event.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007 - 2008, Digium, Inc.
 *
 * Russell Bryant <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Internal generic event system
 *
 * \author Russell Bryant <[email protected]>
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/_private.h"

#include "asterisk/event.h"
#include "asterisk/linkedlists.h"
#include "asterisk/dlinkedlists.h"
#include "asterisk/lock.h"
#include "asterisk/utils.h"
#include "asterisk/unaligned.h"
#include "asterisk/utils.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/astobj2.h"
#include "asterisk/cli.h"

/*!
 * \brief An event information element
 *
 * \note The format of this structure is important. Since these events may
 * be sent directly over a network, changing this structure will break
 * compatibility with older versions. However, at this point, this code
 * has not made it into a release, so it is still fair game for change.
 */
struct ast_event_ie {
 enum ast_event_ie_type ie_type:16;
 /*! Total length of the IE payload */
 uint16_t ie_payload_len;
 unsigned char ie_payload[0];
} __attribute__((packed));

/*!
 * \brief The payload for a string information element
 */
struct ast_event_ie_str_payload {
 /*! \brief A hash calculated with ast_str_hash(), to speed up comparisons */
 uint32_t hash;
 /*! \brief The actual string, null terminated */
 char str[1];
} __attribute__((packed));

/*!
 * \brief An event
 *
 * An ast_event consists of an event header (this structure), and zero or
 * more information elements defined by ast_event_ie.
 *
 * \note The format of this structure is important. Since these events may
 * be sent directly over a network, changing this structure will break
 * compatibility with older versions. However, at this point, this code
 * has not made it into a release, so it is still fair game for change.
 */
struct ast_event {
 /*! Event type */
 enum ast_event_type type:16;
 /*! Total length of the event */
 uint16_t event_len:16;
 /*! The data payload of the event, made up of information elements */
 unsigned char payload[0];
} __attribute__((packed));


struct ast_event_ie_val {
 AST_LIST_ENTRY(ast_event_ie_val) entry;
 enum ast_event_ie_type ie_type;
 enum ast_event_ie_pltype ie_pltype;
 union {
 uint32_t uint;
 struct {
 uint32_t hash;
 const char *str;
 };
 void *raw;
 } payload;
 size_t raw_datalen;
};

/*!
 * \brief Event Names
 */
static const char * const event_names[AST_EVENT_TOTAL] = {
 [AST_EVENT_ALL] = "All",
 [AST_EVENT_CUSTOM] = "Custom",
 [AST_EVENT_MWI] = "MWI",
 [AST_EVENT_SUB] = "Subscription",
 [AST_EVENT_UNSUB] = "Unsubscription",
 [AST_EVENT_DEVICE_STATE] = "DeviceState",
 [AST_EVENT_DEVICE_STATE_CHANGE] = "DeviceStateChange",
 [AST_EVENT_CEL] = "CEL",
 [AST_EVENT_SECURITY] = "Security",
 [AST_EVENT_NETWORK_CHANGE] = "NetworkChange",
 [AST_EVENT_PRESENCE_STATE] = "PresenceState",
 [AST_EVENT_ACL_CHANGE] = "ACLChange",
 [AST_EVENT_PING] = "Ping",
};

