Exit as soon as we found that packet is encapped when
FLOW_DISSECTOR_F_STOP_AT_ENCAP is passed.
Add appropriate selftest cases.
v2:
* Subtract sizeof(struct iphdr) from .iph_inner.tot_len (Willem de Bruijn)
Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Petar Penkov <ppenkov@xxxxxxxxxx>
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/flow_dissector.c | 64 +++++++++++++++++++
tools/testing/selftests/bpf/progs/bpf_flow.c | 8 +++
2 files changed, 72 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index ada032be6199..15265c7a90a3 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -41,6 +41,13 @@ struct ipv4_pkt {
struct tcphdr tcp;
} __packed;
+struct ipip_pkt {
+ struct ethhdr eth;
+ struct iphdr iph;
+ struct iphdr iph_inner;
+ struct tcphdr tcp;
+} __packed;
+
struct svlan_ipv4_pkt {
struct ethhdr eth;
__u16 vlan_tci;
@@ -82,6 +89,7 @@ struct test {
union {
struct ipv4_pkt ipv4;
struct svlan_ipv4_pkt svlan_ipv4;
+ struct ipip_pkt ipip;
struct ipv6_pkt ipv6;
struct ipv6_frag_pkt ipv6_frag;
struct dvlan_ipv6_pkt dvlan_ipv6;
@@ -303,6 +311,62 @@ struct test tests[] = {
},
.flags = FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL,
},
+ {
+ .name = "ipip-encap",
+ .pkt.ipip = {
+ .eth.h_proto = __bpf_constant_htons(ETH_P_IP),
+ .iph.ihl = 5,
+ .iph.protocol = IPPROTO_IPIP,
+ .iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
+ .iph_inner.ihl = 5,
+ .iph_inner.protocol = IPPROTO_TCP,
+ .iph_inner.tot_len =
+ __bpf_constant_htons(MAGIC_BYTES) -
+ sizeof(struct iphdr),
+ .tcp.doff = 5,
+ .tcp.source = 80,
+ .tcp.dest = 8080,
+ },
+ .keys = {
+ .nhoff = 0,
+ .nhoff = ETH_HLEN,
+ .thoff = ETH_HLEN + sizeof(struct iphdr) +
+ sizeof(struct iphdr),
+ .addr_proto = ETH_P_IP,
+ .ip_proto = IPPROTO_TCP,
+ .n_proto = __bpf_constant_htons(ETH_P_IP),
+ .is_encap = true,
+ .sport = 80,
+ .dport = 8080,
+ },
+ },
+ {
+ .name = "ipip-no-encap",
+ .pkt.ipip = {
+ .eth.h_proto = __bpf_constant_htons(ETH_P_IP),
+ .iph.ihl = 5,
+ .iph.protocol = IPPROTO_IPIP,
+ .iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
+ .iph_inner.ihl = 5,
+ .iph_inner.protocol = IPPROTO_TCP,
+ .iph_inner.tot_len =
+ __bpf_constant_htons(MAGIC_BYTES) -
+ sizeof(struct iphdr),
+ .tcp.doff = 5,
+ .tcp.source = 80,
+ .tcp.dest = 8080,
+ },
+ .keys = {
+ .flags = FLOW_DISSECTOR_F_STOP_AT_ENCAP,
+ .nhoff = ETH_HLEN,
+ .thoff = ETH_HLEN + sizeof(struct iphdr),
+ .addr_proto = ETH_P_IP,
+ .ip_proto = IPPROTO_IPIP,
+ .n_proto = __bpf_constant_htons(ETH_P_IP),
+ .is_encap = true,
+ },
+ .flags = FLOW_DISSECTOR_F_STOP_AT_ENCAP,
+ },
};
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 7d73b7bfe609..b6236cdf8564 100644
--- a/tools/testing/selftests/bpf/progs/bpf_flow.c
+++ b/tools/testing/selftests/bpf/progs/bpf_flow.c
@@ -167,9 +167,15 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
return export_flow_keys(keys, BPF_OK);
case IPPROTO_IPIP:
keys->is_encap = true;
+ if (keys->flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
+ return export_flow_keys(keys, BPF_OK);
+
return parse_eth_proto(skb, bpf_htons(ETH_P_IP));
case IPPROTO_IPV6:
keys->is_encap = true;
+ if (keys->flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
+ return export_flow_keys(keys, BPF_OK);
+
return parse_eth_proto(skb, bpf_htons(ETH_P_IPV6));
case IPPROTO_GRE:
gre = bpf_flow_dissect_get_header(skb, sizeof(*gre), &_gre);
@@ -189,6 +195,8 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
keys->thoff += 4; /* Step over sequence number */
keys->is_encap = true;
+ if (keys->flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
+ return export_flow_keys(keys, BPF_OK);
if (gre->proto == bpf_htons(ETH_P_TEB)) {
eth = bpf_flow_dissect_get_header(skb, sizeof(*eth),
--
2.22.0.657.g960e92d24f-goog
