DeforaNetworks/siproxd
DeforaNetworks/siproxd
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- added plugin plugin_fix_bogus_via and plugin_stun

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This commit is contained in:
Thomas Ries 2010-01-07 11:29:00 +00:00
parent 9ed7689e4e
commit 1f71f5743c
3 changed files with 422 additions and 4 deletions
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11
src/Makefile.am
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@ -1,5 +1,5 @@
#
# Copyright (C) 2002-2008 Thomas Ries <tries@gmx.net>
# Copyright (C) 2002-2009 Thomas Ries <tries@gmx.net>
#
# This file is part of Siproxd.
#
@ -29,12 +29,14 @@ pkglib_LTLIBRARIES = plugin_demo.la \
plugin_shortdial.la \
plugin_logcall.la \
plugin_defaulttarget.la \
plugin_fix_bogus_via.la
plugin_fix_bogus_via.la \
plugin_stun.la
DLOPENPLUGINS = -dlopen plugin_demo.la \
-dlopen plugin_shortdial.la \
-dlopen plugin_logcall.la \
-dlopen plugin_defaulttarget.la \
-dlopen plugin_fix_bogus_via.la
-dlopen plugin_fix_bogus_via.la \
-dlopen plugin_stun.la
#
plugin_demo_la_SOURCES = plugin_demo.c
plugin_demo_la_LDFLAGS = -module -avoid-version -shrext '.so'
@ -50,6 +52,9 @@ plugin_defaulttarget_la_LDFLAGS = -module -avoid-version -shrext '.so'
#
plugin_fix_bogus_via_la_SOURCES = plugin_fix_bogus_via.c
plugin_fix_bogus_via_la_LDFLAGS = -module -avoid-version -shrext '.so'
#
plugin_stun_la_SOURCES = plugin_stun.c
plugin_stun_la_LDFLAGS = -module -avoid-version -shrext '.so'
#

2
src/plugin_fix_bogus_via.c
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@ -51,7 +51,7 @@ static struct plugin_config {
/* Instructions for config parser */
static cfgopts_t plugin_cfg_opts[] = {
{ "plugin_fix_bogus_via_networks", TYP_STRING, &plugin_cfg.networks },
{ "plugin_fix_bogus_via_networks", TYP_STRING, &plugin_cfg.networks, {0, NULL} },
{0, 0, 0}
};

413
src/plugin_stun.c Normal file
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@ -0,0 +1,413 @@
/*
Copyright (C) 2009 Thomas Ries <tries@gmx.net>
This file is part of Siproxd.
Siproxd 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.
Siproxd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warrantry 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 Siproxd; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* must be defined before including <plugin.h> */
#define PLUGIN_NAME plugin_stun
#include "config.h"
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <osipparser2/osip_parser.h>
#include <osipparser2/osip_md5.h>
#include "siproxd.h"
#include "digcalc.h"
#include "plugins.h"
#include "log.h"
static char const ident[]="$Id$";
/* Plug-in identification */
static char name[]="plugin_stun";
static char desc[]="Use an external STUN server to determine my public IP";
/* global configuration storage - required for config file location */
extern struct siproxd_config configuration;
/* plugin configuration storage */
static struct plugin_config {
char *server;
int port;
int period;
} plugin_cfg;
/* Instructions for config parser */
static cfgopts_t plugin_cfg_opts[] = {
{ "plugin_stun_server", TYP_STRING, &plugin_cfg.server, {0, NULL} },
{ "plugin_stun_port", TYP_INT4, &plugin_cfg.port, {3478, NULL} },
{ "plugin_stun_period", TYP_INT4, &plugin_cfg.period, {300, NULL} },
{0, 0, 0}
};
/*
* module-local function prototypes
*/
static int stun_validate_response(char *buffer, int len, char *tid);
static int stun_send_request(char *tid);
static int stun_new_transaction_id(char *tid);
/*
* constants used in this module
*/
#define STUN_TID_SIZE 16 /* STUN transaction ID size: 16 bytes */
/*
* Initialization.
* Called once suring siproxd startup.
*/
int PLUGIN_INIT(plugin_def_t *plugin_def) {
/* API version number of siproxd that this plugin is built against.
* This constant will change whenever changes to the API are made
* that require adaptions in the plugin. */
plugin_def->api_version=SIPROXD_API_VERSION;
/* Name and descriptive text of the plugin */
plugin_def->name=name;
plugin_def->desc=desc;
/* Execution mask - during what stages of SIP processing shall
* the plugin be called. */
plugin_def->exe_mask=PLUGIN_PROCESS_RAW|PLUGIN_TIMER;
/* read the config file */
if (read_config(configuration.configfile,
configuration.config_search,
plugin_cfg_opts, name) == STS_FAILURE) {
ERROR("Plugin '%s': could not load config file", name);
return STS_FAILURE;
}
/*&&& resolve STUN server
store IP
*/
INFO("plugin_stun is initialized, using %s:%i as STUN server",
plugin_cfg.server, plugin_cfg.port);
return STS_SUCCESS;
}
/*
* Processing.
