Richard Blimmel / Mbed 2 deprecated CIG_HTTPClient

HTTPClient using static IP

Dependencies:   mbed

NetServices/lwip/core/dns.c@0:d8f2f7d5f31b, 2011-05-30 (annotated)

Committer:
mr_q
Date:
Mon May 30 11:53:37 2011 +0000
Revision:
0:d8f2f7d5f31b
v0.01 Draft

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mr_q 0:d8f2f7d5f31b 1 /**
mr_q 0:d8f2f7d5f31b 2 * @file
mr_q 0:d8f2f7d5f31b 3 * DNS - host name to IP address resolver.
mr_q 0:d8f2f7d5f31b 4 *
mr_q 0:d8f2f7d5f31b 5 */
mr_q 0:d8f2f7d5f31b 6
mr_q 0:d8f2f7d5f31b 7 /**
mr_q 0:d8f2f7d5f31b 8
mr_q 0:d8f2f7d5f31b 9 * This file implements a DNS host name to IP address resolver.
mr_q 0:d8f2f7d5f31b 10
mr_q 0:d8f2f7d5f31b 11 * Port to lwIP from uIP
mr_q 0:d8f2f7d5f31b 12 * by Jim Pettinato April 2007
mr_q 0:d8f2f7d5f31b 13
mr_q 0:d8f2f7d5f31b 14 * uIP version Copyright (c) 2002-2003, Adam Dunkels.
mr_q 0:d8f2f7d5f31b 15 * All rights reserved.
mr_q 0:d8f2f7d5f31b 16 *
mr_q 0:d8f2f7d5f31b 17 * Redistribution and use in source and binary forms, with or without
mr_q 0:d8f2f7d5f31b 18 * modification, are permitted provided that the following conditions
mr_q 0:d8f2f7d5f31b 19 * are met:
mr_q 0:d8f2f7d5f31b 20 * 1. Redistributions of source code must retain the above copyright
mr_q 0:d8f2f7d5f31b 21 * notice, this list of conditions and the following disclaimer.
mr_q 0:d8f2f7d5f31b 22 * 2. Redistributions in binary form must reproduce the above copyright
mr_q 0:d8f2f7d5f31b 23 * notice, this list of conditions and the following disclaimer in the
mr_q 0:d8f2f7d5f31b 24 * documentation and/or other materials provided with the distribution.
mr_q 0:d8f2f7d5f31b 25 * 3. The name of the author may not be used to endorse or promote
mr_q 0:d8f2f7d5f31b 26 * products derived from this software without specific prior
mr_q 0:d8f2f7d5f31b 27 * written permission.
mr_q 0:d8f2f7d5f31b 28 *
mr_q 0:d8f2f7d5f31b 29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
mr_q 0:d8f2f7d5f31b 30 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
mr_q 0:d8f2f7d5f31b 31 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
mr_q 0:d8f2f7d5f31b 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
mr_q 0:d8f2f7d5f31b 33 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mr_q 0:d8f2f7d5f31b 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
mr_q 0:d8f2f7d5f31b 35 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mr_q 0:d8f2f7d5f31b 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
mr_q 0:d8f2f7d5f31b 37 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
mr_q 0:d8f2f7d5f31b 38 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
mr_q 0:d8f2f7d5f31b 39 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mr_q 0:d8f2f7d5f31b 40 *
mr_q 0:d8f2f7d5f31b 41 *
mr_q 0:d8f2f7d5f31b 42 * DNS.C
mr_q 0:d8f2f7d5f31b 43 *
mr_q 0:d8f2f7d5f31b 44 * The lwIP DNS resolver functions are used to lookup a host name and
mr_q 0:d8f2f7d5f31b 45 * map it to a numerical IP address. It maintains a list of resolved
mr_q 0:d8f2f7d5f31b 46 * hostnames that can be queried with the dns_lookup() function.
mr_q 0:d8f2f7d5f31b 47 * New hostnames can be resolved using the dns_query() function.
mr_q 0:d8f2f7d5f31b 48 *
mr_q 0:d8f2f7d5f31b 49 * The lwIP version of the resolver also adds a non-blocking version of
mr_q 0:d8f2f7d5f31b 50 * gethostbyname() that will work with a raw API application. This function
mr_q 0:d8f2f7d5f31b 51 * checks for an IP address string first and converts it if it is valid.
mr_q 0:d8f2f7d5f31b 52 * gethostbyname() then does a dns_lookup() to see if the name is
mr_q 0:d8f2f7d5f31b 53 * already in the table. If so, the IP is returned. If not, a query is
mr_q 0:d8f2f7d5f31b 54 * issued and the function returns with a ERR_INPROGRESS status. The app
mr_q 0:d8f2f7d5f31b 55 * using the dns client must then go into a waiting state.
mr_q 0:d8f2f7d5f31b 56 *
mr_q 0:d8f2f7d5f31b 57 * Once a hostname has been resolved (or found to be non-existent),
mr_q 0:d8f2f7d5f31b 58 * the resolver code calls a specified callback function (which
mr_q 0:d8f2f7d5f31b 59 * must be implemented by the module that uses the resolver).
mr_q 0:d8f2f7d5f31b 60 */
mr_q 0:d8f2f7d5f31b 61
mr_q 0:d8f2f7d5f31b 62 /*-----------------------------------------------------------------------------
mr_q 0:d8f2f7d5f31b 63 * RFC 1035 - Domain names - implementation and specification
mr_q 0:d8f2f7d5f31b 64 * RFC 2181 - Clarifications to the DNS Specification
mr_q 0:d8f2f7d5f31b 65 *----------------------------------------------------------------------------*/
mr_q 0:d8f2f7d5f31b 66
mr_q 0:d8f2f7d5f31b 67 /** @todo: define good default values (rfc compliance) */
mr_q 0:d8f2f7d5f31b 68 /** @todo: improve answer parsing, more checkings... */
mr_q 0:d8f2f7d5f31b 69 /** @todo: check RFC1035 - 7.3. Processing responses */
mr_q 0:d8f2f7d5f31b 70
mr_q 0:d8f2f7d5f31b 71 /*-----------------------------------------------------------------------------
mr_q 0:d8f2f7d5f31b 72 * Includes
mr_q 0:d8f2f7d5f31b 73 *----------------------------------------------------------------------------*/
mr_q 0:d8f2f7d5f31b 74
mr_q 0:d8f2f7d5f31b 75 #include "lwip/opt.h"
mr_q 0:d8f2f7d5f31b 76
mr_q 0:d8f2f7d5f31b 77 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
mr_q 0:d8f2f7d5f31b 78
mr_q 0:d8f2f7d5f31b 79 #include "lwip/udp.h"
mr_q 0:d8f2f7d5f31b 80 #include "lwip/mem.h"
mr_q 0:d8f2f7d5f31b 81 #include "lwip/memp.h"
mr_q 0:d8f2f7d5f31b 82 #include "lwip/dns.h"
mr_q 0:d8f2f7d5f31b 83
mr_q 0:d8f2f7d5f31b 84 #include <string.h>
mr_q 0:d8f2f7d5f31b 85
mr_q 0:d8f2f7d5f31b 86 /** DNS server IP address */
mr_q 0:d8f2f7d5f31b 87 #ifndef DNS_SERVER_ADDRESS
mr_q 0:d8f2f7d5f31b 88 #define DNS_SERVER_ADDRESS(ipaddr) (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */
mr_q 0:d8f2f7d5f31b 89 #endif
mr_q 0:d8f2f7d5f31b 90
mr_q 0:d8f2f7d5f31b 91 /** DNS server port address */
mr_q 0:d8f2f7d5f31b 92 #ifndef DNS_SERVER_PORT
mr_q 0:d8f2f7d5f31b 93 #define DNS_SERVER_PORT 53
mr_q 0:d8f2f7d5f31b 94 #endif
mr_q 0:d8f2f7d5f31b 95
mr_q 0:d8f2f7d5f31b 96 /** DNS maximum number of retries when asking for a name, before "timeout". */
mr_q 0:d8f2f7d5f31b 97 #ifndef DNS_MAX_RETRIES
mr_q 0:d8f2f7d5f31b 98 #define DNS_MAX_RETRIES 4
mr_q 0:d8f2f7d5f31b 99 #endif
mr_q 0:d8f2f7d5f31b 100
mr_q 0:d8f2f7d5f31b 101 /** DNS resource record max. TTL (one week as default) */
mr_q 0:d8f2f7d5f31b 102 #ifndef DNS_MAX_TTL
mr_q 0:d8f2f7d5f31b 103 #define DNS_MAX_TTL 604800
mr_q 0:d8f2f7d5f31b 104 #endif
mr_q 0:d8f2f7d5f31b 105
mr_q 0:d8f2f7d5f31b 106 /* DNS protocol flags */
mr_q 0:d8f2f7d5f31b 107 #define DNS_FLAG1_RESPONSE 0x80
