Line data Source code
1 : #include "fd_h2_conn.h"
2 : #include "fd_h2_callback.h"
3 : #include "fd_h2_proto.h"
4 : #include "fd_h2_rbuf.h"
5 : #include "fd_h2_stream.h"
6 : #include <float.h>
7 :
8 : #if FD_USING_GCC && __GNUC__ >= 15
9 : #pragma GCC diagnostic ignored "-Wunterminated-string-initialization"
10 : #endif
11 :
12 : char const fd_h2_client_preface[24] = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n";
13 :
14 : static fd_h2_settings_t const fd_h2_settings_initial = {
15 : .max_concurrent_streams = UINT_MAX,
16 : .initial_window_size = 65535U,
17 : .max_frame_size = 16384U,
18 : .max_header_list_size = UINT_MAX
19 : };
20 :
21 : static void
22 0 : fd_h2_conn_init_window( fd_h2_conn_t * conn ) {
23 0 : conn->rx_wnd_max = 65535U;
24 0 : conn->rx_wnd = conn->rx_wnd_max;
25 0 : conn->rx_wnd_wmark = (uint)( 0.7f * (float)conn->rx_wnd_max );
26 0 : conn->tx_wnd = 65535U;
27 0 : }
28 :
29 : fd_h2_conn_t *
30 0 : fd_h2_conn_init_client( fd_h2_conn_t * conn ) {
31 0 : *conn = (fd_h2_conn_t) {
32 0 : .self_settings = fd_h2_settings_initial,
33 0 : .peer_settings = fd_h2_settings_initial,
34 0 : .flags = FD_H2_CONN_FLAGS_CLIENT_INITIAL,
35 0 : .tx_stream_next = 1U,
36 0 : .rx_stream_next = 2U
37 0 : };
38 0 : fd_h2_conn_init_window( conn );
39 0 : return conn;
40 0 : }
41 :
42 : fd_h2_conn_t *
43 0 : fd_h2_conn_init_server( fd_h2_conn_t * conn ) {
44 0 : *conn = (fd_h2_conn_t) {
45 0 : .self_settings = fd_h2_settings_initial,
46 0 : .peer_settings = fd_h2_settings_initial,
47 0 : .flags = FD_H2_CONN_FLAGS_SERVER_INITIAL,
48 0 : .tx_stream_next = 2U,
49 0 : .rx_stream_next = 1U
50 0 : };
51 0 : fd_h2_conn_init_window( conn );
52 0 : return conn;
53 0 : }
54 :
55 : static void
56 : fd_h2_setting_encode( uchar * buf,
57 : ushort setting_id,
58 0 : uint setting_value ) {
59 0 : FD_STORE( ushort, buf, fd_ushort_bswap( setting_id ) );
60 0 : FD_STORE( uint, buf+2, fd_uint_bswap ( setting_value ) );
61 0 : }
62 :
63 : #define FD_H2_OUR_SETTINGS_ENCODED_SZ 45
64 :
65 : static void
66 : fd_h2_gen_settings( fd_h2_settings_t const * settings,
67 0 : uchar buf[ FD_H2_OUR_SETTINGS_ENCODED_SZ ] ) {
68 0 : fd_h2_frame_hdr_t hdr = {
69 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_SETTINGS, 36UL ),
70 0 : };
71 0 : fd_memcpy( buf, &hdr, 9UL );
72 :
73 0 : fd_h2_setting_encode( buf+9, FD_H2_SETTINGS_HEADER_TABLE_SIZE, 0U );
74 0 : fd_h2_setting_encode( buf+15, FD_H2_SETTINGS_ENABLE_PUSH, 0U );
75 0 : fd_h2_setting_encode( buf+21, FD_H2_SETTINGS_MAX_CONCURRENT_STREAMS, settings->max_concurrent_streams );
76 0 : fd_h2_setting_encode( buf+27, FD_H2_SETTINGS_INITIAL_WINDOW_SIZE, settings->initial_window_size );
77 0 : fd_h2_setting_encode( buf+33, FD_H2_SETTINGS_MAX_FRAME_SIZE, settings->max_frame_size );
78 0 : fd_h2_setting_encode( buf+39, FD_H2_SETTINGS_MAX_HEADER_LIST_SIZE, settings->max_header_list_size );
79 0 : }
80 :
81 : /* fd_h2_rx_stream_used returns 1 if stream_id was already opened or
82 : implicitly closed by opening a larger ID of the same initiator. */
83 :
84 : static inline int
85 : fd_h2_rx_stream_used( fd_h2_conn_t const * conn,
86 0 : uint stream_id ) {
87 0 : uint next = ((stream_id^conn->tx_stream_next)&1U) ? conn->rx_stream_next : conn->tx_stream_next;
88 0 : return stream_id<next;
89 0 : }
90 :
91 : /* fd_h2_rx_data handles a partial DATA frame. The caller reserves TX
92 : space for a single RST_STREAM or two WINDOW_UPDATE frames. */
93 :
94 : static void
95 : fd_h2_rx_data( fd_h2_conn_t * conn,
96 : fd_h2_rbuf_t * rbuf_rx,
97 : fd_h2_rbuf_t * rbuf_tx,
98 0 : fd_h2_callbacks_t const * cb ) {
99 0 : ulong frame_rem = conn->rx_data_cnt_rem;
100 0 : ulong rbuf_avail = fd_h2_rbuf_used_sz( rbuf_rx );
101 0 : uint stream_id = conn->rx_stream_id;
102 0 : uint chunk_sz = (uint)fd_ulong_min( frame_rem, rbuf_avail );
103 0 : uint wnd_sz = chunk_sz; /* + Pad Length and Padding on the last chunk */
104 0 : uint fin_flag = conn->rx_frame_flags & FD_H2_FLAG_END_STREAM;
105 : /* The rest of the frame must fit before any of it is delivered, even
