[PATCHES] messaging iov / recvfrom

Michael Adam obnox at samba.org
Sat May 31 04:26:17 MDT 2014


Andreas, Jeremy,

attached find a patchset that adds the required
checks for the existence of msg_control.

It also makes samba use the same define name
as socket_wrapper, so that we are consistent
and slightly cleans the use of the defines
in vfs_aio_fork.c, the only previous user
of msg_control.

Review/push/comments appreciated!

Cheers - Michael

On 2014-05-30 at 15:39 -0700, Jeremy Allison wrote:
> On Fri, May 30, 2014 at 09:35:06AM +0200, Andreas Schneider wrote:
> > On Thursday 29 May 2014 14:31:55 Jeremy Allison wrote:
> > > On Mon, May 26, 2014 at 05:07:44PM +0200, Michael Adam wrote:
> > > > Oops, there was a bug in the first patch.
> > > > Sorry for posting prematurely...
> > > > Attaching a fixed version.
> > > > 
> > > > Thanks - Michael
> > > > 
> > > > On 2014-05-26 at 15:52 +0200, Michael Adam wrote:
> > > > > Hi,
> > > > > 
> > > > > as a result of my work towards adding support for fd-passing
> > > > > to our messaging, find attached two first preparatory patches
> > > > > that might already be useful.
> > > > > 
> > > > > The first changes the send_fn to use struct  iovec
> > > > > instead of data blob. (Volker has already looked
> > > > > over this one.)
> > > > > 
> > > > > The second one lets unix_dgram_recv_handler()
> > > > > use recvmsg() instead of recv().
> > > > > 
> > > > > Review/push/comments appreciated.
> > > 
> > > LGTM ! Pushed to autobuild.
> > 
> > 
> > 
> > 
> > I gave a NAK! Why do you push it now?
> 
> Because the only complaint I saw from
> you was clearly incorrect (the bit
> around the dot-initialization).
> 
> I didn't notice the other issue, so
> I assumed it was good to go.
> 
> Sorry !
> 
> Jeremy.
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From f662c6b6493d69de5be3f19a9ab277abe6c78722 Mon Sep 17 00:00:00 2001
From: Michael Adam <obnox at samba.org>
Date: Sat, 31 May 2014 11:58:01 +0200
Subject: [PATCH 1/4] vfs:aio_fork: simplify checking of MSG_CONTROL and
 MSG_ACCTRIGHTS

Signed-off-by: Michael Adam <obnox at samba.org>
---
 source3/modules/vfs_aio_fork.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/source3/modules/vfs_aio_fork.c b/source3/modules/vfs_aio_fork.c
index dc33031..c3dc188 100644
--- a/source3/modules/vfs_aio_fork.c
+++ b/source3/modules/vfs_aio_fork.c
@@ -27,6 +27,10 @@
 #include "lib/async_req/async_sock.h"
 #include "lib/util/tevent_unix.h"
 
+#if !defined(HAVE_MSGHDR_MSG_CONTROL) && !defined(HAVE_MSGHDR_MSG_ACCTRIGHTS)
+# error Can not pass file descriptors
+#endif
+
 #undef recvmsg
 
 #ifndef MAP_FILE
@@ -152,9 +156,11 @@ static ssize_t read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
 	ssize_t n;
 #ifndef HAVE_MSGHDR_MSG_CONTROL
 	int newfd;
-#endif
 
-#ifdef	HAVE_MSGHDR_MSG_CONTROL
+	msg.msg_accrights = (caddr_t) &newfd;
+	msg.msg_accrightslen = sizeof(int);
+#else
+
 	union {
 	  struct cmsghdr	cm;
 	  char				control[CMSG_SPACE(sizeof(int))];
@@ -163,13 +169,6 @@ static ssize_t read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
 
 	msg.msg_control = control_un.control;
 	msg.msg_controllen = sizeof(control_un.control);
-#else
-#if HAVE_MSGHDR_MSG_ACCTRIGHTS
-	msg.msg_accrights = (caddr_t) &newfd;
-	msg.msg_accrightslen = sizeof(int);
-#else
-#error Can not pass file descriptors
-#endif
 #endif
 
 	msg.msg_name = NULL;
-- 
1.9.1


From ddcf24406e4f02fddbfeab4411f212784b3949ac Mon Sep 17 00:00:00 2001
From: Michael Adam <obnox at samba.org>
Date: Sat, 31 May 2014 12:04:05 +0200
Subject: [PATCH 2/4] build: rename HAVE_MSGHDR_MSG_CONTROL to
 HAVE_STRUCT_MSGHDR_MSG_CONTROL

So that we are consistent with the socket_wrapper define.

