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 0 : if( rbuf_avail<frame_rem ) fin_flag = 0;
106 0 : else if( FD_UNLIKELY( conn->rx_frame_flags & FD_H2_FLAG_PADDED ) ) wnd_sz += 1U + conn->rx_pad_rem;
107 :
108 0 : if( FD_UNLIKELY( wnd_sz > conn->rx_wnd ) ) {
109 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
110 0 : return;
111 0 : }
112 0 : conn->rx_wnd -= wnd_sz;
113 :
114 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
115 0 : if( FD_UNLIKELY( !stream ) ) {
116 0 : if( fd_h2_rx_stream_used( conn, stream_id ) ) goto skip_frame; /* RFC 9113 5.1 */
117 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
118 0 : return;
119 0 : }
120 0 : if( FD_UNLIKELY( stream->state!=FD_H2_STREAM_STATE_OPEN &&
121 0 : stream->state!=FD_H2_STREAM_STATE_CLOSING_TX ) ) {
122 0 : if( stream->state==FD_H2_STREAM_STATE_CLOSED ) goto skip_frame;
123 0 : if( FD_UNLIKELY( stream->state!=FD_H2_STREAM_STATE_CLOSING_RX ) ) {
124 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
125 0 : return;
126 0 : }
127 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_STREAM_CLOSED );
128 0 : cb->rst_stream( conn, stream, FD_H2_ERR_STREAM_CLOSED, 0 );
129 0 : goto skip_frame;
130 0 : }
131 :
132 0 : if( FD_UNLIKELY( wnd_sz > stream->rx_wnd ) ) {
133 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_FLOW_CONTROL );
134 0 : cb->rst_stream( conn, stream, FD_H2_ERR_FLOW_CONTROL, 0 );
135 0 : goto skip_frame;
136 0 : }
137 0 : stream->rx_wnd -= wnd_sz;
138 :
139 0 : fd_h2_stream_rx_data( stream, conn, fin_flag );
140 :
141 0 : ulong sz0, sz1;
142 0 : uchar const * peek = fd_h2_rbuf_peek_used( rbuf_rx, &sz0, &sz1 );
143 0 : if( sz0>=chunk_sz ) {
144 0 : sz0 = chunk_sz;
145 0 : sz1 = 0;
146 0 : } else if( sz0+sz1>chunk_sz ) {
147 0 : sz1 = chunk_sz-sz0;
148 0 : }
149 0 : if( FD_LIKELY( !sz1 ) ) {
150 0 : cb->data( conn, stream, peek, sz0, fin_flag );
151 0 : } else {
152 0 : cb->data( conn, stream, peek, sz0, 0 );
153 : /* The first callback may have released the stream. Re-query the stream
154 : map before dispatching the wrapped tail chunk. */
155 0 : stream = cb->stream_query( conn, stream_id );
156 0 : if( FD_LIKELY( stream && !(conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD)) ) ) {
157 0 : cb->data( conn, stream, rbuf_rx->buf0, sz1, fin_flag );
158 0 : }
159 0 : }
160 :
161 0 : skip_frame:
162 0 : conn->rx_data_cnt_rem -= chunk_sz;
163 0 : fd_h2_rbuf_skip( rbuf_rx, chunk_sz );
164 0 : if( FD_UNLIKELY( conn->rx_wnd < conn->rx_wnd_wmark ) ) {
165 0 : conn->flags |= FD_H2_CONN_FLAGS_WINDOW_UPDATE;
166 0 : }
167 0 : }
168 :
169 : static int
170 : fd_h2_rx_headers( fd_h2_conn_t * conn,
171 : fd_h2_rbuf_t * rbuf_tx,
172 : uchar * payload,
173 : ulong payload_sz,
174 : fd_h2_callbacks_t const * cb,
175 : uint frame_flags,
176 0 : uint stream_id ) {
177 :
178 0 : if( FD_UNLIKELY( !stream_id ) ) {
179 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
180 0 : return 0;
181 0 : }
182 :
183 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_PRIORITY ) ) {
