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          * Copy of the tracer version when the first app is registered.
 102          * It is used if we need to regenerate the metadata.
 103          */
 104         uint32_t major;
 105         uint32_t minor;
 106 };
 107
 108 struct ust_registry_channel {
 109         uint64_t key;
 110         /* Id set when replying to a register channel. */
 111         uint32_t chan_id;
 112         enum ustctl_channel_header header_type;
 113
 114         /*
 115          * Flag for this channel if the metadata was dumped once during
 116          * registration. 0 means no, 1 yes.
 117          */
 118         unsigned int metadata_dumped;
 119         /* Indicates if this channel registry has already been registered. */
 120         unsigned int register_done;
 121
 122         /*
 123          * Hash table containing events sent by the UST tracer. MUST be accessed
 124          * with a RCU read side lock acquired.
 125          */
 126         struct lttng_ht *ht;
 127         /* Next event ID available for a newly registered event. */
 128         uint32_t next_event_id;
 129         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 130         uint32_t used_event_id;
 131         /*
 132          * Context fields of the registry. Context are per channel. Allocated by a
 133          * register channel notification from the UST tracer.
 134          */
 135         size_t nr_ctx_fields;
 136         struct ustctl_field *ctx_fields;
 137         struct lttng_ht_node_u64 node;
 138         /* For delayed reclaim */
 139         struct rcu_head rcu_head;
 140 };
 141
 142 /*
 143  * Event registered from a UST tracer sent to the session daemon. This is
 144  * indexed and matched by <event_name/signature>.
 145  */
 146 struct ust_registry_event {
 147         int id;
 148         /* Both objd are set by the tracer. */
 149         int session_objd;
 150         int channel_objd;
 151         /* Name of the event returned by the tracer. */
 152         char name[LTTNG_UST_SYM_NAME_LEN];
 153         char *signature;
 154         int loglevel_value;
 155         size_t nr_fields;
 156         struct ustctl_field *fields;
 157         char *model_emf_uri;
 158         /*
 159          * Flag for this channel if the metadata was dumped once during
 160          * registration. 0 means no, 1 yes.
 161          */
 162         unsigned int metadata_dumped;
 163         /*
 164          * Node in the ust-registry hash table. The event name is used to
 165          * initialize the node and the event_name/signature for the match function.
 166          */
 167         struct lttng_ht_node_u64 node;
 168 };
 169
 170 struct ust_registry_enum {
 171         char name[LTTNG_UST_SYM_NAME_LEN];
 172         struct ustctl_enum_entry *entries;
 173         size_t nr_entries;
 174         uint64_t id;    /* enum id in session */
 175         /* Enumeration node in session hash table. */
 176         struct lttng_ht_node_str node;
 177         /* For delayed reclaim. */
 178         struct rcu_head rcu_head;
 179 };
 180
 181 /*
 182  * Validate that the id has reached the maximum allowed or not.
 183  *
 184  * Return 0 if NOT else 1.
 185  */
 186 static inline int ust_registry_is_max_id(uint32_t id)
 187 {
 188         return (id == UINT32_MAX) ? 1 : 0;
 189 }
 190
 191 /*
 192  * Return next available event id and increment the used counter. The
 193  * ust_registry_is_max_id function MUST be called before in order to validate
 194  * if the maximum number of IDs have been reached. If not, it is safe to call
 195  * this function.
 196  *
 197  * Return a unique channel ID. If max is reached, the used_event_id counter is
 198  * returned.
 199  */
 200 static inline uint32_t ust_registry_get_next_event_id(
 201                 struct ust_registry_channel *r)
 202 {
 203         if (ust_registry_is_max_id(r->used_event_id)) {
 204                 return r->used_event_id;
 205         }
 206
 207         r->used_event_id++;
 208         return r->next_event_id++;
 209 }
 210
 211 /*
 212  * Return next available channel id and increment the used counter. The
 213  * ust_registry_is_max_id function MUST be called before in order to validate
 214  * if the maximum number of IDs have been reached. If not, it is safe to call
 215  * this function.
 216  *
 217  * Return a unique channel ID. If max is reached, the used_channel_id counter
 218  * is returned.
 219  */
 220 static inline uint32_t ust_registry_get_next_chan_id(
 221                 struct ust_registry_session *r)
 222 {
 223         if (ust_registry_is_max_id(r->used_channel_id)) {
 224                 return r->used_channel_id;
 225         }
 226
 227         r->used_channel_id++;
 228         return r->next_channel_id++;
 229 }
 230
 231 /*
 232  * Return registry event count. This is read atomically.
