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linux-next/arch/sparc/include/uapi/asm/socket.h
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

76 lines
1.8 KiB
C

#ifndef _ASM_SOCKET_H
#define _ASM_SOCKET_H
#include <asm/sockios.h>
/* For setsockopt(2) */
#define SOL_SOCKET 0xffff
#define SO_DEBUG 0x0001
#define SO_PASSCRED 0x0002
#define SO_REUSEADDR 0x0004
#define SO_KEEPALIVE 0x0008
#define SO_DONTROUTE 0x0010
#define SO_BROADCAST 0x0020
#define SO_PEERCRED 0x0040
#define SO_LINGER 0x0080
#define SO_OOBINLINE 0x0100
/* To add :#define SO_REUSEPORT 0x0200 */
#define SO_BSDCOMPAT 0x0400
#define SO_RCVLOWAT 0x0800
#define SO_SNDLOWAT 0x1000
#define SO_RCVTIMEO 0x2000
#define SO_SNDTIMEO 0x4000
#define SO_ACCEPTCONN 0x8000
#define SO_SNDBUF 0x1001
#define SO_RCVBUF 0x1002
#define SO_SNDBUFFORCE 0x100a
#define SO_RCVBUFFORCE 0x100b
#define SO_ERROR 0x1007
#define SO_TYPE 0x1008
#define SO_PROTOCOL 0x1028
#define SO_DOMAIN 0x1029
/* Linux specific, keep the same. */
#define SO_NO_CHECK 0x000b
#define SO_PRIORITY 0x000c
#define SO_BINDTODEVICE 0x000d
#define SO_ATTACH_FILTER 0x001a
#define SO_DETACH_FILTER 0x001b
#define SO_GET_FILTER SO_ATTACH_FILTER
#define SO_PEERNAME 0x001c
#define SO_TIMESTAMP 0x001d
#define SCM_TIMESTAMP SO_TIMESTAMP
#define SO_PEERSEC 0x001e
#define SO_PASSSEC 0x001f
#define SO_TIMESTAMPNS 0x0021
#define SCM_TIMESTAMPNS SO_TIMESTAMPNS
#define SO_MARK 0x0022
#define SO_TIMESTAMPING 0x0023
#define SCM_TIMESTAMPING SO_TIMESTAMPING
#define SO_RXQ_OVFL 0x0024
#define SO_WIFI_STATUS 0x0025
#define SCM_WIFI_STATUS SO_WIFI_STATUS
#define SO_PEEK_OFF 0x0026
/* Instruct lower device to use last 4-bytes of skb data as FCS */
#define SO_NOFCS 0x0027
/* Security levels - as per NRL IPv6 - don't actually do anything */
#define SO_SECURITY_AUTHENTICATION 0x5001
#define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002
#define SO_SECURITY_ENCRYPTION_NETWORK 0x5004
#endif /* _ASM_SOCKET_H */