| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License, version 2 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along |
| 14 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #ifndef _LTT_SESSION_H |
| 19 | #define _LTT_SESSION_H |
| 20 | |
| 21 | #include <limits.h> |
| 22 | #include <urcu/list.h> |
| 23 | |
| 24 | #include <common/hashtable/hashtable.h> |
| 25 | |
| 26 | #include "snapshot.h" |
| 27 | #include "trace-kernel.h" |
| 28 | |
| 29 | struct ltt_ust_session; |
| 30 | |
| 31 | /* |
| 32 | * Tracing session list |
| 33 | * |
| 34 | * Statically declared in session.c and can be accessed by using |
| 35 | * session_get_list() function that returns the pointer to the list. |
| 36 | */ |
| 37 | struct ltt_session_list { |
| 38 | /* |
| 39 | * This lock protects any read/write access to the list and |
| 40 | * next_uuid. All public functions in session.c acquire this |
| 41 | * lock and release it before returning. If none of those |
| 42 | * functions are used, the lock MUST be acquired in order to |
| 43 | * iterate or/and do any actions on that list. |
| 44 | */ |
| 45 | pthread_mutex_t lock; |
| 46 | |
| 47 | /* |
| 48 | * Session unique ID generator. The session list lock MUST be |
| 49 | * upon update and read of this counter. |
| 50 | */ |
| 51 | uint64_t next_uuid; |
| 52 | |
| 53 | /* Linked list head */ |
| 54 | struct cds_list_head head; |
| 55 | }; |
| 56 | |
| 57 | /* |
| 58 | * This data structure contains information needed to identify a tracing |
| 59 | * session for both LTTng and UST. |
| 60 | */ |
| 61 | struct ltt_session { |
| 62 | char name[NAME_MAX]; |
| 63 | char hostname[HOST_NAME_MAX]; /* Local hostname. */ |
| 64 | struct ltt_kernel_session *kernel_session; |
| 65 | struct ltt_ust_session *ust_session; |
| 66 | /* |
| 67 | * Protect any read/write on this session data structure. This lock must be |
| 68 | * acquired *before* using any public functions declared below. Use |
| 69 | * session_lock() and session_unlock() for that. |
| 70 | */ |
| 71 | pthread_mutex_t lock; |
| 72 | struct cds_list_head list; |
| 73 | uint64_t id; /* session unique identifier */ |
| 74 | /* UID/GID of the user owning the session */ |
| 75 | uid_t uid; |
| 76 | gid_t gid; |
| 77 | /* |
| 78 | * Network session handle. A value of 0 means that there is no remote |
| 79 | * session established. |
| 80 | */ |
| 81 | uint64_t net_handle; |
| 82 | /* |
| 83 | * This consumer is only set when the create_session_uri call is made. |
| 84 | * This contains the temporary information for a consumer output. Upon |
| 85 | * creation of the UST or kernel session, this consumer, if available, is |
| 86 | * copied into those sessions. |
| 87 | */ |
| 88 | struct consumer_output *consumer; |
| 89 | |
| 90 | /* Did at least ONE start command has been triggered?. */ |
| 91 | unsigned int has_been_started:1; |
| 92 | /* |
| 93 | * Is the session active? Start trace command sets this to 1 and the stop |
| 94 | * command reset it to 0. |
| 95 | */ |
| 96 | unsigned int active:1; |
| 97 | |
| 98 | /* Snapshot representation in a session. */ |
| 99 | struct snapshot snapshot; |
| 100 | /* Indicate if the session has to output the traces or not. */ |
| 101 | unsigned int output_traces; |
| 102 | /* |
| 103 | * This session is in snapshot mode. This means that every channel enabled |
| 104 | * will be set in overwrite mode and mmap. It is considered exclusively for |
| 105 | * snapshot purposes. |
| 106 | */ |
| 107 | unsigned int snapshot_mode; |
| 108 | /* |
| 109 | * Timer set when the session is created for live reading. |
| 110 | */ |
| 111 | int live_timer; |
| 112 | }; |
| 113 | |
| 114 | /* Prototypes */ |
| 115 | int session_create(char *name, uid_t uid, gid_t gid); |
| 116 | int session_destroy(struct ltt_session *session); |
| 117 | |
| 118 | void session_lock(struct ltt_session *session); |
| 119 | void session_lock_list(void); |
| 120 | void session_unlock(struct ltt_session *session); |
| 121 | void session_unlock_list(void); |
| 122 | |
| 123 | struct ltt_session *session_find_by_name(const char *name); |
| 124 | struct ltt_session_list *session_get_list(void); |
| 125 | |
| 126 | int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid); |
| 127 | |
| 128 | #endif /* _LTT_SESSION_H */ |