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BSD 4_1c_2 release
[unix-history] / usr / src / usr.lib / sendmail / aux / syslog.c
/*
** SYSLOG -- log system messages
**
** This program implements a system log, implemented as the
** "/dev/log" mpx file on a pre-4.2bsd system or a port on
** a post-4.2bsd system. This takes a series of lines.
** Each line may have a priority, signified as "<n>" as
** the first three characters of the line. If this is
** not present, a default priority (DefPri) is used, which
** starts out as LOG_ERROR. The default priority can get
** changed using "<*>n".
**
** Timestamps are added if they are not already present.
**
** To kill syslog, send a signal 15 (terminate). In 30
** seconds, syslog will go down. A signal 1 (hup) will
** cause it to reread its configuration file.
**
** Defined Constants:
** MAXLINE -- the maximimum line length that can be
** handled.
** NLOGS -- the maximum number of simultaneous log
** files.
** NUSERS -- the maximum number of people that can
** be designated as "superusers" on your system.
**
** Author:
** Eric Allman, UCB/INGRES and Britton-Lee.
*/
# define NLOGS 10 /* max number of log files */
# define NSUSERS 10 /* max number of special users */
# define MAXLINE 256 /* maximum line length */
# define LOGHOSTNAME 1 /* log hostid on each line */
# include <syslog.h>
# include <errno.h>
# include <stdio.h>
# include <utmp.h>
# include <sys/param.h>
# include <sys/stat.h>
# include <signal.h>
# include <sysexits.h>
# ifdef LOG_IPC
# include <sys/socket.h>
#ifndef LOG_OLDIPC
# include <netinet/in.h>
# include <netdb.h>
#else LOG_OLDIPC
# include <net/in.h>
#endif LOG_OLDIPC
# else LOG_IPC
# include <sys/mx.h>
# endif LOG_IPC
typedef char bool;
# define TRUE 1
# define FALSE 0
# ifdef EBUG
# define dprintf if (Debug) printf
# else
# define dprintf if (0) printf
# endif
static char SccsId[] = "@(#)syslog.c 2.22 12/16/82";
# define UNAMESZ 8 /* length of a login name */
/*
** This structure represents the files that will have log
** copies printed.
*/
struct filed
{
char f_pmask; /* priority mask */
bool f_mark; /* if set, output timing marks */
bool f_tty; /* if set, this is a tty */
FILE *f_file; /* file descriptor; NULL means unallocated */
long f_time; /* the last time anything was output to it */
char f_name[30]; /* filename */
};
struct filed Files[NLOGS];
/* list of superusers */
char Susers[NSUSERS][UNAMESZ+1];
int ShutDown; /* set if going down */
int DefPri = LOG_ERROR; /* the default priority for untagged msgs */
int Debug; /* debug flag */
int LogFile; /* log mx file descriptor */
int MarkIntvl = 15; /* mark interval in minutes */
char *ConfFile; /* configuration file */
# ifdef LOG_IPC
#ifndef LOG_OLDIPC
struct sockaddr_in SyslogAddr;
#else LOG_OLDIPC
struct sockaddr_in SyslogAddr = { AF_INET, LOG_PORT };
struct sockproto SyslogProto = { PF_INET, IPPROTO_UDP };
#endif LOG_OLDIPC
# endif LOG_IPC
main(argc, argv)
int argc;
char **argv;
{
register int i;
register char *p;
extern shutdown();
extern int domark();
extern int errno;
int errct = 0;
FILE *fp;
char *logname = "/dev/log";
#ifndef LOG_OLDIPC
#ifdef LOG_IPC
