| #include <asm/types.h> |
| #include <linux/types.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <stddef.h> |
| #include <stdbool.h> |
| |
| #include <linux/unistd.h> |
| #include <linux/filter.h> |
| #include <linux/bpf_perf_event.h> |
| #include <linux/bpf.h> |
| |
| #include <bpf/bpf.h> |
| |
| #include "../../../include/linux/filter.h" |
| #include "bpf_rlimit.h" |
| #include "bpf_util.h" |
| |
| #define MAX_INSNS 512 |
| #define MAX_MATCHES 16 |
| |
| struct bpf_reg_match { |
| unsigned int line; |
| const char *match; |
| }; |
| |
| struct bpf_align_test { |
| const char *descr; |
| struct bpf_insn insns[MAX_INSNS]; |
| enum { |
| UNDEF, |
| ACCEPT, |
| REJECT |
| } result; |
| enum bpf_prog_type prog_type; |
| /* Matches must be in order of increasing line */ |
| struct bpf_reg_match matches[MAX_MATCHES]; |
| }; |
| |
| static struct bpf_align_test tests[] = { |
| /* Four tests of known constants. These aren't staggeringly |
| * interesting since we track exact values now. |
| */ |
| { |
| .descr = "mov", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_3, 2), |
| BPF_MOV64_IMM(BPF_REG_3, 4), |
| BPF_MOV64_IMM(BPF_REG_3, 8), |
| BPF_MOV64_IMM(BPF_REG_3, 16), |
| BPF_MOV64_IMM(BPF_REG_3, 32), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {1, "R1=ctx(id=0,off=0,imm=0)"}, |
| {1, "R10=fp0"}, |
| {1, "R3_w=inv2"}, |
| {2, "R3_w=inv4"}, |
| {3, "R3_w=inv8"}, |
| {4, "R3_w=inv16"}, |
| {5, "R3_w=inv32"}, |
| }, |
| }, |
| { |
| .descr = "shift", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_3, 4), |
| BPF_MOV64_IMM(BPF_REG_4, 32), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {1, "R1=ctx(id=0,off=0,imm=0)"}, |
| {1, "R10=fp0"}, |
| {1, "R3_w=inv1"}, |
| {2, "R3_w=inv2"}, |
| {3, "R3_w=inv4"}, |
| {4, "R3_w=inv8"}, |
| {5, "R3_w=inv16"}, |
| {6, "R3_w=inv1"}, |
| {7, "R4_w=inv32"}, |
| {8, "R4_w=inv16"}, |
| {9, "R4_w=inv8"}, |
| {10, "R4_w=inv4"}, |
| {11, "R4_w=inv2"}, |
| }, |
| }, |
| { |
| .descr = "addsub", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_3, 4), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 4), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 2), |
| BPF_MOV64_IMM(BPF_REG_4, 8), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {1, "R1=ctx(id=0,off=0,imm=0)"}, |
| {1, "R10=fp0"}, |
| {1, "R3_w=inv4"}, |
| {2, "R3_w=inv8"}, |
| {3, "R3_w=inv10"}, |
| {4, "R4_w=inv8"}, |
| {5, "R4_w=inv12"}, |
| {6, "R4_w=inv14"}, |
| }, |
| }, |
| { |
| .descr = "mul", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_3, 7), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 2), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 4), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {1, "R1=ctx(id=0,off=0,imm=0)"}, |
| {1, "R10=fp0"}, |
| {1, "R3_w=inv7"}, |
| {2, "R3_w=inv7"}, |
| {3, "R3_w=inv14"}, |
| {4, "R3_w=inv56"}, |
| }, |
| }, |
| |
| /* Tests using unknown values */ |
| #define PREP_PKT_POINTERS \ |
| BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, \ |
| offsetof(struct __sk_buff, data)), \ |
| BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, \ |
| offsetof(struct __sk_buff, data_end)) |
| |
| #define LOAD_UNKNOWN(DST_REG) \ |
| PREP_PKT_POINTERS, \ |
| BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), \ |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), \ |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_0, 1), \ |
| BPF_EXIT_INSN(), \ |
| BPF_LDX_MEM(BPF_B, DST_REG, BPF_REG_2, 0) |
| |
| { |
| .descr = "unknown shift", |
| .insns = { |
| LOAD_UNKNOWN(BPF_REG_3), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1), |
| LOAD_UNKNOWN(BPF_REG_4), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 5), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {7, "R0=pkt(id=0,off=8,r=8,imm=0)"}, |
| {7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {8, "R3_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"}, |
| {9, "R3_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| {10, "R3_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"}, |
| {11, "R3_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"}, |
| {18, "R3=pkt_end(id=0,off=0,imm=0)"}, |
| {18, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {19, "R4_w=inv(id=0,umax_value=8160,var_off=(0x0; 0x1fe0))"}, |
