diff options
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 0baa715e4699..ca60d2872da4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -60,6 +60,10 @@ #include <net/xfrm.h> #include <linux/bpf_trace.h> #include <net/xdp_sock.h> +#include <linux/inetdevice.h> +#include <net/ip_fib.h> +#include <net/flow.h> +#include <net/arp.h> /** * sk_filter_trim_cap - run a packet through a socket filter @@ -4032,6 +4036,265 @@ static const struct bpf_func_proto bpf_skb_get_xfrm_state_proto = { }; #endif +#if IS_ENABLED(CONFIG_INET) || IS_ENABLED(CONFIG_IPV6) +static int bpf_fib_set_fwd_params(struct bpf_fib_lookup *params, + const struct neighbour *neigh, + const struct net_device *dev) +{ + memcpy(params->dmac, neigh->ha, ETH_ALEN); + memcpy(params->smac, dev->dev_addr, ETH_ALEN); + params->h_vlan_TCI = 0; + params->h_vlan_proto = 0; + + return dev->ifindex; +} +#endif + +#if IS_ENABLED(CONFIG_INET) +static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, + u32 flags) +{ + struct in_device *in_dev; + struct neighbour *neigh; + struct net_device *dev; + struct fib_result res; + struct fib_nh *nh; + struct flowi4 fl4; + int err; + + dev = dev_get_by_index_rcu(net, params->ifindex); + if (unlikely(!dev)) + return -ENODEV; + + /* verify forwarding is enabled on this interface */ + in_dev = __in_dev_get_rcu(dev); + if (unlikely(!in_dev || !IN_DEV_FORWARD(in_dev))) + return 0; + + if (flags & BPF_FIB_LOOKUP_OUTPUT) { + fl4.flowi4_iif = 1; + fl4.flowi4_oif = params->ifindex; + } else { + fl4.flowi4_iif = params->ifindex; + fl4.flowi4_oif = 0; + } + fl4.flowi4_tos = params->tos & IPTOS_RT_MASK; + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.flowi4_flags = 0; + + fl4.flowi4_proto = params->l4_protocol; + fl4.daddr = params->ipv4_dst; + fl4.saddr = params->ipv4_src; + fl4.fl4_sport = params->sport; + fl4.fl4_dport = params->dport; + + if (flags & BPF_FIB_LOOKUP_DIRECT) { + u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; + struct fib_table *tb; + + tb = fib_get_table(net, tbid); + if (unlikely(!tb)) + return 0; + + err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); + } else { + fl4.flowi4_mark = 0; + fl4.flowi4_secid = 0; + fl4.flowi4_tun_key.tun_id = 0; + fl4.flowi4_uid = sock_net_uid(net, NULL); + + err = fib_lookup(net, &fl4, &res, FIB_LOOKUP_NOREF); + } + + if (err || res.type != RTN_UNICAST) + return 0; + + if (res.fi->fib_nhs > 1) + fib_select_path(net, &res, &fl4, NULL); + + nh = &res.fi->fib_nh[res.nh_sel]; + + /* do not handle lwt encaps right now */ + if (nh->nh_lwtstate) + return 0; + + dev = nh->nh_dev; + if (unlikely(!dev)) + return 0; + + if (nh->nh_gw) + params->ipv4_dst = nh->nh_gw; + + params->rt_metric = res.fi->fib_priority; + + /* xdp and cls_bpf programs are run in RCU-bh so + * rcu_read_lock_bh is not needed here + */ + neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)params->ipv4_dst); + if (neigh) + return bpf_fib_set_fwd_params(params, neigh, dev); + + return 0; +} +#endif + +#if IS_ENABLED(CONFIG_IPV6) +static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, + u32 flags) +{ + struct in6_addr *src = (struct in6_addr *) params->ipv6_src; + struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst; + struct neighbour *neigh; + struct net_device *dev; + struct inet6_dev *idev; + struct fib6_info *f6i; + struct flowi6 fl6; + int strict = 0; + int oif; + + /* link local addresses are never forwarded */ + if (rt6_need_strict(dst) || rt6_need_strict(src)) + return 0; + + dev = dev_get_by_index_rcu(net, params->ifindex); + if (unlikely(!dev)) + return -ENODEV; + + idev = __in6_dev_get_safely(dev); + if (unlikely(!idev || !net->ipv6.devconf_all->forwarding)) + return 0; + + if (flags & BPF_FIB_LOOKUP_OUTPUT) { + fl6.flowi6_iif = 1; + oif = fl6.flowi6_oif = params->ifindex; + } else { + oif = fl6.flowi6_iif = params->ifindex; + fl6.flowi6_oif = 0; + strict = RT6_LOOKUP_F_HAS_SADDR; + } + fl6.flowlabel = params->flowlabel; + fl6.flowi6_scope = 0; + fl6.flowi6_flags = 0; + fl6.mp_hash = 0; + + fl6.flowi6_proto = params->l4_protocol; + fl6.daddr = *dst; + fl6.saddr = *src; + fl6.fl6_sport = params->sport; + fl6.fl6_dport = params->dport; + + if (flags & BPF_FIB_LOOKUP_DIRECT) { + u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; + struct fib6_table *tb; + + tb = ipv6_stub->fib6_get_table(net, tbid); + if (unlikely(!tb)) + return 0; + + f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, strict); + } else { + fl6.flowi6_mark = 0; + fl6.flowi6_secid = 0; + fl6.flowi6_tun_key.tun_id = 0; + fl6.flowi6_uid = sock_net_uid(net, NULL); + + f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict); + } + + if (unlikely(IS_ERR_OR_NULL(f6i) || f6i == net->ipv6.fib6_null_entry)) + return 0; + + if (unlikely(f6i->fib6_flags & RTF_REJECT || + f6i->fib6_type != RTN_UNICAST)) + return 0; + + if (f6i->fib6_nsiblings && fl6.flowi6_oif == 0) + f6i = ipv6_stub->fib6_multipath_select(net, f6i, &fl6, + fl6.flowi6_oif, NULL, + strict); + + if (f6i->fib6_nh.nh_lwtstate) + return 0; + + if (f6i->fib6_flags & RTF_GATEWAY) + *dst = f6i->fib6_nh.nh_gw; + + dev = f6i->fib6_nh.nh_dev; + params->rt_metric = f6i->fib6_metric; + + /* xdp and cls_bpf programs are run in RCU-bh so rcu_read_lock_bh is + * not needed here. Can not use __ipv6_neigh_lookup_noref here + * because we need to get nd_tbl via the stub + */ + neigh = ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128, + ndisc_hashfn, dst, dev); + if (neigh) + return bpf_fib_set_fwd_params(params, neigh, dev); + + return 0; +} +#endif + +BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx, + struct bpf_fib_lookup *, params, int, plen, u32, flags) +{ + if (plen < sizeof(*params)) + return -EINVAL; + + switch (params->family) { +#if IS_ENABLED(CONFIG_INET) + case AF_INET: + return bpf_ipv4_fib_lookup(dev_net(ctx->rxq->dev), params, + flags); +#endif +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + return bpf_ipv6_fib_lookup(dev_net(ctx->rxq->dev), params, + flags); +#endif + } + return 0; +} + +static const struct bpf_func_proto bpf_xdp_fib_lookup_proto = { + .func = bpf_xdp_fib_lookup, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb, + struct bpf_fib_lookup *, params, int, plen, u32, flags) +{ + if (plen < sizeof(*params)) + return -EINVAL; + + switch (params->family) { +#if IS_ENABLED(CONFIG_INET) + case AF_INET: + return bpf_ipv4_fib_lookup(dev_net(skb->dev), params, flags); +#endif +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + return bpf_ipv6_fib_lookup(dev_net(skb->dev), params, flags); +#endif + } + return -ENOTSUPP; +} + +static const struct bpf_func_proto bpf_skb_fib_lookup_proto = { + .func = bpf_skb_fib_lookup, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE, + .arg4_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -4181,6 +4444,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_skb_get_xfrm_state: return &bpf_skb_get_xfrm_state_proto; #endif + case BPF_FUNC_fib_lookup: + return &bpf_skb_fib_lookup_proto; default: return bpf_base_func_proto(func_id); } @@ -4206,6 +4471,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_redirect_map_proto; case BPF_FUNC_xdp_adjust_tail: return &bpf_xdp_adjust_tail_proto; + case BPF_FUNC_fib_lookup: + return &bpf_xdp_fib_lookup_proto; default: return bpf_base_func_proto(func_id); } |