Donatien Garnier
/
ZG2100NetIfSource
Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
lwip/core/dns.c@0:b802fc31f1db, 2010-07-09 (annotated)
- Committer:
- donatien
- Date:
- Fri Jul 09 15:37:23 2010 +0000
- Revision:
- 0:b802fc31f1db
- Child:
- 1:3a7c15057192
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| donatien | 0:b802fc31f1db | 1 | /** |
| donatien | 0:b802fc31f1db | 2 | * @file |
| donatien | 0:b802fc31f1db | 3 | * DNS - host name to IP address resolver. |
| donatien | 0:b802fc31f1db | 4 | * |
| donatien | 0:b802fc31f1db | 5 | */ |
| donatien | 0:b802fc31f1db | 6 | |
| donatien | 0:b802fc31f1db | 7 | /** |
| donatien | 0:b802fc31f1db | 8 | |
| donatien | 0:b802fc31f1db | 9 | * This file implements a DNS host name to IP address resolver. |
| donatien | 0:b802fc31f1db | 10 | |
| donatien | 0:b802fc31f1db | 11 | * Port to lwIP from uIP |
| donatien | 0:b802fc31f1db | 12 | * by Jim Pettinato April 2007 |
| donatien | 0:b802fc31f1db | 13 | |
| donatien | 0:b802fc31f1db | 14 | * uIP version Copyright (c) 2002-2003, Adam Dunkels. |
| donatien | 0:b802fc31f1db | 15 | * All rights reserved. |
| donatien | 0:b802fc31f1db | 16 | * |
| donatien | 0:b802fc31f1db | 17 | * Redistribution and use in source and binary forms, with or without |
| donatien | 0:b802fc31f1db | 18 | * modification, are permitted provided that the following conditions |
| donatien | 0:b802fc31f1db | 19 | * are met: |
| donatien | 0:b802fc31f1db | 20 | * 1. Redistributions of source code must retain the above copyright |
| donatien | 0:b802fc31f1db | 21 | * notice, this list of conditions and the following disclaimer. |
| donatien | 0:b802fc31f1db | 22 | * 2. Redistributions in binary form must reproduce the above copyright |
| donatien | 0:b802fc31f1db | 23 | * notice, this list of conditions and the following disclaimer in the |
| donatien | 0:b802fc31f1db | 24 | * documentation and/or other materials provided with the distribution. |
| donatien | 0:b802fc31f1db | 25 | * 3. The name of the author may not be used to endorse or promote |
| donatien | 0:b802fc31f1db | 26 | * products derived from this software without specific prior |
| donatien | 0:b802fc31f1db | 27 | * written permission. |
| donatien | 0:b802fc31f1db | 28 | * |
| donatien | 0:b802fc31f1db | 29 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
| donatien | 0:b802fc31f1db | 30 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| donatien | 0:b802fc31f1db | 31 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| donatien | 0:b802fc31f1db | 32 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| donatien | 0:b802fc31f1db | 33 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| donatien | 0:b802fc31f1db | 34 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE |
| donatien | 0:b802fc31f1db | 35 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| donatien | 0:b802fc31f1db | 36 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| donatien | 0:b802fc31f1db | 37 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| donatien | 0:b802fc31f1db | 38 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| donatien | 0:b802fc31f1db | 39 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| donatien | 0:b802fc31f1db | 40 | * |
| donatien | 0:b802fc31f1db | 41 | * |
| donatien | 0:b802fc31f1db | 42 | * DNS.C |
| donatien | 0:b802fc31f1db | 43 | * |
| donatien | 0:b802fc31f1db | 44 | * The lwIP DNS resolver functions are used to lookup a host name and |
| donatien | 0:b802fc31f1db | 45 | * map it to a numerical IP address. It maintains a list of resolved |
| donatien | 0:b802fc31f1db | 46 | * hostnames that can be queried with the dns_lookup() function. |
| donatien | 0:b802fc31f1db | 47 | * New hostnames can be resolved using the dns_query() function. |
| donatien | 0:b802fc31f1db | 48 | * |
| donatien | 0:b802fc31f1db | 49 | * The lwIP version of the resolver also adds a non-blocking version of |
| donatien | 0:b802fc31f1db | 50 | * gethostbyname() that will work with a raw API application. This function |
| donatien | 0:b802fc31f1db | 51 | * checks for an IP address string first and converts it if it is valid. |
| donatien | 0:b802fc31f1db | 52 | * gethostbyname() then does a dns_lookup() to see if the name is |
| donatien | 0:b802fc31f1db | 53 | * already in the table. If so, the IP is returned. If not, a query is |
| donatien | 0:b802fc31f1db | 54 | * issued and the function returns with a ERR_INPROGRESS status. The app |
| donatien | 0:b802fc31f1db | 55 | * using the dns client must then go into a waiting state. |
| donatien | 0:b802fc31f1db | 56 | * |
| donatien | 0:b802fc31f1db | 57 | * Once a hostname has been resolved (or found to be non-existent), |
| donatien | 0:b802fc31f1db | 58 | * the resolver code calls a specified callback function (which |
| donatien | 0:b802fc31f1db | 59 | * must be implemented by the module that uses the resolver). |
| donatien | 0:b802fc31f1db | 60 | */ |
| donatien | 0:b802fc31f1db | 61 | |
| donatien | 0:b802fc31f1db | 62 | /*----------------------------------------------------------------------------- |
| donatien | 0:b802fc31f1db | 63 | * RFC 1035 - Domain names - implementation and specification |
| donatien | 0:b802fc31f1db | 64 | * RFC 2181 - Clarifications to the DNS Specification |
| donatien | 0:b802fc31f1db | 65 | *----------------------------------------------------------------------------*/ |
| donatien | 0:b802fc31f1db | 66 | |
| donatien | 0:b802fc31f1db | 67 | /** @todo: define good default values (rfc compliance) */ |
| donatien | 0:b802fc31f1db | 68 | /** @todo: improve answer parsing, more checkings... */ |
| donatien | 0:b802fc31f1db | 69 | /** @todo: check RFC1035 - 7.3. Processing responses */ |
| donatien | 0:b802fc31f1db | 70 | |
| donatien | 0:b802fc31f1db | 71 | /*----------------------------------------------------------------------------- |
| donatien | 0:b802fc31f1db | 72 | * Includes |
| donatien | 0:b802fc31f1db | 73 | *----------------------------------------------------------------------------*/ |
| donatien | 0:b802fc31f1db | 74 | |
| donatien | 0:b802fc31f1db | 75 | #include "lwip/opt.h" |
| donatien | 0:b802fc31f1db | 76 | |
| donatien | 0:b802fc31f1db | 77 | #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */ |
| donatien | 0:b802fc31f1db | 78 | |
| donatien | 0:b802fc31f1db | 79 | #include "lwip/udp.h" |
| donatien | 0:b802fc31f1db | 80 | #include "lwip/mem.h" |
| donatien | 0:b802fc31f1db | 81 | #include "lwip/memp.h" |
| donatien | 0:b802fc31f1db | 82 | #include "lwip/dns.h" |
| donatien | 0:b802fc31f1db | 83 | #include "lwip/debug.h" |
| donatien | 0:b802fc31f1db | 84 | |
| donatien | 0:b802fc31f1db | 85 | #include <string.h> |
| donatien | 0:b802fc31f1db | 86 | |
| donatien | 0:b802fc31f1db | 87 | /** DNS server IP address */ |
| donatien | 0:b802fc31f1db | 88 | #ifndef DNS_SERVER_ADDRESS |
| donatien | 0:b802fc31f1db | 89 | #define DNS_SERVER_ADDRESS(ipaddr) (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */ |
| donatien | 0:b802fc31f1db | 90 | #endif |
| donatien | 0:b802fc31f1db | 91 | |
| donatien | 0:b802fc31f1db | 92 | /** DNS server port address */ |
| donatien | 0:b802fc31f1db | 93 | #ifndef DNS_SERVER_PORT |
| donatien | 0:b802fc31f1db | 94 | #define DNS_SERVER_PORT 53 |
| donatien | 0:b802fc31f1db | 95 | #endif |
| donatien | 0:b802fc31f1db | 96 | |
| donatien | 0:b802fc31f1db | 97 | /** DNS maximum number of retries when asking for a name, before "timeout". */ |
| donatien | 0:b802fc31f1db | 98 | #ifndef DNS_MAX_RETRIES |
| donatien | 0:b802fc31f1db | 99 | #define DNS_MAX_RETRIES 4 |
| donatien | 0:b802fc31f1db | 100 | #endif |
| donatien | 0:b802fc31f1db | 101 | |
| donatien | 0:b802fc31f1db | 102 | /** DNS resource record max. TTL (one week as default) */ |
| donatien | 0:b802fc31f1db | 103 | #ifndef DNS_MAX_TTL |
| donatien | 0:b802fc31f1db | 104 | #define DNS_MAX_TTL 604800 |
| donatien | 0:b802fc31f1db | 105 | #endif |
| donatien | 0:b802fc31f1db | 106 | |
| donatien | 0:b802fc31f1db | 107 | /* DNS protocol flags */ |