106 : if credit is replenished between chunks (RFC 9113 6.9.1). */
107 0 : uint frame_wnd_sz = (uint)frame_rem + ( conn->rx_frame_flags & FD_H2_FLAG_PADDED ? 1U + conn->rx_pad_rem : 0U );
108 0 : if( rbuf_avail<frame_rem ) fin_flag = 0;
109 0 : else wnd_sz = frame_wnd_sz;
110 :
111 0 : if( FD_UNLIKELY( frame_wnd_sz > conn->rx_wnd ) ) {
112 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
113 0 : return;
114 0 : }
115 0 : conn->rx_wnd -= wnd_sz;
116 :
117 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
118 0 : if( FD_UNLIKELY( !stream ) ) {
119 0 : if( fd_h2_rx_stream_used( conn, stream_id ) ) goto skip_frame; /* RFC 9113 5.1 */
120 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
121 0 : return;
122 0 : }
123 0 : if( FD_UNLIKELY( stream->state!=FD_H2_STREAM_STATE_OPEN &&
124 0 : stream->state!=FD_H2_STREAM_STATE_CLOSING_TX ) ) {
125 0 : if( stream->state==FD_H2_STREAM_STATE_CLOSED ) goto skip_frame;
126 0 : if( FD_UNLIKELY( stream->state!=FD_H2_STREAM_STATE_CLOSING_RX ) ) {
127 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
128 0 : return;
129 0 : }
130 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_STREAM_CLOSED );
131 0 : cb->rst_stream( conn, stream, FD_H2_ERR_STREAM_CLOSED, 0 );
132 0 : goto skip_frame;
133 0 : }
134 :
135 0 : if( FD_UNLIKELY( frame_wnd_sz > stream->rx_wnd ) ) {
136 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_FLOW_CONTROL );
137 0 : cb->rst_stream( conn, stream, FD_H2_ERR_FLOW_CONTROL, 0 );
138 0 : goto skip_frame;
139 0 : }
140 0 : stream->rx_wnd -= wnd_sz;
141 :
142 0 : fd_h2_stream_rx_data( stream, conn, fin_flag );
143 :
144 0 : ulong sz0, sz1;
145 0 : uchar const * peek = fd_h2_rbuf_peek_used( rbuf_rx, &sz0, &sz1 );
146 0 : if( sz0>=chunk_sz ) {
147 0 : sz0 = chunk_sz;
148 0 : sz1 = 0;
149 0 : } else if( sz0+sz1>chunk_sz ) {
150 0 : sz1 = chunk_sz-sz0;
151 0 : }
152 0 : if( FD_LIKELY( !sz1 ) ) {
153 0 : cb->data( conn, stream, peek, sz0, fin_flag );
154 0 : } else {
155 0 : cb->data( conn, stream, peek, sz0, 0 );
156 : /* The first callback may have released the stream. Re-query the stream
157 : map before dispatching the wrapped tail chunk. */
158 0 : stream = cb->stream_query( conn, stream_id );
159 0 : if( FD_LIKELY( stream && !stream->rx_aborted && !(conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD)) ) ) {
160 0 : cb->data( conn, stream, rbuf_rx->buf0, sz1, fin_flag );
161 0 : }
162 0 : }
163 :
164 0 : skip_frame:
165 0 : conn->rx_data_cnt_rem -= chunk_sz;
166 0 : fd_h2_rbuf_skip( rbuf_rx, chunk_sz );
167 0 : if( FD_UNLIKELY( conn->rx_wnd < conn->rx_wnd_wmark ) ) {
168 0 : conn->flags |= FD_H2_CONN_FLAGS_WINDOW_UPDATE;
169 0 : }
170 0 : }
171 :
172 : static int
173 : fd_h2_rx_headers( fd_h2_conn_t * conn,
174 : fd_h2_rbuf_t * rbuf_tx,
175 : uchar * payload,
176 : ulong payload_sz,
177 : fd_h2_callbacks_t const * cb,
178 : uint frame_flags,
179 0 : uint stream_id ) {
180 :
181 0 : if( FD_UNLIKELY( !stream_id ) ) {
182 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
183 0 : return 0;
184 0 : }
185 :
186 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_PRIORITY ) ) {
187 0 : if( FD_UNLIKELY( payload_sz<5UL ) ) {
188 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
189 0 : return 0;
190 0 : }
191 0 : payload += 5UL;
192 0 : payload_sz -= 5UL;
193 0 : }
194 :
195 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
196 0 : if( FD_UNLIKELY( !stream || stream->state==FD_H2_STREAM_STATE_CLOSED ) ) {
197 0 : stream = NULL;
198 0 : if( !fd_h2_rx_stream_used( conn, stream_id ) ) {
199 0 : if( FD_UNLIKELY( ((stream_id^conn->tx_stream_next)&1U)==0U ||
200 0 : ((conn->tx_stream_next&1U) && !conn->allow_server_requests) ) ) {
201 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
202 0 : return 0;
203 0 : }
204 : /* Even a refused stream consumes its ID and closes skipped IDs. */
205 0 : conn->rx_stream_next = stream_id+2U;
206 0 : if( FD_LIKELY( conn->stream_active_cnt[0] < conn->self_settings.max_concurrent_streams ) ) {
