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minix/commands/syslogd/syslogd.c
Philip Homburg b4f6994278 Use sprintf to avoid buffer overflows.
2007-04-23 13:04:31 +00:00

933 lines
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/*
** Copyright (c) 1983, 1988
** The Regents of the University of California. All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. All advertising materials mentioning features or use of this software
** must display the following acknowledgement:
** This product includes software developed by the University of
** California, Berkeley and its contributors.
** 4. Neither the name of the University nor the names of its contributors
** may be used to endorse or promote products derived from this software
** without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
**
** #ifndef lint
** char copyright2[] =
** "@(#) Copyright (c) 1983, 1988 Regents of the University of California.\n\
** All rights reserved.\n";
** #endif
**
** #ifndef lint
** static char sccsid[] = "@(#)syslogd.c 5.27 (Berkeley) 10/10/88";
** #endif
**
** -----------------------------------------------------------------------
**
** SYSLOGD -- log system messages
** This program implements a system log.
** It takes a series of lines and outputs them according to the setup
** defined in the configuration file.
** Each line may have a priority, signified as "<n>" as
** the first characters of the line. If this is
** not present, a default priority is used.
**
** To kill syslogd, send a signal 15 (terminate).
** A signal 1 (hup) will cause it to reread its configuration file.
**
** Defined Constants:
** MAXLINE -- the maximimum line length that can be handled.
** MAXSVLINE -- the length of saved messages (for filtering)
** DEFUPRI -- the default priority for user messages
** DEFSPRI -- the default priority for kernel messages
**
** Author: Eric Allman
** extensive changes by Ralph Campbell
** more extensive changes by Eric Allman (again)
** changes by Steve Lord
**
** Extensive rewriting by G. Falzoni <gfalzoni@inwind.it> for porting to Minix
**
** $Log$
** Revision 1.3 2006/04/04 14:22:40 beng
** Fix
**
** Revision 1.2 2006/04/04 14:18:16 beng
** Make syslogd work, even if it can only open klog and not udp or vice versa
** (but not neither)
**
** Revision 1.1 2006/04/03 13:07:42 beng
** Kick out usyslogd in favour of syslogd Giovanni's syslogd port
**
** Revision 1.3 2005/09/16 10:10:12 lsodgf0
** Rework for Minix 3. Adds kernel logs from /dev/klogd
**
** $Id$
*/
#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <time.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/wait.h>
#include <net/netlib.h>
#include <net/hton.h>
#include <net/gen/in.h>
#include <net/gen/udp.h>
#include <net/gen/udp_io.h>
#include <net/gen/netdb.h>
#define SYSLOG_NAMES
#include <syslog.h>
#define KLOGD 1
/** Define following values to your requirements **/
#define MAXLINE 512 /* maximum line length */
#define MAXSVLINE 256 /* maximum saved line length */
#define DEFUPRI (LOG_USER|LOG_NOTICE)
#define DEFSPRI (LOG_KERN|LOG_CRIT)
/* Flags to logmsg() */
#define IGN_CONS 0x001 /* don't print on console */
#define SYNC_FILE 0x002 /* do fsync on file after printing */
#define ADDDATE 0x004 /* add a date to the message */
#define MARK 0x008 /* this message is a mark */
#define CTTY "/dev/log" /* Minix log device (console) */
#define dprintf if(DbgOpt!=0)printf
#if debug == 0
#define DEBUG(statement)
#else
#define DEBUG(statement) statement
#endif
#if !defined PIDFILE
#define PIDFILE "/var/run/syslogd.pid"
#endif
#define UNAMESZ 8 /* length of a login name */
#define MAXUNAMES 20 /* maximum number of user names */
#define MAXFNAME 200 /* max file pathname length */
#define MAXHOSTNAMELEN 64 /* max length of FQDN host name */
/* Intervals at which we flush out "message repeated" messages,
* in seconds after previous message is logged. After each flush,
