diff options
Diffstat (limited to 'samples/bpf')
| -rw-r--r-- | samples/bpf/Makefile | 12 | ||||
| -rw-r--r-- | samples/bpf/libbpf.c | 94 | ||||
| -rw-r--r-- | samples/bpf/libbpf.h | 172 | ||||
| -rw-r--r-- | samples/bpf/test_verifier.c | 548 |
4 files changed, 826 insertions, 0 deletions
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile new file mode 100644 index 000000000000..634391797856 --- /dev/null +++ b/samples/bpf/Makefile @@ -0,0 +1,12 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := test_verifier + +test_verifier-objs := test_verifier.o libbpf.o + +# Tell kbuild to always build the programs +always := $(hostprogs-y) + +HOSTCFLAGS += -I$(objtree)/usr/include diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c new file mode 100644 index 000000000000..ff6504420738 --- /dev/null +++ b/samples/bpf/libbpf.c @@ -0,0 +1,94 @@ +/* eBPF mini library */ +#include <stdlib.h> +#include <stdio.h> +#include <linux/unistd.h> +#include <unistd.h> +#include <string.h> +#include <linux/netlink.h> +#include <linux/bpf.h> +#include <errno.h> +#include "libbpf.h" + +static __u64 ptr_to_u64(void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + +int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, + int max_entries) +{ + union bpf_attr attr = { + .map_type = map_type, + .key_size = key_size, + .value_size = value_size, + .max_entries = max_entries + }; + + return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr)); +} + +int bpf_update_elem(int fd, void *key, void *value) +{ + union bpf_attr attr = { + .map_fd = fd, + .key = ptr_to_u64(key), + .value = ptr_to_u64(value), + }; + + return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); +} + +int bpf_lookup_elem(int fd, void *key, void *value) +{ + union bpf_attr attr = { + .map_fd = fd, + .key = ptr_to_u64(key), + .value = ptr_to_u64(value), + }; + + return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); +} + +int bpf_delete_elem(int fd, void *key) +{ + union bpf_attr attr = { + .map_fd = fd, + .key = ptr_to_u64(key), + }; + + return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); +} + +int bpf_get_next_key(int fd, void *key, void *next_key) +{ + union bpf_attr attr = { + .map_fd = fd, + .key = ptr_to_u64(key), + .next_key = ptr_to_u64(next_key), + }; + + return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); +} + +#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u)) + +char bpf_log_buf[LOG_BUF_SIZE]; + +int bpf_prog_load(enum bpf_prog_type prog_type, + const struct bpf_insn *insns, int prog_len, + const char *license) +{ + union bpf_attr attr = { + .prog_type = prog_type, + .insns = ptr_to_u64((void *) insns), + .insn_cnt = prog_len / sizeof(struct bpf_insn), + .license = ptr_to_u64((void *) license), + .log_buf = ptr_to_u64(bpf_log_buf), + .log_size = LOG_BUF_SIZE, + .log_level = 1, + }; + + bpf_log_buf[0] = 0; + + return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); +} diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h new file mode 100644 index 000000000000..8a31babeca5d --- /dev/null +++ b/samples/bpf/libbpf.h @@ -0,0 +1,172 @@ +/* eBPF mini library */ +#ifndef __LIBBPF_H +#define __LIBBPF_H + +struct bpf_insn; + +int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, + int max_entries); +int bpf_update_elem(int fd, void *key, void *value); +int bpf_lookup_elem(int fd, void *key, void *value); +int bpf_delete_elem(int fd, void *key); +int bpf_get_next_key(int fd, void *key, void *next_key); + +int bpf_prog_load(enum bpf_prog_type prog_type, + const struct bpf_insn *insns, int insn_len, + const char *license); + +#define LOG_BUF_SIZE 8192 +extern char bpf_log_buf[LOG_BUF_SIZE]; + +/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ + +#define BPF_ALU64_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +#define BPF_ALU32_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ + +#define BPF_ALU64_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_ALU32_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Short form of mov, dst_reg = src_reg */ + +#define BPF_MOV64_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* Short form of mov, dst_reg = imm32 */ + +#define BPF_MOV64_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ +#define BPF_LD_IMM64(DST, IMM) \ + BPF_LD_IMM64_RAW(DST, 0, IMM) + +#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_DW | BPF_IMM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = (__u32) (IMM) }), \ + ((struct bpf_insn) { \ + .code = 0, /* zero is reserved opcode */ \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = ((__u64) (IMM)) >> 32 }) + +#define BPF_PSEUDO_MAP_FD 1 + +/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ +#define BPF_LD_MAP_FD(DST, MAP_FD) \ + BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) + + +/* Memory load, dst_reg = *(uint *) (src_reg + off16) */ + +#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Memory store, *(uint *) (dst_reg + off16) = src_reg */ + +#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ + .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) \ + ((struct bpf_insn) { \ + .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ + +#define BPF_JMP_REG(OP, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ + +#define BPF_JMP_IMM(OP, DST, IMM, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Raw code statement block */ + +#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ + ((struct bpf_insn) { \ + .code = CODE, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = IMM }) + +/* Program exit */ + +#define BPF_EXIT_INSN() \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_EXIT, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = 0 }) + +#endif diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c new file mode 100644 index 000000000000..d10992e2740e --- /dev/null +++ b/samples/bpf/test_verifier.c @@ -0,0 +1,548 @@ +/* + * Testsuite for eBPF verifier + * + * Copyright (c) 2014 PLUMgrid, http://plumgrid.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include <stdio.h> +#include <unistd.h> +#include <linux/bpf.h> +#include <errno.h> +#include <linux/unistd.h> +#include <string.h> +#include <linux/filter.h> +#include "libbpf.h" + +#define MAX_INSNS 512 +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) + +struct bpf_test { + const char *descr; + struct bpf_insn insns[MAX_INSNS]; + int fixup[32]; + const char *errstr; + enum { + ACCEPT, + REJECT + } result; +}; + +static struct bpf_test tests[] = { + { + "add+sub+mul", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 2), + BPF_MOV64_IMM(BPF_REG_2, 3), + BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -1), + BPF_ALU64_IMM(BPF_MUL, BPF_REG_1, 3), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "unreachable", + .insns = { + BPF_EXIT_INSN(), + BPF_EXIT_INSN(), + }, + .errstr = "unreachable", + .result = REJECT, + }, + { + "unreachable2", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_JMP_IMM(BPF_JA, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "unreachable", + .result = REJECT, + }, + { + "out of range jump", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "out of range jump2", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, -2), + BPF_EXIT_INSN(), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "test1 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM insn", + .result = REJECT, + }, + { + "test2 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM insn", + .result = REJECT, + }, + { + "test3 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "test4 ld_imm64", + .insns = { + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "test5 ld_imm64", + .insns = { + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "no bpf_exit", + .insns = { + BPF_ALU64_REG(BPF_MOV, BPF_REG_0, BPF_REG_2), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "loop (back-edge)", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, -1), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "loop2 (back-edge)", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_3, BPF_REG_0), + BPF_JMP_IMM(BPF_JA, 0, 0, -4), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "conditional loop", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_3, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, -3), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "read uninitialized register", + .insns = { + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), + }, + .errstr = "R2 !read_ok", + .result = REJECT, + }, + { + "read invalid register", + .insns = { + BPF_MOV64_REG(BPF_REG_0, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R15 is invalid", + .result = REJECT, + }, + { + "program doesn't init R0 before exit", + .insns = { + BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .errstr = "R0 !read_ok", + .result = REJECT, + }, + { + "stack out of bounds", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid stack", + .result = REJECT, + }, + { + "invalid call insn1", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL | BPF_X, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_CALL uses reserved", + .result = REJECT, + }, + { + "invalid call insn2", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 1, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_CALL uses reserved", + .result = REJECT, + }, + { + "invalid function call", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, 1234567), + BPF_EXIT_INSN(), + }, + .errstr = "invalid func 1234567", + .result = REJECT, + }, + { + "uninitialized stack1", + .insns = { + 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_unspec), + BPF_EXIT_INSN(), + }, + .fixup = {2}, + .errstr = "invalid indirect read from stack", + .result = REJECT, + }, + { + "uninitialized stack2", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid read from stack", + .result = REJECT, + }, + { + "check valid