mr_q 0:d8f2f7d5f31b 108 #define DNS_FLAG1_OPCODE_STATUS 0x10
mr_q 0:d8f2f7d5f31b 109 #define DNS_FLAG1_OPCODE_INVERSE 0x08
mr_q 0:d8f2f7d5f31b 110 #define DNS_FLAG1_OPCODE_STANDARD 0x00
mr_q 0:d8f2f7d5f31b 111 #define DNS_FLAG1_AUTHORATIVE 0x04
mr_q 0:d8f2f7d5f31b 112 #define DNS_FLAG1_TRUNC 0x02
mr_q 0:d8f2f7d5f31b 113 #define DNS_FLAG1_RD 0x01
mr_q 0:d8f2f7d5f31b 114 #define DNS_FLAG2_RA 0x80
mr_q 0:d8f2f7d5f31b 115 #define DNS_FLAG2_ERR_MASK 0x0f
mr_q 0:d8f2f7d5f31b 116 #define DNS_FLAG2_ERR_NONE 0x00
mr_q 0:d8f2f7d5f31b 117 #define DNS_FLAG2_ERR_NAME 0x03
mr_q 0:d8f2f7d5f31b 118
mr_q 0:d8f2f7d5f31b 119 /* DNS protocol states */
mr_q 0:d8f2f7d5f31b 120 #define DNS_STATE_UNUSED 0
mr_q 0:d8f2f7d5f31b 121 #define DNS_STATE_NEW 1
mr_q 0:d8f2f7d5f31b 122 #define DNS_STATE_ASKING 2
mr_q 0:d8f2f7d5f31b 123 #define DNS_STATE_DONE 3
mr_q 0:d8f2f7d5f31b 124
mr_q 0:d8f2f7d5f31b 125 #ifdef PACK_STRUCT_USE_INCLUDES
mr_q 0:d8f2f7d5f31b 126 # include "arch/bpstruct.h"
mr_q 0:d8f2f7d5f31b 127 #endif
mr_q 0:d8f2f7d5f31b 128 PACK_STRUCT_BEGIN
mr_q 0:d8f2f7d5f31b 129 /** DNS message header */
mr_q 0:d8f2f7d5f31b 130 struct dns_hdr {
mr_q 0:d8f2f7d5f31b 131 PACK_STRUCT_FIELD(u16_t id);
mr_q 0:d8f2f7d5f31b 132 PACK_STRUCT_FIELD(u8_t flags1);
mr_q 0:d8f2f7d5f31b 133 PACK_STRUCT_FIELD(u8_t flags2);
mr_q 0:d8f2f7d5f31b 134 PACK_STRUCT_FIELD(u16_t numquestions);
mr_q 0:d8f2f7d5f31b 135 PACK_STRUCT_FIELD(u16_t numanswers);
mr_q 0:d8f2f7d5f31b 136 PACK_STRUCT_FIELD(u16_t numauthrr);
mr_q 0:d8f2f7d5f31b 137 PACK_STRUCT_FIELD(u16_t numextrarr);
mr_q 0:d8f2f7d5f31b 138 } PACK_STRUCT_STRUCT;
mr_q 0:d8f2f7d5f31b 139 PACK_STRUCT_END
mr_q 0:d8f2f7d5f31b 140 #ifdef PACK_STRUCT_USE_INCLUDES
mr_q 0:d8f2f7d5f31b 141 # include "arch/epstruct.h"
mr_q 0:d8f2f7d5f31b 142 #endif
mr_q 0:d8f2f7d5f31b 143 #define SIZEOF_DNS_HDR 12
mr_q 0:d8f2f7d5f31b 144
mr_q 0:d8f2f7d5f31b 145 /** DNS query message structure.
mr_q 0:d8f2f7d5f31b 146 No packing needed: only used locally on the stack. */
mr_q 0:d8f2f7d5f31b 147 struct dns_query {
mr_q 0:d8f2f7d5f31b 148 /* DNS query record starts with either a domain name or a pointer
mr_q 0:d8f2f7d5f31b 149 to a name already present somewhere in the packet. */
mr_q 0:d8f2f7d5f31b 150 u16_t type;
mr_q 0:d8f2f7d5f31b 151 u16_t cls;
mr_q 0:d8f2f7d5f31b 152 };
mr_q 0:d8f2f7d5f31b 153 #define SIZEOF_DNS_QUERY 4
mr_q 0:d8f2f7d5f31b 154
mr_q 0:d8f2f7d5f31b 155 /** DNS answer message structure.
mr_q 0:d8f2f7d5f31b 156 No packing needed: only used locally on the stack. */
mr_q 0:d8f2f7d5f31b 157 struct dns_answer {
mr_q 0:d8f2f7d5f31b 158 /* DNS answer record starts with either a domain name or a pointer
mr_q 0:d8f2f7d5f31b 159 to a name already present somewhere in the packet. */
mr_q 0:d8f2f7d5f31b 160 u16_t type;
mr_q 0:d8f2f7d5f31b 161 u16_t cls;
mr_q 0:d8f2f7d5f31b 162 u32_t ttl;
mr_q 0:d8f2f7d5f31b 163 u16_t len;
mr_q 0:d8f2f7d5f31b 164 };
mr_q 0:d8f2f7d5f31b 165 #define SIZEOF_DNS_ANSWER 10
mr_q 0:d8f2f7d5f31b 166
mr_q 0:d8f2f7d5f31b 167 /** DNS table entry */
mr_q 0:d8f2f7d5f31b 168 struct dns_table_entry {
mr_q 0:d8f2f7d5f31b 169 u8_t state;
mr_q 0:d8f2f7d5f31b 170 u8_t numdns;
mr_q 0:d8f2f7d5f31b 171 u8_t tmr;
mr_q 0:d8f2f7d5f31b 172 u8_t retries;
mr_q 0:d8f2f7d5f31b 173 u8_t seqno;
mr_q 0:d8f2f7d5f31b 174 u8_t err;
mr_q 0:d8f2f7d5f31b 175 u32_t ttl;
mr_q 0:d8f2f7d5f31b 176 char name[DNS_MAX_NAME_LENGTH];
mr_q 0:d8f2f7d5f31b 177 ip_addr_t ipaddr;
mr_q 0:d8f2f7d5f31b 178 /* pointer to callback on DNS query done */
mr_q 0:d8f2f7d5f31b 179 dns_found_callback found;
mr_q 0:d8f2f7d5f31b 180 void *arg;
mr_q 0:d8f2f7d5f31b 181 };
mr_q 0:d8f2f7d5f31b 182
mr_q 0:d8f2f7d5f31b 183 #if DNS_LOCAL_HOSTLIST
mr_q 0:d8f2f7d5f31b 184
mr_q 0:d8f2f7d5f31b 185 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
mr_q 0:d8f2f7d5f31b 186 /** Local host-list. For hostnames in this list, no
mr_q 0:d8f2f7d5f31b 187 * external name resolution is performed */
mr_q 0:d8f2f7d5f31b 188 static struct local_hostlist_entry *local_hostlist_dynamic;
mr_q 0:d8f2f7d5f31b 189 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
mr_q 0:d8f2f7d5f31b 190
mr_q 0:d8f2f7d5f31b 191 /** Defining this allows the local_hostlist_static to be placed in a different
mr_q 0:d8f2f7d5f31b 192 * linker section (e.g. FLASH) */
mr_q 0:d8f2f7d5f31b 193 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE
mr_q 0:d8f2f7d5f31b 194 #define DNS_LOCAL_HOSTLIST_STORAGE_PRE static
mr_q 0:d8f2f7d5f31b 195 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */
mr_q 0:d8f2f7d5f31b 196 /** Defining this allows the local_hostlist_static to be placed in a different
mr_q 0:d8f2f7d5f31b 197 * linker section (e.g. FLASH) */
mr_q 0:d8f2f7d5f31b 198 #ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST
mr_q 0:d8f2f7d5f31b 199 #define DNS_LOCAL_HOSTLIST_STORAGE_POST
mr_q 0:d8f2f7d5f31b 200 #endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */
mr_q 0:d8f2f7d5f31b 201 DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[]
mr_q 0:d8f2f7d5f31b 202 DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT;
mr_q 0:d8f2f7d5f31b 203
mr_q 0:d8f2f7d5f31b 204 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
mr_q 0:d8f2f7d5f31b 205
mr_q 0:d8f2f7d5f31b 206 static void dns_init_local();
mr_q 0:d8f2f7d5f31b 207 #endif /* DNS_LOCAL_HOSTLIST */
mr_q 0:d8f2f7d5f31b 208
mr_q 0:d8f2f7d5f31b 209
mr_q 0:d8f2f7d5f31b 210 /* forward declarations */
mr_q 0:d8f2f7d5f31b 211 static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
mr_q 0:d8f2f7d5f31b 212 static void dns_check_entries(void);
mr_q 0:d8f2f7d5f31b 213
mr_q 0:d8f2f7d5f31b 214 /*-----------------------------------------------------------------------------
mr_q 0:d8f2f7d5f31b 215 * Globales
mr_q 0:d8f2f7d5f31b 216 *----------------------------------------------------------------------------*/
mr_q 0:d8f2f7d5f31b 217
mr_q 0:d8f2f7d5f31b 218 /* DNS variables */
mr_q 0:d8f2f7d5f31b 219 static struct udp_pcb *dns_pcb;
mr_q 0:d8f2f7d5f31b 220 static u8_t dns_seqno;
mr_q 0:d8f2f7d5f31b 221 static struct dns_table_entry dns_table[DNS_TABLE_SIZE];
mr_q 0:d8f2f7d5f31b 222 static ip_addr_t dns_servers[DNS_MAX_SERVERS];
mr_q 0:d8f2f7d5f31b 223 /** Contiguous buffer for processing responses */
mr_q 0:d8f2f7d5f31b 224 static u8_t dns_payload_buffer[LWIP_MEM_ALIGN_BUFFER(DNS_MSG_SIZE)];
mr_q 0:d8f2f7d5f31b 225 static u8_t* dns_payload;
mr_q 0:d8f2f7d5f31b 226
mr_q 0:d8f2f7d5f31b 227 /**
mr_q 0:d8f2f7d5f31b 228 * Initialize the resolver: set up the UDP pcb and configure the default server
mr_q 0:d8f2f7d5f31b 229 * (DNS_SERVER_ADDRESS).