184 0 : if( FD_UNLIKELY( payload_sz<5UL ) ) {
185 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
186 0 : return 0;
187 0 : }
188 0 : payload += 5UL;
189 0 : payload_sz -= 5UL;
190 0 : }
191 :
192 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
193 0 : if( FD_UNLIKELY( !stream || stream->state==FD_H2_STREAM_STATE_CLOSED ) ) {
194 0 : stream = NULL;
195 0 : if( !fd_h2_rx_stream_used( conn, stream_id ) ) {
196 0 : if( FD_UNLIKELY( ((stream_id^conn->tx_stream_next)&1U)==0U ||
197 0 : ((conn->tx_stream_next&1U) && !conn->allow_server_requests) ) ) {
198 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
199 0 : return 0;
200 0 : }
201 : /* Even a refused stream consumes its ID and closes skipped IDs. */
202 0 : conn->rx_stream_next = stream_id+2U;
203 0 : if( FD_LIKELY( conn->stream_active_cnt[0] < conn->self_settings.max_concurrent_streams ) ) {
204 0 : stream = cb->stream_create( conn, stream_id );
205 0 : }
206 0 : if( FD_LIKELY( stream ) ) fd_h2_stream_open( stream, conn, stream_id );
207 0 : else fd_h2_tx_rst_stream( rbuf_tx, stream_id, FD_H2_ERR_REFUSED_STREAM );
208 0 : }
209 0 : }
210 :
211 0 : conn->rx_stream_id = stream_id;
212 :
213 : /* Validate discarded blocks and keep state from the first fragment of
214 : a live block in case its stream is released before CONTINUATION. */
215 0 : if( FD_UNLIKELY( !stream || !(frame_flags & FD_H2_FLAG_END_HEADERS) ) ) {
216 0 : conn->rx_hdrs_discard = (uchar)!stream;
217 0 : if( !(frame_flags & FD_H2_FLAG_END_HEADERS) ) conn->flags |= FD_H2_CONN_FLAGS_CONTINUATION;
218 0 : fd_hpack_skip_init( &conn->rx_hpack );
219 0 : if( FD_UNLIKELY( fd_hpack_skip_feed( &conn->rx_hpack, payload, payload_sz, !!(frame_flags & FD_H2_FLAG_END_HEADERS) ) ) ) {
220 0 : fd_h2_conn_error( conn, FD_H2_ERR_COMPRESSION );
221 0 : return 0;
222 0 : }
223 0 : if( !stream ) return 1;
224 0 : }
225 :
226 0 : fd_h2_stream_rx_headers( stream, conn, frame_flags );
227 0 : if( FD_UNLIKELY( stream->state==FD_H2_STREAM_STATE_ILLEGAL ) ) {
228 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
229 0 : return 0;
230 0 : }
231 :
232 0 : cb->headers( conn, stream, payload, payload_sz, frame_flags );
233 :
234 0 : return 1;
235 0 : }
236 :
237 : static int
238 : fd_h2_rx_priority( fd_h2_conn_t * conn,
239 : ulong payload_sz,
240 0 : uint stream_id ) {
241 0 : if( FD_UNLIKELY( payload_sz!=5UL ) ) {
242 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
243 0 : return 0;
244 0 : }
245 0 : if( FD_UNLIKELY( !stream_id ) ) {
246 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
247 0 : return 0;
248 0 : }
249 0 : return 1;
250 0 : }
251 :
252 : static int
253 : fd_h2_rx_continuation( fd_h2_conn_t * conn,
254 : uchar * payload,
255 : ulong payload_sz,
256 : fd_h2_callbacks_t const * cb,
257 : uint frame_flags,
258 0 : uint stream_id ) {
259 :
260 0 : if( FD_UNLIKELY( ( conn->rx_stream_id!=stream_id ) |
261 0 : ( !( conn->flags & FD_H2_CONN_FLAGS_CONTINUATION ) ) |
262 0 : ( !stream_id ) ) ) {
