bsd/miscfs/procfs/procfs_subr.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: procfs_subr.c,v 1.13 1994/06/29 06:34:57 cgd Exp $     */
  23
  24 /*
  25  * Copyright (c) 1993 Jan-Simon Pendry
  26  * Copyright (c) 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Jan-Simon Pendry.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)procfs_subr.c       8.5 (Berkeley) 6/15/94
  61  */
  62
  63 #include <sys/param.h>
  64 #include <sys/systm.h>
  65 #include <sys/time.h>
  66 #include <sys/kernel.h>
  67 #include <sys/proc.h>
  68 #include <sys/vnode.h>
  69 #include <sys/malloc.h>
  70 #include <sys/ubc.h>
  71 #include <miscfs/procfs/procfs.h>
  72
  73 static struct pfsnode *pfshead;
  74 static int pfsvplock;
  75
  76 /*
  77  * allocate a pfsnode/vnode pair.  the vnode is
  78  * referenced, but not locked.
  79  *
  80  * the pid, pfs_type, and mount point uniquely
  81  * identify a pfsnode.  the mount point is needed
  82  * because someone might mount this filesystem
  83  * twice.
  84  *
  85  * all pfsnodes are maintained on a singly-linked
  86  * list.  new nodes are only allocated when they cannot
  87  * be found on this list.  entries on the list are
  88  * removed when the vfs reclaim entry is called.
  89  *
  90  * a single lock is kept for the entire list.  this is
  91  * needed because the getnewvnode() function can block
  92  * waiting for a vnode to become free, in which case there
  93  * may be more than one process trying to get the same
  94  * vnode.  this lock is only taken if we are going to
  95  * call getnewvnode, since the kernel itself is single-threaded.
  96  *
  97  * if an entry is found on the list, then call vget() to
  98  * take a reference.  this is done because there may be
  99  * zero references to it and so it needs to removed from
 100  * the vnode free list.
 101  */
 102 int
 103 procfs_allocvp(mp, vpp, pid, pfs_type)
 104         struct mount *mp;
 105         struct vnode **vpp;
 106         long pid;
 107         pfstype pfs_type;
 108 {
 109         struct pfsnode *pfs;
 110         struct vnode *vp;
 111         struct pfsnode **pp;
 112         int error;
 113
 114 loop:
 115         for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) {
 116                 vp = PFSTOV(pfs);
 117                 if (pfs->pfs_pid == pid &&
 118                     pfs->pfs_type == pfs_type &&
 119                     vp->v_mount == mp) {
 120                         if (vget(vp, 0, current_proc()))
 121                                 goto loop;
 122                         *vpp = vp;
 123                         return (0);
 124                 }
 125         }
 126
 127         /*
 128          * otherwise lock the vp list while we call getnewvnode
 129          * since that can block.
 130          */
 131         if (pfsvplock & PROCFS_LOCKED) {
 132                 pfsvplock |= PROCFS_WANT;
 133                 sleep((caddr_t) &pfsvplock, PINOD);
 134                 goto loop;
 135         }
 136         pfsvplock |= PROCFS_LOCKED;
 137
 138         MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK);
 139         if (error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) {
 140                 FREE(pfs, M_TEMP);
 141                 goto out;
 142         }
 143         vp = *vpp;
 144         vp->v_data = pfs;
 145
 146         pfs->pfs_next = 0;
 147         pfs->pfs_pid = (pid_t) pid;
 148         pfs->pfs_type = pfs_type;
 149         pfs->pfs_vnode = vp;
 150         pfs->pfs_flags = 0;
 151         pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
 152
 153         switch (pfs_type) {
 154         case Proot:     /* /proc = dr-xr-xr-x */
 155                 pfs->pfs_mode = (VREAD|VEXEC) |
 156                                 (VREAD|VEXEC) >> 3 |
 157                                 (VREAD|VEXEC) >> 6;
 158                 vp->v_type = VDIR;
 159                 vp->v_flag |= VROOT;
 160                 break;
 161
 162         case Pcurproc:  /* /proc/curproc = lr--r--r-- */
 163                 pfs->pfs_mode = (VREAD) |
 164                                 (VREAD >> 3) |
 165                                 (VREAD >> 6);
 166                 vp->v_type = VLNK;
 167                 break;
 168
 169         case Pproc:
 170                 pfs->pfs_mode = (VREAD|VEXEC) |
 171                                 (VREAD|VEXEC) >> 3 |
 172                                 (VREAD|VEXEC) >> 6;
 173                 vp->v_type = VDIR;
 174                 break;
 175
 176         case Pfile:
 177         case Pmem:
 178         case Pregs:
 179         case Pfpregs:
