Cache user_ns in struct cred
[linux-2.6.git] / kernel / uid16.c
1 /*
2  *      Wrapper functions for 16bit uid back compatibility. All nicely tied
3  *      together in the faint hope we can take the out in five years time.
4  */
5
6 #include <linux/mm.h>
7 #include <linux/mman.h>
8 #include <linux/notifier.h>
9 #include <linux/reboot.h>
10 #include <linux/prctl.h>
11 #include <linux/capability.h>
12 #include <linux/init.h>
13 #include <linux/highuid.h>
14 #include <linux/security.h>
15 #include <linux/syscalls.h>
16
17 #include <asm/uaccess.h>
18
19 SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
20 {
21         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
22         /* avoid REGPARM breakage on x86: */
23         asmlinkage_protect(3, ret, filename, user, group);
24         return ret;
25 }
26
27 SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
28 {
29         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
30         /* avoid REGPARM breakage on x86: */
31         asmlinkage_protect(3, ret, filename, user, group);
32         return ret;
33 }
34
35 SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
36 {
37         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
38         /* avoid REGPARM breakage on x86: */
39         asmlinkage_protect(3, ret, fd, user, group);
40         return ret;
41 }
42
43 SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
44 {
45         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
46         /* avoid REGPARM breakage on x86: */
47         asmlinkage_protect(2, ret, rgid, egid);
48         return ret;
49 }
50
51 SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
52 {
53         long ret = sys_setgid(low2highgid(gid));
54         /* avoid REGPARM breakage on x86: */
55         asmlinkage_protect(1, ret, gid);
56         return ret;
57 }
58
59 SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
60 {
61         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
62         /* avoid REGPARM breakage on x86: */
63         asmlinkage_protect(2, ret, ruid, euid);
64         return ret;
65 }
66
67 SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
68 {
69         long ret = sys_setuid(low2highuid(uid));
70         /* avoid REGPARM breakage on x86: */
71         asmlinkage_protect(1, ret, uid);
72         return ret;
73 }
74
75 SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
76 {
77         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
78                                  low2highuid(suid));
79         /* avoid REGPARM breakage on x86: */
80         asmlinkage_protect(3, ret, ruid, euid, suid);
81         return ret;
82 }
83
84 SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruid, old_uid_t __user *, euid, old_uid_t __user *, suid)
85 {
86         const struct cred *cred = current_cred();
87         int retval;
88
89         if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
90             !(retval   = put_user(high2lowuid(cred->euid), euid)))
91                 retval = put_user(high2lowuid(cred->suid), suid);
92
93         return retval;
94 }
95
96 SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
97 {
98         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
99                                  low2highgid(sgid));
100         /* avoid REGPARM breakage on x86: */
101         asmlinkage_protect(3, ret, rgid, egid, sgid);
102         return ret;
103 }
104
105
106 SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgid, old_gid_t __user *, egid, old_gid_t __user *, sgid)
107 {
108         const struct cred *cred = current_cred();
109         int retval;
110
111         if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
112             !(retval   = put_user(high2lowgid(cred->egid), egid)))
113                 retval = put_user(high2lowgid(cred->sgid), sgid);
114
115         return retval;
116 }
117
118 SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
119 {
120         long ret = sys_setfsuid(low2highuid(uid));
121         /* avoid REGPARM breakage on x86: */
122         asmlinkage_protect(1, ret, uid);
123         return ret;
124 }
125
126 SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
127 {
128         long ret = sys_setfsgid(low2highgid(gid));
129         /* avoid REGPARM breakage on x86: */
130         asmlinkage_protect(1, ret, gid);
131         return ret;
132 }
133
134 static int groups16_to_user(old_gid_t __user *grouplist,
135     struct group_info *group_info)
136 {
137         int i;
138         old_gid_t group;
139
140         for (i = 0; i < group_info->ngroups; i++) {
141                 group = high2lowgid(GROUP_AT(group_info, i));
142                 if (put_user(group, grouplist+i))
143                         return -EFAULT;
144         }
145
146         return 0;
147 }
148
149 static int groups16_from_user(struct group_info *group_info,
150     old_gid_t __user *grouplist)
151 {
152         int i;
153         old_gid_t group;
154
155         for (i = 0; i < group_info->ngroups; i++) {
156                 if (get_user(group, grouplist+i))
157                         return  -EFAULT;
158                 GROUP_AT(group_info, i) = low2highgid(group);
159         }
160
161         return 0;
162 }
163
164 SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
165 {
166         const struct cred *cred = current_cred();
167         int i;
168
169         if (gidsetsize < 0)
170                 return -EINVAL;
171
172         i = cred->group_info->ngroups;
173         if (gidsetsize) {
174                 if (i > gidsetsize) {
175                         i = -EINVAL;
176                         goto out;
177                 }
178                 if (groups16_to_user(grouplist, cred->group_info)) {
179                         i = -EFAULT;
180                         goto out;
181                 }
182         }
183 out:
184         return i;
185 }
186
187 SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
188 {
189         struct group_info *group_info;
190         int retval;
191
192         if (!nsown_capable(CAP_SETGID))
193                 return -EPERM;
194         if ((unsigned)gidsetsize > NGROUPS_MAX)
195                 return -EINVAL;
196
197         group_info = groups_alloc(gidsetsize);
198         if (!group_info)
199                 return -ENOMEM;
200         retval = groups16_from_user(group_info, grouplist);
201         if (retval) {
202                 put_group_info(group_info);
203                 return retval;
204         }
205
206         retval = set_current_groups(group_info);
207         put_group_info(group_info);
208
209         return retval;
210 }
211
212 SYSCALL_DEFINE0(getuid16)
213 {
214         return high2lowuid(current_uid());
215 }
216
217 SYSCALL_DEFINE0(geteuid16)
218 {
219         return high2lowuid(current_euid());
220 }
221
222 SYSCALL_DEFINE0(getgid16)
223 {
224         return high2lowgid(current_gid());
225 }
226
227 SYSCALL_DEFINE0(getegid16)
228 {
229         return high2lowgid(current_egid());
230 }