Yann Garcia / Mbed 2 deprecated DS130x_I2CApp

This short program illustrates how to use the DS130x_I2C library. My objective is to share the same RTC with Microchip 18F MCU.

Dependencies:   mbed DebugLibrary

NetServices/lwip/core/dns.c@1:995212d326ca, 2011-02-11 (annotated)

Committer:
Yann
Date:
Fri Feb 11 10:17:20 2011 +0000
Revision:
1:995212d326ca
Parent:
0:f30e2135b0db 
V0.0.0.2

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yann 0:f30e2135b0db 1 /**
Yann 0:f30e2135b0db 2 * @file
Yann 0:f30e2135b0db 3 * DNS - host name to IP address resolver.
Yann 0:f30e2135b0db 4 *
Yann 0:f30e2135b0db 5 */
Yann 0:f30e2135b0db 6
Yann 0:f30e2135b0db 7 /**
Yann 0:f30e2135b0db 8
Yann 0:f30e2135b0db 9 * This file implements a DNS host name to IP address resolver.
Yann 0:f30e2135b0db 10
Yann 0:f30e2135b0db 11 * Port to lwIP from uIP
Yann 0:f30e2135b0db 12 * by Jim Pettinato April 2007
Yann 0:f30e2135b0db 13
Yann 0:f30e2135b0db 14 * uIP version Copyright (c) 2002-2003, Adam Dunkels.
Yann 0:f30e2135b0db 15 * All rights reserved.
Yann 0:f30e2135b0db 16 *
Yann 0:f30e2135b0db 17 * Redistribution and use in source and binary forms, with or without
Yann 0:f30e2135b0db 18 * modification, are permitted provided that the following conditions
Yann 0:f30e2135b0db 19 * are met:
Yann 0:f30e2135b0db 20 * 1. Redistributions of source code must retain the above copyright
Yann 0:f30e2135b0db 21 * notice, this list of conditions and the following disclaimer.
Yann 0:f30e2135b0db 22 * 2. Redistributions in binary form must reproduce the above copyright
Yann 0:f30e2135b0db 23 * notice, this list of conditions and the following disclaimer in the
Yann 0:f30e2135b0db 24 * documentation and/or other materials provided with the distribution.
Yann 0:f30e2135b0db 25 * 3. The name of the author may not be used to endorse or promote
Yann 0:f30e2135b0db 26 * products derived from this software without specific prior
Yann 0:f30e2135b0db 27 * written permission.
Yann 0:f30e2135b0db 28 *
Yann 0:f30e2135b0db 29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
Yann 0:f30e2135b0db 30 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
Yann 0:f30e2135b0db 31 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
Yann 0:f30e2135b0db 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
Yann 0:f30e2135b0db 33 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
Yann 0:f30e2135b0db 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
Yann 0:f30e2135b0db 35 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
Yann 0:f30e2135b0db 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
Yann 0:f30e2135b0db 37 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
Yann 0:f30e2135b0db 38 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
Yann 0:f30e2135b0db 39 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Yann 0:f30e2135b0db 40 *
Yann 0:f30e2135b0db 41 *
Yann 0:f30e2135b0db 42 * DNS.C
Yann 0:f30e2135b0db 43 *
Yann 0:f30e2135b0db 44 * The lwIP DNS resolver functions are used to lookup a host name and
Yann 0:f30e2135b0db 45 * map it to a numerical IP address. It maintains a list of resolved
Yann 0:f30e2135b0db 46 * hostnames that can be queried with the dns_lookup() function.
Yann 0:f30e2135b0db 47 * New hostnames can be resolved using the dns_query() function.
Yann 0:f30e2135b0db 48 *
Yann 0:f30e2135b0db 49 * The lwIP version of the resolver also adds a non-blocking version of
Yann 0:f30e2135b0db 50 * gethostbyname() that will work with a raw API application. This function
Yann 0:f30e2135b0db 51 * checks for an IP address string first and converts it if it is valid.
Yann 0:f30e2135b0db 52 * gethostbyname() then does a dns_lookup() to see if the name is
Yann 0:f30e2135b0db 53 * already in the table. If so, the IP is returned. If not, a query is
Yann 0:f30e2135b0db 54 * issued and the function returns with a ERR_INPROGRESS status. The app
Yann 0:f30e2135b0db 55 * using the dns client must then go into a waiting state.
Yann 0:f30e2135b0db 56 *
Yann 0:f30e2135b0db 57 * Once a hostname has been resolved (or found to be non-existent),
Yann 0:f30e2135b0db 58 * the resolver code calls a specified callback function (which
Yann 0:f30e2135b0db 59 * must be implemented by the module that uses the resolver).
Yann 0:f30e2135b0db 60 */
Yann 0:f30e2135b0db 61
Yann 0:f30e2135b0db 62 /*-----------------------------------------------------------------------------
Yann 0:f30e2135b0db 63 * RFC 1035 - Domain names - implementation and specification
Yann 0:f30e2135b0db 64 * RFC 2181 - Clarifications to the DNS Specification
Yann 0:f30e2135b0db 65 *----------------------------------------------------------------------------*/
Yann 0:f30e2135b0db 66
Yann 0:f30e2135b0db 67 /** @todo: define good default values (rfc compliance) */
Yann 0:f30e2135b0db 68 /** @todo: improve answer parsing, more checkings... */
Yann 0:f30e2135b0db 69 /** @todo: check RFC1035 - 7.3. Processing responses */
Yann 0:f30e2135b0db 70
Yann 0:f30e2135b0db 71 /*-----------------------------------------------------------------------------
Yann 0:f30e2135b0db 72 * Includes
Yann 0:f30e2135b0db 73 *----------------------------------------------------------------------------*/
Yann 0:f30e2135b0db 74
Yann 0:f30e2135b0db 75 #include "lwip/opt.h"
Yann 0:f30e2135b0db 76
Yann 0:f30e2135b0db 77 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
Yann 0:f30e2135b0db 78
Yann 0:f30e2135b0db 79 #include "lwip/udp.h"
Yann 0:f30e2135b0db 80 #include "lwip/mem.h"
Yann 0:f30e2135b0db 81 #include "lwip/memp.h"
Yann 0:f30e2135b0db 82 #include "lwip/dns.h"
Yann 0:f30e2135b0db 83
Yann 0:f30e2135b0db 84 #include <string.h>
Yann 0:f30e2135b0db 85
Yann 0:f30e2135b0db 86 /** DNS server IP address */
Yann 0:f30e2135b0db 87 #ifndef DNS_SERVER_ADDRESS
Yann 0:f30e2135b0db 88 #define DNS_SERVER_ADDRESS(ipaddr) (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */
Yann 0:f30e2135b0db 89 #endif
Yann 0:f30e2135b0db 90
Yann 0:f30e2135b0db 91 /** DNS server port address */
Yann 0:f30e2135b0db 92 #ifndef DNS_SERVER_PORT
Yann 0:f30e2135b0db 93 #define DNS_SERVER_PORT 53
Yann 0:f30e2135b0db 94 #endif
Yann 0:f30e2135b0db 95
Yann 0:f30e2135b0db 96 /** DNS maximum number of retries when asking for a name, before "timeout". */
Yann 0:f30e2135b0db 97 #ifndef DNS_MAX_RETRIES
Yann 0:f30e2135b0db 98 #define DNS_MAX_RETRIES 4
Yann 0:f30e2135b0db 99 #endif
Yann 0:f30e2135b0db 100
Yann 0:f30e2135b0db 101 /** DNS resource record max. TTL (one week as default) */
Yann 0:f30e2135b0db 102 #ifndef DNS_MAX_TTL
Yann 0:f30e2135b0db 103 #define DNS_MAX_TTL 604800
Yann 0:f30e2135b0db 104 #endif
Yann 0:f30e2135b0db 105