263 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
264 0 : return 0;
265 0 : }
266 :
267 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_END_HEADERS ) ) {
268 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_CONTINUATION;
269 0 : }
270 :
271 0 : if( FD_UNLIKELY( fd_hpack_skip_feed( &conn->rx_hpack, payload, payload_sz, !!(frame_flags & FD_H2_FLAG_END_HEADERS) ) ) ) {
272 0 : fd_h2_conn_error( conn, FD_H2_ERR_COMPRESSION );
273 0 : return 0;
274 0 : }
275 0 : if( FD_UNLIKELY( conn->rx_hdrs_discard ) ) return 1;
276 :
277 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
278 0 : if( FD_UNLIKELY( !stream ) ) return 1;
279 :
280 0 : fd_h2_stream_rx_headers( stream, conn, frame_flags );
281 0 : if( FD_UNLIKELY( stream->state==FD_H2_STREAM_STATE_ILLEGAL ) ) {
282 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
283 0 : return 0;
284 0 : }
285 :
286 0 : cb->headers( conn, stream, payload, payload_sz, frame_flags );
287 :
288 0 : return 1;
289 0 : }
290 :
291 : static int
292 : fd_h2_rx_rst_stream( fd_h2_conn_t * conn,
293 : uchar const * payload,
294 : ulong payload_sz,
295 : fd_h2_callbacks_t const * cb,
296 0 : uint stream_id ) {
297 0 : if( FD_UNLIKELY( payload_sz!=4UL ) ) {
298 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
299 0 : return 0;
300 0 : }
301 0 : if( FD_UNLIKELY( !stream_id || !fd_h2_rx_stream_used( conn, stream_id ) ) ) {
302 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
303 0 : return 0;
304 0 : }
305 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
306 0 : if( FD_LIKELY( stream && stream->state!=FD_H2_STREAM_STATE_CLOSED ) ) {
307 0 : uint error_code = fd_uint_bswap( FD_LOAD( uint, payload ) );
308 0 : fd_h2_stream_reset( stream, conn );
309 0 : cb->rst_stream( conn, stream, error_code, 1 );
310 : /* stream points to freed memory at this point */
311 0 : }
312 0 : return 1;
313 0 : }
314 :
315 : static int
316 : fd_h2_rx_settings( fd_h2_conn_t * conn,
317 : fd_h2_rbuf_t * rbuf_tx,
318 : uchar const * payload,
319 : ulong payload_sz,
320 : fd_h2_callbacks_t const * cb,
321 : uint frame_flags,
322 0 : uint stream_id ) {
323 :
324 0 : if( FD_UNLIKELY( stream_id ) ) {
325 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
326 0 : return 0;
327 0 : }
328 :
329 0 : if( FD_UNLIKELY( conn->flags & FD_H2_CONN_FLAGS_SERVER_INITIAL ) ) {
330 : /* As a server, the first frame we should send is SETTINGS, not
331 : SETTINGS ACK as generated here */
332 0 : return 0;
333 0 : }
334 :
335 0 : if( frame_flags & FD_H2_FLAG_ACK ) {
336 0 : if( FD_UNLIKELY( payload_sz ) ) {
337 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
338 0 : return 0;
339 0 : }
340 0 : if( FD_UNLIKELY( !conn->setting_tx ) ) {
341 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
342 0 : return 0;
343 0 : }
344 0 : if( conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0 ) {
345 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0;
346 0 : if( !( conn->flags & FD_H2_CONN_FLAGS_HANDSHAKING ) ) {
