[457] | 1 | /**
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| 2 | * @file
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| 3 | * DNS - host name to IP address resolver.
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| 4 | *
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| 5 | * @defgroup dns DNS
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| 6 | * @ingroup callbackstyle_api
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| 7 | *
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| 8 | * Implements a DNS host name to IP address resolver.
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| 9 | *
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| 10 | * The lwIP DNS resolver functions are used to lookup a host name and
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| 11 | * map it to a numerical IP address. It maintains a list of resolved
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| 12 | * hostnames that can be queried with the dns_lookup() function.
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| 13 | * New hostnames can be resolved using the dns_query() function.
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| 14 | *
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| 15 | * The lwIP version of the resolver also adds a non-blocking version of
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| 16 | * gethostbyname() that will work with a raw API application. This function
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| 17 | * checks for an IP address string first and converts it if it is valid.
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| 18 | * gethostbyname() then does a dns_lookup() to see if the name is
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| 19 | * already in the table. If so, the IP is returned. If not, a query is
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| 20 | * issued and the function returns with a ERR_INPROGRESS status. The app
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| 21 | * using the dns client must then go into a waiting state.
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| 22 | *
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| 23 | * Once a hostname has been resolved (or found to be non-existent),
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| 24 | * the resolver code calls a specified callback function (which
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| 25 | * must be implemented by the module that uses the resolver).
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| 26 | *
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| 27 | * Multicast DNS queries are supported for names ending on ".local".
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| 28 | * However, only "One-Shot Multicast DNS Queries" are supported (RFC 6762
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| 29 | * chapter 5.1), this is not a fully compliant implementation of continuous
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| 30 | * mDNS querying!
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| 31 | *
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| 32 | * All functions must be called from TCPIP thread.
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| 33 | *
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| 34 | * @see DNS_MAX_SERVERS
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| 35 | * @see LWIP_DHCP_MAX_DNS_SERVERS
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| 36 | * @see @ref netconn_common for thread-safe access.
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| 37 | */
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| 38 |
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| 39 | /*
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| 40 | * Port to lwIP from uIP
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| 41 | * by Jim Pettinato April 2007
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| 42 | *
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| 43 | * security fixes and more by Simon Goldschmidt
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| 44 | *
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| 45 | * uIP version Copyright (c) 2002-2003, Adam Dunkels.
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| 46 | * All rights reserved.
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| 47 | *
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| 48 | * Redistribution and use in source and binary forms, with or without
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| 49 | * modification, are permitted provided that the following conditions
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| 50 | * are met:
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| 51 | * 1. Redistributions of source code must retain the above copyright
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| 52 | * notice, this list of conditions and the following disclaimer.
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| 53 | * 2. Redistributions in binary form must reproduce the above copyright
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| 54 | * notice, this list of conditions and the following disclaimer in the
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| 55 | * documentation and/or other materials provided with the distribution.
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| 56 | * 3. The name of the author may not be used to endorse or promote
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| 57 | * products derived from this software without specific prior
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| 58 | * written permission.
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| 59 | *
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| 60 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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| 61 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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| 62 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 63 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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| 64 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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| 65 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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| 66 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| 67 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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| 68 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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| 69 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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| 70 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 71 | */
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| 72 |
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| 73 | /*-----------------------------------------------------------------------------
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| 74 | * RFC 1035 - Domain names - implementation and specification
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| 75 | * RFC 2181 - Clarifications to the DNS Specification
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| 76 | *----------------------------------------------------------------------------*/
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| 77 |
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| 78 | /** @todo: define good default values (rfc compliance) */
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| 79 | /** @todo: improve answer parsing, more checkings... */
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| 80 | /** @todo: check RFC1035 - 7.3. Processing responses */
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| 81 | /** @todo: one-shot mDNS: dual-stack fallback to another IP version */
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| 82 |
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| 83 | /*-----------------------------------------------------------------------------
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| 84 | * Includes
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| 85 | *----------------------------------------------------------------------------*/
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| 86 |
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| 87 | #include "lwip/opt.h"
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| 88 |
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| 89 | #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
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| 90 |
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| 91 | #include "lwip/def.h"
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| 92 | #include "lwip/udp.h"
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| 93 | #include "lwip/mem.h"
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| 94 | #include "lwip/memp.h"
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| 95 | #include "lwip/dns.h"
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| 96 | #include "lwip/prot/dns.h"
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| 97 |
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| 98 | #include <string.h>
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| 99 |
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| 100 | /** Random generator function to create random TXIDs and source ports for queries */
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| 101 | #ifndef DNS_RAND_TXID
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| 102 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_XID) != 0)
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| 103 | #define DNS_RAND_TXID LWIP_RAND
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| 104 | #else
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| 105 | static u16_t dns_txid;
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| 106 | #define DNS_RAND_TXID() (++dns_txid)
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| 107 | #endif
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| 108 | #endif
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| 109 |
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| 110 | /** Limits the source port to be >= 1024 by default */
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| 111 | #ifndef DNS_PORT_ALLOWED
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| 112 | #define DNS_PORT_ALLOWED(port) ((port) >= 1024)
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| 113 | #endif
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| 114 |
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| 115 | /** DNS resource record max. TTL (one week as default) */
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| 116 | #ifndef DNS_MAX_TTL
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| 117 | #define DNS_MAX_TTL 604800
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| 118 | #elif DNS_MAX_TTL > 0x7FFFFFFF
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| 119 | #error DNS_MAX_TTL must be a positive 32-bit value
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| 120 | #endif
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| 121 |
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| 122 | #if DNS_TABLE_SIZE > 255
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| 123 | #error DNS_TABLE_SIZE must fit into an u8_t
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| 124 | #endif
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| 125 | #if DNS_MAX_SERVERS > 255
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| 126 | #error DNS_MAX_SERVERS must fit into an u8_t
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| 127 | #endif
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| 128 |
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| 129 | /* The number of parallel requests (i.e. calls to dns_gethostbyname
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| 130 | * that cannot be answered from the DNS table.
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| 131 | * This is set to the table size by default.
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| 132 | */
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| 133 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING) != 0)
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| 134 | #ifndef DNS_MAX_REQUESTS
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| 135 | #define DNS_MAX_REQUESTS DNS_TABLE_SIZE
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| 136 | #else
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| 137 | #if DNS_MAX_REQUESTS > 255
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| 138 | #error DNS_MAX_REQUESTS must fit into an u8_t
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| 139 | #endif
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| 140 | #endif
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| 141 | #else
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| 142 | /* In this configuration, both arrays have to have the same size and are used
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| 143 | * like one entry (used/free) */
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| 144 | #define DNS_MAX_REQUESTS DNS_TABLE_SIZE
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| 145 | #endif
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| 146 |
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| 147 | /* The number of UDP source ports used in parallel */
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| 148 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
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| 149 | #ifndef DNS_MAX_SOURCE_PORTS
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| 150 | #define DNS_MAX_SOURCE_PORTS DNS_MAX_REQUESTS
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| 151 | #else
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| 152 | #if DNS_MAX_SOURCE_PORTS > 255
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| 153 | #error DNS_MAX_SOURCE_PORTS must fit into an u8_t
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| 154 | #endif
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| 155 | #endif
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| 156 | #else
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| 157 | #ifdef DNS_MAX_SOURCE_PORTS
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| 158 | #undef DNS_MAX_SOURCE_PORTS
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| 159 | #endif
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| 160 | #define DNS_MAX_SOURCE_PORTS 1
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| 161 | #endif
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| 162 |
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| 163 | #if LWIP_IPV4 && LWIP_IPV6
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| 164 | #define LWIP_DNS_ADDRTYPE_IS_IPV6(t) (((t) == LWIP_DNS_ADDRTYPE_IPV6_IPV4) || ((t) == LWIP_DNS_ADDRTYPE_IPV6))
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| 165 | #define LWIP_DNS_ADDRTYPE_MATCH_IP(t, ip) (IP_IS_V6_VAL(ip) ? LWIP_DNS_ADDRTYPE_IS_IPV6(t) : (!LWIP_DNS_ADDRTYPE_IS_IPV6(t)))
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| 166 | #define LWIP_DNS_ADDRTYPE_ARG(x) , x
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| 167 | #define LWIP_DNS_ADDRTYPE_ARG_OR_ZERO(x) x
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| 168 | #define LWIP_DNS_SET_ADDRTYPE(x, y) do { x = y; } while(0)
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| 169 | #else
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| 170 | #if LWIP_IPV6
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| 171 | #define LWIP_DNS_ADDRTYPE_IS_IPV6(t) 1
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| 172 | #else
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| 173 | #define LWIP_DNS_ADDRTYPE_IS_IPV6(t) 0
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| 174 | #endif
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| 175 | #define LWIP_DNS_ADDRTYPE_MATCH_IP(t, ip) 1
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| 176 | #define LWIP_DNS_ADDRTYPE_ARG(x)
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| 177 | #define LWIP_DNS_ADDRTYPE_ARG_OR_ZERO(x) 0
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| 178 | #define LWIP_DNS_SET_ADDRTYPE(x, y)
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| 179 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
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| 180 |
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| 181 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
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| 182 | #define LWIP_DNS_ISMDNS_ARG(x) , x
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| 183 | #else
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| 184 | #define LWIP_DNS_ISMDNS_ARG(x)
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| 185 | #endif
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| 186 |
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| 187 | /** DNS query message structure.
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| 188 | No packing needed: only used locally on the stack. */
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| 189 | struct dns_query {
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| 190 | /* DNS query record starts with either a domain name or a pointer
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| 191 | to a name already present somewhere in the packet. */
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| 192 | u16_t type;
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| 193 | u16_t cls;
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| 194 | };
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| 195 | #define SIZEOF_DNS_QUERY 4
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| 196 |
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| 197 | /** DNS answer message structure.
