helpers/log_daemon/file/log_file_daemon.cc

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