| donatien | 0:b802fc31f1db | 108 | #define DNS_FLAG1_RESPONSE 0x80 |
| donatien | 0:b802fc31f1db | 109 | #define DNS_FLAG1_OPCODE_STATUS 0x10 |
| donatien | 0:b802fc31f1db | 110 | #define DNS_FLAG1_OPCODE_INVERSE 0x08 |
| donatien | 0:b802fc31f1db | 111 | #define DNS_FLAG1_OPCODE_STANDARD 0x00 |
| donatien | 0:b802fc31f1db | 112 | #define DNS_FLAG1_AUTHORATIVE 0x04 |
| donatien | 0:b802fc31f1db | 113 | #define DNS_FLAG1_TRUNC 0x02 |
| donatien | 0:b802fc31f1db | 114 | #define DNS_FLAG1_RD 0x01 |
| donatien | 0:b802fc31f1db | 115 | #define DNS_FLAG2_RA 0x80 |
| donatien | 0:b802fc31f1db | 116 | #define DNS_FLAG2_ERR_MASK 0x0f |
| donatien | 0:b802fc31f1db | 117 | #define DNS_FLAG2_ERR_NONE 0x00 |
| donatien | 0:b802fc31f1db | 118 | #define DNS_FLAG2_ERR_NAME 0x03 |
| donatien | 0:b802fc31f1db | 119 | |
| donatien | 0:b802fc31f1db | 120 | /* DNS protocol states */ |
| donatien | 0:b802fc31f1db | 121 | #define DNS_STATE_UNUSED 0 |
| donatien | 0:b802fc31f1db | 122 | #define DNS_STATE_NEW 1 |
| donatien | 0:b802fc31f1db | 123 | #define DNS_STATE_ASKING 2 |
| donatien | 0:b802fc31f1db | 124 | #define DNS_STATE_DONE 3 |
| donatien | 0:b802fc31f1db | 125 | |
| donatien | 0:b802fc31f1db | 126 | #ifdef PACK_STRUCT_USE_INCLUDES |
| donatien | 0:b802fc31f1db | 127 | # include "arch/bpstruct.h" |
| donatien | 0:b802fc31f1db | 128 | #endif |
| donatien | 0:b802fc31f1db | 129 | PACK_STRUCT_BEGIN |
| donatien | 0:b802fc31f1db | 130 | /** DNS message header */ |
| donatien | 0:b802fc31f1db | 131 | struct dns_hdr { |
| donatien | 0:b802fc31f1db | 132 | PACK_STRUCT_FIELD(u16_t id); |
| donatien | 0:b802fc31f1db | 133 | PACK_STRUCT_FIELD(u8_t flags1); |
| donatien | 0:b802fc31f1db | 134 | PACK_STRUCT_FIELD(u8_t flags2); |
| donatien | 0:b802fc31f1db | 135 | PACK_STRUCT_FIELD(u16_t numquestions); |
| donatien | 0:b802fc31f1db | 136 | PACK_STRUCT_FIELD(u16_t numanswers); |
| donatien | 0:b802fc31f1db | 137 | PACK_STRUCT_FIELD(u16_t numauthrr); |
| donatien | 0:b802fc31f1db | 138 | PACK_STRUCT_FIELD(u16_t numextrarr); |
| donatien | 0:b802fc31f1db | 139 | } PACK_STRUCT_STRUCT; |
| donatien | 0:b802fc31f1db | 140 | PACK_STRUCT_END |
| donatien | 0:b802fc31f1db | 141 | #ifdef PACK_STRUCT_USE_INCLUDES |
| donatien | 0:b802fc31f1db | 142 | # include "arch/epstruct.h" |
| donatien | 0:b802fc31f1db | 143 | #endif |
| donatien | 0:b802fc31f1db | 144 | #define SIZEOF_DNS_HDR 12 |
| donatien | 0:b802fc31f1db | 145 | |
| donatien | 0:b802fc31f1db | 146 | /** DNS query message structure. |
| donatien | 0:b802fc31f1db | 147 | No packing needed: only used locally on the stack. */ |
| donatien | 0:b802fc31f1db | 148 | struct dns_query { |
| donatien | 0:b802fc31f1db | 149 | /* DNS query record starts with either a domain name or a pointer |
| donatien | 0:b802fc31f1db | 150 | to a name already present somewhere in the packet. */ |
| donatien | 0:b802fc31f1db | 151 | u16_t type; |
| donatien | 0:b802fc31f1db | 152 | u16_t cls; |
| donatien | 0:b802fc31f1db | 153 | }; |
| donatien | 0:b802fc31f1db | 154 | #define SIZEOF_DNS_QUERY 4 |
| donatien | 0:b802fc31f1db | 155 | |
| donatien | 0:b802fc31f1db | 156 | /** DNS answer message structure. |
| donatien | 0:b802fc31f1db | 157 | No packing needed: only used locally on the stack. */ |
| donatien | 0:b802fc31f1db | 158 | struct dns_answer { |
| donatien | 0:b802fc31f1db | 159 | /* DNS answer record starts with either a domain name or a pointer |
| donatien | 0:b802fc31f1db | 160 | to a name already present somewhere in the packet. */ |
| donatien | 0:b802fc31f1db | 161 | u16_t type; |
| donatien | 0:b802fc31f1db | 162 | u16_t cls; |
| donatien | 0:b802fc31f1db | 163 | u32_t ttl; |
| donatien | 0:b802fc31f1db | 164 | u16_t len; |
| donatien | 0:b802fc31f1db | 165 | }; |
| donatien | 0:b802fc31f1db | 166 | #define SIZEOF_DNS_ANSWER 10 |
| donatien | 0:b802fc31f1db | 167 | |
| donatien | 0:b802fc31f1db | 168 | /** DNS table entry */ |
| donatien | 0:b802fc31f1db | 169 | struct dns_table_entry { |
| donatien | 0:b802fc31f1db | 170 | u8_t state; |
| donatien | 0:b802fc31f1db | 171 | u8_t numdns; |
| donatien | 0:b802fc31f1db | 172 | u8_t tmr; |
| donatien | 0:b802fc31f1db | 173 | u8_t retries; |
| donatien | 0:b802fc31f1db | 174 | u8_t seqno; |
| donatien | 0:b802fc31f1db | 175 | u8_t err; |
| donatien | 0:b802fc31f1db | 176 | u32_t ttl; |
| donatien | 0:b802fc31f1db | 177 | char name[DNS_MAX_NAME_LENGTH]; |
| donatien | 0:b802fc31f1db | 178 | ip_addr_t ipaddr; |
| donatien | 0:b802fc31f1db | 179 | /* pointer to callback on DNS query done */ |
| donatien | 0:b802fc31f1db | 180 | dns_found_callback found; |
| donatien | 0:b802fc31f1db | 181 | void *arg; |
| donatien | 0:b802fc31f1db | 182 | }; |
| donatien | 0:b802fc31f1db | 183 | |
| donatien | 0:b802fc31f1db | 184 | #if DNS_LOCAL_HOSTLIST |
| donatien | 0:b802fc31f1db | 185 | |
| donatien | 0:b802fc31f1db | 186 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
| donatien | 0:b802fc31f1db | 187 | /** Local host-list. For hostnames in this list, no |
| donatien | 0:b802fc31f1db | 188 | * external name resolution is performed */ |
| donatien | 0:b802fc31f1db | 189 | static struct local_hostlist_entry *local_hostlist_dynamic; |
| donatien | 0:b802fc31f1db | 190 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
| donatien | 0:b802fc31f1db | 191 | |
| donatien | 0:b802fc31f1db | 192 | /** Defining this allows the local_hostlist_static to be placed in a different |
| donatien | 0:b802fc31f1db | 193 | * linker section (e.g. FLASH) */ |
| donatien | 0:b802fc31f1db | 194 | #ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE |
| donatien | 0:b802fc31f1db | 195 | #define DNS_LOCAL_HOSTLIST_STORAGE_PRE static |
| donatien | 0:b802fc31f1db | 196 | #endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */ |
| donatien | 0:b802fc31f1db | 197 | /** Defining this allows the local_hostlist_static to be placed in a different |
| donatien | 0:b802fc31f1db | 198 | * linker section (e.g. FLASH) */ |
| donatien | 0:b802fc31f1db | 199 | #ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST |
| donatien | 0:b802fc31f1db | 200 | #define DNS_LOCAL_HOSTLIST_STORAGE_POST |
| donatien | 0:b802fc31f1db | 201 | #endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */ |
| donatien | 0:b802fc31f1db | 202 | DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[] |
| donatien | 0:b802fc31f1db | 203 | DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT; |
| donatien | 0:b802fc31f1db | 204 | |
| donatien | 0:b802fc31f1db | 205 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
| donatien | 0:b802fc31f1db | 206 | |
| donatien | 0:b802fc31f1db | 207 | static void dns_init_local(); |
| donatien | 0:b802fc31f1db | 208 | #endif /* DNS_LOCAL_HOSTLIST */ |
| donatien | 0:b802fc31f1db | 209 | |
| donatien | 0:b802fc31f1db | 210 | |
| donatien | 0:b802fc31f1db | 211 | /* forward declarations */ |
| donatien | 0:b802fc31f1db | 212 | static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); |
| donatien | 0:b802fc31f1db | 213 | static void dns_check_entries(void); |
| donatien | 0:b802fc31f1db | 214 | |
| donatien | 0:b802fc31f1db | 215 | /*----------------------------------------------------------------------------- |
| donatien | 0:b802fc31f1db | 216 | * Globales |
| donatien | 0:b802fc31f1db | 217 | *----------------------------------------------------------------------------*/ |
| donatien | 0:b802fc31f1db | 218 | |
| donatien | 0:b802fc31f1db | 219 | /* DNS variables */ |
| donatien | 0:b802fc31f1db | 220 | static struct udp_pcb *dns_pcb; |
| donatien | 0:b802fc31f1db | 221 | static u8_t dns_seqno; |
| donatien | 0:b802fc31f1db | 222 | static struct dns_table_entry dns_table[DNS_TABLE_SIZE]; |
| donatien | 0:b802fc31f1db | 223 | static ip_addr_t dns_servers[DNS_MAX_SERVERS]; |
| donatien | 0:b802fc31f1db | 224 | /** Contiguous buffer for processing responses */ |
| donatien | 0:b802fc31f1db | 225 | static u8_t dns_payload_buffer[LWIP_MEM_ALIGN_BUFFER(DNS_MSG_SIZE)]; |