* we move to the next interval until we reach the largest. */
#define TIMERINTVL 30 /* interval for checking flush, mark */
#define INTERVAL1 30
#define INTERVAL2 60
#define MAXREPEAT ((sizeof(repeatinterval)/sizeof(repeatinterval[0]))-1)
#define REPEATTIME(f) ((f)->f_time+repeatinterval[(f)->f_repeatcount])
#define BACKOFF(f) {if(++(f)->f_repeatcount>MAXREPEAT)(f)->f_repeatcount=MAXREPEAT;}
/* Values for f_type */
#define F_UNUSED 0 /* unused entry */
#define F_FILE 1 /* regular file */
#define F_TTY 2 /* terminal */
#define F_CONSOLE 3 /* console terminal */
#define F_FORW 4 /* remote machine */
#define F_USERS 5 /* list of users */
#define F_WALL 6 /* everyone logged on */
#define max(a,b) ((a)>=(b)?(a):(b))
/* This structure represents the files that will have log copies printed */
struct filed {
struct filed *f_next; /* next in linked list */
short f_type; /* entry type, see below */
short f_file; /* file descriptor */
time_t f_time; /* time this was last written */
char f_pmask[LOG_NFACILITIES + 1]; /* priority mask */
union {
char f_uname[MAXUNAMES][UNAMESZ + 1];
char f_fname[MAXFNAME];
} f_un;
char f_prevline[MAXSVLINE]; /* last message logged */
char f_lasttime[16]; /* time of last occurrence */
char f_prevhost[MAXHOSTNAMELEN + 1]; /* host from which recd. */
int f_prevpri; /* pri of f_prevline */
int f_prevlen; /* length of f_prevline */
int f_prevcount; /* repetition cnt of prevline */
int f_repeatcount; /* number of "repeated" msgs */
int f_flags; /* store some additional flags */
};
static const char *const TypeNames[] =
{
"UNUSED", "FILE", "TTY", "CONSOLE", "FORW", "USERS", "WALL", NULL,
};
static struct filed *Files = NULL;
static struct filed consfile;
static int DbgOpt = 0; /* debug flag */
static char LocalHostName[MAXHOSTNAMELEN + 1]; /* our hostname */
static int Initialized = 0; /* set when we have initialized ourselves */
static int MarkInterval = 20 * 60; /* interval between marks in seconds */
static int MarkSeq = 0; /* mark sequence number */
static time_t now;
static const char *ConfFile = "/etc/syslog.conf";
static const char *PidFile = PIDFILE; /* "/var/run/syslogd.pid" */
static const char ctty[] = CTTY;
static const char ProgName[] = "syslogd:";
static const char version[] = "1.3 (Minix)";
static const char usage[] =
/* */ "usage:\tsyslogd [-d] [-m markinterval] [-f conf-file]\n"
"\t\t[-p listeningport] [-v] [-?]\n" ;
static const int repeatinterval[] =
/* */ {INTERVAL1, INTERVAL2,}; /* # of secs before flush */
/*
** Name: void wallmsg(struct filed *fLog, char *message);
** Function: Write the specified message to either the entire
** world, or a list of approved users.
*/
void wallmsg(struct filed * fLog, char *message)
{
return;
}
/*
** Name: void fprintlog(struct filed *fLog, int flags, char *message);
** Function:
*/
void fprintlog(struct filed * fLog, int flags, char *message)
{
int len;
char line[MAXLINE + 1];
char repbuf[80];
if (message == NULL) {
if (fLog->f_prevcount > 1) {
sprintf(repbuf, "last message repeated %d times", fLog->f_prevcount);
message = repbuf;
} else
message = fLog->f_prevline;
}
snprintf(line, sizeof(line), "%s %s %s",
fLog->f_lasttime, fLog->f_prevhost, message);
DEBUG(dprintf("Logging to %s", TypeNames[fLog->f_type]);)
fLog->f_time = now;
switch (fLog->f_type) {
case F_UNUSED: /* */
DEBUG(dprintf("\n");)
break;
case F_CONSOLE:
if (flags & IGN_CONS) {
case F_FORW: /* */
DEBUG(dprintf(" (ignored)\n");)
break;
} /* else Fall Through */
case F_TTY:
case F_FILE:
DEBUG(dprintf(" %s\n", fLog->f_un.f_fname);)
strcat(line, fLog->f_type != F_FILE ? "\r\n" : "\n");
len = strlen(line);
if (write(fLog->f_file, line, len) != len) {
/* Handle errors */ ;
} else if (flags & SYNC_FILE)
sync();
break;
case F_USERS:
case F_WALL:
DEBUG(dprintf("\n");)
strcat(line, "\r\n");
wallmsg(fLog, line);
break;
}
fLog->f_prevcount = 0;
return;
