My fork of the HTTPServer (working)
Core/lwIP/core/dns.c@1:284f2df30cf9, 2012-11-20 (annotated)
- Committer:
- screamer
- Date:
- Tue Nov 20 12:18:53 2012 +0000
- Revision:
- 1:284f2df30cf9
- Parent:
- 0:7a64fbb4069d
local changes
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
screamer | 0:7a64fbb4069d | 1 | /** |
screamer | 0:7a64fbb4069d | 2 | * @file |
screamer | 0:7a64fbb4069d | 3 | * DNS - host name to IP address resolver. |
screamer | 0:7a64fbb4069d | 4 | * |
screamer | 0:7a64fbb4069d | 5 | */ |
screamer | 0:7a64fbb4069d | 6 | |
screamer | 0:7a64fbb4069d | 7 | /** |
screamer | 0:7a64fbb4069d | 8 | |
screamer | 0:7a64fbb4069d | 9 | * This file implements a DNS host name to IP address resolver. |
screamer | 0:7a64fbb4069d | 10 | |
screamer | 0:7a64fbb4069d | 11 | * Port to lwIP from uIP |
screamer | 0:7a64fbb4069d | 12 | * by Jim Pettinato April 2007 |
screamer | 0:7a64fbb4069d | 13 | |
screamer | 0:7a64fbb4069d | 14 | * uIP version Copyright (c) 2002-2003, Adam Dunkels. |
screamer | 0:7a64fbb4069d | 15 | * All rights reserved. |
screamer | 0:7a64fbb4069d | 16 | * |
screamer | 0:7a64fbb4069d | 17 | * Redistribution and use in source and binary forms, with or without |
screamer | 0:7a64fbb4069d | 18 | * modification, are permitted provided that the following conditions |
screamer | 0:7a64fbb4069d | 19 | * are met: |
screamer | 0:7a64fbb4069d | 20 | * 1. Redistributions of source code must retain the above copyright |
screamer | 0:7a64fbb4069d | 21 | * notice, this list of conditions and the following disclaimer. |
screamer | 0:7a64fbb4069d | 22 | * 2. Redistributions in binary form must reproduce the above copyright |
screamer | 0:7a64fbb4069d | 23 | * notice, this list of conditions and the following disclaimer in the |
screamer | 0:7a64fbb4069d | 24 | * documentation and/or other materials provided with the distribution. |
screamer | 0:7a64fbb4069d | 25 | * 3. The name of the author may not be used to endorse or promote |
screamer | 0:7a64fbb4069d | 26 | * products derived from this software without specific prior |
screamer | 0:7a64fbb4069d | 27 | * written permission. |
screamer | 0:7a64fbb4069d | 28 | * |
screamer | 0:7a64fbb4069d | 29 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
screamer | 0:7a64fbb4069d | 30 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
screamer | 0:7a64fbb4069d | 31 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
screamer | 0:7a64fbb4069d | 32 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
screamer | 0:7a64fbb4069d | 33 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
screamer | 0:7a64fbb4069d | 34 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE |
screamer | 0:7a64fbb4069d | 35 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
screamer | 0:7a64fbb4069d | 36 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
screamer | 0:7a64fbb4069d | 37 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
screamer | 0:7a64fbb4069d | 38 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
screamer | 0:7a64fbb4069d | 39 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
screamer | 0:7a64fbb4069d | 40 | * |
screamer | 0:7a64fbb4069d | 41 | * |
screamer | 0:7a64fbb4069d | 42 | * DNS.C |
screamer | 0:7a64fbb4069d | 43 | * |
screamer | 0:7a64fbb4069d | 44 | * The lwIP DNS resolver functions are used to lookup a host name and |
screamer | 0:7a64fbb4069d | 45 | * map it to a numerical IP address. It maintains a list of resolved |
screamer | 0:7a64fbb4069d | 46 | * hostnames that can be queried with the dns_lookup() function. |
screamer | 0:7a64fbb4069d | 47 | * New hostnames can be resolved using the dns_query() function. |
screamer | 0:7a64fbb4069d | 48 | * |
screamer | 0:7a64fbb4069d | 49 | * The lwIP version of the resolver also adds a non-blocking version of |
screamer | 0:7a64fbb4069d | 50 | * gethostbyname() that will work with a raw API application. This function |
screamer | 0:7a64fbb4069d | 51 | * checks for an IP address string first and converts it if it is valid. |
screamer | 0:7a64fbb4069d | 52 | * gethostbyname() then does a dns_lookup() to see if the name is |
screamer | 0:7a64fbb4069d | 53 | * already in the table. If so, the IP is returned. If not, a query is |
screamer | 0:7a64fbb4069d | 54 | * issued and the function returns with a ERR_INPROGRESS status. The app |
screamer | 0:7a64fbb4069d | 55 | * using the dns client must then go into a waiting state. |
screamer | 0:7a64fbb4069d | 56 | * |
screamer | 0:7a64fbb4069d | 57 | * Once a hostname has been resolved (or found to be non-existent), |
screamer | 0:7a64fbb4069d | 58 | * the resolver code calls a specified callback function (which |
screamer | 0:7a64fbb4069d | 59 | * must be implemented by the module that uses the resolver). |
screamer | 0:7a64fbb4069d | 60 | */ |
screamer | 0:7a64fbb4069d | 61 | |
screamer | 0:7a64fbb4069d | 62 | /*----------------------------------------------------------------------------- |
screamer | 0:7a64fbb4069d | 63 | * RFC 1035 - Domain names - implementation and specification |
screamer | 0:7a64fbb4069d | 64 | * RFC 2181 - Clarifications to the DNS Specification |
screamer | 0:7a64fbb4069d | 65 | *----------------------------------------------------------------------------*/ |
screamer | 0:7a64fbb4069d | 66 | |
screamer | 0:7a64fbb4069d | 67 | /** @todo: define good default values (rfc compliance) */ |
screamer | 0:7a64fbb4069d | 68 | /** @todo: improve answer parsing, more checkings... */ |
screamer | 0:7a64fbb4069d | 69 | /** @todo: check RFC1035 - 7.3. Processing responses */ |
screamer | 0:7a64fbb4069d | 70 | |
screamer | 0:7a64fbb4069d | 71 | /*----------------------------------------------------------------------------- |
screamer | 0:7a64fbb4069d | 72 | * Includes |
screamer | 0:7a64fbb4069d | 73 | *----------------------------------------------------------------------------*/ |
screamer | 0:7a64fbb4069d | 74 | |
screamer | 0:7a64fbb4069d | 75 | #include "lwip/opt.h" |
screamer | 0:7a64fbb4069d | 76 | |
screamer | 0:7a64fbb4069d | 77 | #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */ |
screamer | 0:7a64fbb4069d | 78 | |
screamer | 0:7a64fbb4069d | 79 | #include "lwip/udp.h" |
screamer | 0:7a64fbb4069d | 80 | #include "lwip/mem.h" |
screamer | 0:7a64fbb4069d | 81 | #include "lwip/dns.h" |
screamer | 0:7a64fbb4069d | 82 | |
screamer | 0:7a64fbb4069d | 83 | #include <string.h> |
screamer | 0:7a64fbb4069d | 84 | |
screamer | 0:7a64fbb4069d | 85 | /** DNS server IP address */ |
screamer | 0:7a64fbb4069d | 86 | #ifndef DNS_SERVER_ADDRESS |
screamer | 0:7a64fbb4069d | 87 | #define DNS_SERVER_ADDRESS inet_addr("208.67.222.222") /* resolver1.opendns.com */ |
screamer | 0:7a64fbb4069d | 88 | #endif |
screamer | 0:7a64fbb4069d | 89 | |
screamer | 0:7a64fbb4069d | 90 | /** DNS server port address */ |
screamer | 0:7a64fbb4069d | 91 | #ifndef DNS_SERVER_PORT |
screamer | 0:7a64fbb4069d | 92 | #define DNS_SERVER_PORT 53 |
screamer | 0:7a64fbb4069d | 93 | #endif |
screamer | 0:7a64fbb4069d | 94 | |
screamer | 0:7a64fbb4069d | 95 | /** DNS maximum number of retries when asking for a name, before "timeout". */ |
screamer | 0:7a64fbb4069d | 96 | #ifndef DNS_MAX_RETRIES |
screamer | 0:7a64fbb4069d | 97 | #define DNS_MAX_RETRIES 4 |
screamer | 0:7a64fbb4069d | 98 | #endif |
screamer | 0:7a64fbb4069d | 99 | |
screamer | 0:7a64fbb4069d | 100 | /** DNS resource record max. TTL (one week as default) */ |
screamer | 0:7a64fbb4069d | 101 | #ifndef DNS_MAX_TTL |
screamer | 0:7a64fbb4069d | 102 | #define DNS_MAX_TTL 604800 |
screamer | 0:7a64fbb4069d | 103 | #endif |
screamer | 0:7a64fbb4069d | 104 | |
screamer | 0:7a64fbb4069d | 105 | /* DNS protocol flags */ |