mr_q 0:d8f2f7d5f31b 230 */
mr_q 0:d8f2f7d5f31b 231 void
mr_q 0:d8f2f7d5f31b 232 dns_init()
mr_q 0:d8f2f7d5f31b 233 {
mr_q 0:d8f2f7d5f31b 234 ip_addr_t dnsserver;
mr_q 0:d8f2f7d5f31b 235
mr_q 0:d8f2f7d5f31b 236 dns_payload = (u8_t *)LWIP_MEM_ALIGN(dns_payload_buffer);
mr_q 0:d8f2f7d5f31b 237
mr_q 0:d8f2f7d5f31b 238 /* initialize default DNS server address */
mr_q 0:d8f2f7d5f31b 239 DNS_SERVER_ADDRESS(&dnsserver);
mr_q 0:d8f2f7d5f31b 240
mr_q 0:d8f2f7d5f31b 241 LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
mr_q 0:d8f2f7d5f31b 242
mr_q 0:d8f2f7d5f31b 243 /* if dns client not yet initialized... */
mr_q 0:d8f2f7d5f31b 244 if (dns_pcb == NULL) {
mr_q 0:d8f2f7d5f31b 245 dns_pcb = udp_new();
mr_q 0:d8f2f7d5f31b 246
mr_q 0:d8f2f7d5f31b 247 if (dns_pcb != NULL) {
mr_q 0:d8f2f7d5f31b 248 /* initialize DNS table not needed (initialized to zero since it is a
mr_q 0:d8f2f7d5f31b 249 * global variable) */
mr_q 0:d8f2f7d5f31b 250 LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
mr_q 0:d8f2f7d5f31b 251 DNS_STATE_UNUSED == 0);
mr_q 0:d8f2f7d5f31b 252
mr_q 0:d8f2f7d5f31b 253 /* initialize DNS client */
mr_q 0:d8f2f7d5f31b 254 udp_bind(dns_pcb, IP_ADDR_ANY, 0);
mr_q 0:d8f2f7d5f31b 255 udp_recv(dns_pcb, dns_recv, NULL);
mr_q 0:d8f2f7d5f31b 256
mr_q 0:d8f2f7d5f31b 257 /* initialize default DNS primary server */
mr_q 0:d8f2f7d5f31b 258 dns_setserver(0, &dnsserver);
mr_q 0:d8f2f7d5f31b 259 }
mr_q 0:d8f2f7d5f31b 260 }
mr_q 0:d8f2f7d5f31b 261 #if DNS_LOCAL_HOSTLIST
mr_q 0:d8f2f7d5f31b 262 dns_init_local();
mr_q 0:d8f2f7d5f31b 263 #endif
mr_q 0:d8f2f7d5f31b 264 }
mr_q 0:d8f2f7d5f31b 265
mr_q 0:d8f2f7d5f31b 266 /**
mr_q 0:d8f2f7d5f31b 267 * Initialize one of the DNS servers.
mr_q 0:d8f2f7d5f31b 268 *
mr_q 0:d8f2f7d5f31b 269 * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
mr_q 0:d8f2f7d5f31b 270 * @param dnsserver IP address of the DNS server to set
mr_q 0:d8f2f7d5f31b 271 */
mr_q 0:d8f2f7d5f31b 272 void
mr_q 0:d8f2f7d5f31b 273 dns_setserver(u8_t numdns, ip_addr_t *dnsserver)
mr_q 0:d8f2f7d5f31b 274 {
mr_q 0:d8f2f7d5f31b 275 if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) &&
mr_q 0:d8f2f7d5f31b 276 (dnsserver != NULL) && !ip_addr_isany(dnsserver)) {
mr_q 0:d8f2f7d5f31b 277 dns_servers[numdns] = (*dnsserver);
mr_q 0:d8f2f7d5f31b 278 }
mr_q 0:d8f2f7d5f31b 279 }
mr_q 0:d8f2f7d5f31b 280
mr_q 0:d8f2f7d5f31b 281 /**
mr_q 0:d8f2f7d5f31b 282 * Obtain one of the currently configured DNS server.
mr_q 0:d8f2f7d5f31b 283 *
mr_q 0:d8f2f7d5f31b 284 * @param numdns the index of the DNS server
mr_q 0:d8f2f7d5f31b 285 * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
mr_q 0:d8f2f7d5f31b 286 * server has not been configured.
mr_q 0:d8f2f7d5f31b 287 */
mr_q 0:d8f2f7d5f31b 288 ip_addr_t
mr_q 0:d8f2f7d5f31b 289 dns_getserver(u8_t numdns)
mr_q 0:d8f2f7d5f31b 290 {
mr_q 0:d8f2f7d5f31b 291 if (numdns < DNS_MAX_SERVERS) {
mr_q 0:d8f2f7d5f31b 292 return dns_servers[numdns];
mr_q 0:d8f2f7d5f31b 293 } else {
mr_q 0:d8f2f7d5f31b 294 return *IP_ADDR_ANY;
mr_q 0:d8f2f7d5f31b 295 }
mr_q 0:d8f2f7d5f31b 296 }
mr_q 0:d8f2f7d5f31b 297
mr_q 0:d8f2f7d5f31b 298 /**
mr_q 0:d8f2f7d5f31b 299 * The DNS resolver client timer - handle retries and timeouts and should
mr_q 0:d8f2f7d5f31b 300 * be called every DNS_TMR_INTERVAL milliseconds (every second by default).
mr_q 0:d8f2f7d5f31b 301 */
mr_q 0:d8f2f7d5f31b 302 void
mr_q 0:d8f2f7d5f31b 303 dns_tmr(void)
mr_q 0:d8f2f7d5f31b 304 {
mr_q 0:d8f2f7d5f31b 305 if (dns_pcb != NULL) {
mr_q 0:d8f2f7d5f31b 306 LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
mr_q 0:d8f2f7d5f31b 307 dns_check_entries();
mr_q 0:d8f2f7d5f31b 308 }
mr_q 0:d8f2f7d5f31b 309 }
mr_q 0:d8f2f7d5f31b 310
mr_q 0:d8f2f7d5f31b 311 #if DNS_LOCAL_HOSTLIST
mr_q 0:d8f2f7d5f31b 312 static void
mr_q 0:d8f2f7d5f31b 313 dns_init_local()
mr_q 0:d8f2f7d5f31b 314 {
mr_q 0:d8f2f7d5f31b 315 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT)
mr_q 0:d8f2f7d5f31b 316 int i;
mr_q 0:d8f2f7d5f31b 317 struct local_hostlist_entry *entry;
mr_q 0:d8f2f7d5f31b 318 /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
mr_q 0:d8f2f7d5f31b 319 struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
mr_q 0:d8f2f7d5f31b 320 size_t namelen;
mr_q 0:d8f2f7d5f31b 321 for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) {
mr_q 0:d8f2f7d5f31b 322 struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
mr_q 0:d8f2f7d5f31b 323 LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL);
mr_q 0:d8f2f7d5f31b 324 namelen = strlen(init_entry->name);
mr_q 0:d8f2f7d5f31b 325 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
mr_q 0:d8f2f7d5f31b 326 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
mr_q 0:d8f2f7d5f31b 327 LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
mr_q 0:d8f2f7d5f31b 328 if (entry != NULL) {
mr_q 0:d8f2f7d5f31b 329 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
mr_q 0:d8f2f7d5f31b 330 MEMCPY((char*)entry->name, init_entry->name, namelen);
mr_q 0:d8f2f7d5f31b 331 ((char*)entry->name)[namelen] = 0;
mr_q 0:d8f2f7d5f31b 332 entry->addr = init_entry->addr;
mr_q 0:d8f2f7d5f31b 333 entry->next = local_hostlist_dynamic;
mr_q 0:d8f2f7d5f31b 334 local_hostlist_dynamic = entry;
mr_q 0:d8f2f7d5f31b 335 }
mr_q 0:d8f2f7d5f31b 336 }
mr_q 0:d8f2f7d5f31b 337 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
mr_q 0:d8f2f7d5f31b 338 }
mr_q 0:d8f2f7d5f31b 339
mr_q 0:d8f2f7d5f31b 340 /**
mr_q 0:d8f2f7d5f31b 341 * Scans the local host-list for a hostname.
mr_q 0:d8f2f7d5f31b 342 *
mr_q 0:d8f2f7d5f31b 343 * @param hostname Hostname to look for in the local host-list
mr_q 0:d8f2f7d5f31b 344 * @return The first IP address for the hostname in the local host-list or
mr_q 0:d8f2f7d5f31b 345 * IPADDR_NONE if not found.