207 0 : stream = cb->stream_create( conn, stream_id );
208 0 : }
209 0 : if( FD_LIKELY( stream ) ) fd_h2_stream_open( stream, conn, stream_id );
210 0 : else fd_h2_tx_rst_stream( rbuf_tx, stream_id, FD_H2_ERR_REFUSED_STREAM );
211 0 : }
212 0 : }
213 :
214 0 : conn->rx_stream_id = stream_id;
215 :
216 : /* Validate every block, as HPACK errors are connection errors (RFC
217 : 9113 4.3), and keep state from the first fragment of a live block
218 : in case its stream is released before CONTINUATION. */
219 0 : conn->rx_hdrs_discard = (uchar)!stream;
220 0 : if( !(frame_flags & FD_H2_FLAG_END_HEADERS) ) conn->flags |= FD_H2_CONN_FLAGS_CONTINUATION;
221 0 : fd_hpack_skip_init( &conn->rx_hpack );
222 0 : if( FD_UNLIKELY( fd_hpack_skip_feed( &conn->rx_hpack, payload, payload_sz, !!(frame_flags & FD_H2_FLAG_END_HEADERS) ) ) ) {
223 0 : fd_h2_conn_error( conn, FD_H2_ERR_COMPRESSION );
224 0 : return 0;
225 0 : }
226 0 : if( !stream ) return 1;
227 :
228 0 : fd_h2_stream_rx_headers( stream, conn, frame_flags );
229 0 : if( FD_UNLIKELY( stream->state==FD_H2_STREAM_STATE_ILLEGAL ) ) {
230 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
231 0 : return 0;
232 0 : }
233 :
234 0 : cb->headers( conn, stream, payload, payload_sz, frame_flags );
235 :
236 0 : return 1;
237 0 : }
238 :
239 : static int
240 : fd_h2_rx_priority( fd_h2_conn_t * conn,
241 : ulong payload_sz,
242 0 : uint stream_id ) {
243 0 : if( FD_UNLIKELY( payload_sz!=5UL ) ) {
244 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
245 0 : return 0;
246 0 : }
247 0 : if( FD_UNLIKELY( !stream_id ) ) {
248 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
249 0 : return 0;
250 0 : }
251 0 : return 1;
252 0 : }
253 :
254 : static int
255 : fd_h2_rx_continuation( fd_h2_conn_t * conn,
256 : uchar * payload,
257 : ulong payload_sz,
258 : fd_h2_callbacks_t const * cb,
259 : uint frame_flags,
260 0 : uint stream_id ) {
261 :
262 0 : if( FD_UNLIKELY( ( conn->rx_stream_id!=stream_id ) |
263 0 : ( !( conn->flags & FD_H2_CONN_FLAGS_CONTINUATION ) ) |
264 0 : ( !stream_id ) ) ) {
265 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
266 0 : return 0;
267 0 : }
268 :
269 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_END_HEADERS ) ) {
270 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_CONTINUATION;
271 0 : }
272 :
273 0 : if( FD_UNLIKELY( fd_hpack_skip_feed( &conn->rx_hpack, payload, payload_sz, !!(frame_flags & FD_H2_FLAG_END_HEADERS) ) ) ) {
274 0 : fd_h2_conn_error( conn, FD_H2_ERR_COMPRESSION );
275 0 : return 0;
276 0 : }
277 0 : if( FD_UNLIKELY( conn->rx_hdrs_discard ) ) return 1;
278 :
279 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
280 0 : if( FD_UNLIKELY( !stream ) ) return 1;
281 :
282 0 : fd_h2_stream_rx_headers( stream, conn, frame_flags );
283 0 : if( FD_UNLIKELY( stream->state==FD_H2_STREAM_STATE_ILLEGAL ) ) {
284 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
285 0 : return 0;
286 0 : }
287 :
288 0 : cb->headers( conn, stream, payload, payload_sz, frame_flags );
289 :
290 0 : return 1;
291 0 : }
292 :
293 : static int
294 : fd_h2_rx_rst_stream( fd_h2_conn_t * conn,
295 : uchar const * payload,
296 : ulong payload_sz,
297 : fd_h2_callbacks_t const * cb,
298 0 : uint stream_id ) {
299 0 : if( FD_UNLIKELY( payload_sz!=4UL ) ) {
300 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
301 0 : return 0;
302 0 : }
303 0 : if( FD_UNLIKELY( !stream_id || !fd_h2_rx_stream_used( conn, stream_id ) ) ) {
304 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
305 0 : return 0;
306 0 : }
307 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
308 0 : if( FD_LIKELY( stream && stream->state!=FD_H2_STREAM_STATE_CLOSED ) ) {
309 0 : uint error_code = fd_uint_bswap( FD_LOAD( uint, payload ) );
310 0 : fd_h2_stream_reset( stream, conn );
311 0 : cb->rst_stream( conn, stream, error_code, 1 );
312 : /* stream points to freed memory at this point */
313 0 : }
314 0 : return 1;
315 0 : }
316 :
317 : static int
318 : fd_h2_rx_settings( fd_h2_conn_t * conn,
319 : fd_h2_rbuf_t * rbuf_tx,