screamer | 0:7a64fbb4069d | 106 | #define DNS_FLAG1_RESPONSE 0x80 |
screamer | 0:7a64fbb4069d | 107 | #define DNS_FLAG1_OPCODE_STATUS 0x10 |
screamer | 0:7a64fbb4069d | 108 | #define DNS_FLAG1_OPCODE_INVERSE 0x08 |
screamer | 0:7a64fbb4069d | 109 | #define DNS_FLAG1_OPCODE_STANDARD 0x00 |
screamer | 0:7a64fbb4069d | 110 | #define DNS_FLAG1_AUTHORATIVE 0x04 |
screamer | 0:7a64fbb4069d | 111 | #define DNS_FLAG1_TRUNC 0x02 |
screamer | 0:7a64fbb4069d | 112 | #define DNS_FLAG1_RD 0x01 |
screamer | 0:7a64fbb4069d | 113 | #define DNS_FLAG2_RA 0x80 |
screamer | 0:7a64fbb4069d | 114 | #define DNS_FLAG2_ERR_MASK 0x0f |
screamer | 0:7a64fbb4069d | 115 | #define DNS_FLAG2_ERR_NONE 0x00 |
screamer | 0:7a64fbb4069d | 116 | #define DNS_FLAG2_ERR_NAME 0x03 |
screamer | 0:7a64fbb4069d | 117 | |
screamer | 0:7a64fbb4069d | 118 | /* DNS protocol states */ |
screamer | 0:7a64fbb4069d | 119 | #define DNS_STATE_UNUSED 0 |
screamer | 0:7a64fbb4069d | 120 | #define DNS_STATE_NEW 1 |
screamer | 0:7a64fbb4069d | 121 | #define DNS_STATE_ASKING 2 |
screamer | 0:7a64fbb4069d | 122 | #define DNS_STATE_DONE 3 |
screamer | 0:7a64fbb4069d | 123 | |
screamer | 0:7a64fbb4069d | 124 | |
screamer | 0:7a64fbb4069d | 125 | // XXX: For C++ compatibility |
screamer | 0:7a64fbb4069d | 126 | #define class mclass |
screamer | 0:7a64fbb4069d | 127 | |
screamer | 0:7a64fbb4069d | 128 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 129 | # include "arch/bpstruct.h" |
screamer | 0:7a64fbb4069d | 130 | #endif |
screamer | 0:7a64fbb4069d | 131 | PACK_STRUCT_BEGIN |
screamer | 0:7a64fbb4069d | 132 | /** DNS message header */ |
screamer | 0:7a64fbb4069d | 133 | struct dns_hdr { |
screamer | 0:7a64fbb4069d | 134 | u16_t id; |
screamer | 0:7a64fbb4069d | 135 | u8_t flags1; |
screamer | 0:7a64fbb4069d | 136 | u8_t flags2; |
screamer | 0:7a64fbb4069d | 137 | u16_t numquestions; |
screamer | 0:7a64fbb4069d | 138 | u16_t numanswers; |
screamer | 0:7a64fbb4069d | 139 | u16_t numauthrr; |
screamer | 0:7a64fbb4069d | 140 | u16_t numextrarr; |
screamer | 0:7a64fbb4069d | 141 | } PACK_STRUCT_STRUCT; |
screamer | 0:7a64fbb4069d | 142 | PACK_STRUCT_END |
screamer | 0:7a64fbb4069d | 143 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 144 | # include "arch/epstruct.h" |
screamer | 0:7a64fbb4069d | 145 | #endif |
screamer | 0:7a64fbb4069d | 146 | #define SIZEOF_DNS_HDR 12 |
screamer | 0:7a64fbb4069d | 147 | |
screamer | 0:7a64fbb4069d | 148 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 149 | # include "arch/bpstruct.h" |
screamer | 0:7a64fbb4069d | 150 | #endif |
screamer | 0:7a64fbb4069d | 151 | PACK_STRUCT_BEGIN |
screamer | 0:7a64fbb4069d | 152 | /** DNS query message structure */ |
screamer | 0:7a64fbb4069d | 153 | struct dns_query { |
screamer | 0:7a64fbb4069d | 154 | /* DNS query record starts with either a domain name or a pointer |
screamer | 0:7a64fbb4069d | 155 | to a name already present somewhere in the packet. */ |
screamer | 0:7a64fbb4069d | 156 | u16_t type; |
screamer | 0:7a64fbb4069d | 157 | u16_t class; |
screamer | 0:7a64fbb4069d | 158 | } PACK_STRUCT_STRUCT; |
screamer | 0:7a64fbb4069d | 159 | PACK_STRUCT_END |
screamer | 0:7a64fbb4069d | 160 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 161 | # include "arch/epstruct.h" |
screamer | 0:7a64fbb4069d | 162 | #endif |
screamer | 0:7a64fbb4069d | 163 | #define SIZEOF_DNS_QUERY 4 |
screamer | 0:7a64fbb4069d | 164 | |
screamer | 0:7a64fbb4069d | 165 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 166 | # include "arch/bpstruct.h" |
screamer | 0:7a64fbb4069d | 167 | #endif |
screamer | 0:7a64fbb4069d | 168 | PACK_STRUCT_BEGIN |
screamer | 0:7a64fbb4069d | 169 | /** DNS answer message structure */ |
screamer | 0:7a64fbb4069d | 170 | struct dns_answer { |
screamer | 0:7a64fbb4069d | 171 | /* DNS answer record starts with either a domain name or a pointer |
screamer | 0:7a64fbb4069d | 172 | to a name already present somewhere in the packet. */ |
screamer | 0:7a64fbb4069d | 173 | u16_t type; |
screamer | 0:7a64fbb4069d | 174 | u16_t class; |
screamer | 0:7a64fbb4069d | 175 | u32_t ttl; |
screamer | 0:7a64fbb4069d | 176 | u16_t len; |
screamer | 0:7a64fbb4069d | 177 | } PACK_STRUCT_STRUCT; |
screamer | 0:7a64fbb4069d | 178 | PACK_STRUCT_END |
screamer | 0:7a64fbb4069d | 179 | #ifdef PACK_STRUCT_USE_INCLUDES |
screamer | 0:7a64fbb4069d | 180 | # include "arch/epstruct.h" |
screamer | 0:7a64fbb4069d | 181 | #endif |
screamer | 0:7a64fbb4069d | 182 | #define SIZEOF_DNS_ANSWER 10 |
screamer | 0:7a64fbb4069d | 183 | |
screamer | 0:7a64fbb4069d | 184 | /** DNS table entry */ |
screamer | 0:7a64fbb4069d | 185 | struct dns_table_entry { |
screamer | 0:7a64fbb4069d | 186 | u8_t state; |
screamer | 0:7a64fbb4069d | 187 | u8_t numdns; |
screamer | 0:7a64fbb4069d | 188 | u8_t tmr; |
screamer | 0:7a64fbb4069d | 189 | u8_t retries; |
screamer | 0:7a64fbb4069d | 190 | u8_t seqno; |
screamer | 0:7a64fbb4069d | 191 | u8_t err; |
screamer | 0:7a64fbb4069d | 192 | u32_t ttl; |
screamer | 0:7a64fbb4069d | 193 | char name[DNS_MAX_NAME_LENGTH]; |
screamer | 0:7a64fbb4069d | 194 | struct ip_addr ipaddr; |
screamer | 0:7a64fbb4069d | 195 | /* pointer to callback on DNS query done */ |
screamer | 0:7a64fbb4069d | 196 | dns_found_callback found; |
screamer | 0:7a64fbb4069d | 197 | void *arg; |
screamer | 0:7a64fbb4069d | 198 | }; |
screamer | 0:7a64fbb4069d | 199 | |
screamer | 0:7a64fbb4069d | 200 | #if DNS_LOCAL_HOSTLIST |
screamer | 0:7a64fbb4069d | 201 | /** struct used for local host-list */ |
screamer | 0:7a64fbb4069d | 202 | struct local_hostlist_entry { |
screamer | 0:7a64fbb4069d | 203 | /** static hostname */ |
screamer | 0:7a64fbb4069d | 204 | const char *name; |
screamer | 0:7a64fbb4069d | 205 | /** static host address in network byteorder */ |
screamer | 0:7a64fbb4069d | 206 | u32_t addr; |
screamer | 0:7a64fbb4069d | 207 | struct local_hostlist_entry *next; |
screamer | 0:7a64fbb4069d | 208 | }; |
screamer | 0:7a64fbb4069d | 209 | |
screamer | 0:7a64fbb4069d | 210 | #if !DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
screamer | 0:7a64fbb4069d | 211 | static struct local_hostlist_entry local_hostlist_static[] = DNS_LOCAL_HOSTLIST_INIT MEM_POSITION; |
screamer | 0:7a64fbb4069d | 212 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
screamer | 0:7a64fbb4069d | 213 | |
screamer | 0:7a64fbb4069d | 214 | /** Local host-list. For hostnames in this list, no |
screamer | 0:7a64fbb4069d | 215 | * external name resolution is performed */ |
screamer | 0:7a64fbb4069d | 216 | static struct local_hostlist_entry *local_hostlist; |
screamer | 0:7a64fbb4069d | 217 | |
screamer | 0:7a64fbb4069d | 218 | static void dns_init_local(); |
screamer | 0:7a64fbb4069d | 219 | #endif /* DNS_LOCAL_HOSTLIST */ |
screamer | 0:7a64fbb4069d | 220 | |
screamer | 0:7a64fbb4069d | 221 | |
screamer | 0:7a64fbb4069d | 222 | /* forward declarations */ |
screamer | 0:7a64fbb4069d | 223 | static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port); |
screamer | 0:7a64fbb4069d | 224 | static void dns_check_entries(void); |
screamer | 0:7a64fbb4069d | 225 | |
screamer | 0:7a64fbb4069d | 226 | /*----------------------------------------------------------------------------- |
screamer | 0:7a64fbb4069d | 227 | * Globales |
screamer | 0:7a64fbb4069d | 228 | *----------------------------------------------------------------------------*/ |
screamer | 0:7a64fbb4069d | 229 | |
screamer | 0:7a64fbb4069d | 230 | /* DNS variables */ |
screamer | 0:7a64fbb4069d | 231 | static struct udp_pcb *dns_pcb; |
screamer | 0:7a64fbb4069d | 232 | static u8_t dns_seqno; |
screamer | 0:7a64fbb4069d | 233 | static struct dns_table_entry dns_table[DNS_TABLE_SIZE] MEM_POSITION; |