mr_q 0:d8f2f7d5f31b 346 */
mr_q 0:d8f2f7d5f31b 347 static u32_t
mr_q 0:d8f2f7d5f31b 348 dns_lookup_local(const char *hostname)
mr_q 0:d8f2f7d5f31b 349 {
mr_q 0:d8f2f7d5f31b 350 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
mr_q 0:d8f2f7d5f31b 351 struct local_hostlist_entry *entry = local_hostlist_dynamic;
mr_q 0:d8f2f7d5f31b 352 while(entry != NULL) {
mr_q 0:d8f2f7d5f31b 353 if(strcmp(entry->name, hostname) == 0) {
mr_q 0:d8f2f7d5f31b 354 return ip4_addr_get_u32(&entry->addr);
mr_q 0:d8f2f7d5f31b 355 }
mr_q 0:d8f2f7d5f31b 356 entry = entry->next;
mr_q 0:d8f2f7d5f31b 357 }
mr_q 0:d8f2f7d5f31b 358 #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
mr_q 0:d8f2f7d5f31b 359 int i;
mr_q 0:d8f2f7d5f31b 360 for (i = 0; i < sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry); i++) {
mr_q 0:d8f2f7d5f31b 361 if(strcmp(local_hostlist_static[i].name, hostname) == 0) {
mr_q 0:d8f2f7d5f31b 362 return ip4_addr_get_u32(&local_hostlist_static[i].addr);
mr_q 0:d8f2f7d5f31b 363 }
mr_q 0:d8f2f7d5f31b 364 }
mr_q 0:d8f2f7d5f31b 365 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
mr_q 0:d8f2f7d5f31b 366 return IPADDR_NONE;
mr_q 0:d8f2f7d5f31b 367 }
mr_q 0:d8f2f7d5f31b 368
mr_q 0:d8f2f7d5f31b 369 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
mr_q 0:d8f2f7d5f31b 370 /** Remove all entries from the local host-list for a specific hostname
mr_q 0:d8f2f7d5f31b 371 * and/or IP addess
mr_q 0:d8f2f7d5f31b 372 *
mr_q 0:d8f2f7d5f31b 373 * @param hostname hostname for which entries shall be removed from the local
mr_q 0:d8f2f7d5f31b 374 * host-list
mr_q 0:d8f2f7d5f31b 375 * @param addr address for which entries shall be removed from the local host-list
mr_q 0:d8f2f7d5f31b 376 * @return the number of removed entries
mr_q 0:d8f2f7d5f31b 377 */
mr_q 0:d8f2f7d5f31b 378 int
mr_q 0:d8f2f7d5f31b 379 dns_local_removehost(const char *hostname, const ip_addr_t *addr)
mr_q 0:d8f2f7d5f31b 380 {
mr_q 0:d8f2f7d5f31b 381 int removed = 0;
mr_q 0:d8f2f7d5f31b 382 struct local_hostlist_entry *entry = local_hostlist_dynamic;
mr_q 0:d8f2f7d5f31b 383 struct local_hostlist_entry *last_entry = NULL;
mr_q 0:d8f2f7d5f31b 384 while (entry != NULL) {
mr_q 0:d8f2f7d5f31b 385 if (((hostname == NULL) || !strcmp(entry->name, hostname)) &&
mr_q 0:d8f2f7d5f31b 386 ((addr == NULL) || ip_addr_cmp(&entry->addr, addr))) {
mr_q 0:d8f2f7d5f31b 387 struct local_hostlist_entry *free_entry;
mr_q 0:d8f2f7d5f31b 388 if (last_entry != NULL) {
mr_q 0:d8f2f7d5f31b 389 last_entry->next = entry->next;
mr_q 0:d8f2f7d5f31b 390 } else {
mr_q 0:d8f2f7d5f31b 391 local_hostlist_dynamic = entry->next;
mr_q 0:d8f2f7d5f31b 392 }
mr_q 0:d8f2f7d5f31b 393 free_entry = entry;
mr_q 0:d8f2f7d5f31b 394 entry = entry->next;
mr_q 0:d8f2f7d5f31b 395 memp_free(MEMP_LOCALHOSTLIST, free_entry);
mr_q 0:d8f2f7d5f31b 396 removed++;
mr_q 0:d8f2f7d5f31b 397 } else {
mr_q 0:d8f2f7d5f31b 398 last_entry = entry;
mr_q 0:d8f2f7d5f31b 399 entry = entry->next;
mr_q 0:d8f2f7d5f31b 400 }
mr_q 0:d8f2f7d5f31b 401 }
mr_q 0:d8f2f7d5f31b 402 return removed;
mr_q 0:d8f2f7d5f31b 403 }
mr_q 0:d8f2f7d5f31b 404
mr_q 0:d8f2f7d5f31b 405 /**
mr_q 0:d8f2f7d5f31b 406 * Add a hostname/IP address pair to the local host-list.
mr_q 0:d8f2f7d5f31b 407 * Duplicates are not checked.
mr_q 0:d8f2f7d5f31b 408 *
mr_q 0:d8f2f7d5f31b 409 * @param hostname hostname of the new entry
mr_q 0:d8f2f7d5f31b 410 * @param addr IP address of the new entry
mr_q 0:d8f2f7d5f31b 411 * @return ERR_OK if succeeded or ERR_MEM on memory error
mr_q 0:d8f2f7d5f31b 412 */
mr_q 0:d8f2f7d5f31b 413 err_t
mr_q 0:d8f2f7d5f31b 414 dns_local_addhost(const char *hostname, const ip_addr_t *addr)
mr_q 0:d8f2f7d5f31b 415 {
mr_q 0:d8f2f7d5f31b 416 struct local_hostlist_entry *entry;
mr_q 0:d8f2f7d5f31b 417 size_t namelen;
mr_q 0:d8f2f7d5f31b 418 LWIP_ASSERT("invalid host name (NULL)", hostname != NULL);
mr_q 0:d8f2f7d5f31b 419 namelen = strlen(hostname);
mr_q 0:d8f2f7d5f31b 420 LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
mr_q 0:d8f2f7d5f31b 421 entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
mr_q 0:d8f2f7d5f31b 422 if (entry == NULL) {
mr_q 0:d8f2f7d5f31b 423 return ERR_MEM;
mr_q 0:d8f2f7d5f31b 424 }
mr_q 0:d8f2f7d5f31b 425 entry->name = (char*)entry + sizeof(struct local_hostlist_entry);
mr_q 0:d8f2f7d5f31b 426 MEMCPY((char*)entry->name, hostname, namelen);
mr_q 0:d8f2f7d5f31b 427 ((char*)entry->name)[namelen] = 0;
mr_q 0:d8f2f7d5f31b 428 ip_addr_copy(entry->addr, *addr);
mr_q 0:d8f2f7d5f31b 429 entry->next = local_hostlist_dynamic;
mr_q 0:d8f2f7d5f31b 430 local_hostlist_dynamic = entry;
mr_q 0:d8f2f7d5f31b 431 return ERR_OK;
mr_q 0:d8f2f7d5f31b 432 }
mr_q 0:d8f2f7d5f31b 433 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
mr_q 0:d8f2f7d5f31b 434 #endif /* DNS_LOCAL_HOSTLIST */
mr_q 0:d8f2f7d5f31b 435
mr_q 0:d8f2f7d5f31b 436 /**
mr_q 0:d8f2f7d5f31b 437 * Look up a hostname in the array of known hostnames.
mr_q 0:d8f2f7d5f31b 438 *
mr_q 0:d8f2f7d5f31b 439 * @note This function only looks in the internal array of known
mr_q 0:d8f2f7d5f31b 440 * hostnames, it does not send out a query for the hostname if none
mr_q 0:d8f2f7d5f31b 441 * was found. The function dns_enqueue() can be used to send a query
mr_q 0:d8f2f7d5f31b 442 * for a hostname.
mr_q 0:d8f2f7d5f31b 443 *
mr_q 0:d8f2f7d5f31b 444 * @param name the hostname to look up
mr_q 0:d8f2f7d5f31b 445 * @return the hostname's IP address, as u32_t (instead of ip_addr_t to
mr_q 0:d8f2f7d5f31b 446 * better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname
mr_q 0:d8f2f7d5f31b 447 * was not found in the cached dns_table.
mr_q 0:d8f2f7d5f31b 448 */
mr_q 0:d8f2f7d5f31b 449 static u32_t
mr_q 0:d8f2f7d5f31b 450 dns_lookup(const char *name)
mr_q 0:d8f2f7d5f31b 451 {
mr_q 0:d8f2f7d5f31b 452 u8_t i;
mr_q 0:d8f2f7d5f31b 453 #if DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN)
mr_q 0:d8f2f7d5f31b 454 u32_t addr;
mr_q 0:d8f2f7d5f31b 455 #endif /* DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN) */
mr_q 0:d8f2f7d5f31b 456 #if DNS_LOCAL_HOSTLIST
mr_q 0:d8f2f7d5f31b 457 if ((addr = dns_lookup_local(name)) != IPADDR_NONE) {
mr_q 0:d8f2f7d5f31b 458 return addr;
mr_q 0:d8f2f7d5f31b 459 }
mr_q 0:d8f2f7d5f31b 460 #endif /* DNS_LOCAL_HOSTLIST */
mr_q 0:d8f2f7d5f31b 461 #ifdef DNS_LOOKUP_LOCAL_EXTERN
mr_q 0:d8f2f7d5f31b 462 if((addr = DNS_LOOKUP_LOCAL_EXTERN(name)) != IPADDR_NONE) {
mr_q 0:d8f2f7d5f31b 463 return addr;
mr_q 0:d8f2f7d5f31b 464 }
mr_q 0:d8f2f7d5f31b 465 #endif /* DNS_LOOKUP_LOCAL_EXTERN */
mr_q 0:d8f2f7d5f31b 466
mr_q 0:d8f2f7d5f31b 467 /* Walk through name list, return entry if found. If not, return NULL. */
mr_q 0:d8f2f7d5f31b 468 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
mr_q 0:d8f2f7d5f31b 469 if ((dns_table[i].state == DNS_STATE_DONE) &&
mr_q 0:d8f2f7d5f31b 470 (strcmp(name, dns_table[i].name) == 0)) {
mr_q 0:d8f2f7d5f31b 471 LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
mr_q 0:d8f2f7d5f31b 472 ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr));
mr_q 0:d8f2f7d5f31b 473 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
mr_q 0:d8f2f7d5f31b 474 return ip4_addr_get_u32(&dns_table[i].ipaddr);
mr_q 0:d8f2f7d5f31b 475 }
mr_q 0:d8f2f7d5f31b 476 }
mr_q 0:d8f2f7d5f31b 477
mr_q 0:d8f2f7d5f31b 478 return IPADDR_NONE;
mr_q 0:d8f2f7d5f31b 479 }
mr_q 0:d8f2f7d5f31b 480
mr_q 0:d8f2f7d5f31b 481 #if DNS_DOES_NAME_CHECK
mr_q 0:d8f2f7d5f31b 482 /**
mr_q 0:d8f2f7d5f31b 483 * Compare the "dotted" name "query" with the encoded name "response"
mr_q 0:d8f2f7d5f31b 484 * to make sure an answer from the DNS server matches the current dns_table
mr_q 0:d8f2f7d5f31b 485 * entry (otherwise, answers might arrive late for hostname not on the list
mr_q 0:d8f2f7d5f31b 486 * any more).
