debian/patches/extra/0020-qemu-nbd-Ignore-SIGPIPE.patch

   1 From 36d48727155c4a440ee23c703778533f87002964 Mon Sep 17 00:00:00 2001
   2 From: Max Reitz <mreitz@redhat.com>
   3 Date: Sun, 11 Jun 2017 14:37:14 +0200
   4 Subject: [PATCH 20/23] qemu-nbd: Ignore SIGPIPE
   5
   6 qemu proper has done so for 13 years
   7 (8a7ddc38a60648257dc0645ab4a05b33d6040063), qemu-img and qemu-io have
   8 done so for four years (526eda14a68d5b3596be715505289b541288ef2a).
   9 Ignoring this signal is especially important in qemu-nbd because
  10 otherwise a client can easily take down the qemu-nbd server by dropping
  11 the connection when the server wants to send something, for example:
  12
  13 $ qemu-nbd -x foo -f raw -t null-co:// &
  14 [1] 12726
  15 $ qemu-io -c quit nbd://localhost/bar
  16 can't open device nbd://localhost/bar: No export with name 'bar' available
  17 [1]  + 12726 broken pipe  qemu-nbd -x foo -f raw -t null-co://
  18
  19 In this case, the client sends an NBD_OPT_ABORT and closes the
  20 connection (because it is not required to wait for a reply), but the
  21 server replies with an NBD_REP_ACK (because it is required to reply).
  22
  23 Signed-off-by: Max Reitz <mreitz@redhat.com>
  24 Message-Id: <20170611123714.31292-1-mreitz@redhat.com>
  25 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  26 ---
  27  qemu-nbd.c | 4 ++++
  28  1 file changed, 4 insertions(+)
  29
  30 diff --git a/qemu-nbd.c b/qemu-nbd.c
  31 index 483dd77a77..5deb37e03e 100644
  32 --- a/qemu-nbd.c
  33 +++ b/qemu-nbd.c
  34 @@ -581,6 +581,10 @@ int main(int argc, char **argv)
  35      sa_sigterm.sa_handler = termsig_handler;
  36      sigaction(SIGTERM, &sa_sigterm, NULL);
  37
  38 +#ifdef CONFIG_POSIX
  39 +    signal(SIGPIPE, SIG_IGN);
  40 +#endif
  41 +
  42      module_call_init(MODULE_INIT_TRACE);
  43      qcrypto_init(&error_fatal);
  44
  45 --
  46 2.11.0
  47