xref: /aosp_15_r20/external/curl/lib/hostip4.c (revision 6236dae45794135f37c4eb022389c904c8b0090d)
1*6236dae4SAndroid Build Coastguard Worker /***************************************************************************
2*6236dae4SAndroid Build Coastguard Worker  *                                  _   _ ____  _
3*6236dae4SAndroid Build Coastguard Worker  *  Project                     ___| | | |  _ \| |
4*6236dae4SAndroid Build Coastguard Worker  *                             / __| | | | |_) | |
5*6236dae4SAndroid Build Coastguard Worker  *                            | (__| |_| |  _ <| |___
6*6236dae4SAndroid Build Coastguard Worker  *                             \___|\___/|_| \_\_____|
7*6236dae4SAndroid Build Coastguard Worker  *
8*6236dae4SAndroid Build Coastguard Worker  * Copyright (C) Daniel Stenberg, <[email protected]>, et al.
9*6236dae4SAndroid Build Coastguard Worker  *
10*6236dae4SAndroid Build Coastguard Worker  * This software is licensed as described in the file COPYING, which
11*6236dae4SAndroid Build Coastguard Worker  * you should have received as part of this distribution. The terms
12*6236dae4SAndroid Build Coastguard Worker  * are also available at https://curl.se/docs/copyright.html.
13*6236dae4SAndroid Build Coastguard Worker  *
14*6236dae4SAndroid Build Coastguard Worker  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15*6236dae4SAndroid Build Coastguard Worker  * copies of the Software, and permit persons to whom the Software is
16*6236dae4SAndroid Build Coastguard Worker  * furnished to do so, under the terms of the COPYING file.
17*6236dae4SAndroid Build Coastguard Worker  *
18*6236dae4SAndroid Build Coastguard Worker  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19*6236dae4SAndroid Build Coastguard Worker  * KIND, either express or implied.
20*6236dae4SAndroid Build Coastguard Worker  *
21*6236dae4SAndroid Build Coastguard Worker  * SPDX-License-Identifier: curl
22*6236dae4SAndroid Build Coastguard Worker  *
23*6236dae4SAndroid Build Coastguard Worker  ***************************************************************************/
24*6236dae4SAndroid Build Coastguard Worker 
25*6236dae4SAndroid Build Coastguard Worker #include "curl_setup.h"
26*6236dae4SAndroid Build Coastguard Worker 
27*6236dae4SAndroid Build Coastguard Worker /***********************************************************************
28*6236dae4SAndroid Build Coastguard Worker  * Only for plain IPv4 builds
29*6236dae4SAndroid Build Coastguard Worker  **********************************************************************/
30*6236dae4SAndroid Build Coastguard Worker #ifdef CURLRES_IPV4 /* plain IPv4 code coming up */
31*6236dae4SAndroid Build Coastguard Worker 
32*6236dae4SAndroid Build Coastguard Worker #ifdef HAVE_NETINET_IN_H
33*6236dae4SAndroid Build Coastguard Worker #include <netinet/in.h>
34*6236dae4SAndroid Build Coastguard Worker #endif
35*6236dae4SAndroid Build Coastguard Worker #ifdef HAVE_NETDB_H
36*6236dae4SAndroid Build Coastguard Worker #include <netdb.h>
37*6236dae4SAndroid Build Coastguard Worker #endif
38*6236dae4SAndroid Build Coastguard Worker #ifdef HAVE_ARPA_INET_H
39*6236dae4SAndroid Build Coastguard Worker #include <arpa/inet.h>
40*6236dae4SAndroid Build Coastguard Worker #endif
41*6236dae4SAndroid Build Coastguard Worker #ifdef __VMS
42*6236dae4SAndroid Build Coastguard Worker #include <in.h>
43*6236dae4SAndroid Build Coastguard Worker #include <inet.h>
44*6236dae4SAndroid Build Coastguard Worker #endif
45*6236dae4SAndroid Build Coastguard Worker 
46*6236dae4SAndroid Build Coastguard Worker #include "urldata.h"
47*6236dae4SAndroid Build Coastguard Worker #include "sendf.h"
48*6236dae4SAndroid Build Coastguard Worker #include "hostip.h"
49*6236dae4SAndroid Build Coastguard Worker #include "hash.h"
50*6236dae4SAndroid Build Coastguard Worker #include "share.h"
51*6236dae4SAndroid Build Coastguard Worker #include "url.h"
52*6236dae4SAndroid Build Coastguard Worker /* The last 3 #include files should be in this order */
53*6236dae4SAndroid Build Coastguard Worker #include "curl_printf.h"
54*6236dae4SAndroid Build Coastguard Worker #include "curl_memory.h"
55*6236dae4SAndroid Build Coastguard Worker #include "memdebug.h"
56*6236dae4SAndroid Build Coastguard Worker 
57*6236dae4SAndroid Build Coastguard Worker /*
58*6236dae4SAndroid Build Coastguard Worker  * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
59*6236dae4SAndroid Build Coastguard Worker  * been set and returns TRUE if they are OK.
