freebsd-skq/sys/netinet/in_rss.h
Adrian Chadd 40c753e3da Implement rss_gethashconfig() - return the currently supported hash methods
by the stack.

Right now the stack isn't really setup for RSS with 4-tuple UDP hashing
for either IPv4 and IPv6.

The specifics:

* The UDP init path udp_init() and udplite_init() specify the hash as
  2-tuple, so the PCBGROUPS code only tries a 2-tuple check;
* The PCBGROUPS and RSS code doesn't know about the UDP hash types
  just yet, so they're never treated as valid hashes.
* For correctness, 4-tuple can't be enabled in the general case because
  UDP datagrams can be more fragmented than IP datagrams may be.

Strictly speaking, TCP datagrams may also be fragmented and this could
cause issues with PCBGROUPS/RSS until the IP defragment path grows some
code to re-calculate the RSS hash.

I'll follow this commit up with awareness of the UDP 4-tuple for those
who wish to configure it, but for now it'll stay disabled.

No drivers (yet) know to use this function when RSS is enabled.
2014-07-20 07:36:59 +00:00

120 lines
4.5 KiB
C

/*-
* Copyright (c) 2010-2011 Juniper Networks, Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson under contract
* to Juniper Networks, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NETINET_IN_RSS_H_
#define _NETINET_IN_RSS_H_
#include <netinet/in.h> /* in_addr_t */
/*
* Supported RSS hash functions.
*/
#define RSS_HASH_NAIVE 0x00000001 /* Poor but fast hash. */
#define RSS_HASH_TOEPLITZ 0x00000002 /* Required by RSS. */
#define RSS_HASH_CRC32 0x00000004 /* Future; some NICs do it. */
#define RSS_HASH_MASK (RSS_HASH_NAIVE | RSS_HASH_TOEPLITZ)
/*
* Instances of struct inpcbinfo declare an RSS hash type indicating what
* header fields are covered.
*/
#define RSS_HASHFIELDS_NONE 0
#define RSS_HASHFIELDS_4TUPLE 1
#define RSS_HASHFIELDS_2TUPLE 2
/*
* Define RSS representations of the M_HASHTYPE_* values, representing
* which particular bits are supported. The NICs can then use this to
* calculate which hash types to enable and which not to enable.
*
* The fact that these line up with M_HASHTYPE_* is not to be relied
* upon.
*/
#define RSS_HASHTYPE_RSS_IPV4 (1 << 1) /* IPv4 2-tuple */
#define RSS_HASHTYPE_RSS_TCP_IPV4 (1 << 2) /* TCPv4 4-tuple */
#define RSS_HASHTYPE_RSS_IPV6 (1 << 3) /* IPv6 2-tuple */
#define RSS_HASHTYPE_RSS_TCP_IPV6 (1 << 4) /* TCPv6 4-tuple */
#define RSS_HASHTYPE_RSS_IPV6_EX (1 << 5) /* IPv6 2-tuple + ext hdrs */
#define RSS_HASHTYPE_RSS_TCP_IPV6_EX (1 << 6) /* TCPv6 4-tiple + ext hdrs */
#define RSS_HASHTYPE_RSS_UDP_IPV4 (1 << 7) /* IPv4 UDP 4-tuple */
#define RSS_HASHTYPE_RSS_UDP_IPV4_EX (1 << 8) /* IPv4 UDP 4-tuple + ext hdrs */
#define RSS_HASHTYPE_RSS_UDP_IPV6 (1 << 9) /* IPv6 UDP 4-tuple */
#define RSS_HASHTYPE_RSS_UDP_IPV6_EX (1 << 10) /* IPv6 UDP 4-tuple + ext hdrs */
/*
* Compile-time limits on the size of the indirection table.
*/
#define RSS_MAXBITS 7
#define RSS_TABLE_MAXLEN (1 << RSS_MAXBITS)
/*
* Maximum key size used throughout. It's OK for hardware to use only the
* first 16 bytes, which is all that's required for IPv4.
*/
#define RSS_KEYSIZE 40
/*
* Device driver interfaces to query RSS properties that must be programmed
* into hardware.
*/
u_int rss_getbits(void);
u_int rss_getbucket(u_int hash);
u_int rss_get_indirection_to_bucket(u_int index);
u_int rss_getcpu(u_int bucket);
void rss_getkey(uint8_t *key);
u_int rss_gethashalgo(void);
u_int rss_getnumbuckets(void);
u_int rss_getnumcpus(void);
u_int rss_gethashconfig(void);
/*
* Network stack interface to generate a hash for a protocol tuple.
*/
uint32_t rss_hash_ip4_4tuple(struct in_addr src, u_short srcport,
struct in_addr dst, u_short dstport);
uint32_t rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst);
uint32_t rss_hash_ip6_4tuple(struct in6_addr src, u_short srcport,
struct in6_addr dst, u_short dstport);
uint32_t rss_hash_ip6_2tuple(struct in6_addr src,
struct in6_addr dst);
/*
* Network stack interface to query desired CPU affinity of a packet.
*/
struct mbuf *rss_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid);
u_int rss_hash2cpuid(uint32_t hash_val, uint32_t hash_type);
int rss_hash2bucket(uint32_t hash_val, uint32_t hash_type,
uint32_t *bucket_id);
int rss_m2bucket(struct mbuf *m, uint32_t *bucket_id);
#endif /* !_NETINET_IN_RSS_H_ */