newlib-cygwin/winsup/cygwin/syslog.cc

550 lines
13 KiB
C++

/* syslog.cc
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
2006 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#define __INSIDE_CYGWIN_NET__
#include "winsup.h"
#include <stdlib.h>
#include <stdio.h>
#include <syslog.h>
#include <stdarg.h>
#include <unistd.h>
#include <sys/un.h>
#include <sys/uio.h>
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "thread.h"
#include "cygtls.h"
/* FIXME: These should probably be in the registry. */
/* FIXME: The Win95 path should be whatever slash is */
#define WIN95_EVENT_LOG_PATH "C:\\CYGWIN_SYSLOG.TXT"
#define CYGWIN_LOG_NAME "Cygwin"
/*
* Utility function to help enable moving
* WIN95_EVENT_LOG_PATH into registry later.
*/
static const char *
get_win95_event_log_path ()
{
return WIN95_EVENT_LOG_PATH;
}
/* openlog: save the passed args. Don't open the
system log (NT) or log file (95) yet. */
extern "C" void
openlog (const char *ident, int logopt, int facility)
{
debug_printf ("openlog called with (%s, %d, %d)",
ident ? ident : "<NULL>", logopt, facility);
if (_my_tls.locals.process_ident != NULL)
{
free (_my_tls.locals.process_ident);
_my_tls.locals.process_ident = NULL;
}
if (ident)
{
_my_tls.locals.process_ident = (char *) malloc (strlen (ident) + 1);
if (!_my_tls.locals.process_ident)
{
debug_printf ("failed to allocate memory for _my_tls.locals.process_ident");
return;
}
strcpy (_my_tls.locals.process_ident, ident);
}
_my_tls.locals.process_logopt = logopt;
_my_tls.locals.process_facility = facility;
}
/* setlogmask: set the log priority mask and return previous mask.
If maskpri is zero, just return previous. */
int
setlogmask (int maskpri)
{
if (maskpri == 0)
return _my_tls.locals.process_logmask;
int old_mask = _my_tls.locals.process_logmask;
_my_tls.locals.process_logmask = maskpri;
return old_mask;
}
/* Private class used to handle formatting of syslog message
It is named pass_handler because it does a two-pass handling of log
strings. The first pass counts the length of the string, and the second
one builds the string. */
class pass_handler
{
private:
FILE *fp_;
char *message_;
int total_len_;
void shutdown ();
/* Explicitly disallow copies */
pass_handler (const pass_handler &);
pass_handler & operator = (const pass_handler &);
public:
pass_handler ();
~pass_handler ();
int initialize (int);
int print (const char *,...);
int print_va (const char *, va_list);
char *get_message () const { return message_; }
void set_message (char *s) { message_ = s; *message_ = '\0'; }
};
pass_handler::pass_handler () : fp_ (0), message_ (0), total_len_ (0)
{
;
}
pass_handler::~pass_handler ()
{
shutdown ();
}
void
pass_handler::shutdown ()
{
if (fp_ != NULL)
{
fclose (fp_);
fp_ = 0;
}
}
int
pass_handler::initialize (int pass_number)
{
shutdown ();
if (pass_number)
return total_len_ + 1;
fp_ = fopen ("/dev/null", "wb");
setbuf (fp_, NULL);
if (fp_ == NULL)
{
debug_printf ("failed to open /dev/null");
return -1;
}
total_len_ = 0;
return 0;
}
int
pass_handler::print (const char *fmt, ...)
