lsquic_headers_stream.c revision a74702c6 
1/* Copyright (c) 2017 - 2022 LiteSpeed Technologies Inc.  See LICENSE. */
2/*
3 * HEADERS stream logic
4 */
5
6#include <assert.h>
7#include <errno.h>
8#include <inttypes.h>
9#include <stdarg.h>
10#include <stdlib.h>
11#include <string.h>
12#include <sys/queue.h>
13
14#include "lsquic.h"
15#include "lsquic_types.h"
16#include "lsquic_int_types.h"
17#include "lsquic_frame_common.h"
18#include "lsquic_frame_reader.h"
19#include "lsquic_frame_writer.h"
20#include "lsquic_mm.h"
21#include "lsquic_engine_public.h"
22#include "lshpack.h"
23
24#include "lsquic_headers_stream.h"
25
26#define MAX_HEADERS_SIZE (64 * 1024)
27#define MAX_HEADER_TABLE_SIZE (512 * 1024)
28
29#define LSQUIC_LOGGER_MODULE LSQLM_HEADERS
30#define LSQUIC_LOG_CONN_ID lsquic_conn_log_cid(\
31                                        lsquic_stream_conn(hs->hs_stream))
32#include "lsquic_logger.h"
33
34static const struct frame_reader_callbacks *frame_callbacks_ptr;
35
36struct headers_stream
37{
38    struct lsquic_stream               *hs_stream;
39    struct lsquic_frame_reader         *hs_fr;
40    struct lsquic_frame_writer         *hs_fw;
41    const struct headers_stream_callbacks
42                                       *hs_callbacks;
43    void                               *hs_cb_ctx;
44    struct lshpack_enc                  hs_henc;
45    struct lshpack_dec                  hs_hdec;
46    enum {
47            HS_IS_SERVER    = (1 << 0),
48            HS_HENC_INITED  = (1 << 1),
49    }                                   hs_flags;
50    struct lsquic_engine_public        *hs_enpub;
51#if LSQUIC_CONN_STATS
52    struct conn_stats                  *hs_conn_stats;
53#endif
54};
55
56
57int
58lsquic_headers_stream_send_settings (struct headers_stream *hs,
59        const struct lsquic_http2_setting *settings, unsigned n_settings)
60{
61    if (0 == lsquic_frame_writer_write_settings(hs->hs_fw, settings,
62                                                            n_settings))
63    {
64        lsquic_stream_wantwrite(hs->hs_stream,
65            lsquic_frame_writer_have_leftovers(hs->hs_fw));
66        return 0;
67    }
68    else
69    {
70        LSQ_WARN("Could not write settings to stream: %s",
71                                                        strerror(errno));
72        return -1;
73    }
74}
75
76
77static lsquic_stream_ctx_t *
78headers_on_new_stream (void *stream_if_ctx, lsquic_stream_t *stream)
79{
80    struct headers_stream *hs = stream_if_ctx;
81
82    lshpack_dec_init(&hs->hs_hdec);
83    if (0 != lshpack_enc_init(&hs->hs_henc))
84    {
85        LSQ_WARN("could not initialize HPACK encoder: %s", strerror(errno));
86        return NULL;
87    }
88    (void) lshpack_enc_use_hist(&hs->hs_henc, 1);
89    hs->hs_flags |= HS_HENC_INITED;
90    hs->hs_stream = stream;
91    LSQ_DEBUG("stream created");
92    hs->hs_fr = lsquic_frame_reader_new((hs->hs_flags & HS_IS_SERVER) ? FRF_SERVER : 0,
93                                MAX_HEADERS_SIZE, &hs->hs_enpub->enp_mm,
94                                stream, lsquic_stream_read, &hs->hs_hdec,
95                                frame_callbacks_ptr, hs,
96#if LSQUIC_CONN_STATS
97                        hs->hs_conn_stats,
98#endif
99                        hs->hs_enpub->enp_hsi_if, hs->hs_enpub->enp_hsi_ctx);
100    if (!hs->hs_fr)
101    {
102        LSQ_WARN("could not create frame reader: %s", strerror(errno));
103        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
104        return NULL;
105    }
106    hs->hs_fw = lsquic_frame_writer_new(&hs->hs_enpub->enp_mm, stream, 0,
