File: /Users/paulross/dev/linux/linux-3.13/include/linux/uidgid.h

Green shading in the line number column means the source is part of the translation unit, red means it is conditionally excluded. Highlighted line numbers link to the translation unit page. Highlighted macros link to the macro page.

       1: #ifndef _LINUX_UIDGID_H
       2: #define _LINUX_UIDGID_H
       3: 
       4: /*
       5:  * A set of types for the internal kernel types representing uids and gids.
       6:  *
       7:  * The types defined in this header allow distinguishing which uids and gids in
       8:  * the kernel are values used by userspace and which uid and gid values are
       9:  * the internal kernel values.  With the addition of user namespaces the values
      10:  * can be different.  Using the type system makes it possible for the compiler
      11:  * to detect when we overlook these differences.
      12:  *
      13:  */
      14: #include <linux/types.h>
      15: #include <linux/highuid.h>
      16: 
      17: struct user_namespace;
      18: extern struct user_namespace init_user_ns;
      19: 
      20: #ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
      21: 
      22: typedef struct {
      23:     uid_t val;
      24: } kuid_t;
      25: 
      26: 
      27: typedef struct {
      28:     gid_t val;
      29: } kgid_t;
      30: 
      31: #define KUIDT_INIT(value) (kuid_t){ value }
      32: #define KGIDT_INIT(value) (kgid_t){ value }
      33: 
      34: static inline uid_t __kuid_val(kuid_t uid)
      35: {
      36:     return uid.val;
      37: }
      38: 
      39: static inline gid_t __kgid_val(kgid_t gid)
      40: {
      41:     return gid.val;
      42: }
      43: 
      44: #else
      45: 
      46: typedef uid_t kuid_t;
      47: typedef gid_t kgid_t;
      48: 
      49: static inline uid_t __kuid_val(kuid_t uid)
      50: {
      51:     return uid;
      52: }
      53: 
      54: static inline gid_t __kgid_val(kgid_t gid)
      55: {
      56:     return gid;
      57: }
      58: 
      59: #define KUIDT_INIT(value) ((kuid_t) value )
      60: #define KGIDT_INIT(value) ((kgid_t) value )
      61: 
      62: #endif
      63: 
      64: #define GLOBAL_ROOT_UID KUIDT_INIT(0)
      65: #define GLOBAL_ROOT_GID KGIDT_INIT(0)
      66: 
      67: #define INVALID_UID KUIDT_INIT(-1)
      68: #define INVALID_GID KGIDT_INIT(-1)
      69: 
      70: static inline bool uid_eq(kuid_t left, kuid_t right)
      71: {
      72:     return __kuid_val(left) == __kuid_val(right);
      73: }
      74: 
      75: static inline bool gid_eq(kgid_t left, kgid_t right)
      76: {
      77:     return __kgid_val(left) == __kgid_val(right);
      78: }
      79: 
      80: static inline bool uid_gt(kuid_t left, kuid_t right)
      81: {
      82:     return __kuid_val(left) > __kuid_val(right);
      83: }
      84: 
      85: static inline bool gid_gt(kgid_t left, kgid_t right)
      86: {
      87:     return __kgid_val(left) > __kgid_val(right);
      88: }
      89: 
      90: static inline bool uid_gte(kuid_t left, kuid_t right)
      91: {
      92:     return __kuid_val(left) >= __kuid_val(right);
      93: }
      94: 
      95: static inline bool gid_gte(kgid_t left, kgid_t right)
      96: {
      97:     return __kgid_val(left) >= __kgid_val(right);
      98: }
      99: 
     100: static inline bool uid_lt(kuid_t left, kuid_t right)
     101: {
     102:     return __kuid_val(left) < __kuid_val(right);
     103: }
     104: 
     105: static inline bool gid_lt(kgid_t left, kgid_t right)
     106: {
     107:     return __kgid_val(left) < __kgid_val(right);
     108: }
     109: 
     110: static inline bool uid_lte(kuid_t left, kuid_t right)
     111: {
     112:     return __kuid_val(left) <= __kuid_val(right);
     113: }
     114: 
     115: static inline bool gid_lte(kgid_t left, kgid_t right)
     116: {
     117:     return __kgid_val(left) <= __kgid_val(right);
     118: }
     119: 
     120: static inline bool uid_valid(kuid_t uid)
     121: {
     122:     return !uid_eq(uid, INVALID_UID);
     123: }
     124: 
     125: static inline bool gid_valid(kgid_t gid)
     126: {
     127:     return !gid_eq(gid, INVALID_GID);
     128: }
     129: 
     130: #ifdef CONFIG_USER_NS
     131: 
     132: extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
     133: extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
     134: 
     135: extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
     136: extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
     137: extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
     138: extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
     139: 
     140: static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
     141: {
     142:     return from_kuid(ns, uid) != (uid_t) -1;
     143: }
     144: 
     145: static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
     146: {
     147:     return from_kgid(ns, gid) != (gid_t) -1;
     148: }
     149: 
     150: #else
     151: 
     152: static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
     153: {
     154:     return KUIDT_INIT(uid);
     155: }
     156: 
     157: static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
     158: {
     159:     return KGIDT_INIT(gid);
     160: }
     161: 
     162: static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
     163: {
     164:     return __kuid_val(kuid);
     165: }
     166: 
     167: static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
     168: {
     169:     return __kgid_val(kgid);
     170: }
     171: 
     172: static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
     173: {
     174:     uid_t uid = from_kuid(to, kuid);
     175:     if (uid == (uid_t)-1)
     176:         uid = overflowuid;
     177:     return uid;
     178: }
     179: 
     180: static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
     181: {
     182:     gid_t gid = from_kgid(to, kgid);
     183:     if (gid == (gid_t)-1)
     184:         gid = overflowgid;
     185:     return gid;
     186: }
     187: 
     188: static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
     189: {
     190:     return true;
     191: }
     192: 
     193: static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
     194: {
     195:     return true;
     196: }
     197: 
     198: #endif /* CONFIG_USER_NS */
     199: 
     200: #endif /* _LINUX_UIDGID_H */
     201: