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#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef _POSIX_SOURCE
#include <signal.h>
#endif
#if defined(HAVE_SYSLOG)
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/syslog.h>
#ifndef _PATH_LOG
#define _PATH_LOG "/dev/log"
#endif
#endif
long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
void __guard_setup (void)
{
int fd;
if (__guard[0]!=0) return;
fd = open ("/dev/urandom", 0);
if (fd != -1) {
ssize_t size = read (fd, (char*)&__guard, sizeof(__guard));
close (fd) ;
if (size == sizeof(__guard)) return;
}
/* If a random generator can't be used, the protector switches the guard
to the "terminator canary" */
((char*)__guard)[0] = 0; ((char*)__guard)[1] = 0;
((char*)__guard)[2] = '\n'; ((char*)__guard)[3] = 255;
}
void __stack_smash_handler (char func[], int damaged)
{
#if defined (__GNU_LIBRARY__)
extern char * __progname;
#endif
const char message[] = ": stack smashing attack in function ";
int bufsz = 512, len;
char buf[bufsz];
#if defined(HAVE_SYSLOG)
int LogFile;
struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
#endif
#ifdef _POSIX_SOURCE
{
sigset_t mask;
sigfillset(&mask);
sigdelset(&mask, SIGABRT); /* Block all signal handlers */
sigprocmask(SIG_BLOCK, &mask, NULL); /* except SIGABRT */
}
#endif
strcpy(buf, "<2>"); len=3; /* send LOG_CRIT */
#if defined (__GNU_LIBRARY__)
strncat(buf, __progname, bufsz-len-1); len = strlen(buf);
#endif
if (bufsz>len) {strncat(buf, message, bufsz-len-1); len = strlen(buf);}
if (bufsz>len) {strncat(buf, func, bufsz-len-1); len = strlen(buf);}
/* print error message */
write (STDERR_FILENO, buf+3, len-3);
#if defined(HAVE_SYSLOG)
if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) != -1) {
/*
* Send "found" message to the "/dev/log" path
*/
SyslogAddr.sun_family = AF_UNIX;
(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
sizeof(SyslogAddr.sun_path) - 1);
SyslogAddr.sun_path[sizeof(SyslogAddr.sun_path) - 1] = '\0';
sendto(LogFile, buf, len, 0, (struct sockaddr *)&SyslogAddr,
sizeof(SyslogAddr));
}
#endif
#ifdef _POSIX_SOURCE
{ /* Make sure the default handler is associated with SIGABRT */
struct sigaction sa;
memset(&sa, 0, sizeof(struct sigaction));
sigfillset(&sa.sa_mask); /* Block all signals */
sa.sa_flags = 0;
sa.sa_handler = SIG_DFL;
sigaction(SIGABRT, &sa, NULL);
(void)kill(getpid(), SIGABRT);
}
#endif
_exit(127);
}
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