/*!
 * \brief IE payload types and names
 */
static const struct ie_map {
 enum ast_event_ie_pltype ie_pltype;
 const char *name;
} ie_maps[AST_EVENT_IE_TOTAL] = {
 [AST_EVENT_IE_NEWMSGS] = { AST_EVENT_IE_PLTYPE_UINT, "NewMessages" },
 [AST_EVENT_IE_OLDMSGS] = { AST_EVENT_IE_PLTYPE_UINT, "OldMessages" },
 [AST_EVENT_IE_MAILBOX] = { AST_EVENT_IE_PLTYPE_STR, "Mailbox" },
 [AST_EVENT_IE_UNIQUEID] = { AST_EVENT_IE_PLTYPE_UINT, "UniqueID" },
 [AST_EVENT_IE_EVENTTYPE] = { AST_EVENT_IE_PLTYPE_UINT, "EventType" },
 [AST_EVENT_IE_EXISTS] = { AST_EVENT_IE_PLTYPE_UINT, "Exists" },
 [AST_EVENT_IE_DEVICE] = { AST_EVENT_IE_PLTYPE_STR, "Device" },
 [AST_EVENT_IE_STATE] = { AST_EVENT_IE_PLTYPE_UINT, "State" },
 [AST_EVENT_IE_CONTEXT] = { AST_EVENT_IE_PLTYPE_STR, "Context" },
 [AST_EVENT_IE_EID] = { AST_EVENT_IE_PLTYPE_RAW, "EntityID" },
 [AST_EVENT_IE_CEL_EVENT_TYPE] = { AST_EVENT_IE_PLTYPE_UINT, "CELEventType" },
 [AST_EVENT_IE_CEL_EVENT_TIME] = { AST_EVENT_IE_PLTYPE_UINT, "CELEventTime" },
 [AST_EVENT_IE_CEL_EVENT_TIME_USEC] = { AST_EVENT_IE_PLTYPE_UINT, "CELEventTimeUSec" },
 [AST_EVENT_IE_CEL_USEREVENT_NAME] = { AST_EVENT_IE_PLTYPE_STR, "CELUserEventName" },
 [AST_EVENT_IE_CEL_CIDNAME] = { AST_EVENT_IE_PLTYPE_STR, "CELCIDName" },
 [AST_EVENT_IE_CEL_CIDNUM] = { AST_EVENT_IE_PLTYPE_STR, "CELCIDNum" },
 [AST_EVENT_IE_CEL_EXTEN] = { AST_EVENT_IE_PLTYPE_STR, "CELExten" },
 [AST_EVENT_IE_CEL_CONTEXT] = { AST_EVENT_IE_PLTYPE_STR, "CELContext" },
 [AST_EVENT_IE_CEL_CHANNAME] = { AST_EVENT_IE_PLTYPE_STR, "CELChanName" },
 [AST_EVENT_IE_CEL_APPNAME] = { AST_EVENT_IE_PLTYPE_STR, "CELAppName" },
 [AST_EVENT_IE_CEL_APPDATA] = { AST_EVENT_IE_PLTYPE_STR, "CELAppData" },
 [AST_EVENT_IE_CEL_AMAFLAGS] = { AST_EVENT_IE_PLTYPE_UINT, "CELAMAFlags" },
 [AST_EVENT_IE_CEL_ACCTCODE] = { AST_EVENT_IE_PLTYPE_STR, "CELAcctCode" },
 [AST_EVENT_IE_CEL_UNIQUEID] = { AST_EVENT_IE_PLTYPE_STR, "CELUniqueID" },
 [AST_EVENT_IE_CEL_USERFIELD] = { AST_EVENT_IE_PLTYPE_STR, "CELUserField" },
 [AST_EVENT_IE_CEL_CIDANI] = { AST_EVENT_IE_PLTYPE_STR, "CELCIDani" },
 [AST_EVENT_IE_CEL_CIDRDNIS] = { AST_EVENT_IE_PLTYPE_STR, "CELCIDrdnis" },
 [AST_EVENT_IE_CEL_CIDDNID] = { AST_EVENT_IE_PLTYPE_STR, "CELCIDdnid" },
 [AST_EVENT_IE_CEL_PEER] = { AST_EVENT_IE_PLTYPE_STR, "CELPeer" },
 [AST_EVENT_IE_CEL_LINKEDID] = { AST_EVENT_IE_PLTYPE_STR, "CELLinkedID" },
