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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2013, Digium, Inc.
*
* Mark Michelson <mmichelson@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*** MODULEINFO
<depend>pjproject</depend>
<depend>res_sip</depend>
<support_level>core</support_level>
***/
#include "asterisk.h"
#include <pjsip.h>
#include "asterisk/res_sip.h"
#include "asterisk/module.h"
#include "asterisk/logger.h"
#include "asterisk/sorcery.h"
#include "asterisk/acl.h"
/*** DOCUMENTATION
<configInfo name="res_sip_acl" language="en_US">
<synopsis>SIP ACL module</synopsis>
<description><para>
<emphasis>ACL</emphasis>
</para>
<para>The ACL module used by <literal>res_sip</literal>. This module is
independent of <literal>endpoints</literal> and operates on all inbound
SIP communication using res_sip.
</para><para>
It should be noted that this module can also reference ACLs from
<filename>acl.conf</filename>.
</para><para>
There are two main ways of creating an access list: <literal>IP-Domain</literal>
and <literal>Contact Header</literal>. It is possible to create a combined ACL using
both IP and Contact.
</para></description>
<configFile name="res_sip.conf">
<configObject name="acl">
<synopsis>Access Control List</synopsis>
<configOption name="acl">
<synopsis>Name of IP ACL</synopsis>
<description><para>
This matches sections configured in <literal>acl.conf</literal>
</para></description>
</configOption>
<configOption name="contactacl">
<synopsis>Name of Contact ACL</synopsis>
<description><para>
This matches sections configured in <literal>acl.conf</literal>
</para></description>
</configOption>
<configOption name="contactdeny">
<synopsis>List of Contact Header addresses to Deny</synopsis>
</configOption>
<configOption name="contactpermit">
<synopsis>List of Contact Header addresses to Permit</synopsis>
</configOption>
<configOption name="deny">
<synopsis>List of IP-domains to deny access from</synopsis>
</configOption>
<configOption name="permit">
<synopsis>List of IP-domains to allow access from</synopsis>
</configOption>
<configOption name="type">
<synopsis>Must be of type 'acl'.</synopsis>
</configOption>
</configObject>
</configFile>
</configInfo>
***/
struct sip_acl {
SORCERY_OBJECT(details);
struct ast_acl_list *acl;
struct ast_acl_list *contact_acl;
};
static int apply_acl(pjsip_rx_data *rdata, struct ast_acl_list *acl)
{
struct ast_sockaddr addr;
if (ast_acl_list_is_empty(acl)) {
return 0;
}
memset(&addr, 0, sizeof(addr));
ast_sockaddr_parse(&addr, rdata->pkt_info.src_name, PARSE_PORT_FORBID);
ast_sockaddr_set_port(&addr, rdata->pkt_info.src_port);
if (ast_apply_acl(acl, &addr, "SIP ACL: ") != AST_SENSE_ALLOW) {
ast_log(LOG_WARNING, "Incoming SIP message from %s did not pass ACL test\n", ast_sockaddr_stringify(&addr));
return 1;
}
return 0;
}
static int extract_contact_addr(pjsip_contact_hdr *contact, struct ast_sockaddr **addrs)
{
pjsip_sip_uri *sip_uri;
char host[256];
if (!contact) {
return 0;
}
if (!PJSIP_URI_SCHEME_IS_SIP(contact->uri) && !PJSIP_URI_SCHEME_IS_SIPS(contact->uri)) {
return 0;
}
sip_uri = pjsip_uri_get_uri(contact->uri);
ast_copy_pj_str(host, &sip_uri->host, sizeof(host));
return ast_sockaddr_resolve(addrs, host, PARSE_PORT_FORBID, AST_AF_UNSPEC);
}
static int apply_contact_acl(pjsip_rx_data *rdata, struct ast_acl_list *contact_acl)
{
int num_contact_addrs;
int forbidden = 0;
struct ast_sockaddr *contact_addrs;
int i;
pjsip_contact_hdr *contact = (pjsip_contact_hdr *)&rdata->msg_info.msg->hdr;
if (ast_acl_list_is_empty(contact_acl)) {
return 0;
}
while ((contact = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_CONTACT, contact->next))) {
num_contact_addrs = extract_contact_addr(contact, &contact_addrs);
