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Message-Id: <20190422155552.222910-8-sdf@google.com>
Date: Mon, 22 Apr 2019 08:55:50 -0700
From: Stanislav Fomichev <sdf@...gle.com>
To: netdev@...r.kernel.org, bpf@...r.kernel.org
Cc: davem@...emloft.net, ast@...nel.org, daniel@...earbox.net,
simon.horman@...ronome.com, willemb@...gle.com,
peterpenkov96@...il.com, Stanislav Fomichev <sdf@...gle.com>
Subject: [PATCH bpf-next v6 7/9] selftests/bpf: run flow dissector tests in
skb-less mode
Export last_dissection map from flow dissector and use a known place in
tun driver to trigger BPF flow dissection.
Signed-off-by: Stanislav Fomichev <sdf@...gle.com>
---
.../selftests/bpf/flow_dissector_load.c | 2 +-
.../selftests/bpf/flow_dissector_load.h | 16 ++-
.../selftests/bpf/prog_tests/flow_dissector.c | 102 +++++++++++++++++-
tools/testing/selftests/bpf/progs/bpf_flow.c | 79 +++++++++-----
4 files changed, 165 insertions(+), 34 deletions(-)
diff --git a/tools/testing/selftests/bpf/flow_dissector_load.c b/tools/testing/selftests/bpf/flow_dissector_load.c
index 7136ab9ffa73..3fd83b9dc1bf 100644
--- a/tools/testing/selftests/bpf/flow_dissector_load.c
+++ b/tools/testing/selftests/bpf/flow_dissector_load.c
@@ -26,7 +26,7 @@ static void load_and_attach_program(void)
struct bpf_object *obj;
ret = bpf_flow_load(&obj, cfg_path_name, cfg_section_name,
- cfg_map_name, &prog_fd);
+ cfg_map_name, NULL, &prog_fd, NULL);
if (ret)
error(1, 0, "bpf_flow_load %s", cfg_path_name);
diff --git a/tools/testing/selftests/bpf/flow_dissector_load.h b/tools/testing/selftests/bpf/flow_dissector_load.h
index 41dd6959feb0..eeb48b6fc827 100644
--- a/tools/testing/selftests/bpf/flow_dissector_load.h
+++ b/tools/testing/selftests/bpf/flow_dissector_load.h
@@ -9,10 +9,12 @@ static inline int bpf_flow_load(struct bpf_object **obj,
const char *path,
const char *section_name,
const char *map_name,
- int *prog_fd)
+ const char *keys_map_name,
+ int *prog_fd,
+ int *keys_fd)
{
struct bpf_program *prog, *main_prog;
- struct bpf_map *prog_array;
+ struct bpf_map *prog_array, *keys;
int prog_array_fd;
int ret, fd, i;
@@ -37,6 +39,16 @@ static inline int bpf_flow_load(struct bpf_object **obj,
if (prog_array_fd < 0)
return ret;
+ if (keys_map_name && keys_fd) {
+ keys = bpf_object__find_map_by_name(*obj, keys_map_name);
+ if (!keys)
+ return -1;
+
+ *keys_fd = bpf_map__fd(keys);
+ if (*keys_fd < 0)
+ return -1;
+ }
+
i = 0;
bpf_object__for_each_program(prog, *obj) {
fd = bpf_program__fd(prog);
diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index 126319f9a97c..51758a0ca55e 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -1,5 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
+#include <error.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
#define CHECK_FLOW_KEYS(desc, got, expected) \
CHECK_ATTR(memcmp(&got, &expected, sizeof(got)) != 0, \
@@ -140,13 +143,73 @@ struct test tests[] = {
},
};
+static int create_tap(const char *ifname)
+{
+ struct ifreq ifr = {
+ .ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS,
+ };
+ int fd, ret;
+
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+
+ fd = open("/dev/net/tun", O_RDWR);
+ if (fd < 0)
+ return -1;
+
+ ret = ioctl(fd, TUNSETIFF, &ifr);
+ if (ret)
+ return -1;
+
+ return fd;
+}
+
+static int tx_tap(int fd, void *pkt, size_t len)
+{
+ struct iovec iov[] = {
+ {
+ .iov_len = len,
+ .iov_base = pkt,
+ },
+ };
+ return writev(fd, iov, ARRAY_SIZE(iov));
+}
+
+static int ifup(const char *ifname)
+{
+ struct ifreq ifr = {};
+ int sk, ret;
+
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+
+ sk = socket(PF_INET, SOCK_DGRAM, 0);
+ if (sk < 0)
+ return -1;
+
+ ret = ioctl(sk, SIOCGIFFLAGS, &ifr);
+ if (ret) {
+ close(sk);
+ return -1;
+ }
+
+ ifr.ifr_flags |= IFF_UP;
+ ret = ioctl(sk, SIOCSIFFLAGS, &ifr);
+ if (ret) {
+ close(sk);
+ return -1;
+ }
+
+ close(sk);
+ return 0;
+}
+
void test_flow_dissector(void)
{
+ int i, err, prog_fd, keys_fd = -1, tap_fd;
struct bpf_object *obj;
- int i, err, prog_fd;
+ __u32 duration = 0;
err = bpf_flow_load(&obj, "./bpf_flow.o", "flow_dissector",
- "jmp_table", &prog_fd);
+ "jmp_table", "last_dissection", &prog_fd, &keys_fd);
if (err) {
error_cnt++;
return;
@@ -171,5 +234,40 @@ void test_flow_dissector(void)
CHECK_FLOW_KEYS(tests[i].name, flow_keys, tests[i].keys);
}
+ /* Do the same tests but for skb-less flow dissector.
