diff options
Diffstat (limited to 'common/elapi/elapi_sink.c')
| -rw-r--r-- | common/elapi/elapi_sink.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/common/elapi/elapi_sink.c b/common/elapi/elapi_sink.c new file mode 100644 index 00000000..3908c3ad --- /dev/null +++ b/common/elapi/elapi_sink.c @@ -0,0 +1,500 @@ +/* + ELAPI + + Module that contains functions that manipulate ELAPI sinks. + + Copyright (C) Dmitri Pal <dpal@redhat.com> 2009 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#define _GNU_SOURCE +#include <sys/types.h> /* for stat() */ +#include <errno.h> /* for errors */ +#include <string.h> /* for memset() and other */ +#include <stdlib.h> /* for free() */ +#include <stdarg.h> /* for va_arg */ +#include <dlfcn.h> /* for dlopen() */ + +#include "elapi_priv.h" +#include "ini_config.h" +#include "file_provider.h" +#include "trace.h" +#include "config.h" + +/* NOTE: Add new provider names here */ +const char *providers[] = { ELAPI_EMB_PRVDR_FILE, + ELAPI_EMB_PRVDR_STDERR, + ELAPI_EMB_PRVDR_SYSLOG, + NULL }; + + +/* This is a traverse callback for sink list */ +int elapi_sink_cb(const char *sink, + int sink_len, + int type, + void *data, + int length, + void *passed_data, + int *stop) +{ + TRACE_FLOW_STRING("elapi_sink_cb", "Entry."); + + /* FIXME THIS IS A PLACEHOLDER FUNCTION FOR NOW */ + + /* Skip header */ + if (type == COL_TYPE_COLLECTION) { + TRACE_FLOW_STRING("elapi_sink_cb - skip header", "Exit."); + return EOK; + } + + printf("Sink: %s\n", sink); + + TRACE_FLOW_STRING("elapi_sink_cb", "Exit."); + return EOK; +} + +/* Destroy sink */ +void elapi_sink_destroy(struct elapi_sink_ctx *context) +{ + TRACE_FLOW_STRING("elapi_sink_destroy", "Entry."); + +#ifdef ELAPI_UTEST + /* FIXME: Can be removeed when the interface is stable */ + /* For testing purposes print the context we are trying to free */ + elapi_print_sink_ctx(context); +#endif + + if (context) { + TRACE_INFO_STRING("Context is not null.", "Destroying sink."); + /* FIXME: Do something about pending data if any */ + /* Assume for now that we do not care about pending data */ + + /* If the private data has been allocated and close callback is there + * call a callback to clean the data and free it. + */ + if (context->sink_cfg.priv_ctx) { + TRACE_INFO_STRING("Calling provider's close function.", ""); + /* Call close function of the provider */ + context->sink_cfg.cpb_cb.close_cb(&(context->sink_cfg.priv_ctx)); + } + + /* Now if the handle of the provider is set, offload the library instance */ + if (context->sink_cfg.libhandle) { + TRACE_INFO_STRING("Offloading shared library.", ""); + dlclose(context->sink_cfg.libhandle); + context->sink_cfg.libhandle = NULL; + } + + if (context->sink_cfg.provider) { + TRACE_INFO_STRING("Cleaning provider.", ""); + free(context->sink_cfg.provider); + context->sink_cfg.provider = NULL; + } + + TRACE_INFO_STRING("Freeing context", ""); + free(context); + } + + TRACE_FLOW_STRING("elapi_sink_destroy", "Exit."); +} + +/* Internal sink cleanup function */ +int elapi_sink_free_cb(const char *sink, + int sink_len, + int type, + void *data, + int length, + void *passed_data, + int *stop) +{ + TRACE_FLOW_STRING("elapi_sink_free_cb", "Entry."); + + /* Skip header */ + if (type == COL_TYPE_COLLECTION) { + TRACE_FLOW_STRING("elapi_sink_free_cb - skip header", "Exit."); + return EOK; + } + + TRACE_INFO_STRING("Cleaning Sink:", sink); + + elapi_sink_destroy(*((struct