 [AST_EVENT_IE_CEL_PEERACCT] = { AST_EVENT_IE_PLTYPE_STR, "CELPeerAcct" },
 [AST_EVENT_IE_CEL_EXTRA] = { AST_EVENT_IE_PLTYPE_STR, "CELExtra" },
 [AST_EVENT_IE_SECURITY_EVENT] = { AST_EVENT_IE_PLTYPE_UINT, "SecurityEvent" },
 [AST_EVENT_IE_EVENT_VERSION] = { AST_EVENT_IE_PLTYPE_UINT, "EventVersion" },
 [AST_EVENT_IE_SERVICE] = { AST_EVENT_IE_PLTYPE_STR, "Service" },
 [AST_EVENT_IE_MODULE] = { AST_EVENT_IE_PLTYPE_STR, "Module" },
 [AST_EVENT_IE_ACCOUNT_ID] = { AST_EVENT_IE_PLTYPE_STR, "AccountID" },
 [AST_EVENT_IE_SESSION_ID] = { AST_EVENT_IE_PLTYPE_STR, "SessionID" },
 [AST_EVENT_IE_SESSION_TV] = { AST_EVENT_IE_PLTYPE_STR, "SessionTV" },
 [AST_EVENT_IE_ACL_NAME] = { AST_EVENT_IE_PLTYPE_STR, "ACLName" },
 [AST_EVENT_IE_LOCAL_ADDR] = { AST_EVENT_IE_PLTYPE_STR, "LocalAddress" },
 [AST_EVENT_IE_REMOTE_ADDR] = { AST_EVENT_IE_PLTYPE_STR, "RemoteAddress" },
 [AST_EVENT_IE_EVENT_TV] = { AST_EVENT_IE_PLTYPE_STR, "EventTV" },
 [AST_EVENT_IE_REQUEST_TYPE] = { AST_EVENT_IE_PLTYPE_STR, "RequestType" },
 [AST_EVENT_IE_REQUEST_PARAMS] = { AST_EVENT_IE_PLTYPE_STR, "RequestParams" },
 [AST_EVENT_IE_AUTH_METHOD] = { AST_EVENT_IE_PLTYPE_STR, "AuthMethod" },
 [AST_EVENT_IE_SEVERITY] = { AST_EVENT_IE_PLTYPE_STR, "Severity" },
 [AST_EVENT_IE_EXPECTED_ADDR] = { AST_EVENT_IE_PLTYPE_STR, "ExpectedAddress" },
 [AST_EVENT_IE_CHALLENGE] = { AST_EVENT_IE_PLTYPE_STR, "Challenge" },
 [AST_EVENT_IE_RESPONSE] = { AST_EVENT_IE_PLTYPE_STR, "Response" },
 [AST_EVENT_IE_EXPECTED_RESPONSE] = { AST_EVENT_IE_PLTYPE_STR, "ExpectedResponse" },
 [AST_EVENT_IE_RECEIVED_CHALLENGE] = { AST_EVENT_IE_PLTYPE_STR, "ReceivedChallenge" },
 [AST_EVENT_IE_RECEIVED_HASH] = { AST_EVENT_IE_PLTYPE_STR, "ReceivedHash" },
 [AST_EVENT_IE_USING_PASSWORD] = { AST_EVENT_IE_PLTYPE_UINT, "UsingPassword" },
 [AST_EVENT_IE_ATTEMPTED_TRANSPORT] = { AST_EVENT_IE_PLTYPE_STR, "AttemptedTransport" },
 [AST_EVENT_IE_CACHABLE] = { AST_EVENT_IE_PLTYPE_UINT, "Cachable" },
 [AST_EVENT_IE_PRESENCE_PROVIDER] = { AST_EVENT_IE_PLTYPE_STR, "PresenceProvider" },
 [AST_EVENT_IE_PRESENCE_STATE] = { AST_EVENT_IE_PLTYPE_UINT, "PresenceState" },
 [AST_EVENT_IE_PRESENCE_SUBTYPE] = { AST_EVENT_IE_PLTYPE_STR, "PresenceSubtype" },
 [AST_EVENT_IE_PRESENCE_MESSAGE] = { AST_EVENT_IE_PLTYPE_STR, "PresenceMessage" },
};

