MEDIUM: h2: make h2_frt_transfer_data() copy via an intermediary buffer
The purpose here is also to ensure we can split the lower from the top
layers. The way the CS_FL_MSG_MORE flag is set was updated so that it's
set or cleared upon exit depending on the buffer's remaining contents.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index e93d22b..cad1ac1 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -2813,10 +2813,10 @@
{
struct h2c *h2c = h2s->h2c;
int block1, block2;
- unsigned int flen = h2c->dfl;
+ unsigned int flen = 0;
unsigned int chklen = 0;
+ struct buffer *csbuf;
- h2s->cs->flags &= ~CS_FL_RCV_MORE;
h2c->flags &= ~H2_CF_DEM_SFULL;
/* The padlen is the first byte before data, and the padding appears
@@ -2840,6 +2840,12 @@
h2c->dff &= ~H2_F_DATA_PADDED;
}
+ csbuf = h2_get_buf(h2c, &h2s->cs->rxbuf);
+ if (!csbuf) {
+ h2c->flags |= H2_CF_DEM_SALLOC;
+ goto out;
+ }
+
flen = h2c->dfl - h2c->dpl;
if (!flen)
goto end_transfer;
@@ -2847,12 +2853,19 @@
if (flen > b_data(&h2c->dbuf)) {
flen = b_data(&h2c->dbuf);
if (!flen)
- return 0;
+ goto leave;
+ }
+
+ if (unlikely(b_space_wraps(csbuf))) {
+ /* it doesn't fit and the buffer is fragmented,
+ * so let's defragment it and try again.
+ */
+ b_slow_realign(csbuf, trash.area, 0);
}
/* chunked-encoding requires more room */
if (h2s->flags & H2_SF_DATA_CHNK) {
- chklen = MIN(flen, count);
+ chklen = MIN(flen, b_room(csbuf));
chklen = (chklen < 16) ? 1 : (chklen < 256) ? 2 :
(chklen < 4096) ? 3 : (chklen < 65536) ? 4 :
(chklen < 1048576) ? 4 : 8;
@@ -2860,10 +2873,12 @@
}
/* does it fit in output buffer or should we wait ? */
- if (flen + chklen > count) {
- if (chklen >= count)
- goto full;
- flen = count - chklen;
+ if (flen + chklen > b_room(csbuf)) {
+ if (chklen >= b_room(csbuf)) {
+ h2c->flags |= H2_CF_DEM_SFULL;
+ goto leave;
+ }
+ flen = b_room(csbuf) - chklen;
}
if (h2s->flags & H2_SF_DATA_CHNK) {
@@ -2878,7 +2893,7 @@
do {
*--beg = hextab[chksz & 0xF];
} while (chksz >>= 4);
- b_putblk(buf, beg, str + sizeof(str) - beg);
+ b_putblk(csbuf, beg, str + sizeof(str) - beg);
}
/* Block1 is the length of the first block before the buffer wraps,
@@ -2890,14 +2905,14 @@
block2 = flen - block1;
if (block1)
- b_putblk(buf, b_head(&h2c->dbuf), block1);
+ b_putblk(csbuf, b_head(&h2c->dbuf), block1);
if (block2)
- b_putblk(buf, b_peek(&h2c->dbuf, block1), block2);
+ b_putblk(csbuf, b_peek(&h2c->dbuf, block1), block2);
if (h2s->flags & H2_SF_DATA_CHNK) {
/* emit the CRLF */
- b_putblk(buf, "\r\n", 2);
+ b_putblk(csbuf, "\r\n", 2);
}
/* now mark the input data as consumed (will be deleted from the buffer
@@ -2910,7 +2925,8 @@
if (h2c->dfl > h2c->dpl) {
/* more data available, transfer stalled on stream full */
- goto more;
+ h2c->flags |= H2_CF_DEM_SFULL;
+ goto leave;
}
end_transfer:
@@ -2920,10 +2936,12 @@
if (h2c->dff & H2_F_DATA_END_STREAM && h2s->flags & H2_SF_DATA_CHNK) {
/* emit the trailing 0 CRLF CRLF */
- if (count < 5)
- goto more;
+ if (b_room(csbuf) < 5) {
+ h2c->flags |= H2_CF_DEM_SFULL;
+ goto leave;
+ }
chklen += 5;
- b_putblk(buf, "0\r\n\r\n", 5);
+ b_putblk(csbuf, "0\r\n\r\n", 5);
}
h2c->rcvd_c += h2c->dpl;
@@ -2931,22 +2949,24 @@
h2c->dpl = 0;
h2c->st0 = H2_CS_FRAME_A; // send the corresponding window update
- /* don't send it before returning data!
- * FIXME: should we instead try to send it much later, after the
- * response ? This would require that we keep a copy of it in h2s.
- */
- if (h2c->dff & H2_F_DATA_END_STREAM) {
- h2s->cs->flags |= CS_FL_EOS;
+ if (h2c->dff & H2_F_DATA_END_STREAM)
h2s->flags |= H2_SF_ES_RCVD;
+
+ leave:
+ /* now transfer possibly pending data from the h2s buffer to the stream buffer */
+ flen = b_xfer(buf, csbuf, count);
+
+ out:
+ if (csbuf && b_data(csbuf))
+ h2s->cs->flags |= CS_FL_RCV_MORE;
+ else {
+ h2s->cs->flags &= ~CS_FL_RCV_MORE;
+ if (h2s->flags & H2_SF_ES_RCVD)
+ h2s->cs->flags |= CS_FL_EOS;
}
- return flen + chklen;
- full:
- flen = chklen = 0;
- more:
- h2c->flags |= H2_CF_DEM_SFULL;
- h2s->cs->flags |= CS_FL_RCV_MORE;
- return flen + chklen;
+ cs_drop_rxbuf(h2s->cs);
+ return flen;
}
/*