Mihail Stoyanov / HTTPServer

My fork of the HTTPServer (working)

Dependents:   DGWWebServer LAN2

Core/lwIP/core/dns.c@0:7a64fbb4069d, 2012-08-06 (annotated)

Committer:
screamer
Date:
Mon Aug 06 09:23:14 2012 +0000
Revision:
0:7a64fbb4069d
[mbed] converted /DGWWebServer/HTTPServer

Who changed what in which revision?

UserRevisionLine numberNew contents of line
screamer 0:7a64fbb4069d 1 /**
screamer 0:7a64fbb4069d 2 * @file
screamer 0:7a64fbb4069d 3 * DNS - host name to IP address resolver.
screamer 0:7a64fbb4069d 4 *
screamer 0:7a64fbb4069d 5 */
screamer 0:7a64fbb4069d 6
screamer 0:7a64fbb4069d 7 /**
screamer 0:7a64fbb4069d 8
screamer 0:7a64fbb4069d 9 * This file implements a DNS host name to IP address resolver.
screamer 0:7a64fbb4069d 10
screamer 0:7a64fbb4069d 11 * Port to lwIP from uIP
screamer 0:7a64fbb4069d 12 * by Jim Pettinato April 2007
screamer 0:7a64fbb4069d 13
screamer 0:7a64fbb4069d 14 * uIP version Copyright (c) 2002-2003, Adam Dunkels.
screamer 0:7a64fbb4069d 15 * All rights reserved.
screamer 0:7a64fbb4069d 16 *
screamer 0:7a64fbb4069d 17 * Redistribution and use in source and binary forms, with or without
screamer 0:7a64fbb4069d 18 * modification, are permitted provided that the following conditions
screamer 0:7a64fbb4069d 19 * are met:
screamer 0:7a64fbb4069d 20 * 1. Redistributions of source code must retain the above copyright
screamer 0:7a64fbb4069d 21 * notice, this list of conditions and the following disclaimer.
screamer 0:7a64fbb4069d 22 * 2. Redistributions in binary form must reproduce the above copyright
screamer 0:7a64fbb4069d 23 * notice, this list of conditions and the following disclaimer in the
screamer 0:7a64fbb4069d 24 * documentation and/or other materials provided with the distribution.
screamer 0:7a64fbb4069d 25 * 3. The name of the author may not be used to endorse or promote
screamer 0:7a64fbb4069d 26 * products derived from this software without specific prior
screamer 0:7a64fbb4069d 27 * written permission.
screamer 0:7a64fbb4069d 28 *
screamer 0:7a64fbb4069d 29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
screamer 0:7a64fbb4069d 30 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
screamer 0:7a64fbb4069d 31 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
screamer 0:7a64fbb4069d 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
screamer 0:7a64fbb4069d 33 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
screamer 0:7a64fbb4069d 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
screamer 0:7a64fbb4069d 35 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
screamer 0:7a64fbb4069d 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
screamer 0:7a64fbb4069d 37 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
screamer 0:7a64fbb4069d 38 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
screamer 0:7a64fbb4069d 39 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
screamer 0:7a64fbb4069d 40 *
screamer 0:7a64fbb4069d 41 *
screamer 0:7a64fbb4069d 42 * DNS.C
screamer 0:7a64fbb4069d 43 *
screamer 0:7a64fbb4069d 44 * The lwIP DNS resolver functions are used to lookup a host name and
screamer 0:7a64fbb4069d 45 * map it to a numerical IP address. It maintains a list of resolved
screamer 0:7a64fbb4069d 46 * hostnames that can be queried with the dns_lookup() function.
screamer 0:7a64fbb4069d 47 * New hostnames can be resolved using the dns_query() function.
screamer 0:7a64fbb4069d 48 *
screamer 0:7a64fbb4069d 49 * The lwIP version of the resolver also adds a non-blocking version of
screamer 0:7a64fbb4069d 50 * gethostbyname() that will work with a raw API application. This function
screamer 0:7a64fbb4069d 51 * checks for an IP address string first and converts it if it is valid.
screamer 0:7a64fbb4069d 52 * gethostbyname() then does a dns_lookup() to see if the name is
screamer 0:7a64fbb4069d 53 * already in the table. If so, the IP is returned. If not, a query is
screamer 0:7a64fbb4069d 54 * issued and the function returns with a ERR_INPROGRESS status. The app
screamer 0:7a64fbb4069d 55 * using the dns client must then go into a waiting state.
screamer 0:7a64fbb4069d 56 *
screamer 0:7a64fbb4069d 57 * Once a hostname has been resolved (or found to be non-existent),
screamer 0:7a64fbb4069d 58 * the resolver code calls a specified callback function (which
screamer 0:7a64fbb4069d 59 * must be implemented by the module that uses the resolver).
screamer 0:7a64fbb4069d 60 */
screamer 0:7a64fbb4069d 61
screamer 0:7a64fbb4069d 62 /*-----------------------------------------------------------------------------
screamer 0:7a64fbb4069d 63 * RFC 1035 - Domain names - implementation and specification
screamer 0:7a64fbb4069d 64 * RFC 2181 - Clarifications to the DNS Specification
screamer 0:7a64fbb4069d 65 *----------------------------------------------------------------------------*/
screamer 0:7a64fbb4069d 66
screamer 0:7a64fbb4069d 67 /** @todo: define good default values (rfc compliance) */
screamer 0:7a64fbb4069d 68 /** @todo: improve answer parsing, more checkings... */
screamer 0:7a64fbb4069d 69 /** @todo: check RFC1035 - 7.3. Processing responses */
screamer 0:7a64fbb4069d 70
screamer 0:7a64fbb4069d 71 /*-----------------------------------------------------------------------------
screamer 0:7a64fbb4069d 72 * Includes
screamer 0:7a64fbb4069d 73 *----------------------------------------------------------------------------*/
screamer 0:7a64fbb4069d 74
screamer 0:7a64fbb4069d 75 #include "lwip/opt.h"
screamer 0:7a64fbb4069d 76
screamer 0:7a64fbb4069d 77 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
screamer 0:7a64fbb4069d 78
screamer 0:7a64fbb4069d 79 #include "lwip/udp.h"
screamer 0:7a64fbb4069d 80 #include "lwip/mem.h"
screamer 0:7a64fbb4069d 81 #include "lwip/dns.h"
screamer 0:7a64fbb4069d 82
screamer 0:7a64fbb4069d 83 #include <string.h>
screamer 0:7a64fbb4069d 84
screamer 0:7a64fbb4069d 85 /** DNS server IP address */
screamer 0:7a64fbb4069d 86 #ifndef DNS_SERVER_ADDRESS
screamer 0:7a64fbb4069d 87 #define DNS_SERVER_ADDRESS inet_addr("208.67.222.222") /* resolver1.opendns.com */
screamer 0:7a64fbb4069d 88 #endif
screamer 0:7a64fbb4069d 89
screamer 0:7a64fbb4069d 90 /** DNS server port address */
screamer 0:7a64fbb4069d 91 #ifndef DNS_SERVER_PORT
screamer 0:7a64fbb4069d 92 #define DNS_SERVER_PORT 53
screamer 0:7a64fbb4069d 93 #endif
screamer 0:7a64fbb4069d 94
screamer 0:7a64fbb4069d 95 /** DNS maximum number of retries when asking for a name, before "timeout". */
screamer 0:7a64fbb4069d 96 #ifndef DNS_MAX_RETRIES
screamer 0:7a64fbb4069d 97 #define DNS_MAX_RETRIES 4
screamer 0:7a64fbb4069d 98 #endif
screamer 0:7a64fbb4069d 99
screamer 0:7a64fbb4069d 100 /** DNS resource record max. TTL (one week as default) */
screamer 0:7a64fbb4069d 101 #ifndef DNS_MAX_TTL
screamer 0:7a64fbb4069d 102 #define DNS_MAX_TTL 604800
screamer 0:7a64fbb4069d 103 #endif
screamer 0:7a64fbb4069d 104
screamer 0:7a64fbb4069d 105 /* DNS protocol flags */
screamer 0:7a64fbb4069d 106 #define DNS_FLAG1_RESPONSE 0x80
screamer 0:7a64fbb4069d 107 #define DNS_FLAG1_OPCODE_STATUS 0x10
