/*
* include/common/h1.h
* This file contains HTTP/1 protocol definitions.
*
* Copyright (C) 2000-2017 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_H1_H
#define _COMMON_H1_H
#include <common/buffer.h>
#include <common/compiler.h>
#include <common/config.h>
#include <common/http.h>
#include <common/http-hdr.h>
#include <common/ist.h>
#include <common/standard.h>
/* Possible states while parsing HTTP/1 messages (request|response) */
enum h1m_state {
H1_MSG_RQBEFORE = 0, // request: leading LF, before start line
H1_MSG_RQBEFORE_CR = 1, // request: leading CRLF, before start line
/* these ones define a request start line */
H1_MSG_RQMETH = 2, // parsing the Method
H1_MSG_RQMETH_SP = 3, // space(s) after the Method
H1_MSG_RQURI = 4, // parsing the Request URI
H1_MSG_RQURI_SP = 5, // space(s) after the Request URI
H1_MSG_RQVER = 6, // parsing the Request Version
H1_MSG_RQLINE_END = 7, // end of request line (CR or LF)
H1_MSG_RPBEFORE = 8, // response: leading LF, before start line
H1_MSG_RPBEFORE_CR = 9, // response: leading CRLF, before start line
/* these ones define a response start line */
H1_MSG_RPVER = 10, // parsing the Response Version
H1_MSG_RPVER_SP = 11, // space(s) after the Response Version
H1_MSG_RPCODE = 12, // response code
H1_MSG_RPCODE_SP = 13, // space(s) after the response code
H1_MSG_RPREASON = 14, // response reason
H1_MSG_RPLINE_END = 15, // end of response line (CR or LF)
/* common header processing */
H1_MSG_HDR_FIRST = 16, // waiting for first header or last CRLF (no LWS possible)
H1_MSG_HDR_NAME = 17, // parsing header name
H1_MSG_HDR_COL = 18, // parsing header colon
H1_MSG_HDR_L1_SP = 19, // parsing header LWS (SP|HT) before value
H1_MSG_HDR_L1_LF = 20, // parsing header LWS (LF) before value
H1_MSG_HDR_L1_LWS = 21, // checking whether it's a new header or an LWS
H1_MSG_HDR_VAL = 22, // parsing header value
H1_MSG_HDR_L2_LF = 23, // parsing header LWS (LF) inside/after value
H1_MSG_HDR_L2_LWS = 24, // checking whether it's a new header or an LWS
H1_MSG_LAST_LF = 25, // parsing last LF, last state for headers
/* Body processing. */
H1_MSG_CHUNK_SIZE = 26, // parsing the chunk size (RFC7230 #4.1)
H1_MSG_DATA = 27, // skipping data chunk / content-length data
H1_MSG_CHUNK_CRLF = 28, // skipping CRLF after data chunk
H1_MSG_TRAILERS = 29, // trailers (post-data entity headers)
/* we enter this state when we've received the end of the current message */
H1_MSG_DONE = 30, // message end received, waiting for resync or close
H1_MSG_TUNNEL = 31, // tunneled data after DONE
} __attribute__((packed));
/* HTTP/1 message flags (32 bit), for use in h1m->flags only */
#define H1_MF_NONE 0x00000000
#define H1_MF_CLEN 0x00000001 // content-length present
#define H1_MF_CHNK 0x00000002 // chunk present, exclusive with c-l
#define H1_MF_RESP 0x00000004 // this message is the response message
#define H1_MF_TOLOWER 0x00000008 // turn the header names to lower case
#define H1_MF_VER_11 0x00000010 // message indicates version 1.1 or above
#define H1_MF_CONN_CLO 0x00000020 // message contains "connection: close"
#define H1_MF_CONN_KAL 0x00000040 // message contains "connection: keep-alive"
#define H1_MF_CONN_UPG 0x00000080 // message contains "connection: upgrade"
#define H1_MF_XFER_LEN 0x00000100 // message xfer size can be determined
#define H1_MF_XFER_ENC 0x00000200 // transfer-encoding is present
#define H1_MF_NO_PHDR 0x00000400 // don't add pseudo-headers in the header list
#define H1_MF_HDRS_ONLY 0x00000800 // parse headers only
#define H1_MF_CLEAN_CONN_HDR 0x00001000 // skip close/keep-alive values of connection headers during parsing
/* Note: for a connection to be persistent, we need this for the request :
* - one of CLEN or CHNK
* - version 1.0 and KAL and not CLO
* - or version 1.1 and not CLO
* For the response it's the same except that UPG must not appear either.