screamer | 0:7a64fbb4069d | 234 | static struct ip_addr dns_servers[DNS_MAX_SERVERS] MEM_POSITION; |
screamer | 0:7a64fbb4069d | 235 | |
screamer | 0:7a64fbb4069d | 236 | #if (DNS_USES_STATIC_BUF == 1) |
screamer | 0:7a64fbb4069d | 237 | static u8_t dns_payload[DNS_MSG_SIZE] MEM_POSITION; |
screamer | 0:7a64fbb4069d | 238 | #endif /* (DNS_USES_STATIC_BUF == 1) */ |
screamer | 0:7a64fbb4069d | 239 | |
screamer | 0:7a64fbb4069d | 240 | /** |
screamer | 0:7a64fbb4069d | 241 | * Initialize the resolver: set up the UDP pcb and configure the default server |
screamer | 0:7a64fbb4069d | 242 | * (DNS_SERVER_ADDRESS). |
screamer | 0:7a64fbb4069d | 243 | */ |
screamer | 0:7a64fbb4069d | 244 | void |
screamer | 0:7a64fbb4069d | 245 | dns_init() |
screamer | 0:7a64fbb4069d | 246 | { |
screamer | 0:7a64fbb4069d | 247 | struct ip_addr dnsserver; |
screamer | 0:7a64fbb4069d | 248 | |
screamer | 0:7a64fbb4069d | 249 | /* initialize default DNS server address */ |
screamer | 0:7a64fbb4069d | 250 | dnsserver.addr = DNS_SERVER_ADDRESS; |
screamer | 0:7a64fbb4069d | 251 | |
screamer | 0:7a64fbb4069d | 252 | LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n")); |
screamer | 0:7a64fbb4069d | 253 | |
screamer | 0:7a64fbb4069d | 254 | /* if dns client not yet initialized... */ |
screamer | 0:7a64fbb4069d | 255 | if (dns_pcb == NULL) { |
screamer | 0:7a64fbb4069d | 256 | dns_pcb = udp_new(); |
screamer | 0:7a64fbb4069d | 257 | |
screamer | 0:7a64fbb4069d | 258 | if (dns_pcb != NULL) { |
screamer | 0:7a64fbb4069d | 259 | /* initialize DNS table not needed (initialized to zero since it is a |
screamer | 0:7a64fbb4069d | 260 | * global variable) */ |
screamer | 0:7a64fbb4069d | 261 | LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0", |
screamer | 0:7a64fbb4069d | 262 | DNS_STATE_UNUSED == 0); |
screamer | 0:7a64fbb4069d | 263 | |
screamer | 0:7a64fbb4069d | 264 | /* initialize DNS client */ |
screamer | 0:7a64fbb4069d | 265 | udp_bind(dns_pcb, IP_ADDR_ANY, 0); |
screamer | 0:7a64fbb4069d | 266 | udp_recv(dns_pcb, dns_recv, NULL); |
screamer | 0:7a64fbb4069d | 267 | |
screamer | 0:7a64fbb4069d | 268 | /* initialize default DNS primary server */ |
screamer | 0:7a64fbb4069d | 269 | dns_setserver(0, &dnsserver); |
screamer | 0:7a64fbb4069d | 270 | } |
screamer | 0:7a64fbb4069d | 271 | } |
screamer | 0:7a64fbb4069d | 272 | #if DNS_LOCAL_HOSTLIST |
screamer | 0:7a64fbb4069d | 273 | dns_init_local(); |
screamer | 0:7a64fbb4069d | 274 | #endif |
screamer | 0:7a64fbb4069d | 275 | } |
screamer | 0:7a64fbb4069d | 276 | |
screamer | 0:7a64fbb4069d | 277 | /** |
screamer | 0:7a64fbb4069d | 278 | * Initialize one of the DNS servers. |
screamer | 0:7a64fbb4069d | 279 | * |
screamer | 0:7a64fbb4069d | 280 | * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS |
screamer | 0:7a64fbb4069d | 281 | * @param dnsserver IP address of the DNS server to set |
screamer | 0:7a64fbb4069d | 282 | */ |
screamer | 0:7a64fbb4069d | 283 | void |
screamer | 0:7a64fbb4069d | 284 | dns_setserver(u8_t numdns, struct ip_addr *dnsserver) |
screamer | 0:7a64fbb4069d | 285 | { |
screamer | 0:7a64fbb4069d | 286 | if ((numdns < DNS_MAX_SERVERS) && (dns_pcb != NULL) && |
screamer | 0:7a64fbb4069d | 287 | (dnsserver != NULL) && (dnsserver->addr !=0 )) { |
screamer | 0:7a64fbb4069d | 288 | dns_servers[numdns] = (*dnsserver); |
screamer | 0:7a64fbb4069d | 289 | } |
screamer | 0:7a64fbb4069d | 290 | } |
screamer | 0:7a64fbb4069d | 291 | |
screamer | 0:7a64fbb4069d | 292 | /** |
screamer | 0:7a64fbb4069d | 293 | * Obtain one of the currently configured DNS server. |
screamer | 0:7a64fbb4069d | 294 | * |
screamer | 0:7a64fbb4069d | 295 | * @param numdns the index of the DNS server |
screamer | 0:7a64fbb4069d | 296 | * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS |
screamer | 0:7a64fbb4069d | 297 | * server has not been configured. |
screamer | 0:7a64fbb4069d | 298 | */ |
screamer | 0:7a64fbb4069d | 299 | struct ip_addr |
screamer | 0:7a64fbb4069d | 300 | dns_getserver(u8_t numdns) |
screamer | 0:7a64fbb4069d | 301 | { |
screamer | 0:7a64fbb4069d | 302 | if (numdns < DNS_MAX_SERVERS) { |
screamer | 0:7a64fbb4069d | 303 | return dns_servers[numdns]; |
screamer | 0:7a64fbb4069d | 304 | } else { |
screamer | 0:7a64fbb4069d | 305 | return *IP_ADDR_ANY; |
screamer | 0:7a64fbb4069d | 306 | } |
screamer | 0:7a64fbb4069d | 307 | } |
screamer | 0:7a64fbb4069d | 308 | |
screamer | 0:7a64fbb4069d | 309 | /** |
screamer | 0:7a64fbb4069d | 310 | * The DNS resolver client timer - handle retries and timeouts and should |
screamer | 0:7a64fbb4069d | 311 | * be called every DNS_TMR_INTERVAL milliseconds (every second by default). |
screamer | 0:7a64fbb4069d | 312 | */ |
screamer | 0:7a64fbb4069d | 313 | void |
screamer | 0:7a64fbb4069d | 314 | dns_tmr(void) |
screamer | 0:7a64fbb4069d | 315 | { |
screamer | 0:7a64fbb4069d | 316 | if (dns_pcb != NULL) { |
screamer | 0:7a64fbb4069d | 317 | LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n")); |
screamer | 0:7a64fbb4069d | 318 | dns_check_entries(); |
screamer | 0:7a64fbb4069d | 319 | } |
screamer | 0:7a64fbb4069d | 320 | } |
screamer | 0:7a64fbb4069d | 321 | |
screamer | 0:7a64fbb4069d | 322 | #if DNS_LOCAL_HOSTLIST |
screamer | 0:7a64fbb4069d | 323 | static void |
screamer | 0:7a64fbb4069d | 324 | dns_init_local() |
screamer | 0:7a64fbb4069d | 325 | { |
screamer | 0:7a64fbb4069d | 326 | #ifdef DNS_LOCAL_HOSTLIST_INIT |
screamer | 0:7a64fbb4069d | 327 | int i; |
screamer | 0:7a64fbb4069d | 328 | struct local_hostlist_entry *entry; |
screamer | 0:7a64fbb4069d | 329 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
screamer | 0:7a64fbb4069d | 330 | /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */ |
screamer | 0:7a64fbb4069d | 331 | struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT; |
screamer | 0:7a64fbb4069d | 332 | for (i = 0; i < sizeof(local_hostlist_init) / sizeof(struct local_hostlist_entry); i++) { |
screamer | 0:7a64fbb4069d | 333 | entry = mem_malloc(sizeof(struct local_hostlist_entry)); |
screamer | 0:7a64fbb4069d | 334 | LWIP_ASSERT("mem-error in dns_init_local", entry != NULL); |
screamer | 0:7a64fbb4069d | 335 | if (entry != NULL) { |
screamer | 0:7a64fbb4069d | 336 | struct local_hostlist_entry *init_entry = &local_hostlist_init[i]; |
screamer | 0:7a64fbb4069d | 337 | entry->name = init_entry->name; |
screamer | 0:7a64fbb4069d | 338 | entry->addr = init_entry->addr; |
screamer | 0:7a64fbb4069d | 339 | entry->next = local_hostlist; |
screamer | 0:7a64fbb4069d | 340 | local_hostlist = entry; |
screamer | 0:7a64fbb4069d | 341 | } |
screamer | 0:7a64fbb4069d | 342 | } |
screamer | 0:7a64fbb4069d | 343 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
screamer | 0:7a64fbb4069d | 344 | /* Static: only adjust the 'next' pointers */ |
screamer | 0:7a64fbb4069d | 345 | entry = NULL; |
screamer | 0:7a64fbb4069d | 346 | local_hostlist = local_hostlist_static; |
screamer | 0:7a64fbb4069d | 347 | for (i = sizeof(local_hostlist_static) / sizeof(struct local_hostlist_entry) - 1; i >= 0; i--) { |
screamer | 0:7a64fbb4069d | 348 | local_hostlist_static[i].next = entry; |
screamer | 0:7a64fbb4069d | 349 | entry = &local_hostlist_static[i]; |
screamer | 0:7a64fbb4069d | 350 | } |
screamer | 0:7a64fbb4069d | 351 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ |
screamer | 0:7a64fbb4069d | 352 | #endif /* DNS_LOCAL_HOSTLIST_INIT */ |
screamer | 0:7a64fbb4069d | 353 | } |
screamer | 0:7a64fbb4069d | 354 | |
screamer | 0:7a64fbb4069d | 355 | static u32_t |
screamer | 0:7a64fbb4069d | 356 | dns_lookup_static(const char *name) |
screamer | 0:7a64fbb4069d | 357 | { |
