Nino Der Kinderen / Mbed 2 deprecated InetTest

Embedded C project:18/12/2014

Dependencies:   DS1307 TextLCD mbed

NetServices/lwip/core/dns.c@0:8d87bc453349, 2014-12-18 (annotated)

Committer:
ninoderkinderen
Date:
Thu Dec 18 09:35:49 2014 +0000
Revision:
0:8d87bc453349
Programma embedded C

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ninoderkinderen 0:8d87bc453349 1 /**
ninoderkinderen 0:8d87bc453349 2 * @file
ninoderkinderen 0:8d87bc453349 3 * DNS - host name to IP address resolver.
ninoderkinderen 0:8d87bc453349 4 *
ninoderkinderen 0:8d87bc453349 5 */
ninoderkinderen 0:8d87bc453349 6
ninoderkinderen 0:8d87bc453349 7 /**
ninoderkinderen 0:8d87bc453349 8
ninoderkinderen 0:8d87bc453349 9 * This file implements a DNS host name to IP address resolver.
ninoderkinderen 0:8d87bc453349 10
ninoderkinderen 0:8d87bc453349 11 * Port to lwIP from uIP
ninoderkinderen 0:8d87bc453349 12 * by Jim Pettinato April 2007
ninoderkinderen 0:8d87bc453349 13
ninoderkinderen 0:8d87bc453349 14 * uIP version Copyright (c) 2002-2003, Adam Dunkels.
ninoderkinderen 0:8d87bc453349 15 * All rights reserved.
ninoderkinderen 0:8d87bc453349 16 *
ninoderkinderen 0:8d87bc453349 17 * Redistribution and use in source and binary forms, with or without
ninoderkinderen 0:8d87bc453349 18 * modification, are permitted provided that the following conditions
ninoderkinderen 0:8d87bc453349 19 * are met:
ninoderkinderen 0:8d87bc453349 20 * 1. Redistributions of source code must retain the above copyright
ninoderkinderen 0:8d87bc453349 21 * notice, this list of conditions and the following disclaimer.
ninoderkinderen 0:8d87bc453349 22 * 2. Redistributions in binary form must reproduce the above copyright
ninoderkinderen 0:8d87bc453349 23 * notice, this list of conditions and the following disclaimer in the
ninoderkinderen 0:8d87bc453349 24 * documentation and/or other materials provided with the distribution.
ninoderkinderen 0:8d87bc453349 25 * 3. The name of the author may not be used to endorse or promote
ninoderkinderen 0:8d87bc453349 26 * products derived from this software without specific prior
ninoderkinderen 0:8d87bc453349 27 * written permission.
ninoderkinderen 0:8d87bc453349 28 *
ninoderkinderen 0:8d87bc453349 29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
ninoderkinderen 0:8d87bc453349 30 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
ninoderkinderen 0:8d87bc453349 31 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ninoderkinderen 0:8d87bc453349 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
ninoderkinderen 0:8d87bc453349 33 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
ninoderkinderen 0:8d87bc453349 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
ninoderkinderen 0:8d87bc453349 35 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
ninoderkinderen 0:8d87bc453349 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
ninoderkinderen 0:8d87bc453349 37 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
ninoderkinderen 0:8d87bc453349 38 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
ninoderkinderen 0:8d87bc453349 39 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
ninoderkinderen 0:8d87bc453349 40 *
ninoderkinderen 0:8d87bc453349 41 *
ninoderkinderen 0:8d87bc453349 42 * DNS.C
ninoderkinderen 0:8d87bc453349 43 *
ninoderkinderen 0:8d87bc453349 44 * The lwIP DNS resolver functions are used to lookup a host name and
ninoderkinderen 0:8d87bc453349 45 * map it to a numerical IP address. It maintains a list of resolved
ninoderkinderen 0:8d87bc453349 46 * hostnames that can be queried with the dns_lookup() function.
ninoderkinderen 0:8d87bc453349 47 * New hostnames can be resolved using the dns_query() function.
ninoderkinderen 0:8d87bc453349 48 *
ninoderkinderen 0:8d87bc453349 49 * The lwIP version of the resolver also adds a non-blocking version of
ninoderkinderen 0:8d87bc453349 50 * gethostbyname() that will work with a raw API application. This function
ninoderkinderen 0:8d87bc453349 51 * checks for an IP address string first and converts it if it is valid.
ninoderkinderen 0:8d87bc453349 52 * gethostbyname() then does a dns_lookup() to see if the name is
ninoderkinderen 0:8d87bc453349 53 * already in the table. If so, the IP is returned. If not, a query is
ninoderkinderen 0:8d87bc453349 54 * issued and the function returns with a ERR_INPROGRESS status. The app
ninoderkinderen 0:8d87bc453349 55 * using the dns client must then go into a waiting state.
ninoderkinderen 0:8d87bc453349 56 *
ninoderkinderen 0:8d87bc453349 57 * Once a hostname has been resolved (or found to be non-existent),
ninoderkinderen 0:8d87bc453349 58 * the resolver code calls a specified callback function (which
ninoderkinderen 0:8d87bc453349 59 * must be implemented by the module that uses the resolver).
ninoderkinderen 0:8d87bc453349 60 */
ninoderkinderen 0:8d87bc453349 61
ninoderkinderen 0:8d87bc453349 62 /*-----------------------------------------------------------------------------
ninoderkinderen 0:8d87bc453349 63 * RFC 1035 - Domain names - implementation and specification
ninoderkinderen 0:8d87bc453349 64 * RFC 2181 - Clarifications to the DNS Specification
ninoderkinderen 0:8d87bc453349 65 *----------------------------------------------------------------------------*/
ninoderkinderen 0:8d87bc453349 66
ninoderkinderen 0:8d87bc453349 67 /** @todo: define good default values (rfc compliance) */
ninoderkinderen 0:8d87bc453349 68 /** @todo: improve answer parsing, more checkings... */
ninoderkinderen 0:8d87bc453349 69 /** @todo: check RFC1035 - 7.3. Processing responses */
ninoderkinderen 0:8d87bc453349 70
ninoderkinderen 0:8d87bc453349 71 /*-----------------------------------------------------------------------------
ninoderkinderen 0:8d87bc453349 72 * Includes
ninoderkinderen 0:8d87bc453349 73 *----------------------------------------------------------------------------*/
ninoderkinderen 0:8d87bc453349 74
ninoderkinderen 0:8d87bc453349 75 #include "lwip/opt.h"
ninoderkinderen 0:8d87bc453349 76
ninoderkinderen 0:8d87bc453349 77 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
ninoderkinderen 0:8d87bc453349 78
ninoderkinderen 0:8d87bc453349 79 #include "lwip/udp.h"
ninoderkinderen 0:8d87bc453349 80 #include "lwip/mem.h"
ninoderkinderen 0:8d87bc453349 81 #include "lwip/memp.h"
ninoderkinderen 0:8d87bc453349 82 #include "lwip/dns.h"
ninoderkinderen 0:8d87bc453349 83
ninoderkinderen 0:8d87bc453349 84 #include <string.h>
ninoderkinderen 0:8d87bc453349 85
ninoderkinderen 0:8d87bc453349 86 /** DNS server IP address */
ninoderkinderen 0:8d87bc453349 87 #ifndef DNS_SERVER_ADDRESS
ninoderkinderen 0:8d87bc453349 88 #define DNS_SERVER_ADDRESS(ipaddr) (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */
ninoderkinderen 0:8d87bc453349 89 #endif
ninoderkinderen 0:8d87bc453349 90
ninoderkinderen 0:8d87bc453349 91 /** DNS server port address */
ninoderkinderen 0:8d87bc453349 92 #ifndef DNS_SERVER_PORT
ninoderkinderen 0:8d87bc453349 93 #define DNS_SERVER_PORT 53
ninoderkinderen 0:8d87bc453349 94 #endif
ninoderkinderen 0:8d87bc453349 95
ninoderkinderen 0:8d87bc453349 96 /** DNS maximum number of retries when asking for a name, before "timeout". */
ninoderkinderen 0:8d87bc453349 97 #ifndef DNS_MAX_RETRIES
ninoderkinderen 0:8d87bc453349 98 #define DNS_MAX_RETRIES 4
ninoderkinderen 0:8d87bc453349 99 #endif
ninoderkinderen 0:8d87bc453349 100
ninoderkinderen 0:8d87bc453349 101 /** DNS resource record max. TTL (one week as default) */
ninoderkinderen 0:8d87bc453349 102 #ifndef DNS_MAX_TTL
ninoderkinderen 0:8d87bc453349 103 #define DNS_MAX_TTL 604800
ninoderkinderen 0:8d87bc453349 104 #endif
ninoderkinderen 0:8d87bc453349 105
ninoderkinderen 0:8d87bc453349 106 /* DNS protocol flags */
ninoderkinderen 0:8d87bc453349 107 #define DNS_FLAG1_RESPONSE 0x80
