usr/src/lib/libbc/libc/gen/common/syslog.c

   1 /*
   2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6 /*
   7  * Copyright (c) 1983 Regents of the University of California.
   8  * All rights reserved.  The Berkeley software License Agreement
   9  * specifies the terms and conditions for redistribution.
  10  */
  11
  12 #pragma ident   "%Z%%M% %I%     %E% SMI"
  13
  14 /*
  15  * SYSLOG -- print message on log file
  16  *
  17  * This routine looks a lot like printf, except that it
  18  * outputs to the log file instead of the standard output.
  19  * Also:
  20  *      adds a timestamp,
  21  *      prints the module name in front of the message,
  22  *      has some other formatting types (or will sometime),
  23  *      adds a newline on the end of the message.
  24  *
  25  * The output of this routine is intended to be read by /etc/syslogd.
  26  *
  27  * Author: Eric Allman
  28  * Modified to use UNIX domain IPC by Ralph Campbell
  29  */
  30
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33 #include <sys/file.h>
  34 #include <sys/signal.h>
  35 #include <sys/syslog.h>
  36 #include <sys/time.h>
  37 #include <sys/unistd.h>
  38 #include <netdb.h>
  39 #include <strings.h>
  40 #include <stdarg.h>
  41 #include <vfork.h>
  42 #include <stdio.h>
  43 #include <errno.h>
  44 #include <malloc.h>
  45
  46
  47 #define MAXLINE 1024                    /* max message size */
  48
  49 #define PRIMASK(p)      (1 << ((p) & LOG_PRIMASK))
  50 #define PRIFAC(p)       (((p) & LOG_FACMASK) >> 3)
  51 #define IMPORTANT       LOG_ERR
  52
  53 static char     *logname = "/dev/log";
  54 static char     *ctty = "/dev/console";
  55 static char     *sysmsg = "/dev/sysmsg";
  56
  57 static struct _syslog {
  58         int     _LogFile;
  59         int     _LogStat;
  60         char    *_LogTag;
  61         int     _LogMask;
  62         struct  sockaddr _SyslogAddr;
  63         char    *_SyslogHost;
  64         int     _LogFacility;
  65 } *_syslog;
  66 #define LogFile (_syslog->_LogFile)
  67 #define LogStat (_syslog->_LogStat)
  68 #define LogTag (_syslog->_LogTag)
  69 #define LogMask (_syslog->_LogMask)
  70 #define SyslogAddr (_syslog->_SyslogAddr)
  71 #define SyslogHost (_syslog->_SyslogHost)
  72 #define LogFacility (_syslog->_LogFacility)
  73
  74
  75 extern char *strerror(int);
  76 extern time_t time();
  77
  78 void    vsyslog(int, char *, va_list);
  79 void    openlog(char *, int, int);
  80 static int      snprintf(char *, size_t, char *, ...);
  81 static int      vsnprintf(char *, size_t, char *, va_list ap);
  82
  83 static int
  84 allocstatic(void)
  85 {
  86         _syslog = (struct _syslog *)calloc(1, sizeof (struct _syslog));
  87         if (_syslog == 0)
  88                 return (0);     /* can't do it */
  89         LogFile = -1;           /* fd for log */
  90         LogStat = 0;            /* status bits, set by openlog() */
  91         LogTag = "syslog";      /* string to tag the entry with */
  92         LogMask = 0xff;         /* mask of priorities to be logged */
  93         LogFacility = LOG_USER; /* default facility code */
  94         return (1);
  95 }
  96
  97 void
  98 syslog(int pri, char *fmt, ...)
  99 {
 100         va_list ap;
 101
 102         va_start(ap, fmt);
 103         vsyslog(pri, fmt, ap);
 104         va_end(ap);
 105 }
 106
 107 void
 108 vsyslog(int pri, char *fmt, va_list ap)
 109 {
 110         char buf[MAXLINE + 1], outline[MAXLINE + 1];
 111         char *b, *f, *o;
 112         int c;
 113         long now;
 114         int pid, olderrno = errno;
 115         int retsiz, outsiz = MAXLINE + 1;
 116         int taglen;
 117 /*
 118  * Maximum tag length is 256 (the pad in outline) minus the size of the
 119  * other things that can go in the pad.
