mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-27 14:14:24 +08:00
a410a0cf98
Define a dscp_t type and its appropriate helpers that ensure ECN bits are not taken into account when handling DSCP. Use this new type to replace the tclass field of struct fib6_rule, so that fib6-rules don't get influenced by ECN bits anymore. Before this patch, fib6-rules didn't make any distinction between the DSCP and ECN bits. Therefore, rules specifying a DSCP (tos or dsfield options in iproute2) stopped working as soon a packets had at least one of its ECN bits set (as a work around one could create four rules for each DSCP value to match, one for each possible ECN value). After this patch fib6-rules only compare the DSCP bits. ECN doesn't influence the result anymore. Also, fib6-rules now must have the ECN bits cleared or they will be rejected. Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* inet_dscp.h: helpers for handling differentiated services codepoints (DSCP)
|
|
*
|
|
* DSCP is defined in RFC 2474:
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +---+---+---+---+---+---+---+---+
|
|
* | DSCP | CU |
|
|
* +---+---+---+---+---+---+---+---+
|
|
*
|
|
* DSCP: differentiated services codepoint
|
|
* CU: currently unused
|
|
*
|
|
* The whole DSCP + CU bits form the DS field.
|
|
* The DS field is also commonly called TOS or Traffic Class (for IPv6).
|
|
*
|
|
* Note: the CU bits are now used for Explicit Congestion Notification
|
|
* (RFC 3168).
|
|
*/
|
|
|
|
#ifndef _INET_DSCP_H
|
|
#define _INET_DSCP_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
/* Special type for storing DSCP values.
|
|
*
|
|
* A dscp_t variable stores a DS field with the CU (ECN) bits cleared.
|
|
* Using dscp_t allows to strictly separate DSCP and ECN bits, thus avoiding
|
|
* bugs where ECN bits are erroneously taken into account during FIB lookups
|
|
* or policy routing.
|
|
*
|
|
* Note: to get the real DSCP value contained in a dscp_t variable one would
|
|
* have to do a bit shift after calling inet_dscp_to_dsfield(). We could have
|
|
* a helper for that, but there's currently no users.
|
|
*/
|
|
typedef u8 __bitwise dscp_t;
|
|
|
|
#define INET_DSCP_MASK 0xfc
|
|
|
|
static inline dscp_t inet_dsfield_to_dscp(__u8 dsfield)
|
|
{
|
|
return (__force dscp_t)(dsfield & INET_DSCP_MASK);
|
|
}
|
|
|
|
static inline __u8 inet_dscp_to_dsfield(dscp_t dscp)
|
|
{
|
|
return (__force __u8)dscp;
|
|
}
|
|
|
|
static inline bool inet_validate_dscp(__u8 val)
|
|
{
|
|
return !(val & ~INET_DSCP_MASK);
|
|
}
|
|
|
|
#endif /* _INET_DSCP_H */
|