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AST-2014-002: chan_sip: Exit early on bad session timers request

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This change allows chan_sip to avoid creation of the channel and
consumption of associated file descriptors altogether if the inbound
request is going to be rejected anyway.

(closes issue ASTERISK-23373)
Reported by: Corey Farrell
Patches:
     chan_sip-earlier-st-1.8.patch uploaded by Corey Farrell (license 5909)
     chan_sip-earlier-st-11.patch uploaded by Corey Farrell (license 5909)
........

Merged revisions 410308 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 410311 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@410329 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Kinsey Moore
2014-03-10 13:25:05 +00:00
parent f119ac4460
commit 8e0c31777c
1 changed files with 160 additions and 143 deletions
Download Patch File Download Diff File Expand all files Collapse all files

303
channels/chan_sip.c
View File

@@ -25210,6 +25210,145 @@ static int handle_request_update(struct sip_pvt *p, struct sip_request *req)
return 0;
}
/*
* \internal \brief Check Session Timers for an INVITE request
*
* \retval 0 ok
* \retval -1 failure
*/
static int handle_request_invite_st(struct sip_pvt *p, struct sip_request *req,
const char *required, int reinvite)
{
const char *p_uac_se_hdr; /* UAC's Session-Expires header string */
const char *p_uac_min_se; /* UAC's requested Min-SE interval (char string) */
int uac_max_se = -1; /* UAC's Session-Expires in integer format */
int uac_min_se = -1; /* UAC's Min-SE in integer format */
int st_active = FALSE; /* Session-Timer on/off boolean */
int st_interval = 0; /* Session-Timer negotiated refresh interval */
enum st_refresher tmp_st_ref = SESSION_TIMER_REFRESHER_AUTO; /* Session-Timer refresher */
int dlg_min_se = -1;
int dlg_max_se = global_max_se;
int rtn;
/* Session-Timers */
if ((p->sipoptions & SIP_OPT_TIMER)) {
enum st_refresher_param st_ref_param = SESSION_TIMER_REFRESHER_PARAM_UNKNOWN;
/* The UAC has requested session-timers for this session. Negotiate
the session refresh interval and who will be the refresher */
ast_debug(2, "Incoming INVITE with 'timer' option supported\n");
/* Allocate Session-Timers struct w/in the dialog */
if (!p->stimer) {
sip_st_alloc(p);
}
/* Parse the Session-Expires header */
p_uac_se_hdr = sip_get_header(req, "Session-Expires");
if (!ast_strlen_zero(p_uac_se_hdr)) {
ast_debug(2, "INVITE also has \"Session-Expires\" header.\n");
rtn = parse_session_expires(p_uac_se_hdr, &uac_max_se, &st_ref_param);
tmp_st_ref = (st_ref_param == SESSION_TIMER_REFRESHER_PARAM_UAC) ? SESSION_TIMER_REFRESHER_THEM : SESSION_TIMER_REFRESHER_US;
if (rtn != 0) {
transmit_response_reliable(p, "400 Session-Expires Invalid Syntax", req);
return -1;
}
}
/* Parse the Min-SE header */
p_uac_min_se = sip_get_header(req, "Min-SE");
if (!ast_strlen_zero(p_uac_min_se)) {
ast_debug(2, "INVITE also has \"Min-SE\" header.\n");
rtn = parse_minse(p_uac_min_se, &uac_min_se);
if (rtn != 0) {
transmit_response_reliable(p, "400 Min-SE Invalid Syntax", req);
return -1;
}
}
dlg_min_se = st_get_se(p, FALSE);
switch (st_get_mode(p, 1)) {
case SESSION_TIMER_MODE_ACCEPT:
case SESSION_TIMER_MODE_ORIGINATE:
if (uac_max_se > 0 && uac_max_se < dlg_min_se) {
transmit_response_with_minse(p, "422 Session Interval Too Small", req, dlg_min_se);
return -1;
}
p->stimer->st_active_peer_ua = TRUE;
st_active = TRUE;
if (st_ref_param == SESSION_TIMER_REFRESHER_PARAM_UNKNOWN) {
tmp_st_ref = st_get_refresher(p);
}
dlg_max_se = st_get_se(p, TRUE);
if (uac_max_se > 0) {
if (dlg_max_se >= uac_min_se) {
st_interval = (uac_max_se < dlg_max_se) ? uac_max_se : dlg_max_se;
} else {
st_interval = uac_max_se;
}
} else if (uac_min_se > 0) {
st_interval = MAX(dlg_max_se, uac_min_se);
} else {
st_interval = dlg_max_se;
}
break;
