Release 1.14.0

- [API Change] Disable packet sending if full batch cannot be sent
  If lsquic_packets_out_f() cannot send the whole batch, disable
  packet sending until lsquic_engine_send_unsent_packets() is called.
- [BUGFIX] Handle case when STREAM frame does not fit.
- [BUGFIX] Always allow incoming STREAM frames to overlap.  Peers
  may send overlapping STREAM frames even if using versions older
  than Q043.
- Custom header set fixes:
  - set "FIN reached" flag when custom header with FIN flag is
    claimed;
  - do not return custom header set for a reset stream.

src/liblsquic/CMakeLists.txt

@@ -51,7 +51,7 @@ SET(lsquic_STAT_SRCS
     lsquic_xxhash.c
     lsquic_buf.c
     lsquic_min_heap.c
-    lshpack.c
+    ../lshpack/lshpack.c
     lsquic_parse_Q044.c
     lsquic_http1x_if.c
     )

src/liblsquic/lsquic_engine.c

@@ -977,13 +977,17 @@ send_batch (lsquic_engine_t *engine, struct conns_out_iter *conns_iter,
         batch->packets[i]->po_sent = now;
     n_sent = engine->packets_out(engine->packets_out_ctx, batch->outs,
                                                                 n_to_send);
+    if (n_sent < (int) n_to_send)
+    {
+        engine->pub.enp_flags &= ~ENPUB_CAN_SEND;
+        LSQ_DEBUG("cannot send packets");
+        EV_LOG_GENERIC_EVENT("cannot send packets");
+    }
     if (n_sent >= 0)
         LSQ_DEBUG("packets out returned %d (out of %u)", n_sent, n_to_send);
     else
     {
-        engine->pub.enp_flags &= ~ENPUB_CAN_SEND;
         LSQ_DEBUG("packets out returned an error: %s", strerror(errno));
-        EV_LOG_GENERIC_EVENT("cannot send packets");
         n_sent = 0;
     }
     if (n_sent > 0)

src/liblsquic/lsquic_full_conn.c

@@ -913,9 +913,6 @@ new_stream_ext (struct full_conn *conn, uint32_t stream_id, int if_idx,
 {
     struct lsquic_stream *stream;
 
-    if (conn->fc_conn.cn_version >= LSQVER_043)
-        stream_ctor_flags |= SCF_ALLOW_OVERLAP;
-
     stream = lsquic_stream_new_ext(stream_id, &conn->fc_pub,
         conn->fc_stream_ifs[if_idx].stream_if,
         conn->fc_stream_ifs[if_idx].stream_if_ctx, conn->fc_settings->es_sfcw,

src/liblsquic/lsquic_parse.h

@@ -73,7 +73,12 @@ struct parse_funcs
                                                 struct packin_parse_state *);
     enum QUIC_FRAME_TYPE
     (*pf_parse_frame_type) (unsigned char);
-    /* Return used buffer length */
+    /* Return used buffer length or a negative value if there was not enough
+     * room to write the stream frame.  In the latter case, the negative of
+     * the negative return value is the number of bytes required.  The
+     * exception is -1, which is a generic error code, as we always need
+     * more than 1 byte to write a STREAM frame.
+     */
     int
     (*pf_gen_stream_frame) (unsigned char *buf, size_t bufsz,
                             uint32_t stream_id, uint64_t offset,

src/liblsquic/lsquic_parse_Q044.c

@@ -117,7 +117,7 @@ gen_long_pkt_header (const struct lsquic_conn *lconn,
     p += 4;
 
 
-    assert(need = p - buf);
+    assert(need == (unsigned int)(p - buf));
     return p - buf;
 }
 

src/liblsquic/lsquic_parse_common.h

@@ -21,4 +21,13 @@ int
 lsquic_iquic_parse_packet_in_begin (struct lsquic_packet_in *,
                 size_t length, int is_server, struct packin_parse_state *);
 
