1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 * $Id: hostip4.c,v 1.1.1.1 2008-09-23 16:32:05 hoffman Exp $
22 ***************************************************************************/
32 #ifdef HAVE_SYS_SOCKET_H
33 #include <sys/socket.h>
35 #ifdef HAVE_NETINET_IN_H
36 #include <netinet/in.h>
41 #ifdef HAVE_ARPA_INET_H
42 #include <arpa/inet.h>
45 #include <stdlib.h> /* required for free() prototypes */
48 #include <unistd.h> /* for the close() proto */
71 #include "inet_pton.h"
73 #define _MPRINTF_REPLACE /* use our functions only */
74 #include <curl/mprintf.h>
76 #if defined(HAVE_INET_NTOA_R) && !defined(HAVE_INET_NTOA_R_DECL)
77 #include "inet_ntoa_r.h"
81 /* The last #include file should be: */
84 /***********************************************************************
85 * Only for plain-ipv4 builds
86 **********************************************************************/
87 #ifdef CURLRES_IPV4 /* plain ipv4 code coming up */
89 * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
90 * been set and returns TRUE if they are OK.
92 bool Curl_ipvalid(struct SessionHandle
*data
)
94 if(data
->set
.ip_version
== CURL_IPRESOLVE_V6
)
95 /* an ipv6 address was requested and we can't get/use one */
98 return TRUE
; /* OK, proceed */
101 #ifdef CURLRES_SYNCH /* the functions below are for synchronous resolves */
104 * Curl_getaddrinfo() - the ipv4 synchronous version.
106 * The original code to this function was from the Dancer source code, written
107 * by Bjorn Reese, it has since been patched and modified considerably.
109 * gethostbyname_r() is the thread-safe version of the gethostbyname()
110 * function. When we build for plain IPv4, we attempt to use this
111 * function. There are _three_ different gethostbyname_r() versions, and we
112 * detect which one this platform supports in the configure script and set up
113 * the HAVE_GETHOSTBYNAME_R_3, HAVE_GETHOSTBYNAME_R_5 or
114 * HAVE_GETHOSTBYNAME_R_6 defines accordingly. Note that HAVE_GETADDRBYNAME
115 * has the corresponding rules. This is primarily on *nix. Note that some unix
116 * flavours have thread-safe versions of the plain gethostbyname() etc.
119 Curl_addrinfo
*Curl_getaddrinfo(struct connectdata
*conn
,
120 const char *hostname
,
124 #if defined(HAVE_GETHOSTBYNAME_R_3)
127 Curl_addrinfo
*ai
= NULL
;
128 struct hostent
*h
= NULL
;
130 struct hostent
*buf
= NULL
;
132 #ifdef CURL_DISABLE_VERBOSE_STRINGS
136 (void)port
; /* unused in IPv4 code */
138 *waitp
= 0; /* don't wait, we act synchronously */
140 if(1 == Curl_inet_pton(AF_INET
, hostname
, &in
))
141 /* This is a dotted IP address 123.123.123.123-style */
142 return Curl_ip2addr(in
, hostname
, port
);
144 #if defined(HAVE_GETHOSTBYNAME_R)
146 * gethostbyname_r() is the preferred resolve function for many platforms.
147 * Since there are three different versions of it, the following code is
148 * somewhat #ifdef-ridden.
153 buf
= (struct hostent
*)calloc(CURL_HOSTENT_SIZE
, 1);
155 return NULL
; /* major failure */
157 * The clearing of the buffer is a workaround for a gethostbyname_r bug in
158 * qnx nto and it is also _required_ for some of these functions on some
162 #ifdef HAVE_GETHOSTBYNAME_R_5
163 /* Solaris, IRIX and more */
164 h
= gethostbyname_r(hostname
,
165 (struct hostent
*)buf
,
166 (char *)buf
+ sizeof(struct hostent
),
167 CURL_HOSTENT_SIZE
- sizeof(struct hostent
),
170 /* If the buffer is too small, it returns NULL and sets errno to
171 * ERANGE. The errno is thread safe if this is compiled with
172 * -D_REENTRANT as then the 'errno' variable is a macro defined to get
173 * used properly for threads.
