src/log.c

   1 /* -------------------------------------------------------------------------
   2  * log.c - htun logging functions
   3  * Copyright (C) 2002 Moshe Jacobson <moshe@runslinux.net>,
   4  *                    Ola NordstrÖm <ola@triblock.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  * -------------------------------------------------------------------------
  20  */
  21 /* $Id: log.c,v 2.5 2005/04/27 20:11:26 jehsom Exp $ */
  22
  23 #include <stdio.h>
  24 #include <unistd.h>
  25 #include <semaphore.h>
  26 #include <stdarg.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <errno.h>
  30 #include <time.h>
  31 #include <pthread.h>
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <fcntl.h>
  35
  36 #include "log.h"
  37 #include "util.h"
  38
  39 /* Allows printf()-like interface to file descriptors without the
  40  * complications that arise from mixing stdio and low level calls
  41  * FIXME: Needs date and time before logfile entries.
  42  */
  43 int lprintf_real( const char *func, log_t *log, unsigned int level, char *fmt, ... ) {
  44     int fd;
  45     int rc;
  46     va_list ap;
  47     time_t now;
  48     char date[50];
  49     static char line[LOGLINE_MAX];
  50     static char threadnum[10];
  51     int cnt;
  52     static char *levels[6] = { "[(bad)] ",
  53                                "[debug] ",
  54                                "[info ] ",
  55                                "[warn ] ",
  56                                "[error] ",
  57                                "[fatal] " };
  58
  59     if(!log) return -1;
  60
  61     /* If this is debug info, and we're not logging it, return */
  62     if( !(log->flags&LOG_DEBUG) && level == DEBUG ) return 0;
  63
  64     fd=log->fd;
  65
  66     /* Prepare the date string */
  67     if( !(log->flags&LOG_NODATE) ) {
  68         now=time(NULL);
  69         strcpy(date,ctime(&now));
  70         date[strlen(date)-6]=' ';
  71         date[strlen(date)-5]='\0';
  72     }
  73
  74     if( !(log->flags&LOG_NOTID) ) {
  75         sprintf(threadnum, "(%lu) ", pthread_self());
  76     }
  77
  78     cnt = snprintf(line, sizeof(line), "%s%s%s%s%s",
  79                    log->flags&LOG_NODATE ? "" : date,
  80                    log->flags&LOG_NOLVL  ? "" :
  81                        (level > FATAL ? levels[0] : levels[level]),
  82                    log->flags&LOG_NOTID ? "" : threadnum,
  83                    log->flags&LOG_FUNC ? func : "",
  84                    log->flags&LOG_FUNC ? ": " : "");
  85
  86     va_start(ap, fmt);
  87     vsnprintf(line+cnt, sizeof(line)-cnt, fmt, ap);
  88     va_end(ap);
  89
  90     line[sizeof(line)-1] = '\0';
  91
  92     if( !(log->flags&LOG_NOLF) ) {
  93         chomp(line);
  94         strcpy(line+strlen(line), "\n");
  95     }
  96
  97     sem_wait(&log->sem);
  98     rc = write(fd, line, strlen(line));
  99     sem_post(&log->sem);
 100
 101     if( !rc ) errno = 0;
 102     return rc;
 103 }
 104
 105 log_t *log_open( char *fname, int flags ) {
 106     log_t *log = malloc(sizeof(log_t));
 107
 108     if(!log) {
 109         fprintf(stderr, "log_open: Unable to malloc()");
 110         goto log_open_a;
 111     }
 112     log->flags=flags;
 113     if( !strcmp(fname,"-") ) {
 114         log->fd = 2;
 115     } else {
 116         log->fd = open(fname, O_WRONLY|O_CREAT|O_NOCTTY |
 117                 (flags&LOG_TRUNC ? O_TRUNC : O_APPEND) , 0666);
 118
 119     }
 120     if( log->fd == -1 ) {
 121         fprintf(stderr, "log_open: Opening logfile %s: %s",
 122                 fname, strerror(errno));
 123         goto log_open_b;
 124     }
 125     if( sem_init(&log->sem, 0, 1) == -1 ) {
 126         fprintf(stderr, "log_open: Could not initialize log semaphore.");
 127         goto log_open_c;
 128     }
 129     return log;
 130
 131 log_open_c:
 132     close(log->fd);
 133 log_open_b:
 134     free(log);
 135 log_open_a:
 136     return NULL;
 137 }
 138
 139 void log_close( log_t *log ) {
 140     sem_wait(&log->sem);
 141     sem_destroy(&log->sem);
 142     close(log->fd);
 143     free(log);
 144     return;
 145 }
 146