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 : long delta = (long)value - (long)conn->peer_settings.initial_window_size;
360 0 : conn->peer_settings.initial_window_size = value;
361 0 : if( FD_UNLIKELY( delta && cb->initial_window_update ) ) {
362 0 : cb->initial_window_update( conn, delta );
363 0 : if( FD_UNLIKELY( conn->flags & FD_H2_CONN_FLAGS_SEND_GOAWAY ) ) return 0;
364 0 : }
365 0 : break;
366 0 : }
367 0 : case FD_H2_SETTINGS_MAX_FRAME_SIZE:
368 0 : if( FD_UNLIKELY( value<0x4000 || value>0xffffff ) ) {
369 : /* Values outside this range MUST be treated as a connection error
370 : (Section 5.4.1) of type PROTOCOL_ERROR. */
371 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
372 0 : return 0;
373 0 : }
374 0 : conn->peer_settings.max_frame_size = value;
375 : /* FIXME validate min */
376 0 : break;
377 0 : case FD_H2_SETTINGS_MAX_HEADER_LIST_SIZE:
378 0 : conn->peer_settings.max_header_list_size = value;
379 0 : break;
380 0 : case FD_H2_SETTINGS_MAX_CONCURRENT_STREAMS:
381 0 : conn->peer_settings.max_concurrent_streams = value;
382 0 : break;
383 0 : }
384 0 : }
385 :
386 3 : fd_h2_frame_hdr_t hdr = {
387 3 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_SETTINGS, 0UL ),
388 3 : .flags = FD_H2_FLAG_ACK
389 3 : };
390 3 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_frame_hdr_t) ) ) {
391 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
392 0 : return 0;
393 0 : }
394 3 : fd_h2_rbuf_push( rbuf_tx, &hdr, sizeof(fd_h2_frame_hdr_t) );
395 :
396 3 : if( conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 ) {
397 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_WAIT_SETTINGS_0;
398 0 : if( !( conn->flags & FD_H2_CONN_FLAGS_HANDSHAKING ) ) {
399 0 : cb->conn_established( conn );
400 0 : }
401 0 : }
402 :
403 3 : return 1;
404 3 : }
405 :
406 : static int
407 0 : fd_h2_rx_push_promise( fd_h2_conn_t * conn ) {
408 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
409 0 : return 0;
410 0 : }
411 :
412 : static int
413 : fd_h2_rx_ping( fd_h2_conn_t * conn,
414 : fd_h2_rbuf_t * rbuf_tx,
415 : uchar const * payload,
416 : ulong payload_sz,
417 : fd_h2_callbacks_t const * cb,
418 : uint frame_flags,
419 6 : uint stream_id ) {
420 6 : if( FD_UNLIKELY( payload_sz!=8UL ) ) {
421 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
422 0 : return 0;
423 0 : }
424 6 : if( FD_UNLIKELY( stream_id ) ) {
425 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
426 0 : return 0;
427 0 : }
428 :
429 6 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_ACK ) ) {
430 :
431 : /* Received an acknowledgement for a PING frame. */
432 3 : if( FD_UNLIKELY( conn->ping_tx==0 ) ) {
433 : /* Unsolicited PING ACK ... Blindly ignore, since RFC 9113
434 : technically doesn't forbid those. */
435 0 : return 1;
436 0 : }
437 3 : cb->ping_ack( conn );
438 3 : conn->ping_tx = (uchar)( conn->ping_tx-1 );
439 :
440 3 : } else {
441 :
442 : /* Received a new PING frame. Generate a PONG. */
443 : /* FIMXE rate limit */
444 3 : fd_h2_ping_t pong = {
445 3 : .hdr = {
446 3 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
447 3 : .flags = FD_H2_FLAG_ACK,
448 3 : },
449 3 : .payload = FD_LOAD( ulong, payload )
450 3 : };
451 3 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) ) {
452 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
453 0 : return 0;
454 0 : }
455 3 : fd_h2_rbuf_push( rbuf_tx, &pong, sizeof(fd_h2_ping_t) );
456 :
457 3 : }
