[PATCH v2 06/25] linux: Add fallback for 64-bit time_t SO_TIMESTAMP{NS}
Adhemerval Zanella
adhemerval.zanella@linaro.org
Tue May 18 20:55:54 GMT 2021
The recvmsg handling is more complicated because it requires check the
returned kernel control message and make some convertions. For
!__ASSUME_TIME64_SYSCALLS it converts the first 32-bit time SO_TIMESTAMP
or SO_TIMESTAMPNS and appends it to the control buffer if has extra
space or returns MSG_CTRUNC otherwise. The 32-bit time field is kept
as-is.
Calls with __TIMESIZE=32 will see the converted 64-bit time control
messages as spurious control message of unknown type. Calls with
__TIMESIZE=64 running on pre-time64 kernels will see the original
message as a spurious control ones of unknown typ while running on
kernel with native 64-bit time support will only see the time64 version
of the control message.
Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
---
include/sys/socket.h | 5 +
sysdeps/unix/sysv/linux/Makefile | 2 +-
sysdeps/unix/sysv/linux/Versions | 1 +
.../unix/sysv/linux/convert_scm_timestamps.c | 96 +++++++++++++++++++
sysdeps/unix/sysv/linux/getsockopt.c | 12 +++
.../sysv/linux/hppa/socket-constants-time64.h | 5 +
.../sysv/linux/mips/socket-constants-time64.h | 5 +
.../linux/powerpc/socket-constants-time64.h | 5 +
sysdeps/unix/sysv/linux/recvmsg.c | 23 +++--
sysdeps/unix/sysv/linux/setsockopt.c | 12 +++
.../unix/sysv/linux/socket-constants-time64.h | 5 +
.../linux/sparc/socket-constants-time64.h | 5 +
12 files changed, 169 insertions(+), 7 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/convert_scm_timestamps.c
diff --git a/include/sys/socket.h b/include/sys/socket.h
index 0e39dd2a3a..15d4a62b26 100644
--- a/include/sys/socket.h
+++ b/include/sys/socket.h
@@ -164,5 +164,10 @@ libc_hidden_proto (__libc_sa_len)
libc_hidden_proto (__cmsg_nxthdr)
+#ifndef __ASSUME_TIME64_SYSCALLS
+extern void __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) ;
+libc_hidden_proto (__convert_scm_timestamps)
+#endif
+
#endif
#endif
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index fb155cf856..e28f6470e3 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -64,7 +64,7 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
time64-support pselect32 \
xstat fxstat lxstat xstat64 fxstat64 lxstat64 \
fxstatat fxstatat64 \
- xmknod xmknodat
+ xmknod xmknodat convert_scm_timestamps
CFLAGS-gethostid.c = -fexceptions
CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 220bb2dffe..148f04c50a 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -177,6 +177,7 @@ libc {
__pread64_nocancel;
__close_nocancel;
__sigtimedwait;
+ __convert_scm_timestamps;
# functions used by nscd
__netlink_assert_response;
}
diff --git a/sysdeps/unix/sysv/linux/convert_scm_timestamps.c b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c
new file mode 100644
index 0000000000..3c123c28ce
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c
@@ -0,0 +1,96 @@
+/* Socket timestamp conversion routines.
+ 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 <kernel-features.h>
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+# include <stdint.h>
+# include <string.h>
+# include <sys/socket.h>
+# include <socket-constants-time64.h>
+
+/* It converts the first SO_TIMESTAMP or SO_TIMESTAMPNS with 32-bit time and
+ appends it to the control buffer. The 32-bit time field is kept as-is.
+
+ Calls with __TIMESIZE=32 will see the converted 64-bit time control
+ messages as spurious control message of unknown type.