60*6236dae4SAndroid Build Coastguard Worker  */
Curl_ipvalid(struct Curl_easy * data,struct connectdata * conn)61*6236dae4SAndroid Build Coastguard Worker bool Curl_ipvalid(struct Curl_easy *data, struct connectdata *conn)
62*6236dae4SAndroid Build Coastguard Worker {
63*6236dae4SAndroid Build Coastguard Worker   (void)data;
64*6236dae4SAndroid Build Coastguard Worker   if(conn->ip_version == CURL_IPRESOLVE_V6)
65*6236dae4SAndroid Build Coastguard Worker     /* An IPv6 address was requested and we cannot get/use one */
66*6236dae4SAndroid Build Coastguard Worker     return FALSE;
67*6236dae4SAndroid Build Coastguard Worker 
68*6236dae4SAndroid Build Coastguard Worker   return TRUE; /* OK, proceed */
69*6236dae4SAndroid Build Coastguard Worker }
70*6236dae4SAndroid Build Coastguard Worker 
71*6236dae4SAndroid Build Coastguard Worker #ifdef CURLRES_SYNCH
72*6236dae4SAndroid Build Coastguard Worker 
73*6236dae4SAndroid Build Coastguard Worker /*
74*6236dae4SAndroid Build Coastguard Worker  * Curl_getaddrinfo() - the IPv4 synchronous version.
75*6236dae4SAndroid Build Coastguard Worker  *
76*6236dae4SAndroid Build Coastguard Worker  * The original code to this function was from the Dancer source code, written
77*6236dae4SAndroid Build Coastguard Worker  * by Bjorn Reese, it has since been patched and modified considerably.
78*6236dae4SAndroid Build Coastguard Worker  *
79*6236dae4SAndroid Build Coastguard Worker  * gethostbyname_r() is the thread-safe version of the gethostbyname()
80*6236dae4SAndroid Build Coastguard Worker  * function. When we build for plain IPv4, we attempt to use this
81*6236dae4SAndroid Build Coastguard Worker  * function. There are _three_ different gethostbyname_r() versions, and we
82*6236dae4SAndroid Build Coastguard Worker  * detect which one this platform supports in the configure script and set up
83*6236dae4SAndroid Build Coastguard Worker  * the HAVE_GETHOSTBYNAME_R_3, HAVE_GETHOSTBYNAME_R_5 or
84*6236dae4SAndroid Build Coastguard Worker  * HAVE_GETHOSTBYNAME_R_6 defines accordingly. Note that HAVE_GETADDRBYNAME
85*6236dae4SAndroid Build Coastguard Worker  * has the corresponding rules. This is primarily on *nix. Note that some Unix
86*6236dae4SAndroid Build Coastguard Worker  * flavours have thread-safe versions of the plain gethostbyname() etc.
