blob: 4da78c86142c54327fd90d0d1d84495711ec4343 [file] [log] [blame]
/*
* HTTP/2 protocol processing
*
* Copyright 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.
*/
#include <inttypes.h>
#include <haproxy/api.h>
#include <haproxy/global.h>
#include <haproxy/h2.h>
#include <haproxy/http-hdr-t.h>
#include <haproxy/http.h>
#include <haproxy/http_htx.h>
#include <haproxy/htx.h>
#include <import/ist.h>
struct h2_frame_definition h2_frame_definition[H2_FT_ENTRIES] = {
[H2_FT_DATA ] = { .dir = 3, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 0, .max_len = H2_MAX_FRAME_LEN, },
[H2_FT_HEADERS ] = { .dir = 3, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 1, .max_len = H2_MAX_FRAME_LEN, },
[H2_FT_PRIORITY ] = { .dir = 3, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 5, .max_len = 5, },
[H2_FT_RST_STREAM ] = { .dir = 3, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 4, .max_len = 4, },
[H2_FT_SETTINGS ] = { .dir = 3, .min_id = 0, .max_id = 0, .min_len = 0, .max_len = H2_MAX_FRAME_LEN, },
[H2_FT_PUSH_PROMISE ] = { .dir = 0, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 4, .max_len = H2_MAX_FRAME_LEN, },
[H2_FT_PING ] = { .dir = 3, .min_id = 0, .max_id = 0, .min_len = 8, .max_len = 8, },
[H2_FT_GOAWAY ] = { .dir = 3, .min_id = 0, .max_id = 0, .min_len = 8, .max_len = H2_MAX_FRAME_LEN, },
[H2_FT_WINDOW_UPDATE] = { .dir = 3, .min_id = 0, .max_id = H2_MAX_STREAM_ID, .min_len = 4, .max_len = 4, },
[H2_FT_CONTINUATION ] = { .dir = 3, .min_id = 1, .max_id = H2_MAX_STREAM_ID, .min_len = 0, .max_len = H2_MAX_FRAME_LEN, },
};
/* Looks into <ist> for forbidden characters for header values (0x00, 0x0A,
* 0x0D), starting at pointer <start> which must be within <ist>. Returns
* non-zero if such a character is found, 0 otherwise. When run on unlikely
* header match, it's recommended to first check for the presence of control
* chars using ist_find_ctl().
*/
static int has_forbidden_char(const struct ist ist, const char *start)
{
do {
if ((uint8_t)*start <= 0x0d &&
(1U << (uint8_t)*start) & ((1<<13) | (1<<10) | (1<<0)))
return 1;
start++;
} while (start < ist.ptr + ist.len);
return 0;
}
/* Parse the Content-Length header field of an HTTP/2 request. The function
* checks all possible occurrences of a comma-delimited value, and verifies
* if any of them doesn't match a previous value. It returns <0 if a value
* differs, 0 if the whole header can be dropped (i.e. already known), or >0
* if the value can be indexed (first one). In the last case, the value might
* be adjusted and the caller must only add the updated value.
*/
int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned long long *body_len)
{
char *e, *n;
unsigned long long cl;
int not_first = !!(*msgf & H2_MSGF_BODY_CL);
struct ist word;
word.ptr = value->ptr;
e = value->ptr + value->len;
while (1) {
if (word.ptr >= e) {
/* empty header or empty value */
goto fail;
}
/* skip leading delimiter and blanks */
if (unlikely(HTTP_IS_LWS(*word.ptr))) {
word.ptr++;
continue;
}
/* digits only now */
for (cl = 0, n = word.ptr; n < e; n++) {
unsigned int c = *n - '0';
if (unlikely(c > 9)) {
/* non-digit */
if (unlikely(n == word.ptr)) // spaces only
goto fail;
break;
}
if (unlikely(!cl && n > word.ptr)) {
/* There was a leading zero before this digit,
* let's trim it.
