samples: bpf: add skb->field examples and tests
- 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@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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@ -1,5 +1,6 @@
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#include <uapi/linux/bpf.h>
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#include <uapi/linux/if_ether.h>
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#include <uapi/linux/if_packet.h>
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#include <uapi/linux/ip.h>
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#include "bpf_helpers.h"
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@ -11,14 +12,17 @@ struct bpf_map_def SEC("maps") my_map = {
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};
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SEC("socket1")
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int bpf_prog1(struct sk_buff *skb)
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int bpf_prog1(struct __sk_buff *skb)
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{
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int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
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long *value;
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if (skb->pkt_type != PACKET_OUTGOING)
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return 0;
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value = bpf_map_lookup_elem(&my_map, &index);
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if (value)
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__sync_fetch_and_add(value, 1);
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__sync_fetch_and_add(value, skb->len);
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return 0;
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}
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@ -40,7 +40,7 @@ int main(int ac, char **argv)
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key = IPPROTO_ICMP;
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assert(bpf_lookup_elem(map_fd[0], &key, &icmp_cnt) == 0);
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printf("TCP %lld UDP %lld ICMP %lld packets\n",
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printf("TCP %lld UDP %lld ICMP %lld bytes\n",
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tcp_cnt, udp_cnt, icmp_cnt);
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sleep(1);
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}
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@ -42,13 +42,13 @@ static inline int proto_ports_offset(__u64 proto)
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}
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}
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static inline int ip_is_fragment(struct sk_buff *ctx, __u64 nhoff)
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static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
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{
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return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
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& (IP_MF | IP_OFFSET);
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}
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static inline __u32 ipv6_addr_hash(struct sk_buff *ctx, __u64 off)
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static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
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{
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__u64 w0 = load_word(ctx, off);
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__u64 w1 = load_word(ctx, off + 4);
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@ -58,7 +58,7 @@ static inline __u32 ipv6_addr_hash(struct sk_buff *ctx, __u64 off)
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return (__u32)(w0 ^ w1 ^ w2 ^ w3);
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}
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static inline __u64 parse_ip(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
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static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
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struct flow_keys *flow)
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{
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__u64 verlen;
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@ -82,7 +82,7 @@ static inline __u64 parse_ip(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
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return nhoff;
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}
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static inline __u64 parse_ipv6(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
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static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
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struct flow_keys *flow)
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{
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*ip_proto = load_byte(skb,
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@ -96,7 +96,7 @@ static inline __u64 parse_ipv6(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto
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return nhoff;
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}
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static inline bool flow_dissector(struct sk_buff *skb, struct flow_keys *flow)
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static inline bool flow_dissector(struct __sk_buff *skb, struct flow_keys *flow)
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{
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__u64 nhoff = ETH_HLEN;
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__u64 ip_proto;
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@ -183,18 +183,23 @@ static inline bool flow_dissector(struct sk_buff *skb, struct flow_keys *flow)
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return true;
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}
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struct pair {
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long packets;
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long bytes;
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};
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struct bpf_map_def SEC("maps") hash_map = {
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.type = BPF_MAP_TYPE_HASH,
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.key_size = sizeof(__be32),
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.value_size = sizeof(long),
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.value_size = sizeof(struct pair),
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.max_entries = 1024,
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};
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SEC("socket2")
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int bpf_prog2(struct sk_buff *skb)
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int bpf_prog2(struct __sk_buff *skb)
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{
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struct flow_keys flow;
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long *value;
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struct pair *value;
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u32 key;
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if (!flow_dissector(skb, &flow))
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@ -203,9 +208,10 @@ int bpf_prog2(struct sk_buff *skb)
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key = flow.dst;
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value = bpf_map_lookup_elem(&hash_map, &key);
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if (value) {
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__sync_fetch_and_add(value, 1);
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__sync_fetch_and_add(&value->packets, 1);
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__sync_fetch_and_add(&value->bytes, skb->len);
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} else {
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long val = 1;
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struct pair val = {1, skb->len};
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bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
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}
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@ -6,6 +6,11 @@
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#include <unistd.h>
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#include <arpa/inet.h>
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struct pair {
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__u64 packets;
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__u64 bytes;
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};
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int main(int ac, char **argv)
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{
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char filename[256];
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@ -29,13 +34,13 @@ int main(int ac, char **argv)
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for (i = 0; i < 5; i++) {
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int key = 0, next_key;
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long long value;
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struct pair value;
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while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
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bpf_lookup_elem(map_fd[0], &next_key, &value);
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printf("ip %s count %lld\n",
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printf("ip %s bytes %lld packets %lld\n",
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inet_ntoa((struct in_addr){htonl(next_key)}),
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value);
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value.bytes, value.packets);
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key = next_key;
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}
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sleep(1);
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@ -14,6 +14,7 @@
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#include <linux/unistd.h>
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#include <string.h>
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#include <linux/filter.h>
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#include <stddef.h>
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#include "libbpf.h"
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#define MAX_INSNS 512
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@ -642,6 +643,75 @@ static struct bpf_test tests[] = {
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},
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.result = ACCEPT,
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},
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{
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"access skb fields ok",
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.insns = {
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, len)),
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BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, mark)),
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BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, pkt_type)),
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BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, queue_mapping)),
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BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
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BPF_EXIT_INSN(),
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},
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.result = ACCEPT,
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},
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{
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"access skb fields bad1",
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.insns = {
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -4),
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BPF_EXIT_INSN(),
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},
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.errstr = "invalid bpf_context access",
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.result = REJECT,
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},
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{
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"access skb fields bad2",
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.insns = {
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BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 9),
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BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
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BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
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BPF_LD_MAP_FD(BPF_REG_1, 0),
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BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
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BPF_EXIT_INSN(),
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BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, pkt_type)),
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BPF_EXIT_INSN(),
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},
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.fixup = {4},
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.errstr = "different pointers",
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.result = REJECT,
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},
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{
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"access skb fields bad3",
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.insns = {
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BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
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offsetof(struct __sk_buff, pkt_type)),
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BPF_EXIT_INSN(),
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BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
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BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
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BPF_LD_MAP_FD(BPF_REG_1, 0),
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BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
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BPF_EXIT_INSN(),
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BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
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BPF_JMP_IMM(BPF_JA, 0, 0, -12),
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},
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.fixup = {6},
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.errstr = "different pointers",
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.result = REJECT,
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},
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};
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static int probe_filter_length(struct bpf_insn *fp)
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