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This library is stripped down version of NetServices library. HTTP server and client function is NOT supported.

lwip/core/dns.c@0:dcf3c92487ca, 2011-07-20 (annotated)

Committer:: idinor
Date:: Wed Jul 20 11:45:39 2011 +0000
Revision:: 0:dcf3c92487ca

Who changed what in which revision?

User	Revision	Line number	New contents of line
idinor	0:dcf3c92487ca	1	/**
idinor	0:dcf3c92487ca	2	* @file
idinor	0:dcf3c92487ca	3	* DNS - host name to IP address resolver.
idinor	0:dcf3c92487ca	4	*
idinor	0:dcf3c92487ca	5	*/
idinor	0:dcf3c92487ca	6
idinor	0:dcf3c92487ca	7	/**
idinor	0:dcf3c92487ca	8
idinor	0:dcf3c92487ca	9	* This file implements a DNS host name to IP address resolver.
idinor	0:dcf3c92487ca	10
idinor	0:dcf3c92487ca	11	* Port to lwIP from uIP
idinor	0:dcf3c92487ca	12	* by Jim Pettinato April 2007
idinor	0:dcf3c92487ca	13
idinor	0:dcf3c92487ca	14	* uIP version Copyright (c) 2002-2003, Adam Dunkels.
idinor	0:dcf3c92487ca	15	* All rights reserved.
idinor	0:dcf3c92487ca	16	*
idinor	0:dcf3c92487ca	17	* Redistribution and use in source and binary forms, with or without
idinor	0:dcf3c92487ca	18	* modification, are permitted provided that the following conditions
idinor	0:dcf3c92487ca	19	* are met:
idinor	0:dcf3c92487ca	20	* 1. Redistributions of source code must retain the above copyright
idinor	0:dcf3c92487ca	21	* notice, this list of conditions and the following disclaimer.
idinor	0:dcf3c92487ca	22	* 2. Redistributions in binary form must reproduce the above copyright
idinor	0:dcf3c92487ca	23	* notice, this list of conditions and the following disclaimer in the
idinor	0:dcf3c92487ca	24	* documentation and/or other materials provided with the distribution.
idinor	0:dcf3c92487ca	25	* 3. The name of the author may not be used to endorse or promote
idinor	0:dcf3c92487ca	26	* products derived from this software without specific prior
idinor	0:dcf3c92487ca	27	* written permission.
idinor	0:dcf3c92487ca	28	*
idinor	0:dcf3c92487ca	29	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
idinor	0:dcf3c92487ca	30	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
idinor	0:dcf3c92487ca	31	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
idinor	0:dcf3c92487ca	32	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
idinor	0:dcf3c92487ca	33	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
idinor	0:dcf3c92487ca	34	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
idinor	0:dcf3c92487ca	35	* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
idinor	0:dcf3c92487ca	36	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
idinor	0:dcf3c92487ca	37	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
idinor	0:dcf3c92487ca	38	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
idinor	0:dcf3c92487ca	39	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
idinor	0:dcf3c92487ca	40	*
idinor	0:dcf3c92487ca	41	*
idinor	0:dcf3c92487ca	42	* DNS.C
idinor	0:dcf3c92487ca	43	*
idinor	0:dcf3c92487ca	44	* The lwIP DNS resolver functions are used to lookup a host name and
idinor	0:dcf3c92487ca	45	* map it to a numerical IP address. It maintains a list of resolved
idinor	0:dcf3c92487ca	46	* hostnames that can be queried with the dns_lookup() function.
idinor	0:dcf3c92487ca	47	* New hostnames can be resolved using the dns_query() function.
idinor	0:dcf3c92487ca	48	*
idinor	0:dcf3c92487ca	49	* The lwIP version of the resolver also adds a non-blocking version of
idinor	0:dcf3c92487ca	50	* gethostbyname() that will work with a raw API application. This function
idinor	0:dcf3c92487ca	51	* checks for an IP address string first and converts it if it is valid.
idinor	0:dcf3c92487ca	52	* gethostbyname() then does a dns_lookup() to see if the name is
idinor	0:dcf3c92487ca	53	* already in the table. If so, the IP is returned. If not, a query is
idinor	0:dcf3c92487ca	54	* issued and the function returns with a ERR_INPROGRESS status. The app
idinor	0:dcf3c92487ca	55	* using the dns client must then go into a waiting state.
idinor	0:dcf3c92487ca	56	*
idinor	0:dcf3c92487ca	57	* Once a hostname has been resolved (or found to be non-existent),
idinor	0:dcf3c92487ca	58	* the resolver code calls a specified callback function (which
idinor	0:dcf3c92487ca	59	* must be implemented by the module that uses the resolver).
idinor	0:dcf3c92487ca	60	*/
idinor	0:dcf3c92487ca	61
idinor	0:dcf3c92487ca	62	/*-----------------------------------------------------------------------------
idinor	0:dcf3c92487ca	63	* RFC 1035 - Domain names - implementation and specification
idinor	0:dcf3c92487ca	64	* RFC 2181 - Clarifications to the DNS Specification
idinor	0:dcf3c92487ca	65	----------------------------------------------------------------------------/
idinor	0:dcf3c92487ca	66
idinor	0:dcf3c92487ca	67	/** @todo: define good default values (rfc compliance) */
idinor	0:dcf3c92487ca	68	/** @todo: improve answer parsing, more checkings... */
idinor	0:dcf3c92487ca	69	/** @todo: check RFC1035 - 7.3. Processing responses */
idinor	0:dcf3c92487ca	70
idinor	0:dcf3c92487ca	71	/*-----------------------------------------------------------------------------
idinor	0:dcf3c92487ca	72	* Includes
idinor	0:dcf3c92487ca	73	----------------------------------------------------------------------------/
idinor	0:dcf3c92487ca	74
idinor	0:dcf3c92487ca	75	#include "lwip/opt.h"
idinor	0:dcf3c92487ca	76
idinor	0:dcf3c92487ca	77	#if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
idinor	0:dcf3c92487ca	78
idinor	0:dcf3c92487ca	79	#include "lwip/udp.h"
idinor	0:dcf3c92487ca	80	#include "lwip/mem.h"
idinor	0:dcf3c92487ca	81	#include "lwip/memp.h"
idinor	0:dcf3c92487ca	82	#include "lwip/dns.h"
idinor	0:dcf3c92487ca	83
idinor	0:dcf3c92487ca	84	#include <string.h>
idinor	0:dcf3c92487ca	85
idinor	0:dcf3c92487ca	86	/** DNS server IP address */
idinor	0:dcf3c92487ca	87	#ifndef DNS_SERVER_ADDRESS
idinor	0:dcf3c92487ca	88	#define DNS_SERVER_ADDRESS(ipaddr) (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */
idinor	0:dcf3c92487ca	89	#endif
idinor	0:dcf3c92487ca	90
idinor	0:dcf3c92487ca	91	/** DNS server port address */
idinor	0:dcf3c92487ca	92	#ifndef DNS_SERVER_PORT
idinor	0:dcf3c92487ca	93	#define DNS_SERVER_PORT 53
idinor	0:dcf3c92487ca	94	#endif
idinor	0:dcf3c92487ca	95
idinor	0:dcf3c92487ca	96	/** DNS maximum number of retries when asking for a name, before "timeout". */
idinor	0:dcf3c92487ca	97	#ifndef DNS_MAX_RETRIES
idinor	0:dcf3c92487ca	98	#define DNS_MAX_RETRIES 4
idinor	0:dcf3c92487ca	99	#endif
idinor	0:dcf3c92487ca	100
idinor	0:dcf3c92487ca	101	/** DNS resource record max. TTL (one week as default) */
idinor	0:dcf3c92487ca	102	#ifndef DNS_MAX_TTL
idinor	0:dcf3c92487ca	103	#define DNS_MAX_TTL 604800
idinor	0:dcf3c92487ca	104	#endif
idinor	0:dcf3c92487ca	105
idinor	0:dcf3c92487ca	106	/* DNS protocol flags */
idinor	0:dcf3c92487ca	107	#define DNS_FLAG1_RESPONSE 0x80
idinor	0:dcf3c92487ca	108	#define DNS_FLAG1_OPCODE_STATUS 0x10
idinor	0:dcf3c92487ca	109	#define DNS_FLAG1_OPCODE_INVERSE 0x08
idinor	0:dcf3c92487ca	110	#define DNS_FLAG1_OPCODE_STANDARD 0x00
idinor	0:dcf3c92487ca	111	#define DNS_FLAG1_AUTHORATIVE 0x04
idinor	0:dcf3c92487ca	112	#define DNS_FLAG1_TRUNC 0x02
idinor	0:dcf3c92487ca	113	#define DNS_FLAG1_RD 0x01
idinor	0:dcf3c92487ca	114	#define DNS_FLAG2_RA 0x80
idinor	0:dcf3c92487ca	115	#define DNS_FLAG2_ERR_MASK 0x0f
idinor	0:dcf3c92487ca	116	#define DNS_FLAG2_ERR_NONE 0x00
idinor	0:dcf3c92487ca	117	#define DNS_FLAG2_ERR_NAME 0x03
idinor	0:dcf3c92487ca	118
idinor	0:dcf3c92487ca	119	/* DNS protocol states */
idinor	0:dcf3c92487ca	120	#define DNS_STATE_UNUSED 0
idinor	0:dcf3c92487ca	121	#define DNS_STATE_NEW 1
idinor	0:dcf3c92487ca	122	#define DNS_STATE_ASKING 2
idinor	0:dcf3c92487ca	123	#define DNS_STATE_DONE 3
idinor	0:dcf3c92487ca	124
idinor	0:dcf3c92487ca	125	#ifdef PACK_STRUCT_USE_INCLUDES
idinor	0:dcf3c92487ca	126	# include "arch/bpstruct.h"
idinor	0:dcf3c92487ca	127	#endif
idinor	0:dcf3c92487ca	128	PACK_STRUCT_BEGIN
idinor	0:dcf3c92487ca	129	/** DNS message header */
idinor	0:dcf3c92487ca	130	struct dns_hdr {
idinor	0:dcf3c92487ca	131	PACK_STRUCT_FIELD(u16_t id);
idinor	0:dcf3c92487ca	132	PACK_STRUCT_FIELD(u8_t flags1);
idinor	0:dcf3c92487ca	133	PACK_STRUCT_FIELD(u8_t flags2);
idinor	0:dcf3c92487ca	134	PACK_STRUCT_FIELD(u16_t numquestions);
idinor	0:dcf3c92487ca	135	PACK_STRUCT_FIELD(u16_t numanswers);
idinor	0:dcf3c92487ca	136	PACK_STRUCT_FIELD(u16_t numauthrr);
idinor	0:dcf3c92487ca	137	PACK_STRUCT_FIELD(u16_t numextrarr);
idinor	0:dcf3c92487ca	138	} PACK_STRUCT_STRUCT;
idinor	0:dcf3c92487ca	139	PACK_STRUCT_END
idinor	0:dcf3c92487ca	140	#ifdef PACK_STRUCT_USE_INCLUDES
idinor	0:dcf3c92487ca	141	# include "arch/epstruct.h"
idinor	0:dcf3c92487ca	142	#endif
idinor	0:dcf3c92487ca	143	#define SIZEOF_DNS_HDR 12
idinor	0:dcf3c92487ca	144
idinor	0:dcf3c92487ca	145	/** DNS query message structure.
