diff options
Diffstat (limited to 'VES5.0/evel/evel-library/code/evel_library/metadata.c')
| -rw-r--r-- | VES5.0/evel/evel-library/code/evel_library/metadata.c | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/VES5.0/evel/evel-library/code/evel_library/metadata.c b/VES5.0/evel/evel-library/code/evel_library/metadata.c new file mode 100644 index 00000000..dfdca052 --- /dev/null +++ b/VES5.0/evel/evel-library/code/evel_library/metadata.c @@ -0,0 +1,607 @@ +/**************************************************************************//** + * @file + * Wrap the OpenStack metadata service. + * + * License + * ------- + * + * Copyright(c) <2016>, AT&T Intellectual Property. All other rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: This product includes + * software developed by the AT&T. + * 4. Neither the name of AT&T nor the names of its contributors may be used to + * endorse or promote products derived from this software without specific + * prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY AT&T INTELLECTUAL PROPERTY ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL AT&T INTELLECTUAL PROPERTY BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + *****************************************************************************/ + +#include <string.h> +#include <assert.h> +#include <malloc.h> + +#include <curl/curl.h> + +#include "evel.h" +#include "evel_internal.h" +#include "jsmn.h" +#include "metadata.h" + +/**************************************************************************//** + * URL on the link-local IP address where we can get the metadata in + * machine-friendly format. + *****************************************************************************/ +static const char * OPENSTACK_METADATA_URL = + "http://169.254.169.254/openstack/latest/meta_data.json"; + +/**************************************************************************//** + * How long we're prepared to wait for the metadata service to respond in + * seconds. + *****************************************************************************/ +static const int OPENSTACK_METADATA_TIMEOUT = 2; + +/**************************************************************************//** + * Size of fields extracted from metadata service. + *****************************************************************************/ +#define MAX_METADATA_STRING 64 + +/**************************************************************************//** + * UUID of the VM extracted from the OpenStack metadata service. + *****************************************************************************/ +static char vm_uuid[MAX_METADATA_STRING+1] = {0}; + +/**************************************************************************//** + * Name of the VM extracted from the OpenStack metadata service. + *****************************************************************************/ +static char vm_name[MAX_METADATA_STRING+1] = {0}; + +/**************************************************************************//** + * How many metadata elements we allow for in the retrieved JSON. + *****************************************************************************/ +static const int MAX_METADATA_TOKENS = 128; + +/*****************************************************************************/ +/* Local prototypes. */ +/*****************************************************************************/ +static EVEL_ERR_CODES json_get_top_level_string(const char * json_string, + const jsmntok_t *tokens, + int json_token_count, + const char * key, + char * value); +static EVEL_ERR_CODES json_get_string(const char * json_string, + const jsmntok_t *tokens, + int json_token_count, + const char * key, + char * value); +static int jsoneq(const char *json, const jsmntok_t *tok, const char *s); + +/**************************************************************************//** + * Download metadata from the OpenStack metadata service. + * + * @param verbosity Controls whether to generate debug to stdout. Zero: + * none. Non-zero: generate debug. + * @returns Status code + * @retval EVEL_SUCCESS On success + * @retval ::EVEL_ERR_CODES On failure. + *****************************************************************************/ +EVEL_ERR_CODES openstack_metadata(int verbosity) +{ + int rc = EVEL_SUCCESS; + CURLcode curl_rc = CURLE_OK; + CURL * curl_handle = NULL; + MEMORY_CHUNK rx_chunk; + char curl_err_string[CURL_ERROR_SIZE] = "<NULL>"; + jsmn_parser json_parser; + jsmntok_t tokens[MAX_METADATA_TOKENS]; + int json_token_count = 0; + + EVEL_ENTER(); + + /***************************************************************************/ + /* Initialize dummy values for the metadata - needed for test */ + /* environments. */ + /***************************************************************************/ + openstack_metadata_initialize(); + + /***************************************************************************/ + /* Get a curl handle which we'll use for accessing the metadata service. */ + /***************************************************************************/ + curl_handle = curl_easy_init(); + if (curl_handle == NULL) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to get libcurl handle"); + goto exit_label; + } + + /***************************************************************************/ + /* Prime the library to give friendly error codes. