Commit 65622ed4 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'rss_key_fill' 



Eric Dumazet says:

====================
net: provide common RSS key infrastructure

RSS (Receive Side Scaling) uses a 40 bytes key to provide hash for incoming
packets to select appropriate incoming queue on NIC.

Hash algo (Toeplitz) is also well known and documented by Microsoft
(search for "Verifying the RSS Hash Calculation")

Problem is that some drivers use a well known key.
It makes very easy for attackers to target one particular RX queue,
knowing that number of RX queues is a power of two, or at least some
small number.

Other drivers use a random value per port, making difficult
tuning on bonding setups.

Lets add a common infrastructure, so that host gets an unique
RSS key, and drivers do not have to worry about this.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents ca245024 6bf79cdd

Documentation/sysctl/net.txt

+22 −0
Original line number Diff line number Diff line
@@ -142,6 +142,28 @@ netdev_max_backlog 
Maximum number  of  packets,  queued  on  the  INPUT  side, when the interface

receives packets faster than kernel can process them.



netdev_rss_key

--------------



RSS (Receive Side Scaling) enabled drivers use a 40 bytes host key that is

randomly generated.

Some user space might need to gather its content even if drivers do not

provide ethtool -x support yet.



myhost:~# cat /proc/sys/net/core/netdev_rss_key

84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8: ... (52 bytes total)



File contains nul bytes if no driver ever called netdev_rss_key_fill() function.

Note:

/proc/sys/net/core/netdev_rss_key contains 52 bytes of key,

but most drivers only use 40 bytes of it.



myhost:~# ethtool -x eth0

RX flow hash indirection table for eth0 with 8 RX ring(s):

    0:    0     1     2     3     4     5     6     7

RSS hash key:

84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8:43:e3:c9:0c:fd:17:55:c2:3a:4d:69:ed:f1:42:89



netdev_tstamp_prequeue

----------------------

drivers/net/ethernet/amd/xgbe/xgbe-main.c

+1 −1
Original line number Diff line number Diff line
@@ -338,7 +338,7 @@ static int xgbe_probe(struct platform_device *pdev) 
	}



	/* Initialize RSS hash key and lookup table */

	get_random_bytes(pdata->rss_key, sizeof(pdata->rss_key));

	netdev_rss_key_fill(pdata->rss_key, sizeof(pdata->rss_key));



	for (i = 0; i < XGBE_RSS_MAX_TABLE_SIZE; i++)

		XGMAC_SET_BITS(pdata->rss_table[i], MAC_RSSDR, DMCH,

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

+1 −1
Original line number Diff line number Diff line
@@ -2099,7 +2099,7 @@ int bnx2x_rss(struct bnx2x *bp, struct bnx2x_rss_config_obj *rss_obj, 


	if (config_hash) {

		/* RSS keys */

		prandom_bytes(params.rss_key, T_ETH_RSS_KEY * 4);

		netdev_rss_key_fill(params.rss_key, T_ETH_RSS_KEY * 4);

		__set_bit(BNX2X_RSS_SET_SRCH, &params.rss_flags);

	}

drivers/net/ethernet/broadcom/tg3.c

+6 −11
Original line number Diff line number Diff line
@@ -10540,19 +10540,14 @@ static int tg3_reset_hw(struct tg3 *tp, bool reset_phy) 
	udelay(100);



	if (tg3_flag(tp, ENABLE_RSS)) {

		u32 rss_key[10];



		tg3_rss_write_indir_tbl(tp);



		/* Setup the "secret" hash key. */

		tw32(MAC_RSS_HASH_KEY_0, 0x5f865437);

		tw32(MAC_RSS_HASH_KEY_1, 0xe4ac62cc);

		tw32(MAC_RSS_HASH_KEY_2, 0x50103a45);

		tw32(MAC_RSS_HASH_KEY_3, 0x36621985);

		tw32(MAC_RSS_HASH_KEY_4, 0xbf14c0e8);

		tw32(MAC_RSS_HASH_KEY_5, 0x1bc27a1e);

		tw32(MAC_RSS_HASH_KEY_6, 0x84f4b556);

		tw32(MAC_RSS_HASH_KEY_7, 0x094ea6fe);

		tw32(MAC_RSS_HASH_KEY_8, 0x7dda01e7);

		tw32(MAC_RSS_HASH_KEY_9, 0xc04d7481);

		netdev_rss_key_fill(rss_key, 10 * sizeof(u32));



		for (i = 0; i < 10 ; i++)

			tw32(MAC_RSS_HASH_KEY_0 + i*4, rss_key[i]);

	}



	tp->rx_mode = RX_MODE_ENABLE;

drivers/net/ethernet/brocade/bna/bnad.c

+1 −1
Original line number Diff line number Diff line
@@ -2054,7 +2054,7 @@ bnad_init_rx_config(struct bnad *bnad, struct bna_rx_config *rx_config) 
				 BFI_ENET_RSS_IPV4_TCP);

		rx_config->rss_config.hash_mask =

				bnad->num_rxp_per_rx - 1;

		get_random_bytes(rx_config->rss_config.toeplitz_hash_key,

		netdev_rss_key_fill(rx_config->rss_config.toeplitz_hash_key,

			sizeof(rx_config->rss_config.toeplitz_hash_key));

	} else {

		rx_config->rss_status = BNA_STATUS_T_DISABLED;

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