ninoderkinderen 0:8d87bc453349 108 #define DNS_FLAG1_OPCODE_STATUS 0x10
ninoderkinderen 0:8d87bc453349 109 #define DNS_FLAG1_OPCODE_INVERSE 0x08
ninoderkinderen 0:8d87bc453349 110 #define DNS_FLAG1_OPCODE_STANDARD 0x00
ninoderkinderen 0:8d87bc453349 111 #define DNS_FLAG1_AUTHORATIVE 0x04
ninoderkinderen 0:8d87bc453349 112 #define DNS_FLAG1_TRUNC 0x02
ninoderkinderen 0:8d87bc453349 113 #define DNS_FLAG1_RD 0x01
ninoderkinderen 0:8d87bc453349 114 #define DNS_FLAG2_RA 0x80
ninoderkinderen 0:8d87bc453349 115 #define DNS_FLAG2_ERR_MASK 0x0f
ninoderkinderen 0:8d87bc453349 116 #define DNS_FLAG2_ERR_NONE 0x00
ninoderkinderen 0:8d87bc453349 117 #define DNS_FLAG2_ERR_NAME 0x03
ninoderkinderen 0:8d87bc453349 118
ninoderkinderen 0:8d87bc453349 119 /* DNS protocol states */
ninoderkinderen 0:8d87bc453349 120 #define DNS_STATE_UNUSED 0
ninoderkinderen 0:8d87bc453349 121 #define DNS_STATE_NEW 1
ninoderkinderen 0:8d87bc453349 122 #define DNS_STATE_ASKING 2
ninoderkinderen 0:8d87bc453349 123 #define DNS_STATE_DONE 3
ninoderkinderen 0:8d87bc453349 124
ninoderkinderen 0:8d87bc453349 125 #ifdef PACK_STRUCT_USE_INCLUDES
ninoderkinderen 0:8d87bc453349 126 # include "arch/bpstruct.h"
ninoderkinderen 0:8d87bc453349 127 #endif
ninoderkinderen 0:8d87bc453349 128 PACK_STRUCT_BEGIN
ninoderkinderen 0:8d87bc453349 129 /** DNS message header */
ninoderkinderen 0:8d87bc453349 130 struct dns_hdr {
ninoderkinderen 0:8d87bc453349 131 PACK_STRUCT_FIELD(u16_t id);
ninoderkinderen 0:8d87bc453349 132 PACK_STRUCT_FIELD(u8_t flags1);
ninoderkinderen 0:8d87bc453349 133 PACK_STRUCT_FIELD(u8_t flags2);
ninoderkinderen 0:8d87bc453349 134 PACK_STRUCT_FIELD(u16_t numquestions);
ninoderkinderen 0:8d87bc453349 135 PACK_STRUCT_FIELD(u16_t numanswers);
ninoderkinderen 0:8d87bc453349 136 PACK_STRUCT_FIELD(u16_t numauthrr);
ninoderkinderen 0:8d87bc453349 137 PACK_STRUCT_FIELD(u16_t numextrarr);
ninoderkinderen 0:8d87bc453349 138 } PACK_STRUCT_STRUCT;
ninoderkinderen 0:8d87bc453349 139 PACK_STRUCT_END
ninoderkinderen 0:8d87bc453349 140 #ifdef PACK_STRUCT_USE_INCLUDES
ninoderkinderen 0:8d87bc453349 141 # include "arch/epstruct.h"
ninoderkinderen 0:8d87bc453349 142 #endif
ninoderkinderen 0:8d87bc453349 143 #define SIZEOF_DNS_HDR 12
ninoderkinderen 0:8d87bc453349 144
ninoderkinderen 0:8d87bc453349 145 /** DNS query message structure.
ninoderkinderen 0:8d87bc453349 146 No packing needed: only used locally on the stack. */
ninoderkinderen 0:8d87bc453349 147 struct dns_query {
ninoderkinderen 0:8d87bc453349 148 /* DNS query record starts with either a domain name or a pointer
ninoderkinderen 0:8d87bc453349 149 to a name already present somewhere in the packet. */
ninoderkinderen 0:8d87bc453349 150 u16_t type;
ninoderkinderen 0:8d87bc453349 151 u16_t cls;
ninoderkinderen 0:8d87bc453349 152 };
ninoderkinderen 0:8d87bc453349 153 #define SIZEOF_DNS_QUERY 4
ninoderkinderen 0:8d87bc453349 154
ninoderkinderen 0:8d87bc453349 155 /** DNS answer message structure.
ninoderkinderen 0:8d87bc453349 156 No packing needed: only used locally on the stack. */
ninoderkinderen 0:8d87bc453349 157 struct dns_answer {
ninoderkinderen 0:8d87bc453349 158 /* DNS answer record starts with either a domain name or a pointer
ninoderkinderen 0:8d87bc453349 159 to a name already present somewhere in the packet. */
ninoderkinderen 0:8d87bc453349 160 u16_t type;
ninoderkinderen 0:8d87bc453349 161 u16_t cls;
ninoderkinderen 0:8d87bc453349 162 u32_t ttl;
ninoderkinderen 0:8d87bc453349 163 u16_t len;
ninoderkinderen 0:8d87bc453349 164 };
ninoderkinderen 0:8d87bc453349 165 #define SIZEOF_DNS_ANSWER 10
ninoderkinderen 0:8d87bc453349 166
ninoderkinderen 0:8d87bc453349 167 /** DNS table entry */
ninoderkinderen 0:8d87bc453349 168 struct dns_table_entry {
ninoderkinderen 0:8d87bc453349 169 u8_t state;
ninoderkinderen 0:8d87bc453349 170 u8_t numdns;
ninoderkinderen 0:8d87bc453349 171 u8_t tmr;
ninoderkinderen 0:8d87bc453349 172 u8_t retries;
ninoderkinderen 0:8d87bc453349 173 u8_t seqno;
ninoderkinderen 0:8d87bc453349 174 u8_t err;
ninoderkinderen 0:8d87bc453349 175 u32_t ttl;
ninoderkinderen 0:8d87bc453349 176 char name[DNS_MAX_NAME_LENGTH];
ninoderkinderen 0:8d87bc453349 177 ip_addr_t ipaddr;
ninoderkinderen 0:8d87bc453349 178 /* pointer to callback on DNS query done */
ninoderkinderen 0:8d87bc453349 179 dns_found_callback found;
ninoderkinderen 0:8d87bc453349 180 void *arg;
ninoderkinderen 0:8d87bc453349 181 };
ninoderkinderen 0:8d87bc453349 182
ninoderkinderen 0:8d87bc453349 183 #if DNS_LOCAL_HOSTLIST
ninoderkinderen 0:8d87bc453349 184
ninoderkinderen 0:8d87bc453349 185 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
ninoderkinderen 0:8d87bc453349 186 /** Local host-list. For hostnames in this list, no
ninoderkinderen 0:8d87bc453349 187 * external name resolution is performed */
ninoderkinderen 0:8d87bc453349 188 static struct local_hostlist_entry *local_hostlist_dynamic;
ninoderkinderen 0:8d87bc453349 189 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
ninoderkinderen 0:8d87bc453349 190
ninoderkinderen 0:8d87bc453349 191 /** Defining this allows the local_hostlist_static to be placed in a different
ninoderkinderen 0:8d87bc453349 192 * linker section (e.g. FLASH) */
ninoderkinderen 0:8d87bc453349 193 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE
ninoderkinderen 0:8d87bc453349 194 #define DNS_LOCAL_HOSTLIST_STORAGE_PRE static
ninoderkinderen 0:8d87bc453349 195 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */
ninoderkinderen 0:8d87bc453349 196 /** Defining this allows the local_hostlist_static to be placed in a different
ninoderkinderen 0:8d87bc453349 197 * linker section (e.g. FLASH) */
ninoderkinderen 0:8d87bc453349 198 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST
ninoderkinderen 0:8d87bc453349 199 #define DNS_LOCAL_HOSTLIST_STORAGE_POST
ninoderkinderen 0:8d87bc453349 200 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */
ninoderkinderen 0:8d87bc453349 201 DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[]
ninoderkinderen 0:8d87bc453349 202 DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT;
ninoderkinderen 0:8d87bc453349 203
ninoderkinderen 0:8d87bc453349 204 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
ninoderkinderen 0:8d87bc453349 205
ninoderkinderen 0:8d87bc453349 206 static void dns_init_local();
ninoderkinderen 0:8d87bc453349 207 #endif /* DNS_LOCAL_HOSTLIST */
ninoderkinderen 0:8d87bc453349 208
ninoderkinderen 0:8d87bc453349 209
ninoderkinderen 0:8d87bc453349 210 /* forward declarations */
ninoderkinderen 0:8d87bc453349 211 static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
ninoderkinderen 0:8d87bc453349 212 static void dns_check_entries(void);
ninoderkinderen 0:8d87bc453349 213
ninoderkinderen 0:8d87bc453349 214 /*-----------------------------------------------------------------------------
ninoderkinderen 0:8d87bc453349 215 * Globales
ninoderkinderen 0:8d87bc453349 216 *----------------------------------------------------------------------------*/
ninoderkinderen 0:8d87bc453349 217
ninoderkinderen 0:8d87bc453349 218 /* DNS variables */
ninoderkinderen 0:8d87bc453349 219 static struct udp_pcb *dns_pcb;
ninoderkinderen 0:8d87bc453349 220 static u8_t dns_seqno;
ninoderkinderen 0:8d87bc453349 221 static struct dns_table_entry dns_table[DNS_TABLE_SIZE];
ninoderkinderen 0:8d87bc453349 222 static ip_addr_t dns_servers[DNS_MAX_SERVERS];
ninoderkinderen 0:8d87bc453349 223 /** Contiguous buffer for processing responses */
ninoderkinderen 0:8d87bc453349 224 static u8_t dns_payload_buffer[LWIP_MEM_ALIGN_BUFFER(DNS_MSG_SIZE)];
ninoderkinderen 0:8d87bc453349 225 static u8_t* dns_payload;
ninoderkinderen 0:8d87bc453349 226
ninoderkinderen 0:8d87bc453349 227 /**
ninoderkinderen 0:8d87bc453349 228 * Initialize the resolver: set up the UDP pcb and configure the default server
ninoderkinderen 0:8d87bc453349 229 * (DNS_SERVER_ADDRESS).