* So in short, for a request it's (CLEN|CHNK) > 0 && !CLO && (VER_11 || KAL)
* and for a response it's (CLEN|CHNK) > 0 && !(CLO|UPG) && (VER_11 || KAL)
*/
/* basic HTTP/1 message state for use in parsers. The err_pos field is special,
* it is pre-set to a negative value (-1 or -2), and once non-negative it contains
* the relative position in the message of the first parse error. -2 is used to tell
* the parser that we want to block the invalid message. -1 is used to only perform
* a silent capture.
*/
struct h1m {
enum h1m_state state; // H1 message state (H1_MSG_*)
/* 24 bits available here */
uint32_t flags; // H1 message flags (H1_MF_*)
uint64_t curr_len; // content-length or last chunk length
uint64_t body_len; // total known size of the body length
uint32_t next; // next byte to parse, relative to buffer's head
int err_pos; // position in the byte stream of the first error (H1 or H2)
int err_state; // state where the first error was met (H1 or H2)
};
/* basic H1 start line, describes either the request and the response */
union h1_sl { /* useful start line pointers, relative to ->sol */
struct {
struct ist m; /* METHOD */
struct ist u; /* URI */
struct ist v; /* VERSION */
enum http_meth_t meth; /* method */
} rq; /* request line : field, length */
struct {
struct ist v; /* VERSION */
struct ist c; /* CODE */
struct ist r; /* REASON */
uint16_t status; /* status code */
} st; /* status line : field, length */
};
int h1_headers_to_hdr_list(char *start, const char *stop,
struct http_hdr *hdr, unsigned int hdr_num,
struct h1m *h1m, union h1_sl *slp);
int h1_measure_trailers(const struct buffer *buf, unsigned int ofs, unsigned int max);
int h1_parse_cont_len_header(struct h1m *h1m, struct ist *value);
void h1_parse_xfer_enc_header(struct h1m *h1m, struct ist value);
void h1_parse_connection_header(struct h1m *h1m, struct ist *value);
/* for debugging, reports the HTTP/1 message state name */
static inline const char *h1m_state_str(enum h1m_state msg_state)
{
switch (msg_state) {
case H1_MSG_RQBEFORE: return "MSG_RQBEFORE";
case H1_MSG_RQBEFORE_CR: return "MSG_RQBEFORE_CR";
case H1_MSG_RQMETH: return "MSG_RQMETH";
case H1_MSG_RQMETH_SP: return "MSG_RQMETH_SP";
case H1_MSG_RQURI: return "MSG_RQURI";
case H1_MSG_RQURI_SP: return "MSG_RQURI_SP";
case H1_MSG_RQVER: return "MSG_RQVER";
case H1_MSG_RQLINE_END: return "MSG_RQLINE_END";
case H1_MSG_RPBEFORE: return "MSG_RPBEFORE";
case H1_MSG_RPBEFORE_CR: return "MSG_RPBEFORE_CR";
case H1_MSG_RPVER: return "MSG_RPVER";
case H1_MSG_RPVER_SP: return "MSG_RPVER_SP";
case H1_MSG_RPCODE: return "MSG_RPCODE";
case H1_MSG_RPCODE_SP: return "MSG_RPCODE_SP";
case H1_MSG_RPREASON: return "MSG_RPREASON";
case H1_MSG_RPLINE_END: return "MSG_RPLINE_END";
case H1_MSG_HDR_FIRST: return "MSG_HDR_FIRST";
case H1_MSG_HDR_NAME: return "MSG_HDR_NAME";
case H1_MSG_HDR_COL: return "MSG_HDR_COL";
case H1_MSG_HDR_L1_SP: return "MSG_HDR_L1_SP";
case H1_MSG_HDR_L1_LF: return "MSG_HDR_L1_LF";
case H1_MSG_HDR_L1_LWS: return "MSG_HDR_L1_LWS";
case H1_MSG_HDR_VAL: return "MSG_HDR_VAL";
case H1_MSG_HDR_L2_LF: return "MSG_HDR_L2_LF";
case H1_MSG_HDR_L2_LWS: return "MSG_HDR_L2_LWS";
case H1_MSG_LAST_LF: return "MSG_LAST_LF";
case H1_MSG_CHUNK_SIZE: return "MSG_CHUNK_SIZE";
case H1_MSG_DATA: return "MSG_DATA";
case H1_MSG_CHUNK_CRLF: return "MSG_CHUNK_CRLF";
case H1_MSG_TRAILERS: return "MSG_TRAILERS";
case H1_MSG_DONE: return "MSG_DONE";
case H1_MSG_TUNNEL: return "MSG_TUNNEL";
default: return "MSG_??????";
}
}
/* This function may be called only in HTTP_MSG_CHUNK_CRLF. It reads the CRLF or
* a possible LF alone at the end of a chunk. The caller should adjust msg->next
* in order to include this part into the next forwarding phase. Note that the
* caller must ensure that head+start points to the first byte to parse. It
* returns the number of bytes parsed on success, so the caller can set msg_state
* to HTTP_MSG_CHUNK_SIZE. If not enough data are available, the function does not
* change anything and returns zero. Otherwise it returns a negative value
* indicating the error positionn relative to <stop>. Note: this function is
* designed to parse wrapped CRLF at the end of the buffer.