{
va_list ap;
va_start (ap, fmt);
int ret = print_va (fmt, ap);
va_end (ap);
return ret;
}
int
pass_handler::print_va (const char *fmt, va_list list)
{
if (fp_ != NULL)
{
int len = vfprintf (fp_, fmt, list);
if (len < 0)
return -1;
total_len_ += len;
return 0;
}
else if (message_ != NULL)
{
char *printpos = &message_[strlen (message_)];
vsprintf (printpos, fmt, list);
return 0;
}
debug_printf ("FAILURE ! fp_ and message_ both 0!! ");
return -1;
}
static NO_COPY muto try_connect_guard;
static enum {
not_inited,
inited_failed,
inited_dgram,
inited_stream
} syslogd_inited;
static int syslogd_sock = -1;
extern "C" int cygwin_socket (int, int, int);
extern "C" int cygwin_connect (int, const struct sockaddr *, int);
static void
connect_syslogd ()
{
struct __stat64 st;
int fd;
struct sockaddr_un sun;
if (syslogd_inited != not_inited && syslogd_sock >= 0)
close (syslogd_sock);
syslogd_inited = inited_failed;
syslogd_sock = -1;
if (stat64 (_PATH_LOG, &st) || !S_ISSOCK (st.st_mode))
return;
if ((fd = cygwin_socket (AF_LOCAL, SOCK_DGRAM, 0)) < 0)
return;
sun.sun_family = AF_LOCAL;
strncpy (sun.sun_path, _PATH_LOG, sizeof sun.sun_path);
if (cygwin_connect (fd, (struct sockaddr *) &sun, sizeof sun))
{
if (get_errno () != EPROTOTYPE)
{
close (fd);
return;
}
/* Retry with SOCK_STREAM. */
if ((fd = cygwin_socket (AF_LOCAL, SOCK_STREAM, 0)) < 0)
return;
if (cygwin_connect (fd, (struct sockaddr *) &sun, sizeof sun))
{
close (fd);
return;
}
syslogd_inited = inited_stream;
}
else
syslogd_inited = inited_dgram;
syslogd_sock = fd;
fcntl (syslogd_sock, F_SETFD, FD_CLOEXEC);
return;
}
static int
try_connect_syslogd (int priority, const char *msg, int len)
{
ssize_t ret = -1;
try_connect_guard.init ("try_connect_guard")->acquire ();
if (syslogd_inited == not_inited)
connect_syslogd ();
if (syslogd_sock >= 0)
{
char pribuf[16];
sprintf (pribuf, "<%d>", priority);
struct iovec iv[2] =
{
{ pribuf, strlen (pribuf) },
{ (char *) msg, len }
};
ret = writev (syslogd_sock, iv, 2);
/* If the syslog daemon has been restarted and /dev/log was
a stream socket, the connection is broken. In this case,
try to reopen the socket and try again. */
if (ret < 0 && syslogd_inited == inited_stream)
{
connect_syslogd ();
if (syslogd_sock >= 0)
ret = writev (syslogd_sock, iv, 2);
}
/* If write fails and LOG_CONS is set, return failure to vsyslog so
it falls back to the usual logging method for this OS. */
if (ret >= 0 || !(_my_tls.locals.process_logopt & LOG_CONS))
ret = syslogd_sock;
}
try_connect_guard.release ();
return ret;
}
/*
* syslog: creates the log message and writes to system
* log (NT) or log file (95). FIXME. WinNT log error messages
* don't look pretty, but in order to fix this we have to
* embed resources in the code and tell the NT registry
* where we are, blech (what happens if we move ?).
* We could, however, add the resources in Cygwin and
* always point to that.
*/
extern "C" void
vsyslog (int priority, const char *message, va_list ap)
{
debug_printf ("%x %s", priority, message);
/* If the priority fails the current mask, reject */
if ((LOG_MASK (LOG_PRI (priority)) & _my_tls.locals.process_logmask) == 0)
{
debug_printf ("failing message %x due to priority mask %x",
priority, _my_tls.locals.process_logmask);
return;
}
/* Add default facility if not in the given priority. */
if (!(priority & LOG_FACMASK))
priority |= _my_tls.locals.process_facility;
/* Translate %m in the message to error text */
char *errtext = strerror (get_errno ());
int errlen = strlen (errtext);
int numfound = 0;
for (const char *cp = message; *cp; cp++)
if (*cp == '%' && cp[1] == 'm')
numfound++;
char *newmessage = (char *) alloca (strlen (message) +
(errlen * numfound) + 1);
if (newmessage == NULL)
{
debug_printf ("failed to allocate newmessage");
return;
}
char *dst = newmessage;
for (const char *cp2 = message; *cp2; cp2++)
if (*cp2 == '%' && cp2[1] == 'm')
{
cp2++;
strcpy (dst, errtext);
while (*dst)
dst++;
}
else
*dst++ = *cp2;
*dst = '\0';
message = newmessage;
/* Work out the priority type - we ignore the facility for now.. */
WORD eventType;
switch (LOG_PRI (priority))
{
case LOG_EMERG:
case LOG_ALERT:
case LOG_CRIT:
case LOG_ERR:
eventType = EVENTLOG_ERROR_TYPE;
break;
case LOG_WARNING:
eventType = EVENTLOG_WARNING_TYPE;
break;
case LOG_NOTICE:
case LOG_INFO:
case LOG_DEBUG:
eventType = EVENTLOG_INFORMATION_TYPE;
break;
default:
eventType = EVENTLOG_ERROR_TYPE;
break;
}
/* We need to know how long the buffer needs to be.
The only legal way I can see of doing this is to
do a vfprintf to /dev/null, and count the bytes
output, then do it again to a malloc'ed string. This
is ugly, slow, but prevents core dumps :-).