Yann 0:f30e2135b0db 106 /* DNS protocol flags */
Yann 0:f30e2135b0db 107 #define DNS_FLAG1_RESPONSE 0x80
Yann 0:f30e2135b0db 108 #define DNS_FLAG1_OPCODE_STATUS 0x10
Yann 0:f30e2135b0db 109 #define DNS_FLAG1_OPCODE_INVERSE 0x08
Yann 0:f30e2135b0db 110 #define DNS_FLAG1_OPCODE_STANDARD 0x00
Yann 0:f30e2135b0db 111 #define DNS_FLAG1_AUTHORATIVE 0x04
Yann 0:f30e2135b0db 112 #define DNS_FLAG1_TRUNC 0x02
Yann 0:f30e2135b0db 113 #define DNS_FLAG1_RD 0x01
Yann 0:f30e2135b0db 114 #define DNS_FLAG2_RA 0x80
Yann 0:f30e2135b0db 115 #define DNS_FLAG2_ERR_MASK 0x0f
Yann 0:f30e2135b0db 116 #define DNS_FLAG2_ERR_NONE 0x00
Yann 0:f30e2135b0db 117 #define DNS_FLAG2_ERR_NAME 0x03
Yann 0:f30e2135b0db 118
Yann 0:f30e2135b0db 119 /* DNS protocol states */
Yann 0:f30e2135b0db 120 #define DNS_STATE_UNUSED 0
Yann 0:f30e2135b0db 121 #define DNS_STATE_NEW 1
Yann 0:f30e2135b0db 122 #define DNS_STATE_ASKING 2
Yann 0:f30e2135b0db 123 #define DNS_STATE_DONE 3
Yann 0:f30e2135b0db 124
Yann 0:f30e2135b0db 125 #ifdef PACK_STRUCT_USE_INCLUDES
Yann 0:f30e2135b0db 126 # include "arch/bpstruct.h"
Yann 0:f30e2135b0db 127 #endif
Yann 0:f30e2135b0db 128 PACK_STRUCT_BEGIN
Yann 0:f30e2135b0db 129 /** DNS message header */
Yann 0:f30e2135b0db 130 struct dns_hdr {
Yann 0:f30e2135b0db 131 PACK_STRUCT_FIELD(u16_t id);
Yann 0:f30e2135b0db 132 PACK_STRUCT_FIELD(u8_t flags1);
Yann 0:f30e2135b0db 133 PACK_STRUCT_FIELD(u8_t flags2);
Yann 0:f30e2135b0db 134 PACK_STRUCT_FIELD(u16_t numquestions);
Yann 0:f30e2135b0db 135 PACK_STRUCT_FIELD(u16_t numanswers);
Yann 0:f30e2135b0db 136 PACK_STRUCT_FIELD(u16_t numauthrr);
Yann 0:f30e2135b0db 137 PACK_STRUCT_FIELD(u16_t numextrarr);
Yann 0:f30e2135b0db 138 } PACK_STRUCT_STRUCT;
Yann 0:f30e2135b0db 139 PACK_STRUCT_END
Yann 0:f30e2135b0db 140 #ifdef PACK_STRUCT_USE_INCLUDES
Yann 0:f30e2135b0db 141 # include "arch/epstruct.h"
Yann 0:f30e2135b0db 142 #endif
Yann 0:f30e2135b0db 143 #define SIZEOF_DNS_HDR 12
Yann 0:f30e2135b0db 144
Yann 0:f30e2135b0db 145 /** DNS query message structure.
Yann 0:f30e2135b0db 146 No packing needed: only used locally on the stack. */
Yann 0:f30e2135b0db 147 struct dns_query {
Yann 0:f30e2135b0db 148 /* DNS query record starts with either a domain name or a pointer
Yann 0:f30e2135b0db 149 to a name already present somewhere in the packet. */
Yann 0:f30e2135b0db 150 u16_t type;
Yann 0:f30e2135b0db 151 u16_t cls;
Yann 0:f30e2135b0db 152 };
Yann 0:f30e2135b0db 153 #define SIZEOF_DNS_QUERY 4
Yann 0:f30e2135b0db 154
Yann 0:f30e2135b0db 155 /** DNS answer message structure.
Yann 0:f30e2135b0db 156 No packing needed: only used locally on the stack. */
Yann 0:f30e2135b0db 157 struct dns_answer {
Yann 0:f30e2135b0db 158 /* DNS answer record starts with either a domain name or a pointer
Yann 0:f30e2135b0db 159 to a name already present somewhere in the packet. */
Yann 0:f30e2135b0db 160 u16_t type;
Yann 0:f30e2135b0db 161 u16_t cls;
Yann 0:f30e2135b0db 162 u32_t ttl;
Yann 0:f30e2135b0db 163 u16_t len;
Yann 0:f30e2135b0db 164 };
Yann 0:f30e2135b0db 165 #define SIZEOF_DNS_ANSWER 10
Yann 0:f30e2135b0db 166
Yann 0:f30e2135b0db 167 /** DNS table entry */
Yann 0:f30e2135b0db 168 struct dns_table_entry {
Yann 0:f30e2135b0db 169 u8_t state;
Yann 0:f30e2135b0db 170 u8_t numdns;
Yann 0:f30e2135b0db 171 u8_t tmr;
Yann 0:f30e2135b0db 172 u8_t retries;
Yann 0:f30e2135b0db 173 u8_t seqno;
Yann 0:f30e2135b0db 174 u8_t err;
Yann 0:f30e2135b0db 175 u32_t ttl;
Yann 0:f30e2135b0db 176 char name[DNS_MAX_NAME_LENGTH];
Yann 0:f30e2135b0db 177 ip_addr_t ipaddr;
Yann 0:f30e2135b0db 178 /* pointer to callback on DNS query done */
Yann 0:f30e2135b0db 179 dns_found_callback found;
Yann 0:f30e2135b0db 180 void *arg;
Yann 0:f30e2135b0db 181 };
Yann 0:f30e2135b0db 182
Yann 0:f30e2135b0db 183 #if DNS_LOCAL_HOSTLIST
Yann 0:f30e2135b0db 184
Yann 0:f30e2135b0db 185 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
Yann 0:f30e2135b0db 186 /** Local host-list. For hostnames in this list, no
Yann 0:f30e2135b0db 187 * external name resolution is performed */
Yann 0:f30e2135b0db 188 static struct local_hostlist_entry *local_hostlist_dynamic;
Yann 0:f30e2135b0db 189 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
Yann 0:f30e2135b0db 190
Yann 0:f30e2135b0db 191 /** Defining this allows the local_hostlist_static to be placed in a different
Yann 0:f30e2135b0db 192 * linker section (e.g. FLASH) */
Yann 0:f30e2135b0db 193 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE
Yann 0:f30e2135b0db 194 #define DNS_LOCAL_HOSTLIST_STORAGE_PRE static
Yann 0:f30e2135b0db 195 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */
Yann 0:f30e2135b0db 196 /** Defining this allows the local_hostlist_static to be placed in a different
Yann 0:f30e2135b0db 197 * linker section (e.g. FLASH) */
Yann 0:f30e2135b0db 198 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST
Yann 0:f30e2135b0db 199 #define DNS_LOCAL_HOSTLIST_STORAGE_POST
Yann 0:f30e2135b0db 200 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */
Yann 0:f30e2135b0db 201 DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[]
Yann 0:f30e2135b0db 202 DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT;
Yann 0:f30e2135b0db 203
Yann 0:f30e2135b0db 204 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
Yann 0:f30e2135b0db 205
Yann 0:f30e2135b0db 206 static void dns_init_local();
Yann 0:f30e2135b0db 207 #endif /* DNS_LOCAL_HOSTLIST */
Yann 0:f30e2135b0db 208
Yann 0:f30e2135b0db 209
Yann 0:f30e2135b0db 210 /* forward declarations */
Yann 0:f30e2135b0db 211 static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
Yann 0:f30e2135b0db 212 static void dns_check_entries(void);
Yann 0:f30e2135b0db 213
Yann 0:f30e2135b0db 214 /*-----------------------------------------------------------------------------
Yann 0:f30e2135b0db 215 * Globales
Yann 0:f30e2135b0db 216 *----------------------------------------------------------------------------*/
Yann 0:f30e2135b0db 217
Yann 0:f30e2135b0db 218 /* DNS variables */
Yann 0:f30e2135b0db 219 static struct udp_pcb *dns_pcb;
Yann 0:f30e2135b0db 220 static u8_t dns_seqno;
Yann 0:f30e2135b0db 221 static struct dns_table_entry dns_table[DNS_TABLE_SIZE];
Yann 0:f30e2135b0db 222 static ip_addr_t dns_servers[DNS_MAX_SERVERS];
Yann 0:f30e2135b0db 223 /** Contiguous buffer for processing responses */
Yann 0:f30e2135b0db 224 static u8_t dns_payload_buffer[LWIP_MEM_ALIGN_BUFFER(DNS_MSG_SIZE)];
Yann 0:f30e2135b0db 225 static u8_t* dns_payload;
Yann 0:f30e2135b0db 226
Yann 0:f30e2135b0db 227 /**
Yann 0:f30e2135b0db 228 * Initialize the resolver: set up the UDP pcb and configure the default server
Yann 0:f30e2135b0db 229 * (DNS_SERVER_ADDRESS).