87*6236dae4SAndroid Build Coastguard Worker  *
88*6236dae4SAndroid Build Coastguard Worker  */
Curl_getaddrinfo(struct Curl_easy * data,const char * hostname,int port,int * waitp)89*6236dae4SAndroid Build Coastguard Worker struct Curl_addrinfo *Curl_getaddrinfo(struct Curl_easy *data,
90*6236dae4SAndroid Build Coastguard Worker                                        const char *hostname,
91*6236dae4SAndroid Build Coastguard Worker                                        int port,
92*6236dae4SAndroid Build Coastguard Worker                                        int *waitp)
93*6236dae4SAndroid Build Coastguard Worker {
94*6236dae4SAndroid Build Coastguard Worker   struct Curl_addrinfo *ai = NULL;
95*6236dae4SAndroid Build Coastguard Worker 
96*6236dae4SAndroid Build Coastguard Worker #ifdef CURL_DISABLE_VERBOSE_STRINGS
97*6236dae4SAndroid Build Coastguard Worker   (void)data;
98*6236dae4SAndroid Build Coastguard Worker #endif
99*6236dae4SAndroid Build Coastguard Worker 
100*6236dae4SAndroid Build Coastguard Worker   *waitp = 0; /* synchronous response only */
101*6236dae4SAndroid Build Coastguard Worker 
102*6236dae4SAndroid Build Coastguard Worker   ai = Curl_ipv4_resolve_r(hostname, port);
103*6236dae4SAndroid Build Coastguard Worker   if(!ai)
104*6236dae4SAndroid Build Coastguard Worker     infof(data, "Curl_ipv4_resolve_r failed for %s", hostname);
105*6236dae4SAndroid Build Coastguard Worker 
106*6236dae4SAndroid Build Coastguard Worker   return ai;
107*6236dae4SAndroid Build Coastguard Worker }
108*6236dae4SAndroid Build Coastguard Worker #endif /* CURLRES_SYNCH */
109*6236dae4SAndroid Build Coastguard Worker #endif /* CURLRES_IPV4 */
110*6236dae4SAndroid Build Coastguard Worker 
111*6236dae4SAndroid Build Coastguard Worker #if defined(CURLRES_IPV4) && \
112*6236dae4SAndroid Build Coastguard Worker    !defined(CURLRES_ARES) && !defined(CURLRES_AMIGA)
113*6236dae4SAndroid Build Coastguard Worker 
114*6236dae4SAndroid Build Coastguard Worker /*
115*6236dae4SAndroid Build Coastguard Worker  * Curl_ipv4_resolve_r() - ipv4 threadsafe resolver function.
116*6236dae4SAndroid Build Coastguard Worker  *
117*6236dae4SAndroid Build Coastguard Worker  * This is used for both synchronous and asynchronous resolver builds,
118*6236dae4SAndroid Build Coastguard Worker  * implying that only threadsafe code and function calls may be used.
119*6236dae4SAndroid Build Coastguard Worker  *
120*6236dae4SAndroid Build Coastguard Worker  */
Curl_ipv4_resolve_r(const char * hostname,int port)121*6236dae4SAndroid Build Coastguard Worker struct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname,
122*6236dae4SAndroid Build Coastguard Worker                                           int port)
123*6236dae4SAndroid Build Coastguard Worker {
124*6236dae4SAndroid Build Coastguard Worker #if !(defined(HAVE_GETADDRINFO) && defined(HAVE_GETADDRINFO_THREADSAFE)) && \
125*6236dae4SAndroid Build Coastguard Worker    defined(HAVE_GETHOSTBYNAME_R_3)
126*6236dae4SAndroid Build Coastguard Worker   int res;
127*6236dae4SAndroid Build Coastguard Worker #endif
128*6236dae4SAndroid Build Coastguard Worker   struct Curl_addrinfo *ai = NULL;
129*6236dae4SAndroid Build Coastguard Worker #if !(defined(HAVE_GETADDRINFO) && defined(HAVE_GETADDRINFO_THREADSAFE))
130*6236dae4SAndroid Build Coastguard Worker   struct hostent *h = NULL;
131*6236dae4SAndroid Build Coastguard Worker   struct hostent *buf = NULL;
132*6236dae4SAndroid Build Coastguard Worker #endif