| donatien | 0:b802fc31f1db | 226 | static u8_t* dns_payload; |
| donatien | 0:b802fc31f1db | 227 | |
| donatien | 0:b802fc31f1db | 228 | /** |
| donatien | 0:b802fc31f1db | 229 | * Initialize the resolver: set up the UDP pcb and configure the default server |
| donatien | 0:b802fc31f1db | 230 | * (DNS_SERVER_ADDRESS). |
| donatien | 0:b802fc31f1db | 231 | */ |
| donatien | 0:b802fc31f1db | 232 | void |
| donatien | 0:b802fc31f1db | 233 | dns_init() |
| donatien | 0:b802fc31f1db | 234 | { |
| donatien | 0:b802fc31f1db | 235 | ip_addr_t dnsserver; |
| donatien | 0:b802fc31f1db | 236 | |
| donatien | 0:b802fc31f1db | 237 | dns_payload = (u8_t *)LWIP_MEM_ALIGN(dns_payload_buffer); |
| donatien | 0:b802fc31f1db | 238 | |
| donatien | 0:b802fc31f1db | 239 | /* initialize default DNS server address */ |
| donatien | 0:b802fc31f1db | 240 | DNS_SERVER_ADDRESS(&dnsserver); |
| donatien | 0:b802fc31f1db | 241 | |
| donatien | 0:b802fc31f1db | 242 | LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n")); |
| donatien | 0:b802fc31f1db | 243 | |
| donatien | 0:b802fc31f1db | 244 | /* if dns client not yet initialized... */ |
| donatien | 0:b802fc31f1db | 245 | if (dns_pcb == NULL) { |
| donatien | 0:b802fc31f1db | 246 | dns_pcb = udp_new(); |
| donatien | 0:b802fc31f1db | 247 | |
| donatien | 0:b802fc31f1db | 248 | if (dns_pcb != NULL) { |
| donatien | 0:b802fc31f1db | 249 | /* initialize DNS table not needed (initialized to zero since it is a |
| donatien | 0:b802fc31f1db | 250 | * global variable) */ |
| donatien | 0:b802fc31f1db | 251 | LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0", |
| donatien | 0:b802fc31f1db | 252 | DNS_STATE_UNUSED == 0); |
| donatien | 0:b802fc31f1db | 253 | |
| donatien | 0:b802fc31f1db | 254 | /* initialize DNS client */ |
| donatien | 0:b802fc31f1db | 255 | udp_bind(dns_pcb, IP_ADDR_ANY, 0); |
| donatien | 0:b802fc31f1db | 256 | udp_recv(dns_pcb, dns_recv, NULL); |
| donatien | 0:b802fc31f1db | 257 | |
| donatien | 0:b802fc31f1db | 258 | /* initialize default DNS primary server */ |
| donatien | 0:b802fc31f1db | 259 | dns_setserver(0, &dnsserver); |
| donatien | 0:b802fc31f1db | 260 | } |
| donatien | 0:b802fc31f1db | 261 | } |
| donatien | 0:b802fc31f1db | 262 | #if DNS_LOCAL_HOSTLIST |
| donatien | 0:b802fc31f1db | 263 | dns_init_local(); |
| donatien | 0:b802fc31f1db | 264 | #endif |
| donatien | 0:b802fc31f1db | 265 | } |
| donatien | 0:b802fc31f1db | 266 | |
| donatien | 0:b802fc31f1db | 267 | /** |
| donatien | 0:b802fc31f1db | 268 | * Initialize one of the DNS servers. |
| donatien | 0:b802fc31f1db | 269 | * |
| donatien | 0:b802fc31f1db | 270 | * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS |
| donatien | 0:b802fc31f1db | 271 | * @param dnsserver IP address of the DNS server to set |
| donatien | 0:b802fc31f1db | 272 | */ |
| donatien | 0:b802fc31f1db | 273 | void |
| donatien | 0:b802fc31f1db | 274 | dns_setserver(u8_t numdns, ip_addr_t *dnsserver) |
| donatien | 0:b802fc31f1db | 275 | { |
| donatien | 0:b802fc31f1db | 276 | if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) && |
| donatien | 0:b802fc31f1db | 277 | (dnsserver != NULL) && !ip_addr_isany(dnsserver)) { |
| donatien | 0:b802fc31f1db | 278 | dns_servers[numdns] = (*dnsserver); |
| donatien | 0:b802fc31f1db | 279 | } |
| donatien | 0:b802fc31f1db | 280 | } |
| donatien | 0:b802fc31f1db | 281 | |
| donatien | 0:b802fc31f1db | 282 | /** |
| donatien | 0:b802fc31f1db | 283 | * Obtain one of the currently configured DNS server. |
| donatien | 0:b802fc31f1db | 284 | * |
| donatien | 0:b802fc31f1db | 285 | * @param numdns the index of the DNS server |
| donatien | 0:b802fc31f1db | 286 | * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS |
| donatien | 0:b802fc31f1db | 287 | * server has not been configured. |
| donatien | 0:b802fc31f1db | 288 | */ |
| donatien | 0:b802fc31f1db | 289 | ip_addr_t |
| donatien | 0:b802fc31f1db | 290 | dns_getserver(u8_t numdns) |
| donatien | 0:b802fc31f1db | 291 | { |
| donatien | 0:b802fc31f1db | 292 | if (numdns < DNS_MAX_SERVERS) { |
| donatien | 0:b802fc31f1db | 293 | return dns_servers[numdns]; |
| donatien | 0:b802fc31f1db | 294 | } else { |
| donatien | 0:b802fc31f1db | 295 | return *IP_ADDR_ANY; |
| donatien | 0:b802fc31f1db | 296 | } |
| donatien | 0:b802fc31f1db | 297 | } |
| donatien | 0:b802fc31f1db | 298 | |
| donatien | 0:b802fc31f1db | 299 | /** |
| donatien | 0:b802fc31f1db | 300 | * The DNS resolver client timer - handle retries and timeouts and should |
| donatien | 0:b802fc31f1db | 301 | * be called every DNS_TMR_INTERVAL milliseconds (every second by default). |
| donatien | 0:b802fc31f1db | 302 | */ |
| donatien | 0:b802fc31f1db | 303 | void |
| donatien | 0:b802fc31f1db | 304 | dns_tmr(void) |
| donatien | 0:b802fc31f1db | 305 | { |
| donatien | 0:b802fc31f1db | 306 | if (dns_pcb != NULL) { |
| donatien | 0:b802fc31f1db | 307 | LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n")); |
| donatien | 0:b802fc31f1db | 308 | dns_check_entries(); |
| donatien | 0:b802fc31f1db | 309 | } |
| donatien | 0:b802fc31f1db | 310 | } |
| donatien | 0:b802fc31f1db | 311 | |
| donatien | 0:b802fc31f1db | 312 | #if DNS_LOCAL_HOSTLIST |
| donatien | 0:b802fc31f1db | 313 | static void |
| donatien | 0:b802fc31f1db | 314 | dns_init_local() |
| donatien | 0:b802fc31f1db | 315 | { |
| donatien | 0:b802fc31f1db | 316 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) |
| donatien | 0:b802fc31f1db | 317 | int i; |
| donatien | 0:b802fc31f1db | 318 | struct local_hostlist_entry *entry; |
| donatien | 0:b802fc31f1db | 319 | /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */ |
| donatien | 0:b802fc31f1db | 320 | struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT; |
| donatien | 0:b802fc31f1db | 321 | size_t namelen; |
| donatien | 0:b802fc31f1db | 322 | for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) { |
| donatien | 0:b802fc31f1db | 323 | struct local_hostlist_entry *init_entry = &local_hostlist_init[i]; |
| donatien | 0:b802fc31f1db | 324 | LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL); |
| donatien | 0:b802fc31f1db | 325 | namelen = strlen(init_entry->name); |
| donatien | 0:b802fc31f1db | 326 | LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN); |
| donatien | 0:b802fc31f1db | 327 | entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST); |
| donatien | 0:b802fc31f1db | 328 | LWIP_ASSERT("mem-error in dns_init_local", entry != NULL); |
| donatien | 0:b802fc31f1db | 329 | if (entry != NULL) { |
| donatien | 0:b802fc31f1db | 330 | entry->name = (char*)entry + sizeof(struct local_hostlist_entry); |
| donatien | 0:b802fc31f1db | 331 | MEMCPY((char*)entry->name, init_entry->name, namelen); |
| donatien | 0:b802fc31f1db | 332 | ((char*)entry->name)[namelen] = 0; |
| donatien | 0:b802fc31f1db | 333 | entry->addr = init_entry->addr; |
| donatien | 0:b802fc31f1db | 334 | entry->next = local_hostlist_dynamic; |
| donatien | 0:b802fc31f1db | 335 | local_hostlist_dynamic = entry; |
| donatien | 0:b802fc31f1db | 336 | } |
| donatien | 0:b802fc31f1db | 337 | } |
| donatien | 0:b802fc31f1db | 338 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */ |
| donatien | 0:b802fc31f1db | 339 | } |
| donatien | 0:b802fc31f1db | 340 | |
| donatien | 0:b802fc31f1db | 341 | /** |
| donatien | 0:b802fc31f1db | 342 | * Scans the local host-list for a hostname. |
| donatien | 0:b802fc31f1db | 343 | * |
| donatien | 0:b802fc31f1db | 344 | * @param hostname Hostname to look for in the local host-list |
| donatien | 0:b802fc31f1db | 345 | * @return The first IP address for the hostname in the local host-list or |
| donatien | 0:b802fc31f1db | 346 | * IPADDR_NONE if not found. |
| donatien | 0:b802fc31f1db | 347 | */ |
| donatien | 0:b802fc31f1db | 348 | static u32_t |
| donatien | 0:b802fc31f1db | 349 | dns_lookup_local(const char *hostname) |
| donatien | 0:b802fc31f1db | 350 | { |
| donatien | 0:b802fc31f1db | 351 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
