^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* eBPF example program:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * - creates arraymap in kernel with key 4 bytes and value 8 bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * - loads eBPF program:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * *(u32*)(fp - 4) = r0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * // assuming packet is IPv4, lookup ip->proto in a map
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * value = bpf_map_lookup_elem(map_fd, fp - 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * if (value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * (*(u64*)value) += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * - attaches this program to loopback interface "lo" raw socket
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * - every second user space reads map[tcp], map[udp], map[icmp] to see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * how many packets of given protocol were seen on "lo"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <assert.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/bpf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <sys/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <arpa/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/if_ether.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <stddef.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <bpf/bpf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include "bpf_insn.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include "sock_example.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) char bpf_log_buf[BPF_LOG_BUF_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) static int test_sock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) int sock = -1, map_fd, prog_fd, i, key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) long long value = 0, tcp_cnt, udp_cnt, icmp_cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(key), sizeof(value),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 256, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (map_fd < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) printf("failed to create map '%s'\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct bpf_insn prog[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) BPF_LD_ABS(BPF_B, ETH_HLEN + offsetof(struct iphdr, protocol) /* R0 = ip->proto */),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) BPF_LD_MAP_FD(BPF_REG_1, map_fd),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) BPF_MOV64_IMM(BPF_REG_0, 0), /* r0 = 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) BPF_EXIT_INSN(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, insns_cnt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (prog_fd < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) printf("failed to load prog '%s'\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) sock = open_raw_sock("lo");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) sizeof(prog_fd)) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) printf("setsockopt %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) for (i = 0; i < 10; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) key = IPPROTO_TCP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) key = IPPROTO_UDP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) key = IPPROTO_ICMP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) printf("TCP %lld UDP %lld ICMP %lld packets\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) tcp_cnt, udp_cnt, icmp_cnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) sleep(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) cleanup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /* maps, programs, raw sockets will auto cleanup on process exit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int main(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) FILE *f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) f = popen("ping -4 -c5 localhost", "r");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) (void)f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return test_sock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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