screamer | 0:7a64fbb4069d | 358 | struct local_hostlist_entry *entry = local_hostlist; |
screamer | 0:7a64fbb4069d | 359 | while(entry != NULL) { |
screamer | 0:7a64fbb4069d | 360 | if(strcmp(entry->name, name) == 0) { |
screamer | 0:7a64fbb4069d | 361 | return htons(entry->addr); |
screamer | 0:7a64fbb4069d | 362 | } |
screamer | 0:7a64fbb4069d | 363 | entry = entry->next; |
screamer | 0:7a64fbb4069d | 364 | } |
screamer | 0:7a64fbb4069d | 365 | return INADDR_NONE; |
screamer | 0:7a64fbb4069d | 366 | } |
screamer | 0:7a64fbb4069d | 367 | |
screamer | 0:7a64fbb4069d | 368 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC |
screamer | 0:7a64fbb4069d | 369 | /** Remove all entries from the local host-list for a specific hostname |
screamer | 0:7a64fbb4069d | 370 | * |
screamer | 0:7a64fbb4069d | 371 | * @param hostname hostname for which entries shall be removed from the local |
screamer | 0:7a64fbb4069d | 372 | * host-list |
screamer | 0:7a64fbb4069d | 373 | * @return the number of removed entries |
screamer | 0:7a64fbb4069d | 374 | */ |
screamer | 0:7a64fbb4069d | 375 | int |
screamer | 0:7a64fbb4069d | 376 | dns_local_removehostname(const char *hostname) |
screamer | 0:7a64fbb4069d | 377 | { |
screamer | 0:7a64fbb4069d | 378 | int removed = 0; |
screamer | 0:7a64fbb4069d | 379 | struct local_hostlist_entry *entry = local_hostlist; |
screamer | 0:7a64fbb4069d | 380 | struct local_hostlist_entry *last_entry = NULL; |
screamer | 0:7a64fbb4069d | 381 | while (entry != NULL) { |
screamer | 0:7a64fbb4069d | 382 | if (!strcmp(entry->name, hostname)) { |
screamer | 0:7a64fbb4069d | 383 | if (last_entry != NULL) { |
screamer | 0:7a64fbb4069d | 384 | last_entry->next = entry->next; |
screamer | 0:7a64fbb4069d | 385 | } else { |
screamer | 0:7a64fbb4069d | 386 | local_hostlist = entry->next; |
screamer | 0:7a64fbb4069d | 387 | } |
screamer | 0:7a64fbb4069d | 388 | mem_free(entry); |
screamer | 0:7a64fbb4069d | 389 | removed++; |
screamer | 0:7a64fbb4069d | 390 | } |
screamer | 0:7a64fbb4069d | 391 | last_entry = entry; |
screamer | 0:7a64fbb4069d | 392 | entry = entry->next; |
screamer | 0:7a64fbb4069d | 393 | } |
screamer | 0:7a64fbb4069d | 394 | return removed; |
screamer | 0:7a64fbb4069d | 395 | } |
screamer | 0:7a64fbb4069d | 396 | |
screamer | 0:7a64fbb4069d | 397 | /** Remove all entries from the local host-list for a specific address |
screamer | 0:7a64fbb4069d | 398 | * |
screamer | 0:7a64fbb4069d | 399 | * @param addr address for which entries shall be removed from the local |
screamer | 0:7a64fbb4069d | 400 | * host-list |
screamer | 0:7a64fbb4069d | 401 | * @return the number of removed entries |
screamer | 0:7a64fbb4069d | 402 | */ |
screamer | 0:7a64fbb4069d | 403 | int |
screamer | 0:7a64fbb4069d | 404 | dns_local_removehostaddr(const struct ip_addr *addr) |
screamer | 0:7a64fbb4069d | 405 | { |
screamer | 0:7a64fbb4069d | 406 | int removed = 0; |
screamer | 0:7a64fbb4069d | 407 | struct local_hostlist_entry *entry = local_hostlist; |
screamer | 0:7a64fbb4069d | 408 | struct local_hostlist_entry *last_entry = NULL; |
screamer | 0:7a64fbb4069d | 409 | while (entry != NULL) { |
screamer | 0:7a64fbb4069d | 410 | if (entry->addr == addr->addr) { |
screamer | 0:7a64fbb4069d | 411 | struct local_hostlist_entry *removed_entry = entry; |
screamer | 0:7a64fbb4069d | 412 | if (last_entry != NULL) { |
screamer | 0:7a64fbb4069d | 413 | last_entry->next = entry->next; |
screamer | 0:7a64fbb4069d | 414 | } else { |
screamer | 0:7a64fbb4069d | 415 | local_hostlist = entry->next; |
screamer | 0:7a64fbb4069d | 416 | } |
screamer | 0:7a64fbb4069d | 417 | entry = entry->next; |
screamer | 0:7a64fbb4069d | 418 | mem_free(removed_entry); |
screamer | 0:7a64fbb4069d | 419 | removed++; |
screamer | 0:7a64fbb4069d | 420 | } else { |
screamer | 0:7a64fbb4069d | 421 | last_entry = entry; |
screamer | 0:7a64fbb4069d | 422 | entry = entry->next; |
screamer | 0:7a64fbb4069d | 423 | } |
screamer | 0:7a64fbb4069d | 424 | } |
screamer | 0:7a64fbb4069d | 425 | return removed; |
screamer | 0:7a64fbb4069d | 426 | } |
screamer | 0:7a64fbb4069d | 427 | |
screamer | 0:7a64fbb4069d | 428 | err_t |
screamer | 0:7a64fbb4069d | 429 | dns_local_addhost(const char *hostname, const struct ip_addr *addr) |
screamer | 0:7a64fbb4069d | 430 | { |
screamer | 0:7a64fbb4069d | 431 | struct local_hostlist_entry *entry; |
screamer | 0:7a64fbb4069d | 432 | entry = mem_malloc(sizeof(struct local_hostlist_entry)); |
screamer | 0:7a64fbb4069d | 433 | if (entry == NULL) { |
screamer | 0:7a64fbb4069d | 434 | return ERR_MEM; |
screamer | 0:7a64fbb4069d | 435 | } |
screamer | 0:7a64fbb4069d | 436 | entry->name = hostname; |
screamer | 0:7a64fbb4069d | 437 | entry->addr = addr->addr; |
screamer | 0:7a64fbb4069d | 438 | entry->next = local_hostlist; |
screamer | 0:7a64fbb4069d | 439 | local_hostlist = entry; |
screamer | 0:7a64fbb4069d | 440 | return ERR_OK; |
screamer | 0:7a64fbb4069d | 441 | } |
screamer | 0:7a64fbb4069d | 442 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/ |
screamer | 0:7a64fbb4069d | 443 | #endif /* DNS_LOCAL_HOSTLIST */ |
screamer | 0:7a64fbb4069d | 444 | |
screamer | 0:7a64fbb4069d | 445 | /** |
screamer | 0:7a64fbb4069d | 446 | * Look up a hostname in the array of known hostnames. |
screamer | 0:7a64fbb4069d | 447 | * |
screamer | 0:7a64fbb4069d | 448 | * @note This function only looks in the internal array of known |
screamer | 0:7a64fbb4069d | 449 | * hostnames, it does not send out a query for the hostname if none |
screamer | 0:7a64fbb4069d | 450 | * was found. The function dns_enqueue() can be used to send a query |
screamer | 0:7a64fbb4069d | 451 | * for a hostname. |
screamer | 0:7a64fbb4069d | 452 | * |
screamer | 0:7a64fbb4069d | 453 | * @param name the hostname to look up |
screamer | 0:7a64fbb4069d | 454 | * @return the hostname's IP address, as u32_t (instead of struct ip_addr to |
screamer | 0:7a64fbb4069d | 455 | * better check for failure: != INADDR_NONE) or INADDR_NONE if the hostname |
screamer | 0:7a64fbb4069d | 456 | * was not found in the cached dns_table. |
screamer | 0:7a64fbb4069d | 457 | */ |
screamer | 0:7a64fbb4069d | 458 | static u32_t |
screamer | 0:7a64fbb4069d | 459 | dns_lookup(const char *name) |
screamer | 0:7a64fbb4069d | 460 | { |
screamer | 0:7a64fbb4069d | 461 | u8_t i; |
screamer | 0:7a64fbb4069d | 462 | #if DNS_LOCAL_HOSTLIST |
screamer | 0:7a64fbb4069d | 463 | u32_t addr; |
screamer | 0:7a64fbb4069d | 464 | |
screamer | 0:7a64fbb4069d | 465 | if ((addr = dns_lookup_static(name)) != INADDR_NONE) { |
screamer | 0:7a64fbb4069d | 466 | return addr; |
screamer | 0:7a64fbb4069d | 467 | } |
screamer | 0:7a64fbb4069d | 468 | #endif /* DNS_LOCAL_HOSTLIST */ |
screamer | 0:7a64fbb4069d | 469 | |
screamer | 0:7a64fbb4069d | 470 | /* Walk through name list, return entry if found. If not, return NULL. */ |
screamer | 0:7a64fbb4069d | 471 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
screamer | 0:7a64fbb4069d | 472 | if ((dns_table[i].state == DNS_STATE_DONE) && |
screamer | 0:7a64fbb4069d | 473 | (strcmp(name, dns_table[i].name) == 0)) { |
screamer | 0:7a64fbb4069d | 474 | LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name)); |
screamer | 0:7a64fbb4069d | 475 | ip_addr_debug_print(DNS_DEBUG, &(dns_table[i].ipaddr)); |
screamer | 0:7a64fbb4069d | 476 | LWIP_DEBUGF(DNS_DEBUG, ("\n")); |
screamer | 0:7a64fbb4069d | 477 | return dns_table[i].ipaddr.addr; |
screamer | 0:7a64fbb4069d | 478 | } |
screamer | 0:7a64fbb4069d | 479 | } |
screamer | 0:7a64fbb4069d | 480 | |
screamer | 0:7a64fbb4069d | 481 | return INADDR_NONE; |
screamer | 0:7a64fbb4069d | 482 | } |
screamer | 0:7a64fbb4069d | 483 | |
