1*9764Ssam /* vfs_vnops.c 4.31 82/12/17 */ 218Sbill 3*9764Ssam #include "../machine/reg.h" 4*9764Ssam 518Sbill #include "../h/param.h" 618Sbill #include "../h/systm.h" 718Sbill #include "../h/dir.h" 818Sbill #include "../h/user.h" 96569Smckusic #include "../h/fs.h" 1018Sbill #include "../h/file.h" 1118Sbill #include "../h/conf.h" 1218Sbill #include "../h/inode.h" 1318Sbill #include "../h/acct.h" 142302Skre #include "../h/mount.h" 154914Swnj #include "../h/socket.h" 164914Swnj #include "../h/socketvar.h" 175581Swnj #include "../h/proc.h" 189165Ssam #include "../h/nami.h" 1918Sbill 2018Sbill /* 214817Swnj * Openi called to allow handler 2218Sbill * of special files to initialize and 2318Sbill * validate before actual IO. 2418Sbill */ 257654Ssam openi(ip, mode) 264817Swnj register struct inode *ip; 2718Sbill { 288565Sroot dev_t dev = (dev_t)ip->i_rdev; 298565Sroot register u_int maj = major(dev); 3018Sbill 314817Swnj switch (ip->i_mode&IFMT) { 3218Sbill 3318Sbill case IFCHR: 344817Swnj if (maj >= nchrdev) 358565Sroot return (ENXIO); 368565Sroot return ((*cdevsw[maj].d_open)(dev, mode)); 3718Sbill 3818Sbill case IFBLK: 394817Swnj if (maj >= nblkdev) 408565Sroot return (ENXIO); 418565Sroot return ((*bdevsw[maj].d_open)(dev, mode)); 4218Sbill } 438565Sroot return (0); 4418Sbill } 4518Sbill 4618Sbill /* 4718Sbill * Check mode permission on inode pointer. 4818Sbill * Mode is READ, WRITE or EXEC. 4918Sbill * In the case of WRITE, the 5018Sbill * read-only status of the file 5118Sbill * system is checked. 5218Sbill * Also in WRITE, prototype text 5318Sbill * segments cannot be written. 5418Sbill * The mode is shifted to select 5518Sbill * the owner/group/other fields. 5618Sbill * The super user is granted all 5718Sbill * permissions. 5818Sbill */ 5918Sbill access(ip, mode) 604817Swnj register struct inode *ip; 614817Swnj int mode; 6218Sbill { 6318Sbill register m; 647867Sroot register int *gp; 6518Sbill 6618Sbill m = mode; 674817Swnj if (m == IWRITE) { 686569Smckusic if (ip->i_fs->fs_ronly != 0) { 698956Sroot if ((ip->i_mode & IFMT) != IFCHR && 708956Sroot (ip->i_mode & IFMT) != IFBLK) { 718956Sroot u.u_error = EROFS; 728956Sroot return (1); 738956Sroot } 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; 867867Sroot for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) 877867Sroot if (ip->i_gid != *gp) 887867Sroot goto found; 897867Sroot m >>= 3; 907867Sroot found: 917867Sroot ; 9218Sbill } 934817Swnj if ((ip->i_mode&m) != 0) 944817Swnj return (0); 9518Sbill u.u_error = EACCES; 964817Swnj return (1); 9718Sbill } 9818Sbill 9918Sbill /* 10018Sbill * Look up a pathname and test if 10118Sbill * the resultant inode is owned by the 10218Sbill * current user. 10318Sbill * If not, try for super-user. 10418Sbill * If permission is granted, 10518Sbill * return inode pointer. 10618Sbill */ 10718Sbill struct inode * 1085990Swnj owner(follow) 1095990Swnj int follow; 11018Sbill { 11118Sbill register struct inode *ip; 11218Sbill 1139165Ssam ip = namei(uchar, LOOKUP, follow); 1144817Swnj if (ip == NULL) 1154817Swnj return (NULL); 1164817Swnj if (u.u_uid == ip->i_uid) 1174817Swnj return (ip); 1184817Swnj if (suser()) 1194817Swnj return (ip); 12018Sbill iput(ip); 1214817Swnj return (NULL); 12218Sbill } 12318Sbill 12418Sbill /* 12518Sbill * Test if the current user is the 12618Sbill * super user. 12718Sbill */ 12818Sbill suser() 12918Sbill { 13018Sbill 1314817Swnj if (u.u_uid == 0) { 13218Sbill u.u_acflag |= ASU; 1334817Swnj return (1); 13418Sbill } 13518Sbill u.u_error = EPERM; 1364817Swnj return (0); 13718Sbill } 138