From: Willy Tarreau Date: Sat, 6 Apr 2013 09:29:39 +0000 (+0200) Subject: BUG/MEDIUM: splicing is broken since 1.5-dev12 X-Git-Tag: v1.5-dev19~76 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4fc90efed039f23d0d48cde895939d3e94410e54;p=thirdparty%2Fhaproxy.git BUG/MEDIUM: splicing is broken since 1.5-dev12 Commit 96199b10 reintroduced the splice() mechanism in the new connection system. However, it failed to account for the number of transferred bytes, allowing more bytes than scheduled to be transferred to the client. This can cause an issue with small-chunked responses, where each packet from the server may contain several chunks, because a single splice() call may succeed, then try to splice() a second time as the pipe is not full, thus consuming the next chunk size. This patch also reverts commit baf2a5 ("OPTIM: splice: detect shutdowns...") because it introduced a related regression. The issue is that splice() may return less data than available also if the pipe is full, so having EPOLLRDHUP after splice() returns less than expected is not a sufficient indication that the input is empty. In both cases, the issue may be detected by the presence of "SD" termination flags in the logs, and worked around by disabling splicing (using "-dS"). This problem was reported by Sander Klein, and no backport is needed. --- diff --git a/src/raw_sock.c b/src/raw_sock.c index ad4a0aafa4..e030253591 100644 --- a/src/raw_sock.c +++ b/src/raw_sock.c @@ -159,10 +159,7 @@ int raw_sock_to_pipe(struct connection *conn, struct pipe *pipe, unsigned int co retval += ret; pipe->data += ret; - - /* if a POLL_HUP was present, we've read the last segment */ - if ((fdtab[conn->t.sock.fd].ev & (FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_HUP) - goto out_read0; + count -= ret; if (pipe->data >= SPLICE_FULL_HINT || ret >= global.tune.recv_enough) { /* We've read enough of it for this time, let's stop before