source: UsbWattMeter/trunk/curl-7.47.1/lib/hostip4.c@ 164

Last change on this file since 164 was 164, checked in by coas-nagasima, 6 years ago

TOPPERS/ECNLサンプルアプリ「USB充電器電力計」を追加

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File size: 10.3 KB
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1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
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 https://curl.haxx.se/docs/copyright.html.
13 *
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.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24
25#ifdef HAVE_NETINET_IN_H
26#include <netinet/in.h>
27#endif
28#ifdef HAVE_NETDB_H
29#include <netdb.h>
30#endif
31#ifdef HAVE_ARPA_INET_H
32#include <arpa/inet.h>
33#endif
34#ifdef __VMS
35#include <in.h>
36#include <inet.h>
37#endif
38
39#ifdef HAVE_PROCESS_H
40#include <process.h>
41#endif
42
43#include "urldata.h"
44#include "sendf.h"
45#include "hostip.h"
46#include "hash.h"
47#include "share.h"
48#include "strerror.h"
49#include "url.h"
50#include "inet_pton.h"
51#include "curl_printf.h"
52#include "curl_memory.h"
53/* The last #include file should be: */
54#include "memdebug.h"
55
56/***********************************************************************
57 * Only for plain IPv4 builds
58 **********************************************************************/
59#ifdef CURLRES_IPV4 /* plain IPv4 code coming up */
60/*
61 * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
62 * been set and returns TRUE if they are OK.
63 */
64bool Curl_ipvalid(struct connectdata *conn)
65{
66 if(conn->ip_version == CURL_IPRESOLVE_V6)
67 /* An IPv6 address was requested and we can't get/use one */
68 return FALSE;
69
70 return TRUE; /* OK, proceed */
71}
72
73#ifdef CURLRES_SYNCH
74
75/*
76 * Curl_getaddrinfo() - the IPv4 synchronous version.
77 *
78 * The original code to this function was from the Dancer source code, written
79 * by Bjorn Reese, it has since been patched and modified considerably.
80 *
81 * gethostbyname_r() is the thread-safe version of the gethostbyname()
82 * function. When we build for plain IPv4, we attempt to use this
83 * function. There are _three_ different gethostbyname_r() versions, and we
84 * detect which one this platform supports in the configure script and set up
85 * the HAVE_GETHOSTBYNAME_R_3, HAVE_GETHOSTBYNAME_R_5 or
86 * HAVE_GETHOSTBYNAME_R_6 defines accordingly. Note that HAVE_GETADDRBYNAME
87 * has the corresponding rules. This is primarily on *nix. Note that some unix
88 * flavours have thread-safe versions of the plain gethostbyname() etc.
89 *
90 */
91Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
92 const char *hostname,
93 int port,
94 int *waitp)
95{
96 Curl_addrinfo *ai = NULL;
97
98#ifdef CURL_DISABLE_VERBOSE_STRINGS
99 (void)conn;
100#endif
101
102 *waitp = 0; /* synchronous response only */
103
104 ai = Curl_ipv4_resolve_r(hostname, port);
105 if(!ai)
106 infof(conn->data, "Curl_ipv4_resolve_r failed for %s\n", hostname);
107
108 return ai;
109}
110#endif /* CURLRES_SYNCH */
111#endif /* CURLRES_IPV4 */
112
113#if defined(CURLRES_IPV4) && !defined(CURLRES_ARES)
114
115/*
116 * Curl_ipv4_resolve_r() - ipv4 threadsafe resolver function.
117 *
118 * This is used for both synchronous and asynchronous resolver builds,
119 * implying that only threadsafe code and function calls may be used.
120 *
121 */
122Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname,
123 int port)
124{
125#if !defined(HAVE_GETADDRINFO_THREADSAFE) && defined(HAVE_GETHOSTBYNAME_R_3)
126 int res;
127#endif
128 Curl_addrinfo *ai = NULL;
129 struct hostent *h = NULL;
130 struct in_addr in;
131 struct hostent *buf = NULL;
132
133 if(Curl_inet_pton(AF_INET, hostname, &in) > 0)
134 /* This is a dotted IP address 123.123.123.123-style */
135 return Curl_ip2addr(AF_INET, &in, hostname, port);
136
137#if defined(HAVE_GETADDRINFO_THREADSAFE)
138 else {
139 struct addrinfo hints;
140 char sbuf[12];
141 char *sbufptr = NULL;
142
143 memset(&hints, 0, sizeof(hints));
144 hints.ai_family = PF_INET;
145 hints.ai_socktype = SOCK_STREAM;
146 if(port) {
147 snprintf(sbuf, sizeof(sbuf), "%d", port);
148 sbufptr = sbuf;
149 }
150
151 (void)Curl_getaddrinfo_ex(hostname, sbufptr, &hints, &ai);
152
153#elif defined(HAVE_GETHOSTBYNAME_R)
154 /*
155 * gethostbyname_r() is the preferred resolve function for many platforms.
156 * Since there are three different versions of it, the following code is
157 * somewhat #ifdef-ridden.
158 */
159 else {
160 int h_errnop;
161
162 buf = calloc(1, CURL_HOSTENT_SIZE);
163 if(!buf)
164 return NULL; /* major failure */
165 /*
166 * The clearing of the buffer is a workaround for a gethostbyname_r bug in
167 * qnx nto and it is also _required_ for some of these functions on some
168 * platforms.
169 */
170
171#if defined(HAVE_GETHOSTBYNAME_R_5)
172 /* Solaris, IRIX and more */
173 h = gethostbyname_r(hostname,
174 (struct hostent *)buf,
175 (char *)buf + sizeof(struct hostent),
