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/*
* include/common/h2.h
* This file contains types and macros used for the HTTP/2 protocol
*
* Copyright (C) 2000-2017 Willy Tarreau - w@1wt.eu
* Copyright (C) 2017 HAProxy Technologies
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef _COMMON_H2_H
#define _COMMON_H2_H
#include <common/config.h>
#include <common/http-hdr.h>
#include <common/htx.h>
#include <common/ist.h>
/* indexes of most important pseudo headers can be simplified to an almost
* linear array by dividing the index by 2 for all values from 1 to 9, and
* caping to 4 for values up to 14 ; thus it fits in a single 24-bit array
* shifted by 3 times the index value/2, or a 32-bit array shifted by 4x.
* Don't change these values, they are assumed by hpack_idx_to_phdr(). There
* is an entry for the Host header field which is not a pseudo-header but
* needs to be tracked as we should only use :authority if it's absent.
*/
enum {
H2_PHDR_IDX_NONE = 0,
H2_PHDR_IDX_AUTH = 1, /* :authority = 1 */
H2_PHDR_IDX_METH = 2, /* :method = 2..3 */
H2_PHDR_IDX_PATH = 3, /* :path = 4..5 */
H2_PHDR_IDX_SCHM = 4, /* :scheme = 6..7 */
H2_PHDR_IDX_STAT = 5, /* :status = 8..14 */
H2_PHDR_IDX_HOST = 6, /* Host, never returned, just a place-holder */
H2_PHDR_NUM_ENTRIES /* must be last */
};
/* bit fields indicating the pseudo-headers found. It also covers the HOST
* header field as well as any non-pseudo-header field (NONE).
*/
enum {
H2_PHDR_FND_NONE = 1 << H2_PHDR_IDX_NONE, /* found a regular header */
H2_PHDR_FND_AUTH = 1 << H2_PHDR_IDX_AUTH,
H2_PHDR_FND_METH = 1 << H2_PHDR_IDX_METH,
H2_PHDR_FND_PATH = 1 << H2_PHDR_IDX_PATH,
H2_PHDR_FND_SCHM = 1 << H2_PHDR_IDX_SCHM,
H2_PHDR_FND_STAT = 1 << H2_PHDR_IDX_STAT,
H2_PHDR_FND_HOST = 1 << H2_PHDR_IDX_HOST,
};
/* frame types, from the standard */
enum h2_ft {
H2_FT_DATA = 0x00, // RFC7540 #6.1
H2_FT_HEADERS = 0x01, // RFC7540 #6.2
H2_FT_PRIORITY = 0x02, // RFC7540 #6.3
H2_FT_RST_STREAM = 0x03, // RFC7540 #6.4
H2_FT_SETTINGS = 0x04, // RFC7540 #6.5
H2_FT_PUSH_PROMISE = 0x05, // RFC7540 #6.6
H2_FT_PING = 0x06, // RFC7540 #6.7
H2_FT_GOAWAY = 0x07, // RFC7540 #6.8
H2_FT_WINDOW_UPDATE = 0x08, // RFC7540 #6.9
H2_FT_CONTINUATION = 0x09, // RFC7540 #6.10
H2_FT_ENTRIES /* must be last */
} __attribute__((packed));
/* frame types, turned to bits or bit fields */
enum {
/* one bit per frame type */
H2_FT_DATA_BIT = 1U << H2_FT_DATA,
H2_FT_HEADERS_BIT = 1U << H2_FT_HEADERS,
H2_FT_PRIORITY_BIT = 1U << H2_FT_PRIORITY,
H2_FT_RST_STREAM_BIT = 1U << H2_FT_RST_STREAM,
H2_FT_SETTINGS_BIT = 1U << H2_FT_SETTINGS,
H2_FT_PUSH_PROMISE_BIT = 1U << H2_FT_PUSH_PROMISE,
H2_FT_PING_BIT = 1U << H2_FT_PING,
H2_FT_GOAWAY_BIT = 1U << H2_FT_GOAWAY,
H2_FT_WINDOW_UPDATE_BIT = 1U << H2_FT_WINDOW_UPDATE,
H2_FT_CONTINUATION_BIT = 1U << H2_FT_CONTINUATION,
/* padded frames */