screamer | 0:7a64fbb4069d | 484 | #if DNS_DOES_NAME_CHECK |
screamer | 0:7a64fbb4069d | 485 | /** |
screamer | 0:7a64fbb4069d | 486 | * Compare the "dotted" name "query" with the encoded name "response" |
screamer | 0:7a64fbb4069d | 487 | * to make sure an answer from the DNS server matches the current dns_table |
screamer | 0:7a64fbb4069d | 488 | * entry (otherwise, answers might arrive late for hostname not on the list |
screamer | 0:7a64fbb4069d | 489 | * any more). |
screamer | 0:7a64fbb4069d | 490 | * |
screamer | 0:7a64fbb4069d | 491 | * @param query hostname (not encoded) from the dns_table |
screamer | 0:7a64fbb4069d | 492 | * @param response encoded hostname in the DNS response |
screamer | 0:7a64fbb4069d | 493 | * @return 0: names equal; 1: names differ |
screamer | 0:7a64fbb4069d | 494 | */ |
screamer | 0:7a64fbb4069d | 495 | static u8_t |
screamer | 0:7a64fbb4069d | 496 | dns_compare_name(unsigned char *query, unsigned char *response) |
screamer | 0:7a64fbb4069d | 497 | { |
screamer | 0:7a64fbb4069d | 498 | unsigned char n; |
screamer | 0:7a64fbb4069d | 499 | |
screamer | 0:7a64fbb4069d | 500 | do { |
screamer | 0:7a64fbb4069d | 501 | n = *response++; |
screamer | 0:7a64fbb4069d | 502 | /** @see RFC 1035 - 4.1.4. Message compression */ |
screamer | 0:7a64fbb4069d | 503 | if ((n & 0xc0) == 0xc0) { |
screamer | 0:7a64fbb4069d | 504 | /* Compressed name */ |
screamer | 0:7a64fbb4069d | 505 | break; |
screamer | 0:7a64fbb4069d | 506 | } else { |
screamer | 0:7a64fbb4069d | 507 | /* Not compressed name */ |
screamer | 0:7a64fbb4069d | 508 | while (n > 0) { |
screamer | 0:7a64fbb4069d | 509 | if ((*query) != (*response)) { |
screamer | 0:7a64fbb4069d | 510 | return 1; |
screamer | 0:7a64fbb4069d | 511 | } |
screamer | 0:7a64fbb4069d | 512 | ++response; |
screamer | 0:7a64fbb4069d | 513 | ++query; |
screamer | 0:7a64fbb4069d | 514 | --n; |
screamer | 0:7a64fbb4069d | 515 | }; |
screamer | 0:7a64fbb4069d | 516 | ++query; |
screamer | 0:7a64fbb4069d | 517 | } |
screamer | 0:7a64fbb4069d | 518 | } while (*response != 0); |
screamer | 0:7a64fbb4069d | 519 | |
screamer | 0:7a64fbb4069d | 520 | return 0; |
screamer | 0:7a64fbb4069d | 521 | } |
screamer | 0:7a64fbb4069d | 522 | #endif /* DNS_DOES_NAME_CHECK */ |
screamer | 0:7a64fbb4069d | 523 | |
screamer | 0:7a64fbb4069d | 524 | /** |
screamer | 0:7a64fbb4069d | 525 | * Walk through a compact encoded DNS name and return the end of the name. |
screamer | 0:7a64fbb4069d | 526 | * |
screamer | 0:7a64fbb4069d | 527 | * @param query encoded DNS name in the DNS server response |
screamer | 0:7a64fbb4069d | 528 | * @return end of the name |
screamer | 0:7a64fbb4069d | 529 | */ |
screamer | 0:7a64fbb4069d | 530 | static unsigned char * |
screamer | 0:7a64fbb4069d | 531 | dns_parse_name(unsigned char *query) |
screamer | 0:7a64fbb4069d | 532 | { |
screamer | 0:7a64fbb4069d | 533 | unsigned char n; |
screamer | 0:7a64fbb4069d | 534 | |
screamer | 0:7a64fbb4069d | 535 | do { |
screamer | 0:7a64fbb4069d | 536 | n = *query++; |
screamer | 0:7a64fbb4069d | 537 | /** @see RFC 1035 - 4.1.4. Message compression */ |
screamer | 0:7a64fbb4069d | 538 | if ((n & 0xc0) == 0xc0) { |
screamer | 0:7a64fbb4069d | 539 | /* Compressed name */ |
screamer | 0:7a64fbb4069d | 540 | break; |
screamer | 0:7a64fbb4069d | 541 | } else { |
screamer | 0:7a64fbb4069d | 542 | /* Not compressed name */ |
screamer | 0:7a64fbb4069d | 543 | while (n > 0) { |
screamer | 0:7a64fbb4069d | 544 | ++query; |
screamer | 0:7a64fbb4069d | 545 | --n; |
screamer | 0:7a64fbb4069d | 546 | }; |
screamer | 0:7a64fbb4069d | 547 | } |
screamer | 0:7a64fbb4069d | 548 | } while (*query != 0); |
screamer | 0:7a64fbb4069d | 549 | |
screamer | 0:7a64fbb4069d | 550 | return query + 1; |
screamer | 0:7a64fbb4069d | 551 | } |
screamer | 0:7a64fbb4069d | 552 | |
screamer | 0:7a64fbb4069d | 553 | /** |
screamer | 0:7a64fbb4069d | 554 | * Send a DNS query packet. |
screamer | 0:7a64fbb4069d | 555 | * |
screamer | 0:7a64fbb4069d | 556 | * @param numdns index of the DNS server in the dns_servers table |
screamer | 0:7a64fbb4069d | 557 | * @param name hostname to query |
screamer | 0:7a64fbb4069d | 558 | * @param id index of the hostname in dns_table, used as transaction ID in the |
screamer | 0:7a64fbb4069d | 559 | * DNS query packet |
screamer | 0:7a64fbb4069d | 560 | * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise |
screamer | 0:7a64fbb4069d | 561 | */ |
screamer | 0:7a64fbb4069d | 562 | static err_t |
screamer | 0:7a64fbb4069d | 563 | dns_send(u8_t numdns, const char* name, u8_t id) |
screamer | 0:7a64fbb4069d | 564 | { |
screamer | 0:7a64fbb4069d | 565 | err_t err; |
screamer | 0:7a64fbb4069d | 566 | struct dns_hdr *hdr; |
screamer | 0:7a64fbb4069d | 567 | struct dns_query qry; |
screamer | 0:7a64fbb4069d | 568 | struct pbuf *p; |
screamer | 0:7a64fbb4069d | 569 | char *query, *nptr; |
screamer | 0:7a64fbb4069d | 570 | const char *pHostname; |
screamer | 0:7a64fbb4069d | 571 | u8_t n; |
screamer | 0:7a64fbb4069d | 572 | |
screamer | 0:7a64fbb4069d | 573 | LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n", |
screamer | 0:7a64fbb4069d | 574 | (u16_t)(numdns), name)); |
screamer | 0:7a64fbb4069d | 575 | LWIP_ASSERT("dns server out of array", numdns < DNS_MAX_SERVERS); |
screamer | 0:7a64fbb4069d | 576 | LWIP_ASSERT("dns server has no IP address set", dns_servers[numdns].addr != 0); |
screamer | 0:7a64fbb4069d | 577 | |
screamer | 0:7a64fbb4069d | 578 | /* if here, we have either a new query or a retry on a previous query to process */ |
screamer | 0:7a64fbb4069d | 579 | p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH + |
screamer | 0:7a64fbb4069d | 580 | SIZEOF_DNS_QUERY, PBUF_RAM); |
screamer | 0:7a64fbb4069d | 581 | if (p != NULL) { |
screamer | 0:7a64fbb4069d | 582 | LWIP_ASSERT("pbuf must be in one piece", p->next == NULL); |
screamer | 0:7a64fbb4069d | 583 | /* fill dns header */ |
screamer | 0:7a64fbb4069d | 584 | hdr = (struct dns_hdr*)p->payload; |
screamer | 0:7a64fbb4069d | 585 | memset(hdr, 0, SIZEOF_DNS_HDR); |
screamer | 0:7a64fbb4069d | 586 | hdr->id = htons(id); |
screamer | 0:7a64fbb4069d | 587 | hdr->flags1 = DNS_FLAG1_RD; |
screamer | 0:7a64fbb4069d | 588 | hdr->numquestions = htons(1); |
screamer | 0:7a64fbb4069d | 589 | query = (char*)hdr + SIZEOF_DNS_HDR; |
screamer | 0:7a64fbb4069d | 590 | pHostname = name; |
screamer | 0:7a64fbb4069d | 591 | --pHostname; |
screamer | 0:7a64fbb4069d | 592 | |
screamer | 0:7a64fbb4069d | 593 | /* convert hostname into suitable query format. */ |
screamer | 0:7a64fbb4069d | 594 | do { |
screamer | 0:7a64fbb4069d | 595 | ++pHostname; |
screamer | 0:7a64fbb4069d | 596 | nptr = query; |
screamer | 0:7a64fbb4069d | 597 | ++query; |
screamer | 0:7a64fbb4069d | 598 | for(n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) { |
screamer | 0:7a64fbb4069d | 599 | *query = *pHostname; |
screamer | 0:7a64fbb4069d | 600 | ++query; |
screamer | 0:7a64fbb4069d | 601 | ++n; |
screamer | 0:7a64fbb4069d | 602 | } |
screamer | 0:7a64fbb4069d | 603 | *nptr = n; |
screamer | 0:7a64fbb4069d | 604 | } while(*pHostname != 0); |
screamer | 0:7a64fbb4069d | 605 | *query++='\0'; |
screamer | 0:7a64fbb4069d | 606 | |
screamer | 0:7a64fbb4069d | 607 | /* fill dns query */ |
screamer | 0:7a64fbb4069d | 608 | qry.type = htons(DNS_RRTYPE_A); |
screamer | 0:7a64fbb4069d | 609 | qry.class = htons(DNS_RRCLASS_IN); |
screamer | 0:7a64fbb4069d | 610 | MEMCPY( query, &qry, SIZEOF_DNS_QUERY); |
screamer | 0:7a64fbb4069d | 611 | |
screamer | 0:7a64fbb4069d | 612 | /* resize pbuf to the exact dns query */ |
screamer | 0:7a64fbb4069d | 613 | pbuf_realloc(p, (query + SIZEOF_DNS_QUERY) - ((char*)(p->payload))); |
