commit 489d0b8b32548bc569cd3067aebf98b030720753
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Thu Jan 27 16:45:18 2022 -0300
Linux: Only generate 64 bit timestamps for 64 bit time_t recvmsg/recvmmsg
The timestamps created by __convert_scm_timestamps only make sense for
64 bit time_t programs, 32 bit time_t programs will ignore 64 bit time_t
timestamps since SO_TIMESTAMP will be defined to old values (either by
glibc or kernel headers).
Worse, if the buffer is not suffice MSG_CTRUNC is set to indicate it
(which breaks some programs [1]).
This patch makes only 64 bit time_t recvmsg and recvmmsg to call
__convert_scm_timestamps. Also, the assumption to called it is changed
from __ASSUME_TIME64_SYSCALLS to __TIMESIZE != 64 since the setsockopt
might be called by libraries built without __TIME_BITS=64. The
MSG_CTRUNC is only set for the 64 bit symbols, it should happen only
if 64 bit time_t programs run older kernels.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://github.com/systemd/systemd/pull/20567
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 948ce73b31fdb0860bcec4b8e62b14e88234f98a)
diff --git a/include/sys/socket.h b/include/sys/socket.h
index a1d749f9fa7b9257..6e4cf5077fb885a9 100644
--- a/include/sys/socket.h
+++ b/include/sys/socket.h
@@ -98,15 +98,21 @@ extern int __sendmmsg (int __fd, struct mmsghdr *__vmessages,
libc_hidden_proto (__sendmmsg)
#endif
-/* Receive a message as described by MESSAGE from socket FD.
- Returns the number of bytes read or -1 for errors. */
extern ssize_t __libc_recvmsg (int __fd, struct msghdr *__message,
int __flags);
extern ssize_t __recvmsg (int __fd, struct msghdr *__message,
int __flags) attribute_hidden;
#if __TIMESIZE == 64
+# define __libc_recvmsg64 __libc_recvmsg
+# define __recvmsg64 __recvmsg
# define __recvmmsg64 __recvmmsg
#else
+extern ssize_t __libc_recvmsg64 (int __fd, struct msghdr *__message,
+ int __flags);
+extern ssize_t __recvmsg64 (int __fd, struct msghdr *__message,
+ int __flags);
+/* Receive a message as described by MESSAGE from socket FD.
+ Returns the number of bytes read or -1 for errors. */
extern int __recvmmsg64 (int __fd, struct mmsghdr *vmessages,
unsigned int vlen, int flags,
struct __timespec64 *timeout);
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 7c75e22c6d0e9ff5..0657f4003e7116c6 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -273,8 +273,14 @@ sysdep_routines += cmsg_nxthdr
CFLAGS-recvmmsg.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-sendmmsg.c = -fexceptions -fasynchronous-unwind-tables
-tests += tst-socket-timestamp
-tests-time64 += tst-socket-timestamp-time64
+tests += \
+ tst-socket-timestamp \
+ tst-socket-timestamp-compat \
+ # tests
+tests-time64 += \
+ tst-socket-timestamp-time64 \
+ tst-socket-timestamp-compat-time64
+ # tests-time64
tests-special += $(objpfx)tst-socket-consts.out
$(objpfx)tst-socket-consts.out: ../sysdeps/unix/sysv/linux/tst-socket-consts.py
diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c
index 5cd107ffa9be0699..fca9f6582db67fd7 100644
--- a/sysdeps/unix/sysv/linux/recvmmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmmsg.c
@@ -20,9 +20,9 @@
#include <sysdep.h>
#include <socketcall.h>
-int
-__recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
- struct __timespec64 *timeout)
+static int
+recvmmsg_syscall (int fd, struct mmsghdr *vmessages, unsigned int vlen,
+ int flags, struct __timespec64 *timeout)
{
#ifndef __NR_recvmmsg_time64
# define __NR_recvmmsg_time64 __NR_recvmmsg
@@ -45,12 +45,6 @@ __recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
