1 /* $NetBSD: procfs_subr.c,v 1.19 1997/06/25 11:32:15 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1993 Jan-Simon Pendry 5 * Copyright (c) 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Jan-Simon Pendry. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)procfs_subr.c 8.5 (Berkeley) 6/15/94 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/time.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 #include <sys/stat.h> 50 51 #include <miscfs/procfs/procfs.h> 52 53 static struct pfsnode *pfshead; 54 static int pfsvplock; 55 56 /* 57 * allocate a pfsnode/vnode pair. the vnode is 58 * referenced, but not locked. 59 * 60 * the pid, pfs_type, and mount point uniquely 61 * identify a pfsnode. the mount point is needed 62 * because someone might mount this filesystem 63 * twice. 64 * 65 * all pfsnodes are maintained on a singly-linked 66 * list. new nodes are only allocated when they cannot 67 * be found on this list. entries on the list are 68 * removed when the vfs reclaim entry is called. 69 * 70 * a single lock is kept for the entire list. this is 71 * needed because the getnewvnode() function can block 72 * waiting for a vnode to become free, in which case there 73 * may be more than one process trying to get the same 74 * vnode. this lock is only taken if we are going to 75 * call getnewvnode, since the kernel itself is single-threaded. 76 * 77 * if an entry is found on the list, then call vget() to 78 * take a reference. this is done because there may be 79 * zero references to it and so it needs to removed from 80 * the vnode free list. 81 */ 82 int 83 procfs_allocvp(mp, vpp, pid, pfs_type) 84 struct mount *mp; 85 struct vnode **vpp; 86 long pid; 87 pfstype pfs_type; 88 { 89 struct pfsnode *pfs; 90 struct vnode *vp; 91 struct pfsnode **pp; 92 int error; 93 94 loop: 95 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { 96 vp = PFSTOV(pfs); 97 if (pfs->pfs_pid == pid && 98 pfs->pfs_type == pfs_type && 99 vp->v_mount == mp) { 100 if (vget(vp, 0)) 101 goto loop; 102 *vpp = vp; 103 return (0); 104 } 105 } 106 107 /* 108 * otherwise lock the vp list while we call getnewvnode 109 * since that can block. 110 */ 111 if (pfsvplock & PROCFS_LOCKED) { 112 pfsvplock |= PROCFS_WANT; 113 sleep((caddr_t) &pfsvplock, PINOD); 114 goto loop; 115 } 116 pfsvplock |= PROCFS_LOCKED; 117 118 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) 119 goto out; 120 vp = *vpp; 121 122 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 123 vp->v_data = pfs; 124 125 pfs->pfs_next = 0; 126 pfs->pfs_pid = (pid_t) pid; 127 pfs->pfs_type = pfs_type; 128 pfs->pfs_vnode = vp; 129 pfs->pfs_flags = 0; 130 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 131 132 switch (pfs_type) { 133 case Proot: /* /proc = dr-xr-xr-x */ 134 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 135 vp->v_type = VDIR; 136 vp->v_flag = VROOT; 137 break; 138 139 case Pcurproc: /* /proc/curproc = lr--r--r-- */ 140 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 141 vp->v_type = VLNK; 142 break; 143 144 case Pproc: /* /proc/N = dr-xr-xr-x */ 145 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 146 vp->v_type = VDIR; 147 break; 148 149 case Pfile: /* /proc/N/file = -rw------- */ 150 case Pmem: /* /proc/N/mem = -rw------- */ 151 case Pregs: /* /proc/N/regs = -rw------- */ 152 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 153 pfs->pfs_mode = S_IRUSR|S_IWUSR; 154 vp->v_type = VREG; 155 break; 156 157 case Pctl: /* /proc/N/ctl = --w------ */ 158 case Pnote: /* /proc/N/note = --w------ */ 159 case