ninoderkinderen 0:8d87bc453349 230 */
ninoderkinderen 0:8d87bc453349 231 void
ninoderkinderen 0:8d87bc453349 232 dns_init()
ninoderkinderen 0:8d87bc453349 233 {
ninoderkinderen 0:8d87bc453349 234 ip_addr_t dnsserver;
ninoderkinderen 0:8d87bc453349 235
ninoderkinderen 0:8d87bc453349 236 dns_payload = (u8_t *)LWIP_MEM_ALIGN(dns_payload_buffer);
ninoderkinderen 0:8d87bc453349 237
ninoderkinderen 0:8d87bc453349 238 /* initialize default DNS server address */
ninoderkinderen 0:8d87bc453349 239 DNS_SERVER_ADDRESS(&dnsserver);
ninoderkinderen 0:8d87bc453349 240
ninoderkinderen 0:8d87bc453349 241 LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
ninoderkinderen 0:8d87bc453349 242
ninoderkinderen 0:8d87bc453349 243 /* if dns client not yet initialized... */
ninoderkinderen 0:8d87bc453349 244 if (dns_pcb == NULL) {
ninoderkinderen 0:8d87bc453349 245 dns_pcb = udp_new();
ninoderkinderen 0:8d87bc453349 246
ninoderkinderen 0:8d87bc453349 247 if (dns_pcb != NULL) {
ninoderkinderen 0:8d87bc453349 248 /* initialize DNS table not needed (initialized to zero since it is a
ninoderkinderen 0:8d87bc453349 249 * global variable) */
ninoderkinderen 0:8d87bc453349 250 LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
ninoderkinderen 0:8d87bc453349 251 DNS_STATE_UNUSED == 0);
ninoderkinderen 0:8d87bc453349 252
ninoderkinderen 0:8d87bc453349 253 /* initialize DNS client */
ninoderkinderen 0:8d87bc453349 254 udp_bind(dns_pcb, IP_ADDR_ANY, 0);
ninoderkinderen 0:8d87bc453349 255 udp_recv(dns_pcb, dns_recv, NULL);
ninoderkinderen 0:8d87bc453349 256
ninoderkinderen 0:8d87bc453349 257 /* initialize default DNS primary server */
ninoderkinderen 0:8d87bc453349 258 dns_setserver(0, &dnsserver);
ninoderkinderen 0:8d87bc453349 259 }
ninoderkinderen 0:8d87bc453349 260 }
ninoderkinderen 0:8d87bc453349 261 #if DNS_LOCAL_HOSTLIST
ninoderkinderen 0:8d87bc453349 262 dns_init_local();
ninoderkinderen 0:8d87bc453349 263 #endif
ninoderkinderen 0:8d87bc453349 264 }
ninoderkinderen 0:8d87bc453349 265
ninoderkinderen 0:8d87bc453349 266 /**
ninoderkinderen 0:8d87bc453349 267 * Initialize one of the DNS servers.
ninoderkinderen 0:8d87bc453349 268 *
ninoderkinderen 0:8d87bc453349 269 * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
ninoderkinderen 0:8d87bc453349 270 * @param dnsserver IP address of the DNS server to set
ninoderkinderen 0:8d87bc453349 271 */
ninoderkinderen 0:8d87bc453349 272 void
ninoderkinderen 0:8d87bc453349 273 dns_setserver(u8_t numdns, ip_addr_t *dnsserver)
ninoderkinderen 0:8d87bc453349 274 {
ninoderkinderen 0:8d87bc453349 275 if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) &&
ninoderkinderen 0:8d87bc453349 276 (dnsserver != NULL) && !ip_addr_isany(dnsserver)) {
ninoderkinderen 0:8d87bc453349 277 dns_servers[numdns] = (*dnsserver);
ninoderkinderen 0:8d87bc453349 278 }
ninoderkinderen 0:8d87bc453349 279 }
ninoderkinderen 0:8d87bc453349 280
ninoderkinderen 0:8d87bc453349 281 /**
ninoderkinderen 0:8d87bc453349 282 * Obtain one of the currently configured DNS server.
ninoderkinderen 0:8d87bc453349 283 *
ninoderkinderen 0:8d87bc453349 284 * @param numdns the index of the DNS server
ninoderkinderen 0:8d87bc453349 285 * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
ninoderkinderen 0:8d87bc453349 286 * server has not been configured.
ninoderkinderen 0:8d87bc453349 287 */
ninoderkinderen 0:8d87bc453349 288 ip_addr_t
ninoderkinderen 0:8d87bc453349 289 dns_getserver(u8_t numdns)
ninoderkinderen 0:8d87bc453349 290 {
ninoderkinderen 0:8d87bc453349 291 if (numdns < DNS_MAX_SERVERS) {
ninoderkinderen 0:8d87bc453349 292 return dns_servers[numdns];
ninoderkinderen 0:8d87bc453349 293 } else {
ninoderkinderen 0:8d87bc453349 294 return *IP_ADDR_ANY;
ninoderkinderen 0:8d87bc453349 295 }
ninoderkinderen 0:8d87bc453349 296 }
ninoderkinderen 0:8d87bc453349 297
ninoderkinderen 0:8d87bc453349 298 /**
ninoderkinderen 0:8d87bc453349 299 * The DNS resolver client timer - handle retries and timeouts and should
ninoderkinderen 0:8d87bc453349 300 * be called every DNS_TMR_INTERVAL milliseconds (every second by default).
ninoderkinderen 0:8d87bc453349 301 */
ninoderkinderen 0:8d87bc453349 302 void
ninoderkinderen 0:8d87bc453349 303 dns_tmr(void)
ninoderkinderen 0:8d87bc453349 304 {
ninoderkinderen 0:8d87bc453349 305 if (dns_pcb != NULL) {
ninoderkinderen 0:8d87bc453349 306 LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
ninoderkinderen 0:8d87bc453349 307 dns_check_entries();
ninoderkinderen 0:8d87bc453349 308 }
ninoderkinderen 0:8d87bc453349 309 }
ninoderkinderen 0:8d87bc453349 310
ninoderkinderen 0:8d87bc453349 311 #if DNS_LOCAL_HOSTLIST
ninoderkinderen 0:8d87bc453349 312 static void
ninoderkinderen 0:8d87bc453349 313 dns_init_local()
ninoderkinderen 0:8d87bc453349 314 {
ninoderkinderen 0:8d87bc453349 315 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT)
ninoderkinderen 0:8d87bc453349 316 int i;
ninoderkinderen 0:8d87bc453349 317 struct local_hostlist_entry *entry;
ninoderkinderen 0:8d87bc453349 318 /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
ninoderkinderen 0:8d87bc453349 319 struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
ninoderkinderen 0:8d87bc453349 320 size_t namelen;
ninoderkinderen 0:8d87bc453349 321 for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) {
ninoderkinderen 0:8d87bc453349 322 struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
ninoderkinderen 0:8d87bc453349 323 LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL);
ninoderkinderen 0:8d87bc453349 324 namelen = strlen(init_entry->name);
ninoderkinderen 0:8d87bc453349 325 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
ninoderkinderen 0:8d87bc453349 326 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
ninoderkinderen 0:8d87bc453349 327 LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
ninoderkinderen 0:8d87bc453349 328 if (entry != NULL) {
ninoderkinderen 0:8d87bc453349 329 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
ninoderkinderen 0:8d87bc453349 330 MEMCPY((char*)entry->name, init_entry->name, namelen);
ninoderkinderen 0:8d87bc453349 331 ((char*)entry->name)[namelen] = 0;
ninoderkinderen 0:8d87bc453349 332 entry->addr = init_entry->addr;
ninoderkinderen 0:8d87bc453349 333 entry->next = local_hostlist_dynamic;
ninoderkinderen 0:8d87bc453349 334 local_hostlist_dynamic = entry;
ninoderkinderen 0:8d87bc453349 335 }
ninoderkinderen 0:8d87bc453349 336 }
ninoderkinderen 0:8d87bc453349 337 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
ninoderkinderen 0:8d87bc453349 338 }
ninoderkinderen 0:8d87bc453349 339
ninoderkinderen 0:8d87bc453349 340 /**
ninoderkinderen 0:8d87bc453349 341 * Scans the local host-list for a hostname.
ninoderkinderen 0:8d87bc453349 342 *
ninoderkinderen 0:8d87bc453349 343 * @param hostname Hostname to look for in the local host-list
ninoderkinderen 0:8d87bc453349 344 * @return The first IP address for the hostname in the local host-list or
ninoderkinderen 0:8d87bc453349 345 * IPADDR_NONE if not found.