screamer | 0:7a64fbb4069d | 614 | |
screamer | 0:7a64fbb4069d | 615 | /* connect to the server for faster receiving */ |
screamer | 0:7a64fbb4069d | 616 | udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT); |
screamer | 0:7a64fbb4069d | 617 | /* send dns packet */ |
screamer | 0:7a64fbb4069d | 618 | err = udp_sendto(dns_pcb, p, &dns_servers[numdns], DNS_SERVER_PORT); |
screamer | 0:7a64fbb4069d | 619 | |
screamer | 0:7a64fbb4069d | 620 | /* free pbuf */ |
screamer | 0:7a64fbb4069d | 621 | pbuf_free(p); |
screamer | 0:7a64fbb4069d | 622 | } else { |
screamer | 0:7a64fbb4069d | 623 | err = ERR_MEM; |
screamer | 0:7a64fbb4069d | 624 | } |
screamer | 0:7a64fbb4069d | 625 | |
screamer | 0:7a64fbb4069d | 626 | return err; |
screamer | 0:7a64fbb4069d | 627 | } |
screamer | 0:7a64fbb4069d | 628 | |
screamer | 0:7a64fbb4069d | 629 | /** |
screamer | 0:7a64fbb4069d | 630 | * dns_check_entry() - see if pEntry has not yet been queried and, if so, sends out a query. |
screamer | 0:7a64fbb4069d | 631 | * Check an entry in the dns_table: |
screamer | 0:7a64fbb4069d | 632 | * - send out query for new entries |
screamer | 0:7a64fbb4069d | 633 | * - retry old pending entries on timeout (also with different servers) |
screamer | 0:7a64fbb4069d | 634 | * - remove completed entries from the table if their TTL has expired |
screamer | 0:7a64fbb4069d | 635 | * |
screamer | 0:7a64fbb4069d | 636 | * @param i index of the dns_table entry to check |
screamer | 0:7a64fbb4069d | 637 | */ |
screamer | 0:7a64fbb4069d | 638 | static void |
screamer | 0:7a64fbb4069d | 639 | dns_check_entry(u8_t i) |
screamer | 0:7a64fbb4069d | 640 | { |
screamer | 0:7a64fbb4069d | 641 | struct dns_table_entry *pEntry = &dns_table[i]; |
screamer | 0:7a64fbb4069d | 642 | |
screamer | 0:7a64fbb4069d | 643 | LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE); |
screamer | 0:7a64fbb4069d | 644 | |
screamer | 0:7a64fbb4069d | 645 | switch(pEntry->state) { |
screamer | 0:7a64fbb4069d | 646 | |
screamer | 0:7a64fbb4069d | 647 | case DNS_STATE_NEW: { |
screamer | 0:7a64fbb4069d | 648 | /* initialize new entry */ |
screamer | 0:7a64fbb4069d | 649 | pEntry->state = DNS_STATE_ASKING; |
screamer | 0:7a64fbb4069d | 650 | pEntry->numdns = 0; |
screamer | 0:7a64fbb4069d | 651 | pEntry->tmr = 1; |
screamer | 0:7a64fbb4069d | 652 | pEntry->retries = 0; |
screamer | 0:7a64fbb4069d | 653 | |
screamer | 0:7a64fbb4069d | 654 | /* send DNS packet for this entry */ |
screamer | 0:7a64fbb4069d | 655 | dns_send(pEntry->numdns, pEntry->name, i); |
screamer | 0:7a64fbb4069d | 656 | break; |
screamer | 0:7a64fbb4069d | 657 | } |
screamer | 0:7a64fbb4069d | 658 | |
screamer | 0:7a64fbb4069d | 659 | case DNS_STATE_ASKING: { |
screamer | 0:7a64fbb4069d | 660 | if (--pEntry->tmr == 0) { |
screamer | 0:7a64fbb4069d | 661 | if (++pEntry->retries == DNS_MAX_RETRIES) { |
screamer | 0:7a64fbb4069d | 662 | if ((pEntry->numdns+1<DNS_MAX_SERVERS) && (dns_servers[pEntry->numdns+1].addr!=0)) { |
screamer | 0:7a64fbb4069d | 663 | /* change of server */ |
screamer | 0:7a64fbb4069d | 664 | pEntry->numdns++; |
screamer | 0:7a64fbb4069d | 665 | pEntry->tmr = 1; |
screamer | 0:7a64fbb4069d | 666 | pEntry->retries = 0; |
screamer | 0:7a64fbb4069d | 667 | break; |
screamer | 0:7a64fbb4069d | 668 | } else { |
screamer | 0:7a64fbb4069d | 669 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", pEntry->name)); |
screamer | 0:7a64fbb4069d | 670 | /* call specified callback function if provided */ |
screamer | 0:7a64fbb4069d | 671 | if (pEntry->found) |
screamer | 0:7a64fbb4069d | 672 | (*pEntry->found)(pEntry->name, NULL, pEntry->arg); |
screamer | 0:7a64fbb4069d | 673 | /* flush this entry */ |
screamer | 0:7a64fbb4069d | 674 | pEntry->state = DNS_STATE_UNUSED; |
screamer | 0:7a64fbb4069d | 675 | pEntry->found = NULL; |
screamer | 0:7a64fbb4069d | 676 | break; |
screamer | 0:7a64fbb4069d | 677 | } |
screamer | 0:7a64fbb4069d | 678 | } |
screamer | 0:7a64fbb4069d | 679 | |
screamer | 0:7a64fbb4069d | 680 | /* wait longer for the next retry */ |
screamer | 0:7a64fbb4069d | 681 | pEntry->tmr = pEntry->retries; |
screamer | 0:7a64fbb4069d | 682 | |
screamer | 0:7a64fbb4069d | 683 | /* send DNS packet for this entry */ |
screamer | 0:7a64fbb4069d | 684 | dns_send(pEntry->numdns, pEntry->name, i); |
screamer | 0:7a64fbb4069d | 685 | } |
screamer | 0:7a64fbb4069d | 686 | break; |
screamer | 0:7a64fbb4069d | 687 | } |
screamer | 0:7a64fbb4069d | 688 | |
screamer | 0:7a64fbb4069d | 689 | case DNS_STATE_DONE: { |
screamer | 0:7a64fbb4069d | 690 | /* if the time to live is nul */ |
screamer | 0:7a64fbb4069d | 691 | if (--pEntry->ttl == 0) { |
screamer | 0:7a64fbb4069d | 692 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", pEntry->name)); |
screamer | 0:7a64fbb4069d | 693 | /* flush this entry */ |
screamer | 0:7a64fbb4069d | 694 | pEntry->state = DNS_STATE_UNUSED; |
screamer | 0:7a64fbb4069d | 695 | pEntry->found = NULL; |
screamer | 0:7a64fbb4069d | 696 | } |
screamer | 0:7a64fbb4069d | 697 | break; |
screamer | 0:7a64fbb4069d | 698 | } |
screamer | 0:7a64fbb4069d | 699 | case DNS_STATE_UNUSED: |
screamer | 0:7a64fbb4069d | 700 | /* nothing to do */ |
screamer | 0:7a64fbb4069d | 701 | break; |
screamer | 0:7a64fbb4069d | 702 | default: |
screamer | 0:7a64fbb4069d | 703 | LWIP_ASSERT("unknown dns_table entry state:", 0); |
screamer | 0:7a64fbb4069d | 704 | break; |
screamer | 0:7a64fbb4069d | 705 | } |
screamer | 0:7a64fbb4069d | 706 | } |
screamer | 0:7a64fbb4069d | 707 | |
screamer | 0:7a64fbb4069d | 708 | /** |
screamer | 0:7a64fbb4069d | 709 | * Call dns_check_entry for each entry in dns_table - check all entries. |
screamer | 0:7a64fbb4069d | 710 | */ |
screamer | 0:7a64fbb4069d | 711 | static void |
screamer | 0:7a64fbb4069d | 712 | dns_check_entries(void) |
screamer | 0:7a64fbb4069d | 713 | { |
screamer | 0:7a64fbb4069d | 714 | u8_t i; |
screamer | 0:7a64fbb4069d | 715 | |
screamer | 0:7a64fbb4069d | 716 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
screamer | 0:7a64fbb4069d | 717 | dns_check_entry(i); |
screamer | 0:7a64fbb4069d | 718 | } |
screamer | 0:7a64fbb4069d | 719 | } |
screamer | 0:7a64fbb4069d | 720 | |
screamer | 0:7a64fbb4069d | 721 | /** |
screamer | 0:7a64fbb4069d | 722 | * Receive input function for DNS response packets arriving for the dns UDP pcb. |
screamer | 0:7a64fbb4069d | 723 | * |
screamer | 0:7a64fbb4069d | 724 | * @params see udp.h |
screamer | 0:7a64fbb4069d | 725 | */ |
screamer | 0:7a64fbb4069d | 726 | static void |
screamer | 0:7a64fbb4069d | 727 | dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port) |
screamer | 0:7a64fbb4069d | 728 | { |
screamer | 0:7a64fbb4069d | 729 | u8_t i; |
screamer | 0:7a64fbb4069d | 730 | char *pHostname; |
screamer | 0:7a64fbb4069d | 731 | struct dns_hdr *hdr; |
screamer | 0:7a64fbb4069d | 732 | struct dns_answer ans; |
screamer | 0:7a64fbb4069d | 733 | struct dns_table_entry *pEntry; |
screamer | 0:7a64fbb4069d | 734 | u8_t nquestions, nanswers; |
screamer | 0:7a64fbb4069d | 735 | #if (DNS_USES_STATIC_BUF == 0) |
screamer | 0:7a64fbb4069d | 736 | u8_t dns_payload[DNS_MSG_SIZE]; |
screamer | 0:7a64fbb4069d | 737 | #endif /* (DNS_USES_STATIC_BUF == 0) */ |
screamer | 0:7a64fbb4069d | 738 | #if (DNS_USES_STATIC_BUF == 2) |
screamer | 0:7a64fbb4069d | 739 | u8_t* dns_payload; |
screamer | 0:7a64fbb4069d | 740 | #endif /* (DNS_USES_STATIC_BUF == 2) */ |
screamer | 0:7a64fbb4069d | 741 | |
screamer | 0:7a64fbb4069d | 742 | LWIP_UNUSED_ARG(arg); |
screamer | 0:7a64fbb4069d | 743 | LWIP_UNUSED_ARG(pcb); |
screamer | 0:7a64fbb4069d | 744 | LWIP_UNUSED_ARG(addr); |
screamer | 0:7a64fbb4069d | 745 | LWIP_UNUSED_ARG(port); |