Yann 0:f30e2135b0db 230 */
Yann 0:f30e2135b0db 231 void
Yann 0:f30e2135b0db 232 dns_init()
Yann 0:f30e2135b0db 233 {
Yann 0:f30e2135b0db 234 ip_addr_t dnsserver;
Yann 0:f30e2135b0db 235
Yann 0:f30e2135b0db 236 dns_payload = (u8_t *)LWIP_MEM_ALIGN(dns_payload_buffer);
Yann 0:f30e2135b0db 237
Yann 0:f30e2135b0db 238 /* initialize default DNS server address */
Yann 0:f30e2135b0db 239 DNS_SERVER_ADDRESS(&dnsserver);
Yann 0:f30e2135b0db 240
Yann 0:f30e2135b0db 241 LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
Yann 0:f30e2135b0db 242
Yann 0:f30e2135b0db 243 /* if dns client not yet initialized... */
Yann 0:f30e2135b0db 244 if (dns_pcb == NULL) {
Yann 0:f30e2135b0db 245 dns_pcb = udp_new();
Yann 0:f30e2135b0db 246
Yann 0:f30e2135b0db 247 if (dns_pcb != NULL) {
Yann 0:f30e2135b0db 248 /* initialize DNS table not needed (initialized to zero since it is a
Yann 0:f30e2135b0db 249 * global variable) */
Yann 0:f30e2135b0db 250 LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
Yann 0:f30e2135b0db 251 DNS_STATE_UNUSED == 0);
Yann 0:f30e2135b0db 252
Yann 0:f30e2135b0db 253 /* initialize DNS client */
Yann 0:f30e2135b0db 254 udp_bind(dns_pcb, IP_ADDR_ANY, 0);
Yann 0:f30e2135b0db 255 udp_recv(dns_pcb, dns_recv, NULL);
Yann 0:f30e2135b0db 256
Yann 0:f30e2135b0db 257 /* initialize default DNS primary server */
Yann 0:f30e2135b0db 258 dns_setserver(0, &dnsserver);
Yann 0:f30e2135b0db 259 }
Yann 0:f30e2135b0db 260 }
Yann 0:f30e2135b0db 261 #if DNS_LOCAL_HOSTLIST
Yann 0:f30e2135b0db 262 dns_init_local();
Yann 0:f30e2135b0db 263 #endif
Yann 0:f30e2135b0db 264 }
Yann 0:f30e2135b0db 265
Yann 0:f30e2135b0db 266 /**
Yann 0:f30e2135b0db 267 * Initialize one of the DNS servers.
Yann 0:f30e2135b0db 268 *
Yann 0:f30e2135b0db 269 * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
Yann 0:f30e2135b0db 270 * @param dnsserver IP address of the DNS server to set
Yann 0:f30e2135b0db 271 */
Yann 0:f30e2135b0db 272 void
Yann 0:f30e2135b0db 273 dns_setserver(u8_t numdns, ip_addr_t *dnsserver)
Yann 0:f30e2135b0db 274 {
Yann 0:f30e2135b0db 275 if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) &&
Yann 0:f30e2135b0db 276 (dnsserver != NULL) && !ip_addr_isany(dnsserver)) {
Yann 0:f30e2135b0db 277 dns_servers[numdns] = (*dnsserver);
Yann 0:f30e2135b0db 278 }
Yann 0:f30e2135b0db 279 }
Yann 0:f30e2135b0db 280
Yann 0:f30e2135b0db 281 /**
Yann 0:f30e2135b0db 282 * Obtain one of the currently configured DNS server.
Yann 0:f30e2135b0db 283 *
Yann 0:f30e2135b0db 284 * @param numdns the index of the DNS server
Yann 0:f30e2135b0db 285 * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
Yann 0:f30e2135b0db 286 * server has not been configured.
Yann 0:f30e2135b0db 287 */
Yann 0:f30e2135b0db 288 ip_addr_t
Yann 0:f30e2135b0db 289 dns_getserver(u8_t numdns)
Yann 0:f30e2135b0db 290 {
Yann 0:f30e2135b0db 291 if (numdns < DNS_MAX_SERVERS) {
Yann 0:f30e2135b0db 292 return dns_servers[numdns];
Yann 0:f30e2135b0db 293 } else {
Yann 0:f30e2135b0db 294 return *IP_ADDR_ANY;
Yann 0:f30e2135b0db 295 }
Yann 0:f30e2135b0db 296 }
Yann 0:f30e2135b0db 297
Yann 0:f30e2135b0db 298 /**
Yann 0:f30e2135b0db 299 * The DNS resolver client timer - handle retries and timeouts and should
Yann 0:f30e2135b0db 300 * be called every DNS_TMR_INTERVAL milliseconds (every second by default).
Yann 0:f30e2135b0db 301 */
Yann 0:f30e2135b0db 302 void
Yann 0:f30e2135b0db 303 dns_tmr(void)
Yann 0:f30e2135b0db 304 {
Yann 0:f30e2135b0db 305 if (dns_pcb != NULL) {
Yann 0:f30e2135b0db 306 LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
Yann 0:f30e2135b0db 307 dns_check_entries();
Yann 0:f30e2135b0db 308 }
Yann 0:f30e2135b0db 309 }
Yann 0:f30e2135b0db 310
Yann 0:f30e2135b0db 311 #if DNS_LOCAL_HOSTLIST
Yann 0:f30e2135b0db 312 static void
Yann 0:f30e2135b0db 313 dns_init_local()
Yann 0:f30e2135b0db 314 {
Yann 0:f30e2135b0db 315 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT)
Yann 0:f30e2135b0db 316 int i;
Yann 0:f30e2135b0db 317 struct local_hostlist_entry *entry;
Yann 0:f30e2135b0db 318 /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
Yann 0:f30e2135b0db 319 struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
Yann 0:f30e2135b0db 320 size_t namelen;
Yann 0:f30e2135b0db 321 for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) {
Yann 0:f30e2135b0db 322 struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
Yann 0:f30e2135b0db 323 LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL);
Yann 0:f30e2135b0db 324 namelen = strlen(init_entry->name);
Yann 0:f30e2135b0db 325 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
Yann 0:f30e2135b0db 326 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
Yann 0:f30e2135b0db 327 LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
Yann 0:f30e2135b0db 328 if (entry != NULL) {
Yann 0:f30e2135b0db 329 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
Yann 0:f30e2135b0db 330 MEMCPY((char*)entry->name, init_entry->name, namelen);
Yann 0:f30e2135b0db 331 ((char*)entry->name)[namelen] = 0;
Yann 0:f30e2135b0db 332 entry->addr = init_entry->addr;
Yann 0:f30e2135b0db 333 entry->next = local_hostlist_dynamic;
Yann 0:f30e2135b0db 334 local_hostlist_dynamic = entry;
Yann 0:f30e2135b0db 335 }
Yann 0:f30e2135b0db 336 }
Yann 0:f30e2135b0db 337 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
Yann 0:f30e2135b0db 338 }
Yann 0:f30e2135b0db 339
Yann 0:f30e2135b0db 340 /**
Yann 0:f30e2135b0db 341 * Scans the local host-list for a hostname.
Yann 0:f30e2135b0db 342 *
Yann 0:f30e2135b0db 343 * @param hostname Hostname to look for in the local host-list
Yann 0:f30e2135b0db 344 * @return The first IP address for the hostname in the local host-list or
Yann 0:f30e2135b0db 345 * IPADDR_NONE if not found.
