resolve.h File Reference

DNS resolver related functions. More...

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/nameser.h>
#include "ip_addr.h"
#include "proxy.h"

Include dependency graph for resolve.h:

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Go to the source code of this file.

Data Structures

struct a_rdata

A rec. struct. More...

struct aaaa_rdata

struct cname_rdata

cname rec. struct More...

struct dns_node

DNS failover related structures. More...

union dns_query

query union More...

struct ebl_rdata

EBL rec. struct. More...

struct naptr_rdata

naptr rec. struct More...

struct rdata

rdata struct More...

struct srv_rdata

srv rec. struct More...

struct txt_rdata

txt rec. struct More...

Defines

#define ANS_SIZE   8192

#define DNS_HDR_SIZE   12

#define get_naptr(_rdata)   ( ((struct naptr_rdata*)(_rdata)->rdata) )

#define get_srv(_rdata)   ( ((struct srv_rdata*)(_rdata)->rdata) )

#define HEX2I(c)

#define MAX_DNS_NAME   256

#define MAX_DNS_STRING   255

#define MAX_QUERY_SIZE   8192

#define rev_resolvehost(ip)   gethostbyaddr((char*)(ip)->u.addr, (ip)->len, (ip)->af);

#define T_EBL   65300

this is not official yet

Functions

struct dns_node * dns_res_copy (struct dns_node *s)

make a perfect copy of a resolver state machine

void free_dns_res (struct proxy_l *p)

free the DNS resolver state machine

void free_rdata_list (struct rdata *head)

frees completely a struct rdata list

int get_next_su (struct proxy_l *p, union sockaddr_union *su, int add_to_bl)

taked the next destination from a resolver state machine

struct rdata * get_record (char *name, int type)

Hets the DNS records for name:type.

int resolv_blacklist_init (void)

Initialize blacklist.

int resolv_init (void)

Initialize the DNS resolver retr_time - time before retransmitting (must be >0) retr_no - retransmissions number servers_no - how many dns servers will be used (from the one listed in /etc/resolv.conf) search - if 0 the search list in /etc/resolv.conf will be ignored (HINT: even if you don't have a search list in resolv.conf, it's still better to set search to 0, because an empty searchlist means in fact search "" => it takes more time) If any of the parameters <0, the default (system specific) value will be used. See also resolv.conf(5).

static struct hostent * resolvehost (char *name, int no_ip_test)

gethostbyname wrappers use this, someday they will use a local cache

struct hostent * sip_resolvehost (str *name, unsigned short *port, unsigned short *proto, int is_sips, struct dns_node **dn)

Resolve SIP hostname to ip address, protocol and port.

static struct ip_addr * str2ip (str *st)

converts a str to an ipv4 address, returns the address or 0 on error Warning: the result is a pointer to a statically allocated structure

static struct ip_addr * str2ip6 (str *st)

returns an ip_addr struct.; on error returns 0 the ip_addr struct is static, so subsequent calls will destroy its content

Variables

int dns_try_ipv6

Detailed Description

DNS resolver related functions.

Definition in file resolve.h.

Define Documentation

#define ANS_SIZE 8192

Definition at line 52 of file resolve.h.

Referenced by get_record().

#define DNS_HDR_SIZE 12

Definition at line 53 of file resolve.h.

Referenced by get_record().

#define get_naptr ( _rdata ) ( ((struct naptr_rdata*)(_rdata)->rdata) )

Definition at line 161 of file resolve.h.

Referenced by filter_and_sort_naptr(), sip_resolvehost(), and srv2dns_node().

#define get_srv ( _rdata ) ( ((struct srv_rdata*)(_rdata)->rdata) )

Definition at line 164 of file resolve.h.

Referenced by a2dns_node().

#define HEX2I ( c )

Value:

(  (((c)>='0') && ((c)<='9'))? (c)-'0' :  \
      (((c)>='A') && ((c)<='F'))? ((c)-'A')+10 : \
      (((c)>='a') && ((c)<='f'))? ((c)-'a')+10 : -1 )

Definition at line 155 of file resolve.h.