case SESSION_TIMER_MODE_REFUSE:
if (p->reqsipoptions & SIP_OPT_TIMER) {
transmit_response_with_unsupported(p, "420 Option Disabled", req, required);
ast_log(LOG_WARNING, "Received SIP INVITE with supported but disabled option: %s\n", required);
return -1;
}
break;
default:
ast_log(LOG_ERROR, "Internal Error %d at %s:%d\n", st_get_mode(p, 1), __FILE__, __LINE__);
break;
}
} else {
/* The UAC did not request session-timers. Asterisk (UAS), will now decide
(based on session-timer-mode in sip.conf) whether to run session-timers for
this session or not. */
switch (st_get_mode(p, 1)) {
case SESSION_TIMER_MODE_ORIGINATE:
st_active = TRUE;
st_interval = st_get_se(p, TRUE);
tmp_st_ref = SESSION_TIMER_REFRESHER_US;
p->stimer->st_active_peer_ua = (p->sipoptions & SIP_OPT_TIMER) ? TRUE : FALSE;
break;
default:
break;
}
}
if (reinvite == 0) {
/* Session-Timers: Start session refresh timer based on negotiation/config */
if (st_active == TRUE) {
p->stimer->st_active = TRUE;
p->stimer->st_interval = st_interval;
p->stimer->st_ref = tmp_st_ref;
}
} else {
if (p->stimer->st_active == TRUE) {
/* Session-Timers: A re-invite request sent within a dialog will serve as
a refresh request, no matter whether the re-invite was sent for refreshing
the session or modifying it.*/
ast_debug (2, "Restarting session-timers on a refresh - %s\n", p->callid);
/* The UAC may be adjusting the session-timers mid-session */
if (st_interval > 0) {
p->stimer->st_interval = st_interval;
p->stimer->st_ref = tmp_st_ref;
}
}
}
return 0;
}
/*!
* \brief Handle incoming INVITE request
* \note If the INVITE has a Replaces header, it is part of an
@@ -25228,19 +25367,9 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, str
struct ast_channel *c = NULL; /* New channel */
struct sip_peer *authpeer = NULL; /* Matching Peer */
int reinvite = 0;
int rtn;
struct ast_party_redirecting redirecting;
struct ast_set_party_redirecting update_redirecting;
const char *p_uac_se_hdr; /* UAC's Session-Expires header string */
const char *p_uac_min_se; /* UAC's requested Min-SE interval (char string) */
int uac_max_se = -1; /* UAC's Session-Expires in integer format */
int uac_min_se = -1; /* UAC's Min-SE in integer format */
int st_active = FALSE; /* Session-Timer on/off boolean */
int st_interval = 0; /* Session-Timer negotiated refresh interval */
enum st_refresher tmp_st_ref = SESSION_TIMER_REFRESHER_AUTO; /* Session-Timer refresher */
int dlg_min_se = -1;
int dlg_max_se = global_max_se;
struct {
char exten[AST_MAX_EXTENSION];
char context[AST_MAX_CONTEXT];
@@ -25699,6 +25828,14 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, str
/* Initialize our tag */
make_our_tag(p);
if (handle_request_invite_st(p, req, required, reinvite)) {
p->invitestate = INV_COMPLETED;
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
/* First invitation - create the channel. Allocation
* failures are handled below. */
@@ -25733,6 +25870,16 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, str
}
if (!req->ignore)
reinvite = 1;
if (handle_request_invite_st(p, req, required, reinvite)) {
p->invitestate = INV_COMPLETED;
if (!p->lastinvite) {
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
}
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
c = p->owner;
change_redirecting_information(p, req, &redirecting, &update_redirecting, FALSE); /*Will return immediately if no Diversion header is present */
if (c) {
@@ -25744,140 +25891,10 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, str
/* Check if OLI/ANI-II is present in From: */
parse_oli(req, p->owner);
/* Session-Timers */
if ((p->sipoptions & SIP_OPT_TIMER)) {
enum st_refresher_param st_ref_param = SESSION_TIMER_REFRESHER_PARAM_UNKNOWN;
/* The UAC has requested session-timers for this session. Negotiate
the session refresh interval and who will be the refresher */
ast_debug(2, "Incoming INVITE with 'timer' option supported\n");