mr_q 0:d8f2f7d5f31b 487 *
mr_q 0:d8f2f7d5f31b 488 * @param query hostname (not encoded) from the dns_table
mr_q 0:d8f2f7d5f31b 489 * @param response encoded hostname in the DNS response
mr_q 0:d8f2f7d5f31b 490 * @return 0: names equal; 1: names differ
mr_q 0:d8f2f7d5f31b 491 */
mr_q 0:d8f2f7d5f31b 492 static u8_t
mr_q 0:d8f2f7d5f31b 493 dns_compare_name(unsigned char *query, unsigned char *response)
mr_q 0:d8f2f7d5f31b 494 {
mr_q 0:d8f2f7d5f31b 495 unsigned char n;
mr_q 0:d8f2f7d5f31b 496
mr_q 0:d8f2f7d5f31b 497 do {
mr_q 0:d8f2f7d5f31b 498 n = *response++;
mr_q 0:d8f2f7d5f31b 499 /** @see RFC 1035 - 4.1.4. Message compression */
mr_q 0:d8f2f7d5f31b 500 if ((n & 0xc0) == 0xc0) {
mr_q 0:d8f2f7d5f31b 501 /* Compressed name */
mr_q 0:d8f2f7d5f31b 502 break;
mr_q 0:d8f2f7d5f31b 503 } else {
mr_q 0:d8f2f7d5f31b 504 /* Not compressed name */
mr_q 0:d8f2f7d5f31b 505 while (n > 0) {
mr_q 0:d8f2f7d5f31b 506 if ((*query) != (*response)) {
mr_q 0:d8f2f7d5f31b 507 return 1;
mr_q 0:d8f2f7d5f31b 508 }
mr_q 0:d8f2f7d5f31b 509 ++response;
mr_q 0:d8f2f7d5f31b 510 ++query;
mr_q 0:d8f2f7d5f31b 511 --n;
mr_q 0:d8f2f7d5f31b 512 };
mr_q 0:d8f2f7d5f31b 513 ++query;
mr_q 0:d8f2f7d5f31b 514 }
mr_q 0:d8f2f7d5f31b 515 } while (*response != 0);
mr_q 0:d8f2f7d5f31b 516
mr_q 0:d8f2f7d5f31b 517 return 0;
mr_q 0:d8f2f7d5f31b 518 }
mr_q 0:d8f2f7d5f31b 519 #endif /* DNS_DOES_NAME_CHECK */
mr_q 0:d8f2f7d5f31b 520
mr_q 0:d8f2f7d5f31b 521 /**
mr_q 0:d8f2f7d5f31b 522 * Walk through a compact encoded DNS name and return the end of the name.
mr_q 0:d8f2f7d5f31b 523 *
mr_q 0:d8f2f7d5f31b 524 * @param query encoded DNS name in the DNS server response
mr_q 0:d8f2f7d5f31b 525 * @return end of the name
mr_q 0:d8f2f7d5f31b 526 */
mr_q 0:d8f2f7d5f31b 527 static unsigned char *
mr_q 0:d8f2f7d5f31b 528 dns_parse_name(unsigned char *query)
mr_q 0:d8f2f7d5f31b 529 {
mr_q 0:d8f2f7d5f31b 530 unsigned char n;
mr_q 0:d8f2f7d5f31b 531
mr_q 0:d8f2f7d5f31b 532 do {
mr_q 0:d8f2f7d5f31b 533 n = *query++;
mr_q 0:d8f2f7d5f31b 534 /** @see RFC 1035 - 4.1.4. Message compression */
mr_q 0:d8f2f7d5f31b 535 if ((n & 0xc0) == 0xc0) {
mr_q 0:d8f2f7d5f31b 536 /* Compressed name */
mr_q 0:d8f2f7d5f31b 537 break;
mr_q 0:d8f2f7d5f31b 538 } else {
mr_q 0:d8f2f7d5f31b 539 /* Not compressed name */
mr_q 0:d8f2f7d5f31b 540 while (n > 0) {
mr_q 0:d8f2f7d5f31b 541 ++query;
mr_q 0:d8f2f7d5f31b 542 --n;
mr_q 0:d8f2f7d5f31b 543 };
mr_q 0:d8f2f7d5f31b 544 }
mr_q 0:d8f2f7d5f31b 545 } while (*query != 0);
mr_q 0:d8f2f7d5f31b 546
mr_q 0:d8f2f7d5f31b 547 return query + 1;
mr_q 0:d8f2f7d5f31b 548 }
mr_q 0:d8f2f7d5f31b 549
mr_q 0:d8f2f7d5f31b 550 /**
mr_q 0:d8f2f7d5f31b 551 * Send a DNS query packet.
mr_q 0:d8f2f7d5f31b 552 *
mr_q 0:d8f2f7d5f31b 553 * @param numdns index of the DNS server in the dns_servers table
mr_q 0:d8f2f7d5f31b 554 * @param name hostname to query
mr_q 0:d8f2f7d5f31b 555 * @param id index of the hostname in dns_table, used as transaction ID in the
mr_q 0:d8f2f7d5f31b 556 * DNS query packet
mr_q 0:d8f2f7d5f31b 557 * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
mr_q 0:d8f2f7d5f31b 558 */
mr_q 0:d8f2f7d5f31b 559 static err_t
mr_q 0:d8f2f7d5f31b 560 dns_send(u8_t numdns, const char* name, u8_t id)
mr_q 0:d8f2f7d5f31b 561 {
mr_q 0:d8f2f7d5f31b 562 err_t err;
mr_q 0:d8f2f7d5f31b 563 struct dns_hdr *hdr;
mr_q 0:d8f2f7d5f31b 564 struct dns_query qry;
mr_q 0:d8f2f7d5f31b 565 struct pbuf *p;
mr_q 0:d8f2f7d5f31b 566 char *query, *nptr;
mr_q 0:d8f2f7d5f31b 567 const char *pHostname;
mr_q 0:d8f2f7d5f31b 568 u8_t n;
mr_q 0:d8f2f7d5f31b 569
mr_q 0:d8f2f7d5f31b 570 LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
mr_q 0:d8f2f7d5f31b 571 (u16_t)(numdns), name));
mr_q 0:d8f2f7d5f31b 572 LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS);
mr_q 0:d8f2f7d5f31b 573 LWIP_ASSERT("dns server has no IP address set", !ip_addr_isany(&dns_servers[numdns]));
mr_q 0:d8f2f7d5f31b 574
mr_q 0:d8f2f7d5f31b 575 /* if here, we have either a new query or a retry on a previous query to process */
mr_q 0:d8f2f7d5f31b 576 p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
mr_q 0:d8f2f7d5f31b 577 SIZEOF_DNS_QUERY, PBUF_RAM);
mr_q 0:d8f2f7d5f31b 578 if (p != NULL) {
mr_q 0:d8f2f7d5f31b 579 LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
mr_q 0:d8f2f7d5f31b 580 /* fill dns header */
mr_q 0:d8f2f7d5f31b 581 hdr = (struct dns_hdr*)p->payload;
mr_q 0:d8f2f7d5f31b 582 memset(hdr, 0, SIZEOF_DNS_HDR);
mr_q 0:d8f2f7d5f31b 583 hdr->id = htons(id);
mr_q 0:d8f2f7d5f31b 584 hdr->flags1 = DNS_FLAG1_RD;
mr_q 0:d8f2f7d5f31b 585 hdr->numquestions = PP_HTONS(1);
mr_q 0:d8f2f7d5f31b 586 query = (char*)hdr + SIZEOF_DNS_HDR;
mr_q 0:d8f2f7d5f31b 587 pHostname = name;
mr_q 0:d8f2f7d5f31b 588 --pHostname;
mr_q 0:d8f2f7d5f31b 589
mr_q 0:d8f2f7d5f31b 590 /* convert hostname into suitable query format. */
mr_q 0:d8f2f7d5f31b 591 do {
mr_q 0:d8f2f7d5f31b 592 ++pHostname;
mr_q 0:d8f2f7d5f31b 593 nptr = query;
mr_q 0:d8f2f7d5f31b 594 ++query;
mr_q 0:d8f2f7d5f31b 595 for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
mr_q 0:d8f2f7d5f31b 596 *query = *pHostname;
mr_q 0:d8f2f7d5f31b 597 ++query;
mr_q 0:d8f2f7d5f31b 598 ++n;
mr_q 0:d8f2f7d5f31b 599 }
mr_q 0:d8f2f7d5f31b 600 *nptr = n;
mr_q 0:d8f2f7d5f31b 601 } while(*pHostname != 0);
mr_q 0:d8f2f7d5f31b 602 *query++='\0';
mr_q 0:d8f2f7d5f31b 603
mr_q 0:d8f2f7d5f31b 604 /* fill dns query */
mr_q 0:d8f2f7d5f31b 605 qry.type = PP_HTONS(DNS_RRTYPE_A);
mr_q 0:d8f2f7d5f31b 606 qry.cls = PP_HTONS(DNS_RRCLASS_IN);
mr_q 0:d8f2f7d5f31b 607 SMEMCPY(query, &qry, SIZEOF_DNS_QUERY);
mr_q 0:d8f2f7d5f31b 608
mr_q 0:d8f2f7d5f31b 609 /* resize pbuf to the exact dns query */
mr_q 0:d8f2f7d5f31b 610 pbuf_realloc(p, (u16_t)((query + SIZEOF_DNS_QUERY) - ((char*)(p->payload))));
mr_q 0:d8f2f7d5f31b 611
mr_q 0:d8f2f7d5f31b 612 /* connect to the server for faster receiving */
mr_q 0:d8f2f7d5f31b 613 udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
mr_q 0:d8f2f7d5f31b 614 /* send dns packet */
mr_q 0:d8f2f7d5f31b 615 err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT);
mr_q 0:d8f2f7d5f31b 616
mr_q 0:d8f2f7d5f31b 617 /* free pbuf */
mr_q 0:d8f2f7d5f31b 618 pbuf_free(p);
mr_q 0:d8f2f7d5f31b 619 } else {
mr_q 0:d8f2f7d5f31b 620 err = ERR_MEM;
mr_q 0:d8f2f7d5f31b 621 }
mr_q 0:d8f2f7d5f31b 622
mr_q 0:d8f2f7d5f31b 623 return err;
mr_q 0:d8f2f7d5f31b 624 }
mr_q 0:d8f2f7d5f31b 625
mr_q 0:d8f2f7d5f31b 626 /**
mr_q 0:d8f2f7d5f31b 627 * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query.
