bfdbb8f260
This commit updates all authorship and copyright information to include a standard header that references the AUTHORS and CREDITS file. This standard header was written by the Debian legal team at the request of Franck Joncourt.
345 lines
9.1 KiB
C
345 lines
9.1 KiB
C
/*
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*****************************************************************************
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*
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* File: http_resolve_host.c
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*
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* Purpose: Routine for using an http request to obtain a client's IP
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* address as seen from the outside world.
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*
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* Fwknop is developed primarily by the people listed in the file 'AUTHORS'.
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* Copyright (C) 2009–2014 fwknop developers and contributors. For a full
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* list of contributors, see the file 'CREDITS'.
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*
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* License (GNU General Public License):
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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* USA
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*
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*****************************************************************************
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*/
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#include "fwknop_common.h"
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#include "utils.h"
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#include <errno.h>
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#ifdef WIN32
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#include <winsock2.h>
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#include <ws2tcpip.h>
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#else
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#if HAVE_SYS_SOCKET_H
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#include <sys/socket.h>
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#endif
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#include <netdb.h>
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#endif
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struct url
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{
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char port[MAX_PORT_STR_LEN+1];
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char host[MAX_URL_HOST_LEN+1];
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char path[MAX_URL_PATH_LEN+1];
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};
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static int
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try_url(struct url *url, fko_cli_options_t *options)
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{
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int sock, res, error, http_buf_len, i;
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int bytes_read = 0, position = 0;
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int o1, o2, o3, o4;
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struct addrinfo *result, *rp, hints;
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char http_buf[HTTP_MAX_REQUEST_LEN] = {0};
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char http_response[HTTP_MAX_RESPONSE_LEN] = {0};
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char *ndx;
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#ifdef WIN32
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WSADATA wsa_data;
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/* Winsock needs to be initialized...
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*/
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res = WSAStartup( MAKEWORD(1,1), &wsa_data );
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if( res != 0 )
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{
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log_msg(LOG_VERBOSITY_ERROR, "Winsock initialization error %d", res );
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return(-1);
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}
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#endif
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/* Build our HTTP request to resolve the external IP (this is similar to
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* to contacting whatismyip.org, but using a different URL).
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*/
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snprintf(http_buf, HTTP_MAX_REQUEST_LEN,
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"GET %s HTTP/1.0\r\nUser-Agent: %s\r\nAccept: */*\r\n"
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"Host: %s\r\nConnection: close\r\n\r\n",
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url->path,
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options->http_user_agent,
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url->host
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);
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http_buf_len = strlen(http_buf);
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memset(&hints, 0, sizeof(struct addrinfo));
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hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
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hints.ai_socktype = SOCK_STREAM;
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hints.ai_protocol = IPPROTO_TCP;
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error = getaddrinfo(url->host, url->port, &hints, &result);
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if (error != 0)
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{
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log_msg(LOG_VERBOSITY_ERROR, "error in getaddrinfo: %s", gai_strerror(error));
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return(-1);
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}
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for (rp = result; rp != NULL; rp = rp->ai_next) {
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sock = socket(rp->ai_family, rp->ai_socktype,
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rp->ai_protocol);
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if (sock < 0)
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continue;
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if ((error = (connect(sock, rp->ai_addr, rp->ai_addrlen) != -1)))
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break; /* made it */
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#ifdef WIN32
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closesocket(sock);
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#else
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close(sock);
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#endif
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}
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if (rp == NULL) {
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log_msg(LOG_VERBOSITY_ERROR, "resolve_ip_http: Could not create socket: ", strerror(errno));
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return(-1);
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}
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freeaddrinfo(result);
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log_msg(LOG_VERBOSITY_DEBUG, "\nHTTP request: %s", http_buf);
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res = send(sock, http_buf, http_buf_len, 0);
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if(res < 0)
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{
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log_msg(LOG_VERBOSITY_ERROR, "resolve_ip_http: write error: ", strerror(errno));
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}
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else if(res != http_buf_len)
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{
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log_msg(LOG_VERBOSITY_WARNING,
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"[#] Warning: bytes sent (%i) not spa data length (%i).",
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res, http_buf_len
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);
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}
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do
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{
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memset(http_buf, 0x0, sizeof(http_buf));
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bytes_read = recv(sock, http_buf, sizeof(http_buf), 0);
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if ( bytes_read > 0 ) {
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if(position + bytes_read >= HTTP_MAX_RESPONSE_LEN)
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break;
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memcpy(&http_response[position], http_buf, bytes_read);
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position += bytes_read;
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}
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}
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while ( bytes_read > 0 );
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http_response[HTTP_MAX_RESPONSE_LEN-1] = '\0';
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#ifdef WIN32
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closesocket(sock);
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#else
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close(sock);
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#endif
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log_msg(LOG_VERBOSITY_DEBUG, "\nHTTP response: %s", http_response);
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/* Move to the end of the HTTP header and to the start of the content.
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*/
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ndx = strstr(http_response, "\r\n\r\n");
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if(ndx == NULL)
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{
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log_msg(LOG_VERBOSITY_ERROR, "Did not find the end of HTTP header.");
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return(-1);
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}
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ndx += 4;
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/* Walk along the content to try to find the end of the IP address.