347 0 : cb->conn_established( conn );
348 0 : }
349 0 : }
350 0 : conn->setting_tx--;
351 0 : return 1;
352 0 : }
353 :
354 0 : if( FD_UNLIKELY( payload_sz % 6 ) ) {
355 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
356 0 : return 0;
357 0 : }
358 :
359 0 : for( ulong off=0UL; off<payload_sz; off+=sizeof(fd_h2_setting_t) ) {
360 0 : fd_h2_setting_t setting = FD_LOAD( fd_h2_setting_t, payload+off );
361 0 : ushort id = fd_ushort_bswap( setting.id );
362 0 : uint value = fd_uint_bswap( setting.value );
363 :
364 0 : switch( id ) {
365 0 : case FD_H2_SETTINGS_ENABLE_PUSH:
366 0 : if( FD_UNLIKELY( value>1 ) ) {
367 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
368 0 : return 0;
369 0 : }
370 0 : break;
371 0 : case FD_H2_SETTINGS_INITIAL_WINDOW_SIZE: {
372 0 : if( FD_UNLIKELY( value>0x7fffffff ) ) {
373 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
374 0 : return 0;
375 0 : }
376 0 : long delta = (long)value - (long)conn->peer_settings.initial_window_size;
377 0 : conn->peer_settings.initial_window_size = value;
378 0 : if( FD_UNLIKELY( delta && cb->initial_window_update ) ) {
379 0 : cb->initial_window_update( conn, delta );
380 0 : if( FD_UNLIKELY( conn->flags & FD_H2_CONN_FLAGS_SEND_GOAWAY ) ) return 0;
381 0 : }
382 0 : break;
383 0 : }
384 0 : case FD_H2_SETTINGS_MAX_FRAME_SIZE:
385 0 : if( FD_UNLIKELY( value<0x4000 || value>0xffffff ) ) {
386 : /* Values outside this range MUST be treated as a connection error
387 : (Section 5.4.1) of type PROTOCOL_ERROR. */
388 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
389 0 : return 0;
390 0 : }
391 0 : conn->peer_settings.max_frame_size = value;
392 : /* FIXME validate min */
393 0 : break;
394 0 : case FD_H2_SETTINGS_MAX_HEADER_LIST_SIZE:
395 0 : conn->peer_settings.max_header_list_size = value;
396 0 : break;
397 0 : case FD_H2_SETTINGS_MAX_CONCURRENT_STREAMS:
398 0 : conn->peer_settings.max_concurrent_streams = value;
399 0 : break;
400 0 : }
401 0 : }
402 :
403 0 : fd_h2_frame_hdr_t hdr = {
404 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_SETTINGS, 0UL ),
405 0 : .flags = FD_H2_FLAG_ACK
406 0 : };
407 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_frame_hdr_t) ) ) {
408 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
409 0 : return 0;
410 0 : }
411 0 : fd_h2_rbuf_push( rbuf_tx, &hdr, sizeof(fd_h2_frame_hdr_t) );
412 :
413 0 : if( conn->flags & FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 ) {
414 0 : conn->flags &= (uchar)~FD_H2_CONN_FLAGS_WAIT_SETTINGS_0;
415 0 : if( !( conn->flags & FD_H2_CONN_FLAGS_HANDSHAKING ) ) {
416 0 : cb->conn_established( conn );
417 0 : }
418 0 : }
419 :
420 0 : return 1;
421 0 : }
422 :
423 : static int
424 0 : fd_h2_rx_push_promise( fd_h2_conn_t * conn ) {
425 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
426 0 : return 0;
427 0 : }
428 :
429 : static int
430 : fd_h2_rx_ping( fd_h2_conn_t * conn,
431 : fd_h2_rbuf_t * rbuf_tx,
432 : uchar const * payload,
433 : ulong payload_sz,
434 : fd_h2_callbacks_t const * cb,