*/
word.ptr = n;
}
if (unlikely(cl > ULLONG_MAX / 10ULL))
goto fail; /* multiply overflow */
cl = cl * 10ULL;
if (unlikely(cl + c < cl))
goto fail; /* addition overflow */
cl = cl + c;
}
/* keep a copy of the exact cleaned value */
word.len = n - word.ptr;
/* skip trailing LWS till next comma or EOL */
for (; n < e; n++) {
if (!HTTP_IS_LWS(*n)) {
if (unlikely(*n != ','))
goto fail;
break;
}
}
/* if duplicate, must be equal */
if (*msgf & H2_MSGF_BODY_CL && cl != *body_len)
goto fail;
/* OK, store this result as the one to be indexed */
*msgf |= H2_MSGF_BODY_CL;
*body_len = cl;
*value = word;
/* Now either n==e and we're done, or n points to the comma,
* and we skip it and continue.
*/
if (n++ == e)
break;
word.ptr = n;
}
/* here we've reached the end with a single value or a series of
* identical values, all matching previous series if any. The last
* parsed value was sent back into <value>. We just have to decide
* if this occurrence has to be indexed (it's the first one) or
* silently skipped (it's not the first one)
*/
return !not_first;
fail:
return -1;
}
/* Prepare the request line into <htx> from pseudo headers stored in <phdr[]>.
* <fields> indicates what was found so far. This should be called once at the
* detection of the first general header field or at the end of the request if
* no general header field was found yet. Returns the created start line on
* success, or NULL on failure. Upon success, <msgf> is updated with a few
* H2_MSGF_* flags indicating what was found while parsing.
*
* The rules below deserve a bit of explanation. There tends to be some
* confusion regarding H2's authority vs the Host header. They are different
* though may sometimes be exchanged. In H2, the request line is broken into :
* - :method
* - :scheme
* - :authority
* - :path
*
* An equivalent HTTP/1.x absolute-form request would then look like :
* <:method> <:scheme>://<:authority><:path> HTTP/x.y
*
* Except for CONNECT which doesn't have scheme nor path and looks like :
* <:method> <:authority> HTTP/x.y
*
* It's worth noting that H2 still supports an encoding to map H1 origin-form
* and asterisk-form requests. These ones do not specify the authority. However
* in H2 they must still specify the scheme, which is not present in H1. Also,
* when encoding an absolute-form H1 request without a path, the path
* automatically becomes "/" except for the OPTIONS method where it
* becomes "*".
*
* As such it is explicitly permitted for an H2 client to send a request
* featuring a Host header and no :authority, though it's not the recommended
* way to use H2 for a client. It is however the only permitted way to encode
* an origin-form H1 request over H2. Thus we need to respect such differences
* as much as possible when re-encoding the H2 request into HTX.
*/
static struct htx_sl *h2_prepare_htx_reqline(uint32_t fields, struct ist *phdr, struct htx *htx, unsigned int *msgf)
{
struct ist uri, meth_sl;
unsigned int flags = HTX_SL_F_NONE;
struct htx_sl *sl;
size_t i;
if ((fields & H2_PHDR_FND_METH) && isteq(phdr[H2_PHDR_IDX_METH], ist("CONNECT"))) {
if (fields & H2_PHDR_FND_PROT) {
/* rfc 8441 Extended Connect Protocol
* #4 :scheme and :path must be present, as well as
* :authority like all h2 requests
*/
if (!(fields & H2_PHDR_FND_SCHM)) {
/* missing scheme */
goto fail;
}
else if (!(fields & H2_PHDR_FND_PATH)) {
/* missing path */
goto fail;
}
else if (!(fields & H2_PHDR_FND_AUTH)) {
/* missing authority */
goto fail;
}
flags |= HTX_SL_F_HAS_SCHM;
if (isteqi(phdr[H2_PHDR_IDX_SCHM], ist("http")))
flags |= HTX_SL_F_SCHM_HTTP;
else if (isteqi(phdr[H2_PHDR_IDX_SCHM], ist("https")))
flags |= HTX_SL_F_SCHM_HTTPS;
else if (!http_validate_scheme(phdr[H2_PHDR_IDX_SCHM]))
htx->flags |= HTX_FL_PARSING_ERROR;
meth_sl = ist("GET");
*msgf |= H2_MSGF_EXT_CONNECT;
/* no ES on the HEADERS frame but no body either for
* Extended CONNECT */
*msgf &= ~H2_MSGF_BODY;
}
else {
/* RFC 7540 #8.2.6 regarding CONNECT: ":scheme" and ":path"
* MUST be omitted ; ":authority" contains the host and port
* to connect to.