133*6236dae4SAndroid Build Coastguard Worker 
134*6236dae4SAndroid Build Coastguard Worker #if defined(HAVE_GETADDRINFO) && defined(HAVE_GETADDRINFO_THREADSAFE)
135*6236dae4SAndroid Build Coastguard Worker   struct addrinfo hints;
136*6236dae4SAndroid Build Coastguard Worker   char sbuf[12];
137*6236dae4SAndroid Build Coastguard Worker   char *sbufptr = NULL;
138*6236dae4SAndroid Build Coastguard Worker 
139*6236dae4SAndroid Build Coastguard Worker   memset(&hints, 0, sizeof(hints));
140*6236dae4SAndroid Build Coastguard Worker   hints.ai_family = PF_INET;
141*6236dae4SAndroid Build Coastguard Worker   hints.ai_socktype = SOCK_STREAM;
142*6236dae4SAndroid Build Coastguard Worker   if(port) {
143*6236dae4SAndroid Build Coastguard Worker     msnprintf(sbuf, sizeof(sbuf), "%d", port);
144*6236dae4SAndroid Build Coastguard Worker     sbufptr = sbuf;
145*6236dae4SAndroid Build Coastguard Worker   }
146*6236dae4SAndroid Build Coastguard Worker 
147*6236dae4SAndroid Build Coastguard Worker   (void)Curl_getaddrinfo_ex(hostname, sbufptr, &hints, &ai);
148*6236dae4SAndroid Build Coastguard Worker 
149*6236dae4SAndroid Build Coastguard Worker #elif defined(HAVE_GETHOSTBYNAME_R)
150*6236dae4SAndroid Build Coastguard Worker   /*
151*6236dae4SAndroid Build Coastguard Worker    * gethostbyname_r() is the preferred resolve function for many platforms.
152*6236dae4SAndroid Build Coastguard Worker    * Since there are three different versions of it, the following code is
153*6236dae4SAndroid Build Coastguard Worker    * somewhat #ifdef-ridden.
154*6236dae4SAndroid Build Coastguard Worker    */
155*6236dae4SAndroid Build Coastguard Worker   int h_errnop;
156*6236dae4SAndroid Build Coastguard Worker 
157*6236dae4SAndroid Build Coastguard Worker   buf = calloc(1, CURL_HOSTENT_SIZE);
158*6236dae4SAndroid Build Coastguard Worker   if(!buf)
159*6236dae4SAndroid Build Coastguard Worker     return NULL; /* major failure */
160*6236dae4SAndroid Build Coastguard Worker   /*
161*6236dae4SAndroid Build Coastguard Worker    * The clearing of the buffer is a workaround for a gethostbyname_r bug in
162*6236dae4SAndroid Build Coastguard Worker    * qnx nto and it is also _required_ for some of these functions on some
163*6236dae4SAndroid Build Coastguard Worker    * platforms.
164*6236dae4SAndroid Build Coastguard Worker    */
165*6236dae4SAndroid Build Coastguard Worker 
166*6236dae4SAndroid Build Coastguard Worker #if defined(HAVE_GETHOSTBYNAME_R_5)
167*6236dae4SAndroid Build Coastguard Worker   /* Solaris, IRIX and more */
168*6236dae4SAndroid Build Coastguard Worker   h = gethostbyname_r(hostname,
169*6236dae4SAndroid Build Coastguard Worker                       (struct hostent *)buf,
170*6236dae4SAndroid Build Coastguard Worker                       (char *)buf + sizeof(struct hostent),
171*6236dae4SAndroid Build Coastguard Worker                       CURL_HOSTENT_SIZE - sizeof(struct hostent),
172*6236dae4SAndroid Build Coastguard Worker                       &h_errnop);
173*6236dae4SAndroid Build Coastguard Worker 
174*6236dae4SAndroid Build Coastguard Worker   /* If the buffer is too small, it returns NULL and sets errno to
175*6236dae4SAndroid Build Coastguard Worker    * ERANGE. The errno is thread safe if this is compiled with
176*6236dae4SAndroid Build Coastguard Worker    * -D_REENTRANT as then the 'errno' variable is a macro defined to get
177*6236dae4SAndroid Build Coastguard Worker    * used properly for threads.