Signed-off-by: Michael Adam <obnox at samba.org>
---
 source3/modules/vfs_aio_fork.c | 8 ++++----
 source3/wscript                | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/source3/modules/vfs_aio_fork.c b/source3/modules/vfs_aio_fork.c
index c3dc188..d8a99b0 100644
--- a/source3/modules/vfs_aio_fork.c
+++ b/source3/modules/vfs_aio_fork.c
@@ -27,7 +27,7 @@
 #include "lib/async_req/async_sock.h"
 #include "lib/util/tevent_unix.h"
 
-#if !defined(HAVE_MSGHDR_MSG_CONTROL) && !defined(HAVE_MSGHDR_MSG_ACCTRIGHTS)
+#if !defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL) && !defined(HAVE_MSGHDR_MSG_ACCTRIGHTS)
 # error Can not pass file descriptors
 #endif
 
@@ -154,7 +154,7 @@ static ssize_t read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
 	struct msghdr msg;
 	struct iovec iov[1];
 	ssize_t n;
-#ifndef HAVE_MSGHDR_MSG_CONTROL
+#ifndef HAVE_STRUCT_MSGHDR_MSG_CONTROL
 	int newfd;
 
 	msg.msg_accrights = (caddr_t) &newfd;
@@ -184,7 +184,7 @@ static ssize_t read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
 		return(n);
 	}
 
-#ifdef	HAVE_MSGHDR_MSG_CONTROL
+#ifdef	HAVE_STRUCT_MSGHDR_MSG_CONTROL
 	if ((cmptr = CMSG_FIRSTHDR(&msg)) != NULL
 	    && cmptr->cmsg_len == CMSG_LEN(sizeof(int))) {
 		if (cmptr->cmsg_level != SOL_SOCKET) {
@@ -218,7 +218,7 @@ static ssize_t write_fd(int fd, void *ptr, size_t nbytes, int sendfd)
 	struct msghdr	msg;
 	struct iovec	iov[1];
 
-#ifdef	HAVE_MSGHDR_MSG_CONTROL
+#ifdef	HAVE_STRUCT_MSGHDR_MSG_CONTROL
 	union {
 		struct cmsghdr	cm;
 		char control[CMSG_SPACE(sizeof(int))];
diff --git a/source3/wscript b/source3/wscript
index 3b38d19..25dfa2e 100644
--- a/source3/wscript
+++ b/source3/wscript
@@ -552,7 +552,7 @@ union {
 msg.msg_control = control_un.control;
 msg.msg_controllen = sizeof(control_un.control);
 ''',
-        'HAVE_MSGHDR_MSG_CONTROL',
+        'HAVE_STRUCT_MSGHDR_MSG_CONTROL',
         msg='Checking if we can use msg_control for passing file descriptors',
         headers='sys/types.h stdlib.h stddef.h sys/socket.h sys/un.h')
     conf.CHECK_CODE('''
@@ -1841,7 +1841,7 @@ main() {
     if conf.CONFIG_SET('HAVE_STATFS_F_FSID'):
         default_shared_modules.extend(TO_LIST('vfs_fileid'))
 
-    if (conf.CONFIG_SET('HAVE_MSGHDR_MSG_CONTROL') or conf.CONFIG_SET('HAVE_MSGHDR_MSG_ACCTRIGHTS')):
+    if (conf.CONFIG_SET('HAVE_STRUCT_MSGHDR_MSG_CONTROL') or conf.CONFIG_SET('HAVE_MSGHDR_MSG_ACCTRIGHTS')):
         default_shared_modules.extend(TO_LIST('vfs_aio_fork'))
 
     if Options.options.with_pthreadpool:
-- 
1.9.1


From 26fbc81116d28b15b830d9151dc460f32ef8b3e7 Mon Sep 17 00:00:00 2001
From: Michael Adam <obnox at samba.org>
Date: Sat, 31 May 2014 12:05:50 +0200
Subject: [PATCH 3/4] build: rename HAVE_MSGHDR_MSG_ACCTRIGHTS to
 HAVE_STRUCT_MSGHDR_MSG_ACCTRIGHTS

for consistency.