}
/*
** Name: void logmsg(int pri, char *msg, char *from, int flags);
** Function: Log a message to the appropriate log files, users, etc.
** based on the priority.
*/
void logmsg(int pri, char *msg, char *from, int flags)
{
struct filed *f;
int fac, prilev;
int omask, msglen;
char *timestamp;
DEBUG(dprintf("logmsg: pri %o, flags %x, from %s, msg %s\n", pri, flags, from, msg);)
/*
omask = sigblock(__sigmask(SIGHUP) | __sigmask(SIGALRM));
*/
/* Check to see if msg looks non-standard. */
msglen = strlen(msg);
if (msglen < 16 || msg[3] != ' ' || msg[6] != ' ' ||
msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
flags |= ADDDATE;
time(&now);
if (flags & ADDDATE)
timestamp = ctime(&now) + 4;
else {
timestamp = msg;
msg += 16;
msglen -= 16;
}
/* Extract facility and priority level */
fac = (flags & MARK) ? LOG_NFACILITIES : LOG_FAC(pri);
prilev = LOG_PRI(pri);
/* Log the message to the particular outputs */
if (!Initialized) {
/* Not yet initialized. Every message goes to console */
f = &consfile;
f->f_file = open(ctty, O_WRONLY | O_NOCTTY);
if (f->f_file >= 0) {
if (!DbgOpt) setsid();
fprintlog(f, flags, msg);
close(f->f_file);
}
} else {
for (f = Files; f; f = f->f_next) {
/* Skip messages that are incorrect priority */
if (f->f_pmask[fac] < prilev || f->f_pmask[fac] == INTERNAL_NOPRI)
continue;
if (f->f_type == F_CONSOLE && (flags & IGN_CONS)) continue;
/* Don't output marks to recently written files */
if ((flags & MARK) && (now - f->f_time) < MarkInterval / 2)
continue;
/* Suppress duplicate lines to this file */
if ((flags & MARK) == 0 && msglen == f->f_prevlen &&
!strcmp(msg, f->f_prevline) &&
!strcmp(from, f->f_prevhost)) {
strncpy(f->f_lasttime, timestamp, 15);
f->f_prevcount += 1;
DEBUG(dprintf("msg repeated %d times, %ld sec of %d\n",
f->f_prevcount, now - f->f_time,
repeatinterval[f->f_repeatcount]);)
/* If domark would have logged this by now,
* flush it now (so we don't hold isolated
* messages), but back off so we'll flush
* less often in the future. */
if (now > REPEATTIME(f)) {
fprintlog(f, flags, (char *) NULL);
BACKOFF(f);
}
} else {
/* New line, save it */
if (f->f_prevcount) fprintlog(f, 0, (char *) NULL);
f->f_repeatcount = 0;
strncpy(f->f_lasttime, timestamp, 15);
strncpy(f->f_prevhost, from, sizeof(f->f_prevhost));
if (msglen < MAXSVLINE) {
f->f_prevlen = msglen;
f->f_prevpri = pri;
strcpy(f->f_prevline, msg);
fprintlog(f, flags, (char *) NULL);
} else {
f->f_prevline[0] = 0;
f->f_prevlen = 0;
fprintlog(f, flags, msg);
}
}
}
}
/*
sigsetmask(omask);
*/
return;
}
/*
** Name: void logerror(char *type);
** Function: Prints syslogd errors in some place.
*/
void logerror(char *type)
{
char buf[100];
if (errno == 0) sprintf(buf, "%s %s", ProgName, type);
else if (errno >= _NERROR)
sprintf(buf, "%s %s - error %d", ProgName, type, errno);
else
sprintf(buf, "%s %s - %s", ProgName, type, strerror(errno));
errno = 0;
dprintf("%s\n", buf);
logmsg(LOG_SYSLOG | LOG_ERR, buf, LocalHostName, ADDDATE);
return;
