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But that is not appropriate when pushing Ethernet header. Add an option to further specify encap L2 type and set the inner_protocol as ETH_P_TEB. Update test_tc_tunnel to verify adding vxlan encapsulation works with this flag. Suggested-by: Willem de Bruijn Signed-off-by: Xuesen Huang Signed-off-by: Zhiyong Cheng Signed-off-by: Li Wang --- include/uapi/linux/bpf.h | 5 + net/core/filter.c | 11 ++- tools/include/uapi/linux/bpf.h | 5 + tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 107 ++++++++++++++++++--- tools/testing/selftests/bpf/test_tc_tunnel.sh | 15 ++- 5 files changed, 124 insertions(+), 19 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 77d7c1b..d791596 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1751,6 +1751,10 @@ struct bpf_stack_build_id { * Use with ENCAP_L3/L4 flags to further specify the tunnel * type; *len* is the length of the inner MAC header. * + * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**: + * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the + * L2 type as Ethernet. + * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be @@ -4088,6 +4092,7 @@ enum { BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (1ULL << 3), BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (1ULL << 4), BPF_F_ADJ_ROOM_NO_CSUM_RESET = (1ULL << 5), + BPF_F_ADJ_ROOM_ENCAP_L2_ETH = (1ULL << 6), }; enum { diff --git a/net/core/filter.c b/net/core/filter.c index 255aeee..8d1fb61 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3412,6 +3412,7 @@ static u32 bpf_skb_net_base_len(const struct sk_buff *skb) BPF_F_ADJ_ROOM_ENCAP_L3_MASK | \ BPF_F_ADJ_ROOM_ENCAP_L4_GRE | \ BPF_F_ADJ_ROOM_ENCAP_L4_UDP | \ + BPF_F_ADJ_ROOM_ENCAP_L2_ETH | \ BPF_F_ADJ_ROOM_ENCAP_L2( \ BPF_ADJ_ROOM_ENCAP_L2_MASK)) @@ -3448,6 +3449,10 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff, flags & BPF_F_ADJ_ROOM_ENCAP_L4_UDP) return -EINVAL; + if (flags & BPF_F_ADJ_ROOM_ENCAP_L2_ETH && + inner_mac_len < ETH_HLEN) + return -EINVAL; + if (skb->encapsulation) return -EALREADY; @@ -3466,7 +3471,11 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff, skb->inner_mac_header = inner_net - inner_mac_len; skb->inner_network_header = inner_net; skb->inner_transport_header = inner_trans; - skb_set_inner_protocol(skb, skb->protocol); + + if (flags & BPF_F_ADJ_ROOM_ENCAP_L2_ETH) + skb_set_inner_protocol(skb, htons(ETH_P_TEB)); + else + skb_set_inner_protocol(skb, skb->protocol); skb->encapsulation = 1; skb_set_network_header(skb, mac_len); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 77d7c1b..d791596 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1751,6 +1751,10 @@ struct bpf_stack_build_id { * Use with ENCAP_L3/L4 flags to further specify the tunnel * type; *len* is the length of the inner MAC header. * + * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**: + * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the + * L2 type as Ethernet. + * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be @@ -4088,6 +4092,7 @@ enum { BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (1ULL << 3), BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (1ULL << 4), BPF_F_ADJ_ROOM_NO_CSUM_RESET = (1ULL << 5), + BPF_F_ADJ_ROOM_ENCAP_L2_ETH = (1ULL << 6), }; enum { diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c index 37bce7a..6e144db 100644 --- a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c +++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c @@ -20,6 +20,14 @@ #include #include +#define encap_ipv4(...) __encap_ipv4(__VA_ARGS__, 0) + +#define encap_ipv4_with_ext_proto(...) __encap_ipv4(__VA_ARGS__) + +#define encap_ipv6(...) __encap_ipv6(__VA_ARGS__, 0) + +#define