openbsd-compat/fake-rfc2553.c

   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 (sa->sa_family != AF_UNSPEC && sa->sa_family != AF_INET)
  55                 return (EAI_FAMILY);
  56         if (serv != NULL) {
  57                 snprintf(tmpserv, sizeof(tmpserv), "%d", ntohs(sin->sin_port));
  58                 if (strlcpy(serv, tmpserv, servlen) >= servlen)
  59                         return (EAI_MEMORY);
  60         }
  61
  62         if (host != NULL) {
  63                 if (flags & NI_NUMERICHOST) {
  64                         if (strlcpy(host, inet_ntoa(sin->sin_addr),
  65                             hostlen) >= hostlen)
  66                                 return (EAI_MEMORY);
  67                         else
  68                                 return (0);
  69                 } else {
  70                         hp = gethostbyaddr((char *)&sin->sin_addr,
  71                             sizeof(struct in_addr), AF_INET);
  72                         if (hp == NULL)
  73                                 return (EAI_NODATA);
  74
  75                         if (strlcpy(host, hp->h_name, hostlen) >= hostlen)
  76                                 return (EAI_MEMORY);
  77                         else
  78                                 return (0);
  79                 }
  80         }
  81         return (0);
  82 }
  83 #endif /* !HAVE_GETNAMEINFO */
  84
  85 #ifndef HAVE_GAI_STRERROR
  86 #ifdef HAVE_CONST_GAI_STRERROR_PROTO
  87 const char *
  88 #else
  89 char *
  90 #endif
  91 gai_strerror(int err)
  92 {
  93         switch (err) {
  94         case EAI_NODATA:
  95                 return ("no address associated with name");
  96         case EAI_MEMORY:
  97                 return ("memory allocation failure.");
  98         case EAI_NONAME:
  99                 return ("nodename nor servname provided, or not known");
 100         case EAI_FAMILY:
 101                 return ("ai_family not supported");
 102         default:
 103                 return ("unknown/invalid error.");
 104         }
 105 }
 106 #endif /* !HAVE_GAI_STRERROR */
 107
 108 #ifndef HAVE_FREEADDRINFO
 109 void
 110 freeaddrinfo(struct addrinfo *ai)
 111 {
 112         struct addrinfo *next;
 113
 114         for(; ai != NULL;) {
 115                 next = ai->ai_next;
 116                 free(ai);
 117                 ai = next;
 118         }
 119 }
 120 #endif /* !HAVE_FREEADDRINFO */
 121
 122 #ifndef HAVE_GETADDRINFO
 123 static struct
 124 addrinfo *malloc_ai(int port, u_long addr, const struct addrinfo *hints)
 125 {
 126         struct addrinfo *ai;
 127
 128         ai = malloc(sizeof(*ai) + sizeof(struct sockaddr_in));
 129         if (ai == NULL)
 130                 return (NULL);
 131
 132         memset(ai, '\0', sizeof(*ai) + sizeof(struct sockaddr_in));
 133
 134         ai->ai_addr = (struct sockaddr *)(ai + 1);
 135         /* XXX -- ssh doesn't use sa_len */
 136         ai->ai_addrlen = sizeof(struct sockaddr_in);
 137         ai->ai_addr->sa_family = ai->ai_family = AF_INET;
 138
 139         ((struct sockaddr_in *)(ai)->ai_addr)->sin_port = port;
 140         ((struct sockaddr_in *)(ai)->ai_addr)->sin_addr.s_addr = addr;
 141
 142         /* XXX: the following is not generally correct, but does what we want */
 143         if (hints->ai_socktype)
 144                 ai->ai_socktype = hints->ai_socktype;
 145         else
 146                 ai->ai_socktype = SOCK_STREAM;
 147
 148         if (hints->ai_protocol)
 149                 ai->ai_protocol = hints->ai_protocol;
 150
 151         return (ai);
 152 }
 153
 154 int
 155 getaddrinfo(const char *hostname, const char *servname,
 156     const struct addrinfo *hints, struct addrinfo **res)
 157 {
 158         struct hostent *hp;
 159         struct servent *sp;
 160         struct in_addr in;
 161         int i;
 162         long int port;
 163         u_long addr;
 164
 165         port = 0;
 166         if (hints && hints->ai_family != AF_UNSPEC &&
 167             hints->ai_family != AF_INET)
 168                 return (EAI_FAMILY);
 169         if (servname != NULL) {
 170                 char *cp;
 171
 172                 port = strtol(servname, &cp, 10);
 173                 if (port > 0 && port <= 65535 && *cp == '\0')
 174                         port = htons(port);
 175                 else if ((sp = getservbyname(servname, NULL)) != NULL)
 176                         port = sp->s_port;
 177                 else
 178                         port = 0;
 179         }
 180
 181         if (hints && hints->ai_flags & AI_PASSIVE) {
 182                 addr = htonl(0x00000000);
 183                 if (hostname && inet_aton(hostname, &in) != 0)
 184                         addr = in.s_addr;
 185                 *res = malloc_ai(port, addr, hints);
 186                 if (*res == NULL)
 187                         return (EAI_MEMORY);
 188                 return (0);
 189         }
 190
 191         if (!hostname) {
 192                 *res = malloc_ai(port, htonl(0x7f000001), hints);
 193                 if (*res == NULL)
 194                         return (EAI_MEMORY);
 195                 return (0);
 196         }
 197
 198         if (inet_aton(hostname, &in)) {
 199                 *res = malloc_ai(port, in.s_addr, hints);
 200                 if (*res == NULL)
 201                         return (EAI_MEMORY);
 202                 return (0);
 203         }
 204
 205         /* Don't try DNS if AI_NUMERICHOST is set */
 206         if (hints && hints->ai_flags & AI_NUMERICHOST)
 207                 return (EAI_NONAME);
 208
 209         hp = gethostbyname(hostname);
 210         if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
 211                 struct addrinfo *cur, *prev;
 212
 213                 cur = prev = *res = NULL;
 214                 for (i = 0; hp->h_addr_list[i]; i++) {
 215                         struct in_addr *in = (struct in_addr *)hp->h_addr_list[i];
 216
 217                         cur = malloc_ai(port, in->s_addr, hints);
 218                         if (cur == NULL) {
 219                                 if (*res != NULL)
 220                                         freeaddrinfo(*res);
 221                                 return (EAI_MEMORY);
 222                         }
 223                         if (prev)
 224                                 prev->ai_next = cur;
 225                         else
 226                                 *res = cur;
 227
 228                         prev = cur;
 229                 }
 230                 return (0);
 231         }
 232
 233         return (EAI_NODATA);
 234 }
 235 #endif /* !HAVE_GETADDRINFO */