Referenced by str2ip6().

#define MAX_DNS_NAME 256

Definition at line 54 of file resolve.h.

Referenced by dns_cname_parser(), dns_ebl_parser(), dns_naptr_parser(), dns_srv_parser(), and sip_resolvehost().

#define MAX_DNS_STRING 255

Definition at line 55 of file resolve.h.

#define MAX_QUERY_SIZE 8192

Definition at line 51 of file resolve.h.

#define rev_resolvehost ( ip ) gethostbyaddr((char*)(ip)->u.addr, (ip)->len, (ip)->af);

Definition at line 150 of file resolve.h.

Referenced by check_via_address(), comp_ip(), and fix_socket_list().

#define T_EBL 65300

this is not official yet

Definition at line 58 of file resolve.h.

Referenced by get_record(), and i_enum_query_2().

Function Documentation

struct dns_node* dns_res_copy ( struct dns_node * s ) [read]

make a perfect copy of a resolver state machine

Definition at line 1310 of file resolve.c.

References dns_node_copy(), dns_node::kids, NULL, and shm_free.

Referenced by shm_clone_proxy().

void free_dns_res ( struct proxy_l * p )

free the DNS resolver state machine

Definition at line 1226 of file resolve.c.

References proxy_l::dn, dns_node::kids, NULL, and shm_free.

Referenced by free_proxy(), free_shm_proxy(), get_next_su(), mk_proxy(), and mk_shm_proxy().

void free_rdata_list ( struct rdata * head )

frees completely a struct rdata list

Definition at line 439 of file resolve.c.

References local_free, rdata::next, and rdata::rdata.

Referenced by do_query(), do_srv_lookup(), enum_pv_query_3(), get_record(), i_enum_query_2(), is_from_user_enum_2(), sip_resolvehost(), and sort_srvs().

int get_next_su	(	struct proxy_l *	p,
		union sockaddr_union *	su,
		int	add_to_bl
	)

taked the next destination from a resolver state machine

Definition at line 1239 of file resolve.c.

References add_list_to_head(), add_rule_to_list(), proxy_l::addr_idx, ip_addr::af, proxy_l::dn, DNS_BL_EXPIRE, proxy_l::flags, free_dns_res(), free_hostent(), free_shm_hostent(), get_next_he(), proxy_l::host, hostent2ip_addr, hostent2su(), hostent_cpy(), hostent_shm_cpy(), net::ip, ip_addr::len, LM_ERR, net::mask, NULL, proxy_l::port, proxy_l::proto, PROXY_SHM_FLAG, and SIP_PORT.

Referenced by do_dns_failover(), forward_request(), forward_sl_request(), t_forward_nonack(), trace_send_duplicate(), and utils_forward().

struct rdata* get_record	(	char *	name,
		int	type
	)			`[read]`

Hets the DNS records for name:type.

Returns:: a dyn. alloc'ed struct rdata linked list with the parsed responses or 0 on error

Note:: see rfc1035 for the query/response format

Definition at line 460 of file resolve.c.

References ANS_SIZE, dns_query::buff, rdata::class, dns_a_parser(), dns_aaaa_parser(), dns_cname_parser(), dns_ebl_parser(), DNS_HDR_SIZE, dns_naptr_parser(), dns_skipname(), dns_srv_parser(), dns_txt_parser(), free_rdata_list(), dns_query::hdr, LM_DBG, LM_ERR, local_free, local_malloc, rdata::next, srv_rdata::priority, rdata::rdata, T_EBL, rdata::ttl, rdata::type, and srv_rdata::weight.

Referenced by do_query(), do_srv_lookup(), dp_can_connect_str(), enum_pv_query_3(), i_enum_query_2(), is_from_user_enum_2(), and sip_resolvehost().

int resolv_blacklist_init ( void )

Initialize blacklist.

