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/*
*****************************************************************************
*
* File: utils.c
*
* Author: Damien S. Stuart
*
* Purpose: General/Generic functions for the fwknop client.
*
* Copyright 2009-2013 Damien Stuart (dstuart@dstuart.org)
*
* License (GNU Public License):
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
*****************************************************************************
*/
#include "common.h"
#include "fwknop_common.h"
#include "utils.h"
#ifndef WIN32
#include <arpa/inet.h>
#endif
static void *get_in_addr(struct sockaddr *sa);
/**
* Structure to handle a protocol string and its associated integer value
*/
typedef struct fko_protocol
{
const char str[PROTOCOL_BUFSIZE]; /*!< String which represents a protocol value for the FKO library */
int val; /*!< Value of the protocol according to the FKO library */
} fko_protocol_t;
static fko_protocol_t fko_protocol_array[] =
{
{ "udpraw", FKO_PROTO_UDP_RAW },
{ "udp", FKO_PROTO_UDP },
{ "tcpraw", FKO_PROTO_TCP_RAW },
{ "tcp", FKO_PROTO_TCP },
{ "icmp", FKO_PROTO_ICMP },
{ "http", FKO_PROTO_HTTP }
};
/* Generic hex dump function.
*/
void
hex_dump(const unsigned char *data, const int size)
{
int ln, i, j = 0;
char ascii_str[17] = {0};
for(i=0; i<size; i++)
{
if((i % 16) == 0)
{
printf(" %s\n 0x%.4x: ", ascii_str, i);
memset(ascii_str, 0x0, 17);
j = 0;
}
printf("%.2x ", data[i]);
ascii_str[j++] = (data[i] < 0x20 || data[i] > 0x7e) ? '.' : data[i];
if(j == 8)
printf(" ");
}
/* Remainder...
*/
ln = strlen(ascii_str);
if(ln > 0)
{
for(i=0; i < 16-ln; i++)
printf(" ");
printf(" %s\n\n", ascii_str);
}
}
/* Determine if a buffer contains only characters from the base64
* encoding set
*/
int
is_base64(const unsigned char *buf, const unsigned short int len)
{
unsigned short int i;
int rv = 1;
for(i=0; i<len; i++)
{
if(!(isalnum(buf[i]) || buf[i] == '/' || buf[i] == '+' || buf[i] == '='))
{
rv = 0;
break;
}
}
return rv;
}
int
verify_file_perms_ownership(const char *file)
{
int res = 1;
#if HAVE_STAT
struct stat st;
/* Every file that the fwknop client deals with should be owned
* by the user and permissions set to 600 (user read/write)
*/
if((stat(file, &st)) != 0)
{
/* if the path doesn't exist, just return, but otherwise something
* went wrong
*/
if(errno == ENOENT)
{
return 0;
} else {
log_msg(LOG_VERBOSITY_ERROR, "[-] stat() against file: %s returned: %s",
file, strerror(errno));
exit(EXIT_FAILURE);
}
}
/* Make sure it is a regular file or symbolic link
*/
if(S_ISREG(st.st_mode) != 1 && S_ISLNK(st.st_mode) != 1)
{
log_msg(LOG_VERBOSITY_WARNING,
"[-] file: %s is not a regular file or symbolic link.",
file
);
res = 0;
}
if((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != (S_IRUSR|S_IWUSR))
{
log_msg(LOG_VERBOSITY_WARNING,
"[-] file: %s permissions should only be user read/write (0600, -rw-------)",
file
);
res = 0;
}
if(st.st_uid != getuid())
{
log_msg(LOG_VERBOSITY_WARNING,
"[-] file: %s not owned by current effective user id.",
file);
res = 0;
}
#endif
return res;
}
/**
* @brief Grab the sin address from the sockaddr structure.
*
* This function returns the sin address as a sockaddr_in or sockaddr_in6
* structure according to the family set (ipv4 or ipv6) in the sockaddr
* structure.
*
* @param sa sockaddr strcuture
*
* @return the sin addr if the sa family is AF_INET or the sin6_addr otherwise.
*/
static void *
get_in_addr(struct sockaddr *sa)
{
if (sa->sa_family == AF_INET)
{
return &(((struct sockaddr_in*)sa)->sin_addr);
}
else
{
return &(((struct sockaddr_in6*)sa)->sin6_addr);
}
}
/**
* @brief Resolve a domain name as an ip adress.