Yann 0:f30e2135b0db 346 */
Yann 0:f30e2135b0db 347 static u32_t
Yann 0:f30e2135b0db 348 dns_lookup_local(const char *hostname)
Yann 0:f30e2135b0db 349 {
Yann 0:f30e2135b0db 350 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
Yann 0:f30e2135b0db 351 struct local_hostlist_entry *entry = local_hostlist_dynamic;
Yann 0:f30e2135b0db 352 while(entry != NULL) {
Yann 0:f30e2135b0db 353 if(strcmp(entry->name, hostname) == 0) {
Yann 0:f30e2135b0db 354 return ip4_addr_get_u32(&entry->addr);
Yann 0:f30e2135b0db 355 }
Yann 0:f30e2135b0db 356 entry = entry->next;
Yann 0:f30e2135b0db 357 }
Yann 0:f30e2135b0db 358 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
Yann 0:f30e2135b0db 359 int i;
Yann 0:f30e2135b0db 360 for (i = 0; i < sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry); i++) {
Yann 0:f30e2135b0db 361 if(strcmp(local_hostlist_static[i].name, hostname) == 0) {
Yann 0:f30e2135b0db 362 return ip4_addr_get_u32(&local_hostlist_static[i].addr);
Yann 0:f30e2135b0db 363 }
Yann 0:f30e2135b0db 364 }
Yann 0:f30e2135b0db 365 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
Yann 0:f30e2135b0db 366 return IPADDR_NONE;
Yann 0:f30e2135b0db 367 }
Yann 0:f30e2135b0db 368
Yann 0:f30e2135b0db 369 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
Yann 0:f30e2135b0db 370 /** Remove all entries from the local host-list for a specific hostname
Yann 0:f30e2135b0db 371 * and/or IP addess
Yann 0:f30e2135b0db 372 *
Yann 0:f30e2135b0db 373 * @param hostname hostname for which entries shall be removed from the local
Yann 0:f30e2135b0db 374 * host-list
Yann 0:f30e2135b0db 375 * @param addr address for which entries shall be removed from the local host-list
Yann 0:f30e2135b0db 376 * @return the number of removed entries
Yann 0:f30e2135b0db 377 */
Yann 0:f30e2135b0db 378 int
Yann 0:f30e2135b0db 379 dns_local_removehost(const char *hostname, const ip_addr_t *addr)
Yann 0:f30e2135b0db 380 {
Yann 0:f30e2135b0db 381 int removed = 0;
Yann 0:f30e2135b0db 382 struct local_hostlist_entry *entry = local_hostlist_dynamic;
Yann 0:f30e2135b0db 383 struct local_hostlist_entry *last_entry = NULL;
Yann 0:f30e2135b0db 384 while (entry != NULL) {
Yann 0:f30e2135b0db 385 if (((hostname == NULL) || !strcmp(entry->name, hostname)) &&
Yann 0:f30e2135b0db 386 ((addr == NULL) || ip_addr_cmp(&entry->addr, addr))) {
Yann 0:f30e2135b0db 387 struct local_hostlist_entry *free_entry;
Yann 0:f30e2135b0db 388 if (last_entry != NULL) {
Yann 0:f30e2135b0db 389 last_entry->next = entry->next;
Yann 0:f30e2135b0db 390 } else {
Yann 0:f30e2135b0db 391 local_hostlist_dynamic = entry->next;
Yann 0:f30e2135b0db 392 }
Yann 0:f30e2135b0db 393 free_entry = entry;
Yann 0:f30e2135b0db 394 entry = entry->next;
Yann 0:f30e2135b0db 395 memp_free(MEMP_LOCALHOSTLIST, free_entry);
Yann 0:f30e2135b0db 396 removed++;
Yann 0:f30e2135b0db 397 } else {
Yann 0:f30e2135b0db 398 last_entry = entry;
Yann 0:f30e2135b0db 399 entry = entry->next;
Yann 0:f30e2135b0db 400 }
Yann 0:f30e2135b0db 401 }
Yann 0:f30e2135b0db 402 return removed;
Yann 0:f30e2135b0db 403 }
Yann 0:f30e2135b0db 404
Yann 0:f30e2135b0db 405 /**
Yann 0:f30e2135b0db 406 * Add a hostname/IP address pair to the local host-list.
Yann 0:f30e2135b0db 407 * Duplicates are not checked.
Yann 0:f30e2135b0db 408 *
Yann 0:f30e2135b0db 409 * @param hostname hostname of the new entry
Yann 0:f30e2135b0db 410 * @param addr IP address of the new entry
Yann 0:f30e2135b0db 411 * @return ERR_OK if succeeded or ERR_MEM on memory error
Yann 0:f30e2135b0db 412 */
Yann 0:f30e2135b0db 413 err_t
Yann 0:f30e2135b0db 414 dns_local_addhost(const char *hostname, const ip_addr_t *addr)
Yann 0:f30e2135b0db 415 {
Yann 0:f30e2135b0db 416 struct local_hostlist_entry *entry;
Yann 0:f30e2135b0db 417 size_t namelen;
Yann 0:f30e2135b0db 418 LWIP_ASSERT("invalid host name (NULL)", hostname != NULL);
Yann 0:f30e2135b0db 419 namelen = strlen(hostname);
Yann 0:f30e2135b0db 420 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
Yann 0:f30e2135b0db 421 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
Yann 0:f30e2135b0db 422 if (entry == NULL) {
Yann 0:f30e2135b0db 423 return ERR_MEM;
Yann 0:f30e2135b0db 424 }
Yann 0:f30e2135b0db 425 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
Yann 0:f30e2135b0db 426 MEMCPY((char*)entry->name, hostname, namelen);
Yann 0:f30e2135b0db 427 ((char*)entry->name)[namelen] = 0;
Yann 0:f30e2135b0db 428 ip_addr_copy(entry->addr, *addr);
Yann 0:f30e2135b0db 429 entry->next = local_hostlist_dynamic;
Yann 0:f30e2135b0db 430 local_hostlist_dynamic = entry;
Yann 0:f30e2135b0db 431 return ERR_OK;
Yann 0:f30e2135b0db 432 }
Yann 0:f30e2135b0db 433 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
Yann 0:f30e2135b0db 434 #endif /* DNS_LOCAL_HOSTLIST */
Yann 0:f30e2135b0db 435
Yann 0:f30e2135b0db 436 /**
Yann 0:f30e2135b0db 437 * Look up a hostname in the array of known hostnames.
Yann 0:f30e2135b0db 438 *
Yann 0:f30e2135b0db 439 * @note This function only looks in the internal array of known
Yann 0:f30e2135b0db 440 * hostnames, it does not send out a query for the hostname if none
Yann 0:f30e2135b0db 441 * was found. The function dns_enqueue() can be used to send a query
Yann 0:f30e2135b0db 442 * for a hostname.
Yann 0:f30e2135b0db 443 *
Yann 0:f30e2135b0db 444 * @param name the hostname to look up
Yann 0:f30e2135b0db 445 * @return the hostname's IP address, as u32_t (instead of ip_addr_t to
Yann 0:f30e2135b0db 446 * better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname
Yann 0:f30e2135b0db 447 * was not found in the cached dns_table.
Yann 0:f30e2135b0db 448 */
Yann 0:f30e2135b0db 449 static u32_t
Yann 0:f30e2135b0db 450 dns_lookup(const char *name)
Yann 0:f30e2135b0db 451 {
Yann 0:f30e2135b0db 452 u8_t i;
Yann 0:f30e2135b0db 453 #if DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN)
Yann 0:f30e2135b0db 454 u32_t addr;
Yann 0:f30e2135b0db 455 #endif /* DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN) */
Yann 0:f30e2135b0db 456 #if DNS_LOCAL_HOSTLIST
Yann 0:f30e2135b0db 457 if ((addr = dns_lookup_local(name)) != IPADDR_NONE) {
Yann 0:f30e2135b0db 458 return addr;
Yann 0:f30e2135b0db 459 }
Yann 0:f30e2135b0db 460 #endif /* DNS_LOCAL_HOSTLIST */
Yann 0:f30e2135b0db 461 #ifdef DNS_LOOKUP_LOCAL_EXTERN
Yann 0:f30e2135b0db 462 if((addr = DNS_LOOKUP_LOCAL_EXTERN(name)) != IPADDR_NONE) {
Yann 0:f30e2135b0db 463 return addr;
Yann 0:f30e2135b0db 464 }
Yann 0:f30e2135b0db 465 #endif /* DNS_LOOKUP_LOCAL_EXTERN */
Yann 0:f30e2135b0db 466
Yann 0:f30e2135b0db 467 /* Walk through name list, return entry if found. If not, return NULL. */
Yann 0:f30e2135b0db 468 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
Yann 0:f30e2135b0db 469 if ((dns_table[i].state == DNS_STATE_DONE) &&
Yann 0:f30e2135b0db 470 (strcmp(name, dns_table[i].name) == 0)) {
Yann 0:f30e2135b0db 471 LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
Yann 0:f30e2135b0db 472 ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr));
Yann 0:f30e2135b0db 473 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
Yann 0:f30e2135b0db 474 return ip4_addr_get_u32(&dns_table[i].ipaddr);
Yann 0:f30e2135b0db 475 }
Yann 0:f30e2135b0db 476 }
Yann 0:f30e2135b0db 477
Yann 0:f30e2135b0db 478 return IPADDR_NONE;
Yann 0:f30e2135b0db 479 }
Yann 0:f30e2135b0db 480
Yann 0:f30e2135b0db 481 #if DNS_DOES_NAME_CHECK
Yann 0:f30e2135b0db 482 /**
Yann 0:f30e2135b0db 483 * Compare the "dotted" name "query" with the encoded name "response"
Yann 0:f30e2135b0db 484 * to make sure an answer from the DNS server matches the current dns_table
Yann 0:f30e2135b0db 485 * entry (otherwise, answers might arrive late for hostname not on the list
Yann 0:f30e2135b0db 486 * any more).