H2_FT_PADDED_MASK = H2_FT_DATA_BIT | H2_FT_HEADERS_BIT | H2_FT_PUSH_PROMISE_BIT,
/* flow controlled frames */
H2_FT_FC_MASK = H2_FT_DATA_BIT,
/* header frames */
H2_FT_HDR_MASK = H2_FT_HEADERS_BIT | H2_FT_PUSH_PROMISE_BIT | H2_FT_CONTINUATION_BIT,
/* frames allowed to arrive late on a stream */
H2_FT_LATE_MASK = H2_FT_WINDOW_UPDATE_BIT | H2_FT_RST_STREAM_BIT | H2_FT_PRIORITY_BIT,
};
/* flags defined for each frame type */
// RFC7540 #6.1
#define H2_F_DATA_END_STREAM 0x01
#define H2_F_DATA_PADDED 0x08
// RFC7540 #6.2
#define H2_F_HEADERS_END_STREAM 0x01
#define H2_F_HEADERS_END_HEADERS 0x04
#define H2_F_HEADERS_PADDED 0x08
#define H2_F_HEADERS_PRIORITY 0x20
// RFC7540 #6.3 : PRIORITY defines no flags
// RFC7540 #6.4 : RST_STREAM defines no flags
// RFC7540 #6.5
#define H2_F_SETTINGS_ACK 0x01
// RFC7540 #6.6
#define H2_F_PUSH_PROMISE_END_HEADERS 0x04
#define H2_F_PUSH_PROMISE_PADDED 0x08
// RFC7540 #6.7
#define H2_F_PING_ACK 0x01
// RFC7540 #6.8 : GOAWAY defines no flags
// RFC7540 #6.9 : WINDOW_UPDATE defines no flags
// PADDED is the exact same among DATA, HEADERS and PUSH_PROMISE (8)
#define H2_F_PADDED 0x08
/* HTTP/2 error codes - RFC7540 #7 */
enum h2_err {
H2_ERR_NO_ERROR = 0x0,
H2_ERR_PROTOCOL_ERROR = 0x1,
H2_ERR_INTERNAL_ERROR = 0x2,
H2_ERR_FLOW_CONTROL_ERROR = 0x3,
H2_ERR_SETTINGS_TIMEOUT = 0x4,
H2_ERR_STREAM_CLOSED = 0x5,
H2_ERR_FRAME_SIZE_ERROR = 0x6,
H2_ERR_REFUSED_STREAM = 0x7,
H2_ERR_CANCEL = 0x8,
H2_ERR_COMPRESSION_ERROR = 0x9,
H2_ERR_CONNECT_ERROR = 0xa,
H2_ERR_ENHANCE_YOUR_CALM = 0xb,
H2_ERR_INADEQUATE_SECURITY = 0xc,
H2_ERR_HTTP_1_1_REQUIRED = 0xd,
} __attribute__((packed));
// RFC7540 #11.3 : Settings Registry
#define H2_SETTINGS_HEADER_TABLE_SIZE 0x0001
#define H2_SETTINGS_ENABLE_PUSH 0x0002
#define H2_SETTINGS_MAX_CONCURRENT_STREAMS 0x0003
#define H2_SETTINGS_INITIAL_WINDOW_SIZE 0x0004
#define H2_SETTINGS_MAX_FRAME_SIZE 0x0005
#define H2_SETTINGS_MAX_HEADER_LIST_SIZE 0x0006
/* some protocol constants */
// PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n
#define H2_CONN_PREFACE \
"\x50\x52\x49\x20\x2a\x20\x48\x54" \
"\x54\x50\x2f\x32\x2e\x30\x0d\x0a" \
"\x0d\x0a\x53\x4d\x0d\x0a\x0d\x0a"
/* some flags related to protocol parsing */
#define H2_MSGF_BODY 0x0001 // a body is present
#define H2_MSGF_BODY_CL 0x0002 // content-length is present
#define H2_MSGF_BODY_TUNNEL 0x0004 // a tunnel is in use (CONNECT)
#define H2_MSGF_RSP_1XX 0x0010 // a 1xx ( != 101) HEADERS frame was received
#define H2_MAX_STREAM_ID ((1U << 31) - 1)
#define H2_MAX_FRAME_LEN ((1U << 24) - 1)
#define H2_DIR_REQ 1
#define H2_DIR_RES 2
#define H2_DIR_BOTH 3
/* constraints imposed by the protocol on each frame type, in terms of stream
* ID values, frame sizes, and direction so that most connection-level checks
* can be centralized regardless of the frame's acceptance.