idinor	0:dcf3c92487ca	146	No packing needed: only used locally on the stack. */
idinor	0:dcf3c92487ca	147	struct dns_query {
idinor	0:dcf3c92487ca	148	/* DNS query record starts with either a domain name or a pointer
idinor	0:dcf3c92487ca	149	to a name already present somewhere in the packet. */
idinor	0:dcf3c92487ca	150	u16_t type;
idinor	0:dcf3c92487ca	151	u16_t cls;
idinor	0:dcf3c92487ca	152	};
idinor	0:dcf3c92487ca	153	#define SIZEOF_DNS_QUERY 4
idinor	0:dcf3c92487ca	154
idinor	0:dcf3c92487ca	155	/** DNS answer message structure.
idinor	0:dcf3c92487ca	156	No packing needed: only used locally on the stack. */
idinor	0:dcf3c92487ca	157	struct dns_answer {
idinor	0:dcf3c92487ca	158	/* DNS answer record starts with either a domain name or a pointer
idinor	0:dcf3c92487ca	159	to a name already present somewhere in the packet. */
idinor	0:dcf3c92487ca	160	u16_t type;
idinor	0:dcf3c92487ca	161	u16_t cls;
idinor	0:dcf3c92487ca	162	u32_t ttl;
idinor	0:dcf3c92487ca	163	u16_t len;
idinor	0:dcf3c92487ca	164	};
idinor	0:dcf3c92487ca	165	#define SIZEOF_DNS_ANSWER 10
idinor	0:dcf3c92487ca	166
idinor	0:dcf3c92487ca	167	/** DNS table entry */
idinor	0:dcf3c92487ca	168	struct dns_table_entry {
idinor	0:dcf3c92487ca	169	u8_t state;
idinor	0:dcf3c92487ca	170	u8_t numdns;
idinor	0:dcf3c92487ca	171	u8_t tmr;
idinor	0:dcf3c92487ca	172	u8_t retries;
idinor	0:dcf3c92487ca	173	u8_t seqno;
idinor	0:dcf3c92487ca	174	u8_t err;
idinor	0:dcf3c92487ca	175	u32_t ttl;
idinor	0:dcf3c92487ca	176	char name[DNS_MAX_NAME_LENGTH];
idinor	0:dcf3c92487ca	177	ip_addr_t ipaddr;
idinor	0:dcf3c92487ca	178	/* pointer to callback on DNS query done */
idinor	0:dcf3c92487ca	179	dns_found_callback found;
idinor	0:dcf3c92487ca	180	void *arg;
idinor	0:dcf3c92487ca	181	};
idinor	0:dcf3c92487ca	182
idinor	0:dcf3c92487ca	183	#if DNS_LOCAL_HOSTLIST
idinor	0:dcf3c92487ca	184
idinor	0:dcf3c92487ca	185	#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
idinor	0:dcf3c92487ca	186	/** Local host-list. For hostnames in this list, no
idinor	0:dcf3c92487ca	187	* external name resolution is performed */
idinor	0:dcf3c92487ca	188	static struct local_hostlist_entry *local_hostlist_dynamic;
idinor	0:dcf3c92487ca	189	#else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
idinor	0:dcf3c92487ca	190
idinor	0:dcf3c92487ca	191	/** Defining this allows the local_hostlist_static to be placed in a different
idinor	0:dcf3c92487ca	192	* linker section (e.g. FLASH) */
idinor	0:dcf3c92487ca	193	#ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE
idinor	0:dcf3c92487ca	194	#define DNS_LOCAL_HOSTLIST_STORAGE_PRE static
idinor	0:dcf3c92487ca	195	#endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */
idinor	0:dcf3c92487ca	196	/** Defining this allows the local_hostlist_static to be placed in a different
idinor	0:dcf3c92487ca	197	* linker section (e.g. FLASH) */
idinor	0:dcf3c92487ca	198	#ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST
idinor	0:dcf3c92487ca	199	#define DNS_LOCAL_HOSTLIST_STORAGE_POST
idinor	0:dcf3c92487ca	200	#endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */
idinor	0:dcf3c92487ca	201	DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[]
idinor	0:dcf3c92487ca	202	DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT;
idinor	0:dcf3c92487ca	203
idinor	0:dcf3c92487ca	204	#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
idinor	0:dcf3c92487ca	205
idinor	0:dcf3c92487ca	206	static void dns_init_local();
idinor	0:dcf3c92487ca	207	#endif /* DNS_LOCAL_HOSTLIST */
idinor	0:dcf3c92487ca	208
idinor	0:dcf3c92487ca	209
idinor	0:dcf3c92487ca	210	/* forward declarations */
idinor	0:dcf3c92487ca	211	static void dns_recv(void s, struct udp_pcb pcb, struct pbuf p, ip_addr_t addr, u16_t port);
idinor	0:dcf3c92487ca	212	static void dns_check_entries(void);
idinor	0:dcf3c92487ca	213
idinor	0:dcf3c92487ca	214	/*-----------------------------------------------------------------------------
idinor	0:dcf3c92487ca	215	* Globales
idinor	0:dcf3c92487ca	216	----------------------------------------------------------------------------/
idinor	0:dcf3c92487ca	217
idinor	0:dcf3c92487ca	218	/* DNS variables */
idinor	0:dcf3c92487ca	219	static struct udp_pcb *dns_pcb;
idinor	0:dcf3c92487ca	220	static u8_t dns_seqno;
idinor	0:dcf3c92487ca	221	static struct dns_table_entry dns_table[DNS_TABLE_SIZE];
idinor	0:dcf3c92487ca	222	static ip_addr_t dns_servers[DNS_MAX_SERVERS];
idinor	0:dcf3c92487ca	223	/** Contiguous buffer for processing responses */
idinor	0:dcf3c92487ca	224	static u8_t dns_payload_buffer[LWIP_MEM_ALIGN_BUFFER(DNS_MSG_SIZE)];
idinor	0:dcf3c92487ca	225	static u8_t* dns_payload;
idinor	0:dcf3c92487ca	226
idinor	0:dcf3c92487ca	227	/**
idinor	0:dcf3c92487ca	228	* Initialize the resolver: set up the UDP pcb and configure the default server
idinor	0:dcf3c92487ca	229	* (DNS_SERVER_ADDRESS).
