gno/usr.sbin/syslogd/syslogd2.c

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/*
* This implementation of syslogd was written by Devin Reade for GNO v2.0.6.
* It was written because Phil Vandry's original version of syslogd didn't
* have sufficient bits for the facility/priority values, and at the time
* his sources weren't available for modification.
*
* $Id: syslogd2.c,v 1.1 1998/10/31 19:02:47 gdr-ftp Exp $
*/
/*
* To Do:
* - get all our configuration from the syslog.conf file, and use that
* information in logMessage()
* - background ourselves
* - eliminate the command line args, except for "-f conf_file"
* - internal error messages should go through a logInternal
* routine so that they can potentially go to a file as well
* as (instead of?) the console
* - the main loop should be rewritten so that it immediately copies
* the data and releases the caller rather than waiting until it
* has parsed the buffer.
* - eliminate various pieces of dead code, clean up comments
* - ensure all routines are properly documented
* - should writeConsole be exported to libc?
* - in order to do 'mark' entries, we could set up a signal handler
* for SIGALRM. We'll either need a semaphore or a signal mask
* set up so that we can't get interrupted by SIGHUP or SIGTERM
* while we're in the SIGALRM handler.
* - should logInternal be using the internal "none" priority?
*/
/*
* How many processes can send to us before they block? We don't need many
* since syslog(3), vsyslog(3), syslogmt(3), and vsyslogmt(3) won't return
* until we handle the request, anyway.
*
* Since sendPort() in the syslog(3) implementation is currently doing a
* busy wait while waiting for syslogd to release it's buffer, we set NPORTS
* to 1 so that any additional senders get blocked by the kernel instead of
* using up clock cycles.
*/
#define NPORTS 1
/*
* Define DEBUG to get syslogd to exit after a NLOOPS loops. Why do we
* need this? Because there is a bug in the v2.0.6 kernel which kills our
* shell if we send a SIGTERM to a child process. Blech. Limiting the
* number of loops lets us proceed with debugging without always having to
* log in again. See PR#53 in the GNO bug report system.
*
#if 0
#define DEBUG
#define NLOOPS 5
#endif
/* We need this for internal structs in <sys/syslog.h> */
#define __SYSLOG_INTERNALS
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/ports.h>
#include <sys/syslog.h>
#include <time.h>
#include <errno.h>
#include <gno/gno.h>
#include <signal.h>
#include <paths.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <fcntl.h>
#ifdef __STACK_CHECK__
#include <err.h>
#endif
#include <assert.h>
#ifndef EOF
#define EOF (-1)
#endif
#define MIN(a,b) ((a) < (b) ? (a) :(b))
#if 0
static void die (const char *message);
#endif
static int logMessage (long facpri, char *msg, int len);
static void logInternal (const char *message, ...);
static int writeConsole (const char *buf, size_t size);
#if 0
static void handle_HUP (int sig, int code);
#endif
static void handle_TERM (int sig, int code);
int Port = -1;
char MessageBuffer[_SYSLOG_BUFFERLEN];
int MessageBufferLen = 0; /* number of used chars in MessageBuffer */
int bytesToCopy;
long FacPri; /* facility/priorty */
time_t Now;
char * LogFile = NULL; /* temporary kludge */
int LogConsole = 0; /* temporary kludge */
int
main(int argc, char **argv) {
int fd, ch;
SyslogDataBuffer_t *dataptr;
char *p, *q;
#ifdef DEBUG
int loopcount = 0;
#endif
#ifdef __STACK_CHECK__
/*
* Don't use the __REPORT_STACK() macro here; we don't want
* to have to call atexit() since we may be in a signal handler
* when we have to die.
