bpf: Add skb->sk, bpf_sk_fullsock and bpf_tcp_sock tests to test_verifer

This patch tests accessing the skb->sk and the new helpers,
bpf_sk_fullsock and bpf_tcp_sock.

The errstr of some existing "reference tracking" tests is changed
with s/bpf_sock/sock/ and s/socket/sock/ where "sock" is from the
verifier's reg_type_str[].
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/bpf_util.h

@@ -48,4 +48,13 @@ static inline unsigned int bpf_num_possible_cpus(void)
 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 #endif
 
+#ifndef sizeof_field
+#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
+#endif
+
+#ifndef offsetofend
+#define offsetofend(TYPE, MEMBER) \
+	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
+#endif
+
 #endif /* __BPF_UTIL__ */

tools/testing/selftests/bpf/verifier/ref_tracking.c

@@ -547,7 +547,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
-	.errstr = "cannot write into socket",
+	.errstr = "cannot write into sock",
 	.result = REJECT,
 },
 {
@@ -562,7 +562,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
-	.errstr = "invalid bpf_sock access off=0 size=8",
+	.errstr = "invalid sock access off=0 size=8",
 	.result = REJECT,
 },
 {

tools/testing/selftests/bpf/verifier/unpriv.c

@@ -365,7 +365,7 @@
 	},
 	.result = REJECT,
 	//.errstr = "same insn cannot be used with different pointers",
-	.errstr = "cannot write into socket",
+	.errstr = "cannot write into sock",
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 },
 {