summaryrefslogtreecommitdiffstats
path: root/src/shared/seccomp-util.h
blob: 7583357e8af64308f482264cd48cd5415115c388 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

#if HAVE_SECCOMP
#include <seccomp.h>
#endif
#include <stdbool.h>
#include <stdint.h>

#include "errno-list.h"
#include "errno-util.h"
#include "parse-util.h"
#include "set.h"
#include "string-util.h"

#if HAVE_SECCOMP

const char* seccomp_arch_to_string(uint32_t c);
int seccomp_arch_from_string(const char *n, uint32_t *ret);

int seccomp_init_for_arch(scmp_filter_ctx *ret, uint32_t arch, uint32_t default_action);

bool is_seccomp_available(void);

typedef struct SyscallFilterSet {
        const char *name;
        const char *help;
        const char *value;
} SyscallFilterSet;

enum {
        /* Please leave DEFAULT first and KNOWN last, but sort the rest alphabetically */
        SYSCALL_FILTER_SET_DEFAULT,
        SYSCALL_FILTER_SET_AIO,
        SYSCALL_FILTER_SET_BASIC_IO,
        SYSCALL_FILTER_SET_CHOWN,
        SYSCALL_FILTER_SET_CLOCK,
        SYSCALL_FILTER_SET_CPU_EMULATION,
        SYSCALL_FILTER_SET_DEBUG,
        SYSCALL_FILTER_SET_FILE_SYSTEM,
        SYSCALL_FILTER_SET_IO_EVENT,
        SYSCALL_FILTER_SET_IPC,
        SYSCALL_FILTER_SET_KEYRING,
        SYSCALL_FILTER_SET_MEMLOCK,
        SYSCALL_FILTER_SET_MODULE,
        SYSCALL_FILTER_SET_MOUNT,
        SYSCALL_FILTER_SET_NETWORK_IO,
        SYSCALL_FILTER_SET_OBSOLETE,
        SYSCALL_FILTER_SET_PKEY,
        SYSCALL_FILTER_SET_PRIVILEGED,
        SYSCALL_FILTER_SET_PROCESS,
        SYSCALL_FILTER_SET_RAW_IO,
        SYSCALL_FILTER_SET_REBOOT,
        SYSCALL_FILTER_SET_RESOURCES,
        SYSCALL_FILTER_SET_SANDBOX,
        SYSCALL_FILTER_SET_SETUID,
        SYSCALL_FILTER_SET_SIGNAL,
        SYSCALL_FILTER_SET_SWAP,
        SYSCALL_FILTER_SET_SYNC,
        SYSCALL_FILTER_SET_SYSTEM_SERVICE,
        SYSCALL_FILTER_SET_TIMER,
        SYSCALL_FILTER_SET_KNOWN,
        _SYSCALL_FILTER_SET_MAX,
};

assert_cc(SYSCALL_FILTER_SET_DEFAULT == 0);
assert_cc(SYSCALL_FILTER_SET_KNOWN == _SYSCALL_FILTER_SET_MAX-1);

extern const SyscallFilterSet syscall_filter_sets[];

const SyscallFilterSet *syscall_filter_set_find(const char *name);

int seccomp_filter_set_add(Hashmap *s, bool b, const SyscallFilterSet *set);

int seccomp_add_syscall_filter_item(
                scmp_filter_ctx *ctx,
                const char *name,
                uint32_t action,
                char **exclude,
                bool log_missing,
                char ***added);

int seccomp_load_syscall_filter_set(uint32_t default_action, const SyscallFilterSet *set, uint32_t action, bool log_missing);
int seccomp_load_syscall_filter_set_raw(uint32_t default_action, Hashmap* set, uint32_t action, bool log_missing);

typedef enum SeccompParseFlags {
        SECCOMP_PARSE_INVERT     = 1 << 0,
        SECCOMP_PARSE_ALLOW_LIST = 1 << 1,
        SECCOMP_PARSE_LOG        = 1 << 2,
        SECCOMP_PARSE_PERMISSIVE = 1 << 3,
} SeccompParseFlags;

int seccomp_parse_syscall_filter(
                const char *name,
                int errno_num,
                Hashmap *filter,
                SeccompParseFlags flags,
                const char *unit,
                const char *filename, unsigned line);

int seccomp_restrict_archs(Set *archs);
int seccomp_restrict_namespaces(unsigned long retain);
int seccomp_protect_sysctl(void);
int seccomp_protect_syslog(void);
int seccomp_restrict_address_families(Set *address_families, bool allow_list);
int seccomp_restrict_realtime_full(int error_code); /* This is mostly for testing code. */
static inline int seccomp_restrict_realtime(void) {
        return seccomp_restrict_realtime_full(EPERM);
}
int seccomp_memory_deny_write_execute(void);
int seccomp_lock_personality(unsigned long personality);
int seccomp_protect_hostname(void);
int seccomp_restrict_suid_sgid(void);

extern uint32_t seccomp_local_archs[];

#define SECCOMP_LOCAL_ARCH_END UINT32_MAX

/* Note: 0 is safe to use here because although SCMP_ARCH_NATIVE is 0, it would
 * never be in the seccomp_local_archs array anyway so we can use it as a
 * marker. */
#define SECCOMP_LOCAL_ARCH_BLOCKED 0

#define SECCOMP_FOREACH_LOCAL_ARCH(arch) \
        for (unsigned _i = ({ (arch) = seccomp_local_archs[0]; 0; });   \
             (arch) != SECCOMP_LOCAL_ARCH_END;                          \
             (arch) = seccomp_local_archs[++_i])                        \
                if ((arch) != SECCOMP_LOCAL_ARCH_BLOCKED)

/* EACCES: does not have the CAP_SYS_ADMIN or no_new_privs == 1
 * ENOMEM: out of memory, failed to allocate space for a libseccomp structure, or would exceed a defined constant
 * EFAULT: addresses passed as args (by libseccomp) are invalid */
static inline bool ERRNO_IS_NEG_SECCOMP_FATAL(intmax_t r) {
        return IN_SET(r,
                      -EPERM,
                      -EACCES,
                      -ENOMEM,
                      -EFAULT);
}
_DEFINE_ABS_WRAPPER(SECCOMP_FATAL);

DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(scmp_filter_ctx, seccomp_release, NULL);

int parse_syscall_archs(char **l, Set **ret_archs);

uint32_t scmp_act_kill_process(void);

int parse_syscall_and_errno(const char *in, char **name, int *error);

int seccomp_suppress_sync(void);

#else

static inline bool is_seccomp_available(void) {
        return false;
}

#endif

/* This is a special value to be used where syscall filters otherwise expect errno numbers, will be
   replaced with real seccomp action. */
enum {
        SECCOMP_ERROR_NUMBER_KILL = INT_MAX - 1,
};

static inline bool seccomp_errno_or_action_is_valid(int n) {
        return n == SECCOMP_ERROR_NUMBER_KILL || errno_is_valid(n);
}

static inline int seccomp_parse_errno_or_action(const char *p) {
        if (streq_ptr(p, "kill"))
                return SECCOMP_ERROR_NUMBER_KILL;
        return parse_errno(p);
}

static inline const char *seccomp_errno_or_action_to_string(int num) {
        if (num == SECCOMP_ERROR_NUMBER_KILL)
                return "kill";
        return errno_to_name(num);
}