*/
_beginStackCheck();
#endif
while ((ch = getopt(argc, argv, "cF:")) != EOF) {
switch(ch) {
case 'c':
LogConsole = 1;
break;
case 'F':
LogFile = optarg;
break;
default:
logInternal("usage: syslogd [-c] [-F logfile]");
exit(1);
}
}
#if 0
{
char *myname;
myname = __prognameGS();
writeConsole(argv[0], strlen(argv[0]));
writeConsole(myname, strlen(myname));
}
#endif
#if 0
signal(SIGHUP, handle_HUP);
#endif
signal(SIGTERM, handle_TERM);
/* detach from controlling terminal */
if ((fd = open(_PATH_TTY, O_RDWR)) < 0) {
logInternal("couldn't open controlling terminal: %s",
strerror(errno));
exit(1);
}
#if 0
if (tcnewpgrp(fd) < 0) {
logInternal("tcnewpgrp failed: %s", strerror(errno));
exit(1);
}
#endif
if (ioctl(fd, TIOCNOTTY, 0) < 0) {
logInternal("ioctl failed: %s", strerror(errno));
exit(1);
}
close(fd);
/* create and bind a port on which programs can contact us */
if ((Port = pcreate(NPORTS)) == -1) {
/*
* Does this actually ever happen? The ports(2) man page
* does not document an error condition for pcreate(2).
*/
logInternal("couldn't create port: %s", strerror(errno));
exit(1);
}
if (pbind (Port, __SYSLOG_PORT_NAME) == -1) {
logInternal("couldn't bind port: %s", strerror(errno));
exit(1);
}
/* now loop forever waiting for messages */
for (;;) {
#ifdef DEBUG
loopcount++;
if (loopcount > NLOOPS) {
# ifdef __STACK_CHECK__
logInternal("%d bytes used", _endStackCheck());
# endif
logInternal("Done debugging loops. Exiting.");
exit(0);
}
#endif
/* block until a message comes in */
dataptr = (SyslogDataBuffer_t *) preceive(Port);
/* verify that this isn't a garbage pointer */
if (dataptr->sdb_magic != _SYSLOG_MAGIC) {
logInternal("Bad magic number 0x%X; message "
"discarded. Caller may hang.",
dataptr->sdb_magic);
continue;
}
/*
* Do the library and daemon agree on the format of the
* SyslogDataBuffer_t structure?
*/
if (dataptr->sdb_version != _SYSLOG_STRUCT_VERSION) {
logInternal("Message version mismatch. Expected %d "
"got %d. Message discarded. Caller may hang.",
_SYSLOG_STRUCT_VERSION,
dataptr->sdb_version);
continue;
}
/*
* Do we have a facility/priority prefix? It's of the
* form "<nnnnn>rest_of_message", where the angle brackets
* are literals. Set FacPri to this value if present,
* otherwise set it to the default value, user.notice.
*
* This should be changed so that we immediately copy the
* buffer and any other required info, then release the caller.
*/
p = dataptr->sdb_buffer;
bytesToCopy = dataptr->sdb_msglen;
if (*p == '<') {
p++;
FacPri = strtol(p, &q, 10);
if (p == q) {
FacPri = LOG_MAKEPRI(LOG_USER, LOG_NOTICE);
--p;
} else if (*q == '>') {
p = q + 1;
} else {
p = q;
}
bytesToCopy -= (p - dataptr->sdb_buffer);
} else {
FacPri = LOG_MAKEPRI(LOG_USER, LOG_NOTICE);
}
/*
* At this point, p points the point in the caller's buffer
* where we should start copying bytes. bytesToCopy
* contains the number of bytes in the callers buffer that
* we should copy.
*
* If the 'needtime' flag is set, we now copy a time stamp
* into our own buffer (the user's buffer is untouched).
*/
if (dataptr->sdb_needtime) {
time(&Now);
q = ctime(&Now) + 4;
q[16] = '\0';
strcpy(MessageBuffer, q);
q = MessageBuffer + 16;
MessageBufferLen = 16;
} else {
q = MessageBuffer;
*q = '\0';
MessageBufferLen = 0;
}
/*
* Now we can also say that q points to the point in
* MessageBuffer to where we should start copying characters.
* MessageBufferLen is the number of characters we've used
* in MessageBuffer.
*
* Copy the message to our buffer, minus any prefix, and
* append a newline. Make sure MessageBuffer is NULL-
* terminated.