| donatien | 0:b802fc31f1db | 352 | struct local_hostlist_entry *entry = local_hostlist_dynamic; |
| donatien | 0:b802fc31f1db | 353 | while(entry != NULL) { |
| donatien | 0:b802fc31f1db | 354 | if(strcmp(entry->name, hostname) == 0) { |
| donatien | 0:b802fc31f1db | 355 | return ip4_addr_get_u32(&entry->addr); |
| donatien | 0:b802fc31f1db | 356 | } |
| donatien | 0:b802fc31f1db | 357 | entry = entry->next; |
| donatien | 0:b802fc31f1db | 358 | } |
| donatien | 0:b802fc31f1db | 359 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
| donatien | 0:b802fc31f1db | 360 | int i; |
| donatien | 0:b802fc31f1db | 361 | for (i = 0; i < sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry); i++) { |
| donatien | 0:b802fc31f1db | 362 | if(strcmp(local_hostlist_static[i].name, hostname) == 0) { |
| donatien | 0:b802fc31f1db | 363 | return ip4_addr_get_u32(&local_hostlist_static[i].addr); |
| donatien | 0:b802fc31f1db | 364 | } |
| donatien | 0:b802fc31f1db | 365 | } |
| donatien | 0:b802fc31f1db | 366 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
| donatien | 0:b802fc31f1db | 367 | return IPADDR_NONE; |
| donatien | 0:b802fc31f1db | 368 | } |
| donatien | 0:b802fc31f1db | 369 | |
| donatien | 0:b802fc31f1db | 370 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
| donatien | 0:b802fc31f1db | 371 | /** Remove all entries from the local host-list for a specific hostname |
| donatien | 0:b802fc31f1db | 372 | * and/or IP addess |
| donatien | 0:b802fc31f1db | 373 | * |
| donatien | 0:b802fc31f1db | 374 | * @param hostname hostname for which entries shall be removed from the local |
| donatien | 0:b802fc31f1db | 375 | * host-list |
| donatien | 0:b802fc31f1db | 376 | * @param addr address for which entries shall be removed from the local host-list |
| donatien | 0:b802fc31f1db | 377 | * @return the number of removed entries |
| donatien | 0:b802fc31f1db | 378 | */ |
| donatien | 0:b802fc31f1db | 379 | int |
| donatien | 0:b802fc31f1db | 380 | dns_local_removehost(const char *hostname, const ip_addr_t *addr) |
| donatien | 0:b802fc31f1db | 381 | { |
| donatien | 0:b802fc31f1db | 382 | int removed = 0; |
| donatien | 0:b802fc31f1db | 383 | struct local_hostlist_entry *entry = local_hostlist_dynamic; |
| donatien | 0:b802fc31f1db | 384 | struct local_hostlist_entry *last_entry = NULL; |
| donatien | 0:b802fc31f1db | 385 | while (entry != NULL) { |
| donatien | 0:b802fc31f1db | 386 | if (((hostname == NULL) || !strcmp(entry->name, hostname)) && |
| donatien | 0:b802fc31f1db | 387 | ((addr == NULL) || ip_addr_cmp(&entry->addr, addr))) { |
| donatien | 0:b802fc31f1db | 388 | struct local_hostlist_entry *free_entry; |
| donatien | 0:b802fc31f1db | 389 | if (last_entry != NULL) { |
| donatien | 0:b802fc31f1db | 390 | last_entry->next = entry->next; |
| donatien | 0:b802fc31f1db | 391 | } else { |
| donatien | 0:b802fc31f1db | 392 | local_hostlist_dynamic = entry->next; |
| donatien | 0:b802fc31f1db | 393 | } |
| donatien | 0:b802fc31f1db | 394 | free_entry = entry; |
| donatien | 0:b802fc31f1db | 395 | entry = entry->next; |
| donatien | 0:b802fc31f1db | 396 | memp_free(MEMP_LOCALHOSTLIST, free_entry); |
| donatien | 0:b802fc31f1db | 397 | removed++; |
| donatien | 0:b802fc31f1db | 398 | } else { |
| donatien | 0:b802fc31f1db | 399 | last_entry = entry; |
| donatien | 0:b802fc31f1db | 400 | entry = entry->next; |
| donatien | 0:b802fc31f1db | 401 | } |
| donatien | 0:b802fc31f1db | 402 | } |
| donatien | 0:b802fc31f1db | 403 | return removed; |
| donatien | 0:b802fc31f1db | 404 | } |
| donatien | 0:b802fc31f1db | 405 | |
| donatien | 0:b802fc31f1db | 406 | /** |
| donatien | 0:b802fc31f1db | 407 | * Add a hostname/IP address pair to the local host-list. |
| donatien | 0:b802fc31f1db | 408 | * Duplicates are not checked. |
| donatien | 0:b802fc31f1db | 409 | * |
| donatien | 0:b802fc31f1db | 410 | * @param hostname hostname of the new entry |
| donatien | 0:b802fc31f1db | 411 | * @param addr IP address of the new entry |
| donatien | 0:b802fc31f1db | 412 | * @return ERR_OK if succeeded or ERR_MEM on memory error |
| donatien | 0:b802fc31f1db | 413 | */ |
| donatien | 0:b802fc31f1db | 414 | err_t |
| donatien | 0:b802fc31f1db | 415 | dns_local_addhost(const char *hostname, const ip_addr_t *addr) |
| donatien | 0:b802fc31f1db | 416 | { |
| donatien | 0:b802fc31f1db | 417 | struct local_hostlist_entry *entry; |
| donatien | 0:b802fc31f1db | 418 | size_t namelen; |
| donatien | 0:b802fc31f1db | 419 | LWIP_ASSERT("invalid host name (NULL)", hostname != NULL); |
| donatien | 0:b802fc31f1db | 420 | namelen = strlen(hostname); |
| donatien | 0:b802fc31f1db | 421 | LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN); |
| donatien | 0:b802fc31f1db | 422 | entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST); |
| donatien | 0:b802fc31f1db | 423 | if (entry == NULL) { |
| donatien | 0:b802fc31f1db | 424 | return ERR_MEM; |
| donatien | 0:b802fc31f1db | 425 | } |
| donatien | 0:b802fc31f1db | 426 | entry->name = (char*)entry + sizeof(struct local_hostlist_entry); |
| donatien | 0:b802fc31f1db | 427 | MEMCPY((char*)entry->name, hostname, namelen); |
| donatien | 0:b802fc31f1db | 428 | ((char*)entry->name)[namelen] = 0; |
| donatien | 0:b802fc31f1db | 429 | ip_addr_copy(entry->addr, *addr); |
| donatien | 0:b802fc31f1db | 430 | entry->next = local_hostlist_dynamic; |
| donatien | 0:b802fc31f1db | 431 | local_hostlist_dynamic = entry; |
| donatien | 0:b802fc31f1db | 432 | return ERR_OK; |
| donatien | 0:b802fc31f1db | 433 | } |
| donatien | 0:b802fc31f1db | 434 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/ |
| donatien | 0:b802fc31f1db | 435 | #endif /* DNS_LOCAL_HOSTLIST */ |
| donatien | 0:b802fc31f1db | 436 | |
| donatien | 0:b802fc31f1db | 437 | /** |
| donatien | 0:b802fc31f1db | 438 | * Look up a hostname in the array of known hostnames. |
| donatien | 0:b802fc31f1db | 439 | * |
| donatien | 0:b802fc31f1db | 440 | * @note This function only looks in the internal array of known |
| donatien | 0:b802fc31f1db | 441 | * hostnames, it does not send out a query for the hostname if none |
| donatien | 0:b802fc31f1db | 442 | * was found. The function dns_enqueue() can be used to send a query |
| donatien | 0:b802fc31f1db | 443 | * for a hostname. |
| donatien | 0:b802fc31f1db | 444 | * |
| donatien | 0:b802fc31f1db | 445 | * @param name the hostname to look up |
| donatien | 0:b802fc31f1db | 446 | * @return the hostname's IP address, as u32_t (instead of ip_addr_t to |
| donatien | 0:b802fc31f1db | 447 | * better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname |
| donatien | 0:b802fc31f1db | 448 | * was not found in the cached dns_table. |
| donatien | 0:b802fc31f1db | 449 | */ |
| donatien | 0:b802fc31f1db | 450 | static u32_t |
| donatien | 0:b802fc31f1db | 451 | dns_lookup(const char *name) |
| donatien | 0:b802fc31f1db | 452 | { |
| donatien | 0:b802fc31f1db | 453 | u8_t i; |
| donatien | 0:b802fc31f1db | 454 | #if DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN) |
| donatien | 0:b802fc31f1db | 455 | u32_t addr; |
| donatien | 0:b802fc31f1db | 456 | #endif /* DNS_LOCAL_HOSTLIST || defined(DNS_LOOKUP_LOCAL_EXTERN) */ |
| donatien | 0:b802fc31f1db | 457 | #if DNS_LOCAL_HOSTLIST |
| donatien | 0:b802fc31f1db | 458 | if ((addr = dns_lookup_local(name)) != IPADDR_NONE) { |
| donatien | 0:b802fc31f1db | 459 | return addr; |
| donatien | 0:b802fc31f1db | 460 | } |
| donatien | 0:b802fc31f1db | 461 | #endif /* DNS_LOCAL_HOSTLIST */ |
| donatien | 0:b802fc31f1db | 462 | #ifdef DNS_LOOKUP_LOCAL_EXTERN |
| donatien | 0:b802fc31f1db | 463 | if((addr = DNS_LOOKUP_LOCAL_EXTERN(name)) != IPADDR_NONE) { |
| donatien | 0:b802fc31f1db | 464 | return addr; |
| donatien | 0:b802fc31f1db | 465 | } |
| donatien | 0:b802fc31f1db | 466 | #endif /* DNS_LOOKUP_LOCAL_EXTERN */ |
| donatien | 0:b802fc31f1db | 467 | |
| donatien | 0:b802fc31f1db | 468 | /* Walk through name list, return entry if found. If not, return NULL. */ |
| donatien | 0:b802fc31f1db | 469 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
