DeforaNetworks/siproxd
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- better branch parameter calculation (via header),

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now honors RFC3261 for stateless proxies (section 16.11)
This commit is contained in:
Thomas Ries
2004-01-27 20:00:42 +00:00
parent fcc4449bca
commit a32207d5bc
3 changed files with 155 additions and 13 deletions
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ChangeLog
+2
View File
@@ -1,6 +1,8 @@
0.5.2
=====
27-Jan-2004: - added doc/KNOWN_BUGS
- better branch parameter calculation (via header),
now honors RFC3261 for stateless proxies (section 16.11)
22-Jan-2004: - ./configure option: --enable-static to build
a completely statically linked executable
- REGISTER honors the expires parameter
src/sip_utils.c
+145 -7
View File
@@ -37,8 +37,10 @@
#include <osipparser2/osip_parser.h>
#include <osipparser2/osip_port.h>
#include <osipparser2/osip_md5.h>
#include "siproxd.h"
#include "digcalc.h"
#include "rewrite_rules.h"
#include "log.h"
@@ -578,8 +580,7 @@ int sip_add_myvia (osip_message_t *request, int interface) {
char tmp[URL_STRING_SIZE];
osip_via_t *via;
int sts;
char branch_id[64];
struct timeval tv;
char branch_id[VIA_BRANCH_SIZE];
if (interface == IF_OUTBOUND) {
sts = get_ip_by_ifname(configuration.outbound_if, &addr);
@@ -597,11 +598,7 @@ int sip_add_myvia (osip_message_t *request, int interface) {
}
}
/* prepare branch ID (the magic cookie z9hG4bK is added) */
gettimeofday (&tv, NULL);
sprintf(branch_id, "z9hG4bK%8.8lx%8.8lx%8.8x",
(long)tv.tv_sec, (long)tv.tv_usec, rand() );
sts = sip_calculate_branch_id(request, branch_id);
sprintf(tmp, "SIP/2.0/UDP %s:%i;branch=%s;", utils_inet_ntoa(addr),
configuration.sip_listen_port, branch_id);
@@ -704,3 +701,144 @@ int sip_rewrite_contact (osip_message_t *sip_msg, int direction) {
return STS_SUCCESS;
}
/*
* SIP_CALCULATE_BRANCH
*
* Calculates a branch parameter according to RFC3261 section 16.11
*
* The returned 'id' will be HASHHEXLEN + strlen(magic_cookie)
* characters (32 + 7) long. The caller must supply at least this
* amount of space in 'id'.
*
* RETURNS
* STS_SUCCESS on success
* STS_FAILURE on error
*/
int sip_calculate_branch_id (osip_message_t *sip_msg, char *id) {
/* RFC3261 section 16.11 recommends the following procedure:
* The stateless proxy MAY use any technique it likes to guarantee
* uniqueness of its branch IDs across transactions. However, the
* following procedure is RECOMMENDED. The proxy examines the
* branch ID in the topmost Via header field of the received
* request. If it begins with the magic cookie, the first
* component of the branch ID of the outgoing request is computed
* as a hash of the received branch ID. Otherwise, the first
* component of the branch ID is computed as a hash of the topmost
* Via, the tag in the To header field, the tag in the From header
* field, the Call-ID header field, the CSeq number (but not
* method), and the Request-URI from the received request. One of
* these fields will always vary across two different
* transactions.
*
* The branch value will consist of:
* - magic cookie "z9hG4bK"
* - 1st part (unique calculated ID
* - 2nd part (value for loop detection) <<- not yet used by siproxd
*/
static char *magic_cookie="z9hG4bK";
osip_via_t *via;
osip_uri_param_t *param=NULL;
osip_call_id_t *call_id=NULL;
HASHHEX hashstring;
hashstring[0]='\0';
/*
* Examine topmost via and look for a magic cookie.