ninoderkinderen 0:8d87bc453349 346 */
ninoderkinderen 0:8d87bc453349 347 static u32_t
ninoderkinderen 0:8d87bc453349 348 dns_lookup_local(const char *hostname)
ninoderkinderen 0:8d87bc453349 349 {
ninoderkinderen 0:8d87bc453349 350 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
ninoderkinderen 0:8d87bc453349 351 struct local_hostlist_entry *entry = local_hostlist_dynamic;
ninoderkinderen 0:8d87bc453349 352 while(entry != NULL) {
ninoderkinderen 0:8d87bc453349 353 if(strcmp(entry->name, hostname) == 0) {
ninoderkinderen 0:8d87bc453349 354 return ip4_addr_get_u32(&entry->addr);
ninoderkinderen 0:8d87bc453349 355 }
ninoderkinderen 0:8d87bc453349 356 entry = entry->next;
ninoderkinderen 0:8d87bc453349 357 }
ninoderkinderen 0:8d87bc453349 358 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
ninoderkinderen 0:8d87bc453349 359 int i;
ninoderkinderen 0:8d87bc453349 360 for (i = 0; i < sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry); i++) {
ninoderkinderen 0:8d87bc453349 361 if(strcmp(local_hostlist_static[i].name, hostname) == 0) {
ninoderkinderen 0:8d87bc453349 362 return ip4_addr_get_u32(&local_hostlist_static[i].addr);
ninoderkinderen 0:8d87bc453349 363 }
ninoderkinderen 0:8d87bc453349 364 }
ninoderkinderen 0:8d87bc453349 365 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
ninoderkinderen 0:8d87bc453349 366 return IPADDR_NONE;
ninoderkinderen 0:8d87bc453349 367 }
ninoderkinderen 0:8d87bc453349 368
ninoderkinderen 0:8d87bc453349 369 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
ninoderkinderen 0:8d87bc453349 370 /** Remove all entries from the local host-list for a specific hostname
ninoderkinderen 0:8d87bc453349 371 * and/or IP addess
ninoderkinderen 0:8d87bc453349 372 *
ninoderkinderen 0:8d87bc453349 373 * @param hostname hostname for which entries shall be removed from the local
ninoderkinderen 0:8d87bc453349 374 * host-list
ninoderkinderen 0:8d87bc453349 375 * @param addr address for which entries shall be removed from the local host-list
ninoderkinderen 0:8d87bc453349 376 * @return the number of removed entries
ninoderkinderen 0:8d87bc453349 377 */
ninoderkinderen 0:8d87bc453349 378 int
ninoderkinderen 0:8d87bc453349 379 dns_local_removehost(const char *hostname, const ip_addr_t *addr)
ninoderkinderen 0:8d87bc453349 380 {
ninoderkinderen 0:8d87bc453349 381 int removed = 0;
ninoderkinderen 0:8d87bc453349 382 struct local_hostlist_entry *entry = local_hostlist_dynamic;
ninoderkinderen 0:8d87bc453349 383 struct local_hostlist_entry *last_entry = NULL;
ninoderkinderen 0:8d87bc453349 384 while (entry != NULL) {
ninoderkinderen 0:8d87bc453349 385 if (((hostname == NULL) || !strcmp(entry->name, hostname)) &&
ninoderkinderen 0:8d87bc453349 386 ((addr == NULL) || ip_addr_cmp(&entry->addr, addr))) {
ninoderkinderen 0:8d87bc453349 387 struct local_hostlist_entry *free_entry;
ninoderkinderen 0:8d87bc453349 388 if (last_entry != NULL) {
ninoderkinderen 0:8d87bc453349 389 last_entry->next = entry->next;
ninoderkinderen 0:8d87bc453349 390 } else {
ninoderkinderen 0:8d87bc453349 391 local_hostlist_dynamic = entry->next;
ninoderkinderen 0:8d87bc453349 392 }
ninoderkinderen 0:8d87bc453349 393 free_entry = entry;
ninoderkinderen 0:8d87bc453349 394 entry = entry->next;
ninoderkinderen 0:8d87bc453349 395 memp_free(MEMP_LOCALHOSTLIST, free_entry);
ninoderkinderen 0:8d87bc453349 396 removed++;
ninoderkinderen 0:8d87bc453349 397 } else {
ninoderkinderen 0:8d87bc453349 398 last_entry = entry;
ninoderkinderen 0:8d87bc453349 399 entry = entry->next;
ninoderkinderen 0:8d87bc453349 400 }
ninoderkinderen 0:8d87bc453349 401 }
ninoderkinderen 0:8d87bc453349 402 return removed;
ninoderkinderen 0:8d87bc453349 403 }
ninoderkinderen 0:8d87bc453349 404
ninoderkinderen 0:8d87bc453349 405 /**
ninoderkinderen 0:8d87bc453349 406 * Add a hostname/IP address pair to the local host-list.
ninoderkinderen 0:8d87bc453349 407 * Duplicates are not checked.
ninoderkinderen 0:8d87bc453349 408 *
ninoderkinderen 0:8d87bc453349 409 * @param hostname hostname of the new entry
ninoderkinderen 0:8d87bc453349 410 * @param addr IP address of the new entry
ninoderkinderen 0:8d87bc453349 411 * @return ERR_OK if succeeded or ERR_MEM on memory error
ninoderkinderen 0:8d87bc453349 412 */
ninoderkinderen 0:8d87bc453349 413 err_t
ninoderkinderen 0:8d87bc453349 414 dns_local_addhost(const char *hostname, const ip_addr_t *addr)
ninoderkinderen 0:8d87bc453349 415 {
ninoderkinderen 0:8d87bc453349 416 struct local_hostlist_entry *entry;
ninoderkinderen 0:8d87bc453349 417 size_t namelen;
ninoderkinderen 0:8d87bc453349 418 LWIP_ASSERT("invalid host name (NULL)", hostname != NULL);
ninoderkinderen 0:8d87bc453349 419 namelen = strlen(hostname);
ninoderkinderen 0:8d87bc453349 420 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
ninoderkinderen 0:8d87bc453349 421 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
ninoderkinderen 0:8d87bc453349 422 if (entry == NULL) {
ninoderkinderen 0:8d87bc453349 423 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 424 }
ninoderkinderen 0:8d87bc453349 425 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
ninoderkinderen 0:8d87bc453349 426 MEMCPY((char*)entry->name, hostname, namelen);
ninoderkinderen 0:8d87bc453349 427 ((char*)entry->name)[namelen] = 0;
ninoderkinderen 0:8d87bc453349 428 ip_addr_copy(entry->addr, *addr);
ninoderkinderen 0:8d87bc453349 429 entry->next = local_hostlist_dynamic;
ninoderkinderen 0:8d87bc453349 430 local_hostlist_dynamic = entry;
ninoderkinderen 0:8d87bc453349 431 return ERR_OK;
ninoderkinderen 0:8d87bc453349 432 }
ninoderkinderen 0:8d87bc453349 433 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
ninoderkinderen 0:8d87bc453349 434 #endif /* DNS_LOCAL_HOSTLIST */
ninoderkinderen 0:8d87bc453349 435
ninoderkinderen 0:8d87bc453349 436 /**
ninoderkinderen 0:8d87bc453349 437 * Look up a hostname in the array of known hostnames.
ninoderkinderen 0:8d87bc453349 438 *
ninoderkinderen 0:8d87bc453349 439 * @note This function only looks in the internal array of known
ninoderkinderen 0:8d87bc453349 440 * hostnames, it does not send out a query for the hostname if none
ninoderkinderen 0:8d87bc453349 441 * was found. The function dns_enqueue() can be used to send a query
ninoderkinderen 0:8d87bc453349 442 * for a hostname.
ninoderkinderen 0:8d87bc453349 443 *
ninoderkinderen 0:8d87bc453349 444 * @param name the hostname to look up
ninoderkinderen 0:8d87bc453349 445 * @return the hostname's IP address, as u32_t (instead of ip_addr_t to
ninoderkinderen 0:8d87bc453349 446 * better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname
ninoderkinderen 0:8d87bc453349 447 * was not found in the cached dns_table.
ninoderkinderen 0:8d87bc453349 448 */
ninoderkinderen 0:8d87bc453349 449 static u32_t
ninoderkinderen 0:8d87bc453349 450 dns_lookup(const char *name)
ninoderkinderen 0:8d87bc453349 451 {
ninoderkinderen 0:8d87bc453349 452 u8_t i;
ninoderkinderen 0:8d87bc453349 453 #if DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN)
ninoderkinderen 0:8d87bc453349 454 u32_t addr;
ninoderkinderen 0:8d87bc453349 455 #endif /* DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN) */
ninoderkinderen 0:8d87bc453349 456 #if DNS_LOCAL_HOSTLIST
ninoderkinderen 0:8d87bc453349 457 if ((addr = dns_lookup_local(name)) != IPADDR_NONE) {
ninoderkinderen 0:8d87bc453349 458 return addr;
ninoderkinderen 0:8d87bc453349 459 }
ninoderkinderen 0:8d87bc453349 460 #endif /* DNS_LOCAL_HOSTLIST */
ninoderkinderen 0:8d87bc453349 461 #ifdef DNS_LOOKUP_LOCAL_EXTERN
ninoderkinderen 0:8d87bc453349 462 if((addr = DNS_LOOKUP_LOCAL_EXTERN(name)) != IPADDR_NONE) {
ninoderkinderen 0:8d87bc453349 463 return addr;
ninoderkinderen 0:8d87bc453349 464 }
ninoderkinderen 0:8d87bc453349 465 #endif /* DNS_LOOKUP_LOCAL_EXTERN */
ninoderkinderen 0:8d87bc453349 466
ninoderkinderen 0:8d87bc453349 467 /* Walk through name list, return entry if found. If not, return NULL. */
ninoderkinderen 0:8d87bc453349 468 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
ninoderkinderen 0:8d87bc453349 469 if ((dns_table[i].state == DNS_STATE_DONE) &&
ninoderkinderen 0:8d87bc453349 470 (strcmp(name, dns_table[i].name) == 0)) {
ninoderkinderen 0:8d87bc453349 471 LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
ninoderkinderen 0:8d87bc453349 472 ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr));
ninoderkinderen 0:8d87bc453349 473 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
ninoderkinderen 0:8d87bc453349 474 return ip4_addr_get_u32(&dns_table[i].ipaddr);
ninoderkinderen 0:8d87bc453349 475 }
ninoderkinderen 0:8d87bc453349 476 }
ninoderkinderen 0:8d87bc453349 477
ninoderkinderen 0:8d87bc453349 478 return IPADDR_NONE;
ninoderkinderen 0:8d87bc453349 479 }
ninoderkinderen 0:8d87bc453349 480
ninoderkinderen 0:8d87bc453349 481 #if DNS_DOES_NAME_CHECK
ninoderkinderen 0:8d87bc453349 482 /**
ninoderkinderen 0:8d87bc453349 483 * Compare the "dotted" name "query" with the encoded name "response"
ninoderkinderen 0:8d87bc453349 484 * to make sure an answer from the DNS server matches the current dns_table
ninoderkinderen 0:8d87bc453349 485 * entry (otherwise, answers might arrive late for hostname not on the list
ninoderkinderen 0:8d87bc453349 486 * any more).
