utils.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  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 || cl->request.method == UH_HTTP_MSG_OPTIONS)
  29                 return false;
  30
  31         /* RFC2616 10.2.5, 10.3.5 */
  32         if (cl->http_code == 204 || cl->http_code == 304)
  33                 return false;
  34
  35         return !cl->request.disable_chunked;
  36 }
  37
  38 void uh_chunk_write(struct client *cl, const void *data, int len)
  39 {
  40         bool chunked = uh_use_chunked(cl);
  41
  42         if (cl->state == CLIENT_STATE_CLEANUP)
  43                 return;
  44
  45         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
  46         if (chunked)
  47                 ustream_printf(cl->us, "%X\r\n", len);
  48         ustream_write(cl->us, data, len, true);
  49         if (chunked)
  50                 ustream_printf(cl->us, "\r\n", len);
  51 }
  52
  53 void uh_chunk_vprintf(struct client *cl, const char *format, va_list arg)
  54 {
  55         char buf[256];
  56         va_list arg2;
  57         int len;
  58
  59         if (cl->state == CLIENT_STATE_CLEANUP)
  60                 return;
  61
  62         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
  63         if (!uh_use_chunked(cl)) {
  64                 ustream_vprintf(cl->us, format, arg);
  65                 return;
  66         }
  67
  68         va_copy(arg2, arg);
  69         len = vsnprintf(buf, sizeof(buf), format, arg2);
  70         va_end(arg2);
  71
  72         ustream_printf(cl->us, "%X\r\n", len);
  73         if (len < sizeof(buf))
  74                 ustream_write(cl->us, buf, len, true);
  75         else
  76                 ustream_vprintf(cl->us, format, arg);
  77         ustream_printf(cl->us, "\r\n", len);
  78 }
  79
  80 void uh_chunk_printf(struct client *cl, const char *format, ...)
  81 {
  82         va_list arg;
  83
  84         va_start(arg, format);
  85         uh_chunk_vprintf(cl, format, arg);
  86         va_end(arg);
  87 }
  88
  89 void uh_chunk_eof(struct client *cl)
  90 {
  91         if (!uh_use_chunked(cl))
  92                 return;
  93
  94         if (cl->state == CLIENT_STATE_CLEANUP)
  95                 return;
  96
  97         ustream_printf(cl->us, "0\r\n\r\n");
  98 }
  99
 100 /* blen is the size of buf; slen is the length of src.  The input-string need
 101 ** not be, and the output string will not be, null-terminated.  Returns the
 102 ** length of the decoded string, -1 on buffer overflow, -2 on malformed string. */
 103 int uh_urldecode(char *buf, int blen, const char *src, int slen)
 104 {
 105         int i;
 106         int len = 0;
 107
 108 #define hex(x) \
 109         (((x) <= '9') ? ((x) - '0') : \
 110                 (((x) <= 'F') ? ((x) - 'A' + 10) : \
 111                         ((x) - 'a' + 10)))
 112
 113         for (i = 0; (i < slen) && (len < blen); i++)
 114         {
 115                 if (src[i] != '%') {
 116                         buf[len++] = src[i];
 117                         continue;
 118                 }
 119
 120                 if (i + 2 >= slen || !isxdigit(src[i + 1]) || !isxdigit(src[i + 2]))
 121                         return -2;
 122
 123                 buf[len++] = (char)(16 * hex(src[i+1]) + hex(src[i+2]));
 124                 i += 2;
 125         }
 126         buf[len] = 0;
 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         static 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 void *src, int slen)
 164 {
 165         const unsigned char *str = src;
 166         unsigned int cout = 0;
 167         unsigned int cin  = 0;
 168         int len = 0;
 169         int i = 0;
 170
 171         for (i = 0; (i <= slen) && (str[i] != 0); i++)
 172         {
 173                 cin = str[i];
 174
 175                 if ((cin >= '0') && (cin <= '9'))
 176                         cin = cin - '0' + 52;
 177                 else if ((cin >= 'A') && (cin <= 'Z'))
 178                         cin = cin - 'A';
 179                 else if ((cin >= 'a') && (cin <= 'z'))
 180                         cin = cin - 'a' + 26;
 181                 else if (cin == '+')
 182                         cin = 62;
 183                 else if (cin == '/')
 184                         cin = 63;
 185                 else if (cin == '=')
 186                         cin = 0;
 187                 else
 188                         continue;
 189
 190                 cout = (cout << 6) | cin;
 191
 192                 if ((i % 4) != 3)
 193                         continue;
 194
 195                 if ((len + 3) >= blen)
 196                         break;
 197
 198                 buf[len++] = (char)(cout >> 16);
 199                 buf[len++] = (char)(cout >> 8);
 200                 buf[len++] = (char)(cout);
 201         }
 202
 203         buf[len++] = 0;
 204         return len;
 205 }
 206
 207 bool uh_path_match(const char *prefix, const char *url)
 208 {
 209         int len = strlen(prefix);
 210
 211         /* A prefix of "/" will - by definition - match any url */
 212         if (prefix[0] == '/' && len == 1)
 213                 return true;
 214
 215         if (strncmp(url, prefix, len) != 0)
 216                 return false;
 217
 218         return url[len] == '/' || url[len] == 0;
 219 }
 220
 221 char *uh_split_header(char *str)
 222 {
 223         char *val;
 224
 225         val = strchr(str, ':');
 226         if (!val)
 227                 return NULL;
 228
 229         *val = 0;
 230         val++;
 231
 232         while (isspace(*val))
 233                 val++;
 234
 235         return val;
 236 }
 237
 238 bool uh_addr_rfc1918(struct uh_addr *addr)
 239 {
 240         uint32_t a;
 241
 242         if (addr->family != AF_INET)
 243                 return false;
 244
 245         a = htonl(addr->in.s_addr);
 246         return ((a >= 0x0A000000) && (a <= 0x0AFFFFFF)) ||
 247                ((a >= 0xAC100000) && (a <= 0xAC1FFFFF)) ||
 248                ((a >= 0xC0A80000) && (a <= 0xC0A8FFFF));
 249
 250         return 0;
 251 }
 252
 253
 254 static bool is_html_special_char(char c)
 255 {
 256         switch (c)
 257         {
 258         case 0x22:
 259         case 0x26:
 260         case 0x27:
 261         case 0x3C:
 262         case 0x3E:
 263                 return true;
 264
 265         default:
 266                 return false;
 267         }
 268 }
 269
 270 char *uh_htmlescape(const char *str)
 271 {
 272         size_t i, len;
 273         char *p, *copy;
 274
 275         for (i = 0, len = 1; str[i]; i++)
 276                 if (is_html_special_char(str[i]))
 277                         len += 6; /* &#x??; */
 278                 else
 279                         len++;
 280
 281         copy = calloc(1, len);
 282
 283         if (!copy)
 284                 return NULL;
 285
 286         for (i = 0, p = copy; str[i]; i++)
 287                 if (is_html_special_char(str[i]))
 288                         p += sprintf(p, "&#x%02x;", (unsigned int)str[i]);
 289                 else
 290                         *p++ = str[i];
 291
 292         return copy;
 293 }