}
/*
** Name: void die(int sig);
** Function: Signal handler for kill signals.
*/
void die(int sig)
{
struct filed *f;
char buf[100];
for (f = Files; f != NULL; f = f->f_next) {
/* Flush any pending output */
if (f->f_prevcount) fprintlog(f, 0, NULL);
}
if (sig >= 0) {
DEBUG(dprintf("%s exiting on signal %d\n", ProgName, sig);)
sprintf(buf, "exiting on signal %d", sig);
errno = 0;
logerror(buf);
}
unlink(PidFile);
exit(sig == (-1) ? EXIT_FAILURE : EXIT_SUCCESS);
}
/*
** Name: void domark(int sig);
** Function: Signal handler for alarm.
** Used for messages filtering and mark facility.
*/
void domark(int sig)
{
struct filed *f;
now = time(NULL);
MarkSeq += TIMERINTVL;
if (MarkSeq >= MarkInterval) {
logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE | MARK);
MarkSeq = 0;
}
for (f = Files; f; f = f->f_next) {
if (f->f_prevcount && now >= REPEATTIME(f)) {
DEBUG(dprintf("flush %s: repeated %d times, %d sec.\n",
TypeNames[f->f_type], f->f_prevcount,
repeatinterval[f->f_repeatcount]);)
fprintlog(f, 0, NULL);
BACKOFF(f);
}
}
signal(SIGALRM, domark);
alarm(TIMERINTVL);
return;
}
/*
** Name: int decode(char *name, struct _code *codetab);
** Function: Decode a symbolic name to a numeric value
*/
int decode(char *name, const struct _code *codetab)
{
const struct _code *c;
char *p;
char buf[40];
DEBUG(dprintf("symbolic name: %s", name);)
if (isdigit(*name)) return (atoi(name));
strcpy(buf, name);
for (p = buf; *p; p += 1) {
if (isupper(*p)) *p = tolower(*p);
}
for (c = codetab; c->c_name; c += 1) {
if (!strcmp(buf, c->c_name)) {
DEBUG(dprintf(" ==> %d\n", c->c_val);)
return (c->c_val);
}
}
return (-1);
}
/*
** Name: void cfline(char *line, struct filed *f);
** Function: Parse a configuration file line
*/
void cfline(char *line, struct filed * fLog)
{
char *p, *q, *bp;
int ix, pri;
char buf[MAXLINE];
char xbuf[200];
DEBUG(dprintf("cfline(%s)\n", line);)
/* Keep sys_errlist stuff out of logerror messages */
errno = 0;
/* Clear out file entry */
memset(fLog, 0, sizeof(*fLog));
for (ix = 0; ix <= LOG_NFACILITIES; ix += 1) /* */
fLog->f_pmask[ix] = INTERNAL_NOPRI;
/* Scan through the list of selectors */
for (p = line; *p && *p != '\t';) {
/* Find the end of this facility name list */
for (q = p; *q && *q != '\t' && *q++ != '.';) continue;
/* Collect priority name */
for (bp = buf; *q && !strchr("\t,;", *q);) *bp++ = *q++;
*bp = '\0';
/* Skip cruft */
while (strchr(", ;", *q)) q++;
/* Decode priority name */
pri = decode(buf, PriNames);
if (pri < 0) {
sprintf(xbuf, "unknown priority name \"%s\"", buf);
logerror(xbuf);
return;
}
/* Scan facilities */
while (*p && !strchr("\t.;", *p)) {
for (bp = buf; *p && !strchr("\t,;.", *p);) *bp++ = *p++;
*bp = '\0';
if (*buf == '*') {
for (ix = 0; ix <= LOG_NFACILITIES; ix += 1)
if ((fLog->f_pmask[ix] < pri) ||
(fLog->f_pmask[ix] == INTERNAL_NOPRI)) {
fLog->f_pmask[ix] = pri;
}
} else {
ix = decode(buf, FacNames);
if (ix < 0) {
