acl.h File Reference

Access Control of various sorts. More...

#include "asterisk/network.h"
#include "asterisk/netsock2.h"
#include "asterisk/io.h"

Include dependency graph for acl.h:

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Go to the source code of this file.

Data Structures
struct	ast_ha
	internal representation of acl entries In principle user applications would have no need for this, but there is sometimes a need to extract individual items, e.g. to print them, and rather than defining iterators to navigate the list, and an externally visible 'struct ast_ha_entry', at least in the short term it is more convenient to make the whole thing public and let users play with them. More...
Defines
#define	AST_SENSE_ALLOW   1
#define	AST_SENSE_DENY   0
Functions
struct ast_ha *	ast_append_ha (const char *sense, const char *stuff, struct ast_ha *path, int *error)
	Add a new rule to a list of HAs.
int	ast_apply_ha (const struct ast_ha *ha, const struct ast_sockaddr *addr)
	Apply a set of rules to a given IP address.
void	ast_copy_ha (const struct ast_ha *from, struct ast_ha *to)
	Copy the contents of one HA to another.
struct ast_ha *	ast_duplicate_ha_list (struct ast_ha *original)
	Duplicate the contents of a list of host access rules.
int	ast_find_ourip (struct ast_sockaddr *ourip, const struct ast_sockaddr *bindaddr, int family)
	Find our IP address.
void	ast_free_ha (struct ast_ha *ha)
	Free a list of HAs.
int	ast_get_ip (struct ast_sockaddr *addr, const char *hostname)
	Get the IP address given a hostname.
int	ast_get_ip_or_srv (struct ast_sockaddr *addr, const char *hostname, const char *service)
	Get the IP address given a hostname and optional service.
int	ast_lookup_iface (char *iface, struct ast_sockaddr *address)
	Find an IP address associated with a specific interface.
int	ast_ouraddrfor (const struct ast_sockaddr *them, struct ast_sockaddr *us)
	Get our local IP address when contacting a remote host.
int	ast_str2cos (const char *value, unsigned int *cos)
	Convert a string to the appropriate COS value.
int	ast_str2tos (const char *value, unsigned int *tos)
	Convert a string to the appropriate TOS value.
const char *	ast_tos2str (unsigned int tos)
	Convert a TOS value into its string representation.

---

Detailed Description

Access Control of various sorts.

Definition in file acl.h.

---

Define Documentation

#define AST_SENSE_ALLOW   1

Definition at line 36 of file acl.h.

Referenced by apply_directmedia_ha(), ast_append_ha(), ast_apply_ha(), ast_sip_ouraddrfor(), and parse_register_contact().

#define AST_SENSE_DENY   0

Definition at line 35 of file acl.h.

Referenced by apply_directmedia_ha(), and ast_append_ha().

---

Function Documentation

struct ast_ha* ast_append_ha	(	const char *	sense,
		const char *	stuff,
		struct ast_ha *	path,
		int *	error
	)		[read]

Add a new rule to a list of HAs.

This adds the new host access rule to the end of the list whose head is specified by the path parameter. Rules are evaluated in a way such that if multiple rules apply to a single IP address/subnet mask, then the rule latest in the list will be used.

Parameters:

	sense	Either "permit" or "deny" (Actually any 'p' word will result in permission, and any other word will result in denial)
	stuff	The IP address and subnet mask, separated with a '/'. The subnet mask can either be in dotted-decimal format or in CIDR notation (i.e. 0-32).
	path	The head of the HA list to which we wish to append our new rule. If NULL is passed, then the new rule will become the head of the list
[out]	error	The integer error points to will be set non-zero if an error occurs

Returns:

The head of the HA list

Definition at line 395 of file acl.c.

References ast_ha::addr, apply_netmask(), ast_calloc, ast_debug, ast_free_ha(), ast_log(), AST_SENSE_ALLOW, AST_SENSE_DENY, ast_sockaddr_ipv4_mapped(), ast_sockaddr_is_ipv4(), ast_sockaddr_parse(), ast_sockaddr_stringify(), ast_strdupa, LOG_NOTICE, LOG_WARNING, ast_ha::netmask, ast_ha::next, parse_cidr_mask(), PARSE_PORT_FORBID, ast_ha::sense, and strsep().