idinor	0:dcf3c92487ca	230	*/
idinor	0:dcf3c92487ca	231	void
idinor	0:dcf3c92487ca	232	dns_init()
idinor	0:dcf3c92487ca	233	{
idinor	0:dcf3c92487ca	234	ip_addr_t dnsserver;
idinor	0:dcf3c92487ca	235
idinor	0:dcf3c92487ca	236	dns_payload = (u8_t *)LWIP_MEM_ALIGN(dns_payload_buffer);
idinor	0:dcf3c92487ca	237
idinor	0:dcf3c92487ca	238	/* initialize default DNS server address */
idinor	0:dcf3c92487ca	239	DNS_SERVER_ADDRESS(&dnsserver);
idinor	0:dcf3c92487ca	240
idinor	0:dcf3c92487ca	241	LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
idinor	0:dcf3c92487ca	242
idinor	0:dcf3c92487ca	243	/* if dns client not yet initialized... */
idinor	0:dcf3c92487ca	244	if (dns_pcb == NULL) {
idinor	0:dcf3c92487ca	245	dns_pcb = udp_new();
idinor	0:dcf3c92487ca	246
idinor	0:dcf3c92487ca	247	if (dns_pcb != NULL) {
idinor	0:dcf3c92487ca	248	/* initialize DNS table not needed (initialized to zero since it is a
idinor	0:dcf3c92487ca	249	* global variable) */
idinor	0:dcf3c92487ca	250	LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
idinor	0:dcf3c92487ca	251	DNS_STATE_UNUSED == 0);
idinor	0:dcf3c92487ca	252
idinor	0:dcf3c92487ca	253	/* initialize DNS client */
idinor	0:dcf3c92487ca	254	udp_bind(dns_pcb, IP_ADDR_ANY, 0);
idinor	0:dcf3c92487ca	255	udp_recv(dns_pcb, dns_recv, NULL);
idinor	0:dcf3c92487ca	256
idinor	0:dcf3c92487ca	257	/* initialize default DNS primary server */
idinor	0:dcf3c92487ca	258	dns_setserver(0, &dnsserver);
idinor	0:dcf3c92487ca	259	}
idinor	0:dcf3c92487ca	260	}
idinor	0:dcf3c92487ca	261	#if DNS_LOCAL_HOSTLIST
idinor	0:dcf3c92487ca	262	dns_init_local();
idinor	0:dcf3c92487ca	263	#endif
idinor	0:dcf3c92487ca	264	}
idinor	0:dcf3c92487ca	265
idinor	0:dcf3c92487ca	266	/**
idinor	0:dcf3c92487ca	267	* Initialize one of the DNS servers.
idinor	0:dcf3c92487ca	268	*
idinor	0:dcf3c92487ca	269	* @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
idinor	0:dcf3c92487ca	270	* @param dnsserver IP address of the DNS server to set
idinor	0:dcf3c92487ca	271	*/
idinor	0:dcf3c92487ca	272	void
idinor	0:dcf3c92487ca	273	dns_setserver(u8_t numdns, ip_addr_t *dnsserver)
idinor	0:dcf3c92487ca	274	{
idinor	0:dcf3c92487ca	275	if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) &&
idinor	0:dcf3c92487ca	276	(dnsserver != NULL) && !ip_addr_isany(dnsserver)) {
idinor	0:dcf3c92487ca	277	dns_servers[numdns] = (*dnsserver);
idinor	0:dcf3c92487ca	278	}
idinor	0:dcf3c92487ca	279	}
idinor	0:dcf3c92487ca	280
idinor	0:dcf3c92487ca	281	/**
idinor	0:dcf3c92487ca	282	* Obtain one of the currently configured DNS server.
idinor	0:dcf3c92487ca	283	*
idinor	0:dcf3c92487ca	284	* @param numdns the index of the DNS server
idinor	0:dcf3c92487ca	285	* @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
idinor	0:dcf3c92487ca	286	* server has not been configured.
idinor	0:dcf3c92487ca	287	*/
idinor	0:dcf3c92487ca	288	ip_addr_t
idinor	0:dcf3c92487ca	289	dns_getserver(u8_t numdns)
idinor	0:dcf3c92487ca	290	{
idinor	0:dcf3c92487ca	291	if (numdns < DNS_MAX_SERVERS) {
idinor	0:dcf3c92487ca	292	return dns_servers[numdns];
idinor	0:dcf3c92487ca	293	} else {
idinor	0:dcf3c92487ca	294	return *IP_ADDR_ANY;
idinor	0:dcf3c92487ca	295	}
idinor	0:dcf3c92487ca	296	}
idinor	0:dcf3c92487ca	297
idinor	0:dcf3c92487ca	298	/**
idinor	0:dcf3c92487ca	299	* The DNS resolver client timer - handle retries and timeouts and should
idinor	0:dcf3c92487ca	300	* be called every DNS_TMR_INTERVAL milliseconds (every second by default).
idinor	0:dcf3c92487ca	301	*/
idinor	0:dcf3c92487ca	302	void
idinor	0:dcf3c92487ca	303	dns_tmr(void)
idinor	0:dcf3c92487ca	304	{
idinor	0:dcf3c92487ca	305	if (dns_pcb != NULL) {
idinor	0:dcf3c92487ca	306	LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
idinor	0:dcf3c92487ca	307	dns_check_entries();
idinor	0:dcf3c92487ca	308	}
idinor	0:dcf3c92487ca	309	}
idinor	0:dcf3c92487ca	310
idinor	0:dcf3c92487ca	311	#if DNS_LOCAL_HOSTLIST
idinor	0:dcf3c92487ca	312	static void
idinor	0:dcf3c92487ca	313	dns_init_local()
idinor	0:dcf3c92487ca	314	{
idinor	0:dcf3c92487ca	315	#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT)
idinor	0:dcf3c92487ca	316	int i;
idinor	0:dcf3c92487ca	317	struct local_hostlist_entry *entry;
idinor	0:dcf3c92487ca	318	/* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
idinor	0:dcf3c92487ca	319	struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
idinor	0:dcf3c92487ca	320	size_t namelen;
idinor	0:dcf3c92487ca	321	for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) {
idinor	0:dcf3c92487ca	322	struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
idinor	0:dcf3c92487ca	323	LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL);
idinor	0:dcf3c92487ca	324	namelen = strlen(init_entry->name);
idinor	0:dcf3c92487ca	325	LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
idinor	0:dcf3c92487ca	326	entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
idinor	0:dcf3c92487ca	327	LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
idinor	0:dcf3c92487ca	328	if (entry != NULL) {
idinor	0:dcf3c92487ca	329	entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
idinor	0:dcf3c92487ca	330	MEMCPY((char*)entry->name, init_entry->name, namelen);
idinor	0:dcf3c92487ca	331	((char*)entry->name)[namelen] = 0;
idinor	0:dcf3c92487ca	332	entry->addr = init_entry->addr;
idinor	0:dcf3c92487ca	333	entry->next = local_hostlist_dynamic;
idinor	0:dcf3c92487ca	334	local_hostlist_dynamic = entry;
idinor	0:dcf3c92487ca	335	}
idinor	0:dcf3c92487ca	336	}
idinor	0:dcf3c92487ca	337	#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
idinor	0:dcf3c92487ca	338	}
idinor	0:dcf3c92487ca	339
idinor	0:dcf3c92487ca	340	/**
idinor	0:dcf3c92487ca	341	* Scans the local host-list for a hostname.
idinor	0:dcf3c92487ca	342	*
idinor	0:dcf3c92487ca	343	* @param hostname Hostname to look for in the local host-list
idinor	0:dcf3c92487ca	344	* @return The first IP address for the hostname in the local host-list or
idinor	0:dcf3c92487ca	345	* IPADDR_NONE if not found.