screamer | 0:7a64fbb4069d | 746 | |
screamer | 0:7a64fbb4069d | 747 | /* is the dns message too big ? */ |
screamer | 0:7a64fbb4069d | 748 | if (p->tot_len > DNS_MSG_SIZE) { |
screamer | 0:7a64fbb4069d | 749 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n")); |
screamer | 0:7a64fbb4069d | 750 | /* free pbuf and return */ |
screamer | 0:7a64fbb4069d | 751 | goto memerr1; |
screamer | 0:7a64fbb4069d | 752 | } |
screamer | 0:7a64fbb4069d | 753 | |
screamer | 0:7a64fbb4069d | 754 | /* is the dns message big enough ? */ |
screamer | 0:7a64fbb4069d | 755 | if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) { |
screamer | 0:7a64fbb4069d | 756 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n")); |
screamer | 0:7a64fbb4069d | 757 | /* free pbuf and return */ |
screamer | 0:7a64fbb4069d | 758 | goto memerr1; |
screamer | 0:7a64fbb4069d | 759 | } |
screamer | 0:7a64fbb4069d | 760 | |
screamer | 0:7a64fbb4069d | 761 | #if (DNS_USES_STATIC_BUF == 2) |
screamer | 0:7a64fbb4069d | 762 | dns_payload = mem_malloc(p->tot_len); |
screamer | 0:7a64fbb4069d | 763 | if (dns_payload == NULL) { |
screamer | 0:7a64fbb4069d | 764 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: mem_malloc error\n")); |
screamer | 0:7a64fbb4069d | 765 | /* free pbuf and return */ |
screamer | 0:7a64fbb4069d | 766 | goto memerr1; |
screamer | 0:7a64fbb4069d | 767 | } |
screamer | 0:7a64fbb4069d | 768 | #endif /* (DNS_USES_STATIC_BUF == 2) */ |
screamer | 0:7a64fbb4069d | 769 | |
screamer | 0:7a64fbb4069d | 770 | /* copy dns payload inside static buffer for processing */ |
screamer | 0:7a64fbb4069d | 771 | if (pbuf_copy_partial(p, dns_payload, p->tot_len, 0) == p->tot_len) { |
screamer | 0:7a64fbb4069d | 772 | /* The ID in the DNS header should be our entry into the name table. */ |
screamer | 0:7a64fbb4069d | 773 | hdr = (struct dns_hdr*)dns_payload; |
screamer | 0:7a64fbb4069d | 774 | i = htons(hdr->id); |
screamer | 0:7a64fbb4069d | 775 | if (i < DNS_TABLE_SIZE) { |
screamer | 0:7a64fbb4069d | 776 | pEntry = &dns_table[i]; |
screamer | 0:7a64fbb4069d | 777 | if(pEntry->state == DNS_STATE_ASKING) { |
screamer | 0:7a64fbb4069d | 778 | /* This entry is now completed. */ |
screamer | 0:7a64fbb4069d | 779 | pEntry->state = DNS_STATE_DONE; |
screamer | 0:7a64fbb4069d | 780 | pEntry->err = hdr->flags2 & DNS_FLAG2_ERR_MASK; |
screamer | 0:7a64fbb4069d | 781 | |
screamer | 0:7a64fbb4069d | 782 | /* We only care about the question(s) and the answers. The authrr |
screamer | 0:7a64fbb4069d | 783 | and the extrarr are simply discarded. */ |
screamer | 0:7a64fbb4069d | 784 | nquestions = htons(hdr->numquestions); |
screamer | 0:7a64fbb4069d | 785 | nanswers = htons(hdr->numanswers); |
screamer | 0:7a64fbb4069d | 786 | |
screamer | 0:7a64fbb4069d | 787 | /* Check for error. If so, call callback to inform. */ |
screamer | 0:7a64fbb4069d | 788 | if (((hdr->flags1 & DNS_FLAG1_RESPONSE) == 0) || (pEntry->err != 0) || (nquestions != 1)) { |
screamer | 0:7a64fbb4069d | 789 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", pEntry->name)); |
screamer | 0:7a64fbb4069d | 790 | /* call callback to indicate error, clean up memory and return */ |
screamer | 0:7a64fbb4069d | 791 | goto responseerr; |
screamer | 0:7a64fbb4069d | 792 | } |
screamer | 0:7a64fbb4069d | 793 | |
screamer | 0:7a64fbb4069d | 794 | #if DNS_DOES_NAME_CHECK |
screamer | 0:7a64fbb4069d | 795 | /* Check if the name in the "question" part match with the name in the entry. */ |
screamer | 0:7a64fbb4069d | 796 | if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) { |
screamer | 0:7a64fbb4069d | 797 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name)); |
screamer | 0:7a64fbb4069d | 798 | /* call callback to indicate error, clean up memory and return */ |
screamer | 0:7a64fbb4069d | 799 | goto responseerr; |
screamer | 0:7a64fbb4069d | 800 | } |
screamer | 0:7a64fbb4069d | 801 | #endif /* DNS_DOES_NAME_CHECK */ |
screamer | 0:7a64fbb4069d | 802 | |
screamer | 0:7a64fbb4069d | 803 | /* Skip the name in the "question" part */ |
screamer | 0:7a64fbb4069d | 804 | pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY; |
screamer | 0:7a64fbb4069d | 805 | |
screamer | 0:7a64fbb4069d | 806 | while(nanswers > 0) { |
screamer | 0:7a64fbb4069d | 807 | /* skip answer resource record's host name */ |
screamer | 0:7a64fbb4069d | 808 | pHostname = (char *) dns_parse_name((unsigned char *)pHostname); |
screamer | 0:7a64fbb4069d | 809 | |
screamer | 0:7a64fbb4069d | 810 | /* Check for IP address type and Internet class. Others are discarded. */ |
screamer | 0:7a64fbb4069d | 811 | MEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER); |
screamer | 0:7a64fbb4069d | 812 | if((ntohs(ans.type) == DNS_RRTYPE_A) && (ntohs(ans.class) == DNS_RRCLASS_IN) && (ntohs(ans.len) == sizeof(struct ip_addr)) ) { |
screamer | 0:7a64fbb4069d | 813 | /* read the answer resource record's TTL, and maximize it if needed */ |
screamer | 0:7a64fbb4069d | 814 | pEntry->ttl = ntohl(ans.ttl); |
screamer | 0:7a64fbb4069d | 815 | if (pEntry->ttl > DNS_MAX_TTL) { |
screamer | 0:7a64fbb4069d | 816 | pEntry->ttl = DNS_MAX_TTL; |
screamer | 0:7a64fbb4069d | 817 | } |
screamer | 0:7a64fbb4069d | 818 | /* read the IP address after answer resource record's header */ |
screamer | 0:7a64fbb4069d | 819 | MEMCPY( &(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(struct ip_addr)); |
screamer | 0:7a64fbb4069d | 820 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name)); |
screamer | 0:7a64fbb4069d | 821 | ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr))); |
screamer | 0:7a64fbb4069d | 822 | LWIP_DEBUGF(DNS_DEBUG, ("\n")); |
screamer | 0:7a64fbb4069d | 823 | /* call specified callback function if provided */ |
screamer | 0:7a64fbb4069d | 824 | if (pEntry->found) { |
screamer | 0:7a64fbb4069d | 825 | (*pEntry->found)(pEntry->name, &pEntry->ipaddr, pEntry->arg); |
screamer | 0:7a64fbb4069d | 826 | } |
screamer | 0:7a64fbb4069d | 827 | /* deallocate memory and return */ |
screamer | 0:7a64fbb4069d | 828 | goto memerr2; |
screamer | 0:7a64fbb4069d | 829 | } else { |
screamer | 0:7a64fbb4069d | 830 | pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len); |
screamer | 0:7a64fbb4069d | 831 | } |
screamer | 0:7a64fbb4069d | 832 | --nanswers; |
screamer | 0:7a64fbb4069d | 833 | } |
screamer | 0:7a64fbb4069d | 834 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", pEntry->name)); |
screamer | 0:7a64fbb4069d | 835 | /* call callback to indicate error, clean up memory and return */ |
screamer | 0:7a64fbb4069d | 836 | goto responseerr; |
screamer | 0:7a64fbb4069d | 837 | } |
screamer | 0:7a64fbb4069d | 838 | } |
screamer | 0:7a64fbb4069d | 839 | } |
screamer | 0:7a64fbb4069d | 840 | |
screamer | 0:7a64fbb4069d | 841 | /* deallocate memory and return */ |
screamer | 0:7a64fbb4069d | 842 | goto memerr2; |
screamer | 0:7a64fbb4069d | 843 | |
screamer | 0:7a64fbb4069d | 844 | responseerr: |
screamer | 0:7a64fbb4069d | 845 | /* ERROR: call specified callback function with NULL as name to indicate an error */ |
screamer | 0:7a64fbb4069d | 846 | if (pEntry->found) { |
screamer | 0:7a64fbb4069d | 847 | (*pEntry->found)(pEntry->name, NULL, pEntry->arg); |
screamer | 0:7a64fbb4069d | 848 | } |
screamer | 0:7a64fbb4069d | 849 | /* flush this entry */ |
screamer | 0:7a64fbb4069d | 850 | pEntry->state = DNS_STATE_UNUSED; |
screamer | 0:7a64fbb4069d | 851 | pEntry->found = NULL; |
screamer | 0:7a64fbb4069d | 852 | |
screamer | 0:7a64fbb4069d | 853 | memerr2: |
screamer | 0:7a64fbb4069d | 854 | #if (DNS_USES_STATIC_BUF == 2) |
screamer | 0:7a64fbb4069d | 855 | /* free dns buffer */ |
screamer | 0:7a64fbb4069d | 856 | mem_free(dns_payload); |