screamer 0:7a64fbb4069d 108 #define DNS_FLAG1_OPCODE_INVERSE 0x08
screamer 0:7a64fbb4069d 109 #define DNS_FLAG1_OPCODE_STANDARD 0x00
screamer 0:7a64fbb4069d 110 #define DNS_FLAG1_AUTHORATIVE 0x04
screamer 0:7a64fbb4069d 111 #define DNS_FLAG1_TRUNC 0x02
screamer 0:7a64fbb4069d 112 #define DNS_FLAG1_RD 0x01
screamer 0:7a64fbb4069d 113 #define DNS_FLAG2_RA 0x80
screamer 0:7a64fbb4069d 114 #define DNS_FLAG2_ERR_MASK 0x0f
screamer 0:7a64fbb4069d 115 #define DNS_FLAG2_ERR_NONE 0x00
screamer 0:7a64fbb4069d 116 #define DNS_FLAG2_ERR_NAME 0x03
screamer 0:7a64fbb4069d 117
screamer 0:7a64fbb4069d 118 /* DNS protocol states */
screamer 0:7a64fbb4069d 119 #define DNS_STATE_UNUSED 0
screamer 0:7a64fbb4069d 120 #define DNS_STATE_NEW 1
screamer 0:7a64fbb4069d 121 #define DNS_STATE_ASKING 2
screamer 0:7a64fbb4069d 122 #define DNS_STATE_DONE 3
screamer 0:7a64fbb4069d 123
screamer 0:7a64fbb4069d 124
screamer 0:7a64fbb4069d 125 // XXX: For C++ compatibility
screamer 0:7a64fbb4069d 126 #define class mclass
screamer 0:7a64fbb4069d 127
screamer 0:7a64fbb4069d 128 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 129 # include "arch/bpstruct.h"
screamer 0:7a64fbb4069d 130 #endif
screamer 0:7a64fbb4069d 131 PACK_STRUCT_BEGIN
screamer 0:7a64fbb4069d 132 /** DNS message header */
screamer 0:7a64fbb4069d 133 struct dns_hdr {
screamer 0:7a64fbb4069d 134 u16_t id;
screamer 0:7a64fbb4069d 135 u8_t flags1;
screamer 0:7a64fbb4069d 136 u8_t flags2;
screamer 0:7a64fbb4069d 137 u16_t numquestions;
screamer 0:7a64fbb4069d 138 u16_t numanswers;
screamer 0:7a64fbb4069d 139 u16_t numauthrr;
screamer 0:7a64fbb4069d 140 u16_t numextrarr;
screamer 0:7a64fbb4069d 141 } PACK_STRUCT_STRUCT;
screamer 0:7a64fbb4069d 142 PACK_STRUCT_END
screamer 0:7a64fbb4069d 143 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 144 # include "arch/epstruct.h"
screamer 0:7a64fbb4069d 145 #endif
screamer 0:7a64fbb4069d 146 #define SIZEOF_DNS_HDR 12
screamer 0:7a64fbb4069d 147
screamer 0:7a64fbb4069d 148 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 149 # include "arch/bpstruct.h"
screamer 0:7a64fbb4069d 150 #endif
screamer 0:7a64fbb4069d 151 PACK_STRUCT_BEGIN
screamer 0:7a64fbb4069d 152 /** DNS query message structure */
screamer 0:7a64fbb4069d 153 struct dns_query {
screamer 0:7a64fbb4069d 154 /* DNS query record starts with either a domain name or a pointer
screamer 0:7a64fbb4069d 155 to a name already present somewhere in the packet. */
screamer 0:7a64fbb4069d 156 u16_t type;
screamer 0:7a64fbb4069d 157 u16_t class;
screamer 0:7a64fbb4069d 158 } PACK_STRUCT_STRUCT;
screamer 0:7a64fbb4069d 159 PACK_STRUCT_END
screamer 0:7a64fbb4069d 160 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 161 # include "arch/epstruct.h"
screamer 0:7a64fbb4069d 162 #endif
screamer 0:7a64fbb4069d 163 #define SIZEOF_DNS_QUERY 4
screamer 0:7a64fbb4069d 164
screamer 0:7a64fbb4069d 165 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 166 # include "arch/bpstruct.h"
screamer 0:7a64fbb4069d 167 #endif
screamer 0:7a64fbb4069d 168 PACK_STRUCT_BEGIN
screamer 0:7a64fbb4069d 169 /** DNS answer message structure */
screamer 0:7a64fbb4069d 170 struct dns_answer {
screamer 0:7a64fbb4069d 171 /* DNS answer record starts with either a domain name or a pointer
screamer 0:7a64fbb4069d 172 to a name already present somewhere in the packet. */
screamer 0:7a64fbb4069d 173 u16_t type;
screamer 0:7a64fbb4069d 174 u16_t class;
screamer 0:7a64fbb4069d 175 u32_t ttl;
screamer 0:7a64fbb4069d 176 u16_t len;
screamer 0:7a64fbb4069d 177 } PACK_STRUCT_STRUCT;
screamer 0:7a64fbb4069d 178 PACK_STRUCT_END
screamer 0:7a64fbb4069d 179 #ifdef PACK_STRUCT_USE_INCLUDES
screamer 0:7a64fbb4069d 180 # include "arch/epstruct.h"
screamer 0:7a64fbb4069d 181 #endif
screamer 0:7a64fbb4069d 182 #define SIZEOF_DNS_ANSWER 10
screamer 0:7a64fbb4069d 183
screamer 0:7a64fbb4069d 184 /** DNS table entry */
screamer 0:7a64fbb4069d 185 struct dns_table_entry {
screamer 0:7a64fbb4069d 186 u8_t state;
screamer 0:7a64fbb4069d 187 u8_t numdns;
screamer 0:7a64fbb4069d 188 u8_t tmr;
screamer 0:7a64fbb4069d 189 u8_t retries;
screamer 0:7a64fbb4069d 190 u8_t seqno;
screamer 0:7a64fbb4069d 191 u8_t err;
screamer 0:7a64fbb4069d 192 u32_t ttl;
screamer 0:7a64fbb4069d 193 char name[DNS_MAX_NAME_LENGTH];
screamer 0:7a64fbb4069d 194 struct ip_addr ipaddr;
screamer 0:7a64fbb4069d 195 /* pointer to callback on DNS query done */
screamer 0:7a64fbb4069d 196 dns_found_callback found;
screamer 0:7a64fbb4069d 197 void *arg;
screamer 0:7a64fbb4069d 198 };
screamer 0:7a64fbb4069d 199
screamer 0:7a64fbb4069d 200 #if DNS_LOCAL_HOSTLIST
screamer 0:7a64fbb4069d 201 /** struct used for local host-list */
screamer 0:7a64fbb4069d 202 struct local_hostlist_entry {
screamer 0:7a64fbb4069d 203 /** static hostname */
screamer 0:7a64fbb4069d 204 const char *name;
screamer 0:7a64fbb4069d 205 /** static host address in network byteorder */
screamer 0:7a64fbb4069d 206 u32_t addr;
screamer 0:7a64fbb4069d 207 struct local_hostlist_entry *next;
screamer 0:7a64fbb4069d 208 };
screamer 0:7a64fbb4069d 209
screamer 0:7a64fbb4069d 210 #if !DNS_LOCAL_HOSTLIST_IS_DYNAMIC
screamer 0:7a64fbb4069d 211 static struct local_hostlist_entry local_hostlist_static[] = DNS_LOCAL_HOSTLIST_INIT MEM_POSITION;
screamer 0:7a64fbb4069d 212 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
screamer 0:7a64fbb4069d 213
screamer 0:7a64fbb4069d 214 /** Local host-list. For hostnames in this list, no
screamer 0:7a64fbb4069d 215 * external name resolution is performed */
screamer 0:7a64fbb4069d 216 static struct local_hostlist_entry *local_hostlist;
screamer 0:7a64fbb4069d 217
screamer 0:7a64fbb4069d 218 static void dns_init_local();
screamer 0:7a64fbb4069d 219 #endif /* DNS_LOCAL_HOSTLIST */
screamer 0:7a64fbb4069d 220
screamer 0:7a64fbb4069d 221
screamer 0:7a64fbb4069d 222 /* forward declarations */
screamer 0:7a64fbb4069d 223 static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port);
screamer 0:7a64fbb4069d 224 static void dns_check_entries(void);
screamer 0:7a64fbb4069d 225
screamer 0:7a64fbb4069d 226 /*-----------------------------------------------------------------------------
screamer 0:7a64fbb4069d 227 * Globales
screamer 0:7a64fbb4069d 228 *----------------------------------------------------------------------------*/
screamer 0:7a64fbb4069d 229
screamer 0:7a64fbb4069d 230 /* DNS variables */
screamer 0:7a64fbb4069d 231 static struct udp_pcb *dns_pcb;
screamer 0:7a64fbb4069d 232 static u8_t dns_seqno;
screamer 0:7a64fbb4069d 233 static struct dns_table_entry dns_table[DNS_TABLE_SIZE] MEM_POSITION;
screamer 0:7a64fbb4069d 234 static struct ip_addr dns_servers[DNS_MAX_SERVERS] MEM_POSITION;
screamer 0:7a64fbb4069d 235
screamer 0:7a64fbb4069d 236 #if (DNS_USES_STATIC_BUF == 1)
screamer 0:7a64fbb4069d 237 static u8_t dns_payload[DNS_MSG_SIZE] MEM_POSITION;
screamer 0:7a64fbb4069d 238 #endif /* (DNS_USES_STATIC_BUF == 1) */
screamer 0:7a64fbb4069d 239
screamer 0:7a64fbb4069d 240 /**
screamer 0:7a64fbb4069d 241 * Initialize the resolver: set up the UDP pcb and configure the default server
screamer 0:7a64fbb4069d 242 * (DNS_SERVER_ADDRESS).