idinor	0:dcf3c92487ca	346	*/
idinor	0:dcf3c92487ca	347	static u32_t
idinor	0:dcf3c92487ca	348	dns_lookup_local(const char *hostname)
idinor	0:dcf3c92487ca	349	{
idinor	0:dcf3c92487ca	350	#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
idinor	0:dcf3c92487ca	351	struct local_hostlist_entry *entry = local_hostlist_dynamic;
idinor	0:dcf3c92487ca	352	while(entry != NULL) {
idinor	0:dcf3c92487ca	353	if(strcmp(entry->name, hostname) == 0) {
idinor	0:dcf3c92487ca	354	return ip4_addr_get_u32(&entry->addr);
idinor	0:dcf3c92487ca	355	}
idinor	0:dcf3c92487ca	356	entry = entry->next;
idinor	0:dcf3c92487ca	357	}
idinor	0:dcf3c92487ca	358	#else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
idinor	0:dcf3c92487ca	359	int i;
idinor	0:dcf3c92487ca	360	for (i = 0; i < sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry); i++) {
idinor	0:dcf3c92487ca	361	if(strcmp(local_hostlist_static[i].name, hostname) == 0) {
idinor	0:dcf3c92487ca	362	return ip4_addr_get_u32(&local_hostlist_static[i].addr);
idinor	0:dcf3c92487ca	363	}
idinor	0:dcf3c92487ca	364	}
idinor	0:dcf3c92487ca	365	#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
idinor	0:dcf3c92487ca	366	return IPADDR_NONE;
idinor	0:dcf3c92487ca	367	}
idinor	0:dcf3c92487ca	368
idinor	0:dcf3c92487ca	369	#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
idinor	0:dcf3c92487ca	370	/** Remove all entries from the local host-list for a specific hostname
idinor	0:dcf3c92487ca	371	* and/or IP addess
idinor	0:dcf3c92487ca	372	*
idinor	0:dcf3c92487ca	373	* @param hostname hostname for which entries shall be removed from the local
idinor	0:dcf3c92487ca	374	* host-list
idinor	0:dcf3c92487ca	375	* @param addr address for which entries shall be removed from the local host-list
idinor	0:dcf3c92487ca	376	* @return the number of removed entries
idinor	0:dcf3c92487ca	377	*/
idinor	0:dcf3c92487ca	378	int
idinor	0:dcf3c92487ca	379	dns_local_removehost(const char hostname, const ip_addr_t addr)
idinor	0:dcf3c92487ca	380	{
idinor	0:dcf3c92487ca	381	int removed = 0;
idinor	0:dcf3c92487ca	382	struct local_hostlist_entry *entry = local_hostlist_dynamic;
idinor	0:dcf3c92487ca	383	struct local_hostlist_entry *last_entry = NULL;
idinor	0:dcf3c92487ca	384	while (entry != NULL) {
idinor	0:dcf3c92487ca	385	if (((hostname == NULL) \|\| !strcmp(entry->name, hostname)) &&
idinor	0:dcf3c92487ca	386	((addr == NULL) \|\| ip_addr_cmp(&entry->addr, addr))) {
idinor	0:dcf3c92487ca	387	struct local_hostlist_entry *free_entry;
idinor	0:dcf3c92487ca	388	if (last_entry != NULL) {
idinor	0:dcf3c92487ca	389	last_entry->next = entry->next;
idinor	0:dcf3c92487ca	390	} else {
idinor	0:dcf3c92487ca	391	local_hostlist_dynamic = entry->next;
idinor	0:dcf3c92487ca	392	}
idinor	0:dcf3c92487ca	393	free_entry = entry;
idinor	0:dcf3c92487ca	394	entry = entry->next;
idinor	0:dcf3c92487ca	395	memp_free(MEMP_LOCALHOSTLIST, free_entry);
idinor	0:dcf3c92487ca	396	removed++;
idinor	0:dcf3c92487ca	397	} else {
idinor	0:dcf3c92487ca	398	last_entry = entry;
idinor	0:dcf3c92487ca	399	entry = entry->next;
idinor	0:dcf3c92487ca	400	}
idinor	0:dcf3c92487ca	401	}
idinor	0:dcf3c92487ca	402	return removed;
idinor	0:dcf3c92487ca	403	}
idinor	0:dcf3c92487ca	404
idinor	0:dcf3c92487ca	405	/**
idinor	0:dcf3c92487ca	406	* Add a hostname/IP address pair to the local host-list.
idinor	0:dcf3c92487ca	407	* Duplicates are not checked.
idinor	0:dcf3c92487ca	408	*
idinor	0:dcf3c92487ca	409	* @param hostname hostname of the new entry
idinor	0:dcf3c92487ca	410	* @param addr IP address of the new entry
idinor	0:dcf3c92487ca	411	* @return ERR_OK if succeeded or ERR_MEM on memory error
idinor	0:dcf3c92487ca	412	*/
idinor	0:dcf3c92487ca	413	err_t
idinor	0:dcf3c92487ca	414	dns_local_addhost(const char hostname, const ip_addr_t addr)
idinor	0:dcf3c92487ca	415	{
idinor	0:dcf3c92487ca	416	struct local_hostlist_entry *entry;
idinor	0:dcf3c92487ca	417	size_t namelen;
idinor	0:dcf3c92487ca	418	LWIP_ASSERT("invalid host name (NULL)", hostname != NULL);
idinor	0:dcf3c92487ca	419	namelen = strlen(hostname);
idinor	0:dcf3c92487ca	420	LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
idinor	0:dcf3c92487ca	421	entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
idinor	0:dcf3c92487ca	422	if (entry == NULL) {
idinor	0:dcf3c92487ca	423	return ERR_MEM;
idinor	0:dcf3c92487ca	424	}
idinor	0:dcf3c92487ca	425	entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
idinor	0:dcf3c92487ca	426	MEMCPY((char*)entry->name, hostname, namelen);
idinor	0:dcf3c92487ca	427	((char*)entry->name)[namelen] = 0;
idinor	0:dcf3c92487ca	428	ip_addr_copy(entry->addr, *addr);
idinor	0:dcf3c92487ca	429	entry->next = local_hostlist_dynamic;
idinor	0:dcf3c92487ca	430	local_hostlist_dynamic = entry;
idinor	0:dcf3c92487ca	431	return ERR_OK;
idinor	0:dcf3c92487ca	432	}
idinor	0:dcf3c92487ca	433	#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
idinor	0:dcf3c92487ca	434	#endif /* DNS_LOCAL_HOSTLIST */
idinor	0:dcf3c92487ca	435
idinor	0:dcf3c92487ca	436	/**
idinor	0:dcf3c92487ca	437	* Look up a hostname in the array of known hostnames.
idinor	0:dcf3c92487ca	438	*
idinor	0:dcf3c92487ca	439	* @note This function only looks in the internal array of known
idinor	0:dcf3c92487ca	440	* hostnames, it does not send out a query for the hostname if none
idinor	0:dcf3c92487ca	441	* was found. The function dns_enqueue() can be used to send a query
idinor	0:dcf3c92487ca	442	* for a hostname.
idinor	0:dcf3c92487ca	443	*
idinor	0:dcf3c92487ca	444	* @param name the hostname to look up
idinor	0:dcf3c92487ca	445	* @return the hostname's IP address, as u32_t (instead of ip_addr_t to
idinor	0:dcf3c92487ca	446	* better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname
idinor	0:dcf3c92487ca	447	* was not found in the cached dns_table.
idinor	0:dcf3c92487ca	448	*/
idinor	0:dcf3c92487ca	449	static u32_t
idinor	0:dcf3c92487ca	450	dns_lookup(const char *name)
idinor	0:dcf3c92487ca	451	{
idinor	0:dcf3c92487ca	452	u8_t i;
idinor	0:dcf3c92487ca	453	#if DNS_LOCAL_HOSTLIST \|\| defined(DNS_LOOKUP_LOCAL_EXTERN)
idinor	0:dcf3c92487ca	454	u32_t addr;
idinor	0:dcf3c92487ca	455	#endif /* DNS_LOCAL_HOSTLIST \|\| defined(DNS_LOOKUP_LOCAL_EXTERN) */
idinor	0:dcf3c92487ca	456	#if DNS_LOCAL_HOSTLIST
idinor	0:dcf3c92487ca	457	if ((addr = dns_lookup_local(name)) != IPADDR_NONE) {
idinor	0:dcf3c92487ca	458	return addr;
idinor	0:dcf3c92487ca	459	}
idinor	0:dcf3c92487ca	460	#endif /* DNS_LOCAL_HOSTLIST */
idinor	0:dcf3c92487ca	461	#ifdef DNS_LOOKUP_LOCAL_EXTERN
idinor	0:dcf3c92487ca	462	if((addr = DNS_LOOKUP_LOCAL_EXTERN(name)) != IPADDR_NONE) {
idinor	0:dcf3c92487ca	463	return addr;
idinor	0:dcf3c92487ca	464	}
idinor	0:dcf3c92487ca	465	#endif /* DNS_LOOKUP_LOCAL_EXTERN */
idinor	0:dcf3c92487ca	466
idinor	0:dcf3c92487ca	467	/* Walk through name list, return entry if found. If not, return NULL. */
idinor	0:dcf3c92487ca	468	for (i = 0; i < DNS_TABLE_SIZE; ++i) {
idinor	0:dcf3c92487ca	469	if ((dns_table[i].state == DNS_STATE_DONE) &&
idinor	0:dcf3c92487ca	470	(strcmp(name, dns_table[i].name) == 0)) {
idinor	0:dcf3c92487ca	471	LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
idinor	0:dcf3c92487ca	472	ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr));
idinor	0:dcf3c92487ca	473	LWIP_DEBUGF(DNS_DEBUG, ("\n"));
idinor	0:dcf3c92487ca	474	return ip4_addr_get_u32(&dns_table[i].ipaddr);
idinor	0:dcf3c92487ca	475	}
idinor	0:dcf3c92487ca	476	}
idinor	0:dcf3c92487ca	477
idinor	0:dcf3c92487ca	478	return IPADDR_NONE;
idinor	0:dcf3c92487ca	479	}
idinor	0:dcf3c92487ca	480
idinor	0:dcf3c92487ca	481	#if DNS_DOES_NAME_CHECK
idinor	0:dcf3c92487ca	482	/**
idinor	0:dcf3c92487ca	483	* Compare the "dotted" name "query" with the encoded name "response"
idinor	0:dcf3c92487ca	484	* to make sure an answer from the DNS server matches the current dns_table
idinor	0:dcf3c92487ca	485	* entry (otherwise, answers might arrive late for hostname not on the list
idinor	0:dcf3c92487ca	486	* any more).