| donatien | 0:b802fc31f1db | 470 | if ((dns_table[i].state == DNS_STATE_DONE) && |
| donatien | 0:b802fc31f1db | 471 | (strcmp(name, dns_table[i].name) == 0)) { |
| donatien | 0:b802fc31f1db | 472 | LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name)); |
| donatien | 0:b802fc31f1db | 473 | ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr)); |
| donatien | 0:b802fc31f1db | 474 | LWIP_DEBUGF(DNS_DEBUG, ("\n")); |
| donatien | 0:b802fc31f1db | 475 | return ip4_addr_get_u32(&dns_table[i].ipaddr); |
| donatien | 0:b802fc31f1db | 476 | } |
| donatien | 0:b802fc31f1db | 477 | } |
| donatien | 0:b802fc31f1db | 478 | |
| donatien | 0:b802fc31f1db | 479 | return IPADDR_NONE; |
| donatien | 0:b802fc31f1db | 480 | } |
| donatien | 0:b802fc31f1db | 481 | |
| donatien | 0:b802fc31f1db | 482 | #if DNS_DOES_NAME_CHECK |
| donatien | 0:b802fc31f1db | 483 | /** |
| donatien | 0:b802fc31f1db | 484 | * Compare the "dotted" name "query" with the encoded name "response" |
| donatien | 0:b802fc31f1db | 485 | * to make sure an answer from the DNS server matches the current dns_table |
| donatien | 0:b802fc31f1db | 486 | * entry (otherwise, answers might arrive late for hostname not on the list |
| donatien | 0:b802fc31f1db | 487 | * any more). |
| donatien | 0:b802fc31f1db | 488 | * |
| donatien | 0:b802fc31f1db | 489 | * @param query hostname (not encoded) from the dns_table |
| donatien | 0:b802fc31f1db | 490 | * @param response encoded hostname in the DNS response |
| donatien | 0:b802fc31f1db | 491 | * @return 0: names equal; 1: names differ |
| donatien | 0:b802fc31f1db | 492 | */ |
| donatien | 0:b802fc31f1db | 493 | static u8_t |
| donatien | 0:b802fc31f1db | 494 | dns_compare_name(unsigned char *query, unsigned char *response) |
| donatien | 0:b802fc31f1db | 495 | { |
| donatien | 0:b802fc31f1db | 496 | unsigned char n; |
| donatien | 0:b802fc31f1db | 497 | |
| donatien | 0:b802fc31f1db | 498 | do { |
| donatien | 0:b802fc31f1db | 499 | n = *response++; |
| donatien | 0:b802fc31f1db | 500 | /** @see RFC 1035 - 4.1.4. Message compression */ |
| donatien | 0:b802fc31f1db | 501 | if ((n & 0xc0) == 0xc0) { |
| donatien | 0:b802fc31f1db | 502 | /* Compressed name */ |
| donatien | 0:b802fc31f1db | 503 | break; |
| donatien | 0:b802fc31f1db | 504 | } else { |
| donatien | 0:b802fc31f1db | 505 | /* Not compressed name */ |
| donatien | 0:b802fc31f1db | 506 | while (n > 0) { |
| donatien | 0:b802fc31f1db | 507 | if ((*query) != (*response)) { |
| donatien | 0:b802fc31f1db | 508 | return 1; |
| donatien | 0:b802fc31f1db | 509 | } |
| donatien | 0:b802fc31f1db | 510 | ++response; |
| donatien | 0:b802fc31f1db | 511 | ++query; |
| donatien | 0:b802fc31f1db | 512 | --n; |
| donatien | 0:b802fc31f1db | 513 | }; |
| donatien | 0:b802fc31f1db | 514 | ++query; |
| donatien | 0:b802fc31f1db | 515 | } |
| donatien | 0:b802fc31f1db | 516 | } while (*response != 0); |
| donatien | 0:b802fc31f1db | 517 | |
| donatien | 0:b802fc31f1db | 518 | return 0; |
| donatien | 0:b802fc31f1db | 519 | } |
| donatien | 0:b802fc31f1db | 520 | #endif /* DNS_DOES_NAME_CHECK */ |
| donatien | 0:b802fc31f1db | 521 | |
| donatien | 0:b802fc31f1db | 522 | /** |
| donatien | 0:b802fc31f1db | 523 | * Walk through a compact encoded DNS name and return the end of the name. |
| donatien | 0:b802fc31f1db | 524 | * |
| donatien | 0:b802fc31f1db | 525 | * @param query encoded DNS name in the DNS server response |
| donatien | 0:b802fc31f1db | 526 | * @return end of the name |
| donatien | 0:b802fc31f1db | 527 | */ |
| donatien | 0:b802fc31f1db | 528 | static unsigned char * |
| donatien | 0:b802fc31f1db | 529 | dns_parse_name(unsigned char *query) |
| donatien | 0:b802fc31f1db | 530 | { |
| donatien | 0:b802fc31f1db | 531 | unsigned char n; |
| donatien | 0:b802fc31f1db | 532 | |
| donatien | 0:b802fc31f1db | 533 | do { |
| donatien | 0:b802fc31f1db | 534 | n = *query++; |
| donatien | 0:b802fc31f1db | 535 | /** @see RFC 1035 - 4.1.4. Message compression */ |
| donatien | 0:b802fc31f1db | 536 | if ((n & 0xc0) == 0xc0) { |
| donatien | 0:b802fc31f1db | 537 | /* Compressed name */ |
| donatien | 0:b802fc31f1db | 538 | break; |
| donatien | 0:b802fc31f1db | 539 | } else { |
| donatien | 0:b802fc31f1db | 540 | /* Not compressed name */ |
| donatien | 0:b802fc31f1db | 541 | while (n > 0) { |
| donatien | 0:b802fc31f1db | 542 | ++query; |
| donatien | 0:b802fc31f1db | 543 | --n; |
| donatien | 0:b802fc31f1db | 544 | }; |
| donatien | 0:b802fc31f1db | 545 | } |
| donatien | 0:b802fc31f1db | 546 | } while (*query != 0); |
| donatien | 0:b802fc31f1db | 547 | |
| donatien | 0:b802fc31f1db | 548 | return query + 1; |
| donatien | 0:b802fc31f1db | 549 | } |
| donatien | 0:b802fc31f1db | 550 | |
| donatien | 0:b802fc31f1db | 551 | /** |
| donatien | 0:b802fc31f1db | 552 | * Send a DNS query packet. |
| donatien | 0:b802fc31f1db | 553 | * |
| donatien | 0:b802fc31f1db | 554 | * @param numdns index of the DNS server in the dns_servers table |
| donatien | 0:b802fc31f1db | 555 | * @param name hostname to query |
| donatien | 0:b802fc31f1db | 556 | * @param id index of the hostname in dns_table, used as transaction ID in the |
| donatien | 0:b802fc31f1db | 557 | * DNS query packet |
| donatien | 0:b802fc31f1db | 558 | * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise |
| donatien | 0:b802fc31f1db | 559 | */ |
| donatien | 0:b802fc31f1db | 560 | static err_t |
| donatien | 0:b802fc31f1db | 561 | dns_send(u8_t numdns, const char* name, u8_t id) |
| donatien | 0:b802fc31f1db | 562 | { |
| donatien | 0:b802fc31f1db | 563 | err_t err; |
| donatien | 0:b802fc31f1db | 564 | struct dns_hdr *hdr; |
| donatien | 0:b802fc31f1db | 565 | struct dns_query qry; |
| donatien | 0:b802fc31f1db | 566 | struct pbuf *p; |
| donatien | 0:b802fc31f1db | 567 | char *query, *nptr; |
| donatien | 0:b802fc31f1db | 568 | const char *pHostname; |
| donatien | 0:b802fc31f1db | 569 | u8_t n; |
| donatien | 0:b802fc31f1db | 570 | |
| donatien | 0:b802fc31f1db | 571 | LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n", |
| donatien | 0:b802fc31f1db | 572 | (u16_t)(numdns), name)); |
| donatien | 0:b802fc31f1db | 573 | LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS); |
| donatien | 0:b802fc31f1db | 574 | LWIP_ASSERT("dns server has no IP address set", !ip_addr_isany(&dns_servers[numdns])); |
| donatien | 0:b802fc31f1db | 575 | |
| donatien | 0:b802fc31f1db | 576 | /* if here, we have either a new query or a retry on a previous query to process */ |
| donatien | 0:b802fc31f1db | 577 | p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH + |
| donatien | 0:b802fc31f1db | 578 | SIZEOF_DNS_QUERY, PBUF_RAM); |
| donatien | 0:b802fc31f1db | 579 | if (p != NULL) { |
| donatien | 0:b802fc31f1db | 580 | LWIP_ASSERT("pbuf must be in one piece", p->next == NULL); |
| donatien | 0:b802fc31f1db | 581 | /* fill dns header */ |
| donatien | 0:b802fc31f1db | 582 | hdr = (struct dns_hdr*)p->payload; |
| donatien | 0:b802fc31f1db | 583 | memset(hdr, 0, SIZEOF_DNS_HDR); |
| donatien | 0:b802fc31f1db | 584 | hdr->id = htons(id); |
| donatien | 0:b802fc31f1db | 585 | hdr->flags1 = DNS_FLAG1_RD; |
| donatien | 0:b802fc31f1db | 586 | hdr->numquestions = PP_HTONS(1); |
| donatien | 0:b802fc31f1db | 587 | query = (char*)hdr + SIZEOF_DNS_HDR; |
| donatien | 0:b802fc31f1db | 588 | pHostname = name; |
| donatien | 0:b802fc31f1db | 589 | --pHostname; |
| donatien | 0:b802fc31f1db | 590 | |
| donatien | 0:b802fc31f1db | 591 | /* convert hostname into suitable query format. */ |
| donatien | 0:b802fc31f1db | 592 | do { |
| donatien | 0:b802fc31f1db | 593 | ++pHostname; |
| donatien | 0:b802fc31f1db | 594 | nptr = query; |
| donatien | 0:b802fc31f1db | 595 | ++query; |
| donatien | 0:b802fc31f1db | 596 | for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) { |
| donatien | 0:b802fc31f1db | 597 | *query = *pHostname; |
| donatien | 0:b802fc31f1db | 598 | ++query; |
| donatien | 0:b802fc31f1db | 599 | ++n; |
| donatien | 0:b802fc31f1db | 600 | } |
