BUG/MAJOR: h2: reset the parser's state on mux buffer full

The h2 parser has this specificity that if it cannot send the headers
frame resulting from the headers it just parsed, it needs to drop it
and parse it again later. Since commit 8852850 ("MEDIUM: h1: let the
caller pass the initial parser's state"), when this happens the parser
remains in the data state and the headers are not parsed again next
time, resulting in a parse error. Let's reset the parser on exit there.

No backport is needed.

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 53364356b665daf9c51cb07e1f7125b5f6be50bf..8d63ccde1140b26176f2e5dfde29ee1d93c97052 100644 (file)
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3123,8 +3123,6 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
         * block does not wrap and we can safely read it this way without
         * having to realign the buffer.
         */
-       h1m->state = H1_MSG_RPBEFORE;
-       h1m->next  = 0;
        ret = h1_headers_to_hdr_list(b_peek(buf, ofs), b_peek(buf, ofs) + max,
                                     list, sizeof(list)/sizeof(list[0]), h1m, &sl);
        if (ret <= 0) {
@@ -3155,12 +3153,8 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
                b_slow_realign(&h2c->mbuf, trash.area, b_data(&h2c->mbuf));
        }
 
-       if (outbuf.size < 9) {
-               h2c->flags |= H2_CF_MUX_MFULL;
-               h2s->flags |= H2_SF_BLK_MROOM;
-               ret = 0;
-               goto end;
-       }
+       if (outbuf.size < 9)
+               goto full;
 
        /* len: 0x000000 (fill later), type: 1(HEADERS), flags: ENDH=4 */
        memcpy(outbuf.area, "\x00\x00\x00\x01\x04", 5);
@@ -3189,11 +3183,7 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
        else {
                if (b_space_wraps(&h2c->mbuf))
                        goto realign_again;
-
-               h2c->flags |= H2_CF_MUX_MFULL;
-               h2s->flags |= H2_SF_BLK_MROOM;
-               ret = 0;
-               goto end;
+               goto full;
        }
 
        /* encode all headers, stop at empty name */
@@ -3213,11 +3203,7 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
                        /* output full */
                        if (b_space_wraps(&h2c->mbuf))
                                goto realign_again;
-
-                       h2c->flags |= H2_CF_MUX_MFULL;
-                       h2s->flags |= H2_SF_BLK_MROOM;
-                       ret = 0;
-                       goto end;
+                       goto full;
                }
        }
 
@@ -3265,6 +3251,13 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
  end:
        //fprintf(stderr, "[%d] sent simple H2 response (sid=%d) = %d bytes (%d in, ep=%u, es=%s)\n", h2c->st0, h2s->id, outbuf.len, ret, h1m->err_pos, h1_msg_state_str(h1m->err_state));
        return ret;
+ full:
+       h1m_init_res(h1m);
+       h1m->err_pos = -1; // don't care about errors on the response path
+       h2c->flags |= H2_CF_MUX_MFULL;
+       h2s->flags |= H2_SF_BLK_MROOM;
+       ret = 0;
+       goto end;
 }
 
 /* Try to send a DATA frame matching HTTP/1 response present at offset <ofs>