From 9c122adadbf4377eb77195b3944be10a59d9484f Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 25 Feb 2015 13:08:31 -0500 Subject: [PATCH] nbd: Fix nbd_receive_options() The client flags are sent exactly once overall, not once per option. Signed-off-by: Max Reitz Message-Id: <1424887718-10800-19-git-send-email-mreitz@redhat.com> Signed-off-by: Paolo Bonzini --- nbd.c | 49 +++++++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 20 deletions(-) diff --git a/nbd.c b/nbd.c index 3d550f750a..fb8a4d47f3 100644 --- a/nbd.c +++ b/nbd.c @@ -350,30 +350,39 @@ fail: static int nbd_receive_options(NBDClient *client) { + int csock = client->sock; + uint32_t flags; + + /* Client sends: + [ 0 .. 3] client flags + + [ 0 .. 7] NBD_OPTS_MAGIC + [ 8 .. 11] NBD option + [12 .. 15] Data length + ... Rest of request + + [ 0 .. 7] NBD_OPTS_MAGIC + [ 8 .. 11] Second NBD option + [12 .. 15] Data length + ... Rest of request + */ + + if (read_sync(csock, &flags, sizeof(flags)) != sizeof(flags)) { + LOG("read failed"); + return -EIO; + } + TRACE("Checking client flags"); + be32_to_cpus(&flags); + if (flags != 0 && flags != NBD_FLAG_C_FIXED_NEWSTYLE) { + LOG("Bad client flags received"); + return -EIO; + } + while (1) { - int csock = client->sock, ret; + int ret; uint32_t tmp, length; uint64_t magic; - /* Client sends: - [ 0 .. 3] client flags - [ 4 .. 11] NBD_OPTS_MAGIC - [12 .. 15] NBD option - [16 .. 19] length - ... Rest of request - */ - - if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { - LOG("read failed"); - return -EINVAL; - } - TRACE("Checking client flags"); - tmp = be32_to_cpu(tmp); - if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { - LOG("Bad client flags received"); - return -EINVAL; - } - if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { LOG("read failed"); return -EINVAL; -- 2.39.2