pts32 = &ts32;
}
- socklen_t csize[IOV_MAX];
- if (vlen > IOV_MAX)
- vlen = IOV_MAX;
- for (int i = 0; i < vlen; i++)
- csize[i] = vmessages[i].msg_hdr.msg_controllen;
-
# ifdef __ASSUME_RECVMMSG_SYSCALL
r = SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32);
# else
@@ -60,11 +54,31 @@ __recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
{
if (timeout != NULL)
*timeout = valid_timespec_to_timespec64 (ts32);
+ }
+#endif
+ return r;
+}
+
+int
+__recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
+ struct __timespec64 *timeout)
+{
+#if __TIMESIZE != 64
+ socklen_t csize[IOV_MAX];
+ if (vlen > IOV_MAX)
+ vlen = IOV_MAX;
+ for (int i = 0; i < vlen; i++)
+ csize[i] = vmessages[i].msg_hdr.msg_controllen;
+#endif
+ int r = recvmmsg_syscall (fd, vmessages, vlen, flags, timeout);
+#if __TIMESIZE != 64
+ if (r > 0)
+ {
for (int i=0; i < r; i++)
__convert_scm_timestamps (&vmessages[i].msg_hdr, csize[i]);
}
-#endif /* __ASSUME_TIME64_SYSCALLS */
+#endif
return r;
}
#if __TIMESIZE != 64
@@ -80,7 +94,7 @@ __recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
ts64 = valid_timespec_to_timespec64 (*timeout);
pts64 = &ts64;
}
- int r = __recvmmsg64 (fd, vmessages, vlen, flags, pts64);
+ int r = recvmmsg_syscall (fd, vmessages, vlen, flags, pts64);
if (r >= 0 && timeout != NULL)
/* The remanining timeout will be always less the input TIMEOUT. */
*timeout = valid_timespec64_to_timespec (ts64);
diff --git a/sysdeps/unix/sysv/linux/recvmsg.c b/sysdeps/unix/sysv/linux/recvmsg.c
index 07212f7c8641a921..c4b4704fd65d80c1 100644
--- a/sysdeps/unix/sysv/linux/recvmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmsg.c
@@ -20,29 +20,41 @@
#include <sysdep-cancel.h>
#include <socketcall.h>
+static int
+__recvmsg_syscall (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
-__libc_recvmsg (int fd, struct msghdr *msg, int flags)
+__libc_recvmsg64 (int fd, struct msghdr *msg, int flags)
{
ssize_t r;
-#ifndef __ASSUME_TIME64_SYSCALLS
+#if __TIMESIZE != 64
socklen_t orig_controllen = msg != NULL ? msg->msg_controllen : 0;
#endif
-#ifdef __ASSUME_RECVMSG_SYSCALL
- r = SYSCALL_CANCEL (recvmsg, fd, msg, flags);
-#else
- r = SOCKETCALL_CANCEL (recvmsg, fd, msg, flags);
-#endif
+ r = __recvmsg_syscall (fd, msg, flags);
-#ifndef __ASSUME_TIME64_SYSCALLS
+#if __TIMESIZE != 64
if (r >= 0 && orig_controllen != 0)
__convert_scm_timestamps (msg, orig_controllen);
#endif
return r;
}
-weak_alias (__libc_recvmsg, recvmsg)
-weak_alias (__libc_recvmsg, __recvmsg)
#if __TIMESIZE != 64
-weak_alias (__recvmsg, __recvmsg64)
+weak_alias (__libc_recvmsg64, __recvmsg64)
+
+ssize_t
+__libc_recvmsg (int fd, struct msghdr *msg, int flags)
+{
+ return __recvmsg_syscall (fd, msg, flags);
+}
#endif
+weak_alias (__libc_recvmsg, recvmsg)
+weak_alias (__libc_recvmsg, __recvmsg)
diff --git a/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat-time64.c b/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat-time64.c
new file mode 100644
index 0000000000000000..96a0bef0bf4a908b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat-time64.c
@@ -0,0 +1 @@
+#include "tst-socket-timestamp-compat.c"
diff --git a/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat.c b/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat.c
new file mode 100644
index 0000000000000000..de261dae5a6385cf
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-socket-timestamp-compat.c
@@ -0,0 +1,265 @@
+/* Check recvmsg/recvmmsg 64-bit timestamp support.
