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_name
  88  *
  89  *      Return a ltt_session structure ptr that matches name.
  90  *      If no session found, NULL is returned.
  91  */
  92 struct ltt_session *find_session_by_name(char *name)
  93 {
  94         int found = 0;
  95         struct ltt_session *iter;
  96
  97         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
  98                 if (strncmp(iter->name, name, strlen(name)) == 0) {
  99                         found = 1;
 100                         break;
 101                 }
 102         }
 103
 104         if (!found) {
 105                 iter = NULL;
 106         }
 107
 108         return iter;
 109 }
 110
 111 /*
 112  *      destroy_session
 113  *
 114  *  Delete session from the global session list
 115  *  and free the memory.
 116  *
 117  *  Return -1 if no session is found.
 118  *  On success, return 1;
 119  */
 120 int destroy_session(char *name)
 121 {
 122         int found = -1;
 123         struct ltt_session *iter;
 124
 125         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 126                 if (strcmp(iter->name, name) == 0) {
 127                         DBG("Destroying session %s", iter->name);
 128                         del_session_list(iter);
 129                         free(iter);
 130                         found = 1;
 131                         break;
 132                 }
 133         }
 134
 135         return found;
 136 }
 137
 138 /*
 139  *      create_session
 140  *
 141  *      Create a brand new session and add it to the global session list.
 142  */
 143 int create_session(char *name, char *path)
 144 {
 145         int ret;
 146         char date_time[NAME_MAX];
 147         struct ltt_session *new_session;
 148         time_t rawtime;
 149         struct tm *timeinfo;
 150
 151         new_session = find_session_by_name(name);
 152         if (new_session != NULL) {
 153                 ret = -EEXIST;
 154                 goto error_exist;
 155         }
 156
 157         /* Allocate session data structure */
 158         new_session = malloc(sizeof(struct ltt_session));
 159         if (new_session == NULL) {
 160                 perror("malloc");
 161                 ret = -ENOMEM;
 162                 goto error_malloc;
 163         }
 164
 165         /* Define session name */
 166         if (name != NULL) {
 167                 if (asprintf(&new_session->name, "%s", name) < 0) {
 168                         ret = -ENOMEM;
 169                         goto error_asprintf;
 170                 }
 171         } else {
 172                 ERR("No session name given");
 173                 ret = -1;
 174                 goto error;
 175         }
 176
 177         /* Define session system path */
 178         if (path != NULL) {
 179                 if (strstr(name, "auto-") == NULL) {
 180                         time(&rawtime);
 181                         timeinfo = localtime(&rawtime);
 182                         strftime(date_time, sizeof(date_time), "-%Y%m%d-%H%M%S", timeinfo);
 183                 } else {
 184                         date_time[0] = '\0';
 185                 }
 186
 187                 if (asprintf(&new_session->path, "%s/%s%s", path, name, date_time) < 0) {
 188                         ret = -ENOMEM;
 189                         goto error_asprintf;
 190                 }
 191         } else {
 192                 ERR("No session path given");
 193                 ret = -1;
 194                 goto error;
 195         }
 196
 197         /*
 198          * Set consumer (identifier) to 0. This means that there is
 199          * NO consumer attach to that session yet.
 200          */
 201         new_session->ust_consumer = 0;
 202
 203         /* Init kernel session */
 204         new_session->kernel_session = NULL;
 205
 206         /* Init list */
 207         CDS_INIT_LIST_HEAD(&new_session->ust_traces);
 208
 209         /* Set trace list counter */
 210         new_session->ust_trace_count = 0;
 211
 212         /* Add new session to the global session list */
 213         add_session_list(new_session);
 214
 215         DBG("Tracing session %s created in %s", name, new_session->path);
 216
 217         return 0;
 218
 219 error:
 220 error_asprintf:
 221         if (new_session != NULL) {
 222                 free(new_session);
 223         }
 224
 225 error_exist:
 226 error_malloc:
 227         return ret;
 228 }
 229
 230 /*
 231  *  get_lttng_session
 232  *
 233  *  Iterate over the global session list and fill the lttng_session array.
 234  */
 235 void get_lttng_session(struct lttng_session *sessions)
 236 {
 237         int i = 0;
 238         struct ltt_session *iter;
 239         struct lttng_session lsess;
 240
 241         DBG("Getting all available session");
 242
 243         /* Iterate over session list and append data after
 244          * the control struct in the buffer.
 245          */
 246         cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
 247                 strncpy(lsess.path, iter->path, sizeof(lsess.path));
 248                 lsess.path[sizeof(lsess.path) - 1] = '\0';
 249                 strncpy(lsess.name, iter->name, sizeof(lsess.name));
 250                 lsess.name[sizeof(lsess.name) - 1] = '\0';
 251                 memcpy(&sessions[i], &lsess, sizeof(lsess));
 252                 i++;
 253                 /* Reset struct for next pass */
 254                 memset(&lsess, 0, sizeof(lsess));
 255         }
 256 }
 257