1 /* 2 * Copyright (c) 1997 Andrew G Morgan <morgan (at) kernel.org> 3 * 4 * This file contains internal definitions for the various functions in 5 * this small capability library. 6 */ 7 8 #ifndef LIBCAP_H 9 #define LIBCAP_H 10 11 #include <errno.h> 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <stdint.h> 16 #include <sys/capability.h> 17 18 #ifndef __u8 19 #define __u8 uint8_t 20 #endif /* __8 */ 21 22 #ifndef __u32 23 #define __u32 uint32_t 24 #endif /* __u32 */ 25 26 /* include the names for the caps and a definition of __CAP_BITS */ 27 #include "cap_names.h" 28 29 #ifndef _LINUX_CAPABILITY_U32S_1 30 # define _LINUX_CAPABILITY_U32S_1 1 31 #endif /* ndef _LINUX_CAPABILITY_U32S */ 32 33 /* 34 * Do we match the local kernel? 35 */ 36 37 #if !defined(_LINUX_CAPABILITY_VERSION) 38 39 # error Kernel <linux/capability.h> does not support library 40 # error file "libcap.h" --> fix and recompile libcap 41 42 #elif !defined(_LINUX_CAPABILITY_VERSION_2) 43 44 # warning Kernel <linux/capability.h> does not support 64-bit capabilities 45 # warning and libcap is being built with no support for 64-bit capabilities 46 47 # ifndef _LINUX_CAPABILITY_VERSION_1 48 # define _LINUX_CAPABILITY_VERSION_1 0x19980330 49 # endif 50 51 # _LIBCAP_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_1 52 # _LIBCAP_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_1 53 54 #elif defined(_LINUX_CAPABILITY_VERSION_3) 55 56 # if (_LINUX_CAPABILITY_VERSION_3 != 0x20080522) 57 # error Kernel <linux/capability.h> v3 does not match library 58 # error file "libcap.h" --> fix and recompile libcap 59 # else 60 # define _LIBCAP_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3 61 # define _LIBCAP_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3 62 # endif 63 64 #elif (_LINUX_CAPABILITY_VERSION_2 != 0x20071026) 65 66 # error Kernel <linux/capability.h> does not match library 67 # error file "libcap.h" --> fix and recompile libcap 68 69 #else 70 71 # define _LIBCAP_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_2 72 # define _LIBCAP_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_2 73 74 #endif 75 76 #undef _LINUX_CAPABILITY_VERSION 77 #undef _LINUX_CAPABILITY_U32S 78 79 /* 80 * This is a pointer to a struct containing three consecutive 81 * capability sets in the order of the cap_flag_t type: the are 82 * effective,inheritable and permitted. This is the type that the 83 * user-space routines think of as 'internal' capabilities - this is 84 * the type that is passed to the kernel with the system calls related 85 * to processes. 86 */ 87 88 #if defined(VFS_CAP_REVISION_MASK) && !defined(VFS_CAP_U32) 89 # define VFS_CAP_U32_1 1 90 # define XATTR_CAPS_SZ_1 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_1)) 91 # define VFS_CAP_U32 VFS_CAP_U32_1 92 struct _cap_vfs_cap_data { 93 __le32 magic_etc; 94 struct { 95 __le32 permitted; 96 __le32 inheritable; 97 } data[VFS_CAP_U32_1]; 98 }; 99 # define vfs_cap_data _cap_vfs_cap_data 100 #endif 101 102 #ifndef CAP_TO_INDEX 103 # define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ 104 #endif /* ndef CAP_TO_INDEX */ 105 106 #ifndef CAP_TO_MASK 107 # define CAP_TO_MASK(x) (1 << ((x) & 