spill/fill", + .insns = { + /* spill R1(ctx) into stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + + /* fill it back into R2 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8), + + /* should be able to access R0 = *(R2 + 8) */ + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check corrupted spill/fill", + .insns = { + /* spill R1(ctx) into stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + + /* mess up with R1 pointer on stack */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -7, 0x23), + + /* fill back into R0 should fail */ + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), + + BPF_EXIT_INSN(), + }, + .errstr = "corrupted spill", + .result = REJECT, + }, + { + "invalid src register in STX", + .insns = { + BPF_STX_MEM(BPF_B, BPF_REG_10, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R15 is invalid", + .result = REJECT, + }, + { + "invalid dst register in STX", + .insns = { + BPF_STX_MEM(BPF_B, 14, BPF_REG_10, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R14 is invalid", + .result = REJECT, + }, + { + "invalid dst register in ST", + .insns = { + BPF_ST_MEM(BPF_B, 14, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R14 is invalid", + .result = REJECT, + }, + { + "invalid src register in LDX", + .insns = { + BPF_LDX_MEM(BPF_B, BPF_REG_0, 12, 0), + BPF_EXIT_INSN(), + }, + .errstr = "R12 is invalid", + .result = REJECT, + }, + { + "invalid dst register in LDX", + .insns = { + BPF_LDX_MEM(BPF_B, 11, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .errstr = "R11 is invalid", + .result = REJECT, + }, + { + "junk insn", + .insns = { + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM", + .result = REJECT, + }, + { + "junk insn2", + .insns = { + BPF_RAW_INSN(1, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_LDX uses reserved fields", + .result = REJECT, + }, + { + "junk insn3", + .insns = { + BPF_RAW_INSN(-1, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_ALU opcode f0", + .result = REJECT, + }, + { + "junk insn4", + .insns = { + BPF_RAW_INSN(-1, -1, -1, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_ALU opcode f0", + .result = REJECT, + }, + { + "junk insn5", + .insns = { + BPF_RAW_INSN(0x7f, -1, -1, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_ALU uses reserved fields", + .result = REJECT, + }, + { + "misaligned read from stack", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -4), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "invalid map_fd for function call", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_ALU64_REG(BPF_MOV, 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_unspec), + BPF_EXIT_INSN(), + }, + .errstr = "fd 0 is not pointing to valid bpf_map", + .result = REJECT, + }, + { + "don't check return value before access", + .insns = { + 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_unspec), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "R0 invalid mem access 'map_value_or_null'", + .result = REJECT, + }, + { + "access memory with incorrect alignment", + .insns = { + 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_unspec), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "sometimes access memory with incorrect alignment", + .insns = { + 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_unspec), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "R0 invalid mem access", + .result = REJECT, + }, +}; + +static int probe_filter_length(struct bpf_insn *fp) +{ + int len = 0; + + for (len = MAX_INSNS - 1; len > 0; --len) + if (fp[len].code != 0 || fp[len].imm != 0) + break; + + return len + 1; +} + +static int create_map(void) +{ + long long key, value = 0; + int map_fd; + + map_fd = bpf_create_map(BPF_MAP_TYPE_UNSPEC, sizeof(key), sizeof(value), 1024); + if (map_fd < 0) { + printf("failed to create map '%s'\n", strerror(errno)); + } + + return map_fd; +} + +static int test(void) +{ + int prog_fd, i; + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + struct bpf_insn *prog = tests[i].insns; + int prog_len = probe_filter_length(prog); + int *fixup = tests[i].fixup; + int map_fd = -1; + + if (*fixup) { + map_fd = create_map(); + + do { + prog[*fixup].imm = map_fd; + fixup++; + } while (*fixup); + } + printf("#%d %s ", i, tests[i].descr); + + prog_fd = bpf_prog_load(BPF_PROG_TYPE_UNSPEC, prog, + prog_len * sizeof(struct bpf_insn), + "GPL"); + + if (tests[i].result == ACCEPT) { + if (prog_fd < 0) { + printf("FAIL\nfailed to load prog '%s'\n", + strerror(errno)); + printf("%s", bpf_log_buf); + goto fail; + } + } else { + if (prog_fd >= 0) { + printf("FAIL\nunexpected success to load\n"); + printf("%s", bpf_log_buf); + goto fail; + } + if (strstr(bpf_log_buf, tests[i].errstr) == 0) { + printf("FAIL\nunexpected error message: %s", + bpf_log_buf); + goto fail; + } + } + + printf("OK\n"); +fail: + if (map_fd >= 0) + close(map_fd); + close(prog_fd); + + } + + return 0; +} + +int main(void) +{ + return test(); +} |