435 : uint frame_flags,
436 0 : uint stream_id ) {
437 0 : if( FD_UNLIKELY( payload_sz!=8UL ) ) {
438 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
439 0 : return 0;
440 0 : }
441 0 : if( FD_UNLIKELY( stream_id ) ) {
442 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
443 0 : return 0;
444 0 : }
445 :
446 0 : if( FD_UNLIKELY( frame_flags & FD_H2_FLAG_ACK ) ) {
447 :
448 : /* Received an acknowledgement for a PING frame. */
449 0 : if( FD_UNLIKELY( conn->ping_tx==0 ) ) {
450 : /* Unsolicited PING ACK ... Blindly ignore, since RFC 9113
451 : technically doesn't forbid those. */
452 0 : return 1;
453 0 : }
454 0 : cb->ping_ack( conn );
455 0 : conn->ping_tx = (uchar)( conn->ping_tx-1 );
456 :
457 0 : } else {
458 :
459 : /* Received a new PING frame. Generate a PONG. */
460 : /* FIMXE rate limit */
461 0 : fd_h2_ping_t pong = {
462 0 : .hdr = {
463 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
464 0 : .flags = FD_H2_FLAG_ACK,
465 0 : },
466 0 : .payload = FD_LOAD( ulong, payload )
467 0 : };
468 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) ) {
469 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
470 0 : return 0;
471 0 : }
472 0 : fd_h2_rbuf_push( rbuf_tx, &pong, sizeof(fd_h2_ping_t) );
473 :
474 0 : }
475 :
476 0 : return 1;
477 0 : }
478 :
479 : void
480 : fd_h2_tx_rst_stream( fd_h2_rbuf_t * rbuf_tx,
481 : uint stream_id,
482 0 : uint h2_err ) {
483 0 : fd_h2_rst_stream_t rst_stream = {
484 0 : .hdr = {
485 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_RST_STREAM, 4UL ),
486 0 : .flags = 0U,
487 0 : .r_stream_id = fd_uint_bswap( stream_id )
488 0 : },
489 0 : .error_code = fd_uint_bswap( h2_err )
490 0 : };
491 0 : fd_h2_rbuf_push( rbuf_tx, &rst_stream, sizeof(fd_h2_rst_stream_t) );
492 0 : }
493 :
494 : int
495 : fd_h2_tx_ping( fd_h2_conn_t * conn,
496 0 : fd_h2_rbuf_t * rbuf_tx ) {
497 0 : ulong ping_tx = conn->ping_tx;
498 0 : if( FD_UNLIKELY( ( fd_h2_rbuf_free_sz( rbuf_tx )<sizeof(fd_h2_ping_t) ) |
499 0 : ( ping_tx>=UCHAR_MAX ) ) ) {
500 0 : return 0; /* blocked */
501 0 : }
502 :
503 0 : fd_h2_ping_t ping = {
504 0 : .hdr = {
505 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_PING, 8UL ),
506 0 : .flags = 0U,
507 0 : .r_stream_id = 0UL
508 0 : },
509 0 : .payload = 0UL
510 0 : };
511 0 : fd_h2_rbuf_push( rbuf_tx, &ping, sizeof(fd_h2_ping_t) );
512 0 : conn->ping_tx = (uchar)( ping_tx+1 );
513 0 : return 1;
514 0 : }
515 :
516 : static int
517 : fd_h2_rx_goaway( fd_h2_conn_t * conn,
518 : fd_h2_callbacks_t const * cb,
519 : uchar const * payload,
520 : ulong payload_sz,
521 0 : uint stream_id ) {
522 :
523 0 : if( FD_UNLIKELY( stream_id ) ) {
524 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
525 0 : return 0;
526 0 : }
527 0 : if( FD_UNLIKELY( payload_sz<8UL ) ) {
528 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
529 0 : return 0;
530 0 : }
531 :
532 0 : uint error_code = fd_uint_bswap( FD_LOAD( uint, payload+4UL ) );
533 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