Definition at line 115 of file resolve.c.

References BL_BY_DEFAULT, BL_DO_EXPIRE, create_bl_head(), disable_dns_blacklist, DNS_REVOLVER_BL_ID, DNS_REVOLVER_BL_NAME, LM_ERR, bl_head::name, NULL, and str_init.

Referenced by main().

int resolv_init ( void )

Initialize the DNS resolver retr_time - time before retransmitting (must be >0) retr_no - retransmissions number servers_no - how many dns servers will be used (from the one listed in /etc/resolv.conf) search - if 0 the search list in /etc/resolv.conf will be ignored (HINT: even if you don't have a search list in resolv.conf, it's still better to set search to 0, because an empty searchlist means in fact search "" => it takes more time) If any of the parameters <0, the default (system specific) value will be used. See also resolv.conf(5).

Returns:: 0 on success, -1 on error

Definition at line 93 of file resolve.c.

References dns_retr_no, dns_retr_time, dns_search_list, dns_servers_no, and LM_WARN.

Referenced by main().

static struct hostent* resolvehost	(	char *	name,
		int	no_ip_test
	)			`[static, read]`

gethostbyname wrappers use this, someday they will use a local cache

Definition at line 315 of file resolve.h.

References dns_try_ipv6, ip_addr2he(), _str::len, _str::s, s, str2ip(), and str2ip6().

Referenced by add_dest2list(), comp_ip(), do_srv_lookup(), fix_actions(), fix_socket_list(), get_next_he(), mi_mod_init(), seas_init(), sip_resolvehost(), and start_stats_server().

struct hostent* sip_resolvehost	(	str *	name,
		unsigned short *	port,
		unsigned short *	proto,
		int	is_sips,
		struct dns_node **	dn
	)			`[read]`

Resolve SIP hostname to ip address, protocol and port.

Resolve SIP hostname to ip address, protocol and port if necessary. If no port is given, it will be resolved with SRV, if additional no protocol is given, then it will be resolved with NAPTR. This function fallback from NAPTR to SRV and then to A record lookup, if no valid records could be found. If the NAPTR lookup fails, it will use the TLS (for SIPS) or UDP protocol, if the SRV lookup fails, it will use the default port for SIP or SIPS. If the hostname is already an IP address, it will also use the default port and protocol.

Parameters:

	name	hostname
	port	port, set to 0 if you want to resolve it
	proto	SIP protocol, set to PROTO_NONE if you want to resolve it
	is_sips	set to true for SIPS
	dn	DNS node

Returns:: host IP address, or zero on errors

Definition at line 978 of file resolve.c.

References do_srv_lookup(), filter_and_sort_naptr(), free_rdata_list(), get_naptr, get_naptr_proto(), get_record(), ip_addr2he(), _str::len, LM_DBG, LM_ERR, LM_WARN, MAX_DNS_NAME, rdata::next, NULL, PROTO_NONE, PROTO_SCTP, PROTO_TCP, PROTO_TLS, PROTO_UDP, resolvehost(), _str::s, shm_free, SIP_PORT, SIPS_PORT, srv2dns_node(), SRV_MAX_PREFIX_LEN, SRV_SCTP_PREFIX, SRV_SCTP_PREFIX_LEN, SRV_TCP_PREFIX, SRV_TCP_PREFIX_LEN, SRV_TLS_PREFIX, SRV_TLS_PREFIX_LEN, SRV_UDP_PREFIX, SRV_UDP_PREFIX_LEN, str2ip(), and str2ip6().

Referenced by check_via_address(), get_natping_socket(), is_from_user_enum_2(), mk_proxy(), mk_shm_proxy(), nh_timer(), and update_sock_struct_from_via().

static struct ip_addr* str2ip ( str * st ) [static, read]

converts a str to an ipv4 address, returns the address or 0 on error Warning: the result is a pointer to a statically allocated structure

Definition at line 171 of file resolve.h.