+ Copyright (C) 2022 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 <arpa/inet.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/xsocket.h>
+#include <support/xunistd.h>
+#include <stdbool.h>
+
+/* AF_INET socket and address used to receive data. */
+static int srv;
+static struct sockaddr_in srv_addr;
+
+static int
+do_sendto (const struct sockaddr_in *addr, int payload)
+{
+ int s = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+ xconnect (s, (const struct sockaddr *) addr, sizeof (*addr));
+
+ xsendto (s, &payload, sizeof (payload), 0, (const struct sockaddr *) addr,
+ sizeof (*addr));
+
+ xclose (s);
+
+ return 0;
+}
+
+static void
+do_recvmsg_ancillary (bool use_multi_call, struct mmsghdr *mmhdr,
+ void *msgbuf, size_t msgbuflen, int exp_payload)
+{
+ int payload;
+ struct iovec iov =
+ {
+ .iov_base = &payload,
+ .iov_len = sizeof (payload)
+ };
+ mmhdr->msg_hdr.msg_name = NULL;
+ mmhdr->msg_hdr.msg_iov = &iov;
+ mmhdr->msg_hdr.msg_iovlen = 1;
+ mmhdr->msg_hdr.msg_control = msgbuf;
+ mmhdr->msg_hdr.msg_controllen = msgbuflen;
+
+ int r;
+ if (use_multi_call)
+ {
+ r = recvmmsg (srv, mmhdr, 1, 0, NULL);
+ if (r >= 0)
+ r = mmhdr->msg_len;
+ }
+ else
+ r = recvmsg (srv, &mmhdr->msg_hdr, 0);
+ TEST_COMPARE (r, sizeof (int));
+ TEST_COMPARE (payload, exp_payload);
+}
+
+/* Check if recvmsg create the additional 64 bit timestamp if only 32 bit
+ is enabled for 64 bit recvmsg symbol. */
+static void
+do_test_large_buffer (bool mc)
+{
+ struct mmsghdr mmhdr = { 0 };
+ /* It should be large enought for either timeval/timespec and the
+ 64 time type as well. */
+
+ union
+ {
+ struct cmsghdr cmsghdr;
+ char msgbuf[512];
+ } control;
+
+ /* Enable 32 bit timeval precision and check if no 64 bit timeval stamp
+ is created. */
+ {
+ int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMP_OLD, &(int){1},
+ sizeof (int));
+ TEST_VERIFY_EXIT (r != -1);
+
+ do_sendto (&srv_addr, 42);
+ do_recvmsg_ancillary (mc, &mmhdr, &control, sizeof control, 42);
+
+ bool found_timestamp = false;
+ for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr);
+ cmsg != NULL;
+ cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg))
+ {
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ if (sizeof (time_t) > 4 && cmsg->cmsg_type == SO_TIMESTAMP_NEW)
+ found_timestamp = true;
+ else
+ TEST_VERIFY (cmsg->cmsg_type != SO_TIMESTAMP_NEW);
+ }
+
+ TEST_COMPARE (found_timestamp, sizeof (time_t) > 4);
+ }
+
+ /* Same as before, but for timespec. */
+ {
+ int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMPNS_OLD, &(int){1},
+ sizeof (int));
+ TEST_VERIFY_EXIT (r != -1);
+
+ do_sendto (&srv_addr, 42);
+ do_recvmsg_ancillary (mc, &mmhdr, &control, sizeof control, 42);
+
+ bool found_timestamp = false;
+ for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr);
+ cmsg != NULL;
+ cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg))
+ {
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ if (sizeof (time_t) > 4 && cmsg->cmsg_type == SO_TIMESTAMPNS_NEW)
+ found_timestamp = true;
+ else
+ TEST_VERIFY (cmsg->cmsg_type != SO_TIMESTAMPNS_NEW);
+ }
+
+ TEST_COMPARE (found_timestamp, sizeof (time_t) > 4);
+ }
+}
+