+
+ Calls with __TIMESIZE=64 running on pre-time64 kernels will see the
+ original message as a spurious control ones of unknown typ while running
+ on kernel with native 64-bit time support will only see the time64 version
+ of the control message. */
+void
+__convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize)
+{
+ if (msg->msg_control == NULL || msg->msg_controllen == 0)
+ return;
+
+ /* The returned control message format for SO_TIMESTAMP_NEW is a
+ 'struct __kernel_sock_timeval' while for SO_TIMESTAMPNS_NEW is a
+ 'struct __kernel_timespec'. In either case it is two uint64_t
+ members. */
+ uint64_t tvts[2];
+
+ struct cmsghdr *cmsg, *last = NULL;
+ int type = 0;
+
+ for (cmsg = CMSG_FIRSTHDR (msg);
+ cmsg != NULL;
+ cmsg = CMSG_NXTHDR (msg, cmsg))
+ {
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ switch (cmsg->cmsg_type)
+ {
+ case COMPAT_SO_TIMESTAMP_OLD:
+ if (type != 0)
+ break;
+ type = COMPAT_SO_TIMESTAMP_NEW;
+ goto common;
+
+ case COMPAT_SO_TIMESTAMPNS_OLD:
+ type = COMPAT_SO_TIMESTAMPNS_NEW;
+
+ /* fallthrough */
+ common:
+ memcpy (tvts, CMSG_DATA (cmsg), sizeof (tvts));
+ break;
+ }
+
+ last = cmsg;
+ }
+
+ if (last == NULL || type == 0)
+ return;
+
+ if (CMSG_SPACE (sizeof tvts) > msgsize - msg->msg_controllen)
+ {
+ msg->msg_flags |= MSG_CTRUNC;
+ return;
+ }
+
+ msg->msg_controllen += CMSG_SPACE (sizeof tvts);
+ cmsg = CMSG_NXTHDR(msg, last);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = type;
+ cmsg->cmsg_len = CMSG_LEN (sizeof tvts);
+ memcpy (CMSG_DATA (cmsg), tvts, sizeof tvts);
+}
+libc_hidden_def (__convert_scm_timestamps)
+#endif
diff --git a/sysdeps/unix/sysv/linux/getsockopt.c b/sysdeps/unix/sysv/linux/getsockopt.c
index c8e502d976..14b782d0da 100644
--- a/sysdeps/unix/sysv/linux/getsockopt.c
+++ b/sysdeps/unix/sysv/linux/getsockopt.c
@@ -67,6 +67,18 @@ getsockopt32 (int fd, int level, int optname, void *optval,
*tv64 = valid_timeval32_to_timeval64 (tv32);
*len = sizeof (*tv64);
}
+ break;
+
+ case COMPAT_SO_TIMESTAMP_NEW:
+ case COMPAT_SO_TIMESTAMPNS_NEW:
+ {
+ if (optname == COMPAT_SO_TIMESTAMP_NEW)
+ optname = COMPAT_SO_TIMESTAMP_OLD;
+ if (optname == COMPAT_SO_TIMESTAMPNS_NEW)
+ optname = COMPAT_SO_TIMESTAMPNS_OLD;
+ r = getsockopt_syscall (fd, level, optname, optval, len);
+ }
+ break;
}
return r;
diff --git a/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h b/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h
index ea721e0fc2..f3b98012d5 100644
--- a/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h
+++ b/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h
@@ -27,4 +27,9 @@
#define COMPAT_SO_RCVTIMEO_NEW 16448
#define COMPAT_SO_SNDTIMEO_NEW 16449
+#define COMPAT_SO_TIMESTAMP_OLD 0x4012
+#define COMPAT_SO_TIMESTAMPNS_OLD 0x4013
+#define COMPAT_SO_TIMESTAMP_NEW 0x4038
+#define COMPAT_SO_TIMESTAMPNS_NEW 0x4039
+
#endif
diff --git a/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h b/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h
index ab8bd62853..31fa69fa9f 100644
--- a/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h
+++ b/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h
@@ -27,4 +27,9 @@
#define COMPAT_SO_RCVTIMEO_NEW 66
#define COMPAT_SO_SNDTIMEO_NEW 67
+#define COMPAT_SO_TIMESTAMP_OLD 29
+#define COMPAT_SO_TIMESTAMPNS_OLD 35
+#define COMPAT_SO_TIMESTAMP_NEW 63
+#define COMPAT_SO_TIMESTAMPNS_NEW 64
