getnameinfo.cc
Go to the documentation of this file.
1/*
2 * Copyright (C) 1996-2022 The Squid Software Foundation and contributors
3 *
4 * Squid software is distributed under GPLv2+ license and includes
5 * contributions from numerous individuals and organizations.
6 * Please see the COPYING and CONTRIBUTORS files for details.
7 */
8
9/*
10 * Shamelessly duplicated from the fetchmail public sources
11 * for use by the Squid Project under GNU Public License.
12 *
13 * Update/Maintenance History:
14 *
15 * 16-Aug-2007 : Copied from fetchmail 6.3.8
16 * - added protection around library headers
17 * - added use of alternative name xgetnameinfo
18 * to split from any OS-provided.
19 *
20 * 06-Oct-2007 : Various fixes to allow the build on MinGW
21 * - use srtncpy instead of strlcpy
22 * - use xinet_ntop instead of inet_ntop
23 * - use SQUIDHOSTNAMELEN instead of MAXHOSTNAMELEN
24 *
25 * 13-Jan-2015 : Various fixed for C++ and MinGW native build
26 *
27 * Original License and code follows.
28 */
29#include "squid.h"
30
31/* KAME: getnameinfo.c,v 1.72 2005/01/13 04:12:03 itojun Exp */
32
33/*
34 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the project nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 */
61
62/*
63 * Issues to be discussed:
64 * - RFC2553 says that we should raise error on short buffer. X/Open says
65 * we need to truncate the result. We obey RFC2553 (and X/Open should be
66 * modified). ipngwg rough consensus seems to follow RFC2553. RFC3493 says
67 * nothing about it, but defines a new error code EAI_OVERFLOW which seems
68 * to be intended the code for this case.
69 * - What is "local" in NI_NOFQDN? (see comments in the code)
70 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
71 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
72 * sin6_scope_id is filled - standardization status?
73 * - what should we do if we should do getservbyport("sctp")?
74 */
75
76/*
77 * Considerations about thread-safeness
78 * The code in this file is thread-safe, and so the thread-safeness of
79 * getnameinfo() depends on the property of backend functions.
80 * - getservbyport() is not thread safe for most systems we are targeting.
81 * - getipnodebyaddr() is thread safe. However, many resolver libraries
82 * used in the function are not thread safe.
83 * - gethostbyaddr() is usually not thread safe.
84 */
85
86#if !HAVE_DECL_GETNAMEINFO
87
88#if HAVE_SYS_SOCKET_H
89#include <sys/socket.h>
90#endif
91#if HAVE_NET_IF_H
92#include <net/if.h>
93#endif
94#if HAVE_NETINET_IN_H
95#include <netinet/in.h>
96#endif
97#if HAVE_ARPA_INET_H
98#include <arpa/inet.h>
99#endif
100#if HAVE_ARPA_NAMESER_H
101#include <arpa/nameser.h>
102#endif
103#if HAVE_NETDB_H
104#include <netdb.h>
105#endif
106#if HAVE_RESOLV_H
107#include <resolv.h>
108#endif
109#if HAVE_STRING_H
110#include <string.h>
111#endif
112#if HAVE_STDDEF_H
113#include <stddef.h>
114#endif
115#if HAVE_ERRNO_H
116#include <errno.h>
117#endif
118#if HAVE_INTTYPES_H
119#include <inttypes.h>
120#endif
121
122#if _SQUID_WINDOWS_
123#undef IN_ADDR
124#include <ws2tcpip.h>
125#endif
126
127static const struct afd {
128 int a_af;
131 int a_off;
133} afdl [] = {
134#if INET6
135 { PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
136 offsetof(struct sockaddr_in6, sin6_addr),
137 offsetof(struct sockaddr_in6, sin6_port)
138 },
139#endif
140 { PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
141 offsetof(struct sockaddr_in, sin_addr),
142 offsetof(struct sockaddr_in, sin_port)
143 },
144 {0, 0, 0, 0, 0},
146
147#if INET6