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| 198 | No packing needed: only used locally on the stack. */
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| 199 | struct dns_answer {
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| 200 | /* DNS answer record starts with either a domain name or a pointer
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| 201 | to a name already present somewhere in the packet. */
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| 202 | u16_t type;
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| 203 | u16_t cls;
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| 204 | u32_t ttl;
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| 205 | u16_t len;
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| 206 | };
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| 207 | #define SIZEOF_DNS_ANSWER 10
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| 208 | /* maximum allowed size for the struct due to non-packed */
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| 209 | #define SIZEOF_DNS_ANSWER_ASSERT 12
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| 210 |
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| 211 | /* DNS table entry states */
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| 212 | typedef enum {
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| 213 | DNS_STATE_UNUSED = 0,
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| 214 | DNS_STATE_NEW = 1,
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| 215 | DNS_STATE_ASKING = 2,
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| 216 | DNS_STATE_DONE = 3
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| 217 | } dns_state_enum_t;
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| 218 |
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| 219 | /** DNS table entry */
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| 220 | struct dns_table_entry {
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| 221 | u32_t ttl;
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| 222 | ip_addr_t ipaddr;
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| 223 | u16_t txid;
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| 224 | u8_t state;
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| 225 | u8_t server_idx;
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| 226 | u8_t tmr;
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| 227 | u8_t retries;
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| 228 | u8_t seqno;
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| 229 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
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| 230 | u8_t pcb_idx;
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| 231 | #endif
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| 232 | char name[DNS_MAX_NAME_LENGTH];
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| 233 | #if LWIP_IPV4 && LWIP_IPV6
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| 234 | u8_t reqaddrtype;
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| 235 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
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| 236 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
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| 237 | u8_t is_mdns;
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| 238 | #endif
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| 239 | };
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| 240 |
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| 241 | /** DNS request table entry: used when dns_gehostbyname cannot answer the
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| 242 | * request from the DNS table */
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| 243 | struct dns_req_entry {
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| 244 | /* pointer to callback on DNS query done */
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| 245 | dns_found_callback found;
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| 246 | /* argument passed to the callback function */
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| 247 | void *arg;
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| 248 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING) != 0)
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| 249 | u8_t dns_table_idx;
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| 250 | #endif
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| 251 | #if LWIP_IPV4 && LWIP_IPV6
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| 252 | u8_t reqaddrtype;
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| 253 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
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| 254 | };
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| 255 |
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| 256 | #if DNS_LOCAL_HOSTLIST
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| 257 |
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| 258 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
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| 259 | /** Local host-list. For hostnames in this list, no
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| 260 | * external name resolution is performed */
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| 261 | static struct local_hostlist_entry *local_hostlist_dynamic;
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| 262 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
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| 263 |
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| 264 | /** Defining this allows the local_hostlist_static to be placed in a different
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| 265 | * linker section (e.g. FLASH) */
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| 266 | #ifndef DNS_LOCAL_HOSTLIST_STORAGE_PRE
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| 267 | #define DNS_LOCAL_HOSTLIST_STORAGE_PRE static
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| 268 | #endif /* DNS_LOCAL_HOSTLIST_STORAGE_PRE */
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| 269 | /** Defining this allows the local_hostlist_static to be placed in a different
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| 270 | * linker section (e.g. FLASH) */
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| 271 | #ifndef DNS_LOCAL_HOSTLIST_STORAGE_POST
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| 272 | #define DNS_LOCAL_HOSTLIST_STORAGE_POST
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| 273 | #endif /* DNS_LOCAL_HOSTLIST_STORAGE_POST */
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| 274 | DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static[]
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| 275 | DNS_LOCAL_HOSTLIST_STORAGE_POST = DNS_LOCAL_HOSTLIST_INIT;
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| 276 |
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| 277 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
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| 278 |
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| 279 | static void dns_init_local(void);
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| 280 | static err_t dns_lookup_local(const char *hostname, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype));
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| 281 | #endif /* DNS_LOCAL_HOSTLIST */
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| 282 |
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| 283 |
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| 284 | /* forward declarations */
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| 285 | static void dns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
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| 286 | static void dns_check_entries(void);
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| 287 | static void dns_call_found(u8_t idx, ip_addr_t *addr);
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| 288 |
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| 289 | /*-----------------------------------------------------------------------------
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| 290 | * Globals
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| 291 | *----------------------------------------------------------------------------*/
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| 292 |
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| 293 | /* DNS variables */
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| 294 | static struct udp_pcb *dns_pcbs[DNS_MAX_SOURCE_PORTS];
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| 295 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
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| 296 | static u8_t dns_last_pcb_idx;
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| 297 | #endif
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| 298 | static u8_t dns_seqno;
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| 299 | static struct dns_table_entry dns_table[DNS_TABLE_SIZE];
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| 300 | static struct dns_req_entry dns_requests[DNS_MAX_REQUESTS];
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| 301 | static ip_addr_t dns_servers[DNS_MAX_SERVERS];
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| 302 |
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| 303 | #if LWIP_IPV4
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| 304 | const ip_addr_t dns_mquery_v4group = DNS_MQUERY_IPV4_GROUP_INIT;
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| 305 | #endif /* LWIP_IPV4 */
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| 306 | #if LWIP_IPV6
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| 307 | const ip_addr_t dns_mquery_v6group = DNS_MQUERY_IPV6_GROUP_INIT;
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| 308 | #endif /* LWIP_IPV6 */
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| 309 |
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| 310 | /**
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| 311 | * Initialize the resolver: set up the UDP pcb and configure the default server
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| 312 | * (if DNS_SERVER_ADDRESS is set).
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| 313 | */
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| 314 | void
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| 315 | dns_init(void)
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| 316 | {
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| 317 | #ifdef DNS_SERVER_ADDRESS
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| 318 | /* initialize default DNS server address */
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| 319 | ip_addr_t dnsserver;
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| 320 | DNS_SERVER_ADDRESS(&dnsserver);
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| 321 | dns_setserver(0, &dnsserver);
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| 322 | #endif /* DNS_SERVER_ADDRESS */
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| 323 |
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| 324 | LWIP_ASSERT("sanity check SIZEOF_DNS_QUERY",
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| 325 | sizeof(struct dns_query) == SIZEOF_DNS_QUERY);
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| 326 | LWIP_ASSERT("sanity check SIZEOF_DNS_ANSWER",
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| 327 | sizeof(struct dns_answer) <= SIZEOF_DNS_ANSWER_ASSERT);
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| 328 |
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| 329 | LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
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| 330 |
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| 331 | /* if dns client not yet initialized... */
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| 332 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) == 0)
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| 333 | if (dns_pcbs[0] == NULL) {
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| 334 | dns_pcbs[0] = udp_new_ip_type(IPADDR_TYPE_ANY);
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| 335 | LWIP_ASSERT("dns_pcbs[0] != NULL", dns_pcbs[0] != NULL);
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| 336 |
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| 337 | /* initialize DNS table not needed (initialized to zero since it is a
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| 338 | * global variable) */
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| 339 | LWIP_ASSERT("For implicit initialization to work, DNS_STATE_UNUSED needs to be 0",
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| 340 | DNS_STATE_UNUSED == 0);
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| 341 |
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| 342 | /* initialize DNS client */
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| 343 | udp_bind(dns_pcbs[0], IP_ANY_TYPE, 0);
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| 344 | udp_recv(dns_pcbs[0], dns_recv, NULL);
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| 345 | }
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| 346 | #endif
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| 347 |
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| 348 | #if DNS_LOCAL_HOSTLIST
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| 349 | dns_init_local();
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| 350 | #endif
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| 351 | }
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| 352 |
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| 353 | /**
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| 354 | * @ingroup dns
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| 355 | * Initialize one of the DNS servers.
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| 356 | *
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| 357 | * @param numdns the index of the DNS server to set must be < DNS_MAX_SERVERS
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| 358 | * @param dnsserver IP address of the DNS server to set
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| 359 | */
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| 360 | void
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| 361 | dns_setserver(u8_t numdns, const ip_addr_t *dnsserver)
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| 362 | {
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| 363 | if (numdns < DNS_MAX_SERVERS) {
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| 364 | if (dnsserver != NULL) {
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| 365 | dns_servers[numdns] = (*dnsserver);
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| 366 | } else {
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| 367 | dns_servers[numdns] = *IP_ADDR_ANY;
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| 368 | }
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| 369 | }
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| 370 | }
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| 371 |
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| 372 | /**
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| 373 | * @ingroup dns
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| 374 | * Obtain one of the currently configured DNS server.
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| 375 | *
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| 376 | * @param numdns the index of the DNS server
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| 377 | * @return IP address of the indexed DNS server or "ip_addr_any" if the DNS
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| 378 | * server has not been configured.
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| 379 | */
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| 380 | const ip_addr_t *
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| 381 | dns_getserver(u8_t numdns)
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| 382 | {
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| 383 | if (numdns < DNS_MAX_SERVERS) {
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| 384 | return &dns_servers[numdns];
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| 385 | } else {
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| 386 | return IP_ADDR_ANY;
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| 387 | }
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| 388 | }
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| 389 |
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| 390 | /**
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| 391 | * The DNS resolver client timer - handle retries and timeouts and should
|
---|
| 392 | * be called every DNS_TMR_INTERVAL milliseconds (every second by default).
|
---|
| 393 | */
|
---|
| 394 | void
|
---|
| 395 | dns_tmr(void)
|
---|
| 396 | {
|
---|
| 397 | LWIP_DEBUGF(DNS_DEBUG, ("dns_tmr: dns_check_entries\n"));
|
---|
| 398 | dns_check_entries();
|
---|
| 399 | }
|
---|
| 400 |
|
---|
| 401 | #if DNS_LOCAL_HOSTLIST
|
---|
| 402 | static void
|
---|
| 403 | dns_init_local(void)
|
---|
| 404 | {
|
---|
| 405 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT)
|
---|
| 406 | size_t i;
|
---|
| 407 | struct local_hostlist_entry *entry;
|
---|
| 408 | /* Dynamic: copy entries from DNS_LOCAL_HOSTLIST_INIT to list */
|
---|
| 409 | struct local_hostlist_entry local_hostlist_init[] = DNS_LOCAL_HOSTLIST_INIT;
|
---|
| 410 | size_t namelen;
|
---|
| 411 | for (i = 0; i < LWIP_ARRAYSIZE(local_hostlist_init); i++) {
|
---|
| 412 | struct local_hostlist_entry *init_entry = &local_hostlist_init[i];
|
---|
| 413 | LWIP_ASSERT("invalid host name (NULL)", init_entry->name != NULL);
|
---|
| 414 | namelen = strlen(init_entry->name);
|
---|
| 415 | LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
|
---|
| 416 | entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
|
---|
| 417 | LWIP_ASSERT("mem-error in dns_init_local", entry != NULL);
|
---|
| 418 | if (entry != NULL) {
|
---|
| 419 | char *entry_name = (char *)entry + sizeof(struct local_hostlist_entry);
|
---|
| 420 | MEMCPY(entry_name, init_entry->name, namelen);
|
---|
| 421 | entry_name[namelen] = 0;
|
---|
| 422 | entry->name = entry_name;
|
---|
| 423 | entry->addr = init_entry->addr;
|
---|
| 424 | entry->next = local_hostlist_dynamic;
|
---|
| 425 | local_hostlist_dynamic = entry;
|
---|
| 426 | }
|
---|
| 427 | }
|
---|
| 428 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
|
---|
| 429 | }
|
---|
| 430 |
|
---|
| 431 | /**
|
---|
| 432 | * @ingroup dns
|
---|
| 433 | * Iterate the local host-list for a hostname.
|
---|
| 434 | *
|
---|
| 435 | * @param iterator_fn a function that is called for every entry in the local host-list
|
---|
| 436 | * @param iterator_arg 3rd argument passed to iterator_fn
|
---|
| 437 | * @return the number of entries in the local host-list
|
---|
| 438 | */
|
---|
| 439 | size_t
|
---|
| 440 | dns_local_iterate(dns_found_callback iterator_fn, void *iterator_arg)
|
---|
| 441 | {
|
---|
| 442 | size_t i;
|
---|
| 443 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
|
---|
| 444 | struct local_hostlist_entry *entry = local_hostlist_dynamic;
|
---|
| 445 | i = 0;
|
---|
| 446 | while (entry != NULL) {
|
---|
| 447 | if (iterator_fn != NULL) {
|
---|
| 448 | iterator_fn(entry->name, &entry->addr, iterator_arg);
|
---|
| 449 | }
|
---|
| 450 | i++;
|
---|
| 451 | entry = entry->next;
|
---|
| 452 | }
|
---|
| 453 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
|
---|
| 454 | for (i = 0; i < LWIP_ARRAYSIZE(local_hostlist_static); i++) {
|
---|
| 455 | if (iterator_fn != NULL) {
|
---|
| 456 | iterator_fn(local_hostlist_static[i].name, &local_hostlist_static[i].addr, iterator_arg);
|
---|
| 457 | }
|
---|
| 458 | }
|
---|
| 459 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
|
---|
| 460 | return i;
|
---|
| 461 | }
|
---|
| 462 |
|
---|
| 463 | /**
|
---|
| 464 | * @ingroup dns
|
---|
| 465 | * Scans the local host-list for a hostname.
