1 /*
2  * Redistribution and use in source and binary forms, with or without modification,
3  * are permitted provided that the following conditions are met:
4  *
5  * 1. Redistributions of source code must retain the above copyright notice,
6  *    this list of conditions and the following disclaimer.
7  * 2. Redistributions in binary form must reproduce the above copyright notice,
8  *    this list of conditions and the following disclaimer in the documentation
9  *    and/or other materials provided with the distribution.
10  * 3. The name of the author may not be used to endorse or promote products
11  *    derived from this software without specific prior written permission.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
14  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
16  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
17  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
18  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
19  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
20  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
21  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
22  * OF SUCH DAMAGE.
23  *
24  * This file is part of the lwIP TCP/IP stack.
25  *
26  * Author: Simon Goldschmidt
27  *
28  */
29 
30 #include "lwip/opt.h"
31 
32 #if LWIP_DNS && LWIP_SOCKET
33 
34 #include <stddef.h> /* for size_t */
35 
36 #include "lwip/sockets.h"
37 
38 /* some rarely used options */
39 #ifndef LWIP_DNS_API_DECLARE_H_ERRNO
40 #define LWIP_DNS_API_DECLARE_H_ERRNO 1
41 #endif
42 
43 #ifndef LWIP_DNS_API_DEFINE_ERRORS
44 #define LWIP_DNS_API_DEFINE_ERRORS 1
45 #endif
46 
47 #ifndef LWIP_DNS_API_DECLARE_STRUCTS
48 #define LWIP_DNS_API_DECLARE_STRUCTS 1
49 #endif
50 
51 #if LWIP_DNS_API_DEFINE_ERRORS
52 /** Errors used by the DNS API functions, h_errno can be one of them */
53 #define EAI_NONAME      200
54 #define EAI_SERVICE     201
55 #define EAI_FAIL        202
56 #define EAI_MEMORY      203
57 
58 #define HOST_NOT_FOUND  210
59 #define NO_DATA         211
60 #define NO_RECOVERY     212
61 #define TRY_AGAIN       213
62 #endif /* LWIP_DNS_API_DEFINE_ERRORS */
63 
64 #if LWIP_DNS_API_DECLARE_STRUCTS
65 struct hostent {
66     char  *h_name;      /* Official name of the host. */
67     char **h_aliases;   /* A pointer to an array of pointers to alternative host names,
68                            terminated by a null pointer. */
69     int    h_addrtype;  /* Address type. */
70     int    h_length;    /* The length, in bytes, of the address. */
71     char **h_addr_list; /* A pointer to an array of pointers to network addresses (in
72                            network byte order) for the host, terminated by a null pointer. */
73 #define h_addr h_addr_list[0] /* for backward compatibility */
74 };
75 
76 struct addrinfo {
77     int               ai_flags;      /* Input flags. */
78     int               ai_family;     /* Address family of socket. */
79     int               ai_socktype;   /* Socket type. */
80     int               ai_protocol;   /* Protocol of socket. */
81     socklen_t         ai_addrlen;    /* Length of socket address. */
82     struct sockaddr  *ai_addr;       /* Socket address of socket. */
83     char             *ai_canonname;  /* Canonical name of service location. */
84     struct addrinfo  *ai_next;       /* Pointer to next in list. */
85 };
86 #endif /* LWIP_DNS_API_DECLARE_STRUCTS */
87 
88 #if LWIP_DNS_API_DECLARE_H_ERRNO
89 /* application accessable error code set by the DNS API functions */
90 extern int h_errno;
91 #endif /* LWIP_DNS_API_DECLARE_H_ERRNO*/
92 
93 struct hostent *lwip_gethostbyname(const char *name);
94 int lwip_gethostbyname_r(const char *name, struct hostent *ret, char *buf,
95                 size_t buflen, struct hostent **result, int *h_errnop);
96 void lwip_freeaddrinfo(struct addrinfo *ai);
97 int lwip_getaddrinfo(const char *nodename,
98        const char *servname,
99        const struct addrinfo *hints,
100        struct addrinfo **res);
101 
102 #if LWIP_COMPAT_SOCKETS
103 #define gethostbyname(name) lwip_gethostbyname(name)
104 #define gethostbyname_r(name, ret, buf, buflen, result, h_errnop) \
105        lwip_gethostbyname_r(name, ret, buf, buflen, result, h_errnop)
106 #define freeaddrinfo(addrinfo) lwip_freeaddrinfo(a)
107 #define getaddrinfo(nodname, servname, hints, res) \
108        lwip_getaddrinfo(nodname, servname, hints, res)
109 #endif /* LWIP_COMPAT_SOCKETS */
110 
111 #endif /* LWIP_DNS && LWIP_SOCKET */
112