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