* If it is there, I use THIS branch parameter as input for
* our hash calculation
*/
via = osip_list_get (sip_msg->vias, 0);
if (via == NULL) {
ERROR("have a SIP message without any via header");
return STS_FAILURE;
}
param=NULL;
osip_via_param_get_byname(via, "branch", &param);
if (param && param->gvalue) {
if (strncmp(param->gvalue, magic_cookie,
strlen(magic_cookie))) {
/* calculate MD5 hash */
MD5_CTX Md5Ctx;
HASH HA1;
MD5Init(&Md5Ctx);
MD5Update(&Md5Ctx, param->gvalue,
strlen(param->gvalue));
MD5Final(HA1, &Md5Ctx);
CvtHex(HA1, hashstring);
DEBUGC(DBCLASS_BABBLE, "existing branch -> branch hash [%s]",
hashstring);
}
}
/*
* If I don't have a branch parameter in the existing topmost via,
* then I need:
* - the topmost via
* - the tag in the To header field
* - the tag in the From header field
* - the Call-ID header field
* - the CSeq number (but not method)
* - the Request-URI from the received request
*/
if (hashstring[0] == '\0') {
/* calculate MD5 hash */
MD5_CTX Md5Ctx;
HASH HA1;
char *tmp;
MD5Init(&Md5Ctx);
/* topmost via */
if (osip_via_to_str(via, &tmp)) {
MD5Update(&Md5Ctx, tmp, strlen(tmp));
osip_free(tmp);
}
/* Tag in To header */
osip_to_get_tag(sip_msg->to, &param);
if (param && param->gvalue) {
MD5Update(&Md5Ctx, param->gvalue, strlen(param->gvalue));
}
/* Tag in From header */
osip_from_get_tag(sip_msg->from, &param);
if (param && param->gvalue) {
MD5Update(&Md5Ctx, param->gvalue, strlen(param->gvalue));
}
/* Call-ID */
call_id = osip_message_get_call_id(sip_msg);
if (osip_call_id_to_str(call_id, &tmp)) {
MD5Update(&Md5Ctx, tmp, strlen(tmp));
osip_free(tmp);
}
/* CSeq number (but not method) */
tmp = osip_cseq_get_number(sip_msg->cseq);
if (tmp) {
MD5Update(&Md5Ctx, tmp, strlen(tmp));
}
/* Request URI */
if (osip_uri_to_str(sip_msg->req_uri, &tmp)) {
MD5Update(&Md5Ctx, tmp, strlen(tmp));
osip_free(tmp);
}
MD5Final(HA1, &Md5Ctx);
CvtHex(HA1, hashstring);
DEBUGC(DBCLASS_BABBLE, "non-existing branch -> branch hash [%s]",
hashstring);
}
/* include the magic cookie */
sprintf(id, "%s%s", magic_cookie, hashstring);
return STS_SUCCESS;
}
src/siproxd.h
+8 -6
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@@ -67,6 +67,7 @@ int sip_gen_response(osip_message_t *request, int code); /*X*/
int sip_add_myvia (osip_message_t *request, int interface); /*X*/
int sip_del_myvia (osip_message_t *response); /*X*/
int sip_rewrite_contact (osip_message_t *sip_msg, int direction); /*X*/
int sip_calculate_branch_id (osip_message_t *sip_msg, char *id); /*X*/
/* readconf.c */
int read_config(char *name, int search); /*X*/
@@ -81,15 +82,16 @@ int rtp_stop_fwd (osip_call_id_t *callid, int direction); /*X*/
void rtpproxy_kill( void ); /*X*/
/* accessctl.c */
int accesslist_check(struct sockaddr_in from);
int accesslist_check(struct sockaddr_in from);
/* security.c */
int security_check_raw(char *sip_buffer, int size); /*X*/
int security_check_sip(osip_message_t *sip); /*X*/
int security_check_raw(char *sip_buffer, int size); /*X*/
int security_check_sip(osip_message_t *sip); /*X*/
/* auth.c */
int authenticate_proxy(osip_message_t *request); /*X*/
int auth_include_authrq(osip_message_t *response); /*X*/
int authenticate_proxy(osip_message_t *request); /*X*/
int auth_include_authrq(osip_message_t *response); /*X*/
void CvtHex(char *hash, char *hashstring);
@@ -172,7 +174,7 @@ struct siproxd_config {
#define HOSTNAME_SIZE 64 /* max string length of a hostname */
#define USERNAME_SIZE 64 /* max string length of a username (auth) */
#define PASSWORD_SIZE 64 /* max string length of a password (auth) */
#define VIA_BRANCH_SIZE 64 /* max string length for via branch param */
/* scratch buffer for gethostbyname_r() */
#if defined(PR_NETDB_BUF_SIZE)
#define GETHOSTBYNAME_BUFLEN PR_NETDB_BUF_SIZE