1 /* $NetBSD: procfs_subr.c,v 1.38 2001/09/15 16:12:59 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) ((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 Pmaps: /* /proc/N/maps = -r--r--r-- */ 160 case Pstatus: /* /proc/N/status = -r--r--r-- */ 161 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 162 case Pmeminfo: /* /proc/meminfo = -r--r--r-- */ 163 case Pcpuinfo: /* /proc/cpuinfo = -r--r--r-- */ 164 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 165 vp->v_type = VREG; 166 break; 167 168 default: 169 panic("procfs_allocvp"); 170 } 171 172 procfs_hashins(pfs); 173 uvm_vnp_setsize(vp, 0); 174 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 175 176 return (error); 177 } 178 179 int 180 procfs_freevp(vp) 181 struct vnode *vp; 182 { 183 struct pfsnode *pfs = VTOPFS(vp); 184 185 procfs_hashrem(pfs); 186 187 FREE(vp->v_data, M_TEMP); 188 vp->v_data = 0; 189 return (0); 190 } 191 192 int 193 procfs_rw(v) 194 void *v; 195 { 196 struct vop_read_args *ap = v; 197 struct vnode *vp = ap->a_vp; 198 struct uio *uio = ap->a_uio; 199 struct proc *curp = uio->uio_procp; 200 struct pfsnode *pfs = VTOPFS(vp); 201 struct proc *p; 202 203 p = PFIND(pfs->pfs_pid); 204 if (p == 0) 205 return (EINVAL); 206 207 switch (pfs->pfs_type) { 208 case Pregs: 209 case Pfpregs: 210 case Pmem: 211 /* 212 * Do not allow init to be modified while in secure mode; it 213 * could be duped into changing the security level. 214 */ 215 if (uio->uio_rw == UIO_WRITE && 216 p == initproc && securelevel > -1) 217 return (EPERM); 218 break; 219 220 default: 221 break; 222 } 223 224 switch (pfs->pfs_type) { 225 case Pnote: 226 case Pnotepg: 227 return (procfs_donote(curp, p, pfs, uio)); 228 229 case Pregs: 230 return (procfs_doregs(curp, p, pfs, uio)); 231 232 case Pfpregs: 233 return (procfs_dofpregs(curp, p, pfs, uio)); 234 235 case Pctl: 236 return (procfs_doctl(curp, p, pfs, uio)); 237 238 case Pstatus: 239 return (procfs_dostatus(curp, p, pfs, uio)); 240 241 case Pmap: 242 return (procfs_domap(curp, p, pfs, uio, 0)); 243 244 case Pmaps: 245 return (procfs_domap(curp, p, pfs, uio, 1)); 246 247 case Pmem: 248 return (procfs_domem(curp, p, pfs, uio)); 249 250 case Pcmdline: 251 return (procfs_docmdline(curp, p, pfs, uio)); 252 253 case Pmeminfo: 254 return (procfs_domeminfo(curp, p, pfs, uio)); 255 case Pcpuinfo: 256 return (procfs_docpuinfo(curp, p, pfs, uio)); 257 258 default: 259 return (EOPNOTSUPP); 260 } 261 } 262 263 /* 264 * Get a string from userland into (buf). Strip a trailing 265 * nl character (to allow easy access from the shell). 266 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 267 * will automatically add a nul char at the end. 268 * 269 * Returns 0 on success or the following errors 270 * 271 * EINVAL: file offset is non-zero. 272 * EMSGSIZE: message is longer than kernel buffer 273 * EFAULT: user i/o buffer is not addressable 274 */ 275 int 276 vfs_getuserstr(uio, buf, buflenp) 277 struct uio *uio; 278 char *buf; 279 int *buflenp; 280 { 281 int xlen; 282 int error; 283 284 if (uio->uio_offset != 0) 285 return (EINVAL); 286 287 xlen = *buflenp; 288 289 /* must be able to read the whole string in one go */ 290 if (xlen < uio->uio_resid) 291 return (EMSGSIZE); 292 xlen = uio->uio_resid; 293 294 if ((error = uiomove(buf, xlen, uio)) != 0) 295 return (error); 296 297 /* allow multiple writes without seeks */ 298 uio->uio_offset = 0; 299 300 /* cleanup string and remove trailing newline */ 301 buf[xlen] = '\0'; 302 xlen = strlen(buf); 303 if (xlen > 0 && buf[xlen-1] == '\n') 304 buf[--xlen] = '\0'; 305 *buflenp = xlen; 306 307 return (0); 308 } 309 310 const vfs_namemap_t * 311 vfs_findname(nm, buf, buflen) 312 const vfs_namemap_t *nm; 313 const char *buf; 314 int buflen; 315 { 316 317 for (; nm->nm_name; nm++) 318 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 319 return (nm); 320 321 return (0); 322 } 323 324 /* 325 * Initialize pfsnode hash table. 