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/*
* Copyright (c) 2010 Aalto University and RWTH Aachen University.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* @file
* @brief Few "utility" functions for the firewall
*
* @todo the actual utility of this file seems questionable (should be removed)
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include "libcore/debug.h"
#include "helpers.h"
/**
* A wrapper for inet_ntop(). Converts a numeric IPv6 address to a string.
*
* @param addrp an IPv6 address to be converted to a string
*
* @return A static pointer to a string containing the the IPv6 address.
* Caller must not try to deallocate. On error, returns NULL and sets
* errno (see man inet_ntop).
*
* @note this function is not re-entrant and should not be used with threads
*
*/
const char *addr_to_numeric(const struct in6_addr *addrp)
{
static char buf[50 + 1];
return inet_ntop(AF_INET6, addrp, buf, sizeof(buf));
}
/**
* A wrapper for inet_pton(). Converts a string to a numeric IPv6 address
*
* @param num the string to be converted into an in6_addr structure
*
* @return A static pointer to an in6_addr structure corresponding to the
* given "num" string. Caller must not try to deallocate.
* On error, returns NULL and sets errno (see man inet_ntop).
*
* @note this function is not re-entrant and should not be used with threads
*/
struct in6_addr *numeric_to_addr(const char *num)
{
static struct in6_addr ap;
int err;
if ((err = inet_pton(AF_INET6, num, &ap)) == 1) {
return ≈
}
return NULL;
}
/**
* Executes a command and prints an error if command wasn't successful.
*
* @param command The command. The caller of this function must take
* care that command does not contain malicious code.
* @return Exit code on success, -1 on failure.
*/
int system_print(const char *const command)
{
int ret;
if ((ret = system(command)) == -1) {
HIP_ERROR("Could not execute command `%s'", command);
return -1;
}
HIP_DEBUG("$ %s -> %d\n", command, WEXITSTATUS(ret));
return WEXITSTATUS(ret);
}
/**
* printf()-like wrapper around system_print.
* Fails and returns an error if the resulting command line
* would be longer than ::MAX_COMMAND_LINE characters.
*
* @param command The command. This is a printf format string.
* The caller of this function must take care that command
* does not contain malicious code.
* @return Exit code on success, -1 on failure.
*/
int system_printf(const char *const command, ...)
{
char bfr[MAX_COMMAND_LINE + 1];
va_list vargs;
va_start(vargs, command);
const int ret = vsnprintf(bfr, sizeof(bfr), command, vargs);
if (ret <= 0) {
HIP_ERROR("vsnprintf failed\n");
va_end(vargs);
return -1;
}
// cast to unsigned value (we know that ret >= 0)
if ((unsigned) ret > MAX_COMMAND_LINE) {
HIP_ERROR("Format '%s' results in unexpectedly large command line "
"(%d characters): not executed.\n", command, ret);
va_end(vargs);
return -1;
}
va_end(vargs);
return system_print(bfr);
}
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