|
---|
| 466 | *
|
---|
| 467 | * @param hostname Hostname to look for in the local host-list
|
---|
| 468 | * @param addr the first IP address for the hostname in the local host-list or
|
---|
| 469 | * IPADDR_NONE if not found.
|
---|
| 470 | * @param dns_addrtype - LWIP_DNS_ADDRTYPE_IPV4_IPV6: try to resolve IPv4 (ATTENTION: no fallback here!)
|
---|
| 471 | * - LWIP_DNS_ADDRTYPE_IPV6_IPV4: try to resolve IPv6 (ATTENTION: no fallback here!)
|
---|
| 472 | * - LWIP_DNS_ADDRTYPE_IPV4: try to resolve IPv4 only
|
---|
| 473 | * - LWIP_DNS_ADDRTYPE_IPV6: try to resolve IPv6 only
|
---|
| 474 | * @return ERR_OK if found, ERR_ARG if not found
|
---|
| 475 | */
|
---|
| 476 | err_t
|
---|
| 477 | dns_local_lookup(const char *hostname, ip_addr_t *addr, u8_t dns_addrtype)
|
---|
| 478 | {
|
---|
| 479 | LWIP_UNUSED_ARG(dns_addrtype);
|
---|
| 480 | return dns_lookup_local(hostname, addr LWIP_DNS_ADDRTYPE_ARG(dns_addrtype));
|
---|
| 481 | }
|
---|
| 482 |
|
---|
| 483 | /* Internal implementation for dns_local_lookup and dns_lookup */
|
---|
| 484 | static err_t
|
---|
| 485 | dns_lookup_local(const char *hostname, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype))
|
---|
| 486 | {
|
---|
| 487 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
|
---|
| 488 | struct local_hostlist_entry *entry = local_hostlist_dynamic;
|
---|
| 489 | while (entry != NULL) {
|
---|
| 490 | if ((lwip_stricmp(entry->name, hostname) == 0) &&
|
---|
| 491 | LWIP_DNS_ADDRTYPE_MATCH_IP(dns_addrtype, entry->addr)) {
|
---|
| 492 | if (addr) {
|
---|
| 493 | ip_addr_copy(*addr, entry->addr);
|
---|
| 494 | }
|
---|
| 495 | return ERR_OK;
|
---|
| 496 | }
|
---|
| 497 | entry = entry->next;
|
---|
| 498 | }
|
---|
| 499 | #else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
|
---|
| 500 | size_t i;
|
---|
| 501 | for (i = 0; i < LWIP_ARRAYSIZE(local_hostlist_static); i++) {
|
---|
| 502 | if ((lwip_stricmp(local_hostlist_static[i].name, hostname) == 0) &&
|
---|
| 503 | LWIP_DNS_ADDRTYPE_MATCH_IP(dns_addrtype, local_hostlist_static[i].addr)) {
|
---|
| 504 | if (addr) {
|
---|
| 505 | ip_addr_copy(*addr, local_hostlist_static[i].addr);
|
---|
| 506 | }
|
---|
| 507 | return ERR_OK;
|
---|
| 508 | }
|
---|
| 509 | }
|
---|
| 510 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
|
---|
| 511 | return ERR_ARG;
|
---|
| 512 | }
|
---|
| 513 |
|
---|
| 514 | #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
|
---|
| 515 | /**
|
---|
| 516 | * @ingroup dns
|
---|
| 517 | * Remove all entries from the local host-list for a specific hostname
|
---|
| 518 | * and/or IP address
|
---|
| 519 | *
|
---|
| 520 | * @param hostname hostname for which entries shall be removed from the local
|
---|
| 521 | * host-list
|
---|
| 522 | * @param addr address for which entries shall be removed from the local host-list
|
---|
| 523 | * @return the number of removed entries
|
---|
| 524 | */
|
---|
| 525 | int
|
---|
| 526 | dns_local_removehost(const char *hostname, const ip_addr_t *addr)
|
---|
| 527 | {
|
---|
| 528 | int removed = 0;
|
---|
| 529 | struct local_hostlist_entry *entry = local_hostlist_dynamic;
|
---|
| 530 | struct local_hostlist_entry *last_entry = NULL;
|
---|
| 531 | while (entry != NULL) {
|
---|
| 532 | if (((hostname == NULL) || !lwip_stricmp(entry->name, hostname)) &&
|
---|
| 533 | ((addr == NULL) || ip_addr_cmp(&entry->addr, addr))) {
|
---|
| 534 | struct local_hostlist_entry *free_entry;
|
---|
| 535 | if (last_entry != NULL) {
|
---|
| 536 | last_entry->next = entry->next;
|
---|
| 537 | } else {
|
---|
| 538 | local_hostlist_dynamic = entry->next;
|
---|
| 539 | }
|
---|
| 540 | free_entry = entry;
|
---|
| 541 | entry = entry->next;
|
---|
| 542 | memp_free(MEMP_LOCALHOSTLIST, free_entry);
|
---|
| 543 | removed++;
|
---|
| 544 | } else {
|
---|
| 545 | last_entry = entry;
|
---|
| 546 | entry = entry->next;
|
---|
| 547 | }
|
---|
| 548 | }
|
---|
| 549 | return removed;
|
---|
| 550 | }
|
---|
| 551 |
|
---|
| 552 | /**
|
---|
| 553 | * @ingroup dns
|
---|
| 554 | * Add a hostname/IP address pair to the local host-list.
|
---|
| 555 | * Duplicates are not checked.
|
---|
| 556 | *
|
---|
| 557 | * @param hostname hostname of the new entry
|
---|
| 558 | * @param addr IP address of the new entry
|
---|
| 559 | * @return ERR_OK if succeeded or ERR_MEM on memory error
|
---|
| 560 | */
|
---|
| 561 | err_t
|
---|
| 562 | dns_local_addhost(const char *hostname, const ip_addr_t *addr)
|
---|
| 563 | {
|
---|
| 564 | struct local_hostlist_entry *entry;
|
---|
| 565 | size_t namelen;
|
---|
| 566 | char *entry_name;
|
---|
| 567 | LWIP_ASSERT("invalid host name (NULL)", hostname != NULL);
|
---|
| 568 | namelen = strlen(hostname);
|
---|
| 569 | LWIP_ASSERT("namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN", namelen <= DNS_LOCAL_HOSTLIST_MAX_NAMELEN);
|
---|
| 570 | entry = (struct local_hostlist_entry *)memp_malloc(MEMP_LOCALHOSTLIST);
|
---|
| 571 | if (entry == NULL) {
|
---|
| 572 | return ERR_MEM;
|
---|
| 573 | }
|
---|
| 574 | entry_name = (char *)entry + sizeof(struct local_hostlist_entry);
|
---|
| 575 | MEMCPY(entry_name, hostname, namelen);
|
---|
| 576 | entry_name[namelen] = 0;
|
---|
| 577 | entry->name = entry_name;
|
---|
| 578 | ip_addr_copy(entry->addr, *addr);
|
---|
| 579 | entry->next = local_hostlist_dynamic;
|
---|
| 580 | local_hostlist_dynamic = entry;
|
---|
| 581 | return ERR_OK;
|
---|
| 582 | }
|
---|
| 583 | #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC*/
|
---|
| 584 | #endif /* DNS_LOCAL_HOSTLIST */
|
---|
| 585 |
|
---|
| 586 | /**
|
---|
| 587 | * @ingroup dns
|
---|
| 588 | * Look up a hostname in the array of known hostnames.
|
---|
| 589 | *
|
---|
| 590 | * @note This function only looks in the internal array of known
|
---|
| 591 | * hostnames, it does not send out a query for the hostname if none
|
---|
| 592 | * was found. The function dns_enqueue() can be used to send a query
|
---|
| 593 | * for a hostname.
|
---|
| 594 | *
|
---|
| 595 | * @param name the hostname to look up
|
---|
| 596 | * @param addr the hostname's IP address, as u32_t (instead of ip_addr_t to
|
---|
| 597 | * better check for failure: != IPADDR_NONE) or IPADDR_NONE if the hostname
|
---|
| 598 | * was not found in the cached dns_table.
|
---|
| 599 | * @return ERR_OK if found, ERR_ARG if not found
|
---|
| 600 | */
|
---|
| 601 | static err_t
|
---|
| 602 | dns_lookup(const char *name, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype))
|
---|
| 603 | {
|
---|
| 604 | u8_t i;
|
---|
| 605 | #if DNS_LOCAL_HOSTLIST
|
---|
| 606 | if (dns_lookup_local(name, addr LWIP_DNS_ADDRTYPE_ARG(dns_addrtype)) == ERR_OK) {
|
---|
| 607 | return ERR_OK;
|
---|
| 608 | }
|
---|
| 609 | #endif /* DNS_LOCAL_HOSTLIST */
|
---|
| 610 | #ifdef DNS_LOOKUP_LOCAL_EXTERN
|
---|
| 611 | if (DNS_LOOKUP_LOCAL_EXTERN(name, addr, LWIP_DNS_ADDRTYPE_ARG_OR_ZERO(dns_addrtype)) == ERR_OK) {
|
---|
| 612 | return ERR_OK;
|
---|
| 613 | }
|
---|
| 614 | #endif /* DNS_LOOKUP_LOCAL_EXTERN */
|
---|
| 615 |
|
---|
| 616 | /* Walk through name list, return entry if found. If not, return NULL. */
|
---|
| 617 | for (i = 0; i < DNS_TABLE_SIZE; ++i) {
|
---|
| 618 | if ((dns_table[i].state == DNS_STATE_DONE) &&
|
---|
| 619 | (lwip_strnicmp(name, dns_table[i].name, sizeof(dns_table[i].name)) == 0) &&
|
---|
| 620 | LWIP_DNS_ADDRTYPE_MATCH_IP(dns_addrtype, dns_table[i].ipaddr)) {
|
---|
| 621 | LWIP_DEBUGF(DNS_DEBUG, ("dns_lookup: \"%s\": found = ", name));
|
---|
| 622 | ip_addr_debug_print_val(DNS_DEBUG, dns_table[i].ipaddr);
|
---|
| 623 | LWIP_DEBUGF(DNS_DEBUG, ("\n"));
|
---|
| 624 | if (addr) {
|
---|
| 625 | ip_addr_copy(*addr, dns_table[i].ipaddr);
|
---|
| 626 | }
|
---|
| 627 | return ERR_OK;
|
---|
| 628 | }
|
---|
| 629 | }
|
---|
| 630 |
|
---|
| 631 | return ERR_ARG;
|
---|
| 632 | }
|
---|
| 633 |
|
---|
| 634 | /**
|
---|
| 635 | * Compare the "dotted" name "query" with the encoded name "response"
|
---|
| 636 | * to make sure an answer from the DNS server matches the current dns_table
|
---|
| 637 | * entry (otherwise, answers might arrive late for hostname not on the list
|
---|
| 638 | * any more).
|
---|
| 639 | *
|
---|
| 640 | * For now, this function compares case-insensitive to cope with all kinds of
|
---|
| 641 | * servers. This also means that "dns 0x20 bit encoding" must be checked
|
---|
| 642 | * externally, if we want to implement it.
|
---|
| 643 | * Currently, the request is sent exactly as passed in by he user request.