Pnotepg: /* /proc/N/notepg = --w------ */ 160 pfs->pfs_mode = S_IWUSR; 161 vp->v_type = VREG; 162 break; 163 164 case Pstatus: /* /proc/N/status = -r--r--r-- */ 165 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 166 vp->v_type = VREG; 167 break; 168 169 default: 170 panic("procfs_allocvp"); 171 } 172 173 /* add to procfs vnode list */ 174 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 175 continue; 176 *pp = pfs; 177 178 out: 179 pfsvplock &= ~PROCFS_LOCKED; 180 181 if (pfsvplock & PROCFS_WANT) { 182 pfsvplock &= ~PROCFS_WANT; 183 wakeup((caddr_t) &pfsvplock); 184 } 185 186 return (error); 187 } 188 189 int 190 procfs_freevp(vp) 191 struct vnode *vp; 192 { 193 struct pfsnode **pfspp; 194 struct pfsnode *pfs = VTOPFS(vp); 195 196 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 197 if (*pfspp == pfs) { 198 *pfspp = pfs->pfs_next; 199 break; 200 } 201 } 202 203 FREE(vp->v_data, M_TEMP); 204 vp->v_data = 0; 205 return (0); 206 } 207 208 int 209 procfs_rw(v) 210 void *v; 211 { 212 struct vop_read_args *ap = v; 213 struct vnode *vp = ap->a_vp; 214 struct uio *uio = ap->a_uio; 215 struct proc *curp = uio->uio_procp; 216 struct pfsnode *pfs = VTOPFS(vp); 217 struct proc *p; 218 219 p = PFIND(pfs->pfs_pid); 220 if (p == 0) 221 return (EINVAL); 222 223 switch (pfs->pfs_type) { 224 case Pregs: 225 case Pfpregs: 226 case Pmem: 227 /* 228 * Do not allow init to be modified while in secure mode; it 229 * could be duped into changing the security level. 230 */ 231 if (uio->uio_rw == UIO_WRITE && 232 p == initproc && securelevel > -1) 233 return (EPERM); 234 break; 235 236 default: 237 break; 238 } 239 240 switch (pfs->pfs_type) { 241 case Pnote: 242 case Pnotepg: 243 return (procfs_donote(curp, p, pfs, uio)); 244 245 case Pregs: 246 return (procfs_doregs(curp, p, pfs, uio)); 247 248 case Pfpregs: 249 return (procfs_dofpregs(curp, p, pfs, uio)); 250 251 case Pctl: 252 return (procfs_doctl(curp, p, pfs, uio)); 253 254 case Pstatus: 255 return (procfs_dostatus(curp, p, pfs, uio)); 256 257 case Pmem: 258 return (procfs_domem(curp, p, pfs, uio)); 259 260 default: 261 return (EOPNOTSUPP); 262 } 263 } 264 265 /* 266 * Get a string from userland into (buf). Strip a trailing 267 * nl character (to allow easy access from the shell). 268 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 269 * will automatically add a nul char at the end. 270 * 271 * Returns 0 on success or the following errors 272 * 273 * EINVAL: file offset is non-zero. 274 * EMSGSIZE: message is longer than kernel buffer 275 * EFAULT: user i/o buffer is not addressable 276 */ 277 int 278 vfs_getuserstr(uio, buf, buflenp) 279 struct uio *uio; 280 char *buf; 281 int *buflenp; 282 { 283 int xlen; 284 int error; 285 286 if (uio->uio_offset != 0) 287 return (EINVAL); 288 289 xlen = *buflenp; 290 291 /* must be able to read the whole string in one go */ 292 if (xlen < uio->uio_resid) 293 return (EMSGSIZE); 294 xlen = uio->uio_resid; 295 296 if ((error = uiomove(buf, xlen, uio)) != 0) 297 return (error); 298 299 /* allow multiple writes without seeks */ 300 uio->uio_offset = 0; 301 302 /* cleanup string and remove trailing newline */ 303 buf[xlen] = '\0'; 304 xlen = strlen(buf); 305 if (xlen > 0 && buf[xlen-1] == '\n') 306 buf[--xlen] = '\0'; 307 *buflenp = xlen; 308 309 return (0); 310 } 311 312 vfs_namemap_t * 313 vfs_findname(nm, buf, buflen) 314 vfs_namemap_t *nm; 315 char *buf; 316 int buflen; 317 { 318 319 for (; nm->nm_name; nm++) 320 if (bcmp(buf, nm->nm_name, buflen+1) == 0) 321 return (nm); 322 323 return (0); 324 } 325