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#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
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