diff options
| -rw-r--r-- | samples/bpf/Makefile | 3 | ||||
| -rw-r--r-- | samples/bpf/cookie_uid_helper_example.c | 217 | ||||
| -rw-r--r-- | samples/bpf/libbpf.h | 10 | ||||
| -rw-r--r-- | samples/bpf/run_cookie_uid_helper_example.sh | 14 |
4 files changed, 244 insertions, 0 deletions
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 91c1d616d975..d42b495b0992 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -35,6 +35,7 @@ hostprogs-y += tc_l2_redirect hostprogs-y += lwt_len_hist hostprogs-y += xdp_tx_iptunnel hostprogs-y += test_map_in_map +hostprogs-y += per_socket_stats_example # Libbpf dependencies LIBBPF := ../../tools/lib/bpf/bpf.o @@ -74,6 +75,7 @@ tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o +per_socket_stats_example-objs := $(LIBBPF) cookie_uid_helper_example.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -108,6 +110,7 @@ always += sampleip_kern.o always += lwt_len_hist_kern.o always += xdp_tx_iptunnel_kern.o always += test_map_in_map_kern.o +always += cookie_uid_helper_example.o HOSTCFLAGS += -I$(objtree)/usr/include HOSTCFLAGS += -I$(srctree)/tools/lib/ diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c new file mode 100644 index 000000000000..f6e5e58931c5 --- /dev/null +++ b/samples/bpf/cookie_uid_helper_example.c @@ -0,0 +1,217 @@ +/* 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 + * Then generate some traffic in variate ways. ping 0 -c 10 would work + * but the cookie and uid in this case could both be 0. A sample output + * with some traffic generated by web browser 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 + * + * 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 <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" + +struct stats { + uint32_t uid; + uint64_t packets; + uint64_t bytes; +}; + +static int map_fd, prog_fd; + +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 + offsetof(struct stats, uid)), + BPF_ST_MEM(BPF_DW, BPF_REG_10, + -32 + 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 + 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 INPUT -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, 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); + } + } +} + +int main(int argc, char *argv[]) +{ + if (argc > 2) { + printf("Too many argument provided\n"); + return 1; + } else if (argc < 2) { + printf("Usage: %s bpfObjName\n", argv[0]); + return 1; + } + + maps_create(); + prog_load(); + prog_attach_iptables(argv[1]); + + while (true) { + print_table(); + printf("\n"); + sleep(1); + }; + + return 0; +} diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h index 3705fba453a0..8ab36a04c174 100644 --- a/samples/bpf/libbpf.h +++ b/samples/bpf/libbpf.h @@ -135,6 +135,16 @@ struct bpf_insn; .off = OFF, \ .imm = 0 }) +/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ + +#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ diff --git a/samples/bpf/run_cookie_uid_helper_example.sh b/samples/bpf/run_cookie_uid_helper_example.sh new file mode 100644 index 000000000000..40da8aa75c44 --- /dev/null +++ b/samples/bpf/run_cookie_uid_helper_example.sh @@ -0,0 +1,14 @@ +#!/bin/bash +local_dir="$(pwd)" +root_dir=$local_dir/../.. +mnt_dir=$(mktemp -d --tmp) + +on_exit() { + iptables -D INPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT + umount ${mnt_dir} + rm -r ${mnt_dir} +} + +trap on_exit EXIT +mount -t bpf bpf ${mnt_dir} +./per_socket_stats_example ${mnt_dir}/bpf_prog |