const char *ast_event_get_type_name(const struct ast_event *event)
{
 enum ast_event_type type;

 type = ast_event_get_type(event);

 if ((unsigned int)type >= ARRAY_LEN(event_names)) {
 ast_log(LOG_ERROR, "Invalid event type - '%u'\n", type);
 return "";
 }

 return event_names[type];
}

const char *ast_event_get_ie_type_name(enum ast_event_ie_type ie_type)
{
 if (ie_type <= 0 || ie_type >= ARRAY_LEN(ie_maps)) {
 ast_log(LOG_ERROR, "Invalid IE type - '%d'\n", ie_type);
 return "";
 }

 return ie_maps[ie_type].name;
}

enum ast_event_ie_pltype ast_event_get_ie_pltype(enum ast_event_ie_type ie_type)
{
 if (ie_type <= 0 || ie_type >= ARRAY_LEN(ie_maps)) {
 ast_log(LOG_ERROR, "Invalid IE type - '%d'\n", ie_type);
 return AST_EVENT_IE_PLTYPE_UNKNOWN;
 }

 return ie_maps[ie_type].ie_pltype;
}

size_t ast_event_get_size(const struct ast_event *event)
{
 size_t res;

 res = ntohs(event->event_len);

 return res;
}

/*! \brief Subscription event check list. */
struct ast_ev_check_list {
 AST_LIST_HEAD_NOLOCK(, ast_event_ie_val) ie_vals;
};

int ast_event_iterator_init(struct ast_event_iterator *iterator, const struct ast_event *event)
{
 int res = 0;

 iterator->event_len = ast_event_get_size(event);
 iterator->event = event;
 if (iterator->event_len >= sizeof(*event) + sizeof(struct ast_event_ie)) {
 iterator->ie = (struct ast_event_ie *) ( ((char *) event) + sizeof(*event) );
 } else {
 iterator->ie = NULL;
 res = -1;
 }

 return res;
}

int ast_event_iterator_next(struct ast_event_iterator *iterator)
{
 iterator->ie = (struct ast_event_ie *) ( ((char *) iterator->ie) + sizeof(*iterator->ie) + ntohs(iterator->ie->ie_payload_len));
 return ((iterator->event_len <= (((char *) iterator->ie) - ((char *) iterator->event))) ? -1 : 0);
}

enum ast_event_ie_type ast_event_iterator_get_ie_type(struct ast_event_iterator *iterator)
{
 return ntohs(iterator->ie->ie_type);
}

uint32_t ast_event_iterator_get_ie_uint(struct ast_event_iterator *iterator)
{
 return ntohl(get_unaligned_uint32(iterator->ie->ie_payload));
}

const char *ast_event_iterator_get_ie_str(struct ast_event_iterator *iterator)
{
 const struct ast_event_ie_str_payload *str_payload;

 str_payload = (struct ast_event_ie_str_payload *) iterator->ie->ie_payload;

 return str_payload ? str_payload->str : NULL;
}

static void *event_iterator_get_ie_raw(struct ast_event_iterator *iterator)
{
 return iterator->ie->ie_payload;
}

enum ast_event_type ast_event_get_type(const struct ast_event *event)
{
 return ntohs(event->type);
}

uint32_t ast_event_get_ie_uint(const struct ast_event *event, enum ast_event_ie_type ie_type)
{
 const uint32_t *ie_val;

 ie_val = ast_event_get_ie_raw(event, ie_type);

 return ie_val ? ntohl(get_unaligned_uint32(ie_val)) : 0;
}

const char *ast_event_get_ie_str(const struct ast_event *event, enum ast_event_ie_type ie_type)
{
 const struct ast_event_ie_str_payload *str_payload;

