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Commit 07f3355d authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Jason Gunthorpe
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infiniband: i40iw, nes: don't use wall time for TCP sequence numbers 



The nes infiniband driver uses current_kernel_time() to get a nanosecond
granunarity timestamp to initialize its tcp sequence counters. This is
one of only a few remaining users of that deprecated function, so we
should try to get rid of it.

Aside from using a deprecated API, there are several problems I see here:

- Using a CLOCK_REALTIME based time source makes it predictable in
  case the time base is synchronized.
- Using a coarse timestamp means it only gets updated once per jiffie,
  making it even more predictable in order to avoid having to access
  the hardware clock source
- The upper 2 bits are always zero because the nanoseconds are at most
  999999999.

For the Linux TCP implementation, we use secure_tcp_seq(), which appears
to be appropriate here as well, and solves all the above problems.

i40iw uses a variant of the same code, so I do that same thing there
for ipv4. Unlike nes, i40e also supports ipv6, which needs to call
secure_tcpv6_seq instead.

Acked-by: default avatarShiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 59b851db

drivers/infiniband/hw/i40iw/Kconfig

+1 −0
Original line number Diff line number Diff line 
config INFINIBAND_I40IW

	tristate "Intel(R) Ethernet X722 iWARP Driver"

	depends on INET && I40E

	depends on IPV6 || !IPV6

	depends on PCI

	select GENERIC_ALLOCATOR

	---help---

drivers/infiniband/hw/i40iw/i40iw_cm.c

+21 −5
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ 
#include <net/addrconf.h>

#include <net/ip6_route.h>

#include <net/ip_fib.h>

#include <net/secure_seq.h>

#include <net/tcp.h>

#include <asm/checksum.h>
@@ -2164,7 +2165,6 @@ static struct i40iw_cm_node *i40iw_make_cm_node( 
				   struct i40iw_cm_listener *listener)

{

	struct i40iw_cm_node *cm_node;

	struct timespec ts;

	int oldarpindex;

	int arpindex;

	struct net_device *netdev = iwdev->netdev;
@@ -2214,10 +2214,26 @@ static struct i40iw_cm_node *i40iw_make_cm_node( 
	cm_node->tcp_cntxt.rcv_wscale = I40IW_CM_DEFAULT_RCV_WND_SCALE;

	cm_node->tcp_cntxt.rcv_wnd =

			I40IW_CM_DEFAULT_RCV_WND_SCALED >> I40IW_CM_DEFAULT_RCV_WND_SCALE;

	ts = current_kernel_time();

	cm_node->tcp_cntxt.loc_seq_num = ts.tv_nsec;

	cm_node->tcp_cntxt.mss = (cm_node->ipv4) ? (iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV4) :

				 (iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV6);

	if (cm_node->ipv4) {

		cm_node->tcp_cntxt.loc_seq_num = secure_tcp_seq(htonl(cm_node->loc_addr[0]),

							htonl(cm_node->rem_addr[0]),

							htons(cm_node->loc_port),

							htons(cm_node->rem_port));

		cm_node->tcp_cntxt.mss = iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV4;

	} else if (IS_ENABLED(CONFIG_IPV6)) {

		__be32 loc[4] = {

			htonl(cm_node->loc_addr[0]), htonl(cm_node->loc_addr[1]),

			htonl(cm_node->loc_addr[2]), htonl(cm_node->loc_addr[3])

		};

		__be32 rem[4] = {

			htonl(cm_node->rem_addr[0]), htonl(cm_node->rem_addr[1]),

			htonl(cm_node->rem_addr[2]), htonl(cm_node->rem_addr[3])

		};

		cm_node->tcp_cntxt.loc_seq_num = secure_tcpv6_seq(loc, rem,

							htons(cm_node->loc_port),

							htons(cm_node->rem_port));

		cm_node->tcp_cntxt.mss = iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV6;

	}



	cm_node->iwdev = iwdev;

	cm_node->dev = &iwdev->sc_dev;

drivers/infiniband/hw/nes/nes_cm.c

+5 −3
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ 
#include <net/neighbour.h>

#include <net/route.h>

#include <net/ip_fib.h>

#include <net/secure_seq.h>

#include <net/tcp.h>

#include <linux/fcntl.h>
@@ -1445,7 +1446,6 @@ static struct nes_cm_node *make_cm_node(struct nes_cm_core *cm_core, 
					struct nes_cm_listener *listener)

{

	struct nes_cm_node *cm_node;

	struct timespec ts;

	int oldarpindex = 0;

	int arpindex = 0;

	struct nes_device *nesdev;
@@ -1496,8 +1496,10 @@ static struct nes_cm_node *make_cm_node(struct nes_cm_core *cm_core, 
	cm_node->tcp_cntxt.rcv_wscale = NES_CM_DEFAULT_RCV_WND_SCALE;

	cm_node->tcp_cntxt.rcv_wnd = NES_CM_DEFAULT_RCV_WND_SCALED >>

				     NES_CM_DEFAULT_RCV_WND_SCALE;

	ts = current_kernel_time();

	cm_node->tcp_cntxt.loc_seq_num = htonl(ts.tv_nsec);

	cm_node->tcp_cntxt.loc_seq_num = secure_tcp_seq(htonl(cm_node->loc_addr),

							htonl(cm_node->rem_addr),

							htons(cm_node->loc_port),

							htons(cm_node->rem_port));

	cm_node->tcp_cntxt.mss = nesvnic->max_frame_size - sizeof(struct iphdr) -

				 sizeof(struct tcphdr) - ETH_HLEN - VLAN_HLEN;

	cm_node->tcp_cntxt.rcv_nxt = 0;

net/core/secure_seq.c

+1 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ u32 secure_tcp_seq(__be32 saddr, __be32 daddr, 
			    &net_secret);

	return seq_scale(hash);

}

EXPORT_SYMBOL_GPL(secure_tcp_seq);



u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)

{