sprintf(xbuf, "unknown facility name \"%s\"", buf);
logerror(xbuf);
return;
}
if ((fLog->f_pmask[ix >> 3] < pri) ||
(fLog->f_pmask[ix >> 3] == INTERNAL_NOPRI)) {
fLog->f_pmask[ix >> 3] = pri;
}
}
while (*p == ',' || *p == ' ') p++;
}
p = q;
}
/* Skip to action part */
while (*p == '\t' || *p == ' ') p++;
DEBUG(dprintf("leading char in action: %c\n", *p);)
switch (*p) {
case '@': /* Logging to a remote host */
break; /* NOT IMPLEMENTED */
case '/': /* Logging to a local file/device */
strcpy(fLog->f_un.f_fname, p);
DEBUG(dprintf("filename: %s\n", p); /* ASP */)
if ((fLog->f_file = open(p, O_WRONLY | O_APPEND | O_CREAT | O_NOCTTY, 0644)) < 0) {
fLog->f_file = F_UNUSED;
sprintf(xbuf, "unknown file/device (%s)", p);
logerror(xbuf);
break;
}
if (isatty(fLog->f_file)) {
if (!DbgOpt) setsid();
fLog->f_type = F_TTY;
} else
fLog->f_type = F_FILE;
if (strcmp(p, ctty) == 0) fLog->f_type = F_CONSOLE;
break;
case '*': /* Logging to all users */
DEBUG(dprintf("write-all\n");)
fLog->f_type = F_WALL;
break;
default: /* Logging to selected users */
DEBUG(dprintf("users: %s\n", p); /* ASP */)
for (ix = 0; ix < MAXUNAMES && *p; ix += 1) {
for (q = p; *q && *q != ',';) q += 1;
strncpy(fLog->f_un.f_uname[ix], p, UNAMESZ);
if ((q - p) > UNAMESZ)
fLog->f_un.f_uname[ix][UNAMESZ] = '\0';
else
fLog->f_un.f_uname[ix][q - p] = '\0';
while (*q == ',' || *q == ' ') q++;
p = q;
}
fLog->f_type = F_USERS;
break;
}
}
/*
** Name: void printline(char *hname, char *msg);
** Function: Takes a raw input line, decodes the message and
** prints the message on the appropriate log files.
*/
void printline(char *hname, char *msg)
{
char line[MAXLINE + 1];
char *p = msg, *q = line;
int ch, pri = DEFUPRI;
/* Test for special codes */
if (*p == '<') {
pri = 0;
while (isdigit(*++p)) {
if ((*p - '0') < 8) {
/* Only 3 bits allocated for pri -- ASP */
pri = 10 * pri + (*p - '0');
} else
pri = 10 * pri + 7;
}
if (*p == '>') ++p;
}
if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) pri = DEFUPRI;
/* Does not allow users to log kernel messages */
if (LOG_FAC(pri) == LOG_KERN) pri = LOG_MAKEPRI(LOG_USER, LOG_PRI(pri));
/* Copies message to local buffer, translating control characters */
while ((ch = *p++ & 0177) != '\0' && q < &line[sizeof(line) - 1]) {
if (ch == '\n') /* Removes newlines */
*q++ = ' ';
else if (iscntrl(ch)) { /* Translates control characters */
*q++ = '^';
*q++ = ch ^ 0100;
} else
*q++ = ch;
}
*q = '\0';
logmsg(pri, line, hname, 0);
return;
}
/*
** Name: void printkline(char *hname, char *msg);
** Function: Takes a raw input line from kernel and
** prints the message on the appropriate log files.
*/
void printkline(char *hname, char *msg)
{
char line[MAXLINE + 1];
char *p = msg, *q = line;
int ch, pri = DEFUPRI;
/* Copies message to local buffer, adding source program tag */
snprintf(line, sizeof(line), "kernel: %s", msg);
logmsg(LOG_KERN | LOG_INFO, line, hname, ADDDATE);
return;