Referenced by __init_manager(), add_calltoken_ignore(), build_callno_limits(), build_device(), build_gateway(), build_peer(), build_user(), config_parse_variables(), and reload_config().

{
   struct ast_ha *ha;
   struct ast_ha *prev = NULL;
   struct ast_ha *ret;
   char *tmp = ast_strdupa(stuff);
   char *address = NULL, *mask = NULL;
   int addr_is_v4;

   ret = path;
   while (path) {
      prev = path;
      path = path->next;
   }

   if (!(ha = ast_calloc(1, sizeof(*ha)))) {
      if (error) {
         *error = 1;
      }
      return ret;
   }

   address = strsep(&tmp, "/");
   if (!address) {
      address = tmp;
   } else {
      mask = tmp;
   }

   if (!ast_sockaddr_parse(&ha->addr, address, PARSE_PORT_FORBID)) {
      ast_log(LOG_WARNING, "Invalid IP address: %s\n", address);
      ast_free_ha(ha);
      if (error) {
         *error = 1;
      }
      return ret;
   }

   /* If someone specifies an IPv4-mapped IPv6 address,
    * we just convert this to an IPv4 ACL
    */
   if (ast_sockaddr_ipv4_mapped(&ha->addr, &ha->addr)) {
      ast_log(LOG_NOTICE, "IPv4-mapped ACL network address specified. "
            "Converting to an IPv4 ACL network address.\n");
   }

   addr_is_v4 = ast_sockaddr_is_ipv4(&ha->addr);

   if (!mask) {
      parse_cidr_mask(&ha->netmask, addr_is_v4, addr_is_v4 ? "32" : "128");
   } else if (strchr(mask, ':') || strchr(mask, '.')) {
      int mask_is_v4;
      /* Mask is of x.x.x.x or x:x:x:x:x:x:x:x variety */
      if (!ast_sockaddr_parse(&ha->netmask, mask, PARSE_PORT_FORBID)) {
         ast_log(LOG_WARNING, "Invalid netmask: %s\n", mask);
         ast_free_ha(ha);
         if (error) {
            *error = 1;
         }
         return ret;
      }
      /* If someone specifies an IPv4-mapped IPv6 netmask,
       * we just convert this to an IPv4 ACL
       */
      if (ast_sockaddr_ipv4_mapped(&ha->netmask, &ha->netmask)) {
         ast_log(LOG_NOTICE, "IPv4-mapped ACL netmask specified. "
               "Converting to an IPv4 ACL netmask.\n");
      }
      mask_is_v4 = ast_sockaddr_is_ipv4(&ha->netmask);
      if (addr_is_v4 ^ mask_is_v4) {
         ast_log(LOG_WARNING, "Address and mask are not using same address scheme.\n");
         ast_free_ha(ha);
         if (error) {
            *error = 1;
         }
         return ret;
      }
   } else if (parse_cidr_mask(&ha->netmask, addr_is_v4, mask)) {
      ast_log(LOG_WARNING, "Invalid CIDR netmask: %s\n", mask);
      ast_free_ha(ha);
      if (error) {
         *error = 1;
      }
      return ret;
   }

   if (apply_netmask(&ha->addr, &ha->netmask, &ha->addr)) {
      /* This shouldn't happen because ast_sockaddr_parse would
       * have failed much earlier on an unsupported address scheme
       */
      char *failmask = ast_strdupa(ast_sockaddr_stringify(&ha->netmask));
      char *failaddr = ast_strdupa(ast_sockaddr_stringify(&ha->addr));
      ast_log(LOG_WARNING, "Unable to apply netmask %s to address %s\n", failmask, failaddr);
      ast_free_ha(ha);
      if (error) {
         *error = 1;
      }
      return ret;
   }

   ha->sense = strncasecmp(sense, "p", 1) ? AST_SENSE_DENY : AST_SENSE_ALLOW;

   ha->next = NULL;
   if (prev) {
      prev->next = ha;
   } else {
      ret = ha;
   }