screamer 0:7a64fbb4069d 243 */
screamer 0:7a64fbb4069d 244 void
screamer 0:7a64fbb4069d 245 dns_init()
screamer 0:7a64fbb4069d 246 {
screamer 0:7a64fbb4069d 247 struct ip_addr dnsserver;
screamer 0:7a64fbb4069d 248
screamer 0:7a64fbb4069d 249 /* initialize default DNS server address */
screamer 0:7a64fbb4069d 250 dnsserver.addr = DNS_SERVER_ADDRESS;
screamer 0:7a64fbb4069d 251
screamer 0:7a64fbb4069d 252 LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
screamer 0:7a64fbb4069d 253
screamer 0:7a64fbb4069d 254 /* if dns client not yet initialized... */
screamer 0:7a64fbb4069d 255 if (dns_pcb == NULL) {
screamer 0:7a64fbb4069d 256 dns_pcb = udp_new();
screamer 0:7a64fbb4069d 257
screamer 0:7a64fbb4069d 258 if (dns_pcb != NULL) {
screamer 0:7a64fbb4069d 259 /* initialize DNS table not needed (initialized to zero since it is a
screamer 0:7a64fbb4069d 260 * global variable) */
screamer 0:7a64fbb4069d 261 LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
screamer 0:7a64fbb4069d 262 DNS_STATE_UNUSED == 0);
screamer 0:7a64fbb4069d 263
screamer 0:7a64fbb4069d 264 /* initialize DNS client */
screamer 0:7a64fbb4069d 265 udp_bind(dns_pcb, IP_ADDR_ANY, 0);
screamer 0:7a64fbb4069d 266 udp_recv(dns_pcb, dns_recv, NULL);
screamer 0:7a64fbb4069d 267
screamer 0:7a64fbb4069d 268 /* initialize default DNS primary server */
screamer 0:7a64fbb4069d 269 dns_setserver(0, &dnsserver);
screamer 0:7a64fbb4069d 270 }
screamer 0:7a64fbb4069d 271 }
screamer 0:7a64fbb4069d 272 #if DNS_LOCAL_HOSTLIST
screamer 0:7a64fbb4069d 273 dns_init_local();
screamer 0:7a64fbb4069d 274 #endif
screamer 0:7a64fbb4069d 275 }
screamer 0:7a64fbb4069d 276
screamer 0:7a64fbb4069d 277 /**
screamer 0:7a64fbb4069d 278 * Initialize one of the DNS servers.
screamer 0:7a64fbb4069d 279 *
screamer 0:7a64fbb4069d 280 * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
screamer 0:7a64fbb4069d 281 * @param dnsserver IP address of the DNS server to set
screamer 0:7a64fbb4069d 282 */
screamer 0:7a64fbb4069d 283 void
screamer 0:7a64fbb4069d 284 dns_setserver(u8_t numdns, struct ip_addr *dnsserver)
screamer 0:7a64fbb4069d 285 {
screamer 0:7a64fbb4069d 286 if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) &&
screamer 0:7a64fbb4069d 287 (dnsserver != NULL) && (dnsserver->addr !=0 )) {
screamer 0:7a64fbb4069d 288 dns_servers[numdns] = (*dnsserver);
screamer 0:7a64fbb4069d 289 }
screamer 0:7a64fbb4069d 290 }
screamer 0:7a64fbb4069d 291
screamer 0:7a64fbb4069d 292 /**
screamer 0:7a64fbb4069d 293 * Obtain one of the currently configured DNS server.
screamer 0:7a64fbb4069d 294 *
screamer 0:7a64fbb4069d 295 * @param numdns the index of the DNS server
screamer 0:7a64fbb4069d 296 * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
screamer 0:7a64fbb4069d 297 * server has not been configured.
screamer 0:7a64fbb4069d 298 */
screamer 0:7a64fbb4069d 299 struct ip_addr
screamer 0:7a64fbb4069d 300 dns_getserver(u8_t numdns)
screamer 0:7a64fbb4069d 301 {
screamer 0:7a64fbb4069d 302 if (numdns < DNS_MAX_SERVERS) {
screamer 0:7a64fbb4069d 303 return dns_servers[numdns];
screamer 0:7a64fbb4069d 304 } else {
screamer 0:7a64fbb4069d 305 return *IP_ADDR_ANY;
screamer 0:7a64fbb4069d 306 }
screamer 0:7a64fbb4069d 307 }
screamer 0:7a64fbb4069d 308
screamer 0:7a64fbb4069d 309 /**
screamer 0:7a64fbb4069d 310 * The DNS resolver client timer - handle retries and timeouts and should
screamer 0:7a64fbb4069d 311 * be called every DNS_TMR_INTERVAL milliseconds (every second by default).
screamer 0:7a64fbb4069d 312 */
screamer 0:7a64fbb4069d 313 void
screamer 0:7a64fbb4069d 314 dns_tmr(void)
screamer 0:7a64fbb4069d 315 {
screamer 0:7a64fbb4069d 316 if (dns_pcb != NULL) {
screamer 0:7a64fbb4069d 317 LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
screamer 0:7a64fbb4069d 318 dns_check_entries();
screamer 0:7a64fbb4069d 319 }
screamer 0:7a64fbb4069d 320 }
screamer 0:7a64fbb4069d 321
screamer 0:7a64fbb4069d 322 #if DNS_LOCAL_HOSTLIST
screamer 0:7a64fbb4069d 323 static void
screamer 0:7a64fbb4069d 324 dns_init_local()
screamer 0:7a64fbb4069d 325 {
screamer 0:7a64fbb4069d 326 #ifdef DNS_LOCAL_HOSTLIST_INIT
screamer 0:7a64fbb4069d 327 int i;
screamer 0:7a64fbb4069d 328 struct local_hostlist_entry *entry;
screamer 0:7a64fbb4069d 329 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
screamer 0:7a64fbb4069d 330 /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
screamer 0:7a64fbb4069d 331 struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
screamer 0:7a64fbb4069d 332 for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) {
screamer 0:7a64fbb4069d 333 entry = mem_malloc(sizeof(struct local_hostlist_entry));
screamer 0:7a64fbb4069d 334 LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
screamer 0:7a64fbb4069d 335 if (entry != NULL) {
screamer 0:7a64fbb4069d 336 struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
screamer 0:7a64fbb4069d 337 entry->name = init_entry->name;
screamer 0:7a64fbb4069d 338 entry->addr = init_entry->addr;
screamer 0:7a64fbb4069d 339 entry->next = local_hostlist;
screamer 0:7a64fbb4069d 340 local_hostlist = entry;
screamer 0:7a64fbb4069d 341 }
screamer 0:7a64fbb4069d 342 }
screamer 0:7a64fbb4069d 343 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
screamer 0:7a64fbb4069d 344 /* Static: only adjust the 'next' pointers */
screamer 0:7a64fbb4069d 345 entry = NULL;
screamer 0:7a64fbb4069d 346 local_hostlist = local_hostlist_static;
screamer 0:7a64fbb4069d 347 for (i = sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry) - 1; i >= 0; i--) {
screamer 0:7a64fbb4069d 348 local_hostlist_static[i].next = entry;
screamer 0:7a64fbb4069d 349 entry = &local_hostlist_static[i];
screamer 0:7a64fbb4069d 350 }
screamer 0:7a64fbb4069d 351 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
screamer 0:7a64fbb4069d 352 #endif /* DNS_LOCAL_HOSTLIST_INIT */
screamer 0:7a64fbb4069d 353 }
screamer 0:7a64fbb4069d 354
screamer 0:7a64fbb4069d 355 static u32_t
screamer 0:7a64fbb4069d 356 dns_lookup_static(const char *name)
screamer 0:7a64fbb4069d 357 {
screamer 0:7a64fbb4069d 358 struct local_hostlist_entry *entry = local_hostlist;
screamer 0:7a64fbb4069d 359 while(entry != NULL) {
screamer 0:7a64fbb4069d 360 if(strcmp(entry->name, name) == 0) {
screamer 0:7a64fbb4069d 361 return htons(entry->addr);
screamer 0:7a64fbb4069d 362 }
screamer 0:7a64fbb4069d 363 entry = entry->next;
screamer 0:7a64fbb4069d 364 }
screamer 0:7a64fbb4069d 365 return INADDR_NONE;
screamer 0:7a64fbb4069d 366 }
screamer 0:7a64fbb4069d 367
screamer 0:7a64fbb4069d 368 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
