MINOR: h3: transcode H3 response headers into HTX blocks

Finalize HTTP/3 response transcoding into HTX message. This patch
implements conversion of HTTP/3 headers provided by the server into HTX
blocks.

Special checks have been implemented to reject connection-specific
headers, causing the stream to be shut in error. Also, handling of
content-length requires that the body size is equal to the value
advertized in the header to prevent HTTP desync.
This commit is contained in:
Amaury Denoyelle 2025-06-16 16:32:57 +02:00
parent d83255fdc3
commit 2284aa0d6a

View File

@ -152,7 +152,7 @@ DECLARE_STATIC_POOL(pool_head_h3c, "h3c", sizeof(struct h3c));
#define H3_SF_UNI_INIT 0x00000001 /* stream type not parsed for unidirectional stream */
#define H3_SF_UNI_NO_H3 0x00000002 /* unidirectional stream does not carry H3 frames */
#define H3_SF_HAVE_CLEN 0x00000004 /* content-length header is present */
#define H3_SF_HAVE_CLEN 0x00000004 /* content-length header is present; relevant either for request or response depending on the side of the connection */
struct h3s {
struct h3c *h3c;
@ -1099,13 +1099,15 @@ static ssize_t h3_resp_headers_to_htx(struct qcs *qcs, const struct buffer *buf,
struct h3s *h3s = qcs->ctx;
struct h3c *h3c = h3s->h3c;
struct buffer *appbuf = NULL;
struct buffer *tmp = get_trash_chunk();
struct htx *htx = NULL;
struct htx_sl *sl;
struct http_hdr list[global.tune.max_http_hdr * 2];
unsigned int flags = HTX_SL_F_NONE;
struct ist status = IST_NULL;
unsigned char h, t, u;
int hdr_idx;
int hdr_idx, ret;
int qpack_err;
/* RFC 9114 4.1.2. Malformed Requests and Responses
*
@ -1129,6 +1131,20 @@ static ssize_t h3_resp_headers_to_htx(struct qcs *qcs, const struct buffer *buf,
TRACE_ENTER(H3_EV_RX_FRAME|H3_EV_RX_HDR, qcs->qcc->conn, qcs);
/* TODO support buffer wrapping */
BUG_ON(b_head(buf) + len >= b_wrap(buf));
ret = qpack_decode_fs((const unsigned char *)b_head(buf), len, tmp,
list, sizeof(list) / sizeof(list[0]));
if (ret < 0) {
TRACE_ERROR("QPACK decoding error", H3_EV_RX_FRAME|H3_EV_RX_HDR, qcs->qcc->conn, qcs);
if ((qpack_err = qpack_err_decode(ret)) >= 0) {
h3c->err = qpack_err;
qcc_report_glitch(qcs->qcc, 1);
}
len = -1;
goto out;
}
appbuf = qcc_get_stream_rxbuf(qcs);
BUG_ON(!appbuf || b_data(appbuf)); /* TODO */
BUG_ON(!b_size(appbuf)); /* TODO */
@ -1211,6 +1227,71 @@ static ssize_t h3_resp_headers_to_htx(struct qcs *qcs, const struct buffer *buf,
}
sl->info.res.status = h * 100 + t * 10 + u;
/* now treat standard headers */
while (1) {
if (isteq(list[hdr_idx].n, ist("")))
break;
if (_h3_handle_hdr(qcs, &list[hdr_idx])) {
h3s->err = H3_ERR_MESSAGE_ERROR;
qcc_report_glitch(h3c->qcc, 1);
len = -1;
goto out;
}
if (isteq(list[hdr_idx].n, ist("connection")) ||
isteq(list[hdr_idx].n, ist("proxy-connection")) ||
isteq(list[hdr_idx].n, ist("keep-alive")) ||
isteq(list[hdr_idx].n, ist("upgrade")) ||
isteq(list[hdr_idx].n, ist("transfer-encoding"))) {
/* forbidden connection-specific fields */
TRACE_ERROR("invalid connection header", H3_EV_RX_FRAME|H3_EV_RX_HDR, qcs->qcc->conn, qcs);
h3s->err = H3_ERR_MESSAGE_ERROR;
qcc_report_glitch(h3c->qcc, 1);
len = -1;
goto out;
}
else if (isteq(list[hdr_idx].n, ist("content-length"))) {
ret = http_parse_cont_len_header(&list[hdr_idx].v,
&h3s->body_len,
h3s->flags & H3_SF_HAVE_CLEN);
if (ret < 0) {
TRACE_ERROR("invalid content-length", H3_EV_RX_FRAME|H3_EV_RX_HDR, qcs->qcc->conn, qcs);
h3s->err = H3_ERR_MESSAGE_ERROR;
qcc_report_glitch(h3c->qcc, 1);
len = -1;
goto out;
}
else if (!ret) {
/* Skip duplicated value. */
++hdr_idx;
continue;
}
h3s->flags |= H3_SF_HAVE_CLEN;
sl->flags |= HTX_SL_F_CLEN;
/* This will fail if current frame is the last one and
* content-length is not null.
*/
if (h3_check_body_size(qcs, fin)) {
len = -1;
goto out;
}
}
if (!htx_add_header(htx, list[hdr_idx].n, _h3_trim_header(list[hdr_idx].v))) {
len = -1;
goto out;
}
++hdr_idx;
}
/* Check the number of blocks against "tune.http.maxhdr" value before adding EOH block */
if (htx_nbblks(htx) > global.tune.max_http_hdr) {
len = -1;
goto out;
}
if (!htx_add_endof(htx, HTX_BLK_EOH)) {
len = -1;
goto out;