178*6236dae4SAndroid Build Coastguard Worker    */
179*6236dae4SAndroid Build Coastguard Worker 
180*6236dae4SAndroid Build Coastguard Worker   if(h) {
181*6236dae4SAndroid Build Coastguard Worker     ;
182*6236dae4SAndroid Build Coastguard Worker   }
183*6236dae4SAndroid Build Coastguard Worker   else
184*6236dae4SAndroid Build Coastguard Worker #elif defined(HAVE_GETHOSTBYNAME_R_6)
185*6236dae4SAndroid Build Coastguard Worker   /* Linux */
186*6236dae4SAndroid Build Coastguard Worker 
187*6236dae4SAndroid Build Coastguard Worker   (void)gethostbyname_r(hostname,
188*6236dae4SAndroid Build Coastguard Worker                       (struct hostent *)buf,
189*6236dae4SAndroid Build Coastguard Worker                       (char *)buf + sizeof(struct hostent),
190*6236dae4SAndroid Build Coastguard Worker                       CURL_HOSTENT_SIZE - sizeof(struct hostent),
191*6236dae4SAndroid Build Coastguard Worker                       &h, /* DIFFERENCE */
192*6236dae4SAndroid Build Coastguard Worker                       &h_errnop);
193*6236dae4SAndroid Build Coastguard Worker   /* Redhat 8, using glibc 2.2.93 changed the behavior. Now all of a
194*6236dae4SAndroid Build Coastguard Worker    * sudden this function returns EAGAIN if the given buffer size is too
195*6236dae4SAndroid Build Coastguard Worker    * small. Previous versions are known to return ERANGE for the same
196*6236dae4SAndroid Build Coastguard Worker    * problem.
197*6236dae4SAndroid Build Coastguard Worker    *
198*6236dae4SAndroid Build Coastguard Worker    * This would not be such a big problem if older versions would not
199*6236dae4SAndroid Build Coastguard Worker    * sometimes return EAGAIN on a common failure case. Alas, we cannot
200*6236dae4SAndroid Build Coastguard Worker    * assume that EAGAIN *or* ERANGE means ERANGE for any given version of
201*6236dae4SAndroid Build Coastguard Worker    * glibc.
202*6236dae4SAndroid Build Coastguard Worker    *
203*6236dae4SAndroid Build Coastguard Worker    * For now, we do that and thus we may call the function repeatedly and
204*6236dae4SAndroid Build Coastguard Worker    * fail for older glibc versions that return EAGAIN, until we run out of
205*6236dae4SAndroid Build Coastguard Worker    * buffer size (step_size grows beyond CURL_HOSTENT_SIZE).
206*6236dae4SAndroid Build Coastguard Worker    *
207*6236dae4SAndroid Build Coastguard Worker    * If anyone has a better fix, please tell us!
208*6236dae4SAndroid Build Coastguard Worker    *
209*6236dae4SAndroid Build Coastguard Worker    * -------------------------------------------------------------------
210*6236dae4SAndroid Build Coastguard Worker    *
211*6236dae4SAndroid Build Coastguard Worker    * On October 23rd 2003, Dan C dug up more details on the mysteries of
212*6236dae4SAndroid Build Coastguard Worker    * gethostbyname_r() in glibc:
213*6236dae4SAndroid Build Coastguard Worker    *
214*6236dae4SAndroid Build Coastguard Worker    * In glibc 2.2.5 the interface is different (this has also been
215*6236dae4SAndroid Build Coastguard Worker    * discovered in glibc 2.1.1-6 as shipped by Redhat 6). What I cannot
216*6236dae4SAndroid Build Coastguard Worker    * explain, is that tests performed on glibc 2.2.4-34 and 2.2.4-32
217*6236dae4SAndroid Build Coastguard Worker    * (shipped/upgraded by Redhat 7.2) do not show this behavior!
218*6236dae4SAndroid Build Coastguard Worker    *
219*6236dae4SAndroid Build Coastguard Worker    * In this "buggy" version, the return code is -1 on error and 'errno'
220*6236dae4SAndroid Build Coastguard Worker    * is set to the ERANGE or EAGAIN code. Note that 'errno' is not a
221*6236dae4SAndroid Build Coastguard Worker    * thread-safe variable.
