utils.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19
  20 #include <ctype.h>
  21 #include "uhttpd.h"
  22
  23 bool uh_use_chunked(struct client *cl)
  24 {
  25         if (cl->request.version != UH_HTTP_VER_1_1)
  26                 return false;
  27
  28         if (cl->request.method == UH_HTTP_MSG_HEAD)
  29                 return false;
  30
  31         return true;
  32 }
  33
  34 void uh_chunk_write(struct client *cl, const void *data, int len)
  35 {
  36         bool chunked = uh_use_chunked(cl);
  37
  38         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
  39         if (chunked)
  40                 ustream_printf(cl->us, "%X\r\n", len);
  41         ustream_write(cl->us, data, len, true);
  42         if (chunked)
  43                 ustream_printf(cl->us, "\r\n", len);
  44 }
  45
  46 void uh_chunk_vprintf(struct client *cl, const char *format, va_list arg)
  47 {
  48         char buf[256];
  49         va_list arg2;
  50         int len;
  51
  52         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
  53         if (!uh_use_chunked(cl)) {
  54                 ustream_vprintf(cl->us, format, arg);
  55                 return;
  56         }
  57
  58         va_copy(arg2, arg);
  59         len = vsnprintf(buf, sizeof(buf), format, arg2);
  60         va_end(arg2);
  61
  62         ustream_printf(cl->us, "%X\r\n", len);
  63         if (len < sizeof(buf))
  64                 ustream_write(cl->us, buf, len, true);
  65         else
  66                 ustream_vprintf(cl->us, format, arg);
  67         ustream_printf(cl->us, "\r\n", len);
  68 }
  69
  70 void uh_chunk_printf(struct client *cl, const char *format, ...)
  71 {
  72         va_list arg;
  73
  74         va_start(arg, format);
  75         uh_chunk_vprintf(cl, format, arg);
  76         va_end(arg);
  77 }
  78
  79 void uh_chunk_eof(struct client *cl)
  80 {
  81         if (!uh_use_chunked(cl))
  82                 return;
  83
  84         ustream_printf(cl->us, "0\r\n\r\n");
  85 }
  86
  87 /* blen is the size of buf; slen is the length of src.  The input-string need
  88 ** not be, and the output string will not be, null-terminated.  Returns the
  89 ** length of the decoded string, -1 on buffer overflow, -2 on malformed string. */
  90 int uh_urldecode(char *buf, int blen, const char *src, int slen)
  91 {
  92         int i;
  93         int len = 0;
  94
  95 #define hex(x) \
  96         (((x) <= '9') ? ((x) - '0') : \
  97                 (((x) <= 'F') ? ((x) - 'A' + 10) : \
  98                         ((x) - 'a' + 10)))
  99
 100         for (i = 0; (i < slen) && (len < blen); i++)
 101         {
 102                 if (src[i] == '%')
 103                 {
 104                         if (((i+2) < slen) && isxdigit(src[i+1]) && isxdigit(src[i+2]))
 105                         {
 106                                 buf[len++] = (char)(16 * hex(src[i+1]) + hex(src[i+2]));
 107                                 i += 2;
 108                         }
 109                         else
 110                         {
 111                                 /* Encoding error: it's hard to think of a
 112                                 ** scenario in which returning an incorrect
 113                                 ** 'decoding' of the malformed string is
 114                                 ** preferable to signaling an error condition. */
 115                                 #if 0 /* WORSE_IS_BETTER */
 116                                     buf[len++] = '%';
 117                                 #else
 118                                     return -2;
 119                                 #endif
 120                         }
 121                 }
 122                 else
 123                 {
 124                         buf[len++] = src[i];
 125                 }
 126         }
 127
 128         return (i == slen) ? len : -1;
 129 }
 130
 131 /* blen is the size of buf; slen is the length of src.  The input-string need
 132 ** not be, and the output string will not be, null-terminated.  Returns the
 133 ** length of the encoded string, or -1 on error (buffer overflow) */
 134 int uh_urlencode(char *buf, int blen, const char *src, int slen)
 135 {
 136         int i;
 137         int len = 0;
 138         const char hex[] = "0123456789abcdef";
 139
 140         for (i = 0; (i < slen) && (len < blen); i++)
 141         {
 142                 if( isalnum(src[i]) || (src[i] == '-') || (src[i] == '_') ||
 143                     (src[i] == '.') || (src[i] == '~') )
 144                 {
 145                         buf[len++] = src[i];
 146                 }
 147                 else if ((len+3) <= blen)
 148                 {
 149                         buf[len++] = '%';
 150                         buf[len++] = hex[(src[i] >> 4) & 15];
 151                         buf[len++] = hex[ src[i]       & 15];
 152                 }
 153                 else
 154                 {
 155                         len = -1;
 156                         break;
 157                 }
 158         }
 159
 160         return (i == slen) ? len : -1;
 161 }
 162
 163 int uh_b64decode(char *buf, int blen, const unsigned char *src, int slen)
 164 {
 165         int i = 0;
 166         int len = 0;
 167
 168         unsigned int cin  = 0;
 169         unsigned int cout = 0;
 170
 171
 172         for (i = 0; (i <= slen) && (src[i] != 0); i++)
 173         {
 174                 cin = src[i];
 175
 176                 if ((cin >= '0') && (cin <= '9'))
 177                         cin = cin - '0' + 52;
 178                 else if ((cin >= 'A') && (cin <= 'Z'))
 179                         cin = cin - 'A';
 180                 else if ((cin >= 'a') && (cin <= 'z'))
 181                         cin = cin - 'a' + 26;
 182                 else if (cin == '+')
 183                         cin = 62;
 184                 else if (cin == '/')
 185                         cin = 63;
 186                 else if (cin == '=')
 187                         cin = 0;
 188                 else
 189                         continue;
 190
 191                 cout = (cout << 6) | cin;
 192
 193                 if ((i % 4) == 3)
 194                 {
 195                         if ((len + 3) < blen)
 196                         {
 197                                 buf[len++] = (char)(cout >> 16);
 198                                 buf[len++] = (char)(cout >> 8);
 199                                 buf[len++] = (char)(cout);
 200                         }
 201                         else
 202                         {
 203                                 break;
 204                         }
 205                 }
 206         }
 207
 208         buf[len++] = 0;
 209         return len;
 210 }