Signed-off-by: Michael Adam <obnox at samba.org>
---
 source3/modules/vfs_aio_fork.c | 2 +-
 source3/wscript                | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/source3/modules/vfs_aio_fork.c b/source3/modules/vfs_aio_fork.c
index d8a99b0..97ec1cd 100644
--- a/source3/modules/vfs_aio_fork.c
+++ b/source3/modules/vfs_aio_fork.c
@@ -27,7 +27,7 @@
 #include "lib/async_req/async_sock.h"
 #include "lib/util/tevent_unix.h"
 
-#if !defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL) && !defined(HAVE_MSGHDR_MSG_ACCTRIGHTS)
+#if !defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL) && !defined(HAVE_STRUCT_MSGHDR_MSG_ACCTRIGHTS)
 # error Can not pass file descriptors
 #endif
 
diff --git a/source3/wscript b/source3/wscript
index 25dfa2e..cf9d787 100644
--- a/source3/wscript
+++ b/source3/wscript
@@ -561,7 +561,7 @@ int fd;
 msg.msg_acctrights = (caddr_t) &fd;
 msg.msg_acctrightslen = sizeof(fd);
 ''',
-        'HAVE_MSGHDR_MSG_ACCTRIGHTS',
+        'HAVE_STRUCT_MSGHDR_MSG_ACCTRIGHTS',
         msg='Checking if we can use msg_acctrights for passing file descriptors',
         headers='sys/types.h stdlib.h stddef.h sys/socket.h sys/un.h')
 
@@ -1841,7 +1841,7 @@ main() {
     if conf.CONFIG_SET('HAVE_STATFS_F_FSID'):
         default_shared_modules.extend(TO_LIST('vfs_fileid'))
 
-    if (conf.CONFIG_SET('HAVE_STRUCT_MSGHDR_MSG_CONTROL') or conf.CONFIG_SET('HAVE_MSGHDR_MSG_ACCTRIGHTS')):
+    if (conf.CONFIG_SET('HAVE_STRUCT_MSGHDR_MSG_CONTROL') or conf.CONFIG_SET('HAVE_STRUCT_MSGHDR_MSG_ACCTRIGHTS')):
         default_shared_modules.extend(TO_LIST('vfs_aio_fork'))
 
     if Options.options.with_pthreadpool:
-- 
1.9.1


From e2f20a2b3bc3626ffc7cc807870d1fffb816c1fc Mon Sep 17 00:00:00 2001
From: Michael Adam <obnox at samba.org>
Date: Sat, 31 May 2014 12:16:08 +0200
Subject: [PATCH 4/4] s3:messaging: protect use of msg_control with
 HAVE_STRUCT_MSGHDR_MSG_CONTROL

Signed-off-by: Michael Adam <obnox at samba.org>
---
 source3/lib/unix_msg/unix_msg.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/source3/lib/unix_msg/unix_msg.c b/source3/lib/unix_msg/unix_msg.c
index bcabd28..602ecc6 100644
--- a/source3/lib/unix_msg/unix_msg.c
+++ b/source3/lib/unix_msg/unix_msg.c
@@ -244,8 +244,10 @@ static void unix_dgram_recv_handler(struct poll_watch *w, int fd, short events,
 	msg = (struct msghdr) {
 		.msg_iov = &iov,
 		.msg_iovlen = 1,
+#ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
 		.msg_control = NULL,
 		.msg_controllen = 0,
+#endif
 	};
 
 	received = recvmsg(fd, &msg, 0);
@@ -509,8 +511,10 @@ static int unix_dgram_send(struct unix_dgram_ctx *ctx, const char *dst_sock,
 	msg.msg_namelen = sizeof(addr);
 	msg.msg_iov = discard_const_p(struct iovec, iov);
 	msg.msg_iovlen = iovlen;
+#ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
 	msg.msg_control = NULL;
 	msg.msg_controllen = 0;
+#endif
 	msg.msg_flags = 0;
 
 	ret = sendmsg(ctx->sock, &msg, 0);
-- 
1.9.1

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