DeforaNetworks/siproxd
DeforaNetworks/siproxd
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- plugin_prefix: correct handling of outgoing ACKs

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(could lead to calls being aborted by one side)
This commit is contained in:
Thomas Ries 2011-06-17 16:15:41 +00:00
parent eef75b43b8
commit 3b37e1f906
1 changed files with 130 additions and 12 deletions
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142
src/plugin_prefix.c
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@ -35,6 +35,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <netinet/in.h>
@ -52,6 +53,11 @@ static char const ident[]="$Id$";
static char name[]="plugin_prefix";
static char desc[]="Adds a dial-prefix as defined in config file";
/* constants */
#define REDIRECTED_TAG "redirected"
#define REDIRECTED_VAL "prefix"
#define CACHE_TIMEOUT 20
/* global configuration storage - required for config file location */
extern struct siproxd_config configuration;
@ -68,9 +74,24 @@ static cfgopts_t plugin_cfg_opts[] = {
};
/* local storage needed by plugin */
/* Call-ID cache, single linked list, dynamically alocated elements */
typedef struct {
void *next;
osip_call_id_t *call_id;
time_t ts;
} redirected_cache_element_t;
/* The Queue Head is static */
static redirected_cache_element_t redirected_cache;
/* local prototypes */
static int plugin_prefix_redirect(sip_ticket_t *ticket);
static int plugin_prefix(sip_ticket_t *ticket);
static int add_to_redirected_cache(sip_ticket_t *ticket);
static int is_in_redirected_cache(sip_ticket_t *ticket);
static int expire_redirected_cache(void);
/*
@ -136,28 +157,31 @@ static int plugin_prefix(sip_ticket_t *ticket) {
if (!MSG_IS_INVITE(ticket->sipmsg) && !MSG_IS_ACK(ticket->sipmsg))
return STS_SUCCESS;
/* expire old cache entries */
expire_redirected_cache();
/* REQ URI with username must exist, prefix string must exist */
if (!req_url || !req_url->username || !plugin_cfg.prefix_akey)
return STS_SUCCESS; /* ignore */
/* Loop avoidance:
* If this INVITE has already been redirected by a prior 302
* moved response a "redirected" parameter should be present in the
* moved response a "REDIRECTED_TAG" parameter should be present in the
* URI.
* Hopefully all UAs (Clients) do honor RFC3261 and copy the
* *full* URI form the contact header into the new request header
* upon a 3xx response.
*/
if (req_url) {
osip_uri_param_get_byname(&(req_url->url_params), "redirected", &r);
if (r && r->gvalue && strcmp(r->gvalue,"true")== 0) {
osip_uri_param_get_byname(&(req_url->url_params), REDIRECTED_TAG, &r);
if (r && r->gvalue && strcmp(r->gvalue,REDIRECTED_VAL)== 0) {
DEBUGC(DBCLASS_PLUGIN,"Packet has already been redirected (ReqURI)");
return STS_SUCCESS;
}
}
if (to_url) {
osip_uri_param_get_byname(&(to_url->url_params), "redirected", &r);
if (r && r->gvalue && strcmp(r->gvalue,"true")== 0) {
osip_uri_param_get_byname(&(to_url->url_params), REDIRECTED_TAG, &r);
if (r && r->gvalue && strcmp(r->gvalue,REDIRECTED_VAL)== 0) {
DEBUGC(DBCLASS_PLUGIN,"Packet has already been redirected (ToURI)");
return STS_SUCCESS;
}
@ -172,11 +196,19 @@ static int plugin_prefix(sip_ticket_t *ticket) {
DEBUGC(DBCLASS_PLUGIN,"processing INVITE");
sts=plugin_prefix_redirect(ticket);
}
/* outgoing ACK request: is result of a local 3xx answer (moved...) */
/* outgoing ACK request: is result of a local 3xx answer (moved...)
*
* Only consume that particular ACK that belongs to a sent 302 answer,
* nothing else. Otherwise the ACK from the redirected call will get
* consumed as well and causes the call to be aborted (timeout).
* We keep a cache with Call-Ids of such "302 moved" dialogs.
* Only consume such ACKs that are part of such a dialog.
