| | 1 | /* vfs_vnops.c 4.30 82/11/13 */ |
| | 2 | |
| | 3 | #include "../h/param.h" |
| | 4 | #include "../h/systm.h" |
| | 5 | #include "../h/dir.h" |
| | 6 | #include "../h/user.h" |
| | 7 | #include "../h/fs.h" |
| | 8 | #include "../h/file.h" |
| | 9 | #include "../h/conf.h" |
| | 10 | #include "../h/inode.h" |
| | 11 | #include "../h/reg.h" |
| | 12 | #include "../h/acct.h" |
| | 13 | #include "../h/mount.h" |
| | 14 | #include "../h/socket.h" |
| | 15 | #include "../h/socketvar.h" |
| | 16 | #include "../h/proc.h" |
| | 17 | #include "../h/nami.h" |
| | 18 | |
| | 19 | /* |
| | 20 | * Openi called to allow handler |
| | 21 | * of special files to initialize and |
| | 22 | * validate before actual IO. |
| | 23 | */ |
| | 24 | openi(ip, mode) |
| | 25 | register struct inode *ip; |
| | 26 | { |
| | 27 | dev_t dev = (dev_t)ip->i_rdev; |
| | 28 | register u_int maj = major(dev); |
| | 29 | |
| | 30 | switch (ip->i_mode&IFMT) { |
| | 31 | |
| | 32 | case IFCHR: |
| | 33 | if (maj >= nchrdev) |
| | 34 | return (ENXIO); |
| | 35 | return ((*cdevsw[maj].d_open)(dev, mode)); |
| | 36 | |
| | 37 | case IFBLK: |
| | 38 | if (maj >= nblkdev) |
| | 39 | return (ENXIO); |
| | 40 | return ((*bdevsw[maj].d_open)(dev, mode)); |
| | 41 | } |
| | 42 | return (0); |
| | 43 | } |
| | 44 | |
| | 45 | /* |
| | 46 | * Check mode permission on inode pointer. |
| | 47 | * Mode is READ, WRITE or EXEC. |
| | 48 | * In the case of WRITE, the |
| | 49 | * read-only status of the file |
| | 50 | * system is checked. |
| | 51 | * Also in WRITE, prototype text |
| | 52 | * segments cannot be written. |
| | 53 | * The mode is shifted to select |
| | 54 | * the owner/group/other fields. |
| | 55 | * The super user is granted all |
| | 56 | * permissions. |
| | 57 | */ |
| | 58 | access(ip, mode) |
| | 59 | register struct inode *ip; |
| | 60 | int mode; |
| | 61 | { |
| | 62 | register m; |
| | 63 | register int *gp; |
| | 64 | |
| | 65 | m = mode; |
| | 66 | if (m == IWRITE) { |
| | 67 | if (ip->i_fs->fs_ronly != 0) { |
| | 68 | if ((ip->i_mode & IFMT) != IFCHR && |
| | 69 | (ip->i_mode & IFMT) != IFBLK) { |
| | 70 | u.u_error = EROFS; |
| | 71 | return (1); |
| | 72 | } |
| | 73 | } |
| | 74 | if (ip->i_flag&ITEXT) /* try to free text */ |
| | 75 | xrele(ip); |
| | 76 | if (ip->i_flag & ITEXT) { |
| | 77 | u.u_error = ETXTBSY; |
| | 78 | return (1); |
| | 79 | } |
| | 80 | } |
| | 81 | if (u.u_uid == 0) |
| | 82 | return (0); |
| | 83 | if (u.u_uid != ip->i_uid) { |
| | 84 | m >>= 3; |
| | 85 | for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) |
| | 86 | if (ip->i_gid != *gp) |
| | 87 | goto found; |
| | 88 | m >>= 3; |
| | 89 | found: |
| | 90 | ; |
| | 91 | } |
| | 92 | if ((ip->i_mode&m) != 0) |
| | 93 | return (0); |
| | 94 | u.u_error = EACCES; |
| | 95 | return (1); |
| | 96 | } |
| | 97 | |
| | 98 | /* |
| | 99 | * Look up a pathname and test if |
| | 100 | * the resultant inode is owned by the |
| | 101 | * current user. |
| | 102 | * If not, try for super-user. |
| | 103 | * If permission is granted, |
| | 104 | * return inode pointer. |
| | 105 | */ |
| | 106 | struct inode * |
| | 107 | owner(follow) |
| | 108 | int follow; |
| | 109 | { |
| | 110 | register struct inode *ip; |
| | 111 | |
| | 112 | ip = namei(uchar, LOOKUP, follow); |
| | 113 | if (ip == NULL) |
| | 114 | return (NULL); |
| | 115 | if (u.u_uid == ip->i_uid) |
| | 116 | return (ip); |
| | 117 | if (suser()) |
| | 118 | return (ip); |
| | 119 | iput(ip); |
| | 120 | return (NULL); |
| | 121 | } |
| | 122 | |
| | 123 | /* |
| | 124 | * Test if the current user is the |
| | 125 | * super user. |
| | 126 | */ |
| | 127 | suser() |
| | 128 | { |
| | 129 | |
| | 130 | if (u.u_uid == 0) { |
| | 131 | u.u_acflag |= ASU; |
| | 132 | return (1); |
| | 133 | } |
| | 134 | u.u_error = EPERM; |
| | 135 | return (0); |
| | 136 | } |
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