1 /* $NetBSD: procfs_subr.c,v 1.28 1999/09/02 23:33:45 thorpej 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 static struct pfsnode *pfshead; 55 static int pfsvplock; 56 57 #define ISSET(t, f) ((t) & (f)) 58 59 /* 60 * allocate a pfsnode/vnode pair. the vnode is 61 * referenced, and locked. 62 * 63 * the pid, pfs_type, and mount point uniquely 64 * identify a pfsnode. the mount point is needed 65 * because someone might mount this filesystem 66 * twice. 67 * 68 * all pfsnodes are maintained on a singly-linked 69 * list. new nodes are only allocated when they cannot 70 * be found on this list. entries on the list are 71 * removed when the vfs reclaim entry is called. 72 * 73 * a single lock is kept for the entire list. this is 74 * needed because the getnewvnode() function can block 75 * waiting for a vnode to become free, in which case there 76 * may be more than one process trying to get the same 77 * vnode. this lock is only taken if we are going to 78 * call getnewvnode, since the kernel itself is single-threaded. 79 * 80 * if an entry is found on the list, then call vget() to 81 * take a reference. this is done because there may be 82 * zero references to it and so it needs to removed from 83 * the vnode free list. 84 */ 85 int 86 procfs_allocvp(mp, vpp, pid, pfs_type) 87 struct mount *mp; 88 struct vnode **vpp; 89 long pid; 90 pfstype pfs_type; 91 { 92 struct pfsnode *pfs; 93 struct vnode *vp; 94 struct pfsnode **pp; 95 int error; 96 97 loop: 98 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { 99 vp = PFSTOV(pfs); 100 if (pfs->pfs_pid == pid && 101 pfs->pfs_type == pfs_type && 102 vp->v_mount == mp) { 103 if (vget(vp, LK_EXCLUSIVE)) 104 goto loop; 105 *vpp = vp; 106 return (0); 107 } 108 } 109 110 /* 111 * otherwise lock the vp list while we call getnewvnode 112 * since that can block. 113 */ 114 if (pfsvplock & PROCFS_LOCKED) { 115 pfsvplock |= PROCFS_WANT; 116 sleep((caddr_t) &pfsvplock, PINOD); 117 goto loop; 118 } 119 pfsvplock |= PROCFS_LOCKED; 120 121 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) 122 goto out; 123 vp = *vpp; 124 125 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 126 vp->v_data = pfs; 127 128 pfs->pfs_next = 0; 129 pfs->pfs_pid = (pid_t) pid; 130 pfs->pfs_type = pfs_type; 131 pfs->pfs_vnode = vp; 132 pfs->pfs_flags = 0; 133 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 134 135 switch (pfs_type) { 136 case Proot: /* /proc = dr-xr-xr-x */ 137 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 138 vp->v_type = VDIR; 139 vp->v_flag = VROOT; 140 break; 141 142 case Pcurproc: /* /proc/curproc = lr-xr-xr-x */ 143 case Pself: /* /proc/self = lr-xr-xr-x */ 144 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 145 vp->v_type = VLNK; 146 break; 147 148 case Pproc: /* /proc/N = dr-xr-xr-x */ 149 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 150 vp->v_type = VDIR; 151 break; 152 153 case Pfile: /* /proc/N/file = -rw------- */ 154 case Pmem: /* /proc/N/mem = -rw------- */ 155 case Pregs: /* /proc/N/regs = -rw------- */ 156 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 157 pfs->pfs_mode = S_IRUSR|S_IWUSR; 158 vp->v_type = VREG; 159 break; 160 161 case Pctl: /* /proc/N/ctl = --w------ */ 162 case Pnote: /* /proc/N/note = --w------ */ 163 case Pnotepg: /* /proc/N/notepg = --w------ */ 164 pfs->pfs_mode = S_IWUSR; 165 vp->v_type = VREG; 166 break; 167 168 case Pmap: /* /proc/N/map = -r--r--r-- */ 169 case Pstatus: /* /proc/N/status = -r--r--r-- */ 170 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 171 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 172 vp->v_type = VREG; 173 break; 174 175 default: 176 panic("procfs_allocvp"); 177 } 178 179 VOP_LOCK(vp, LK_EXCLUSIVE); 180 181 /* add to procfs vnode list */ 182 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 183 continue; 184 *pp = pfs; 185 186 out: 187 pfsvplock &= ~PROCFS_LOCKED; 188 189 if (pfsvplock & PROCFS_WANT) { 190 pfsvplock &= ~PROCFS_WANT; 191 wakeup((caddr_t) &pfsvplock); 192 } 193 194 return (error); 195 } 196 197 int 198 procfs_freevp(vp) 199 struct vnode *vp; 200 { 201 struct pfsnode **pfspp; 202 struct pfsnode *pfs = VTOPFS(vp); 203 204 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 205 if (*pfspp == pfs) { 206 *pfspp = pfs->pfs_next; 207 break; 208 } 209 } 210 211 FREE(vp->v_data, M_TEMP); 212 vp->v_data = 0; 213 return (0); 214 } 215 216 int 217 procfs_rw(v) 218 void *v; 219 { 220 struct vop_read_args *ap = v; 221 struct vnode *vp = ap->a_vp; 222 struct uio *uio = ap->a_uio; 223 struct proc *curp = uio->uio_procp; 224 struct pfsnode *pfs = VTOPFS(vp); 225 struct proc *p; 226 227 p = PFIND(pfs->pfs_pid); 228 if (p == 0) 229 return (EINVAL); 230 231 switch (pfs->pfs_type) { 232 case Pregs: 233 case Pfpregs: 234 case Pmem: 235 /* 236 * Do not allow init to be modified while in secure mode; it 237 * could be duped into changing the security level. 238 */ 239 if (uio->uio_rw == UIO_WRITE && 240 p == initproc && securelevel > -1) 241 return (EPERM); 242 break; 243 244 default: 245 break; 246 } 247 248 switch (pfs->pfs_type) { 249 case Pnote: 250 case Pnotepg: 251 return (procfs_donote(curp, p, pfs, uio)); 252 253 case Pregs: 254 return (procfs_doregs(curp, p, pfs, uio)); 255 256 case Pfpregs: 257 return (procfs_dofpregs(curp, p, pfs, uio)); 258 259 case Pctl: 260 return (procfs_doctl(curp, p, pfs, uio)); 261 262 case Pstatus: 263 return (procfs_dostatus(curp, p, pfs, uio)); 264 265 case Pmap: 266 return (procfs_domap(curp, p, pfs, uio)); 267 268 case Pmem: 269 return (procfs_domem(curp, p, pfs, uio)); 270 271 case Pcmdline: 272 return (procfs_docmdline(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)) != 0) 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 (memcmp(buf, nm->nm_name, buflen+1) == 0) 335 return (nm); 336 337 return (0); 338 } 339