|
---|
| 644 | *
|
---|
| 645 | * @param query hostname (not encoded) from the dns_table
|
---|
| 646 | * @param p pbuf containing the encoded hostname in the DNS response
|
---|
| 647 | * @param start_offset offset into p where the name starts
|
---|
| 648 | * @return 0xFFFF: names differ, other: names equal -> offset behind name
|
---|
| 649 | */
|
---|
| 650 | static u16_t
|
---|
| 651 | dns_compare_name(const char *query, struct pbuf *p, u16_t start_offset)
|
---|
| 652 | {
|
---|
| 653 | int n;
|
---|
| 654 | u16_t response_offset = start_offset;
|
---|
| 655 |
|
---|
| 656 | do {
|
---|
| 657 | n = pbuf_try_get_at(p, response_offset);
|
---|
| 658 | if ((n < 0) || (response_offset == 0xFFFF)) {
|
---|
| 659 | /* error or overflow */
|
---|
| 660 | return 0xFFFF;
|
---|
| 661 | }
|
---|
| 662 | response_offset++;
|
---|
| 663 | /** @see RFC 1035 - 4.1.4. Message compression */
|
---|
| 664 | if ((n & 0xc0) == 0xc0) {
|
---|
| 665 | /* Compressed name: cannot be equal since we don't send them */
|
---|
| 666 | return 0xFFFF;
|
---|
| 667 | } else {
|
---|
| 668 | /* Not compressed name */
|
---|
| 669 | while (n > 0) {
|
---|
| 670 | int c = pbuf_try_get_at(p, response_offset);
|
---|
| 671 | if (c < 0) {
|
---|
| 672 | return 0xFFFF;
|
---|
| 673 | }
|
---|
| 674 | if (lwip_tolower((*query)) != lwip_tolower((u8_t)c)) {
|
---|
| 675 | return 0xFFFF;
|
---|
| 676 | }
|
---|
| 677 | if (response_offset == 0xFFFF) {
|
---|
| 678 | /* would overflow */
|
---|
| 679 | return 0xFFFF;
|
---|
| 680 | }
|
---|
| 681 | response_offset++;
|
---|
| 682 | ++query;
|
---|
| 683 | --n;
|
---|
| 684 | }
|
---|
| 685 | ++query;
|
---|
| 686 | }
|
---|
| 687 | n = pbuf_try_get_at(p, response_offset);
|
---|
| 688 | if (n < 0) {
|
---|
| 689 | return 0xFFFF;
|
---|
| 690 | }
|
---|
| 691 | } while (n != 0);
|
---|
| 692 |
|
---|
| 693 | if (response_offset == 0xFFFF) {
|
---|
| 694 | /* would overflow */
|
---|
| 695 | return 0xFFFF;
|
---|
| 696 | }
|
---|
| 697 | return (u16_t)(response_offset + 1);
|
---|
| 698 | }
|
---|
| 699 |
|
---|
| 700 | /**
|
---|
| 701 | * Walk through a compact encoded DNS name and return the end of the name.
|
---|
| 702 | *
|
---|
| 703 | * @param p pbuf containing the name
|
---|
| 704 | * @param query_idx start index into p pointing to encoded DNS name in the DNS server response
|
---|
| 705 | * @return index to end of the name
|
---|
| 706 | */
|
---|
| 707 | static u16_t
|
---|
| 708 | dns_skip_name(struct pbuf *p, u16_t query_idx)
|
---|
| 709 | {
|
---|
| 710 | int n;
|
---|
| 711 | u16_t offset = query_idx;
|
---|
| 712 |
|
---|
| 713 | do {
|
---|
| 714 | n = pbuf_try_get_at(p, offset++);
|
---|
| 715 | if ((n < 0) || (offset == 0)) {
|
---|
| 716 | return 0xFFFF;
|
---|
| 717 | }
|
---|
| 718 | /** @see RFC 1035 - 4.1.4. Message compression */
|
---|
| 719 | if ((n & 0xc0) == 0xc0) {
|
---|
| 720 | /* Compressed name: since we only want to skip it (not check it), stop here */
|
---|
| 721 | break;
|
---|
| 722 | } else {
|
---|
| 723 | /* Not compressed name */
|
---|
| 724 | if (offset + n >= p->tot_len) {
|
---|
| 725 | return 0xFFFF;
|
---|
| 726 | }
|
---|
| 727 | offset = (u16_t)(offset + n);
|
---|
| 728 | }
|
---|
| 729 | n = pbuf_try_get_at(p, offset);
|
---|
| 730 | if (n < 0) {
|
---|
| 731 | return 0xFFFF;
|
---|
| 732 | }
|
---|
| 733 | } while (n != 0);
|
---|
| 734 |
|
---|
| 735 | if (offset == 0xFFFF) {
|
---|
| 736 | return 0xFFFF;
|
---|
| 737 | }
|
---|
| 738 | return (u16_t)(offset + 1);
|
---|
| 739 | }
|
---|
| 740 |
|
---|
| 741 | /**
|
---|
| 742 | * Send a DNS query packet.
|
---|
| 743 | *
|
---|
| 744 | * @param idx the DNS table entry index for which to send a request
|
---|
| 745 | * @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
|
---|
| 746 | */
|
---|
| 747 | static err_t
|
---|
| 748 | dns_send(u8_t idx)
|
---|
| 749 | {
|
---|
| 750 | err_t err;
|
---|
| 751 | struct dns_hdr hdr;
|
---|
| 752 | struct dns_query qry;
|
---|
| 753 | struct pbuf *p;
|
---|
| 754 | u16_t query_idx, copy_len;
|
---|
| 755 | const char *hostname, *hostname_part;
|
---|
| 756 | u8_t n;
|
---|
| 757 | u8_t pcb_idx;
|
---|
| 758 | struct dns_table_entry *entry = &dns_table[idx];
|
---|
| 759 |
|
---|
| 760 | LWIP_DEBUGF(DNS_DEBUG, ("dns_send: dns_servers[%"U16_F"] \"%s\": request\n",
|
---|
| 761 | (u16_t)(entry->server_idx), entry->name));
|
---|
| 762 | LWIP_ASSERT("dns server out of array", entry->server_idx < DNS_MAX_SERVERS);
|
---|
| 763 | if (ip_addr_isany_val(dns_servers[entry->server_idx])
|
---|
| 764 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 765 | && !entry->is_mdns
|
---|
| 766 | #endif
|
---|
| 767 | ) {
|
---|
| 768 | /* DNS server not valid anymore, e.g. PPP netif has been shut down */
|
---|
| 769 | /* call specified callback function if provided */
|
---|
| 770 | dns_call_found(idx, NULL);
|
---|
| 771 | /* flush this entry */
|
---|
| 772 | entry->state = DNS_STATE_UNUSED;
|
---|
| 773 | return ERR_OK;
|
---|
| 774 | }
|
---|
| 775 |
|
---|
| 776 | /* if here, we have either a new query or a retry on a previous query to process */
|
---|
| 777 | p = pbuf_alloc(PBUF_TRANSPORT, (u16_t)(SIZEOF_DNS_HDR + strlen(entry->name) + 2 +
|
---|
| 778 | SIZEOF_DNS_QUERY), PBUF_RAM);
|
---|
| 779 | if (p != NULL) {
|
---|
| 780 | const ip_addr_t *dst;
|
---|
| 781 | u16_t dst_port;
|
---|
| 782 | /* fill dns header */
|
---|
| 783 | memset(&hdr, 0, SIZEOF_DNS_HDR);
|
---|
| 784 | hdr.id = lwip_htons(entry->txid);
|
---|
| 785 | hdr.flags1 = DNS_FLAG1_RD;
|
---|
| 786 | hdr.numquestions = PP_HTONS(1);
|
---|
| 787 | pbuf_take(p, &hdr, SIZEOF_DNS_HDR);
|
---|
| 788 | hostname = entry->name;
|
---|
| 789 | --hostname;
|
---|
| 790 |
|
---|
| 791 | /* convert hostname into suitable query format. */
|
---|
| 792 | query_idx = SIZEOF_DNS_HDR;
|
---|
| 793 | do {
|
---|
| 794 | ++hostname;
|
---|
| 795 | hostname_part = hostname;
|
---|
| 796 | for (n = 0; *hostname != '.' && *hostname != 0; ++hostname) {
|
---|
| 797 | ++n;
|
---|
| 798 | }
|
---|
| 799 | copy_len = (u16_t)(hostname - hostname_part);
|
---|
| 800 | if (query_idx + n + 1 > 0xFFFF) {
|
---|
| 801 | /* u16_t overflow */
|
---|
| 802 | goto overflow_return;
|
---|
| 803 | }
|
---|
| 804 | pbuf_put_at(p, query_idx, n);
|
---|
| 805 | pbuf_take_at(p, hostname_part, copy_len, (u16_t)(query_idx + 1));
|
---|
| 806 | query_idx = (u16_t)(query_idx + n + 1);
|
---|
| 807 | } while (*hostname != 0);
|
---|
| 808 | pbuf_put_at(p, query_idx, 0);
|
---|
| 809 | query_idx++;
|
---|
| 810 |
|
---|
| 811 | /* fill dns query */
|
---|
| 812 | if (LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype)) {
|
---|
| 813 | qry.type = PP_HTONS(DNS_RRTYPE_AAAA);
|
---|
| 814 | } else {
|
---|
| 815 | qry.type = PP_HTONS(DNS_RRTYPE_A);
|
---|
| 816 | }
|
---|
| 817 | qry.cls = PP_HTONS(DNS_RRCLASS_IN);
|
---|
| 818 | pbuf_take_at(p, &qry, SIZEOF_DNS_QUERY, query_idx);
|
---|
| 819 |
|
---|
| 820 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
|
---|
| 821 | pcb_idx = entry->pcb_idx;
|
---|
| 822 | #else
|
---|
| 823 | pcb_idx = 0;
|
---|
| 824 | #endif
|
---|
| 825 | /* send dns packet */
|
---|
| 826 | LWIP_DEBUGF(DNS_DEBUG, ("sending DNS request ID %d for name \"%s\" to server %d\r\n",
|
---|
| 827 | entry->txid, entry->name, entry->server_idx));
|
---|
| 828 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 829 | if (entry->is_mdns) {
|
---|
| 830 | dst_port = DNS_MQUERY_PORT;
|
---|
| 831 | #if LWIP_IPV6
|
---|
| 832 | if (LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype)) {
|
---|
| 833 | dst = &dns_mquery_v6group;
|
---|
| 834 | }
|
---|
| 835 | #endif
|
---|
| 836 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 837 | else
|
---|
| 838 | #endif
|
---|
| 839 | #if LWIP_IPV4
|
---|
| 840 | {
|
---|