| donatien | 0:b802fc31f1db | 601 | *nptr = n; |
| donatien | 0:b802fc31f1db | 602 | } while(*pHostname != 0); |
| donatien | 0:b802fc31f1db | 603 | *query++='\0'; |
| donatien | 0:b802fc31f1db | 604 | |
| donatien | 0:b802fc31f1db | 605 | /* fill dns query */ |
| donatien | 0:b802fc31f1db | 606 | qry.type = PP_HTONS(DNS_RRTYPE_A); |
| donatien | 0:b802fc31f1db | 607 | qry.cls = PP_HTONS(DNS_RRCLASS_IN); |
| donatien | 0:b802fc31f1db | 608 | SMEMCPY(query, &qry, SIZEOF_DNS_QUERY); |
| donatien | 0:b802fc31f1db | 609 | |
| donatien | 0:b802fc31f1db | 610 | /* resize pbuf to the exact dns query */ |
| donatien | 0:b802fc31f1db | 611 | pbuf_realloc(p, (u16_t)((query + SIZEOF_DNS_QUERY) - ((char*)(p->payload)))); |
| donatien | 0:b802fc31f1db | 612 | |
| donatien | 0:b802fc31f1db | 613 | /* connect to the server for faster receiving */ |
| donatien | 0:b802fc31f1db | 614 | udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT); |
| donatien | 0:b802fc31f1db | 615 | /* send dns packet */ |
| donatien | 0:b802fc31f1db | 616 | err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT); |
| donatien | 0:b802fc31f1db | 617 | |
| donatien | 0:b802fc31f1db | 618 | /* free pbuf */ |
| donatien | 0:b802fc31f1db | 619 | pbuf_free(p); |
| donatien | 0:b802fc31f1db | 620 | } else { |
| donatien | 0:b802fc31f1db | 621 | err = ERR_MEM; |
| donatien | 0:b802fc31f1db | 622 | } |
| donatien | 0:b802fc31f1db | 623 | |
| donatien | 0:b802fc31f1db | 624 | return err; |
| donatien | 0:b802fc31f1db | 625 | } |
| donatien | 0:b802fc31f1db | 626 | |
| donatien | 0:b802fc31f1db | 627 | /** |
| donatien | 0:b802fc31f1db | 628 | * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query. |
| donatien | 0:b802fc31f1db | 629 | * Check an entry in the dns_table: |
| donatien | 0:b802fc31f1db | 630 | * - send out query for new entries |
| donatien | 0:b802fc31f1db | 631 | * - retry old pending entries on timeout (also with different servers) |
| donatien | 0:b802fc31f1db | 632 | * - remove completed entries from the table if their TTL has expired |
| donatien | 0:b802fc31f1db | 633 | * |
| donatien | 0:b802fc31f1db | 634 | * @param i index of the dns_table entry to check |
| donatien | 0:b802fc31f1db | 635 | */ |
| donatien | 0:b802fc31f1db | 636 | static void |
| donatien | 0:b802fc31f1db | 637 | dns_check_entry(u8_t i) |
| donatien | 0:b802fc31f1db | 638 | { |
| donatien | 0:b802fc31f1db | 639 | err_t err; |
| donatien | 0:b802fc31f1db | 640 | struct dns_table_entry *pEntry = &dns_table[i]; |
| donatien | 0:b802fc31f1db | 641 | |
| donatien | 0:b802fc31f1db | 642 | LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE); |
| donatien | 0:b802fc31f1db | 643 | |
| donatien | 0:b802fc31f1db | 644 | switch(pEntry->state) { |
| donatien | 0:b802fc31f1db | 645 | |
| donatien | 0:b802fc31f1db | 646 | case DNS_STATE_NEW: { |
| donatien | 0:b802fc31f1db | 647 | /* initialize new entry */ |
| donatien | 0:b802fc31f1db | 648 | pEntry->state = DNS_STATE_ASKING; |
| donatien | 0:b802fc31f1db | 649 | pEntry->numdns = 0; |
| donatien | 0:b802fc31f1db | 650 | pEntry->tmr = 1; |
| donatien | 0:b802fc31f1db | 651 | pEntry->retries = 0; |
| donatien | 0:b802fc31f1db | 652 | |
| donatien | 0:b802fc31f1db | 653 | /* send DNS packet for this entry */ |
| donatien | 0:b802fc31f1db | 654 | err = dns_send(pEntry->numdns, pEntry->name, i); |
| donatien | 0:b802fc31f1db | 655 | if (err != ERR_OK) { |
| donatien | 0:b802fc31f1db | 656 | LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING, |
| donatien | 0:b802fc31f1db | 657 | ("dns_send returned error: %d\n", err)); |
| donatien | 0:b802fc31f1db | 658 | } |
| donatien | 0:b802fc31f1db | 659 | break; |
| donatien | 0:b802fc31f1db | 660 | } |
| donatien | 0:b802fc31f1db | 661 | |
| donatien | 0:b802fc31f1db | 662 | case DNS_STATE_ASKING: { |
| donatien | 0:b802fc31f1db | 663 | if (--pEntry->tmr == 0) { |
| donatien | 0:b802fc31f1db | 664 | if (++pEntry->retries == DNS_MAX_RETRIES) { |
| donatien | 0:b802fc31f1db | 665 | if ((pEntry->numdns+1<DNS_MAX_SERVERS) && !ip_addr_isany(&dns_servers[pEntry->numdns+1])) { |
| donatien | 0:b802fc31f1db | 666 | /* change of server */ |
| donatien | 0:b802fc31f1db | 667 | pEntry->numdns++; |
| donatien | 0:b802fc31f1db | 668 | pEntry->tmr = 1; |
| donatien | 0:b802fc31f1db | 669 | pEntry->retries = 0; |
| donatien | 0:b802fc31f1db | 670 | break; |
| donatien | 0:b802fc31f1db | 671 | } else { |
| donatien | 0:b802fc31f1db | 672 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name)); |
| donatien | 0:b802fc31f1db | 673 | /* call specified callback function if provided */ |
| donatien | 0:b802fc31f1db | 674 | if (pEntry->found) |
| donatien | 0:b802fc31f1db | 675 | (*pEntry->found)(pEntry->name, NULL, pEntry->arg); |
| donatien | 0:b802fc31f1db | 676 | /* flush this entry */ |
| donatien | 0:b802fc31f1db | 677 | pEntry->state = DNS_STATE_UNUSED; |
| donatien | 0:b802fc31f1db | 678 | pEntry->found = NULL; |
| donatien | 0:b802fc31f1db | 679 | break; |
| donatien | 0:b802fc31f1db | 680 | } |
| donatien | 0:b802fc31f1db | 681 | } |
| donatien | 0:b802fc31f1db | 682 | |
| donatien | 0:b802fc31f1db | 683 | /* wait longer for the next retry */ |
| donatien | 0:b802fc31f1db | 684 | pEntry->tmr = pEntry->retries; |
| donatien | 0:b802fc31f1db | 685 | |
| donatien | 0:b802fc31f1db | 686 | /* send DNS packet for this entry */ |
| donatien | 0:b802fc31f1db | 687 | err = dns_send(pEntry->numdns, pEntry->name, i); |
| donatien | 0:b802fc31f1db | 688 | if (err != ERR_OK) { |
| donatien | 0:b802fc31f1db | 689 | LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING, |
| donatien | 0:b802fc31f1db | 690 | ("dns_send returned error: %d\n", err)); |
| donatien | 0:b802fc31f1db | 691 | } |
| donatien | 0:b802fc31f1db | 692 | } |
| donatien | 0:b802fc31f1db | 693 | break; |
| donatien | 0:b802fc31f1db | 694 | } |
| donatien | 0:b802fc31f1db | 695 | |
| donatien | 0:b802fc31f1db | 696 | case DNS_STATE_DONE: { |
| donatien | 0:b802fc31f1db | 697 | /* if the time to live is nul */ |
| donatien | 0:b802fc31f1db | 698 | if (--pEntry->ttl == 0) { |
| donatien | 0:b802fc31f1db | 699 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name)); |
| donatien | 0:b802fc31f1db | 700 | /* flush this entry */ |
| donatien | 0:b802fc31f1db | 701 | pEntry->state = DNS_STATE_UNUSED; |
| donatien | 0:b802fc31f1db | 702 | pEntry->found = NULL; |
| donatien | 0:b802fc31f1db | 703 | } |
| donatien | 0:b802fc31f1db | 704 | break; |
| donatien | 0:b802fc31f1db | 705 | } |
| donatien | 0:b802fc31f1db | 706 | case DNS_STATE_UNUSED: |
| donatien | 0:b802fc31f1db | 707 | /* nothing to do */ |
| donatien | 0:b802fc31f1db | 708 | break; |
| donatien | 0:b802fc31f1db | 709 | default: |
| donatien | 0:b802fc31f1db | 710 | LWIP_ASSERT("unknown dns_table entry state:", 0); |
| donatien | 0:b802fc31f1db | 711 | break; |
| donatien | 0:b802fc31f1db | 712 | } |
| donatien | 0:b802fc31f1db | 713 | } |
| donatien | 0:b802fc31f1db | 714 | |
| donatien | 0:b802fc31f1db | 715 | /** |
| donatien | 0:b802fc31f1db | 716 | * Call dns_check_entry for each entry in dns_table - check all entries. |
| donatien | 0:b802fc31f1db | 717 | */ |
| donatien | 0:b802fc31f1db | 718 | static void |
| donatien | 0:b802fc31f1db | 719 | dns_check_entries(void) |
| donatien | 0:b802fc31f1db | 720 | { |
| donatien | 0:b802fc31f1db | 721 | u8_t i; |
| donatien | 0:b802fc31f1db | 722 | |
| donatien | 0:b802fc31f1db | 723 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
| donatien | 0:b802fc31f1db | 724 | dns_check_entry(i); |
| donatien | 0:b802fc31f1db | 725 | } |
| donatien | 0:b802fc31f1db | 726 | } |
| donatien | 0:b802fc31f1db | 727 | |
| donatien | 0:b802fc31f1db | 728 | /** |
| donatien | 0:b802fc31f1db | 729 | * Receive input function for DNS response packets arriving for the dns UDP pcb. |
| donatien | 0:b802fc31f1db | 730 | * |
| donatien | 0:b802fc31f1db | 731 | * @params see udp.h |
| donatien | 0:b802fc31f1db | 732 | */ |
| donatien | 0:b802fc31f1db | 733 | static void |
