src/log/ModUdp.cc

   1 /*
   2  * DEBUG: section 50    Log file handling
   3  * AUTHOR: Adrian Chadd
   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 "comm.h"
  35 #include "comm/Connection.h"
  36 #include "disk.h"
  37 #include "fd.h"
  38 #include "log/File.h"
  39 #include "log/ModUdp.h"
  40 #include "Parsing.h"
  41 #include "SquidConfig.h"
  42
  43 #if HAVE_ERRNO_H
  44 #include <errno.h>
  45 #endif
  46
  47 /*
  48  * This logfile UDP module is mostly inspired by a patch by Tim Starling
  49  * from Wikimedia.
  50  *
  51  * It doesn't do any UDP buffering - it'd be quite a bit of work for
  52  * something which the kernel could be doing for you!
  53  */
  54
  55 typedef struct {
  56     int fd;
  57     char *buf;
  58     size_t bufsz;
  59     int offset;
  60 } l_udp_t;
  61
  62 static void
  63 logfile_mod_udp_write(Logfile * lf, const char *buf, size_t len)
  64 {
  65     l_udp_t *ll = (l_udp_t *) lf->data;
  66     ssize_t s;
  67     s = write(ll->fd, (char const *) buf, len);
  68     fd_bytes(ll->fd, s, FD_WRITE);
  69 #if 0
  70     if (s < 0) {
  71         debugs(1, DBG_IMPORTANT, "logfile (udp): got errno (" << errno << "):" << xstrerror());
  72     }
  73     if (s != len) {
  74         debugs(1, DBG_IMPORTANT, "logfile (udp): len=" << len << ", wrote=" << s);
  75     }
  76 #endif
  77
  78     /* We don't worry about network errors for now */
  79 }
  80
  81 static void
  82 logfile_mod_udp_flush(Logfile * lf)
  83 {
  84     l_udp_t *ll = (l_udp_t *) lf->data;
  85     if (0 == ll->offset)
  86         return;
  87     logfile_mod_udp_write(lf, ll->buf, (size_t) ll->offset);
  88     ll->offset = 0;
  89 }
  90
  91 static void
  92 logfile_mod_udp_writeline(Logfile * lf, const char *buf, size_t len)
  93 {
  94     l_udp_t *ll = (l_udp_t *) lf->data;
  95
  96     if (0 == ll->bufsz) {
  97         /* buffering disabled */
  98         logfile_mod_udp_write(lf, buf, len);
  99         return;
 100     }
 101     if (ll->offset > 0 && (ll->offset + len + 4) > ll->bufsz)
 102         logfile_mod_udp_flush(lf);
 103
 104     if (len > ll->bufsz) {
 105         /* too big to fit in buffer */
 106         logfile_mod_udp_write(lf, buf, len);
 107         return;
 108     }
 109     /* buffer it */
 110     memcpy(ll->buf + ll->offset, buf, len);
 111
 112     ll->offset += len;
 113
 114     assert(ll->offset >= 0);
 115
 116     assert((size_t) ll->offset <= ll->bufsz);
 117 }
 118
 119 static void
 120 logfile_mod_udp_linestart(Logfile * lf)
 121 {
 122 }
 123
 124 static void
 125 logfile_mod_udp_lineend(Logfile * lf)
 126 {
 127 }
 128
 129 static void
 130 logfile_mod_udp_rotate(Logfile * lf)
 131 {
 132     return;
 133 }
 134
 135 static void
 136 logfile_mod_udp_close(Logfile * lf)
 137 {
 138     l_udp_t *ll = (l_udp_t *) lf->data;
 139     lf->f_flush(lf);
 140
 141     if (ll->fd >= 0)
 142         file_close(ll->fd);
 143
 144     if (ll->buf)
 145         xfree(ll->buf);
 146
 147     xfree(lf->data);
 148     lf->data = NULL;
 149 }
 150
 151 /*
 152  * This code expects the path to be //host:port
 153  */
 154 int
 155 logfile_mod_udp_open(Logfile * lf, const char *path, size_t bufsz, int fatal_flag)
 156 {
 157     Ip::Address addr;
 158     char *strAddr;
 159
 160     lf->f_close = logfile_mod_udp_close;
 161     lf->f_linewrite = logfile_mod_udp_writeline;
 162     lf->f_linestart = logfile_mod_udp_linestart;
 163     lf->f_lineend = logfile_mod_udp_lineend;
 164     lf->f_flush = logfile_mod_udp_flush;
 165     lf->f_rotate = logfile_mod_udp_rotate;
 166
 167     l_udp_t *ll = static_cast<l_udp_t*>(xcalloc(1, sizeof(*ll)));
 168     lf->data = ll;
 169
 170     if (strncmp(path, "//", 2) == 0) {
 171         path += 2;
 172     }
 173     strAddr = xstrdup(path);
 174     if (!GetHostWithPort(strAddr, &addr)) {
 175         if (lf->flags.fatal) {
 176             fatalf("Invalid UDP logging address '%s'\n", lf->path);
 177         } else {
 178             debugs(50, DBG_IMPORTANT, "Invalid UDP logging address '" << lf->path << "'");
 179             safe_free(strAddr);
 180             return FALSE;
 181         }
 182     }
 183     safe_free(strAddr);
 184
 185     Ip::Address any_addr;
 186     any_addr.SetAnyAddr();
 187
 188     // require the sending UDP port to be of the right family for the destination address.
 189     if (addr.IsIPv4())
 190         any_addr.SetIPv4();
 191
 192     ll->fd = comm_open(SOCK_DGRAM, IPPROTO_UDP, any_addr, COMM_NONBLOCKING, "UDP log socket");
 193     if (ll->fd < 0) {
 194         if (lf->flags.fatal) {
 195             fatalf("Unable to open UDP socket for logging\n");
 196         } else {
 197             debugs(50, DBG_IMPORTANT, "Unable to open UDP socket for logging");
 198             return FALSE;
 199         }
 200     } else if (!comm_connect_addr(ll->fd, &addr)) {
 201         if (lf->flags.fatal) {
 202             fatalf("Unable to connect to %s for UDP log: %s\n", lf->path, xstrerror());
 203         } else {
 204             debugs(50, DBG_IMPORTANT, "Unable to connect to " << lf->path << " for UDP log: " << xstrerror());
 205             return FALSE;
 206         }
 207     }
 208     if (ll->fd == -1) {
 209         if (ENOENT == errno && fatal_flag) {
 210             fatalf("Cannot open '%s' because\n"
 211                    "\tthe parent directory does not exist.\n"
 212                    "\tPlease create the directory.\n", path);
 213         } else if (EACCES == errno && fatal_flag) {
 214             fatalf("Cannot open '%s' for writing.\n"
 215                    "\tThe parent directory must be writeable by the\n"
 216                    "\tuser '%s', which is the cache_effective_user\n"
 217                    "\tset in squid.conf.", path, Config.effectiveUser);
 218         } else {
 219             debugs(50, DBG_IMPORTANT, "logfileOpen (UDP): " << lf->path << ": " << xstrerror());
 220             return 0;
 221         }
 222     }
 223     /* Force buffer size to something roughly fitting inside an MTU */
 224     /*
 225      * XXX note the receive side needs to receive the whole packet at once;
 226      * applications like netcat have a small default receive buffer and will
 227      * truncate!
 228      */
 229     bufsz = 1400;
 230     if (bufsz > 0) {
 231         ll->buf = static_cast<char*>(xmalloc(bufsz));
 232         ll->bufsz = bufsz;
 233     }
 234
 235     return 1;
 236 }