| {20, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"}, |
| {21, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"}, |
| {22, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| {23, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"}, |
| }, |
| }, |
| { |
| .descr = "unknown mul", |
| .insns = { |
| LOAD_UNKNOWN(BPF_REG_3), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_3), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 1), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_3), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_3), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 4), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_3), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 8), |
| BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {8, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {9, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {11, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"}, |
| {12, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {13, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| {14, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {15, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"}, |
| {16, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"}, |
| }, |
| }, |
| { |
| .descr = "packet const offset", |
| .insns = { |
| PREP_PKT_POINTERS, |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| |
| /* Skip over ethernet header. */ |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| |
| BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 0), |
| BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 1), |
| BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 2), |
| BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 3), |
| BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 0), |
| BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 2), |
| BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0), |
| |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| {4, "R5_w=pkt(id=0,off=0,r=0,imm=0)"}, |
| {5, "R5_w=pkt(id=0,off=14,r=0,imm=0)"}, |
| {6, "R4_w=pkt(id=0,off=14,r=0,imm=0)"}, |
| {10, "R2=pkt(id=0,off=0,r=18,imm=0)"}, |
| {10, "R5=pkt(id=0,off=14,r=18,imm=0)"}, |
| {10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"}, |
| {14, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"}, |
| {15, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"}, |
| }, |
| }, |
| { |
| .descr = "packet variable offset", |
| .insns = { |
| LOAD_UNKNOWN(BPF_REG_6), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2), |
| |
| /* First, add a constant to the R5 packet pointer, |
| * then a variable with a known alignment. |
| */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0), |
| |
| /* Now, test in the other direction. Adding first |
| * the variable offset to R5, then the constant. |
| */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0), |
| |
| /* Test multiple accumulations of unknown values |
| * into a packet pointer. |
| */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 4), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0), |
| |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| /* Calculated offset in R6 has unknown value, but known |
| * alignment of 4. |
| */ |
| {8, "R2=pkt(id=0,off=0,r=8,imm=0)"}, |
| {8, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Offset is added to packet pointer R5, resulting in |
| * known fixed offset, and variable offset from R6. |
| */ |
| {11, "R5_w=pkt(id=1,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* At the time the word size load is performed from R5, |
| * it's total offset is NET_IP_ALIGN + reg->off (0) + |
| * reg->aux_off (14) which is 16. Then the variable |
| * offset is considered using reg->aux_off_align which |
| * is 4 and meets the load's requirements. |
| */ |
| {15, "R4=pkt(id=1,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| {15, "R5=pkt(id=1,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Variable offset is added to R5 packet pointer, |
| * resulting in auxiliary alignment of 4. |
| */ |
| {18, "R5_w=pkt(id=2,off=0,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Constant offset is added to R5, resulting in |