*/
static inline int h1_skip_chunk_crlf(const struct buffer *buf, int start, int stop)
{
const char *ptr = b_peek(buf, start);
int bytes = 1;
if (stop <= start)
return 0;
/* NB: we'll check data availability at the end. It's not a
* problem because whatever we match first will be checked
* against the correct length.
*/
if (*ptr == '\r') {
bytes++;
ptr++;
if (ptr >= b_wrap(buf))
ptr = b_orig(buf);
}
if (bytes > stop - start)
return 0;
if (*ptr != '\n') // negative position to stop
return ptr - __b_peek(buf, stop);
return bytes;
}
/* Parse the chunk size start at buf + start and stops before buf + stop. The
* positions are relative to the buffer's head.
* It returns the chunk size in <res> and the amount of bytes read this way :
* < 0 : error at this position relative to <stop>
* = 0 : not enough bytes to read a complete chunk size
* > 0 : number of bytes successfully read that the caller can skip
* On success, the caller should adjust its msg->next to point to the first
* byte of data after the chunk size, so that we know we can forward exactly
* msg->next bytes, and msg->sol to contain the exact number of bytes forming
* the chunk size. That way it is always possible to differentiate between the
* start of the body and the start of the data. Note: this function is designed
* to parse wrapped CRLF at the end of the buffer.
*/
static inline int h1_parse_chunk_size(const struct buffer *buf, int start, int stop, unsigned int *res)
{
const char *ptr = b_peek(buf, start);
const char *ptr_old = ptr;
const char *end = b_wrap(buf);
unsigned int chunk = 0;
stop -= start; // bytes left
start = stop; // bytes to transfer
/* The chunk size is in the following form, though we are only
* interested in the size and CRLF :
* 1*HEXDIGIT *WSP *[ ';' extensions ] CRLF
*/
while (1) {
int c;
if (!stop)
return 0;
c = hex2i(*ptr);
if (c < 0) /* not a hex digit anymore */
break;
if (unlikely(++ptr >= end))
ptr = b_orig(buf);
if (unlikely(chunk & 0xF8000000)) /* integer overflow will occur if result >= 2GB */
goto error;
chunk = (chunk << 4) + c;
stop--;
}
/* empty size not allowed */
if (unlikely(ptr == ptr_old))
goto error;
while (HTTP_IS_SPHT(*ptr)) {
if (++ptr >= end)
ptr = b_orig(buf);
if (--stop == 0)
return 0;
}
/* Up to there, we know that at least one byte is present at *ptr. Check
* for the end of chunk size.
*/
while (1) {
if (likely(HTTP_IS_CRLF(*ptr))) {
/* we now have a CR or an LF at ptr */
if (likely(*ptr == '\r')) {
if (++ptr >= end)
ptr = b_orig(buf);
if (--stop == 0)
return 0;
}
if (*ptr != '\n')
goto error;
if (++ptr >= end)
ptr = b_orig(buf);
--stop;
/* done */
break;
}
else if (likely(*ptr == ';')) {
/* chunk extension, ends at next CRLF */
if (++ptr >= end)
ptr = b_orig(buf);
if (--stop == 0)
return 0;
while (!HTTP_IS_CRLF(*ptr)) {
if (++ptr >= end)
ptr = b_orig(buf);
if (--stop == 0)
return 0;
}
/* we have a CRLF now, loop above */
continue;
}
else
goto error;
}
/* OK we found our CRLF and now <ptr> points to the next byte, which may
* or may not be present. Let's return the number of bytes parsed.
*/
*res = chunk;
return start - stop;
error:
*res = 0; // just to stop gcc's -Wuninitialized warning :-(
return -stop;
}
/* initializes an H1 message for a request */
static inline struct h1m *h1m_init_req(struct h1m *h1m)
{
h1m->state = H1_MSG_RQBEFORE;
h1m->next = 0;
h1m->flags = H1_MF_NONE;
h1m->curr_len = 0;
h1m->body_len = 0;
h1m->err_pos = -2;
h1m->err_state = 0;
return h1m;
}
/* initializes an H1 message for a response */
static inline struct h1m *h1m_init_res(struct h1m *h1m)
{
h1m->state = H1_MSG_RPBEFORE;
h1m->next = 0;
h1m->flags = H1_MF_RESP;
h1m->curr_len = 0;
h1m->body_len = 0;
h1m->err_pos = -2;
h1m->err_state = 0;
return h1m;
}
#endif /* _COMMON_H1_H */