1 #ifndef HEADER_CURL_HOSTIP_H 2 #define HEADER_CURL_HOSTIP_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2021, 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 ***************************************************************************/ 24 25 #include "curl_setup.h" 26 #include "hash.h" 27 #include "curl_addrinfo.h" 28 #include "timeval.h" /* for timediff_t */ 29 #include "asyn.h" 30 31 #ifdef HAVE_SETJMP_H 32 #include <setjmp.h> 33 #endif 34 35 #ifdef NETWARE 36 #undef in_addr_t 37 #define in_addr_t unsigned long 38 #endif 39 40 /* Allocate enough memory to hold the full name information structs and 41 * everything. OSF1 is known to require at least 8872 bytes. The buffer 42 * required for storing all possible aliases and IP numbers is according to 43 * Stevens' Unix Network Programming 2nd edition, p. 304: 8192 bytes! 44 */ 45 #define CURL_HOSTENT_SIZE 9000 46 47 #define CURL_TIMEOUT_RESOLVE 300 /* when using asynch methods, we allow this 48 many seconds for a name resolve */ 49 50 #define CURL_ASYNC_SUCCESS CURLE_OK 51 52 struct addrinfo; 53 struct hostent; 54 struct Curl_easy; 55 struct connectdata; 56 57 /* 58 * Curl_global_host_cache_init() initializes and sets up a global DNS cache. 59 * Global DNS cache is general badness. Do not use. This will be removed in 60 * a future version. Use the share interface instead! 61 * 62 * Returns a struct Curl_hash pointer on success, NULL on failure. 63 */ 64 struct Curl_hash *Curl_global_host_cache_init(void); 65 66 struct Curl_dns_entry { 67 struct Curl_addrinfo *addr; 68 /* timestamp == 0 -- permanent CURLOPT_RESOLVE entry (doesn't time out) */ 69 time_t timestamp; 70 /* use-counter, use Curl_resolv_unlock to release reference */ 71 long inuse; 72 }; 73 74 bool Curl_host_is_ipnum(const char *hostname); 75 76 /* 77 * Curl_resolv() returns an entry with the info for the specified host 78 * and port. 79 * 80 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after 81 * use, or we'll leak memory! 82 */ 83 /* return codes */ 84 enum resolve_t { 85 CURLRESOLV_TIMEDOUT = -2, 86 CURLRESOLV_ERROR = -1, 87 CURLRESOLV_RESOLVED = 0, 88 CURLRESOLV_PENDING = 1 89 }; 90 enum resolve_t Curl_resolv(struct Curl_easy *data, 91 const char *hostname, 92 int port, 93 bool allowDOH, 94 struct Curl_dns_entry **dnsentry); 95 enum resolve_t Curl_resolv_timeout(struct Curl_easy *data, 96 const char *hostname, int port, 97 struct Curl_dns_entry **dnsentry, 98 timediff_t timeoutms); 99 100 #ifdef ENABLE_IPV6 101 /* 102 * Curl_ipv6works() returns TRUE if IPv6 seems to work. 103 */ 104 bool Curl_ipv6works(struct Curl_easy *data); 105 #else 106 #define Curl_ipv6works(x) FALSE 107 #endif 108 109 /* 110 * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've 111 * been set and returns TRUE if they are OK. 112 */ 113 bool Curl_ipvalid(struct Curl_easy *data, struct connectdata *conn); 114 115 116 /* 117 * Curl_getaddrinfo() is the generic low-level name resolve API within this 118 * source file. There are several versions of this function - for different 119 * name resolve layers (selected at build-time). They all take this same set 120 * of arguments 121 */ 122 struct Curl_addrinfo *Curl_getaddrinfo(struct Curl_easy *data, 123 const char *hostname, 124 int port, 125 int *waitp); 126 127 128 /* unlock a previously resolved dns entry */ 129 void Curl_resolv_unlock(struct Curl_easy *data, 130 struct Curl_dns_entry *dns); 131 132 /* init a new dns cache and return success */ 133 int Curl_mk_dnscache(struct Curl_hash *hash); 134 135 /* prune old entries from the DNS cache */ 136 void Curl_hostcache_prune(struct Curl_easy *data); 137 138 /* Return # of addresses in a Curl_addrinfo struct */ 139 int Curl_num_addresses(const struct Curl_addrinfo *addr); 140 141 /* IPv4 threadsafe resolve function used for synch and asynch builds */ 142 struct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, int port); 143 144 CURLcode Curl_once_resolved(struct Curl_easy *data, bool *protocol_connect); 145 146 /* 147 * Curl_addrinfo_callback() is used when we build with any asynch specialty. 