1. 19 1月, 2013 12 次提交
  2. 18 1月, 2013 27 次提交
  3. 17 1月, 2013 1 次提交
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      sk-filter: Add ability to lock a socket filter program · d59577b6
      Vincent Bernat 提交于
      While a privileged program can open a raw socket, attach some
      restrictive filter and drop its privileges (or send the socket to an
      unprivileged program through some Unix socket), the filter can still
      be removed or modified by the unprivileged program. This commit adds a
      socket option to lock the filter (SO_LOCK_FILTER) preventing any
      modification of a socket filter program.
      
      This is similar to OpenBSD BIOCLOCK ioctl on bpf sockets, except even
      root is not allowed change/drop the filter.
      
      The state of the lock can be read with getsockopt(). No error is
      triggered if the state is not changed. -EPERM is returned when a user
      tries to remove the lock or to change/remove the filter while the lock
      is active. The check is done directly in sk_attach_filter() and
      sk_detach_filter() and does not affect only setsockopt() syscall.
      Signed-off-by: NVincent Bernat <bernat@luffy.cx>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d59577b6