*/
if (fields & H2_PHDR_FND_SCHM) {
/* scheme not allowed */
goto fail;
}
else if (fields & H2_PHDR_FND_PATH) {
/* path not allowed */
goto fail;
}
else if (!(fields & H2_PHDR_FND_AUTH)) {
/* missing authority */
goto fail;
}
meth_sl = phdr[H2_PHDR_IDX_METH];
}
*msgf |= H2_MSGF_BODY_TUNNEL;
}
else if ((fields & (H2_PHDR_FND_METH|H2_PHDR_FND_SCHM|H2_PHDR_FND_PATH)) !=
(H2_PHDR_FND_METH|H2_PHDR_FND_SCHM|H2_PHDR_FND_PATH)) {
/* RFC 7540 #8.1.2.3 : all requests MUST include exactly one
* valid value for the ":method", ":scheme" and ":path" phdr
* unless it is a CONNECT request.
*/
if (!(fields & H2_PHDR_FND_METH)) {
/* missing method */
goto fail;
}
else if (!(fields & H2_PHDR_FND_SCHM)) {
/* missing scheme */
goto fail;
}
else {
/* missing path */
goto fail;
}
}
else { /* regular methods */
/* RFC3986#6.2.2.1: scheme is case-insensitive. We need to
* classify the scheme as "present/http", "present/https",
* "present/other", "absent" so as to decide whether or not
* we're facing a normalized URI that will have to be encoded
* in origin or absolute form. Indeed, 7540#8.1.2.3 says that
* clients should use the absolute form, thus we cannot infer
* whether or not the client wanted to use a proxy here.
*/
flags |= HTX_SL_F_HAS_SCHM;
if (isteqi(phdr[H2_PHDR_IDX_SCHM], ist("http")))
flags |= HTX_SL_F_SCHM_HTTP;
else if (isteqi(phdr[H2_PHDR_IDX_SCHM], ist("https")))
flags |= HTX_SL_F_SCHM_HTTPS;
else if (!http_validate_scheme(phdr[H2_PHDR_IDX_SCHM]))
htx->flags |= HTX_FL_PARSING_ERROR;
meth_sl = phdr[H2_PHDR_IDX_METH];
}
if (fields & H2_PHDR_FND_PATH) {
/* 7540#8.1.2.3: :path must not be empty, and must be either
* '*' or an RFC3986 "path-absolute" starting with a "/" but
* not with "//".
* However, this "path-absolute" was a mistake which was
* later fixed in http2bis as "absolute-path" to match
* HTTP/1, thus also allowing "//".
*/
if (unlikely(!phdr[H2_PHDR_IDX_PATH].len))
goto fail;
else if (unlikely(phdr[H2_PHDR_IDX_PATH].ptr[0] != '/')) {
if (!isteq(phdr[H2_PHDR_IDX_PATH], ist("*")))
goto fail;
}
}
if (!(flags & HTX_SL_F_HAS_SCHM)) {
/* no scheme, use authority only (CONNECT) */
uri = phdr[H2_PHDR_IDX_AUTH];
flags |= HTX_SL_F_HAS_AUTHORITY;
}
else if (fields & H2_PHDR_FND_AUTH) {
/* authority is present, let's use the absolute form. We simply
* use the trash to concatenate them since all of them MUST fit
* in a bufsize since it's where they come from.
*/
uri = ist2bin(trash.area, phdr[H2_PHDR_IDX_SCHM]);
istcat(&uri, ist("://"), trash.size);
istcat(&uri, phdr[H2_PHDR_IDX_AUTH], trash.size);
if (!isteq(phdr[H2_PHDR_IDX_PATH], ist("*")))
istcat(&uri, phdr[H2_PHDR_IDX_PATH], trash.size);
flags |= HTX_SL_F_HAS_AUTHORITY;
if (flags & (HTX_SL_F_SCHM_HTTP|HTX_SL_F_SCHM_HTTPS)) {
/* we don't know if it was originally an absolute or a
* relative request because newer versions of HTTP use
* the absolute URI format by default, which we call
* the normalized URI format internally. This is the
* strongly recommended way of sending a request for
* a regular client, so we cannot distinguish this
* from a request intended for a proxy. For other
* schemes however there is no doubt.
