/
dlg_cseq.c
561 lines (497 loc) · 14.1 KB
/
dlg_cseq.c
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/*
* Copyright (C) 2014 Daniel-Constantin Mierla (asipto.com)
*
* This file is part of Kamailio, a free SIP server.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
*
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
/*!
* \file
* \brief Cseq handling
* \ingroup dialog
* Module: \ref dialog
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "../../core/events.h"
#include "../../core/ut.h"
#include "../../core/trim.h"
#include "../../core/data_lump.h"
#include "../../core/srapi.h"
#include "../../core/parser/parse_to.h"
#include "../../core/parser/parse_from.h"
#include "../../core/parser/parse_cseq.h"
#include "../../modules/tm/tm_load.h"
#include "dlg_handlers.h"
#include "dlg_var.h"
#include "dlg_cseq.h"
extern struct tm_binds d_tmb;
static str _dlg_cseq_diff_var_name = str_init("cseq_diff");
/**
*
*/
static int dlg_cseq_prepare_msg(sip_msg_t *msg)
{
LM_DBG("prepare msg for cseq update operations\n");
if(msg->first_line.type==SIP_REQUEST) {
if(!IS_SIP(msg)) {
LM_DBG("non sip request message\n");
return 1;
}
} else if(msg->first_line.type==SIP_REPLY) {
if(!IS_SIP_REPLY(msg)) {
LM_DBG("non sip reply message\n");
return 1;
}
} else {
LM_DBG("non sip message\n");
return 1;
}
if((!msg->cseq && (parse_headers(msg,HDR_CSEQ_F,0)<0 || !msg->cseq))
|| !msg->cseq->parsed){
LM_DBG("parsing cseq header failed\n");
return 2;
}
if(msg->first_line.type==SIP_REPLY) {
/* reply to local transaction -- nothing to do */
if (parse_headers(msg, HDR_VIA2_F, 0)==-1
|| (msg->via2==0) || (msg->via2->error!=PARSE_OK)) {
if(get_cseq(msg)->method_id != METHOD_CANCEL) {
LM_DBG("no second via in this message \n");
return 3;
}
}
}
if(parse_from_header(msg)<0) {
LM_ERR("cannot parse FROM header\n");
return 3;
}
if(parse_to_header(msg)<0 || msg->to==NULL) {
LM_ERR("cannot parse TO header\n");
return 3;
}
if(get_to(msg)==NULL) {
LM_ERR("cannot get TO header\n");
return 3;
}
return 0;
}
/**
*
*/
static int dlg_cseq_prepare_new_msg(sip_msg_t *msg)
{
LM_DBG("prepare new msg for cseq update operations\n");
if (parse_msg(msg->buf, msg->len, msg)!=0) {
LM_DBG("outbuf buffer parsing failed!");
return 1;
}
return dlg_cseq_prepare_msg(msg);
}
/**
*
*/
int dlg_cseq_update(sip_msg_t *msg)
{
dlg_cell_t *dlg = NULL;
unsigned int direction;
unsigned int ninc = 0;
unsigned int vinc = 0;
str nval;
str *pval;
sr_cfgenv_t *cenv = NULL;
if(dlg_cseq_prepare_msg(msg)!=0) {
return -1;
}
if(msg->first_line.type==SIP_REPLY) {
/* nothing to do for outgoing replies */
goto done;
}
LM_DBG("initiating cseq updates\n");
direction = DLG_DIR_NONE;
dlg = dlg_lookup_msg_dialog(msg, &direction);
if(dlg == NULL) {
LM_DBG("no dialog for this request\n");
goto done;
}
/* supported only for downstrem direction */
if(direction != DLG_DIR_DOWNSTREAM) {
LM_DBG("request not going downstream (%u)\n", direction);
goto done;
}
cenv = sr_cfgenv_get();
ninc = 1;
/* take the increment value from dialog */
if((dlg->iflags&DLG_IFLAG_CSEQ_DIFF)==DLG_IFLAG_CSEQ_DIFF) {
/* get dialog variable holding cseq diff */
pval = get_dlg_variable(dlg, &_dlg_cseq_diff_var_name);
if(pval==NULL || pval->s==NULL || pval->len<=0) {
LM_DBG("dialog marked with cseq diff but no variable set yet\n");