 str_payload = ast_event_get_ie_raw(event, ie_type);

 return str_payload ? str_payload->str : NULL;
}

const void *ast_event_get_ie_raw(const struct ast_event *event, enum ast_event_ie_type ie_type)
{
 struct ast_event_iterator iterator;
 int res;

 for (res = ast_event_iterator_init(&iterator, event); !res; res = ast_event_iterator_next(&iterator)) {
 if (ast_event_iterator_get_ie_type(&iterator) == ie_type) {
 return event_iterator_get_ie_raw(&iterator);
 }
 }

 return NULL;
}

static uint16_t event_iterator_get_ie_raw_payload_len(struct ast_event_iterator *iterator)
{
 return ntohs(iterator->ie->ie_payload_len);
}

uint16_t ast_event_get_ie_raw_payload_len(const struct ast_event *event, enum ast_event_ie_type ie_type)
{
 struct ast_event_iterator iterator;
 int res;

 for (res = ast_event_iterator_init(&iterator, event); !res; res = ast_event_iterator_next(&iterator)) {
 if (ast_event_iterator_get_ie_type(&iterator) == ie_type) {
 return event_iterator_get_ie_raw_payload_len(&iterator);
 }
 }

 return 0;
}


int ast_event_append_ie_str(struct ast_event **event, enum ast_event_ie_type ie_type,
 const char *str)
{
 struct ast_event_ie_str_payload *str_payload;
 size_t payload_len;

 payload_len = sizeof(*str_payload) + strlen(str);
 str_payload = ast_alloca(payload_len);

 strcpy(str_payload->str, str);
 str_payload->hash = ast_str_hash(str);

 return ast_event_append_ie_raw(event, ie_type, str_payload, payload_len);
}

int ast_event_append_ie_uint(struct ast_event **event, enum ast_event_ie_type ie_type,
 uint32_t data)
{
 data = htonl(data);
 return ast_event_append_ie_raw(event, ie_type, &data, sizeof(data));
}

int ast_event_append_ie_bitflags(struct ast_event **event, enum ast_event_ie_type ie_type,
 uint32_t flags)
{
 flags = htonl(flags);
 return ast_event_append_ie_raw(event, ie_type, &flags, sizeof(flags));
}

int ast_event_append_ie_raw(struct ast_event **event, enum ast_event_ie_type ie_type,
 const void *data, size_t data_len)
{
 struct ast_event_ie *ie;
 struct ast_event *old_event;
 unsigned int extra_len;
 uint16_t event_len;

 event_len = ntohs((*event)->event_len);
 extra_len = sizeof(*ie) + data_len;

 old_event = *event;
 *event = ast_realloc(*event, event_len + extra_len);
 if (!*event) {
 ast_free(old_event);
 return -1;
 }

 ie = (struct ast_event_ie *) ( ((char *) *event) + event_len );
 ie->ie_type = htons(ie_type);
 ie->ie_payload_len = htons(data_len);
 memcpy(ie->ie_payload, data, data_len);

 (*event)->event_len = htons(event_len + extra_len);

 return 0;
}

struct ast_event *ast_event_new(enum ast_event_type type, ...)
{
 va_list ap;
 struct ast_event *event;
 enum ast_event_ie_type ie_type;
 struct ast_event_ie_val *ie_val;
 AST_LIST_HEAD_NOLOCK_STATIC(ie_vals, ast_event_ie_val);