*/
flags |= HTX_SL_F_NORMALIZED_URI;
}
}
else {
/* usual schemes with or without authority, use origin form */
uri = phdr[H2_PHDR_IDX_PATH];
if (fields & H2_PHDR_FND_AUTH)
flags |= HTX_SL_F_HAS_AUTHORITY;
}
/* The method is a non-empty token (RFC7231#4.1) */
if (!meth_sl.len)
goto fail;
for (i = 0; i < meth_sl.len; i++) {
if (!HTTP_IS_TOKEN(meth_sl.ptr[i]))
htx->flags |= HTX_FL_PARSING_ERROR;
}
/* make sure the final URI isn't empty. Note that 7540#8.1.2.3 states
* that :path must not be empty.
*/
if (!uri.len)
goto fail;
/* The final URI must not contain LWS nor CTL characters */
for (i = 0; i < uri.len; i++) {
unsigned char c = uri.ptr[i];
if (HTTP_IS_LWS(c) || HTTP_IS_CTL(c))
htx->flags |= HTX_FL_PARSING_ERROR;
}
/* Set HTX start-line flags */
flags |= HTX_SL_F_VER_11; // V2 in fact
flags |= HTX_SL_F_XFER_LEN; // xfer len always known with H2
sl = htx_add_stline(htx, HTX_BLK_REQ_SL, flags, meth_sl, uri, ist("HTTP/2.0"));
if (!sl)
goto fail;
sl->info.req.meth = find_http_meth(meth_sl.ptr, meth_sl.len);
if (sl->info.req.meth == HTTP_METH_HEAD)
*msgf |= H2_MSGF_BODYLESS_RSP;
return sl;
fail:
return NULL;
}
/* Takes an H2 request present in the headers list <list> terminated by a name
* being <NULL,0> and emits the equivalent HTX request according to the rules
* documented in RFC7540 #8.1.2. The output contents are emitted in <htx>, and
* non-zero is returned if some bytes were emitted. In case of error, a
* negative error code is returned.
*
* Upon success, <msgf> is filled with a few H2_MSGF_* flags indicating what
* was found while parsing. The caller must set it to zero in or H2_MSGF_BODY
* if a body is detected (!ES).
*
* The headers list <list> must be composed of :
* - n.name != NULL, n.len > 0 : literal header name
* - n.name == NULL, n.len > 0 : indexed pseudo header name number <n.len>
* among H2_PHDR_IDX_*
* - n.name ignored, n.len == 0 : end of list
* - in all cases except the end of list, v.name and v.len must designate a
* valid value.
*
* The Cookie header will be reassembled at the end, and for this, the <list>
* will be used to create a linked list, so its contents may be destroyed.
*
* When <relaxed> is non-nul, some non-dangerous checks will be ignored. This
* is in order to satisfy "option accept-invalid-http-request" for
* interoperability purposes.
*/
int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, int relaxed)
{
struct ist phdr_val[H2_PHDR_NUM_ENTRIES];
uint32_t fields; /* bit mask of H2_PHDR_FND_* */
uint32_t idx;
int ck, lck; /* cookie index and last cookie index */
int phdr;
int ret;
int i;
struct htx_sl *sl = NULL;
unsigned int sl_flags = 0;
const char *ctl;
lck = ck = -1; // no cookie for now
fields = 0;
for (idx = 0; list[idx].n.len != 0; idx++) {
if (!list[idx].n.ptr) {
/* this is an indexed pseudo-header */
phdr = list[idx].n.len;
}
else {
/* this can be any type of header */
/* RFC7540#8.1.2: upper case not allowed in header field names.
* #10.3: header names must be valid (i.e. match a token).
* For pseudo-headers we check from 2nd char and for other ones
* from the first char, because HTTP_IS_TOKEN() also excludes
* the colon.
*/
phdr = h2_str_to_phdr(list[idx].n);
for (i = !!phdr; i < list[idx].n.len; i++)
if ((uint8_t)(list[idx].n.ptr[i] - 'A') < 'Z' - 'A' || !HTTP_IS_TOKEN(list[idx].n.ptr[i]))
goto fail;
}
/* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of
* rejecting NUL, CR and LF characters. For :path we reject all CTL
* chars, spaces, and '#'.