*/
else if (MSG_IS_ACK(ticket->sipmsg)) {
/* make sure we only catch ACKs caused by myself (**02 -> *02 legitime) */
DEBUGC(DBCLASS_PLUGIN,"processing ACK");
sts=STS_SIP_SENT; /* eat up the ACK that was directed to myself */
if (is_in_redirected_cache(ticket) == STS_TRUE) {
DEBUGC(DBCLASS_PLUGIN,"processing ACK (consume it)");
sts=STS_SIP_SENT; /* eat up the ACK that was directed to myself */
}
}
return sts;
@ -192,6 +224,7 @@ static int plugin_prefix_redirect(sip_ticket_t *ticket) {
size_t username_len;
osip_contact_t *contact = NULL;
add_to_redirected_cache(ticket);
/* including \0 + leading character(s) */
username_len=strlen(to_user) + strlen(plugin_cfg.prefix_akey) + 1;
@ -216,13 +249,13 @@ static int plugin_prefix_redirect(sip_ticket_t *ticket) {
osip_uri_clone(to_url, &contact->url);
/*
* Add the 'redirected=true' parameter to URI. Required to figure out
* Add the 'REDIRECTED_TAG=REDIRECTED_VAL' parameter to URI. Required to figure out
* if this INVITE has already been processed (redirected) and
* does not need further attention by this plugin.
* THIS IS REQUIRED TO AVOID A LOOP
*/
osip_uri_param_add(&(contact->url->url_params), osip_strdup("redirected"),
osip_strdup("true"));
osip_uri_param_add(&(contact->url->url_params), osip_strdup(REDIRECTED_TAG),
osip_strdup(REDIRECTED_VAL));
/* only copy the part that really belongs to the username */
snprintf(new_to_user, username_len, "%s%s",
@ -243,3 +276,88 @@ static int plugin_prefix_redirect(sip_ticket_t *ticket) {
return STS_SIP_SENT;
}
/*
* cache handling
*/
static int add_to_redirected_cache(sip_ticket_t *ticket) {
redirected_cache_element_t *e;
DEBUGC(DBCLASS_PLUGIN, "entered add_to_redirected_cache()");
/* allocate */
e=malloc(sizeof(redirected_cache_element_t));
if (e == NULL) {
ERROR("out of memory");
return STS_FAILURE;
}
/* populate element */
e->next = NULL;
e->ts = time(NULL);
osip_call_id_clone(ticket->sipmsg->call_id, &(e->call_id));
/* add to head of queue */
e->next = redirected_cache.next;
redirected_cache.next = e;
DEBUGC(DBCLASS_PLUGIN, "left add_to_redirected_cache()");
return STS_SUCCESS;
}
static int is_in_redirected_cache(sip_ticket_t *ticket) {
redirected_cache_element_t *p, *p_prev;
DEBUGC(DBCLASS_BABBLE, "entered is_in_redirected_cache");
/* iterate through queue */
p_prev=NULL;
for (p=&redirected_cache; p; p=p->next) {
DEBUGC(DBCLASS_BABBLE, "l: p=%p, p->next=%p", p, p->next);
if ( (p != &redirected_cache) && (p_prev != NULL) ) {
if (compare_callid(ticket->sipmsg->call_id, p->call_id) == STS_SUCCESS) {
DEBUGC(DBCLASS_BABBLE, "remove p=%p", p);
/* remove from queue */
p_prev->next = p->next;
free(p);
DEBUGC(DBCLASS_BABBLE, "left is_in_redirected_cache - FOUND");
return STS_TRUE;
} /* if compare_callid */
}
p_prev = p;
} /* for */
DEBUGC(DBCLASS_BABBLE, "left is_in_redirected_cache - NOT FOUND");
return STS_FALSE;
}
/*
* Run through the whole Call-Id cache and remove
* expired elements.
*/
static int expire_redirected_cache(void) {
redirected_cache_element_t *p, *p_prev;
time_t now;
DEBUGC(DBCLASS_BABBLE, "entered expire_redirected_cache");
now = time(NULL);
/* iterate through queue */
p_prev=NULL;
for (p=&redirected_cache; p; p=p->next) {
DEBUGC(DBCLASS_BABBLE, "1: p=%p, p->next=%p", p, p->next);
if ( (p != &redirected_cache) && (p_prev != NULL) ) {
DEBUGC(DBCLASS_BABBLE,"ts:%i, now:%i", (int)p->ts, (int)now);
if ((p->ts + CACHE_TIMEOUT) < now) {
DEBUGC(DBCLASS_BABBLE, "remove p=%p", p);
/* remove from queue */
p_prev->next = p->next;
free(p);
/* the current element is being removed and invalidated,
* set the iteration pointer to a valid element. */
p = p_prev;
} /* if timeout */
DEBUGC(DBCLASS_BABBLE, "2: p=%p, p->next=%p", p, p->next);
}
p_prev = p;
} /* for */
DEBUGC(DBCLASS_BABBLE, "left expire_redirected_cache");
return STS_FALSE;
}