mr_q 0:d8f2f7d5f31b 628 * Check an entry in the dns_table:
mr_q 0:d8f2f7d5f31b 629 * - send out query for new entries
mr_q 0:d8f2f7d5f31b 630 * - retry old pending entries on timeout (also with different servers)
mr_q 0:d8f2f7d5f31b 631 * - remove completed entries from the table if their TTL has expired
mr_q 0:d8f2f7d5f31b 632 *
mr_q 0:d8f2f7d5f31b 633 * @param i index of the dns_table entry to check
mr_q 0:d8f2f7d5f31b 634 */
mr_q 0:d8f2f7d5f31b 635 static void
mr_q 0:d8f2f7d5f31b 636 dns_check_entry(u8_t i)
mr_q 0:d8f2f7d5f31b 637 {
mr_q 0:d8f2f7d5f31b 638 err_t err;
mr_q 0:d8f2f7d5f31b 639 struct dns_table_entry *pEntry = &dns_table[i];
mr_q 0:d8f2f7d5f31b 640
mr_q 0:d8f2f7d5f31b 641 LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
mr_q 0:d8f2f7d5f31b 642
mr_q 0:d8f2f7d5f31b 643 switch(pEntry->state) {
mr_q 0:d8f2f7d5f31b 644
mr_q 0:d8f2f7d5f31b 645 case DNS_STATE_NEW: {
mr_q 0:d8f2f7d5f31b 646 /* initialize new entry */
mr_q 0:d8f2f7d5f31b 647 pEntry->state = DNS_STATE_ASKING;
mr_q 0:d8f2f7d5f31b 648 pEntry->numdns = 0;
mr_q 0:d8f2f7d5f31b 649 pEntry->tmr = 1;
mr_q 0:d8f2f7d5f31b 650 pEntry->retries = 0;
mr_q 0:d8f2f7d5f31b 651
mr_q 0:d8f2f7d5f31b 652 /* send DNS packet for this entry */
mr_q 0:d8f2f7d5f31b 653 err = dns_send(pEntry->numdns, pEntry->name, i);
mr_q 0:d8f2f7d5f31b 654 if (err != ERR_OK) {
mr_q 0:d8f2f7d5f31b 655 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
mr_q 0:d8f2f7d5f31b 656 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
mr_q 0:d8f2f7d5f31b 657 }
mr_q 0:d8f2f7d5f31b 658 break;
mr_q 0:d8f2f7d5f31b 659 }
mr_q 0:d8f2f7d5f31b 660
mr_q 0:d8f2f7d5f31b 661 case DNS_STATE_ASKING: {
mr_q 0:d8f2f7d5f31b 662 if (--pEntry->tmr == 0) {
mr_q 0:d8f2f7d5f31b 663 if (++pEntry->retries == DNS_MAX_RETRIES) {
mr_q 0:d8f2f7d5f31b 664 if ((pEntry->numdns+1<DNS_MAX_SERVERS) && !ip_addr_isany(&dns_servers[pEntry->numdns+1])) {
mr_q 0:d8f2f7d5f31b 665 /* change of server */
mr_q 0:d8f2f7d5f31b 666 pEntry->numdns++;
mr_q 0:d8f2f7d5f31b 667 pEntry->tmr = 1;
mr_q 0:d8f2f7d5f31b 668 pEntry->retries = 0;
mr_q 0:d8f2f7d5f31b 669 break;
mr_q 0:d8f2f7d5f31b 670 } else {
mr_q 0:d8f2f7d5f31b 671 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name));
mr_q 0:d8f2f7d5f31b 672 /* call specified callback function if provided */
mr_q 0:d8f2f7d5f31b 673 if (pEntry->found)
mr_q 0:d8f2f7d5f31b 674 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
mr_q 0:d8f2f7d5f31b 675 /* flush this entry */
mr_q 0:d8f2f7d5f31b 676 pEntry->state = DNS_STATE_UNUSED;
mr_q 0:d8f2f7d5f31b 677 pEntry->found = NULL;
mr_q 0:d8f2f7d5f31b 678 break;
mr_q 0:d8f2f7d5f31b 679 }
mr_q 0:d8f2f7d5f31b 680 }
mr_q 0:d8f2f7d5f31b 681
mr_q 0:d8f2f7d5f31b 682 /* wait longer for the next retry */
mr_q 0:d8f2f7d5f31b 683 pEntry->tmr = pEntry->retries;
mr_q 0:d8f2f7d5f31b 684
mr_q 0:d8f2f7d5f31b 685 /* send DNS packet for this entry */
mr_q 0:d8f2f7d5f31b 686 err = dns_send(pEntry->numdns, pEntry->name, i);
mr_q 0:d8f2f7d5f31b 687 if (err != ERR_OK) {
mr_q 0:d8f2f7d5f31b 688 LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
mr_q 0:d8f2f7d5f31b 689 ("dns_send returned error: %d\n", err)); //FIX DG, lwip_strerr is part of lwip/api
mr_q 0:d8f2f7d5f31b 690 }
mr_q 0:d8f2f7d5f31b 691 }
mr_q 0:d8f2f7d5f31b 692 break;
mr_q 0:d8f2f7d5f31b 693 }
mr_q 0:d8f2f7d5f31b 694
mr_q 0:d8f2f7d5f31b 695 case DNS_STATE_DONE: {
mr_q 0:d8f2f7d5f31b 696 /* if the time to live is nul */
mr_q 0:d8f2f7d5f31b 697 if (--pEntry->ttl == 0) {
mr_q 0:d8f2f7d5f31b 698 LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name));
mr_q 0:d8f2f7d5f31b 699 /* flush this entry */
mr_q 0:d8f2f7d5f31b 700 pEntry->state = DNS_STATE_UNUSED;
mr_q 0:d8f2f7d5f31b 701 pEntry->found = NULL;
mr_q 0:d8f2f7d5f31b 702 }
mr_q 0:d8f2f7d5f31b 703 break;
mr_q 0:d8f2f7d5f31b 704 }
mr_q 0:d8f2f7d5f31b 705 case DNS_STATE_UNUSED:
mr_q 0:d8f2f7d5f31b 706 /* nothing to do */
mr_q 0:d8f2f7d5f31b 707 break;
mr_q 0:d8f2f7d5f31b 708 default:
mr_q 0:d8f2f7d5f31b 709 LWIP_ASSERT("unknown dns_table entry state:", 0);
mr_q 0:d8f2f7d5f31b 710 break;
mr_q 0:d8f2f7d5f31b 711 }
mr_q 0:d8f2f7d5f31b 712 }
mr_q 0:d8f2f7d5f31b 713
mr_q 0:d8f2f7d5f31b 714 /**
mr_q 0:d8f2f7d5f31b 715 * Call dns_check_entry for each entry in dns_table - check all entries.
mr_q 0:d8f2f7d5f31b 716 */
mr_q 0:d8f2f7d5f31b 717 static void
mr_q 0:d8f2f7d5f31b 718 dns_check_entries(void)
mr_q 0:d8f2f7d5f31b 719 {
mr_q 0:d8f2f7d5f31b 720 u8_t i;
mr_q 0:d8f2f7d5f31b 721
mr_q 0:d8f2f7d5f31b 722 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
mr_q 0:d8f2f7d5f31b 723 dns_check_entry(i);
mr_q 0:d8f2f7d5f31b 724 }
mr_q 0:d8f2f7d5f31b 725 }
mr_q 0:d8f2f7d5f31b 726
mr_q 0:d8f2f7d5f31b 727 /**
mr_q 0:d8f2f7d5f31b 728 * Receive input function for DNS response packets arriving for the dns UDP pcb.