*/
if (bytesToCopy > _SYSLOG_BUFFERLEN-2) {
bytesToCopy = _SYSLOG_BUFFERLEN-2;
}
MessageBufferLen += bytesToCopy;
if (bytesToCopy == 0) {
q[0] = '\r';
q[1] = '\0';
MessageBufferLen++;
} else {
memcpy(q, p, bytesToCopy);
if (q[bytesToCopy-1] != '\r') {
q[bytesToCopy++] = '\r';
MessageBufferLen++;
}
q[bytesToCopy] = '\0';
}
/*
* We have our own version of the message now, so we can
* release the caller's data buffer and then proceed to print
* our own copy.
*
* See the comments in the syslog(3) code as to why we do
* it with a busy-wait.
*/
dataptr->sdb_busywait = 0;
/* print the message */
logMessage(FacPri, MessageBuffer, MessageBufferLen);
}
/*NOTREACHED*/
return 0;
}
/*
* Print the message <msg> of length <len> to the relevent files based on
* the facility/priority value <facpri>.
*
* This routine is still a kludge. We need information parsed from the
* /etc/syslog.conf file to be referenced here.
*
* The following globals must already be set:
* LogConsole (temporary kludge)
* LogFile (temporary kludge)
*/
static int
logMessage (long facpri, const char *msg, int len) {
int result = 0;
if (LogConsole) {
if (writeConsole(msg, len) != 0) {
result = 1;
}
}
if (LogFile != NULL) {
int logfd;
if ((logfd = open(LogFile, O_RDWR | O_APPEND)) > -1) {
/*
* Don't throw an error if it fails; the file may
* not exist.
*
* Always having to open/write/close the file is
* a pain in the ass, but on the GS we need to do
* this to ensure that the file remains readable
* to other processes.
*/
if (write(logfd, msg, len) < 0) {
result = 1;
}
close(logfd);
}
}
return result;
}
/*
* Choke and puke.
* If <message> is not the empty string, print it out to console, first,
* prefixed by "syslogd: ".
*
* Careful what you call here; we may be inside a signal handler.
*/
#if 0
static void
die (const char *message)
{
#define BUFFER_LEN 80
#define HEADER "syslogd: "
static char buffer[BUFFER_LEN];
if ((message != NULL) && (*message != '\0')) {
sprintmt(buffer, BUFFER_LEN, "syslogd: %s\r", message);
writeConsole(buffer, strlen(buffer));
}
kill(getpid(), SIGKILL);
}
#endif
#pragma databank 1
#define MSG_QUIT "received a quit signal\r"
#if 0
static void
handle_HUP (int sig, int code) {
#define MSG_HUP "received a SIGHUP\r"
/* we should re-read the config file here */
writeConsole(MSG_HUP, sizeof(MSG_HUP)-1);
}
#endif
static void
handle_TERM (int sig, int code) {
#if 1
if (Port != -1) {
pdelete(Port, NULL);
}
kill(getpid(), SIGKILL);
#else
if (pdelete(Port, NULL) != 0) {
die("failed to delete port on exit");
}
die(""); /* don't print a message */
#endif
}
#pragma databank 0
static int
writeConsole (const char *buf, size_t size) {
#if 1
int fd;
if ((fd = open(_PATH_CONSOLE, O_WRONLY)) < 0) {
return -1;
}
/* we should probably loop to ensure that the write completes */
write(fd, buf, size);
close(fd);
return 0;
#else
#endif
}
#pragma optimize 78
#pragma debug 0
static void
logInternal (const char *message, ...) {
#define BUFFER_SIZE 256
static char buffer[BUFFER_SIZE];
time_t now;
va_list ap;
char *p;
va_start(ap, message);
/*
* Put our prefix at the front of the message.
*/
time(&now);
p = ctime(&now) + 4;
p[16] = '\0';
p = sprintmt(buffer, BUFFER_SIZE, "%s syslogd[%d]: ", p, getpid());
p = vsprintmt(p, p - buffer, message, ap);
logMessage(LOG_MAKEPRI(LOG_DAEMON, LOG_CRIT), buffer, p - buffer);
#if 0
if ((p - buffer) < BUFFER_SIZE) {
*p++ = '\r';
*p = '\0';
} else {
*(p-1) = '\r';
}
writeConsole(buffer, p-buffer);
#endif
va_end(ap);
}