1 /* $NetBSD: procfs_subr.c,v 1.34 2000/11/27 08:39:46 chs Exp $ */ 2 3 /* 4 * Copyright (c) 1994 Christopher G. Demetriou. All rights reserved. 5 * Copyright (c) 1993 Jan-Simon Pendry 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Jan-Simon Pendry. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/time.h> 46 #include <sys/kernel.h> 47 #include <sys/proc.h> 48 #include <sys/vnode.h> 49 #include <sys/malloc.h> 50 #include <sys/stat.h> 51 52 #include <miscfs/procfs/procfs.h> 53 54 void procfs_hashins __P((struct pfsnode *)); 55 void procfs_hashrem __P((struct pfsnode *)); 56 struct vnode *procfs_hashget __P((pid_t, pfstype, struct mount *)); 57 58 LIST_HEAD(pfs_hashhead, pfsnode) *pfs_hashtbl; 59 u_long pfs_ihash; /* size of hash table - 1 */ 60 #define PFSPIDHASH(pid) (&pfs_hashtbl[(pid) & pfs_ihash]) 61 62 struct lock pfs_hashlock; 63 struct simplelock pfs_hash_slock; 64 65 #define ISSET(t, f) ((t) & (f)) 66 67 /* 68 * allocate a pfsnode/vnode pair. the vnode is 69 * referenced, and locked. 70 * 71 * the pid, pfs_type, and mount point uniquely 72 * identify a pfsnode. the mount point is needed 73 * because someone might mount this filesystem 74 * twice. 75 * 76 * all pfsnodes are maintained on a singly-linked 77 * list. new nodes are only allocated when they cannot 78 * be found on this list. entries on the list are 79 * removed when the vfs reclaim entry is called. 80 * 81 * a single lock is kept for the entire list. this is 82 * needed because the getnewvnode() function can block 83 * waiting for a vnode to become free, in which case there 84 * may be more than one process trying to get the same 85 * vnode. this lock is only taken if we are going to 86 * call getnewvnode, since the kernel itself is single-threaded. 87 * 88 * if an entry is found on the list, then call vget() to 89 * take a reference. this is done because there may be 90 * zero references to it and so it needs to removed from 91 * the vnode free list. 92 */ 93 int 94 procfs_allocvp(mp, vpp, pid, pfs_type) 95 struct mount *mp; 96 struct vnode **vpp; 97 long pid; 98 pfstype pfs_type; 99 { 100 struct pfsnode *pfs; 101 struct vnode *vp; 102 int error; 103 104 do { 105 if ((*vpp = procfs_hashget(pid, pfs_type, mp)) != NULL) 106 return (0); 107 } while (lockmgr(&pfs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0)); 108 109 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) { 110 *vpp = NULL; 111 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 112 return (error); 113 } 114 vp = *vpp; 115 116 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 117 vp->v_data = pfs; 118 119 pfs->pfs_pid = (pid_t) pid; 120 pfs->pfs_type = pfs_type; 121 pfs->pfs_vnode = vp; 122 pfs->pfs_flags = 0; 123 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 124 125 switch (pfs_type) { 126 case Proot: /* /proc = dr-xr-xr-x */ 127 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 128 vp->v_type = VDIR; 129 vp->v_flag = VROOT; 130 break; 131 132 case Pcurproc: /* /proc/curproc = lr-xr-xr-x */ 133 case Pself: /* /proc/self = lr-xr-xr-x */ 134 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 135 vp->v_type = VLNK; 136 break; 137 138 case Pproc: /* /proc/N = dr-xr-xr-x */ 139 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 140 vp->v_type = VDIR; 141 break; 142 143 case Pfile: /* /proc/N/file = -rw------- */ 144 case Pmem: /* /proc/N/mem = -rw------- */ 145 case Pregs: /* /proc/N/regs = -rw------- */ 146 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 147 pfs->pfs_mode = S_IRUSR|S_IWUSR; 148 vp->v_type = VREG; 149 break; 150 151 case Pctl: /* /proc/N/ctl = --w------ */ 152 case Pnote: /* /proc/N/note = --w------ */ 153 case Pnotepg: /* /proc/N/notepg = --w------ */ 154 pfs->pfs_mode = S_IWUSR; 155 vp->v_type = VREG; 156 break; 157 158 case Pmap: /* /proc/N/map = -r--r--r-- */ 159 case Pstatus: /* /proc/N/status = -r--r--r-- */ 160 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 161 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 162 vp->v_type = VREG; 163 break; 164 165 default: 166 panic("procfs_allocvp"); 167 } 168 169 procfs_hashins(pfs); 170 uvm_vnp_setsize(vp, 0); 171 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 172 173 return (error); 174 } 175 176 int 177 procfs_freevp(vp) 178 struct vnode *vp; 179 { 180 struct pfsnode *pfs = VTOPFS(vp); 181 182 procfs_hashrem(pfs); 183 184 FREE(vp->v_data, M_TEMP); 185 vp->v_data = 0; 186 return (0); 187 } 188 189 int 190 procfs_rw(v) 191 void *v; 192 { 193 struct vop_read_args *ap = v; 194 struct vnode *vp = ap->a_vp; 195 struct uio *uio = ap->a_uio; 196 struct proc *curp = uio->uio_procp; 197 struct pfsnode *pfs = VTOPFS(vp); 198 struct proc *p; 199 200 p = PFIND(pfs->pfs_pid); 201 if (p == 0) 202 return (EINVAL); 203 204 switch (pfs->pfs_type) { 205 case Pregs: 206 case Pfpregs: 207 case Pmem: 208 /* 209 * Do not allow init to be modified while in secure mode; it 210 * could be duped into changing the security level. 