Commit | Line | Data |
---|---|---|
94368568 | 1 | /* vfs_vnops.c 6.3 84/08/29 */ |
961945a8 SL |
2 | |
3 | #include "../machine/reg.h" | |
fc96c615 | 4 | |
94368568 JB |
5 | #include "param.h" |
6 | #include "systm.h" | |
7 | #include "dir.h" | |
8 | #include "user.h" | |
9 | #include "fs.h" | |
10 | #include "file.h" | |
11 | #include "conf.h" | |
12 | #include "inode.h" | |
13 | #include "acct.h" | |
14 | #include "mount.h" | |
15 | #include "socket.h" | |
16 | #include "socketvar.h" | |
17 | #include "proc.h" | |
fc96c615 | 18 | |
fc96c615 BJ |
19 | /* |
20 | * Check mode permission on inode pointer. | |
21 | * Mode is READ, WRITE or EXEC. | |
22 | * In the case of WRITE, the | |
23 | * read-only status of the file | |
24 | * system is checked. | |
25 | * Also in WRITE, prototype text | |
26 | * segments cannot be written. | |
27 | * The mode is shifted to select | |
28 | * the owner/group/other fields. | |
29 | * The super user is granted all | |
30 | * permissions. | |
31 | */ | |
32 | access(ip, mode) | |
fdd90ee3 BJ |
33 | register struct inode *ip; |
34 | int mode; | |
fc96c615 BJ |
35 | { |
36 | register m; | |
197da11b | 37 | register int *gp; |
fc96c615 BJ |
38 | |
39 | m = mode; | |
fdd90ee3 | 40 | if (m == IWRITE) { |
40123f2c SL |
41 | /* |
42 | * Disallow write attempts on read-only | |
43 | * file systems; unless the file is a block | |
44 | * or character device resident on the | |
45 | * file system. | |
46 | */ | |
6459ebe0 | 47 | if (ip->i_fs->fs_ronly != 0) { |
77cc8249 BJ |
48 | if ((ip->i_mode & IFMT) != IFCHR && |
49 | (ip->i_mode & IFMT) != IFBLK) { | |
50 | u.u_error = EROFS; | |
51 | return (1); | |
52 | } | |
fc96c615 | 53 | } |
40123f2c SL |
54 | /* |
55 | * If there's shared text associated with | |
56 | * the inode, try to free it up once. If | |
57 | * we fail, we can't allow writing. | |
58 | */ | |
59 | if (ip->i_flag&ITEXT) | |
fc96c615 | 60 | xrele(ip); |
fdd90ee3 | 61 | if (ip->i_flag & ITEXT) { |
fc96c615 | 62 | u.u_error = ETXTBSY; |
fdd90ee3 | 63 | return (1); |
fc96c615 BJ |
64 | } |
65 | } | |
40123f2c SL |
66 | /* |
67 | * If you're the super-user, | |
68 | * you always get access. | |
69 | */ | |
fdd90ee3 BJ |
70 | if (u.u_uid == 0) |
71 | return (0); | |
40123f2c SL |
72 | /* |
73 | * Access check is based on only | |
74 | * one of owner, group, public. | |
75 | * If not owner, then check group. | |
76 | * If not a member of the group, then | |
77 | * check public access. | |
78 | */ | |
fdd90ee3 | 79 | if (u.u_uid != ip->i_uid) { |
fc96c615 | 80 | m >>= 3; |
40123f2c SL |
81 | if (u.u_gid == ip->i_gid) |
82 | goto found; | |
8f3338c3 SL |
83 | gp = u.u_groups; |
84 | for (; gp < &u.u_groups[NGROUPS] && *gp != NOGROUP; gp++) | |
4060c051 | 85 | if (ip->i_gid == *gp) |
197da11b BJ |
86 | goto found; |
87 | m >>= 3; | |
88 | found: | |
89 | ; | |
fc96c615 | 90 | } |
fdd90ee3 BJ |
91 | if ((ip->i_mode&m) != 0) |
92 | return (0); | |
fc96c615 | 93 | u.u_error = EACCES; |
fdd90ee3 | 94 | return (1); |
fc96c615 BJ |
95 | } |
96 | ||
97 | /* | |
98 | * Look up a pathname and test if | |
99 | * the resultant inode is owned by the | |
100 | * current user. | |
101 | * If not, try for super-user. | |
102 | * If permission is granted, | |
103 | * return inode pointer. | |
104 | */ | |
105 | struct inode * | |
715baff1 KM |
106 | owner(fname, follow) |
107 | caddr_t fname; | |
5485e062 | 108 | int follow; |
fc96c615 BJ |
109 | { |
110 | register struct inode *ip; | |
715baff1 | 111 | register struct nameidata *ndp = &u.u_nd; |
fc96c615 | 112 | |
715baff1 KM |
113 | ndp->ni_nameiop = LOOKUP | follow; |
114 | ndp->ni_segflg = UIO_USERSPACE; | |
115 | ndp->ni_dirp = fname; | |
116 | ip = namei(ndp); | |
fdd90ee3 BJ |
117 | if (ip == NULL) |
118 | return (NULL); | |
119 | if (u.u_uid == ip->i_uid) | |
120 | return (ip); | |
121 | if (suser()) | |
122 | return (ip); | |
fc96c615 | 123 | iput(ip); |
fdd90ee3 | 124 | return (NULL); |
fc96c615 BJ |
125 | } |
126 | ||
127 | /* | |
128 | * Test if the current user is the | |
129 | * super user. | |
130 | */ | |
131 | suser() | |
132 | { | |
133 | ||
fdd90ee3 | 134 | if (u.u_uid == 0) { |
fc96c615 | 135 | u.u_acflag |= ASU; |
fdd90ee3 | 136 | return (1); |
fc96c615 BJ |
137 | } |
138 | u.u_error = EPERM; | |
fdd90ee3 | 139 | return (0); |
fc96c615 | 140 | } |