This patchset adds support for getsockopt (SOCKET_URING_OP_GETSOCKOPT) and setsockopt (SOCKET_URING_OP_SETSOCKOPT) in io_uring commands. SOCKET_URING_OP_SETSOCKOPT implements generic case, covering all levels and optnames. SOCKET_URING_OP_GETSOCKOPT is limited, for now, to SOL_SOCKET level, which seems to be the most common level parameter for get/setsockopt(2). In order to keep the implementation (and tests) simple, some refactors were done prior to the changes, as follows: Patches 1-2: Modify the BPF hooks to support sockptr_t, so, these functions become flexible enough to accept user or kernel pointers for optval/optlen. Patch 3: Extract the core setsockopt() core function from __sys_setsockopt, so, the code code could be reused by other callers, such as io_uring. Patch 4: Pass compat mode to the file/socket callbacks. Patch 5: Move io_uring helpers from io_uring_zerocopy_tx to a generic io_uring headers. This simplify the testcase (last patch) PS1: For getsockopt command, the optlen field is not a userspace pointers, but an absolute value, so this is slightly different from getsockopt(2) behaviour. The new optlen value is returned in cqe->res. PS2: The userspace pointers need to be alive until the operation is completed. These changes were tested with a new test[1] in liburing, as also with bpf/progs/sockopt test case, which is now adapted to run using both system calls and io_uring commands. [1] Link: https://github.com/leitao/liburing/blob/getsock/test/socket-getsetsock-cmd.c RFC -> V1: * Copy user memory at io_uring subsystem, and call proto_ops callbacks using kernel memory * Implement all the cases for SOCKET_URING_OP_SETSOCKOPT V1 -> V2 * Implemented the BPF part * Using user pointers from optval to avoid kmalloc in io_uring part. V2 -> V3: * Break down __sys_setsockopt and reuse the core code, avoiding duplicated code. This removed the requirement to export sock_use_custom_sol_socket() as done in v2. * Added io_uring test to selftests/bpf/sockopt. * Fixed "compat" argument, by passing it to the issue_flags. Breno Leitao (9): bpf: Leverage sockptr_t in BPF getsockopt hook bpf: Leverage sockptr_t in BPF setsockopt hook net/socket: Break down __sys_setsockopt io_uring/cmd: Pass compat mode in issue_flags selftests/net: Extract uring helpers to be reusable io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT io_uring/cmd: BPF hook for getsockopt cmd selftests/bpf/sockopt: Add io_uring support
