 0d31d3d686
			
		
	
	0d31d3d686
	
	
	
		
			
			git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@24356 ec53bebd-3082-4978-b11e-865c3cabbd6b
		
			
				
	
	
		
			272 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			272 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 1998 Kungliga Tekniska Högskolan
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|  * (Royal Institute of Technology, Stockholm, Sweden).
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  *
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * 3. Neither the name of the Institute nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #include <config.h>
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| 
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| #include "roken.h"
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| 
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| #undef roken_gethostbyname
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| #undef roken_gethostbyaddr
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| 
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| static struct sockaddr_in dns_addr;
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| static char *dns_req;
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| 
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| static int
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| make_address(const char *address, struct in_addr *ip)
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| {
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|     if(inet_aton(address, ip) == 0){
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| 	/* try to resolve as hostname, it might work if the address we
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|            are trying to lookup is local, for instance a web proxy */
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| 	struct hostent *he = gethostbyname(address);
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| 	if(he) {
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| 	    unsigned char *p = (unsigned char*)he->h_addr;
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| 	    ip->s_addr = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
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| 	} else {
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| 	    return -1;
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| 	}
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|     }
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|     return 0;
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| }
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| 
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| static int
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| setup_int(const char *proxy_host, short proxy_port,
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| 	  const char *dns_host, short dns_port,
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| 	  const char *dns_path)
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| {
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|     memset(&dns_addr, 0, sizeof(dns_addr));
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|     if(dns_req)
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| 	free(dns_req);
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|     if(proxy_host) {
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| 	if(make_address(proxy_host, &dns_addr.sin_addr) != 0)
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| 	    return -1;
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| 	dns_addr.sin_port = htons(proxy_port);
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| 	asprintf(&dns_req, "http://%s:%d%s", dns_host, dns_port, dns_path);
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|     } else {
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| 	if(make_address(dns_host, &dns_addr.sin_addr) != 0)
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| 	    return -1;
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| 	dns_addr.sin_port = htons(dns_port);
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| 	asprintf(&dns_req, "%s", dns_path);
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|     }
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|     dns_addr.sin_family = AF_INET;
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|     return 0;
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| }
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| 
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| static void
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| split_spec(const char *spec, char **host, int *port, char **path, int def_port)
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| {
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|     char *p;
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|     *host = strdup(spec);
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|     p = strchr(*host, ':');
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|     if(p) {
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| 	*p++ = '\0';
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| 	if(sscanf(p, "%d", port) != 1)
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| 	    *port = def_port;
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|     } else
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| 	*port = def_port;
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|     p = strchr(p ? p : *host, '/');
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|     if(p) {
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| 	if(path)
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| 	    *path = strdup(p);
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| 	*p = '\0';
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|     }else
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| 	if(path)
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| 	    *path = NULL;
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| }
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| 
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| 
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| int ROKEN_LIB_FUNCTION
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| roken_gethostby_setup(const char *proxy_spec, const char *dns_spec)
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| {
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|     char *proxy_host = NULL;
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|     int proxy_port = 0;
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|     char *dns_host, *dns_path;
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|     int dns_port;
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| 
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|     int ret = -1;
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| 
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|     split_spec(dns_spec, &dns_host, &dns_port, &dns_path, 80);
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|     if(dns_path == NULL)
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| 	goto out;
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|     if(proxy_spec)
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| 	split_spec(proxy_spec, &proxy_host, &proxy_port, NULL, 80);
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|     ret = setup_int(proxy_host, proxy_port, dns_host, dns_port, dns_path);
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| out:
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|     free(proxy_host);
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|     free(dns_host);
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|     free(dns_path);
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|     return ret;
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| }
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| 
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| 
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| /* Try to lookup a name or an ip-address using http as transport
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|    mechanism. See the end of this file for an example program. */
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| static struct hostent*
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| roken_gethostby(const char *hostname)
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| {
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|     int s;
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|     struct sockaddr_in addr;
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|     char *request;
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|     char buf[1024];
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|     int offset = 0;
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|     int n;
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|     char *p, *foo;
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| 
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|     if(dns_addr.sin_family == 0)
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| 	return NULL; /* no configured host */
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|     addr = dns_addr;
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|     asprintf(&request, "GET %s?%s HTTP/1.0\r\n\r\n", dns_req, hostname);