458 :
459 6 : return 1;
460 6 : }
461 :
462 : int
463 : fd_h2_tx_ping( fd_h2_conn_t * conn,
464 3 : fd_h2_rbuf_t * rbuf_tx ) {
465 3 : ulong ping_tx = conn->ping_tx;
466 3 : if( FD_UNLIKELY( ( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) |
467 3 : ( ping_tx>=UCHAR_MAX ) ) ) {
468 0 : return 0; /* blocked */
469 0 : }
470 :
471 3 : fd_h2_ping_t ping = {
472 3 : .hdr = {
473 3 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
474 3 : .flags = 0U,
475 3 : .r_stream_id = 0UL
476 3 : },
477 3 : .payload = 0UL
478 3 : };
479 3 : fd_h2_rbuf_push( rbuf_tx, &ping, sizeof(fd_h2_ping_t) );
480 3 : conn->ping_tx = (uchar)( ping_tx+1 );
481 3 : return 1;
482 3 : }
483 :
484 : static int
485 : fd_h2_rx_goaway( fd_h2_conn_t * conn,
486 : fd_h2_callbacks_t const * cb,
487 : uchar const * payload,
488 : ulong payload_sz,
489 0 : uint stream_id ) {
490 :
491 0 : if( FD_UNLIKELY( stream_id ) ) {
492 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
493 0 : return 0;
494 0 : }
495 0 : if( FD_UNLIKELY( payload_sz<8UL ) ) {
496 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
497 0 : return 0;
498 0 : }
499 :
500 0 : uint error_code = fd_uint_bswap( FD_LOAD( uint, payload+4UL ) );
501 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
502 0 : cb->conn_final( conn, error_code, 1 /* peer */ );
503 :
504 0 : return 1;
505 0 : }
506 :
507 : static int
508 : fd_h2_rx_window_update( fd_h2_conn_t * conn,
509 : fd_h2_rbuf_t * rbuf_tx,
510 : fd_h2_callbacks_t const * cb,
511 : uchar const * payload,
512 : ulong payload_sz,
513 0 : uint stream_id ) {
514 0 : if( FD_UNLIKELY( payload_sz!=4UL ) ) {
515 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
516 0 : return 0;
517 0 : }
518 0 : uint increment = fd_uint_bswap( FD_LOAD( uint, payload ) ) & 0x7fffffff;
519 :
520 0 : if( !stream_id ) {
521 :
522 : /* Connection-level window update */
523 0 : uint tx_wnd = conn->tx_wnd;
524 0 : if( FD_UNLIKELY( !increment ) ) {
525 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
526 0 : return 0;
527 0 : }
528 0 : uint tx_wnd_new;
529 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( tx_wnd, increment, &tx_wnd_new ) ) ) {
530 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
531 0 : return 0;
532 0 : }
533 0 : conn->tx_wnd = tx_wnd_new;
534 0 : cb->window_update( conn, (uint)increment );
535 :
536 0 : } else {
537 :
538 0 : if( FD_UNLIKELY( stream_id >= fd_ulong_max( conn->rx_stream_next, conn->tx_stream_next ) ) ) {
539 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
540 0 : return 0;
541 0 : }
542 :
543 0 : if( FD_UNLIKELY( !increment ) ) {
544 0 : fd_h2_tx_rst_stream( rbuf_tx, stream_id, FD_H2_ERR_PROTOCOL );
545 0 : return 1;
546 0 : }
547 :
548 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
549 0 : if( FD_UNLIKELY( !stream ) ) {
550 0 : fd_h2_tx_rst_stream( rbuf_tx, stream_id, FD_H2_ERR_STREAM_CLOSED );
551 0 : return 1;
552 0 : }
553 :
554 : /* Stream-level window update */
555 0 : uint tx_wnd_new;
556 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( stream->tx_wnd, increment, &tx_wnd_new ) ) ) {
557 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_FLOW_CONTROL );
558 0 : cb->rst_stream( conn, stream, FD_H2_ERR_FLOW_CONTROL, 0 );
559 : /* stream points to freed memory at this point */
560 0 : return 1;
561 0 : }
562 0 : stream->tx_wnd = tx_wnd_new;
563 0 : cb->stream_window_update( conn, stream, (uint)increment );
564 :
565 0 : }
566 :