| 841 | dst = &dns_mquery_v4group;
|
---|
| 842 | }
|
---|
| 843 | #endif
|
---|
| 844 | } else
|
---|
| 845 | #endif /* LWIP_DNS_SUPPORT_MDNS_QUERIES */
|
---|
| 846 | {
|
---|
| 847 | dst_port = DNS_SERVER_PORT;
|
---|
| 848 | dst = &dns_servers[entry->server_idx];
|
---|
| 849 | }
|
---|
| 850 | err = udp_sendto(dns_pcbs[pcb_idx], p, dst, dst_port);
|
---|
| 851 |
|
---|
| 852 | /* free pbuf */
|
---|
| 853 | pbuf_free(p);
|
---|
| 854 | } else {
|
---|
| 855 | err = ERR_MEM;
|
---|
| 856 | }
|
---|
| 857 |
|
---|
| 858 | return err;
|
---|
| 859 | overflow_return:
|
---|
| 860 | pbuf_free(p);
|
---|
| 861 | return ERR_VAL;
|
---|
| 862 | }
|
---|
| 863 |
|
---|
| 864 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
|
---|
| 865 | static struct udp_pcb *
|
---|
| 866 | dns_alloc_random_port(void)
|
---|
| 867 | {
|
---|
| 868 | err_t err;
|
---|
| 869 | struct udp_pcb *pcb;
|
---|
| 870 |
|
---|
| 871 | pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
|
---|
| 872 | if (pcb == NULL) {
|
---|
| 873 | /* out of memory, have to reuse an existing pcb */
|
---|
| 874 | return NULL;
|
---|
| 875 | }
|
---|
| 876 | do {
|
---|
| 877 | u16_t port = (u16_t)DNS_RAND_TXID();
|
---|
| 878 | if (DNS_PORT_ALLOWED(port)) {
|
---|
| 879 | err = udp_bind(pcb, IP_ANY_TYPE, port);
|
---|
| 880 | } else {
|
---|
| 881 | /* this port is not allowed, try again */
|
---|
| 882 | err = ERR_USE;
|
---|
| 883 | }
|
---|
| 884 | } while (err == ERR_USE);
|
---|
| 885 | if (err != ERR_OK) {
|
---|
| 886 | udp_remove(pcb);
|
---|
| 887 | return NULL;
|
---|
| 888 | }
|
---|
| 889 | udp_recv(pcb, dns_recv, NULL);
|
---|
| 890 | return pcb;
|
---|
| 891 | }
|
---|
| 892 |
|
---|
| 893 | /**
|
---|
| 894 | * dns_alloc_pcb() - allocates a new pcb (or reuses an existing one) to be used
|
---|
| 895 | * for sending a request
|
---|
| 896 | *
|
---|
| 897 | * @return an index into dns_pcbs
|
---|
| 898 | */
|
---|
| 899 | static u8_t
|
---|
| 900 | dns_alloc_pcb(void)
|
---|
| 901 | {
|
---|
| 902 | u8_t i;
|
---|
| 903 | u8_t idx;
|
---|
| 904 |
|
---|
| 905 | for (i = 0; i < DNS_MAX_SOURCE_PORTS; i++) {
|
---|
| 906 | if (dns_pcbs[i] == NULL) {
|
---|
| 907 | break;
|
---|
| 908 | }
|
---|
| 909 | }
|
---|
| 910 | if (i < DNS_MAX_SOURCE_PORTS) {
|
---|
| 911 | dns_pcbs[i] = dns_alloc_random_port();
|
---|
| 912 | if (dns_pcbs[i] != NULL) {
|
---|
| 913 | /* succeeded */
|
---|
| 914 | dns_last_pcb_idx = i;
|
---|
| 915 | return i;
|
---|
| 916 | }
|
---|
| 917 | }
|
---|
| 918 | /* if we come here, creating a new UDP pcb failed, so we have to use
|
---|
| 919 | an already existing one (so overflow is no issue) */
|
---|
| 920 | for (i = 0, idx = (u8_t)(dns_last_pcb_idx + 1); i < DNS_MAX_SOURCE_PORTS; i++, idx++) {
|
---|
| 921 | if (idx >= DNS_MAX_SOURCE_PORTS) {
|
---|
| 922 | idx = 0;
|
---|
| 923 | }
|
---|
| 924 | if (dns_pcbs[idx] != NULL) {
|
---|
| 925 | dns_last_pcb_idx = idx;
|
---|
| 926 | return idx;
|
---|
| 927 | }
|
---|
| 928 | }
|
---|
| 929 | return DNS_MAX_SOURCE_PORTS;
|
---|
| 930 | }
|
---|
| 931 | #endif /* ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0) */
|
---|
| 932 |
|
---|
| 933 | /**
|
---|
| 934 | * dns_call_found() - call the found callback and check if there are duplicate
|
---|
| 935 | * entries for the given hostname. If there are any, their found callback will
|
---|
| 936 | * be called and they will be removed.
|
---|
| 937 | *
|
---|
| 938 | * @param idx dns table index of the entry that is resolved or removed
|
---|
| 939 | * @param addr IP address for the hostname (or NULL on error or memory shortage)
|
---|
| 940 | */
|
---|
| 941 | static void
|
---|
| 942 | dns_call_found(u8_t idx, ip_addr_t *addr)
|
---|
| 943 | {
|
---|
| 944 | #if ((LWIP_DNS_SECURE & (LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING | LWIP_DNS_SECURE_RAND_SRC_PORT)) != 0)
|
---|
| 945 | u8_t i;
|
---|
| 946 | #endif
|
---|
| 947 |
|
---|
| 948 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 949 | if (addr != NULL) {
|
---|
| 950 | /* check that address type matches the request and adapt the table entry */
|
---|
| 951 | if (IP_IS_V6_VAL(*addr)) {
|
---|
| 952 | LWIP_ASSERT("invalid response", LWIP_DNS_ADDRTYPE_IS_IPV6(dns_table[idx].reqaddrtype));
|
---|
| 953 | dns_table[idx].reqaddrtype = LWIP_DNS_ADDRTYPE_IPV6;
|
---|
| 954 | } else {
|
---|
| 955 | LWIP_ASSERT("invalid response", !LWIP_DNS_ADDRTYPE_IS_IPV6(dns_table[idx].reqaddrtype));
|
---|
| 956 | dns_table[idx].reqaddrtype = LWIP_DNS_ADDRTYPE_IPV4;
|
---|
| 957 | }
|
---|
| 958 | }
|
---|
| 959 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 960 |
|
---|
| 961 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING) != 0)
|
---|
| 962 | for (i = 0; i < DNS_MAX_REQUESTS; i++) {
|
---|
| 963 | if (dns_requests[i].found && (dns_requests[i].dns_table_idx == idx)) {
|
---|
| 964 | (*dns_requests[i].found)(dns_table[idx].name, addr, dns_requests[i].arg);
|
---|
| 965 | /* flush this entry */
|
---|
| 966 | dns_requests[i].found = NULL;
|
---|
| 967 | }
|
---|
| 968 | }
|
---|
| 969 | #else
|
---|
| 970 | if (dns_requests[idx].found) {
|
---|
| 971 | (*dns_requests[idx].found)(dns_table[idx].name, addr, dns_requests[idx].arg);
|
---|
| 972 | }
|
---|
| 973 | dns_requests[idx].found = NULL;
|
---|
| 974 | #endif
|
---|
| 975 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
|
---|
| 976 | /* close the pcb used unless other request are using it */
|
---|
| 977 | for (i = 0; i < DNS_MAX_REQUESTS; i++) {
|
---|
| 978 | if (i == idx) {
|
---|
| 979 | continue; /* only check other requests */
|
---|
| 980 | }
|
---|
| 981 | if (dns_table[i].state == DNS_STATE_ASKING) {
|
---|
| 982 | if (dns_table[i].pcb_idx == dns_table[idx].pcb_idx) {
|
---|
| 983 | /* another request is still using the same pcb */
|
---|
| 984 | dns_table[idx].pcb_idx = DNS_MAX_SOURCE_PORTS;
|
---|
| 985 | break;
|
---|
| 986 | }
|
---|
| 987 | }
|
---|
| 988 | }
|
---|
| 989 | if (dns_table[idx].pcb_idx < DNS_MAX_SOURCE_PORTS) {
|
---|
| 990 | /* if we come here, the pcb is not used any more and can be removed */
|
---|
| 991 | udp_remove(dns_pcbs[dns_table[idx].pcb_idx]);
|
---|
| 992 | dns_pcbs[dns_table[idx].pcb_idx] = NULL;
|
---|
| 993 | dns_table[idx].pcb_idx = DNS_MAX_SOURCE_PORTS;
|
---|
| 994 | }
|
---|
| 995 | #endif
|
---|
| 996 | }
|
---|
| 997 |
|
---|
| 998 | /* Create a query transmission ID that is unique for all outstanding queries */
|
---|
| 999 | static u16_t
|
---|
| 1000 | dns_create_txid(void)
|
---|
| 1001 | {
|
---|
| 1002 | u16_t txid;
|
---|
| 1003 | u8_t i;
|
---|
| 1004 |
|
---|
| 1005 | again:
|
---|
| 1006 | txid = (u16_t)DNS_RAND_TXID();
|
---|
| 1007 |
|
---|
| 1008 | /* check whether the ID is unique */
|
---|
| 1009 | for (i = 0; i < DNS_TABLE_SIZE; i++) {
|
---|
| 1010 | if ((dns_table[i].state == DNS_STATE_ASKING) &&
|
---|
| 1011 | (dns_table[i].txid == txid)) {
|
---|
| 1012 | /* ID already used by another pending query */
|
---|
| 1013 | goto again;
|
---|
| 1014 | }
|
---|
| 1015 | }
|
---|
| 1016 |
|
---|
| 1017 | return txid;
|
---|
| 1018 | }
|
---|
| 1019 |
|
---|
| 1020 | /**
|
---|
| 1021 | * Check whether there are other backup DNS servers available to try
|
---|
| 1022 | */
|
---|
| 1023 | static u8_t
|
---|
| 1024 | dns_backupserver_available(struct dns_table_entry *pentry)
|
---|
| 1025 | {
|
---|
| 1026 | u8_t ret = 0;
|
---|
| 1027 |
|
---|
| 1028 | if (pentry) {
|
---|
| 1029 | if ((pentry->server_idx + 1 < DNS_MAX_SERVERS) && !ip_addr_isany_val(dns_servers[pentry->server_idx + 1])) {
|
---|
| 1030 | ret = 1;
|
---|
| 1031 | }
|
---|
| 1032 | }
|
---|
| 1033 |
|
---|
| 1034 | return ret;
|
---|
| 1035 | }
|
---|
| 1036 |
|
---|
| 1037 | /**
|
---|
| 1038 | * dns_check_entry() - see if entry has not yet been queried and, if so, sends out a query.
