1 #ifndef HEADER_CURL_HOSTIP_H 2 #define HEADER_CURL_HOSTIP_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 11 * 12 * This software is licensed as described in the file COPYING, which 13 * you should have received as part of this distribution. The terms 14 * are also available at https://curl.se/docs/copyright.html. 15 * 16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 17 * copies of the Software, and permit persons to whom the Software is 18 * furnished to do so, under the terms of the COPYING file. 19 * 20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 21 * KIND, either express or implied. 22 * 23 * SPDX-License-Identifier: curl 24 * 25 ***************************************************************************/ 26 27 #include "curl_setup.h" 28 #include "hash.h" 29 #include "curl_addrinfo.h" 30 #include "timeval.h" /* for timediff_t */ 31 #include "asyn.h" 32 33 #include <setjmp.h> 34 35 /* Allocate enough memory to hold the full name information structs and 36 * everything. OSF1 is known to require at least 8872 bytes. The buffer 37 * required for storing all possible aliases and IP numbers is according to 38 * Stevens' Unix Network Programming 2nd edition, p. 304: 8192 bytes! 39 */ 40 #define CURL_HOSTENT_SIZE 9000 41 42 #define CURL_TIMEOUT_RESOLVE 300 /* when using asynch methods, we allow this 43 many seconds for a name resolve */ 44 45 #define CURL_ASYNC_SUCCESS CURLE_OK 46 47 struct addrinfo; 48 struct hostent; 49 struct Curl_easy; 50 struct connectdata; 51 52 /* 53 * Curl_global_host_cache_init() initializes and sets up a global DNS cache. 54 * Global DNS cache is general badness. Do not use. This will be removed in 55 * a future version. Use the share interface instead! 56 * 57 * Returns a struct Curl_hash pointer on success, NULL on failure. 58 */ 59 struct Curl_hash *Curl_global_host_cache_init(void); 60 61 struct Curl_dns_entry { 62 struct Curl_addrinfo *addr; 63 /* timestamp == 0 -- permanent CURLOPT_RESOLVE entry (doesn't time out) */ 64 time_t timestamp; 65 /* use-counter, use Curl_resolv_unlock to release reference */ 66 long inuse; 67 }; 68 69 bool Curl_host_is_ipnum(const char *hostname); 70 71 /* 72 * Curl_resolv() returns an entry with the info for the specified host 73 * and port. 74 * 75 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after 76 * use, or we'll leak memory! 77 */ 78 /* return codes */ 79 enum resolve_t { 80 CURLRESOLV_TIMEDOUT = -2, 81 CURLRESOLV_ERROR = -1, 82 CURLRESOLV_RESOLVED = 0, 83 CURLRESOLV_PENDING = 1 84 }; 85 enum resolve_t Curl_resolv(struct Curl_easy *data, 86 const char *hostname, 87 int port, 88 bool allowDOH, 89 struct Curl_dns_entry **dnsentry); 90 enum resolve_t Curl_resolv_timeout(struct Curl_easy *data, 91 const char *hostname, int port, 92 struct Curl_dns_entry **dnsentry, 93 timediff_t timeoutms); 94 95 #ifdef ENABLE_IPV6 96 /* 97 * Curl_ipv6works() returns TRUE if IPv6 seems to work. 98 */ 99 bool Curl_ipv6works(struct Curl_easy *data); 100 #else 101 #define Curl_ipv6works(x) FALSE 102 #endif 103 104 /* 105 * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've 106 * been set and returns TRUE if they are OK. 107 */ 108 bool Curl_ipvalid(struct Curl_easy *data, struct connectdata *conn); 109 110 111 /* 112 * Curl_getaddrinfo() is the generic low-level name resolve API within this 113 * source file. There are several versions of this function - for different 114 * name resolve layers (selected at build-time). They all take this same set 115 * of arguments 116 */ 117 struct Curl_addrinfo *Curl_getaddrinfo(struct Curl_easy *data, 