148static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
149 size_t, int));
150static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int));
151#endif
152
153int
154xgetnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags)
155{
156 const struct afd *afd;
157 struct servent *sp;
158 struct hostent *hp;
159 unsigned short port;
160 int family, i;
161 const char *addr;
162 uint32_t v4a;
163 char numserv[512];
164
165 if (!sa)
166 return EAI_FAIL;
167
168#if HAVE_SA_LEN /*XXX*/
169 if (sa->sa_len != salen)
170 return EAI_FAIL;
171#endif
172
173 family = sa->sa_family;
174 for (i = 0; afdl[i].a_af; i++)
175 if (afdl[i].a_af == family) {
176 afd = &afdl[i];
177 goto found;
178 }
179 return EAI_FAMILY;
180
181found:
182 if (salen != afd->a_socklen)
183 return EAI_FAIL;
184
185 /* network byte order */
186 memcpy(&port, (const char *)sa + afd->a_portoff, sizeof(port));
187 addr = (const char *)sa + afd->a_off;
188
189 if (!serv || servlen == 0) {
190 /*
191 * do nothing in this case.
192 * in case you are wondering if "&&" is more correct than
193 * "||" here: RFC3493 says that !serv OR servlen == 0
194 * means that the caller does not want the result.
195 */
196 } else {
197 if (flags & NI_NUMERICSERV)
198 sp = nullptr;
199 else {
201 (flags & NI_DGRAM) ? "udp" : "tcp");
202 }
203 if (sp) {
204 if (strlen(sp->s_name) + 1 > servlen)
205 return EAI_OVERFLOW;
206 xstrncpy(serv, sp->s_name, servlen);
207 } else {
208 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
209 if (strlen(numserv) + 1 > servlen)
210 return EAI_OVERFLOW;
211 xstrncpy(serv, numserv, servlen);
212 }
213 }
214
215 switch (sa->sa_family) {
216 case AF_INET:
217 v4a = (uint32_t)
218 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
219 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
220 flags |= NI_NUMERICHOST;
221 v4a >>= IN_CLASSA_NSHIFT;
222 if (v4a == 0)
223 flags |= NI_NUMERICHOST;
224 break;
225#if INET6
226 case AF_INET6: {
227 const struct sockaddr_in6 *sin6;
228 sin6 = (const struct sockaddr_in6 *)sa;
229 switch (sin6->sin6_addr.s6_addr[0]) {
230 case 0x00:
231 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
232 ;
233 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
234 ;
235 else
236 flags |= NI_NUMERICHOST;
237 break;
238 default:
239 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
240 flags |= NI_NUMERICHOST;
241 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
242 flags |= NI_NUMERICHOST;
243 break;
244 }
245 }
246 break;
247#endif
248 }
249 if (!host || hostlen == 0) {
250 /*
251 * do nothing in this case.
252 * in case you are wondering if "&&" is more correct than
253 * "||" here: RFC3493 says that !host or hostlen == 0
254 * means that the caller does not want the result.
255 */
256 } else if (flags & NI_NUMERICHOST) {
257 /* NUMERICHOST and NAMEREQD conflicts with each other */
258 if (flags & NI_NAMEREQD)
259 return EAI_NONAME;
260
261 goto numeric;
262 } else {
263#if USE_GETIPNODEBY
264 int h_error = 0;
265 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
266#else
267 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
268#endif
269
270 if (hp) {
271 if (strlen(hp->h_name) + 1 > hostlen) {
272#if USE_GETIPNODEBY
273 freehostent(hp);
274#endif
275 return EAI_OVERFLOW;
276 }
277 xstrncpy(host, hp->h_name, hostlen);
278#if USE_GETIPNODEBY
279 freehostent(hp);
280#endif
281 } else {
282 if (flags & NI_NAMEREQD)
283 return EAI_NONAME;
284
285numeric:
286 switch (afd->a_af) {
287#if INET6
288 case AF_INET6: {
289 int error;
290