|
---|
| 1039 | * Check an entry in the dns_table:
|
---|
| 1040 | * - send out query for new entries
|
---|
| 1041 | * - retry old pending entries on timeout (also with different servers)
|
---|
| 1042 | * - remove completed entries from the table if their TTL has expired
|
---|
| 1043 | *
|
---|
| 1044 | * @param i index of the dns_table entry to check
|
---|
| 1045 | */
|
---|
| 1046 | static void
|
---|
| 1047 | dns_check_entry(u8_t i)
|
---|
| 1048 | {
|
---|
| 1049 | err_t err;
|
---|
| 1050 | struct dns_table_entry *entry = &dns_table[i];
|
---|
| 1051 |
|
---|
| 1052 | LWIP_ASSERT("array index out of bounds", i < DNS_TABLE_SIZE);
|
---|
| 1053 |
|
---|
| 1054 | switch (entry->state) {
|
---|
| 1055 | case DNS_STATE_NEW:
|
---|
| 1056 | /* initialize new entry */
|
---|
| 1057 | entry->txid = dns_create_txid();
|
---|
| 1058 | entry->state = DNS_STATE_ASKING;
|
---|
| 1059 | entry->server_idx = 0;
|
---|
| 1060 | entry->tmr = 1;
|
---|
| 1061 | entry->retries = 0;
|
---|
| 1062 |
|
---|
| 1063 | /* send DNS packet for this entry */
|
---|
| 1064 | err = dns_send(i);
|
---|
| 1065 | if (err != ERR_OK) {
|
---|
| 1066 | LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
|
---|
| 1067 | ("dns_send returned error: %s\n", lwip_strerr(err)));
|
---|
| 1068 | }
|
---|
| 1069 | break;
|
---|
| 1070 | case DNS_STATE_ASKING:
|
---|
| 1071 | if (--entry->tmr == 0) {
|
---|
| 1072 | if (++entry->retries == DNS_MAX_RETRIES) {
|
---|
| 1073 | if (dns_backupserver_available(entry)
|
---|
| 1074 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 1075 | && !entry->is_mdns
|
---|
| 1076 | #endif /* LWIP_DNS_SUPPORT_MDNS_QUERIES */
|
---|
| 1077 | ) {
|
---|
| 1078 | /* change of server */
|
---|
| 1079 | entry->server_idx++;
|
---|
| 1080 | entry->tmr = 1;
|
---|
| 1081 | entry->retries = 0;
|
---|
| 1082 | } else {
|
---|
| 1083 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": timeout\n", entry->name));
|
---|
| 1084 | /* call specified callback function if provided */
|
---|
| 1085 | dns_call_found(i, NULL);
|
---|
| 1086 | /* flush this entry */
|
---|
| 1087 | entry->state = DNS_STATE_UNUSED;
|
---|
| 1088 | break;
|
---|
| 1089 | }
|
---|
| 1090 | } else {
|
---|
| 1091 | /* wait longer for the next retry */
|
---|
| 1092 | entry->tmr = entry->retries;
|
---|
| 1093 | }
|
---|
| 1094 |
|
---|
| 1095 | /* send DNS packet for this entry */
|
---|
| 1096 | err = dns_send(i);
|
---|
| 1097 | if (err != ERR_OK) {
|
---|
| 1098 | LWIP_DEBUGF(DNS_DEBUG | LWIP_DBG_LEVEL_WARNING,
|
---|
| 1099 | ("dns_send returned error: %s\n", lwip_strerr(err)));
|
---|
| 1100 | }
|
---|
| 1101 | }
|
---|
| 1102 | break;
|
---|
| 1103 | case DNS_STATE_DONE:
|
---|
| 1104 | /* if the time to live is nul */
|
---|
| 1105 | if ((entry->ttl == 0) || (--entry->ttl == 0)) {
|
---|
| 1106 | LWIP_DEBUGF(DNS_DEBUG, ("dns_check_entry: \"%s\": flush\n", entry->name));
|
---|
| 1107 | /* flush this entry, there cannot be any related pending entries in this state */
|
---|
| 1108 | entry->state = DNS_STATE_UNUSED;
|
---|
| 1109 | }
|
---|
| 1110 | break;
|
---|
| 1111 | case DNS_STATE_UNUSED:
|
---|
| 1112 | /* nothing to do */
|
---|
| 1113 | break;
|
---|
| 1114 | default:
|
---|
| 1115 | LWIP_ASSERT("unknown dns_table entry state:", 0);
|
---|
| 1116 | break;
|
---|
| 1117 | }
|
---|
| 1118 | }
|
---|
| 1119 |
|
---|
| 1120 | /**
|
---|
| 1121 | * Call dns_check_entry for each entry in dns_table - check all entries.
|
---|
| 1122 | */
|
---|
| 1123 | static void
|
---|
| 1124 | dns_check_entries(void)
|
---|
| 1125 | {
|
---|
| 1126 | u8_t i;
|
---|
| 1127 |
|
---|
| 1128 | for (i = 0; i < DNS_TABLE_SIZE; ++i) {
|
---|
| 1129 | dns_check_entry(i);
|
---|
| 1130 | }
|
---|
| 1131 | }
|
---|
| 1132 |
|
---|
| 1133 | /**
|
---|
| 1134 | * Save TTL and call dns_call_found for correct response.
|
---|
| 1135 | */
|
---|
| 1136 | static void
|
---|
| 1137 | dns_correct_response(u8_t idx, u32_t ttl)
|
---|
| 1138 | {
|
---|
| 1139 | struct dns_table_entry *entry = &dns_table[idx];
|
---|
| 1140 |
|
---|
| 1141 | entry->state = DNS_STATE_DONE;
|
---|
| 1142 |
|
---|
| 1143 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", entry->name));
|
---|
| 1144 | ip_addr_debug_print_val(DNS_DEBUG, entry->ipaddr);
|
---|
| 1145 | LWIP_DEBUGF(DNS_DEBUG, ("\n"));
|
---|
| 1146 |
|
---|
| 1147 | /* read the answer resource record's TTL, and maximize it if needed */
|
---|
| 1148 | entry->ttl = ttl;
|
---|
| 1149 | if (entry->ttl > DNS_MAX_TTL) {
|
---|
| 1150 | entry->ttl = DNS_MAX_TTL;
|
---|
| 1151 | }
|
---|
| 1152 | dns_call_found(idx, &entry->ipaddr);
|
---|
| 1153 |
|
---|
| 1154 | if (entry->ttl == 0) {
|
---|
| 1155 | /* RFC 883, page 29: "Zero values are
|
---|
| 1156 | interpreted to mean that the RR can only be used for the
|
---|
| 1157 | transaction in progress, and should not be cached."
|
---|
| 1158 | -> flush this entry now */
|
---|
| 1159 | /* entry reused during callback? */
|
---|
| 1160 | if (entry->state == DNS_STATE_DONE) {
|
---|
| 1161 | entry->state = DNS_STATE_UNUSED;
|
---|
| 1162 | }
|
---|
| 1163 | }
|
---|
| 1164 | }
|
---|
| 1165 |
|
---|
| 1166 | /**
|
---|
| 1167 | * Receive input function for DNS response packets arriving for the dns UDP pcb.
|
---|
| 1168 | */
|
---|
| 1169 | static void
|
---|
| 1170 | dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
|
---|
| 1171 | {
|
---|
| 1172 | u8_t i;
|
---|
| 1173 | u16_t txid;
|
---|
| 1174 | u16_t res_idx;
|
---|
| 1175 | struct dns_hdr hdr;
|
---|
| 1176 | struct dns_answer ans;
|
---|
| 1177 | struct dns_query qry;
|
---|
| 1178 | u16_t nquestions, nanswers;
|
---|
| 1179 |
|
---|
| 1180 | LWIP_UNUSED_ARG(arg);
|
---|
| 1181 | LWIP_UNUSED_ARG(pcb);
|
---|
| 1182 | LWIP_UNUSED_ARG(port);
|
---|
| 1183 |
|
---|
| 1184 | /* is the dns message big enough ? */
|
---|
| 1185 | if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY)) {
|
---|
| 1186 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
|
---|
| 1187 | /* free pbuf and return */
|
---|
| 1188 | goto ignore_packet;
|
---|
| 1189 | }
|
---|
| 1190 |
|
---|
| 1191 | /* copy dns payload inside static buffer for processing */
|
---|
| 1192 | if (pbuf_copy_partial(p, &hdr, SIZEOF_DNS_HDR, 0) == SIZEOF_DNS_HDR) {
|
---|
| 1193 | /* Match the ID in the DNS header with the name table. */
|
---|
| 1194 | txid = lwip_htons(hdr.id);
|
---|
| 1195 | for (i = 0; i < DNS_TABLE_SIZE; i++) {
|
---|
| 1196 | struct dns_table_entry *entry = &dns_table[i];
|
---|
| 1197 | if ((entry->state == DNS_STATE_ASKING) &&
|
---|
| 1198 | (entry->txid == txid)) {
|
---|
| 1199 |
|
---|
| 1200 | /* We only care about the question(s) and the answers. The authrr
|
---|
| 1201 | and the extrarr are simply discarded. */
|
---|
| 1202 | nquestions = lwip_htons(hdr.numquestions);
|
---|
| 1203 | nanswers = lwip_htons(hdr.numanswers);
|
---|
| 1204 |
|
---|
| 1205 | /* Check for correct response. */
|
---|
| 1206 | if ((hdr.flags1 & DNS_FLAG1_RESPONSE) == 0) {
|
---|
| 1207 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": not a response\n", entry->name));
|
---|
| 1208 | goto ignore_packet; /* ignore this packet */
|
---|
| 1209 | }
|
---|
| 1210 | if (nquestions != 1) {
|
---|
| 1211 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", entry->name));
|
---|
| 1212 | goto ignore_packet; /* ignore this packet */
|
---|
| 1213 | }
|
---|
| 1214 |
|
---|
| 1215 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 1216 | if (!entry->is_mdns)
|
---|
| 1217 | #endif /* LWIP_DNS_SUPPORT_MDNS_QUERIES */
|
---|
| 1218 | {
|
---|
| 1219 | /* Check whether response comes from the same network address to which the
|
---|
| 1220 | question was sent. (RFC 5452) */
|
---|
| 1221 | if (!ip_addr_cmp(addr, &dns_servers[entry->server_idx])) {
|
---|
| 1222 | goto ignore_packet; /* ignore this packet */
|
---|
| 1223 | }
|
---|
| 1224 | }
|
---|
| 1225 |
|
---|
| 1226 | /* Check if the name in the "question" part match with the name in the entry and
|
---|
| 1227 | skip it if equal. */
|
---|
| 1228 | res_idx = dns_compare_name(entry->name, p, SIZEOF_DNS_HDR);
|
---|
| 1229 | if (res_idx == 0xFFFF) {
|
---|
| 1230 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", entry->name));
|
---|
| 1231 | goto ignore_packet; /* ignore this packet */
|
---|
| 1232 | }
|
---|
| 1233 |
|
---|
| 1234 | /* check if "question" part matches the request */
|
---|
| 1235 | if (pbuf_copy_partial(p, &qry, SIZEOF_DNS_QUERY, res_idx) != SIZEOF_DNS_QUERY) {
|
---|
| 1236 | goto ignore_packet; /* ignore this packet */
|
---|
| 1237 | }
|
---|
| 1238 | if ((qry.cls != PP_HTONS(DNS_RRCLASS_IN)) ||
|
---|
| 1239 | (LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype) && (qry.type != PP_HTONS(DNS_RRTYPE_AAAA))) ||
|
---|
| 1240 | (!LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype) && (qry.type != PP_HTONS(DNS_RRTYPE_A)))) {
|
---|
| 1241 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", entry->name));
|
---|
| 1242 | goto ignore_packet; /* ignore this packet */
|
---|
| 1243 | }
|
---|
| 1244 | /* skip the rest of the "question" part */
|
---|
| 1245 | if (res_idx + SIZEOF_DNS_QUERY > 0xFFFF) {
|
---|
| 1246 | goto ignore_packet;
|
---|
| 1247 | }
|
---|
| 1248 | res_idx = (u16_t)(res_idx + SIZEOF_DNS_QUERY);
|
---|
| 1249 |
|
---|
| 1250 | /* Check for error. If so, call callback to inform. */
|
---|
| 1251 | if (hdr.flags2 & DNS_FLAG2_ERR_MASK) {
|
---|
| 1252 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in flags\n", entry->name));
|
---|
| 1253 |
|
---|
| 1254 | /* if there is another backup DNS server to try
|
---|
| 1255 | * then don't stop the DNS request
|
---|
| 1256 | */
|
---|
| 1257 | if (dns_backupserver_available(entry)) {
|
---|
| 1258 | /* avoid retrying the same server */
|
---|
| 1259 | entry->retries = DNS_MAX_RETRIES-1;
|
---|
| 1260 | entry->tmr = 1;
|
---|
| 1261 |
|
---|
| 1262 | /* contact next available server for this entry */
|
---|
| 1263 | dns_check_entry(i);
|
---|
| 1264 |
|
---|
| 1265 | goto ignore_packet;
|
---|
| 1266 | }
|
---|
| 1267 | } else {
|
---|
| 1268 | while ((nanswers > 0) && (res_idx < p->tot_len)) {
|
---|
| 1269 | /* skip answer resource record's host name */
|
---|
| 1270 | res_idx = dns_skip_name(p, res_idx);
|
---|
| 1271 | if (res_idx == 0xFFFF) {
|
---|
| 1272 | goto ignore_packet; /* ignore this packet */
|
---|
| 1273 | }
|
---|
| 1274 |
|
---|
| 1275 | /* Check for IP address type and Internet class. Others are discarded. */
|
---|
| 1276 | if (pbuf_copy_partial(p, &ans, SIZEOF_DNS_ANSWER, res_idx) != SIZEOF_DNS_ANSWER) {
|
