| Message ID | 1485089498-6673-2-git-send-email-jhs@emojatatu.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
On 01/22/2017 04:51 AM, Jamal Hadi Salim wrote: > 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?
On 17-01-22 01:13 PM, Florian Fainelli wrote: > > > >> + 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? > yes, I am. Thanks for catching this. V6 coming up. cheers, jamal
Sun, Jan 22, 2017 at 07:57:17PM CET, jhs@mojatatu.com wrote: >On 17-01-22 01:13 PM, Florian Fainelli wrote: >> >> > >> >> > + 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? >> > >yes, I am. Thanks for catching this. V6 coming up. Btw, you don't have to send cover letter for a single patch. In fact, you should not.
On 17-01-22 02:32 PM, Jiri Pirko wrote: > Sun, Jan 22, 2017 at 07:57:17PM CET, jhs@mojatatu.com wrote: >> On 17-01-22 01:13 PM, Florian Fainelli wrote: >>> >>> >> >>> >>>> + 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? >>> >> >> yes, I am. Thanks for catching this. V6 coming up. > > Btw, you don't have to send cover letter for a single patch. In fact, you > should not. > You can see i write small novels in my commit logs. Do you suggest i put the git history there as well? cheers, jamal
diff --git a/include/net/act_api.h b/include/net/act_api.h index 1d71644..cfa2ae3 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -41,6 +41,7 @@ struct tc_action { struct rcu_head tcfa_rcu; struct gnet_stats_basic_cpu __percpu *cpu_bstats; struct gnet_stats_queue __percpu *cpu_qstats; + struct tc_cookie *act_cookie; }; #define tcf_head common.tcfa_head #define tcf_index common.tcfa_index diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index f0a0514..b43077e 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -515,4 +515,12 @@ struct tc_cls_bpf_offload { u32 gen_flags; }; + +/* This structure holds cookie structure that is passed from user + * to the kernel for actions and classifiers + */ +struct tc_cookie { + u8 *data; + u32 len; +}; #endif diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index fd373eb..345551e 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -4,6 +4,8 @@ #include <linux/types.h> #include <linux/pkt_sched.h> +#define TC_COOKIE_MAX_SIZE 16 + /* Action attributes */ enum { TCA_ACT_UNSPEC, @@ -12,6 +14,7 @@ enum { TCA_ACT_INDEX, TCA_ACT_STATS, TCA_ACT_PAD, + TCA_ACT_COOKIE, __TCA_ACT_MAX }; diff --git a/net/sched/act_api.c b/net/sched/act_api.c index cd08df9..84052630 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -24,6 +24,7 @@ #include <net/net_namespace.h> #include <net/sock.h> #include <net/sch_generic.h> +#include <net/pkt_cls.h> #include <net/act_api.h> #include <net/netlink.h> @@ -33,6 +34,8 @@ static void free_tcf(struct rcu_head *head) free_percpu(p->cpu_bstats); free_percpu(p->cpu_qstats); + kfree(p->act_cookie->data); + kfree(p->act_cookie); kfree(p); } @@ -475,6 +478,12 @@ int tcf_action_destroy(struct list_head *actions, int bind) goto nla_put_failure; if (tcf_action_copy_stats(skb, a, 0)) goto nla_put_failure; + if (a->act_cookie) { + if (nla_put(skb, TCA_ACT_COOKIE, a->act_cookie->len, + a->act_cookie->data)) + goto nla_put_failure; + } + nest = nla_nest_start(skb, TCA_OPTIONS); if (nest == NULL) goto nla_put_failure; @@ -575,6 +584,32 @@ struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla, if (err < 0) goto err_mod; + if (tb[TCA_ACT_COOKIE]) { + int cklen = nla_len(tb[TCA_ACT_COOKIE]); + + if (cklen > TC_COOKIE_MAX_SIZE) { + err = -EINVAL; + tcf_hash_release(a, bind); + goto err_mod; + } + + a->act_cookie = kzalloc(sizeof(*a->act_cookie), GFP_KERNEL); + if (!a->act_cookie) { + err = -ENOMEM; + tcf_hash_release(a, bind); + goto err_mod; + } + + 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; + } + a->act_cookie->len = cklen; + } + /* module count goes up only when brand new policy is created * if it exists and is only bound to in a_o->init() then * ACT_P_CREATED is not returned (a zero is).