goto done;
}
if(str2int(pval, &vinc)<0) {
LM_ERR("invalid dlg cseq diff var value: %.*s\n",
pval->len, pval->s);
goto done;
}
}
vinc += ninc;
if(vinc==0) {
LM_DBG("nothing to increment\n");
goto done;
}
nval.s = int2str(vinc, &nval.len);
if(set_dlg_variable(dlg, &_dlg_cseq_diff_var_name, &nval) <0) {
LM_ERR("failed to set the dlg cseq diff var\n");
goto done;
}
str2int(&get_cseq(msg)->number, &ninc);
vinc += ninc;
nval.s = int2str(vinc, &nval.len);
trim(&nval);
LM_DBG("adding auth cseq header value: %.*s\n", nval.len, nval.s);
if(parse_headers(msg, HDR_EOH_F, 0)==-1) {
LM_ERR("failed to parse all headers\n");
}
sr_hdr_add_zs(msg, cenv->uac_cseq_auth.s, &nval);
done:
if(dlg!=NULL) dlg_release(dlg);
return 0;
}
/**
*
*/
int dlg_cseq_refresh(sip_msg_t *msg, dlg_cell_t *dlg,
unsigned int direction)
{
unsigned int ninc = 0;
unsigned int vinc = 0;
str nval;
str *pval;
sr_cfgenv_t *cenv = NULL;
if(dlg_cseq_prepare_msg(msg)!=0) {
goto error;
}
if(msg->first_line.type==SIP_REPLY) {
/* nothing to do for outgoing replies */
goto done;
}
LM_DBG("initiating cseq refresh\n");
/* supported only for downstrem direction */
if(direction != DLG_DIR_DOWNSTREAM) {
LM_DBG("request not going downstream (%u)\n", direction);
goto done;
}
/* take the increment value from dialog */
if(!((dlg->iflags&DLG_IFLAG_CSEQ_DIFF)==DLG_IFLAG_CSEQ_DIFF)) {
LM_DBG("no cseq refresh required\n");
goto done;
}
/* get dialog variable holding cseq diff */
pval = get_dlg_variable(dlg, &_dlg_cseq_diff_var_name);
if(pval==NULL || pval->s==NULL || pval->len<=0) {
LM_DBG("dialog marked with cseq diff but no variable set yet\n");
goto done;
}
if(str2int(pval, &vinc)<0) {
LM_ERR("invalid dlg cseq diff var value: %.*s\n",
pval->len, pval->s);
goto done;
}
if(vinc==0) {
LM_DBG("nothing to increment\n");
goto done;
}
str2int(&get_cseq(msg)->number, &ninc);
vinc += ninc;
nval.s = int2str(vinc, &nval.len);
trim(&nval);
LM_DBG("adding cseq refresh header value: %.*s\n", nval.len, nval.s);
if(parse_headers(msg, HDR_EOH_F, 0)==-1) {
LM_ERR("failed to parse all headers\n");
}
cenv = sr_cfgenv_get();
sr_hdr_add_zs(msg, cenv->uac_cseq_refresh.s, &nval);
done:
return 0;
error:
return -1;
}
/**
*
*/
int dlg_cseq_msg_received(sr_event_param_t *evp)
{
sip_msg_t msg;
str *obuf;
struct via_body *via;
str vcseq;
obuf = (str*)evp->data;
memset(&msg, 0, sizeof(sip_msg_t));
msg.buf = obuf->s;
msg.len = obuf->len;
if(dlg_cseq_prepare_new_msg(&msg)!=0) {
goto done;
}
if(msg.first_line.type==SIP_REQUEST) {
/* nothing to do for incoming requests */
goto done;
}
via = (struct via_body*)msg.h_via1->parsed;
if(via->branch==NULL || via->branch->value.len<=0) {
LM_DBG("no branch parameter in top via\n");
goto done;
}
vcseq.s = via->branch->value.s + via->branch->value.len - 1;
vcseq.len = 0;
while(vcseq.s>via->branch->value.s) {
if(*vcseq.s=='.') {
if(vcseq.len<3) {
LM_DBG("no matching the starting point length\n");
goto done;
}
if(vcseq.s[1]!='c' || vcseq.s[2]!='s') {
LM_DBG("no matching the starting placeholder\n");
goto done;
}
vcseq.len++;
break;
}
vcseq.len++;
vcseq.s--;
}
LM_DBG("via cseq cookie [%.*s] val [%.*s]\n", vcseq.len, vcseq.s,
vcseq.len-3, vcseq.s+3);
if(vcseq.len-3>get_cseq(&msg)->number.len) {
/* higher length to update - wrong */