   {
      const char *addr = ast_strdupa(ast_sockaddr_stringify(&ha->addr));
      const char *mask = ast_strdupa(ast_sockaddr_stringify(&ha->netmask));

      ast_debug(1, "%s/%s sense %d appended to acl for peer\n", addr, mask, ha->sense);
   }

   return ret;
}

int ast_apply_ha	(	const struct ast_ha *	ha,
		const struct ast_sockaddr *	addr
	)

Apply a set of rules to a given IP address.

The list of host access rules is traversed, beginning with the input rule. If the IP address given matches a rule, the "sense" of that rule is used as the return value. Note that if an IP address matches multiple rules that the last one matched will be the one whose sense will be returned.

Parameters:

ha	The head of the list of host access rules to follow
addr	An ast_sockaddr whose address is considered when matching rules

Return values:

AST_SENSE_ALLOW	The IP address passes our ACL
AST_SENSE_DENY	The IP address fails our ACL

Definition at line 514 of file acl.c.

References ast_ha::addr, apply_netmask(), ast_copy_string(), ast_debug, ast_inet_ntoa(), AST_SENSE_ALLOW, ast_sockaddr_cmp_addr(), ast_sockaddr_ipv4_mapped(), ast_sockaddr_is_ipv4(), ast_sockaddr_is_ipv4_mapped(), ast_sockaddr_is_ipv6(), ast_ha::netmask, ast_ha::next, and ast_ha::sense.

Referenced by apply_directmedia_ha(), ast_sip_ouraddrfor(), auth_http_callback(), authenticate(), check_access(), check_peer_ok(), parse_register_contact(), register_verify(), and skinny_register().

{
   /* Start optimistic */
   int res = AST_SENSE_ALLOW;
   const struct ast_ha *current_ha;

   for (current_ha = ha; current_ha; current_ha = current_ha->next) {
      struct ast_sockaddr result;
      struct ast_sockaddr mapped_addr;
      const struct ast_sockaddr *addr_to_use;
#if 0 /* debugging code */
      char iabuf[INET_ADDRSTRLEN];
      char iabuf2[INET_ADDRSTRLEN];
      /* DEBUG */
      ast_copy_string(iabuf, ast_inet_ntoa(sin->sin_addr), sizeof(iabuf));
      ast_copy_string(iabuf2, ast_inet_ntoa(ha->netaddr), sizeof(iabuf2));
      ast_debug(1, "##### Testing %s with %s\n", iabuf, iabuf2);
#endif
      if (ast_sockaddr_is_ipv4(&ha->addr)) {
         if (ast_sockaddr_is_ipv6(addr)) {
            if (ast_sockaddr_is_ipv4_mapped(addr)) {
               /* IPv4 ACLs apply to IPv4-mapped addresses */
               ast_sockaddr_ipv4_mapped(addr, &mapped_addr);
               addr_to_use = &mapped_addr;
            } else {
               /* An IPv4 ACL does not apply to an IPv6 address */
               continue;
            }
         } else {
            /* Address is IPv4 and ACL is IPv4. No biggie */
            addr_to_use = addr;
         }
      } else {
         if (ast_sockaddr_is_ipv6(addr) && !ast_sockaddr_is_ipv4_mapped(addr)) {
            addr_to_use = addr;
         } else {
            /* Address is IPv4 or IPv4 mapped but ACL is IPv6. Skip */
            continue;
         }
      }

      /* For each rule, if this address and the netmask = the net address
         apply the current rule */
      if (apply_netmask(addr_to_use, &current_ha->netmask, &result)) {
         /* Unlikely to happen since we know the address to be IPv4 or IPv6 */
         continue;
      }
      if (!ast_sockaddr_cmp_addr(&result, &current_ha->addr)) {
         res = current_ha->sense;
      }
   }
   return res;
}

void ast_copy_ha	(	const struct ast_ha *	from,
		struct ast_ha *	to
	)

Copy the contents of one HA to another.