 180                 pfs->pfs_mode = (VREAD|VWRITE);
 181                 vp->v_type = VREG;
 182                 break;
 183
 184         case Pctl:
 185         case Pnote:
 186         case Pnotepg:
 187                 pfs->pfs_mode = (VWRITE);
 188                 vp->v_type = VREG;
 189                 break;
 190
 191         case Pstatus:
 192                 pfs->pfs_mode = (VREAD) |
 193                                 (VREAD >> 3) |
 194                                 (VREAD >> 6);
 195                 vp->v_type = VREG;
 196                 break;
 197
 198         default:
 199                 panic("procfs_allocvp");
 200         }
 201
 202         if (vp->v_type == VREG)
 203                 ubc_info_init(vp);
 204
 205         /* add to procfs vnode list */
 206         for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next)
 207                 continue;
 208         *pp = pfs;
 209
 210 out:
 211         pfsvplock &= ~PROCFS_LOCKED;
 212
 213         if (pfsvplock & PROCFS_WANT) {
 214                 pfsvplock &= ~PROCFS_WANT;
 215                 wakeup((caddr_t) &pfsvplock);
 216         }
 217
 218         return (error);
 219 }
 220
 221 int
 222 procfs_freevp(vp)
 223         struct vnode *vp;
 224 {
 225         struct pfsnode **pfspp;
 226         struct pfsnode *pfs = VTOPFS(vp);
 227
 228         for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) {
 229                 if (*pfspp == pfs) {
 230                         *pfspp = pfs->pfs_next;
 231                         break;
 232                 }
 233         }
 234
 235         FREE(vp->v_data, M_TEMP);
 236         vp->v_data = 0;
 237         return (0);
 238 }
 239
 240 int
 241 procfs_rw(ap)
 242         struct vop_read_args *ap;
 243 {
 244         struct vnode *vp = ap->a_vp;
 245         struct uio *uio = ap->a_uio;
 246         struct proc *curp = uio->uio_procp;
 247         struct pfsnode *pfs = VTOPFS(vp);
 248         struct proc *p;
 249
 250         p = PFIND(pfs->pfs_pid);
 251         if (p == 0)
 252                 return (EINVAL);
 253
 254         switch (pfs->pfs_type) {
 255         case Pnote:
 256         case Pnotepg:
 257                 return (procfs_donote(curp, p, pfs, uio));
 258
 259         case Pregs:
 260                 return (procfs_doregs(curp, p, pfs, uio));
 261
 262         case Pfpregs:
 263                 return (procfs_dofpregs(curp, p, pfs, uio));
 264
 265         case Pctl:
 266                 return (procfs_doctl(curp, p, pfs, uio));
 267
 268         case Pstatus:
 269                 return (procfs_dostatus(curp, p, pfs, uio));
 270
 271         case Pmem:
 272                 return (procfs_domem(curp, p, pfs, uio));
 273
 274         default:
 275                 return (EOPNOTSUPP);
 276         }
 277 }
 278
 279 /*
 280  * Get a string from userland into (buf).  Strip a trailing
 281  * nl character (to allow easy access from the shell).
 282  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
 283  * will automatically add a nul char at the end.
 284  *
 285  * Returns 0 on success or the following errors
 286  *
 287  * EINVAL:    file offset is non-zero.
 288  * EMSGSIZE:  message is longer than kernel buffer
 289  * EFAULT:    user i/o buffer is not addressable
 290  */
 291 int
 292 vfs_getuserstr(uio, buf, buflenp)
 293         struct uio *uio;
 294         char *buf;
 295         int *buflenp;
 296 {
 297         int xlen;
 298         int error;
 299
 300         if (uio->uio_offset != 0)
 301                 return (EINVAL);
 302
 303         xlen = *buflenp;
 304
 305         /* must be able to read the whole string in one go */
 306         if (xlen < uio->uio_resid)
 307                 return (EMSGSIZE);
 308         xlen = uio->uio_resid;
 309
 310         if (error = uiomove(buf, xlen, uio))
 311                 return (error);
 312
 313         /* allow multiple writes without seeks */
 314         uio->uio_offset = 0;
 315
 316         /* cleanup string and remove trailing newline */
 317         buf[xlen] = '\0';
 318         xlen = strlen(buf);
 319         if (xlen > 0 && buf[xlen-1] == '\n')
 320                 buf[--xlen] = '\0';
 321         *buflenp = xlen;
 322
 323         return (0);
 324 }
 325
 326 vfs_namemap_t *
 327 vfs_findname(nm, buf, buflen)
 328         vfs_namemap_t *nm;
 329         char *buf;
 330         int buflen;
 331 {
 332
 333         for (; nm->nm_name; nm++)
 334                 if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0)
 335                         return (nm);
 336
 337         return (0);
 338 }