+ * We use a known path in the net/tun driver that calls
+ * eth_get_headlen and we manually export bpf_flow_keys
+ * via BPF map in this case.
+ *
+ * Note, that since eth_get_headlen operates on a L2 level,
+ * we adjust exported nhoff/thoff by ETH_HLEN.
+ */
+
+ err = bpf_prog_attach(prog_fd, 0, BPF_FLOW_DISSECTOR, 0);
+ CHECK(err, "bpf_prog_attach", "err %d errno %d", err, errno);
+
+ tap_fd = create_tap("tap0");
+ CHECK(tap_fd < 0, "create_tap", "tap_fd %d errno %d", tap_fd, errno);
+ err = ifup("tap0");
+ CHECK(err, "ifup", "err %d errno %d", err, errno);
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ struct bpf_flow_keys flow_keys = {};
+ struct bpf_prog_test_run_attr tattr = {};
+ __u32 key = 0;
+
+ err = tx_tap(tap_fd, &tests[i].pkt, sizeof(tests[i].pkt));
+ CHECK(err < 0, "tx_tap", "err %d errno %d", err, errno);
+
+ err = bpf_map_lookup_elem(keys_fd, &key, &flow_keys);
+ CHECK_ATTR(err, tests[i].name, "bpf_map_lookup_elem %d\n", err);
+
+ flow_keys.nhoff -= ETH_HLEN;
+ flow_keys.thoff -= ETH_HLEN;
+
+ CHECK_ATTR(err, tests[i].name, "skb-less err %d\n", err);
+ CHECK_FLOW_KEYS(tests[i].name, flow_keys, tests[i].keys);
+ }
+
bpf_object__close(obj);
}
diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c
index 75b17cada539..81ad9a0b29d0 100644
--- a/tools/testing/selftests/bpf/progs/bpf_flow.c
+++ b/tools/testing/selftests/bpf/progs/bpf_flow.c
@@ -64,6 +64,25 @@ struct bpf_map_def SEC("maps") jmp_table = {
.max_entries = 8
};
+struct bpf_map_def SEC("maps") last_dissection = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(struct bpf_flow_keys),
+ .max_entries = 1,
+};
+
+static __always_inline int export_flow_keys(struct bpf_flow_keys *keys,
+ int ret)
+{
+ struct bpf_flow_keys *val;
+ __u32 key = 0;
+
+ val = bpf_map_lookup_elem(&last_dissection, &key);
+ if (val)
+ memcpy(val, keys, sizeof(*val));
+ return ret;
+}
+
static __always_inline void *bpf_flow_dissect_get_header(struct __sk_buff *skb,
__u16 hdr_size,
void *buffer)
@@ -109,10 +128,10 @@ static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto)
break;
default:
/* Protocol not supported */
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
}
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
}
SEC("flow_dissector")
@@ -139,8 +158,8 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
case IPPROTO_ICMP:
icmp = bpf_flow_dissect_get_header(skb, sizeof(*icmp), &_icmp);
if (!icmp)
- return BPF_DROP;
- return BPF_OK;
+ return export_flow_keys(keys, BPF_DROP);
+ return export_flow_keys(keys, BPF_OK);
case IPPROTO_IPIP:
keys->is_encap = true;
return parse_eth_proto(skb, bpf_htons(ETH_P_IP));
@@ -150,11 +169,11 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
case IPPROTO_GRE:
gre = bpf_flow_dissect_get_header(skb, sizeof(*gre), &_gre);
if (!gre)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
if (bpf_htons(gre->flags & GRE_VERSION))
/* Only inspect standard GRE packets with version 0 */
- return BPF_OK;
+ return export_flow_keys(keys, BPF_OK);
keys->thoff += sizeof(*gre); /* Step over GRE Flags and Proto */
if (GRE_IS_CSUM(gre->flags))
@@ -170,7 +189,7 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
eth = bpf_flow_dissect_get_header(skb, sizeof(*eth),
&_eth);
if (!eth)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->thoff += sizeof(*eth);
@@ -181,31 +200,31 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
case IPPROTO_TCP:
tcp = bpf_flow_dissect_get_header(skb, sizeof(*tcp), &_tcp);
if (!tcp)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
if (tcp->doff < 5)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
if ((__u8 *)tcp + (tcp->doff << 2) > data_end)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->sport = tcp->source;
keys->dport = tcp->dest;
- return BPF_OK;
+ return export_flow_keys(keys, BPF_OK);
