selftests/bpf: Use CAP_BPF and CAP_PERFMON in tests

Make all test_verifier test exercise CAP_BPF and CAP_PERFMON
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200513230355.7858-4-alexei.starovoitov@gmail.com

tools/testing/selftests/bpf/test_verifier.c

@@ -818,10 +818,18 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 	}
 }
 
+struct libcap {
+	struct __user_cap_header_struct hdr;
+	struct __user_cap_data_struct data[2];
+};
+
 static int set_admin(bool admin)
 {
 	cap_t caps;
-	const cap_value_t cap_val = CAP_SYS_ADMIN;
+	/* need CAP_BPF, CAP_NET_ADMIN, CAP_PERFMON to load progs */
+	const cap_value_t cap_net_admin = CAP_NET_ADMIN;
+	const cap_value_t cap_sys_admin = CAP_SYS_ADMIN;
+	struct libcap *cap;
 	int ret = -1;
 
 	caps = cap_get_proc();
@@ -829,11 +837,26 @@ static int set_admin(bool admin)
 		perror("cap_get_proc");
 		return -1;
 	}
-	if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_val,
+	cap = (struct libcap *)caps;
+	if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_sys_admin, CAP_CLEAR)) {
+		perror("cap_set_flag clear admin");
+		goto out;
+	}
+	if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_net_admin,
 				admin ? CAP_SET : CAP_CLEAR)) {
-		perror("cap_set_flag");
+		perror("cap_set_flag set_or_clear net");
 		goto out;
 	}
+	/* libcap is likely old and simply ignores CAP_BPF and CAP_PERFMON,
+	 * so update effective bits manually
+	 */
+	if (admin) {
+		cap->data[1].effective |= 1 << (38 /* CAP_PERFMON */ - 32);
+		cap->data[1].effective |= 1 << (39 /* CAP_BPF */ - 32);
+	} else {
+		cap->data[1].effective &= ~(1 << (38 - 32));
+		cap->data[1].effective &= ~(1 << (39 - 32));
+	}
 	if (cap_set_proc(caps)) {
 		perror("cap_set_proc");
 		goto out;
@@ -1067,9 +1090,11 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
 
 static bool is_admin(void)
 {
+	cap_flag_value_t net_priv = CAP_CLEAR;
+	bool perfmon_priv = false;
+	bool bpf_priv = false;
+	struct libcap *cap;
 	cap_t caps;
-	cap_flag_value_t sysadmin = CAP_CLEAR;
-	const cap_value_t cap_val = CAP_SYS_ADMIN;
 
 #ifdef CAP_IS_SUPPORTED
 	if (!CAP_IS_SUPPORTED(CAP_SETFCAP)) {
@@ -1082,11 +1107,14 @@ static bool is_admin(void)
 		perror("cap_get_proc");
 		return false;
 	}
-	if (cap_get_flag(caps, cap_val, CAP_EFFECTIVE, &sysadmin))
-		perror("cap_get_flag");
+	cap = (struct libcap *)caps;
+	bpf_priv = cap->data[1].effective & (1 << (39/* CAP_BPF */ - 32));
+	perfmon_priv = cap->data[1].effective & (1 << (38/* CAP_PERFMON */ - 32));
+	if (cap_get_flag(caps, CAP_NET_ADMIN, CAP_EFFECTIVE, &net_priv))
+		perror("cap_get_flag NET");
 	if (cap_free(caps))
 		perror("cap_free");
-	return (sysadmin == CAP_SET);
+	return bpf_priv && perfmon_priv && net_priv == CAP_SET;
 }
 
 static void get_unpriv_disabled()

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

@@ -19,7 +19,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 2),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 1,
@@ -315,7 +315,7 @@
 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "allowed for root only",
+	.errstr_unpriv = "allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = POINTER_VALUE,
@@ -346,7 +346,7 @@
 	BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_2),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "allowed for root only",
+	.errstr_unpriv = "allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = TEST_DATA_LEN + TEST_DATA_LEN - ETH_HLEN - ETH_HLEN,
@@ -397,7 +397,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.fixup_map_hash_48b = { 3 },
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
@@ -1064,7 +1064,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "allowed for root only",
+	.errstr_unpriv = "allowed for",
 	.result_unpriv = REJECT,
 	.errstr = "R0 !read_ok",
 	.result = REJECT,
@@ -1977,7 +1977,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
@@ -2003,7 +2003,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.errstr = "!read_ok",
 	.result = REJECT,
 },
@@ -2028,7 +2028,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.errstr = "!read_ok",
 	.result = REJECT,
 },

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

@@ -85,7 +85,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 12),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -103,7 +103,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 12),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -121,7 +121,7 @@
 	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, -5),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -137,7 +137,7 @@
 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
@@ -152,7 +152,7 @@
 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+	.errstr_unpriv = "function calls to other bpf functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,