+/* Instead of just -1 like CHECK_SPACE(), this macro returns the number
+ * of bytes needed.
+ */
+#define CHECK_STREAM_SPACE(need, pstart, pend) do {                 \
+    if ((intptr_t) (need) > ((pend) - (pstart))) {                  \
+        return -((int) (need));                                     \
+    }                                                               \
+} while (0)
+
 #endif

src/liblsquic/lsquic_parse_gquic_be.c

@@ -222,7 +222,7 @@ gquic_be_gen_stream_frame (unsigned char *buf, size_t buf_len, uint32_t stream_i
         dlen = (size < n_avail) << 1;
         n_avail -= dlen;
 
-        CHECK_SPACE(1 + olen + slen + dlen +
+        CHECK_STREAM_SPACE(1 + olen + slen + dlen +
             + 1 /* We need to write at least 1 byte */, buf, buf + buf_len);
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -255,7 +255,7 @@ gquic_be_gen_stream_frame (unsigned char *buf, size_t buf_len, uint32_t stream_i
     else
     {
         dlen = 2;
-        CHECK_SPACE(1 + slen + olen + 2, buf, buf + buf_len);
+        CHECK_STREAM_SPACE(1 + slen + olen + 2, buf, buf + buf_len);
 #if __BYTE_ORDER == __LITTLE_ENDIAN
         stream_id = bswap_32(stream_id);
 #endif

src/liblsquic/lsquic_parse_gquic_le.c

@@ -217,7 +217,7 @@ gquic_le_gen_stream_frame (unsigned char *buf, size_t buf_len, uint32_t stream_i
         dlen = (size < n_avail) << 1;
         n_avail -= dlen;
 
-        CHECK_SPACE(1 + olen + slen + dlen +
+        CHECK_STREAM_SPACE(1 + olen + slen + dlen +
             + 1 /* We need to write at least 1 byte */, buf, buf + buf_len);
 
         memcpy(p, &stream_id, slen);
@@ -238,7 +238,7 @@ gquic_le_gen_stream_frame (unsigned char *buf, size_t buf_len, uint32_t stream_i
     else
     {
         dlen = 2;
-        CHECK_SPACE(1 + slen + olen + 2, buf, buf + buf_len);
+        CHECK_STREAM_SPACE(1 + slen + olen + 2, buf, buf + buf_len);
         memcpy(p, &stream_id, slen);
         p += slen;
         memcpy(p, &offset, olen);

src/liblsquic/lsquic_stream.c

@@ -273,8 +273,6 @@ lsquic_stream_new_ext (uint32_t id, struct lsquic_conn_public *conn_pub,
         lsquic_stream_call_on_new(stream);
     if (ctor_flags & SCF_DISP_RW_ONCE)
         stream->stream_flags |= STREAM_RW_ONCE;
-    if (ctor_flags & SCF_ALLOW_OVERLAP)
-        stream->stream_flags |= STREAM_ALLOW_OVERLAP;
     return stream;
 }
 
