1 /* util.h
2  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
3  * Use of this source code is governed by a BSD-style license that can be
4  * found in the LICENSE file.
5  *
6  * Logging and other utility functions.
7  */
8 
9 #ifndef _UTIL_H_
10 #define _UTIL_H_
11 
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <sys/types.h>
15 #include <syslog.h>
16 #include <unistd.h>
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 #if defined(USE_EXIT_ON_DIE)
23 #define do_abort() exit(1)
24 #else
25 #define do_abort() abort()
26 #endif
27 
28 /* clang-format off */
29 #define die(_msg, ...) do { \
30 	do_log(LOG_ERR, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__); \
31 	do_abort(); \
32 } while (0)
33 
34 #define pdie(_msg, ...) \
35 	die(_msg ": %m", ## __VA_ARGS__)
36 
37 #define warn(_msg, ...) \
38 	do_log(LOG_WARNING, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__)
39 
40 #define pwarn(_msg, ...) \
41 	warn(_msg ": %m", ## __VA_ARGS__)
42 
43 #define info(_msg, ...) \
44 	do_log(LOG_INFO, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__)
45 
46 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
47 /* clang-format on */
48 
49 extern const char *log_syscalls[];
50 extern const size_t log_syscalls_len;
51 
52 enum logging_system_t {
53 	/* Log to syslog. This is the default. */
54 	LOG_TO_SYSLOG = 0,
55 
56 	/* Log to a file descriptor. */
57 	LOG_TO_FD,
58 };
59 
60 extern void do_log(int priority, const char *format, ...)
61     __attribute__((__format__(__printf__, 2, 3)));
62 
is_android(void)63 static inline int is_android(void)
64 {
65 #if defined(__ANDROID__)
66 	return 1;
67 #else
68 	return 0;
69 #endif
70 }
71 
72 void __asan_init(void) __attribute__((weak));
73 
running_with_asan(void)74 static inline int running_with_asan(void)
75 {
76 	return &__asan_init != 0;
77 }
78 
79 int lookup_syscall(const char *name);
80 const char *lookup_syscall_name(int nr);
81 
82 long int parse_constant(char *constant_str, char **endptr);
83 int parse_size(size_t *size, const char *sizespec);
84 
85 char *strip(char *s);
86 
87 /*
88  * tokenize: locate the next token in @stringp using the @delim
89  * @stringp A pointer to the string to scan for tokens
90  * @delim   The delimiter to split by
91  *
92  * Note that, unlike strtok, @delim is not a set of characters, but the full
93  * delimiter.  e.g. "a,;b,;c" with a delim of ",;" will yield ["a","b","c"].
94  *
95  * Note that, unlike strtok, this may return an empty token.  e.g. "a,,b" with
96  * strtok will yield ["a","b"], but this will yield ["a","","b"].
97  */
98 char *tokenize(char **stringp, const char *delim);
99 
100 char *path_join(const char *external_path, const char *internal_path);
101 
102 /*
103  * consumebytes: consumes @length bytes from a buffer @buf of length @buflength
104  * @length    Number of bytes to consume
105  * @buf       Buffer to consume from
106  * @buflength Size of @buf
107  *
108  * Returns a pointer to the base of the bytes, or NULL for errors.
109  */
110 void *consumebytes(size_t length, char **buf, size_t *buflength);
111 
112 /*
113  * consumestr: consumes a C string from a buffer @buf of length @length
114  * @buf    Buffer to consume
115  * @length Length of buffer
116  *
117  * Returns a pointer to the base of the string, or NULL for errors.
118  */
119 char *consumestr(char **buf, size_t *buflength);
120 
121 /*
122  * init_logging: initializes the module-wide logging.
123  * @logger       The logging system to use.
124  * @fd           The file descriptor to log into. Ignored unless
125  *               @logger = LOG_TO_FD.
126  * @min_priority The minimum priority to display. Corresponds to syslog's
127                  priority parameter. Ignored unless @logger = LOG_TO_FD.
128  */
129 void init_logging(enum logging_system_t logger, int fd, int min_priority);
130 
131 #ifdef __cplusplus
132 }; /* extern "C" */
133 #endif
134 
135 #endif /* _UTIL_H_ */
136