xref: /freebsd/crypto/openssh/openbsd-compat/fake-rfc2553.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*
2  * Copyright (C) 2000-2003 Damien Miller.  All rights reserved.
3  * Copyright (C) 1999 WIDE Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Pseudo-implementation of RFC2553 name / address resolution functions
32  *
33  * But these functions are not implemented correctly. The minimum subset
34  * is implemented for ssh use only. For example, this routine assumes
35  * that ai_family is AF_INET. Don't use it for another purpose.
36  */
37 
38 #include "includes.h"
39 
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #include <netinet/in.h>
44 #include <arpa/inet.h>
45 
46 #ifndef HAVE_GETNAMEINFO
47 int getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
48                 size_t hostlen, char *serv, size_t servlen, int flags)
49 {
50 	struct sockaddr_in *sin = (struct sockaddr_in *)sa;
51 	struct hostent *hp;
52 	char tmpserv[16];
53 
54 	if (serv != NULL) {
55 		snprintf(tmpserv, sizeof(tmpserv), "%d", ntohs(sin->sin_port));
56 		if (strlcpy(serv, tmpserv, servlen) >= servlen)
57 			return (EAI_MEMORY);
58 	}
59 
60 	if (host != NULL) {
61 		if (flags & NI_NUMERICHOST) {
62 			if (strlcpy(host, inet_ntoa(sin->sin_addr),
63 			    hostlen) >= hostlen)
64 				return (EAI_MEMORY);
65 			else
66 				return (0);
67 		} else {
68 			hp = gethostbyaddr((char *)&sin->sin_addr,
69 			    sizeof(struct in_addr), AF_INET);
70 			if (hp == NULL)
71 				return (EAI_NODATA);
72 
73 			if (strlcpy(host, hp->h_name, hostlen) >= hostlen)
74 				return (EAI_MEMORY);
75 			else
76 				return (0);
77 		}
78 	}
79 	return (0);
80 }
81 #endif /* !HAVE_GETNAMEINFO */
82 
83 #ifndef HAVE_GAI_STRERROR
84 #ifdef HAVE_CONST_GAI_STRERROR_PROTO
85 const char *
86 #else
87 char *
88 #endif
89 gai_strerror(int err)
90 {
91 	switch (err) {
92 	case EAI_NODATA:
93 		return ("no address associated with name");
94 	case EAI_MEMORY:
95 		return ("memory allocation failure.");
96 	case EAI_NONAME:
97 		return ("nodename nor servname provided, or not known");
98 	default:
99 		return ("unknown/invalid error.");
100 	}
101 }
102 #endif /* !HAVE_GAI_STRERROR */
103 
104 #ifndef HAVE_FREEADDRINFO
105 void
106 freeaddrinfo(struct addrinfo *ai)
107 {
108 	struct addrinfo *next;
109 
110 	for(; ai != NULL;) {
111 		next = ai->ai_next;
112 		free(ai);
113 		ai = next;
114 	}
115 }
116 #endif /* !HAVE_FREEADDRINFO */
117 
118 #ifndef HAVE_GETADDRINFO
119 static struct
120 addrinfo *malloc_ai(int port, u_long addr, const struct addrinfo *hints)
121 {
122 	struct addrinfo *ai;
123 
124 	ai = malloc(sizeof(*ai) + sizeof(struct sockaddr_in));
125 	if (ai == NULL)
126 		return (NULL);
127 
128 	memset(ai, '\0', sizeof(*ai) + sizeof(struct sockaddr_in));
129 
130 	ai->ai_addr = (struct sockaddr *)(ai + 1);
131 	/* XXX -- ssh doesn't use sa_len */
132 	ai->ai_addrlen = sizeof(struct sockaddr_in);
133 	ai->ai_addr->sa_family = ai->ai_family = AF_INET;
134 
135 	((struct sockaddr_in *)(ai)->ai_addr)->sin_port = port;
136 	((struct sockaddr_in *)(ai)->ai_addr)->sin_addr.s_addr = addr;
137 
138 	/* XXX: the following is not generally correct, but does what we want */
139 	if (hints->ai_socktype)
140 		ai->ai_socktype = hints->ai_socktype;
141 	else
142 		ai->ai_socktype = SOCK_STREAM;
143 
144 	if (hints->ai_protocol)
145 		ai->ai_protocol = hints->ai_protocol;
146 
147 	return (ai);
148 }
149 
150 int
151 getaddrinfo(const char *hostname, const char *servname,
152     const struct addrinfo *hints, struct addrinfo **res)
153 {
154 	struct hostent *hp;
155 	struct servent *sp;
156 	struct in_addr in;
157 	int i;
158 	long int port;
159 	u_long addr;
160 
161 	port = 0;
162 	if (servname != NULL) {
163 		char *cp;
164 
165 		port = strtol(servname, &cp, 10);
166 		if (port > 0 && port <= 65535 && *cp == '\0')
167 			port = htons(port);
168 		else if ((sp = getservbyname(servname, NULL)) != NULL)
169 			port = sp->s_port;
170 		else
171 			port = 0;
172 	}
173 
174 	if (hints && hints->ai_flags & AI_PASSIVE) {
175 		addr = htonl(0x00000000);
176 		if (hostname && inet_aton(hostname, &in) != 0)
177 			addr = in.s_addr;
178 		*res = malloc_ai(port, addr, hints);
179 		if (*res == NULL)
180 			return (EAI_MEMORY);
181 		return (0);
182 	}
183 
184 	if (!hostname) {
185 		*res = malloc_ai(port, htonl(0x7f000001), hints);
186 		if (*res == NULL)
187 			return (EAI_MEMORY);
188 		return (0);
189 	}
190 
191 	if (inet_aton(hostname, &in)) {
192 		*res = malloc_ai(port, in.s_addr, hints);
193 		if (*res == NULL)
194 			return (EAI_MEMORY);
195 		return (0);
196 	}
197 
198 	/* Don't try DNS if AI_NUMERICHOST is set */
199 	if (hints && hints->ai_flags & AI_NUMERICHOST)
200 		return (EAI_NONAME);
201 
202 	hp = gethostbyname(hostname);
203 	if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
204 		struct addrinfo *cur, *prev;
205 
206 		cur = prev = *res = NULL;
207 		for (i = 0; hp->h_addr_list[i]; i++) {
208 			struct in_addr *in = (struct in_addr *)hp->h_addr_list[i];
209 
210 			cur = malloc_ai(port, in->s_addr, hints);
211 			if (cur == NULL) {
212 				if (*res != NULL)
213 					freeaddrinfo(*res);
214 				return (EAI_MEMORY);
215 			}
216 			if (prev)
217 				prev->ai_next = cur;
218 			else
219 				*res = cur;
220 
221 			prev = cur;
222 		}
223 		return (0);
224 	}
225 
226 	return (EAI_NODATA);
227 }
228 #endif /* !HAVE_GETADDRINFO */
229