subversion/svnserve/log-escape.c

   1 /*
   2  * log-escape.c :  Functions for escaping log items
   3  *                 copied from Apache httpd
   4  *
   5  * ====================================================================
   6  * Licensed to the Apache Software Foundation (ASF) under one or more
   7  * contributor license agreements.  See the NOTICE file distributed with
   8  * this work for additional information regarding copyright ownership.
   9  * The ASF licenses this file to You under the Apache License, Version 2.0
  10  * (the "License"); you may not use this file except in compliance with
  11  * the License.  You may obtain a copy of the License at
  12  *
  13  *     http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  *
  21  * ====================================================================
  22  *
  23  * Copyright (c) 2008 CollabNet.  All rights reserved.
  24  *
  25  * This software is licensed as described in the file COPYING, which
  26  * you should have received as part of this distribution.  The terms
  27  * are also available at http://subversion.tigris.org/license-1.html.
  28  * If newer versions of this license are posted there, you may use a
  29  * newer version instead, at your option.
  30  *
  31  * This software consists of voluntary contributions made by many
  32  * individuals.  For exact contribution history, see the revision
  33  * history and logs, available at http://subversion.tigris.org/.
  34  * ====================================================================
  35  */
  36
  37
  38 #include <apr.h>
  39 #include <apr_lib.h>
  40 #define APR_WANT_STRFUNC
  41 #include <apr_want.h>
  42
  43 /* copied from httpd-2.2.4/server/util.c */
  44 /* c2x takes an unsigned, and expects the caller has guaranteed that
  45  * 0 <= what < 256... which usually means that you have to cast to
  46  * unsigned char first, because (unsigned)(char)(x) first goes through
  47  * signed extension to an int before the unsigned cast.
  48  *
  49  * The reason for this assumption is to assist gcc code generation --
  50  * the unsigned char -> unsigned extension is already done earlier in
  51  * both uses of this code, so there's no need to waste time doing it
  52  * again.
  53  */
  54 static const char c2x_table[] = "0123456789abcdef";
  55
  56 /* copied from httpd-2.2.4/server/util.c */
  57 static APR_INLINE unsigned char *c2x(unsigned what, unsigned char prefix,
  58                                      unsigned char *where)
  59 {
  60 #if APR_CHARSET_EBCDIC
  61     what = apr_xlate_conv_byte(ap_hdrs_to_ascii, (unsigned char)what);
  62 #endif /*APR_CHARSET_EBCDIC*/
  63     *where++ = prefix;
  64     *where++ = c2x_table[what >> 4];
  65     *where++ = c2x_table[what & 0xf];
  66     return where;
  67 }
  68
  69 /* copied from httpd-2.2.4/server/util.c */
  70 apr_size_t escape_errorlog_item(char *dest, const char *source,
  71                                 apr_size_t buflen)
  72 {
  73     unsigned char *d, *ep;
  74     const unsigned char *s;
  75
  76     if (!source || !buflen) { /* be safe */
  77         return 0;
  78     }
  79
  80     d = (unsigned char *)dest;
  81     s = (const unsigned char *)source;
  82     ep = d + buflen - 1;
  83
  84     for (; d < ep && *s; ++s) {
  85
  86         /* httpd-2.2.4/server/util.c has this:
  87              if (TEST_CHAR(*s, T_ESCAPE_LOGITEM)) {
  88            which does this same check with a fast lookup table.  Well,
  89            mostly the same; we don't escape quotes, as that does.
  90         */
  91         if (*s && (!apr_isprint(*s) || *s == '\\' || apr_iscntrl(*s))) {
  92             *d++ = '\\';
  93             if (d >= ep) {
  94                 --d;
  95                 break;
  96             }
  97
  98             switch(*s) {
  99             case '\b':
 100                 *d++ = 'b';
 101                 break;
 102             case '\n':
 103                 *d++ = 'n';
 104                 break;
 105             case '\r':
 106                 *d++ = 'r';
 107                 break;
 108             case '\t':
 109                 *d++ = 't';
 110                 break;
 111             case '\v':
 112                 *d++ = 'v';
 113                 break;
 114             case '\\':
 115                 *d++ = *s;
 116                 break;
 117             case '"': /* no need for this in error log */
 118                 d[-1] = *s;
 119                 break;
 120             default:
 121                 if (d >= ep - 2) {
 122                     ep = --d; /* break the for loop as well */
 123                     break;
 124                 }
 125                 c2x(*s, 'x', d);
 126                 d += 3;
 127             }
 128         }
 129         else {
 130             *d++ = *s;
 131         }
 132     }
 133     *d = '\0';
 134
 135     return (d - (unsigned char *)dest);
 136 }