1#ifndef HEADER_CURL_HOSTIP_H
2#define HEADER_CURL_HOSTIP_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2011, 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 "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
51struct addrinfo;
52struct hostent;
53struct SessionHandle;
54struct 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 */
63struct curl_hash *Curl_global_host_cache_init(void);
64void Curl_global_host_cache_dtor(void);
65
66struct Curl_dns_entry {
67  Curl_addrinfo *addr;
68  /* timestamp == 0 -- entry not in hostcache
69     timestamp != 0 -- entry is in hostcache */
70  time_t timestamp;
71  long inuse;      /* use-counter, make very sure you decrease this
72                      when you're done using the address you received */
73};
74
75/*
76 * Curl_resolv() returns an entry with the info for the specified host
77 * and port.
78 *
79 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after
80 * use, or we'll leak memory!
81 */
82/* return codes */
83#define CURLRESOLV_TIMEDOUT -2
84#define CURLRESOLV_ERROR    -1
85#define CURLRESOLV_RESOLVED  0
86#define CURLRESOLV_PENDING   1
87int Curl_resolv(struct connectdata *conn, const char *hostname,
88                int port, struct Curl_dns_entry **dnsentry);
89int Curl_resolv_timeout(struct connectdata *conn, const char *hostname,
90                        int port, struct Curl_dns_entry **dnsentry,
91                        long timeoutms);
92
93#ifdef CURLRES_IPV6
94/*
95 * Curl_ipv6works() returns TRUE if ipv6 seems to work.
96 */
97bool Curl_ipv6works(void);
98#else
99#define Curl_ipv6works() FALSE
100#endif
101
102/*
103 * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
104 * been set and returns TRUE if they are OK.
105 */
106bool Curl_ipvalid(struct connectdata *conn);
107
108
109/*
110 * Curl_getaddrinfo() is the generic low-level name resolve API within this
111 * source file. There are several versions of this function - for different
112 * name resolve layers (selected at build-time). They all take this same set
113 * of arguments
114 */
115Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
116                                const char *hostname,
117                                int port,
118                                int *waitp);
119
120
121/* unlock a previously resolved dns entry */
122void Curl_resolv_unlock(struct SessionHandle *data,
123                        struct Curl_dns_entry *dns);
124
125/* for debugging purposes only: */
126void Curl_scan_cache_used(void *user, void *ptr);
127
128/* make a new dns cache and return the handle */
129struct curl_hash *Curl_mk_dnscache(void);
130
131/* prune old entries from the DNS cache */
132void Curl_hostcache_prune(struct SessionHandle *data);
133
134/* Return # of adresses in a Curl_addrinfo struct */
135int Curl_num_addresses (const Curl_addrinfo *addr);
136
137#if defined(CURLDEBUG) && defined(HAVE_GETNAMEINFO)
138int curl_dogetnameinfo(GETNAMEINFO_QUAL_ARG1 GETNAMEINFO_TYPE_ARG1 sa,
139                       GETNAMEINFO_TYPE_ARG2 salen,
140                       char *host, GETNAMEINFO_TYPE_ARG46 hostlen,
141                       char *serv, GETNAMEINFO_TYPE_ARG46 servlen,
142                       GETNAMEINFO_TYPE_ARG7 flags,
143                       int line, const char *source);
144#endif
145
146/* IPv4 threadsafe resolve function used for synch and asynch builds */
147Curl_addrinfo *Curl_ipv4_resolve_r(const char * hostname, int port);
148
149CURLcode Curl_async_resolved(struct connectdata *conn,
150                             bool *protocol_connect);
151
152#ifndef CURLRES_ASYNCH
153#define Curl_async_resolved(x,y) CURLE_OK
154#endif
155
156/*
157 * Curl_addrinfo_callback() is used when we build with any asynch specialty.
158 * Handles end of async request processing. Inserts ai into hostcache when
159 * status is CURL_ASYNC_SUCCESS. Twiddles fields in conn to indicate async
160 * request completed whether successful or failed.
161 */
162CURLcode Curl_addrinfo_callback(struct connectdata *conn,
163                                int status,
164                                Curl_addrinfo *ai);
165
166/*
167 * Curl_printable_address() returns a printable version of the 1st address
168 * given in the 'ip' argument. The result will be stored in the buf that is
169 * bufsize bytes big.
170 */
171const char *Curl_printable_address(const Curl_addrinfo *ip,
172                                   char *buf, size_t bufsize);
173
174/*
175 * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
176 *
177 * Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
178 */
179struct Curl_dns_entry *
180Curl_cache_addr(struct SessionHandle *data, Curl_addrinfo *addr,
181                const char *hostname, int port);
182
183#ifndef INADDR_NONE
184#define CURL_INADDR_NONE (in_addr_t) ~0
185#else
186#define CURL_INADDR_NONE INADDR_NONE
187#endif
188
189#ifdef HAVE_SIGSETJMP
190/* Forward-declaration of variable defined in hostip.c. Beware this
191 * is a global and unique instance. This is used to store the return
192 * address that we can jump back to from inside a signal handler.
193 * This is not thread-safe stuff.
194 */
195extern sigjmp_buf curl_jmpenv;
196#endif
197
198#endif /* HEADER_CURL_HOSTIP_H */
199