ninoderkinderen 0:8d87bc453349 487 *
ninoderkinderen 0:8d87bc453349 488 * @param query hostname (not encoded) from the dns_table
ninoderkinderen 0:8d87bc453349 489 * @param response encoded hostname in the DNS response
ninoderkinderen 0:8d87bc453349 490 * @return 0: names equal; 1: names differ
ninoderkinderen 0:8d87bc453349 491 */
ninoderkinderen 0:8d87bc453349 492 static u8_t
ninoderkinderen 0:8d87bc453349 493 dns_compare_name(unsigned char *query, unsigned char *response)
ninoderkinderen 0:8d87bc453349 494 {
ninoderkinderen 0:8d87bc453349 495 unsigned char n;
ninoderkinderen 0:8d87bc453349 496
ninoderkinderen 0:8d87bc453349 497 do {
ninoderkinderen 0:8d87bc453349 498 n = *response++;
ninoderkinderen 0:8d87bc453349 499 /** @see RFC 1035 - 4.1.4. Message compression */
ninoderkinderen 0:8d87bc453349 500 if ((n & 0xc0) == 0xc0) {
ninoderkinderen 0:8d87bc453349 501 /* Compressed name */
ninoderkinderen 0:8d87bc453349 502 break;
ninoderkinderen 0:8d87bc453349 503 } else {
ninoderkinderen 0:8d87bc453349 504 /* Not compressed name */
ninoderkinderen 0:8d87bc453349 505 while (n > 0) {
ninoderkinderen 0:8d87bc453349 506 if ((*query) != (*response)) {
ninoderkinderen 0:8d87bc453349 507 return 1;
ninoderkinderen 0:8d87bc453349 508 }
ninoderkinderen 0:8d87bc453349 509 ++response;
ninoderkinderen 0:8d87bc453349 510 ++query;
ninoderkinderen 0:8d87bc453349 511 --n;
ninoderkinderen 0:8d87bc453349 512 };
ninoderkinderen 0:8d87bc453349 513 ++query;
ninoderkinderen 0:8d87bc453349 514 }
ninoderkinderen 0:8d87bc453349 515 } while (*response != 0);
ninoderkinderen 0:8d87bc453349 516
ninoderkinderen 0:8d87bc453349 517 return 0;
ninoderkinderen 0:8d87bc453349 518 }
ninoderkinderen 0:8d87bc453349 519 #endif /* DNS_DOES_NAME_CHECK */
ninoderkinderen 0:8d87bc453349 520
ninoderkinderen 0:8d87bc453349 521 /**
ninoderkinderen 0:8d87bc453349 522 * Walk through a compact encoded DNS name and return the end of the name.
ninoderkinderen 0:8d87bc453349 523 *
ninoderkinderen 0:8d87bc453349 524 * @param query encoded DNS name in the DNS server response
ninoderkinderen 0:8d87bc453349 525 * @return end of the name
ninoderkinderen 0:8d87bc453349 526 */
ninoderkinderen 0:8d87bc453349 527 static unsigned char *
ninoderkinderen 0:8d87bc453349 528 dns_parse_name(unsigned char *query)
ninoderkinderen 0:8d87bc453349 529 {
ninoderkinderen 0:8d87bc453349 530 unsigned char n;
ninoderkinderen 0:8d87bc453349 531
ninoderkinderen 0:8d87bc453349 532 do {
ninoderkinderen 0:8d87bc453349 533 n = *query++;
ninoderkinderen 0:8d87bc453349 534 /** @see RFC 1035 - 4.1.4. Message compression */
ninoderkinderen 0:8d87bc453349 535 if ((n & 0xc0) == 0xc0) {
ninoderkinderen 0:8d87bc453349 536 /* Compressed name */
ninoderkinderen 0:8d87bc453349 537 break;
ninoderkinderen 0:8d87bc453349 538 } else {
ninoderkinderen 0:8d87bc453349 539 /* Not compressed name */
ninoderkinderen 0:8d87bc453349 540 while (n > 0) {
ninoderkinderen 0:8d87bc453349 541 ++query;
ninoderkinderen 0:8d87bc453349 542 --n;
ninoderkinderen 0:8d87bc453349 543 };
ninoderkinderen 0:8d87bc453349 544 }
ninoderkinderen 0:8d87bc453349 545 } while (*query != 0);
ninoderkinderen 0:8d87bc453349 546
ninoderkinderen 0:8d87bc453349 547 return query + 1;
ninoderkinderen 0:8d87bc453349 548 }
ninoderkinderen 0:8d87bc453349 549
ninoderkinderen 0:8d87bc453349 550 /**
ninoderkinderen 0:8d87bc453349 551 * Send a DNS query packet.
ninoderkinderen 0:8d87bc453349 552 *
ninoderkinderen 0:8d87bc453349 553 * @param numdns index of the DNS server in the dns_servers table
ninoderkinderen 0:8d87bc453349 554 * @param name hostname to query
ninoderkinderen 0:8d87bc453349 555 * @param id index of the hostname in dns_table, used as transaction ID in the
ninoderkinderen 0:8d87bc453349 556 * DNS query packet
ninoderkinderen 0:8d87bc453349 557 * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
ninoderkinderen 0:8d87bc453349 558 */
ninoderkinderen 0:8d87bc453349 559 static err_t
ninoderkinderen 0:8d87bc453349 560 dns_send(u8_t numdns, const char* name, u8_t id)
ninoderkinderen 0:8d87bc453349 561 {
ninoderkinderen 0:8d87bc453349 562 err_t err;
ninoderkinderen 0:8d87bc453349 563 struct dns_hdr *hdr;
ninoderkinderen 0:8d87bc453349 564 struct dns_query qry;
ninoderkinderen 0:8d87bc453349 565 struct pbuf *p;
ninoderkinderen 0:8d87bc453349 566 char *query, *nptr;
ninoderkinderen 0:8d87bc453349 567 const char *pHostname;
ninoderkinderen 0:8d87bc453349 568 u8_t n;
ninoderkinderen 0:8d87bc453349 569
ninoderkinderen 0:8d87bc453349 570 LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
ninoderkinderen 0:8d87bc453349 571 (u16_t)(numdns), name));
ninoderkinderen 0:8d87bc453349 572 LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS);
ninoderkinderen 0:8d87bc453349 573 LWIP_ASSERT("dns server has no IP address set", !ip_addr_isany(&dns_servers[numdns]));
ninoderkinderen 0:8d87bc453349 574
ninoderkinderen 0:8d87bc453349 575 /* if here, we have either a new query or a retry on a previous query to process */
ninoderkinderen 0:8d87bc453349 576 p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
ninoderkinderen 0:8d87bc453349 577 SIZEOF_DNS_QUERY, PBUF_RAM);
ninoderkinderen 0:8d87bc453349 578 if (p != NULL) {
ninoderkinderen 0:8d87bc453349 579 LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
ninoderkinderen 0:8d87bc453349 580 /* fill dns header */
ninoderkinderen 0:8d87bc453349 581 hdr = (struct dns_hdr*)p->payload;
ninoderkinderen 0:8d87bc453349 582 memset(hdr, 0, SIZEOF_DNS_HDR);
ninoderkinderen 0:8d87bc453349 583 hdr->id = htons(id);
ninoderkinderen 0:8d87bc453349 584 hdr->flags1 = DNS_FLAG1_RD;
ninoderkinderen 0:8d87bc453349 585 hdr->numquestions = PP_HTONS(1);
ninoderkinderen 0:8d87bc453349 586 query = (char*)hdr + SIZEOF_DNS_HDR;
ninoderkinderen 0:8d87bc453349 587 pHostname = name;
ninoderkinderen 0:8d87bc453349 588 --pHostname;
ninoderkinderen 0:8d87bc453349 589
ninoderkinderen 0:8d87bc453349 590 /* convert hostname into suitable query format. */
ninoderkinderen 0:8d87bc453349 591 do {
ninoderkinderen 0:8d87bc453349 592 ++pHostname;
ninoderkinderen 0:8d87bc453349 593 nptr = query;
ninoderkinderen 0:8d87bc453349 594 ++query;
ninoderkinderen 0:8d87bc453349 595 for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
ninoderkinderen 0:8d87bc453349 596 *query = *pHostname;
ninoderkinderen 0:8d87bc453349 597 ++query;
ninoderkinderen 0:8d87bc453349 598 ++n;
ninoderkinderen 0:8d87bc453349 599 }
ninoderkinderen 0:8d87bc453349 600 *nptr = n;
ninoderkinderen 0:8d87bc453349 601 } while(*pHostname != 0);
ninoderkinderen 0:8d87bc453349 602 *query++='\0';
ninoderkinderen 0:8d87bc453349 603
ninoderkinderen 0:8d87bc453349 604 /* fill dns query */
ninoderkinderen 0:8d87bc453349 605 qry.type = PP_HTONS(DNS_RRTYPE_A);
ninoderkinderen 0:8d87bc453349 606 qry.cls = PP_HTONS(DNS_RRCLASS_IN);
ninoderkinderen 0:8d87bc453349 607 SMEMCPY(query, &qry, SIZEOF_DNS_QUERY);
ninoderkinderen 0:8d87bc453349 608
ninoderkinderen 0:8d87bc453349 609 /* resize pbuf to the exact dns query */
ninoderkinderen 0:8d87bc453349 610 pbuf_realloc(p, (u16_t)((query + SIZEOF_DNS_QUERY) - ((char*)(p->payload))));
ninoderkinderen 0:8d87bc453349 611
ninoderkinderen 0:8d87bc453349 612 /* connect to the server for faster receiving */
ninoderkinderen 0:8d87bc453349 613 udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
ninoderkinderen 0:8d87bc453349 614 /* send dns packet */
ninoderkinderen 0:8d87bc453349 615 err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT);
ninoderkinderen 0:8d87bc453349 616
ninoderkinderen 0:8d87bc453349 617 /* free pbuf */
ninoderkinderen 0:8d87bc453349 618 pbuf_free(p);
ninoderkinderen 0:8d87bc453349 619 } else {
ninoderkinderen 0:8d87bc453349 620 err = ERR_MEM;
ninoderkinderen 0:8d87bc453349 621 }
ninoderkinderen 0:8d87bc453349 622
ninoderkinderen 0:8d87bc453349 623 return err;
ninoderkinderen 0:8d87bc453349 624 }
ninoderkinderen 0:8d87bc453349 625
ninoderkinderen 0:8d87bc453349 626 /**
ninoderkinderen 0:8d87bc453349 627 * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query.