*
*/
int PLUGIN_PROCESS(int stage, sip_ticket_t *ticket){
static time_t next_stun_send=0;
static int rq_pending=0; /* !=0 if waiting for response (ongoing dialog) */
static char stun_transaction_id[STUN_TID_SIZE];
time_t now;
int sts;
/* stage contains the PLUGIN_* value - the stage of SIP processing. */
DEBUGC(DBCLASS_BABBLE, "called in stage %i, rq_pending=%i",
stage, rq_pending);
time(&now);
switch (stage) {
case PLUGIN_TIMER:
if (next_stun_send <= now) {
/* compose and send new STUN request */
DEBUGC(DBCLASS_BABBLE, "preparing to send STUN request");
/* allocate transaction ID if a new STUN transaction */
if (rq_pending == 0) {
sts = stun_new_transaction_id(stun_transaction_id);
}
/* send STUN BIND request */
sts = stun_send_request(stun_transaction_id);
rq_pending=1;
/* 10 seconds T/O to receive answer until retrying */
next_stun_send = now + 10;
}
break;
case PLUGIN_PROCESS_RAW:
/* raw UDP packet: ticket->raw_buffer, len: ticket->raw_buffer_len */
sts = stun_validate_response(ticket->raw_buffer,
ticket->raw_buffer_len,
stun_transaction_id);
if (sts == STS_SUCCESS) {
/* is a valid response to our last STUN request */
/* This is about what we get:
+-----------------+-----------------+
|........¦..type..|........¦...len..| [0]..[4]
+-----------------+-----------------+
| Transaction ID | [5]..
| |
| |
| | ..[19]
+-----------------+-----------------+
|........¦.type...|........¦...len..| [20].. Attribute
+-----------------+-----------------+
| len bytes |
| |
+-----------------+-----------------+
|........¦.type...|........¦...len..| Attribute
+-----------------+-----------------+
| |
...
*/
{ /* clean up & move to function! */
int i, j;
int len=ticket->raw_buffer_len;
char *buffer=ticket->raw_buffer;
int iptype;
int port;
unsigned char ip[4];
char ipstring[IPSTRING_SIZE];
int got_address=0;
i=20; // 1st attribute position
while (i+4 <= len) {
int attr_typ = ntohs(*((int *)&buffer[i]) & 0x0000ffff);
int attr_len = ntohs(*((int *)&buffer[i+2]) & 0x0000ffff);
DEBUGC(DBCLASS_BABBLE,"STUN response: i=%i, type=%i, len=%i",
i, attr_typ, attr_len);
/* check if attribute is fully contained in message */
if ((i+4+attr_len) > len) {
DEBUGC(DBCLASS_BABBLE,"corrupt STUN response");
break;
}
/* advance to start of attribute */
i = i+4;
switch (attr_typ) {
/* 0x0001 Mapped Address */
case 0x0001:
DEBUGC(DBCLASS_BABBLE,"Mapped Addr, len=%i", attr_len);
iptype=*((int*)&buffer[i+1]) & 0x000000ff;
if (iptype != 0x0001) {
DEBUGC(DBCLASS_BABBLE,
"Mapped Addr, wrong proto family [%i]", iptype);
break;
}
port=htons(*((int*)&buffer[i+2]) & 0x0000ffff);
memcpy(ip,&buffer[i+4], 4);
DEBUGC(DBCLASS_BABBLE,"STUN: public IP %u.%u.%u.%u:%i",
ip[0], ip[1], ip[2], ip[3], port);
/* remember normal IP address only if not yet known */
if (got_address == 0) {
snprintf(ipstring, IPSTRING_SIZE-1, "%u.%u.%u.%u",
ip[0], ip[1], ip[2], ip[3]);
ipstring[IPSTRING_SIZE-1]='\0';
got_address=1;
}
break;
/* 0x8020 XOR Mapped Address */
case 0x8020:
DEBUGC(DBCLASS_BABBLE,"XOR Mapped Addr, len=%i", attr_len);
iptype=*((int*)&buffer[i+1]) & 0x000000ff;
if (iptype != 0x0001) {
DEBUGC(DBCLASS_BABBLE,
"Mapped Addr, wrong proto family [%i]", iptype);
break;
}
port=*((int*)&buffer[i+2]) & 0x0000ffff;
/* XOR the port with start of TID */
port = htons(port ^ *((short int*)stun_transaction_id));
memcpy(ip,&buffer[i+4], 4);
/* XOR the IP with start of TID */
for (j=0; j<4; j++) {
ip[j]=ip[j] ^ stun_transaction_id[j];
}
DEBUGC(DBCLASS_BABBLE,"STUN: public IP %u.%u.%u.%u:%i",
ip[0], ip[1], ip[2], ip[3], port);
/* remember XORed IP address always (preferred) */
snprintf(ipstring, IPSTRING_SIZE-1, "%u.%u.%u.%u",
ip[0], ip[1], ip[2], ip[3]);
ipstring[IPSTRING_SIZE-1]='\0';
got_address=1;
break;
default:
/* don't care... */
break;
}
/* advance to next attribute */
i=i+attr_len;
}
if (got_address && (
(configuration.outbound_host == NULL) ||
(strcmp(configuration.outbound_host, ipstring) != 0) ) ) {
INFO("STUN: public IP has changed %s -> %s",
(configuration.outbound_host) ?
