From 71c99e32b926159ea628352751f66383d7d04d17 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 25 Jul 2019 15:52:30 -0700 Subject: [PATCH] bpf/flow_dissector: support ipv6 flow_label and BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL Add support for exporting ipv6 flow label via bpf_flow_keys. Export flow label from bpf_flow.c and also return early when BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL is passed. Acked-by: Petar Penkov Acked-by: Willem de Bruijn Acked-by: Song Liu Cc: Song Liu Cc: Willem de Bruijn Cc: Petar Penkov Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 1 + net/core/flow_dissector.c | 9 ++++ tools/include/uapi/linux/bpf.h | 1 + .../selftests/bpf/prog_tests/flow_dissector.c | 46 +++++++++++++++++++ tools/testing/selftests/bpf/progs/bpf_flow.c | 10 ++++ 5 files changed, 67 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 88b9d743036f..e985f07a98ed 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3533,6 +3533,7 @@ struct bpf_flow_keys { }; }; __u32 flags; + __be32 flow_label; }; struct bpf_func_info { diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 50ed1a688709..9741b593ea53 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -737,6 +737,7 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, struct flow_dissector_key_basic *key_basic; struct flow_dissector_key_addrs *key_addrs; struct flow_dissector_key_ports *key_ports; + struct flow_dissector_key_tags *key_tags; key_control = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CONTROL, @@ -781,6 +782,14 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, key_ports->src = flow_keys->sport; key_ports->dst = flow_keys->dport; } + + if (dissector_uses_key(flow_dissector, + FLOW_DISSECTOR_KEY_FLOW_LABEL)) { + key_tags = skb_flow_dissector_target(flow_dissector, + FLOW_DISSECTOR_KEY_FLOW_LABEL, + target_container); + key_tags->flow_label = ntohl(flow_keys->flow_label); + } } bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 2e4b0848d795..3d7fc67ec1b8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3530,6 +3530,7 @@ struct bpf_flow_keys { }; }; __u32 flags; + __be32 flow_label; }; struct bpf_func_info { diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c index 8e8c18aced9b..ef83f145a6f1 100644 --- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c +++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c @@ -20,6 +20,7 @@ "is_encap=%u/%u " \ "ip_proto=0x%x/0x%x " \ "n_proto=0x%x/0x%x " \ + "flow_label=0x%x/0x%x " \ "sport=%u/%u " \ "dport=%u/%u\n", \ got.nhoff, expected.nhoff, \ @@ -30,6 +31,7 @@ got.is_encap, expected.is_encap, \ got.ip_proto, expected.ip_proto, \ got.n_proto, expected.n_proto, \ + got.flow_label, expected.flow_label, \ got.sport, expected.sport, \ got.dport, expected.dport) @@ -257,6 +259,50 @@ struct test tests[] = { .is_first_frag = true, }, }, + { + .name = "ipv6-flow-label", + .pkt.ipv6 = { + .eth.h_proto = __bpf_constant_htons(ETH_P_IPV6), + .iph.nexthdr = IPPROTO_TCP, + .iph.payload_len = __bpf_constant_htons(MAGIC_BYTES), + .iph.flow_lbl = { 0xb, 0xee, 0xef }, + .tcp.doff = 5, + .tcp.source = 80, + .tcp.dest = 8080, + }, + .keys = { + .nhoff = ETH_HLEN, + .thoff = ETH_HLEN + sizeof(struct ipv6hdr), + .addr_proto = ETH_P_IPV6, + .ip_proto = IPPROTO_TCP, + .n_proto = __bpf_constant_htons(ETH_P_IPV6), + .sport = 80, + .dport = 8080, + .flow_label = __bpf_constant_htonl(0xbeeef), + }, + }, + { + .name = "ipv6-no-flow-label", + .pkt.ipv6 = { + .eth.h_proto = __bpf_constant_htons(ETH_P_IPV6), + .iph.nexthdr = IPPROTO_TCP, + .iph.payload_len = __bpf_constant_htons(MAGIC_BYTES), + .iph.flow_lbl = { 0xb, 0xee, 0xef }, + .tcp.doff = 5, + .tcp.source = 80, + .tcp.dest = 8080, + }, + .keys = { + .flags = BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL, + .nhoff = ETH_HLEN, + .thoff = ETH_HLEN + sizeof(struct ipv6hdr), + .addr_proto = ETH_P_IPV6, + .ip_proto = IPPROTO_TCP, + .n_proto = __bpf_constant_htons(ETH_P_IPV6), + .flow_label = __bpf_constant_htonl(0xbeeef), + }, + .flags = BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL, + }, }; static int create_tap(const char *ifname) diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c index f931cd3db9d4..7fbfa22f33df 100644 --- a/tools/testing/selftests/bpf/progs/bpf_flow.c +++ b/tools/testing/selftests/bpf/progs/bpf_flow.c @@ -83,6 +83,12 @@ static __always_inline int export_flow_keys(struct bpf_flow_keys *keys, return ret; } +#define IPV6_FLOWLABEL_MASK __bpf_constant_htonl(0x000FFFFF) +static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr) +{ + return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK; +} + static __always_inline void *bpf_flow_dissect_get_header(struct __sk_buff *skb, __u16 hdr_size, void *buffer) @@ -308,6 +314,10 @@ PROG(IPV6)(struct __sk_buff *skb) keys->thoff += sizeof(struct ipv6hdr); keys->ip_proto = ip6h->nexthdr; + keys->flow_label = ip6_flowlabel(ip6h); + + if (keys->flags & BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) + return export_flow_keys(keys, BPF_OK); return parse_ipv6_proto(skb, ip6h->nexthdr); }