534 0 : cb->conn_final( conn, error_code, 1 /* peer */ );
535 :
536 0 : return 1;
537 0 : }
538 :
539 : static int
540 : fd_h2_rx_window_update( fd_h2_conn_t * conn,
541 : fd_h2_rbuf_t * rbuf_tx,
542 : fd_h2_callbacks_t const * cb,
543 : uchar const * payload,
544 : ulong payload_sz,
545 0 : uint stream_id ) {
546 0 : if( FD_UNLIKELY( payload_sz!=4UL ) ) {
547 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
548 0 : return 0;
549 0 : }
550 0 : uint increment = fd_uint_bswap( FD_LOAD( uint, payload ) ) & 0x7fffffff;
551 :
552 0 : if( !stream_id ) {
553 :
554 : /* Connection-level window update */
555 0 : uint tx_wnd = conn->tx_wnd;
556 0 : if( FD_UNLIKELY( !increment ) ) {
557 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
558 0 : return 0;
559 0 : }
560 0 : uint tx_wnd_new;
561 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( tx_wnd, increment, &tx_wnd_new ) || tx_wnd_new>0x7fffffffU ) ) {
562 0 : fd_h2_conn_error( conn, FD_H2_ERR_FLOW_CONTROL );
563 0 : return 0;
564 0 : }
565 0 : conn->tx_wnd = tx_wnd_new;
566 0 : cb->window_update( conn, (uint)increment );
567 :
568 0 : } else {
569 :
570 0 : if( FD_UNLIKELY( !fd_h2_rx_stream_used( conn, stream_id ) ) ) {
571 0 : fd_h2_conn_error( conn, FD_H2_ERR_PROTOCOL );
572 0 : return 0;
573 0 : }
574 :
575 0 : fd_h2_stream_t * stream = cb->stream_query( conn, stream_id );
576 0 : if( FD_UNLIKELY( !stream || stream->state==FD_H2_STREAM_STATE_CLOSED ) ) {
577 0 : return 1;
578 0 : }
579 :
580 0 : if( FD_UNLIKELY( !increment ) ) {
581 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_PROTOCOL );
582 0 : cb->rst_stream( conn, stream, FD_H2_ERR_PROTOCOL, 0 );
583 0 : return 1;
584 0 : }
585 :
586 : /* Stream-level window update */
587 0 : uint tx_wnd_new;
588 0 : if( FD_UNLIKELY( __builtin_uadd_overflow( stream->tx_wnd, increment, &tx_wnd_new ) || tx_wnd_new>0x7fffffffU ) ) {
589 0 : fd_h2_stream_error( stream, conn, rbuf_tx, FD_H2_ERR_FLOW_CONTROL );
590 0 : cb->rst_stream( conn, stream, FD_H2_ERR_FLOW_CONTROL, 0 );
591 : /* stream points to freed memory at this point */
592 0 : return 1;
593 0 : }
594 0 : stream->tx_wnd = tx_wnd_new;
595 0 : cb->stream_window_update( conn, stream, (uint)increment );
596 :
597 0 : }
598 :
599 0 : return 1;
600 0 : }
601 :
602 : /* fd_h2_rx_frame handles a complete frame. Returns 1 on success, and
603 : 0 on connection error. */
604 :
605 : static int
606 : fd_h2_rx_frame( fd_h2_conn_t * conn,
607 : fd_h2_rbuf_t * rbuf_tx,
608 : uchar * payload,
609 : ulong payload_sz,
610 : fd_h2_callbacks_t const * cb,
611 : uint frame_type,
612 : uint frame_flags,
613 0 : uint stream_id ) {
614 0 : switch( frame_type ) {
615 0 : case FD_H2_FRAME_TYPE_HEADERS:
616 0 : return fd_h2_rx_headers( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
617 0 : case FD_H2_FRAME_TYPE_PRIORITY:
618 0 : return fd_h2_rx_priority( conn, payload_sz, stream_id );
619 0 : case FD_H2_FRAME_TYPE_RST_STREAM:
620 0 : return fd_h2_rx_rst_stream( conn, payload, payload_sz, cb, stream_id );