screamer | 0:7a64fbb4069d | 857 | #endif /* (DNS_USES_STATIC_BUF == 2) */ |
screamer | 0:7a64fbb4069d | 858 | |
screamer | 0:7a64fbb4069d | 859 | memerr1: |
screamer | 0:7a64fbb4069d | 860 | /* free pbuf */ |
screamer | 0:7a64fbb4069d | 861 | pbuf_free(p); |
screamer | 0:7a64fbb4069d | 862 | return; |
screamer | 0:7a64fbb4069d | 863 | } |
screamer | 0:7a64fbb4069d | 864 | |
screamer | 0:7a64fbb4069d | 865 | /** |
screamer | 0:7a64fbb4069d | 866 | * Queues a new hostname to resolve and sends out a DNS query for that hostname |
screamer | 0:7a64fbb4069d | 867 | * |
screamer | 0:7a64fbb4069d | 868 | * @param name the hostname that is to be queried |
screamer | 0:7a64fbb4069d | 869 | * @param found a callback founction to be called on success, failure or timeout |
screamer | 0:7a64fbb4069d | 870 | * @param callback_arg argument to pass to the callback function |
screamer | 0:7a64fbb4069d | 871 | * @return @return a err_t return code. |
screamer | 0:7a64fbb4069d | 872 | */ |
screamer | 0:7a64fbb4069d | 873 | static err_t |
screamer | 0:7a64fbb4069d | 874 | dns_enqueue(const char *name, dns_found_callback found, void *callback_arg) |
screamer | 0:7a64fbb4069d | 875 | { |
screamer | 0:7a64fbb4069d | 876 | u8_t i; |
screamer | 0:7a64fbb4069d | 877 | u8_t lseq, lseqi; |
screamer | 0:7a64fbb4069d | 878 | struct dns_table_entry *pEntry = NULL; |
screamer | 0:7a64fbb4069d | 879 | |
screamer | 0:7a64fbb4069d | 880 | /* search an unused entry, or the oldest one */ |
screamer | 0:7a64fbb4069d | 881 | lseq = lseqi = 0; |
screamer | 0:7a64fbb4069d | 882 | for (i = 0; i < DNS_TABLE_SIZE; ++i) { |
screamer | 0:7a64fbb4069d | 883 | pEntry = &dns_table[i]; |
screamer | 0:7a64fbb4069d | 884 | /* is it an unused entry ? */ |
screamer | 0:7a64fbb4069d | 885 | if (pEntry->state == DNS_STATE_UNUSED) |
screamer | 0:7a64fbb4069d | 886 | break; |
screamer | 0:7a64fbb4069d | 887 | |
screamer | 0:7a64fbb4069d | 888 | /* check if this is the oldest completed entry */ |
screamer | 0:7a64fbb4069d | 889 | if (pEntry->state == DNS_STATE_DONE) { |
screamer | 0:7a64fbb4069d | 890 | if ((dns_seqno - pEntry->seqno) > lseq) { |
screamer | 0:7a64fbb4069d | 891 | lseq = dns_seqno - pEntry->seqno; |
screamer | 0:7a64fbb4069d | 892 | lseqi = i; |
screamer | 0:7a64fbb4069d | 893 | } |
screamer | 0:7a64fbb4069d | 894 | } |
screamer | 0:7a64fbb4069d | 895 | } |
screamer | 0:7a64fbb4069d | 896 | |
screamer | 0:7a64fbb4069d | 897 | /* if we don't have found an unused entry, use the oldest completed one */ |
screamer | 0:7a64fbb4069d | 898 | if (i == DNS_TABLE_SIZE) { |
screamer | 0:7a64fbb4069d | 899 | if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) { |
screamer | 0:7a64fbb4069d | 900 | /* no entry can't be used now, table is full */ |
screamer | 0:7a64fbb4069d | 901 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name)); |
screamer | 0:7a64fbb4069d | 902 | return ERR_MEM; |
screamer | 0:7a64fbb4069d | 903 | } else { |
screamer | 0:7a64fbb4069d | 904 | /* use the oldest completed one */ |
screamer | 0:7a64fbb4069d | 905 | i = lseqi; |
screamer | 0:7a64fbb4069d | 906 | pEntry = &dns_table[i]; |
screamer | 0:7a64fbb4069d | 907 | } |
screamer | 0:7a64fbb4069d | 908 | } |
screamer | 0:7a64fbb4069d | 909 | |
screamer | 0:7a64fbb4069d | 910 | /* use this entry */ |
screamer | 0:7a64fbb4069d | 911 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i))); |
screamer | 0:7a64fbb4069d | 912 | |
screamer | 0:7a64fbb4069d | 913 | /* fill the entry */ |
screamer | 0:7a64fbb4069d | 914 | pEntry->state = DNS_STATE_NEW; |
screamer | 0:7a64fbb4069d | 915 | pEntry->seqno = dns_seqno++; |
screamer | 0:7a64fbb4069d | 916 | pEntry->found = found; |
screamer | 0:7a64fbb4069d | 917 | pEntry->arg = callback_arg; |
screamer | 0:7a64fbb4069d | 918 | strcpy(pEntry->name, name); |
screamer | 0:7a64fbb4069d | 919 | |
screamer | 0:7a64fbb4069d | 920 | /* force to send query without waiting timer */ |
screamer | 0:7a64fbb4069d | 921 | dns_check_entry(i); |
screamer | 0:7a64fbb4069d | 922 | |
screamer | 0:7a64fbb4069d | 923 | /* dns query is enqueued */ |
screamer | 0:7a64fbb4069d | 924 | return ERR_INPROGRESS; |
screamer | 0:7a64fbb4069d | 925 | } |
screamer | 0:7a64fbb4069d | 926 | |
screamer | 0:7a64fbb4069d | 927 | /** |
screamer | 0:7a64fbb4069d | 928 | * Resolve a hostname (string) into an IP address. |
screamer | 0:7a64fbb4069d | 929 | * NON-BLOCKING callback version for use with raw API!!! |
screamer | 0:7a64fbb4069d | 930 | * |
screamer | 0:7a64fbb4069d | 931 | * Returns immediately with one of err_t return codes: |
screamer | 0:7a64fbb4069d | 932 | * - ERR_OK if hostname is a valid IP address string or the host |
screamer | 0:7a64fbb4069d | 933 | * name is already in the local names table. |
screamer | 0:7a64fbb4069d | 934 | * - ERR_INPROGRESS enqueue a request to be sent to the DNS server |
screamer | 0:7a64fbb4069d | 935 | * for resolution if no errors are present. |
screamer | 0:7a64fbb4069d | 936 | * |
screamer | 0:7a64fbb4069d | 937 | * @param hostname the hostname that is to be queried |
screamer | 0:7a64fbb4069d | 938 | * @param addr pointer to a struct ip_addr where to store the address if it is already |
screamer | 0:7a64fbb4069d | 939 | * cached in the dns_table (only valid if ERR_OK is returned!) |
screamer | 0:7a64fbb4069d | 940 | * @param found a callback function to be called on success, failure or timeout (only if |
screamer | 0:7a64fbb4069d | 941 | * ERR_INPROGRESS is returned!) |
screamer | 0:7a64fbb4069d | 942 | * @param callback_arg argument to pass to the callback function |
screamer | 0:7a64fbb4069d | 943 | * @return a err_t return code. |
screamer | 0:7a64fbb4069d | 944 | */ |
screamer | 0:7a64fbb4069d | 945 | err_t |
screamer | 0:7a64fbb4069d | 946 | dns_gethostbyname(const char *hostname, struct ip_addr *addr, dns_found_callback found, |
screamer | 0:7a64fbb4069d | 947 | void *callback_arg) |
screamer | 0:7a64fbb4069d | 948 | { |
screamer | 0:7a64fbb4069d | 949 | /* not initialized or no valid server yet, or invalid addr pointer |
screamer | 0:7a64fbb4069d | 950 | * or invalid hostname or invalid hostname length */ |
screamer | 0:7a64fbb4069d | 951 | if ((dns_pcb == NULL) || (addr == NULL) || |
screamer | 0:7a64fbb4069d | 952 | (!hostname) || (!hostname[0]) || |
screamer | 0:7a64fbb4069d | 953 | (strlen(hostname) >= DNS_MAX_NAME_LENGTH)) { |
screamer | 0:7a64fbb4069d | 954 | return ERR_VAL; |
screamer | 0:7a64fbb4069d | 955 | } |
screamer | 0:7a64fbb4069d | 956 | |
screamer | 0:7a64fbb4069d | 957 | #if LWIP_HAVE_LOOPIF |
screamer | 0:7a64fbb4069d | 958 | if (strcmp(hostname,"localhost")==0) { |
screamer | 0:7a64fbb4069d | 959 | addr->addr = INADDR_LOOPBACK; |
screamer | 0:7a64fbb4069d | 960 | return ERR_OK; |
screamer | 0:7a64fbb4069d | 961 | } |
screamer | 0:7a64fbb4069d | 962 | #endif /* LWIP_HAVE_LOOPIF */ |
screamer | 0:7a64fbb4069d | 963 | |
screamer | 0:7a64fbb4069d | 964 | /* host name already in octet notation? set ip addr and return ERR_OK |
screamer | 0:7a64fbb4069d | 965 | * already have this address cached? */ |
screamer | 0:7a64fbb4069d | 966 | if (((addr->addr = inet_addr(hostname)) != INADDR_NONE) || |
screamer | 0:7a64fbb4069d | 967 | ((addr->addr = dns_lookup(hostname)) != INADDR_NONE)) { |
screamer | 0:7a64fbb4069d | 968 | return ERR_OK; |
screamer | 0:7a64fbb4069d | 969 | } |
screamer | 0:7a64fbb4069d | 970 | |
screamer | 0:7a64fbb4069d | 971 | /* queue query with specified callback */ |
screamer | 0:7a64fbb4069d | 972 | return dns_enqueue(hostname, found, callback_arg); |
screamer | 0:7a64fbb4069d | 973 | } |
screamer | 0:7a64fbb4069d | 974 | |
screamer | 0:7a64fbb4069d | 975 | #endif /* LWIP_DNS */ |