*/
pass_handler pass;
for (int pass_number = 0; pass_number < 2; ++pass_number)
{
int n = pass.initialize (pass_number);
if (n == -1)
return;
else if (n > 0)
pass.set_message ((char *) alloca (n));
/* Deal with ident_string */
if (_my_tls.locals.process_ident != NULL)
{
if (pass.print ("%s: ", _my_tls.locals.process_ident) == -1)
return;
}
if (_my_tls.locals.process_logopt & LOG_PID)
{
if (pass.print ("PID %u: ", getpid ()) == -1)
return;
}
if (!wincap.has_eventlog ())
{
/* Add a priority string - not needed for systems with
eventlog capability. */
switch (LOG_PRI (priority))
{
case LOG_EMERG:
pass.print ("%s: ", "LOG_EMERG");
break;
case LOG_ALERT:
pass.print ("%s: ", "LOG_ALERT");
break;
case LOG_CRIT:
pass.print ("%s: ", "LOG_CRIT");
break;
case LOG_ERR:
pass.print ("%s: ", "LOG_ERR");
break;
case LOG_WARNING:
pass.print ("%s: ", "LOG_WARNING");
break;
case LOG_NOTICE:
pass.print ("%s: ", "LOG_NOTICE");
break;
case LOG_INFO:
pass.print ("%s: ", "LOG_INFO");
break;
case LOG_DEBUG:
pass.print ("%s: ", "LOG_DEBUG");
break;
default:
pass.print ("%s: ", "LOG_ERR");
break;
}
}
/* Print out the variable part */
if (pass.print_va (message, ap) == -1)
return;
}
const char *msg_strings[1];
char *total_msg = pass.get_message ();
int len = strlen (total_msg);
if (len != 0 && (total_msg[len - 1] == '\n'))
total_msg[--len] = '\0';
msg_strings[0] = total_msg;
if (_my_tls.locals.process_logopt & LOG_PERROR)
{
write (STDERR_FILENO, total_msg, len);
write (STDERR_FILENO, "\n", 1);
}
int fd;
if ((fd = try_connect_syslogd (priority, total_msg, len + 1)) >= 0)
;
else if (wincap.has_eventlog ())
{
/* For NT, open the event log and send the message */
HANDLE hEventSrc = RegisterEventSourceA (NULL, (_my_tls.locals.process_ident != NULL) ?
_my_tls.locals.process_ident : CYGWIN_LOG_NAME);
if (hEventSrc == NULL)
{
debug_printf ("RegisterEventSourceA failed with %E");
return;
}
if (!ReportEventA (hEventSrc, eventType, 0, 0,
cygheap->user.sid (), 1, 0, msg_strings, NULL))
debug_printf ("ReportEventA failed with %E");
DeregisterEventSource (hEventSrc);
}
else
{
/* Under Windows 95, append the message to the log file */
char timestamp[24];
time_t ctime;
FILE *fp = fopen (get_win95_event_log_path (), "a");
if (fp == NULL)
{
debug_printf ("failed to open file %s",
get_win95_event_log_path ());
return;
}
strftime (timestamp, sizeof timestamp, "%Y-%m-%d %H:%M:%S : ",
localtime (&(ctime = time (NULL))));
/* Now to prevent several syslog messages from being
interleaved, we must lock the first byte of the file
This works on Win32 even if we created the file above.
*/
HANDLE fHandle = cygheap->fdtab[fileno (fp)]->get_handle ();
for (int i = 0;; i++)
if (LockFile (fHandle, 0, 0, 1, 0) == FALSE)
if (i == 3)
{
debug_printf ("failed to lock file %s", get_win95_event_log_path ());
fclose (fp);
return;
}
else
usleep (1000);
else
break;
fputs (timestamp, fp);
fputs (msg_strings[0], fp);
fputc ('\n', fp);
fclose (fp);
}
}
extern "C" void
syslog (int priority, const char *message, ...)
{
va_list ap;
va_start (ap, message);
vsyslog (priority, message, ap);
va_end (ap);
}
static NO_COPY muto klog_guard;
fhandler_mailslot *dev_kmsg;
extern "C" void
vklog (int priority, const char *message, va_list ap)
{
/* TODO: kernel messages are under our control entirely and they should
be quick. No playing with /dev/null, but a fixed upper size for now. */
char buf[2060]; /* 2048 + a prority */
if (!(priority & ~LOG_PRIMASK))
priority = LOG_KERN | LOG_PRI (priority);
__small_sprintf (buf, "<%d>", priority);
__small_vsprintf (buf + strlen (buf), message, ap);
klog_guard.init ("klog_guard")->acquire ();
if (!dev_kmsg)
dev_kmsg = (fhandler_mailslot *) build_fh_name ("/dev/kmsg");
if (dev_kmsg && !dev_kmsg->get_handle ())
dev_kmsg->open (O_WRONLY, 0);
if (dev_kmsg && dev_kmsg->get_handle ())
dev_kmsg->write (buf, strlen (buf) + 1);
klog_guard.release ();
}
extern "C" void
klog (int priority, const char *message, ...)
{
va_list ap;
va_start (ap, message);
vklog (priority, message, ap);
va_end (ap);
}
extern "C" void
closelog (void)
{
try_connect_guard.init ("try_connect_guard")->acquire ();
if (syslogd_inited != not_inited && syslogd_sock >= 0)
{
close (syslogd_sock);
syslogd_sock = -1;
syslogd_inited = not_inited;
}
try_connect_guard.release ();
}