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1 #ifndef HEADER_CURL_HOSTIP_H
2 #define HEADER_CURL_HOSTIP_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2015, 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 http://curl.haxx.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 "asyn.h"
29 
30 #ifdef HAVE_SETJMP_H
31 #include <setjmp.h>
32 #endif
33 
34 #ifdef NETWARE
35 #undef in_addr_t
36 #define in_addr_t unsigned long
37 #endif
38 
39 /* Allocate enough memory to hold the full name information structs and
40  * everything. OSF1 is known to require at least 8872 bytes. The buffer
41  * required for storing all possible aliases and IP numbers is according to
42  * Stevens' Unix Network Programming 2nd edition, p. 304: 8192 bytes!
43  */
44 #define CURL_HOSTENT_SIZE 9000
45 
46 #define CURL_TIMEOUT_RESOLVE 300 /* when using asynch methods, we allow this
47                                     many seconds for a name resolve */
48 
49 #define CURL_ASYNC_SUCCESS CURLE_OK
50 
51 struct addrinfo;
52 struct hostent;
53 struct SessionHandle;
54 struct connectdata;
55 
56 /*
57  * Curl_global_host_cache_init() initializes and sets up a global DNS cache.
58  * Global DNS cache is general badness. Do not use. This will be removed in
59  * a future version. Use the share interface instead!
60  *
61  * Returns a struct curl_hash pointer on success, NULL on failure.
62  */
63 struct curl_hash *Curl_global_host_cache_init(void);
64 void Curl_global_host_cache_dtor(void);
65 
66 struct Curl_dns_entry {
67   Curl_addrinfo *addr;
68   /* timestamp == 0 -- CURLOPT_RESOLVE entry, doesn't timeout */
69   time_t timestamp;
70   /* use-counter, use Curl_resolv_unlock to release reference */
71   long inuse;
72 };
73 
74 /*
75  * Curl_resolv() returns an entry with the info for the specified host
76  * and port.
77  *
78  * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after
79  * use, or we'll leak memory!
80  */
81 /* return codes */
82 #define CURLRESOLV_TIMEDOUT -2
83 #define CURLRESOLV_ERROR    -1
84 #define CURLRESOLV_RESOLVED  0
85 #define CURLRESOLV_PENDING   1
86 int Curl_resolv(struct connectdata *conn, const char *hostname,
87                 int port, struct Curl_dns_entry **dnsentry);
88 int Curl_resolv_timeout(struct connectdata *conn, const char *hostname,
89                         int port, struct Curl_dns_entry **dnsentry,
90                         long timeoutms);
91 
92 #ifdef CURLRES_IPV6
93 /*
94  * Curl_ipv6works() returns TRUE if IPv6 seems to work.
95  */
96 bool Curl_ipv6works(void);
97 #else
98 #define Curl_ipv6works() FALSE
99 #endif
100 
101 /*
102  * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
103  * been set and returns TRUE if they are OK.
104  */
105 bool Curl_ipvalid(struct connectdata *conn);
106 
107 
108 /*
109  * Curl_getaddrinfo() is the generic low-level name resolve API within this
110  * source file. There are several versions of this function - for different
111  * name resolve layers (selected at build-time). They all take this same set
112  * of arguments
113  */
114 Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
115                                 const char *hostname,
116                                 int port,
117                                 int *waitp);
118 
119 
120 /* unlock a previously resolved dns entry */
121 void Curl_resolv_unlock(struct SessionHandle *data,
122                         struct Curl_dns_entry *dns);
123 
124 /* for debugging purposes only: */
125 void Curl_scan_cache_used(void *user, void *ptr);
126 
127 /* init a new dns cache and return success */
128 int Curl_mk_dnscache(struct curl_hash *hash);
129 
130 /* prune old entries from the DNS cache */
131 void Curl_hostcache_prune(struct SessionHandle *data);
132 
133 /* Return # of adresses in a Curl_addrinfo struct */
134 int Curl_num_addresses (const Curl_addrinfo *addr);
135 
136 #if defined(CURLDEBUG) && defined(HAVE_GETNAMEINFO)
137 int curl_dogetnameinfo(GETNAMEINFO_QUAL_ARG1 GETNAMEINFO_TYPE_ARG1 sa,
138                        GETNAMEINFO_TYPE_ARG2 salen,
139                        char *host, GETNAMEINFO_TYPE_ARG46 hostlen,
140                        char *serv, GETNAMEINFO_TYPE_ARG46 servlen,
141                        GETNAMEINFO_TYPE_ARG7 flags,
142                        int line, const char *source);
143 #endif
144 
145 /* IPv4 threadsafe resolve function used for synch and asynch builds */
146 Curl_addrinfo *Curl_ipv4_resolve_r(const char * hostname, int port);
147 
148 CURLcode Curl_async_resolved(struct connectdata *conn,
149                              bool *protocol_connect);
150 
151 #ifndef CURLRES_ASYNCH
152 #define Curl_async_resolved(x,y) CURLE_OK
153 #endif
154 
155 /*
156  * Curl_addrinfo_callback() is used when we build with any asynch specialty.
