Author: jilles
Date: Tue Mar 19 20:58:17 2013
New Revision: 248534
URL: http://svnweb.freebsd.org/changeset/base/248534
Log:
Implement SOCK_CLOEXEC, SOCK_NONBLOCK and MSG_CMSG_CLOEXEC.
This change allows creating file descriptors with close-on-exec set in some
situations. SOCK_CLOEXEC and SOCK_NONBLOCK can be OR'ed in socket() and
socketpair()'s type parameter, and MSG_CMSG_CLOEXEC to recvmsg() makes file
descriptors (SCM_RIGHTS) atomically close-on-exec.
The numerical values for SOCK_CLOEXEC and SOCK_NONBLOCK are as in NetBSD.
MSG_CMSG_CLOEXEC is the first free bit for MSG_*.
The SOCK_* flags are not passed to MAC because this may cause incorrect
failures and can be done later via fcntl() anyway. On the other hand, audit
is expected to cope with the new flags.
For MSG_CMSG_CLOEXEC, unp_externalize() is extended to take a flags
argument.
Reviewed by: kib
Modified:
head/lib/libc/sys/recv.2
head/lib/libc/sys/socket.2
head/lib/libc/sys/socketpair.2
head/share/man/man4/unix.4
head/sys/kern/uipc_socket.c
head/sys/kern/uipc_syscalls.c
head/sys/kern/uipc_usrreq.c
head/sys/sys/domain.h
head/sys/sys/socket.h
Modified: head/lib/libc/sys/recv.2
==============================================================================
--- head/lib/libc/sys/recv.2 Tue Mar 19 20:20:00 2013 (r248533)
+++ head/lib/libc/sys/recv.2 Tue Mar 19 20:58:17 2013 (r248534)
@@ -28,7 +28,7 @@
.\" @(#)recv.2 8.3 (Berkeley) 2/21/94
.\" $FreeBSD$
.\"
-.Dd September 12, 2012
+.Dd March 19, 2013
.Dt RECV 2
.Os
.Sh NAME
@@ -121,11 +121,12 @@ argument to a
function is formed by
.Em or Ap ing
one or more of the values:
-.Bl -column ".Dv MSG_DONTWAIT" -offset indent
+.Bl -column ".Dv MSG_CMSG_CLOEXEC" -offset indent
.It Dv MSG_OOB Ta process out-of-band data
.It Dv MSG_PEEK Ta peek at incoming message
.It Dv MSG_WAITALL Ta wait for full request or error
.It Dv MSG_DONTWAIT Ta do not block
+.It Dv MSG_CMSG_CLOEXEC Ta set received fds close-on-exec
.El
.Pp
The
@@ -227,6 +228,10 @@ and
.Fa cmsg_type
set to
.Dv SCM_RIGHTS .
+The close-on-exec flag on received descriptors is set according to the
+.Dv MSG_CMSG_CLOEXEC
+flag passed to
+.Fn recvmsg .
.Pp
Process credentials can also be passed as ancillary data for
.Dv AF_UNIX
Modified: head/lib/libc/sys/socket.2
==============================================================================
--- head/lib/libc/sys/socket.2 Tue Mar 19 20:20:00 2013 (r248533)
+++ head/lib/libc/sys/socket.2 Tue Mar 19 20:58:17 2013 (r248534)
@@ -28,7 +28,7 @@
.\" From: @(#)socket.2 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
-.Dd December 7, 2012
+.Dd March 19, 2013
.Dt SOCKET 2
.Os
.Sh NAME
@@ -115,6 +115,15 @@ which is available only to the super-use
which is planned,
but not yet implemented, are not described here.
.Pp
+Additionally, the following flags are allowed in the
+.Fa type
+argument:
+.Pp
+.Bd -literal -offset indent -compact
+SOCK_CLOEXEC Set close-on-exec on the new descriptor,
+SOCK_NONBLOCK Set non-blocking mode on the new socket
+.Ed
+.Pp
The
.Fa protocol
argument
Modified: head/lib/libc/sys/socketpair.2
==============================================================================
--- head/lib/libc/sys/socketpair.2 Tue Mar 19 20:20:00 2013
(r248533)
+++ head/lib/libc/sys/socketpair.2 Tue Mar 19 20:58:17 2013
(r248534)
@@ -28,7 +28,7 @@
.\" @(#)socketpair.2 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
-.Dd June 4, 1993
+.Dd March 19, 2013
.Dt SOCKETPAIR 2
.Os
.Sh NAME
@@ -57,6 +57,14 @@ are returned in
and
.Fa sv Ns [1] .
The two sockets are indistinguishable.
+.Pp
+The
+.Dv SOCK_CLOEXEC
+and
+.Dv SOCK_NONBLOCK
+flags in the
+.Fa type
+argument apply to both descriptors.
.Sh RETURN VALUES
.Rv -std socketpair
.Sh ERRORS
@@ -79,6 +87,7 @@ process address space.