This copies the internals of the 'from' HA to the 'to' HA. It is important that the 'to' HA has been allocated prior to calling this function

Parameters:

from	Source HA to copy
to	Destination HA to copy to

Return values:

void

Definition at line 230 of file acl.c.

References ast_ha::addr, ast_sockaddr_copy(), ast_ha::netmask, and ast_ha::sense.

Referenced by add_calltoken_ignore(), ast_duplicate_ha(), and build_callno_limits().

{
   ast_sockaddr_copy(&to->addr, &from->addr);
   ast_sockaddr_copy(&to->netmask, &from->netmask);
   to->sense = from->sense;
}

struct ast_ha* ast_duplicate_ha_list

(

struct ast_ha *

original

)

[read]

Duplicate the contents of a list of host access rules.

A deep copy of all ast_has in the list is made. The returned value is allocated on the heap and must be freed independently of the input parameter when finished.

Note:

This function is not actually used anywhere.

Parameters:

original

The ast_ha to copy

Return values:

The	head of the list of duplicated ast_has

Definition at line 252 of file acl.c.

References ast_duplicate_ha(), and ast_ha::next.

Referenced by create_addr_from_peer().

{
   struct ast_ha *start = original;
   struct ast_ha *ret = NULL;
   struct ast_ha *current, *prev = NULL;

   while (start) {
      current = ast_duplicate_ha(start);  /* Create copy of this object */
      if (prev) {
         prev->next = current;           /* Link previous to this object */
      }

      if (!ret) {
         ret = current;                  /* Save starting point */
      }

      start = start->next;                /* Go to next object */
      prev = current;                     /* Save pointer to this object */
   }
   return ret;                             /* Return start of list */
}

int ast_find_ourip	(	struct ast_sockaddr *	ourip,
		const struct ast_sockaddr *	bindaddr,
		int	family
	)

Find our IP address.

This function goes through many iterations in an attempt to find our IP address. If any step along the way should fail, we move to the next item in the list. Here are the steps taken:

• If bindaddr has a non-zero IP address, that is copied into ourip
• We use a combination of gethostname and ast_gethostbyname to find our IP address.
• We use ast_ouraddrfor with 198.41.0.4 as the destination IP address
• We try some platform-specific socket operations to find the IP address

Parameters:

[out]	ourip	Our IP address is written here when it is found
	bindaddr	A hint used for finding our IP. See the steps above for more details
	family	Only addresses of the given family will be returned. Use 0 or AST_SOCKADDR_UNSPEC to get addresses of all families.

Return values:

0	Success
-1	Failure

Definition at line 736 of file acl.c.

References ast_debug, ast_log(), ast_ouraddrfor(), ast_sockaddr_copy(), ast_sockaddr_is_any(), get_local_address(), LOG_WARNING, MAXHOSTNAMELEN, ourhost, PARSE_PORT_FORBID, and resolve_first().

Referenced by __oh323_rtp_create(), gtalk_get_local_ip(), jingle_create_candidates(), load_module(), and reload_config().

{
   char ourhost[MAXHOSTNAMELEN] = "";
   struct ast_sockaddr root;

   /* just use the bind address if it is nonzero */
   if (!ast_sockaddr_is_any(bindaddr)) {
      ast_sockaddr_copy(ourip, bindaddr);
      ast_debug(3, "Attached to given IP address\n");
      return 0;
   }
   /* try to use our hostname */
   if (gethostname(ourhost, sizeof(ourhost) - 1)) {
      ast_log(LOG_WARNING, "Unable to get hostname\n");
   } else {
      if (resolve_first(ourip, ourhost, PARSE_PORT_FORBID, family) == 0) {
         return 0;
      }
   }
   ast_debug(3, "Trying to check A.ROOT-SERVERS.NET and get our IP address for that connection\n");
   /* A.ROOT-SERVERS.NET. */
   if (!resolve_first(&root, "A.ROOT-SERVERS.NET", PARSE_PORT_FORBID, 0) &&
       !ast_ouraddrfor(&root, ourip)) {
      return 0;
   }
   return get_local_address(ourip);
}

void ast_free_ha

(

struct ast_ha *

ha

)

Free a list of HAs.

