src/log/ModStdio.cc

   1 /*
   2  * DEBUG: section 50    Log file handling
   3  * AUTHOR: Duane Wessels
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #include "squid.h"
  34 #include "fde.h"
  35 #include "globals.h"
  36 #include "log/File.h"
  37 #include "log/ModStdio.h"
  38 #include "protos.h"
  39
  40 typedef struct {
  41     int fd;
  42     char *buf;
  43     size_t bufsz;
  44     int offset;
  45 } l_stdio_t;
  46
  47 /*
  48  * Aborts with fatal message if write() returns something other
  49  * than its length argument.
  50  */
  51 static void
  52 logfileWriteWrapper(Logfile * lf, const void *buf, size_t len)
  53 {
  54     l_stdio_t *ll = (l_stdio_t *) lf->data;
  55     size_t s;
  56     s = FD_WRITE_METHOD(ll->fd, (char const *) buf, len);
  57     fd_bytes(ll->fd, s, FD_WRITE);
  58
  59     if (s == len)
  60         return;
  61
  62     if (!lf->flags.fatal)
  63         return;
  64
  65     fatalf("logfileWrite: %s: %s\n", lf->path, xstrerror());
  66 }
  67
  68 static void
  69 logfile_mod_stdio_writeline(Logfile * lf, const char *buf, size_t len)
  70 {
  71     l_stdio_t *ll = (l_stdio_t *) lf->data;
  72
  73     if (0 == ll->bufsz) {
  74         /* buffering disabled */
  75         logfileWriteWrapper(lf, buf, len);
  76         return;
  77     }
  78     if (ll->offset > 0 && (ll->offset + len) > ll->bufsz)
  79         logfileFlush(lf);
  80
  81     if (len > ll->bufsz) {
  82         /* too big to fit in buffer */
  83         logfileWriteWrapper(lf, buf, len);
  84         return;
  85     }
  86     /* buffer it */
  87     memcpy(ll->buf + ll->offset, buf, len);
  88
  89     ll->offset += len;
  90
  91     assert(ll->offset >= 0);
  92
  93     assert((size_t) ll->offset <= ll->bufsz);
  94 }
  95
  96 static void
  97 logfile_mod_stdio_linestart(Logfile * lf)
  98 {
  99 }
 100
 101 static void
 102 logfile_mod_stdio_lineend(Logfile * lf)
 103 {
 104     lf->f_flush(lf);
 105 }
 106
 107 static void
 108 logfile_mod_stdio_flush(Logfile * lf)
 109 {
 110     l_stdio_t *ll = (l_stdio_t *) lf->data;
 111     if (0 == ll->offset)
 112         return;
 113     logfileWriteWrapper(lf, ll->buf, (size_t) ll->offset);
 114     ll->offset = 0;
 115 }
 116
 117 static void
 118 logfile_mod_stdio_rotate(Logfile * lf)
 119 {
 120 #ifdef S_ISREG
 121
 122     struct stat sb;
 123 #endif
 124
 125     int i;
 126     char from[MAXPATHLEN];
 127     char to[MAXPATHLEN];
 128     l_stdio_t *ll = (l_stdio_t *) lf->data;
 129     assert(lf->path);
 130     const char *realpath = lf->path+6; // skip 'stdio:' prefix.
 131     assert(realpath);
 132
 133 #ifdef S_ISREG
 134
 135     if (stat(realpath, &sb) == 0)
 136         if (S_ISREG(sb.st_mode) == 0)
 137             return;
 138
 139 #endif
 140
 141     debugs(0, DBG_IMPORTANT, "Rotate log file " << lf->path);
 142
 143     /* Rotate numbers 0 through N up one */
 144     for (i = Config.Log.rotateNumber; i > 1;) {
 145         --i;
 146         snprintf(from, MAXPATHLEN, "%s.%d", realpath, i - 1);
 147         snprintf(to, MAXPATHLEN, "%s.%d", realpath, i);
 148         xrename(from, to);
 149     }
 150
 151     /* Rotate the current log to .0 */
 152     logfileFlush(lf);
 153
 154     file_close(ll->fd);         /* always close */
 155
 156     if (Config.Log.rotateNumber > 0) {
 157         snprintf(to, MAXPATHLEN, "%s.%d", realpath, 0);
 158         xrename(realpath, to);
 159     }
 160     /* Reopen the log.  It may have been renamed "manually" */
 161     ll->fd = file_open(realpath, O_WRONLY | O_CREAT | O_TEXT);
 162
 163     if (DISK_ERROR == ll->fd && lf->flags.fatal) {
 164         debugs(50, DBG_CRITICAL, "ERROR: logfileRotate: " << lf->path << ": " << xstrerror());
 165         fatalf("Cannot open %s: %s", lf->path, xstrerror());
 166     }
 167 }
 168
 169 static void
 170 logfile_mod_stdio_close(Logfile * lf)
 171 {
 172     l_stdio_t *ll = (l_stdio_t *) lf->data;
 173     lf->f_flush(lf);
 174
 175     if (ll->fd >= 0)
 176         file_close(ll->fd);
 177
 178     if (ll->buf)
 179         xfree(ll->buf);
 180
 181     xfree(lf->data);
 182     lf->data = NULL;
 183 }
 184
 185 /*
 186  * This code expects the path to be a writable filename
 187  */
 188 int
 189 logfile_mod_stdio_open(Logfile * lf, const char *path, size_t bufsz, int fatal_flag)
 190 {
 191     lf->f_close = logfile_mod_stdio_close;
 192     lf->f_linewrite = logfile_mod_stdio_writeline;
 193     lf->f_linestart = logfile_mod_stdio_linestart;
 194     lf->f_lineend = logfile_mod_stdio_lineend;
 195     lf->f_flush = logfile_mod_stdio_flush;
 196     lf->f_rotate = logfile_mod_stdio_rotate;
 197
 198     l_stdio_t *ll = static_cast<l_stdio_t*>(xcalloc(1, sizeof(*ll)));
 199     lf->data = ll;
 200
 201     ll->fd = file_open(path, O_WRONLY | O_CREAT | O_TEXT);
 202
 203     if (DISK_ERROR == ll->fd) {
 204         if (ENOENT == errno && fatal_flag) {
 205             fatalf("Cannot open '%s' because\n"
 206                    "\tthe parent directory does not exist.\n"
 207                    "\tPlease create the directory.\n", path);
 208         } else if (EACCES == errno && fatal_flag) {
 209             fatalf("Cannot open '%s' for writing.\n"
 210                    "\tThe parent directory must be writeable by the\n"
 211                    "\tuser '%s', which is the cache_effective_user\n"
 212                    "\tset in squid.conf.", path, Config.effectiveUser);
 213         } else if (EISDIR == errno && fatal_flag) {
 214             fatalf("Cannot open '%s' because it is a directory, not a file.\n", path);
 215         } else {
 216             debugs(50, DBG_IMPORTANT, "ERROR: logfileOpen " << lf->path << ": " << xstrerror());
 217             return 0;
 218         }
 219     }
 220     if (bufsz > 0) {
 221         ll->buf = static_cast<char*>(xmalloc(bufsz));
 222         ll->bufsz = bufsz;
 223     }
 224     return 1;
 225 }