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