118 const char *hostname, 119 int port, 120 int *waitp); 121 122 123 /* unlock a previously resolved dns entry */ 124 void Curl_resolv_unlock(struct Curl_easy *data, 125 struct Curl_dns_entry *dns); 126 127 /* init a new dns cache */ 128 void Curl_init_dnscache(struct Curl_hash *hash, int hashsize); 129 130 /* prune old entries from the DNS cache */ 131 void Curl_hostcache_prune(struct Curl_easy *data); 132 133 /* IPv4 threadsafe resolve function used for synch and asynch builds */ 134 struct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, int port); 135 136 CURLcode Curl_once_resolved(struct Curl_easy *data, bool *protocol_connect); 137 138 /* 139 * Curl_addrinfo_callback() is used when we build with any asynch specialty. 140 * Handles end of async request processing. Inserts ai into hostcache when 141 * status is CURL_ASYNC_SUCCESS. Twiddles fields in conn to indicate async 142 * request completed whether successful or failed. 143 */ 144 CURLcode Curl_addrinfo_callback(struct Curl_easy *data, 145 int status, 146 struct Curl_addrinfo *ai); 147 148 /* 149 * Curl_printable_address() returns a printable version of the 1st address 150 * given in the 'ip' argument. The result will be stored in the buf that is 151 * bufsize bytes big. 152 */ 153 void Curl_printable_address(const struct Curl_addrinfo *ip, 154 char *buf, size_t bufsize); 155 156 /* 157 * Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache. 158 * 159 * Returns the Curl_dns_entry entry pointer or NULL if not in the cache. 160 * 161 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after 162 * use, or we'll leak memory! 163 */ 164 struct Curl_dns_entry * 165 Curl_fetch_addr(struct Curl_easy *data, 166 const char *hostname, 167 int port); 168 169 /* 170 * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache. 171 * 172 * Returns the Curl_dns_entry entry pointer or NULL if the storage failed. 173 */ 174 struct Curl_dns_entry * 175 Curl_cache_addr(struct Curl_easy *data, struct Curl_addrinfo *addr, 176 const char *hostname, size_t hostlen, int port); 177 178 #ifndef INADDR_NONE 179 #define CURL_INADDR_NONE (in_addr_t) ~0 180 #else 181 #define CURL_INADDR_NONE INADDR_NONE 182 #endif 183 184 /* 185 * Function provided by the resolver backend to set DNS servers to use. 186 */ 187 CURLcode Curl_set_dns_servers(struct Curl_easy *data, char *servers); 188 189 /* 190 * Function provided by the resolver backend to set 191 * outgoing interface to use for DNS requests 192 */ 193 CURLcode Curl_set_dns_interface(struct Curl_easy *data, 194 const char *interf); 195 196 /* 197 * Function provided by the resolver backend to set 198 * local IPv4 address to use as source address for DNS requests 199 */ 200 CURLcode Curl_set_dns_local_ip4(struct Curl_easy *data, 201 const char *local_ip4); 202 203 /* 204 * Function provided by the resolver backend to set 205 * local IPv6 address to use as source address for DNS requests 206 */ 207 CURLcode Curl_set_dns_local_ip6(struct Curl_easy *data, 208 const char *local_ip6); 209 210 /* 211 * Clean off entries from the cache 212 */ 213 void Curl_hostcache_clean(struct Curl_easy *data, struct Curl_hash *hash); 214 215 /* 216 * Populate the cache with specified entries from CURLOPT_RESOLVE. 217 */ 218 CURLcode Curl_loadhostpairs(struct Curl_easy *data); 219 CURLcode Curl_resolv_check(struct Curl_easy *data, 220 struct Curl_dns_entry **dns); 221 int Curl_resolv_getsock(struct Curl_easy *data, 222 curl_socket_t *socks); 223 224 CURLcode Curl_resolver_error(struct Curl_easy *data); 225 #endif /* HEADER_CURL_HOSTIP_H */ 226