Re: [PATCH net-next v5 1/1] net sched actions: Add support for user cookies
From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2017-01-22 18:13:34
On 01/22/2017 04:51 AM, Jamal Hadi Salim wrote:
quoted hunk ↗ jump to hunk
From: Jamal Hadi Salim <jhs@mojatatu.com> Introduce optional 128-bit action cookie. Like all other cookie schemes in the networking world (eg in protocols like http or existing kernel fib protocol field, etc) the idea is to save user state that when retrieved serves as a correlator. The kernel _should not_ intepret it. The user can store whatever they wish in the 128 bits. Sample exercise(showing variable length use of cookie) .. create an accept action with cookie a1b2c3d4 sudo $TC actions add action ok index 1 cookie a1b2c3d4 .. dump all gact actions.. sudo $TC -s actions ls action gact action order 0: gact action pass random type none pass val 0 index 1 ref 1 bind 0 installed 5 sec used 5 sec Action statistics: Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 cookie a1b2c3d4 .. bind the accept action to a filter.. sudo $TC filter add dev lo parent ffff: protocol ip prio 1 \ u32 match ip dst 127.0.0.1/32 flowid 1:1 action gact index 1 ... send some traffic.. $ ping 127.0.0.1 -c 3 PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.020 ms 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.038 ms--- 127.0.0.1 ping statistics ---3 packets transmitted, 3 received, 0% packet loss, time 2109ms rtt min/avg/max/mdev = 0.020/0.028/0.038/0.008 ms 1 ... show some stats $ sudo $TC -s actions get action gact index 1 action order 1: gact action pass random type none pass val 0 index 1 ref 2 bind 1 installed 204 sec used 5 sec Action statistics: Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 cookie a1b2c3d4 .. try longer cookie... $ sudo $TC actions replace action ok index 1 cookie 1234567890abcdef .. dump.. $ sudo $TC -s actions ls action gact action order 1: gact action pass random type none pass val 0 index 1 ref 2 bind 1 installed 204 sec used 5 sec Action statistics: Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 cookie 1234567890abcdef Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
+ a->act_cookie->data = nla_memdup(tb[TCA_ACT_COOKIE],
+ GFP_KERNEL);
+ if (!a->act_cookie->data) {
+ err = -ENOMEM;
+ tcf_hash_release(a, bind);
+ goto err_mod;
+ }Are not you leaking a->act_cookie here in case nla_memdup() fails here? -- Florian