}
/*
** Name: void init(int sig);
** Function: Initialize syslogd from configuration file.
** Used at startup or after a SIGHUP signal.
*/
void init(int sig)
{
int i;
FILE *cf;
struct filed *fLog, *next, **nextp;
char *p;
char cline[BUFSIZ];
DEBUG(dprintf("init\n");)
/* Close all open log files. */
Initialized = 0;
for (fLog = Files; fLog != NULL; fLog = next) {
/* Flush any pending output */
if (fLog->f_prevcount) fprintlog(fLog, 0, NULL);
switch (fLog->f_type) {
case F_FILE:
case F_TTY:
case F_CONSOLE: close(fLog->f_file); break;
}
next = fLog->f_next;
free((char *) fLog);
}
Files = NULL;
nextp = &Files;
/* Open the configuration file */
if ((cf = fopen(ConfFile, "r")) != NULL) {
/* Foreach line in the configuration table, open that file. */
fLog = NULL;
while (fgets(cline, sizeof(cline), cf) != NULL) {
/* Check for end-of-section, comments, strip off
* trailing spaces and newline character. */
for (p = cline; isspace(*p); p += 1);
if (*p == '\0' || *p == '#') continue;
for (p = strchr(cline, '\0'); isspace(*--p););
*++p = '\0';
fLog = (struct filed *) calloc(1, sizeof(*fLog));
*nextp = fLog;
nextp = &fLog->f_next;
cfline(cline, fLog);
}
/* Close the configuration file */
fclose(cf);
Initialized = 1;
DEBUG (
if (DbgOpt) {
for (fLog = Files; fLog; fLog = fLog->f_next) {
for (i = 0; i <= LOG_NFACILITIES; i += 1)
if (fLog->f_pmask[i] == INTERNAL_NOPRI)
printf("X ");
else
printf("%d ", fLog->f_pmask[i]);
printf("%s: ", TypeNames[fLog->f_type]);
switch (fLog->f_type) {
case F_FILE:
case F_TTY:
case F_CONSOLE:
printf("%s", fLog->f_un.f_fname);
break;
case F_FORW:
break;
case F_USERS:
for (i = 0; i < MAXUNAMES && *fLog->f_un.f_uname[i]; i += 1)
printf("%s, ", fLog->f_un.f_uname[i]);
break;
}
printf("\n");
}
}
)
logmsg(LOG_SYSLOG | LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE);
signal(SIGHUP, init);
DEBUG(dprintf("%s restarted\n", ProgName);)
} else {
DEBUG(dprintf("cannot open %s\n", ConfFile);)
*nextp = (struct filed *) calloc(1, sizeof(*fLog));
cfline("*.ERR\t" CTTY, *nextp);
(*nextp)->f_next = (struct filed *) calloc(1, sizeof(*fLog));
cfline("*.PANIC\t*", (*nextp)->f_next);
Initialized = 1;
}
return;
}
/*
** Name: void daemonize(char *line);
** Function: Clone itself and becomes a daemon releasing unnecessay resources.
*/
void daemonize(char *line)
{
int lfd, len, pid;
if ((lfd = open(PidFile, O_CREAT | O_RDWR, 0600)) > 0) {
len = read(lfd, line, 10);
line[len] = '\0';
close(lfd);
if ((kill(len = atoi(line), 0) < 0 && errno == ESRCH) || len == 0) {
if (!DbgOpt) {
/* Parent ends and child becomes a daemon */
if ((pid = fork()) > 0) {
/* Write process id. in pid file */
lfd = open(PidFile, O_TRUNC | O_WRONLY);
len = sprintf(line, "%5d", pid);
write(lfd, line, len);
close(lfd);
/* Wait for initialization to complete */
exit(EXIT_SUCCESS);
}
sleep(1);
setsid(); /* Set as session leader */
chdir("/"); /* Change to the root directory */
/* Get rid of all open files */
for (lfd = STDERR_FILENO + 1; lfd < OPEN_MAX; lfd += 1)
close(lfd);
}
} else {
fprintf(stderr, "\n%s already running\n", ProgName);
exit(EXIT_FAILURE);
}
} else {
fprintf(stderr, "\n%s can't open %s (%s)\n", ProgName, PidFile, strerror(errno));
exit(EXIT_FAILURE);
}
return;
}
/*
** Name: int main(int argc, char **argv);
** Function: Syslog daemon entry point
*/
int main(int argc, char **argv)
{