/* Allocate Session-Timers struct w/in the dialog */
if (!p->stimer)
sip_st_alloc(p);
/* Parse the Session-Expires header */
p_uac_se_hdr = sip_get_header(req, "Session-Expires");
if (!ast_strlen_zero(p_uac_se_hdr)) {
ast_debug(2, "INVITE also has \"Session-Expires\" header.\n");
rtn = parse_session_expires(p_uac_se_hdr, &uac_max_se, &st_ref_param);
tmp_st_ref = (st_ref_param == SESSION_TIMER_REFRESHER_PARAM_UAC) ? SESSION_TIMER_REFRESHER_THEM : SESSION_TIMER_REFRESHER_US;
if (rtn != 0) {
transmit_response_reliable(p, "400 Session-Expires Invalid Syntax", req);
p->invitestate = INV_COMPLETED;
if (!p->lastinvite) {
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
}
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
}
/* Parse the Min-SE header */
p_uac_min_se = sip_get_header(req, "Min-SE");
if (!ast_strlen_zero(p_uac_min_se)) {
ast_debug(2, "INVITE also has \"Min-SE\" header.\n");
rtn = parse_minse(p_uac_min_se, &uac_min_se);
if (rtn != 0) {
transmit_response_reliable(p, "400 Min-SE Invalid Syntax", req);
p->invitestate = INV_COMPLETED;
if (!p->lastinvite) {
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
}
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
}
dlg_min_se = st_get_se(p, FALSE);
switch (st_get_mode(p, 1)) {
case SESSION_TIMER_MODE_ACCEPT:
case SESSION_TIMER_MODE_ORIGINATE:
if (uac_max_se > 0 && uac_max_se < dlg_min_se) {
transmit_response_with_minse(p, "422 Session Interval Too Small", req, dlg_min_se);
p->invitestate = INV_COMPLETED;
if (!p->lastinvite) {
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
}
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
p->stimer->st_active_peer_ua = TRUE;
st_active = TRUE;
if (st_ref_param == SESSION_TIMER_REFRESHER_PARAM_UNKNOWN) {
tmp_st_ref = st_get_refresher(p);
}
dlg_max_se = st_get_se(p, TRUE);
if (uac_max_se > 0) {
if (dlg_max_se >= uac_min_se) {
st_interval = (uac_max_se < dlg_max_se) ? uac_max_se : dlg_max_se;
} else {
st_interval = uac_max_se;
}
} else if (uac_min_se > 0) {
st_interval = MAX(dlg_max_se, uac_min_se);
} else {
st_interval = dlg_max_se;
}
break;
case SESSION_TIMER_MODE_REFUSE:
if (p->reqsipoptions & SIP_OPT_TIMER) {
transmit_response_with_unsupported(p, "420 Option Disabled", req, required);
ast_log(LOG_WARNING, "Received SIP INVITE with supported but disabled option: %s\n", required);
p->invitestate = INV_COMPLETED;
if (!p->lastinvite) {
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
}
res = INV_REQ_ERROR;
goto request_invite_cleanup;
}
break;
default:
ast_log(LOG_ERROR, "Internal Error %d at %s:%d\n", st_get_mode(p, 1), __FILE__, __LINE__);
break;
}
} else {
/* The UAC did not request session-timers. Asterisk (UAS), will now decide
(based on session-timer-mode in sip.conf) whether to run session-timers for
this session or not. */
switch (st_get_mode(p, 1)) {
case SESSION_TIMER_MODE_ORIGINATE:
st_active = TRUE;
st_interval = st_get_se(p, TRUE);
tmp_st_ref = SESSION_TIMER_REFRESHER_US;
p->stimer->st_active_peer_ua = (p->sipoptions & SIP_OPT_TIMER) ? TRUE : FALSE;
break;
default:
break;
}
}
if (reinvite == 0) {
/* Session-Timers: Start session refresh timer based on negotiation/config */
if (st_active == TRUE) {
p->stimer->st_active = TRUE;
p->stimer->st_interval = st_interval;
p->stimer->st_ref = tmp_st_ref;
start_session_timer(p);
}
} else {
if (p->stimer->st_active == TRUE) {
/* Session-Timers: A re-invite request sent within a dialog will serve as
a refresh request, no matter whether the re-invite was sent for refreshing
the session or modifying it.*/
ast_debug (2, "Restarting session-timers on a refresh - %s\n", p->callid);
/* The UAC may be adjusting the session-timers mid-session */
if (st_interval > 0) {
p->stimer->st_interval = st_interval;
p->stimer->st_ref = tmp_st_ref;
}
if (reinvite == 0) {
start_session_timer(p);
} else {
restart_session_timer(p);
}
}