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Diffstat (limited to 'samples/bpf/cookie_uid_helper_example.c')
-rw-r--r--samples/bpf/cookie_uid_helper_example.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c
new file mode 100644
index 000000000000..b08ab4e88929
--- /dev/null
+++ b/samples/bpf/cookie_uid_helper_example.c
@@ -0,0 +1,321 @@
+/* This test is a demo of using get_socket_uid and get_socket_cookie
+ * helper function to do per socket based network traffic monitoring.
+ * It requires iptables version higher then 1.6.1. to load pinned eBPF
+ * program into the xt_bpf match.
+ *
+ * TEST:
+ * ./run_cookie_uid_helper_example.sh -option
+ * option:
+ * -t: do traffic monitoring test, the program will continuously
+ * print out network traffic happens after program started A sample
+ * output is shown below:
+ *
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 132, uid: 0x0, Pakcet Count: 2, Bytes Count: 286
+ * cookie: 812, uid: 0x3e8, Pakcet Count: 3, Bytes Count: 1726
+ * cookie: 802, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 831, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 0, uid: 0x0, Pakcet Count: 6, Bytes Count: 712
+ * cookie: 880, uid: 0xfffe, Pakcet Count: 1, Bytes Count: 70
+ *
+ * -s: do getsockopt SO_COOKIE test, the program will set up a pair of
+ * UDP sockets and send packets between them. And read out the traffic data
+ * directly from the ebpf map based on the socket cookie.
+ *
+ * Clean up: if using shell script, the script file will delete the iptables
+ * rule and unmount the bpf program when exit. Else the iptables rule need
+ * to be deleted by hand, see run_cookie_uid_helper_example.sh for detail.
+ */
+
+#define _GNU_SOURCE
+
+#define offsetof(type, member) __builtin_offsetof(type, member)
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <limits.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include "libbpf.h"
+
+#define PORT 8888
+
+struct stats {
+ uint32_t uid;
+ uint64_t packets;
+ uint64_t bytes;
+};
+
+static int map_fd, prog_fd;
+
+static bool test_finish;
+
+static void maps_create(void)
+{
+ map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(uint32_t),
+ sizeof(struct stats), 100, 0);
+ if (map_fd < 0)
+ error(1, errno, "map create failed!\n");
+}
+
+static void prog_load(void)
+{
+ static char log_buf[1 << 16];
+
+ struct bpf_insn prog[] = {
+ /*
+ * Save sk_buff for future usage. value stored in R6 to R10 will
+ * not be reset after a bpf helper function call.
+ */
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+ /*
+ * pc1: BPF_FUNC_get_socket_cookie takes one parameter,
+ * R1: sk_buff
+ */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_get_socket_cookie),
+ /* pc2-4: save &socketCookie to r7 for future usage*/
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ /*
+ * pc5-8: set up the registers for BPF_FUNC_map_lookup_elem,
+ * it takes two parameters (R1: map_fd, R2: &socket_cookie)
+ */
+ BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_map_lookup_elem),
+ /*
+ * pc9. if r0 != 0x0, go to pc+14, since we have the cookie
+ * stored already
+ * Otherwise do pc10-22 to setup a new data entry.
+ */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 14),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_get_socket_uid),
+ /*
+ * Place a struct stats in the R10 stack and sequentially
+ * place the member value into the memory. Packets value
+ * is set by directly place a IMM value 1 into the stack.
+ */
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0,
+ -32 + (__s16)offsetof(struct stats, uid)),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10,
+ -32 + (__s16)offsetof(struct stats, packets), 1),
+ /*
+ * __sk_buff is a special struct used for eBPF program to
+ * directly access some sk_buff field.