+/* Check if recvmsg does not create the additional 64 bit timestamp if
+ only 32 bit timestamp is enabled if the ancillary buffer is not large
+ enought. Also checks if MSG_CTRUNC is set iff for 64 bit recvmsg
+ symbol. */
+static void
+do_test_small_buffer (bool mc)
+{
+ struct mmsghdr mmhdr = { 0 };
+
+ /* Enable 32 bit timeval precision and check if no 64 bit timeval stamp
+ is created. */
+ {
+ int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMP_OLD, &(int){1},
+ sizeof (int));
+ TEST_VERIFY_EXIT (r != -1);
+
+ union
+ {
+ struct cmsghdr cmsghdr;
+ char msgbuf[CMSG_SPACE (sizeof (struct timeval))];
+ } control;
+
+ do_sendto (&srv_addr, 42);
+ do_recvmsg_ancillary (mc, &mmhdr, &control, sizeof control, 42);
+
+ bool found_timestamp = false;
+ for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr);
+ cmsg != NULL;
+ cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg))
+ {
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ if (sizeof (time_t) > 4 && cmsg->cmsg_type == SO_TIMESTAMP_NEW)
+ found_timestamp = true;
+ else
+ TEST_VERIFY (cmsg->cmsg_type != SO_TIMESTAMP_NEW);
+ }
+
+ if (sizeof (time_t) > 4)
+ {
+ TEST_VERIFY ((mmhdr.msg_hdr.msg_flags & MSG_CTRUNC));
+ TEST_COMPARE (found_timestamp, 0);
+ }
+ else
+ {
+ TEST_VERIFY (!(mmhdr.msg_hdr.msg_flags & MSG_CTRUNC));
+ TEST_COMPARE (found_timestamp, 0);
+ }
+ }
+
+ /* Same as before, but for timespec. */
+ {
+ int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMPNS_OLD, &(int){1},
+ sizeof (int));
+ TEST_VERIFY_EXIT (r != -1);
+
+ union
+ {
+ struct cmsghdr cmsghdr;
+ char msgbuf[CMSG_SPACE (sizeof (struct timespec))];
+ } control;
+
+ do_sendto (&srv_addr, 42);
+ do_recvmsg_ancillary (mc, &mmhdr, &control, sizeof control, 42);
+
+ bool found_timestamp = false;
+ for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr);
+ cmsg != NULL;
+ cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg))
+ {
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ if (sizeof (time_t) > 4 && cmsg->cmsg_type == SO_TIMESTAMPNS_NEW)
+ found_timestamp = true;
+ else
+ TEST_VERIFY (cmsg->cmsg_type != SO_TIMESTAMPNS_NEW);
+ }
+
+ if (sizeof (time_t) > 4)
+ {
+ TEST_VERIFY ((mmhdr.msg_hdr.msg_flags & MSG_CTRUNC));
+ TEST_COMPARE (found_timestamp, 0);
+ }
+ else
+ {
+ TEST_VERIFY ((mmhdr.msg_hdr.msg_flags & MSG_CTRUNC) == 0);
+ TEST_COMPARE (found_timestamp, 0);
+ }
+ }
+}
+
+static int
+do_test (void)
+{
+ /* This test only make sense for ABIs that support 32 bit time_t socket
+ timestampss. */
+ if (sizeof (time_t) > 4 && __WORDSIZE == 64)
+ return 0;
+
+ srv = xsocket (AF_INET, SOCK_DGRAM, 0);
+ srv_addr = (struct sockaddr_in) {
+ .sin_family = AF_INET,
+ .sin_addr = {.s_addr = htonl (INADDR_LOOPBACK) },
+ };
+ xbind (srv, (struct sockaddr *) &srv_addr, sizeof (srv_addr));
+ {
+ socklen_t sa_len = sizeof (srv_addr);
+ xgetsockname (srv, (struct sockaddr *) &srv_addr, &sa_len);
+ TEST_VERIFY (sa_len == sizeof (srv_addr));
+ }
+
+ /* Check recvmsg; */
+ do_test_large_buffer (false);
+ do_test_small_buffer (false);
+ /* Check recvmmsg. */
+ do_test_large_buffer (true);
+ do_test_small_buffer (true);
+
+ return 0;
+}
+
+#include <support/test-driver.c>