On 8/8/23 6:40 AM, Breno Leitao wrote:
Add support for BPF hooks for io_uring setsockopts command.
This implementation follows a similar approach to what
__sys_setsockopt() does, but, operates only on kernel memory instead of
user memory (which is also possible, but not preferred since the kernel
memory is already available)
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
io_uring/uring_cmd.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 3693e5779229..b7b27e4dbddd 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -205,23 +205,42 @@ static inline int io_uring_cmd_setsockopt(struct socket *sock,
{
void __user *optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
int optname = READ_ONCE(cmd->sqe->optname);
+ sockptr_t optval_s = USER_SOCKPTR(optval);
int optlen = READ_ONCE(cmd->sqe->optlen);
int level = READ_ONCE(cmd->sqe->level);
+ char *kernel_optval = NULL;
int err;
err = security_socket_setsockopt(sock, level, optname);
if (err)
return err;
+ if (!in_compat_syscall()) {
+ err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level,
+ &optname,
+ USER_SOCKPTR(optval),
+ &optlen,
+ &kernel_optval);
+ if (err < 0)
+ return err;
+ if (err > 0)
+ return 0;
+
+ /* Replace optval by the one returned by BPF */
+ if (kernel_optval)
+ optval_s = KERNEL_SOCKPTR(kernel_optval);
+ }
+
if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
err = sock_setsockopt(sock, level, optname,
- USER_SOCKPTR(optval), optlen);
+ optval_s, optlen);
else if (unlikely(!sock->ops->setsockopt))
err = -EOPNOTSUPP;
else
err = sock->ops->setsockopt(sock, level, optname,
- USER_SOCKPTR(koptval), optlen);
+ optval_s, optlen);
The bpf side changes make sense. Thanks.
With all the bpf pieces in place, __sys_{get,set}sockopt() is looking very
similar to io_uring_cmd_{get,set}sockopt(). There are small differences like one
takes fd and another already has a sock ptr, and io_uring_cmd_getsockopt() is
SOL_SOCKET only. In general, can they be refactored somehow such that future
changes don't have to be made in multiple places?