31)) 108 #endif /* ndef CAP_TO_MASK */ 109 110 #define NUMBER_OF_CAP_SETS 3 /* effective, inheritable, permitted */ 111 #define __CAP_BLKS (_LIBCAP_CAPABILITY_U32S) 112 #define CAP_SET_SIZE (__CAP_BLKS * sizeof(__u32)) 113 114 #define CAP_T_MAGIC 0xCA90D0 115 struct _cap_struct { 116 struct __user_cap_header_struct head; 117 union { 118 struct __user_cap_data_struct set; 119 __u32 flat[NUMBER_OF_CAP_SETS]; 120 } u[_LIBCAP_CAPABILITY_U32S]; 121 }; 122 123 /* the maximum bits supportable */ 124 #define __CAP_MAXBITS (__CAP_BLKS * 32) 125 126 /* string magic for cap_free */ 127 #define CAP_S_MAGIC 0xCA95D0 128 129 /* 130 * kernel API cap set abstraction 131 */ 132 133 #define raise_cap(x,set) u[(x)>>5].flat[set] |= (1<<((x)&31)) 134 #define lower_cap(x,set) u[(x)>>5].flat[set] &= ~(1<<((x)&31)) 135 #define isset_cap(y,x,set) ((y)->u[(x)>>5].flat[set] & (1<<((x)&31))) 136 137 /* 138 * Private definitions for internal use by the library. 139 */ 140 141 #define __libcap_check_magic(c,magic) ((c) && *(-1+(__u32 *)(c)) == (magic)) 142 #define good_cap_t(c) __libcap_check_magic(c, CAP_T_MAGIC) 143 #define good_cap_string(c) __libcap_check_magic(c, CAP_S_MAGIC) 144 145 /* 146 * These match CAP_DIFFERS() expectations 147 */ 148 #define LIBCAP_EFF (1 << CAP_EFFECTIVE) 149 #define LIBCAP_INH (1 << CAP_INHERITABLE) 150 #define LIBCAP_PER (1 << CAP_PERMITTED) 151 152 /* 153 * library debugging 154 */ 155 #ifdef DEBUG 156 157 #include <stdio.h> 158 # define _cap_debug(f, x...) do { \ 159 fprintf(stderr, "%s(%s:%d): ", __FUNCTION__, __FILE__, __LINE__); \ 160 fprintf(stderr, f, ## x); \ 161 fprintf(stderr, "\n"); \ 162 } while (0) 163 164 # define _cap_debugcap(s, c, set) do { \ 165 unsigned _cap_index; \ 166 fprintf(stderr, "%s(%s:%d): %s", __FUNCTION__, __FILE__, __LINE__, s); \ 167 for (_cap_index=_LIBCAP_CAPABILITY_U32S; _cap_index-- > 0; ) { \ 168 fprintf(stderr, "%08x", (c).u[_cap_index].flat[set]); \ 169 } \ 170 fprintf(stderr, "\n"); \ 171 } while (0) 172 173 #else /* !DEBUG */ 174 175 # define _cap_debug(f, x...) 176 # define _cap_debugcap(s, c, set) 177 178 #endif /* DEBUG */ 179 180 extern char *_libcap_strdup(const char *text); 181 182 /* 183 * These are semi-public prototypes, they will only be defined in 184 * <sys/capability.h> if _POSIX_SOURCE is not #define'd, so we 185 * place them here too. 186 */ 187 188 extern int capset(cap_user_header_t header, cap_user_data_t data); 189 extern int capget(cap_user_header_t header, const cap_user_data_t data); 190 extern int capgetp(pid_t pid, cap_t cap_d); 191 extern int capsetp(pid_t pid, cap_t cap_d); 192 193 /* prctl based API for altering character of current process */ 194 #define PR_GET_KEEPCAPS 7 195 #define PR_SET_KEEPCAPS 8 196 #define PR_CAPBSET_READ 23 197 #define PR_CAPBSET_DROP 24 198 #define PR_GET_SECUREBITS 27 199 #define PR_SET_SECUREBITS 28 200 201 /* 202 * The library compares sizeof() with integer return values. To avoid 203 * signed/unsigned comparisons, leading to unfortunate 204 * misinterpretations of -1, we provide a convenient cast-to-signed-integer 205 * version of sizeof(). 206 */ 207 #define ssizeof(x) ((ssize_t) sizeof(x)) 208 209 #endif /* LIBCAP_H */ 210