auto int lenSyslogAddr;
struct servent *sp;
#endif LOG_IPC
#endif LOG_OLDIPC
static char *defconf = "/etc/syslog.conf";
static char *defpid = "/etc/syslog.pid";
char line[300];
#ifndef LOG_OLDIPC
#ifdef LOG_IPC
/* set up initial port assignment */
sp = getservbyname("syslog", "udp");
if (sp == NULL)
{
perror("Cannot get server");
exit(EX_OSFILE);
}
SyslogAddr.sin_family = AF_INET;
SyslogAddr.sin_port = sp->s_port;
SyslogAddr.sin_addr.s_addr = INADDR_ANY;
#endif LOG_IPC
#endif LOG_OLDIPC
while (--argc > 0)
{
p = *++argv;
if (p[0] == '-')
{
switch (p[1])
{
case 'm': /* set mark interval */
MarkIntvl = atoi(&p[2]);
if (MarkIntvl <= 0)
MarkIntvl = 1;
break;
case 'f': /* configuration file */
if (p[2] != '\0')
ConfFile = &p[2];
else
ConfFile = defconf;
break;
case 'd': /* debug */
Debug++;
if (ConfFile == NULL)
ConfFile = "./syslog.conf";
break;
# ifdef LOG_IPC
case 'p': /* port */
SyslogAddr.sin_port = htons(atoi(&p[2]));
break;
# endif LOG_IPC
}
}
}
if (ConfFile == NULL)
ConfFile = defconf;
/* try to ignore all signals */
if (!Debug)
{
for (i = 1; i < NSIG; i++)
signal(i, SIG_IGN);
}
else
signal(SIGINT, shutdown);
signal(SIGTERM, shutdown);
signal(SIGALRM, domark);
alarm(MarkIntvl*60);
/* close all files */
if (!Debug)
for (i = 0; i < NOFILE; i++)
close(i);
# ifdef LOG_IPC
logname = "IPC socket";
#ifndef LOG_OLDIPC
LogFile = socket(AF_INET, SOCK_DGRAM, 0, 0);
if (LogFile >= 0 && bind(LogFile, &SyslogAddr, sizeof SyslogAddr, 0) < 0)
{
close(LogFile);
LogFile = -1;
}
#else LOG_OLDIPC
LogFile = socket(SOCK_DGRAM, &SyslogProto, &SyslogAddr, 0);
#endif LOG_OLDIPC
# else LOG_IPC
/* create the "/dev/log" device */
if (Debug)
logname = "log";
unlink(logname);
LogFile = mpx(logname, 0222);
chmod(logname, 0222);
# endif LOG_IPC
if (LogFile < 0)
{
fp = fopen("/dev/console", "w");
fprintf(fp, "\r\nsyslog: cannot create %s (%d)\r\n", logname, errno);
dprintf("cannot create %s (%d)\n", logname, errno);
exit(EX_OSFILE);
}
/* now we can run as daemon safely */
setuid(1);
dprintf("off & running....\n");
if (!Debug)
{
if (fork() == 0)
{
/* tuck my process id away */
fp = fopen(defpid, "w");
if (fp != NULL)
{
fprintf(fp, "%d\n", getpid());
fclose(fp);
}
}
else
exit(0);
}
init();
for (;;)
{
# ifdef LOG_IPC
#ifndef LOG_OLDIPC
lenSyslogAddr = sizeof SyslogAddr;
i = recvfrom(LogFile, line, sizeof line, 0, &SyslogAddr, &lenSyslogAddr);
#else LOG_OLDIPC
i = receive(LogFile, &SyslogAddr, line, sizeof line);
#endif LOG_OLDIPC
# else LOG_IPC
i = read(LogFile, line, sizeof line);
# endif LOG_IPC
if (i < 0)
{
if (errno == EINTR)
continue;
logerror("read");
errct++;
if (errct > 1000)
{
logmsg(LOG_SALERT, "syslog: too many errors");
die();
}
sleep(15);
continue;
}
# ifdef LOG_IPC
line[i] = '\0';
printline(line, raddr(SyslogAddr.sin_addr.s_addr));
# else LOG_IPC
crack(line, i);
# endif LOG_IPC
}
}
\f/*
** LOGERROR -- log an error on the log.
**
** Parameters:
** type -- string to print as error type.
**
** Returns:
** none.
**
** Side Effects:
** outputs the error code in errno to someplace.
*/
logerror(type)
char *type;
{
char buf[50];
extern int errno;
sprintf(buf, "log %s error %d\n", type, errno);
errno = 0;
logmsg(LOG_SALERT, buf);