| donatien | 0:b802fc31f1db | 734 | dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) |
| donatien | 0:b802fc31f1db | 735 | { |
| donatien | 0:b802fc31f1db | 736 | u16_t i; |
| donatien | 0:b802fc31f1db | 737 | char *pHostname; |
| donatien | 0:b802fc31f1db | 738 | struct dns_hdr *hdr; |
| donatien | 0:b802fc31f1db | 739 | struct dns_answer ans; |
| donatien | 0:b802fc31f1db | 740 | struct dns_table_entry *pEntry; |
| donatien | 0:b802fc31f1db | 741 | u16_t nquestions, nanswers; |
| donatien | 0:b802fc31f1db | 742 | |
| donatien | 0:b802fc31f1db | 743 | LWIP_UNUSED_ARG(arg); |
| donatien | 0:b802fc31f1db | 744 | LWIP_UNUSED_ARG(pcb); |
| donatien | 0:b802fc31f1db | 745 | LWIP_UNUSED_ARG(addr); |
| donatien | 0:b802fc31f1db | 746 | LWIP_UNUSED_ARG(port); |
| donatien | 0:b802fc31f1db | 747 | |
| donatien | 0:b802fc31f1db | 748 | /* is the dns message too big ? */ |
| donatien | 0:b802fc31f1db | 749 | if (p->tot_len > DNS_MSG_SIZE) { |
| donatien | 0:b802fc31f1db | 750 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n")); |
| donatien | 0:b802fc31f1db | 751 | /* free pbuf and return */ |
| donatien | 0:b802fc31f1db | 752 | goto memerr; |
| donatien | 0:b802fc31f1db | 753 | } |
| donatien | 0:b802fc31f1db | 754 | |
| donatien | 0:b802fc31f1db | 755 | /* is the dns message big enough ? */ |
| donatien | 0:b802fc31f1db | 756 | if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) { |
| donatien | 0:b802fc31f1db | 757 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n")); |
| donatien | 0:b802fc31f1db | 758 | /* free pbuf and return */ |
| donatien | 0:b802fc31f1db | 759 | goto memerr; |
| donatien | 0:b802fc31f1db | 760 | } |
| donatien | 0:b802fc31f1db | 761 | |
| donatien | 0:b802fc31f1db | 762 | /* copy dns payload inside static buffer for processing */ |
| donatien | 0:b802fc31f1db | 763 | if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) { |
| donatien | 0:b802fc31f1db | 764 | /* The ID in the DNS header should be our entry into the name table. */ |
| donatien | 0:b802fc31f1db | 765 | hdr = (struct dns_hdr*)dns_payload; |
| donatien | 0:b802fc31f1db | 766 | i = htons(hdr->id); |
| donatien | 0:b802fc31f1db | 767 | if (i < DNS_TABLE_SIZE) { |
| donatien | 0:b802fc31f1db | 768 | pEntry = &dns_table[i]; |
| donatien | 0:b802fc31f1db | 769 | if(pEntry->state == DNS_STATE_ASKING) { |
| donatien | 0:b802fc31f1db | 770 | /* This entry is now completed. */ |
| donatien | 0:b802fc31f1db | 771 | pEntry->state = DNS_STATE_DONE; |
| donatien | 0:b802fc31f1db | 772 | pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK; |
| donatien | 0:b802fc31f1db | 773 | |
| donatien | 0:b802fc31f1db | 774 | /* We only care about the question(s) and the answers. The authrr |
| donatien | 0:b802fc31f1db | 775 | and the extrarr are simply discarded. */ |
| donatien | 0:b802fc31f1db | 776 | nquestions = htons(hdr->numquestions); |
| donatien | 0:b802fc31f1db | 777 | nanswers = htons(hdr->numanswers); |
| donatien | 0:b802fc31f1db | 778 | |
| donatien | 0:b802fc31f1db | 779 | /* Check for error. If so, call callback to inform. */ |
| donatien | 0:b802fc31f1db | 780 | if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) { |
| donatien | 0:b802fc31f1db | 781 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name)); |
| donatien | 0:b802fc31f1db | 782 | /* call callback to indicate error, clean up memory and return */ |
| donatien | 0:b802fc31f1db | 783 | goto responseerr; |
| donatien | 0:b802fc31f1db | 784 | } |
| donatien | 0:b802fc31f1db | 785 | |
| donatien | 0:b802fc31f1db | 786 | #if DNS_DOES_NAME_CHECK |
| donatien | 0:b802fc31f1db | 787 | /* Check if the name in the "question" part match with the name in the entry. */ |
| donatien | 0:b802fc31f1db | 788 | if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) { |
| donatien | 0:b802fc31f1db | 789 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name)); |
| donatien | 0:b802fc31f1db | 790 | /* call callback to indicate error, clean up memory and return */ |
| donatien | 0:b802fc31f1db | 791 | goto responseerr; |
| donatien | 0:b802fc31f1db | 792 | } |
| donatien | 0:b802fc31f1db | 793 | #endif /* DNS_DOES_NAME_CHECK */ |
| donatien | 0:b802fc31f1db | 794 | |
| donatien | 0:b802fc31f1db | 795 | /* Skip the name in the "question" part */ |
| donatien | 0:b802fc31f1db | 796 | pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY; |
| donatien | 0:b802fc31f1db | 797 | |
| donatien | 0:b802fc31f1db | 798 | while (nanswers > 0) { |
| donatien | 0:b802fc31f1db | 799 | /* skip answer resource record's host name */ |
| donatien | 0:b802fc31f1db | 800 | pHostname = (char *) dns_parse_name((unsigned char *)pHostname); |
| donatien | 0:b802fc31f1db | 801 | |
| donatien | 0:b802fc31f1db | 802 | /* Check for IP address type and Internet class. Others are discarded. */ |
| donatien | 0:b802fc31f1db | 803 | SMEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER); |
| donatien | 0:b802fc31f1db | 804 | if((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) && |
| donatien | 0:b802fc31f1db | 805 | (ans.len == PP_HTONS(sizeof(ip_addr_t))) ) { |
| donatien | 0:b802fc31f1db | 806 | /* read the answer resource record's TTL, and maximize it if needed */ |
| donatien | 0:b802fc31f1db | 807 | pEntry->ttl = ntohl(ans.ttl); |
| donatien | 0:b802fc31f1db | 808 | if (pEntry->ttl > DNS_MAX_TTL) { |
| donatien | 0:b802fc31f1db | 809 | pEntry->ttl = DNS_MAX_TTL; |
| donatien | 0:b802fc31f1db | 810 | } |
| donatien | 0:b802fc31f1db | 811 | /* read the IP address after answer resource record's header */ |
| donatien | 0:b802fc31f1db | 812 | SMEMCPY(&(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(ip_addr_t)); |
| donatien | 0:b802fc31f1db | 813 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name)); |
| donatien | 0:b802fc31f1db | 814 | ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr))); |
| donatien | 0:b802fc31f1db | 815 | LWIP_DEBUGF(DNS_DEBUG, ("\n")); |
| donatien | 0:b802fc31f1db | 816 | /* call specified callback function if provided */ |
| donatien | 0:b802fc31f1db | 817 | if (pEntry->found) { |
| donatien | 0:b802fc31f1db | 818 | (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg); |
| donatien | 0:b802fc31f1db | 819 | } |
| donatien | 0:b802fc31f1db | 820 | /* deallocate memory and return */ |
| donatien | 0:b802fc31f1db | 821 | goto memerr; |
| donatien | 0:b802fc31f1db | 822 | } else { |
| donatien | 0:b802fc31f1db | 823 | pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len); |
| donatien | 0:b802fc31f1db | 824 | } |
| donatien | 0:b802fc31f1db | 825 | --nanswers; |
| donatien | 0:b802fc31f1db | 826 | } |
| donatien | 0:b802fc31f1db | 827 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name)); |
| donatien | 0:b802fc31f1db | 828 | /* call callback to indicate error, clean up memory and return */ |
| donatien | 0:b802fc31f1db | 829 | goto responseerr; |
| donatien | 0:b802fc31f1db | 830 | } |
| donatien | 0:b802fc31f1db | 831 | } |
| donatien | 0:b802fc31f1db | 832 | } |
| donatien | 0:b802fc31f1db | 833 | |
| donatien | 0:b802fc31f1db | 834 | /* deallocate memory and return */ |
| donatien | 0:b802fc31f1db | 835 | goto memerr; |
| donatien | 0:b802fc31f1db | 836 | |
| donatien | 0:b802fc31f1db | 837 | responseerr: |
| donatien | 0:b802fc31f1db | 838 | /* ERROR: call specified callback function with NULL as name to indicate an error */ |
| donatien | 0:b802fc31f1db | 839 | if (pEntry->found) { |
| donatien | 0:b802fc31f1db | 840 | (*pEntry->found)(pEntry->name, NULL, pEntry->arg); |
| donatien | 0:b802fc31f1db | 841 | } |
| donatien | 0:b802fc31f1db | 842 | /* flush this entry */ |
| donatien | 0:b802fc31f1db | 843 | pEntry->state = DNS_STATE_UNUSED; |
| donatien | 0:b802fc31f1db | 844 | pEntry->found = NULL; |
| donatien | 0:b802fc31f1db | 845 | |
| donatien | 0:b802fc31f1db | 846 | memerr: |
| donatien | 0:b802fc31f1db | 847 | /* free pbuf */ |
| donatien | 0:b802fc31f1db | 848 | pbuf_free(p); |
| donatien | 0:b802fc31f1db | 849 | return; |