Given the head of a list of HAs, it and all appended HAs are freed

Parameters:

ha	The head of the list of HAs to free

Return values:

void

Definition at line 219 of file acl.c.

References ast_free, and ast_ha::next.

Referenced by __init_manager(), __sip_destroy(), add_calltoken_ignore(), ast_append_ha(), build_callno_limits(), build_peer(), build_user(), destroy_gateway(), oh323_destroy_peer(), oh323_destroy_user(), peer_destructor(), reload_config(), sip_destroy_peer(), unload_module(), and user_destructor().

{
   struct ast_ha *hal;
   while (ha) {
      hal = ha;
      ha = ha->next;
      ast_free(hal);
   }
}

int ast_get_ip	(	struct ast_sockaddr *	addr,
		const char *	hostname
	)

Get the IP address given a hostname.

Similar in nature to ast_gethostbyname, except that instead of getting an entire hostent structure, you instead are given only the IP address inserted into a ast_sockaddr structure.

Parameters:

addr	The IP address found. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
hostname	The hostname to look up

Return values:

0	Success
-1	Failure

Definition at line 692 of file acl.c.

References ast_get_ip_or_srv().

Referenced by build_gateway(), build_peer(), build_user(), config_parse_variables(), peer_set_srcaddr(), setup_stunaddr(), and stun_monitor_request().

{
   return ast_get_ip_or_srv(addr, hostname, NULL);
}

int ast_get_ip_or_srv	(	struct ast_sockaddr *	addr,
		const char *	hostname,
		const char *	service
	)

Get the IP address given a hostname and optional service.

If the service parameter is non-NULL, then an SRV lookup will be made by prepending the service to the hostname parameter, separated by a '.' For example, if hostname is "example.com" and service is "_sip._udp" then an SRV lookup will be done for "_sip._udp.example.com". If service is NULL, then this function acts exactly like a call to ast_get_ip.

Parameters:

addr	The IP address found. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
hostname	The hostname to look up
service	A specific service provided by the host. A NULL service results in an A-record lookup instead of an SRV lookup

Return values:

0	Success
-1	Failure

Definition at line 589 of file acl.c.

References ast_get_srv(), ast_sockaddr_set_port, PARSE_PORT_FORBID, resolve_first(), and ast_sockaddr::ss.

Referenced by ast_dnsmgr_lookup(), ast_get_ip(), create_addr(), dnsmgr_refresh(), and proxy_update().

{
   char srv[256];
   char host[256];
   int srv_ret = 0;
   int tportno;

   if (service) {
      snprintf(srv, sizeof(srv), "%s.%s", service, hostname);
      if ((srv_ret = ast_get_srv(NULL, host, sizeof(host), &tportno, srv)) > 0) {
         hostname = host;
      }
   }

   if (resolve_first(addr, hostname, PARSE_PORT_FORBID, addr->ss.ss_family) != 0) {
      return -1;
   }

   if (srv_ret > 0) {
      ast_sockaddr_set_port(addr, tportno);
   }

   return 0;
}

int ast_lookup_iface	(	char *	iface,
		struct ast_sockaddr *	address
	)

Find an IP address associated with a specific interface.

Given an interface such as "eth0" we find the primary IP address associated with it using the SIOCGIFADDR ioctl. If the ioctl call should fail, we populate address with 0s.

Note:

This function is not actually used anywhere

Parameters:

	iface	The interface name whose IP address we wish to find
[out]	address	The interface's IP address is placed into this param

Return values:

-1	Failure. address is filled with 0s
0	Success

int ast_ouraddrfor	(	const struct ast_sockaddr *	them,
		struct ast_sockaddr *	us
	)

Get our local IP address when contacting a remote host.