291 if ((error = ip6_parsenumeric(sa, addr, host,
292 hostlen,
293 flags)) != 0)
294 return(error);
295 break;
296 }
297#endif
298 default:
299 if (!inet_ntop(afd->a_af, addr, host, hostlen))
300 return EAI_SYSTEM;
301 break;
302 }
303 }
304 }
305 return(0);
306}
307
308#if INET6
309static int
310ip6_parsenumeric(sa, addr, host, hostlen, flags)
311const struct sockaddr *sa;
312const char *addr;
313char *host;
314size_t hostlen;
315int flags;
316{
317 int numaddrlen;
318 char numaddr[512];
319
320 if (!inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)))
321 return EAI_SYSTEM;
322
323 numaddrlen = strlen(numaddr);
324 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
325 return EAI_OVERFLOW;
326 xstrncpy(host, numaddr, hostlen);
327
328 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
329 char zonebuf[SQUIDHOSTNAMELEN];
330 int zonelen;
331
332 zonelen = ip6_sa2str(
333 (const struct sockaddr_in6 *)(const void *)sa,
334 zonebuf, sizeof(zonebuf), flags);
335 if (zonelen < 0)
336 return EAI_OVERFLOW;
337 if (zonelen + 1 + numaddrlen + 1 > hostlen)
338 return EAI_OVERFLOW;
339
340 /* construct <numeric-addr><delim><zoneid> */
341 memcpy(host + numaddrlen + 1, zonebuf,
342 (size_t)zonelen);
343 host[numaddrlen] = SCOPE_DELIMITER;
344 host[numaddrlen + 1 + zonelen] = '\0';
345 }
346
347 return 0;
348}
349
350/* ARGSUSED */
351static int
352ip6_sa2str(sa6, buf, bufsiz, flags)
353const struct sockaddr_in6 *sa6;
354char *buf;
355size_t bufsiz;
356int flags;
357{
358 unsigned int ifindex;
359 const struct in6_addr *a6;
360 int n;
361
362 ifindex = (unsigned int)sa6->sin6_scope_id;
363 a6 = &sa6->sin6_addr;
364
366 if ((flags & NI_NUMERICSCOPE) != 0) {
367 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
368 if (n < 0 || n >= bufsiz)
369 return -1;
370 else
371 return n;
372 }
373#endif
374
375 /* if_indextoname() does not take buffer size. not a good api... */
376 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
377 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) {
378 char *p = if_indextoname(ifindex, buf);
379 if (p)
380 return (strlen(p));
381 }
382
383 /* last resort */
384 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
385 if (n < 0 || n >= bufsiz)
386 return -1;
387 else
388 return n;
389}
390#endif /* INET6 */
391#endif /* HAVE_DECL_GETNAMEINFO */
392
void error(char *format,...)
struct _sp sp
static int port
Definition: ldap_backend.cc:70
#define EAI_OVERFLOW
Definition: getaddrinfo.h:60
#define EAI_SYSTEM
Definition: getaddrinfo.h:56
#define IN_EXPERIMENTAL(a)
Definition: getaddrinfo.h:64
static const struct afd afdl[]
int xgetnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags)
Definition: getnameinfo.cc:154
#define inet_ntop
Definition: inet_ntop.h:25
#define EAI_NONAME
struct hostent * getipnodebyaddr()
#define EAI_FAMILY
#define NI_NAMEREQD
#define NI_NUMERICHOST
struct hostent * gethostbyaddr()
#define SCOPE_DELIMITER
#define NI_NUMERICSCOPE
void freehostent()
#define NI_DGRAM
#define EAI_FAIL
struct servent * getservbyport()
#define NI_NUMERICSERV
#define SQUIDHOSTNAMELEN
Definition: rfc2181.h:30
int a_portoff
Definition: getnameinfo.cc:132
int a_off
Definition: getnameinfo.cc:131
int a_socklen
Definition: getnameinfo.cc:130
int a_addrlen
Definition: getnameinfo.cc:129
int a_af
Definition: getnameinfo.cc:128
int unsigned int
Definition: stub_fd.cc:19
int socklen_t
Definition: types.h:158
char * xstrncpy(char *dst, const char *src, size_t n)
Definition: xstring.cc:37

 

Introduction

Documentation

Support

Miscellaneous

Web Site Translations

Mirrors