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, + CURLOPT_ERRORBUFFER, + curl_err_string); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to initialize libcurl to provide friendly errors. " + "Error code=%d", curl_rc); + goto exit_label; + } + + /***************************************************************************/ + /* Set the URL for the metadata API. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, CURLOPT_URL, OPENSTACK_METADATA_URL); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to initialize libcurl with the API URL. " + "Error code=%d (%s)", curl_rc, curl_err_string); + goto exit_label; + } + + /***************************************************************************/ + /* send all data to this function. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, + CURLOPT_WRITEFUNCTION, + evel_write_callback); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to initialize libcurl with the write callback. " + "Error code=%d (%s)", curl_rc, curl_err_string); + goto exit_label; + } + + /***************************************************************************/ + /* some servers don't like requests that are made without a user-agent */ + /* field, so we provide one. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, + CURLOPT_USERAGENT, + "libcurl-agent/1.0"); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to initialize libcurl to upload. Error code=%d (%s)", + curl_rc, curl_err_string); + goto exit_label; + } + + /***************************************************************************/ + /* Set the timeout for the operation. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, + CURLOPT_TIMEOUT, + OPENSTACK_METADATA_TIMEOUT); + if (curl_rc != CURLE_OK) + { + rc = EVEL_NO_METADATA; + EVEL_ERROR("Failed to initialize libcurl to set timeout. " + "Error code=%d (%s)", curl_rc, curl_err_string); + goto exit_label; + } + + /***************************************************************************/ + /* Create the memory chunk to be used for the response to the post. The */ + /* will be realloced. */ + /***************************************************************************/ + rx_chunk.memory = malloc(1); + assert(rx_chunk.memory != NULL); + rx_chunk.size = 0; + + /***************************************************************************/ + /* Point to the data to be received. */ + /***************************************************************************/ + curl_rc = curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&rx_chunk); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to initialize libcurl to receive metadata. " + "Error code=%d (%s)", curl_rc, curl_err_string); + goto exit_label; + } + EVEL_DEBUG("Initialized data to receive"); + + /***************************************************************************/ + /* If running in verbose mode generate more output. */ + /***************************************************************************/ + if (verbosity > 0) + { + curl_rc = curl_easy_setopt(curl_handle, CURLOPT_VERBOSE, 1L); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + log_error_state("Failed to initialize libcurl to be verbose. " + "Error code=%d", curl_rc); + goto exit_label; + } + } + + /***************************************************************************/ + /* Now run off and do what you've been told! */ + /***************************************************************************/ + curl_rc = curl_easy_perform(curl_handle); + if (curl_rc != CURLE_OK) + { + rc = EVEL_CURL_LIBRARY_FAIL; + EVEL_ERROR("Failed to transfer the data from metadata service. " + "Error code=%d (%s)", curl_rc, curl_err_string); + } + else + { + /*************************************************************************/ + /* We have some metadata available, so break it out into tokens. */ + /*************************************************************************/ + EVEL_DEBUG("Received metadata size = %d", rx_chunk.size); + EVEL_INFO("Received metadata = %s", rx_chunk.memory); + jsmn_init(&json_parser); + json_token_count = jsmn_parse(&json_parser, + rx_chunk.memory, rx_chunk.size, + tokens, MAX_METADATA_TOKENS); + + /*************************************************************************/ + /* Check that we parsed some data and that the top level is as expected. */ + /*************************************************************************/ + if (json_token_count < 0 || tokens[0].type != JSMN_OBJECT) + { + rc = EVEL_BAD_METADATA; + EVEL_ERROR("Failed to parse received JSON OpenStack metadata. " + "Error code=%d", json_token_count); + goto exit_label; + } + else + { + EVEL_DEBUG("Extracted %d tokens from the JSON OpenStack