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* Note: We are expecting the content to be just an IP address
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* (possibly followed by whitespace or other not-digit value).
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*/
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for(i=0; i<MAX_IPV4_STR_LEN; i++) {
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if(! isdigit(*(ndx+i)) && *(ndx+i) != '.')
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break;
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}
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/* Terminate at the first non-digit and non-dot.
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*/
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*(ndx+i) = '\0';
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/* Now that we have what we think is an IP address string. We make
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* sure the format and values are sane.
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*/
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if((sscanf(ndx, "%u.%u.%u.%u", &o1, &o2, &o3, &o4)) == 4
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&& o1 >= 0 && o1 <= 255
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&& o2 >= 0 && o2 <= 255
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&& o3 >= 0 && o3 <= 255
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&& o4 >= 0 && o4 <= 255)
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{
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strlcpy(options->allow_ip_str, ndx, sizeof(options->allow_ip_str));
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log_msg(LOG_VERBOSITY_INFO,
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"\n[+] Resolved external IP (via http://%s%s) as: %s",
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url->host,
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url->path,
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options->allow_ip_str);
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return(1);
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}
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else
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{
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log_msg(LOG_VERBOSITY_ERROR,
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"[-] From http://%s%s\n Invalid IP (%s) in HTTP response:\n\n%s",
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url->host, url->path, ndx, http_response);
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return(-1);
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}
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}
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static int
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parse_url(char *res_url, struct url* url)
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{
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char *s_ndx, *e_ndx;
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int tlen, tlen_offset, port, is_err;
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/* https is not supported.
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*/
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if(strncasecmp(res_url, "https", 5) == 0)
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{
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log_msg(LOG_VERBOSITY_ERROR, "[*] https is not yet supported for http-resolve-ip.");
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return(-1);
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}
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/* Strip off http:// portion if necessary
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*/
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if(strncasecmp(res_url, "http://", 7) == 0)
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s_ndx = res_url + 7;
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else
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s_ndx = res_url;
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/* Look for a colon in case an alternate port was specified.
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*/
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e_ndx = strchr(s_ndx, ':');
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if(e_ndx != NULL)
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{
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port = strtol_wrapper(e_ndx+1, 1, MAX_PORT, NO_EXIT_UPON_ERR, &is_err);
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if(is_err != FKO_SUCCESS)
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{
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log_msg(LOG_VERBOSITY_ERROR,
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"[*] resolve-url port value is invalid, must be in [%d-%d]",
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1, MAX_PORT);
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return(-1);
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}
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snprintf(url->port, sizeof(url->port)-1, "%u", port);
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/* Get the offset we need to skip the port portion when we
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* extract the hostname part.
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*/
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tlen_offset = strlen(url->port)+1;
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}
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else
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{
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strlcpy(url->port, "80", sizeof(url->port));
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tlen_offset = 0;
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}
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/* Get rid of any trailing slash
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*/
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if(res_url[strlen(res_url)-1] == '/')
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res_url[strlen(res_url)-1] = '\0';
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e_ndx = strchr(s_ndx, '/');
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if(e_ndx == NULL)
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tlen = strlen(s_ndx)+1;
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else
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tlen = (e_ndx-s_ndx)+1;
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tlen -= tlen_offset;
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if(tlen > MAX_URL_HOST_LEN)
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{
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log_msg(LOG_VERBOSITY_ERROR, "resolve-url hostname portion is too large.");
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return(-1);
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}
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strlcpy(url->host, s_ndx, tlen);
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if(e_ndx != NULL)
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{
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if(strlen(e_ndx) > MAX_URL_PATH_LEN)
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{
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log_msg(LOG_VERBOSITY_ERROR, "resolve-url path portion is too large.");
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return(-1);
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}
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strlcpy(url->path, e_ndx, sizeof(url->path));
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}
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else
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{
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/* default to "GET /" if there isn't a more specific URL
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*/
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strlcpy(url->path, "/", sizeof(url->path));
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}
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return(0);
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}
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int
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resolve_ip_http(fko_cli_options_t *options)
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{
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int res;
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struct url url;
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memset(&url, 0, sizeof(url));
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if(options->resolve_url != NULL)
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{
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if(parse_url(options->resolve_url, &url) < 0)
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{
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log_msg(LOG_VERBOSITY_ERROR, "Error parsing resolve-url");
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return(-1);
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}
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res = try_url(&url, options);
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} else {
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strlcpy(url.port, "80", sizeof(url.port));
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strlcpy(url.host, HTTP_RESOLVE_HOST, sizeof(url.host));
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strlcpy(url.path, HTTP_RESOLVE_URL, sizeof(url.path));
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res = try_url(&url, options);
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if(res != 1)
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{
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/* try the backup url (just switches the host to cipherdyne.com)
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*/
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strlcpy(url.host, HTTP_BACKUP_RESOLVE_HOST, sizeof(url.host));
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#ifndef WIN32
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sleep(2);
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#endif
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res = try_url(&url, options);
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}
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}
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return(res);
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}
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/***EOF***/
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