211 */ 212 if (uio->uio_rw == UIO_WRITE && 213 p == initproc && securelevel > -1) 214 return (EPERM); 215 break; 216 217 default: 218 break; 219 } 220 221 switch (pfs->pfs_type) { 222 case Pnote: 223 case Pnotepg: 224 return (procfs_donote(curp, p, pfs, uio)); 225 226 case Pregs: 227 return (procfs_doregs(curp, p, pfs, uio)); 228 229 case Pfpregs: 230 return (procfs_dofpregs(curp, p, pfs, uio)); 231 232 case Pctl: 233 return (procfs_doctl(curp, p, pfs, uio)); 234 235 case Pstatus: 236 return (procfs_dostatus(curp, p, pfs, uio)); 237 238 case Pmap: 239 return (procfs_domap(curp, p, pfs, uio)); 240 241 case Pmem: 242 return (procfs_domem(curp, p, pfs, uio)); 243 244 case Pcmdline: 245 return (procfs_docmdline(curp, p, pfs, uio)); 246 247 default: 248 return (EOPNOTSUPP); 249 } 250 } 251 252 /* 253 * Get a string from userland into (buf). Strip a trailing 254 * nl character (to allow easy access from the shell). 255 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 256 * will automatically add a nul char at the end. 257 * 258 * Returns 0 on success or the following errors 259 * 260 * EINVAL: file offset is non-zero. 261 * EMSGSIZE: message is longer than kernel buffer 262 * EFAULT: user i/o buffer is not addressable 263 */ 264 int 265 vfs_getuserstr(uio, buf, buflenp) 266 struct uio *uio; 267 char *buf; 268 int *buflenp; 269 { 270 int xlen; 271 int error; 272 273 if (uio->uio_offset != 0) 274 return (EINVAL); 275 276 xlen = *buflenp; 277 278 /* must be able to read the whole string in one go */ 279 if (xlen < uio->uio_resid) 280 return (EMSGSIZE); 281 xlen = uio->uio_resid; 282 283 if ((error = uiomove(buf, xlen, uio)) != 0) 284 return (error); 285 286 /* allow multiple writes without seeks */ 287 uio->uio_offset = 0; 288 289 /* cleanup string and remove trailing newline */ 290 buf[xlen] = '\0'; 291 xlen = strlen(buf); 292 if (xlen > 0 && buf[xlen-1] == '\n') 293 buf[--xlen] = '\0'; 294 *buflenp = xlen; 295 296 return (0); 297 } 298 299 vfs_namemap_t * 300 vfs_findname(nm, buf, buflen) 301 vfs_namemap_t *nm; 302 char *buf; 303 int buflen; 304 { 305 306 for (; nm->nm_name; nm++) 307 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 308 return (nm); 309 310 return (0); 311 } 312 313 /* 314 * Initialize pfsnode hash table. 315 */ 316 void 317 procfs_hashinit() 318 { 319 lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0); 320 pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, 321 M_WAITOK, &pfs_ihash); 322 simple_lock_init(&pfs_hash_slock); 323 } 324 325 /* 326 * Free pfsnode hash table. 327 */ 328 void 329 procfs_hashdone() 330 { 331 hashdone(pfs_hashtbl, M_UFSMNT); 332 } 333 334 struct vnode * 335 procfs_hashget(pid, type, mp) 336 pid_t pid; 337 pfstype type; 338 struct mount *mp; 339 { 340 struct pfsnode *pp; 341 struct vnode *vp; 342 343 loop: 344 simple_lock(&pfs_hash_slock); 345 for (pp = PFSPIDHASH(pid)->lh_first; pp; pp = pp->pfs_hash.le_next) { 346 vp = PFSTOV(pp); 347 if (pid == pp->pfs_pid && pp->pfs_type == type && 348 vp->v_mount == mp) { 349 simple_lock(&vp->v_interlock); 350 simple_unlock(&pfs_hash_slock); 351 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) 352 goto loop; 353 return (vp); 354 } 355 } 356 simple_unlock(&pfs_hash_slock); 357 return (NULL); 358 } 359 360 /* 361 * Insert the pfsnode into the hash table and lock it. 362 */ 363 void 364 procfs_hashins(pp) 365 struct pfsnode *pp; 366 { 367 struct pfs_hashhead *ppp; 368 369 /* lock the pfsnode, then put it on the appropriate hash list */ 370 lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0); 371 372 simple_lock(&pfs_hash_slock); 373 ppp = PFSPIDHASH(pp->pfs_pid); 374 LIST_INSERT_HEAD(ppp, pp, pfs_hash); 375 simple_unlock(&pfs_hash_slock); 376 } 377 378 /* 379 * Remove the pfsnode from the hash table. 380 */ 381 void 382 procfs_hashrem(pp) 383 struct pfsnode *pp; 384 { 385 simple_lock(&pfs_hash_slock); 386 LIST_REMOVE(pp, pfs_hash); 387 simple_unlock(&pfs_hash_slock); 388 } 389 390 void 391 procfs_revoke_vnodes(p, arg) 392 struct proc *p; 393 void *arg; 394 { 395 struct pfsnode *pfs, *pnext; 396 struct vnode *vp; 397 struct mount *mp = (struct mount *)arg; 398 399 if (!(p->p_flag & P_SUGID)) 400 return; 401 402 for (pfs = PFSPIDHASH(p->p_pid)->lh_first; pfs; pfs = pnext) { 403 vp = PFSTOV(pfs); 404 pnext = pfs->pfs_hash.le_next; 405 if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid && 406 vp->v_mount == mp) 407 VOP_REVOKE(vp, REVOKEALL); 408 } 409 } 410