mr_q 0:d8f2f7d5f31b 729 *
mr_q 0:d8f2f7d5f31b 730 * @params see udp.h
mr_q 0:d8f2f7d5f31b 731 */
mr_q 0:d8f2f7d5f31b 732 static void
mr_q 0:d8f2f7d5f31b 733 dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
mr_q 0:d8f2f7d5f31b 734 {
mr_q 0:d8f2f7d5f31b 735 u16_t i;
mr_q 0:d8f2f7d5f31b 736 char *pHostname;
mr_q 0:d8f2f7d5f31b 737 struct dns_hdr *hdr;
mr_q 0:d8f2f7d5f31b 738 struct dns_answer ans;
mr_q 0:d8f2f7d5f31b 739 struct dns_table_entry *pEntry;
mr_q 0:d8f2f7d5f31b 740 u16_t nquestions, nanswers;
mr_q 0:d8f2f7d5f31b 741
mr_q 0:d8f2f7d5f31b 742 LWIP_UNUSED_ARG(arg);
mr_q 0:d8f2f7d5f31b 743 LWIP_UNUSED_ARG(pcb);
mr_q 0:d8f2f7d5f31b 744 LWIP_UNUSED_ARG(addr);
mr_q 0:d8f2f7d5f31b 745 LWIP_UNUSED_ARG(port);
mr_q 0:d8f2f7d5f31b 746
mr_q 0:d8f2f7d5f31b 747 /* is the dns message too big ? */
mr_q 0:d8f2f7d5f31b 748 if (p->tot_len > DNS_MSG_SIZE) {
mr_q 0:d8f2f7d5f31b 749 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
mr_q 0:d8f2f7d5f31b 750 /* free pbuf and return */
mr_q 0:d8f2f7d5f31b 751 goto memerr;
mr_q 0:d8f2f7d5f31b 752 }
mr_q 0:d8f2f7d5f31b 753
mr_q 0:d8f2f7d5f31b 754 /* is the dns message big enough ? */
mr_q 0:d8f2f7d5f31b 755 if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
mr_q 0:d8f2f7d5f31b 756 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
mr_q 0:d8f2f7d5f31b 757 /* free pbuf and return */
mr_q 0:d8f2f7d5f31b 758 goto memerr;
mr_q 0:d8f2f7d5f31b 759 }
mr_q 0:d8f2f7d5f31b 760
mr_q 0:d8f2f7d5f31b 761 /* copy dns payload inside static buffer for processing */
mr_q 0:d8f2f7d5f31b 762 if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) {
mr_q 0:d8f2f7d5f31b 763 /* The ID in the DNS header should be our entry into the name table. */
mr_q 0:d8f2f7d5f31b 764 hdr = (struct dns_hdr*)dns_payload;
mr_q 0:d8f2f7d5f31b 765 i = htons(hdr->id);
mr_q 0:d8f2f7d5f31b 766 if (i < DNS_TABLE_SIZE) {
mr_q 0:d8f2f7d5f31b 767 pEntry = &dns_table[i];
mr_q 0:d8f2f7d5f31b 768 if(pEntry->state == DNS_STATE_ASKING) {
mr_q 0:d8f2f7d5f31b 769 /* This entry is now completed. */
mr_q 0:d8f2f7d5f31b 770 pEntry->state = DNS_STATE_DONE;
mr_q 0:d8f2f7d5f31b 771 pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK;
mr_q 0:d8f2f7d5f31b 772
mr_q 0:d8f2f7d5f31b 773 /* We only care about the question(s) and the answers. The authrr
mr_q 0:d8f2f7d5f31b 774 and the extrarr are simply discarded. */
mr_q 0:d8f2f7d5f31b 775 nquestions = htons(hdr->numquestions);
mr_q 0:d8f2f7d5f31b 776 nanswers = htons(hdr->numanswers);
mr_q 0:d8f2f7d5f31b 777
mr_q 0:d8f2f7d5f31b 778 /* Check for error. If so, call callback to inform. */
mr_q 0:d8f2f7d5f31b 779 if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) {
mr_q 0:d8f2f7d5f31b 780 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name));
mr_q 0:d8f2f7d5f31b 781 /* call callback to indicate error, clean up memory and return */
mr_q 0:d8f2f7d5f31b 782 goto responseerr;
mr_q 0:d8f2f7d5f31b 783 }
mr_q 0:d8f2f7d5f31b 784
mr_q 0:d8f2f7d5f31b 785 #if DNS_DOES_NAME_CHECK
mr_q 0:d8f2f7d5f31b 786 /* Check if the name in the "question" part match with the name in the entry. */
mr_q 0:d8f2f7d5f31b 787 if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) {
mr_q 0:d8f2f7d5f31b 788 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
mr_q 0:d8f2f7d5f31b 789 /* call callback to indicate error, clean up memory and return */
mr_q 0:d8f2f7d5f31b 790 goto responseerr;
mr_q 0:d8f2f7d5f31b 791 }
mr_q 0:d8f2f7d5f31b 792 #endif /* DNS_DOES_NAME_CHECK */
mr_q 0:d8f2f7d5f31b 793
mr_q 0:d8f2f7d5f31b 794 /* Skip the name in the "question" part */
mr_q 0:d8f2f7d5f31b 795 pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
mr_q 0:d8f2f7d5f31b 796
mr_q 0:d8f2f7d5f31b 797 while (nanswers > 0) {
mr_q 0:d8f2f7d5f31b 798 /* skip answer resource record's host name */
mr_q 0:d8f2f7d5f31b 799 pHostname = (char *) dns_parse_name((unsigned char *)pHostname);
mr_q 0:d8f2f7d5f31b 800
mr_q 0:d8f2f7d5f31b 801 /* Check for IP address type and Internet class. Others are discarded. */
mr_q 0:d8f2f7d5f31b 802 SMEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
mr_q 0:d8f2f7d5f31b 803 if((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) &&
mr_q 0:d8f2f7d5f31b 804 (ans.len == PP_HTONS(sizeof(ip_addr_t))) ) {
mr_q 0:d8f2f7d5f31b 805 /* read the answer resource record's TTL, and maximize it if needed */
mr_q 0:d8f2f7d5f31b 806 pEntry->ttl = ntohl(ans.ttl);
mr_q 0:d8f2f7d5f31b 807 if (pEntry->ttl > DNS_MAX_TTL) {
mr_q 0:d8f2f7d5f31b 808 pEntry->ttl = DNS_MAX_TTL;
mr_q 0:d8f2f7d5f31b 809 }
mr_q 0:d8f2f7d5f31b 810 /* read the IP address after answer resource record's header */
mr_q 0:d8f2f7d5f31b 811 SMEMCPY(&(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(ip_addr_t));
mr_q 0:d8f2f7d5f31b 812 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
mr_q 0:d8f2f7d5f31b 813 ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
mr_q 0:d8f2f7d5f31b 814 LWIP_DEBUGF(DNS_DEBUG, ("\n"));
mr_q 0:d8f2f7d5f31b 815 /* call specified callback function if provided */
mr_q 0:d8f2f7d5f31b 816 if (pEntry->found) {
mr_q 0:d8f2f7d5f31b 817 (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg);
mr_q 0:d8f2f7d5f31b 818 }
mr_q 0:d8f2f7d5f31b 819 /* deallocate memory and return */
mr_q 0:d8f2f7d5f31b 820 goto memerr;
mr_q 0:d8f2f7d5f31b 821 } else {
mr_q 0:d8f2f7d5f31b 822 pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
mr_q 0:d8f2f7d5f31b 823 }
mr_q 0:d8f2f7d5f31b 824 --nanswers;
mr_q 0:d8f2f7d5f31b 825 }
mr_q 0:d8f2f7d5f31b 826 LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name));
mr_q 0:d8f2f7d5f31b 827 /* call callback to indicate error, clean up memory and return */
mr_q 0:d8f2f7d5f31b 828 goto responseerr;
mr_q 0:d8f2f7d5f31b 829 }
mr_q 0:d8f2f7d5f31b 830 }
mr_q 0:d8f2f7d5f31b 831 }
mr_q 0:d8f2f7d5f31b 832
mr_q 0:d8f2f7d5f31b 833 /* deallocate memory and return */
mr_q 0:d8f2f7d5f31b 834 goto memerr;
mr_q 0:d8f2f7d5f31b 835
mr_q 0:d8f2f7d5f31b 836 responseerr:
mr_q 0:d8f2f7d5f31b 837 /* ERROR: call specified callback function with NULL as name to indicate an error */
mr_q 0:d8f2f7d5f31b 838 if (pEntry->found) {
mr_q 0:d8f2f7d5f31b 839 (*pEntry->found)(pEntry->name, NULL, pEntry->arg);
mr_q 0:d8f2f7d5f31b 840 }
mr_q 0:d8f2f7d5f31b 841 /* flush this entry */
mr_q 0:d8f2f7d5f31b 842 pEntry->state = DNS_STATE_UNUSED;
mr_q 0:d8f2f7d5f31b 843 pEntry->found = NULL;
mr_q 0:d8f2f7d5f31b 844
mr_q 0:d8f2f7d5f31b 845 memerr:
mr_q 0:d8f2f7d5f31b 846 /* free pbuf */
mr_q 0:d8f2f7d5f31b 847 pbuf_free(p);
mr_q 0:d8f2f7d5f31b 848 return;
mr_q 0:d8f2f7d5f31b 849 }
mr_q 0:d8f2f7d5f31b 850
mr_q 0:d8f2f7d5f31b 851 /**
mr_q 0:d8f2f7d5f31b 852 * Queues a new hostname to resolve and sends out a DNS query for that hostname
mr_q 0:d8f2f7d5f31b 853 *
mr_q 0:d8f2f7d5f31b 854 * @param name the hostname that is to be queried
mr_q 0:d8f2f7d5f31b 855 * @param found a callback founction to be called on success, failure or timeout
mr_q 0:d8f2f7d5f31b 856 * @param callback_arg argument to pass to the callback function
mr_q 0:d8f2f7d5f31b 857 * @return @return a err_t return code.