 233  */
 234 static inline uint32_t ust_registry_get_event_count(
 235                 struct ust_registry_channel *r)
 236 {
 237         return (uint32_t) uatomic_read(&r->used_event_id);
 238 }
 239
 240 #ifdef HAVE_LIBLTTNG_UST_CTL
 241
 242 void ust_registry_channel_destroy(struct ust_registry_session *session,
 243                 struct ust_registry_channel *chan);
 244 struct ust_registry_channel *ust_registry_channel_find(
 245                 struct ust_registry_session *session, uint64_t key);
 246 int ust_registry_channel_add(struct ust_registry_session *session,
 247                 uint64_t key);
 248 void ust_registry_channel_del_free(struct ust_registry_session *session,
 249                 uint64_t key);
 250
 251 int ust_registry_session_init(struct ust_registry_session **sessionp,
 252                 struct ust_app *app,
 253                 uint32_t bits_per_long,
 254                 uint32_t uint8_t_alignment,
 255                 uint32_t uint16_t_alignment,
 256                 uint32_t uint32_t_alignment,
 257                 uint32_t uint64_t_alignment,
 258                 uint32_t long_alignment,
 259                 int byte_order,
 260                 uint32_t major,
 261                 uint32_t minor,
 262                 const char *root_shm_path,
 263                 const char *shm_path,
 264                 uid_t euid,
 265                 gid_t egid);
 266 void ust_registry_session_destroy(struct ust_registry_session *session);
 267
 268 int ust_registry_create_event(struct ust_registry_session *session,
 269                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 270                 char *sig, size_t nr_fields, struct ustctl_field *fields,
 271                 int loglevel_value, char *model_emf_uri, int buffer_type,
 272                 uint32_t *event_id_p, struct ust_app *app);
 273 struct ust_registry_event *ust_registry_find_event(
 274                 struct ust_registry_channel *chan, char *name, char *sig);
 275 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 276                 struct ust_registry_event *event);
 277
 278 /* app can be NULL for registry shared across applications. */
 279 int ust_metadata_session_statedump(struct ust_registry_session *session,
 280                 struct ust_app *app, uint32_t major, uint32_t minor);
 281 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 282                 struct ust_registry_channel *chan);
 283 int ust_metadata_event_statedump(struct ust_registry_session *session,
 284                 struct ust_registry_channel *chan,
 285                 struct ust_registry_event *event);
 286 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
 287                 int session_objd, char *name,
 288                 struct ustctl_enum_entry *entries, size_t nr_entries,
 289                 uint64_t *enum_id);
 290 struct ust_registry_enum *
 291         ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
 292                 const char *name, uint64_t id);
 293
 294 #else /* HAVE_LIBLTTNG_UST_CTL */
 295
 296 static inline
 297 void ust_registry_channel_destroy(struct ust_registry_session *session,
 298                 struct ust_registry_channel *chan)
 299 {}
 300 static inline
 301 struct ust_registry_channel *ust_registry_channel_find(
 302                 struct ust_registry_session *session, uint64_t key)
 303 {
 304         return NULL;
 305 }
 306 static inline
 307 int ust_registry_channel_add(struct ust_registry_session *session,
 308                 uint64_t key)
 309 {
 310         return 0;
 311 }
 312 static inline
 313 void ust_registry_channel_del_free(struct ust_registry_session *session,
 314                 uint64_t key)
 315 {}
 316 static inline
 317 int ust_registry_session_init(struct ust_registry_session **sessionp,
 318                 struct ust_app *app,
 319                 uint32_t bits_per_long,
 320                 uint32_t uint8_t_alignment,
 321                 uint32_t uint16_t_alignment,
 322                 uint32_t uint32_t_alignment,
 323                 uint32_t uint64_t_alignment,
 324                 uint32_t long_alignment,
 325                 int byte_order)
 326 {
 327         return 0;
 328 }
 329 static inline
 330 void ust_registry_session_destroy(struct ust_registry_session *session)
 331 {}
 332 static inline
 333 int ust_registry_create_event(struct ust_registry_session *session,
 334                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 335                 char *sig, size_t nr_fields, struct ustctl_field *fields,
 336                 int loglevel_value, char *model_emf_uri, int buffer_type,
 337                 uint32_t *event_id_p)
 338 {
 339         return 0;
 340 }
 341 static inline
 342 struct ust_registry_event *ust_registry_find_event(
 343                 struct ust_registry_channel *chan, char *name, char *sig)
 344 {
 345         return NULL;
 346 }
 347 static inline
 348 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 349                 struct ust_registry_event *event)
 350 {}
 351
 352 /* The app object can be NULL for registry shared across applications. */
 353 static inline
 354 int ust_metadata_session_statedump(struct ust_registry_session *session,
 355                 struct ust_app *app)
 356 {
 357         return 0;
 358 }
 359 static inline
 360 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 361                 struct ust_registry_channel *chan)
 362 {
 363         return 0;
 364 }
 365 static inline
 366 int ust_metadata_event_statedump(struct ust_registry_session *session,
 367                 struct ust_registry_channel *chan,
 368                 struct ust_registry_event *event)
 369 {
 370         return 0;
 371 }
 372 static inline
 373 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
 374                 int session_objd, char *name,
 375                 struct ustctl_enum_entry *entries, size_t nr_entries,
 376                 uint64_t *enum_id)
 377 {
 378         return 0;
 379 }
 380 static inline
 381 struct ust_registry_enum *
 382         ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
 383                 const char *name, uint64_t id)
 384 {
 385         return NULL;
 386 }
 387
 388 #endif /* HAVE_LIBLTTNG_UST_CTL */
 389
 390 #endif /* LTTNG_UST_REGISTRY_H */