222*6236dae4SAndroid Build Coastguard Worker    */
223*6236dae4SAndroid Build Coastguard Worker 
224*6236dae4SAndroid Build Coastguard Worker   if(!h) /* failure */
225*6236dae4SAndroid Build Coastguard Worker #elif defined(HAVE_GETHOSTBYNAME_R_3)
226*6236dae4SAndroid Build Coastguard Worker   /* AIX, Digital UNIX/Tru64, HP-UX 10, more? */
227*6236dae4SAndroid Build Coastguard Worker 
228*6236dae4SAndroid Build Coastguard Worker   /* For AIX 4.3 or later, we do not use gethostbyname_r() at all, because of
229*6236dae4SAndroid Build Coastguard Worker    * the plain fact that it does not return unique full buffers on each
230*6236dae4SAndroid Build Coastguard Worker    * call, but instead several of the pointers in the hostent structs will
231*6236dae4SAndroid Build Coastguard Worker    * point to the same actual data! This have the unfortunate down-side that
232*6236dae4SAndroid Build Coastguard Worker    * our caching system breaks down horribly. Luckily for us though, AIX 4.3
233*6236dae4SAndroid Build Coastguard Worker    * and more recent versions have a "completely thread-safe"[*] libc where
234*6236dae4SAndroid Build Coastguard Worker    * all the data is stored in thread-specific memory areas making calls to
235*6236dae4SAndroid Build Coastguard Worker    * the plain old gethostbyname() work fine even for multi-threaded
236*6236dae4SAndroid Build Coastguard Worker    * programs.
237*6236dae4SAndroid Build Coastguard Worker    *
238*6236dae4SAndroid Build Coastguard Worker    * This AIX 4.3 or later detection is all made in the configure script.
239*6236dae4SAndroid Build Coastguard Worker    *
240*6236dae4SAndroid Build Coastguard Worker    * Troels Walsted Hansen helped us work this out on March 3rd, 2003.
241*6236dae4SAndroid Build Coastguard Worker    *
242*6236dae4SAndroid Build Coastguard Worker    * [*] = much later we have found out that it is not at all "completely
243*6236dae4SAndroid Build Coastguard Worker    * thread-safe", but at least the gethostbyname() function is.
244*6236dae4SAndroid Build Coastguard Worker    */
245*6236dae4SAndroid Build Coastguard Worker 
246*6236dae4SAndroid Build Coastguard Worker   if(CURL_HOSTENT_SIZE >=
247*6236dae4SAndroid Build Coastguard Worker      (sizeof(struct hostent) + sizeof(struct hostent_data))) {
248*6236dae4SAndroid Build Coastguard Worker 
249*6236dae4SAndroid Build Coastguard Worker     /* August 22nd, 2000: Albert Chin-A-Young brought an updated version
250*6236dae4SAndroid Build Coastguard Worker      * that should work! September 20: Richard Prescott worked on the buffer
251*6236dae4SAndroid Build Coastguard Worker      * size dilemma.
252*6236dae4SAndroid Build Coastguard Worker      */
253*6236dae4SAndroid Build Coastguard Worker 
254*6236dae4SAndroid Build Coastguard Worker     res = gethostbyname_r(hostname,
255*6236dae4SAndroid Build Coastguard Worker                           (struct hostent *)buf,
256*6236dae4SAndroid Build Coastguard Worker                           (struct hostent_data *)((char *)buf +
257*6236dae4SAndroid Build Coastguard Worker                                                   sizeof(struct hostent)));
258*6236dae4SAndroid Build Coastguard Worker     h_errnop = SOCKERRNO; /* we do not deal with this, but set it anyway */
259*6236dae4SAndroid Build Coastguard Worker   }
260*6236dae4SAndroid Build Coastguard Worker   else
261*6236dae4SAndroid Build Coastguard Worker     res = -1; /* failure, too smallish buffer size */
262*6236dae4SAndroid Build Coastguard Worker 
263*6236dae4SAndroid Build Coastguard Worker   if(!res) { /* success */
264*6236dae4SAndroid Build Coastguard Worker 
265*6236dae4SAndroid Build Coastguard Worker     h = buf; /* result expected in h */
266*6236dae4SAndroid Build Coastguard Worker 
267*6236dae4SAndroid Build Coastguard Worker     /* This is the worst kind of the different gethostbyname_r() interfaces.