---|
| 1277 | goto ignore_packet; /* ignore this packet */
|
---|
| 1278 | }
|
---|
| 1279 | if (res_idx + SIZEOF_DNS_ANSWER > 0xFFFF) {
|
---|
| 1280 | goto ignore_packet;
|
---|
| 1281 | }
|
---|
| 1282 | res_idx = (u16_t)(res_idx + SIZEOF_DNS_ANSWER);
|
---|
| 1283 |
|
---|
| 1284 | if (ans.cls == PP_HTONS(DNS_RRCLASS_IN)) {
|
---|
| 1285 | #if LWIP_IPV4
|
---|
| 1286 | if ((ans.type == PP_HTONS(DNS_RRTYPE_A)) && (ans.len == PP_HTONS(sizeof(ip4_addr_t)))) {
|
---|
| 1287 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1288 | if (!LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype))
|
---|
| 1289 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1290 | {
|
---|
| 1291 | ip4_addr_t ip4addr;
|
---|
| 1292 | /* read the IP address after answer resource record's header */
|
---|
| 1293 | if (pbuf_copy_partial(p, &ip4addr, sizeof(ip4_addr_t), res_idx) != sizeof(ip4_addr_t)) {
|
---|
| 1294 | goto ignore_packet; /* ignore this packet */
|
---|
| 1295 | }
|
---|
| 1296 | ip_addr_copy_from_ip4(dns_table[i].ipaddr, ip4addr);
|
---|
| 1297 | pbuf_free(p);
|
---|
| 1298 | /* handle correct response */
|
---|
| 1299 | dns_correct_response(i, lwip_ntohl(ans.ttl));
|
---|
| 1300 | return;
|
---|
| 1301 | }
|
---|
| 1302 | }
|
---|
| 1303 | #endif /* LWIP_IPV4 */
|
---|
| 1304 | #if LWIP_IPV6
|
---|
| 1305 | if ((ans.type == PP_HTONS(DNS_RRTYPE_AAAA)) && (ans.len == PP_HTONS(sizeof(ip6_addr_p_t)))) {
|
---|
| 1306 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1307 | if (LWIP_DNS_ADDRTYPE_IS_IPV6(entry->reqaddrtype))
|
---|
| 1308 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1309 | {
|
---|
| 1310 | ip6_addr_p_t ip6addr;
|
---|
| 1311 | /* read the IP address after answer resource record's header */
|
---|
| 1312 | if (pbuf_copy_partial(p, &ip6addr, sizeof(ip6_addr_p_t), res_idx) != sizeof(ip6_addr_p_t)) {
|
---|
| 1313 | goto ignore_packet; /* ignore this packet */
|
---|
| 1314 | }
|
---|
| 1315 | /* @todo: scope ip6addr? Might be required for link-local addresses at least? */
|
---|
| 1316 | ip_addr_copy_from_ip6_packed(dns_table[i].ipaddr, ip6addr);
|
---|
| 1317 | pbuf_free(p);
|
---|
| 1318 | /* handle correct response */
|
---|
| 1319 | dns_correct_response(i, lwip_ntohl(ans.ttl));
|
---|
| 1320 | return;
|
---|
| 1321 | }
|
---|
| 1322 | }
|
---|
| 1323 | #endif /* LWIP_IPV6 */
|
---|
| 1324 | }
|
---|
| 1325 | /* skip this answer */
|
---|
| 1326 | if ((int)(res_idx + lwip_htons(ans.len)) > 0xFFFF) {
|
---|
| 1327 | goto ignore_packet; /* ignore this packet */
|
---|
| 1328 | }
|
---|
| 1329 | res_idx = (u16_t)(res_idx + lwip_htons(ans.len));
|
---|
| 1330 | --nanswers;
|
---|
| 1331 | }
|
---|
| 1332 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1333 | if ((entry->reqaddrtype == LWIP_DNS_ADDRTYPE_IPV4_IPV6) ||
|
---|
| 1334 | (entry->reqaddrtype == LWIP_DNS_ADDRTYPE_IPV6_IPV4)) {
|
---|
| 1335 | if (entry->reqaddrtype == LWIP_DNS_ADDRTYPE_IPV4_IPV6) {
|
---|
| 1336 | /* IPv4 failed, try IPv6 */
|
---|
| 1337 | dns_table[i].reqaddrtype = LWIP_DNS_ADDRTYPE_IPV6;
|
---|
| 1338 | } else {
|
---|
| 1339 | /* IPv6 failed, try IPv4 */
|
---|
| 1340 | dns_table[i].reqaddrtype = LWIP_DNS_ADDRTYPE_IPV4;
|
---|
| 1341 | }
|
---|
| 1342 | pbuf_free(p);
|
---|
| 1343 | dns_table[i].state = DNS_STATE_NEW;
|
---|
| 1344 | dns_check_entry(i);
|
---|
| 1345 | return;
|
---|
| 1346 | }
|
---|
| 1347 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1348 | LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": error in response\n", entry->name));
|
---|
| 1349 | }
|
---|
| 1350 | /* call callback to indicate error, clean up memory and return */
|
---|
| 1351 | pbuf_free(p);
|
---|
| 1352 | dns_call_found(i, NULL);
|
---|
| 1353 | dns_table[i].state = DNS_STATE_UNUSED;
|
---|
| 1354 | return;
|
---|
| 1355 | }
|
---|
| 1356 | }
|
---|
| 1357 | }
|
---|
| 1358 |
|
---|
| 1359 | ignore_packet:
|
---|
| 1360 | /* deallocate memory and return */
|
---|
| 1361 | pbuf_free(p);
|
---|
| 1362 | return;
|
---|
| 1363 | }
|
---|
| 1364 |
|
---|
| 1365 | /**
|
---|
| 1366 | * Queues a new hostname to resolve and sends out a DNS query for that hostname
|
---|
| 1367 | *
|
---|
| 1368 | * @param name the hostname that is to be queried
|
---|
| 1369 | * @param hostnamelen length of the hostname
|
---|
| 1370 | * @param found a callback function to be called on success, failure or timeout
|
---|
| 1371 | * @param callback_arg argument to pass to the callback function
|
---|
| 1372 | * @return err_t return code.
|
---|
| 1373 | */
|
---|
| 1374 | static err_t
|
---|
| 1375 | dns_enqueue(const char *name, size_t hostnamelen, dns_found_callback found,
|
---|
| 1376 | void *callback_arg LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype) LWIP_DNS_ISMDNS_ARG(u8_t is_mdns))
|
---|
| 1377 | {
|
---|
| 1378 | u8_t i;
|
---|
| 1379 | u8_t lseq, lseqi;
|
---|
| 1380 | struct dns_table_entry *entry = NULL;
|
---|
| 1381 | size_t namelen;
|
---|
| 1382 | struct dns_req_entry *req;
|
---|
| 1383 |
|
---|
| 1384 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING) != 0)
|
---|
| 1385 | u8_t r;
|
---|
| 1386 | /* check for duplicate entries */
|
---|
| 1387 | for (i = 0; i < DNS_TABLE_SIZE; i++) {
|
---|
| 1388 | if ((dns_table[i].state == DNS_STATE_ASKING) &&
|
---|
| 1389 | (lwip_strnicmp(name, dns_table[i].name, sizeof(dns_table[i].name)) == 0)) {
|
---|
| 1390 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1391 | if (dns_table[i].reqaddrtype != dns_addrtype) {
|
---|
| 1392 | /* requested address types don't match
|
---|
| 1393 | this can lead to 2 concurrent requests, but mixing the address types
|
---|
| 1394 | for the same host should not be that common */
|
---|
| 1395 | continue;
|
---|
| 1396 | }
|
---|
| 1397 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1398 | /* this is a duplicate entry, find a free request entry */
|
---|
| 1399 | for (r = 0; r < DNS_MAX_REQUESTS; r++) {
|
---|
| 1400 | if (dns_requests[r].found == 0) {
|
---|
| 1401 | dns_requests[r].found = found;
|
---|
| 1402 | dns_requests[r].arg = callback_arg;
|
---|
| 1403 | dns_requests[r].dns_table_idx = i;
|
---|
| 1404 | LWIP_DNS_SET_ADDRTYPE(dns_requests[r].reqaddrtype, dns_addrtype);
|
---|
| 1405 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": duplicate request\n", name));
|
---|
| 1406 | return ERR_INPROGRESS;
|
---|
| 1407 | }
|
---|
| 1408 | }
|
---|
| 1409 | }
|
---|
| 1410 | }
|
---|
| 1411 | /* no duplicate entries found */
|
---|
| 1412 | #endif
|
---|
| 1413 |
|
---|
| 1414 | /* search an unused entry, or the oldest one */
|
---|
| 1415 | lseq = 0;
|
---|
| 1416 | lseqi = DNS_TABLE_SIZE;
|
---|
| 1417 | for (i = 0; i < DNS_TABLE_SIZE; ++i) {
|
---|
| 1418 | entry = &dns_table[i];
|
---|
| 1419 | /* is it an unused entry ? */
|
---|
| 1420 | if (entry->state == DNS_STATE_UNUSED) {
|
---|
| 1421 | break;
|
---|
| 1422 | }
|
---|
| 1423 | /* check if this is the oldest completed entry */
|
---|
| 1424 | if (entry->state == DNS_STATE_DONE) {
|
---|
| 1425 | u8_t age = (u8_t)(dns_seqno - entry->seqno);
|
---|
| 1426 | if (age > lseq) {
|
---|
| 1427 | lseq = age;
|
---|
| 1428 | lseqi = i;
|
---|
| 1429 | }
|
---|
| 1430 | }
|
---|
| 1431 | }
|
---|
| 1432 |
|
---|
| 1433 | /* if we don't have found an unused entry, use the oldest completed one */
|
---|
| 1434 | if (i == DNS_TABLE_SIZE) {
|
---|
| 1435 | if ((lseqi >= DNS_TABLE_SIZE) || (dns_table[lseqi].state != DNS_STATE_DONE)) {
|
---|
| 1436 | /* no entry can be used now, table is full */
|
---|
| 1437 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS entries table is full\n", name));
|
---|
| 1438 | return ERR_MEM;
|
---|
| 1439 | } else {
|
---|
| 1440 | /* use the oldest completed one */
|
---|
| 1441 | i = lseqi;
|
---|
| 1442 | entry = &dns_table[i];
|
---|
| 1443 | }
|
---|
| 1444 | }
|
---|
| 1445 |
|
---|
| 1446 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING) != 0)
|
---|
| 1447 | /* find a free request entry */
|
---|
| 1448 | req = NULL;
|
---|
| 1449 | for (r = 0; r < DNS_MAX_REQUESTS; r++) {
|
---|
| 1450 | if (dns_requests[r].found == NULL) {
|
---|
| 1451 | req = &dns_requests[r];
|
---|
| 1452 | break;
|
---|
| 1453 | }
|
---|
| 1454 | }
|
---|
| 1455 | if (req == NULL) {
|
---|
| 1456 | /* no request entry can be used now, table is full */
|
---|
| 1457 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": DNS request entries table is full\n", name));
|
---|
| 1458 | return ERR_MEM;
|
---|
| 1459 | }
|
---|
| 1460 | req->dns_table_idx = i;
|
---|
| 1461 | #else
|
---|
| 1462 | /* in this configuration, the entry index is the same as the request index */
|
---|
| 1463 | req = &dns_requests[i];
|
---|
| 1464 | #endif
|
---|
| 1465 |
|
---|
| 1466 | /* use this entry */
|
---|
| 1467 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS entry %"U16_F"\n", name, (u16_t)(i)));
|
---|
| 1468 |
|
---|
| 1469 | /* fill the entry */
|
---|
| 1470 | entry->state = DNS_STATE_NEW;
|
---|
| 1471 | entry->seqno = dns_seqno;
|
---|
| 1472 | LWIP_DNS_SET_ADDRTYPE(entry->reqaddrtype, dns_addrtype);
|
---|
| 1473 | LWIP_DNS_SET_ADDRTYPE(req->reqaddrtype, dns_addrtype);
|
---|
| 1474 | req->found = found;
|
---|
| 1475 | req->arg = callback_arg;
|
---|
| 1476 | namelen = LWIP_MIN(hostnamelen, DNS_MAX_NAME_LENGTH - 1);
|
---|
| 1477 | MEMCPY(entry->name, name, namelen);
|
---|
| 1478 | entry->name[namelen] = 0;
|
---|
| 1479 |
|
---|
| 1480 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) != 0)
|
---|
| 1481 | entry->pcb_idx = dns_alloc_pcb();
|
---|
| 1482 | if (entry->pcb_idx >= DNS_MAX_SOURCE_PORTS) {
|
---|
| 1483 | /* failed to get a UDP pcb */
|
---|
| 1484 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": failed to allocate a pcb\n", name));
|
---|
| 1485 | entry->state = DNS_STATE_UNUSED;
|
---|
| 1486 | req->found = NULL;
|
---|
| 1487 | return ERR_MEM;
|
---|
| 1488 | }
|
---|
| 1489 | LWIP_DEBUGF(DNS_DEBUG, ("dns_enqueue: \"%s\": use DNS pcb %"U16_F"\n", name, (u16_t)(entry->pcb_idx)));
|
---|
| 1490 | #endif
|
---|
| 1491 |
|
---|
| 1492 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 1493 | entry->is_mdns = is_mdns;
|
---|
| 1494 | #endif
|
---|
| 1495 |
|
---|
| 1496 | dns_seqno++;
|
---|
| 1497 |
|
---|
| 1498 | /* force to send query without waiting timer */
|
---|
| 1499 | dns_check_entry(i);
|
---|
| 1500 |
|
---|
| 1501 | /* dns query is enqueued */
|
---|
| 1502 | return ERR_INPROGRESS;
|
---|
| 1503 | }
|
---|
| 1504 |
|
---|
| 1505 | /**
|
---|
| 1506 | * @ingroup dns
|
---|
| 1507 | * Resolve a hostname (string) into an IP address.