*/
if (phdr == H2_PHDR_IDX_PATH && !relaxed) {
ctl = ist_find_range(list[idx].v, 0, '#');
if (unlikely(ctl) && http_path_has_forbidden_char(list[idx].v, ctl))
goto fail;
} else {
ctl = ist_find_ctl(list[idx].v);
if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
goto fail;
}
if (phdr > 0 && phdr < H2_PHDR_NUM_ENTRIES) {
/* insert a pseudo header by its index (in phdr) and value (in value) */
if (fields & ((1 << phdr) | H2_PHDR_FND_NONE)) {
if (fields & H2_PHDR_FND_NONE) {
/* pseudo header field after regular headers */
goto fail;
}
else {
/* repeated pseudo header field */
goto fail;
}
}
fields |= 1 << phdr;
phdr_val[phdr] = list[idx].v;
continue;
}
else if (phdr != 0) {
/* invalid pseudo header -- should never happen here */
goto fail;
}
/* regular header field in (name,value) */
if (unlikely(!(fields & H2_PHDR_FND_NONE))) {
/* no more pseudo-headers, time to build the request line */
sl = h2_prepare_htx_reqline(fields, phdr_val, htx, msgf);
if (!sl)
goto fail;
fields |= H2_PHDR_FND_NONE;
/* http2bis draft recommends to drop Host in favor of :authority when
* the latter is present. This is required to make sure there is no
* discrepancy between the authority and the host header, especially
* since routing rules usually involve Host. Here we already know if
* :authority was found so we can emit it right now and mark the host
* as filled so that it's skipped later.
*/
if (fields & H2_PHDR_FND_AUTH) {
if (!htx_add_header(htx, ist("host"), phdr_val[H2_PHDR_IDX_AUTH]))
goto fail;
fields |= H2_PHDR_FND_HOST;
}
}
if (isteq(list[idx].n, ist("host"))) {
if (fields & H2_PHDR_FND_HOST)
continue;
fields |= H2_PHDR_FND_HOST;
}
if (isteq(list[idx].n, ist("content-length"))) {
ret = h2_parse_cont_len_header(msgf, &list[idx].v, body_len);
if (ret < 0)
goto fail;
sl_flags |= HTX_SL_F_CLEN;
if (ret == 0)
continue; // skip this duplicate
}
/* these ones are forbidden in requests (RFC7540#8.1.2.2) */
if (isteq(list[idx].n, ist("connection")) ||
isteq(list[idx].n, ist("proxy-connection")) ||
isteq(list[idx].n, ist("keep-alive")) ||
isteq(list[idx].n, ist("upgrade")) ||
isteq(list[idx].n, ist("transfer-encoding")))
goto fail;
if (isteq(list[idx].n, ist("te")) && !isteq(list[idx].v, ist("trailers")))
goto fail;
/* cookie requires special processing at the end */
if (isteq(list[idx].n, ist("cookie"))) {
list[idx].n.len = -1;
if (ck < 0)
ck = idx;
else
list[lck].n.len = idx;
lck = idx;
continue;
}
if (!htx_add_header(htx, list[idx].n, list[idx].v))
goto fail;
}
/* RFC7540#8.1.2.1 mandates to reject response pseudo-headers (:status) */
if (fields & H2_PHDR_FND_STAT)
goto fail;
/* Let's dump the request now if not yet emitted. */
if (!(fields & H2_PHDR_FND_NONE)) {
sl = h2_prepare_htx_reqline(fields, phdr_val, htx, msgf);
if (!sl)
goto fail;
}
if (*msgf & H2_MSGF_BODY_TUNNEL)
*msgf &= ~(H2_MSGF_BODY|H2_MSGF_BODY_CL);
if (!(*msgf & H2_MSGF_BODY) || ((*msgf & H2_MSGF_BODY_CL) && *body_len == 0) ||
(*msgf & H2_MSGF_BODY_TUNNEL)) {
/* Request without body or tunnel requested */
sl_flags |= HTX_SL_F_BODYLESS;
htx->flags |= HTX_FL_EOM;
}
if (*msgf & H2_MSGF_EXT_CONNECT) {
if (!htx_add_header(htx, ist("upgrade"), phdr_val[H2_PHDR_IDX_PROT]))
goto fail;
if (!htx_add_header(htx, ist("connection"), ist("upgrade")))
goto fail;
sl_flags |= HTX_SL_F_CONN_UPG;
}
/* update the start line with last detected header info */
sl->flags |= sl_flags;
/* complete with missing Host if needed (we may validate this test if
* no regular header was found).