ninoderkinderen 0:8d87bc453349 628 * Check an entry in the dns_table:
ninoderkinderen 0:8d87bc453349 629 * - send out query for new entries
ninoderkinderen 0:8d87bc453349 630 * - retry old pending entries on timeout (also with different servers)
ninoderkinderen 0:8d87bc453349 631 * - remove completed entries from the table if their TTL has expired
ninoderkinderen 0:8d87bc453349 632 *
ninoderkinderen 0:8d87bc453349 633 * @param i index of the dns_table entry to check
ninoderkinderen 0:8d87bc453349 634 */
ninoderkinderen 0:8d87bc453349 635 static void
ninoderkinderen 0:8d87bc453349 636 dns_check_entry(u8_t i)
ninoderkinderen 0:8d87bc453349 637 {
ninoderkinderen 0:8d87bc453349 638 err_t err;
ninoderkinderen 0:8d87bc453349 639 struct dns_table_entry *pEntry = &dns_table[i];
ninoderkinderen 0:8d87bc453349 640
ninoderkinderen 0:8d87bc453349 641 LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
ninoderkinderen 0:8d87bc453349 642
ninoderkinderen 0:8d87bc453349 643 switch(pEntry->state) {
ninoderkinderen 0:8d87bc453349 644
ninoderkinderen 0:8d87bc453349 645 case DNS_STATE_NEW: {
ninoderkinderen 0:8d87bc453349 646 /* initialize new entry */
ninoderkinderen 0:8d87bc453349 647 pEntry->state = DNS_STATE_ASKING;
ninoderkinderen 0:8d87bc453349 648 pEntry->numdns = 0;
ninoderkinderen 0:8d87bc453349 649 pEntry->tmr = 1;
ninoderkinderen 0:8d87bc453349 650 pEntry->retries = 0;
ninoderkinderen 0:8d87bc453349 651
ninoderkinderen 0:8d87bc453349 652 /* send DNS packet for this entry */
ninoderkinderen 0:8d87bc453349 653 err = dns_send(pEntry->numdns, pEntry->name, i);
ninoderkinderen 0:8d87bc453349 654 if (err != ERR_OK) {
ninoderkinderen 0:8d87bc453349 655 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
ninoderkinderen 0:8d87bc453349 656 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
ninoderkinderen 0:8d87bc453349 657 }
ninoderkinderen 0:8d87bc453349 658 break;
ninoderkinderen 0:8d87bc453349 659 }
ninoderkinderen 0:8d87bc453349 660
ninoderkinderen 0:8d87bc453349 661 case DNS_STATE_ASKING: {
ninoderkinderen 0:8d87bc453349 662 if (--pEntry->tmr == 0) {
ninoderkinderen 0:8d87bc453349 663 if (++pEntry->retries == DNS_MAX_RETRIES) {
ninoderkinderen 0:8d87bc453349 664 if ((pEntry->numdns+1<DNS_MAX_SERVERS) && !ip_addr_isany(&dns_servers[pEntry->numdns+1])) {
ninoderkinderen 0:8d87bc453349 665 /* change of server */
ninoderkinderen 0:8d87bc453349 666 pEntry->numdns++;
ninoderkinderen 0:8d87bc453349 667 pEntry->tmr = 1;
ninoderkinderen 0:8d87bc453349 668 pEntry->retries = 0;
ninoderkinderen 0:8d87bc453349 669 break;
ninoderkinderen 0:8d87bc453349 670 } else {
ninoderkinderen 0:8d87bc453349 671 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name));
ninoderkinderen 0:8d87bc453349 672 /* call specified callback function if provided */
ninoderkinderen 0:8d87bc453349 673 if (pEntry->found)
ninoderkinderen 0:8d87bc453349 674 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
ninoderkinderen 0:8d87bc453349 675 /* flush this entry */
ninoderkinderen 0:8d87bc453349 676 pEntry->state = DNS_STATE_UNUSED;
ninoderkinderen 0:8d87bc453349 677 pEntry->found = NULL;
ninoderkinderen 0:8d87bc453349 678 break;
ninoderkinderen 0:8d87bc453349 679 }
ninoderkinderen 0:8d87bc453349 680 }
ninoderkinderen 0:8d87bc453349 681
ninoderkinderen 0:8d87bc453349 682 /* wait longer for the next retry */
ninoderkinderen 0:8d87bc453349 683 pEntry->tmr = pEntry->retries;
ninoderkinderen 0:8d87bc453349 684
ninoderkinderen 0:8d87bc453349 685 /* send DNS packet for this entry */
ninoderkinderen 0:8d87bc453349 686 err = dns_send(pEntry->numdns, pEntry->name, i);
ninoderkinderen 0:8d87bc453349 687 if (err != ERR_OK) {
ninoderkinderen 0:8d87bc453349 688 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
ninoderkinderen 0:8d87bc453349 689 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
ninoderkinderen 0:8d87bc453349 690 }
ninoderkinderen 0:8d87bc453349 691 }
ninoderkinderen 0:8d87bc453349 692 break;
ninoderkinderen 0:8d87bc453349 693 }
ninoderkinderen 0:8d87bc453349 694
ninoderkinderen 0:8d87bc453349 695 case DNS_STATE_DONE: {
ninoderkinderen 0:8d87bc453349 696 /* if the time to live is nul */
ninoderkinderen 0:8d87bc453349 697 if (--pEntry->ttl == 0) {
ninoderkinderen 0:8d87bc453349 698 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name));
ninoderkinderen 0:8d87bc453349 699 /* flush this entry */
ninoderkinderen 0:8d87bc453349 700 pEntry->state = DNS_STATE_UNUSED;
ninoderkinderen 0:8d87bc453349 701 pEntry->found = NULL;
ninoderkinderen 0:8d87bc453349 702 }
ninoderkinderen 0:8d87bc453349 703 break;
ninoderkinderen 0:8d87bc453349 704 }
ninoderkinderen 0:8d87bc453349 705 case DNS_STATE_UNUSED:
ninoderkinderen 0:8d87bc453349 706 /* nothing to do */
ninoderkinderen 0:8d87bc453349 707 break;
ninoderkinderen 0:8d87bc453349 708 default:
ninoderkinderen 0:8d87bc453349 709 LWIP_ASSERT("unknown dns_table entry state:", 0);
ninoderkinderen 0:8d87bc453349 710 break;
ninoderkinderen 0:8d87bc453349 711 }
ninoderkinderen 0:8d87bc453349 712 }
ninoderkinderen 0:8d87bc453349 713
ninoderkinderen 0:8d87bc453349 714 /**
ninoderkinderen 0:8d87bc453349 715 * Call dns_check_entry for each entry in dns_table - check all entries.
ninoderkinderen 0:8d87bc453349 716 */
ninoderkinderen 0:8d87bc453349 717 static void
ninoderkinderen 0:8d87bc453349 718 dns_check_entries(void)
ninoderkinderen 0:8d87bc453349 719 {
ninoderkinderen 0:8d87bc453349 720 u8_t i;
ninoderkinderen 0:8d87bc453349 721
ninoderkinderen 0:8d87bc453349 722 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
ninoderkinderen 0:8d87bc453349 723 dns_check_entry(i);
ninoderkinderen 0:8d87bc453349 724 }
ninoderkinderen 0:8d87bc453349 725 }
ninoderkinderen 0:8d87bc453349 726
ninoderkinderen 0:8d87bc453349 727 /**
ninoderkinderen 0:8d87bc453349 728 * Receive input function for DNS response packets arriving for the dns UDP pcb.