.Sh SEE ALSO
.Xr pipe 2 ,
.Xr read 2 ,
+.Xr socket 2 ,
.Xr write 2
.Sh HISTORY
The
Modified: head/share/man/man4/unix.4
==============================================================================
--- head/share/man/man4/unix.4 Tue Mar 19 20:20:00 2013 (r248533)
+++ head/share/man/man4/unix.4 Tue Mar 19 20:58:17 2013 (r248534)
@@ -32,7 +32,7 @@
.\" @(#)unix.4 8.1 (Berkeley) 6/9/93
.\" $FreeBSD$
.\"
-.Dd November 16, 2012
+.Dd March 19, 2013
.Dt UNIX 4
.Os
.Sh NAME
@@ -153,13 +153,15 @@ plus the size of the array of file descr
.Pp
The received descriptor is a
.Em duplicate
-of the sender's descriptor, as if it were created with a call to
-.Xr dup 2 .
-Per-process descriptor flags, set with
-.Xr fcntl 2 ,
-are
-.Em not
-passed to a receiver.
+of the sender's descriptor, as if it were created via
+.Li dup(fd)
+or
+.Li fcntl(fd, F_DUPFD_CLOEXEC, 0)
+depending on whether
+.Dv MSG_CMSG_CLOEXEC
+is passed in the
+.Xr recvmsg 2
+call.
Descriptors that are awaiting delivery, or that are
purposely not received, are automatically closed by the system
when the destination socket is closed.
Modified: head/sys/kern/uipc_socket.c
==============================================================================
--- head/sys/kern/uipc_socket.c Tue Mar 19 20:20:00 2013 (r248533)
+++ head/sys/kern/uipc_socket.c Tue Mar 19 20:58:17 2013 (r248534)
@@ -1727,7 +1727,7 @@ dontblock:
SOCKBUF_UNLOCK(&so->so_rcv);
VNET_SO_ASSERT(so);
error = (*pr->pr_domain->dom_externalize)
- (cm, controlp);
+ (cm, controlp, flags);
SOCKBUF_LOCK(&so->so_rcv);
} else if (controlp != NULL)
*controlp = cm;
@@ -2361,7 +2361,7 @@ soreceive_dgram(struct socket *so, struc
cm->m_next = NULL;
if (pr->pr_domain->dom_externalize != NULL) {
error = (*pr->pr_domain->dom_externalize)
- (cm, controlp);
+ (cm, controlp, flags);
} else if (controlp != NULL)
*controlp = cm;
else
Modified: head/sys/kern/uipc_syscalls.c
==============================================================================
--- head/sys/kern/uipc_syscalls.c Tue Mar 19 20:20:00 2013
(r248533)
+++ head/sys/kern/uipc_syscalls.c Tue Mar 19 20:58:17 2013
(r248534)
@@ -164,25 +164,40 @@ sys_socket(td, uap)
{
struct socket *so;
struct file *fp;
- int fd, error;
+ int fd, error, type, oflag, fflag;
AUDIT_ARG_SOCKET(uap->domain, uap->type, uap->protocol);
+
+ type = uap->type;
+ oflag = 0;
+ fflag = 0;
+ if ((type & SOCK_CLOEXEC) != 0) {
+ type &= ~SOCK_CLOEXEC;
+ oflag |= O_CLOEXEC;
+ }
+ if ((type & SOCK_NONBLOCK) != 0) {
+ type &= ~SOCK_NONBLOCK;
+ fflag |= FNONBLOCK;
+ }
+
#ifdef MAC
- error = mac_socket_check_create(td->td_ucred, uap->domain, uap->type,
+ error = mac_socket_check_create(td->td_ucred, uap->domain, type,
uap->protocol);
if (error)
return (error);
#endif
- error = falloc(td, &fp, &fd, 0);
+ error = falloc(td, &fp, &fd, oflag);
if (error)
return (error);
/* An extra reference on `fp' has been held for us by falloc(). */
- error = socreate(uap->domain, &so, uap->type, uap->protocol,
+ error = socreate(uap->domain, &so, type, uap->protocol,
td->td_ucred, td);
if (error) {
fdclose(td->td_proc->p_fd, fp, fd, td);
} else {
- finit(fp, FREAD | FWRITE, DTYPE_SOCKET, so, &socketops);
+ finit(fp, FREAD | FWRITE | fflag, DTYPE_SOCKET, so, &socketops);
+ if ((fflag & FNONBLOCK) != 0)
+ (void) fo_ioctl(fp, FIONBIO, &fflag, td->td_ucred, td);
td->td_retval[0] = fd;
}
fdrop(fp, td);
@@ -648,9 +663,20 @@ kern_socketpair(struct thread *td, int d
struct filedesc *fdp = td->td_proc->p_fd;
struct file *fp1, *fp2;
struct socket *so1, *so2;
- int fd, error;
+ int fd, error, oflag, fflag;
AUDIT_ARG_SOCKET(domain, type, protocol);
+
+ oflag = 0;
+ fflag = 0;
+ if ((type & SOCK_CLOEXEC) != 0) {
+ type &= ~SOCK_CLOEXEC;
+ oflag |= O_CLOEXEC;
+ }
+ if ((type & SOCK_NONBLOCK) != 0) {
+ type &= ~SOCK_NONBLOCK;
+ fflag |= FNONBLOCK;
+ }
#ifdef MAC