*
* @param dns_str Name of the host to resolve.
* @param hints Hints to reduce the number of result from getaddrinfo()
* @param ip_str String where to store the resolve ip address
* @param ip_bufsize Number of bytes available in the ip_str buffer
*
* @return 0 if successful, 1 if an error occured.
*/
int
resolve_dest_adr(const char *dns_str, struct addrinfo *hints, char *ip_str, size_t ip_bufsize)
{
int error; /* Function error return code */
struct addrinfo *result; /* Result of getaddrinfo() */
struct addrinfo *rp; /* Element of the linked list returned by getaddrinfo() */
#if WIN32 && WINVER <= 0x0600
struct sockaddr_in *in;
char *win_ip;
#else
struct sockaddr_in *sai_remote; /* Remote host information as a sockaddr_in structure */
#endif
/* Try to resolve the host name */
error = getaddrinfo(dns_str, NULL, hints, &result);
if (error != 0)
fprintf(stderr, "resolve_dest_adr() : %s\n", gai_strerror(error));
else
{
error = 1;
/* Go through the linked list of addrinfo structures */
for (rp = result; rp != NULL; rp = rp->ai_next)
{
memset(ip_str, 0, ip_bufsize);
#if WIN32 && WINVER <= 0x0600
/* On older Windows systems (anything before Vista?),
* we use inet_ntoa for now.
*/
in = (struct sockaddr_in*)(rp->ai_addr);
win_ip = inet_ntoa(in->sin_addr);
if (win_ip != NULL && (strlcpy(ip_str, win_ip, ip_bufsize) > 0))
#else
sai_remote = (struct sockaddr_in *)get_in_addr((struct sockaddr *)(rp->ai_addr));
if (inet_ntop(rp->ai_family, sai_remote, ip_str, ip_bufsize) != NULL)
#endif
{
error = 0;
break;
}
else
log_msg(LOG_VERBOSITY_ERROR, "resolve_dest_adr() : inet_ntop (%d) - %s", errno, strerror(errno));
}
/* Free our result from getaddrinfo() */
freeaddrinfo(result);
}
return error;
}
/**
* @brief Return a protocol string according to a protocol integer value
*
* This function checks if the protocol integer is valid, and write the protocol
* string associated.
*
* @param proto protocol inetger value (UDP_RAW, UDP, TCPRAW...)
* @param proto_str Buffer to write the protocol string
* @param proto_size size of the protocol string buffer
*
* @return -1 if the protocol integer value is not supported, 0 otherwise
*/
short
proto_inttostr(int proto, char *proto_str, size_t proto_size)
{
short proto_error = -1;
unsigned char ndx_proto; /* Index for the fko_protocol_t structure */
/* Initialize the protocol string */
memset(proto_str, 0, proto_size);
/* Look into the fko_protocol_array to find out the right protocol */
for (ndx_proto = 0 ; ndx_proto < ARRAY_SIZE(fko_protocol_array) ; ndx_proto++)
{
/* If the protocol matches, grab it */
if (fko_protocol_array[ndx_proto].val == proto)
{
strlcpy(proto_str, fko_protocol_array[ndx_proto].str, proto_size);
proto_error = 0;
break;
}
}
return proto_error;
}
/**
* @brief Convert a protocol string to its integer value.
*
* @param pr_str Protocol string (UDP_RAW, UDP, TCPRAW...)
*
* @return -1 if the protocol string is not supported, otherwise the protocol value
*/
short
proto_strtoint(const char *pr_str)
{
unsigned char ndx_proto; /* Index for the fko_protocol_t structure */
int proto_int = -1; /* Protocol integer value */
/* Look into the fko_protocol_array to find out the right protocol */
for (ndx_proto = 0 ; ndx_proto < ARRAY_SIZE(fko_protocol_array) ; ndx_proto++)
{
/* If the protocol matches, grab it */
if (strcasecmp(pr_str, fko_protocol_array[ndx_proto].str) == 0)
{
proto_int = fko_protocol_array[ndx_proto].val;
break;
}
}
return proto_int;
}
/***EOF***/
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