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