char *p, *udpdev, *eol;
int nfd, kfd, len, fdmax;
int ch, port = 0;
fd_set fdset;
struct nwio_udpopt udpopt;
struct servent *sp;
char line[MAXLINE + 1];
while ((ch = getopt(argc, argv, "df:m:p:v?")) != EOF) {
switch ((char) ch) {
case 'd': /* Debug */
DbgOpt += 1;
break;
case 'f': /* Set configuration file */
ConfFile = optarg;
break;
case 'm': /* Set mark interval */
MarkInterval = atoi(optarg) * 60;
break;
case 'p': /* Set listening port */
port = atoi(optarg);
break;
case 'v': /* Print version */
fprintf(stderr, "%s version %s\n", ProgName, version);
return EXIT_FAILURE;
case '?': /* Help */
default:
fprintf(stderr, usage);
return EXIT_FAILURE;
}
}
if (argc -= optind) {
fprintf(stderr, usage);
return EXIT_FAILURE;
}
daemonize(line);
/* Get the official name of local host. */
gethostname(LocalHostName, sizeof(LocalHostName) - 1);
if ((p = strchr(LocalHostName, '.'))) *p = '\0';
udpdev = (p = getenv("UDP_DEVICE")) ? p : UDP_DEVICE;
sp = getservbyname("syslog", "udp");
signal(SIGTERM, die);
signal(SIGINT, DbgOpt ? die : SIG_IGN);
signal(SIGQUIT, DbgOpt ? die : SIG_IGN);
signal(SIGALRM, domark);
alarm(TIMERINTVL);
/* Open UDP device */
nfd = open(udpdev, O_NONBLOCK | O_RDONLY);
/* Configures the UDP device */
udpopt.nwuo_flags = NWUO_SHARED | NWUO_LP_SET | NWUO_EN_LOC |
NWUO_DI_BROAD | NWUO_RP_SET | NWUO_RA_SET |
NWUO_RWDATONLY | NWUO_DI_IPOPT;
udpopt.nwuo_locport = udpopt.nwuo_remport =
port == 0 ? sp->s_port : htons(port);
udpopt.nwuo_remaddr = udpopt.nwuo_locaddr = htonl(0x7F000001L);
if(nfd >= 0) {
while (ioctl(nfd, NWIOSUDPOPT, &udpopt) < 0 ||
ioctl(nfd, NWIOGUDPOPT, &udpopt) < 0) {
if (errno == EAGAIN) {
sleep(1);
continue;
}
logerror("Set/Get UDP options failed");
return EXIT_FAILURE;
}
}
/* Open kernel log device */
kfd = open("/dev/klog", O_NONBLOCK | O_RDONLY);
if(kfd < 0 && nfd < 0) {
logerror("open /dev/klog and udp device failed - can't log anything");
return EXIT_FAILURE;
}
fdmax = max(nfd, kfd) + 1;
DEBUG(dprintf("off & running....\n");)
init(-1); /* Initilizes log data structures */
for (;;) { /* Main loop */
FD_ZERO(&fdset); /* Setup descriptors for select */
if(nfd >= 0) FD_SET(nfd, &fdset);
if(kfd >= 0) FD_SET(kfd, &fdset);
if (select(fdmax, &fdset, NULL, NULL, NULL) <= 0) {
sleep(1);
continue;
}
if (nfd >= 0 && FD_ISSET(nfd, &fdset)) {
/* Read a message from application programs */
len = read(nfd, line, MAXLINE);
if (len > 0) { /* Got a message */
line[len] = '\0';
dprintf("got a message (%d, %#x)\n", nfd, len);
printline(LocalHostName, line);
} else if (len < 0) { /* Got an error or signal while reading */
if (errno != EINTR) /* */
logerror("Receive error from UDP channel");
} else { /* (len == 0) Channel has been closed */
logerror("UDP channel has closed");
close(nfd);
die(-1);
}
}
if (kfd >= 0 && FD_ISSET(kfd, &fdset)) {
static char linebuf[5*1024];
/* Read a message from kernel (klog) */
len = read(kfd, linebuf, sizeof(linebuf)-2);
dprintf("got a message (%d, %#x)\n", kfd, len);
for (ch = 0; ch < len; ch += 1)
if (linebuf[ch] == '\0') linebuf[ch] = ' ';
if (linebuf[len - 1] == '\n') len -= 1;
linebuf[len] = '\n';
linebuf[len + 1] = '\0';
p = linebuf;
while(eol = strchr(p, '\n')) {
*eol = '\0';
printkline(LocalHostName, p);
p = eol+1;
}
}
}
/* Control never gets here */
}
/** syslogd.c **/
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