[PATCH v2 07/25] linux: Add recvvmsg fallback for 64-bit time_t SO_TIMESTAMP{NS}
Adhemerval Zanella
adhemerval.zanella@linaro.org
Tue May 18 20:55:55 GMT 2021
Handle the SO_TIMESTAMP{NS} similar to recvmsg: 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.
Also for !__ASSUME_TIME64_SYSCALLS it limits the maximum number of
'struct mmsghdr *' to IOV_MAX (and also increases the stack size
requirement to IOV_MAX times sizeof (socklen_t)). The Linux imposes
a similar limit to sendmmsg, so bound the array size on recvmmsg is not
unreasonable. And this will be used only on older when building with
32-bit time support.
Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
---
sysdeps/unix/sysv/linux/recvmmsg.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c
index 672ba20332..5cd107ffa9 100644
--- a/sysdeps/unix/sysv/linux/recvmmsg.c
+++ b/sysdeps/unix/sysv/linux/recvmmsg.c
@@ -44,13 +44,26 @@ __recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
ts32 = valid_timespec64_to_timespec (*timeout);
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
r = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32);
# endif
- if (r >= 0 && timeout != NULL)
- *timeout = valid_timespec_to_timespec64 (ts32);
+ if (r >= 0)
+ {
+ if (timeout != NULL)
+ *timeout = valid_timespec_to_timespec64 (ts32);
+
+ for (int i=0; i < r; i++)
+ __convert_scm_timestamps (&vmessages[i].msg_hdr, csize[i]);
+ }
#endif /* __ASSUME_TIME64_SYSCALLS */
return r;
}
--
2.30.2
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