326 */ 327 void 328 procfs_hashinit() 329 { 330 lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0); 331 pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, 332 M_WAITOK, &pfs_ihash); 333 simple_lock_init(&pfs_hash_slock); 334 } 335 336 void 337 procfs_hashreinit() 338 { 339 struct pfsnode *pp; 340 struct pfs_hashhead *oldhash, *hash; 341 u_long oldmask, mask, val; 342 int i; 343 344 hash = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, M_WAITOK, 345 &mask); 346 347 simple_lock(&pfs_hash_slock); 348 oldhash = pfs_hashtbl; 349 oldmask = pfs_ihash; 350 pfs_hashtbl = hash; 351 pfs_ihash = mask; 352 for (i = 0; i <= oldmask; i++) { 353 while ((pp = LIST_FIRST(&oldhash[i])) != NULL) { 354 LIST_REMOVE(pp, pfs_hash); 355 val = PFSPIDHASH(pp->pfs_pid); 356 LIST_INSERT_HEAD(&hash[val], pp, pfs_hash); 357 } 358 } 359 simple_unlock(&pfs_hash_slock); 360 hashdone(oldhash, M_UFSMNT); 361 } 362 363 /* 364 * Free pfsnode hash table. 365 */ 366 void 367 procfs_hashdone() 368 { 369 hashdone(pfs_hashtbl, M_UFSMNT); 370 } 371 372 struct vnode * 373 procfs_hashget(pid, type, mp) 374 pid_t pid; 375 pfstype type; 376 struct mount *mp; 377 { 378 struct pfs_hashhead *ppp; 379 struct pfsnode *pp; 380 struct vnode *vp; 381 382 loop: 383 simple_lock(&pfs_hash_slock); 384 ppp = &pfs_hashtbl[PFSPIDHASH(pid)]; 385 LIST_FOREACH(pp, ppp, pfs_hash) { 386 vp = PFSTOV(pp); 387 if (pid == pp->pfs_pid && pp->pfs_type == type && 388 vp->v_mount == mp) { 389 simple_lock(&vp->v_interlock); 390 simple_unlock(&pfs_hash_slock); 391 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) 392 goto loop; 393 return (vp); 394 } 395 } 396 simple_unlock(&pfs_hash_slock); 397 return (NULL); 398 } 399 400 /* 401 * Insert the pfsnode into the hash table and lock it. 402 */ 403 void 404 procfs_hashins(pp) 405 struct pfsnode *pp; 406 { 407 struct pfs_hashhead *ppp; 408 409 /* lock the pfsnode, then put it on the appropriate hash list */ 410 lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0); 411 412 simple_lock(&pfs_hash_slock); 413 ppp = &pfs_hashtbl[PFSPIDHASH(pp->pfs_pid)]; 414 LIST_INSERT_HEAD(ppp, pp, pfs_hash); 415 simple_unlock(&pfs_hash_slock); 416 } 417 418 /* 419 * Remove the pfsnode from the hash table. 420 */ 421 void 422 procfs_hashrem(pp) 423 struct pfsnode *pp; 424 { 425 simple_lock(&pfs_hash_slock); 426 LIST_REMOVE(pp, pfs_hash); 427 simple_unlock(&pfs_hash_slock); 428 } 429 430 void 431 procfs_revoke_vnodes(p, arg) 432 struct proc *p; 433 void *arg; 434 { 435 struct pfsnode *pfs, *pnext; 436 struct vnode *vp; 437 struct mount *mp = (struct mount *)arg; 438 struct pfs_hashhead *ppp; 439 440 if (!(p->p_flag & P_SUGID)) 441 return; 442 443 ppp = &pfs_hashtbl[PFSPIDHASH(p->p_pid)]; 444 for (pfs = LIST_FIRST(ppp); pfs; pfs = pnext) { 445 vp = PFSTOV(pfs); 446 pnext = LIST_NEXT(pfs, pfs_hash); 447 if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid && 448 vp->v_mount == mp) 449 VOP_REVOKE(vp, REVOKEALL); 450 } 451 } 452