1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2019, 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 /***********************************************************************
26  * Only for IPv6-enabled builds
27  **********************************************************************/
28 #ifdef CURLRES_IPV6
29 
30 #ifdef HAVE_NETINET_IN_H
31 #include <netinet/in.h>
32 #endif
33 #ifdef HAVE_NETDB_H
34 #include <netdb.h>
35 #endif
36 #ifdef HAVE_ARPA_INET_H
37 #include <arpa/inet.h>
38 #endif
39 #ifdef __VMS
40 #include <in.h>
41 #include <inet.h>
42 #endif
43 
44 #ifdef HAVE_PROCESS_H
45 #include <process.h>
46 #endif
47 
48 #include "urldata.h"
49 #include "sendf.h"
50 #include "hostip.h"
51 #include "hash.h"
52 #include "share.h"
53 #include "strerror.h"
54 #include "url.h"
55 #include "inet_pton.h"
56 #include "connect.h"
57 /* The last 3 #include files should be in this order */
58 #include "curl_printf.h"
59 #include "curl_memory.h"
60 #include "memdebug.h"
61 
62 /*
63  * Curl_ipv6works() returns TRUE if IPv6 seems to work.
64  */
Curl_ipv6works(void)65 bool Curl_ipv6works(void)
66 {
67   /* the nature of most system is that IPv6 status doesn't come and go
68      during a program's lifetime so we only probe the first time and then we
69      have the info kept for fast re-use */
70   static int ipv6_works = -1;
71   if(-1 == ipv6_works) {
72     /* probe to see if we have a working IPv6 stack */
73     curl_socket_t s = socket(PF_INET6, SOCK_DGRAM, 0);
74     if(s == CURL_SOCKET_BAD)
75       /* an IPv6 address was requested but we can't get/use one */
76       ipv6_works = 0;
77     else {
78       ipv6_works = 1;
79       Curl_closesocket(NULL, s);
80     }
81   }
82   return (ipv6_works>0)?TRUE:FALSE;
83 }
84 
85 /*
86  * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
87  * been set and returns TRUE if they are OK.
88  */
Curl_ipvalid(struct connectdata * conn)89 bool Curl_ipvalid(struct connectdata *conn)
90 {
91   if(conn->ip_version == CURL_IPRESOLVE_V6)
92     return Curl_ipv6works();
93 
94   return TRUE;
95 }
96 
97 #if defined(CURLRES_SYNCH)
98 
99 #ifdef DEBUG_ADDRINFO
dump_addrinfo(struct connectdata * conn,const Curl_addrinfo * ai)100 static void dump_addrinfo(struct connectdata *conn, const Curl_addrinfo *ai)
101 {
102   printf("dump_addrinfo:\n");
103   for(; ai; ai = ai->ai_next) {
104     char buf[INET6_ADDRSTRLEN];
105     printf("    fam %2d, CNAME %s, ",
106            ai->ai_family, ai->ai_canonname ? ai->ai_canonname : "<none>");
107     if(Curl_printable_address(ai, buf, sizeof(buf)))
108       printf("%s\n", buf);
109     else {
110       char buffer[STRERROR_LEN];
111       printf("failed; %s\n",
112              Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
113     }
114   }
115 }
116 #else
117 #define dump_addrinfo(x,y) Curl_nop_stmt
118 #endif
119 
120 /*
121  * Curl_getaddrinfo() when built IPv6-enabled (non-threading and
122  * non-ares version).
123  *
124  * Returns name information about the given hostname and port number. If
125  * successful, the 'addrinfo' is returned and the forth argument will point to
126  * memory we need to free after use. That memory *MUST* be freed with
127  * Curl_freeaddrinfo(), nothing else.
128  */
Curl_getaddrinfo(struct connectdata * conn,const char * hostname,int port,int * waitp)129 Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
130                                 const char *hostname,
131                                 int port,
132                                 int *waitp)
133 {
134   struct addrinfo hints;
135   Curl_addrinfo *res;
136   int error;
137   char sbuf[12];
138   char *sbufptr = NULL;
139 #ifndef USE_RESOLVE_ON_IPS
140   char addrbuf[128];
141 #endif
142   int pf;
143 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
144   struct Curl_easy *data = conn->data;
145 #endif
146 
147   *waitp = 0; /* synchronous response only */
148 
149   /* Check if a limited name resolve has been requested */
150   switch(conn->ip_version) {
151   case CURL_IPRESOLVE_V4:
152     pf = PF_INET;
153     break;
154   case CURL_IPRESOLVE_V6:
155     pf = PF_INET6;
156     break;
157   default:
158     pf = PF_UNSPEC;
159     break;
160   }
161 
162   if((pf != PF_INET) && !Curl_ipv6works())
163     /* The stack seems to be a non-IPv6 one */
164     pf = PF_INET;
165 
166   memset(&hints, 0, sizeof(hints));
167   hints.ai_family = pf;
168   hints.ai_socktype = (conn->transport == TRNSPRT_TCP) ?
169     SOCK_STREAM : SOCK_DGRAM;
170 
171 #ifndef USE_RESOLVE_ON_IPS
172   /*
173    * The AI_NUMERICHOST must not be set to get synthesized IPv6 address from
174    * an IPv4 address on iOS and Mac OS X.
175    */
176   if((1 == Curl_inet_pton(AF_INET, hostname, addrbuf)) ||
177      (1 == Curl_inet_pton(AF_INET6, hostname, addrbuf))) {
178     /* the given address is numerical only, prevent a reverse lookup */
179     hints.ai_flags = AI_NUMERICHOST;
180   }
181 #endif
182 
183   if(port) {
184     msnprintf(sbuf, sizeof(sbuf), "%d", port);
185     sbufptr = sbuf;
186   }
187 
188   error = Curl_getaddrinfo_ex(hostname, sbufptr, &hints, &res);
189   if(error) {
190     infof(data, "getaddrinfo(3) failed for %s:%d\n", hostname, port);
191     return NULL;
192   }
193 
194   if(port) {
195     Curl_addrinfo_set_port(res, port);
196   }
197 
198   dump_addrinfo(conn, res);
199 
200   return res;
201 }
202 #endif /* CURLRES_SYNCH */
203 
204 #endif /* CURLRES_IPV6 */
205