[5/7] support: Add support_socket_time64_timestamp

Message ID 20210705183027.3804093-6-adhemerval.zanella@linaro.org
State Superseded
Headers show
Series
  • Linux 64-bit time_t socket fixes
Related show

Commit Message

Adhemerval Zanella via Libc-alpha July 5, 2021, 6:30 p.m.
Check if the socket support 64-bit network packages timestamps
(SO_TIMESTAMP and SO_TIMESTAMPNS).  This will be used on recvmsg
and recvmmsg tests to check if the timestamp should be generated.
---
 support/Makefile                          |  1 +
 support/support.h                         |  3 +
 support/support_socket_time64_timestamp.c | 68 +++++++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 support/support_socket_time64_timestamp.c

-- 
2.30.2

Comments

Adhemerval Zanella via Libc-alpha July 5, 2021, 6:46 p.m. | #1
* Adhemerval Zanella via Libc-alpha:

> Check if the socket support 64-bit network packages timestamps

> (SO_TIMESTAMP and SO_TIMESTAMPNS).  This will be used on recvmsg

> and recvmmsg tests to check if the timestamp should be generated.


Is it possible to probe with getsockopt instead?  Otherwise please
document that this function disables SO_TIMESTAMP.

> +      r = syscall (__NR_setsockopt, 14 /* SOCKOP_setsockopt  */ , args);


Should that be __NR_socketcall?

Thanks,
Florian
Adhemerval Zanella via Libc-alpha July 5, 2021, 6:51 p.m. | #2
On 05/07/2021 15:46, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:

> 

>> Check if the socket support 64-bit network packages timestamps

>> (SO_TIMESTAMP and SO_TIMESTAMPNS).  This will be used on recvmsg

>> and recvmmsg tests to check if the timestamp should be generated.

> 

> Is it possible to probe with getsockopt instead?  Otherwise please

> document that this function disables SO_TIMESTAMP.


I think it would work.

> 

>> +      r = syscall (__NR_setsockopt, 14 /* SOCKOP_setsockopt  */ , args);

> 

> Should that be __NR_socketcall?


Indeed, I will send an updated version.

Patch

diff --git a/support/Makefile b/support/Makefile
index 5c69f0de4b..7659357b28 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -76,6 +76,7 @@  libsupport-routines = \
   support_set_small_thread_stack_size \
   support_shared_allocate \
   support_small_stack_thread_attribute \
+  support_socket_time64_timestamp \
   support_stat_nanoseconds \
   support_subprocess \
   support_test_compare_blob \
diff --git a/support/support.h b/support/support.h
index 9ec8ecb8d7..bf74a2584b 100644
--- a/support/support.h
+++ b/support/support.h
@@ -154,6 +154,9 @@  extern bool support_select_modifies_timeout (void);
    tv_usec larger than 1000000.  */
 extern bool support_select_normalizes_timeout (void);
 
+/* Return true if socket FD supports 64-bit timestamps.  */
+extern bool support_socket_time64_timestamp (int fd);
+
 /* Create a timer that trigger after SEC seconds and NSEC nanoseconds.  If
    REPEAT is true the timer will repeat indefinitely.  If CALLBACK is not
    NULL, the function will be called when the timer expires; otherwise a
diff --git a/support/support_socket_time64_timestamp.c b/support/support_socket_time64_timestamp.c
new file mode 100644
index 0000000000..2d5af65471
--- /dev/null
+++ b/support/support_socket_time64_timestamp.c
@@ -0,0 +1,68 @@ 
+/* Return whether socket supports 64-bit timestamps.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include <support/support.h>
+
+#ifdef __linux__
+# include <socket-constants-time64.h>
+
+static int
+__attribute_used__
+setsockopt_syscall (int fd, int enable)
+{
+  int level = SOL_SOCKET;
+  int optname = COMPAT_SO_TIMESTAMP_NEW;
+  int optval = enable;
+
+  int r = syscall (__NR_setsockopt, fd, level, optname, &optval,
+		   sizeof (optval));
+#  ifdef __NR_setsockopt
+  if (r == -1 && errno == ENOSYS)
+    {
+      long int args[] = { fd, level, optname, (long int) &optval,
+			  sizeof (optval) };
+      r = syscall (__NR_setsockopt, 14 /* SOCKOP_setsockopt  */ , args);
+    }
+#  endif
+  return r;
+}
+#endif
+
+bool
+support_socket_time64_timestamp (int fd)
+{
+#ifdef __linux__
+# if __LINUX_KERNEL_VERSION >= 0x050100                          \
+   || __WORDSIZE == 64                                           \
+   || (defined __SYSCALL_WORDSIZE && __SYSCALL_WORDSIZE == 64)
+  return true;
+# else
+  int r = setsockopt_syscall (fd, 1);
+  if (r == -1 && errno == ENOPROTOOPT)
+    return false;
+  setsockopt_syscall (fd, 0);
+  return true;
+# endif
+#else
+  return false;
+#endif
+}