320 : uchar const * payload,
321 : ulong payload_sz,
322 : fd_h2_callbacks_t const * cb,
323 : uint frame_flags,
324 0 : uint stream_id ) {
325 :
326 0 : if( FD_UNLIKELY( stream_id ) ) {
327 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
328 0 : return 0;
329 0 : }
330 :
331 0 : if( frame_flags & FD_H2_FLAG_ACK ) {
332 0 : if( FD_UNLIKELY( payload_sz ) ) {
333 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
334 0 : return 0;
335 0 : }
336 0 : if( FD_UNLIKELY( !conn->setting_tx ) ) {
337 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
338 0 : return 0;
339 0 : }
340 0 : if( conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0 ) {
341 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0;
342 0 : if( !( conn->flags & FD_H2_CONN_FLAGS_HANDSHAKING ) ) {
343 0 : cb->conn_established( conn );
344 0 : }
345 0 : }
346 0 : conn->setting_tx--;
347 0 : return 1;
348 0 : }
349 :
350 0 : if( FD_UNLIKELY( payload_sz % 6 ) ) {
351 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
352 0 : return 0;
353 0 : }
354 :
355 0 : for( ulong off=0UL; off<payload_sz; off+=sizeof(fd_h2_setting_t) ) {
356 0 : fd_h2_setting_t setting = FD_LOAD( fd_h2_setting_t, payload+off );
357 0 : ushort id = fd_ushort_bswap( setting.id );
358 0 : uint value = fd_uint_bswap( setting.value );
359 :
360 0 : switch( id ) {
361 0 : case FD_H2_SETTINGS_ENABLE_PUSH:
362 0 : if( FD_UNLIKELY( value>1 ) ) {
363 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
364 0 : return 0;
365 0 : }
366 0 : break;
367 0 : case FD_H2_SETTINGS_INITIAL_WINDOW_SIZE: {
368 0 : if( FD_UNLIKELY( value>0x7fffffff ) ) {
369 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
370 0 : return 0;
371 0 : }
372 0 : long delta = (long)value - (long)conn->peer_settings.initial_window_size;
373 0 : conn->peer_settings.initial_window_size = value;
374 0 : if( FD_UNLIKELY( delta && cb->initial_window_update ) ) {
375 0 : cb->initial_window_update( conn, delta );
376 0 : if( FD_UNLIKELY( conn->flags & FD_H2_CONN_FLAGS_SEND_GOAWAY ) ) return 0;
377 0 : }
378 0 : break;
379 0 : }
380 0 : case FD_H2_SETTINGS_MAX_FRAME_SIZE:
381 0 : if( FD_UNLIKELY( value<0x4000 || value>0xffffff ) ) {
382 : /* Values outside this range MUST be treated as a connection error
383 : (Section 5.4.1) of type PROTOCOL_ERROR. */
384 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
385 0 : return 0;
386 0 : }
387 0 : conn->peer_settings.max_frame_size = value;
388 : /* FIXME validate min */
389 0 : break;
390 0 : case FD_H2_SETTINGS_MAX_HEADER_LIST_SIZE:
391 0 : conn->peer_settings.max_header_list_size = value;
392 0 : break;
393 0 : case FD_H2_SETTINGS_MAX_CONCURRENT_STREAMS:
394 0 : conn->peer_settings.max_concurrent_streams = value;
395 0 : break;
396 0 : }
397 0 : }
398 :
399 0 : fd_h2_frame_hdr_t hdr = {
400 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_SETTINGS, 0UL ),
401 0 : .flags = FD_H2_FLAG_ACK
402 0 : };
403 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_frame_hdr_t) ) ) {
404 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
405 0 : return 0;
406 0 : }
407 0 : fd_h2_rbuf_push( rbuf_tx, &hdr, sizeof(fd_h2_frame_hdr_t) );
408 :
409 0 : if( conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 ) {
410 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_WAIT_SETTINGS_0;
411 0 : if( !( conn->flags & FD_H2_CONN_FLAGS_HANDSHAKING ) ) {
412 0 : cb->conn_established( conn );
413 0 : }
414 0 : }
415 :
416 0 : return 1;
417 0 : }
418 :
419 : static int
420 0 : fd_h2_rx_push_promise( fd_h2_conn_t * conn ) {
421 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
422 0 : return 0;
423 0 : }
424 :
425 : static int
426 : fd_h2_rx_ping( fd_h2_conn_t * conn,
427 : fd_h2_rbuf_t * rbuf_tx,
428 : uchar const * payload,
429 : ulong payload_sz,
430 : fd_h2_callbacks_t const * cb,
431 : uint frame_flags,
432 0 : uint stream_id ) {
433 0 : if( FD_UNLIKELY( payload_sz!=8UL ) ) {
434 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
435 0 : return 0;
436 0 : }
437 0 : if( FD_UNLIKELY( stream_id ) ) {