621 0 : case FD_H2_FRAME_TYPE_SETTINGS:
622 0 : return fd_h2_rx_settings( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
623 0 : case FD_H2_FRAME_TYPE_PUSH_PROMISE:
624 0 : return fd_h2_rx_push_promise( conn );
625 0 : case FD_H2_FRAME_TYPE_CONTINUATION:
626 0 : return fd_h2_rx_continuation( conn, payload, payload_sz, cb, frame_flags&FD_H2_FLAG_END_HEADERS, stream_id );
627 0 : case FD_H2_FRAME_TYPE_PING:
628 0 : return fd_h2_rx_ping( conn, rbuf_tx, payload, payload_sz, cb, frame_flags, stream_id );
629 0 : case FD_H2_FRAME_TYPE_GOAWAY:
630 0 : return fd_h2_rx_goaway( conn, cb, payload, payload_sz, stream_id );
631 0 : case FD_H2_FRAME_TYPE_WINDOW_UPDATE:
632 0 : return fd_h2_rx_window_update( conn, rbuf_tx, cb, payload, payload_sz, stream_id );
633 0 : default:
634 0 : return 1;
635 0 : }
636 0 : }
637 :
638 : /* fd_h2_rx1 handles one frame. */
639 :
640 : static void
641 : fd_h2_rx1( fd_h2_conn_t * conn,
642 : fd_h2_rbuf_t * rbuf_rx,
643 : fd_h2_rbuf_t * rbuf_tx,
644 : uchar * scratch,
645 : ulong scratch_sz,
646 0 : fd_h2_callbacks_t const * cb ) {
647 : /* All frames except DATA are fully buffered, thus assume that current
648 : frame is a DATA frame if rx_data_cnt_rem != 0. */
649 0 : if( conn->rx_data_cnt_rem ) {
650 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<2UL*sizeof(fd_h2_window_update_t) ) ) return;
651 0 : fd_h2_rx_data( conn, rbuf_rx, rbuf_tx, cb );
652 0 : return;
653 0 : }
654 0 : if( FD_UNLIKELY( conn->rx_pad_rem ) ) {
655 0 : ulong pad_rem = conn->rx_pad_rem;
656 0 : ulong rbuf_avail = fd_h2_rbuf_used_sz( rbuf_rx );
657 0 : uint chunk_sz = (uint)fd_ulong_min( pad_rem, rbuf_avail );
658 0 : fd_h2_rbuf_skip( rbuf_rx, chunk_sz );
659 0 : conn->rx_pad_rem = (uchar)( conn->rx_pad_rem - chunk_sz );
660 0 : return;
661 0 : }
662 :
663 : /* A new frame starts. Peek the header. */
664 0 : if( FD_UNLIKELY( fd_h2_rbuf_used_sz( rbuf_rx )<sizeof(fd_h2_frame_hdr_t) ) ) {
665 0 : conn->rx_suppress = rbuf_rx->lo_off + sizeof(fd_h2_frame_hdr_t);
666 0 : return;
667 0 : }
668 0 : fd_h2_rbuf_t rx_peek = *rbuf_rx;
669 0 : fd_h2_frame_hdr_t hdr;
670 0 : fd_h2_rbuf_pop_copy( &rx_peek, &hdr, sizeof(fd_h2_frame_hdr_t) );
671 0 : uint const frame_type = fd_h2_frame_type ( hdr.typlen );
672 0 : uint const frame_sz = fd_h2_frame_length( hdr.typlen );
673 :
674 0 : if( FD_UNLIKELY( frame_sz > conn->self_settings.max_frame_size ) ) {
675 0 : fd_h2_conn_error( conn, FD_H2_ERR_FRAME_SIZE );
676 0 : return;
677 0 : }
678 0 : if( FD_UNLIKELY( (!!( conn->flags & FD_H2_CONN_FLAGS_CONTINUATION ) ) &
679 0 : ( frame_type!=FD_H2_FRAME_TYPE_CONTINUATION ) ) ) {
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. */
775 0 : if( FD_UNLIKELY( conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD) ) ) return;
776 :
777 : /* All other logic below can only proceed if new data arrived. */
778 0 : if( FD_UNLIKELY( !fd_h2_rbuf_used_sz( rbuf_rx ) ) ) return;
779 :
780 : /* Slowloris defense: Guess how much bytes are required to progress