+
#endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h b/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h
index 1e48dcca8d..889251895b 100644
--- a/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h
+++ b/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h
@@ -27,4 +27,9 @@
#define COMPAT_SO_RCVTIMEO_NEW 66
#define COMPAT_SO_SNDTIMEO_NEW 67
+#define COMPAT_SO_TIMESTAMP_OLD 29
+#define COMPAT_SO_TIMESTAMPNS_OLD 35
+#define COMPAT_SO_TIMESTAMP_NEW 63
+#define COMPAT_SO_TIMESTAMPNS_NEW 64
+
#endif
diff --git a/sysdeps/unix/sysv/linux/recvmsg.c b/sysdeps/unix/sysv/linux/recvmsg.c
index b209b4ad99..a2a600228b 100644
--- a/sysdeps/unix/sysv/linux/recvmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmsg.c
@@ -19,16 +19,27 @@
#include <sys/socket.h>
#include <sysdep-cancel.h>
#include <socketcall.h>
-#include <shlib-compat.h>
ssize_t
__libc_recvmsg (int fd, struct msghdr *msg, int flags)
{
-# ifdef __ASSUME_RECVMSG_SYSCALL
- return SYSCALL_CANCEL (recvmsg, fd, msg, flags);
-# else
- return SOCKETCALL_CANCEL (recvmsg, fd, msg, flags);
-# endif
+ ssize_t r;
+#ifndef __ASSUME_TIME64_SYSCALLS
+ socklen_t orig_controllen = msg->msg_controllen;
+#endif
+
+#ifdef __ASSUME_RECVMSG_SYSCALL
+ r = SYSCALL_CANCEL (recvmsg, fd, msg, flags);
+#else
+ r = SOCKETCALL_CANCEL (recvmsg, fd, msg, flags);
+#endif
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+ if (r >= 0)
+ __convert_scm_timestamps (msg, orig_controllen);
+#endif
+
+ return r;
}
weak_alias (__libc_recvmsg, recvmsg)
weak_alias (__libc_recvmsg, __recvmsg)
diff --git a/sysdeps/unix/sysv/linux/setsockopt.c b/sysdeps/unix/sysv/linux/setsockopt.c
index 6505202265..a4780a9d33 100644
--- a/sysdeps/unix/sysv/linux/setsockopt.c
+++ b/sysdeps/unix/sysv/linux/setsockopt.c
@@ -69,6 +69,18 @@ setsockopt32 (int fd, int level, int optname, const void *optval,
r = setsockopt_syscall (fd, level, optname, &tv32, sizeof (tv32));
}
+ break;
+
+ case COMPAT_SO_TIMESTAMP_NEW:
+ case COMPAT_SO_TIMESTAMPNS_NEW:
+ {
+ if (optname == COMPAT_SO_TIMESTAMP_NEW)
+ optname = COMPAT_SO_TIMESTAMP_OLD;
+ if (optname == COMPAT_SO_TIMESTAMPNS_NEW)
+ optname = COMPAT_SO_TIMESTAMPNS_OLD;
+ r = setsockopt_syscall (fd, level, optname, NULL, 0);
+ }
+ break;
}
return r;
diff --git a/sysdeps/unix/sysv/linux/socket-constants-time64.h b/sysdeps/unix/sysv/linux/socket-constants-time64.h
index e5a3777f28..7f7ca05504 100644
--- a/sysdeps/unix/sysv/linux/socket-constants-time64.h
+++ b/sysdeps/unix/sysv/linux/socket-constants-time64.h
@@ -27,4 +27,9 @@
#define COMPAT_SO_RCVTIMEO_NEW 66
#define COMPAT_SO_SNDTIMEO_NEW 67
+#define COMPAT_SO_TIMESTAMP_OLD 29
+#define COMPAT_SO_TIMESTAMPNS_OLD 35
+#define COMPAT_SO_TIMESTAMP_NEW 63
+#define COMPAT_SO_TIMESTAMPNS_NEW 64
+
#endif
diff --git a/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h b/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h
index b137abdeea..56358923e1 100644
--- a/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h
+++ b/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h
@@ -27,4 +27,9 @@
#define COMPAT_SO_RCVTIMEO_NEW 68
#define COMPAT_SO_SNDTIMEO_NEW 69
+#define COMPAT_SO_TIMESTAMP_OLD 0x001d
+#define COMPAT_SO_TIMESTAMPNS_OLD 0x0021
+#define COMPAT_SO_TIMESTAMP_NEW 0x0046
+#define COMPAT_SO_TIMESTAMPNS_NEW 0x0042
+
#endif
--
2.30.2
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