Yann 0:f30e2135b0db 487 *
Yann 0:f30e2135b0db 488 * @param query hostname (not encoded) from the dns_table
Yann 0:f30e2135b0db 489 * @param response encoded hostname in the DNS response
Yann 0:f30e2135b0db 490 * @return 0: names equal; 1: names differ
Yann 0:f30e2135b0db 491 */
Yann 0:f30e2135b0db 492 static u8_t
Yann 0:f30e2135b0db 493 dns_compare_name(unsigned char *query, unsigned char *response)
Yann 0:f30e2135b0db 494 {
Yann 0:f30e2135b0db 495 unsigned char n;
Yann 0:f30e2135b0db 496
Yann 0:f30e2135b0db 497 do {
Yann 0:f30e2135b0db 498 n = *response++;
Yann 0:f30e2135b0db 499 /** @see RFC 1035 - 4.1.4. Message compression */
Yann 0:f30e2135b0db 500 if ((n & 0xc0) == 0xc0) {
Yann 0:f30e2135b0db 501 /* Compressed name */
Yann 0:f30e2135b0db 502 break;
Yann 0:f30e2135b0db 503 } else {
Yann 0:f30e2135b0db 504 /* Not compressed name */
Yann 0:f30e2135b0db 505 while (n > 0) {
Yann 0:f30e2135b0db 506 if ((*query) != (*response)) {
Yann 0:f30e2135b0db 507 return 1;
Yann 0:f30e2135b0db 508 }
Yann 0:f30e2135b0db 509 ++response;
Yann 0:f30e2135b0db 510 ++query;
Yann 0:f30e2135b0db 511 --n;
Yann 0:f30e2135b0db 512 };
Yann 0:f30e2135b0db 513 ++query;
Yann 0:f30e2135b0db 514 }
Yann 0:f30e2135b0db 515 } while (*response != 0);
Yann 0:f30e2135b0db 516
Yann 0:f30e2135b0db 517 return 0;
Yann 0:f30e2135b0db 518 }
Yann 0:f30e2135b0db 519 #endif /* DNS_DOES_NAME_CHECK */
Yann 0:f30e2135b0db 520
Yann 0:f30e2135b0db 521 /**
Yann 0:f30e2135b0db 522 * Walk through a compact encoded DNS name and return the end of the name.
Yann 0:f30e2135b0db 523 *
Yann 0:f30e2135b0db 524 * @param query encoded DNS name in the DNS server response
Yann 0:f30e2135b0db 525 * @return end of the name
Yann 0:f30e2135b0db 526 */
Yann 0:f30e2135b0db 527 static unsigned char *
Yann 0:f30e2135b0db 528 dns_parse_name(unsigned char *query)
Yann 0:f30e2135b0db 529 {
Yann 0:f30e2135b0db 530 unsigned char n;
Yann 0:f30e2135b0db 531
Yann 0:f30e2135b0db 532 do {
Yann 0:f30e2135b0db 533 n = *query++;
Yann 0:f30e2135b0db 534 /** @see RFC 1035 - 4.1.4. Message compression */
Yann 0:f30e2135b0db 535 if ((n & 0xc0) == 0xc0) {
Yann 0:f30e2135b0db 536 /* Compressed name */
Yann 0:f30e2135b0db 537 break;
Yann 0:f30e2135b0db 538 } else {
Yann 0:f30e2135b0db 539 /* Not compressed name */
Yann 0:f30e2135b0db 540 while (n > 0) {
Yann 0:f30e2135b0db 541 ++query;
Yann 0:f30e2135b0db 542 --n;
Yann 0:f30e2135b0db 543 };
Yann 0:f30e2135b0db 544 }
Yann 0:f30e2135b0db 545 } while (*query != 0);
Yann 0:f30e2135b0db 546
Yann 0:f30e2135b0db 547 return query + 1;
Yann 0:f30e2135b0db 548 }
Yann 0:f30e2135b0db 549
Yann 0:f30e2135b0db 550 /**
Yann 0:f30e2135b0db 551 * Send a DNS query packet.
Yann 0:f30e2135b0db 552 *
Yann 0:f30e2135b0db 553 * @param numdns index of the DNS server in the dns_servers table
Yann 0:f30e2135b0db 554 * @param name hostname to query
Yann 0:f30e2135b0db 555 * @param id index of the hostname in dns_table, used as transaction ID in the
Yann 0:f30e2135b0db 556 * DNS query packet
Yann 0:f30e2135b0db 557 * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
Yann 0:f30e2135b0db 558 */
Yann 0:f30e2135b0db 559 static err_t
Yann 0:f30e2135b0db 560 dns_send(u8_t numdns, const char* name, u8_t id)
Yann 0:f30e2135b0db 561 {
Yann 0:f30e2135b0db 562 err_t err;
Yann 0:f30e2135b0db 563 struct dns_hdr *hdr;
Yann 0:f30e2135b0db 564 struct dns_query qry;
Yann 0:f30e2135b0db 565 struct pbuf *p;
Yann 0:f30e2135b0db 566 char *query, *nptr;
Yann 0:f30e2135b0db 567 const char *pHostname;
Yann 0:f30e2135b0db 568 u8_t n;
Yann 0:f30e2135b0db 569
Yann 0:f30e2135b0db 570 LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
Yann 0:f30e2135b0db 571 (u16_t)(numdns), name));
Yann 0:f30e2135b0db 572 LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS);
Yann 0:f30e2135b0db 573 LWIP_ASSERT("dns server has no IP address set", !ip_addr_isany(&dns_servers[numdns]));
Yann 0:f30e2135b0db 574
Yann 0:f30e2135b0db 575 /* if here, we have either a new query or a retry on a previous query to process */
Yann 0:f30e2135b0db 576 p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
Yann 0:f30e2135b0db 577 SIZEOF_DNS_QUERY, PBUF_RAM);
Yann 0:f30e2135b0db 578 if (p != NULL) {
Yann 0:f30e2135b0db 579 LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
Yann 0:f30e2135b0db 580 /* fill dns header */
Yann 0:f30e2135b0db 581 hdr = (struct dns_hdr*)p->payload;
Yann 0:f30e2135b0db 582 memset(hdr, 0, SIZEOF_DNS_HDR);
Yann 0:f30e2135b0db 583 hdr->id = htons(id);
Yann 0:f30e2135b0db 584 hdr->flags1 = DNS_FLAG1_RD;
Yann 0:f30e2135b0db 585 hdr->numquestions = PP_HTONS(1);
Yann 0:f30e2135b0db 586 query = (char*)hdr + SIZEOF_DNS_HDR;
Yann 0:f30e2135b0db 587 pHostname = name;
Yann 0:f30e2135b0db 588 --pHostname;
Yann 0:f30e2135b0db 589
Yann 0:f30e2135b0db 590 /* convert hostname into suitable query format. */
Yann 0:f30e2135b0db 591 do {
Yann 0:f30e2135b0db 592 ++pHostname;
Yann 0:f30e2135b0db 593 nptr = query;
Yann 0:f30e2135b0db 594 ++query;
Yann 0:f30e2135b0db 595 for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
Yann 0:f30e2135b0db 596 *query = *pHostname;
Yann 0:f30e2135b0db 597 ++query;
Yann 0:f30e2135b0db 598 ++n;
Yann 0:f30e2135b0db 599 }
Yann 0:f30e2135b0db 600 *nptr = n;
Yann 0:f30e2135b0db 601 } while(*pHostname != 0);
Yann 0:f30e2135b0db 602 *query++='\0';
Yann 0:f30e2135b0db 603
Yann 0:f30e2135b0db 604 /* fill dns query */
Yann 0:f30e2135b0db 605 qry.type = PP_HTONS(DNS_RRTYPE_A);
Yann 0:f30e2135b0db 606 qry.cls = PP_HTONS(DNS_RRCLASS_IN);
Yann 0:f30e2135b0db 607 SMEMCPY(query, &qry, SIZEOF_DNS_QUERY);
Yann 0:f30e2135b0db 608
Yann 0:f30e2135b0db 609 /* resize pbuf to the exact dns query */
Yann 0:f30e2135b0db 610 pbuf_realloc(p, (u16_t)((query + SIZEOF_DNS_QUERY) - ((char*)(p->payload))));
Yann 0:f30e2135b0db 611
Yann 0:f30e2135b0db 612 /* connect to the server for faster receiving */
Yann 0:f30e2135b0db 613 udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
Yann 0:f30e2135b0db 614 /* send dns packet */
Yann 0:f30e2135b0db 615 err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT);
Yann 0:f30e2135b0db 616
Yann 0:f30e2135b0db 617 /* free pbuf */
Yann 0:f30e2135b0db 618 pbuf_free(p);
Yann 0:f30e2135b0db 619 } else {
Yann 0:f30e2135b0db 620 err = ERR_MEM;
Yann 0:f30e2135b0db 621 }
Yann 0:f30e2135b0db 622
Yann 0:f30e2135b0db 623 return err;
Yann 0:f30e2135b0db 624 }
Yann 0:f30e2135b0db 625
Yann 0:f30e2135b0db 626 /**
Yann 0:f30e2135b0db 627 * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query.
