1 /* lsm.h - header file for lib directory
2 *
3 * Copyright 2015 Rob Landley <rob@landley.net>
4 */
5
6 #if CFG_TOYBOX_SELINUX
7 #include <selinux/selinux.h>
8 #else
9 #define is_selinux_enabled() 0
10 #define setfscreatecon(...) (-1)
11 #define getcon(...) (-1)
12 #define getfilecon(...) (-1)
13 #define lgetfilecon(...) (-1)
14 #define fgetfilecon(...) (-1)
15 #define setfilecon(...) (-1)
16 #define lsetfilecon(...) (-1)
17 #define fsetfilecon(...) (-1)
18 #endif
19
20 #if CFG_TOYBOX_SMACK
21 #include <sys/smack.h>
22 #include <sys/xattr.h>
23 #include <linux/xattr.h>
24 #else
25 #define XATTR_NAME_SMACK 0
26 //ssize_t fgetxattr (int fd, char *name, void *value, size_t size);
27 #define smack_smackfs_path(...) (-1)
28 #define smack_new_label_from_self(...) (-1)
29 #define smack_new_label_from_path(...) (-1)
30 #define smack_new_label_from_file(...) (-1)
31 #define smack_set_label_for_self(...) (-1)
32 #define smack_set_label_for_path(...) (-1)
33 #define smack_set_label_for_file(...) (-1)
34 #endif
35
36 // This turns into "return 0" when no LSM and lets code optimize out.
lsm_enabled(void)37 static inline int lsm_enabled(void)
38 {
39 if (CFG_TOYBOX_SMACK) return !!smack_smackfs_path();
40 else return is_selinux_enabled() == 1;
41 }
42
lsm_name(void)43 static inline char *lsm_name(void)
44 {
45 if (CFG_TOYBOX_SMACK) return "Smack";
46 if (CFG_TOYBOX_SELINUX) return "SELinux";
47
48 return "LSM";
49 }
50
51 // Fetch this process's lsm context
lsm_context(void)52 static inline char *lsm_context(void)
53 {
54 int ok = 0;
55 char *result;
56
57 if (CFG_TOYBOX_SMACK) ok = smack_new_label_from_self(&result) > 0;
58 else ok = getcon(&result) == 0;
59
60 return ok ? result : strdup("?");
61 }
62
63 // Set default label to apply to newly created stuff (NULL to clear it)
lsm_set_create(char * context)64 static inline int lsm_set_create(char *context)
65 {
66 if (CFG_TOYBOX_SMACK) return smack_set_label_for_self(context);
67 else return setfscreatecon(context);
68 }
69
70 // Label a file, following symlinks
lsm_set_context(char * filename,char * context)71 static inline int lsm_set_context(char *filename, char *context)
72 {
73 if (CFG_TOYBOX_SMACK)
74 return smack_set_label_for_path(filename, XATTR_NAME_SMACK, 1, context);
75 else return setfilecon(filename, context);
76 }
77
78 // Label a file, don't follow symlinks
lsm_lset_context(char * filename,char * context)79 static inline int lsm_lset_context(char *filename, char *context)
80 {
81 if (CFG_TOYBOX_SMACK)
82 return smack_set_label_for_path(filename, XATTR_NAME_SMACK, 0, context);
83 else return lsetfilecon(filename, context);
84 }
85
86 // Label a file by filehandle
lsm_fset_context(int file,char * context)87 static inline int lsm_fset_context(int file, char *context)
88 {
89 if (CFG_TOYBOX_SMACK)
90 return smack_set_label_for_file(file, XATTR_NAME_SMACK, context);
91 else return fsetfilecon(file, context);
92 }
93
94 // returns -1 in case of error or else the length of the context */
95 // context can be NULL to get the length only */
lsm_get_context(char * filename,char ** context)96 static inline int lsm_get_context(char *filename, char **context)
97 {
98 if (CFG_TOYBOX_SMACK)
99 return smack_new_label_from_path(filename, XATTR_NAME_SMACK, 1, context);
100 else return getfilecon(filename, context);
101 }
102
lsm_lget_context(char * filename,char ** context)103 static inline int lsm_lget_context(char *filename, char **context)
104 {
105 if (CFG_TOYBOX_SMACK)
106 return smack_new_label_from_path(filename, XATTR_NAME_SMACK, 0, context);
107 else return lgetfilecon(filename, context);
108 }
109
lsm_fget_context(int file,char ** context)110 static inline int lsm_fget_context(int file, char **context)
111 {
112 if (CFG_TOYBOX_SMACK)
113 return smack_new_label_from_file(file, XATTR_NAME_SMACK, context);
114 return fgetfilecon(file, context);
115 }
116