screamer 0:7a64fbb4069d 369 /** Remove all entries from the local host-list for a specific hostname
screamer 0:7a64fbb4069d 370 *
screamer 0:7a64fbb4069d 371 * @param hostname hostname for which entries shall be removed from the local
screamer 0:7a64fbb4069d 372 * host-list
screamer 0:7a64fbb4069d 373 * @return the number of removed entries
screamer 0:7a64fbb4069d 374 */
screamer 0:7a64fbb4069d 375 int
screamer 0:7a64fbb4069d 376 dns_local_removehostname(const char *hostname)
screamer 0:7a64fbb4069d 377 {
screamer 0:7a64fbb4069d 378 int removed = 0;
screamer 0:7a64fbb4069d 379 struct local_hostlist_entry *entry = local_hostlist;
screamer 0:7a64fbb4069d 380 struct local_hostlist_entry *last_entry = NULL;
screamer 0:7a64fbb4069d 381 while (entry != NULL) {
screamer 0:7a64fbb4069d 382 if (!strcmp(entry->name, hostname)) {
screamer 0:7a64fbb4069d 383 if (last_entry != NULL) {
screamer 0:7a64fbb4069d 384 last_entry->next = entry->next;
screamer 0:7a64fbb4069d 385 } else {
screamer 0:7a64fbb4069d 386 local_hostlist = entry->next;
screamer 0:7a64fbb4069d 387 }
screamer 0:7a64fbb4069d 388 mem_free(entry);
screamer 0:7a64fbb4069d 389 removed++;
screamer 0:7a64fbb4069d 390 }
screamer 0:7a64fbb4069d 391 last_entry = entry;
screamer 0:7a64fbb4069d 392 entry = entry->next;
screamer 0:7a64fbb4069d 393 }
screamer 0:7a64fbb4069d 394 return removed;
screamer 0:7a64fbb4069d 395 }
screamer 0:7a64fbb4069d 396
screamer 0:7a64fbb4069d 397 /** Remove all entries from the local host-list for a specific address
screamer 0:7a64fbb4069d 398 *
screamer 0:7a64fbb4069d 399 * @param addr address for which entries shall be removed from the local
screamer 0:7a64fbb4069d 400 * host-list
screamer 0:7a64fbb4069d 401 * @return the number of removed entries
screamer 0:7a64fbb4069d 402 */
screamer 0:7a64fbb4069d 403 int
screamer 0:7a64fbb4069d 404 dns_local_removehostaddr(const struct ip_addr *addr)
screamer 0:7a64fbb4069d 405 {
screamer 0:7a64fbb4069d 406 int removed = 0;
screamer 0:7a64fbb4069d 407 struct local_hostlist_entry *entry = local_hostlist;
screamer 0:7a64fbb4069d 408 struct local_hostlist_entry *last_entry = NULL;
screamer 0:7a64fbb4069d 409 while (entry != NULL) {
screamer 0:7a64fbb4069d 410 if (entry->addr == addr->addr) {
screamer 0:7a64fbb4069d 411 struct local_hostlist_entry *removed_entry = entry;
screamer 0:7a64fbb4069d 412 if (last_entry != NULL) {
screamer 0:7a64fbb4069d 413 last_entry->next = entry->next;
screamer 0:7a64fbb4069d 414 } else {
screamer 0:7a64fbb4069d 415 local_hostlist = entry->next;
screamer 0:7a64fbb4069d 416 }
screamer 0:7a64fbb4069d 417 entry = entry->next;
screamer 0:7a64fbb4069d 418 mem_free(removed_entry);
screamer 0:7a64fbb4069d 419 removed++;
screamer 0:7a64fbb4069d 420 } else {
screamer 0:7a64fbb4069d 421 last_entry = entry;
screamer 0:7a64fbb4069d 422 entry = entry->next;
screamer 0:7a64fbb4069d 423 }
screamer 0:7a64fbb4069d 424 }
screamer 0:7a64fbb4069d 425 return removed;
screamer 0:7a64fbb4069d 426 }
screamer 0:7a64fbb4069d 427
screamer 0:7a64fbb4069d 428 err_t
screamer 0:7a64fbb4069d 429 dns_local_addhost(const char *hostname, const struct ip_addr *addr)
screamer 0:7a64fbb4069d 430 {
screamer 0:7a64fbb4069d 431 struct local_hostlist_entry *entry;
screamer 0:7a64fbb4069d 432 entry = mem_malloc(sizeof(struct local_hostlist_entry));
screamer 0:7a64fbb4069d 433 if (entry == NULL) {
screamer 0:7a64fbb4069d 434 return ERR_MEM;
screamer 0:7a64fbb4069d 435 }
screamer 0:7a64fbb4069d 436 entry->name = hostname;
screamer 0:7a64fbb4069d 437 entry->addr = addr->addr;
screamer 0:7a64fbb4069d 438 entry->next = local_hostlist;
screamer 0:7a64fbb4069d 439 local_hostlist = entry;
screamer 0:7a64fbb4069d 440 return ERR_OK;
screamer 0:7a64fbb4069d 441 }
screamer 0:7a64fbb4069d 442 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
screamer 0:7a64fbb4069d 443 #endif /* DNS_LOCAL_HOSTLIST */
screamer 0:7a64fbb4069d 444
screamer 0:7a64fbb4069d 445 /**
screamer 0:7a64fbb4069d 446 * Look up a hostname in the array of known hostnames.
screamer 0:7a64fbb4069d 447 *
screamer 0:7a64fbb4069d 448 * @note This function only looks in the internal array of known
screamer 0:7a64fbb4069d 449 * hostnames, it does not send out a query for the hostname if none
screamer 0:7a64fbb4069d 450 * was found. The function dns_enqueue() can be used to send a query
screamer 0:7a64fbb4069d 451 * for a hostname.
screamer 0:7a64fbb4069d 452 *
screamer 0:7a64fbb4069d 453 * @param name the hostname to look up
screamer 0:7a64fbb4069d 454 * @return the hostname's IP address, as u32_t (instead of struct ip_addr to
screamer 0:7a64fbb4069d 455 * better check for failure: != INADDR_NONE) or INADDR_NONE if the hostname
screamer 0:7a64fbb4069d 456 * was not found in the cached dns_table.
screamer 0:7a64fbb4069d 457 */
screamer 0:7a64fbb4069d 458 static u32_t
screamer 0:7a64fbb4069d 459 dns_lookup(const char *name)
screamer 0:7a64fbb4069d 460 {
screamer 0:7a64fbb4069d 461 u8_t i;
screamer 0:7a64fbb4069d 462 #if DNS_LOCAL_HOSTLIST
screamer 0:7a64fbb4069d 463 u32_t addr;
screamer 0:7a64fbb4069d 464
screamer 0:7a64fbb4069d 465 if ((addr = dns_lookup_static(name)) != INADDR_NONE) {
screamer 0:7a64fbb4069d 466 return addr;
screamer 0:7a64fbb4069d 467 }
screamer 0:7a64fbb4069d 468 #endif /* DNS_LOCAL_HOSTLIST */
screamer 0:7a64fbb4069d 469
screamer 0:7a64fbb4069d 470 /* Walk through name list, return entry if found. If not, return NULL. */
screamer 0:7a64fbb4069d 471 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
screamer 0:7a64fbb4069d 472 if ((dns_table[i].state == DNS_STATE_DONE) &&
screamer 0:7a64fbb4069d 473 (strcmp(name, dns_table[i].name) == 0)) {
screamer 0:7a64fbb4069d 474 LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
screamer 0:7a64fbb4069d 475 ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr));
screamer 0:7a64fbb4069d 476 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
screamer 0:7a64fbb4069d 477 return dns_table[i].ipaddr.addr;
screamer 0:7a64fbb4069d 478 }
screamer 0:7a64fbb4069d 479 }
screamer 0:7a64fbb4069d 480
screamer 0:7a64fbb4069d 481 return INADDR_NONE;
screamer 0:7a64fbb4069d 482 }
screamer 0:7a64fbb4069d 483
screamer 0:7a64fbb4069d 484 #if DNS_DOES_NAME_CHECK
screamer 0:7a64fbb4069d 485 /**
screamer 0:7a64fbb4069d 486 * Compare the "dotted" name "query" with the encoded name "response"
screamer 0:7a64fbb4069d 487 * to make sure an answer from the DNS server matches the current dns_table
screamer 0:7a64fbb4069d 488 * entry (otherwise, answers might arrive late for hostname not on the list
screamer 0:7a64fbb4069d 489 * any more).
