1*8956Sroot /* vfs_vnops.c 4.29 82/10/31 */ 218Sbill 318Sbill #include "../h/param.h" 418Sbill #include "../h/systm.h" 518Sbill #include "../h/dir.h" 618Sbill #include "../h/user.h" 76569Smckusic #include "../h/fs.h" 818Sbill #include "../h/file.h" 918Sbill #include "../h/conf.h" 1018Sbill #include "../h/inode.h" 1118Sbill #include "../h/reg.h" 1218Sbill #include "../h/acct.h" 132302Skre #include "../h/mount.h" 144914Swnj #include "../h/socket.h" 154914Swnj #include "../h/socketvar.h" 165581Swnj #include "../h/proc.h" 1718Sbill 1818Sbill /* 194817Swnj * Openi called to allow handler 2018Sbill * of special files to initialize and 2118Sbill * validate before actual IO. 2218Sbill */ 237654Ssam openi(ip, mode) 244817Swnj register struct inode *ip; 2518Sbill { 268565Sroot dev_t dev = (dev_t)ip->i_rdev; 278565Sroot register u_int maj = major(dev); 2818Sbill 294817Swnj switch (ip->i_mode&IFMT) { 3018Sbill 3118Sbill case IFCHR: 324817Swnj if (maj >= nchrdev) 338565Sroot return (ENXIO); 348565Sroot return ((*cdevsw[maj].d_open)(dev, mode)); 3518Sbill 3618Sbill case IFBLK: 374817Swnj if (maj >= nblkdev) 388565Sroot return (ENXIO); 398565Sroot return ((*bdevsw[maj].d_open)(dev, mode)); 4018Sbill } 418565Sroot return (0); 4218Sbill } 4318Sbill 4418Sbill /* 4518Sbill * Check mode permission on inode pointer. 4618Sbill * Mode is READ, WRITE or EXEC. 4718Sbill * In the case of WRITE, the 4818Sbill * read-only status of the file 4918Sbill * system is checked. 5018Sbill * Also in WRITE, prototype text 5118Sbill * segments cannot be written. 5218Sbill * The mode is shifted to select 5318Sbill * the owner/group/other fields. 5418Sbill * The super user is granted all 5518Sbill * permissions. 5618Sbill */ 5718Sbill access(ip, mode) 584817Swnj register struct inode *ip; 594817Swnj int mode; 6018Sbill { 6118Sbill register m; 627867Sroot register int *gp; 6318Sbill 6418Sbill m = mode; 654817Swnj if (m == IWRITE) { 666569Smckusic if (ip->i_fs->fs_ronly != 0) { 67*8956Sroot if ((ip->i_mode & IFMT) != IFCHR && 68*8956Sroot (ip->i_mode & IFMT) != IFBLK) { 69*8956Sroot u.u_error = EROFS; 70*8956Sroot return (1); 71*8956Sroot } 7218Sbill } 7318Sbill if (ip->i_flag&ITEXT) /* try to free text */ 7418Sbill xrele(ip); 754817Swnj if (ip->i_flag & ITEXT) { 7618Sbill u.u_error = ETXTBSY; 774817Swnj return (1); 7818Sbill } 7918Sbill } 804817Swnj if (u.u_uid == 0) 814817Swnj return (0); 824817Swnj if (u.u_uid != ip->i_uid) { 8318Sbill m >>= 3; 847867Sroot for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) 857867Sroot if (ip->i_gid != *gp) 867867Sroot goto found; 877867Sroot m >>= 3; 887867Sroot found: 897867Sroot ; 9018Sbill } 914817Swnj if ((ip->i_mode&m) != 0) 924817Swnj return (0); 9318Sbill u.u_error = EACCES; 944817Swnj return (1); 9518Sbill } 9618Sbill 9718Sbill /* 9818Sbill * Look up a pathname and test if 9918Sbill * the resultant inode is owned by the 10018Sbill * current user. 10118Sbill * If not, try for super-user. 10218Sbill * If permission is granted, 10318Sbill * return inode pointer. 10418Sbill */ 10518Sbill struct inode * 1065990Swnj owner(follow) 1075990Swnj int follow; 10818Sbill { 10918Sbill register struct inode *ip; 11018Sbill 1115990Swnj ip = namei(uchar, 0, follow); 1124817Swnj if (ip == NULL) 1134817Swnj return (NULL); 1144817Swnj if (u.u_uid == ip->i_uid) 1154817Swnj return (ip); 1164817Swnj if (suser()) 1174817Swnj return (ip); 11818Sbill iput(ip); 1194817Swnj return (NULL); 12018Sbill } 12118Sbill 12218Sbill /* 12318Sbill * Test if the current user is the 12418Sbill * super user. 12518Sbill */ 12618Sbill suser() 12718Sbill { 12818Sbill 1294817Swnj if (u.u_uid == 0) { 13018Sbill u.u_acflag |= ASU; 1314817Swnj return (1); 13218Sbill } 13318Sbill u.u_error = EPERM; 1344817Swnj return (0); 13518Sbill } 136