diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index c15d39456e146196b24bafed159099baa57e03e9..ccd6d8bffa4d8d0744c70c3591f948d6520b634a 100644 --- a/include/net/cls_cgroup.h +++ b/include/net/cls_cgroup.h @@ -49,9 +49,38 @@ static inline void sock_update_classid(struct sock *sk) if (classid != sk->sk_classid) sk->sk_classid = classid; } + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + u32 classid = task_cls_state(current)->classid; + + /* Due to the nature of the classifier it is required to ignore all + * packets originating from softirq context as accessing `current' + * would lead to false results. + * + * This test assumes that all callers of dev_queue_xmit() explicitly + * disable bh. Knowing this, it is possible to detect softirq based + * calls by looking at the number of nested bh disable calls because + * softirqs always disables bh. + */ + if (in_serving_softirq()) { + /* If there is an sk_classid we'll use that. */ + if (!skb->sk) + return 0; + + classid = skb->sk->sk_classid; + } + + return classid; +} #else /* !CONFIG_CGROUP_NET_CLASSID */ static inline void sock_update_classid(struct sock *sk) { } + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + return 0; +} #endif /* CONFIG_CGROUP_NET_CLASSID */ #endif /* _NET_CLS_CGROUP_H */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 29ef6f99e43d1d46586fb308c15b0c65bfc33e17..2de87e58b12b06672a99d822ed251833c1151754 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -249,6 +249,13 @@ enum bpf_func_id { * Return: 0 on success */ BPF_FUNC_get_current_comm, + + /** + * bpf_get_cgroup_classid(skb) - retrieve a proc's classid + * @skb: pointer to skb + * Return: classid if != 0 + */ + BPF_FUNC_get_cgroup_classid, __BPF_FUNC_MAX_ID, }; diff --git a/net/core/filter.c b/net/core/filter.c index be3098fb65e45624e2e5a94b0f653d66e68293d9..247450a5e3879ff0d2c5740f14d1e9c2e66478a1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -47,6 +47,7 @@ #include #include #include +#include /** * sk_filter - run a packet through a socket filter @@ -1424,6 +1425,18 @@ const struct bpf_func_proto bpf_clone_redirect_proto = { .arg3_type = ARG_ANYTHING, }; +static u64 bpf_get_cgroup_classid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +{ + return task_get_classid((struct sk_buff *) (unsigned long) r1); +} + +static const struct bpf_func_proto bpf_get_cgroup_classid_proto = { + .func = bpf_get_cgroup_classid, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + static const struct bpf_func_proto * sk_filter_func_proto(enum bpf_func_id func_id) { @@ -1461,6 +1474,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) return &bpf_l4_csum_replace_proto; case BPF_FUNC_clone_redirect: return &bpf_clone_redirect_proto; + case BPF_FUNC_get_cgroup_classid: + return &bpf_get_cgroup_classid_proto; default: return sk_filter_func_proto(func_id); } diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index ea611b21641241737223f34334c0189df00d11e7..4c85bd3a750cbb02c743779f28cbde6ceacb5ecf 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -30,35 +30,16 @@ static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res) { struct cls_cgroup_head *head = rcu_dereference_bh(tp->root); - u32 classid; - - classid = task_cls_state(current)->classid; - - /* - * Due to the nature of the classifier it is required to ignore all - * packets originating from softirq context as accessing `current' - * would lead to false results. - * - * This test assumes that all callers of dev_queue_xmit() explicitely - * disable bh. Knowing this, it is possible to detect softirq based - * calls by looking at the number of nested bh disable calls because - * softirqs always disables bh. - */ - if (in_serving_softirq()) { - /* If there is an sk_classid we'll use that. */ - if (!skb->sk) - return -1; - classid = skb->sk->sk_classid; - } + u32 classid = task_get_classid(skb); if (!classid) return -1; - if (!tcf_em_tree_match(skb, &head->ematches, NULL)) return -1; res->classid = classid; res->class = 0; + return tcf_exts_exec(skb, &head->exts, res); }