screamer 0:7a64fbb4069d 490 *
screamer 0:7a64fbb4069d 491 * @param query hostname (not encoded) from the dns_table
screamer 0:7a64fbb4069d 492 * @param response encoded hostname in the DNS response
screamer 0:7a64fbb4069d 493 * @return 0: names equal; 1: names differ
screamer 0:7a64fbb4069d 494 */
screamer 0:7a64fbb4069d 495 static u8_t
screamer 0:7a64fbb4069d 496 dns_compare_name(unsigned char *query, unsigned char *response)
screamer 0:7a64fbb4069d 497 {
screamer 0:7a64fbb4069d 498 unsigned char n;
screamer 0:7a64fbb4069d 499
screamer 0:7a64fbb4069d 500 do {
screamer 0:7a64fbb4069d 501 n = *response++;
screamer 0:7a64fbb4069d 502 /** @see RFC 1035 - 4.1.4. Message compression */
screamer 0:7a64fbb4069d 503 if ((n & 0xc0) == 0xc0) {
screamer 0:7a64fbb4069d 504 /* Compressed name */
screamer 0:7a64fbb4069d 505 break;
screamer 0:7a64fbb4069d 506 } else {
screamer 0:7a64fbb4069d 507 /* Not compressed name */
screamer 0:7a64fbb4069d 508 while (n > 0) {
screamer 0:7a64fbb4069d 509 if ((*query) != (*response)) {
screamer 0:7a64fbb4069d 510 return 1;
screamer 0:7a64fbb4069d 511 }
screamer 0:7a64fbb4069d 512 ++response;
screamer 0:7a64fbb4069d 513 ++query;
screamer 0:7a64fbb4069d 514 --n;
screamer 0:7a64fbb4069d 515 };
screamer 0:7a64fbb4069d 516 ++query;
screamer 0:7a64fbb4069d 517 }
screamer 0:7a64fbb4069d 518 } while (*response != 0);
screamer 0:7a64fbb4069d 519
screamer 0:7a64fbb4069d 520 return 0;
screamer 0:7a64fbb4069d 521 }
screamer 0:7a64fbb4069d 522 #endif /* DNS_DOES_NAME_CHECK */
screamer 0:7a64fbb4069d 523
screamer 0:7a64fbb4069d 524 /**
screamer 0:7a64fbb4069d 525 * Walk through a compact encoded DNS name and return the end of the name.
screamer 0:7a64fbb4069d 526 *
screamer 0:7a64fbb4069d 527 * @param query encoded DNS name in the DNS server response
screamer 0:7a64fbb4069d 528 * @return end of the name
screamer 0:7a64fbb4069d 529 */
screamer 0:7a64fbb4069d 530 static unsigned char *
screamer 0:7a64fbb4069d 531 dns_parse_name(unsigned char *query)
screamer 0:7a64fbb4069d 532 {
screamer 0:7a64fbb4069d 533 unsigned char n;
screamer 0:7a64fbb4069d 534
screamer 0:7a64fbb4069d 535 do {
screamer 0:7a64fbb4069d 536 n = *query++;
screamer 0:7a64fbb4069d 537 /** @see RFC 1035 - 4.1.4. Message compression */
screamer 0:7a64fbb4069d 538 if ((n & 0xc0) == 0xc0) {
screamer 0:7a64fbb4069d 539 /* Compressed name */
screamer 0:7a64fbb4069d 540 break;
screamer 0:7a64fbb4069d 541 } else {
screamer 0:7a64fbb4069d 542 /* Not compressed name */
screamer 0:7a64fbb4069d 543 while (n > 0) {
screamer 0:7a64fbb4069d 544 ++query;
screamer 0:7a64fbb4069d 545 --n;
screamer 0:7a64fbb4069d 546 };
screamer 0:7a64fbb4069d 547 }
screamer 0:7a64fbb4069d 548 } while (*query != 0);
screamer 0:7a64fbb4069d 549
screamer 0:7a64fbb4069d 550 return query + 1;
screamer 0:7a64fbb4069d 551 }
screamer 0:7a64fbb4069d 552
screamer 0:7a64fbb4069d 553 /**
screamer 0:7a64fbb4069d 554 * Send a DNS query packet.
screamer 0:7a64fbb4069d 555 *
screamer 0:7a64fbb4069d 556 * @param numdns index of the DNS server in the dns_servers table
screamer 0:7a64fbb4069d 557 * @param name hostname to query
screamer 0:7a64fbb4069d 558 * @param id index of the hostname in dns_table, used as transaction ID in the
screamer 0:7a64fbb4069d 559 * DNS query packet
screamer 0:7a64fbb4069d 560 * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
screamer 0:7a64fbb4069d 561 */
screamer 0:7a64fbb4069d 562 static err_t
screamer 0:7a64fbb4069d 563 dns_send(u8_t numdns, const char* name, u8_t id)
screamer 0:7a64fbb4069d 564 {
screamer 0:7a64fbb4069d 565 err_t err;
screamer 0:7a64fbb4069d 566 struct dns_hdr *hdr;
screamer 0:7a64fbb4069d 567 struct dns_query qry;
screamer 0:7a64fbb4069d 568 struct pbuf *p;
screamer 0:7a64fbb4069d 569 char *query, *nptr;
screamer 0:7a64fbb4069d 570 const char *pHostname;
screamer 0:7a64fbb4069d 571 u8_t n;
screamer 0:7a64fbb4069d 572
screamer 0:7a64fbb4069d 573 LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
screamer 0:7a64fbb4069d 574 (u16_t)(numdns), name));
screamer 0:7a64fbb4069d 575 LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS);
screamer 0:7a64fbb4069d 576 LWIP_ASSERT("dns server has no IP address set", dns_servers[numdns].addr != 0);
screamer 0:7a64fbb4069d 577
screamer 0:7a64fbb4069d 578 /* if here, we have either a new query or a retry on a previous query to process */
screamer 0:7a64fbb4069d 579 p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
screamer 0:7a64fbb4069d 580 SIZEOF_DNS_QUERY, PBUF_RAM);
screamer 0:7a64fbb4069d 581 if (p != NULL) {
screamer 0:7a64fbb4069d 582 LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
screamer 0:7a64fbb4069d 583 /* fill dns header */
screamer 0:7a64fbb4069d 584 hdr = (struct dns_hdr*)p->payload;
screamer 0:7a64fbb4069d 585 memset(hdr, 0, SIZEOF_DNS_HDR);
screamer 0:7a64fbb4069d 586 hdr->id = htons(id);
screamer 0:7a64fbb4069d 587 hdr->flags1 = DNS_FLAG1_RD;
screamer 0:7a64fbb4069d 588 hdr->numquestions = htons(1);
screamer 0:7a64fbb4069d 589 query = (char*)hdr + SIZEOF_DNS_HDR;
screamer 0:7a64fbb4069d 590 pHostname = name;
screamer 0:7a64fbb4069d 591 --pHostname;
screamer 0:7a64fbb4069d 592
screamer 0:7a64fbb4069d 593 /* convert hostname into suitable query format. */
screamer 0:7a64fbb4069d 594 do {
screamer 0:7a64fbb4069d 595 ++pHostname;
screamer 0:7a64fbb4069d 596 nptr = query;
screamer 0:7a64fbb4069d 597 ++query;
screamer 0:7a64fbb4069d 598 for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
screamer 0:7a64fbb4069d 599 *query = *pHostname;
screamer 0:7a64fbb4069d 600 ++query;
screamer 0:7a64fbb4069d 601 ++n;
screamer 0:7a64fbb4069d 602 }
screamer 0:7a64fbb4069d 603 *nptr = n;
screamer 0:7a64fbb4069d 604 } while(*pHostname != 0);
screamer 0:7a64fbb4069d 605 *query++='\0';
screamer 0:7a64fbb4069d 606
screamer 0:7a64fbb4069d 607 /* fill dns query */
screamer 0:7a64fbb4069d 608 qry.type = htons(DNS_RRTYPE_A);
screamer 0:7a64fbb4069d 609 qry.class = htons(DNS_RRCLASS_IN);
screamer 0:7a64fbb4069d 610 MEMCPY( query, &qry, SIZEOF_DNS_QUERY);
screamer 0:7a64fbb4069d 611
screamer 0:7a64fbb4069d 612 /* resize pbuf to the exact dns query */
screamer 0:7a64fbb4069d 613 pbuf_realloc(p, (query + SIZEOF_DNS_QUERY) - ((char*)(p->payload)));
screamer 0:7a64fbb4069d 614
screamer 0:7a64fbb4069d 615 /* connect to the server for faster receiving */
screamer 0:7a64fbb4069d 616 udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
screamer 0:7a64fbb4069d 617 /* send dns packet */
screamer 0:7a64fbb4069d 618 err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT);
screamer 0:7a64fbb4069d 619
screamer 0:7a64fbb4069d 620 /* free pbuf */
screamer 0:7a64fbb4069d 621 pbuf_free(p);
screamer 0:7a64fbb4069d 622 } else {
screamer 0:7a64fbb4069d 623 err = ERR_MEM;
screamer 0:7a64fbb4069d 624 }
screamer 0:7a64fbb4069d 625
screamer 0:7a64fbb4069d 626 return err;
screamer 0:7a64fbb4069d 627 }
screamer 0:7a64fbb4069d 628
screamer 0:7a64fbb4069d 629 /**
screamer 0:7a64fbb4069d 630 * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query.