encap_ipv6_with_ext_proto(...) __encap_ipv6(__VA_ARGS__) + static const int cfg_port = 8000; static const int cfg_udp_src = 20000; @@ -27,11 +35,24 @@ #define UDP_PORT 5555 #define MPLS_OVER_UDP_PORT 6635 #define ETH_OVER_UDP_PORT 7777 +#define VXLAN_UDP_PORT 8472 + +#define EXTPROTO_VXLAN 0x1 + +#define VXLAN_N_VID (1u << 24) +#define VXLAN_VNI_MASK bpf_htonl((VXLAN_N_VID - 1) << 8) +#define VXLAN_FLAGS 0x8 +#define VXLAN_VNI 1 /* MPLS label 1000 with S bit (last label) set and ttl of 255. */ static const __u32 mpls_label = __bpf_constant_htonl(1000 << 12 | MPLS_LS_S_MASK | 0xff); +struct vxlanhdr { + __be32 vx_flags; + __be32 vx_vni; +} __attribute__((packed)); + struct gre_hdr { __be16 flags; __be16 protocol; @@ -45,13 +66,13 @@ struct gre_hdr { struct v4hdr { struct iphdr ip; union l4hdr l4hdr; - __u8 pad[16]; /* enough space for L2 header */ + __u8 pad[24]; /* space for L2 header / vxlan header ... */ } __attribute__((packed)); struct v6hdr { struct ipv6hdr ip; union l4hdr l4hdr; - __u8 pad[16]; /* enough space for L2 header */ + __u8 pad[24]; /* space for L2 header / vxlan header ... */ } __attribute__((packed)); static __always_inline void set_ipv4_csum(struct iphdr *iph) @@ -69,14 +90,15 @@ static __always_inline void set_ipv4_csum(struct iphdr *iph) iph->check = ~((csum & 0xffff) + (csum >> 16)); } -static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, - __u16 l2_proto) +static __always_inline int __encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, + __u16 l2_proto, __u16 ext_proto) { __u16 udp_dst = UDP_PORT; struct iphdr iph_inner; struct v4hdr h_outer; struct tcphdr tcph; int olen, l2_len; + __u8 *l2_hdr = NULL; int tcp_off; __u64 flags; @@ -141,7 +163,11 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, break; case ETH_P_TEB: l2_len = ETH_HLEN; - udp_dst = ETH_OVER_UDP_PORT; + if (ext_proto & EXTPROTO_VXLAN) { + udp_dst = VXLAN_UDP_PORT; + l2_len += sizeof(struct vxlanhdr); + } else + udp_dst = ETH_OVER_UDP_PORT; break; } flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len); @@ -171,14 +197,26 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, } /* add L2 encap (if specified) */ + l2_hdr = (__u8 *)&h_outer + olen; switch (l2_proto) { case ETH_P_MPLS_UC: - *((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label; + *(__u32 *)l2_hdr = mpls_label; break; case ETH_P_TEB: - if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen, - ETH_HLEN)) + flags |= BPF_F_ADJ_ROOM_ENCAP_L2_ETH; + + if (ext_proto & EXTPROTO_VXLAN) { + struct vxlanhdr *vxlan_hdr = (struct vxlanhdr *)l2_hdr; + + vxlan_hdr->vx_flags = VXLAN_FLAGS; + vxlan_hdr->vx_vni = bpf_htonl((VXLAN_VNI & VXLAN_VNI_MASK) << 8); + + l2_hdr += sizeof(struct vxlanhdr); + } + + if (bpf_skb_load_bytes(skb, 0, l2_hdr, ETH_HLEN)) return TC_ACT_SHOT; + break; } olen += l2_len; @@ -214,14 +252,15 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, return TC_ACT_OK; } -static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, - __u16 l2_proto) +static __always_inline int __encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, + __u16 l2_proto, __u16 ext_proto) { __u16 udp_dst = UDP_PORT; struct ipv6hdr iph_inner; struct v6hdr h_outer; struct tcphdr tcph; int olen, l2_len; + __u8 *l2_hdr = NULL; __u16 tot_len; __u64 flags; @@ -249,7 +288,11 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, break; case ETH_P_TEB: l2_len = ETH_HLEN; - udp_dst = ETH_OVER_UDP_PORT; + if (ext_proto & EXTPROTO_VXLAN) { + udp_dst = VXLAN_UDP_PORT; + l2_len += sizeof(struct vxlanhdr); + } else + udp_dst = ETH_OVER_UDP_PORT; break; } flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len); @@ -267,7 +310,7 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, h_outer.l4hdr.udp.source = __bpf_constant_htons(cfg_udp_src); h_outer.l4hdr.udp.dest = bpf_htons(udp_dst); tot_len = bpf_ntohs(iph_inner.payload_len) + sizeof(iph_inner) + - sizeof(h_outer.l4hdr.udp); + sizeof(h_outer.l4hdr.udp) + l2_len; h_outer.l4hdr.udp.check = 0; h_outer.l4hdr.udp.len = bpf_htons(tot_len); break; @@ -278,13 +321,24 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, } /* add L2 encap (if specified) */ + l2_hdr = (__u8 *)&h_outer + olen; switch (l2_proto) { case ETH_P_MPLS_UC: - *((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label; + *(__u32 *)l2_hdr = mpls_label; break; case ETH_P_TEB: - if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen, - ETH_HLEN)) + flags |= BPF_F_ADJ_ROOM_ENCAP_L2_ETH; + + if (ext_proto & EXTPROTO_VXLAN) { + struct vxlanhdr *vxlan_hdr = (struct vxlanhdr *)l2_hdr; + + vxlan_hdr->vx_flags = VXLAN_FLAGS; + vxlan_hdr->vx_vni = bpf_htonl((VXLAN_VNI & VXLAN_VNI_MASK) << 8); + + l2_hdr += sizeof(struct vxlanhdr); + } + + if (bpf_skb_load_bytes(skb, 0, l2_hdr, ETH_HLEN)) return TC_ACT_SHOT; break; } @@ -372,6 +426,16 @@ int __encap_udp_eth(struct __sk_buff *skb) return TC_ACT_OK; } +SEC("encap_vxlan_eth") +int __encap_vxlan_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4_with_ext_proto(skb, IPPROTO_UDP, + ETH_P_TEB, EXTPROTO_VXLAN); + else + return TC_ACT_OK; +} + SEC("encap_sit_none") int __encap_sit_none(struct __sk_buff *skb) { @@ -444,6 +508,16 @@ int __encap_ip6udp_eth(struct __sk_buff *skb) return TC_ACT_OK; } +SEC("encap_ip6vxlan_eth") +int __encap_ip6vxlan_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6_with_ext_proto(skb, IPPROTO_UDP, + ETH_P_TEB, EXTPROTO_VXLAN); + else + return TC_ACT_OK; +} + static int decap_internal(struct __sk_buff *skb, int off, int len, char proto) { char buf[sizeof(struct v6hdr)]; @@ -479,6 +553,9 @@ static int decap_internal(struct __sk_buff *skb, int off, int len, char proto) case ETH_OVER_UDP_PORT: olen += ETH_HLEN; break; + case VXLAN_UDP_PORT: + olen += ETH_HLEN + sizeof(struct vxlanhdr); + break; } break; default: diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh index 7c76b84..c9dde9b 100755 --- a/tools/testing/selftests/bpf/test_tc_tunnel.sh +++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh @@ -44,8 +44,8 @@ setup() { # clamp route to reserve room for tunnel headers ip -netns "${ns1}" -4 route flush table main ip -netns "${ns1}" -6 route flush table main - ip -netns "${ns1}" -4 route add "${ns2_v4}" mtu 1458 dev veth1 - ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1438 dev veth1 + ip -netns "${ns1}" -4 route add "${ns2_v4}" mtu 1450 dev veth1 + ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1430 dev veth1 sleep 1 @@ -105,6 +105,12 @@ if [[ "$#" -eq "0" ]]; then echo "sit" $0 ipv6 sit none 100 + echo "ip4 vxlan" + $0 ipv4 vxlan eth 2000 + + echo "ip6 vxlan" + $0 ipv6 ip6vxlan eth 2000 + for mac in none mpls eth ; do echo "ip gre $mac" $0 ipv4 gre $mac 100 @@ -214,6 +220,9 @@ if [[ "$tuntype" =~ "udp" ]]; then targs="encap fou encap-sport auto encap-dport $dport" elif [[ "$tuntype" =~ "gre" && "$mac" == "eth" ]]; then ttype=$gretaptype +elif [[ "$tuntype" =~ "vxlan" && "$mac" == "eth" ]]; then + ttype="vxlan" + targs="id 1 dstport 8472 udp6zerocsumrx" else ttype=$tuntype targs="" @@ -242,7 +251,7 @@ if [[ "$tuntype" == "ip6udp" && "$mac" == "mpls" ]]; then elif [[ "$tuntype" =~ "udp" && "$mac" == "eth" ]]; then # No support for TEB fou tunnel; expect failure. expect_tun_fail=1 -elif [[ "$tuntype" =~ "gre" && "$mac" == "eth" ]]; then +elif [[ "$tuntype" =~ (gre|vxlan) && "$mac" == "eth" ]]; then # Share ethernet address between tunnel/veth2 so L2 decap works. ethaddr=$(ip netns exec "${ns2}" ip link show veth2 | \ awk '/ether/ { print $2 }')