mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
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@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Stanislav Fomichev
Daniel Borkmann
parent
c9cb2c1e11
commit
0905beec9f
|
|
@ -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);
|
||||
|
||||
|
|
|
|||
|
|
@ -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);
|
||||
|
|
|
|||
|
|
@ -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);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -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);
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user