From fca5fdf67de9e092fda23c9eb059ba968e7b5267 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 16 Mar 2016 01:42:51 +0100 Subject: [PATCH] ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it eBPF defines this as BPF_TUNLEN_MAX and OVS just uses the hard-coded value inside struct sw_flow_key. Thus, add and use IP_TUNNEL_OPTS_MAX for this, which makes the code a bit more generic and allows to remove BPF_TUNLEN_MAX from eBPF code. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/net/ip_tunnels.h | 7 +++++++ net/core/filter.c | 9 ++------- net/ipv4/ip_tunnel_core.c | 6 ++++++ net/openvswitch/flow.h | 2 +- 4 files changed, 16 insertions(+), 8 deletions(-) diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 5dc2e454f866..c35dda9ec991 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -7,6 +7,8 @@ #include #include #include +#include + #include #include #include @@ -57,6 +59,11 @@ struct ip_tunnel_key { #define IP_TUNNEL_INFO_TX 0x01 /* represents tx tunnel parameters */ #define IP_TUNNEL_INFO_IPV6 0x02 /* key contains IPv6 addresses */ +/* Maximum tunnel options length. */ +#define IP_TUNNEL_OPTS_MAX \ + GENMASK((FIELD_SIZEOF(struct ip_tunnel_info, \ + options_len) * BITS_PER_BYTE) - 1, 0) + struct ip_tunnel_info { struct ip_tunnel_key key; #ifdef CONFIG_DST_CACHE diff --git a/net/core/filter.c b/net/core/filter.c index 4c35d8325c34..b7177d01ecb0 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1904,8 +1904,6 @@ static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = { .arg4_type = ARG_ANYTHING, }; -#define BPF_TUNLEN_MAX 255 - static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5) { struct sk_buff *skb = (struct sk_buff *) (long) r1; @@ -1915,7 +1913,7 @@ static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5) if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1)))) return -EINVAL; - if (unlikely(size > BPF_TUNLEN_MAX)) + if (unlikely(size > IP_TUNNEL_OPTS_MAX)) return -ENOMEM; ip_tunnel_info_opts_set(info, from, size); @@ -1936,13 +1934,10 @@ static const struct bpf_func_proto * bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) { if (!md_dst) { - BUILD_BUG_ON(FIELD_SIZEOF(struct ip_tunnel_info, - options_len) != 1); - /* Race is not possible, since it's called from verifier * that is holding verifier mutex. */ - md_dst = metadata_dst_alloc_percpu(BPF_TUNLEN_MAX, + md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX, GFP_KERNEL); if (!md_dst) return NULL; diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index eaca2449a09a..d27276f6f8dd 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -398,6 +398,12 @@ static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = { void __init ip_tunnel_core_init(void) { + /* If you land here, make sure whether increasing ip_tunnel_info's + * options_len is a reasonable choice with its usage in front ends + * (f.e., it's part of flow keys, etc). + */ + BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255); + lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP); lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6); } diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h index 1d055c559eaf..03378e75a67c 100644 --- a/net/openvswitch/flow.h +++ b/net/openvswitch/flow.h @@ -55,7 +55,7 @@ struct ovs_tunnel_info { FIELD_SIZEOF(struct sw_flow_key, recirc_id)) struct sw_flow_key { - u8 tun_opts[255]; + u8 tun_opts[IP_TUNNEL_OPTS_MAX]; u8 tun_opts_len; struct ip_tunnel_key tun_key; /* Encapsulating tunnel key. */ struct { -- 2.34.1