107            &hs->hs_henc, lsquic_stream_writef,
108#if LSQUIC_CONN_STATS
109            hs->hs_conn_stats,
110#endif
111            (hs->hs_flags & HS_IS_SERVER));
112    if (!hs->hs_fw)
113    {
114        LSQ_WARN("could not create frame writer: %s", strerror(errno));
115        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
116        return NULL;
117    }
118    lsquic_stream_wantread(stream, 1);
119    return (lsquic_stream_ctx_t *) hs;
120}
121
122
123static void
124headers_on_read (lsquic_stream_t *stream, struct lsquic_stream_ctx *ctx)
125{
126    struct headers_stream *hs = (struct headers_stream *) ctx;
127    if (0 != lsquic_frame_reader_read(hs->hs_fr))
128    {
129        LSQ_ERROR("frame reader failed");
130        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
131    }
132}
133
134
135static void
136headers_on_write (lsquic_stream_t *stream, struct lsquic_stream_ctx *ctx)
137{
138    struct headers_stream *hs = (struct headers_stream *) ctx;
139    assert(lsquic_frame_writer_have_leftovers(hs->hs_fw));
140    int s = lsquic_frame_writer_flush(hs->hs_fw);
141    if (0 == s)
142    {
143        LSQ_DEBUG("flushed");
144        lsquic_stream_wantwrite(stream,
145            lsquic_frame_writer_have_leftovers(hs->hs_fw));
146    }
147    else
148    {
149        LSQ_WARN("Error writing to stream: %s", strerror(errno));
150        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
151    }
152}
153
154
155static void
156headers_on_close (lsquic_stream_t *stream, struct lsquic_stream_ctx *ctx)
157{
158    struct headers_stream *hs = (struct headers_stream *) ctx;
159    LSQ_DEBUG("stream closed");
160}
161
162
163int
164lsquic_headers_stream_send_headers (struct headers_stream *hs,
165    lsquic_stream_id_t stream_id, const struct lsquic_http_headers *headers,
166    int eos, unsigned weight)
167{
168    LSQ_DEBUG("received compressed headers to send");
169    int s;
170    s = lsquic_frame_writer_write_headers(hs->hs_fw, stream_id, headers, eos,
171                                                                        weight);
172    if (0 == s)
173    {
174        lsquic_stream_wantwrite(hs->hs_stream,
175            lsquic_frame_writer_have_leftovers(hs->hs_fw));
176    }
177    else
178        LSQ_INFO("Error writing headers: %s", strerror(errno));
179    return s;
180}
181
182
183int
184lsquic_headers_stream_send_priority (struct headers_stream *hs,
185        lsquic_stream_id_t stream_id, int exclusive,
186        lsquic_stream_id_t dep_stream_id, unsigned weight)
187{
188    LSQ_DEBUG("received priority to send");
189    int s;
190    if (stream_id == dep_stream_id)
191    {
192        LSQ_INFO("stream cannot depend on itself"); /* RFC 7540, Sec. 5.3.1. */
193        return -1;
194    }
195    s = lsquic_frame_writer_write_priority(hs->hs_fw, stream_id, exclusive,
196                                                        dep_stream_id, weight);
197    if (0 == s)
198    {
199        lsquic_stream_wantwrite(hs->hs_stream,
200            lsquic_frame_writer_have_leftovers(hs->hs_fw));
201    }
202    else
203        LSQ_INFO("Error writing priority frame: %s", strerror(errno));
204    return s;
205}
206
207
208struct headers_stream *
209lsquic_headers_stream_new (int is_server, struct lsquic_engine_public *enpub,
210                           const struct headers_stream_callbacks *callbacks,
211#if LSQUIC_CONN_STATS
212                           struct conn_stats *conn_stats,
213#endif
214                           void *cb_ctx)
215{