438 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
439 0 : return 0;
440 0 : }
441 :
442 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_ACK ) ) {
443 :
444 : /* Received an acknowledgement for a PING frame. */
445 0 : if( FD_UNLIKELY( conn->ping_tx==0 || FD_LOAD( ulong, payload )!=0UL ) ) {
446 0 : return 1;
447 0 : }
448 0 : cb->ping_ack( conn );
449 0 : conn->ping_tx = (uchar)( conn->ping_tx-1 );
450 :
451 0 : } else {
452 :
453 : /* Received a new PING frame. Generate a PONG. */
454 : /* FIMXE rate limit */
455 0 : fd_h2_ping_t pong = {
456 0 : .hdr = {
457 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
458 0 : .flags = FD_H2_FLAG_ACK,
459 0 : },
460 0 : .payload = FD_LOAD( ulong, payload )
461 0 : };
462 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) ) {
463 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
464 0 : return 0;
465 0 : }
466 0 : fd_h2_rbuf_push( rbuf_tx, &pong, sizeof(fd_h2_ping_t) );
467 :
468 0 : }
469 :
470 0 : return 1;
471 0 : }
472 :
473 : void
474 : fd_h2_tx_rst_stream( fd_h2_rbuf_t * rbuf_tx,
475 : uint stream_id,
476 0 : uint h2_err ) {
477 0 : fd_h2_rst_stream_t rst_stream = {
478 0 : .hdr = {
479 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_RST_STREAM, 4UL ),
480 0 : .flags = 0U,
481 0 : .r_stream_id = fd_uint_bswap( stream_id )
482 0 : },
483 0 : .error_code = fd_uint_bswap( h2_err )
484 0 : };
485 0 : fd_h2_rbuf_push( rbuf_tx, &rst_stream, sizeof(fd_h2_rst_stream_t) );
486 0 : }
487 :
488 : int
489 : fd_h2_tx_ping( fd_h2_conn_t * conn,
490 0 : fd_h2_rbuf_t * rbuf_tx ) {
491 0 : ulong ping_tx = conn->ping_tx;
492 0 : if( FD_UNLIKELY( ( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) |
493 0 : ( ping_tx>=UCHAR_MAX ) ) ) {
494 0 : return 0; /* blocked */
495 0 : }
496 :
497 0 : fd_h2_ping_t ping = {
498 0 : .hdr = {
499 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
500 0 : .flags = 0U,
501 0 : .r_stream_id = 0UL
502 0 : },
503 0 : .payload = 0UL
504 0 : };
505 0 : fd_h2_rbuf_push( rbuf_tx, &ping, sizeof(fd_h2_ping_t) );
506 0 : conn->ping_tx = (uchar)( ping_tx+1 );
507 0 : return 1;
508 0 : }
509 :
510 : static int
511 : fd_h2_rx_goaway( fd_h2_conn_t * conn,
512 : fd_h2_callbacks_t const * cb,
513 : uchar const * payload,
514 : ulong payload_sz,
515 0 : uint stream_id ) {
516 :
517 0 : if( FD_UNLIKELY( stream_id ) ) {
518 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
519 0 : return 0;
520 0 : }
521 0 : if( FD_UNLIKELY( payload_sz<8UL ) ) {
522 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
523 0 : return 0;
524 0 : }
525 :
526 0 : uint error_code = fd_uint_bswap( FD_LOAD( uint, payload+4UL ) );
527 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
528 0 : cb->conn_final( conn, error_code, 1 /* peer */ );
529 :
530 0 : return 1;
531 0 : }
532 :
533 : static int
534 : fd_h2_rx_window_update( fd_h2_conn_t * conn,
535 : fd_h2_rbuf_t * rbuf_tx,
536 : fd_h2_callbacks_t const * cb,
537 : uchar const * payload,
538 : ulong payload_sz,
539 0 : uint stream_id ) {
540 0 : if( FD_UNLIKELY( payload_sz!=4UL ) ) {
541 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
542 0 : return 0;
543 0 : }
544 0 : uint increment = fd_uint_bswap( FD_LOAD( uint, payload ) ) & 0x7fffffff;
545 :
546 0 : if( !stream_id ) {
547 :
548 : /* Connection-level window update */
549 0 : uint tx_wnd = conn->tx_wnd;
550 0 : if( FD_UNLIKELY( !increment ) ) {
551 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
552 0 : return 0;
553 0 : }
554 0 : uint tx_wnd_new;
555 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( tx_wnd, increment, &tx_wnd_new ) || tx_wnd_new>0x7fffffffU ) ) {
556 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
557 0 : return 0;
558 0 : }
559 0 : conn->tx_wnd = tx_wnd_new;
560 0 : cb->window_update( conn, (uint)increment );
561 :
562 0 : } else {
563 :
564 0 : if( FD_UNLIKELY( !fd_h2_rx_stream_used( conn, stream_id ) ) ) {
565 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
566 0 : return 0;
567 0 : }
568 :