elapi_sink_ctx **)(data))); + + TRACE_FLOW_STRING("elapi_sink_free_cb", "Exit."); + return EOK; +} + +/* Function to read sink common configuration */ +static int elapi_read_sink_cfg(struct elapi_sink_cfg *sink_cfg, + char *name, + struct collection_item *ini_config) +{ + int error = EOK; + struct collection_item *cfg_item = NULL; + const char *provider; + + TRACE_FLOW_STRING("elapi_read_sink_cfg", "Entry point"); + + /*********** Provider *************/ + + /* First check if this sink is properly configured and get its provider */ + error = get_config_item(name, + ELAPI_SINK_PROVIDER, + ini_config, + &cfg_item); + if (error) { + TRACE_ERROR_NUMBER("Attempt to read \"provider\" attribute returned error", error); + return error; + } + + /* Do we have provider? */ + if (cfg_item == NULL) { + /* There is no provider - return error */ + TRACE_ERROR_STRING("Required key is missing in the configuration.", "Fatal Error!"); + return ENOENT; + } + + /* Get provider value */ + provider = get_const_string_config_value(cfg_item, &error); + if ((error) || (!provider)) { + TRACE_ERROR_STRING("Invalid \"provider\" value", "Fatal Error!"); + return EINVAL; + } + + /* Save provider inside configuration data */ + sink_cfg->provider = strdup(provider); + if (sink_cfg->provider == NULL) { + /* Failed to save the provider value */ + TRACE_ERROR_STRING("Failed to save \"provider\" value.", "Fatal Error!"); + return ENOMEM; + } + + /*********** Required *************/ + /* Next is "required" field */ + cfg_item = NULL; + error = get_config_item(name, + ELAPI_SINK_REQUIRED, + ini_config, + &cfg_item); + if (error) { + TRACE_ERROR_NUMBER("Attempt to read \"required\" attribute returned error", error); + return error; + } + + /* Do we have "required"? */ + if (cfg_item == NULL) { + /* There is no attribute - assume default */ + TRACE_INFO_STRING("No \"required\" attribute.", "Assume optional"); + sink_cfg->required = 0; + } + else { + sink_cfg->required = (uint32_t) get_bool_config_value(cfg_item, '\0', &error); + if (error) { + TRACE_ERROR_STRING("Invalid \"required\" value", "Fatal Error!"); + return EINVAL; + } + } + + /*********** Onerror *************/ + /* Next is "onerror" field */ + cfg_item = NULL; + error = get_config_item(name, + ELAPI_SINK_ONERROR, + ini_config, + &cfg_item); + if (error) { + TRACE_ERROR_NUMBER("Attempt to read \"onerror\" attribute returned error", error); + return error; + } + + /* Do we have "required"? */ + if (cfg_item == NULL) { + /* There is no attribute - assume default */ + TRACE_INFO_STRING("No \"onerror\" attribute.", "Assume retry (0)"); + sink_cfg->onerror = 0; + } + else { + sink_cfg->onerror = (uint32_t) get_unsigned_config_value(cfg_item, 1, 0, &error); + if (error) { + TRACE_ERROR_STRING("Invalid \"onerror\" value", "Fatal Error!"); + return EINVAL; + } + } + + /*********** Timeout *************/ + /* Next is "timeout" field */ + cfg_item = NULL; + error = get_config_item(name, + ELAPI_SINK_TIMEOUT, + ini_config, + &cfg_item); + if (error) { + TRACE_ERROR_NUMBER("Attempt to read \"timeout\" attribute returned error", error); + return error; + } + + /* Do we have "required"? */ + if (cfg_item == NULL) { + /* There is no attribute - assume default */ + TRACE_INFO_STRING("No \"timeout\" attribute.", "Assume default timeout"); + sink_cfg->timeout = ELAPI_SINK_DEFAULT_TIMEOUT; + } + else { + sink_cfg->timeout = (uint32_t) get_unsigned_config_value(cfg_item, + 1, + ELAPI_SINK_DEFAULT_TIMEOUT, + &error); + if (error) { + TRACE_ERROR_STRING("Invalid \"timeout\" value", "Fatal Error!"); + return EINVAL; + } + } + + /*********** Synch *************/ + /* Next is "synch" field */ + cfg_item = NULL; + error = get_config_item(name, + ELAPI_SINK_SYNCH, + ini_config, + &cfg_item); + if (error) { + TRACE_ERROR_NUMBER("Attempt to read \"synch\" attribute returned error", error); + return error; + } + + /* Do we have "required"? */ + if (cfg_item == NULL) { + /* There is no attribute - assume default */ + TRACE_INFO_STRING("No \"synch\" attribute.", "Assume retry (0)"); + sink_cfg->synch = 0; + } + else { + sink_cfg->synch = (uint32_t) get_bool_config_value(cfg_item, '\0', &error); + if (error) { + TRACE_ERROR_STRING("Invalid \"synch\" value", "Fatal Error!"); + return EINVAL; + } + } + + TRACE_FLOW_STRING("elapi_read_sink_cfg", "Exit"); + return error; +} + +/* Function to load external sink library */ +static int elapi_load_lib(void **libhandle, sink_cpb_fn *sink_fn, char *name) +{ + char sink_lib_name[SINK_LIB_NAME_SIZE]; + sink_cpb_fn sink_symbol = NULL; + void *handle = NULL; + char *lib_error = NULL; + + TRACE_FLOW_STRING("elapi_load_lib", "Entry point"); + + if ((strlen(name) + sizeof(SINK_NAME_TEMPLATE)) >= SINK_LIB_NAME_SIZE) { + TRACE_ERROR_STRING("Provider string is too long:", name); + return EINVAL; + } + + sprintf(sink_lib_name, SINK_NAME_TEMPLATE, name); + TRACE_INFO_STRING("Name of the library to try to load:", sink_lib_name); + + /* Load library */ + handle = dlopen(sink_lib_name, RTLD_LAZY); + if (!handle) { + TRACE_ERROR_STRING("Dlopen returned error", dlerror()); + return ELIBACC; + } + + /* Clear any existing error */ + dlerror(); + /* Get addres to the main entry point */ + sink_symbol = (sink_cpb_fn)(dlsym(handle, SINK_ENTRY_POINT)); + if ((lib_error = dlerror()) != NULL) { + TRACE_ERROR_STRING("Dlsym returned error", lib_error); + dlclose(handle); + return ELIBACC; + } + + *libhandle = handle; + *sink_fn = sink_symbol; + + TRACE_FLOW_STRING("elapi_load_lib", "Exit"); + return EOK; +} + +/* Function to load sink provider */ +int elapi_sink_loader(struct elapi_sink_cfg *sink_cfg) +{ + int error = EOK; + int num = 0; + + TRACE_FLOW_STRING("elapi_sink_loader", "Entry point"); + + while (providers[num]) { + TRACE_INFO_STRING("Checking provider:", providers[num]); + if (strcasecmp(providers[num], sink_cfg->provider) == 0) break; + num++; + } + + TRACE_INFO_NUMBER("Provider number:", num); + + /* NOTE: Add provider handler into the switch below */ + switch (num) { + case ELAPI_EMB_PRVDR_FILENUM: + TRACE_INFO_STRING("Using \"file\" provider:", ""); + sink_cfg->ability = file_ability; + break; +/* FIXME: Not implemented yet + case ELAPI_EMB_PRVDR_STDERRNUM: + TRACE_INFO_STRING("Using \"stderr\" provider:", ""); + sink_cfg->ability = stderr_ability; + break; + case ELAPI_EMB_PRVDR_SYSLOGNUM: + TRACE_INFO_STRING("Using \"syslog\" provider:", ""); + sink_cfg->ability = syslog_ability; + break; +*/ + default: + /* It is an external provider */ + error = elapi_load_lib(&(sink_cfg->libhandle), &(sink_cfg->ability), sink_cfg->provider); + if (error) { + TRACE_ERROR_NUMBER("Failed to load library", error); + return error; + } + break; + } + + TRACE_FLOW_STRING("elapi_sink_loader", "Exit"); + return error; +} + + +/* Function to load sink provider */ +int elapi_load_sink(struct elapi_sink_cfg *sink_cfg, + char *name, + struct collection_item *ini_config) +{ + int error = EOK; + TRACE_FLOW_STRING("elapi_load_sink", "Entry point"); + + /* Use sink loading wrapper */ + error = elapi_sink_loader(sink_cfg); + if (error) { + TRACE_ERROR_NUMBER("Failed to load sink", error); + return error; + } + + /* Call ability function to fill in the pointers */ + sink_cfg->ability(&(sink_cfg->cpb_cb)); + + /* Make sure the callbacks are initialized */ + if ((sink_cfg->cpb_cb.init_cb == NULL) || + (sink_cfg->cpb_cb.submit_cb == NULL) || + (sink_cfg->cpb_cb.close_cb == NULL)) { + TRACE_ERROR_NUMBER("One of the callbacks is missing", + "Bad provider!"); + return EINVAL; + } + + + /* Call init entry point */ + /* NOTE: it is the responsibility of the provider + * to enforce singleton in case provider can't + * be loaded more than once like syslog for example. + */ + error = sink_cfg->cpb_cb.init_cb(&(sink_cfg->priv_ctx), + name, + ini_config); + if (error) { + TRACE_ERROR_NUMBER("Failed to initalize sink", error); + return error; + } + + TRACE_FLOW_STRING("elapi_load_sink", "Exit"); + return error; + +} + +/* Function to create a sink */ +int elapi_sink_create(struct elapi_sink_ctx **sink_ctx, + char *name, + struct collection_item *ini_config) +{ + int error = EOK; + uint32_t required; + struct elapi_sink_ctx *sink_context = NULL; + + TRACE_FLOW_STRING("elapi_sink_create", "Entry point"); + + /* Allocate context */ + sink_context = (struct elapi_sink_ctx *)malloc(sizeof(struct elapi_sink_ctx)); + if (sink_context == NULL) { + TRACE_ERROR_NUMBER("Memory allocation failed. Error", ENOMEM); + return ENOMEM; + } + + /* Initialize the allocatable items so that we can call destroy function + * in case of error. + * FIXME - add initialization here for other elements as they are added. + */ + + sink_context->async_mode = 0; + sink_context->in_queue = NULL; + sink_context->pending = NULL; + sink_context->sink_cfg.provider = NULL; + sink_context->sink_cfg.priv_ctx = NULL; + sink_context->sink_cfg.libhandle = NULL; + sink_context->sink_cfg.ability = NULL; + sink_context->sink_cfg.cpb_cb.init_cb = NULL; + sink_context->sink_cfg.cpb_cb.submit_cb = NULL; + sink_context->sink_cfg.cpb_cb.close_cb = NULL; + + /* Read common fields */ + error = elapi_read_sink_cfg(&(sink_context->sink_cfg), + name, ini_config); + if (error) { + TRACE_ERROR_NUMBER("Failed to read sink configuration", error); + elapi_sink_destroy(sink_context); + return error; + } + + TRACE_INFO_NUMBER("Address of init function", + sink_context->sink_cfg.cpb_cb.init_cb); + TRACE_INFO_NUMBER("Address of submit function", + sink_context->sink_cfg.cpb_cb.submit_cb); + TRACE_INFO_NUMBER("Address of close function", + sink_context->sink_cfg.cpb_cb.close_cb); + + /* Load sink */ + error = elapi_load_sink(&(sink_context->sink_cfg), + name, ini_config); + if (error) { + TRACE_ERROR_NUMBER("Failed to load sink", error); + required = sink_context->sink_cfg.required; + elapi_sink_destroy(sink_context); + if (required) { + TRACE_ERROR_NUMBER("Sink is required so returning error", error); + return error; + } + else { + *sink_ctx = NULL; + TRACE_FLOW_STRING("Sink is not required so OK", "Exit"); + return EOK; + } + } + + /* We are done so return the context to the caller */ + *sink_ctx = sink_context; + + TRACE_FLOW_STRING("elapi_sink_create", "Exit"); + return error; +} |