216    struct headers_stream *hs = calloc(1, sizeof(*hs));
217    if (!hs)
218        return NULL;
219    hs->hs_callbacks = callbacks;
220    hs->hs_cb_ctx    = cb_ctx;
221    if (is_server)
222        hs->hs_flags = HS_IS_SERVER;
223    else
224        hs->hs_flags = 0;
225    hs->hs_enpub     = enpub;
226#if LSQUIC_CONN_STATS
227    hs->hs_conn_stats= conn_stats;
228#endif
229    return hs;
230}
231
232
233void
234lsquic_headers_stream_destroy (struct headers_stream *hs)
235{
236    if (hs->hs_fr)
237        lsquic_frame_reader_destroy(hs->hs_fr);
238    if (hs->hs_fw)
239        lsquic_frame_writer_destroy(hs->hs_fw);
240    if (hs->hs_flags & HS_HENC_INITED)
241        lshpack_enc_cleanup(&hs->hs_henc);
242    lshpack_dec_cleanup(&hs->hs_hdec);
243    free(hs);
244}
245
246
247static const struct lsquic_stream_if headers_stream_if =
248{
249    .on_new_stream = headers_on_new_stream,
250    .on_read       = headers_on_read,
251    .on_write      = headers_on_write,
252    .on_close      = headers_on_close,
253};
254
255
256const struct lsquic_stream_if *const lsquic_headers_stream_if =
257                                                &headers_stream_if;
258
259
260static void
261headers_on_incoming_headers (void *ctx, struct uncompressed_headers *uh)
262{
263    struct headers_stream *hs = ctx;
264    hs->hs_callbacks->hsc_on_headers(hs->hs_cb_ctx, uh);
265}
266
267
268static void
269headers_on_push_promise (void *ctx, struct uncompressed_headers *uh)
270{
271    struct headers_stream *hs = ctx;
272    hs->hs_callbacks->hsc_on_push_promise(hs->hs_cb_ctx, uh);
273}
274
275
276static void
277headers_on_priority (void *ctx, lsquic_stream_id_t stream_id, int exclusive,
278                     lsquic_stream_id_t dep_stream_id, unsigned weight)
279{
280    struct headers_stream *hs = ctx;
281    hs->hs_callbacks->hsc_on_priority(hs->hs_cb_ctx, stream_id, exclusive,
282                                                    dep_stream_id, weight);
283}
284
285
286static void
287headers_on_error (void *ctx, lsquic_stream_id_t stream_id,
288                                            enum frame_reader_error err)
289{
290    struct headers_stream *hs = ctx;
291    switch (err)
292    {
293    case FR_ERR_BAD_HEADER:
294    case FR_ERR_DECOMPRESS:
295    case FR_ERR_SELF_DEP_STREAM:
296        LSQ_INFO("error %u is a stream error (stream %"PRIu64")", err,
297                                                                    stream_id);
298        hs->hs_callbacks->hsc_on_stream_error(hs->hs_cb_ctx, stream_id);
299        break;
300    case FR_ERR_INVALID_FRAME_SIZE:
301    case FR_ERR_NONZERO_STREAM_ID:
302    case FR_ERR_UNEXPECTED_PUSH:
303    case FR_ERR_ZERO_STREAM_ID:
304    case FR_ERR_EXPECTED_CONTIN:
305    case FR_ERR_OTHER_ERROR:
306        LSQ_INFO("error %u is a connection error (stream %"PRIu64")", err,
307                                                                    stream_id);
308        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
309        break;
310    }
311}
312
313
314static void
315headers_on_settings (void *ctx, uint16_t setting_id, uint32_t setting_value)
316{
317    struct headers_stream *hs = ctx;
318    switch (setting_id)
319    {
320    case SETTINGS_HEADER_TABLE_SIZE:
321        if (setting_value > MAX_HEADER_TABLE_SIZE)
322        {
323            LSQ_INFO("tried to update table size to %u, which is larger than "
324                "allowed maximum of %u bytes", setting_value,
325                MAX_HEADER_TABLE_SIZE);
326            hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