*/
if ((fields & (H2_PHDR_FND_HOST|H2_PHDR_FND_AUTH)) == H2_PHDR_FND_AUTH) {
/* missing Host field, use :authority instead */
if (!htx_add_header(htx, ist("host"), phdr_val[H2_PHDR_IDX_AUTH]))
goto fail;
}
/* now we may have to build a cookie list. We'll dump the values of all
* visited headers.
*/
if (ck >= 0) {
uint32_t fs; // free space
uint32_t bs; // block size
uint32_t vl; // value len
uint32_t tl; // total length
struct htx_blk *blk;
blk = htx_add_header(htx, ist("cookie"), list[ck].v);
if (!blk)
goto fail;
tl = list[ck].v.len;
fs = htx_free_data_space(htx);
bs = htx_get_blksz(blk);
/* for each extra cookie, we'll extend the cookie's value and
* insert "; " before the new value.
*/
fs += tl; // first one is already counted
while ((ck = list[ck].n.len) >= 0) {
vl = list[ck].v.len;
tl += vl + 2;
if (tl > fs)
goto fail;
htx_change_blk_value_len(htx, blk, tl);
*(char *)(htx_get_blk_ptr(htx, blk) + bs + 0) = ';';
*(char *)(htx_get_blk_ptr(htx, blk) + bs + 1) = ' ';
memcpy(htx_get_blk_ptr(htx, blk) + bs + 2, list[ck].v.ptr, vl);
bs += vl + 2;
}
}
/* now send the end of headers marker */
if (!htx_add_endof(htx, HTX_BLK_EOH))
goto fail;
/* proceed to scheme-based normalization on target-URI */
if (fields & H2_PHDR_FND_SCHM)
http_scheme_based_normalize(htx);
ret = 1;
return ret;
fail:
return -1;
}
/* Prepare the status line into <htx> from pseudo headers stored in <phdr[]>.
* <fields> indicates what was found so far. This should be called once at the
* detection of the first general header field or at the end of the message if
* no general header field was found yet. Returns the created start line on
* success, or NULL on failure. Upon success, <msgf> is updated with a few
* H2_MSGF_* flags indicating what was found while parsing.
*/
static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr, struct htx *htx, unsigned int *msgf)
{
unsigned int status, flags = HTX_SL_F_NONE;
struct htx_sl *sl;
struct ist stat;
/* only :status is allowed as a pseudo header */
if (!(fields & H2_PHDR_FND_STAT))
goto fail;
if (phdr[H2_PHDR_IDX_STAT].len != 3)
goto fail;
/* if Extended CONNECT is used, convert status code from 200 to htx 101
* following rfc 8441 */
if (unlikely(*msgf & H2_MSGF_EXT_CONNECT) &&
isteq(phdr[H2_PHDR_IDX_STAT], ist("200"))) {
stat = ist("101");
status = 101;
}
else {
unsigned char h, t, u;
stat = phdr[H2_PHDR_IDX_STAT];
h = stat.ptr[0] - '0';
t = stat.ptr[1] - '0';
u = stat.ptr[2] - '0';
if (h > 9 || t > 9 || u > 9)
goto fail;
status = h * 100 + t * 10 + u;
}
/* 101 responses are not supported in H2, so return a error.
* On 1xx responses there is no ES on the HEADERS frame but there is no
* body. So remove the flag H2_MSGF_BODY and add H2_MSGF_RSP_1XX to
* notify the decoder another HEADERS frame is expected.
* 204/304 response have no body by definition. So remove the flag
* H2_MSGF_BODY and set H2_MSGF_BODYLESS_RSP.
*
* Note however that there is a special condition for Extended CONNECT.
* In this case, we explicitly convert it to HTX 101 to mimic
* Get+Upgrade HTTP/1.1 mechanism
*/
if (status == 101) {
if (!(*msgf & H2_MSGF_EXT_CONNECT))
goto fail;
}
else if (status < 200) {
*msgf |= H2_MSGF_RSP_1XX;
*msgf &= ~H2_MSGF_BODY;
}
else if (status == 204 || status == 304) {
*msgf &= ~H2_MSGF_BODY;
*msgf |= H2_MSGF_BODYLESS_RSP;
}
/* Set HTX start-line flags */
flags |= HTX_SL_F_VER_11; // V2 in fact
flags |= HTX_SL_F_XFER_LEN; // xfer len always known with H2
sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, ist("HTTP/2.0"), stat, ist(""));
if (!sl)
goto fail;
sl->info.res.status = status;
return sl;
fail:
return NULL;
}
/* Takes an H2 response present in the headers list <list> terminated by a name
* being <NULL,0> and emits the equivalent HTX response according to the rules
* documented in RFC7540 #8.1.2. The output contents are emitted in <htx>, and
* a positive value is returned if some bytes were emitted. In case of error, a
* negative error code is returned.