configuration.outbound_host:"NULL" ,
ipstring);
if (configuration.outbound_host) {
free(configuration.outbound_host);
}
configuration.outbound_host=malloc(IPSTRING_SIZE);
strcpy(configuration.outbound_host, ipstring);
}
}
/*&&&
if XOR address and normal address do not match I may have a
serious problem (IP provider not passing public IPs to clients).
Some linksys routers seem to alter the "normal" IP to be
the WAN IP, that may make such a situation visible.
How can we deal with such a thing? We cannot change the NAT on
the provider side, can we? This will be WAY out os scope of siproxds
capabilities.
I should issue an WARNING on such a detected situation.
*/
rq_pending=0; /* received answer, good */
next_stun_send = now + plugin_cfg.period;
DEBUGC(DBCLASS_BABBLE,"next STUN request in %i sec at %i",
plugin_cfg.period, (int)next_stun_send);
return STS_FAILURE; /* done, do not further process as SIP */
}
break;
default:
break;
}
return STS_SUCCESS;
}
/*
* De-Initialization.
* Called during shutdown of siproxd. Gives the plugin the chance
* to clean up its mess (e.g. dynamic memory allocation, database
* connections, whatever the plugin messes around with)
*/
int PLUGIN_END(plugin_def_t *plugin_def){
return STS_SUCCESS;
}
/*
* module-local functions
*/
static int stun_validate_response(char *buffer, int len, char *tid){
/* expect min. STUN header + 1 attribute */
if (len < 24) {
DEBUGC(DBCLASS_BABBLE,"stun_validate_response: no STUN response (too short)");
return STS_FAILURE;
}
if (ntohs(*((int*)&buffer[0]) & 0x0000ffff) != 0x0101) {
DEBUGC(DBCLASS_BABBLE,"stun_validate_response: no STUN response (type)");
return STS_FAILURE;
}
if (memcmp(&buffer[4], tid, STUN_TID_SIZE) != 0) {
DEBUGC(DBCLASS_BABBLE,"stun_validate_response: wrono STUN response (TID)");
return STS_FAILURE;
}
DEBUGC(DBCLASS_BABBLE,"valid STUN response");
return STS_SUCCESS;
}
static int stun_send_request(char *tid){
struct in_addr addr;
int sts;
char stun_rq[28]; /*&&& testing */
int size=28;
/* name resolution */
if (utils_inet_aton(plugin_cfg.server, &addr) == 0)
{
/* need name resolution */
DEBUGC(DBCLASS_DNS,"resolving name:%s", plugin_cfg.server);
sts = get_ip_by_host(plugin_cfg.server, &addr);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_DNS, "stun_send_request: cannot resolve STUN server [%s]",
plugin_cfg.server);
return STS_FAILURE;
}
}
/* compose STUN BIND request - poor mans way */
stun_rq[0]=0x00; // type
stun_rq[1]=0x01;
stun_rq[2]=0x00; // length
stun_rq[3]=0x08;
memcpy (&stun_rq[4], tid, STUN_TID_SIZE);
stun_rq[20]=0x00; // ATTR change request
stun_rq[21]=0x03;
stun_rq[22]=0x00; // ATTR len 4
stun_rq[23]=0x04;
stun_rq[24]=0x00; // Change IP not set, Change port not set
stun_rq[25]=0x00;
stun_rq[26]=0x00;
stun_rq[27]=0x00;
/* and send via the SIP UDP port */
sts = sipsock_send(addr, plugin_cfg.port, PROTO_UDP, stun_rq, size);
return STS_SUCCESS;
}
static int stun_new_transaction_id(char *tid) {
time_t now;
/* OSIP MD5 hash lenght is 16 bytes (32 hex digits),
* so this does fit for STUN transaction ID... */
osip_MD5_CTX Md5Ctx;
HASH HA1;
time(&now);
/* calc MD5 from servername + timestamp */
osip_MD5Init(&Md5Ctx);
if (plugin_cfg.server) osip_MD5Update(&Md5Ctx,
(unsigned char*)plugin_cfg.server,
strlen(plugin_cfg.server));
osip_MD5Update(&Md5Ctx, (unsigned char*)&now, sizeof(now));
osip_MD5Final(HA1, &Md5Ctx);
memcpy(tid, HA1, (STUN_TID_SIZE<HASHLEN)? STUN_TID_SIZE:HASHLEN);
return STS_SUCCESS;
}