src/common/context.c

   1 /*
   2  * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include "context.h"
   9 #include <stddef.h>
  10 #include <string.h>
  11 #include <common/error.h>
  12 #include <common/macros.h>
  13
  14 LTTNG_HIDDEN
  15 int parse_application_context(const char *str, char **out_provider_name,
  16                 char **out_ctx_name)
  17 {
  18         const char app_ctx_prefix[] = "$app.";
  19         char *provider_name = NULL, *ctx_name = NULL;
  20         size_t i, len, colon_pos = 0, provider_name_len, ctx_name_len;
  21
  22         if (!str || !out_provider_name || !out_ctx_name) {
  23                 goto not_found;
  24         }
  25
  26         len = strlen(str);
  27         if (len <= sizeof(app_ctx_prefix) - 1) {
  28                 goto not_found;
  29         }
  30
  31         /* String starts with $app. */
  32         if (strncmp(str, app_ctx_prefix, sizeof(app_ctx_prefix) - 1)) {
  33                 goto not_found;
  34         }
  35
  36         /* Validate that the ':' separator is present. */
  37         for (i = sizeof(app_ctx_prefix); i < len; i++) {
  38                 const char c = str[i];
  39
  40                 if (c == ':') {
  41                         colon_pos = i;
  42                         break;
  43                 }
  44         }
  45
  46         /*
  47          * No colon found or no ctx name ("$app.provider:") or no provider name
  48          * given ("$app.:..."), which is invalid.
  49          */
  50         if (!colon_pos || colon_pos == len ||
  51                         colon_pos == sizeof(app_ctx_prefix)) {
  52                 goto not_found;
  53         }
  54
  55         provider_name_len = colon_pos - sizeof(app_ctx_prefix) + 2;
  56         provider_name = zmalloc(provider_name_len);
  57         if (!provider_name) {
  58                 PERROR("malloc provider_name");
  59                 goto not_found;
  60         }
  61         strncpy(provider_name, str + sizeof(app_ctx_prefix) - 1,
  62                         provider_name_len - 1);
  63
  64         ctx_name_len = len - colon_pos;
  65         ctx_name = zmalloc(ctx_name_len);
  66         if (!ctx_name) {
  67                 PERROR("malloc ctx_name");
  68                 goto not_found;
  69         }
  70         strncpy(ctx_name, str + colon_pos + 1, ctx_name_len - 1);
  71
  72         *out_provider_name = provider_name;
  73         *out_ctx_name = ctx_name;
  74         return 0;
  75 not_found:
  76         free(provider_name);
  77         free(ctx_name);
  78         return -1;
  79 }
  80