metadata. ", + json_token_count); + } + + /*************************************************************************/ + /* Find the keys we want from the metadata. */ + /*************************************************************************/ + if (json_get_string(rx_chunk.memory, + tokens, + json_token_count, + "uuid", + vm_uuid) != EVEL_SUCCESS) + { + rc = EVEL_BAD_METADATA; + EVEL_ERROR("Failed to extract UUID from OpenStack metadata"); + } + else + { + EVEL_DEBUG("UUID: %s", vm_uuid); + } + if (json_get_top_level_string(rx_chunk.memory, + tokens, + json_token_count, + "name", + vm_name) != EVEL_SUCCESS) + { + rc = EVEL_BAD_METADATA; + EVEL_ERROR("Failed to extract VM Name from OpenStack metadata"); + } + else + { + EVEL_DEBUG("VM Name: %s", vm_name); + } + } + +exit_label: + + /***************************************************************************/ + /* Shut down the cURL library in a tidy manner. */ + /***************************************************************************/ + if (curl_handle != NULL) + { + curl_easy_cleanup(curl_handle); + curl_handle = NULL; + } + free(rx_chunk.memory); + + EVEL_EXIT(); + return rc; +} + +/**************************************************************************//** + * Initialize default values for vm_name and vm_uuid - for testing purposes. + *****************************************************************************/ +void openstack_metadata_initialize() +{ + strncpy(vm_uuid, + "Dummy VM UUID - No Metadata available", + MAX_METADATA_STRING); + strncpy(vm_name, + "Dummy VM name - No Metadata available", + MAX_METADATA_STRING); +} + +/**************************************************************************//** + * Get a string value from supplied JSON by matching the key. + * + * As the structure of the metadata we're looking at is pretty straightforward + * we don't do anything complex (a la XPath) to extract nested keys with the + * same leaf name, for example. Simply walk the structure until we find a + * string with the correct value. + * + * @param[in] json_string The string which contains the JSON and has already + * been parsed. + * @param[in] tokens The tokens which the JSON parser found in the JSON. + * @param[in] json_token_count How many tokens were found. + * @param[in] key The key we're looking for. + * @param[out] value The string we found at @p key. + * + * @returns Status code + * @retval EVEL_SUCCESS On success - contents of @p value updated. + * @retval EVEL_JSON_KEY_NOT_FOUND Key not found - @p value not updated. + * @retval EVEL_BAD_JSON Parser hit unexpected data - @p value not + * updated. + *****************************************************************************/ +static EVEL_ERR_CODES json_get_string(const char * json_string, + const jsmntok_t * tokens, + int json_token_count, + const char * key, + char * value) +{ + EVEL_ERR_CODES rc = EVEL_JSON_KEY_NOT_FOUND; + int token_num = 0; + int token_len = 0; + + EVEL_ENTER(); + + /***************************************************************************/ + /* Check assumptions. */ + /***************************************************************************/ + assert(json_string != NULL); + assert(tokens != NULL); + assert(json_token_count >= 0); + assert(key != NULL); + assert(value != NULL); + + for (token_num = 0; token_num < json_token_count; token_num++) + { + switch(tokens[token_num].type) + { + case JSMN_OBJECT: + EVEL_DEBUG("Skipping object"); + break; + + case JSMN_ARRAY: + EVEL_DEBUG("Skipping array"); + break; + + case JSMN_STRING: + /***********************************************************************/ + /* This is a string, so may be what we want. Compare keys. */ + /***********************************************************************/ + if (jsoneq(json_string, &tokens[token_num], key) == 0) + { + token_len = tokens[token_num + 1].end - tokens[token_num + 1].start; + EVEL_DEBUG("Token %d len %d matches at %d to %d", token_num, + tokens[token_num + 1].start, + tokens[token_num + 1].end); + strncpy(value, json_string + tokens[token_num + 1].start, token_len); + value[token_len] = '\0'; + EVEL_DEBUG("Extracted key: \"%s\" Value: \"%s\"", key, value); + rc = EVEL_SUCCESS; + goto exit_label; + } + else + { + EVEL_DEBUG("String key did not match"); + } + + /***********************************************************************/ + /* Step over the value, whether we used it or not. */ + /***********************************************************************/ + token_num++; + break; + + case JSMN_PRIMITIVE: + EVEL_INFO("Skipping primitive"); + break; + + case JSMN_UNDEFINED: + default: + rc = EVEL_BAD_JSON_FORMAT; + EVEL_ERROR("Unexpected JSON format at token %d (%d)", + token_num, + tokens[token_num].type); + goto exit_label; + } + } + +exit_label: + EVEL_EXIT(); + return rc; +} + +/**************************************************************************//** + * Get a top-level string value from supplied JSON by matching the key. + * + * Unlike json_get_string, this only returns a value that is in the top-level + * JSON object. + * + * @param[in] json_string