idinor	0:dcf3c92487ca	487	*
idinor	0:dcf3c92487ca	488	* @param query hostname (not encoded) from the dns_table
idinor	0:dcf3c92487ca	489	* @param response encoded hostname in the DNS response
idinor	0:dcf3c92487ca	490	* @return 0: names equal; 1: names differ
idinor	0:dcf3c92487ca	491	*/
idinor	0:dcf3c92487ca	492	static u8_t
idinor	0:dcf3c92487ca	493	dns_compare_name(unsigned char query, unsigned char response)
idinor	0:dcf3c92487ca	494	{
idinor	0:dcf3c92487ca	495	unsigned char n;
idinor	0:dcf3c92487ca	496
idinor	0:dcf3c92487ca	497	do {
idinor	0:dcf3c92487ca	498	n = *response++;
idinor	0:dcf3c92487ca	499	/** @see RFC 1035 - 4.1.4. Message compression */
idinor	0:dcf3c92487ca	500	if ((n & 0xc0) == 0xc0) {
idinor	0:dcf3c92487ca	501	/* Compressed name */
idinor	0:dcf3c92487ca	502	break;
idinor	0:dcf3c92487ca	503	} else {
idinor	0:dcf3c92487ca	504	/* Not compressed name */
idinor	0:dcf3c92487ca	505	while (n > 0) {
idinor	0:dcf3c92487ca	506	if ((query) != (response)) {
idinor	0:dcf3c92487ca	507	return 1;
idinor	0:dcf3c92487ca	508	}
idinor	0:dcf3c92487ca	509	++response;
idinor	0:dcf3c92487ca	510	++query;
idinor	0:dcf3c92487ca	511	--n;
idinor	0:dcf3c92487ca	512	};
idinor	0:dcf3c92487ca	513	++query;
idinor	0:dcf3c92487ca	514	}
idinor	0:dcf3c92487ca	515	} while (*response != 0);
idinor	0:dcf3c92487ca	516
idinor	0:dcf3c92487ca	517	return 0;
idinor	0:dcf3c92487ca	518	}
idinor	0:dcf3c92487ca	519	#endif /* DNS_DOES_NAME_CHECK */
idinor	0:dcf3c92487ca	520
idinor	0:dcf3c92487ca	521	/**
idinor	0:dcf3c92487ca	522	* Walk through a compact encoded DNS name and return the end of the name.
idinor	0:dcf3c92487ca	523	*
idinor	0:dcf3c92487ca	524	* @param query encoded DNS name in the DNS server response
idinor	0:dcf3c92487ca	525	* @return end of the name
idinor	0:dcf3c92487ca	526	*/
idinor	0:dcf3c92487ca	527	static unsigned char *
idinor	0:dcf3c92487ca	528	dns_parse_name(unsigned char *query)
idinor	0:dcf3c92487ca	529	{
idinor	0:dcf3c92487ca	530	unsigned char n;
idinor	0:dcf3c92487ca	531
idinor	0:dcf3c92487ca	532	do {
idinor	0:dcf3c92487ca	533	n = *query++;
idinor	0:dcf3c92487ca	534	/** @see RFC 1035 - 4.1.4. Message compression */
idinor	0:dcf3c92487ca	535	if ((n & 0xc0) == 0xc0) {
idinor	0:dcf3c92487ca	536	/* Compressed name */
idinor	0:dcf3c92487ca	537	break;
idinor	0:dcf3c92487ca	538	} else {
idinor	0:dcf3c92487ca	539	/* Not compressed name */
idinor	0:dcf3c92487ca	540	while (n > 0) {
idinor	0:dcf3c92487ca	541	++query;
idinor	0:dcf3c92487ca	542	--n;
idinor	0:dcf3c92487ca	543	};
idinor	0:dcf3c92487ca	544	}
idinor	0:dcf3c92487ca	545	} while (*query != 0);
idinor	0:dcf3c92487ca	546
idinor	0:dcf3c92487ca	547	return query + 1;
idinor	0:dcf3c92487ca	548	}
idinor	0:dcf3c92487ca	549
idinor	0:dcf3c92487ca	550	/**
idinor	0:dcf3c92487ca	551	* Send a DNS query packet.
idinor	0:dcf3c92487ca	552	*
idinor	0:dcf3c92487ca	553	* @param numdns index of the DNS server in the dns_servers table
idinor	0:dcf3c92487ca	554	* @param name hostname to query
idinor	0:dcf3c92487ca	555	* @param id index of the hostname in dns_table, used as transaction ID in the
idinor	0:dcf3c92487ca	556	* DNS query packet
idinor	0:dcf3c92487ca	557	* @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
idinor	0:dcf3c92487ca	558	*/
idinor	0:dcf3c92487ca	559	static err_t
idinor	0:dcf3c92487ca	560	dns_send(u8_t numdns, const char* name, u8_t id)
idinor	0:dcf3c92487ca	561	{
idinor	0:dcf3c92487ca	562	err_t err;
idinor	0:dcf3c92487ca	563	struct dns_hdr *hdr;
idinor	0:dcf3c92487ca	564	struct dns_query qry;
idinor	0:dcf3c92487ca	565	struct pbuf *p;
idinor	0:dcf3c92487ca	566	char query, nptr;
idinor	0:dcf3c92487ca	567	const char *pHostname;
idinor	0:dcf3c92487ca	568	u8_t n;
idinor	0:dcf3c92487ca	569
idinor	0:dcf3c92487ca	570	LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
idinor	0:dcf3c92487ca	571	(u16_t)(numdns), name));
idinor	0:dcf3c92487ca	572	LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS);
idinor	0:dcf3c92487ca	573	LWIP_ASSERT("dns server has no IP address set", !ip_addr_isany(&dns_servers[numdns]));
idinor	0:dcf3c92487ca	574
idinor	0:dcf3c92487ca	575	/* if here, we have either a new query or a retry on a previous query to process */
idinor	0:dcf3c92487ca	576	p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
idinor	0:dcf3c92487ca	577	SIZEOF_DNS_QUERY, PBUF_RAM);
idinor	0:dcf3c92487ca	578	if (p != NULL) {
idinor	0:dcf3c92487ca	579	LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
idinor	0:dcf3c92487ca	580	/* fill dns header */
idinor	0:dcf3c92487ca	581	hdr = (struct dns_hdr*)p->payload;
idinor	0:dcf3c92487ca	582	memset(hdr, 0, SIZEOF_DNS_HDR);
idinor	0:dcf3c92487ca	583	hdr->id = htons(id);
idinor	0:dcf3c92487ca	584	hdr->flags1 = DNS_FLAG1_RD;
idinor	0:dcf3c92487ca	585	hdr->numquestions = PP_HTONS(1);
idinor	0:dcf3c92487ca	586	query = (char*)hdr + SIZEOF_DNS_HDR;
idinor	0:dcf3c92487ca	587	pHostname = name;
idinor	0:dcf3c92487ca	588	--pHostname;
idinor	0:dcf3c92487ca	589
idinor	0:dcf3c92487ca	590	/* convert hostname into suitable query format. */
idinor	0:dcf3c92487ca	591	do {
idinor	0:dcf3c92487ca	592	++pHostname;
idinor	0:dcf3c92487ca	593	nptr = query;
idinor	0:dcf3c92487ca	594	++query;
idinor	0:dcf3c92487ca	595	for(n = 0; pHostname != '.' && pHostname != 0; ++pHostname) {
idinor	0:dcf3c92487ca	596	query = pHostname;
idinor	0:dcf3c92487ca	597	++query;
idinor	0:dcf3c92487ca	598	++n;
idinor	0:dcf3c92487ca	599	}
idinor	0:dcf3c92487ca	600	*nptr = n;
idinor	0:dcf3c92487ca	601	} while(*pHostname != 0);
idinor	0:dcf3c92487ca	602	*query++='\0';
idinor	0:dcf3c92487ca	603
idinor	0:dcf3c92487ca	604	/* fill dns query */
idinor	0:dcf3c92487ca	605	qry.type = PP_HTONS(DNS_RRTYPE_A);
idinor	0:dcf3c92487ca	606	qry.cls = PP_HTONS(DNS_RRCLASS_IN);
idinor	0:dcf3c92487ca	607	SMEMCPY(query, &qry, SIZEOF_DNS_QUERY);
idinor	0:dcf3c92487ca	608
idinor	0:dcf3c92487ca	609	/* resize pbuf to the exact dns query */
idinor	0:dcf3c92487ca	610	pbuf_realloc(p, (u16_t)((query + SIZEOF_DNS_QUERY) - ((char*)(p->payload))));
idinor	0:dcf3c92487ca	611
idinor	0:dcf3c92487ca	612	/* connect to the server for faster receiving */
idinor	0:dcf3c92487ca	613	udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
idinor	0:dcf3c92487ca	614	/* send dns packet */
idinor	0:dcf3c92487ca	615	err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT);
idinor	0:dcf3c92487ca	616
idinor	0:dcf3c92487ca	617	/* free pbuf */
idinor	0:dcf3c92487ca	618	pbuf_free(p);
idinor	0:dcf3c92487ca	619	} else {
idinor	0:dcf3c92487ca	620	err = ERR_MEM;
idinor	0:dcf3c92487ca	621	}
idinor	0:dcf3c92487ca	622
idinor	0:dcf3c92487ca	623	return err;
idinor	0:dcf3c92487ca	624	}
idinor	0:dcf3c92487ca	625
idinor	0:dcf3c92487ca	626	/**
idinor	0:dcf3c92487ca	627	* dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query.