}
\f
# ifndef LOG_IPC
/*
** CRACK -- parse & handle a log line
**
** Parameters:
** rec -- the input record.
** bc -- the byte count for rec.
**
** Returns:
** nothing
**
** Side Effects:
** rec is output.
*/
# define skip(rec, n) ((struct rh *) (((char *) rec) + n))
crack(rec, bc)
register struct rh *rec;
int bc;
{
struct rh *endrec;
endrec = skip(rec, bc);
while (rec < endrec)
{
if (rec->count == 0)
{
/* control record from mpx file */
dprintf("%d byte control message\n", rec->ccount);
control(rec);
}
else
{
/* data record -- process message */
messg(rec);
}
rec->count += rec->ccount;
if (rec->count & 01)
rec->count++;
rec = skip(rec, rec->count + sizeof *rec);
}
}
\f/*
** CONTROL -- handle mpx control messages.
**
** Parameters:
** rec -- control message.
**
** Returns:
** none.
**
** Side Effects:
** as necessary for that control message.
*/
short NoIoctl[] = { M_IOANS };
control(rec)
register struct rh *rec;
{
register int cmd;
register short val;
register short *ap;
# ifdef MPXDEBUG
char dbbuf[100];
# endif MPXDEBUG
ap = (short *) (((char *) rec) + sizeof *rec);
cmd = *ap++ & 0377;
val = *ap++;
# ifdef MPXDEBUG
sprintf(dbbuf, "syslog: ctl ch=%x cmd=%d val=%d", rec->index, cmd, val);
logmsg(LOG_DEBUG, dbbuf);
# endif MPXDEBUG
switch (cmd)
{
case M_WATCH: /* attempted connect; value is uid */
dprintf("WATCH, uid=%d\n", val);
attach(rec->index, LogFile);
break;
case M_CLOSE: /* close channel; value is unused */
dprintf("CLOSE, val=%d\n", val);
detach(rec->index, LogFile);
break;
case M_IOCTL:
dprintf("IOCTL, val=%d\n", val);
wmpxctl(rec->index, NoIoctl, sizeof NoIoctl);
break;
default:
dprintf("unknown cmd %d, val=%d\n", cmd, val);
break;
}
}
\f/*
** WMPXCTL -- write mpx control message
**
** Parameters:
** index -- index to write to.
** buf -- place to write.
** len -- length to write.
**
** Returns:
** none.
**
** Side Effects:
** writes to LogFile.
*/
wmpxctl(index, buf, cnt)
int index;
char *buf;
int cnt;
{
struct wh wbuf;
wbuf.index = index;
wbuf.count = 0;
wbuf.ccount = cnt;
wbuf.data = buf;
write(LogFile, &wbuf, sizeof wbuf);
}
\f/*
** MESSG -- log message
**
** Parameters:
** rec -- record of data.
**
** Returns:
** nothing.
**
** Side Effects:
** sends the record to the system log.
*/
messg(rec)
register struct rh *rec;
{
char endchar;
char *endptr;
register char *q;
q = (char *) rec + sizeof *rec;
endptr = &q[rec->count];
endchar = *endptr;
*endptr = '\0';
printline(q, NULL);
*endptr = endchar;
}
# endif LOG_IPC
\f/*
** PRINTLINE -- print one line
**
** This is really it -- we have one line -- we crack it and
** and print it appropriately.
**
** Parameters:
** q -- pointer to the line.
** tag -- the name of the host this is from.
**
** Returns:
** none.
**
** Side Effects:
** q is broken up and printed.
*/
printline(q, tag)
register char *q;
{
register int i;
static int pri;
register char *p;
static char buf[1000];
static char *bp = buf;
dprintf("message = ``%s''\n", q);
while (*q != '\0')
{
if (bp == buf)
{
# if LOGHOSTNAME > 0
if (tag != NULL)
{
strcpy(bp, tag);
strcat(bp, ": ");
bp += strlen(bp);
}
# endif LOGHOSTNAME
/* test for special codes */
pri = DefPri;
if (q[0] == '<' && q[2] == '>')
{
switch (q[1])
{
case '*': /* reset default message priority */
dprintf("default priority = %c\n", q[3]);
i = q[3] - '0';
if (i > 0 && i <= 9)
DefPri = i;
continue;
case '$': /* reconfigure */
dprintf("reconfigure\n");
init();
continue;
}
q++;
pri = *q++ - '0';
q++;
if (pri < 0 || pri > 9)
pri = DefPri;
}
else
pri = DefPri;
}
while (*q != '\0' && *q != '\n')
{
if (*q != '\r')
*bp++ = *q;
q++;
}
if (*q == '\0')
continue;
*bp++ = '\0';
q++;
bp = buf;
/* output the line to all files */
logmsg(pri, bp);
bp = buf;
