diff options
Diffstat (limited to 'libcap/libcap.h')
| -rw-r--r-- | libcap/libcap.h | 46 |
1 files changed, 33 insertions, 13 deletions
diff --git a/libcap/libcap.h b/libcap/libcap.h index 67fa0d0..f4a72fe 100644 --- a/libcap/libcap.h +++ b/libcap/libcap.h @@ -9,6 +9,7 @@ #define LIBCAP_H #include <errno.h> +#include <sched.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -113,6 +114,7 @@ struct _cap_vfs_cap_data { #define CAP_T_MAGIC 0xCA90D0 struct _cap_struct { + __u8 mutex; struct __user_cap_header_struct head; union { struct __user_cap_data_struct set; @@ -121,6 +123,24 @@ struct _cap_struct { uid_t rootid; }; +/* + * Elementary exclusive locking primatives for situations where + * linking with pthreads needs it, but such linking is not common. + * + * _cap_mu_blocked(x) attempts to lock x but if already locked, returns true + * _cap_mu_lock(x) attempts to lock and waits until the lock is granted + * _cap_mu_unlock(x) unconditionally unlocks the lock + * _cap_mu_unlock_return(x, y) unlock lock x and return value y + */ +#define _cap_mu_blocked(x) \ + __atomic_test_and_set((void *)(x), __ATOMIC_SEQ_CST) +#define _cap_mu_lock(x) \ + while (_cap_mu_blocked(x)) sched_yield() +#define _cap_mu_unlock(x) \ + __atomic_clear((void *) (x), __ATOMIC_SEQ_CST) +#define _cap_mu_unlock_return(x, y) \ + do { _cap_mu_unlock(x); return (y); } while (0) + /* the maximum bits supportable */ #define __CAP_MAXBITS (__CAP_BLKS * 32) @@ -128,10 +148,15 @@ struct _cap_struct { #define CAP_S_MAGIC 0xCA95D0 /* iab set magic for cap_free */ -#define CAP_IAB_MAGIC 0xCA9AB +#define CAP_IAB_MAGIC 0xCA91AB /* launcher magic for cap_free */ -#define CAP_LAUNCH_MAGIC 0xCA91A +#define CAP_LAUNCH_MAGIC 0xCA91AC + +#define magic_of(x) ((x) ? *(-2 + (const __u32 *) x) : 0) +#define good_cap_t(x) (CAP_T_MAGIC == magic_of(x)) +#define good_cap_iab_t(x) (CAP_IAB_MAGIC == magic_of(x)) +#define good_cap_launch_t(x) (CAP_LAUNCH_MAGIC == magic_of(x)) /* * kernel API cap set abstraction @@ -142,16 +167,6 @@ struct _cap_struct { #define isset_cap(y, x, set) ((y)->u[(x) >> 5].flat[set] & (1u << ((x)&31))) /* - * Private definitions for internal use by the library. - */ - -#define __libcap_check_magic(c,magic) ((c) && *(-1+(__u32 *)(c)) == (magic)) -#define good_cap_t(c) __libcap_check_magic(c, CAP_T_MAGIC) -#define good_cap_string(c) __libcap_check_magic(c, CAP_S_MAGIC) -#define good_cap_iab_t(c) __libcap_check_magic(c, CAP_IAB_MAGIC) -#define good_cap_launch_t(c) __libcap_check_magic(c, CAP_LAUNCH_MAGIC) - -/* * These match CAP_DIFFERS() expectations */ #define LIBCAP_EFF (1 << CAP_EFFECTIVE) @@ -187,6 +202,9 @@ struct _cap_struct { #endif /* DEBUG */ extern char *_libcap_strdup(const char *text); +extern void _libcap_initialize(void); + +#define EXECABLE_INITIALIZE _libcap_initialize() /* * These are semi-public prototypes, they will only be defined in @@ -227,7 +245,7 @@ extern int capsetp(pid_t pid, cap_t cap_d); min = mid + 1; \ } \ } \ - val = min ? min : fallback; \ + val = min ? (min <= high ? min : fallback) : fallback; \ } while(0) /* @@ -238,6 +256,7 @@ extern int capsetp(pid_t pid, cap_t cap_d); * applied. */ struct cap_iab_s { + __u8 mutex; __u32 i[_LIBCAP_CAPABILITY_U32S]; __u32 a[_LIBCAP_CAPABILITY_U32S]; __u32 nb[_LIBCAP_CAPABILITY_U32S]; @@ -254,6 +273,7 @@ struct cap_iab_s { * multithreaded applications. */ struct cap_launch_s { + __u8 mutex; /* * Once forked but before active privilege is changed, this * function (if non-NULL) is called. |