if (num_contact_addrs <= 0) {
continue;
}
for (i = 0; i < num_contact_addrs; ++i) {
if (ast_apply_acl(contact_acl, &contact_addrs[i], "SIP Contact ACL: ") != AST_SENSE_ALLOW) {
ast_log(LOG_WARNING, "Incoming SIP message from %s did not pass ACL test\n", ast_sockaddr_stringify(&contact_addrs[i]));
forbidden = 1;
break;
}
}
ast_free(contact_addrs);
if (forbidden) {
/* No use checking other contacts if we already have failed ACL check */
break;
}
}
return forbidden;
}
static int check_acls(void *obj, void *arg, int flags)
{
struct sip_acl *acl = obj;
pjsip_rx_data *rdata = arg;
if (apply_acl(rdata, acl->acl) || apply_contact_acl(rdata, acl->contact_acl)) {
return CMP_MATCH | CMP_STOP;
}
return 0;
}
static pj_bool_t acl_on_rx_msg(pjsip_rx_data *rdata)
{
int forbidden = 0;
struct ao2_container *acls = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "acl", AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
struct sip_acl *matched_acl;
if (!acls) {
ast_log(LOG_ERROR, "Unable to retrieve ACL sorcery data\n");
return PJ_FALSE;
}
matched_acl = ao2_callback(acls, 0, check_acls, rdata);
if (matched_acl) {
forbidden = 1;
ao2_ref(matched_acl, -1);
}
ao2_ref(acls, -1);
if (forbidden) {
if (rdata->msg_info.msg->line.req.method.id != PJSIP_ACK_METHOD) {
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 403, NULL, NULL, NULL);
}
return PJ_TRUE;
}
return PJ_FALSE;
}
static pjsip_module acl_module = {
.name = { "ACL Module", 14 },
/* This should run after a logger but before anything else */
.priority = 1,
.on_rx_request = acl_on_rx_msg,
};
static int acl_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
struct sip_acl *acl = obj;
int error;
int ignore;
if (!strncmp(var->name, "contact", 7)) {
ast_append_acl(var->name + 7, var->value, &acl->contact_acl, &error, &ignore);
} else {
ast_append_acl(var->name, var->value, &acl->acl, &error, &ignore);
}
return error;
}
static void sip_acl_destructor(void *obj)
{
struct sip_acl *acl = obj;
acl->acl = ast_free_acl_list(acl->acl);
acl->contact_acl = ast_free_acl_list(acl->contact_acl);
}
static void *sip_acl_alloc(const char *name)
{
struct sip_acl *acl = ao2_alloc(sizeof(*acl), sip_acl_destructor);
if (!acl) {
return NULL;
}
return acl;
}
static int load_acls(void)
{
ast_sorcery_apply_default(ast_sip_get_sorcery(), "acl", "config", "res_sip.conf,criteria=type=acl");
if (ast_sorcery_object_register(ast_sip_get_sorcery(), "acl", sip_acl_alloc, NULL, NULL)) {
ast_log(LOG_ERROR, "Failed to register SIP ACL object with sorcery\n");
return -1;
}
ast_sorcery_object_field_register(ast_sip_get_sorcery(), "acl", "type", "", OPT_NOOP_T, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "permit", "", acl_handler, NULL, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "deny", "", acl_handler, NULL, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "acl", "", acl_handler, NULL, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "contactpermit", "", acl_handler, NULL, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "contactdeny", "", acl_handler, NULL, 0, 0);
ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "acl", "contactacl", "", acl_handler, NULL, 0, 0);
/* XXX Is there a more selective way to do this? (i.e. Just reload a specific object type?) */
ast_sorcery_reload(ast_sip_get_sorcery());
return 0;
}
static int load_module(void)
{
if (load_acls()) {
return AST_MODULE_LOAD_DECLINE;
}
ast_sip_register_service(&acl_module);
return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module(void)
{
ast_sip_unregister_service(&acl_module);
return 0;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "SIP ACL Resource",
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND,
);
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