/* We might want to have a separate check for socket pairs. */
error = mac_socket_check_create(td->td_ucred, domain, type,
@@ -665,12 +691,12 @@ kern_socketpair(struct thread *td, int d
if (error)
goto free1;
/* On success extra reference to `fp1' and 'fp2' is set by falloc. */
- error = falloc(td, &fp1, &fd, 0);
+ error = falloc(td, &fp1, &fd, oflag);
if (error)
goto free2;
rsv[0] = fd;
fp1->f_data = so1; /* so1 already has ref count */
- error = falloc(td, &fp2, &fd, 0);
+ error = falloc(td, &fp2, &fd, oflag);
if (error)
goto free3;
fp2->f_data = so2; /* so2 already has ref count */
@@ -686,8 +712,14 @@ kern_socketpair(struct thread *td, int d
if (error)
goto free4;
}
- finit(fp1, FREAD | FWRITE, DTYPE_SOCKET, fp1->f_data, &socketops);
- finit(fp2, FREAD | FWRITE, DTYPE_SOCKET, fp2->f_data, &socketops);
+ finit(fp1, FREAD | FWRITE | fflag, DTYPE_SOCKET, fp1->f_data,
+ &socketops);
+ finit(fp2, FREAD | FWRITE | fflag, DTYPE_SOCKET, fp2->f_data,
+ &socketops);
+ if ((fflag & FNONBLOCK) != 0) {
+ (void) fo_ioctl(fp1, FIONBIO, &fflag, td->td_ucred, td);
+ (void) fo_ioctl(fp2, FIONBIO, &fflag, td->td_ucred, td);
+ }
fdrop(fp1, td);
fdrop(fp2, td);
return (0);
Modified: head/sys/kern/uipc_usrreq.c
==============================================================================
--- head/sys/kern/uipc_usrreq.c Tue Mar 19 20:20:00 2013 (r248533)
+++ head/sys/kern/uipc_usrreq.c Tue Mar 19 20:58:17 2013 (r248534)
@@ -288,7 +288,7 @@ static void unp_freerights(struct filede
static void unp_init(void);
static int unp_internalize(struct mbuf **, struct thread *);
static void unp_internalize_fp(struct file *);
-static int unp_externalize(struct mbuf *, struct mbuf **);
+static int unp_externalize(struct mbuf *, struct mbuf **, int);
static int unp_externalize_fp(struct file *);
static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *);
static void unp_process_defers(void * __unused, int);
@@ -1695,7 +1695,7 @@ unp_freerights(struct filedescent **fdep
}
static int
-unp_externalize(struct mbuf *control, struct mbuf **controlp)
+unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
{
struct thread *td = curthread; /* XXX */
struct cmsghdr *cm = mtod(control, struct cmsghdr *);
@@ -1765,6 +1765,8 @@ unp_externalize(struct mbuf *control, st
fde->fde_file = fdep[0]->fde_file;
filecaps_move(&fdep[0]->fde_caps,
&fde->fde_caps);
+ if ((flags & MSG_CMSG_CLOEXEC) != 0)
+ fde->fde_flags |= UF_EXCLOSE;
unp_externalize_fp(fde->fde_file);
*fdp = f;
}
Modified: head/sys/sys/domain.h
==============================================================================
--- head/sys/sys/domain.h Tue Mar 19 20:20:00 2013 (r248533)
+++ head/sys/sys/domain.h Tue Mar 19 20:58:17 2013 (r248534)
@@ -51,7 +51,7 @@ struct domain {
void (*dom_destroy) /* cleanup structures / state */
(void);
int (*dom_externalize) /* externalize access rights */
- (struct mbuf *, struct mbuf **);
+ (struct mbuf *, struct mbuf **, int);
void (*dom_dispose) /* dispose of internalized rights */
(struct mbuf *);
struct protosw *dom_protosw, *dom_protoswNPROTOSW;
Modified: head/sys/sys/socket.h
==============================================================================
--- head/sys/sys/socket.h Tue Mar 19 20:20:00 2013 (r248533)
+++ head/sys/sys/socket.h Tue Mar 19 20:58:17 2013 (r248534)
@@ -95,6 +95,14 @@ typedef __uid_t uid_t;
#endif
#define SOCK_SEQPACKET 5 /* sequenced packet stream */
+#if __BSD_VISIBLE
+/*
+ * Creation flags, OR'ed into socket() and socketpair() type argument.
+ */
+#define SOCK_CLOEXEC 0x10000000
+#define SOCK_NONBLOCK 0x20000000
+#endif
+
/*
* Option flags per-socket.
*/
@@ -459,6 +467,7 @@ struct msghdr {
#endif
#if __BSD_VISIBLE
#define MSG_NOSIGNAL 0x20000 /* do not generate SIGPIPE on
EOF */
+#define MSG_CMSG_CLOEXEC 0x40000 /* make received fds
close-on-exec */
#endif
/*
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