diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 72f3080afa1e73ee3403144332d82674a1a88dc1..42aa19abab86c201281480a9795a1c76f40d97cd 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -220,6 +220,16 @@ enum bpf_func_id { * Return: 0 on success */ BPF_FUNC_tail_call, + + /** + * bpf_clone_redirect(skb, ifindex, flags) - redirect to another netdev + * @skb: pointer to skb + * @ifindex: ifindex of the net device + * @flags: bit 0 - if set, redirect to ingress instead of egress + * other bits - reserved + * Return: 0 on success + */ + BPF_FUNC_clone_redirect, __BPF_FUNC_MAX_ID, }; diff --git a/net/core/filter.c b/net/core/filter.c index b78a010a957f44ce209648fb986c3b4fd4a1575b..64c121c0965520529c0813ed6d81356b8469afa2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -46,6 +46,7 @@ #include #include #include +#include /** * sk_filter - run a packet through a socket filter @@ -1407,6 +1408,43 @@ const struct bpf_func_proto bpf_l4_csum_replace_proto = { .arg5_type = ARG_ANYTHING, }; +#define BPF_IS_REDIRECT_INGRESS(flags) ((flags) & 1) + +static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) +{ + struct sk_buff *skb = (struct sk_buff *) (long) r1, *skb2; + struct net_device *dev; + + dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex); + if (unlikely(!dev)) + return -EINVAL; + + if (unlikely(!(dev->flags & IFF_UP))) + return -EINVAL; + + skb2 = skb_clone(skb, GFP_ATOMIC); + if (unlikely(!skb2)) + return -ENOMEM; + + if (G_TC_AT(skb2->tc_verd) & AT_INGRESS) + skb_push(skb2, skb2->mac_len); + + if (BPF_IS_REDIRECT_INGRESS(flags)) + return dev_forward_skb(dev, skb2); + + skb2->dev = dev; + return dev_queue_xmit(skb2); +} + +const struct bpf_func_proto bpf_clone_redirect_proto = { + .func = bpf_clone_redirect, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * sk_filter_func_proto(enum bpf_func_id func_id) { @@ -1440,6 +1478,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) return &bpf_l3_csum_replace_proto; case BPF_FUNC_l4_csum_replace: return &bpf_l4_csum_replace_proto; + case BPF_FUNC_clone_redirect: + return &bpf_clone_redirect_proto; default: return sk_filter_func_proto(func_id); }