Commit Graph

2 Commits

Author SHA1 Message Date
Davide Caratti a01c245438 net/sched: fix a couple of splats in the error path of tfc_gate_init()
trying to configure TC 'act_gate' rules with invalid control actions, the
following splat can be observed:

 general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
 CPU: 1 PID: 2143 Comm: tc Not tainted 5.7.0-rc6+ #168
 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
 RIP: 0010:hrtimer_active+0x56/0x290
 [...]
  Call Trace:
  hrtimer_try_to_cancel+0x6d/0x330
  hrtimer_cancel+0x11/0x20
  tcf_gate_cleanup+0x15/0x30 [act_gate]
  tcf_action_cleanup+0x58/0x170
  __tcf_action_put+0xb0/0xe0
  __tcf_idr_release+0x68/0x90
  tcf_gate_init+0x7c7/0x19a0 [act_gate]
  tcf_action_init_1+0x60f/0x960
  tcf_action_init+0x157/0x2a0
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x2a3/0x39d
  rtnetlink_rcv_msg+0x5f3/0x920
  netlink_rcv_skb+0x121/0x350
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x714/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5b4/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x9a/0x370
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

this is caused by hrtimer_cancel(), running before hrtimer_init(). Fix it
ensuring to call hrtimer_cancel() only if clockid is valid, and the timer
has been initialized. After fixing this splat, the same error path causes
another problem:

 general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 CPU: 1 PID: 980 Comm: tc Not tainted 5.7.0-rc6+ #168
 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
 RIP: 0010:release_entry_list+0x4a/0x240 [act_gate]
 [...]
 Call Trace:
  tcf_action_cleanup+0x58/0x170
  __tcf_action_put+0xb0/0xe0
  __tcf_idr_release+0x68/0x90
  tcf_gate_init+0x7ab/0x19a0 [act_gate]
  tcf_action_init_1+0x60f/0x960
  tcf_action_init+0x157/0x2a0
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x2a3/0x39d
  rtnetlink_rcv_msg+0x5f3/0x920
  netlink_rcv_skb+0x121/0x350
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x714/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5b4/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x9a/0x370
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

the problem is similar: tcf_action_cleanup() was trying to release a list
without initializing it first. Ensure that INIT_LIST_HEAD() is called for
every newly created 'act_gate' action, same as what was done to 'act_ife'
with commit 44c23d7159 ("net/sched: act_ife: initalize ife->metalist
earlier").

Fixes: a51c328df3 ("net: qos: introduce a gate control flow action")
CC: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-01 11:36:36 -07:00
Po Liu a51c328df3 net: qos: introduce a gate control flow action
Introduce a ingress frame gate control flow action.
Tc gate action does the work like this:
Assume there is a gate allow specified ingress frames can be passed at
specific time slot, and be dropped at specific time slot. Tc filter
chooses the ingress frames, and tc gate action would specify what slot
does these frames can be passed to device and what time slot would be
dropped.
Tc gate action would provide an entry list to tell how much time gate
keep open and how much time gate keep state close. Gate action also
assign a start time to tell when the entry list start. Then driver would
repeat the gate entry list cyclically.
For the software simulation, gate action requires the user assign a time
clock type.

Below is the setting example in user space. Tc filter a stream source ip
address is 192.168.0.20 and gate action own two time slots. One is last
200ms gate open let frame pass another is last 100ms gate close let
frames dropped. When the ingress frames have reach total frames over
8000000 bytes, the excessive frames will be dropped in that 200000000ns
time slot.

> tc qdisc add dev eth0 ingress

> tc filter add dev eth0 parent ffff: protocol ip \
	   flower src_ip 192.168.0.20 \
	   action gate index 2 clockid CLOCK_TAI \
	   sched-entry open 200000000 -1 8000000 \
	   sched-entry close 100000000 -1 -1

> tc chain del dev eth0 ingress chain 0

"sched-entry" follow the name taprio style. Gate state is
"open"/"close". Follow with period nanosecond. Then next item is internal
priority value means which ingress queue should put. "-1" means
wildcard. The last value optional specifies the maximum number of
MSDU octets that are permitted to pass the gate during the specified
time interval.
Base-time is not set will be 0 as default, as result start time would
be ((N + 1) * cycletime) which is the minimal of future time.

Below example shows filtering a stream with destination mac address is
10:00:80:00:00:00 and ip type is ICMP, follow the action gate. The gate
action would run with one close time slot which means always keep close.
The time cycle is total 200000000ns. The base-time would calculate by:

 1357000000000 + (N + 1) * cycletime

When the total value is the future time, it will be the start time.
The cycletime here would be 200000000ns for this case.

> tc filter add dev eth0 parent ffff:  protocol ip \
	   flower skip_hw ip_proto icmp dst_mac 10:00:80:00:00:00 \
	   action gate index 12 base-time 1357000000000 \
	   sched-entry close 200000000 -1 -1 \
	   clockid CLOCK_TAI

Signed-off-by: Po Liu <Po.Liu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:08:19 -07:00