1 /* $NetBSD: procfs_subr.c,v 1.26 1999/03/12 18:45:40 christos 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, but not 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, 0)) 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 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 144 vp->v_type = VLNK; 145 break; 146 147 case Pproc: /* /proc/N = dr-xr-xr-x */ 148 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 149 vp->v_type = VDIR; 150 break; 151 152 case Pfile: /* /proc/N/file = -rw------- */ 153 case Pmem: /* /proc/N/mem = -rw------- */ 154 case Pregs: /* /proc/N/regs = -rw------- */ 155 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 156 pfs->pfs_mode = S_IRUSR|S_IWUSR; 157 vp->v_type = VREG; 158 break; 159 160 case Pctl: /* /proc/N/ctl = --w------ */ 161 case Pnote: /* /proc/N/note = --w------ */ 162 case Pnotepg: /* /proc/N/notepg = --w------ */ 163 pfs->pfs_mode = S_IWUSR; 164 vp->v_type = VREG; 165 break; 166 167 case Pmap: /* /proc/N/map = -r--r--r-- */ 168 case Pstatus: /* /proc/N/status = -r--r--r-- */ 169 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 170 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 171 vp->v_type = VREG; 172 break; 173 174 default: 175 panic("procfs_allocvp"); 176 } 177 178 /* add to procfs vnode list */ 179 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 180 continue; 181 *pp = pfs; 182 183 out: 184 pfsvplock &= ~PROCFS_LOCKED; 185 186 if (pfsvplock & PROCFS_WANT) { 187 pfsvplock &= ~PROCFS_WANT; 188 wakeup((caddr_t) &pfsvplock); 189 } 190 191 return (error); 192 } 193 194 int 195 procfs_freevp(vp) 196 struct vnode *vp; 197 { 198 struct pfsnode **pfspp; 199 struct pfsnode *pfs = VTOPFS(vp); 200 201 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 202 if (*pfspp == pfs) { 203 *pfspp = pfs->pfs_next; 204 break; 205 } 206 } 207 208 FREE(vp->v_data, M_TEMP); 209 vp->v_data = 0; 210 return (0); 211 } 212 213 int 214 procfs_rw(v) 215 void *v; 216 { 217 struct vop_read_args *ap = v; 218 struct vnode *vp = ap->a_vp; 219 struct uio *uio = ap->a_uio; 220 struct proc *curp = uio->uio_procp; 221 struct pfsnode *pfs = VTOPFS(vp); 222 struct proc *p; 223 224 p = PFIND(pfs->pfs_pid); 225 if (p == 0) 226 return (EINVAL); 227 228 switch (pfs->pfs_type) { 229 case Pregs: 230 case Pfpregs: 231 case Pmem: 232 /* 233 * Do not allow init to be modified while in secure mode; it 234 * could be duped into changing the security level. 235 */ 236 if (uio->uio_rw == UIO_WRITE && 237 p == initproc && securelevel > -1) 238 return (EPERM); 239 break; 240 241 default: 242 break; 243 } 244 245 switch (pfs->pfs_type) { 246 case Pnote: 247 case Pnotepg: 248 return (procfs_donote(curp, p, pfs, uio)); 249 250 case Pregs: 251 return (procfs_doregs(curp, p, pfs, uio)); 252 253 case Pfpregs: 254 return (procfs_dofpregs(curp, p, pfs, uio)); 255 256 case Pctl: 257 return (procfs_doctl(curp, p, pfs, uio)); 258 259 case Pstatus: 260 return (procfs_dostatus(curp, p, pfs, uio)); 261 262 case Pmap: 263 return (procfs_domap(curp, p, pfs, uio)); 264 265 case Pmem: 266 return (procfs_domem(curp, p, pfs, uio)); 267 268 case Pcmdline: 269 return (procfs_docmdline(curp, p, pfs, uio)); 270 271 default: 272 return (EOPNOTSUPP); 273 } 274 } 275 276 /* 277 * Get a string from userland into (buf). Strip a trailing 278 * nl character (to allow easy access from the shell). 279 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 280 * will automatically add a nul char at the end. 281 * 282 * Returns 0 on success or the following errors 283 * 284 * EINVAL: file offset is non-zero. 285 * EMSGSIZE: message is longer than kernel buffer 286 * EFAULT: user i/o buffer is not addressable 287 */ 288 int 289 vfs_getuserstr(uio, buf, buflenp) 290 struct uio *uio; 291 char *buf; 292 int *buflenp; 293 { 294 int xlen; 295 int error; 296 297 if (uio->uio_offset != 0) 298 return (EINVAL); 299 300 xlen = *buflenp; 301 302 /* must be able to read the whole string in one go */ 303 if (xlen < uio->uio_resid) 304 return (EMSGSIZE); 305 xlen = uio->uio_resid; 306 307 if ((error = uiomove(buf, xlen, uio)) != 0) 308 return (error); 309 310 /* allow multiple writes without seeks */ 311 uio->uio_offset = 0; 312 313 /* cleanup string and remove trailing newline */ 314 buf[xlen] = '\0'; 315 xlen = strlen(buf); 316 if (xlen > 0 && buf[xlen-1] == '\n') 317 buf[--xlen] = '\0'; 318 *buflenp = xlen; 319 320 return (0); 321 } 322 323 vfs_namemap_t * 324 vfs_findname(nm, buf, buflen) 325 vfs_namemap_t *nm; 326 char *buf; 327 int buflen; 328 { 329 330 for (; nm->nm_name; nm++) 331 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 332 return (nm); 333 334 return (0); 335 } 336