diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 25 | ||||
| -rw-r--r-- | net/core/filter.c | 48 |
2 files changed, 72 insertions, 1 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c8383a289f7b..e6679393b687 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -774,6 +774,15 @@ union bpf_attr { * @xdp_md: pointer to xdp_md * @delta: A negative integer to be added to xdp_md.data_end * Return: 0 on success or negative on error + * + * int bpf_skb_get_xfrm_state(skb, index, xfrm_state, size, flags) + * retrieve XFRM state + * @skb: pointer to skb + * @index: index of the xfrm state in the secpath + * @key: pointer to 'struct bpf_xfrm_state' + * @size: size of 'struct bpf_xfrm_state' + * @flags: room for future extensions + * Return: 0 on success or negative error */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -841,7 +850,8 @@ union bpf_attr { FN(msg_cork_bytes), \ FN(msg_pull_data), \ FN(bind), \ - FN(xdp_adjust_tail), + FN(xdp_adjust_tail), \ + FN(skb_get_xfrm_state), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -947,6 +957,19 @@ struct bpf_tunnel_key { __u32 tunnel_label; }; +/* user accessible mirror of in-kernel xfrm_state. + * new fields can only be added to the end of this structure + */ +struct bpf_xfrm_state { + __u32 reqid; + __u32 spi; /* Stored in network byte order */ + __u16 family; + union { + __u32 remote_ipv4; /* Stored in network byte order */ + __u32 remote_ipv6[4]; /* Stored in network byte order */ + }; +}; + /* Generic BPF return codes which all BPF program types may support. * The values are binary compatible with their TC_ACT_* counter-part to * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT diff --git a/net/core/filter.c b/net/core/filter.c index e25bc4a3aa1a..8e45c6c7ab08 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -57,6 +57,7 @@ #include <net/sock_reuseport.h> #include <net/busy_poll.h> #include <net/tcp.h> +#include <net/xfrm.h> #include <linux/bpf_trace.h> /** @@ -3743,6 +3744,49 @@ static const struct bpf_func_proto bpf_bind_proto = { .arg3_type = ARG_CONST_SIZE, }; +#ifdef CONFIG_XFRM +BPF_CALL_5(bpf_skb_get_xfrm_state, struct sk_buff *, skb, u32, index, + struct bpf_xfrm_state *, to, u32, size, u64, flags) +{ + const struct sec_path *sp = skb_sec_path(skb); + const struct xfrm_state *x; + + if (!sp || unlikely(index >= sp->len || flags)) + goto err_clear; + + x = sp->xvec[index]; + + if (unlikely(size != sizeof(struct bpf_xfrm_state))) + goto err_clear; + + to->reqid = x->props.reqid; + to->spi = x->id.spi; + to->family = x->props.family; + if (to->family == AF_INET6) { + memcpy(to->remote_ipv6, x->props.saddr.a6, + sizeof(to->remote_ipv6)); + } else { + to->remote_ipv4 = x->props.saddr.a4; + } + + return 0; +err_clear: + memset(to, 0, size); + return -EINVAL; +} + +static const struct bpf_func_proto bpf_skb_get_xfrm_state_proto = { + .func = bpf_skb_get_xfrm_state, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_UNINIT_MEM, + .arg4_type = ARG_CONST_SIZE, + .arg5_type = ARG_ANYTHING, +}; +#endif + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -3884,6 +3928,10 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_socket_cookie_proto; case BPF_FUNC_get_socket_uid: return &bpf_get_socket_uid_proto; +#ifdef CONFIG_XFRM + case BPF_FUNC_skb_get_xfrm_state: + return &bpf_skb_get_xfrm_state_proto; +#endif default: return bpf_base_func_proto(func_id); } |