ninoderkinderen 0:8d87bc453349 729 *
ninoderkinderen 0:8d87bc453349 730 * @params see udp.h
ninoderkinderen 0:8d87bc453349 731 */
ninoderkinderen 0:8d87bc453349 732 static void
ninoderkinderen 0:8d87bc453349 733 dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
ninoderkinderen 0:8d87bc453349 734 {
ninoderkinderen 0:8d87bc453349 735 u16_t i;
ninoderkinderen 0:8d87bc453349 736 char *pHostname;
ninoderkinderen 0:8d87bc453349 737 struct dns_hdr *hdr;
ninoderkinderen 0:8d87bc453349 738 struct dns_answer ans;
ninoderkinderen 0:8d87bc453349 739 struct dns_table_entry *pEntry;
ninoderkinderen 0:8d87bc453349 740 u16_t nquestions, nanswers;
ninoderkinderen 0:8d87bc453349 741
ninoderkinderen 0:8d87bc453349 742 LWIP_UNUSED_ARG(arg);
ninoderkinderen 0:8d87bc453349 743 LWIP_UNUSED_ARG(pcb);
ninoderkinderen 0:8d87bc453349 744 LWIP_UNUSED_ARG(addr);
ninoderkinderen 0:8d87bc453349 745 LWIP_UNUSED_ARG(port);
ninoderkinderen 0:8d87bc453349 746
ninoderkinderen 0:8d87bc453349 747 /* is the dns message too big ? */
ninoderkinderen 0:8d87bc453349 748 if (p->tot_len > DNS_MSG_SIZE) {
ninoderkinderen 0:8d87bc453349 749 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
ninoderkinderen 0:8d87bc453349 750 /* free pbuf and return */
ninoderkinderen 0:8d87bc453349 751 goto memerr;
ninoderkinderen 0:8d87bc453349 752 }
ninoderkinderen 0:8d87bc453349 753
ninoderkinderen 0:8d87bc453349 754 /* is the dns message big enough ? */
ninoderkinderen 0:8d87bc453349 755 if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
ninoderkinderen 0:8d87bc453349 756 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
ninoderkinderen 0:8d87bc453349 757 /* free pbuf and return */
ninoderkinderen 0:8d87bc453349 758 goto memerr;
ninoderkinderen 0:8d87bc453349 759 }
ninoderkinderen 0:8d87bc453349 760
ninoderkinderen 0:8d87bc453349 761 /* copy dns payload inside static buffer for processing */
ninoderkinderen 0:8d87bc453349 762 if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) {
ninoderkinderen 0:8d87bc453349 763 /* The ID in the DNS header should be our entry into the name table. */
ninoderkinderen 0:8d87bc453349 764 hdr = (struct dns_hdr*)dns_payload;
ninoderkinderen 0:8d87bc453349 765 i = htons(hdr->id);
ninoderkinderen 0:8d87bc453349 766 if (i < DNS_TABLE_SIZE) {
ninoderkinderen 0:8d87bc453349 767 pEntry = &dns_table[i];
ninoderkinderen 0:8d87bc453349 768 if(pEntry->state == DNS_STATE_ASKING) {
ninoderkinderen 0:8d87bc453349 769 /* This entry is now completed. */
ninoderkinderen 0:8d87bc453349 770 pEntry->state = DNS_STATE_DONE;
ninoderkinderen 0:8d87bc453349 771 pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK;
ninoderkinderen 0:8d87bc453349 772
ninoderkinderen 0:8d87bc453349 773 /* We only care about the question(s) and the answers. The authrr
ninoderkinderen 0:8d87bc453349 774 and the extrarr are simply discarded. */
ninoderkinderen 0:8d87bc453349 775 nquestions = htons(hdr->numquestions);
ninoderkinderen 0:8d87bc453349 776 nanswers = htons(hdr->numanswers);
ninoderkinderen 0:8d87bc453349 777
ninoderkinderen 0:8d87bc453349 778 /* Check for error. If so, call callback to inform. */
ninoderkinderen 0:8d87bc453349 779 if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) {
ninoderkinderen 0:8d87bc453349 780 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name));
ninoderkinderen 0:8d87bc453349 781 /* call callback to indicate error, clean up memory and return */
ninoderkinderen 0:8d87bc453349 782 goto responseerr;
ninoderkinderen 0:8d87bc453349 783 }
ninoderkinderen 0:8d87bc453349 784
ninoderkinderen 0:8d87bc453349 785 #if DNS_DOES_NAME_CHECK
ninoderkinderen 0:8d87bc453349 786 /* Check if the name in the "question" part match with the name in the entry. */
ninoderkinderen 0:8d87bc453349 787 if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) {
ninoderkinderen 0:8d87bc453349 788 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
ninoderkinderen 0:8d87bc453349 789 /* call callback to indicate error, clean up memory and return */
ninoderkinderen 0:8d87bc453349 790 goto responseerr;
ninoderkinderen 0:8d87bc453349 791 }
ninoderkinderen 0:8d87bc453349 792 #endif /* DNS_DOES_NAME_CHECK */
ninoderkinderen 0:8d87bc453349 793
ninoderkinderen 0:8d87bc453349 794 /* Skip the name in the "question" part */
ninoderkinderen 0:8d87bc453349 795 pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
ninoderkinderen 0:8d87bc453349 796
ninoderkinderen 0:8d87bc453349 797 while (nanswers > 0) {
ninoderkinderen 0:8d87bc453349 798 /* skip answer resource record's host name */
ninoderkinderen 0:8d87bc453349 799 pHostname = (char *) dns_parse_name((unsigned char *)pHostname);
ninoderkinderen 0:8d87bc453349 800
ninoderkinderen 0:8d87bc453349 801 /* Check for IP address type and Internet class. Others are discarded. */
ninoderkinderen 0:8d87bc453349 802 SMEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
ninoderkinderen 0:8d87bc453349 803 if((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) &&
ninoderkinderen 0:8d87bc453349 804 (ans.len == PP_HTONS(sizeof(ip_addr_t))) ) {
ninoderkinderen 0:8d87bc453349 805 /* read the answer resource record's TTL, and maximize it if needed */
ninoderkinderen 0:8d87bc453349 806 pEntry->ttl = ntohl(ans.ttl);
ninoderkinderen 0:8d87bc453349 807 if (pEntry->ttl > DNS_MAX_TTL) {
ninoderkinderen 0:8d87bc453349 808 pEntry->ttl = DNS_MAX_TTL;
ninoderkinderen 0:8d87bc453349 809 }
ninoderkinderen 0:8d87bc453349 810 /* read the IP address after answer resource record's header */
ninoderkinderen 0:8d87bc453349 811 SMEMCPY(&(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(ip_addr_t));
ninoderkinderen 0:8d87bc453349 812 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
ninoderkinderen 0:8d87bc453349 813 ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
ninoderkinderen 0:8d87bc453349 814 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
ninoderkinderen 0:8d87bc453349 815 /* call specified callback function if provided */
ninoderkinderen 0:8d87bc453349 816 if (pEntry->found) {
ninoderkinderen 0:8d87bc453349 817 (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg);
ninoderkinderen 0:8d87bc453349 818 }
ninoderkinderen 0:8d87bc453349 819 /* deallocate memory and return */
ninoderkinderen 0:8d87bc453349 820 goto memerr;
ninoderkinderen 0:8d87bc453349 821 } else {
ninoderkinderen 0:8d87bc453349 822 pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
ninoderkinderen 0:8d87bc453349 823 }
ninoderkinderen 0:8d87bc453349 824 --nanswers;
ninoderkinderen 0:8d87bc453349 825 }
ninoderkinderen 0:8d87bc453349 826 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name));
ninoderkinderen 0:8d87bc453349 827 /* call callback to indicate error, clean up memory and return */
ninoderkinderen 0:8d87bc453349 828 goto responseerr;
ninoderkinderen 0:8d87bc453349 829 }
ninoderkinderen 0:8d87bc453349 830 }
ninoderkinderen 0:8d87bc453349 831 }
ninoderkinderen 0:8d87bc453349 832
ninoderkinderen 0:8d87bc453349 833 /* deallocate memory and return */
ninoderkinderen 0:8d87bc453349 834 goto memerr;
ninoderkinderen 0:8d87bc453349 835
ninoderkinderen 0:8d87bc453349 836 responseerr:
ninoderkinderen 0:8d87bc453349 837 /* ERROR: call specified callback function with NULL as name to indicate an error */
ninoderkinderen 0:8d87bc453349 838 if (pEntry->found) {
ninoderkinderen 0:8d87bc453349 839 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
ninoderkinderen 0:8d87bc453349 840 }
ninoderkinderen 0:8d87bc453349 841 /* flush this entry */
ninoderkinderen 0:8d87bc453349 842 pEntry->state = DNS_STATE_UNUSED;
ninoderkinderen 0:8d87bc453349 843 pEntry->found = NULL;
ninoderkinderen 0:8d87bc453349 844
ninoderkinderen 0:8d87bc453349 845 memerr:
ninoderkinderen 0:8d87bc453349 846 /* free pbuf */
ninoderkinderen 0:8d87bc453349 847 pbuf_free(p);
ninoderkinderen 0:8d87bc453349 848 return;
ninoderkinderen 0:8d87bc453349 849 }
ninoderkinderen 0:8d87bc453349 850
ninoderkinderen 0:8d87bc453349 851 /**
ninoderkinderen 0:8d87bc453349 852 * Queues a new hostname to resolve and sends out a DNS query for that hostname
ninoderkinderen 0:8d87bc453349 853 *
ninoderkinderen 0:8d87bc453349 854 * @param name the hostname that is to be queried
ninoderkinderen 0:8d87bc453349 855 * @param found a callback founction to be called on success, failure or timeout
ninoderkinderen 0:8d87bc453349 856 * @param callback_arg argument to pass to the callback function
ninoderkinderen 0:8d87bc453349 857 * @return @return a err_t return code.