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
udp = bpf_flow_dissect_get_header(skb, sizeof(*udp), &_udp);
if (!udp)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->sport = udp->source;
keys->dport = udp->dest;
- return BPF_OK;
+ return export_flow_keys(keys, BPF_OK);
default:
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
}
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
}
static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr)
@@ -225,7 +244,7 @@ static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr)
return parse_ip_proto(skb, nexthdr);
}
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
}
PROG(IP)(struct __sk_buff *skb)
@@ -238,11 +257,11 @@ PROG(IP)(struct __sk_buff *skb)
iph = bpf_flow_dissect_get_header(skb, sizeof(*iph), &_iph);
if (!iph)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
/* IP header cannot be smaller than 20 bytes */
if (iph->ihl < 5)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->addr_proto = ETH_P_IP;
keys->ipv4_src = iph->saddr;
@@ -250,7 +269,7 @@ PROG(IP)(struct __sk_buff *skb)
keys->thoff += iph->ihl << 2;
if (data + keys->thoff > data_end)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
if (iph->frag_off & bpf_htons(IP_MF | IP_OFFSET)) {
keys->is_frag = true;
@@ -264,7 +283,7 @@ PROG(IP)(struct __sk_buff *skb)
}
if (done)
- return BPF_OK;
+ return export_flow_keys(keys, BPF_OK);
return parse_ip_proto(skb, iph->protocol);
}
@@ -276,7 +295,7 @@ PROG(IPV6)(struct __sk_buff *skb)
ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h);
if (!ip6h)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->addr_proto = ETH_P_IPV6;
memcpy(&keys->ipv6_src, &ip6h->saddr, 2*sizeof(ip6h->saddr));
@@ -288,11 +307,12 @@ PROG(IPV6)(struct __sk_buff *skb)
PROG(IPV6OP)(struct __sk_buff *skb)
{
+ struct bpf_flow_keys *keys = skb->flow_keys;
struct ipv6_opt_hdr *ip6h, _ip6h;
ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h);
if (!ip6h)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
/* hlen is in 8-octets and does not include the first 8 bytes
* of the header
@@ -309,7 +329,7 @@ PROG(IPV6FR)(struct __sk_buff *skb)
fragh = bpf_flow_dissect_get_header(skb, sizeof(*fragh), &_fragh);
if (!fragh)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->thoff += sizeof(*fragh);
keys->is_frag = true;
@@ -321,13 +341,14 @@ PROG(IPV6FR)(struct __sk_buff *skb)
PROG(MPLS)(struct __sk_buff *skb)
{
+ struct bpf_flow_keys *keys = skb->flow_keys;
struct mpls_label *mpls, _mpls;
mpls = bpf_flow_dissect_get_header(skb, sizeof(*mpls), &_mpls);
if (!mpls)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
- return BPF_OK;
+ return export_flow_keys(keys, BPF_OK);
}
PROG(VLAN)(struct __sk_buff *skb)
@@ -339,10 +360,10 @@ PROG(VLAN)(struct __sk_buff *skb)
if (keys->n_proto == bpf_htons(ETH_P_8021AD)) {
vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan);
if (!vlan)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
if (vlan->h_vlan_encapsulated_proto != bpf_htons(ETH_P_8021Q))
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->nhoff += sizeof(*vlan);
keys->thoff += sizeof(*vlan);
@@ -350,14 +371,14 @@ PROG(VLAN)(struct __sk_buff *skb)
vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan);
if (!vlan)
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->nhoff += sizeof(*vlan);
keys->thoff += sizeof(*vlan);
/* Only allow 8021AD + 8021Q double tagging and no triple tagging.*/
if (vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021AD) ||
vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021Q))
- return BPF_DROP;
+ return export_flow_keys(keys, BPF_DROP);
keys->n_proto = vlan->h_vlan_encapsulated_proto;
return parse_eth_proto(skb, vlan->h_vlan_encapsulated_proto);
--
2.21.0.593.g511ec345e18-goog
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