| * reg->off of 14. |
| */ |
| {19, "R5_w=pkt(id=2,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off |
| * (14) which is 16. Then the variable offset is 4-byte |
| * aligned, so the total offset is 4-byte aligned and |
| * meets the load's requirements. |
| */ |
| {23, "R4=pkt(id=2,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| {23, "R5=pkt(id=2,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Constant offset is added to R5 packet pointer, |
| * resulting in reg->off value of 14. |
| */ |
| {26, "R5_w=pkt(id=0,off=14,r=8"}, |
| /* Variable offset is added to R5, resulting in a |
| * variable offset of (4n). |
| */ |
| {27, "R5_w=pkt(id=3,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Constant is added to R5 again, setting reg->off to 18. */ |
| {28, "R5_w=pkt(id=3,off=18,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* And once more we add a variable; resulting var_off |
| * is still (4n), fixed offset is not changed. |
| * Also, we create a new reg->id. |
| */ |
| {29, "R5_w=pkt(id=4,off=18,r=0,umax_value=2040,var_off=(0x0; 0x7fc)"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off (18) |
| * which is 20. Then the variable offset is (4n), so |
| * the total offset is 4-byte aligned and meets the |
| * load's requirements. |
| */ |
| {33, "R4=pkt(id=4,off=22,r=22,umax_value=2040,var_off=(0x0; 0x7fc)"}, |
| {33, "R5=pkt(id=4,off=18,r=22,umax_value=2040,var_off=(0x0; 0x7fc)"}, |
| }, |
| }, |
| { |
| .descr = "packet variable offset 2", |
| .insns = { |
| /* Create an unknown offset, (4n+2)-aligned */ |
| LOAD_UNKNOWN(BPF_REG_6), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14), |
| /* Add it to the packet pointer */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| /* Check bounds and perform a read */ |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0), |
| /* Make a (4n) offset from the value we just read */ |
| BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xff), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2), |
| /* Add it to the packet pointer */ |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| /* Check bounds and perform a read */ |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0), |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| /* Calculated offset in R6 has unknown value, but known |
| * alignment of 4. |
| */ |
| {8, "R2=pkt(id=0,off=0,r=8,imm=0)"}, |
| {8, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Adding 14 makes R6 be (4n+2) */ |
| {9, "R6_w=inv(id=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"}, |
| /* Packet pointer has (4n+2) offset */ |
| {11, "R5_w=pkt(id=1,off=0,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"}, |
| {13, "R4=pkt(id=1,off=4,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off (0) |
| * which is 2. Then the variable offset is (4n+2), so |
| * the total offset is 4-byte aligned and meets the |
| * load's requirements. |
| */ |
| {15, "R5=pkt(id=1,off=0,r=4,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"}, |
| /* Newly read value in R6 was shifted left by 2, so has |
| * known alignment of 4. |
| */ |
| {18, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Added (4n) to packet pointer's (4n+2) var_off, giving |
| * another (4n+2). |
| */ |
| {19, "R5_w=pkt(id=2,off=0,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"}, |
| {21, "R4=pkt(id=2,off=4,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off (0) |
| * which is 2. Then the variable offset is (4n+2), so |
| * the total offset is 4-byte aligned and meets the |
| * load's requirements. |
| */ |
| {23, "R5=pkt(id=2,off=0,r=4,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"}, |
| }, |
| }, |
| { |
| .descr = "dubious pointer arithmetic", |
| .insns = { |
| PREP_PKT_POINTERS, |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| /* (ptr - ptr) << 2 */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_3), |
| BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_5, 2), |
| /* We have a (4n) value. Let's make a packet offset |
| * out of it. First add 14, to make it a (4n+2) |
| */ |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14), |
| /* Then make sure it's nonnegative */ |