Yann 0:f30e2135b0db 628 * Check an entry in the dns_table:
Yann 0:f30e2135b0db 629 * - send out query for new entries
Yann 0:f30e2135b0db 630 * - retry old pending entries on timeout (also with different servers)
Yann 0:f30e2135b0db 631 * - remove completed entries from the table if their TTL has expired
Yann 0:f30e2135b0db 632 *
Yann 0:f30e2135b0db 633 * @param i index of the dns_table entry to check
Yann 0:f30e2135b0db 634 */
Yann 0:f30e2135b0db 635 static void
Yann 0:f30e2135b0db 636 dns_check_entry(u8_t i)
Yann 0:f30e2135b0db 637 {
Yann 0:f30e2135b0db 638 err_t err;
Yann 0:f30e2135b0db 639 struct dns_table_entry *pEntry = &dns_table[i];
Yann 0:f30e2135b0db 640
Yann 0:f30e2135b0db 641 LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
Yann 0:f30e2135b0db 642
Yann 0:f30e2135b0db 643 switch(pEntry->state) {
Yann 0:f30e2135b0db 644
Yann 0:f30e2135b0db 645 case DNS_STATE_NEW: {
Yann 0:f30e2135b0db 646 /* initialize new entry */
Yann 0:f30e2135b0db 647 pEntry->state = DNS_STATE_ASKING;
Yann 0:f30e2135b0db 648 pEntry->numdns = 0;
Yann 0:f30e2135b0db 649 pEntry->tmr = 1;
Yann 0:f30e2135b0db 650 pEntry->retries = 0;
Yann 0:f30e2135b0db 651
Yann 0:f30e2135b0db 652 /* send DNS packet for this entry */
Yann 0:f30e2135b0db 653 err = dns_send(pEntry->numdns, pEntry->name, i);
Yann 0:f30e2135b0db 654 if (err != ERR_OK) {
Yann 0:f30e2135b0db 655 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
Yann 0:f30e2135b0db 656 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
Yann 0:f30e2135b0db 657 }
Yann 0:f30e2135b0db 658 break;
Yann 0:f30e2135b0db 659 }
Yann 0:f30e2135b0db 660
Yann 0:f30e2135b0db 661 case DNS_STATE_ASKING: {
Yann 0:f30e2135b0db 662 if (--pEntry->tmr == 0) {
Yann 0:f30e2135b0db 663 if (++pEntry->retries == DNS_MAX_RETRIES) {
Yann 0:f30e2135b0db 664 if ((pEntry->numdns+1<DNS_MAX_SERVERS) && !ip_addr_isany(&dns_servers[pEntry->numdns+1])) {
Yann 0:f30e2135b0db 665 /* change of server */
Yann 0:f30e2135b0db 666 pEntry->numdns++;
Yann 0:f30e2135b0db 667 pEntry->tmr = 1;
Yann 0:f30e2135b0db 668 pEntry->retries = 0;
Yann 0:f30e2135b0db 669 break;
Yann 0:f30e2135b0db 670 } else {
Yann 0:f30e2135b0db 671 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name));
Yann 0:f30e2135b0db 672 /* call specified callback function if provided */
Yann 0:f30e2135b0db 673 if (pEntry->found)
Yann 0:f30e2135b0db 674 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
Yann 0:f30e2135b0db 675 /* flush this entry */
Yann 0:f30e2135b0db 676 pEntry->state = DNS_STATE_UNUSED;
Yann 0:f30e2135b0db 677 pEntry->found = NULL;
Yann 0:f30e2135b0db 678 break;
Yann 0:f30e2135b0db 679 }
Yann 0:f30e2135b0db 680 }
Yann 0:f30e2135b0db 681
Yann 0:f30e2135b0db 682 /* wait longer for the next retry */
Yann 0:f30e2135b0db 683 pEntry->tmr = pEntry->retries;
Yann 0:f30e2135b0db 684
Yann 0:f30e2135b0db 685 /* send DNS packet for this entry */
Yann 0:f30e2135b0db 686 err = dns_send(pEntry->numdns, pEntry->name, i);
Yann 0:f30e2135b0db 687 if (err != ERR_OK) {
Yann 0:f30e2135b0db 688 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
Yann 0:f30e2135b0db 689 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
Yann 0:f30e2135b0db 690 }
Yann 0:f30e2135b0db 691 }
Yann 0:f30e2135b0db 692 break;
Yann 0:f30e2135b0db 693 }
Yann 0:f30e2135b0db 694
Yann 0:f30e2135b0db 695 case DNS_STATE_DONE: {
Yann 0:f30e2135b0db 696 /* if the time to live is nul */
Yann 0:f30e2135b0db 697 if (--pEntry->ttl == 0) {
Yann 0:f30e2135b0db 698 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name));
Yann 0:f30e2135b0db 699 /* flush this entry */
Yann 0:f30e2135b0db 700 pEntry->state = DNS_STATE_UNUSED;
Yann 0:f30e2135b0db 701 pEntry->found = NULL;
Yann 0:f30e2135b0db 702 }
Yann 0:f30e2135b0db 703 break;
Yann 0:f30e2135b0db 704 }
Yann 0:f30e2135b0db 705 case DNS_STATE_UNUSED:
Yann 0:f30e2135b0db 706 /* nothing to do */
Yann 0:f30e2135b0db 707 break;
Yann 0:f30e2135b0db 708 default:
Yann 0:f30e2135b0db 709 LWIP_ASSERT("unknown dns_table entry state:", 0);
Yann 0:f30e2135b0db 710 break;
Yann 0:f30e2135b0db 711 }
Yann 0:f30e2135b0db 712 }
Yann 0:f30e2135b0db 713
Yann 0:f30e2135b0db 714 /**
Yann 0:f30e2135b0db 715 * Call dns_check_entry for each entry in dns_table - check all entries.
Yann 0:f30e2135b0db 716 */
Yann 0:f30e2135b0db 717 static void
Yann 0:f30e2135b0db 718 dns_check_entries(void)
Yann 0:f30e2135b0db 719 {
Yann 0:f30e2135b0db 720 u8_t i;
Yann 0:f30e2135b0db 721
Yann 0:f30e2135b0db 722 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
Yann 0:f30e2135b0db 723 dns_check_entry(i);
Yann 0:f30e2135b0db 724 }
Yann 0:f30e2135b0db 725 }
Yann 0:f30e2135b0db 726
Yann 0:f30e2135b0db 727 /**
Yann 0:f30e2135b0db 728 * Receive input function for DNS response packets arriving for the dns UDP pcb.
