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