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05 April 2024, 19:05:47 UTC
Revision ca10b9e9a8ca7342ee07065289cbe74ac128c169 authored by Eric Dumazet on 08 April 2013, 17:58:11 UTC, committed by David S. Miller on 09 April 2013, 17:23:11 UTC 
selinux: add a skb_owned_by() hook
 
Commit 90ba9b1986b5ac (tcp: tcp_make_synack() can use alloc_skb())
broke certain SELinux/NetLabel configurations by no longer correctly
assigning the sock to the outgoing SYNACK packet.

Cost of atomic operations on the LISTEN socket is quite big,
and we would like it to happen only if really needed.

This patch introduces a new security_ops->skb_owned_by() method,
that is a void operation unless selinux is active.

Reported-by: Miroslav Vadkerti <mvadkert@redhat.com>
Diagnosed-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-security-module@vger.kernel.org
Acked-by: James Morris <james.l.morris@oracle.com>
Tested-by: Paul Moore <pmoore@redhat.com>
Acked-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent c802d75
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Tip revision: ca10b9e9a8ca7342ee07065289cbe74ac128c169 authored by Eric Dumazet on 08 April 2013, 17:58:11 UTC
selinux: add a skb_owned_by() hook
Tip revision: ca10b9e
crc32defs.h 
/*
 * There are multiple 16-bit CRC polynomials in common use, but this is
 * *the* standard CRC-32 polynomial, first popularized by Ethernet.
 * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0
 */
#define CRCPOLY_LE 0xedb88320
#define CRCPOLY_BE 0x04c11db7

/*
 * This is the CRC32c polynomial, as outlined by Castagnoli.
 * x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+
 * x^8+x^6+x^0
 */
#define CRC32C_POLY_LE 0x82F63B78

/* Try to choose an implementation variant via Kconfig */
#ifdef CONFIG_CRC32_SLICEBY8
# define CRC_LE_BITS 64
# define CRC_BE_BITS 64
#endif
#ifdef CONFIG_CRC32_SLICEBY4
# define CRC_LE_BITS 32
# define CRC_BE_BITS 32
#endif
#ifdef CONFIG_CRC32_SARWATE
# define CRC_LE_BITS 8
# define CRC_BE_BITS 8
#endif
#ifdef CONFIG_CRC32_BIT
# define CRC_LE_BITS 1
# define CRC_BE_BITS 1
#endif

/*
 * How many bits at a time to use.  Valid values are 1, 2, 4, 8, 32 and 64.
 * For less performance-sensitive, use 4 or 8 to save table size.
 * For larger systems choose same as CPU architecture as default.
 * This works well on X86_64, SPARC64 systems. This may require some
 * elaboration after experiments with other architectures.
 */
#ifndef CRC_LE_BITS
#  ifdef CONFIG_64BIT
#  define CRC_LE_BITS 64
#  else
#  define CRC_LE_BITS 32
#  endif
#endif
#ifndef CRC_BE_BITS
#  ifdef CONFIG_64BIT
#  define CRC_BE_BITS 64
#  else
#  define CRC_BE_BITS 32
#  endif
#endif

/*
 * Little-endian CRC computation.  Used with serial bit streams sent
 * lsbit-first.  Be sure to use cpu_to_le32() to append the computed CRC.
 */
#if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
	CRC_LE_BITS & CRC_LE_BITS-1
# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}"
#endif

/*
 * Big-endian CRC computation.  Used with serial bit streams sent
 * msbit-first.  Be sure to use cpu_to_be32() to append the computed CRC.
 */
#if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
	CRC_BE_BITS & CRC_BE_BITS-1
# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}"
#endif
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