|
---|
| 1508 | * NON-BLOCKING callback version for use with raw API!!!
|
---|
| 1509 | *
|
---|
| 1510 | * Returns immediately with one of err_t return codes:
|
---|
| 1511 | * - ERR_OK if hostname is a valid IP address string or the host
|
---|
| 1512 | * name is already in the local names table.
|
---|
| 1513 | * - ERR_INPROGRESS enqueue a request to be sent to the DNS server
|
---|
| 1514 | * for resolution if no errors are present.
|
---|
| 1515 | * - ERR_ARG: dns client not initialized or invalid hostname
|
---|
| 1516 | *
|
---|
| 1517 | * @param hostname the hostname that is to be queried
|
---|
| 1518 | * @param addr pointer to a ip_addr_t where to store the address if it is already
|
---|
| 1519 | * cached in the dns_table (only valid if ERR_OK is returned!)
|
---|
| 1520 | * @param found a callback function to be called on success, failure or timeout (only if
|
---|
| 1521 | * ERR_INPROGRESS is returned!)
|
---|
| 1522 | * @param callback_arg argument to pass to the callback function
|
---|
| 1523 | * @return a err_t return code.
|
---|
| 1524 | */
|
---|
| 1525 | err_t
|
---|
| 1526 | dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found,
|
---|
| 1527 | void *callback_arg)
|
---|
| 1528 | {
|
---|
| 1529 | return dns_gethostbyname_addrtype(hostname, addr, found, callback_arg, LWIP_DNS_ADDRTYPE_DEFAULT);
|
---|
| 1530 | }
|
---|
| 1531 |
|
---|
| 1532 | /**
|
---|
| 1533 | * @ingroup dns
|
---|
| 1534 | * Like dns_gethostbyname, but returned address type can be controlled:
|
---|
| 1535 | * @param hostname the hostname that is to be queried
|
---|
| 1536 | * @param addr pointer to a ip_addr_t where to store the address if it is already
|
---|
| 1537 | * cached in the dns_table (only valid if ERR_OK is returned!)
|
---|
| 1538 | * @param found a callback function to be called on success, failure or timeout (only if
|
---|
| 1539 | * ERR_INPROGRESS is returned!)
|
---|
| 1540 | * @param callback_arg argument to pass to the callback function
|
---|
| 1541 | * @param dns_addrtype - LWIP_DNS_ADDRTYPE_IPV4_IPV6: try to resolve IPv4 first, try IPv6 if IPv4 fails only
|
---|
| 1542 | * - LWIP_DNS_ADDRTYPE_IPV6_IPV4: try to resolve IPv6 first, try IPv4 if IPv6 fails only
|
---|
| 1543 | * - LWIP_DNS_ADDRTYPE_IPV4: try to resolve IPv4 only
|
---|
| 1544 | * - LWIP_DNS_ADDRTYPE_IPV6: try to resolve IPv6 only
|
---|
| 1545 | */
|
---|
| 1546 | err_t
|
---|
| 1547 | dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *addr, dns_found_callback found,
|
---|
| 1548 | void *callback_arg, u8_t dns_addrtype)
|
---|
| 1549 | {
|
---|
| 1550 | size_t hostnamelen;
|
---|
| 1551 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 1552 | u8_t is_mdns;
|
---|
| 1553 | #endif
|
---|
| 1554 | /* not initialized or no valid server yet, or invalid addr pointer
|
---|
| 1555 | * or invalid hostname or invalid hostname length */
|
---|
| 1556 | if ((addr == NULL) ||
|
---|
| 1557 | (!hostname) || (!hostname[0])) {
|
---|
| 1558 | return ERR_ARG;
|
---|
| 1559 | }
|
---|
| 1560 | #if ((LWIP_DNS_SECURE & LWIP_DNS_SECURE_RAND_SRC_PORT) == 0)
|
---|
| 1561 | if (dns_pcbs[0] == NULL) {
|
---|
| 1562 | return ERR_ARG;
|
---|
| 1563 | }
|
---|
| 1564 | #endif
|
---|
| 1565 | hostnamelen = strlen(hostname);
|
---|
| 1566 | if (hostnamelen >= DNS_MAX_NAME_LENGTH) {
|
---|
| 1567 | LWIP_DEBUGF(DNS_DEBUG, ("dns_gethostbyname: name too long to resolve"));
|
---|
| 1568 | return ERR_ARG;
|
---|
| 1569 | }
|
---|
| 1570 |
|
---|
| 1571 |
|
---|
| 1572 | #if LWIP_HAVE_LOOPIF
|
---|
| 1573 | if (strcmp(hostname, "localhost") == 0) {
|
---|
| 1574 | ip_addr_set_loopback(LWIP_DNS_ADDRTYPE_IS_IPV6(dns_addrtype), addr);
|
---|
| 1575 | return ERR_OK;
|
---|
| 1576 | }
|
---|
| 1577 | #endif /* LWIP_HAVE_LOOPIF */
|
---|
| 1578 |
|
---|
| 1579 | /* host name already in octet notation? set ip addr and return ERR_OK */
|
---|
| 1580 | if (ipaddr_aton(hostname, addr)) {
|
---|
| 1581 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1582 | if ((IP_IS_V6(addr) && (dns_addrtype != LWIP_DNS_ADDRTYPE_IPV4)) ||
|
---|
| 1583 | (IP_IS_V4(addr) && (dns_addrtype != LWIP_DNS_ADDRTYPE_IPV6)))
|
---|
| 1584 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1585 | {
|
---|
| 1586 | return ERR_OK;
|
---|
| 1587 | }
|
---|
| 1588 | }
|
---|
| 1589 | /* already have this address cached? */
|
---|
| 1590 | if (dns_lookup(hostname, addr LWIP_DNS_ADDRTYPE_ARG(dns_addrtype)) == ERR_OK) {
|
---|
| 1591 | return ERR_OK;
|
---|
| 1592 | }
|
---|
| 1593 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
| 1594 | if ((dns_addrtype == LWIP_DNS_ADDRTYPE_IPV4_IPV6) || (dns_addrtype == LWIP_DNS_ADDRTYPE_IPV6_IPV4)) {
|
---|
| 1595 | /* fallback to 2nd IP type and try again to lookup */
|
---|
| 1596 | u8_t fallback;
|
---|
| 1597 | if (dns_addrtype == LWIP_DNS_ADDRTYPE_IPV4_IPV6) {
|
---|
| 1598 | fallback = LWIP_DNS_ADDRTYPE_IPV6;
|
---|
| 1599 | } else {
|
---|
| 1600 | fallback = LWIP_DNS_ADDRTYPE_IPV4;
|
---|
| 1601 | }
|
---|
| 1602 | if (dns_lookup(hostname, addr LWIP_DNS_ADDRTYPE_ARG(fallback)) == ERR_OK) {
|
---|
| 1603 | return ERR_OK;
|
---|
| 1604 | }
|
---|
| 1605 | }
|
---|
| 1606 | #else /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1607 | LWIP_UNUSED_ARG(dns_addrtype);
|
---|
| 1608 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
| 1609 |
|
---|
| 1610 | #if LWIP_DNS_SUPPORT_MDNS_QUERIES
|
---|
| 1611 | if (strstr(hostname, ".local") == &hostname[hostnamelen] - 6) {
|
---|
| 1612 | is_mdns = 1;
|
---|
| 1613 | } else {
|
---|
| 1614 | is_mdns = 0;
|
---|
| 1615 | }
|
---|
| 1616 |
|
---|
| 1617 | if (!is_mdns)
|
---|
| 1618 | #endif /* LWIP_DNS_SUPPORT_MDNS_QUERIES */
|
---|
| 1619 | {
|
---|
| 1620 | /* prevent calling found callback if no server is set, return error instead */
|
---|
| 1621 | if (ip_addr_isany_val(dns_servers[0])) {
|
---|
| 1622 | return ERR_VAL;
|
---|
| 1623 | }
|
---|
| 1624 | }
|
---|
| 1625 |
|
---|
| 1626 | /* queue query with specified callback */
|
---|
| 1627 | return dns_enqueue(hostname, hostnamelen, found, callback_arg LWIP_DNS_ADDRTYPE_ARG(dns_addrtype)
|
---|
| 1628 | LWIP_DNS_ISMDNS_ARG(is_mdns));
|
---|
| 1629 | }
|
---|
| 1630 |
|
---|
| 1631 | #endif /* LWIP_DNS */
|
---|