helpers/log_daemon/file/log_file_daemon.cc

   1 #include "squid.h"
   2
   3 #if HAVE_STDIO_H
   4 #include <stdio.h>
   5 #endif
   6 #if HAVE_UNISTD_H
   7 #include <unistd.h>
   8 #endif
   9 #if HAVE_FCNTL_H
  10 #include <fcntl.h>
  11 #endif
  12 #if HAVE_ASSERT_H
  13 #include <assert.h>
  14 #endif
  15 #if HAVE_SYS_PARAM_H
  16 #include <sys/param.h>
  17 #endif
  18 #if HAVE_SYS_STAT_H
  19 #include <sys/stat.h>
  20 #endif
  21 #if HAVE_SIGNAL_H
  22 #include <signal.h>
  23 #endif
  24 #if HAVE_ERRNO_H
  25 #include <errno.h>
  26 #endif
  27 #if HAVE_STRING_H
  28 #include <string.h>
  29 #endif
  30 #if HAVE_PATHS_H
  31 #include <paths.h>
  32 #endif
  33
  34 #include "defines.h"
  35
  36 /* parse buffer - ie, length of longest expected line */
  37 #define LOGFILE_BUF_LEN         65536
  38
  39 static void
  40 rotate(const char *path, int rotate_count)
  41 {
  42 #ifdef S_ISREG
  43     struct stat sb;
  44 #endif
  45     int i;
  46     char from[MAXPATHLEN];
  47     char to[MAXPATHLEN];
  48     assert(path);
  49 #ifdef S_ISREG
  50     if (stat(path, &sb) == 0)
  51         if (S_ISREG(sb.st_mode) == 0)
  52             return;
  53 #endif
  54     /* Rotate numbers 0 through N up one */
  55     for (i = rotate_count; i > 1;) {
  56         i--;
  57         snprintf(from, MAXPATHLEN, "%s.%d", path, i - 1);
  58         snprintf(to, MAXPATHLEN, "%s.%d", path, i);
  59 #if _SQUID_OS2_ || _SQUID_WINDOWS_
  60         remove(to);
  61 #endif
  62         rename(from, to);
  63     }
  64     if (rotate_count > 0) {
  65         snprintf(to, MAXPATHLEN, "%s.%d", path, 0);
  66 #if _SQUID_OS2_ || _SQUID_WINDOWS_
  67         remove(to);
  68 #endif
  69         rename(path, to);
  70     }
  71 }
  72
  73 /**
  74  * The commands:
  75  *
  76  * L<data>\n - logfile data
  77  * R\n - rotate file
  78  * T\n - truncate file
  79  * O\n - repoen file
  80  * F\n - flush file
  81  * r<n>\n - set rotate count to <n>
  82  * b<n>\n - 1 = buffer output, 0 = don't buffer output
  83  */
  84 int
  85 main(int argc, char *argv[])
  86 {
  87     int t;
  88     FILE *fp;
  89     char buf[LOGFILE_BUF_LEN];
  90     int rotate_count = 10;
  91     int do_buffer = 1;
  92
  93     if (argc < 2) {
  94         printf("Error: usage: %s <logfile>\n", argv[0]);
  95         exit(1);
  96     }
  97     fp = fopen(argv[1], "a");
  98     if (fp == NULL) {
  99         perror("fopen");
 100         exit(1);
 101     }
 102     setbuf(stdout, NULL);
 103     close(2);
 104     t = open(_PATH_DEVNULL, O_RDWR);
 105     assert(t > -1);
 106     dup2(t, 2);
 107
 108     while (fgets(buf, LOGFILE_BUF_LEN, stdin)) {
 109         /* First byte indicates what we're logging! */
 110         switch (buf[0]) {
 111         case 'L':
 112             if (buf[1] != '\0') {
 113                 fprintf(fp, "%s", buf + 1);
 114                 /* try to detect the 32-bit file too big write error and rotate */
 115                 int err = ferror(fp);
 116                 clearerr(fp);
 117                 if (err < 0) {
 118                     /* file too big - recover by rotating the logs and starting a new one.
 119                      * out of device space - recover by rotating and hoping that rotation count drops a big one.
 120                      */
 121                     if (err == EFBIG || err == ENOSPC) {
 122                         fprintf(stderr, "WARNING: %s writing %s. Attempting to recover via a log rotation.\n",strerror(err),argv[1]);
 123                         fclose(fp);
 124                         rotate(argv[1], rotate_count);
 125                         fp = fopen(argv[1], "a");
 126                         if (fp == NULL) {
 127                             perror("fopen");
 128                             exit(1);
 129                         }
 130                         fprintf(fp, "%s", buf + 1);
 131                     } else {
 132                         perror("fprintf");
 133                         exit(1);
 134                     }
 135                 }
 136             }
 137             if (!do_buffer)
 138                 fflush(fp);
 139             break;
 140         case 'R':
 141             fclose(fp);
 142             rotate(argv[1], rotate_count);
 143             fp = fopen(argv[1], "a");
 144             if (fp == NULL) {
 145                 perror("fopen");
 146                 exit(1);
 147             }
 148             break;
 149         case 'T':
 150             break;
 151         case 'O':
 152             break;
 153         case 'r':
 154             //fprintf(fp, "SET ROTATE: %s\n", buf + 1);
 155             rotate_count = atoi(buf + 1);
 156             break;
 157         case 'b':
 158             //fprintf(fp, "SET BUFFERED: %s\n", buf + 1);
 159             do_buffer = (buf[1] == '1');
 160             break;
 161         case 'F':
 162             fflush(fp);
 163             break;
 164         default:
 165             /* Just in case .. */
 166             fprintf(fp, "%s", buf);
 167             break;
 168         }
 169     }
 170     fclose(fp);
 171     fp = NULL;
 172     exit(0);
 173 }