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Mon Sep 18 15:33:26 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>

Browse Source 
Removed unixm/unix domain sockets and switch to Datagram Unix
    Sockets.  This should remove one possibility to play DoS with
    syslogd.  Thanks to Olaf Kirch <okir@caldera.de> for the patch.
This commit is contained in:
Joey Schulze 2000-09-18 13:41:33 +00:00
parent f5c0fbfb22
commit 728d79d925
2 changed files with 37 additions and 62 deletions
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2
CHANGES
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@ -16,4 +16,6 @@ Version 1.4
addresses converted to symbols, once with the raw text. Allows
external programs such as ksymoops do their own processing on the
original data.
. Olaf Kirch <okir@caldera.de>
- Remove Unix Domain Sockets and switch to Datagram Unix Sockets
. Several bugfixes and improvements, please refer to the .c files

97
syslogd.c
View File

@ -431,6 +431,11 @@ static char sccsid[] = "@(#)syslogd.c 5.27 (Berkeley) 10/10/88";
* Fixed bug in printchopped() that caused syslogd to emit
* kern.emerg messages when splitting long lines. Thanks to
* Daniel Jacobowitz <dan@debian.org> for the fix.
*
* Mon Sep 18 15:33:26 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>
* Removed unixm/unix domain sockets and switch to Datagram Unix
* Sockets. This should remove one possibility to play DoS with
* syslogd. Thanks to Olaf Kirch <okir@caldera.de> for the patch.
*/
@ -787,14 +792,16 @@ int main(argc, argv)
* read(). This is in contrary to readfds which is a list of
* file descriptors where activity is monitored by select()
* and from which one cannot read(). -Joey
*
* Changed: unixm is gone, since we now use datagram unix sockets.
* Hence we recv() from unix sockets directly (rather than
* first accept()ing connections on them), so there's no need
* for separate book-keeping. --okir
*/
fd_set unixm, readfds;
fd_set readfds;
#ifndef TESTING
int fd;
#ifdef SYSLOG_UNIXAF
struct sockaddr_un fromunix;
#endif
#ifdef SYSLOG_INET
struct sockaddr_in frominet;
char *from;
@ -1010,7 +1017,6 @@ int main(argc, argv)
#endif
/* Main loop begins here. */
FD_ZERO(&unixm);
for (;;) {
int nfds;
errno = 0;
@ -1029,12 +1035,6 @@ int main(argc, argv)
if (funix[i]>maxfds) maxfds=funix[i];
}
}
/* Copy accepted connections */
for (nfds= 0; nfds < FD_SETSIZE; ++nfds)
if (FD_ISSET(nfds, &unixm)) {
FD_SET(nfds, &readfds);
if (nfds>maxfds) maxfds=nfds;
}
#endif
#endif
#ifdef SYSLOG_INET
@ -1097,57 +1097,19 @@ int main(argc, argv)
#ifndef TESTING
#ifdef SYSLOG_UNIXAF
if ( debugging_on )
{
dprintf("Checking UNIX connections, active: ");
for (nfds= 0; nfds < maxfds; ++nfds)
if ( FD_ISSET(nfds, &unixm) )
dprintf("%d ", nfds);
dprintf("\n");
}
for (fd= 0; fd <= maxfds; ++fd)
if ( FD_ISSET(fd, &readfds) && FD_ISSET(fd, &unixm) ) {
dprintf("Message from UNIX socket #%d.\n", fd);
for (i = 0; i < nfunix; i++) {
if ((fd = funix[i]) != -1 && FD_ISSET(fd, &readfds)) {
memset(line, '\0', sizeof(line));
i = read(fd, line, MAXLINE);
i = recv(fd, line, MAXLINE - 2, 0);
dprintf("Message from UNIX socket: #%d\n", fd);
if (i > 0) {
printchopped(LocalHostName, line, i, fd);
} else if (i < 0) {
if (errno != EINTR) {
logerror("recvfrom unix");
}
} else {
dprintf("Unix socket (%d) closed.\n", fd);
if ( parts[fd] != (char *) 0 )
{
logerror("Printing partial message");
line[0] = '\0';
printchopped(LocalHostName, line, \
strlen(parts[fd]) + 1, \
fd);
}
/* reset it */
for (i = 1; i < nfunix; i++) {
if (funix[i] == fd)
funix[i] = -1;
}
close(fd);
FD_CLR(fd, &unixm);
}
line[i] = line[i+1] = '\0';
printchopped(LocalHostName, line, i + 2, fd);
} else if (i < 0 && errno != EINTR) {
dprintf("UNIX socket error: %d = %s.\n", \
errno, strerror(errno));
logerror("recvfrom UNIX");
}
/* Accept a new unix connection */
for (i = 0; i < nfunix; i++)
if (funix[i] != -1 && FD_ISSET(funix[i], &readfds)) {
len = sizeof(fromunix);
if ((fd = accept(funix[i], (struct sockaddr *) &fromunix,
&len)) >= 0) {
FD_SET(fd, &unixm);
dprintf("New UNIX connect assigned to fd: " \
"%d.\n", fd);
FD_SET(fd, &readfds);
} else {
dprintf("Error accepting UNIX connection: " \
"%d = %s.\n", errno, strerror(errno));
}
}
#endif
@ -1178,6 +1140,8 @@ int main(argc, argv)
dprintf("INET socket error: %d = %s.\n", \
errno, strerror(errno));
logerror("recvfrom inet");
/* should be harmless now that we set
* BSDCOMPAT on the socket */
sleep(10);
}
}
@ -1225,10 +1189,10 @@ static int create_unix_socket(const char *path)
memset(&sunx, 0, sizeof(sunx));
sunx.sun_family = AF_UNIX;
(void) strncpy(sunx.sun_path, path, sizeof(sunx.sun_path));
fd = socket(AF_UNIX, SOCK_STREAM, 0);
fd = socket(AF_UNIX, SOCK_DGRAM, 0);
if (fd < 0 || bind(fd, (struct sockaddr *) &sunx,
sizeof(sunx.sun_family)+strlen(sunx.sun_path)) < 0 ||
chmod(path, 0666) < 0 || listen(fd, 5) < 0) {
chmod(path, 0666) < 0) {
(void) snprintf(line, sizeof(line), "cannot create %s", path);
logerror(line);
dprintf("cannot create %s (%d).\n", path, errno);
@ -1258,7 +1222,16 @@ static int create_inet_socket()
sin.sin_port = LogPort;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, \
(char *) &on, sizeof(on)) < 0 ) {
logerror("setsockopt, suspending inet");
logerror("setsockopt(REUSEADDR), suspending inet");
close(fd);
return -1;
}
/* We need to enable BSD compatibility. Otherwise an attacker
* could flood our log files by sending us tons of ICMP errors.
*/
if (setsockopt(fd, SOL_SOCKET, SO_BSDCOMPAT, \
(char *) &on, sizeof(on)) < 0) {
logerror("setsockopt(BSDCOMPAT), suspending inet");
close(fd);
return -1;
}