ninoderkinderen 0:8d87bc453349 858 */
ninoderkinderen 0:8d87bc453349 859 static err_t
ninoderkinderen 0:8d87bc453349 860 dns_enqueue(const char *name, dns_found_callback found, void *callback_arg)
ninoderkinderen 0:8d87bc453349 861 {
ninoderkinderen 0:8d87bc453349 862 u8_t i;
ninoderkinderen 0:8d87bc453349 863 u8_t lseq, lseqi;
ninoderkinderen 0:8d87bc453349 864 struct dns_table_entry *pEntry = NULL;
ninoderkinderen 0:8d87bc453349 865 size_t namelen;
ninoderkinderen 0:8d87bc453349 866
ninoderkinderen 0:8d87bc453349 867 /* search an unused entry, or the oldest one */
ninoderkinderen 0:8d87bc453349 868 lseq = lseqi = 0;
ninoderkinderen 0:8d87bc453349 869 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
ninoderkinderen 0:8d87bc453349 870 pEntry = &dns_table[i];
ninoderkinderen 0:8d87bc453349 871 /* is it an unused entry ? */
ninoderkinderen 0:8d87bc453349 872 if (pEntry->state == DNS_STATE_UNUSED)
ninoderkinderen 0:8d87bc453349 873 break;
ninoderkinderen 0:8d87bc453349 874
ninoderkinderen 0:8d87bc453349 875 /* check if this is the oldest completed entry */
ninoderkinderen 0:8d87bc453349 876 if (pEntry->state == DNS_STATE_DONE) {
ninoderkinderen 0:8d87bc453349 877 if ((dns_seqno - pEntry->seqno) > lseq) {
ninoderkinderen 0:8d87bc453349 878 lseq = dns_seqno - pEntry->seqno;
ninoderkinderen 0:8d87bc453349 879 lseqi = i;
ninoderkinderen 0:8d87bc453349 880 }
ninoderkinderen 0:8d87bc453349 881 }
ninoderkinderen 0:8d87bc453349 882 }
ninoderkinderen 0:8d87bc453349 883
ninoderkinderen 0:8d87bc453349 884 /* if we don't have found an unused entry, use the oldest completed one */
ninoderkinderen 0:8d87bc453349 885 if (i == DNS_TABLE_SIZE) {
ninoderkinderen 0:8d87bc453349 886 if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) {
ninoderkinderen 0:8d87bc453349 887 /* no entry can't be used now, table is full */
ninoderkinderen 0:8d87bc453349 888 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
ninoderkinderen 0:8d87bc453349 889 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 890 } else {
ninoderkinderen 0:8d87bc453349 891 /* use the oldest completed one */
ninoderkinderen 0:8d87bc453349 892 i = lseqi;
ninoderkinderen 0:8d87bc453349 893 pEntry = &dns_table[i];
ninoderkinderen 0:8d87bc453349 894 }
ninoderkinderen 0:8d87bc453349 895 }
ninoderkinderen 0:8d87bc453349 896
ninoderkinderen 0:8d87bc453349 897 /* use this entry */
ninoderkinderen 0:8d87bc453349 898 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
ninoderkinderen 0:8d87bc453349 899
ninoderkinderen 0:8d87bc453349 900 /* fill the entry */
ninoderkinderen 0:8d87bc453349 901 pEntry->state = DNS_STATE_NEW;
ninoderkinderen 0:8d87bc453349 902 pEntry->seqno = dns_seqno++;
ninoderkinderen 0:8d87bc453349 903 pEntry->found = found;
ninoderkinderen 0:8d87bc453349 904 pEntry->arg = callback_arg;
ninoderkinderen 0:8d87bc453349 905 namelen = LWIP_MIN(strlen(name), DNS_MAX_NAME_LENGTH-1);
ninoderkinderen 0:8d87bc453349 906 MEMCPY(pEntry->name, name, namelen);
ninoderkinderen 0:8d87bc453349 907 pEntry->name[namelen] = 0;
ninoderkinderen 0:8d87bc453349 908
ninoderkinderen 0:8d87bc453349 909 /* force to send query without waiting timer */
ninoderkinderen 0:8d87bc453349 910 dns_check_entry(i);
ninoderkinderen 0:8d87bc453349 911
ninoderkinderen 0:8d87bc453349 912 /* dns query is enqueued */
ninoderkinderen 0:8d87bc453349 913 return ERR_INPROGRESS;
ninoderkinderen 0:8d87bc453349 914 }
ninoderkinderen 0:8d87bc453349 915
ninoderkinderen 0:8d87bc453349 916 /**
ninoderkinderen 0:8d87bc453349 917 * Resolve a hostname (string) into an IP address.
ninoderkinderen 0:8d87bc453349 918 * NON-BLOCKING callback version for use with raw API!!!
ninoderkinderen 0:8d87bc453349 919 *
ninoderkinderen 0:8d87bc453349 920 * Returns immediately with one of err_t return codes:
ninoderkinderen 0:8d87bc453349 921 * - ERR_OK if hostname is a valid IP address string or the host
ninoderkinderen 0:8d87bc453349 922 * name is already in the local names table.
ninoderkinderen 0:8d87bc453349 923 * - ERR_INPROGRESS enqueue a request to be sent to the DNS server
ninoderkinderen 0:8d87bc453349 924 * for resolution if no errors are present.
ninoderkinderen 0:8d87bc453349 925 *
ninoderkinderen 0:8d87bc453349 926 * @param hostname the hostname that is to be queried
ninoderkinderen 0:8d87bc453349 927 * @param addr pointer to a ip_addr_t where to store the address if it is already
ninoderkinderen 0:8d87bc453349 928 * cached in the dns_table (only valid if ERR_OK is returned!)
ninoderkinderen 0:8d87bc453349 929 * @param found a callback function to be called on success, failure or timeout (only if
ninoderkinderen 0:8d87bc453349 930 * ERR_INPROGRESS is returned!)
ninoderkinderen 0:8d87bc453349 931 * @param callback_arg argument to pass to the callback function
ninoderkinderen 0:8d87bc453349 932 * @return a err_t return code.
ninoderkinderen 0:8d87bc453349 933 */
ninoderkinderen 0:8d87bc453349 934 err_t
ninoderkinderen 0:8d87bc453349 935 dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found,
ninoderkinderen 0:8d87bc453349 936 void *callback_arg)
ninoderkinderen 0:8d87bc453349 937 {
ninoderkinderen 0:8d87bc453349 938 u32_t ipaddr;
ninoderkinderen 0:8d87bc453349 939 /* not initialized or no valid server yet, or invalid addr pointer
ninoderkinderen 0:8d87bc453349 940 * or invalid hostname or invalid hostname length */
ninoderkinderen 0:8d87bc453349 941 if ((dns_pcb == NULL) || (addr == NULL) ||
ninoderkinderen 0:8d87bc453349 942 (!hostname) || (!hostname[0]) ||
ninoderkinderen 0:8d87bc453349 943 (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) {
ninoderkinderen 0:8d87bc453349 944 return ERR_VAL;
ninoderkinderen 0:8d87bc453349 945 }
ninoderkinderen 0:8d87bc453349 946
ninoderkinderen 0:8d87bc453349 947 #if LWIP_HAVE_LOOPIF
ninoderkinderen 0:8d87bc453349 948 if (strcmp(hostname, "localhost")==0) {
ninoderkinderen 0:8d87bc453349 949 ip_addr_set_loopback(addr);
ninoderkinderen 0:8d87bc453349 950 return ERR_OK;
ninoderkinderen 0:8d87bc453349 951 }
ninoderkinderen 0:8d87bc453349 952 #endif /* LWIP_HAVE_LOOPIF */
ninoderkinderen 0:8d87bc453349 953
ninoderkinderen 0:8d87bc453349 954 /* host name already in octet notation? set ip addr and return ERR_OK */
ninoderkinderen 0:8d87bc453349 955 ipaddr = ipaddr_addr(hostname);
ninoderkinderen 0:8d87bc453349 956 if (ipaddr == IPADDR_NONE) {
ninoderkinderen 0:8d87bc453349 957 /* already have this address cached? */
ninoderkinderen 0:8d87bc453349 958 ipaddr = dns_lookup(hostname);
ninoderkinderen 0:8d87bc453349 959 }
ninoderkinderen 0:8d87bc453349 960 if (ipaddr != IPADDR_NONE) {
ninoderkinderen 0:8d87bc453349 961 ip4_addr_set_u32(addr, ipaddr);
ninoderkinderen 0:8d87bc453349 962 return ERR_OK;
ninoderkinderen 0:8d87bc453349 963 }
ninoderkinderen 0:8d87bc453349 964
ninoderkinderen 0:8d87bc453349 965 /* queue query with specified callback */
ninoderkinderen 0:8d87bc453349 966 return dns_enqueue(hostname, found, callback_arg);
ninoderkinderen 0:8d87bc453349 967 }
ninoderkinderen 0:8d87bc453349 968
ninoderkinderen 0:8d87bc453349 969 #endif /* LWIP_DNS */