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 "disk.h"
  35 #include "fd.h"
  36 #include "fde.h"
  37 #include "globals.h"
  38 #include "log/File.h"
  39 #include "log/ModStdio.h"
  40 #include "SquidConfig.h"
  41
  42 #include <cerrno>
  43
  44 typedef struct {
  45     int fd;
  46     char *buf;
  47     size_t bufsz;
  48     int offset;
  49 } l_stdio_t;
  50
  51 /*
  52  * Aborts with fatal message if write() returns something other
  53  * than its length argument.
  54  */
  55 static void
  56 logfileWriteWrapper(Logfile * lf, const void *buf, size_t len)
  57 {
  58     l_stdio_t *ll = (l_stdio_t *) lf->data;
  59     size_t s;
  60     s = FD_WRITE_METHOD(ll->fd, (char const *) buf, len);
  61     fd_bytes(ll->fd, s, FD_WRITE);
  62
  63     if (s == len)
  64         return;
  65
  66     if (!lf->flags.fatal)
  67         return;
  68
  69     fatalf("logfileWrite: %s: %s\n", lf->path, xstrerror());
  70 }
  71
  72 static void
  73 logfile_mod_stdio_writeline(Logfile * lf, const char *buf, size_t len)
  74 {
  75     l_stdio_t *ll = (l_stdio_t *) lf->data;
  76
  77     if (0 == ll->bufsz) {
  78         /* buffering disabled */
  79         logfileWriteWrapper(lf, buf, len);
  80         return;
  81     }
  82     if (ll->offset > 0 && (ll->offset + len) > ll->bufsz)
  83         logfileFlush(lf);
  84
  85     if (len > ll->bufsz) {
  86         /* too big to fit in buffer */
  87         logfileWriteWrapper(lf, buf, len);
  88         return;
  89     }
  90     /* buffer it */
  91     memcpy(ll->buf + ll->offset, buf, len);
  92
  93     ll->offset += len;
  94
  95     assert(ll->offset >= 0);
  96
  97     assert((size_t) ll->offset <= ll->bufsz);
  98 }
  99
 100 static void
 101 logfile_mod_stdio_linestart(Logfile * lf)
 102 {
 103 }
 104
 105 static void
 106 logfile_mod_stdio_lineend(Logfile * lf)
 107 {
 108     lf->f_flush(lf);
 109 }
 110
 111 static void
 112 logfile_mod_stdio_flush(Logfile * lf)
 113 {
 114     l_stdio_t *ll = (l_stdio_t *) lf->data;
 115     if (0 == ll->offset)
 116         return;
 117     logfileWriteWrapper(lf, ll->buf, (size_t) ll->offset);
 118     ll->offset = 0;
 119 }
 120
 121 static void
 122 logfile_mod_stdio_rotate(Logfile * lf)
 123 {
 124 #ifdef S_ISREG
 125
 126     struct stat sb;
 127 #endif
 128
 129     int i;
 130     char from[MAXPATHLEN];
 131     char to[MAXPATHLEN];
 132     l_stdio_t *ll = (l_stdio_t *) lf->data;
 133     assert(lf->path);
 134     const char *realpath = lf->path+6; // skip 'stdio:' prefix.
 135     assert(realpath);
 136
 137 #ifdef S_ISREG
 138
 139     if (stat(realpath, &sb) == 0)
 140         if (S_ISREG(sb.st_mode) == 0)
 141             return;
 142
 143 #endif
 144
 145     debugs(0, DBG_IMPORTANT, "Rotate log file " << lf->path);
 146
 147     /* Rotate numbers 0 through N up one */
 148     for (i = Config.Log.rotateNumber; i > 1;) {
 149         --i;
 150         snprintf(from, MAXPATHLEN, "%s.%d", realpath, i - 1);
 151         snprintf(to, MAXPATHLEN, "%s.%d", realpath, i);
 152         xrename(from, to);
 153     }
 154
 155     /* Rotate the current log to .0 */
 156     logfileFlush(lf);
 157
 158     file_close(ll->fd);         /* always close */
 159
 160     if (Config.Log.rotateNumber > 0) {
 161         snprintf(to, MAXPATHLEN, "%s.%d", realpath, 0);
 162         xrename(realpath, to);
 163     }
 164     /* Reopen the log.  It may have been renamed "manually" */
 165     ll->fd = file_open(realpath, O_WRONLY | O_CREAT | O_TEXT);
 166
 167     if (DISK_ERROR == ll->fd && lf->flags.fatal) {
 168         debugs(50, DBG_CRITICAL, "ERROR: logfileRotate: " << lf->path << ": " << xstrerror());
 169         fatalf("Cannot open %s: %s", lf->path, xstrerror());
 170     }
 171 }
 172
 173 static void
 174 logfile_mod_stdio_close(Logfile * lf)
 175 {
 176     l_stdio_t *ll = (l_stdio_t *) lf->data;
 177     lf->f_flush(lf);
 178
 179     if (ll->fd >= 0)
 180         file_close(ll->fd);
 181
 182     if (ll->buf)
 183         xfree(ll->buf);
 184
 185     xfree(lf->data);
 186     lf->data = NULL;
 187 }
 188
 189 /*
 190  * This code expects the path to be a writable filename
 191  */
 192 int
 193 logfile_mod_stdio_open(Logfile * lf, const char *path, size_t bufsz, int fatal_flag)
 194 {
 195     lf->f_close = logfile_mod_stdio_close;
 196     lf->f_linewrite = logfile_mod_stdio_writeline;
 197     lf->f_linestart = logfile_mod_stdio_linestart;
 198     lf->f_lineend = logfile_mod_stdio_lineend;
 199     lf->f_flush = logfile_mod_stdio_flush;
 200     lf->f_rotate = logfile_mod_stdio_rotate;
 201
 202     l_stdio_t *ll = static_cast<l_stdio_t*>(xcalloc(1, sizeof(*ll)));
 203     lf->data = ll;
 204
 205     ll->fd = file_open(path, O_WRONLY | O_CREAT | O_TEXT);
 206
 207     if (DISK_ERROR == ll->fd) {
 208         if (ENOENT == errno && fatal_flag) {
 209             fatalf("Cannot open '%s' because\n"
 210                    "\tthe parent directory does not exist.\n"
 211                    "\tPlease create the directory.\n", path);
 212         } else if (EACCES == errno && fatal_flag) {
 213             fatalf("Cannot open '%s' for writing.\n"
 214                    "\tThe parent directory must be writeable by the\n"
 215                    "\tuser '%s', which is the cache_effective_user\n"
 216                    "\tset in squid.conf.", path, Config.effectiveUser);
 217         } else if (EISDIR == errno && fatal_flag) {
 218             fatalf("Cannot open '%s' because it is a directory, not a file.\n", path);
 219         } else {
 220             debugs(50, DBG_IMPORTANT, "ERROR: logfileOpen " << lf->path << ": " << xstrerror());
 221             return 0;
 222         }
 223     }
 224     if (bufsz > 0) {
 225         ll->buf = static_cast<char*>(xmalloc(bufsz));
 226         ll->bufsz = bufsz;
 227     }
 228     return 1;
 229 }