}
}
\f/*
** SHUTDOWN -- shutdown the logger
**
** This should only be done when the system is going down.
**
** Parameters:
** none
**
** Returns:
** none
**
** Side Effects:
** Starts up an alarm clock, to let other things
** happen. Alarm clock will call "die".
**
** Called By:
** main
** signal 15 (terminate)
*/
shutdown()
{
extern die();
logmsg(LOG_CRIT, "syslog: shutdown within 30 seconds\n");
ShutDown++;
signal(SIGALRM, die);
alarm(30);
signal(SIGTERM, die);
if (Debug)
signal(SIGINT, die);
}
\f/*
** DIE -- really die.
**
** Parameters:
** none
**
** Returns:
** never
**
** Side Effects:
** Syslog dies.
**
** Requires:
** exit (sys)
**
** Called By:
** alarm clock (signal 14)
*/
die()
{
alarm(0);
logmsg(LOG_CRIT, "syslog: down\n");
sleep(2); /* wait for output to drain */
# ifndef LOG_IPC
if (!Debug)
unlink("/dev/log");
# endif LOG_IPC
sync();
exit(0);
}
\f/*
** STAMPED -- tell if line is already time stamped.
**
** Accepts time stamps of the form "Sep 13 00:15:17".
** Currently just looks for blanks and colons.
**
** Parameters:
** l -- the line to check.
**
** Returns:
** nonzero -- if the line is time stamped.
** zero -- otherwise.
**
** Side Effects:
** none.
*/
stamped(l)
register char *l;
{
register int i;
/* timestamps are at least 15 bytes long */
for (i = 0; i < 15; i++)
if (l[i] == '\0')
return (0);
/* and they have blanks & colons in well-known places */
if (l[3] != ' ' || l[6] != ' ' || l[9] != ':' || l[12] != ':')
return (0);
return (1);
}
\f/*
** LOGMSG -- log a message to the outputs
**
** Arranges to get the message to the correct places
** based on the priority of the message. A timestamp
** is prepended to the message if one does not already
** exist.
**
** Parameters:
** pri -- the message priority.
** msg -- the message to be logged.
**
** Returns:
** none
**
** Side Effects:
** possibly messages to all users, or just specific
** users.
*/
logmsg(pri, msg)
int pri;
char *msg;
{
register char *m;
register char *p;
register struct filed *f;
register int l;
register int i;
char buf[MAXLINE+2];
auto int st;
auto long now;
extern char *ctime();
extern int errno;
p = buf;
l = MAXLINE;
/* output a time stamp if one is not already there */
time(&now);
if (!stamped(msg))
{
m = &ctime(&now)[4];
for (i = 16; i > 0; i--)
*p++ = *m++;
l -= 16;
}
/* find the end of the message */
for (m = msg; *m != '\0' &&l -- >= 0; )
*p++ = *m++;
if (*--m != '\n')
*p++ = '\n';
/* log the message to the particular outputs */
for (i = 0; i < NLOGS; i++)
{
f = &Files[i];
if (f->f_file == NULL)
continue;
if (pri < 0)
{
if (!f->f_mark || f->f_time + MarkIntvl*60 > now)
continue;
}
else if (f->f_pmask < pri)
continue;
fseek(f->f_file, 0L, 2);
errno = 0;
fwrite(buf, p - buf, 1, f->f_file);
if (f->f_tty)
fwrite("\r", 1, 1, f->f_file);
f->f_time = now;
fflush(f->f_file);
if (ferror(f->f_file))
{
char namebuf[40];
fclose(f->f_file);
f->f_file = NULL;
sprintf(namebuf, "write %s", f->f_name);
logerror(namebuf);
}
}
/* let's be paranoid.... */
sync();