The string which contains the JSON and has already + * been parsed. + * @param[in] tokens The tokens which the JSON parser found in the JSON. + * @param[in] json_token_count How many tokens were found. + * @param[in] key The key we're looking for. + * @param[out] value The string we found at @p key. + * + * @returns Status code + * @retval EVEL_SUCCESS On success - contents of @p value updated. + * @retval EVEL_JSON_KEY_NOT_FOUND Key not found - @p value not updated. + * @retval EVEL_BAD_JSON Parser hit unexpected data - @p value not + * updated. + *****************************************************************************/ +static EVEL_ERR_CODES json_get_top_level_string(const char * json_string, + const jsmntok_t * tokens, + int json_token_count, + const char * key, + char * value) +{ + EVEL_ERR_CODES rc = EVEL_JSON_KEY_NOT_FOUND; + int token_num = 0; + int token_len = 0; + int bracket_count = 0; + int string_index = 0; + int increment = 0; + + EVEL_ENTER(); + + /***************************************************************************/ + /* Check assumptions. */ + /***************************************************************************/ + assert(json_string != NULL); + assert(tokens != NULL); + assert(json_token_count >= 0); + assert(key != NULL); + assert(value != NULL); + + for (token_num = 0; token_num < json_token_count; token_num++) + { + switch(tokens[token_num].type) + { + case JSMN_OBJECT: + EVEL_DEBUG("Skipping object"); + break; + + case JSMN_ARRAY: + EVEL_DEBUG("Skipping array"); + break; + + case JSMN_STRING: + /***********************************************************************/ + /* This is a string, so may be what we want. Compare keys. */ + /***********************************************************************/ + if (jsoneq(json_string, &tokens[token_num], key) == 0) + { + /*********************************************************************/ + /* Count the difference in the number of opening and closing */ + /* brackets up to this token. This needs to be 1 for a top-level */ + /* string. Let's just hope we don't have any strings containing */ + /* brackets. */ + /*********************************************************************/ + increment = ((string_index < tokens[token_num].start) ? 1 : -1); + + while (string_index != tokens[token_num].start) + { + if (json_string[string_index] == '{') + { + bracket_count += increment; + } + else if (json_string[string_index] == '}') + { + bracket_count -= increment; + } + + string_index += increment; + } + + if (bracket_count == 1) + { + token_len = tokens[token_num + 1].end - tokens[token_num + 1].start; + EVEL_DEBUG("Token %d len %d matches at top level at %d to %d", + token_num, + tokens[token_num + 1].start, + tokens[token_num + 1].end); + strncpy(value, json_string + tokens[token_num + 1].start, token_len); + value[token_len] = '\0'; + EVEL_DEBUG("Extracted key: \"%s\" Value: \"%s\"", key, value); + rc = EVEL_SUCCESS; + goto exit_label; + } + else + { + EVEL_DEBUG("String key did match, but not at top level"); + } + } + else + { + EVEL_DEBUG("String key did not match"); + } + + /***********************************************************************/ + /* Step over the value, whether we used it or not. */ + /***********************************************************************/ + token_num++; + break; + + case JSMN_PRIMITIVE: + EVEL_INFO("Skipping primitive"); + break; + + case JSMN_UNDEFINED: + default: + rc = EVEL_BAD_JSON_FORMAT; + EVEL_ERROR("Unexpected JSON format at token %d (%d)", + token_num, + tokens[token_num].type); + goto exit_label; + } + } + +exit_label: + EVEL_EXIT(); + return rc; +} + +/**************************************************************************//** + * Compare a JSON string token with a value. + * + * @param[in] json The string which contains the JSON and has already been + * parsed. + * @param[in] tok The token which the JSON parser found in the JSON. + * @param[in] s The string we're looking for. + * + * @returns Whether the token matches the string or not. + * @retval 0 Value matches + * @retval -1 Value does not match. + *****************************************************************************/ +static int jsoneq(const char *json, const jsmntok_t *tok, const char *s) { + if (tok->type == JSMN_STRING && (int) strlen(s) == tok->end - tok->start && + strncmp(json + tok->start, s, tok->end - tok->start) == 0) { + return 0; + } + return -1; +} + +/**************************************************************************//** + * Get the VM name provided by the metadata service. + * + * @returns VM name + *****************************************************************************/ +const char *openstack_vm_name() +{ + return vm_name; +} + +/**************************************************************************//** + * Get the VM UUID provided by the metadata service. + * + * @returns VM UUID + *****************************************************************************/ +const char *openstack_vm_uuid() +{ + return vm_uuid; +} |