idinor	0:dcf3c92487ca	628	* Check an entry in the dns_table:
idinor	0:dcf3c92487ca	629	* - send out query for new entries
idinor	0:dcf3c92487ca	630	* - retry old pending entries on timeout (also with different servers)
idinor	0:dcf3c92487ca	631	* - remove completed entries from the table if their TTL has expired
idinor	0:dcf3c92487ca	632	*
idinor	0:dcf3c92487ca	633	* @param i index of the dns_table entry to check
idinor	0:dcf3c92487ca	634	*/
idinor	0:dcf3c92487ca	635	static void
idinor	0:dcf3c92487ca	636	dns_check_entry(u8_t i)
idinor	0:dcf3c92487ca	637	{
idinor	0:dcf3c92487ca	638	err_t err;
idinor	0:dcf3c92487ca	639	struct dns_table_entry *pEntry = &dns_table[i];
idinor	0:dcf3c92487ca	640
idinor	0:dcf3c92487ca	641	LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
idinor	0:dcf3c92487ca	642
idinor	0:dcf3c92487ca	643	switch(pEntry->state) {
idinor	0:dcf3c92487ca	644
idinor	0:dcf3c92487ca	645	case DNS_STATE_NEW: {
idinor	0:dcf3c92487ca	646	/* initialize new entry */
idinor	0:dcf3c92487ca	647	pEntry->state = DNS_STATE_ASKING;
idinor	0:dcf3c92487ca	648	pEntry->numdns = 0;
idinor	0:dcf3c92487ca	649	pEntry->tmr = 1;
idinor	0:dcf3c92487ca	650	pEntry->retries = 0;
idinor	0:dcf3c92487ca	651
idinor	0:dcf3c92487ca	652	/* send DNS packet for this entry */
idinor	0:dcf3c92487ca	653	err = dns_send(pEntry->numdns, pEntry->name, i);
idinor	0:dcf3c92487ca	654	if (err != ERR_OK) {
idinor	0:dcf3c92487ca	655	LWIP_DEBUGF(DNS_DEBUG \| LWIP_DBG_LEVEL_WARNING,
idinor	0:dcf3c92487ca	656	("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
idinor	0:dcf3c92487ca	657	}
idinor	0:dcf3c92487ca	658	break;
idinor	0:dcf3c92487ca	659	}
idinor	0:dcf3c92487ca	660
idinor	0:dcf3c92487ca	661	case DNS_STATE_ASKING: {
idinor	0:dcf3c92487ca	662	if (--pEntry->tmr == 0) {
idinor	0:dcf3c92487ca	663	if (++pEntry->retries == DNS_MAX_RETRIES) {
idinor	0:dcf3c92487ca	664	if ((pEntry->numdns+1<DNS_MAX_SERVERS) && !ip_addr_isany(&dns_servers[pEntry->numdns+1])) {
idinor	0:dcf3c92487ca	665	/* change of server */
idinor	0:dcf3c92487ca	666	pEntry->numdns++;
idinor	0:dcf3c92487ca	667	pEntry->tmr = 1;
idinor	0:dcf3c92487ca	668	pEntry->retries = 0;
idinor	0:dcf3c92487ca	669	break;
idinor	0:dcf3c92487ca	670	} else {
idinor	0:dcf3c92487ca	671	LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name));
idinor	0:dcf3c92487ca	672	/* call specified callback function if provided */
idinor	0:dcf3c92487ca	673	if (pEntry->found)
idinor	0:dcf3c92487ca	674	(*pEntry->found)(pEntry->name, NULL, pEntry->arg);
idinor	0:dcf3c92487ca	675	/* flush this entry */
idinor	0:dcf3c92487ca	676	pEntry->state = DNS_STATE_UNUSED;
idinor	0:dcf3c92487ca	677	pEntry->found = NULL;
idinor	0:dcf3c92487ca	678	break;
idinor	0:dcf3c92487ca	679	}
idinor	0:dcf3c92487ca	680	}
idinor	0:dcf3c92487ca	681
idinor	0:dcf3c92487ca	682	/* wait longer for the next retry */
idinor	0:dcf3c92487ca	683	pEntry->tmr = pEntry->retries;
idinor	0:dcf3c92487ca	684
idinor	0:dcf3c92487ca	685	/* send DNS packet for this entry */
idinor	0:dcf3c92487ca	686	err = dns_send(pEntry->numdns, pEntry->name, i);
idinor	0:dcf3c92487ca	687	if (err != ERR_OK) {
idinor	0:dcf3c92487ca	688	LWIP_DEBUGF(DNS_DEBUG \| LWIP_DBG_LEVEL_WARNING,
idinor	0:dcf3c92487ca	689	("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
idinor	0:dcf3c92487ca	690	}
idinor	0:dcf3c92487ca	691	}
idinor	0:dcf3c92487ca	692	break;
idinor	0:dcf3c92487ca	693	}
idinor	0:dcf3c92487ca	694
idinor	0:dcf3c92487ca	695	case DNS_STATE_DONE: {
idinor	0:dcf3c92487ca	696	/* if the time to live is nul */
idinor	0:dcf3c92487ca	697	if (--pEntry->ttl == 0) {
idinor	0:dcf3c92487ca	698	LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name));
idinor	0:dcf3c92487ca	699	/* flush this entry */
idinor	0:dcf3c92487ca	700	pEntry->state = DNS_STATE_UNUSED;
idinor	0:dcf3c92487ca	701	pEntry->found = NULL;
idinor	0:dcf3c92487ca	702	}
idinor	0:dcf3c92487ca	703	break;
idinor	0:dcf3c92487ca	704	}
idinor	0:dcf3c92487ca	705	case DNS_STATE_UNUSED:
idinor	0:dcf3c92487ca	706	/* nothing to do */
idinor	0:dcf3c92487ca	707	break;
idinor	0:dcf3c92487ca	708	default:
idinor	0:dcf3c92487ca	709	LWIP_ASSERT("unknown dns_table entry state:", 0);
idinor	0:dcf3c92487ca	710	break;
idinor	0:dcf3c92487ca	711	}
idinor	0:dcf3c92487ca	712	}
idinor	0:dcf3c92487ca	713
idinor	0:dcf3c92487ca	714	/**
idinor	0:dcf3c92487ca	715	* Call dns_check_entry for each entry in dns_table - check all entries.
idinor	0:dcf3c92487ca	716	*/
idinor	0:dcf3c92487ca	717	static void
idinor	0:dcf3c92487ca	718	dns_check_entries(void)
idinor	0:dcf3c92487ca	719	{
idinor	0:dcf3c92487ca	720	u8_t i;
idinor	0:dcf3c92487ca	721
idinor	0:dcf3c92487ca	722	for (i = 0; i < DNS_TABLE_SIZE; ++i) {
idinor	0:dcf3c92487ca	723	dns_check_entry(i);
idinor	0:dcf3c92487ca	724	}
idinor	0:dcf3c92487ca	725	}
idinor	0:dcf3c92487ca	726
idinor	0:dcf3c92487ca	727	/**
idinor	0:dcf3c92487ca	728	* Receive input function for DNS response packets arriving for the dns UDP pcb.