*/
struct h2_frame_definition {
int32_t dir; /* 0=none, 1=request, 2=response, 3=both */
int32_t min_id; /* minimum allowed stream ID */
int32_t max_id; /* maximum allowed stream ID */
int32_t min_len; /* minimum frame length */
int32_t max_len; /* maximum frame length */
};
extern struct h2_frame_definition h2_frame_definition[H2_FT_ENTRIES];
/* various protocol processing functions */
int h2_make_h1_request(struct http_hdr *list, char *out, int osize, unsigned int *msgf, unsigned long long *body_len);
int h2_make_h1_trailers(struct http_hdr *list, char *out, int osize);
int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned long long *body_len);
int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len);
int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len);
int h2_make_htx_trailers(struct http_hdr *list, struct htx *htx);
/*
* Some helpful debugging functions.
*/
/* returns a bit corresponding to the frame type */
static inline unsigned int h2_ft_bit(enum h2_ft ft)
{
return 1U << ft;
}
/* returns the frame type as a string */
static inline const char *h2_ft_str(int type)
{
switch (type) {
case H2_FT_DATA : return "DATA";
case H2_FT_HEADERS : return "HEADERS";
case H2_FT_PRIORITY : return "PRIORITY";
case H2_FT_RST_STREAM : return "RST_STREAM";
case H2_FT_SETTINGS : return "SETTINGS";
case H2_FT_PUSH_PROMISE : return "PUSH_PROMISE";
case H2_FT_PING : return "PING";
case H2_FT_GOAWAY : return "GOAWAY";
case H2_FT_WINDOW_UPDATE : return "WINDOW_UPDATE";
default : return "_UNKNOWN_";
}
}
/* Returns an error code if the frame is valid protocol-wise, otherwise 0. <ft>
* is the frame type (H2_FT_*), <dir> is the direction (1=req, 2=res), <id> is
* the stream ID from the frame header, <len> is the frame length from the
* header. The purpose is to be able to quickly return a PROTOCOL_ERROR or
* FRAME_SIZE_ERROR connection error even for situations where the frame will
* be ignored. <mfs> must be the max frame size currently in place for the
* protocol.
*/
static inline int h2_frame_check(enum h2_ft ft, int dir, int32_t id, int32_t len, int32_t mfs)
{
struct h2_frame_definition *fd;
if (ft >= H2_FT_ENTRIES)
return H2_ERR_NO_ERROR; // ignore unhandled frame types
fd = &h2_frame_definition[ft];
if (!(dir & fd->dir))
return H2_ERR_PROTOCOL_ERROR;
if (id < fd->min_id || id > fd->max_id)
return H2_ERR_PROTOCOL_ERROR;
if (len < fd->min_len || len > fd->max_len)
return H2_ERR_FRAME_SIZE_ERROR;
if (len > mfs)
return H2_ERR_FRAME_SIZE_ERROR;
if (ft == H2_FT_SETTINGS && (len % 6) != 0)
return H2_ERR_FRAME_SIZE_ERROR; // RFC7540#6.5
return H2_ERR_NO_ERROR;
}
/* returns the pseudo-header <str> corresponds to among H2_PHDR_IDX_*, 0 if not a
* pseudo-header, or -1 if not a valid pseudo-header.
*/
static inline int h2_str_to_phdr(const struct ist str)
{
if (*str.ptr == ':') {
if (isteq(str, ist(":path"))) return H2_PHDR_IDX_PATH;
else if (isteq(str, ist(":method"))) return H2_PHDR_IDX_METH;
else if (isteq(str, ist(":scheme"))) return H2_PHDR_IDX_SCHM;
else if (isteq(str, ist(":status"))) return H2_PHDR_IDX_STAT;
else if (isteq(str, ist(":authority"))) return H2_PHDR_IDX_AUTH;
/* all other names starting with ':' */
return -1;
}
/* not a pseudo header */
return 0;
}
/* returns the pseudo-header name <num> as a string, or ":UNKNOWN" if unknown */
static inline const char *h2_phdr_to_str(int phdr)
{
switch (phdr) {
case H2_PHDR_IDX_NONE: return ":NONE";
case H2_PHDR_IDX_AUTH: return ":authority";
case H2_PHDR_IDX_METH: return ":method";
case H2_PHDR_IDX_PATH: return ":path";
case H2_PHDR_IDX_SCHM: return ":scheme";
case H2_PHDR_IDX_STAT: return ":status";
case H2_PHDR_IDX_HOST: return "Host";
default: return ":UNKNOWN";
}
}
#endif /* _COMMON_H2_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/