crypto/external/bsd/heimdal/dist/lib/roken/roken_gethostby.c

   1 /*      $NetBSD: roken_gethostby.c,v 1.1.1.2 2014/04/24 12:45:52 pettai Exp $   */
   2
   3 /*
   4  * Copyright (c) 1998 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #include <krb5/roken.h>
  39
  40 #undef roken_gethostbyname
  41 #undef roken_gethostbyaddr
  42
  43 static struct sockaddr_in dns_addr;
  44 static char *dns_req;
  45
  46 static int
  47 make_address(const char *address, struct in_addr *ip)
  48 {
  49     if(inet_aton(address, ip) == 0){
  50         /* try to resolve as hostname, it might work if the address we
  51            are trying to lookup is local, for instance a web proxy */
  52         struct hostent *he = gethostbyname(address);
  53         if(he) {
  54             unsigned char *p = (unsigned char*)he->h_addr;
  55             ip->s_addr = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
  56         } else {
  57             return -1;
  58         }
  59     }
  60     return 0;
  61 }
  62
  63 static int
  64 setup_int(const char *proxy_host, short proxy_port,
  65           const char *dns_host, short dns_port,
  66           const char *dns_path)
  67 {
  68     memset(&dns_addr, 0, sizeof(dns_addr));
  69     if(dns_req)
  70         free(dns_req);
  71     dns_req = NULL;
  72     if(proxy_host) {
  73         if(make_address(proxy_host, &dns_addr.sin_addr) != 0)
  74             return -1;
  75         dns_addr.sin_port = htons(proxy_port);
  76         if (asprintf(&dns_req, "http://%s:%d%s", dns_host, dns_port, dns_path) < 0)
  77             return -1;
  78     } else {
  79         if(make_address(dns_host, &dns_addr.sin_addr) != 0)
  80             return -1;
  81         dns_addr.sin_port = htons(dns_port);
  82         asprintf(&dns_req, "%s", dns_path);
  83     }
  84     dns_addr.sin_family = AF_INET;
  85     return 0;
  86 }
  87
  88 static void
  89 split_spec(const char *spec, char **host, int *port, char **path, int def_port)
  90 {
  91     char *p;
  92     *host = strdup(spec);
  93     p = strchr(*host, ':');
  94     if(p) {
  95         *p++ = '\0';
  96         if(sscanf(p, "%d", port) != 1)
  97             *port = def_port;
  98     } else
  99         *port = def_port;
 100     p = strchr(p ? p : *host, '/');
 101     if(p) {
 102         if(path)
 103             *path = strdup(p);
 104         *p = '\0';
 105     }else
 106         if(path)
 107             *path = NULL;
 108 }
 109
 110
 111 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 112 roken_gethostby_setup(const char *proxy_spec, const char *dns_spec)
 113 {
 114     char *proxy_host = NULL;
 115     int proxy_port = 0;
 116     char *dns_host, *dns_path;
 117     int dns_port;
 118
 119     int ret = -1;
 120
 121     split_spec(dns_spec, &dns_host, &dns_port, &dns_path, 80);
 122     if(dns_path == NULL)
 123         goto out;
 124     if(proxy_spec)
 125         split_spec(proxy_spec, &proxy_host, &proxy_port, NULL, 80);
 126     ret = setup_int(proxy_host, proxy_port, dns_host, dns_port, dns_path);
 127 out:
 128     free(proxy_host);
 129     free(dns_host);
 130     free(dns_path);
 131     return ret;
 132 }
 133
 134
 135 /* Try to lookup a name or an ip-address using http as transport
 136    mechanism. See the end of this file for an example program. */
 137 static struct hostent*
 138 roken_gethostby(const char *hostname)
 139 {
 140     int s;
 141     struct sockaddr_in addr;
 142     char *request = NULL;
 143     char buf[1024];
 144     int offset = 0;
 145     int n;
 146     char *p, *foo;
 147     size_t len;
 148
 149     if(dns_addr.sin_family == 0)
 150         return NULL; /* no configured host */
 151     addr = dns_addr;
 152     if (asprintf(&request, "GET %s?%s HTTP/1.0\r\n\r\n", dns_req, hostname) < 0)
 153         return NULL;
 154     if(request == NULL)
