From 4a30a71401db8844c548ae16809284f7138df02e Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 8 Sep 2020 09:08:10 -0300 Subject: linux: Add recvvmsg fallback for 64-bit time_t SO_TIMESTAMP{NS} 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). Reviewed-by: Lukasz Majewski Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- sysdeps/unix/sysv/linux/recvmmsg.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'sysdeps/unix/sysv/linux/recvmmsg.c') 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; } -- cgit 1.4.1