herrie/src/util.c

   1 /*
   2  * Copyright (c) 2006-2011 Ed Schouten <ed@80386.nl>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26 /**
  27  * @file util.c
  28  * @brief General utility functions
  29  */
  30
  31 #include "stdinc.h"
  32
  33 #include "util.h"
  34
  35 #ifdef BUILD_SCROBBLER
  36 /**
  37  * @brief Convert a numerical value to a hexadecimal character.
  38  */
  39 static inline char
  40 toxdigit(char val)
  41 {
  42         if (val < 10)
  43                 return (val + '0');
  44         else
  45                 return (val - 10 + 'a');
  46 }
  47
  48 void
  49 hex_encode(unsigned char *bin, char *hex, size_t len)
  50 {
  51         while (len-- > 0) {
  52                 *hex++ = toxdigit(*bin >> 4);
  53                 *hex++ = toxdigit(*bin++ & 0x0f);
  54         }
  55 }
  56 #endif /* BUILD_SCROBBLER */
  57
  58 char *
  59 http_escape(const char *str, const char *prepend)
  60 {
  61         const char *c;
  62         const char allowed[] = "-_.!~*'()/";
  63         GString *ret;
  64
  65         if (prepend == NULL)
  66                 prepend = "";
  67
  68         /* Argument may be empty */
  69         if (str == NULL)
  70                 return g_strdup(prepend);
  71
  72         ret = g_string_new(prepend);
  73
  74         for (c = str; *c != '\0'; c++) {
  75                 if (*c == ' ')
  76                         g_string_append_c(ret, '+');
  77                 else if (g_ascii_isalnum(*c) || strchr(allowed, *c) != NULL)
  78                         /* Character is allowed */
  79                         g_string_append_c(ret, *c);
  80                 else
  81                         /* Reserved or unwise character */
  82                         g_string_append_printf(ret, "%%%02hhx",
  83                             (const unsigned char)*c);
  84         }
  85
  86         return g_string_free(ret, FALSE);
  87 }
  88
  89 #ifdef BUILD_XSPF
  90 /**
  91  * @brief Unescape a string according to HTTP/1.1. The conversion will
  92  *        be performed in place. The arguments point to the read and
  93  *        write offsets. In almost all cases, they must point to the
  94  *        same string.
  95  */
  96 static void
  97 http_unescape(char *r, char *w)
  98 {
  99         for (; *r != '\0'; r++, w++) {
 100                 if (r[0] == '%' &&
 101                     g_ascii_isxdigit(r[1]) && g_ascii_isxdigit(r[2])) {
 102                         /* Character needs to be unescaped */
 103                         *w = g_ascii_xdigit_value(r[1]) << 4;
 104                         *w |= g_ascii_xdigit_value(r[2]);
 105                         /* Move two bytes more */
 106                         r += 2;
 107                 } else if (*r == '+') {
 108                         /* Convert + back to space */
 109                         *w = ' ';
 110                 } else {
 111                         /* Ordinary character */
 112                         *w = *r;
 113                 }
 114         }
 115
 116         /* Null terminate the output */
 117         *w = '\0';
 118 }
 119
 120 char *
 121 url_escape(const char *str)
 122 {
 123         if (strstr(str, "://") == NULL) {
 124                 return http_escape(str, "file://");
 125         } else {
 126                 return g_strdup(str);
 127         }
 128 }
 129
 130 char *
 131 url_unescape(char *str)
 132 {
 133         if (strncmp(str, "file://", 7) == 0) {
 134                 http_unescape(str + 7, str);
 135                 /* XXX: slash conversion */
 136         }
 137
 138         return (str);
 139 }
 140 #endif /* BUILD_XSPF */