src/common/context.c

   1 /*
   2  * context.c
   3  *
   4  * LTTng context utilities.
   5  *
   6  * Copyright 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this library; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "context.h"
  23 #include <stddef.h>
  24 #include <string.h>
  25 #include <common/error.h>
  26 #include <common/macros.h>
  27
  28 LTTNG_HIDDEN
  29 int parse_application_context(const char *str, char **out_provider_name,
  30                 char **out_ctx_name)
  31 {
  32         const char app_ctx_prefix[] = "$app.";
  33         char *provider_name = NULL, *ctx_name = NULL;
  34         size_t i, len, colon_pos = 0, provider_name_len, ctx_name_len;
  35
  36         if (!str || !out_provider_name || !out_ctx_name) {
  37                 goto not_found;
  38         }
  39
  40         len = strlen(str);
  41         if (len <= sizeof(app_ctx_prefix) - 1) {
  42                 goto not_found;
  43         }
  44
  45         /* String starts with $app. */
  46         if (strncmp(str, app_ctx_prefix, sizeof(app_ctx_prefix) - 1)) {
  47                 goto not_found;
  48         }
  49
  50         /* Validate that the ':' separator is present. */
  51         for (i = sizeof(app_ctx_prefix); i < len; i++) {
  52                 const char c = str[i];
  53
  54                 if (c == ':') {
  55                         colon_pos = i;
  56                         break;
  57                 }
  58         }
  59
  60         /*
  61          * No colon found or no ctx name ("$app.provider:") or no provider name
  62          * given ("$app.:..."), which is invalid.
  63          */
  64         if (!colon_pos || colon_pos == len ||
  65                         colon_pos == sizeof(app_ctx_prefix)) {
  66                 goto not_found;
  67         }
  68
  69         provider_name_len = colon_pos - sizeof(app_ctx_prefix) + 2;
  70         provider_name = zmalloc(provider_name_len);
  71         if (!provider_name) {
  72                 PERROR("malloc provider_name");
  73                 goto not_found;
  74         }
  75         strncpy(provider_name, str + sizeof(app_ctx_prefix) - 1,
  76                         provider_name_len - 1);
  77
  78         ctx_name_len = len - colon_pos;
  79         ctx_name = zmalloc(ctx_name_len);
  80         if (!ctx_name) {
  81                 PERROR("malloc ctx_name");
  82                 goto not_found;
  83         }
  84         strncpy(ctx_name, str + colon_pos + 1, ctx_name_len - 1);
  85
  86         *out_provider_name = provider_name;
  87         *out_ctx_name = ctx_name;
  88         return 0;
  89 not_found:
  90         free(provider_name);
  91         free(ctx_name);
  92         return -1;
  93 }
  94