linux_dsm_epyc7002/arch/mn10300/include/uapi/asm
Pavel Emelyanov a8fc927780 sk-filter: Add ability to get socket filter program (v2)
The SO_ATTACH_FILTER option is set only. I propose to add the get
ability by using SO_ATTACH_FILTER in getsockopt. To be less
irritating to eyes the SO_GET_FILTER alias to it is declared. This
ability is required by checkpoint-restore project to be able to
save full state of a socket.

There are two issues with getting filter back.

First, kernel modifies the sock_filter->code on filter load, thus in
order to return the filter element back to user we have to decode it
into user-visible constants. Fortunately the modification in question
is interconvertible.

Second, the BPF_S_ALU_DIV_K code modifies the command argument k to
speed up the run-time division by doing kernel_k = reciprocal(user_k).
Bad news is that different user_k may result in same kernel_k, so we
can't get the original user_k back. Good news is that we don't have
to do it. What we need to is calculate a user2_k so, that

  reciprocal(user2_k) == reciprocal(user_k) == kernel_k

i.e. if it's re-loaded back the compiled again value will be exactly
the same as it was. That said, the user2_k can be calculated like this

  user2_k = reciprocal(kernel_k)

with an exception, that if kernel_k == 0, then user2_k == 1.

The optlen argument is treated like this -- when zero, kernel returns
the amount of sock_fprog elements in filter, otherwise it should be
large enough for the sock_fprog array.

changes since v1:
* Declared SO_GET_FILTER in all arch headers
* Added decode of vlan-tag codes

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01 11:17:15 -04:00
..
auxvec.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
bitsperlong.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
byteorder.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
errno.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
fcntl.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
ioctl.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
ioctls.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
ipcbuf.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
Kbuild UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
kvm_para.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
mman.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
msgbuf.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
param.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
poll.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
posix_types.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
ptrace.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
resource.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
sembuf.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
setup.h UAPI: Make arch/mn10300/include/uapi/asm/setup.h non-empty 2012-10-17 12:32:35 +01:00
shmbuf.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
sigcontext.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
siginfo.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
signal.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
socket.h sk-filter: Add ability to get socket filter program (v2) 2012-11-01 11:17:15 -04:00
sockios.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
stat.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
statfs.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
swab.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
termbits.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
termios.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
types.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00
unistd.h UAPI: (Scripted) Disintegrate arch/mn10300/include/asm 2012-10-10 12:10:10 +01:00