DeforaNetworks/fwknop
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Changed http_resolve_host code to make it work with or without trailing whitespace in returned content. Updated the IP address format and value checking code. Switched back to whatsmyip.com as default IP resolver.

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git-svn-id: file:///home/mbr/svn/fwknop/trunk@132 510a4753-2344-4c79-9c09-4d669213fbeb
This commit is contained in:
Damien Stuart
2009-08-11 01:40:47 +00:00
parent 08aa1ef2e8
commit eaa179a6c1
2 changed files with 62 additions and 30 deletions
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6
client/fwknop_common.h
View File

@@ -50,10 +50,10 @@
#define TIME_OFFSET_DAYS 86400
/* For resolving the allow IP via HTTP and sending SPA packets over
* HTTP
* HTTP - http://www.whatismyip.com/automation/n09230945.asp
*/
#define HTTP_RESOLVE_HOST "www.cipherdyne.org"
#define HTTP_RESOLVE_URL "/cgi/myip.cgi"
#define HTTP_RESOLVE_HOST "www.whatismyip.com"
#define HTTP_RESOLVE_URL "/automation/n09230945.asp"
#define HTTP_MAX_REQUEST_LEN 2000
#define HTTP_MAX_RESPONSE_LEN 2000
#define HTTP_MAX_USER_AGENT_LEN 50

86
client/http_resolve_host.c
View File

@@ -27,6 +27,8 @@
#include "fwknop_common.h"
#include "utils.h"
#include <errno.h>
#ifdef WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
@@ -41,9 +43,24 @@ int
resolve_ip_http(fko_cli_options_t *options)
{
int sock, res, error, http_buf_len, i;
int o1, o2, o3, o4;
struct addrinfo *result, *rp, hints;
char http_buf[HTTP_MAX_REQUEST_LEN];
char http_response[HTTP_MAX_RESPONSE_LEN];
char http_response[HTTP_MAX_RESPONSE_LEN] = {0};
char *ndx;
#ifdef WIN32
WSADATA wsa_data;
/* Winsock needs to be initialized...
*/
res = WSAStartup( MAKEWORD(1,1), &wsa_data );
if( res != 0 )
{
fprintf(stderr, "[*] Winsock initialization error %d\n", res );
return(-1);
}
#endif
/* Build our HTTP request to resolve the external IP (this is similar to
* to contacting whatismyip.org, but using a different URL).
@@ -115,36 +132,51 @@ resolve_ip_http(fko_cli_options_t *options)
close(sock);
#endif
/* Now parse the response for the IP address (which should be at
* the end of the string
*/
for (i=res-3; i >= 0; i--)
{
if(http_response[i] == '\n')
break;
if(http_response[i] != '.' && ! isdigit(http_response[i]))
{
fprintf(stderr, "[*] Invalid IP in HTTP response.\n");
return(-1);
}
}
/* Move to the end of the HTTP header and to the start of the content.
*/
ndx = strstr(http_response, "\r\n\r\n");
if(ndx == NULL)
{
fprintf(stderr, "[*] Did not find the end of HTTP header.\n");
return(-1);
}
ndx += 4;
if (i < MIN_IP_STR_LEN)
/* Walk along the content to try to find the end of the IP address.
* Note: We are expecting the content to be just an IP address
* (possibly followed by whitespace or other not-digit value).
*/
for(i=0; i<MAX_IP_STR_LEN; i++) {
if(! isdigit(*(ndx+i)) && *(ndx+i) != '.')
break;
}
/* Terminate at the first non-digit and non-dot.
*/
*(ndx+i) = '\0';
/* Now that we have what we think is an IP address string. We make
* sure the format and values are sane.
*/
if((sscanf(ndx, "%u.%u.%u.%u", &o1, &o2, &o3, &o4)) == 4
&& o1 >= 0 && o1 <= 255
&& o2 >= 0 && o2 <= 255
&& o3 >= 0 && o3 <= 255
&& o4 >= 0 && o4 <= 255)
{
strlcpy(options->allow_ip_str, ndx, MAX_IP_STR_LEN);
if(options->verbose)
printf("[+] Resolved external IP (via http://%s%s) as: %s\n",
HTTP_RESOLVE_HOST, HTTP_RESOLVE_URL, options->allow_ip_str);
return(0);
}
else
{
fprintf(stderr, "[*] Invalid IP in HTTP response.\n");
fprintf(stderr, "[*] Invalid IP (%s) in HTTP response.\n", ndx);
return(-1);
}
http_response[res-1] = '\0';
strlcpy(options->allow_ip_str,
(http_response + i+1), (res - (i+2)));
if(options->verbose)
printf("[+] Resolved external IP (via http://%s%s) as: %s\n",
HTTP_RESOLVE_HOST, HTTP_RESOLVE_URL, options->allow_ip_str);
return(0);
}
/***EOF***/