LM_DBG("cseq in message (%d) shorter than in via (%d)\n",
get_cseq(&msg)->number.len, vcseq.len-3);
goto done;
}
if(vcseq.len-3==get_cseq(&msg)->number.len) {
/* same length - overwrite in the buffer */
memcpy(get_cseq(&msg)->number.s, vcseq.s+3, vcseq.len-3);
} else {
/* pad beginning with space */
strncpy(get_cseq(&msg)->number.s, " ",
get_cseq(&msg)->number.len - vcseq.len + 3);
memcpy(get_cseq(&msg)->number.s + get_cseq(&msg)->number.len
- vcseq.len + 3, vcseq.s+3, vcseq.len-3);
}
/* our via, will be removed anyhow - let's change cseq part of branch
* to a z parameter instead of shifting content to remove it */
vcseq.s[0] = ';';
vcseq.s[1] = 'z';
vcseq.s[2] = '=';
done:
free_sip_msg(&msg);
return 0;
}
/**
*
*/
int dlg_cseq_msg_sent(sr_event_param_t *evp)
{
sip_msg_t msg;
str *obuf;
unsigned int direction;
dlg_cell_t *dlg = NULL;
str nval = STR_NULL;
char tbuf[BUF_SIZE];
int tbuf_len = 0;
struct via_body *via;
hdr_field_t *hfk = NULL;
sr_cfgenv_t *cenv = NULL;
str nbuf = STR_NULL;
obuf = (str*)evp->data;
memset(&msg, 0, sizeof(sip_msg_t));
msg.buf = obuf->s;
msg.len = obuf->len;
cenv = sr_cfgenv_get();
if(dlg_cseq_prepare_new_msg(&msg)!=0) {
goto done;
}
if(msg.first_line.type==SIP_REPLY) {
/* nothing to do for outgoing replies */
goto done;
}
if(!IS_SIP(&msg)) {
/* nothing to do for non-sip requests */
goto done;
}
if(get_to(&msg)->tag_value.len<=0) {
/* intial request - handle only INVITEs */
if(msg.first_line.u.request.method_value!=METHOD_INVITE) {
goto done;
}
}
LM_DBG("tracking cseq updates\n");
via = (struct via_body*)msg.h_via1->parsed;
if(via->branch==NULL || via->branch->value.len<=0) {
LM_DBG("no branch parameter in top via\n");
goto done;
}
direction = DLG_DIR_NONE;
dlg = dlg_lookup_msg_dialog(&msg, &direction);
if(dlg == NULL) {
LM_DBG("no dialog for this request\n");
goto done;
}
/* supported only for downstrem direction */
if(direction != DLG_DIR_DOWNSTREAM) {
LM_DBG("request not going downstream (%u)\n", direction);
goto done;
}
if(parse_headers(&msg, HDR_EOH_F, 0)==-1) {
LM_ERR("failed to parse all headers\n");
}
/* check if transaction is marked for a new increment */
hfk = sr_hdr_get_z(&msg, cenv->uac_cseq_auth.s);
if(hfk!=NULL) {
LM_DBG("new cseq inc requested\n");
nval = hfk->body;
trim(&nval);
} else {
LM_DBG("new cseq inc not requested\n");
}
if(nval.len<=0) {
hfk = sr_hdr_get_z(&msg, cenv->uac_cseq_refresh.s);
if(hfk!=NULL) {
LM_DBG("cseq refresh requested\n");
nval = hfk->body;
trim(&nval);
} else {
LM_DBG("cseq refresh not requested\n");
}
}
if(nval.len<=0) {
LM_DBG("cseq refresh requested, but no new value found\n");
goto done;
}
if(msg.len + 3 + 2*nval.len>=BUF_SIZE) {
LM_ERR("new messages is too big\n");
goto done;
}
LM_DBG("updating cseq to: %.*s\n", nval.len, nval.s);
/* new cseq value */
dlg->iflags |= DLG_IFLAG_CSEQ_DIFF;
if(via->branch->value.s<get_cseq(&msg)->number.s) {
/* Via is before CSeq */
/* copy first part till after via branch */
tbuf_len = via->branch->value.s + via->branch->value.len - msg.buf;
memcpy(tbuf, msg.buf, tbuf_len);
/* complete via branch */
tbuf[tbuf_len++] = '.';
tbuf[tbuf_len++] = 'c';
tbuf[tbuf_len++] = 's';
memcpy(tbuf+tbuf_len, get_cseq(&msg)->number.s, get_cseq(&msg)->number.len);
tbuf_len += get_cseq(&msg)->number.len;
/* copy till beginning of cseq number */