/*
** Output alert and subalert priority messages to terminals.
**
** We double fork here so that we can continue. Our
** child will fork again and die; we wait for him.
** Then process one inherits our grandchildren, we
** can run off and have a good time. Our grandchild
** actually tries to do the writing (by calling
** wallmsg).
**
** Anything go wrong? -- just give up.
*/
if (pri <= LOG_SALERT && pri > 0)
{
if (fork() == 0)
{
if (fork() == 0)
{
wallmsg(pri == LOG_ALERT, buf, p - buf);
exit(0);
}
else
exit(0);
}
else
while (wait(&st) >= 0)
continue;
}
}
\f/*
** INIT -- Initialize syslog from configuration table
**
** The configuration table consists of a series of lines
** broken into two sections by a blank line. The first
** section gives a list of files to log on. The first
** character is a digit which is the priority mask for
** that file. If the second digit is an asterisk, then
** syslog arranges for something to be printed every fifteen
** minutes (even if only a null line), so that crashes and
** other events can be localized. The rest of the line is
** the pathname of the log file. The second section is
** a list of user names; these people are all notified
** when subalert messages occur (if they are logged on).
**
** The configuration table will be reread by this routine
** if a signal 1 occurs; for that reason, it is tricky
** about not re-opening files and closing files it will
** not be using.
**
** Parameters:
** none
**
** Returns:
** none
**
** Side Effects:
** 'Files' and 'Susers' are (re)initialized.
*/
init()
{
register int i;
register FILE *cf;
char cline[40];
register struct filed *f;
register char *p;
int mark;
int pmask;
dprintf("init\n");
/* ignore interrupts during this routine */
signal(SIGHUP, SIG_IGN);
logmsg(LOG_INFO, "reinitializing\n");
/* open the configuration file */
if ((cf = fopen(ConfFile, "r")) == NULL)
{
dprintf("cannot open %s\n", ConfFile);
return;
}
/*
** Close all open files.
*/
for (f = Files; f < &Files[NLOGS]; f++)
{
if (f->f_file != NULL)
fclose(f->f_file);
f->f_file = NULL;
}
/*
** Foreach line in the conf table, open that file.
*/
f = Files;
while (fgets(cline, sizeof cline, cf) != NULL)
{
dprintf("F: got line >%s<\n", cline, 0);
/* check for end-of-section */
if (cline[0] == '\n')
break;
/* strip off possible newline character */
for (p = cline; *p != '\0' && *p != '\n'; p++)
continue;
*p = '\0';
/* extract priority mask and mark flag */
p = cline;
mark = FALSE;
pmask = *p++ - '0';
if (*p == '*')
{
p++;
mark = TRUE;
}
/* insure that it is null-terminated */
p[sizeof Files[0].f_name - 1] = '\0';
if (f >= &Files[NLOGS])
continue;
/* mark entry as used and update flags */
strcpy(f->f_name, p);
f->f_file = fopen(p, "a");
f->f_time = 0;
f->f_pmask = pmask;
f->f_mark = mark;
f->f_tty = isatty(fileno(f->f_file));
dprintf("File %s pmask %d mark %d tty %d\n", p, pmask, mark, f->f_tty);
f++;
}
/*
** Read the list of users.
**
** Anyone in this list is informed directly if s/he
** is logged in when a "subalert" or higher priority
** message comes through.
**
** Out with the old order, in with the new.
*/
for (i = 0; i < NSUSERS && fgets(cline, sizeof cline, cf) != NULL; i++)
{
/* strip off newline */
for (p = cline; *p != '\0' && *p != '\n'; p++)
continue;
*p = '\0';
cline[8] = '\0';
strcpy(Susers[i], cline, 8);
}
/* zero the rest of the old superusers */
for (; i < NSUSERS; i++)
Susers[i][0] = '\0';
/* close the configuration file */
fclose(cf);
logmsg(LOG_INFO, "syslog restart\n");
/* arrange for signal 1 to reconfigure */
signal(SIGHUP, init);