157  * Handles end of async request processing. Inserts ai into hostcache when
158  * status is CURL_ASYNC_SUCCESS. Twiddles fields in conn to indicate async
159  * request completed whether successful or failed.
160  */
161 CURLcode Curl_addrinfo_callback(struct connectdata *conn,
162                                 int status,
163                                 Curl_addrinfo *ai);
164 
165 /*
166  * Curl_printable_address() returns a printable version of the 1st address
167  * given in the 'ip' argument. The result will be stored in the buf that is
168  * bufsize bytes big.
169  */
170 const char *Curl_printable_address(const Curl_addrinfo *ip,
171                                    char *buf, size_t bufsize);
172 
173 /*
174  * Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache.
175  *
176  * Returns the Curl_dns_entry entry pointer or NULL if not in the cache.
177  *
178  * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after
179  * use, or we'll leak memory!
180  */
181 struct Curl_dns_entry *
182 Curl_fetch_addr(struct connectdata *conn,
183                 const char *hostname,
184                 int port);
185 /*
186  * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
187  *
188  * Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
189  */
190 struct Curl_dns_entry *
191 Curl_cache_addr(struct SessionHandle *data, Curl_addrinfo *addr,
192                 const char *hostname, int port);
193 
194 #ifndef INADDR_NONE
195 #define CURL_INADDR_NONE (in_addr_t) ~0
196 #else
197 #define CURL_INADDR_NONE INADDR_NONE
198 #endif
199 
200 #ifdef HAVE_SIGSETJMP
201 /* Forward-declaration of variable defined in hostip.c. Beware this
202  * is a global and unique instance. This is used to store the return
203  * address that we can jump back to from inside a signal handler.
204  * This is not thread-safe stuff.
205  */
206 extern sigjmp_buf curl_jmpenv;
207 #endif
208 
209 /*
210  * Function provided by the resolver backend to set DNS servers to use.
211  */
212 CURLcode Curl_set_dns_servers(struct SessionHandle *data, char *servers);
213 
214 /*
215  * Function provided by the resolver backend to set
216  * outgoing interface to use for DNS requests
217  */
218 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
219                                 const char *interf);
220 
221 /*
222  * Function provided by the resolver backend to set
223  * local IPv4 address to use as source address for DNS requests
224  */
225 CURLcode Curl_set_dns_local_ip4(struct SessionHandle *data,
226                                 const char *local_ip4);
227 
228 /*
229  * Function provided by the resolver backend to set
230  * local IPv6 address to use as source address for DNS requests
231  */
232 CURLcode Curl_set_dns_local_ip6(struct SessionHandle *data,
233                                 const char *local_ip6);
234 
235 /*
236  * Clean off entries from the cache
237  */
238 void Curl_hostcache_clean(struct SessionHandle *data, struct curl_hash *hash);
239 
240 /*
241  * Destroy the hostcache of this handle.
242  */
243 void Curl_hostcache_destroy(struct SessionHandle *data);
244 
245 /*
246  * Populate the cache with specified entries from CURLOPT_RESOLVE.
247  */
248 CURLcode Curl_loadhostpairs(struct SessionHandle *data);
249 
250 #endif /* HEADER_CURL_HOSTIP_H */
251