From: Arnd Bergmann <arnd@arndb.de>
To: Faisal Latif <faisal.latif@intel.com>,
Shiraz Saleem <shiraz.saleem@intel.com>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
"David S. Miller" <davem@davemloft.net>,
Arnd Bergmann <arnd@arndb.de>
Cc: y2038@lists.linaro.org, netdev@vger.kernel.org,
Henry Orosco <henry.orosco@intel.com>,
Tatyana Nikolova <tatyana.e.nikolova@intel.com>,
Mustafa Ismail <mustafa.ismail@intel.com>,
Jia-Ju Bai <baijiaju1990@gmail.com>,
Yuval Shaia <yuval.shaia@oracle.com>,
Bart Van Assche <bart.vanassche@wdc.com>,
Kees Cook <keescook@chromium.org>,
"Reshetova, Elena" <elena.reshetova@intel.com>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] infiniband: i40iw, nes: don't use wall time for TCP sequence numbers
Date: Mon, 18 Jun 2018 16:44:17 +0200 [thread overview]
Message-ID: <20180618144443.137068-1-arnd@arndb.de> (raw)
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.
I'm doing the same change in both versions of the nes driver, with
i40iw being a later copy of the same code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
The above change is just a guess at what it should look like,
please review carefully and Ack/Nak as appropriate.
---
drivers/infiniband/hw/i40iw/i40iw_cm.c | 8 +++++---
drivers/infiniband/hw/nes/nes_cm.c | 8 +++++---
net/core/secure_seq.c | 1 +
3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c b/drivers/infiniband/hw/i40iw/i40iw_cm.c
index 7b2655128b9f..da221d07f2dd 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
@@ -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;
@@ -2214,8 +2214,10 @@ 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.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 = (cm_node->ipv4) ? (iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV4) :
(iwdev->vsi.mtu - I40IW_MTU_TO_MSS_IPV6);
diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index 6cdfbf8c5674..2b67ace5b614 100644
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -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;
diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 7232274de334..af6ad467ed61 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -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)
{
--
2.9.0
next reply other threads:[~2018-06-18 14:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 14:44 Arnd Bergmann [this message]
2018-06-23 0:01 ` [PATCH] infiniband: i40iw, nes: don't use wall time for TCP sequence numbers Shiraz Saleem
2018-06-27 13:24 ` Arnd Bergmann
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