idinor	0:dcf3c92487ca	729	*
idinor	0:dcf3c92487ca	730	* @params see udp.h
idinor	0:dcf3c92487ca	731	*/
idinor	0:dcf3c92487ca	732	static void
idinor	0:dcf3c92487ca	733	dns_recv(void arg, struct udp_pcb pcb, struct pbuf p, ip_addr_t addr, u16_t port)
idinor	0:dcf3c92487ca	734	{
idinor	0:dcf3c92487ca	735	u16_t i;
idinor	0:dcf3c92487ca	736	char *pHostname;
idinor	0:dcf3c92487ca	737	struct dns_hdr *hdr;
idinor	0:dcf3c92487ca	738	struct dns_answer ans;
idinor	0:dcf3c92487ca	739	struct dns_table_entry *pEntry;
idinor	0:dcf3c92487ca	740	u16_t nquestions, nanswers;
idinor	0:dcf3c92487ca	741
idinor	0:dcf3c92487ca	742	LWIP_UNUSED_ARG(arg);
idinor	0:dcf3c92487ca	743	LWIP_UNUSED_ARG(pcb);
idinor	0:dcf3c92487ca	744	LWIP_UNUSED_ARG(addr);
idinor	0:dcf3c92487ca	745	LWIP_UNUSED_ARG(port);
idinor	0:dcf3c92487ca	746
idinor	0:dcf3c92487ca	747	/* is the dns message too big ? */
idinor	0:dcf3c92487ca	748	if (p->tot_len > DNS_MSG_SIZE) {
idinor	0:dcf3c92487ca	749	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
idinor	0:dcf3c92487ca	750	/* free pbuf and return */
idinor	0:dcf3c92487ca	751	goto memerr;
idinor	0:dcf3c92487ca	752	}
idinor	0:dcf3c92487ca	753
idinor	0:dcf3c92487ca	754	/* is the dns message big enough ? */
idinor	0:dcf3c92487ca	755	if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
idinor	0:dcf3c92487ca	756	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
idinor	0:dcf3c92487ca	757	/* free pbuf and return */
idinor	0:dcf3c92487ca	758	goto memerr;
idinor	0:dcf3c92487ca	759	}
idinor	0:dcf3c92487ca	760
idinor	0:dcf3c92487ca	761	/* copy dns payload inside static buffer for processing */
idinor	0:dcf3c92487ca	762	if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) {
idinor	0:dcf3c92487ca	763	/* The ID in the DNS header should be our entry into the name table. */
idinor	0:dcf3c92487ca	764	hdr = (struct dns_hdr*)dns_payload;
idinor	0:dcf3c92487ca	765	i = htons(hdr->id);
idinor	0:dcf3c92487ca	766	if (i < DNS_TABLE_SIZE) {
idinor	0:dcf3c92487ca	767	pEntry = &dns_table[i];
idinor	0:dcf3c92487ca	768	if(pEntry->state == DNS_STATE_ASKING) {
idinor	0:dcf3c92487ca	769	/* This entry is now completed. */
idinor	0:dcf3c92487ca	770	pEntry->state = DNS_STATE_DONE;
idinor	0:dcf3c92487ca	771	pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK;
idinor	0:dcf3c92487ca	772
idinor	0:dcf3c92487ca	773	/* We only care about the question(s) and the answers. The authrr
idinor	0:dcf3c92487ca	774	and the extrarr are simply discarded. */
idinor	0:dcf3c92487ca	775	nquestions = htons(hdr->numquestions);
idinor	0:dcf3c92487ca	776	nanswers = htons(hdr->numanswers);
idinor	0:dcf3c92487ca	777
idinor	0:dcf3c92487ca	778	/* Check for error. If so, call callback to inform. */
idinor	0:dcf3c92487ca	779	if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) \|\| (pEntry->err != 0) \|\| (nquestions != 1)) {
idinor	0:dcf3c92487ca	780	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name));
idinor	0:dcf3c92487ca	781	/* call callback to indicate error, clean up memory and return */
idinor	0:dcf3c92487ca	782	goto responseerr;
idinor	0:dcf3c92487ca	783	}
idinor	0:dcf3c92487ca	784
idinor	0:dcf3c92487ca	785	#if DNS_DOES_NAME_CHECK
idinor	0:dcf3c92487ca	786	/* Check if the name in the "question" part match with the name in the entry. */
idinor	0:dcf3c92487ca	787	if (dns_compare_name((unsigned char )(pEntry->name), (unsigned char )dns_payload + SIZEOF_DNS_HDR) != 0) {
idinor	0:dcf3c92487ca	788	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
idinor	0:dcf3c92487ca	789	/* call callback to indicate error, clean up memory and return */
idinor	0:dcf3c92487ca	790	goto responseerr;
idinor	0:dcf3c92487ca	791	}
idinor	0:dcf3c92487ca	792	#endif /* DNS_DOES_NAME_CHECK */
idinor	0:dcf3c92487ca	793
idinor	0:dcf3c92487ca	794	/* Skip the name in the "question" part */
idinor	0:dcf3c92487ca	795	pHostname = (char ) dns_parse_name((unsigned char )dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
idinor	0:dcf3c92487ca	796
idinor	0:dcf3c92487ca	797	while (nanswers > 0) {
idinor	0:dcf3c92487ca	798	/* skip answer resource record's host name */
idinor	0:dcf3c92487ca	799	pHostname = (char ) dns_parse_name((unsigned char )pHostname);
idinor	0:dcf3c92487ca	800
idinor	0:dcf3c92487ca	801	/* Check for IP address type and Internet class. Others are discarded. */
idinor	0:dcf3c92487ca	802	SMEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
idinor	0:dcf3c92487ca	803	if((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) &&
idinor	0:dcf3c92487ca	804	(ans.len == PP_HTONS(sizeof(ip_addr_t))) ) {
idinor	0:dcf3c92487ca	805	/* read the answer resource record's TTL, and maximize it if needed */
idinor	0:dcf3c92487ca	806	pEntry->ttl = ntohl(ans.ttl);
idinor	0:dcf3c92487ca	807	if (pEntry->ttl > DNS_MAX_TTL) {
idinor	0:dcf3c92487ca	808	pEntry->ttl = DNS_MAX_TTL;
idinor	0:dcf3c92487ca	809	}
idinor	0:dcf3c92487ca	810	/* read the IP address after answer resource record's header */
idinor	0:dcf3c92487ca	811	SMEMCPY(&(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(ip_addr_t));
idinor	0:dcf3c92487ca	812	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
idinor	0:dcf3c92487ca	813	ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
idinor	0:dcf3c92487ca	814	LWIP_DEBUGF(DNS_DEBUG, ("\n"));
idinor	0:dcf3c92487ca	815	/* call specified callback function if provided */
idinor	0:dcf3c92487ca	816	if (pEntry->found) {
idinor	0:dcf3c92487ca	817	(*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg);
idinor	0:dcf3c92487ca	818	}
idinor	0:dcf3c92487ca	819	/* deallocate memory and return */
idinor	0:dcf3c92487ca	820	goto memerr;
idinor	0:dcf3c92487ca	821	} else {
idinor	0:dcf3c92487ca	822	pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
idinor	0:dcf3c92487ca	823	}
idinor	0:dcf3c92487ca	824	--nanswers;
idinor	0:dcf3c92487ca	825	}
idinor	0:dcf3c92487ca	826	LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name));
idinor	0:dcf3c92487ca	827	/* call callback to indicate error, clean up memory and return */
idinor	0:dcf3c92487ca	828	goto responseerr;
idinor	0:dcf3c92487ca	829	}
idinor	0:dcf3c92487ca	830	}
idinor	0:dcf3c92487ca	831	}
idinor	0:dcf3c92487ca	832
idinor	0:dcf3c92487ca	833	/* deallocate memory and return */
idinor	0:dcf3c92487ca	834	goto memerr;
idinor	0:dcf3c92487ca	835
idinor	0:dcf3c92487ca	836	responseerr:
idinor	0:dcf3c92487ca	837	/* ERROR: call specified callback function with NULL as name to indicate an error */
idinor	0:dcf3c92487ca	838	if (pEntry->found) {
idinor	0:dcf3c92487ca	839	(*pEntry->found)(pEntry->name, NULL, pEntry->arg);
idinor	0:dcf3c92487ca	840	}
idinor	0:dcf3c92487ca	841	/* flush this entry */
idinor	0:dcf3c92487ca	842	pEntry->state = DNS_STATE_UNUSED;
idinor	0:dcf3c92487ca	843	pEntry->found = NULL;
idinor	0:dcf3c92487ca	844
idinor	0:dcf3c92487ca	845	memerr:
idinor	0:dcf3c92487ca	846	/* free pbuf */
idinor	0:dcf3c92487ca	847	pbuf_free(p);
idinor	0:dcf3c92487ca	848	return;
idinor	0:dcf3c92487ca	849	}
idinor	0:dcf3c92487ca	850
idinor	0:dcf3c92487ca	851	/**
idinor	0:dcf3c92487ca	852	* Queues a new hostname to resolve and sends out a DNS query for that hostname
idinor	0:dcf3c92487ca	853	*
idinor	0:dcf3c92487ca	854	* @param name the hostname that is to be queried
idinor	0:dcf3c92487ca	855	* @param found a callback founction to be called on success, failure or timeout
idinor	0:dcf3c92487ca	856	* @param callback_arg argument to pass to the callback function
idinor	0:dcf3c92487ca	857	* @return @return a err_t return code.
