t euid,
 258                 gid_t egid);
 259 void ust_registry_session_destroy(struct ust_registry_session *session);
 260
 261 int ust_registry_create_event(struct ust_registry_session *session,
 262                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 263                 char *sig, size_t nr_fields, struct ustctl_field *fields,
 264                 int loglevel_value, char *model_emf_uri, int buffer_type,
 265                 uint32_t *event_id_p, struct ust_app *app);
 266 struct ust_registry_event *ust_registry_find_event(
 267                 struct ust_registry_channel *chan, char *name, char *sig);
 268 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 269                 struct ust_registry_event *event);
 270
 271 /* app can be NULL for registry shared across applications. */
 272 int ust_metadata_session_statedump(struct ust_registry_session *session,
 273                 struct ust_app *app, uint32_t major, uint32_t minor);
 274 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 275                 struct ust_registry_channel *chan);
 276 int ust_metadata_event_statedump(struct ust_registry_session *session,
 277                 struct ust_registry_channel *chan,
 278                 struct ust_registry_event *event);
 279 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
 280                 int session_objd, char *name,
 281                 struct ustctl_enum_entry *entries, size_t nr_entries,
 282                 uint64_t *enum_id);
 283 struct ust_registry_enum *
 284         ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
 285                 const char *name, uint64_t id);
 286
 287 #else /* HAVE_LIBLTTNG_UST_CTL */
 288
 289 static inline
 290 void ust_registry_channel_destroy(struct ust_registry_session *session,
 291                 struct ust_registry_channel *chan)
 292 {}
 293 static inline
 294 struct ust_registry_channel *ust_registry_channel_find(
 295                 struct ust_registry_session *session, uint64_t key)
 296 {
 297         return NULL;
 298 }
 299 static inline
 300 int ust_registry_channel_add(struct ust_registry_session *session,
 301                 uint64_t key)
 302 {
 303         return 0;
 304 }
 305 static inline
 306 void ust_registry_channel_del_free(struct ust_registry_session *session,
 307                 uint64_t key)
 308 {}
 309 static inline
 310 int ust_registry_session_init(struct ust_registry_session **sessionp,
 311                 struct ust_app *app,
 312                 uint32_t bits_per_long,
 313                 uint32_t uint8_t_alignment,
 314                 uint32_t uint16_t_alignment,
 315                 uint32_t uint32_t_alignment,
 316                 uint32_t uint64_t_alignment,
 317                 uint32_t long_alignment,
 318                 int byte_order)
 319 {
 320         return 0;
 321 }
 322 static inline
 323 void ust_registry_session_destroy(struct ust_registry_session *session)
 324 {}
 325 static inline
 326 int ust_registry_create_event(struct ust_registry_session *session,
 327                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 328                 char *sig, size_t nr_fields, struct ustctl_field *fields,
 329                 int loglevel_value, char *model_emf_uri, int buffer_type,
 330                 uint32_t *event_id_p)
 331 {
 332         return 0;
 333 }
 334 static inline
 335 struct ust_registry_event *ust_registry_find_event(
 336                 struct ust_registry_channel *chan, char *name, char *sig)
 337 {
 338         return NULL;
 339 }
 340 static inline
 341 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 342                 struct ust_registry_event *event)
 343 {}
 344
 345 /* The app object can be NULL for registry shared across applications. */
 346 static inline
 347 int ust_metadata_session_statedump(struct ust_registry_session *session,
 348                 struct ust_app *app)
 349 {
 350         return 0;
 351 }
 352 static inline
 353 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 354                 struct ust_registry_channel *chan)
 355 {
 356         return 0;
 357 }
 358 static inline
 359 int ust_metadata_event_statedump(struct ust_registry_session *session,
 360                 struct ust_registry_channel *chan,
 361                 struct ust_registry_event *event)
 362 {
 363         return 0;
 364 }
 365 static inline
 366 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
 367                 int session_objd, char *name,
 368                 struct ustctl_enum_entry *entries, size_t nr_entries,
 369                 uint64_t *enum_id)
 370 {
 371         return 0;
 372 }
 373 static inline
 374 struct ust_registry_enum *
 375         ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
 376                 const char *name, uint64_t id)
 377 {
 378         return NULL;
 379 }
 380
 381 #endif /* HAVE_LIBLTTNG_UST_CTL */
 382
 383 #endif /* LTTNG_UST_REGISTRY_H */