screamer 0:7a64fbb4069d 631 * Check an entry in the dns_table:
screamer 0:7a64fbb4069d 632 * - send out query for new entries
screamer 0:7a64fbb4069d 633 * - retry old pending entries on timeout (also with different servers)
screamer 0:7a64fbb4069d 634 * - remove completed entries from the table if their TTL has expired
screamer 0:7a64fbb4069d 635 *
screamer 0:7a64fbb4069d 636 * @param i index of the dns_table entry to check
screamer 0:7a64fbb4069d 637 */
screamer 0:7a64fbb4069d 638 static void
screamer 0:7a64fbb4069d 639 dns_check_entry(u8_t i)
screamer 0:7a64fbb4069d 640 {
screamer 0:7a64fbb4069d 641 struct dns_table_entry *pEntry = &dns_table[i];
screamer 0:7a64fbb4069d 642
screamer 0:7a64fbb4069d 643 LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
screamer 0:7a64fbb4069d 644
screamer 0:7a64fbb4069d 645 switch(pEntry->state) {
screamer 0:7a64fbb4069d 646
screamer 0:7a64fbb4069d 647 case DNS_STATE_NEW: {
screamer 0:7a64fbb4069d 648 /* initialize new entry */
screamer 0:7a64fbb4069d 649 pEntry->state = DNS_STATE_ASKING;
screamer 0:7a64fbb4069d 650 pEntry->numdns = 0;
screamer 0:7a64fbb4069d 651 pEntry->tmr = 1;
screamer 0:7a64fbb4069d 652 pEntry->retries = 0;
screamer 0:7a64fbb4069d 653
screamer 0:7a64fbb4069d 654 /* send DNS packet for this entry */
screamer 0:7a64fbb4069d 655 dns_send(pEntry->numdns, pEntry->name, i);
screamer 0:7a64fbb4069d 656 break;
screamer 0:7a64fbb4069d 657 }
screamer 0:7a64fbb4069d 658
screamer 0:7a64fbb4069d 659 case DNS_STATE_ASKING: {
screamer 0:7a64fbb4069d 660 if (--pEntry->tmr == 0) {
screamer 0:7a64fbb4069d 661 if (++pEntry->retries == DNS_MAX_RETRIES) {
screamer 0:7a64fbb4069d 662 if ((pEntry->numdns+1<DNS_MAX_SERVERS) && (dns_servers[pEntry->numdns+1].addr!=0)) {
screamer 0:7a64fbb4069d 663 /* change of server */
screamer 0:7a64fbb4069d 664 pEntry->numdns++;
screamer 0:7a64fbb4069d 665 pEntry->tmr = 1;
screamer 0:7a64fbb4069d 666 pEntry->retries = 0;
screamer 0:7a64fbb4069d 667 break;
screamer 0:7a64fbb4069d 668 } else {
screamer 0:7a64fbb4069d 669 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name));
screamer 0:7a64fbb4069d 670 /* call specified callback function if provided */
screamer 0:7a64fbb4069d 671 if (pEntry->found)
screamer 0:7a64fbb4069d 672 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
screamer 0:7a64fbb4069d 673 /* flush this entry */
screamer 0:7a64fbb4069d 674 pEntry->state = DNS_STATE_UNUSED;
screamer 0:7a64fbb4069d 675 pEntry->found = NULL;
screamer 0:7a64fbb4069d 676 break;
screamer 0:7a64fbb4069d 677 }
screamer 0:7a64fbb4069d 678 }
screamer 0:7a64fbb4069d 679
screamer 0:7a64fbb4069d 680 /* wait longer for the next retry */
screamer 0:7a64fbb4069d 681 pEntry->tmr = pEntry->retries;
screamer 0:7a64fbb4069d 682
screamer 0:7a64fbb4069d 683 /* send DNS packet for this entry */
screamer 0:7a64fbb4069d 684 dns_send(pEntry->numdns, pEntry->name, i);
screamer 0:7a64fbb4069d 685 }
screamer 0:7a64fbb4069d 686 break;
screamer 0:7a64fbb4069d 687 }
screamer 0:7a64fbb4069d 688
screamer 0:7a64fbb4069d 689 case DNS_STATE_DONE: {
screamer 0:7a64fbb4069d 690 /* if the time to live is nul */
screamer 0:7a64fbb4069d 691 if (--pEntry->ttl == 0) {
screamer 0:7a64fbb4069d 692 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name));
screamer 0:7a64fbb4069d 693 /* flush this entry */
screamer 0:7a64fbb4069d 694 pEntry->state = DNS_STATE_UNUSED;
screamer 0:7a64fbb4069d 695 pEntry->found = NULL;
screamer 0:7a64fbb4069d 696 }
screamer 0:7a64fbb4069d 697 break;
screamer 0:7a64fbb4069d 698 }
screamer 0:7a64fbb4069d 699 case DNS_STATE_UNUSED:
screamer 0:7a64fbb4069d 700 /* nothing to do */
screamer 0:7a64fbb4069d 701 break;
screamer 0:7a64fbb4069d 702 default:
screamer 0:7a64fbb4069d 703 LWIP_ASSERT("unknown dns_table entry state:", 0);
screamer 0:7a64fbb4069d 704 break;
screamer 0:7a64fbb4069d 705 }
screamer 0:7a64fbb4069d 706 }
screamer 0:7a64fbb4069d 707
screamer 0:7a64fbb4069d 708 /**
screamer 0:7a64fbb4069d 709 * Call dns_check_entry for each entry in dns_table - check all entries.
screamer 0:7a64fbb4069d 710 */
screamer 0:7a64fbb4069d 711 static void
screamer 0:7a64fbb4069d 712 dns_check_entries(void)
screamer 0:7a64fbb4069d 713 {
screamer 0:7a64fbb4069d 714 u8_t i;
screamer 0:7a64fbb4069d 715
screamer 0:7a64fbb4069d 716 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
screamer 0:7a64fbb4069d 717 dns_check_entry(i);
screamer 0:7a64fbb4069d 718 }
screamer 0:7a64fbb4069d 719 }
screamer 0:7a64fbb4069d 720
screamer 0:7a64fbb4069d 721 /**
screamer 0:7a64fbb4069d 722 * Receive input function for DNS response packets arriving for the dns UDP pcb.