memcpy(tbuf+tbuf_len, via->branch->value.s + via->branch->value.len,
get_cseq(&msg)->number.s - via->branch->value.s
- via->branch->value.len);
tbuf_len += get_cseq(&msg)->number.s - via->branch->value.s
- via->branch->value.len;
/* add new value */
memcpy(tbuf+tbuf_len, nval.s, nval.len);
tbuf_len += nval.len;
if(hfk && hfk->name.s > get_cseq(&msg)->number.s) {
/* copy from after cseq number to the beginning of hfk */
memcpy(tbuf+tbuf_len, get_cseq(&msg)->number.s+get_cseq(&msg)->number.len,
hfk->name.s - get_cseq(&msg)->number.s
- get_cseq(&msg)->number.len);
tbuf_len += hfk->name.s - get_cseq(&msg)->number.s
- get_cseq(&msg)->number.len;
/* copy from after hfk to the end of sip message */
memcpy(tbuf+tbuf_len, hfk->name.s + hfk->len,
msg.buf + msg.len - hfk->name.s - hfk->len);
tbuf_len += msg.buf + msg.len - hfk->name.s - hfk->len;
} else {
/* copy from after cseq number to the end of sip message */
memcpy(tbuf+tbuf_len, get_cseq(&msg)->number.s+get_cseq(&msg)->number.len,
msg.buf + msg.len - get_cseq(&msg)->number.s
- get_cseq(&msg)->number.len);
tbuf_len += msg.buf+msg.len - get_cseq(&msg)->number.s
- get_cseq(&msg)->number.len;
}
} else {
/* CSeq is before Via */
/* copy till beginning of cseq number */
tbuf_len = get_cseq(&msg)->number.s - msg.buf;
memcpy(tbuf, msg.buf, tbuf_len);
/* add new value */
memcpy(tbuf+tbuf_len, nval.s, nval.len);
tbuf_len += nval.len;
/* copy from after cseq number to the after via branch */
memcpy(tbuf+tbuf_len, get_cseq(&msg)->number.s+get_cseq(&msg)->number.len,
via->branch->value.s + via->branch->value.len
- get_cseq(&msg)->number.s - get_cseq(&msg)->number.len);
tbuf_len += via->branch->value.s + via->branch->value.len
- get_cseq(&msg)->number.s - get_cseq(&msg)->number.len;
/* complete via branch */
tbuf[tbuf_len++] = '.';
tbuf[tbuf_len++] = 'c';
tbuf[tbuf_len++] = 's';
memcpy(tbuf+tbuf_len, get_cseq(&msg)->number.s, get_cseq(&msg)->number.len);
tbuf_len += get_cseq(&msg)->number.len;
if(hfk && hfk->name.s > get_cseq(&msg)->number.s) {
/* copy from after via to the beginning of hfk */
memcpy(tbuf+tbuf_len, via->branch->value.s + via->branch->value.len,
hfk->name.s - via->branch->value.s
- via->branch->value.len);
tbuf_len += hfk->name.s - via->branch->value.s
- via->branch->value.len;
/* copy from after hfk to the end of sip message */
memcpy(tbuf+tbuf_len, hfk->name.s + hfk->len,
msg.buf + msg.len - hfk->name.s - hfk->len);
tbuf_len += msg.buf + msg.len - hfk->name.s - hfk->len;
} else {
/* copy from after via to the end of sip message */
memcpy(tbuf+tbuf_len, via->branch->value.s + via->branch->value.len,
msg.buf + msg.len - via->branch->value.s
- via->branch->value.len);
tbuf_len += msg.buf+msg.len - via->branch->value.s
- via->branch->value.len;
}
}
/* replace old msg content */
nbuf.s = pkg_malloc((tbuf_len+1)*sizeof(char));
if(nbuf.s==NULL) {
LM_ERR("not enough memory for new message\n");
goto done;
}
pkg_free(obuf->s);
obuf->s = nbuf.s;
memcpy(obuf->s, tbuf, tbuf_len);
obuf->s[tbuf_len] = 0;
obuf->len = tbuf_len;
done:
if(dlg!=NULL) dlg_release(dlg);
free_sip_msg(&msg);
return 0;
}
/**
*
*/
int dlg_register_cseq_callbacks(void)
{
sr_event_register_cb(SREV_NET_DATA_IN, dlg_cseq_msg_received);
sr_event_register_cb(SREV_NET_DATA_OUT, dlg_cseq_msg_sent);
return 0;
}