mr_q 0:d8f2f7d5f31b 858 */
mr_q 0:d8f2f7d5f31b 859 static err_t
mr_q 0:d8f2f7d5f31b 860 dns_enqueue(const char *name, dns_found_callback found, void *callback_arg)
mr_q 0:d8f2f7d5f31b 861 {
mr_q 0:d8f2f7d5f31b 862 u8_t i;
mr_q 0:d8f2f7d5f31b 863 u8_t lseq, lseqi;
mr_q 0:d8f2f7d5f31b 864 struct dns_table_entry *pEntry = NULL;
mr_q 0:d8f2f7d5f31b 865 size_t namelen;
mr_q 0:d8f2f7d5f31b 866
mr_q 0:d8f2f7d5f31b 867 /* search an unused entry, or the oldest one */
mr_q 0:d8f2f7d5f31b 868 lseq = lseqi = 0;
mr_q 0:d8f2f7d5f31b 869 for (i = 0; i < DNS_TABLE_SIZE; ++i) {
mr_q 0:d8f2f7d5f31b 870 pEntry = &dns_table[i];
mr_q 0:d8f2f7d5f31b 871 /* is it an unused entry ? */
mr_q 0:d8f2f7d5f31b 872 if (pEntry->state == DNS_STATE_UNUSED)
mr_q 0:d8f2f7d5f31b 873 break;
mr_q 0:d8f2f7d5f31b 874
mr_q 0:d8f2f7d5f31b 875 /* check if this is the oldest completed entry */
mr_q 0:d8f2f7d5f31b 876 if (pEntry->state == DNS_STATE_DONE) {
mr_q 0:d8f2f7d5f31b 877 if ((dns_seqno - pEntry->seqno) > lseq) {
mr_q 0:d8f2f7d5f31b 878 lseq = dns_seqno - pEntry->seqno;
mr_q 0:d8f2f7d5f31b 879 lseqi = i;
mr_q 0:d8f2f7d5f31b 880 }
mr_q 0:d8f2f7d5f31b 881 }
mr_q 0:d8f2f7d5f31b 882 }
mr_q 0:d8f2f7d5f31b 883
mr_q 0:d8f2f7d5f31b 884 /* if we don't have found an unused entry, use the oldest completed one */
mr_q 0:d8f2f7d5f31b 885 if (i == DNS_TABLE_SIZE) {
mr_q 0:d8f2f7d5f31b 886 if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) {
mr_q 0:d8f2f7d5f31b 887 /* no entry can't be used now, table is full */
mr_q 0:d8f2f7d5f31b 888 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
mr_q 0:d8f2f7d5f31b 889 return ERR_MEM;
mr_q 0:d8f2f7d5f31b 890 } else {
mr_q 0:d8f2f7d5f31b 891 /* use the oldest completed one */
mr_q 0:d8f2f7d5f31b 892 i = lseqi;
mr_q 0:d8f2f7d5f31b 893 pEntry = &dns_table[i];
mr_q 0:d8f2f7d5f31b 894 }
mr_q 0:d8f2f7d5f31b 895 }
mr_q 0:d8f2f7d5f31b 896
mr_q 0:d8f2f7d5f31b 897 /* use this entry */
mr_q 0:d8f2f7d5f31b 898 LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
mr_q 0:d8f2f7d5f31b 899
mr_q 0:d8f2f7d5f31b 900 /* fill the entry */
mr_q 0:d8f2f7d5f31b 901 pEntry->state = DNS_STATE_NEW;
mr_q 0:d8f2f7d5f31b 902 pEntry->seqno = dns_seqno++;
mr_q 0:d8f2f7d5f31b 903 pEntry->found = found;
mr_q 0:d8f2f7d5f31b 904 pEntry->arg = callback_arg;
mr_q 0:d8f2f7d5f31b 905 namelen = LWIP_MIN(strlen(name), DNS_MAX_NAME_LENGTH-1);
mr_q 0:d8f2f7d5f31b 906 MEMCPY(pEntry->name, name, namelen);
mr_q 0:d8f2f7d5f31b 907 pEntry->name[namelen] = 0;
mr_q 0:d8f2f7d5f31b 908
mr_q 0:d8f2f7d5f31b 909 /* force to send query without waiting timer */
mr_q 0:d8f2f7d5f31b 910 dns_check_entry(i);
mr_q 0:d8f2f7d5f31b 911
mr_q 0:d8f2f7d5f31b 912 /* dns query is enqueued */
mr_q 0:d8f2f7d5f31b 913 return ERR_INPROGRESS;
mr_q 0:d8f2f7d5f31b 914 }
mr_q 0:d8f2f7d5f31b 915
mr_q 0:d8f2f7d5f31b 916 /**
mr_q 0:d8f2f7d5f31b 917 * Resolve a hostname (string) into an IP address.
mr_q 0:d8f2f7d5f31b 918 * NON-BLOCKING callback version for use with raw API!!!
mr_q 0:d8f2f7d5f31b 919 *
mr_q 0:d8f2f7d5f31b 920 * Returns immediately with one of err_t return codes:
mr_q 0:d8f2f7d5f31b 921 * - ERR_OK if hostname is a valid IP address string or the host
mr_q 0:d8f2f7d5f31b 922 * name is already in the local names table.
mr_q 0:d8f2f7d5f31b 923 * - ERR_INPROGRESS enqueue a request to be sent to the DNS server
mr_q 0:d8f2f7d5f31b 924 * for resolution if no errors are present.
mr_q 0:d8f2f7d5f31b 925 *
mr_q 0:d8f2f7d5f31b 926 * @param hostname the hostname that is to be queried
mr_q 0:d8f2f7d5f31b 927 * @param addr pointer to a ip_addr_t where to store the address if it is already
mr_q 0:d8f2f7d5f31b 928 * cached in the dns_table (only valid if ERR_OK is returned!)
mr_q 0:d8f2f7d5f31b 929 * @param found a callback function to be called on success, failure or timeout (only if
mr_q 0:d8f2f7d5f31b 930 * ERR_INPROGRESS is returned!)
mr_q 0:d8f2f7d5f31b 931 * @param callback_arg argument to pass to the callback function
mr_q 0:d8f2f7d5f31b 932 * @return a err_t return code.
mr_q 0:d8f2f7d5f31b 933 */
mr_q 0:d8f2f7d5f31b 934 err_t
mr_q 0:d8f2f7d5f31b 935 dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found,
mr_q 0:d8f2f7d5f31b 936 void *callback_arg)
mr_q 0:d8f2f7d5f31b 937 {
mr_q 0:d8f2f7d5f31b 938 u32_t ipaddr;
mr_q 0:d8f2f7d5f31b 939 /* not initialized or no valid server yet, or invalid addr pointer
mr_q 0:d8f2f7d5f31b 940 * or invalid hostname or invalid hostname length */
mr_q 0:d8f2f7d5f31b 941 if ((dns_pcb == NULL) || (addr == NULL) ||
mr_q 0:d8f2f7d5f31b 942 (!hostname) || (!hostname[0]) ||
mr_q 0:d8f2f7d5f31b 943 (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) {
mr_q 0:d8f2f7d5f31b 944 return ERR_VAL;
mr_q 0:d8f2f7d5f31b 945 }
mr_q 0:d8f2f7d5f31b 946
mr_q 0:d8f2f7d5f31b 947 #if LWIP_HAVE_LOOPIF
mr_q 0:d8f2f7d5f31b 948 if (strcmp(hostname, "localhost")==0) {
mr_q 0:d8f2f7d5f31b 949 ip_addr_set_loopback(addr);
mr_q 0:d8f2f7d5f31b 950 return ERR_OK;
mr_q 0:d8f2f7d5f31b 951 }
mr_q 0:d8f2f7d5f31b 952 #endif /* LWIP_HAVE_LOOPIF */
mr_q 0:d8f2f7d5f31b 953
mr_q 0:d8f2f7d5f31b 954 /* host name already in octet notation? set ip addr and return ERR_OK */
mr_q 0:d8f2f7d5f31b 955 ipaddr = ipaddr_addr(hostname);
mr_q 0:d8f2f7d5f31b 956 if (ipaddr == IPADDR_NONE) {
mr_q 0:d8f2f7d5f31b 957 /* already have this address cached? */
mr_q 0:d8f2f7d5f31b 958 ipaddr = dns_lookup(hostname);
mr_q 0:d8f2f7d5f31b 959 }
mr_q 0:d8f2f7d5f31b 960 if (ipaddr != IPADDR_NONE) {
mr_q 0:d8f2f7d5f31b 961 ip4_addr_set_u32(addr, ipaddr);
mr_q 0:d8f2f7d5f31b 962 return ERR_OK;
mr_q 0:d8f2f7d5f31b 963 }
mr_q 0:d8f2f7d5f31b 964
mr_q 0:d8f2f7d5f31b 965 /* queue query with specified callback */
mr_q 0:d8f2f7d5f31b 966 return dns_enqueue(hostname, found, callback_arg);
mr_q 0:d8f2f7d5f31b 967 }
mr_q 0:d8f2f7d5f31b 968
mr_q 0:d8f2f7d5f31b 969 #endif /* LWIP_DNS */