idinor	0:dcf3c92487ca	858	*/
idinor	0:dcf3c92487ca	859	static err_t
idinor	0:dcf3c92487ca	860	dns_enqueue(const char name, dns_found_callback found, void callback_arg)
idinor	0:dcf3c92487ca	861	{
idinor	0:dcf3c92487ca	862	u8_t i;
idinor	0:dcf3c92487ca	863	u8_t lseq, lseqi;
idinor	0:dcf3c92487ca	864	struct dns_table_entry *pEntry = NULL;
idinor	0:dcf3c92487ca	865	size_t namelen;
idinor	0:dcf3c92487ca	866
idinor	0:dcf3c92487ca	867	/* search an unused entry, or the oldest one */
idinor	0:dcf3c92487ca	868	lseq = lseqi = 0;
idinor	0:dcf3c92487ca	869	for (i = 0; i < DNS_TABLE_SIZE; ++i) {
idinor	0:dcf3c92487ca	870	pEntry = &dns_table[i];
idinor	0:dcf3c92487ca	871	/* is it an unused entry ? */
idinor	0:dcf3c92487ca	872	if (pEntry->state == DNS_STATE_UNUSED)
idinor	0:dcf3c92487ca	873	break;
idinor	0:dcf3c92487ca	874
idinor	0:dcf3c92487ca	875	/* check if this is the oldest completed entry */
idinor	0:dcf3c92487ca	876	if (pEntry->state == DNS_STATE_DONE) {
idinor	0:dcf3c92487ca	877	if ((dns_seqno - pEntry->seqno) > lseq) {
idinor	0:dcf3c92487ca	878	lseq = dns_seqno - pEntry->seqno;
idinor	0:dcf3c92487ca	879	lseqi = i;
idinor	0:dcf3c92487ca	880	}
idinor	0:dcf3c92487ca	881	}
idinor	0:dcf3c92487ca	882	}
idinor	0:dcf3c92487ca	883
idinor	0:dcf3c92487ca	884	/* if we don't have found an unused entry, use the oldest completed one */
idinor	0:dcf3c92487ca	885	if (i == DNS_TABLE_SIZE) {
idinor	0:dcf3c92487ca	886	if ((lseqi >= DNS_TABLE_SIZE) \|\| (dns_table[lseqi].state != DNS_STATE_DONE)) {
idinor	0:dcf3c92487ca	887	/* no entry can't be used now, table is full */
idinor	0:dcf3c92487ca	888	LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
idinor	0:dcf3c92487ca	889	return ERR_MEM;
idinor	0:dcf3c92487ca	890	} else {
idinor	0:dcf3c92487ca	891	/* use the oldest completed one */
idinor	0:dcf3c92487ca	892	i = lseqi;
idinor	0:dcf3c92487ca	893	pEntry = &dns_table[i];
idinor	0:dcf3c92487ca	894	}
idinor	0:dcf3c92487ca	895	}
idinor	0:dcf3c92487ca	896
idinor	0:dcf3c92487ca	897	/* use this entry */
idinor	0:dcf3c92487ca	898	LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
idinor	0:dcf3c92487ca	899
idinor	0:dcf3c92487ca	900	/* fill the entry */
idinor	0:dcf3c92487ca	901	pEntry->state = DNS_STATE_NEW;
idinor	0:dcf3c92487ca	902	pEntry->seqno = dns_seqno++;
idinor	0:dcf3c92487ca	903	pEntry->found = found;
idinor	0:dcf3c92487ca	904	pEntry->arg = callback_arg;
idinor	0:dcf3c92487ca	905	namelen = LWIP_MIN(strlen(name), DNS_MAX_NAME_LENGTH-1);
idinor	0:dcf3c92487ca	906	MEMCPY(pEntry->name, name, namelen);
idinor	0:dcf3c92487ca	907	pEntry->name[namelen] = 0;
idinor	0:dcf3c92487ca	908
idinor	0:dcf3c92487ca	909	/* force to send query without waiting timer */
idinor	0:dcf3c92487ca	910	dns_check_entry(i);
idinor	0:dcf3c92487ca	911
idinor	0:dcf3c92487ca	912	/* dns query is enqueued */
idinor	0:dcf3c92487ca	913	return ERR_INPROGRESS;
idinor	0:dcf3c92487ca	914	}
idinor	0:dcf3c92487ca	915
idinor	0:dcf3c92487ca	916	/**
idinor	0:dcf3c92487ca	917	* Resolve a hostname (string) into an IP address.
idinor	0:dcf3c92487ca	918	* NON-BLOCKING callback version for use with raw API!!!
idinor	0:dcf3c92487ca	919	*
idinor	0:dcf3c92487ca	920	* Returns immediately with one of err_t return codes:
idinor	0:dcf3c92487ca	921	* - ERR_OK if hostname is a valid IP address string or the host
idinor	0:dcf3c92487ca	922	* name is already in the local names table.
idinor	0:dcf3c92487ca	923	* - ERR_INPROGRESS enqueue a request to be sent to the DNS server
idinor	0:dcf3c92487ca	924	* for resolution if no errors are present.
idinor	0:dcf3c92487ca	925	*
idinor	0:dcf3c92487ca	926	* @param hostname the hostname that is to be queried
idinor	0:dcf3c92487ca	927	* @param addr pointer to a ip_addr_t where to store the address if it is already
idinor	0:dcf3c92487ca	928	* cached in the dns_table (only valid if ERR_OK is returned!)
idinor	0:dcf3c92487ca	929	* @param found a callback function to be called on success, failure or timeout (only if
idinor	0:dcf3c92487ca	930	* ERR_INPROGRESS is returned!)
idinor	0:dcf3c92487ca	931	* @param callback_arg argument to pass to the callback function
idinor	0:dcf3c92487ca	932	* @return a err_t return code.
idinor	0:dcf3c92487ca	933	*/
idinor	0:dcf3c92487ca	934	err_t
idinor	0:dcf3c92487ca	935	dns_gethostbyname(const char hostname, ip_addr_t addr, dns_found_callback found,
idinor	0:dcf3c92487ca	936	void *callback_arg)
idinor	0:dcf3c92487ca	937	{
idinor	0:dcf3c92487ca	938	u32_t ipaddr;
idinor	0:dcf3c92487ca	939	/* not initialized or no valid server yet, or invalid addr pointer
idinor	0:dcf3c92487ca	940	* or invalid hostname or invalid hostname length */
idinor	0:dcf3c92487ca	941	if ((dns_pcb == NULL) \|\| (addr == NULL) \|\|
idinor	0:dcf3c92487ca	942	(!hostname) \|\| (!hostname[0]) \|\|
idinor	0:dcf3c92487ca	943	(strlen(hostname) >= DNS_MAX_NAME_LENGTH)) {
idinor	0:dcf3c92487ca	944	return ERR_VAL;
idinor	0:dcf3c92487ca	945	}
idinor	0:dcf3c92487ca	946
idinor	0:dcf3c92487ca	947	#if LWIP_HAVE_LOOPIF
idinor	0:dcf3c92487ca	948	if (strcmp(hostname, "localhost")==0) {
idinor	0:dcf3c92487ca	949	ip_addr_set_loopback(addr);
idinor	0:dcf3c92487ca	950	return ERR_OK;
idinor	0:dcf3c92487ca	951	}
idinor	0:dcf3c92487ca	952	#endif /* LWIP_HAVE_LOOPIF */
idinor	0:dcf3c92487ca	953
idinor	0:dcf3c92487ca	954	/* host name already in octet notation? set ip addr and return ERR_OK */
idinor	0:dcf3c92487ca	955	ipaddr = ipaddr_addr(hostname);
idinor	0:dcf3c92487ca	956	if (ipaddr == IPADDR_NONE) {
idinor	0:dcf3c92487ca	957	/* already have this address cached? */
idinor	0:dcf3c92487ca	958	ipaddr = dns_lookup(hostname);
idinor	0:dcf3c92487ca	959	}
idinor	0:dcf3c92487ca	960	if (ipaddr != IPADDR_NONE) {
idinor	0:dcf3c92487ca	961	ip4_addr_set_u32(addr, ipaddr);
idinor	0:dcf3c92487ca	962	return ERR_OK;
idinor	0:dcf3c92487ca	963	}
idinor	0:dcf3c92487ca	964
idinor	0:dcf3c92487ca	965	/* queue query with specified callback */
idinor	0:dcf3c92487ca	966	return dns_enqueue(hostname, found, callback_arg);
idinor	0:dcf3c92487ca	967	}
idinor	0:dcf3c92487ca	968
idinor	0:dcf3c92487ca	969	#endif /* LWIP_DNS */

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Type:	Library
Created:	20 Jul 2011
Imports:	35
Forks:	0
Commits:	1
Dependents:	1
Dependencies:	0
Followers:	1

lwip/core/dns.c@0:dcf3c92487ca, 2011-07-20 (annotated)

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