569 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
570 0 : if( FD_UNLIKELY( !stream || stream->state==FD_H2_STREAM_STATE_CLOSED ) ) {
571 0 : return 1;
572 0 : }
573 :
574 0 : if( FD_UNLIKELY( !increment ) ) {
575 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_PROTOCOL );
576 0 : cb->rst_stream( conn, stream, FD_H2_ERR_PROTOCOL, 0 );
577 0 : return 1;
578 0 : }
579 :
580 : /* Stream-level window update */
581 0 : uint tx_wnd_new;
582 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( stream->tx_wnd, increment, &tx_wnd_new ) || tx_wnd_new>0x7fffffffU ) ) {
583 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_FLOW_CONTROL );
584 0 : cb->rst_stream( conn, stream, FD_H2_ERR_FLOW_CONTROL, 0 );
585 : /* stream points to freed memory at this point */
586 0 : return 1;
587 0 : }
588 0 : stream->tx_wnd = tx_wnd_new;
589 0 : cb->stream_window_update( conn, stream, (uint)increment );
590 :
591 0 : }
592 :
593 0 : return 1;
594 0 : }
595 :
596 : /* fd_h2_rx_frame handles a complete frame. Returns 1 on success, and
597 : 0 on connection error. */
598 :
599 : static int
600 : fd_h2_rx_frame( fd_h2_conn_t * conn,
601 : fd_h2_rbuf_t * rbuf_tx,
602 : uchar * payload,
603 : ulong payload_sz,
604 : fd_h2_callbacks_t const * cb,
605 : uint frame_type,
606 : uint frame_flags,
607 0 : uint stream_id ) {
608 0 : switch( frame_type ) {
609 0 : case FD_H2_FRAME_TYPE_HEADERS:
610 0 : return fd_h2_rx_headers( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
611 0 : case FD_H2_FRAME_TYPE_PRIORITY:
612 0 : return fd_h2_rx_priority( conn, payload_sz, stream_id );
613 0 : case FD_H2_FRAME_TYPE_RST_STREAM:
614 0 : return fd_h2_rx_rst_stream( conn, payload, payload_sz, cb, stream_id );
615 0 : case FD_H2_FRAME_TYPE_SETTINGS:
616 0 : return fd_h2_rx_settings( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
617 0 : case FD_H2_FRAME_TYPE_PUSH_PROMISE:
618 0 : return fd_h2_rx_push_promise( conn );
619 0 : case FD_H2_FRAME_TYPE_CONTINUATION:
620 0 : return fd_h2_rx_continuation( conn, payload, payload_sz, cb, frame_flags&FD_H2_FLAG_END_HEADERS, stream_id );
621 0 : case FD_H2_FRAME_TYPE_PING:
622 0 : return fd_h2_rx_ping( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
623 0 : case FD_H2_FRAME_TYPE_GOAWAY:
624 0 : return fd_h2_rx_goaway( conn, cb, payload, payload_sz, stream_id );
625 0 : case FD_H2_FRAME_TYPE_WINDOW_UPDATE:
626 0 : return fd_h2_rx_window_update( conn, rbuf_tx, cb, payload, payload_sz, stream_id );
627 0 : default:
628 0 : return 1;
629 0 : }
630 0 : }
631 :
632 : /* fd_h2_rx1 handles one frame. */
633 :
634 : static void
635 : fd_h2_rx1( fd_h2_conn_t * conn,
636 : fd_h2_rbuf_t * rbuf_rx,
637 : fd_h2_rbuf_t * rbuf_tx,
638 : uchar * scratch,
639 : ulong scratch_sz,
640 0 : fd_h2_callbacks_t const * cb ) {
641 : /* All frames except DATA are fully buffered, thus assume that current
642 : frame is a DATA frame if rx_data_cnt_rem != 0. */
643 0 : if( conn->rx_data_cnt_rem ) {
644 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<2UL*sizeof(fd_h2_window_update_t) ) ) return;
645 0 : fd_h2_rx_data( conn, rbuf_rx, rbuf_tx, cb );
646 0 : return;
647 0 : }
648 0 : if( FD_UNLIKELY( conn->rx_pad_rem ) ) {
649 0 : ulong pad_rem = conn->rx_pad_rem;
650 0 : ulong rbuf_avail = fd_h2_rbuf_used_sz( rbuf_rx );
651 0 : uint chunk_sz = (uint)fd_ulong_min( pad_rem, rbuf_avail );
652 0 : fd_h2_rbuf_skip( rbuf_rx, chunk_sz );
653 0 : conn->rx_pad_rem = (uchar)( conn->rx_pad_rem - chunk_sz );
654 0 : return;
655 0 : }
656 :
657 : /* A new frame starts. Peek the header. */
658 0 : if( FD_UNLIKELY( fd_h2_rbuf_used_sz( rbuf_rx )<sizeof(fd_h2_frame_hdr_t) ) ) {
659 0 : conn->rx_suppress = rbuf_rx->lo_off + sizeof(fd_h2_frame_hdr_t);
660 0 : return;
661 0 : }
662 0 : fd_h2_rbuf_t rx_peek = *rbuf_rx;
663 0 : fd_h2_frame_hdr_t hdr;
664 0 : fd_h2_rbuf_pop_copy( &rx_peek, &hdr, sizeof(fd_h2_frame_hdr_t) );
665 0 : uint const frame_type = fd_h2_frame_type ( hdr.typlen );
666 0 : uint const frame_sz = fd_h2_frame_length( hdr.typlen );
667 :
668 0 : if( FD_UNLIKELY( frame_sz > conn->self_settings.max_frame_size ) ) {
