[PATCH v2 net-next 2/2] samples: bpf: add skb->field examples and tests
From: Alexei Starovoitov
Date: Fri Mar 13 2015 - 14:58:13 EST
- modify sockex1 example to count number of bytes in outgoing packets
- modify sockex2 example to count number of bytes and packets per flow
- add 4 stress tests that exercise 'skb->field' code path of verifier
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
---
samples/bpf/sockex1_kern.c | 8 +++--
samples/bpf/sockex1_user.c | 2 +-
samples/bpf/sockex2_kern.c | 26 +++++++++-------
samples/bpf/sockex2_user.c | 11 +++++--
samples/bpf/test_verifier.c | 70 +++++++++++++++++++++++++++++++++++++++++++
5 files changed, 101 insertions(+), 16 deletions(-)
diff --git a/samples/bpf/sockex1_kern.c b/samples/bpf/sockex1_kern.c
index 066892662915..ed18e9a4909c 100644
--- a/samples/bpf/sockex1_kern.c
+++ b/samples/bpf/sockex1_kern.c
@@ -1,5 +1,6 @@
#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
#include <uapi/linux/ip.h>
#include "bpf_helpers.h"
@@ -11,14 +12,17 @@ struct bpf_map_def SEC("maps") my_map = {
};
SEC("socket1")
-int bpf_prog1(struct sk_buff *skb)
+int bpf_prog1(struct __sk_buff *skb)
{
int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
long *value;
+ if (skb->pkt_type != PACKET_OUTGOING)
+ return 0;
+
value = bpf_map_lookup_elem(&my_map, &index);
if (value)
- __sync_fetch_and_add(value, 1);
+ __sync_fetch_and_add(value, skb->len);
return 0;
}
diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c
index 34a443ff3831..678ce4693551 100644
--- a/samples/bpf/sockex1_user.c
+++ b/samples/bpf/sockex1_user.c
@@ -40,7 +40,7 @@ int main(int ac, char **argv)
key = IPPROTO_ICMP;
assert(bpf_lookup_elem(map_fd[0], &key, &icmp_cnt) == 0);
- printf("TCP %lld UDP %lld ICMP %lld packets\n",
+ printf("TCP %lld UDP %lld ICMP %lld bytes\n",
tcp_cnt, udp_cnt, icmp_cnt);
sleep(1);
}
diff --git a/samples/bpf/sockex2_kern.c b/samples/bpf/sockex2_kern.c
index 6f0135f0f217..ba0e177ff561 100644
--- a/samples/bpf/sockex2_kern.c
+++ b/samples/bpf/sockex2_kern.c
@@ -42,13 +42,13 @@ static inline int proto_ports_offset(__u64 proto)
}
}
-static inline int ip_is_fragment(struct sk_buff *ctx, __u64 nhoff)
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
{
return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
& (IP_MF | IP_OFFSET);
}
-static inline __u32 ipv6_addr_hash(struct sk_buff *ctx, __u64 off)
+static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
{
__u64 w0 = load_word(ctx, off);
__u64 w1 = load_word(ctx, off + 4);
@@ -58,7 +58,7 @@ static inline __u32 ipv6_addr_hash(struct sk_buff *ctx, __u64 off)
return (__u32)(w0 ^ w1 ^ w2 ^ w3);
}
-static inline __u64 parse_ip(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
struct flow_keys *flow)
{
__u64 verlen;
@@ -82,7 +82,7 @@ static inline __u64 parse_ip(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
return nhoff;
}
-static inline __u64 parse_ipv6(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
struct flow_keys *flow)
{
*ip_proto = load_byte(skb,
@@ -96,7 +96,7 @@ static inline __u64 parse_ipv6(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto
return nhoff;
}
-static inline bool flow_dissector(struct sk_buff *skb, struct flow_keys *flow)
+static inline bool flow_dissector(struct __sk_buff *skb, struct flow_keys *flow)
{
__u64 nhoff = ETH_HLEN;
__u64 ip_proto;
@@ -183,18 +183,23 @@ static inline bool flow_dissector(struct sk_buff *skb, struct flow_keys *flow)
return true;
}
+struct pair {
+ long packets;
+ long bytes;
+};
+
struct bpf_map_def SEC("maps") hash_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(__be32),
- .value_size = sizeof(long),
+ .value_size = sizeof(struct pair),
.max_entries = 1024,
};
SEC("socket2")
-int bpf_prog2(struct sk_buff *skb)
+int bpf_prog2(struct __sk_buff *skb)
{
struct flow_keys flow;
- long *value;
+ struct pair *value;
u32 key;
if (!flow_dissector(skb, &flow))
@@ -203,9 +208,10 @@ int bpf_prog2(struct sk_buff *skb)
key = flow.dst;
value = bpf_map_lookup_elem(&hash_map, &key);
if (value) {
- __sync_fetch_and_add(value, 1);
+ __sync_fetch_and_add(&value->packets, 1);
+ __sync_fetch_and_add(&value->bytes, skb->len);
} else {
- long val = 1;
+ struct pair val = {1, skb->len};
bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
}
diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
index d2d5f5a790d3..29a276d766fc 100644
--- a/samples/bpf/sockex2_user.c
+++ b/samples/bpf/sockex2_user.c
@@ -6,6 +6,11 @@
#include <unistd.h>
#include <arpa/inet.h>
+struct pair {
+ __u64 packets;
+ __u64 bytes;
+};
+
int main(int ac, char **argv)
{
char filename[256];
@@ -29,13 +34,13 @@ int main(int ac, char **argv)
for (i = 0; i < 5; i++) {
int key = 0, next_key;
- long long value;
+ struct pair value;
while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
bpf_lookup_elem(map_fd[0], &next_key, &value);
- printf("ip %s count %lld\n",
+ printf("ip %s bytes %lld packets %lld\n",
inet_ntoa((struct in_addr){htonl(next_key)}),
- value);
+ value.bytes, value.packets);
key = next_key;
}
sleep(1);
diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c
index 7b56b59fad8e..df6dbb6576f6 100644
--- a/samples/bpf/test_verifier.c
+++ b/samples/bpf/test_verifier.c
@@ -14,6 +14,7 @@
#include <linux/unistd.h>
#include <string.h>
#include <linux/filter.h>
+#include <stddef.h>
#include "libbpf.h"
#define MAX_INSNS 512
@@ -642,6 +643,75 @@ static struct bpf_test tests[] = {
},
.result = ACCEPT,
},
+ {
+ "access skb fields ok",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, len)),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, mark)),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, pkt_type)),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, queue_mapping)),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ },
+ {
+ "access skb fields bad1",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -4),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "invalid bpf_context access",
+ .result = REJECT,
+ },
+ {
+ "access skb fields bad2",
+ .insns = {
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 9),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, pkt_type)),
+ BPF_EXIT_INSN(),
+ },
+ .fixup = {4},
+ .errstr = "different pointers",
+ .result = REJECT,
+ },
+ {
+ "access skb fields bad3",
+ .insns = {
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, pkt_type)),
+ BPF_EXIT_INSN(),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JA, 0, 0, -12),
+ },
+ .fixup = {6},
+ .errstr = "different pointers",
+ .result = REJECT,
+ },
};
static int probe_filter_length(struct bpf_insn *fp)
--
1.7.9.5
--
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