Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 330 lines (298 sloc) 7.836 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
#include <stddef.h>
#include "picohttpparser.h"

/* $Id$ */

#if __GNUC__ >= 3
# define likely(x) __builtin_expect(!!(x), 1)
# define unlikely(x) __builtin_expect(!!(x), 0)
#else
# define likely(x) (x)
# define unlikely(x) (x)
#endif

#define CHECK_EOF() \
if (buf == buf_end) { \
*ret = -2; \
return NULL; \
}

#define EXPECT_CHAR(ch) \
CHECK_EOF(); \
if (*buf++ != ch) { \
*ret = -1; \
return NULL; \
}

#define ADVANCE_TOKEN(tok, toklen) do { \
const char* tok_start = buf; \
for (; ; ++buf) { \
CHECK_EOF(); \
if (*buf == ' ') { \
break; \
} else if (*buf == '\015' || *buf == '\012') { \
*ret = -1; \
return NULL; \
} \
} \
tok = tok_start; \
toklen = buf - tok_start; \
} while (0)

static const char* get_token_to_eol(const char* buf, const char* buf_end,
const char** token, size_t* token_len,
int* ret)
{
  const char* token_start = buf;
  
  while (1) {
    if (likely(buf_end - buf >= 16)) {
      unsigned i;
      for (i = 0; i < 16; i++, ++buf) {
if (unlikely((unsigned char)*buf <= '\015')
&& (*buf == '\015' || *buf == '\012')) {
goto EOL_FOUND;
}
      }
    } else {
      for (; ; ++buf) {
CHECK_EOF();
if (unlikely((unsigned char)*buf <= '\015')
&& (*buf == '\015' || *buf == '\012')) {
goto EOL_FOUND;
}
      }
    }
  }
 EOL_FOUND:
  if (*buf == '\015') {
    ++buf;
    EXPECT_CHAR('\012');
    *token_len = buf - 2 - token_start;
  } else { /* should be: *buf == '\012' */
    *token_len = buf - token_start;
    ++buf;
  }
  *token = token_start;
  
  return buf;
}
  
static const char* is_complete(const char* buf, const char* buf_end,
size_t last_len, int* ret)
{
  int ret_cnt = 0;
  buf = last_len < 3 ? buf : buf + last_len - 3;
  
  while (1) {
    CHECK_EOF();
    if (*buf == '\015') {
      ++buf;
      CHECK_EOF();
      EXPECT_CHAR('\012');
      ++ret_cnt;
    } else if (*buf == '\012') {
      ++buf;
      ++ret_cnt;
    } else {
      ++buf;
      ret_cnt = 0;
    }
    if (ret_cnt == 2) {
      return buf;
    }
  }
  
  *ret = -2;
  return NULL;
}

/* *_buf is always within [buf, buf_end) upon success */
static const char* parse_int(const char* buf, const char* buf_end, int* value,
int* ret)
{
  int v;
  CHECK_EOF();
  if (! ('0' <= *buf && *buf <= '9')) {
    *ret = -1;
    return NULL;
  }
  v = 0;
  for (; ; ++buf) {
    CHECK_EOF();
    if ('0' <= *buf && *buf <= '9') {
      v = v * 10 + *buf - '0';
    } else {
      break;
    }
  }
  
  *value = v;
  return buf;
}

/* returned pointer is always within [buf, buf_end), or null */
static const char* parse_http_version(const char* buf, const char* buf_end,
int* minor_version, int* ret)
{
  EXPECT_CHAR('H'); EXPECT_CHAR('T'); EXPECT_CHAR('T'); EXPECT_CHAR('P');
  EXPECT_CHAR('/'); EXPECT_CHAR('1'); EXPECT_CHAR('.');
  return parse_int(buf, buf_end, minor_version, ret);
}

static const char* parse_headers(const char* buf, const char* buf_end,
struct phr_header* headers,
size_t* num_headers, size_t max_headers,
int* ret)
{
  for (; ; ++*num_headers) {
    CHECK_EOF();
    if (*buf == '\015') {
      ++buf;
      EXPECT_CHAR('\012');
      break;
    } else if (*buf == '\012') {
      ++buf;
      break;
    }
    if (*num_headers == max_headers) {
      *ret = -1;
      return NULL;
    }
    if (*num_headers == 0 || ! (*buf == ' ' || *buf == '\t')) {
      /* parsing name, but do not discard SP before colon, see
* http://www.mozilla.org/security/announce/2006/mfsa2006-33.html */
      headers[*num_headers].name = buf;
      for (; ; ++buf) {
CHECK_EOF();
if (*buf == ':') {
break;
} else if (*buf < ' ') {
*ret = -1;
return NULL;
}
      }
      headers[*num_headers].name_len = buf - headers[*num_headers].name;
      ++buf;
      for (; ; ++buf) {
CHECK_EOF();
if (! (*buf == ' ' || *buf == '\t')) {
break;
}
      }
    } else {
      headers[*num_headers].name = NULL;
      headers[*num_headers].name_len = 0;
    }
    if ((buf = get_token_to_eol(buf, buf_end, &headers[*num_headers].value,
&headers[*num_headers].value_len, ret))
== NULL) {
      return NULL;
    }
  }
  return buf;
}