| BPF_JMP_IMM(BPF_JSGE, BPF_REG_5, 0, 1), |
| BPF_EXIT_INSN(), |
| /* Add it to packet pointer */ |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_2), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_5), |
| /* Check bounds and perform a read */ |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_6), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_6, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .result = REJECT, |
| .matches = { |
| {4, "R5_w=pkt_end(id=0,off=0,imm=0)"}, |
| /* (ptr - ptr) << 2 == unknown, (4n) */ |
| {6, "R5_w=inv(id=0,smax_value=9223372036854775804,umax_value=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc)"}, |
| /* (4n) + 14 == (4n+2). We blow our bounds, because |
| * the add could overflow. |
| */ |
| {7, "R5=inv(id=0,smin_value=-9223372036854775806,smax_value=9223372036854775806,umin_value=2,umax_value=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"}, |
| /* Checked s>=0 */ |
| {9, "R5=inv(id=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"}, |
| /* packet pointer + nonnegative (4n+2) */ |
| {11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"}, |
| {13, "R4=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"}, |
| /* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine. |
| * We checked the bounds, but it might have been able |
| * to overflow if the packet pointer started in the |
| * upper half of the address space. |
| * So we did not get a 'range' on R6, and the access |
| * attempt will fail. |
| */ |
| {15, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"}, |
| } |
| }, |
| { |
| .descr = "variable subtraction", |
| .insns = { |
| /* Create an unknown offset, (4n+2)-aligned */ |
| LOAD_UNKNOWN(BPF_REG_6), |
| BPF_MOV64_REG(BPF_REG_7, BPF_REG_6), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14), |
| /* Create another unknown, (4n)-aligned, and subtract |
| * it from the first one |
| */ |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2), |
| BPF_ALU64_REG(BPF_SUB, BPF_REG_6, BPF_REG_7), |
| /* Bounds-check the result */ |
| BPF_JMP_IMM(BPF_JSGE, BPF_REG_6, 0, 1), |
| BPF_EXIT_INSN(), |
| /* Add it to the packet pointer */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6), |
| /* Check bounds and perform a read */ |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| /* Calculated offset in R6 has unknown value, but known |
| * alignment of 4. |
| */ |
| {7, "R2=pkt(id=0,off=0,r=8,imm=0)"}, |
| {9, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Adding 14 makes R6 be (4n+2) */ |
| {10, "R6_w=inv(id=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"}, |
| /* New unknown value in R7 is (4n) */ |
| {11, "R7_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"}, |
| /* Subtracting it from R6 blows our unsigned bounds */ |
| {12, "R6=inv(id=0,smin_value=-1006,smax_value=1034,umin_value=2,umax_value=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"}, |
| /* Checked s>= 0 */ |
| {14, "R6=inv(id=0,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc))"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off (0) |
| * which is 2. Then the variable offset is (4n+2), so |
| * the total offset is 4-byte aligned and meets the |
| * load's requirements. |
| */ |
| {20, "R5=pkt(id=1,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc)"}, |
| |
| }, |
| }, |
| { |
| .descr = "pointer variable subtraction", |
| .insns = { |
| /* Create an unknown offset, (4n+2)-aligned and bounded |
| * to [14,74] |
| */ |
| LOAD_UNKNOWN(BPF_REG_6), |
| BPF_MOV64_REG(BPF_REG_7, BPF_REG_6), |
| BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xf), |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14), |
| /* Subtract it from the packet pointer */ |
| BPF_MOV64_REG(BPF_REG_5, BPF_REG_2), |
| BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_6), |
| /* Create another unknown, (4n)-aligned and >= 74. |
| * That in fact means >= 76, since 74 % 4 == 2 |
| */ |
| BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 76), |
| /* Add it to the packet pointer */ |
| BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_7), |
| /* Check bounds and perform a read */ |
| BPF_MOV64_REG(BPF_REG_4, BPF_REG_5), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4), |
| BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1), |
| BPF_EXIT_INSN(), |
| BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .prog_type = BPF_PROG_TYPE_SCHED_CLS, |
| .matches = { |
| /* Calculated offset in R6 has unknown value, but known |
| * alignment of 4. |
| */ |
| {7, "R2=pkt(id=0,off=0,r=8,imm=0)"}, |
| {10, "R6_w=inv(id=0,umax_value=60,var_off=(0x0; 0x3c))"}, |
| /* Adding 14 makes R6 be (4n+2) */ |
| {11, "R6_w=inv(id=0,umin_value=14,umax_value=74,var_off=(0x2; 0x7c))"}, |
| /* Subtracting from packet pointer overflows ubounds */ |
| {13, "R5_w=pkt(id=1,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c))"}, |
| /* New unknown value in R7 is (4n), >= 76 */ |
| {15, "R7_w=inv(id=0,umin_value=76,umax_value=1096,var_off=(0x0; 0x7fc))"}, |
| /* Adding it to packet pointer gives nice bounds again */ |
| {16, "R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"}, |
| /* At the time the word size load is performed from R5, |
| * its total fixed offset is NET_IP_ALIGN + reg->off (0) |
| * which is 2. Then the variable offset is (4n+2), so |
| * the total offset is 4-byte aligned and meets the |
| * load's requirements. |
| */ |
| {20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"}, |
| }, |
| }, |
| }; |
| |
| static int probe_filter_length(const struct bpf_insn *fp) |
| { |
| int len; |
| |
| for (len = MAX_INSNS - 1; len > 0; --len) |
| if (fp[len].code != 0 || fp[len].imm != 0) |
| break; |
| return len + 1; |
| } |
| |
| static char bpf_vlog[32768]; |
| |
| static int do_test_single(struct bpf_align_test *test) |
| { |
| struct bpf_insn *prog = test->insns; |
| int prog_type = test->prog_type; |
| char bpf_vlog_copy[32768]; |
| const char *line_ptr; |
| int cur_line = -1; |
| int prog_len, i; |
| int fd_prog; |
| int ret; |
| |
| prog_len = probe_filter_length(prog); |
| fd_prog = bpf_verify_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER, |
| prog, prog_len, BPF_F_STRICT_ALIGNMENT, |
| "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 2); |
| if (fd_prog < 0 && test->result != REJECT) { |
| printf("Failed to load program.\n"); |
| printf("%s", bpf_vlog); |
| ret = 1; |
| } else if (fd_prog >= 0 && test->result == REJECT) { |
| printf("Unexpected success to load!\n"); |
| printf("%s", bpf_vlog); |
| ret = 1; |
| close(fd_prog); |
| } else { |
| ret = 0; |
| /* We make a local copy so that we can strtok() it */ |
| strncpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy)); |
| line_ptr = strtok(bpf_vlog_copy, "\n"); |
| for (i = 0; i < MAX_MATCHES; i++) { |
| struct bpf_reg_match m = test->matches[i]; |
| |
| if (!m.match) |
| break; |
| while (line_ptr) { |
| cur_line = -1; |
| sscanf(line_ptr, "%u: ", &cur_line); |
| if (cur_line == m.line) |
| break; |
| line_ptr = strtok(NULL, "\n"); |
| } |
| if (!line_ptr) { |
| printf("Failed to find line %u for match: %s\n", |
| m.line, m.match); |
| ret = 1; |
| printf("%s", bpf_vlog); |
| break; |
| } |
| if (!strstr(line_ptr, m.match)) { |
| printf("Failed to find match %u: %s\n", |
| m.line, m.match); |
| ret = 1; |
| printf("%s", bpf_vlog); |
| break; |
| } |
| } |
| if (fd_prog >= 0) |
| close(fd_prog); |
| } |
| return ret; |
| } |
| |
| static int do_test(unsigned int from, unsigned int to) |
| { |
| int all_pass = 0; |
| int all_fail = 0; |
| unsigned int i; |
| |
| for (i = from; i < to; i++) { |
| struct bpf_align_test *test = &tests[i]; |
| int fail; |
| |
| printf("Test %3d: %s ... ", |
| i, test->descr); |
| fail = do_test_single(test); |
| if (fail) { |
| all_fail++; |
| printf("FAIL\n"); |
| } else { |
| all_pass++; |
| printf("PASS\n"); |
| } |
| } |
| printf("Results: %d pass %d fail\n", |
| all_pass, all_fail); |
| return all_fail ? EXIT_FAILURE : EXIT_SUCCESS; |
| } |
| |
| int main(int argc, char **argv) |
| { |
| unsigned int from = 0, to = ARRAY_SIZE(tests); |
| |
| if (argc == 3) { |
| unsigned int l = atoi(argv[argc - 2]); |
| unsigned int u = atoi(argv[argc - 1]); |
| |
| if (l < to && u < to) { |
| from = l; |
| to = u + 1; |
| } |
| } else if (argc == 2) { |
| unsigned int t = atoi(argv[argc - 1]); |
| |
| if (t < to) { |
| from = t; |
| to = t + 1; |
| } |
| } |
| return do_test(from, to); |
| } |
