/**
* Gether the message information about SST from the current message
* being processed.
*
* @param msg The current message to parse.
* @param minfo The SST information found in the message.
*
* @return 0 on success, -1 on a parsing error.
*/
static int parse_msg_for_sst_info(struct sip_msg *msg, sst_msg_info_t *minfo)
{
int rtn = 0;
struct session_expires se = {0,0};
if (!msg || !minfo) {
return (-1);
}
/*
* parse the supported infor
*/
minfo->supported = 0; /*Clear it */
minfo->se = 0;
minfo->refresher = sst_refresher_unspecified;
minfo->min_se = 0;
/*
* The parse_supported() will return 0 if found and parsed OK, -1
* if not found or an error parsing the one it did find! So assume
* it is not found if unsuccessfull.
*/
if ((rtn = parse_supported(msg)) == 0) {
if ((((struct option_tag_body*)msg->supported->parsed)->option_tags_all
& F_OPTION_TAG_TIMER)) {
minfo->supported = 1;
}
}
/*
* Parse the Min-SE: header next.
*/
minfo->min_se = 0;
if ((rtn = parse_min_se(msg, &minfo->min_se)) != parse_sst_success) {
minfo->min_se = 0; /* Make sure it statys clean */
}
minfo->se = 0;
if ((rtn = parse_session_expires(msg, &se)) == parse_sst_success) {
minfo->se = se.interval;
minfo->refresher = se.refresher;
}
return(0);
}
/**
* The sstCheckMin() script command handler. Return 1 (true) if the
* MIN-SE: of the message is too small compared to the sst_min_se
* value. This will allow the script to reply to this INVITE with a
* "422 Session Timer Too Small" response. if sst_min_se was never set
* the recommended value of 1800 seconds will be used.
*
* If the flag (str1) is set to 1, the 422 reply will be sent with the
* sst MIN_SE value in the header. If the flag is not set or is NULL,
* no reply is sent.
* @param msg - The sip message from the script (INVITE only)
* @param flag - Reply mode Flag. 0/NULL do not send reply, 1 send 422
* reply if Session-Expires is to small with the MIN-SE
* header in the reply
* @param str2 - Not used.
*
* @return 1 if the MIN-SE is too small, -1 if it is OK, or It could
* not be checked.
*
* NOTE: returning 0 == drop message, 1 == true, -1 == false in the
* script.
*/
int sst_check_min(struct sip_msg *msg, char *flag, char *str2)
{
enum parse_sst_result result;
struct session_expires se = {0,0};
unsigned minse = 0;
/*
* Only look in INVITES. We can't reply with a 422 to a 2xx reply
* now can we. This check can ONLY be done on the INVITE/UPDATE.
*/
if (msg->first_line.type == SIP_REQUEST &&
msg->first_line.u.request.method_value == METHOD_INVITE) {
/*
* First see if there is an Session-Expires: header. If there
* is, also look for a MIN-SE: header. If there is, use the
* minimum value of the two to compare with srt1. All MUST not
* be less then 90 and 1800 is recomended. See RCF section 4.
*/
if ((result = parse_session_expires(msg, &se)) != parse_sst_success) {
if (result != parse_sst_header_not_found) {
LM_ERR("failed to parse Session-Expires headers.\n");
return 0; /* Error drop the message */
}
/* Session-Expires not supported/stated */
LM_DBG("No Session-Expires header found. retuning false (-1)\n");
/*
* NOTE: 0 == drop message, 1 == true, -1 == false
*/
return -1;
}
/*
* We have a Session_expire header. Now look for the MIN-SE.
*/
if ((result = parse_min_se(msg, &minse)) != parse_sst_success) {
if (result != parse_sst_header_not_found) {
/*
* This is an error. The header was found but could
* not parse it.
*/
LM_ERR("failed to parse MIN-SE header.\n");
return -1;
}
/*
* If not stated, use the value from the session-expires
* header
*/
LM_DBG("No MIN-SE header found.\n");
minse = 90 /*this is the recommended value*/ /*se.interval*/;
}
LM_DBG("Session-Expires: %d; MIN-SE: %d\n", se.interval, minse);
/*
* Now compare our MIN-SE with the messages and see if it is
* too small. We will take the smaller of the messages
* Session-expires and min-se if stated.
*/
if (sst_min_se > MIN(minse, se.interval)) {
/*
* Too small. See if we need to send the 422 and are able
* to send it.
*/
if (flag) {
char minse_hdr[3+1+2+1+1+11+CRLF_LEN+2+1];
int hdr_len = 3+1+2+1+1+11+CRLF_LEN+2;
memset(minse_hdr, 0, hdr_len+1);
hdr_len = snprintf(minse_hdr, hdr_len,
"%s%d%s", "MIN-SE: ", sst_min_se,CRLF);
LM_DBG("Sending 422: %.*s\n", hdr_len, minse_hdr);
if (send_response(msg, 422, &sst_422_rpl, minse_hdr, hdr_len)){
LM_ERR("Error sending 422 reply.\n");
}
}
LM_DBG("Done returning true (1)\n");
return 1; /* return true */
}
}
LM_DBG("Done returning false (-1)\n");
/*
* All is good.
*/
return -1; /* return false */
}