567 0 : return 1;
568 0 : }
569 :
570 : /* fd_h2_rx_frame handles a complete frame. Returns 1 on success, and
571 : 0 on connection error. */
572 :
573 : static int
574 : fd_h2_rx_frame( fd_h2_conn_t * conn,
575 : fd_h2_rbuf_t * rbuf_tx,
576 : uchar * payload,
577 : ulong payload_sz,
578 : fd_h2_callbacks_t const * cb,
579 : uint frame_type,
580 : uint frame_flags,
581 9 : uint stream_id ) {
582 9 : switch( frame_type ) {
583 0 : case FD_H2_FRAME_TYPE_HEADERS:
584 0 : return fd_h2_rx_headers( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
585 0 : case FD_H2_FRAME_TYPE_PRIORITY:
586 0 : return fd_h2_rx_priority( conn, payload_sz, stream_id );
587 0 : case FD_H2_FRAME_TYPE_RST_STREAM:
588 0 : return fd_h2_rx_rst_stream( conn, payload, payload_sz, cb, stream_id );
589 3 : case FD_H2_FRAME_TYPE_SETTINGS:
590 3 : return fd_h2_rx_settings( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
591 0 : case FD_H2_FRAME_TYPE_PUSH_PROMISE:
592 0 : return fd_h2_rx_push_promise( conn );
593 0 : case FD_H2_FRAME_TYPE_CONTINUATION:
594 0 : return fd_h2_rx_continuation( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
595 6 : case FD_H2_FRAME_TYPE_PING:
596 6 : return fd_h2_rx_ping( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
597 0 : case FD_H2_FRAME_TYPE_GOAWAY:
598 0 : return fd_h2_rx_goaway( conn, cb, payload, payload_sz, stream_id );
599 0 : case FD_H2_FRAME_TYPE_WINDOW_UPDATE:
600 0 : return fd_h2_rx_window_update( conn, rbuf_tx, cb, payload, payload_sz, stream_id );
601 0 : default:
602 0 : return 1;
603 9 : }
604 9 : }
605 :
606 : /* fd_h2_rx1 handles one frame. */
607 :
608 : static void
609 : fd_h2_rx1( fd_h2_conn_t * conn,
610 : fd_h2_rbuf_t * rbuf_rx,
611 : fd_h2_rbuf_t * rbuf_tx,
612 : uchar * scratch,
613 : ulong scratch_sz,
614 24 : fd_h2_callbacks_t const * cb ) {
615 : /* All frames except DATA are fully buffered, thus assume that current
616 : frame is a DATA frame if rx_data_cnt_rem != 0. */
617 24 : if( conn->rx_data_cnt_rem ) {
618 0 : fd_h2_rx_data( conn, rbuf_rx, rbuf_tx, cb );
619 0 : return;
620 0 : }
621 24 : if( FD_UNLIKELY( conn->rx_pad_rem ) ) {
622 6 : ulong pad_rem = conn->rx_pad_rem;
623 6 : ulong rbuf_avail = fd_h2_rbuf_used_sz( rbuf_rx );
624 6 : uint chunk_sz = (uint)fd_ulong_min( pad_rem, rbuf_avail );
625 6 : fd_h2_rbuf_skip( rbuf_rx, chunk_sz );
626 6 : conn->rx_pad_rem = (uchar)( conn->rx_pad_rem - chunk_sz );
627 6 : return;
628 6 : }
629 :
630 : /* A new frame starts. Peek the header. */
631 18 : if( FD_UNLIKELY( fd_h2_rbuf_used_sz( rbuf_rx )<sizeof(fd_h2_frame_hdr_t) ) ) {
632 0 : conn->rx_suppress = rbuf_rx->lo_off + sizeof(fd_h2_frame_hdr_t);
633 0 : return;
634 0 : }
635 18 : fd_h2_rbuf_t rx_peek = *rbuf_rx;
636 18 : fd_h2_frame_hdr_t hdr;
637 18 : fd_h2_rbuf_pop_copy( &rx_peek, &hdr, sizeof(fd_h2_frame_hdr_t) );
638 18 : uint const frame_type = fd_h2_frame_type ( hdr.typlen );
639 18 : uint const frame_sz = fd_h2_frame_length( hdr.typlen );
640 :
641 18 : if( FD_UNLIKELY( frame_sz > conn->self_settings.max_frame_size ) ) {
642 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
643 0 : return;
644 0 : }
645 18 : if( FD_UNLIKELY( (!!( conn->flags & FD_H2_CONN_FLAGS_CONTINUATION ) ) &
646 18 : ( frame_type!=FD_H2_FRAME_TYPE_CONTINUATION ) ) ) {
647 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
648 0 : return;
649 0 : }
650 :
651 : /* Peek padding */
652 18 : uint pad_sz = 0U;
