linux: Add fallback for 64-bit time_t SO_{RCV,SND}TIMEO

The constant values will be changed for __TIMESIZE=64, so binaries built
with 64-bit time support might fail to work properly on old kernels.
Both {get,set}sockopt will retry the syscall with the old constant
values and the timeout value adjusted when kernel returns ENOTPROTOPT.

It also adds an internal only SO_{RCV,SND}TIMEO where
COMPAT_SO_{RCV,SND}TIMEO_OLD indicates pre 32-bit time support and
COMPAT_SO_{RCV,SND}TIMEO_NEW indicates time64 support.  It allows to
refer to constant independently of the time_t ABI and kernel version
used.

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 63 insertions, 8 deletions

diff --git a/sysdeps/unix/sysv/linux/setsockopt.c b/sysdeps/unix/sysv/linux/setsockopt.c
index 12fd7bdcde..6505202265 100644
--- a/sysdeps/unix/sysv/linux/setsockopt.c
+++ b/sysdeps/unix/sysv/linux/setsockopt.c
@@ -15,21 +15,76 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <signal.h>
 #include <sys/socket.h>
-
+#include <time.h>
+#include <sysdep.h>
 #include <socketcall.h>
-#include <kernel-features.h>
-#include <sys/syscall.h>
+#include <socket-constants-time64.h>
 
-int
-setsockopt (int fd, int level, int optname, const void *optval, socklen_t len)
+static int
+setsockopt_syscall (int fd, int level, int optname, const void *optval,
+		    socklen_t len)
 {
 #ifdef __ASSUME_SETSOCKOPT_SYSCALL
-  return INLINE_SYSCALL (setsockopt, 5, fd, level, optname, optval, len);
+  return INLINE_SYSCALL_CALL (setsockopt, fd, level, optname, optval, len);
 #else
   return SOCKETCALL (setsockopt, fd, level, optname, optval, len);
 #endif
 }
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+static int
+setsockopt32 (int fd, int level, int optname, const void *optval,
+	      socklen_t len)
+{
+  int r = -1;
+
+  if (level != SOL_SOCKET)
+    return r;
+
+  switch (optname)
+    {
+    case COMPAT_SO_RCVTIMEO_NEW:
+    case COMPAT_SO_SNDTIMEO_NEW:
+      {
+        if (len < sizeof (struct __timeval64))
+	  {
+	    __set_errno (EINVAL);
+	    break;
+	  }
+
+	struct __timeval64 *tv64 = (struct __timeval64 *) optval;
+	if (! in_time_t_range (tv64->tv_sec))
+	  {
+	    __set_errno (EOVERFLOW);
+	    break;
+	  }
+
+	if (optname == COMPAT_SO_RCVTIMEO_NEW)
+	  optname = COMPAT_SO_RCVTIMEO_OLD;
+	if (optname == COMPAT_SO_SNDTIMEO_NEW)
+	  optname = COMPAT_SO_SNDTIMEO_OLD;
+
+	struct __timeval32 tv32 = valid_timeval64_to_timeval32 (*tv64);
+
+	r = setsockopt_syscall (fd, level, optname, &tv32, sizeof (tv32));
+      }
+    }
+
+  return r;
+}
+#endif
+
+int
+setsockopt (int fd, int level, int optname, const void *optval, socklen_t len)
+{
+  int r = setsockopt_syscall (fd, level, optname, optval, len);
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+  if (r == -1 && errno == ENOPROTOOPT)
+    r = setsockopt32 (fd, level, optname, optval, len);
+#endif
+
+  return r;
+}
 weak_alias (setsockopt, __setsockopt)