*
* Upon success, <msgf> is filled with a few H2_MSGF_* flags indicating what
* was found while parsing. The caller must set it to zero in or H2_MSGF_BODY
* if a body is detected (!ES).
*
* The headers list <list> must be composed of :
* - n.name != NULL, n.len > 0 : literal header name
* - n.name == NULL, n.len > 0 : indexed pseudo header name number <n.len>
* among H2_PHDR_IDX_*
* - n.name ignored, n.len == 0 : end of list
* - in all cases except the end of list, v.name and v.len must designate a
* valid value.
*
* <upgrade_protocol> is only used if the htx status code is 101 indicating a
* response to an upgrade or h2-equivalent request.
*/
int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, char *upgrade_protocol)
{
struct ist phdr_val[H2_PHDR_NUM_ENTRIES];
uint32_t fields; /* bit mask of H2_PHDR_FND_* */
uint32_t idx;
int phdr;
int ret;
int i;
struct htx_sl *sl = NULL;
unsigned int sl_flags = 0;
const char *ctl;
fields = 0;
for (idx = 0; list[idx].n.len != 0; idx++) {
if (!list[idx].n.ptr) {
/* this is an indexed pseudo-header */
phdr = list[idx].n.len;
}
else {
/* this can be any type of header */
/* RFC7540#8.1.2: upper case not allowed in header field names.
* #10.3: header names must be valid (i.e. match a token).
* For pseudo-headers we check from 2nd char and for other ones
* from the first char, because HTTP_IS_TOKEN() also excludes
* the colon.
*/
phdr = h2_str_to_phdr(list[idx].n);
for (i = !!phdr; i < list[idx].n.len; i++)
if ((uint8_t)(list[idx].n.ptr[i] - 'A') < 'Z' - 'A' || !HTTP_IS_TOKEN(list[idx].n.ptr[i]))
goto fail;
}
/* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of
* rejecting NUL, CR and LF characters.
*/
ctl = ist_find_ctl(list[idx].v);
if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
goto fail;
if (phdr > 0 && phdr < H2_PHDR_NUM_ENTRIES) {
/* insert a pseudo header by its index (in phdr) and value (in value) */
if (fields & ((1 << phdr) | H2_PHDR_FND_NONE)) {
if (fields & H2_PHDR_FND_NONE) {
/* pseudo header field after regular headers */
goto fail;
}
else {
/* repeated pseudo header field */
goto fail;
}
}
fields |= 1 << phdr;
phdr_val[phdr] = list[idx].v;
continue;
}
else if (phdr != 0) {
/* invalid pseudo header -- should never happen here */
goto fail;
}
/* regular header field in (name,value) */
if (!(fields & H2_PHDR_FND_NONE)) {
/* no more pseudo-headers, time to build the status line */
sl = h2_prepare_htx_stsline(fields, phdr_val, htx, msgf);
if (!sl)
goto fail;
fields |= H2_PHDR_FND_NONE;
}
if (isteq(list[idx].n, ist("content-length"))) {
ret = h2_parse_cont_len_header(msgf, &list[idx].v, body_len);
if (ret < 0)
goto fail;
sl_flags |= HTX_SL_F_CLEN;
if (ret == 0)
continue; // skip this duplicate
}
/* these ones are forbidden in responses (RFC7540#8.1.2.2) */
if (isteq(list[idx].n, ist("connection")) ||
isteq(list[idx].n, ist("proxy-connection")) ||
isteq(list[idx].n, ist("keep-alive")) ||
isteq(list[idx].n, ist("upgrade")) ||
isteq(list[idx].n, ist("transfer-encoding")))
goto fail;
if (!htx_add_header(htx, list[idx].n, list[idx].v))
goto fail;
}
/* RFC7540#8.1.2.1 mandates to reject request pseudo-headers */
if (fields & (H2_PHDR_FND_AUTH|H2_PHDR_FND_METH|H2_PHDR_FND_PATH|H2_PHDR_FND_SCHM))
goto fail;
/* Let's dump the request now if not yet emitted. */