@@ -559,17 +557,12 @@ lsquic_stream_frame_in (lsquic_stream_t *stream, stream_frame_t *frame)
     }
     else if (INS_FRAME_OVERLAP == ins_frame)
     {
-        if (stream->stream_flags & STREAM_ALLOW_OVERLAP)
-        {
-            LSQ_DEBUG("overlap: switching DATA IN implementation");
-            stream->data_in = stream->data_in->di_if->di_switch_impl(
-                                        stream->data_in, stream->read_offset);
-            if (stream->data_in)
-                goto insert_frame;
-            stream->data_in = data_in_error_new();
-        }
-        else
-            LSQ_DEBUG("overlap not supported");
+        LSQ_DEBUG("overlap: switching DATA IN implementation");
+        stream->data_in = stream->data_in->di_if->di_switch_impl(
+                                    stream->data_in, stream->read_offset);
+        if (stream->data_in)
+            goto insert_frame;
+        stream->data_in = data_in_error_new();
         lsquic_packet_in_put(stream->conn_pub->mm, frame->packet_in);
         lsquic_malo_put(frame);
         return -1;
@@ -1573,6 +1566,7 @@ stream_write_to_packet (struct frame_gen_ctx *fg_ctx, const size_t size)
                                                         stream->tosend_off);
     need_at_least = stream_header_sz + (size > 0);
     hsk = LSQUIC_STREAM_HANDSHAKE == stream->id;
+  get_packet:
     packet_out = get_packet[hsk](send_ctl, need_at_least, stream);
     if (!packet_out)
         return SWTP_STOP;
@@ -1588,8 +1582,18 @@ stream_write_to_packet (struct frame_gen_ctx *fg_ctx, const size_t size)
                 frame_gen_fin(fg_ctx), size, frame_gen_read, fg_ctx);
     if (len < 0)
     {
-        LSQ_ERROR("could not generate stream frame");
-        return SWTP_ERROR;
+        if (-len > (int) need_at_least)
+        {
+            LSQ_DEBUG("need more room (%d bytes) than initially calculated "
+                "%u bytes, will try again", -len, need_at_least);
+            need_at_least = -len;
+            goto get_packet;
+        }
+        else
+        {
+            LSQ_ERROR("could not generate stream frame");
+            return SWTP_ERROR;
+        }
     }
 
     EV_LOG_GENERATED_STREAM_FRAME(LSQUIC_LOG_CONN_ID, pf,
@@ -2181,6 +2185,13 @@ lsquic_stream_get_hset (struct lsquic_stream *stream)
 {
     void *hset;
 
+    if (stream->stream_flags & STREAM_RST_FLAGS)
+    {
+        LSQ_INFO("%s: stream is reset, no headers returned", __func__);
+        errno = ECONNRESET;
+        return NULL;
+    }
+
     if ((stream->stream_flags & (STREAM_USE_HEADERS|STREAM_HAVE_UH))
                                         != (STREAM_USE_HEADERS|STREAM_HAVE_UH))
     {
@@ -2204,6 +2215,11 @@ lsquic_stream_get_hset (struct lsquic_stream *stream)
     hset = stream->uh->uh_hset;
     stream->uh->uh_hset = NULL;
     destroy_uh(stream);
+    if (stream->stream_flags & STREAM_HEAD_IN_FIN)
+    {
+        stream->stream_flags |= STREAM_FIN_REACHED;
+        SM_HISTORY_APPEND(stream, SHE_REACH_FIN);
+    }
     LSQ_DEBUG("return header set");
     return hset;
 }

src/liblsquic/lsquic_stream.h

@@ -62,7 +62,6 @@ struct lsquic_stream
         STREAM_ONNEW_DONE   = (1 <<26),     /* on_new_stream has been called */
         STREAM_AUTOSWITCH   = (1 <<27),
         STREAM_RW_ONCE      = (1 <<28),     /* When set, read/write events are dispatched once per call */
-        STREAM_ALLOW_OVERLAP= (1 <<29),
     }                               stream_flags;
 
     /* There are more than one reason that a stream may be put onto
@@ -140,7 +139,6 @@ enum stream_ctor_flags
                                    * performance.
                                    */
     SCF_DISP_RW_ONCE  = (1 << 3),
-    SCF_ALLOW_OVERLAP = (1 << 4), /* Allow STREAM frames to overlap */
 };
 
 lsquic_stream_t *

src/lshpack/lshpack.c

@@ -36,7 +36,7 @@ SOFTWARE.
 #if LS_HPACK_EMIT_TEST_CODE
 #include "lshpack-test.h"
 #endif
-#include XXH_HEADER_NAME
+#include "lsquic_xxhash.h"
 
 #define HPACK_STATIC_TABLE_SIZE   61
 #define INITIAL_DYNAMIC_TABLE_SIZE  4096