1*7654Ssam /* vfs_vnops.c 4.26 82/08/03 */ 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 */ 23*7654Ssam openi(ip, mode) 244817Swnj register struct inode *ip; 2518Sbill { 2618Sbill dev_t dev; 2718Sbill register unsigned int maj; 2818Sbill 296569Smckusic dev = (dev_t)ip->i_rdev; 3018Sbill maj = major(dev); 314817Swnj switch (ip->i_mode&IFMT) { 3218Sbill 3318Sbill case IFCHR: 344817Swnj if (maj >= nchrdev) 3518Sbill goto bad; 36*7654Ssam (*cdevsw[maj].d_open)(dev, mode); 3718Sbill break; 3818Sbill 3918Sbill case IFBLK: 404817Swnj if (maj >= nblkdev) 4118Sbill goto bad; 42*7654Ssam (*bdevsw[maj].d_open)(dev, mode); 4318Sbill } 4418Sbill return; 4518Sbill 4618Sbill bad: 4718Sbill u.u_error = ENXIO; 4818Sbill } 4918Sbill 5018Sbill /* 5118Sbill * Check mode permission on inode pointer. 5218Sbill * Mode is READ, WRITE or EXEC. 5318Sbill * In the case of WRITE, the 5418Sbill * read-only status of the file 5518Sbill * system is checked. 5618Sbill * Also in WRITE, prototype text 5718Sbill * segments cannot be written. 5818Sbill * The mode is shifted to select 5918Sbill * the owner/group/other fields. 6018Sbill * The super user is granted all 6118Sbill * permissions. 6218Sbill */ 6318Sbill access(ip, mode) 644817Swnj register struct inode *ip; 654817Swnj int mode; 6618Sbill { 6718Sbill register m; 6818Sbill 6918Sbill m = mode; 704817Swnj if (m == IWRITE) { 716569Smckusic if (ip->i_fs->fs_ronly != 0) { 7218Sbill u.u_error = EROFS; 734817Swnj return (1); 7418Sbill } 7518Sbill if (ip->i_flag&ITEXT) /* try to free text */ 7618Sbill xrele(ip); 774817Swnj if (ip->i_flag & ITEXT) { 7818Sbill u.u_error = ETXTBSY; 794817Swnj return (1); 8018Sbill } 8118Sbill } 824817Swnj if (u.u_uid == 0) 834817Swnj return (0); 844817Swnj if (u.u_uid != ip->i_uid) { 8518Sbill m >>= 3; 865855Swnj if (ip->i_gid >= NGRPS || 875855Swnj (u.u_grps[ip->i_gid/(sizeof(int)*8)] & 885855Swnj (1 << ip->i_gid%(sizeof(int)*8)) == 0)) 8918Sbill m >>= 3; 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