781 : ahead of time based on the frame's type and size. */
782 0 : if( FD_UNLIKELY( rbuf_rx->hi_off < conn->rx_suppress ) ) return;
783 :
784 : /* Handle frames */
785 0 : for(;;) {
786 0 : ulong lo0 = rbuf_rx->lo_off;
787 0 : fd_h2_rx1( conn, rbuf_rx, rbuf_tx, scratch, scratch_sz, cb );
788 0 : ulong lo1 = rbuf_rx->lo_off;
789 :
790 : /* Terminate when no more bytes are available to read */
791 0 : if( !fd_h2_rbuf_used_sz( rbuf_rx ) ) break;
792 :
793 : /* Terminate when the frame handler didn't make progress (e.g. due
794 : to rbuf_tx full, or due to incomplete read from rbuf_tx)*/
795 0 : if( FD_UNLIKELY( lo0==lo1 ) ) break;
796 :
797 : /* Terminate if the conn died */
798 0 : if( FD_UNLIKELY( conn->flags & (FD_H2_CONN_FLAGS_SEND_GOAWAY|FD_H2_CONN_FLAGS_DEAD) ) ) break;
799 0 : }
800 0 : }
801 :
802 : void
803 : fd_h2_tx_control( fd_h2_conn_t * conn,
804 : fd_h2_rbuf_t * rbuf_tx,
805 0 : fd_h2_callbacks_t const * cb ) {
806 :
807 0 : if( FD_UNLIKELY( fd_h2_rbuf_free_sz( rbuf_tx )<128 ) ) return;
808 :
809 0 : switch( fd_uint_find_lsb( (uint)conn->flags | 0x10000u ) ) {
810 :
811 0 : case FD_H2_CONN_FLAGS_LG_CLIENT_INITIAL:
812 0 : fd_h2_rbuf_push( rbuf_tx, fd_h2_client_preface, sizeof(fd_h2_client_preface) );
813 0 : __attribute__((fallthrough));
814 :
815 0 : case FD_H2_CONN_FLAGS_LG_SERVER_INITIAL: {
816 0 : uchar buf[ FD_H2_OUR_SETTINGS_ENCODED_SZ ];
817 0 : fd_h2_gen_settings( &conn->self_settings, buf );
818 0 : fd_h2_rbuf_push( rbuf_tx, buf, sizeof(buf) );
819 0 : conn->setting_tx++;
820 0 : conn->flags = FD_H2_CONN_FLAGS_WAIT_SETTINGS_0 | FD_H2_CONN_FLAGS_WAIT_SETTINGS_ACK_0;
821 0 : break;
822 0 : }
823 :
824 0 : goaway:
825 0 : case FD_H2_CONN_FLAGS_LG_SEND_GOAWAY: {
826 0 : fd_h2_goaway_t goaway = {
827 0 : .hdr = {
828 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_GOAWAY, 8UL )
829 0 : },
830 0 : .last_stream_id = 0, /* FIXME */
831 0 : .error_code = fd_uint_bswap( (uint)conn->conn_error )
832 0 : };
833 0 : conn->flags = FD_H2_CONN_FLAGS_DEAD;
834 0 : fd_h2_rbuf_push( rbuf_tx, &goaway, sizeof(fd_h2_goaway_t) );
835 0 : cb->conn_final( conn, conn->conn_error, 0 /* local */ );
836 0 : break;
837 0 : }
838 :
839 0 : case FD_H2_CONN_FLAGS_LG_WINDOW_UPDATE: {
840 0 : uint increment = conn->rx_wnd_max - conn->rx_wnd;
841 0 : if( FD_UNLIKELY( increment>0x7fffffff ) ) {
842 0 : fd_h2_conn_error( conn, FD_H2_ERR_INTERNAL );
843 0 : goto goaway;
844 0 : }
845 0 : if( FD_UNLIKELY( increment==0 ) ) break;
846 0 : fd_h2_window_update_t window_update = {
847 0 : .hdr = {
848 0 : .typlen = fd_h2_frame_typlen( FD_H2_FRAME_TYPE_WINDOW_UPDATE, 4UL )
849 0 : },
850 0 : .increment = fd_uint_bswap( increment )
851 0 : };
852 0 : fd_h2_rbuf_push( rbuf_tx, &window_update, sizeof(fd_h2_window_update_t) );
853 0 : conn->rx_wnd = conn->rx_wnd_max;
854 0 : conn->flags = (ushort)( (conn->flags) & (~FD_H2_CONN_FLAGS_WINDOW_UPDATE) );
855 0 : break;
856 0 : }
857 :
858 0 : default:
859 0 : break;
860 :
861 0 : }
862 :
863 0 : }
|