653 : /* Bytes remaining in this frame payload excluding padding length and padding. */
654 18 : uint payload_sz = frame_sz;
655 18 : if( ( frame_type==FD_H2_FRAME_TYPE_DATA ||
656 18 : frame_type==FD_H2_FRAME_TYPE_HEADERS ||
657 18 : frame_type==FD_H2_FRAME_TYPE_PUSH_PROMISE ) &&
658 18 : !!( hdr.flags & FD_H2_FLAG_PADDED ) ) {
659 6 : if( FD_UNLIKELY( fd_h2_rbuf_used_sz( &rx_peek )<1UL ) ) return;
660 6 : pad_sz = rx_peek.lo[0];
661 6 : payload_sz -= 1U; // Exclude Pad Length field
662 6 : payload_sz -= pad_sz; // Exclude padding
663 : /* If the length of the padding is the length of the
664 : frame payload or greater, the recipient MUST treat this as a
665 : connection error (Section 5.4.1) of type PROTOCOL_ERROR. */
666 6 : if( FD_UNLIKELY( pad_sz>=frame_sz ) ) {
667 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
668 0 : return;
669 0 : }
670 6 : fd_h2_rbuf_skip( &rx_peek, 1UL );
671 6 : }
672 :
673 : /* Special case: Process data incrementally */
674 18 : if( frame_type==FD_H2_FRAME_TYPE_DATA ) {
675 : /* The amount of data is the remainder of the
676 : frame payload after subtracting the length of the other fields
677 : that are present [that is, padding length and padding]. */
678 9 : conn->rx_data_cnt_rem = payload_sz;
679 9 : conn->rx_frame_flags = hdr.flags;
680 9 : conn->rx_stream_id = fd_h2_frame_stream_id( hdr.r_stream_id );
681 9 : conn->rx_pad_rem = (uchar)pad_sz;
682 9 : *rbuf_rx = rx_peek;
683 9 : if( FD_UNLIKELY( !conn->rx_stream_id ) ) {
684 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
685 0 : return;
686 0 : }
687 9 : fd_h2_rx_data( conn, rbuf_rx, rbuf_tx, cb );
688 9 : return;
689 9 : }
690 :
691 : /* Consume all or nothing */
692 9 : ulong const tot_sz = sizeof(fd_h2_frame_hdr_t) + frame_sz;
693 9 : if( FD_UNLIKELY( tot_sz>rbuf_rx->bufsz ) ) {
694 : /* Frame will never fit in the buffer */
695 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
696 0 : return;
697 0 : }
698 9 : if( FD_UNLIKELY( tot_sz>fd_h2_rbuf_used_sz( rbuf_rx ) ) ) {
699 0 : conn->rx_suppress = rbuf_rx->lo_off + tot_sz;
700 0 : return;
701 0 : }
702 :
703 9 : if( FD_UNLIKELY( scratch_sz < payload_sz ) ) {
704 0 : if( FD_UNLIKELY( scratch_sz < conn->self_settings.max_frame_size ) ) {
705 0 : FD_LOG_WARNING(( "scratch buffer too small: scratch_sz=%lu max_frame_size=%u)",
706 0 : scratch_sz, conn->self_settings.max_frame_size ));
707 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
708 0 : return;
709 0 : }
710 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
711 0 : return;
712 0 : }
713 :
714 : /* Ensure TX buffer has enough free space for control frame responses
715 : that frame handlers might generate. The largest is the PONG reply
716 : (17 bytes); RST_STREAM is 13. If there is not enough space, defer
717 : processing until the TX buffer drains. */
718 9 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) ) return;
719 :
720 9 : *rbuf_rx = rx_peek;
721 9 : uchar * frame = fd_h2_rbuf_pop( rbuf_rx, scratch, payload_sz );
722 9 : int ok =
723 9 : fd_h2_rx_frame( conn, rbuf_tx, frame, payload_sz, cb,
724 9 : frame_type,
725 9 : hdr.flags,
726 9 : fd_h2_frame_stream_id( hdr.r_stream_id ) );
727 9 : (void)ok; /* FIXME */
728 9 : fd_h2_rbuf_skip( rbuf_rx, pad_sz );
729 9 : }
730 :
731 : void
732 : fd_h2_rx( fd_h2_conn_t * conn,
733 : fd_h2_rbuf_t * rbuf_rx,
734 : fd_h2_rbuf_t * rbuf_tx,
735 : uchar * scratch,
736 : ulong scratch_sz,
737 39 : fd_h2_callbacks_t const * cb ) {