References ip_addr::addr, ip_addr::addr32, ip_addr::af, ip_addr::len, _str::len, LM_DBG, _str::s, s, and ip_addr::u.

Referenced by allow_address(), do_from_gw(), do_to_gw(), pike_check_req(), resolvehost(), rfc1918address(), and sip_resolvehost().

static struct ip_addr* str2ip6 ( str * st ) [static, read]

returns an ip_addr struct.; on error returns 0 the ip_addr struct is static, so subsequent calls will destroy its content

Definition at line 216 of file resolve.h.

References ip_addr::addr, ip_addr::addr16, ip_addr::af, hex, HEX2I, ip_addr::len, _str::len, LM_DBG, _str::s, s, and ip_addr::u.

Referenced by grep_sock_info(), resolvehost(), and sip_resolvehost().

Variable Documentation

int dns_try_ipv6

default off

Definition at line 66 of file resolve.c.

Referenced by resolvehost().


Data Structures
struct	a_rdata
	A rec. struct. More...
struct	aaaa_rdata
struct	cname_rdata
	cname rec. struct More...
struct	dns_node
	DNS failover related structures. More...
union	dns_query
	query union More...
struct	ebl_rdata
	EBL rec. struct. More...
struct	naptr_rdata
	naptr rec. struct More...
struct	rdata
	rdata struct More...
struct	srv_rdata
	srv rec. struct More...
struct	txt_rdata
	txt rec. struct More...
Defines
#define	ANS_SIZE 8192
#define	DNS_HDR_SIZE 12
#define	get_naptr(_rdata) ( ((struct naptr_rdata*)(_rdata)->rdata) )
#define	get_srv(_rdata) ( ((struct srv_rdata*)(_rdata)->rdata) )
#define	HEX2I(c)
#define	MAX_DNS_NAME 256
#define	MAX_DNS_STRING 255
#define	MAX_QUERY_SIZE 8192
#define	rev_resolvehost(ip) gethostbyaddr((char*)(ip)->u.addr, (ip)->len, (ip)->af);
#define	T_EBL 65300
	this is not official yet
Functions
struct dns_node *	dns_res_copy (struct dns_node *s)
	make a perfect copy of a resolver state machine
void	free_dns_res (struct proxy_l *p)
	free the DNS resolver state machine
void	free_rdata_list (struct rdata *head)
	frees completely a struct rdata list
int	get_next_su (struct proxy_l p, union sockaddr_union su, int add_to_bl)
	taked the next destination from a resolver state machine
struct rdata *	get_record (char *name, int type)
	Hets the DNS records for name:type.
int	resolv_blacklist_init (void)
	Initialize blacklist.
int	resolv_init (void)
	Initialize the DNS resolver retr_time - time before retransmitting (must be >0) retr_no - retransmissions number servers_no - how many dns servers will be used (from the one listed in /etc/resolv.conf) search - if 0 the search list in /etc/resolv.conf will be ignored (HINT: even if you don't have a search list in resolv.conf, it's still better to set search to 0, because an empty searchlist means in fact search "" => it takes more time) If any of the parameters <0, the default (system specific) value will be used. See also resolv.conf(5).
static struct hostent *	resolvehost (char *name, int no_ip_test)
	gethostbyname wrappers use this, someday they will use a local cache
struct hostent *	sip_resolvehost (str name, unsigned short port, unsigned short proto, int is_sips, struct dns_node *dn)
	Resolve SIP hostname to ip address, protocol and port.
static struct ip_addr *	str2ip (str *st)
	converts a str to an ipv4 address, returns the address or 0 on error Warning: the result is a pointer to a statically allocated structure
static struct ip_addr *	str2ip6 (str *st)
	returns an ip_addr struct.; on error returns 0 the ip_addr struct is static, so subsequent calls will destroy its content
Variables
int	dns_try_ipv6