screamer 0:7a64fbb4069d 723 *
screamer 0:7a64fbb4069d 724 * @params see udp.h
screamer 0:7a64fbb4069d 725 */
screamer 0:7a64fbb4069d 726 static void
screamer 0:7a64fbb4069d 727 dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
screamer 0:7a64fbb4069d 728 {
screamer 0:7a64fbb4069d 729 u8_t i;
screamer 0:7a64fbb4069d 730 char *pHostname;
screamer 0:7a64fbb4069d 731 struct dns_hdr *hdr;
screamer 0:7a64fbb4069d 732 struct dns_answer ans;
screamer 0:7a64fbb4069d 733 struct dns_table_entry *pEntry;
screamer 0:7a64fbb4069d 734 u8_t nquestions, nanswers;
screamer 0:7a64fbb4069d 735 #if (DNS_USES_STATIC_BUF == 0)
screamer 0:7a64fbb4069d 736 u8_t dns_payload[DNS_MSG_SIZE];
screamer 0:7a64fbb4069d 737 #endif /* (DNS_USES_STATIC_BUF == 0) */
screamer 0:7a64fbb4069d 738 #if (DNS_USES_STATIC_BUF == 2)
screamer 0:7a64fbb4069d 739 u8_t* dns_payload;
screamer 0:7a64fbb4069d 740 #endif /* (DNS_USES_STATIC_BUF == 2) */
screamer 0:7a64fbb4069d 741
screamer 0:7a64fbb4069d 742 LWIP_UNUSED_ARG(arg);
screamer 0:7a64fbb4069d 743 LWIP_UNUSED_ARG(pcb);
screamer 0:7a64fbb4069d 744 LWIP_UNUSED_ARG(addr);
screamer 0:7a64fbb4069d 745 LWIP_UNUSED_ARG(port);
screamer 0:7a64fbb4069d 746
screamer 0:7a64fbb4069d 747 /* is the dns message too big ? */
screamer 0:7a64fbb4069d 748 if (p->tot_len > DNS_MSG_SIZE) {
screamer 0:7a64fbb4069d 749 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
screamer 0:7a64fbb4069d 750 /* free pbuf and return */
screamer 0:7a64fbb4069d 751 goto memerr1;
screamer 0:7a64fbb4069d 752 }
screamer 0:7a64fbb4069d 753
screamer 0:7a64fbb4069d 754 /* is the dns message big enough ? */
screamer 0:7a64fbb4069d 755 if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
screamer 0:7a64fbb4069d 756 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
screamer 0:7a64fbb4069d 757 /* free pbuf and return */
screamer 0:7a64fbb4069d 758 goto memerr1;
screamer 0:7a64fbb4069d 759 }
screamer 0:7a64fbb4069d 760
screamer 0:7a64fbb4069d 761 #if (DNS_USES_STATIC_BUF == 2)
screamer 0:7a64fbb4069d 762 dns_payload = mem_malloc(p->tot_len);
screamer 0:7a64fbb4069d 763 if (dns_payload == NULL) {
screamer 0:7a64fbb4069d 764 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: mem_malloc error\n"));
screamer 0:7a64fbb4069d 765 /* free pbuf and return */
screamer 0:7a64fbb4069d 766 goto memerr1;
screamer 0:7a64fbb4069d 767 }
screamer 0:7a64fbb4069d 768 #endif /* (DNS_USES_STATIC_BUF == 2) */
screamer 0:7a64fbb4069d 769
screamer 0:7a64fbb4069d 770 /* copy dns payload inside static buffer for processing */
screamer 0:7a64fbb4069d 771 if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) {
screamer 0:7a64fbb4069d 772 /* The ID in the DNS header should be our entry into the name table. */
screamer 0:7a64fbb4069d 773 hdr = (struct dns_hdr*)dns_payload;
screamer 0:7a64fbb4069d 774 i = htons(hdr->id);
screamer 0:7a64fbb4069d 775 if (i < DNS_TABLE_SIZE) {
screamer 0:7a64fbb4069d 776 pEntry = &dns_table[i];
screamer 0:7a64fbb4069d 777 if(pEntry->state == DNS_STATE_ASKING) {
screamer 0:7a64fbb4069d 778 /* This entry is now completed. */
screamer 0:7a64fbb4069d 779 pEntry->state = DNS_STATE_DONE;
screamer 0:7a64fbb4069d 780 pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK;
screamer 0:7a64fbb4069d 781
screamer 0:7a64fbb4069d 782 /* We only care about the question(s) and the answers. The authrr
screamer 0:7a64fbb4069d 783 and the extrarr are simply discarded. */
screamer 0:7a64fbb4069d 784 nquestions = htons(hdr->numquestions);
screamer 0:7a64fbb4069d 785 nanswers = htons(hdr->numanswers);
screamer 0:7a64fbb4069d 786
screamer 0:7a64fbb4069d 787 /* Check for error. If so, call callback to inform. */
screamer 0:7a64fbb4069d 788 if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) {
screamer 0:7a64fbb4069d 789 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name));
screamer 0:7a64fbb4069d 790 /* call callback to indicate error, clean up memory and return */
screamer 0:7a64fbb4069d 791 goto responseerr;
screamer 0:7a64fbb4069d 792 }
screamer 0:7a64fbb4069d 793
screamer 0:7a64fbb4069d 794 #if DNS_DOES_NAME_CHECK
screamer 0:7a64fbb4069d 795 /* Check if the name in the "question" part match with the name in the entry. */
screamer 0:7a64fbb4069d 796 if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) {
screamer 0:7a64fbb4069d 797 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
screamer 0:7a64fbb4069d 798 /* call callback to indicate error, clean up memory and return */
screamer 0:7a64fbb4069d 799 goto responseerr;
screamer 0:7a64fbb4069d 800 }
screamer 0:7a64fbb4069d 801 #endif /* DNS_DOES_NAME_CHECK */
screamer 0:7a64fbb4069d 802
screamer 0:7a64fbb4069d 803 /* Skip the name in the "question" part */
screamer 0:7a64fbb4069d 804 pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
screamer 0:7a64fbb4069d 805
screamer 0:7a64fbb4069d 806 while(nanswers > 0) {
screamer 0:7a64fbb4069d 807 /* skip answer resource record's host name */
screamer 0:7a64fbb4069d 808 pHostname = (char *) dns_parse_name((unsigned char *)pHostname);
screamer 0:7a64fbb4069d 809
screamer 0:7a64fbb4069d 810 /* Check for IP address type and Internet class. Others are discarded. */
screamer 0:7a64fbb4069d 811 MEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
screamer 0:7a64fbb4069d 812 if((ntohs(ans.type) == DNS_RRTYPE_A) && (ntohs(ans.class) == DNS_RRCLASS_IN) && (ntohs(ans.len) == sizeof(struct ip_addr)) ) {
screamer 0:7a64fbb4069d 813 /* read the answer resource record's TTL, and maximize it if needed */
screamer 0:7a64fbb4069d 814 pEntry->ttl = ntohl(ans.ttl);
screamer 0:7a64fbb4069d 815 if (pEntry->ttl > DNS_MAX_TTL) {
screamer 0:7a64fbb4069d 816 pEntry->ttl = DNS_MAX_TTL;
screamer 0:7a64fbb4069d 817 }
screamer 0:7a64fbb4069d 818 /* read the IP address after answer resource record's header */
screamer 0:7a64fbb4069d 819 MEMCPY( &(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(struct ip_addr));
screamer 0:7a64fbb4069d 820 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
screamer 0:7a64fbb4069d 821 ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
screamer 0:7a64fbb4069d 822 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
screamer 0:7a64fbb4069d 823 /* call specified callback function if provided */
screamer 0:7a64fbb4069d 824 if (pEntry->found) {
screamer 0:7a64fbb4069d 825 (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg);
screamer 0:7a64fbb4069d 826 }
screamer 0:7a64fbb4069d 827 /* deallocate memory and return */
screamer 0:7a64fbb4069d 828 goto memerr2;
screamer 0:7a64fbb4069d 829 } else {
screamer 0:7a64fbb4069d 830 pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
screamer 0:7a64fbb4069d 831 }
screamer 0:7a64fbb4069d 832 --nanswers;
screamer 0:7a64fbb4069d 833 }
screamer 0:7a64fbb4069d 834 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name));
screamer 0:7a64fbb4069d 835 /* call callback to indicate error, clean up memory and return */
screamer 0:7a64fbb4069d 836 goto responseerr;
screamer 0:7a64fbb4069d 837 }
screamer 0:7a64fbb4069d 838 }
screamer 0:7a64fbb4069d 839 }
screamer 0:7a64fbb4069d 840
screamer 0:7a64fbb4069d 841 /* deallocate memory and return */
screamer 0:7a64fbb4069d 842 goto memerr2;
screamer 0:7a64fbb4069d 843
screamer 0:7a64fbb4069d 844 responseerr:
screamer 0:7a64fbb4069d 845 /* ERROR: call specified callback function with NULL as name to indicate an error */
screamer 0:7a64fbb4069d 846 if (pEntry->found) {
screamer 0:7a64fbb4069d 847 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
screamer 0:7a64fbb4069d 848 }
screamer 0:7a64fbb4069d 849 /* flush this entry */
screamer 0:7a64fbb4069d 850 pEntry->state = DNS_STATE_UNUSED;
screamer 0:7a64fbb4069d 851 pEntry->found = NULL;
screamer 0:7a64fbb4069d 852
screamer 0:7a64fbb4069d 853 memerr2:
screamer 0:7a64fbb4069d 854 #if (DNS_USES_STATIC_BUF == 2)
screamer 0:7a64fbb4069d 855 /* free dns buffer */
screamer 0:7a64fbb4069d 856 mem_free(dns_payload);
screamer 0:7a64fbb4069d 857 #endif /* (DNS_USES_STATIC_BUF == 2) */
screamer 0:7a64fbb4069d 858
screamer 0:7a64fbb4069d 859 memerr1:
screamer 0:7a64fbb4069d 860 /* free pbuf */
screamer 0:7a64fbb4069d 861 pbuf_free(p);
screamer 0:7a64fbb4069d 862 return;
screamer 0:7a64fbb4069d 863 }
screamer 0:7a64fbb4069d 864
screamer 0:7a64fbb4069d 865 /**
screamer 0:7a64fbb4069d 866 * Queues a new hostname to resolve and sends out a DNS query for that hostname
screamer 0:7a64fbb4069d 867 *
screamer 0:7a64fbb4069d 868 * @param name the hostname that is to be queried
screamer 0:7a64fbb4069d 869 * @param found a callback founction to be called on success, failure or timeout
screamer 0:7a64fbb4069d 870 * @param callback_arg argument to pass to the callback function
screamer 0:7a64fbb4069d 871 * @return @return a err_t return code.
