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 #ifndef HAVE_GETNAMEINFO
  41 int getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
  42                 size_t hostlen, char *serv, size_t servlen, int flags)
  43 {
  44         struct sockaddr_in *sin = (struct sockaddr_in *)sa;
  45         struct hostent *hp;
  46         char tmpserv[16];
  47
  48         if (serv != NULL) {
  49                 snprintf(tmpserv, sizeof(tmpserv), "%d", ntohs(sin->sin_port));
  50                 if (strlcpy(serv, tmpserv, servlen) >= servlen)
  51                         return (EAI_MEMORY);
  52         }
  53
  54         if (host != NULL) {
  55                 if (flags & NI_NUMERICHOST) {
  56                         if (strlcpy(host, inet_ntoa(sin->sin_addr),
  57                             hostlen) >= hostlen)
  58                                 return (EAI_MEMORY);
  59                         else
  60                                 return (0);
  61                 } else {
  62                         hp = gethostbyaddr((char *)&sin->sin_addr,
  63                             sizeof(struct in_addr), AF_INET);
  64                         if (hp == NULL)
  65                                 return (EAI_NODATA);
  66
  67                         if (strlcpy(host, hp->h_name, hostlen) >= hostlen)
  68                                 return (EAI_MEMORY);
  69                         else
  70                                 return (0);
  71                 }
  72         }
  73         return (0);
  74 }
  75 #endif /* !HAVE_GETNAMEINFO */
  76
  77 #ifndef HAVE_GAI_STRERROR
  78 #ifdef HAVE_CONST_GAI_STRERROR_PROTO
  79 const char *
  80 #else
  81 char *
  82 #endif
  83 gai_strerror(int err)
  84 {
  85         switch (err) {
  86         case EAI_NODATA:
  87                 return ("no address associated with name");
  88         case EAI_MEMORY:
  89                 return ("memory allocation failure.");
  90         case EAI_NONAME:
  91                 return ("nodename nor servname provided, or not known");
  92         default:
  93                 return ("unknown/invalid error.");
  94         }
  95 }
  96 #endif /* !HAVE_GAI_STRERROR */
  97
  98 #ifndef HAVE_FREEADDRINFO
  99 void
 100 freeaddrinfo(struct addrinfo *ai)
 101 {
 102         struct addrinfo *next;
 103
 104         for(; ai != NULL;) {
 105                 next = ai->ai_next;
 106                 free(ai);
 107                 ai = next;
 108         }
 109 }
 110 #endif /* !HAVE_FREEADDRINFO */
 111
 112 #ifndef HAVE_GETADDRINFO
 113 static struct
 114 addrinfo *malloc_ai(int port, u_long addr, const struct addrinfo *hints)
 115 {
 116         struct addrinfo *ai;
 117
 118         ai = malloc(sizeof(*ai) + sizeof(struct sockaddr_in));
 119         if (ai == NULL)
 120                 return (NULL);
 121
 122         memset(ai, '\0', sizeof(*ai) + sizeof(struct sockaddr_in));
 123
 124         ai->ai_addr = (struct sockaddr *)(ai + 1);
 125         /* XXX -- ssh doesn't use sa_len */
 126         ai->ai_addrlen = sizeof(struct sockaddr_in);
 127         ai->ai_addr->sa_family = ai->ai_family = AF_INET;
 128
 129         ((struct sockaddr_in *)(ai)->ai_addr)->sin_port = port;
 130         ((struct sockaddr_in *)(ai)->ai_addr)->sin_addr.s_addr = addr;
 131
 132         /* XXX: the following is not generally correct, but does what we want */
 133         if (hints->ai_socktype)
 134                 ai->ai_socktype = hints->ai_socktype;
 135         else
 136                 ai->ai_socktype = SOCK_STREAM;
 137
 138         if (hints->ai_protocol)
 139                 ai->ai_protocol = hints->ai_protocol;
 140
 141         return (ai);
 142 }
 143
 144 int
 145 getaddrinfo(const char *hostname, const char *servname,
 146     const struct addrinfo *hints, struct addrinfo **res)
 147 {
 148         struct hostent *hp;
 149         struct servent *sp;
 150         struct in_addr in;
 151         int i;
 152         long int port;
 153         u_long addr;
 154
 155         port = 0;
 156         if (servname != NULL) {
 157                 char *cp;
 158
 159                 port = strtol(servname, &cp, 10);
 160                 if (port > 0 && port <= 65535 && *cp == '\0')
 161                         port = htons(port);
 162                 else if ((sp = getservbyname(servname, NULL)) != NULL)
 163                         port = sp->s_port;
 164                 else
 165                         port = 0;
 166         }
 167
 168         if (hints && hints->ai_flags & AI_PASSIVE) {
 169                 addr = htonl(0x00000000);
 170                 if (hostname && inet_aton(hostname, &in) != 0)
 171                         addr = in.s_addr;
 172                 *res = malloc_ai(port, addr, hints);
 173                 if (*res == NULL)
 174                         return (EAI_MEMORY);
 175                 return (0);
 176         }
 177
 178         if (!hostname) {
 179                 *res = malloc_ai(port, htonl(0x7f000001), hints);
 180                 if (*res == NULL)
 181                         return (EAI_MEMORY);
 182                 return (0);
 183         }
 184
 185         if (inet_aton(hostname, &in)) {
 186                 *res = malloc_ai(port, in.s_addr, hints);
 187                 if (*res == NULL)
 188                         return (EAI_MEMORY);
 189                 return (0);
 190         }
 191
 192         /* Don't try DNS if AI_NUMERICHOST is set */
 193         if (hints && hints->ai_flags & AI_NUMERICHOST)
 194                 return (EAI_NONAME);
 195
 196         hp = gethostbyname(hostname);
 197         if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
 198                 struct addrinfo *cur, *prev;
 199
 200                 cur = prev = *res = NULL;
 201                 for (i = 0; hp->h_addr_list[i]; i++) {
 202                         struct in_addr *in = (struct in_addr *)hp->h_addr_list[i];
 203
 204                         cur = malloc_ai(port, in->s_addr, hints);
 205                         if (cur == NULL) {
 206                                 if (*res != NULL)
 207                                         freeaddrinfo(*res);
 208                                 return (EAI_MEMORY);
 209                         }
 210                         if (prev)
 211                                 prev->ai_next = cur;
 212                         else
 213                                 *res = cur;
 214
 215                         prev = cur;
 216                 }
 217                 return (0);
 218         }
 219
 220         return (EAI_NODATA);
 221 }
 222 #endif /* !HAVE_GETADDRINFO */