148 * Handles end of async request processing. Inserts ai into hostcache when 149 * status is CURL_ASYNC_SUCCESS. Twiddles fields in conn to indicate async 150 * request completed whether successful or failed. 151 */ 152 CURLcode Curl_addrinfo_callback(struct Curl_easy *data, 153 int status, 154 struct Curl_addrinfo *ai); 155 156 /* 157 * Curl_printable_address() returns a printable version of the 1st address 158 * given in the 'ip' argument. The result will be stored in the buf that is 159 * bufsize bytes big. 160 */ 161 void Curl_printable_address(const struct Curl_addrinfo *ip, 162 char *buf, size_t bufsize); 163 164 /* 165 * Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache. 166 * 167 * Returns the Curl_dns_entry entry pointer or NULL if not in the cache. 168 * 169 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after 170 * use, or we'll leak memory! 171 */ 172 struct Curl_dns_entry * 173 Curl_fetch_addr(struct Curl_easy *data, 174 const char *hostname, 175 int port); 176 177 /* 178 * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache. 179 * 180 * Returns the Curl_dns_entry entry pointer or NULL if the storage failed. 181 */ 182 struct Curl_dns_entry * 183 Curl_cache_addr(struct Curl_easy *data, struct Curl_addrinfo *addr, 184 const char *hostname, int port); 185 186 #ifndef INADDR_NONE 187 #define CURL_INADDR_NONE (in_addr_t) ~0 188 #else 189 #define CURL_INADDR_NONE INADDR_NONE 190 #endif 191 192 #ifdef HAVE_SIGSETJMP 193 /* Forward-declaration of variable defined in hostip.c. Beware this 194 * is a global and unique instance. This is used to store the return 195 * address that we can jump back to from inside a signal handler. 196 * This is not thread-safe stuff. 197 */ 198 extern sigjmp_buf curl_jmpenv; 199 #endif 200 201 /* 202 * Function provided by the resolver backend to set DNS servers to use. 203 */ 204 CURLcode Curl_set_dns_servers(struct Curl_easy *data, char *servers); 205 206 /* 207 * Function provided by the resolver backend to set 208 * outgoing interface to use for DNS requests 209 */ 210 CURLcode Curl_set_dns_interface(struct Curl_easy *data, 211 const char *interf); 212 213 /* 214 * Function provided by the resolver backend to set 215 * local IPv4 address to use as source address for DNS requests 216 */ 217 CURLcode Curl_set_dns_local_ip4(struct Curl_easy *data, 218 const char *local_ip4); 219 220 /* 221 * Function provided by the resolver backend to set 222 * local IPv6 address to use as source address for DNS requests 223 */ 224 CURLcode Curl_set_dns_local_ip6(struct Curl_easy *data, 225 const char *local_ip6); 226 227 /* 228 * Clean off entries from the cache 229 */ 230 void Curl_hostcache_clean(struct Curl_easy *data, struct Curl_hash *hash); 231 232 /* 233 * Populate the cache with specified entries from CURLOPT_RESOLVE. 234 */ 235 CURLcode Curl_loadhostpairs(struct Curl_easy *data); 236 CURLcode Curl_resolv_check(struct Curl_easy *data, 237 struct Curl_dns_entry **dns); 238 int Curl_resolv_getsock(struct Curl_easy *data, 239 curl_socket_t *socks); 240 241 CURLcode Curl_resolver_error(struct Curl_easy *data); 242 #endif /* HEADER_CURL_HOSTIP_H */ 243