Yann 0:f30e2135b0db 729 *
Yann 0:f30e2135b0db 730 * @params see udp.h
Yann 0:f30e2135b0db 731 */
Yann 0:f30e2135b0db 732 static void
Yann 0:f30e2135b0db 733 dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
Yann 0:f30e2135b0db 734 {
Yann 0:f30e2135b0db 735 u16_t i;
Yann 0:f30e2135b0db 736 char *pHostname;
Yann 0:f30e2135b0db 737 struct dns_hdr *hdr;
Yann 0:f30e2135b0db 738 struct dns_answer ans;
Yann 0:f30e2135b0db 739 struct dns_table_entry *pEntry;
Yann 0:f30e2135b0db 740 u16_t nquestions, nanswers;
Yann 0:f30e2135b0db 741
Yann 0:f30e2135b0db 742 LWIP_UNUSED_ARG(arg);
Yann 0:f30e2135b0db 743 LWIP_UNUSED_ARG(pcb);
Yann 0:f30e2135b0db 744 LWIP_UNUSED_ARG(addr);
Yann 0:f30e2135b0db 745 LWIP_UNUSED_ARG(port);
Yann 0:f30e2135b0db 746
Yann 0:f30e2135b0db 747 /* is the dns message too big ? */
Yann 0:f30e2135b0db 748 if (p->tot_len > DNS_MSG_SIZE) {
Yann 0:f30e2135b0db 749 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
Yann 0:f30e2135b0db 750 /* free pbuf and return */
Yann 0:f30e2135b0db 751 goto memerr;
Yann 0:f30e2135b0db 752 }
Yann 0:f30e2135b0db 753
Yann 0:f30e2135b0db 754 /* is the dns message big enough ? */
Yann 0:f30e2135b0db 755 if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
Yann 0:f30e2135b0db 756 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
Yann 0:f30e2135b0db 757 /* free pbuf and return */
Yann 0:f30e2135b0db 758 goto memerr;
Yann 0:f30e2135b0db 759 }
Yann 0:f30e2135b0db 760
Yann 0:f30e2135b0db 761 /* copy dns payload inside static buffer for processing */
Yann 0:f30e2135b0db 762 if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) {
Yann 0:f30e2135b0db 763 /* The ID in the DNS header should be our entry into the name table. */
Yann 0:f30e2135b0db 764 hdr = (struct dns_hdr*)dns_payload;
Yann 0:f30e2135b0db 765 i = htons(hdr->id);
Yann 0:f30e2135b0db 766 if (i < DNS_TABLE_SIZE) {
Yann 0:f30e2135b0db 767 pEntry = &dns_table[i];
Yann 0:f30e2135b0db 768 if(pEntry->state == DNS_STATE_ASKING) {
Yann 0:f30e2135b0db 769 /* This entry is now completed. */
Yann 0:f30e2135b0db 770 pEntry->state = DNS_STATE_DONE;
Yann 0:f30e2135b0db 771 pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK;
Yann 0:f30e2135b0db 772
Yann 0:f30e2135b0db 773 /* We only care about the question(s) and the answers. The authrr
Yann 0:f30e2135b0db 774 and the extrarr are simply discarded. */
Yann 0:f30e2135b0db 775 nquestions = htons(hdr->numquestions);
Yann 0:f30e2135b0db 776 nanswers = htons(hdr->numanswers);
Yann 0:f30e2135b0db 777
Yann 0:f30e2135b0db 778 /* Check for error. If so, call callback to inform. */
Yann 0:f30e2135b0db 779 if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) {
Yann 0:f30e2135b0db 780 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name));
Yann 0:f30e2135b0db 781 /* call callback to indicate error, clean up memory and return */
Yann 0:f30e2135b0db 782 goto responseerr;
Yann 0:f30e2135b0db 783 }
Yann 0:f30e2135b0db 784
Yann 0:f30e2135b0db 785 #if DNS_DOES_NAME_CHECK
Yann 0:f30e2135b0db 786 /* Check if the name in the "question" part match with the name in the entry. */
Yann 0:f30e2135b0db 787 if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) {
Yann 0:f30e2135b0db 788 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
Yann 0:f30e2135b0db 789 /* call callback to indicate error, clean up memory and return */
Yann 0:f30e2135b0db 790 goto responseerr;
Yann 0:f30e2135b0db 791 }
Yann 0:f30e2135b0db 792 #endif /* DNS_DOES_NAME_CHECK */
Yann 0:f30e2135b0db 793
Yann 0:f30e2135b0db 794 /* Skip the name in the "question" part */
Yann 0:f30e2135b0db 795 pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
Yann 0:f30e2135b0db 796
Yann 0:f30e2135b0db 797 while (nanswers > 0) {
Yann 0:f30e2135b0db 798 /* skip answer resource record's host name */
Yann 0:f30e2135b0db 799 pHostname = (char *) dns_parse_name((unsigned char *)pHostname);
Yann 0:f30e2135b0db 800
Yann 0:f30e2135b0db 801 /* Check for IP address type and Internet class. Others are discarded. */
Yann 0:f30e2135b0db 802 SMEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
Yann 0:f30e2135b0db 803 if((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) &&
Yann 0:f30e2135b0db 804 (ans.len == PP_HTONS(sizeof(ip_addr_t))) ) {
Yann 0:f30e2135b0db 805 /* read the answer resource record's TTL, and maximize it if needed */
Yann 0:f30e2135b0db 806 pEntry->ttl = ntohl(ans.ttl);
Yann 0:f30e2135b0db 807 if (pEntry->ttl > DNS_MAX_TTL) {
Yann 0:f30e2135b0db 808 pEntry->ttl = DNS_MAX_TTL;
Yann 0:f30e2135b0db 809 }
Yann 0:f30e2135b0db 810 /* read the IP address after answer resource record's header */
Yann 0:f30e2135b0db 811 SMEMCPY(&(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(ip_addr_t));
Yann 0:f30e2135b0db 812 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
Yann 0:f30e2135b0db 813 ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
Yann 0:f30e2135b0db 814 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
Yann 0:f30e2135b0db 815 /* call specified callback function if provided */
Yann 0:f30e2135b0db 816 if (pEntry->found) {
Yann 0:f30e2135b0db 817 (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg);
Yann 0:f30e2135b0db 818 }
Yann 0:f30e2135b0db 819 /* deallocate memory and return */
Yann 0:f30e2135b0db 820 goto memerr;
Yann 0:f30e2135b0db 821 } else {
Yann 0:f30e2135b0db 822 pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
Yann 0:f30e2135b0db 823 }
Yann 0:f30e2135b0db 824 --nanswers;
Yann 0:f30e2135b0db 825 }
Yann 0:f30e2135b0db 826 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name));
Yann 0:f30e2135b0db 827 /* call callback to indicate error, clean up memory and return */
Yann 0:f30e2135b0db 828 goto responseerr;
Yann 0:f30e2135b0db 829 }
Yann 0:f30e2135b0db 830 }
Yann 0:f30e2135b0db 831 }
Yann 0:f30e2135b0db 832
Yann 0:f30e2135b0db 833 /* deallocate memory and return */
Yann 0:f30e2135b0db 834 goto memerr;
Yann 0:f30e2135b0db 835
Yann 0:f30e2135b0db 836 responseerr:
Yann 0:f30e2135b0db 837 /* ERROR: call specified callback function with NULL as name to indicate an error */
Yann 0:f30e2135b0db 838 if (pEntry->found) {
Yann 0:f30e2135b0db 839 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
Yann 0:f30e2135b0db 840 }
Yann 0:f30e2135b0db 841 /* flush this entry */
Yann 0:f30e2135b0db 842 pEntry->state = DNS_STATE_UNUSED;
Yann 0:f30e2135b0db 843 pEntry->found = NULL;
Yann 0:f30e2135b0db 844
Yann 0:f30e2135b0db 845 memerr:
Yann 0:f30e2135b0db 846 /* free pbuf */
Yann 0:f30e2135b0db 847 pbuf_free(p);
Yann 0:f30e2135b0db 848 return;
Yann 0:f30e2135b0db 849 }
Yann 0:f30e2135b0db 850
Yann 0:f30e2135b0db 851 /**
Yann 0:f30e2135b0db 852 * Queues a new hostname to resolve and sends out a DNS query for that hostname
Yann 0:f30e2135b0db 853 *
Yann 0:f30e2135b0db 854 * @param name the hostname that is to be queried
Yann 0:f30e2135b0db 855 * @param found a callback founction to be called on success, failure or timeout
Yann 0:f30e2135b0db 856 * @param callback_arg argument to pass to the callback function
Yann 0:f30e2135b0db 857 * @return @return a err_t return code.