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|     if(request == NULL)
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| 	return NULL;
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|     s  = socket(AF_INET, SOCK_STREAM, 0);
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|     if(s < 0) {
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| 	free(request);
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| 	return NULL;
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|     }
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|     if(connect(s, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
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| 	close(s);
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| 	free(request);
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| 	return NULL;
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|     }
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|     if(write(s, request, strlen(request)) != strlen(request)) {
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| 	close(s);
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| 	free(request);
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| 	return NULL;
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|     }
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|     free(request);
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|     while(1) {
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| 	n = read(s, buf + offset, sizeof(buf) - offset);
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| 	if(n <= 0)
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| 	    break;
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| 	offset += n;
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|     }
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|     buf[offset] = '\0';
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|     close(s);
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|     p = strstr(buf, "\r\n\r\n"); /* find end of header */
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|     if(p) p += 4;
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|     else return NULL;
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|     foo = NULL;
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|     p = strtok_r(p, " \t\r\n", &foo);
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|     if(p == NULL)
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| 	return NULL;
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|     {
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| 	/* make a hostent to return */
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| #define MAX_ADDRS 16
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| 	static struct hostent he;
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| 	static char addrs[4 * MAX_ADDRS];
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| 	static char *addr_list[MAX_ADDRS + 1];
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| 	int num_addrs = 0;
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| 	
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| 	he.h_name = p;
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| 	he.h_aliases = NULL;
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| 	he.h_addrtype = AF_INET;
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| 	he.h_length = 4;
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| 	
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| 	while((p = strtok_r(NULL, " \t\r\n", &foo)) && num_addrs < MAX_ADDRS) {
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| 	    struct in_addr ip;
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| 	    inet_aton(p, &ip);
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| 	    ip.s_addr = ntohl(ip.s_addr);
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| 	    addr_list[num_addrs] = &addrs[num_addrs * 4];
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| 	    addrs[num_addrs * 4 + 0] = (ip.s_addr >> 24) & 0xff;
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| 	    addrs[num_addrs * 4 + 1] = (ip.s_addr >> 16) & 0xff;
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| 	    addrs[num_addrs * 4 + 2] = (ip.s_addr >> 8) & 0xff;
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| 	    addrs[num_addrs * 4 + 3] = (ip.s_addr >> 0) & 0xff;
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| 	    addr_list[++num_addrs] = NULL;
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| 	}
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| 	he.h_addr_list = addr_list;
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| 	return &he;
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|     }
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| }
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| 
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| struct hostent*
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| roken_gethostbyname(const char *hostname)
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| {
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|     struct hostent *he;
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|     he = gethostbyname(hostname);
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|     if(he)
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| 	return he;
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|     return roken_gethostby(hostname);
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| }
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| 
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| struct hostent* ROKEN_LIB_FUNCTION
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| roken_gethostbyaddr(const void *addr, size_t len, int type)
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| {
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|     struct in_addr a;
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|     const char *p;
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|     struct hostent *he;
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|     he = gethostbyaddr(addr, len, type);
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|     if(he)
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| 	return he;
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|     if(type != AF_INET || len != 4)
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| 	return NULL;
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|     p = addr;
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|     a.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
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|     return roken_gethostby(inet_ntoa(a));
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| }
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| 
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| #if 0
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| 
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| /* this program can be used as a cgi `script' to lookup names and
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|    ip-addresses */
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| 
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <netdb.h>
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| #include <sys/param.h>
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| 
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| int
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| main(int argc, char **argv)
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| {
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|     char *query = getenv("QUERY_STRING");
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|     char host[MAXHOSTNAMELEN];
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|     int i;
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|     struct hostent *he;
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| 
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|     printf("Content-type: text/plain\n\n");
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|     if(query == NULL)
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| 	exit(0);
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|     he = gethostbyname(query);
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|     strncpy(host, he->h_name, sizeof(host));
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|     host[sizeof(host) - 1] = '\0';
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|     he = gethostbyaddr(he->h_addr, he->h_length, AF_INET);
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|     printf("%s\n", he->h_name);
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|     for(i = 0; he->h_addr_list[i]; i++) {
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| 	struct in_addr ip;
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| 	unsigned char *p = (unsigned char*)he->h_addr_list[i];
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| 	ip.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
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| 	printf("%s\n", inet_ntoa(ip));
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|     }
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|     exit(0);
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| }
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| 
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| #endif
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