From 25dab96205221b595968f4b88b7a26bf69282b26 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 16 Nov 2022 13:58:13 +0100 Subject: tap: Revert recently added checks in tap_handler_passt() This reverts commit 198f87835dc4 ("tap: Return -EIO from tap_handler_passt() on inconsistent packet stream") and commit 510dace86ccf ("tap: Keep stream consistent if qemu length descriptor spans two recv() calls"). I can hit occasional failures in perf/passt_tcp tests where we seem to be getting excess data at the end of a recv(), and for some reason I couldn't figure out yet, if we just ignore it, subsequent recv() calls from qemu return correct data. If we close the connection, qemu can't talk to us anymore, of course. Signed-off-by: Stefano Brivio --- tap.c | 20 ++++---------------- 1 file changed, 4 insertions(+), 16 deletions(-) diff --git a/tap.c b/tap.c index b7ac996..d26af58 100644 --- a/tap.c +++ b/tap.c @@ -747,31 +747,19 @@ redo: return -ECONNRESET; } - while (n > 0) { - ssize_t len; - - /* Force receiving at least a complete length descriptor to - * avoid an inconsistent stream. - */ - if (n < (ssize_t)sizeof(uint32_t)) { - rem = recv(c->fd_tap, p + n, - (ssize_t)sizeof(uint32_t) - n, 0); - if ((n += rem) != (ssize_t)sizeof(uint32_t)) - return -EIO; - } - - len = ntohl(*(uint32_t *)p); + while (n > (ssize_t)sizeof(uint32_t)) { + ssize_t len = ntohl(*(uint32_t *)p); p += sizeof(uint32_t); n -= sizeof(uint32_t); /* At most one packet might not fit in a single read, and this - * also needs to be blocking. + * needs to be blocking. */ if (len > n) { rem = recv(c->fd_tap, p + n, len - n, 0); if ((n += rem) != len) - return -EIO; + return 0; } /* Complete the partial read above before discarding a malformed -- cgit v1.2.3