On Thu, 06 Feb 2020 at 11:21:11 -0700, Todd C. Miller wrote:
> On Thu, 06 Feb 2020 10:45:44 -0700, "Theo de Raadt" wrote:
>
> > That feels better, and will be more atomic.
>
> Unfortunately, we can't do this in ptmioctl() since we don't have
> the index of the open ptm device to use to check for the presence
> of UF_EXCLOSE. So it has to be done in libc instead.
Alright, so like this then?
Index: stdlib/posix_openpt.3
===================================================================
RCS file: /cvs/src/lib/libc/stdlib/posix_openpt.3,v
retrieving revision 1.4
diff -u -p -u -p -r1.4 posix_openpt.3
--- stdlib/posix_openpt.3 25 Jan 2019 00:19:25 -0000 1.4
+++ stdlib/posix_openpt.3 6 Feb 2020 17:34:15 -0000
@@ -45,7 +45,7 @@ argument is formed by bitwise-inclusive
.Tn OR Ns 'ing
the following values defined in
.In fcntl.h :
-.Bl -tag -width O_NOCTTY -offset indent
+.Bl -tag -width O_CLOEXEC -offset indent
.It Dv O_RDWR
Open for reading and writing.
.It Dv O_NOCTTY
@@ -53,6 +53,8 @@ Prevent the device from being made the c
This flag has no effect on
.Ox
and is included for compatibility with other systems.
+.It Dv O_CLOEXEC
+Set the close-on-exec flag for the new file descriptor.
.El
.Pp
The
@@ -95,6 +97,10 @@ The
.Fn posix_openpt
function conforms to
.St -p1003.1-2001 .
+.Pp
+The ability to use
+.Dv O_CLOEXEC
+is an extension to that standard.
.Sh HISTORY
The
.Fn posix_openpt
Index: stdlib/posix_pty.c
===================================================================
RCS file: /cvs/src/lib/libc/stdlib/posix_pty.c,v
retrieving revision 1.3
diff -u -p -u -p -r1.3 posix_pty.c
--- stdlib/posix_pty.c 25 Jan 2019 00:19:25 -0000 1.3
+++ stdlib/posix_pty.c 6 Feb 2020 17:34:15 -0000
@@ -36,7 +36,7 @@ posix_openpt(int oflag)
/* User must specify O_RDWR in oflag. */
if ((oflag & O_ACCMODE) != O_RDWR ||
- (oflag & ~(O_ACCMODE | O_NOCTTY)) != 0) {
+ (oflag & ~(O_ACCMODE | O_NOCTTY | O_CLOEXEC)) != 0) {
errno = EINVAL;
return -1;
}
@@ -46,7 +46,11 @@ posix_openpt(int oflag)
if (fd != -1) {
if (ioctl(fd, PTMGET, &ptm) != -1) {
close(ptm.sfd);
- mfd = ptm.cfd;
+ if ((oflag & O_CLOEXEC) &&
+ fcntl(ptm.cfd, F_SETFD, FD_CLOEXEC) == -1)
+ close(ptm.cfd);
+ else
+ mfd = ptm.cfd;
}
close(fd);
}
