ltt-sessiond/session.c

   1 /*
   2  * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <time.h>
  24 #include <urcu/list.h>
  25
  26 #include "lttngerr.h"
  27 #include "session.h"
  28
  29 /* Variables */
  30 static unsigned int session_count;
  31
  32 /* Static internal function */
  33 static void add_session_list(struct ltt_session *ls);
  34 static void del_session_list(struct ltt_session *ls);
  35
  36 /* Init global session list */
  37 struct ltt_session_list ltt_session_list = {
  38         .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
  39 };
  40
  41 /*
  42  *  get_session_list
  43  *
  44  *  Return a pointer to the session list.
  45  */
  46 struct ltt_session_list *get_session_list(void)
  47 {
  48         return &ltt_session_list;
  49 }
  50
  51 /*
  52  *  get_session_count
  53  *
  54  *  Return session_count
  55  */
  56 unsigned int get_session_count(void)
  57 {
  58         return session_count;
  59 }
  60
  61 /*
  62  *  add_session_list
  63  *
  64  *  Add a ltt_session structure to the global list.
  65  */
  66 static void add_session_list(struct ltt_session *ls)
  67 {
  68         cds_list_add(&ls->list, &ltt_session_list.head);
  69         session_count++;
  70 }
  71
  72 /*
  73  *  del_session_list
  74  *
  75  *  Delete a ltt_session structure to the global list.
  76  */
  77 static void del_session_list(struct ltt_session *ls)
  78 {
  79         cds_list_del(&ls->list);
  80         /* Sanity check */
  81         if (session_count != 0) {
  82                 session_count--;
  83         }
  84 }
  85
  86 /*
  87  *      find_session_by_uuid
  88  *
  89  *      Return a ltt_session structure ptr that matches the uuid.
  90  */
  91 struct ltt_session *find_session_by_uuid(uuid_t session_id)
  92 {
  93         int found = 0;
  94         struct ltt_session *iter;
  95
  96         /* Sanity check for NULL session_id */
  97         if (uuid_is_null(session_id)) {
  98                 goto end;
  99         }
 100
 101         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 102                 if (uuid_compare(iter->uuid, session_id) == 0) {
 103                         found = 1;
 104                         break;
 105                 }
 106         }
 107
 108 end:
 109         if (!found) {
 110                 iter = NULL;
 111         }
 112         return iter;
 113 }
 114
 115 /*
 116  *      find_session_by_name
 117  *
 118  *      Return a ltt_session structure ptr that matches name.
 119  *      If no session found, NULL is returned.
 120  */
 121 struct ltt_session *find_session_by_name(char *name)
 122 {
 123         int found = 0;
 124         struct ltt_session *iter;
 125
 126         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 127                 if (strncmp(iter->name, name, strlen(name)) == 0) {
 128                         found = 1;
 129                         break;
 130                 }
 131         }
 132
 133         if (!found) {
 134                 iter = NULL;
 135         }
 136
 137         return iter;
 138 }
 139
 140 /*
 141  *      destroy_session
 142  *
 143  *  Delete session from the global session list
 144  *  and free the memory.
 145  *
 146  *  Return -1 if no session is found.
 147  *  On success, return 1;
 148  */
 149 int destroy_session(char *name)
 150 {
 151         int found = -1;
 152         struct ltt_session *iter;
 153
 154         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 155                 if (strcmp(iter->name, name) == 0) {
 156                         DBG("Destroying session %s", iter->name);
 157                         del_session_list(iter);
 158                         free(iter);
 159                         found = 1;
 160                         break;
 161                 }
 162         }
 163
 164         return found;
 165 }
 166
 167 /*
 168  *      create_session
 169  *
 170  *      Create a brand new session and add it to the global session list.
 171  */
 172 int create_session(char *name, char *path)
 173 {
 174         int ret;
 175         char date_time[NAME_MAX];
 176         struct ltt_session *new_session;
 177         time_t rawtime;
 178         struct tm *timeinfo;
 179
 180         new_session = find_session_by_name(name);
 181         if (new_session != NULL) {
 182                 ret = -EEXIST;
 183                 goto error_exist;
 184         }
 185
 186         /* Allocate session data structure */
 187         new_session = malloc(sizeof(struct ltt_session));
 188         if (new_session == NULL) {
 189                 perror("malloc");
 190                 ret = -ENOMEM;
 191                 goto error_malloc;
 192         }
 193
 194         /* Define session name */
 195         if (name != NULL) {
 196                 if (asprintf(&new_session->name, "%s", name) < 0) {
 197                         ret = -ENOMEM;
 198                         goto error_asprintf;
 199                 }
 200         } else {
 201                 ERR("No session name given");
 202                 ret = -1;
 203                 goto error;
 204         }
 205
 206         /* Define session system path */
 207         if (path != NULL) {
 208                 if (strstr(name, "auto-") == NULL) {
 209                         time(&rawtime);
 210                         timeinfo = localtime(&rawtime);
 211                         strftime(date_time, sizeof(date_time), "-%Y%m%d-%H%M%S", timeinfo);
 212                 } else {
 213                         date_time[0] = '\0';
 214                 }
 215
 216                 if (asprintf(&new_session->path, "%s/%s%s", path, name, date_time) < 0) {
 217                         ret = -ENOMEM;
 218                         goto error_asprintf;
 219                 }
 220         } else {
 221                 ERR("No session path given");
 222                 ret = -1;
 223                 goto error;
 224         }
 225
 226         /* UUID generation */
 227         uuid_generate(new_session->uuid);
 228
 229         /*
 230          * Set consumer (identifier) to 0. This means that there is
 231          * NO consumer attach to that session yet.
 232          */
 233         new_session->ust_consumer = 0;
 234
 235         /* Init kernel session */
 236         new_session->kernel_session = NULL;
 237         new_session->kern_session_count = 0;
 238
 239         /* Init list */
 240         CDS_INIT_LIST_HEAD(&new_session->ust_traces);
 241
 242         /* Set trace list counter */
 243         new_session->ust_trace_count = 0;
 244
 245         /* Add new session to the global session list */
 246         add_session_list(new_session);
 247
 248         DBG("Tracing session %s created in %s", name, new_session->path);
 249
 250         return 0;
 251
 252 error:
 253 error_asprintf:
 254         if (new_session != NULL) {
 255                 free(new_session);
 256         }
 257
 258 error_exist:
 259 error_malloc:
 260         return ret;
 261 }
 262
 263 /*
 264  *  get_lttng_session
 265  *
 266  *  Iterate over the global session list and fill the lttng_session array.
 267  */
 268 void get_lttng_session(struct lttng_session *sessions)
 269 {
 270         int i = 0;
 271         struct ltt_session *iter;
 272         struct lttng_session lsess;
 273
 274         DBG("Getting all available session");
 275
 276         /* Iterate over session list and append data after
 277          * the control struct in the buffer.
 278          */
 279         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 280                 strncpy(lsess.path, iter->path, sizeof(lsess.path));
 281                 lsess.path[sizeof(lsess.path) - 1] = '\0';
 282                 strncpy(lsess.name, iter->name, sizeof(lsess.name));
 283                 lsess.name[sizeof(lsess.name) - 1] = '\0';
 284                 memcpy(&sessions[i], &lsess, sizeof(lsess));
 285                 i++;
 286                 /* Reset struct for next pass */
 287                 memset(&lsess, 0, sizeof(lsess));
 288         }
 289 }
 290