| donatien | 0:b802fc31f1db | 850 | } |
| donatien | 0:b802fc31f1db | 851 | |
| donatien | 0:b802fc31f1db | 852 | /** |
| donatien | 0:b802fc31f1db | 853 | * Queues a new hostname to resolve and sends out a DNS query for that hostname |
| donatien | 0:b802fc31f1db | 854 | * |
| donatien | 0:b802fc31f1db | 855 | * @param name the hostname that is to be queried |
| donatien | 0:b802fc31f1db | 856 | * @param found a callback founction to be called on success, failure or timeout |
| donatien | 0:b802fc31f1db | 857 | * @param callback_arg argument to pass to the callback function |
| donatien | 0:b802fc31f1db | 858 | * @return @return a err_t return code. |
| donatien | 0:b802fc31f1db | 859 | */ |
| donatien | 0:b802fc31f1db | 860 | static err_t |
| donatien | 0:b802fc31f1db | 861 | dns_enqueue(const char *name, dns_found_callback found, void *callback_arg) |
| donatien | 0:b802fc31f1db | 862 | { |
| donatien | 0:b802fc31f1db | 863 | u8_t i; |
| donatien | 0:b802fc31f1db | 864 | u8_t lseq, lseqi; |
| donatien | 0:b802fc31f1db | 865 | struct dns_table_entry *pEntry = NULL; |
| donatien | 0:b802fc31f1db | 866 | size_t namelen; |
| donatien | 0:b802fc31f1db | 867 | |
| donatien | 0:b802fc31f1db | 868 | /* search an unused entry, or the oldest one */ |
| donatien | 0:b802fc31f1db | 869 | lseq = lseqi = 0; |
| donatien | 0:b802fc31f1db | 870 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
| donatien | 0:b802fc31f1db | 871 | pEntry = &dns_table[i]; |
| donatien | 0:b802fc31f1db | 872 | /* is it an unused entry ? */ |
| donatien | 0:b802fc31f1db | 873 | if (pEntry->state == DNS_STATE_UNUSED) |
| donatien | 0:b802fc31f1db | 874 | break; |
| donatien | 0:b802fc31f1db | 875 | |
| donatien | 0:b802fc31f1db | 876 | /* check if this is the oldest completed entry */ |
| donatien | 0:b802fc31f1db | 877 | if (pEntry->state == DNS_STATE_DONE) { |
| donatien | 0:b802fc31f1db | 878 | if ((dns_seqno - pEntry->seqno) > lseq) { |
| donatien | 0:b802fc31f1db | 879 | lseq = dns_seqno - pEntry->seqno; |
| donatien | 0:b802fc31f1db | 880 | lseqi = i; |
| donatien | 0:b802fc31f1db | 881 | } |
| donatien | 0:b802fc31f1db | 882 | } |
| donatien | 0:b802fc31f1db | 883 | } |
| donatien | 0:b802fc31f1db | 884 | |
| donatien | 0:b802fc31f1db | 885 | /* if we don't have found an unused entry, use the oldest completed one */ |
| donatien | 0:b802fc31f1db | 886 | if (i == DNS_TABLE_SIZE) { |
| donatien | 0:b802fc31f1db | 887 | if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) { |
| donatien | 0:b802fc31f1db | 888 | /* no entry can't be used now, table is full */ |
| donatien | 0:b802fc31f1db | 889 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name)); |
| donatien | 0:b802fc31f1db | 890 | return ERR_MEM; |
| donatien | 0:b802fc31f1db | 891 | } else { |
| donatien | 0:b802fc31f1db | 892 | /* use the oldest completed one */ |
| donatien | 0:b802fc31f1db | 893 | i = lseqi; |
| donatien | 0:b802fc31f1db | 894 | pEntry = &dns_table[i]; |
| donatien | 0:b802fc31f1db | 895 | } |
| donatien | 0:b802fc31f1db | 896 | } |
| donatien | 0:b802fc31f1db | 897 | |
| donatien | 0:b802fc31f1db | 898 | /* use this entry */ |
| donatien | 0:b802fc31f1db | 899 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i))); |
| donatien | 0:b802fc31f1db | 900 | |
| donatien | 0:b802fc31f1db | 901 | /* fill the entry */ |
| donatien | 0:b802fc31f1db | 902 | pEntry->state = DNS_STATE_NEW; |
| donatien | 0:b802fc31f1db | 903 | pEntry->seqno = dns_seqno++; |
| donatien | 0:b802fc31f1db | 904 | pEntry->found = found; |
| donatien | 0:b802fc31f1db | 905 | pEntry->arg = callback_arg; |
| donatien | 0:b802fc31f1db | 906 | namelen = LWIP_MIN(strlen(name), DNS_MAX_NAME_LENGTH-1); |
| donatien | 0:b802fc31f1db | 907 | MEMCPY(pEntry->name, name, namelen); |
| donatien | 0:b802fc31f1db | 908 | pEntry->name[namelen] = 0; |
| donatien | 0:b802fc31f1db | 909 | |
| donatien | 0:b802fc31f1db | 910 | /* force to send query without waiting timer */ |
| donatien | 0:b802fc31f1db | 911 | dns_check_entry(i); |
| donatien | 0:b802fc31f1db | 912 | |
| donatien | 0:b802fc31f1db | 913 | /* dns query is enqueued */ |
| donatien | 0:b802fc31f1db | 914 | return ERR_INPROGRESS; |
| donatien | 0:b802fc31f1db | 915 | } |
| donatien | 0:b802fc31f1db | 916 | |
| donatien | 0:b802fc31f1db | 917 | /** |
| donatien | 0:b802fc31f1db | 918 | * Resolve a hostname (string) into an IP address. |
| donatien | 0:b802fc31f1db | 919 | * NON-BLOCKING callback version for use with raw API!!! |
| donatien | 0:b802fc31f1db | 920 | * |
| donatien | 0:b802fc31f1db | 921 | * Returns immediately with one of err_t return codes: |
| donatien | 0:b802fc31f1db | 922 | * - ERR_OK if hostname is a valid IP address string or the host |
| donatien | 0:b802fc31f1db | 923 | * name is already in the local names table. |
| donatien | 0:b802fc31f1db | 924 | * - ERR_INPROGRESS enqueue a request to be sent to the DNS server |
| donatien | 0:b802fc31f1db | 925 | * for resolution if no errors are present. |
| donatien | 0:b802fc31f1db | 926 | * |
| donatien | 0:b802fc31f1db | 927 | * @param hostname the hostname that is to be queried |
| donatien | 0:b802fc31f1db | 928 | * @param addr pointer to a ip_addr_t where to store the address if it is already |
| donatien | 0:b802fc31f1db | 929 | * cached in the dns_table (only valid if ERR_OK is returned!) |
| donatien | 0:b802fc31f1db | 930 | * @param found a callback function to be called on success, failure or timeout (only if |
| donatien | 0:b802fc31f1db | 931 | * ERR_INPROGRESS is returned!) |
| donatien | 0:b802fc31f1db | 932 | * @param callback_arg argument to pass to the callback function |
| donatien | 0:b802fc31f1db | 933 | * @return a err_t return code. |
| donatien | 0:b802fc31f1db | 934 | */ |
| donatien | 0:b802fc31f1db | 935 | err_t |
| donatien | 0:b802fc31f1db | 936 | dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found, |
| donatien | 0:b802fc31f1db | 937 | void *callback_arg) |
| donatien | 0:b802fc31f1db | 938 | { |
| donatien | 0:b802fc31f1db | 939 | u32_t ipaddr; |
| donatien | 0:b802fc31f1db | 940 | /* not initialized or no valid server yet, or invalid addr pointer |
| donatien | 0:b802fc31f1db | 941 | * or invalid hostname or invalid hostname length */ |
| donatien | 0:b802fc31f1db | 942 | if ((dns_pcb == NULL) || (addr == NULL) || |
| donatien | 0:b802fc31f1db | 943 | (!hostname) || (!hostname[0]) || |
| donatien | 0:b802fc31f1db | 944 | (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) { |
| donatien | 0:b802fc31f1db | 945 | return ERR_VAL; |
| donatien | 0:b802fc31f1db | 946 | } |
| donatien | 0:b802fc31f1db | 947 | |
| donatien | 0:b802fc31f1db | 948 | #if LWIP_HAVE_LOOPIF |
| donatien | 0:b802fc31f1db | 949 | if (strcmp(hostname, "localhost")==0) { |
| donatien | 0:b802fc31f1db | 950 | ip_addr_set_loopback(addr); |
| donatien | 0:b802fc31f1db | 951 | return ERR_OK; |
| donatien | 0:b802fc31f1db | 952 | } |
| donatien | 0:b802fc31f1db | 953 | #endif /* LWIP_HAVE_LOOPIF */ |
| donatien | 0:b802fc31f1db | 954 | |
| donatien | 0:b802fc31f1db | 955 | /* host name already in octet notation? set ip addr and return ERR_OK */ |
| donatien | 0:b802fc31f1db | 956 | ipaddr = ipaddr_addr(hostname); |
| donatien | 0:b802fc31f1db | 957 | if (ipaddr == IPADDR_NONE) { |
| donatien | 0:b802fc31f1db | 958 | /* already have this address cached? */ |
| donatien | 0:b802fc31f1db | 959 | ipaddr = dns_lookup(hostname); |
| donatien | 0:b802fc31f1db | 960 | } |
| donatien | 0:b802fc31f1db | 961 | if (ipaddr != IPADDR_NONE) { |
| donatien | 0:b802fc31f1db | 962 | ip4_addr_set_u32(addr, ipaddr); |
| donatien | 0:b802fc31f1db | 963 | return ERR_OK; |
| donatien | 0:b802fc31f1db | 964 | } |
| donatien | 0:b802fc31f1db | 965 | |
| donatien | 0:b802fc31f1db | 966 | /* queue query with specified callback */ |
| donatien | 0:b802fc31f1db | 967 | return dns_enqueue(hostname, found, callback_arg); |
| donatien | 0:b802fc31f1db | 968 | } |
| donatien | 0:b802fc31f1db | 969 | |
| donatien | 0:b802fc31f1db | 970 | #endif /* LWIP_DNS */ |