screamer 0:7a64fbb4069d 872 */
screamer 0:7a64fbb4069d 873 static err_t
screamer 0:7a64fbb4069d 874 dns_enqueue(const char *name, dns_found_callback found, void *callback_arg)
screamer 0:7a64fbb4069d 875 {
screamer 0:7a64fbb4069d 876 u8_t i;
screamer 0:7a64fbb4069d 877 u8_t lseq, lseqi;
screamer 0:7a64fbb4069d 878 struct dns_table_entry *pEntry = NULL;
screamer 0:7a64fbb4069d 879
screamer 0:7a64fbb4069d 880 /* search an unused entry, or the oldest one */
screamer 0:7a64fbb4069d 881 lseq = lseqi = 0;
screamer 0:7a64fbb4069d 882 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
screamer 0:7a64fbb4069d 883 pEntry = &dns_table[i];
screamer 0:7a64fbb4069d 884 /* is it an unused entry ? */
screamer 0:7a64fbb4069d 885 if (pEntry->state == DNS_STATE_UNUSED)
screamer 0:7a64fbb4069d 886 break;
screamer 0:7a64fbb4069d 887
screamer 0:7a64fbb4069d 888 /* check if this is the oldest completed entry */
screamer 0:7a64fbb4069d 889 if (pEntry->state == DNS_STATE_DONE) {
screamer 0:7a64fbb4069d 890 if ((dns_seqno - pEntry->seqno) > lseq) {
screamer 0:7a64fbb4069d 891 lseq = dns_seqno - pEntry->seqno;
screamer 0:7a64fbb4069d 892 lseqi = i;
screamer 0:7a64fbb4069d 893 }
screamer 0:7a64fbb4069d 894 }
screamer 0:7a64fbb4069d 895 }
screamer 0:7a64fbb4069d 896
screamer 0:7a64fbb4069d 897 /* if we don't have found an unused entry, use the oldest completed one */
screamer 0:7a64fbb4069d 898 if (i == DNS_TABLE_SIZE) {
screamer 0:7a64fbb4069d 899 if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) {
screamer 0:7a64fbb4069d 900 /* no entry can't be used now, table is full */
screamer 0:7a64fbb4069d 901 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
screamer 0:7a64fbb4069d 902 return ERR_MEM;
screamer 0:7a64fbb4069d 903 } else {
screamer 0:7a64fbb4069d 904 /* use the oldest completed one */
screamer 0:7a64fbb4069d 905 i = lseqi;
screamer 0:7a64fbb4069d 906 pEntry = &dns_table[i];
screamer 0:7a64fbb4069d 907 }
screamer 0:7a64fbb4069d 908 }
screamer 0:7a64fbb4069d 909
screamer 0:7a64fbb4069d 910 /* use this entry */
screamer 0:7a64fbb4069d 911 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
screamer 0:7a64fbb4069d 912
screamer 0:7a64fbb4069d 913 /* fill the entry */
screamer 0:7a64fbb4069d 914 pEntry->state = DNS_STATE_NEW;
screamer 0:7a64fbb4069d 915 pEntry->seqno = dns_seqno++;
screamer 0:7a64fbb4069d 916 pEntry->found = found;
screamer 0:7a64fbb4069d 917 pEntry->arg = callback_arg;
screamer 0:7a64fbb4069d 918 strcpy(pEntry->name, name);
screamer 0:7a64fbb4069d 919
screamer 0:7a64fbb4069d 920 /* force to send query without waiting timer */
screamer 0:7a64fbb4069d 921 dns_check_entry(i);
screamer 0:7a64fbb4069d 922
screamer 0:7a64fbb4069d 923 /* dns query is enqueued */
screamer 0:7a64fbb4069d 924 return ERR_INPROGRESS;
screamer 0:7a64fbb4069d 925 }
screamer 0:7a64fbb4069d 926
screamer 0:7a64fbb4069d 927 /**
screamer 0:7a64fbb4069d 928 * Resolve a hostname (string) into an IP address.
screamer 0:7a64fbb4069d 929 * NON-BLOCKING callback version for use with raw API!!!
screamer 0:7a64fbb4069d 930 *
screamer 0:7a64fbb4069d 931 * Returns immediately with one of err_t return codes:
screamer 0:7a64fbb4069d 932 * - ERR_OK if hostname is a valid IP address string or the host
screamer 0:7a64fbb4069d 933 * name is already in the local names table.
screamer 0:7a64fbb4069d 934 * - ERR_INPROGRESS enqueue a request to be sent to the DNS server
screamer 0:7a64fbb4069d 935 * for resolution if no errors are present.
screamer 0:7a64fbb4069d 936 *
screamer 0:7a64fbb4069d 937 * @param hostname the hostname that is to be queried
screamer 0:7a64fbb4069d 938 * @param addr pointer to a struct ip_addr where to store the address if it is already
screamer 0:7a64fbb4069d 939 * cached in the dns_table (only valid if ERR_OK is returned!)
screamer 0:7a64fbb4069d 940 * @param found a callback function to be called on success, failure or timeout (only if
screamer 0:7a64fbb4069d 941 * ERR_INPROGRESS is returned!)
screamer 0:7a64fbb4069d 942 * @param callback_arg argument to pass to the callback function
screamer 0:7a64fbb4069d 943 * @return a err_t return code.
screamer 0:7a64fbb4069d 944 */
screamer 0:7a64fbb4069d 945 err_t
screamer 0:7a64fbb4069d 946 dns_gethostbyname(const char *hostname, struct ip_addr *addr, dns_found_callback found,
screamer 0:7a64fbb4069d 947 void *callback_arg)
screamer 0:7a64fbb4069d 948 {
screamer 0:7a64fbb4069d 949 /* not initialized or no valid server yet, or invalid addr pointer
screamer 0:7a64fbb4069d 950 * or invalid hostname or invalid hostname length */
screamer 0:7a64fbb4069d 951 if ((dns_pcb == NULL) || (addr == NULL) ||
screamer 0:7a64fbb4069d 952 (!hostname) || (!hostname[0]) ||
screamer 0:7a64fbb4069d 953 (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) {
screamer 0:7a64fbb4069d 954 return ERR_VAL;
screamer 0:7a64fbb4069d 955 }
screamer 0:7a64fbb4069d 956
screamer 0:7a64fbb4069d 957 #if LWIP_HAVE_LOOPIF
screamer 0:7a64fbb4069d 958 if (strcmp(hostname,"localhost")==0) {
screamer 0:7a64fbb4069d 959 addr->addr = INADDR_LOOPBACK;
screamer 0:7a64fbb4069d 960 return ERR_OK;
screamer 0:7a64fbb4069d 961 }
screamer 0:7a64fbb4069d 962 #endif /* LWIP_HAVE_LOOPIF */
screamer 0:7a64fbb4069d 963
screamer 0:7a64fbb4069d 964 /* host name already in octet notation? set ip addr and return ERR_OK
screamer 0:7a64fbb4069d 965 * already have this address cached? */
screamer 0:7a64fbb4069d 966 if (((addr->addr = inet_addr(hostname)) != INADDR_NONE) ||
screamer 0:7a64fbb4069d 967 ((addr->addr = dns_lookup(hostname)) != INADDR_NONE)) {
screamer 0:7a64fbb4069d 968 return ERR_OK;
screamer 0:7a64fbb4069d 969 }
screamer 0:7a64fbb4069d 970
screamer 0:7a64fbb4069d 971 /* queue query with specified callback */
screamer 0:7a64fbb4069d 972 return dns_enqueue(hostname, found, callback_arg);
screamer 0:7a64fbb4069d 973 }
screamer 0:7a64fbb4069d 974
screamer 0:7a64fbb4069d 975 #endif /* LWIP_DNS */