180 #endif /* HAVE_GETHOSTBYNAME_R_5 */
181 #ifdef HAVE_GETHOSTBYNAME_R_6
184 (void)gethostbyname_r(hostname
,
185 (struct hostent
*)buf
,
186 (char *)buf
+ sizeof(struct hostent
),
187 CURL_HOSTENT_SIZE
- sizeof(struct hostent
),
190 /* Redhat 8, using glibc 2.2.93 changed the behavior. Now all of a
191 * sudden this function returns EAGAIN if the given buffer size is too
192 * small. Previous versions are known to return ERANGE for the same
195 * This wouldn't be such a big problem if older versions wouldn't
196 * sometimes return EAGAIN on a common failure case. Alas, we can't
197 * assume that EAGAIN *or* ERANGE means ERANGE for any given version of
200 * For now, we do that and thus we may call the function repeatedly and
201 * fail for older glibc versions that return EAGAIN, until we run out of
202 * buffer size (step_size grows beyond CURL_HOSTENT_SIZE).
204 * If anyone has a better fix, please tell us!
206 * -------------------------------------------------------------------
208 * On October 23rd 2003, Dan C dug up more details on the mysteries of
209 * gethostbyname_r() in glibc:
211 * In glibc 2.2.5 the interface is different (this has also been
212 * discovered in glibc 2.1.1-6 as shipped by Redhat 6). What I can't
213 * explain, is that tests performed on glibc 2.2.4-34 and 2.2.4-32
214 * (shipped/upgraded by Redhat 7.2) don't show this behavior!
216 * In this "buggy" version, the return code is -1 on error and 'errno'
217 * is set to the ERANGE or EAGAIN code. Note that 'errno' is not a
218 * thread-safe variable.
222 #endif/* HAVE_GETHOSTBYNAME_R_6 */
223 #ifdef HAVE_GETHOSTBYNAME_R_3
224 /* AIX, Digital Unix/Tru64, HPUX 10, more? */
226 /* For AIX 4.3 or later, we don't use gethostbyname_r() at all, because of
227 * the plain fact that it does not return unique full buffers on each
228 * call, but instead several of the pointers in the hostent structs will
229 * point to the same actual data! This have the unfortunate down-side that
230 * our caching system breaks down horribly. Luckily for us though, AIX 4.3
231 * and more recent versions have a "completely thread-safe"[*] libc where
232 * all the data is stored in thread-specific memory areas making calls to
233 * the plain old gethostbyname() work fine even for multi-threaded
236 * This AIX 4.3 or later detection is all made in the configure script.
238 * Troels Walsted Hansen helped us work this out on March 3rd, 2003.
240 * [*] = much later we've found out that it isn't at all "completely
241 * thread-safe", but at least the gethostbyname() function is.
244 if(CURL_HOSTENT_SIZE
>=
245 (sizeof(struct hostent
)+sizeof(struct hostent_data
))) {
247 /* August 22nd, 2000: Albert Chin-A-Young brought an updated version
248 * that should work! September 20: Richard Prescott worked on the buffer
252 res
= gethostbyname_r(hostname
,
253 (struct hostent
*)buf
,
254 (struct hostent_data
*)((char *)buf
+
255 sizeof(struct hostent
)));
256 h_errnop
= SOCKERRNO
; /* we don't deal with this, but set it anyway */
259 res
= -1; /* failure, too smallish buffer size */
261 if(!res
) { /* success */
263 h
= buf
; /* result expected in h */
265 /* This is the worst kind of the different gethostbyname_r() interfaces.
266 * Since we don't know how big buffer this particular lookup required,
267 * we can't realloc down the huge alloc without doing closer analysis of
268 * the returned data. Thus, we always use CURL_HOSTENT_SIZE for every
269 * name lookup. Fixing this would require an extra malloc() and then
270 * calling Curl_addrinfo_copy() that subsequent realloc()s down the new
271 * memory area to the actually used amount.
275 #endif /* HAVE_GETHOSTBYNAME_R_3 */
277 infof(conn
->data
, "gethostbyname_r(2) failed for %s\n", hostname
);
278 h
= NULL
; /* set return code to NULL */
281 #else /* HAVE_GETHOSTBYNAME_R */
283 * Here is code for platforms that don't have gethostbyname_r() or for
284 * which the gethostbyname() is the preferred() function.
287 #if (defined(NETWARE) && !defined(__NOVELL_LIBC__))
288 h
= gethostbyname((char*)hostname
);
290 h
= gethostbyname(hostname
);
293 infof(conn
->data
, "gethostbyname(2) failed for %s\n", hostname
);
294 #endif /*HAVE_GETHOSTBYNAME_R */
298 ai
= Curl_he2ai(h
, port
);
300 if(buf
) /* used a *_r() function */
307 #endif /* CURLRES_SYNCH */
308 #endif /* CURLRES_IPV4 */