if (!(fields & H2_PHDR_FND_NONE)) {
sl = h2_prepare_htx_stsline(fields, phdr_val, htx, msgf);
if (!sl)
goto fail;
}
if (sl->info.res.status == 101 && upgrade_protocol) {
if (!htx_add_header(htx, ist("connection"), ist("upgrade")))
goto fail;
if (!htx_add_header(htx, ist("upgrade"), ist(upgrade_protocol)))
goto fail;
sl_flags |= HTX_SL_F_CONN_UPG;
}
if ((*msgf & H2_MSGF_BODY_TUNNEL) &&
((sl->info.res.status >= 200 && sl->info.res.status < 300) || sl->info.res.status == 101))
*msgf &= ~(H2_MSGF_BODY|H2_MSGF_BODY_CL);
else
*msgf &= ~H2_MSGF_BODY_TUNNEL;
if (!(*msgf & H2_MSGF_BODY) || ((*msgf & H2_MSGF_BODY_CL) && *body_len == 0) ||
(*msgf & H2_MSGF_BODY_TUNNEL)) {
/* Response without body or tunnel successfully established */
sl_flags |= HTX_SL_F_BODYLESS;
htx->flags |= HTX_FL_EOM;
}
/* update the start line with last detected header info */
sl->flags |= sl_flags;
if ((*msgf & (H2_MSGF_BODY|H2_MSGF_BODY_TUNNEL|H2_MSGF_BODY_CL)) == H2_MSGF_BODY) {
/* FIXME: Do we need to signal anything when we have a body and
* no content-length, to have the equivalent of H1's chunked
* encoding?
*/
}
/* now send the end of headers marker */
if (!htx_add_endof(htx, HTX_BLK_EOH))
goto fail;
ret = 1;
return ret;
fail:
return -1;
}
/* Takes an H2 headers list <list> terminated by a name being <NULL,0> and emits
* the equivalent HTX trailers blocks. The output contents are emitted in <htx>,
* and a positive value is returned if some bytes were emitted. In case of
* error, a negative error code is returned. The caller must have verified that
* the message in the buffer is compatible with receipt of trailers.
*
* The headers list <list> must be composed of :
* - n.name != NULL, n.len > 0 : literal header name
* - n.name == NULL, n.len > 0 : indexed pseudo header name number <n.len>
* among H2_PHDR_IDX_* (illegal here)
* - n.name ignored, n.len == 0 : end of list
* - in all cases except the end of list, v.name and v.len must designate a
* valid value.
*/
int h2_make_htx_trailers(struct http_hdr *list, struct htx *htx)
{
const char *ctl;
uint32_t idx;
int i;
for (idx = 0; list[idx].n.len != 0; idx++) {
if (!list[idx].n.ptr) {
/* This is an indexed pseudo-header (RFC7540#8.1.2.1) */
goto fail;
}
/* RFC7540#8.1.2: upper case not allowed in header field names.
* #10.3: header names must be valid (i.e. match a token). This
* also catches pseudo-headers which are forbidden in trailers.
*/
for (i = 0; i < list[idx].n.len; i++)
if ((uint8_t)(list[idx].n.ptr[i] - 'A') < 'Z' - 'A' || !HTTP_IS_TOKEN(list[idx].n.ptr[i]))
goto fail;
/* these ones are forbidden in trailers (RFC7540#8.1.2.2) */
if (isteq(list[idx].n, ist("host")) ||
isteq(list[idx].n, ist("content-length")) ||
isteq(list[idx].n, ist("connection")) ||
isteq(list[idx].n, ist("proxy-connection")) ||
isteq(list[idx].n, ist("keep-alive")) ||
isteq(list[idx].n, ist("upgrade")) ||
isteq(list[idx].n, ist("te")) ||
isteq(list[idx].n, ist("transfer-encoding")))
goto fail;
/* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of
* rejecting NUL, CR and LF characters.
*/
ctl = ist_find_ctl(list[idx].v);
if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
goto fail;
if (!htx_add_trailer(htx, list[idx].n, list[idx].v))
goto fail;
}
if (!htx_add_endof(htx, HTX_BLK_EOT))
goto fail;
return 1;
fail:
return -1;
}