+ */
+ BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+ offsetof(struct __sk_buff, len)),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1,
+ -32 + (__s16)offsetof(struct stats, bytes)),
+ /*
+ * add new map entry using BPF_FUNC_map_update_elem, it takes
+ * 4 parameters (R1: map_fd, R2: &socket_cookie, R3: &stats,
+ * R4: flags)
+ */
+ BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -32),
+ BPF_MOV64_IMM(BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_map_update_elem),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 5),
+ /*
+ * pc24-30 update the packet info to a exist data entry, it can
+ * be done by directly write to pointers instead of using
+ * BPF_FUNC_map_update_elem helper function
+ */
+ BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_1, 1),
+ BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1,
+ offsetof(struct stats, packets)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+ offsetof(struct __sk_buff, len)),
+ BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1,
+ offsetof(struct stats, bytes)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6,
+ offsetof(struct __sk_buff, len)),
+ BPF_EXIT_INSN(),
+ };
+ prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog,
+ ARRAY_SIZE(prog), "GPL", 0,
+ log_buf, sizeof(log_buf));
+ if (prog_fd < 0)
+ error(1, errno, "failed to load prog\n%s\n", log_buf);
+}
+
+static void prog_attach_iptables(char *file)
+{
+ int ret;
+ char rules[100];
+
+ if (bpf_obj_pin(prog_fd, file))
+ error(1, errno, "bpf_obj_pin");
+ if (strlen(file) > 50) {
+ printf("file path too long: %s\n", file);
+ exit(1);
+ }
+ sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
+ file);
+ ret = system(rules);
+ if (ret < 0) {
+ printf("iptables rule update failed: %d/n", WEXITSTATUS(ret));
+ exit(1);
+ }
+}
+
+static void print_table(void)
+{
+ struct stats curEntry;
+ uint32_t curN = UINT32_MAX;
+ uint32_t nextN;
+ int res;
+
+ while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) {
+ curN = nextN;
+ res = bpf_map_lookup_elem(map_fd, &curN, &curEntry);
+ if (res < 0) {
+ error(1, errno, "fail to get entry value of Key: %u\n",
+ curN);
+ } else {
+ printf("cookie: %u, uid: 0x%x, Packet Count: %lu,"
+ " Bytes Count: %lu\n", curN, curEntry.uid,
+ curEntry.packets, curEntry.bytes);
+ }
+ }
+}
+
+static void udp_client(void)
+{
+ struct sockaddr_in si_other = {0};
+ struct sockaddr_in si_me = {0};
+ struct stats dataEntry;
+ int s_rcv, s_send, i, recv_len;
+ char message = 'a';
+ char buf;
+ uint64_t cookie;
+ int res;
+ socklen_t cookie_len = sizeof(cookie);
+ socklen_t slen = sizeof(si_other);
+
+ s_rcv = socket(PF_INET, SOCK_DGRAM, 0);
+ if (s_rcv < 0)
+ error(1, errno, "rcv socket creat failed!\n");
+ si_other.sin_family = AF_INET;
+ si_other.sin_port = htons(PORT);
+ if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0)
+ error(1, errno, "inet_aton\n");
+ if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1)
+ error(1, errno, "bind\n");
+ s_send = socket(PF_INET, SOCK_DGRAM, 0);
+ if (s_send < 0)
+ error(1, errno, "send socket creat failed!\n");
+ res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len);
+ if (res < 0)
+ printf("get cookie failed: %s\n", strerror(errno));
+ res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+ if (res != -1)
+ error(1, errno, "socket stat found while flow not active\n");
+ for (i = 0; i < 10; i++) {
+ res = sendto(s_send, &message, sizeof(message), 0,
+ (struct sockaddr *)&si_other, slen);
+ if (res == -1)
+ error(1, errno, "send\n");
+ if (res != sizeof(message))
+ error(1, 0, "%uB != %luB\n", res, sizeof(message));
+ recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0,
+ (struct sockaddr *)&si_me, &slen);
+ if (recv_len < 0)
+ error(1, errno, "revieve\n");
+ res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr),
+ sizeof(si_me.sin_addr));
+ if (res != 0)
+ error(1, EFAULT, "sender addr error: %d\n", res);
+ printf("Message received: %c\n", buf);
+ res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+ if (res < 0)
+ error(1, errno, "lookup sk stat failed, cookie: %lu\n",
+ cookie);
+ printf("cookie: %lu, uid: 0x%x, Packet Count: %lu,"
+ " Bytes Count: %lu\n\n", cookie, dataEntry.uid,
+ dataEntry.packets, dataEntry.bytes);
+ }
+ close(s_send);
+ close(s_rcv);
+}
+
+static int usage(void)
+{
+ printf("Usage: ./run_cookie_uid_helper_example.sh"
+ " bpfObjName -option\n"
+ " -t traffic monitor test\n"
+ " -s getsockopt cookie test\n");
+ return 1;
+}
+
+static void finish(int ret)
+{
+ test_finish = true;
+}
+
+int main(int argc, char *argv[])
+{
+ int opt;
+ bool cfg_test_traffic = false;
+ bool cfg_test_cookie = false;
+
+ if (argc != 3)
+ return usage();
+ while ((opt = getopt(argc, argv, "ts")) != -1) {
+ switch (opt) {
+ case 't':
+ cfg_test_traffic = true;
+ break;
+ case 's':
+ cfg_test_cookie = true;
+ break;
+
+ default:
+ printf("unknown option %c\n", opt);
+ usage();
+ return -1;
+ }
+ }
+ maps_create();
+ prog_load();
+ prog_attach_iptables(argv[2]);
+ if (cfg_test_traffic) {
+ if (signal(SIGINT, finish) == SIG_ERR)
+ error(1, errno, "register handler failed");
+ while (!test_finish) {
+ print_table();
+ printf("\n");
+ sleep(1);
+ };
+ } else if (cfg_test_cookie) {
+ udp_client();
+ }
+ close(prog_fd);
+ close(map_fd);
+ return 0;
+}