const char* parse_request(const char* buf, const char* buf_end,
const char** method, size_t* method_len,
const char** path, size_t* path_len,
int* minor_version, struct phr_header* headers,
size_t* num_headers, size_t max_headers, int* ret)
{
  /* skip first empty line (some clients add CRLF after POST content) */
  CHECK_EOF();
  if (*buf == '\015') {
    ++buf;
    EXPECT_CHAR('\012');
  } else if (*buf == '\012') {
    ++buf;
  }
  
  /* parse request line */
  ADVANCE_TOKEN(*method, *method_len);
  ++buf;
  ADVANCE_TOKEN(*path, *path_len);
  ++buf;
  if ((buf = parse_http_version(buf, buf_end, minor_version, ret)) == NULL) {
    return NULL;
  }
  if (*buf == '\015') {
    ++buf;
    EXPECT_CHAR('\012');
  } else if (*buf == '\012') {
    ++buf;
  } else {
    *ret = -1;
    return NULL;
  }
  
  return parse_headers(buf, buf_end, headers, num_headers, max_headers, ret);
}

int phr_parse_request(const char* buf_start, size_t len, const char** method,
size_t* method_len, const char** path, size_t* path_len,
int* minor_version, struct phr_header* headers,
size_t* num_headers, size_t last_len)
{
  const char * buf = buf_start, * buf_end = buf_start + len;
  size_t max_headers = *num_headers;
  int r;
  
  *method = NULL;
  *method_len = 0;
  *path = NULL;
  *path_len = 0;
  *minor_version = -1;
  *num_headers = 0;
  
  /* if last_len != 0, check if the request is complete (a fast countermeasure
againt slowloris */
  if (last_len != 0 && is_complete(buf, buf_end, last_len, &r) == NULL) {
    return r;
  }
  
  if ((buf = parse_request(buf, buf_end, method, method_len, path, path_len,
minor_version, headers, num_headers, max_headers,
&r))
      == NULL) {
    return r;
  }
  
  return buf - buf_start;
}

static const char* parse_response(const char* buf, const char* buf_end,
int* minor_version, int* status,
const char** msg, size_t* msg_len,
struct phr_header* headers,
size_t* num_headers, size_t max_headers,
int* ret)
{
  /* parse "HTTP/1.x" */
  if ((buf = parse_http_version(buf, buf_end, minor_version, ret)) == NULL) {
    return NULL;
  }
  /* skip space */
  if (*buf++ != ' ') {
    *ret = -1;
    return NULL;
  }
  /* parse status code */
  if ((buf = parse_int(buf, buf_end, status, ret)) == NULL) {
    return NULL;
  }
  /* skip space */
  if (*buf++ != ' ') {
    *ret = -1;
    return NULL;
  }
  /* get message */
  if ((buf = get_token_to_eol(buf, buf_end, msg, msg_len, ret)) == NULL) {
    return NULL;
  }
  
  return parse_headers(buf, buf_end, headers, num_headers, max_headers, ret);
}

int phr_parse_response(const char* buf_start, size_t len, int* minor_version,
int* status, const char** msg, size_t* msg_len,
struct phr_header* headers, size_t* num_headers,
size_t last_len)
{
  const char * buf = buf_start, * buf_end = buf + len;
  size_t max_headers = *num_headers;
  int r;
  
  *minor_version = -1;
  *status = 0;
  *msg = NULL;
  *msg_len = 0;
  *num_headers = 0;
  
  /* if last_len != 0, check if the response is complete (a fast countermeasure
against slowloris */
  if (last_len != 0 && is_complete(buf, buf_end, last_len, &r) == NULL) {
    return r;
  }
  
  if ((buf = parse_response(buf, buf_end, minor_version, status, msg, msg_len,
headers, num_headers, max_headers, &r))
      == NULL) {
    return r;
  }
  
  return buf - buf_start;
}

#undef CHECK_EOF
#undef EXPECT_CHAR
#undef ADVANCE_TOKEN
Something went wrong with that request. Please try again.