samples/bpf: add verifier tests

add few tests for "pointer to packet" logic of the verifier

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c
index 9eba8d1..fe2fcec 100644 (file)
--- a/samples/bpf/test_verifier.c
+++ b/samples/bpf/test_verifier.c
@@ -1448,6 +1448,86 @@ static struct bpf_test tests[] = {
                .result = ACCEPT,
                .prog_type = BPF_PROG_TYPE_SCHED_CLS,
        },
+       {
+               "pkt: test1",
+               .insns = {
+                       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)),
+                       BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+                       BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+                       BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+                       BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_EXIT_INSN(),
+               },
+               .result = ACCEPT,
+               .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+       },
+       {
+               "pkt: test2",
+               .insns = {
+                       BPF_MOV64_IMM(BPF_REG_0, 1),
+                       BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1,
+                                   offsetof(struct __sk_buff, data_end)),
+                       BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+                                   offsetof(struct __sk_buff, data)),
+                       BPF_MOV64_REG(BPF_REG_5, BPF_REG_3),
+                       BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
+                       BPF_JMP_REG(BPF_JGT, BPF_REG_5, BPF_REG_4, 15),
+                       BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_3, 7),
+                       BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_3, 12),
+                       BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 14),
+                       BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+                                   offsetof(struct __sk_buff, data)),
+                       BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_4),
+                       BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
+                       BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 48),
+                       BPF_ALU64_IMM(BPF_RSH, BPF_REG_2, 48),
+                       BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_2),
+                       BPF_MOV64_REG(BPF_REG_2, BPF_REG_3),
+                       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 8),
+                       BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1,
+                                   offsetof(struct __sk_buff, data_end)),
+                       BPF_JMP_REG(BPF_JGT, BPF_REG_2, BPF_REG_1, 1),
+                       BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_3, 4),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_EXIT_INSN(),
+               },
+               .result = ACCEPT,
+               .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+       },
+       {
+               "pkt: test3",
+               .insns = {
+                       BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+                                   offsetof(struct __sk_buff, data)),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_EXIT_INSN(),
+               },
+               .errstr = "invalid bpf_context access off=76",
+               .result = REJECT,
+               .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
+       },
+       {
+               "pkt: test4",
+               .insns = {
+                       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)),
+                       BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+                       BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+                       BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+                       BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_EXIT_INSN(),
+               },
+               .errstr = "cannot write",
+               .result = REJECT,
+               .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+       },
 };
 
 static int probe_filter_length(struct bpf_insn *fp)