Yann 0:f30e2135b0db 858 */
Yann 0:f30e2135b0db 859 static err_t
Yann 0:f30e2135b0db 860 dns_enqueue(const char *name, dns_found_callback found, void *callback_arg)
Yann 0:f30e2135b0db 861 {
Yann 0:f30e2135b0db 862 u8_t i;
Yann 0:f30e2135b0db 863 u8_t lseq, lseqi;
Yann 0:f30e2135b0db 864 struct dns_table_entry *pEntry = NULL;
Yann 0:f30e2135b0db 865 size_t namelen;
Yann 0:f30e2135b0db 866
Yann 0:f30e2135b0db 867 /* search an unused entry, or the oldest one */
Yann 0:f30e2135b0db 868 lseq = lseqi = 0;
Yann 0:f30e2135b0db 869 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
Yann 0:f30e2135b0db 870 pEntry = &dns_table[i];
Yann 0:f30e2135b0db 871 /* is it an unused entry ? */
Yann 0:f30e2135b0db 872 if (pEntry->state == DNS_STATE_UNUSED)
Yann 0:f30e2135b0db 873 break;
Yann 0:f30e2135b0db 874
Yann 0:f30e2135b0db 875 /* check if this is the oldest completed entry */
Yann 0:f30e2135b0db 876 if (pEntry->state == DNS_STATE_DONE) {
Yann 0:f30e2135b0db 877 if ((dns_seqno - pEntry->seqno) > lseq) {
Yann 0:f30e2135b0db 878 lseq = dns_seqno - pEntry->seqno;
Yann 0:f30e2135b0db 879 lseqi = i;
Yann 0:f30e2135b0db 880 }
Yann 0:f30e2135b0db 881 }
Yann 0:f30e2135b0db 882 }
Yann 0:f30e2135b0db 883
Yann 0:f30e2135b0db 884 /* if we don't have found an unused entry, use the oldest completed one */
Yann 0:f30e2135b0db 885 if (i == DNS_TABLE_SIZE) {
Yann 0:f30e2135b0db 886 if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) {
Yann 0:f30e2135b0db 887 /* no entry can't be used now, table is full */
Yann 0:f30e2135b0db 888 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
Yann 0:f30e2135b0db 889 return ERR_MEM;
Yann 0:f30e2135b0db 890 } else {
Yann 0:f30e2135b0db 891 /* use the oldest completed one */
Yann 0:f30e2135b0db 892 i = lseqi;
Yann 0:f30e2135b0db 893 pEntry = &dns_table[i];
Yann 0:f30e2135b0db 894 }
Yann 0:f30e2135b0db 895 }
Yann 0:f30e2135b0db 896
Yann 0:f30e2135b0db 897 /* use this entry */
Yann 0:f30e2135b0db 898 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
Yann 0:f30e2135b0db 899
Yann 0:f30e2135b0db 900 /* fill the entry */
Yann 0:f30e2135b0db 901 pEntry->state = DNS_STATE_NEW;
Yann 0:f30e2135b0db 902 pEntry->seqno = dns_seqno++;
Yann 0:f30e2135b0db 903 pEntry->found = found;
Yann 0:f30e2135b0db 904 pEntry->arg = callback_arg;
Yann 0:f30e2135b0db 905 namelen = LWIP_MIN(strlen(name), DNS_MAX_NAME_LENGTH-1);
Yann 0:f30e2135b0db 906 MEMCPY(pEntry->name, name, namelen);
Yann 0:f30e2135b0db 907 pEntry->name[namelen] = 0;
Yann 0:f30e2135b0db 908
Yann 0:f30e2135b0db 909 /* force to send query without waiting timer */
Yann 0:f30e2135b0db 910 dns_check_entry(i);
Yann 0:f30e2135b0db 911
Yann 0:f30e2135b0db 912 /* dns query is enqueued */
Yann 0:f30e2135b0db 913 return ERR_INPROGRESS;
Yann 0:f30e2135b0db 914 }
Yann 0:f30e2135b0db 915
Yann 0:f30e2135b0db 916 /**
Yann 0:f30e2135b0db 917 * Resolve a hostname (string) into an IP address.
Yann 0:f30e2135b0db 918 * NON-BLOCKING callback version for use with raw API!!!
Yann 0:f30e2135b0db 919 *
Yann 0:f30e2135b0db 920 * Returns immediately with one of err_t return codes:
Yann 0:f30e2135b0db 921 * - ERR_OK if hostname is a valid IP address string or the host
Yann 0:f30e2135b0db 922 * name is already in the local names table.
Yann 0:f30e2135b0db 923 * - ERR_INPROGRESS enqueue a request to be sent to the DNS server
Yann 0:f30e2135b0db 924 * for resolution if no errors are present.
Yann 0:f30e2135b0db 925 *
Yann 0:f30e2135b0db 926 * @param hostname the hostname that is to be queried
Yann 0:f30e2135b0db 927 * @param addr pointer to a ip_addr_t where to store the address if it is already
Yann 0:f30e2135b0db 928 * cached in the dns_table (only valid if ERR_OK is returned!)
Yann 0:f30e2135b0db 929 * @param found a callback function to be called on success, failure or timeout (only if
Yann 0:f30e2135b0db 930 * ERR_INPROGRESS is returned!)
Yann 0:f30e2135b0db 931 * @param callback_arg argument to pass to the callback function
Yann 0:f30e2135b0db 932 * @return a err_t return code.
Yann 0:f30e2135b0db 933 */
Yann 0:f30e2135b0db 934 err_t
Yann 0:f30e2135b0db 935 dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found,
Yann 0:f30e2135b0db 936 void *callback_arg)
Yann 0:f30e2135b0db 937 {
Yann 0:f30e2135b0db 938 u32_t ipaddr;
Yann 0:f30e2135b0db 939 /* not initialized or no valid server yet, or invalid addr pointer
Yann 0:f30e2135b0db 940 * or invalid hostname or invalid hostname length */
Yann 0:f30e2135b0db 941 if ((dns_pcb == NULL) || (addr == NULL) ||
Yann 0:f30e2135b0db 942 (!hostname) || (!hostname[0]) ||
Yann 0:f30e2135b0db 943 (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) {
Yann 0:f30e2135b0db 944 return ERR_VAL;
Yann 0:f30e2135b0db 945 }
Yann 0:f30e2135b0db 946
Yann 0:f30e2135b0db 947 #if LWIP_HAVE_LOOPIF
Yann 0:f30e2135b0db 948 if (strcmp(hostname, "localhost")==0) {
Yann 0:f30e2135b0db 949 ip_addr_set_loopback(addr);
Yann 0:f30e2135b0db 950 return ERR_OK;
Yann 0:f30e2135b0db 951 }
Yann 0:f30e2135b0db 952 #endif /* LWIP_HAVE_LOOPIF */
Yann 0:f30e2135b0db 953
Yann 0:f30e2135b0db 954 /* host name already in octet notation? set ip addr and return ERR_OK */
Yann 0:f30e2135b0db 955 ipaddr = ipaddr_addr(hostname);
Yann 0:f30e2135b0db 956 if (ipaddr == IPADDR_NONE) {
Yann 0:f30e2135b0db 957 /* already have this address cached? */
Yann 0:f30e2135b0db 958 ipaddr = dns_lookup(hostname);
Yann 0:f30e2135b0db 959 }
Yann 0:f30e2135b0db 960 if (ipaddr != IPADDR_NONE) {
Yann 0:f30e2135b0db 961 ip4_addr_set_u32(addr, ipaddr);
Yann 0:f30e2135b0db 962 return ERR_OK;
Yann 0:f30e2135b0db 963 }
Yann 0:f30e2135b0db 964
Yann 0:f30e2135b0db 965 /* queue query with specified callback */
Yann 0:f30e2135b0db 966 return dns_enqueue(hostname, found, callback_arg);
Yann 0:f30e2135b0db 967 }
Yann 0:f30e2135b0db 968
Yann 0:f30e2135b0db 969 #endif /* LWIP_DNS */