 155         return NULL;
 156     s  = socket(AF_INET, SOCK_STREAM, 0);
 157     if(s < 0) {
 158         free(request);
 159         return NULL;
 160     }
 161     if(connect(s, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
 162         close(s);
 163         free(request);
 164         return NULL;
 165     }
 166
 167     len = strlen(request);
 168     if(write(s, request, len) != (ssize_t)len) {
 169         close(s);
 170         free(request);
 171         return NULL;
 172     }
 173     free(request);
 174     while(1) {
 175         n = read(s, buf + offset, sizeof(buf) - offset);
 176         if(n <= 0)
 177             break;
 178         offset += n;
 179     }
 180     buf[offset] = '\0';
 181     close(s);
 182     p = strstr(buf, "\r\n\r\n"); /* find end of header */
 183     if(p) p += 4;
 184     else return NULL;
 185     foo = NULL;
 186     p = strtok_r(p, " \t\r\n", &foo);
 187     if(p == NULL)
 188         return NULL;
 189     {
 190         /* make a hostent to return */
 191 #define MAX_ADDRS 16
 192         static struct hostent he;
 193         static char addrs[4 * MAX_ADDRS];
 194         static char *addr_list[MAX_ADDRS + 1];
 195         int num_addrs = 0;
 196
 197         he.h_name = p;
 198         he.h_aliases = NULL;
 199         he.h_addrtype = AF_INET;
 200         he.h_length = 4;
 201
 202         while((p = strtok_r(NULL, " \t\r\n", &foo)) && num_addrs < MAX_ADDRS) {
 203             struct in_addr ip;
 204             inet_aton(p, &ip);
 205             ip.s_addr = ntohl(ip.s_addr);
 206             addr_list[num_addrs] = &addrs[num_addrs * 4];
 207             addrs[num_addrs * 4 + 0] = (ip.s_addr >> 24) & 0xff;
 208             addrs[num_addrs * 4 + 1] = (ip.s_addr >> 16) & 0xff;
 209             addrs[num_addrs * 4 + 2] = (ip.s_addr >> 8) & 0xff;
 210             addrs[num_addrs * 4 + 3] = (ip.s_addr >> 0) & 0xff;
 211             addr_list[++num_addrs] = NULL;
 212         }
 213         he.h_addr_list = addr_list;
 214         return &he;
 215     }
 216 }
 217
 218 ROKEN_LIB_FUNCTION struct hostent* ROKEN_LIB_CALL
 219 roken_gethostbyname(const char *hostname)
 220 {
 221     struct hostent *he;
 222     he = gethostbyname(hostname);
 223     if(he)
 224         return he;
 225     return roken_gethostby(hostname);
 226 }
 227
 228 ROKEN_LIB_FUNCTION struct hostent* ROKEN_LIB_CALL
 229 roken_gethostbyaddr(const void *addr, size_t len, int type)
 230 {
 231     struct in_addr a;
 232     const char *p;
 233     struct hostent *he;
 234     he = gethostbyaddr(addr, len, type);
 235     if(he)
 236         return he;
 237     if(type != AF_INET || len != 4)
 238         return NULL;
 239     p = addr;
 240     a.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
 241     return roken_gethostby(inet_ntoa(a));
 242 }
 243
 244 #if 0
 245
 246 /* this program can be used as a cgi `script' to lookup names and
 247    ip-addresses */
 248
 249 #include <stdio.h>
 250 #include <stdlib.h>
 251 #include <netdb.h>
 252 #include <sys/param.h>
 253
 254 int
 255 main(int argc, char **argv)
 256 {
 257     char *query = getenv("QUERY_STRING");
 258     char host[MAXHOSTNAMELEN];
 259     int i;
 260     struct hostent *he;
 261
 262     printf("Content-type: text/plain\n\n");
 263     if(query == NULL)
 264         exit(0);
 265     he = gethostbyname(query);
 266     strncpy(host, he->h_name, sizeof(host));
 267     host[sizeof(host) - 1] = '\0';
 268     he = gethostbyaddr(he->h_addr, he->h_length, AF_INET);
 269     printf("%s\n", he->h_name);
 270     for(i = 0; he->h_addr_list[i]; i++) {
 271         struct in_addr ip;
 272         unsigned char *p = (unsigned char*)he->h_addr_list[i];
 273         ip.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
 274         printf("%s\n", inet_ntoa(ip));
 275     }
 276     exit(0);
 277 }
 278
 279 #endif