327        }
328        else
329        {
330            LSQ_INFO("update hpack table size to %u", setting_value);
331            lshpack_enc_set_max_capacity(&hs->hs_henc, setting_value);
332        }
333        break;
334    case SETTINGS_MAX_HEADER_LIST_SIZE:
335        LSQ_INFO("set max header list size to %u", setting_value);
336        lsquic_frame_writer_max_header_list_size(hs->hs_fw, setting_value);
337        break;
338    case SETTINGS_ENABLE_PUSH:
339        LSQ_INFO("got setting enable_push: %u", setting_value);
340        if (hs->hs_flags & HS_IS_SERVER)
341        {
342            if (setting_value <= 1)
343                hs->hs_callbacks->hsc_on_enable_push(hs->hs_cb_ctx,
344                                                            setting_value);
345            else
346            {
347                LSQ_INFO("invalid value of enable_push");
348                hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
349            }
350        }
351        else
352        {
353            LSQ_INFO("it is an error to receive enable_push setting in "
354                     "client mode");
355            hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
356        }
357        break;
358    case SETTINGS_MAX_CONCURRENT_STREAMS:
359    case SETTINGS_INITIAL_WINDOW_SIZE:
360    case SETTINGS_MAX_FRAME_SIZE:
361        /* [draft-ietf-quic-http-00], Section 3 */
362        LSQ_INFO("Specifying setting 0x%X is a QUIC error", setting_id);
363        hs->hs_callbacks->hsc_on_conn_error(hs->hs_cb_ctx);
364        break;
365    default:
366        LSQ_INFO("Ignoring unknown setting 0x%X; value 0x%X", setting_id,
367                                                                setting_value);
368        break;
369    }
370}
371
372
373int
374lsquic_headers_stream_push_promise (struct headers_stream *hs,
375        lsquic_stream_id_t stream_id64, lsquic_stream_id_t promised_stream_id64,
376        const struct lsquic_http_headers *headers)
377{
378    uint32_t stream_id = stream_id64;
379    uint32_t promised_stream_id = promised_stream_id64;
380    int s;
381    LSQ_DEBUG("promising stream %u in response to stream %u",
382                                            promised_stream_id, stream_id);
383    s = lsquic_frame_writer_write_promise(hs->hs_fw, stream_id,
384                                                promised_stream_id, headers);
385    if (0 == s)
386    {
387        lsquic_stream_wantwrite(hs->hs_stream,
388            lsquic_frame_writer_have_leftovers(hs->hs_fw));
389    }
390    else
391        LSQ_INFO("Error writing push promise: %s", strerror(errno));
392    return s;
393}
394
395
396size_t
397lsquic_headers_stream_mem_used (const struct headers_stream *hs)
398{
399    size_t size;
400
401    size = sizeof(*hs);
402    size += lsquic_frame_reader_mem_used(hs->hs_fr);
403    size += lsquic_frame_writer_mem_used(hs->hs_fw);
404    /* XXX: does not cover HPACK encoder and HPACK decoder */
405
406    return size;
407}
408
409
410struct lsquic_stream *
411lsquic_headers_stream_get_stream (const struct headers_stream *hs)
412{
413    return hs->hs_stream;
414}
415
416
417static const struct frame_reader_callbacks frame_callbacks = {
418    .frc_on_headers      = headers_on_incoming_headers,
419    .frc_on_push_promise = headers_on_push_promise,
420    .frc_on_error        = headers_on_error,
421    .frc_on_settings     = headers_on_settings,
422    .frc_on_priority     = headers_on_priority,
423};
424
425static const struct frame_reader_callbacks *frame_callbacks_ptr = &frame_callbacks;
426
427