669 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
670 0 : return;
671 0 : }
672 0 : if( FD_UNLIKELY( (!!( conn->flags & FD_H2_CONN_FLAGS_CONTINUATION ) ) &
673 0 : ( frame_type!=FD_H2_FRAME_TYPE_CONTINUATION ) ) ) {
674 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
675 0 : return;
676 0 : }
677 : /* The peer's preface is a non-ACK SETTINGS frame (RFC 9113 3.4) */
678 0 : if( FD_UNLIKELY( (conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_0) &&
679 0 : (frame_type!=FD_H2_FRAME_TYPE_SETTINGS || (hdr.flags & FD_H2_FLAG_ACK)) ) ) {
680 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
681 0 : return;
682 0 : }
683 :
684 : /* Peek padding */
685 0 : uint pad_sz = 0U;
686 : /* Bytes remaining in this frame payload excluding padding length and padding. */
687 0 : uint payload_sz = frame_sz;
688 0 : if( ( frame_type==FD_H2_FRAME_TYPE_DATA ||
689 0 : frame_type==FD_H2_FRAME_TYPE_HEADERS ||
690 0 : frame_type==FD_H2_FRAME_TYPE_PUSH_PROMISE ) &&
691 0 : !!( hdr.flags & FD_H2_FLAG_PADDED ) ) {
692 0 : if( FD_UNLIKELY( fd_h2_rbuf_used_sz( &rx_peek )<1UL ) ) return;
693 0 : pad_sz = rx_peek.lo[0];
694 0 : payload_sz -= 1U; // Exclude Pad Length field
695 0 : payload_sz -= pad_sz; // Exclude padding
696 : /* If the length of the padding is the length of the
697 : frame payload or greater, the recipient MUST treat this as a
698 : connection error (Section 5.4.1) of type PROTOCOL_ERROR. */
699 0 : if( FD_UNLIKELY( pad_sz>=frame_sz ) ) {
700 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
701 0 : return;
702 0 : }
703 0 : fd_h2_rbuf_skip( &rx_peek, 1UL );
704 0 : }
705 :
706 : /* Special case: Process data incrementally */
707 0 : if( frame_type==FD_H2_FRAME_TYPE_DATA ) {
708 : /* Reserve responses before consuming the header, including for
709 : empty DATA frames that have no pending-data counter to retry. */
710 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<2UL*sizeof(fd_h2_window_update_t) ) ) return;
711 : /* The amount of data is the remainder of the
712 : frame payload after subtracting the length of the other fields
713 : that are present [that is, padding length and padding]. */
714 0 : conn->rx_data_cnt_rem = payload_sz;
715 0 : conn->rx_frame_flags = hdr.flags;
716 0 : conn->rx_stream_id = fd_h2_frame_stream_id( hdr.r_stream_id );
717 0 : conn->rx_pad_rem = (uchar)pad_sz;
718 0 : *rbuf_rx = rx_peek;
719 0 : if( FD_UNLIKELY( !conn->rx_stream_id ) ) {
720 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
721 0 : return;
722 0 : }
723 0 : fd_h2_rx_data( conn, rbuf_rx, rbuf_tx, cb );
724 0 : return;
725 0 : }
726 :
727 : /* Consume all or nothing */
728 0 : ulong const tot_sz = sizeof(fd_h2_frame_hdr_t) + frame_sz;
729 0 : if( FD_UNLIKELY( tot_sz>rbuf_rx->bufsz ) ) {
730 : /* Frame will never fit in the buffer */
731 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
732 0 : return;
733 0 : }
734 0 : if( FD_UNLIKELY( tot_sz>fd_h2_rbuf_used_sz( rbuf_rx ) ) ) {
735 0 : conn->rx_suppress = rbuf_rx->lo_off + tot_sz;
736 0 : return;
737 0 : }
738 :
739 0 : if( FD_UNLIKELY( scratch_sz < payload_sz ) ) {
740 0 : if( FD_UNLIKELY( scratch_sz < conn->self_settings.max_frame_size ) ) {
741 0 : FD_LOG_WARNING(( "scratch buffer too small: scratch_sz=%lu max_frame_size=%u)",
742 0 : scratch_sz, conn->self_settings.max_frame_size ));
743 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
744 0 : return;
745 0 : }
746 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
747 0 : return;
748 0 : }
749 :
750 : /* Ensure TX buffer has enough free space for control frame responses
751 : that frame handlers might generate. The largest is the PONG reply
752 : (17 bytes); RST_STREAM is 13. If there is not enough space, defer
753 : processing until the TX buffer drains. */
754 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) ) return;
755 :
756 0 : *rbuf_rx = rx_peek;
757 0 : uchar * frame = fd_h2_rbuf_pop( rbuf_rx, scratch, payload_sz );
758 0 : fd_h2_rx_frame( conn, rbuf_tx, frame, payload_sz, cb,