176 CURL_HOSTENT_SIZE - sizeof(struct hostent),
177 &h_errnop);
178
179 /* If the buffer is too small, it returns NULL and sets errno to
180 * ERANGE. The errno is thread safe if this is compiled with
181 * -D_REENTRANT as then the 'errno' variable is a macro defined to get
182 * used properly for threads.
183 */
184
185 if(h) {
186 ;
187 }
188 else
189#elif defined(HAVE_GETHOSTBYNAME_R_6)
190 /* Linux */
191
192 (void)gethostbyname_r(hostname,
193 (struct hostent *)buf,
194 (char *)buf + sizeof(struct hostent),
195 CURL_HOSTENT_SIZE - sizeof(struct hostent),
196 &h, /* DIFFERENCE */
197 &h_errnop);
198 /* Redhat 8, using glibc 2.2.93 changed the behavior. Now all of a
199 * sudden this function returns EAGAIN if the given buffer size is too
200 * small. Previous versions are known to return ERANGE for the same
201 * problem.
202 *
203 * This wouldn't be such a big problem if older versions wouldn't
204 * sometimes return EAGAIN on a common failure case. Alas, we can't
205 * assume that EAGAIN *or* ERANGE means ERANGE for any given version of
206 * glibc.
207 *
208 * For now, we do that and thus we may call the function repeatedly and
209 * fail for older glibc versions that return EAGAIN, until we run out of
210 * buffer size (step_size grows beyond CURL_HOSTENT_SIZE).
211 *
212 * If anyone has a better fix, please tell us!
213 *
214 * -------------------------------------------------------------------
215 *
216 * On October 23rd 2003, Dan C dug up more details on the mysteries of
217 * gethostbyname_r() in glibc:
218 *
219 * In glibc 2.2.5 the interface is different (this has also been
220 * discovered in glibc 2.1.1-6 as shipped by Redhat 6). What I can't
221 * explain, is that tests performed on glibc 2.2.4-34 and 2.2.4-32
222 * (shipped/upgraded by Redhat 7.2) don't show this behavior!
223 *
224 * In this "buggy" version, the return code is -1 on error and 'errno'
225 * is set to the ERANGE or EAGAIN code. Note that 'errno' is not a
226 * thread-safe variable.
227 */
228
229 if(!h) /* failure */
230#elif defined(HAVE_GETHOSTBYNAME_R_3)
231 /* AIX, Digital Unix/Tru64, HPUX 10, more? */
232
233 /* For AIX 4.3 or later, we don't use gethostbyname_r() at all, because of
234 * the plain fact that it does not return unique full buffers on each
235 * call, but instead several of the pointers in the hostent structs will
236 * point to the same actual data! This have the unfortunate down-side that
237 * our caching system breaks down horribly. Luckily for us though, AIX 4.3
238 * and more recent versions have a "completely thread-safe"[*] libc where
239 * all the data is stored in thread-specific memory areas making calls to
240 * the plain old gethostbyname() work fine even for multi-threaded
241 * programs.
242 *
243 * This AIX 4.3 or later detection is all made in the configure script.
244 *
245 * Troels Walsted Hansen helped us work this out on March 3rd, 2003.
246 *
247 * [*] = much later we've found out that it isn't at all "completely
248 * thread-safe", but at least the gethostbyname() function is.
249 */
250
251 if(CURL_HOSTENT_SIZE >=
252 (sizeof(struct hostent)+sizeof(struct hostent_data))) {
253
254 /* August 22nd, 2000: Albert Chin-A-Young brought an updated version
255 * that should work! September 20: Richard Prescott worked on the buffer
256 * size dilemma.
257 */
258
259 res = gethostbyname_r(hostname,
260 (struct hostent *)buf,
261 (struct hostent_data *)((char *)buf +
262 sizeof(struct hostent)));
263 h_errnop = SOCKERRNO; /* we don't deal with this, but set it anyway */
264 }
265 else
266 res = -1; /* failure, too smallish buffer size */
267
268 if(!res) { /* success */
269
270 h = buf; /* result expected in h */
271
272 /* This is the worst kind of the different gethostbyname_r() interfaces.
273 * Since we don't know how big buffer this particular lookup required,
274 * we can't realloc down the huge alloc without doing closer analysis of
275 * the returned data. Thus, we always use CURL_HOSTENT_SIZE for every
276 * name lookup. Fixing this would require an extra malloc() and then
277 * calling Curl_addrinfo_copy() that subsequent realloc()s down the new
278 * memory area to the actually used amount.
279 */
280 }
281 else
282#endif /* HAVE_...BYNAME_R_5 || HAVE_...BYNAME_R_6 || HAVE_...BYNAME_R_3 */
283 {
284 h = NULL; /* set return code to NULL */
285 free(buf);
286 }
287#else /* HAVE_GETADDRINFO_THREADSAFE || HAVE_GETHOSTBYNAME_R */
288 /*
289 * Here is code for platforms that don't have a thread safe
290 * getaddrinfo() nor gethostbyname_r() function or for which
291 * gethostbyname() is the preferred one.
292 */
293 else {
294 h = gethostbyname((void*)hostname);
295#endif /* HAVE_GETADDRINFO_THREADSAFE || HAVE_GETHOSTBYNAME_R */
296 }
297
298 if(h) {
299 ai = Curl_he2ai(h, port);
300
301 if(buf) /* used a *_r() function */
302 free(buf);
303 }
304
305 return ai;
306}
307#endif /* defined(CURLRES_IPV4) && !defined(CURLRES_ARES) */
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