738 : /* Pre-receive TX work */
739 :
740 : /* Stop handling frames on conn error. */
741 39 : if( FD_UNLIKELY( conn->flags & FD_H2_CONN_FLAGS_DEAD ) ) return;
742 :
743 : /* All other logic below can only proceed if new data arrived. */
744 39 : if( FD_UNLIKELY( !fd_h2_rbuf_used_sz( rbuf_rx ) ) ) return;
745 :
746 : /* Slowloris defense: Guess how much bytes are required to progress
747 : ahead of time based on the frame's type and size. */
748 15 : if( FD_UNLIKELY( rbuf_rx->hi_off < conn->rx_suppress ) ) return;
749 :
750 : /* Handle frames */
751 24 : for(;;) {
752 24 : ulong lo0 = rbuf_rx->lo_off;
753 24 : fd_h2_rx1( conn, rbuf_rx, rbuf_tx, scratch, scratch_sz, cb );
754 24 : ulong lo1 = rbuf_rx->lo_off;
755 :
756 : /* Terminate when no more bytes are available to read */
757 24 : if( !fd_h2_rbuf_used_sz( rbuf_rx ) ) break;
758 :
759 : /* Terminate when the frame handler didn't make progress (e.g. due
760 : to rbuf_tx full, or due to incomplete read from rbuf_tx)*/
761 9 : if( FD_UNLIKELY( lo0==lo1 ) ) break;
762 :
763 : /* Terminate if the conn died */
764 9 : if( FD_UNLIKELY( conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD) ) ) break;
765 9 : }
766 15 : }
767 :
768 : void
769 : fd_h2_tx_control( fd_h2_conn_t * conn,
770 : fd_h2_rbuf_t * rbuf_tx,
771 0 : fd_h2_callbacks_t const * cb ) {
772 :
773 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<128 ) ) return;
774 :
775 0 : switch( fd_uint_find_lsb( (uint)conn->flags | 0x10000u ) ) {
776 :
777 0 : case FD_H2_CONN_FLAGS_LG_CLIENT_INITIAL:
778 0 : fd_h2_rbuf_push( rbuf_tx, fd_h2_client_preface, sizeof(fd_h2_client_preface) );
779 0 : __attribute__((fallthrough));
780 :
781 0 : case FD_H2_CONN_FLAGS_LG_SERVER_INITIAL: {
782 0 : uchar buf[ FD_H2_OUR_SETTINGS_ENCODED_SZ ];
783 0 : fd_h2_gen_settings( &conn->self_settings, buf );
784 0 : fd_h2_rbuf_push( rbuf_tx, buf, sizeof(buf) );
785 0 : conn->setting_tx++;
786 0 : conn->flags = FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 | FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0;
787 0 : break;
788 0 : }
789 :
790 0 : goaway:
791 0 : case FD_H2_CONN_FLAGS_LG_SEND_GOAWAY: {
792 0 : fd_h2_goaway_t goaway = {
793 0 : .hdr = {
794 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_GOAWAY, 8UL )
795 0 : },
796 0 : .last_stream_id = 0, /* FIXME */
797 0 : .error_code = fd_uint_bswap( (uint)conn->conn_error )
798 0 : };
799 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
800 0 : fd_h2_rbuf_push( rbuf_tx, &goaway, sizeof(fd_h2_goaway_t) );
801 0 : cb->conn_final( conn, conn->conn_error, 0 /* local */ );
802 0 : break;
803 0 : }
804 :
805 0 : case FD_H2_CONN_FLAGS_LG_WINDOW_UPDATE: {
806 0 : uint increment = conn->rx_wnd_max - conn->rx_wnd;
807 0 : if( FD_UNLIKELY( increment>0x7fffffff ) ) {
808 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
809 0 : goto goaway;
810 0 : }
811 0 : if( FD_UNLIKELY( increment==0 ) ) break;
812 0 : fd_h2_window_update_t window_update = {
813 0 : .hdr = {
814 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_WINDOW_UPDATE, 4UL )
815 0 : },
816 0 : .increment = fd_uint_bswap( increment )
817 0 : };
818 0 : fd_h2_rbuf_push( rbuf_tx, &window_update, sizeof(fd_h2_window_update_t) );
819 0 : conn->rx_wnd = conn->rx_wnd_max;
820 0 : conn->flags = (ushort)( (conn->flags) & (~FD_H2_CONN_FLAGS_WINDOW_UPDATE) );
821 0 : break;
822 0 : }
823 :
824 0 : default:
825 0 : break;
826 :
827 0 : }
828 :
829 0 : }
|
