Bluetooth: Fix hci_sock_recvmsg return value
If recvmsg is called with a destination buffer that is too small to receive the contents of skb in its entirety, the return value from recvmsg was inconsistent with common SOCK_SEQPACKET or SOCK_DGRAM semantics. If destination buffer provided by userspace is too small (e.g. len < copied), then MSG_TRUNC flag is set and copied is returned. Instead, it should return the length of the message, which is consistent with how other datagram based sockets act. Quoting 'man recv': "All three calls return the length of the message on successful comple‐ tion. If a message is too long to fit in the supplied buffer, excess bytes may be discarded depending on the type of socket the message is received from." and "MSG_TRUNC (since Linux 2.2) For raw (AF_PACKET), Internet datagram (since Linux 2.4.27/2.6.8), netlink (since Linux 2.6.22), and UNIX datagram (since Linux 3.4) sockets: return the real length of the packet or datagram, even when it was longer than the passed buffer." Signed-off-by:Denis Kenzior <denkenz@gmail.com> Signed-off-by:
Marcel Holtmann <marcel@holtmann.org>
parent
b5f34f94
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