}
\f/*
** WALLMSG -- Write a message to the world at large
**
** This writes the specified message to either the entire
** world, or at least a list of approved users.
**
** It scans the utmp file. For each user logged in, it
** checks to see if the user is on the approved list, or if
** this is an "alert" priority message. In either case,
** it opens a line to that typewriter (unless mesg permission
** is denied) and outputs the message to that terminal.
**
** Parameters:
** toall -- if non-zero, writes the message to everyone.
** msg -- the message to write.
** len -- the length of the message.
**
** Returns:
** none
**
** Side Effects:
** none
**
** Requires:
** open(sys)
** read(sys)
** write(sys)
** fstat(sys)
** strcmp(sys)
** fork(sys)
** sleep(sys)
** exit(sys)
** close(sys)
**
** Called By:
** logmsg
*/
wallmsg(toall, msg, len)
int toall;
char *msg;
int len;
{
struct utmp ut;
register int i;
register char *p;
int uf;
struct stat statbuf;
auto long t;
extern char *ctime();
/* open the user login file */
uf = open("/etc/utmp", 0);
if (uf < 0)
return;
/* scan the user login file */
while (read(uf, &ut, sizeof ut) == sizeof ut)
{
/* is this slot used? */
if (ut.ut_name[0] == '\0')
continue;
/* if not "alert", check if this user is super */
if (!toall)
{
for (i = 0; i < NSUSERS; i++)
{
if (namecheck(Susers[i], ut.ut_name))
break;
}
if (i >= NSUSERS)
{
/* nope, just a serf */
continue;
}
}
/* fork so that the open can't hang us */
if (fork() != 0)
continue;
sleep(1);
/* compute the device name */
# ifdef V6
p = "/dev/ttyx";
p[8] = ut.ut_tty;
# else
p = "/dev/12345678";
strcpyn(&p[5], ut.ut_line, 8);
# endif
/* open the terminal */
i = open(p, 1);
if (i < 0)
exit(1);
/* does he have write permission? */
if (fstat(i, &statbuf) < 0 || (statbuf.st_mode & 02) == 0)
{
/* no, just pass him by */
dprintf("Drop user, mode=%o\n", statbuf.st_mode, 0);
close(i);
exit(0);
}
/* yes, output the message */
time(&t);
write(i, "\015\n\007Broadcast message from System at ", 36);
write(i, ctime(&t), 24);
write(i, "...\015\n", 5);
write(i, msg, len);
write(i, "\015\n", 2);
/* all finished! go away */
exit(0);
}
/* close the user login file */
close(uf);
}
\f/*
** CHECKNAME -- Do an equality comparison on names.
**
** Does right blank padding.
**
** Parameters:
** a, b -- pointers to the names to check.
**
** Returns:
** 1 if equal
** 0 otherwise.
**
** Side Effects:
** none
**
** Requires:
** none
**
** Called By:
** wallmsg
*/
namecheck(a, b)
register char *a, *b;
{
register int i;
for (i = 0; i < 8; i++)
{
if (*a != *b)
{
if (!((*a == ' ' && *b == '\0') || (*a == '\0' && *b == ' ')))
return (0);
}
if (*a != ' ' && *a != '\0')
a++;
if (*b != ' ' && *b != '\0')
b++;
}
return (1);
}
\f/*
** DOMARK -- Make sure every marked file gets output every 15 minutes
**
** Just calls "logmsg" with a negative priority every time it
** gets called.
**
** Algorithm:
** create timestamp.
** call logmsg.
**
** Parameters:
** none
**
** Returns:
** none
**
** Side Effects:
** sets the alarm clock to call itself after MarkIntvl
** minutes.
**
** Requires:
** logmsg
**
** Called By:
** system alarm clock.
** init
*/
domark()
{
auto long t;
extern char *ctime();
register char *p;
register char *q;
char buf[40];
alarm(0);
dprintf("domark\n");
time(&t);
q = buf;
for (p = " --- MARK --- "; (*q++ = *p++) != '\0'; )
continue;
q--;
for (p = ctime(&t); (*q++ = *p++) != '\0'; )
continue;
logmsg(-1, buf);
signal(SIGALRM, domark);
alarm(MarkIntvl*60);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.