This function will attempt to connect(2) to them over UDP using a source port of 5060. If the connect(2) call is successful, then we inspect the sockaddr_in output parameter of connect(2) to determine the IP address used to connect to them. This IP address is then copied into us.

Parameters:

	them	The IP address to which we wish to attempt to connect
[out]	us	The source IP address used to connect to them

Return values:

-1	Failure
0	Success

Definition at line 697 of file acl.c.

References ast_connect(), ast_debug, ast_getsockname(), ast_log(), ast_sockaddr_is_ipv6(), ast_sockaddr_port, ast_sockaddr_set_port, ast_sockaddr_stringify_addr(), ast_strdupa, LOG_ERROR, and LOG_WARNING.

Referenced by ast_find_ourip(), ast_sip_ouraddrfor(), build_gateway(), find_subchannel_and_lock(), and gtalk_get_local_ip().

{
   int port;
   int s;

   port = ast_sockaddr_port(us);

   if ((s = socket(ast_sockaddr_is_ipv6(them) ? AF_INET6 : AF_INET,
         SOCK_DGRAM, 0)) < 0) {
      ast_log(LOG_ERROR, "Cannot create socket\n");
      return -1;
   }

   if (ast_connect(s, them)) {
      ast_log(LOG_WARNING, "Cannot connect\n");
      close(s);
      return -1;
   }
   if (ast_getsockname(s, us)) {

      ast_log(LOG_WARNING, "Cannot get socket name\n");
      close(s);
      return -1;
   }
   close(s);

   {
      const char *them_addr = ast_strdupa(ast_sockaddr_stringify_addr(them));
      const char *us_addr = ast_strdupa(ast_sockaddr_stringify_addr(us));

      ast_debug(3, "For destination '%s', our source address is '%s'.\n",
            them_addr, us_addr);
   }

   ast_sockaddr_set_port(us, port);

   return 0;
}

int ast_str2cos	(	const char *	value,
		unsigned int *	cos
	)

Convert a string to the appropriate COS value.

Parameters:

	value	The COS string to convert
[out]	cos	The integer representation of that COS value

Return values:

-1	Failure
0	Success

Definition at line 645 of file acl.c.

Referenced by config_parse_variables(), reload_config(), and set_config().

{
   int fval;

   if (sscanf(value, "%30d", &fval) == 1) {
      if (fval < 8) {
          *cos = fval;
          return 0;
      }
   }

   return -1;
}

int ast_str2tos	(	const char *	value,
		unsigned int *	tos
	)

Convert a string to the appropriate TOS value.

Parameters:

	value	The TOS string to convert
[out]	tos	The integer representation of that TOS value

Return values:

-1	Failure
0	Success

Definition at line 659 of file acl.c.

References ARRAY_LEN, name, and dscp_codepoint::space.

Referenced by config_parse_variables(), iax_template_parse(), reload_config(), and set_config().

{
   int fval;
   unsigned int x;

   if (sscanf(value, "%30i", &fval) == 1) {
      *tos = fval & 0xFF;
      return 0;
   }

   for (x = 0; x < ARRAY_LEN(dscp_pool1); x++) {
      if (!strcasecmp(value, dscp_pool1[x].name)) {
         *tos = dscp_pool1[x].space << 2;
         return 0;
      }
   }

   return -1;
}

const char* ast_tos2str

(

unsigned int

tos

)

Convert a TOS value into its string representation.

Parameters:

tos	The TOS value to look up

Returns:

The string equivalent of the TOS value

Definition at line 679 of file acl.c.

References ARRAY_LEN, dscp_codepoint::name, and dscp_codepoint::space.

Referenced by sip_show_settings().

{
   unsigned int x;

   for (x = 0; x < ARRAY_LEN(dscp_pool1); x++) {
      if (dscp_pool1[x].space == (tos >> 2)) {
         return dscp_pool1[x].name;
      }
   }

   return "unknown";
}