268*6236dae4SAndroid Build Coastguard Worker      * Since we do not know how big buffer this particular lookup required,
269*6236dae4SAndroid Build Coastguard Worker      * we cannot realloc down the huge alloc without doing closer analysis of
270*6236dae4SAndroid Build Coastguard Worker      * the returned data. Thus, we always use CURL_HOSTENT_SIZE for every
271*6236dae4SAndroid Build Coastguard Worker      * name lookup. Fixing this would require an extra malloc() and then
272*6236dae4SAndroid Build Coastguard Worker      * calling Curl_addrinfo_copy() that subsequent realloc()s down the new
273*6236dae4SAndroid Build Coastguard Worker      * memory area to the actually used amount.
274*6236dae4SAndroid Build Coastguard Worker      */
275*6236dae4SAndroid Build Coastguard Worker   }
276*6236dae4SAndroid Build Coastguard Worker   else
277*6236dae4SAndroid Build Coastguard Worker #endif /* HAVE_...BYNAME_R_5 || HAVE_...BYNAME_R_6 || HAVE_...BYNAME_R_3 */
278*6236dae4SAndroid Build Coastguard Worker   {
279*6236dae4SAndroid Build Coastguard Worker     h = NULL; /* set return code to NULL */
280*6236dae4SAndroid Build Coastguard Worker     free(buf);
281*6236dae4SAndroid Build Coastguard Worker   }
282*6236dae4SAndroid Build Coastguard Worker #else /* (HAVE_GETADDRINFO && HAVE_GETADDRINFO_THREADSAFE) ||
283*6236dae4SAndroid Build Coastguard Worker           HAVE_GETHOSTBYNAME_R */
284*6236dae4SAndroid Build Coastguard Worker   /*
285*6236dae4SAndroid Build Coastguard Worker    * Here is code for platforms that do not have a thread safe
286*6236dae4SAndroid Build Coastguard Worker    * getaddrinfo() nor gethostbyname_r() function or for which
287*6236dae4SAndroid Build Coastguard Worker    * gethostbyname() is the preferred one.
288*6236dae4SAndroid Build Coastguard Worker    */
289*6236dae4SAndroid Build Coastguard Worker   h = gethostbyname((void *)hostname);
290*6236dae4SAndroid Build Coastguard Worker #endif /* (HAVE_GETADDRINFO && HAVE_GETADDRINFO_THREADSAFE) ||
291*6236dae4SAndroid Build Coastguard Worker            HAVE_GETHOSTBYNAME_R */
292*6236dae4SAndroid Build Coastguard Worker 
293*6236dae4SAndroid Build Coastguard Worker #if !(defined(HAVE_GETADDRINFO) && defined(HAVE_GETADDRINFO_THREADSAFE))
294*6236dae4SAndroid Build Coastguard Worker   if(h) {
295*6236dae4SAndroid Build Coastguard Worker     ai = Curl_he2ai(h, port);
296*6236dae4SAndroid Build Coastguard Worker 
297*6236dae4SAndroid Build Coastguard Worker     if(buf) /* used a *_r() function */
298*6236dae4SAndroid Build Coastguard Worker       free(buf);
299*6236dae4SAndroid Build Coastguard Worker   }
300*6236dae4SAndroid Build Coastguard Worker #endif
301*6236dae4SAndroid Build Coastguard Worker 
302*6236dae4SAndroid Build Coastguard Worker   return ai;
303*6236dae4SAndroid Build Coastguard Worker }
304*6236dae4SAndroid Build Coastguard Worker #endif /* defined(CURLRES_IPV4) && !defined(CURLRES_ARES) &&
305*6236dae4SAndroid Build Coastguard Worker                                    !defined(CURLRES_AMIGA) */
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