759 0 : frame_type,
760 0 : hdr.flags,
761 0 : fd_h2_frame_stream_id( hdr.r_stream_id ) );
762 0 : fd_h2_rbuf_skip( rbuf_rx, pad_sz );
763 0 : }
764 :
765 : void
766 : fd_h2_rx( fd_h2_conn_t * conn,
767 : fd_h2_rbuf_t * rbuf_rx,
768 : fd_h2_rbuf_t * rbuf_tx,
769 : uchar * scratch,
770 : ulong scratch_sz,
771 0 : fd_h2_callbacks_t const * cb ) {
772 : /* Pre-receive TX work */
773 :
774 : /* Stop handling frames on conn error. Defer them until our preface
775 : is queued, so no reply precedes it (RFC 9113 3.4). */
776 0 : if( FD_UNLIKELY( conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD|
777 0 : FD_H2_CONN_FLAGS_CLIENT_INITIAL|FD_H2_CONN_FLAGS_SERVER_INITIAL) ) ) return;
778 :
779 : /* All other logic below can only proceed if new data arrived. */
780 0 : if( FD_UNLIKELY( !fd_h2_rbuf_used_sz( rbuf_rx ) ) ) return;
781 :
782 : /* Slowloris defense: Guess how much bytes are required to progress
783 : ahead of time based on the frame's type and size. */
784 0 : if( FD_UNLIKELY( rbuf_rx->hi_off < conn->rx_suppress ) ) return;
785 :
786 : /* Handle frames */
787 0 : for(;;) {
788 0 : ulong lo0 = rbuf_rx->lo_off;
789 0 : fd_h2_rx1( conn, rbuf_rx, rbuf_tx, scratch, scratch_sz, cb );
790 0 : ulong lo1 = rbuf_rx->lo_off;
791 :
792 : /* Terminate when no more bytes are available to read */
793 0 : if( !fd_h2_rbuf_used_sz( rbuf_rx ) ) break;
794 :
795 : /* Terminate when the frame handler didn't make progress (e.g. due
796 : to rbuf_tx full, or due to incomplete read from rbuf_tx)*/
797 0 : if( FD_UNLIKELY( lo0==lo1 ) ) break;
798 :
799 : /* Terminate if the conn died */
800 0 : if( FD_UNLIKELY( conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD) ) ) break;
801 0 : }
802 0 : }
803 :
804 : void
805 : fd_h2_tx_control( fd_h2_conn_t * conn,
806 : fd_h2_rbuf_t * rbuf_tx,
807 0 : fd_h2_callbacks_t const * cb ) {
808 :
809 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<128 ) ) return;
810 :
811 0 : switch( fd_uint_find_lsb( (uint)conn->flags | 0x10000u ) ) {
812 :
813 0 : case FD_H2_CONN_FLAGS_LG_CLIENT_INITIAL:
814 0 : fd_h2_rbuf_push( rbuf_tx, fd_h2_client_preface, sizeof(fd_h2_client_preface) );
815 0 : __attribute__((fallthrough));
816 :
817 0 : case FD_H2_CONN_FLAGS_LG_SERVER_INITIAL: {
818 0 : uchar buf[ FD_H2_OUR_SETTINGS_ENCODED_SZ ];
819 0 : fd_h2_gen_settings( &conn->self_settings, buf );
820 0 : fd_h2_rbuf_push( rbuf_tx, buf, sizeof(buf) );
821 0 : conn->setting_tx++;
822 0 : conn->flags = FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 | FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0;
823 0 : break;
824 0 : }
825 :
826 0 : goaway:
827 0 : case FD_H2_CONN_FLAGS_LG_SEND_GOAWAY: {
828 0 : fd_h2_goaway_t goaway = {
829 0 : .hdr = {
830 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_GOAWAY, 8UL )
831 0 : },
832 0 : .last_stream_id = 0, /* FIXME */
833 0 : .error_code = fd_uint_bswap( (uint)conn->conn_error )
834 0 : };
835 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
836 0 : fd_h2_rbuf_push( rbuf_tx, &goaway, sizeof(fd_h2_goaway_t) );
837 0 : cb->conn_final( conn, conn->conn_error, 0 /* local */ );
838 0 : break;
839 0 : }
840 :
841 0 : case FD_H2_CONN_FLAGS_LG_WINDOW_UPDATE: {
842 0 : uint increment = conn->rx_wnd_max - conn->rx_wnd;
843 0 : if( FD_UNLIKELY( increment>0x7fffffff ) ) {
844 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
845 0 : goto goaway;
846 0 : }
847 0 : if( FD_UNLIKELY( increment==0 ) ) break;
848 0 : fd_h2_window_update_t window_update = {
849 0 : .hdr = {
850 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_WINDOW_UPDATE, 4UL )
851 0 : },
852 0 : .increment = fd_uint_bswap( increment )
853 0 : };
854 0 : fd_h2_rbuf_push( rbuf_tx, &window_update, sizeof(fd_h2_window_update_t) );
855 0 : conn->rx_wnd = conn->rx_wnd_max;
856 0 : conn->flags = (ushort)( (conn->flags) & (~FD_H2_CONN_FLAGS_WINDOW_UPDATE) );
857 0 : break;
858 0 : }
859 :
860 0 : default:
861 0 : break;
862 :
863 0 : }
864 :
865 0 : }
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