 /* Invalid type */
 if (type >= AST_EVENT_TOTAL) {
 ast_log(LOG_WARNING, "Someone tried to create an event of invalid "
 "type '%u'!\n", type);
 return NULL;
 }

 va_start(ap, type);
 for (ie_type = va_arg(ap, enum ast_event_ie_type);
 ie_type != AST_EVENT_IE_END;
 ie_type = va_arg(ap, enum ast_event_ie_type))
 {
 struct ast_event_ie_val *ie_value = ast_malloc(sizeof(*ie_value));
 int insert = 0;

 memset(ie_value, 0, sizeof(*ie_value));
 ie_value->ie_type = ie_type;
 ie_value->ie_pltype = va_arg(ap, enum ast_event_ie_pltype);

 switch (ie_value->ie_pltype) {
 case AST_EVENT_IE_PLTYPE_UINT:
 ie_value->payload.uint = va_arg(ap, uint32_t);
 insert = 1;
 break;
 case AST_EVENT_IE_PLTYPE_BITFLAGS:
 ie_value->payload.uint = va_arg(ap, uint32_t);
 insert = 1;
 break;
 case AST_EVENT_IE_PLTYPE_STR:
 ie_value->payload.str = va_arg(ap, const char *);
 insert = 1;
 break;
 case AST_EVENT_IE_PLTYPE_RAW:
 {
 void *data = va_arg(ap, void *);
 size_t datalen = va_arg(ap, size_t);
 ie_value->payload.raw = ast_malloc(datalen);
 memcpy(ie_value->payload.raw, data, datalen);
 ie_value->raw_datalen = datalen;
 insert = 1;
 break;
 }
 case AST_EVENT_IE_PLTYPE_UNKNOWN:
 case AST_EVENT_IE_PLTYPE_EXISTS:
 break;
 }

 if (insert) {
 AST_LIST_INSERT_TAIL(&ie_vals, ie_value, entry);
 } else {
 ast_log(LOG_WARNING, "Unsupported PLTYPE(%d)\n", ie_value->ie_pltype);
 }
 }
 va_end(ap);

 if (!(event = ast_calloc(1, sizeof(*event)))) {
 return NULL;
 }

 event->type = htons(type);
 event->event_len = htons(sizeof(*event));

 AST_LIST_TRAVERSE(&ie_vals, ie_val, entry) {
 switch (ie_val->ie_pltype) {
 case AST_EVENT_IE_PLTYPE_STR:
 ast_event_append_ie_str(&event, ie_val->ie_type, ie_val->payload.str);
 break;
 case AST_EVENT_IE_PLTYPE_UINT:
 ast_event_append_ie_uint(&event, ie_val->ie_type, ie_val->payload.uint);
 break;
 case AST_EVENT_IE_PLTYPE_BITFLAGS:
 ast_event_append_ie_bitflags(&event, ie_val->ie_type, ie_val->payload.uint);
 break;
 case AST_EVENT_IE_PLTYPE_RAW:
 ast_event_append_ie_raw(&event, ie_val->ie_type,
 ie_val->payload.raw, ie_val->raw_datalen);
 break;
 case AST_EVENT_IE_PLTYPE_EXISTS:
 case AST_EVENT_IE_PLTYPE_UNKNOWN:
 break;
 }

 /* realloc inside one of the append functions failed */
 if (!event) {
 goto cleanup;
 }
 }

 if (!ast_event_get_ie_raw(event, AST_EVENT_IE_EID)) {
 /* If the event is originating on this server, add the server's
 * entity ID to the event. */
 ast_event_append_eid(&event);
 }

cleanup:
 AST_LIST_TRAVERSE_SAFE_BEGIN(&ie_vals, ie_val, entry) {
 AST_LIST_REMOVE_CURRENT(entry);

 if (ie_val->ie_pltype == AST_EVENT_IE_PLTYPE_RAW) {
 ast_free(ie_val->payload.raw);
 }
 ast_free(ie_val);
 }
 AST_LIST_TRAVERSE_SAFE_END;

 return event;
}

int ast_event_append_eid(struct ast_event **event)
{
 return ast_event_append_ie_raw(event, AST_EVENT_IE_EID,
 &ast_eid_default, sizeof(ast_eid_default));
}

void ast_event_destroy(struct ast_event *event)
{
 ast_free(event);
}

size_t ast_event_minimum_length(void)
{
 return sizeof(struct ast_event);
}