diff options
Diffstat (limited to 'source4/heimdal/lib/roken/roken_gethostby.c')
| -rw-r--r-- | source4/heimdal/lib/roken/roken_gethostby.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/source4/heimdal/lib/roken/roken_gethostby.c b/source4/heimdal/lib/roken/roken_gethostby.c new file mode 100644 index 0000000000..2df3f83e36 --- /dev/null +++ b/source4/heimdal/lib/roken/roken_gethostby.c @@ -0,0 +1,274 @@ +/* + * Copyright (c) 1998 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +RCSID("$Id: roken_gethostby.c,v 1.7 2005/04/12 11:29:03 lha Exp $"); +#endif + +#include <roken.h> + +#undef roken_gethostbyname +#undef roken_gethostbyaddr + +static struct sockaddr_in dns_addr; +static char *dns_req; + +static int +make_address(const char *address, struct in_addr *ip) +{ + if(inet_aton(address, ip) == 0){ + /* try to resolve as hostname, it might work if the address we + are trying to lookup is local, for instance a web proxy */ + struct hostent *he = gethostbyname(address); + if(he) { + unsigned char *p = (unsigned char*)he->h_addr; + ip->s_addr = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; + } else { + return -1; + } + } + return 0; +} + +static int +setup_int(const char *proxy_host, short proxy_port, + const char *dns_host, short dns_port, + const char *dns_path) +{ + memset(&dns_addr, 0, sizeof(dns_addr)); + if(dns_req) + free(dns_req); + if(proxy_host) { + if(make_address(proxy_host, &dns_addr.sin_addr) != 0) + return -1; + dns_addr.sin_port = htons(proxy_port); + asprintf(&dns_req, "http://%s:%d%s", dns_host, dns_port, dns_path); + } else { + if(make_address(dns_host, &dns_addr.sin_addr) != 0) + return -1; + dns_addr.sin_port = htons(dns_port); + asprintf(&dns_req, "%s", dns_path); + } + dns_addr.sin_family = AF_INET; + return 0; +} + +static void +split_spec(const char *spec, char **host, int *port, char **path, int def_port) +{ + char *p; + *host = strdup(spec); + p = strchr(*host, ':'); + if(p) { + *p++ = '\0'; + if(sscanf(p, "%d", port) != 1) + *port = def_port; + } else + *port = def_port; + p = strchr(p ? p : *host, '/'); + if(p) { + if(path) + *path = strdup(p); + *p = '\0'; + }else + if(path) + *path = NULL; +} + + +int ROKEN_LIB_FUNCTION +roken_gethostby_setup(const char *proxy_spec, const char *dns_spec) +{ + char *proxy_host = NULL; + int proxy_port; + char *dns_host, *dns_path; + int dns_port; + + int ret = -1; + + split_spec(dns_spec, &dns_host, &dns_port, &dns_path, 80); + if(dns_path == NULL) + goto out; + if(proxy_spec) + split_spec(proxy_spec, &proxy_host, &proxy_port, NULL, 80); + ret = setup_int(proxy_host, proxy_port, dns_host, dns_port, dns_path); +out: + free(proxy_host); + free(dns_host); + free(dns_path); + return ret; +} + + +/* Try to lookup a name or an ip-address using http as transport + mechanism. See the end of this file for an example program. */ +static struct hostent* +roken_gethostby(const char *hostname) +{ + int s; + struct sockaddr_in addr; + char *request; + char buf[1024]; + int offset = 0; + int n; + char *p, *foo; + + if(dns_addr.sin_family == 0) + return NULL; /* no configured host */ + addr = dns_addr; + asprintf(&request, "GET %s?%s HTTP/1.0\r\n\r\n", dns_req, hostname); + if(request == NULL) + return NULL; + s = socket(AF_INET, SOCK_STREAM, 0); + if(s < 0) { + free(request); + return NULL; + } + if(connect(s, (struct sockaddr*)&addr, sizeof(addr)) < 0) { + close(s); + free(request); + return NULL; + } + if(write(s, request, strlen(request)) != strlen(request)) { + close(s); + free(request); + return NULL; + } + free(request); + while(1) { + n = read(s, buf + offset, sizeof(buf) - offset); + if(n <= 0) + break; + offset += n; + } + buf[offset] = '\0'; + close(s); + p = strstr(buf, "\r\n\r\n"); /* find end of header */ + if(p) p += 4; + else return NULL; + foo = NULL; + p = strtok_r(p, " \t\r\n", &foo); + if(p == NULL) + return NULL; + { + /* make a hostent to return */ +#define MAX_ADDRS 16 + static struct hostent he; + static char addrs[4 * MAX_ADDRS]; + static char *addr_list[MAX_ADDRS]; + int num_addrs = 0; + + he.h_name = p; + he.h_aliases = NULL; + he.h_addrtype = AF_INET; + he.h_length = 4; + + while((p = strtok_r(NULL, " \t\r\n", &foo)) && num_addrs < MAX_ADDRS) { + struct in_addr ip; + inet_aton(p, &ip); + ip.s_addr = ntohl(ip.s_addr); + addr_list[num_addrs] = &addrs[num_addrs * 4]; + addrs[num_addrs * 4 + 0] = (ip.s_addr >> 24) & 0xff; + addrs[num_addrs * 4 + 1] = (ip.s_addr >> 16) & 0xff; + addrs[num_addrs * 4 + 2] = (ip.s_addr >> 8) & 0xff; + addrs[num_addrs * 4 + 3] = (ip.s_addr >> 0) & 0xff; + addr_list[++num_addrs] = NULL; + } + he.h_addr_list = addr_list; + return &he; + } +} + +struct hostent* +roken_gethostbyname(const char *hostname) +{ + struct hostent *he; + he = gethostbyname(hostname); + if(he) + return he; + return roken_gethostby(hostname); +} + +struct hostent* ROKEN_LIB_FUNCTION +roken_gethostbyaddr(const void *addr, size_t len, int type) +{ + struct in_addr a; + const char *p; + struct hostent *he; + he = gethostbyaddr(addr, len, type); + if(he) + return he; + if(type != AF_INET || len != 4) + return NULL; + p = addr; + a.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]); + return roken_gethostby(inet_ntoa(a)); +} + +#if 0 + +/* this program can be used as a cgi `script' to lookup names and + ip-addresses */ + +#include <stdio.h> +#include <stdlib.h> +#include <netdb.h> +#include <sys/param.h> + +int +main(int argc, char **argv) +{ + char *query = getenv("QUERY_STRING"); + char host[MAXHOSTNAMELEN]; + int i; + struct hostent *he; + + printf("Content-type: text/plain\n\n"); + if(query == NULL) + exit(0); + he = gethostbyname(query); + strncpy(host, he->h_name, sizeof(host)); + host[sizeof(host) - 1] = '\0'; + he = gethostbyaddr(he->h_addr, he->h_length, AF_INET); + printf("%s\n", he->h_name); + for(i = 0; he->h_addr_list[i]; i++) { + struct in_addr ip; + unsigned char *p = (unsigned char*)he->h_addr_list[i]; + ip.s_addr = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]); + printf("%s\n", inet_ntoa(ip)); + } + exit(0); +} + +#endif |