 120  */
 121 #define MAX_TAG 230
 122
 123
 124         if (_syslog == 0 && !allocstatic())
 125                 return;
 126
 127         /* see if we should just throw out this message */
 128         if (pri <= 0 || PRIFAC(pri) >= LOG_NFACILITIES ||
 129             (PRIMASK(pri) & LogMask) == 0)
 130                 return;
 131         if (LogFile < 0)
 132                 openlog(LogTag, LogStat | LOG_NDELAY, 0);
 133
 134         /* set default facility if none specified */
 135         if ((pri & LOG_FACMASK) == 0)
 136                 pri |= LogFacility;
 137
 138         /* build the message */
 139         o = outline;
 140         (void) time(&now);
 141         (void) sprintf(o, "<%d>%.15s ", pri, ctime(&now) + 4);
 142         o += strlen(o);
 143
 144         if (LogTag) {
 145                 taglen = strlen(LogTag) < MAX_TAG ? strlen(LogTag) : MAX_TAG;
 146                 strncpy(o, LogTag, taglen);
 147                 o[taglen] = '\0';
 148                 o += strlen(o);
 149         }
 150         if (LogStat & LOG_PID) {
 151                 (void) sprintf(o, "[%d]", getpid());
 152                 o += strlen(o);
 153         }
 154         if (LogTag) {
 155                 (void) strcpy(o, ": ");
 156                 o += 2;
 157         }
 158
 159         b = buf;
 160         f = fmt;
 161         while ((c = *f++) != '\0' && c != '\n' && b < &buf[MAXLINE]) {
 162                 char *errstr;
 163
 164                 if (c != '%') {
 165                         *b++ = c;
 166                         continue;
 167                 }
 168                 if ((c = *f++) != 'm') {
 169                         *b++ = '%';
 170                         *b++ = c;
 171                         continue;
 172                 }
 173                 if ((errstr = strerror(olderrno)) == NULL)
 174                         (void) snprintf(b, &buf[MAXLINE] - b, "error %d",
 175                             olderrno);
 176                 else {
 177                         while (*errstr != '\0' && b < &buf[MAXLINE]) {
 178                                 if (*errstr == '%') {
 179                                         strcpy(b, "%%");
 180                                         b += 2;
 181                                 }
 182                                 else
 183                                         *b++ = *errstr;
 184                                 errstr++;
 185                         }
 186                         *b = '\0';
 187                 }
 188                 b += strlen(b);
 189         }
 190         if (b > buf && *(b-1) != '\n')  /* ensure at least one newline */
 191                 *b++ = '\n';
 192         *b = '\0';
 193         (void) vsnprintf(o, &outline[sizeof (outline)] - o, buf, ap);
 194         c = strlen(outline) + 1;        /* add one for NULL byte */
 195         if (c > MAXLINE) {
 196                 c = MAXLINE;
 197                 outline[MAXLINE-1] = '\0';
 198         }
 199
 200         /* output the message to the local logger */
 201         if (sendto(LogFile, outline, c, 0, &SyslogAddr,
 202             sizeof (SyslogAddr)) >= 0)
 203                 return;
 204         if (!(LogStat & LOG_CONS))
 205                 return;
 206
 207         /* output the message to the console */
 208         pid = vfork();
 209         if (pid == -1)
 210                 return;
 211         if (pid == 0) {
 212                 int fd;
 213
 214                 (void) signal(SIGALRM, SIG_DFL);
 215                 (void) sigsetmask(sigblock(0) & ~sigmask(SIGALRM));
 216                 (void) alarm(5);
 217                 if (((fd = open(sysmsg, O_WRONLY)) >= 0) ||
 218                     (fd = open(ctty, O_WRONLY)) >= 0) {
 219                         (void) alarm(0);
 220                         if (outsiz > 2) {       /* Just in case */
 221                                 (void) strcat(o, "\r\n");
 222                                 c += 2;
 223                         }
 224                         o = index(outline, '>') + 1;
 225                         (void) write(fd, o, c - (o - outline));
 226                         (void) close(fd);
 227                 } else
 228                         (void) alarm(0);
 229                 _exit(0);
 230         }
 231         if (!(LogStat & LOG_NOWAIT))
 232                 while ((c = wait((int *)0)) > 0 && c != pid)
 233                         ;
 234 }
 235
 236 /*
 237  * OPENLOG -- open system log
 238  */
 239 void
 240 openlog(char *ident, int logstat, int logfac)
 241 {
 242         if (_syslog == 0 && !allocstatic())
 243                 return;
 244         if (ident != NULL)
 245                 LogTag = ident;
 246         LogStat = logstat;
 247         if (logfac != 0)
 248                 LogFacility = logfac & LOG_FACMASK;
 249         if (LogFile >= 0)
 250                 return;
 251         SyslogAddr.sa_family = AF_UNIX;
 252         (void) strncpy(SyslogAddr.sa_data, logname,
 253             sizeof (SyslogAddr.sa_data));
 254         if (LogStat & LOG_NDELAY) {
 255                 LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
 256                 (void) fcntl(LogFile, F_SETFD, 1);
 257         }
 258 }
 259
 260 /*
 261  * CLOSELOG -- close the system log
 262  */
 263 void
 264 closelog(void)
 265 {
 266
 267         if (_syslog == 0)
 268                 return;
 269         (void) close(LogFile);
 270         LogFile = -1;
 271 }
 272
 273 /*
 274  * SETLOGMASK -- set the log mask level
 275  */
 276 int
 277 setlogmask(int pmask)
 278 {
 279         int omask;
 280
 281         if (_syslog == 0 && !allocstatic())
 282                 return (-1);
 283         omask = LogMask;
 284         if (pmask != 0)
 285                 LogMask = pmask;
 286         return (omask);
 287 }
 288
 289 /*
 290  * snprintf/vsnprintf -- These routines are here
 291  * temporarily to solve bugid 1220257. Perhaps
 292  * they could become a public interface at some
 293  * point but not for now.
 294  */
 295
 296 extern int _doprnt();
 297
 298 static int
 299 snprintf(char *string, size_t n, char *format, ...)
 300 {
 301         int count;
 302         FILE siop;
 303         va_list ap;
 304
 305         if (n == 0)
 306                 return (0);
 307         siop._cnt = n - 1;
 308         siop._base = siop._ptr = (unsigned char *)string;
 309         siop._flag = _IOWRT+_IOSTRG;
 310         va_start(ap, format);
 311         count = _doprnt(format, ap, &siop);
 312         va_end(ap);
 313         *siop._ptr = '\0';      /* plant terminating null character */
 314         return (count);
 315 }
 316
 317 static int
 318 vsnprintf(char *string, size_t n, char *format, va_list ap)
 319 {
 320         int count;
 321         FILE siop;
 322
 323         if (n == 0)
 324                 return (0);
 325         siop._cnt = n - 1;
 326         siop._base = siop._ptr = (unsigned char *)string;
 327         siop._flag = _IOWRT+_IOSTRG;
 328         count = _doprnt(format, ap, &siop);
 329         *siop._ptr = '\0';      /* plant terminating null character */
 330         return (count);
 331 }