[Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.

[Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.

[Vic Lee]

Sometimes sorecvfrom() is called from slirp.c because revents == G_IO_IN,
but there is 0 bytes available and recvfrom could be blocking indefinitely.
This is likely due to 0-length udp payload. This also adds an error
checking for ioctlsocket.

Signed-off-by: Vic Lee <llyzs.vic@gmail.com>
---
 slirp/socket.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/slirp/socket.c b/slirp/socket.c
index 4876ea3f31..03266128b1 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -529,6 +529,15 @@ sorecvfrom(struct socket *so)
           int n;
 #endif
 
+	  if (ioctlsocket(so->s, FIONREAD, &n) != 0) {
+	      DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
+			  errno,strerror(errno)));
+	      return;
+	  }
+	  if (n == 0) {
+	      return;
+	  }
+
 	  m = m_get(so->slirp);
 	  if (!m) {
 	      return;
@@ -552,7 +561,6 @@ sorecvfrom(struct socket *so)
 	   */
 	  len = M_FREEROOM(m);
 	  /* if (so->so_fport != htons(53)) { */
-	  ioctlsocket(so->s, FIONREAD, &n);
 
 	  if (n > len) {
 	    n = (m->m_data - m->m_dat) + m->m_len + n + 1;
-- 
2.20.1

Re: [Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.

[no-reply]

Patchew URL: https://patchew.org/QEMU/20190301064809.3074-1-llyzs.vic@gmail.com/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Message-id: 20190301064809.3074-1-llyzs.vic@gmail.com
Subject: [Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 * [new tag]               patchew/20190301064809.3074-1-llyzs.vic@gmail.com -> patchew/20190301064809.3074-1-llyzs.vic@gmail.com
Switched to a new branch 'test'
0987e4851f slirp: check for ioctlsocket error and 0-length udp payload.

=== OUTPUT BEGIN ===
ERROR: code indent should never use tabs
#23: FILE: slirp/socket.c:532:
+^I  if (ioctlsocket(so->s, FIONREAD, &n) != 0) {$

ERROR: suspect code indent for conditional statements (10, 14)
#23: FILE: slirp/socket.c:532:
+         if (ioctlsocket(so->s, FIONREAD, &n) != 0) {
+             DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",

ERROR: code indent should never use tabs
#24: FILE: slirp/socket.c:533:
+^I      DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",$

ERROR: space required after that ',' (ctx:VxV)
#24: FILE: slirp/socket.c:533:
+             DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
                             ^

ERROR: code indent should never use tabs
#25: FILE: slirp/socket.c:534:
+^I^I^I  errno,strerror(errno)));$

ERROR: space required after that ',' (ctx:VxV)
#25: FILE: slirp/socket.c:534:
+                         errno,strerror(errno)));
                               ^

ERROR: code indent should never use tabs
#26: FILE: slirp/socket.c:535:
+^I      return;$

ERROR: code indent should never use tabs
#27: FILE: slirp/socket.c:536:
+^I  }$

ERROR: code indent should never use tabs
#28: FILE: slirp/socket.c:537:
+^I  if (n == 0) {$

ERROR: suspect code indent for conditional statements (10, 14)
#28: FILE: slirp/socket.c:537:
+         if (n == 0) {
+             return;

ERROR: code indent should never use tabs
#29: FILE: slirp/socket.c:538:
+^I      return;$

ERROR: code indent should never use tabs
#30: FILE: slirp/socket.c:539:
+^I  }$

total: 12 errors, 0 warnings, 22 lines checked

Commit 0987e4851f60 (slirp: check for ioctlsocket error and 0-length udp payload.) has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/20190301064809.3074-1-llyzs.vic@gmail.com/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@redhat.com

Re: [Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.

[Samuel Thibault]

Vic Lee, le ven. 01 mars 2019 14:48:09 +0800, a ecrit:
> Sometimes sorecvfrom() is called from slirp.c because revents == G_IO_IN,
> but there is 0 bytes available and recvfrom could be blocking indefinitely.
> This is likely due to 0-length udp payload. This also adds an error
> checking for ioctlsocket.
> 
> Signed-off-by: Vic Lee <llyzs.vic@gmail.com>

Applied to my tree, thanks!

Samuel

Re: [Qemu-devel] [PATCH v2] slirp: check for ioctlsocket error and 0-length udp payload.

[no-reply]

Patchew URL: https://patchew.org/QEMU/20190301064809.3074-1-llyzs.vic@gmail.com/



Hi,

This series failed the docker-mingw@fedora build test. Please find the testing commands and
their output below. If you have Docker installed, you can probably reproduce it
locally.

=== TEST SCRIPT BEGIN ===
#!/bin/bash
time make docker-test-mingw@fedora SHOW_ENV=1 J=14 NETWORK=1
=== TEST SCRIPT END ===

                 from /tmp/qemu-test/src/slirp/slirp.h:50,
                 from /tmp/qemu-test/src/slirp/socket.c:8:
/tmp/qemu-test/src/slirp/socket.c: In function 'sorecvfrom':
/tmp/qemu-test/src/slirp/socket.c:533:20: error: 'dfd' undeclared (first use in this function)
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
                    ^~~
/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0/glib/gmessages.h:345:32: note: in definition of macro 'g_debug'
---
/tmp/qemu-test/src/slirp/socket.c:533:8: note: in expansion of macro 'DEBUG_MISC'
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
        ^~~~~~~~~~
/tmp/qemu-test/src/slirp/socket.c:533:23: error: left-hand operand of comma expression has no effect [-Werror=unused-value]
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
                       ^
/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0/glib/gmessages.h:345:32: note: in definition of macro 'g_debug'
---
/tmp/qemu-test/src/slirp/socket.c:533:8: note: in expansion of macro 'DEBUG_MISC'
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
        ^~~~~~~~~~
/tmp/qemu-test/src/slirp/socket.c:533:54: error: left-hand operand of comma expression has no effect [-Werror=unused-value]
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
                                                      ^
/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0/glib/gmessages.h:345:32: note: in definition of macro 'g_debug'
---
/tmp/qemu-test/src/slirp/socket.c:533:8: note: in expansion of macro 'DEBUG_MISC'
        DEBUG_MISC((dfd," ioctlsocket errno = %d-%s\n",
        ^~~~~~~~~~
/tmp/qemu-test/src/slirp/socket.c:533:8: error: format not a string literal and no format arguments [-Werror=format-security]
cc1: all warnings being treated as errors
make: *** [/tmp/qemu-test/src/rules.mak:69: slirp/socket.o] Error 1
Traceback (most recent call last):


The full log is available at
http://patchew.org/logs/20190301064809.3074-1-llyzs.vic@gmail.com/testing.docker-mingw@fedora/?type=message.
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Please send your feedback to patchew-devel@redhat.com