| 1 | /* |
| 2 | * Copyright (c) 1993 Jan-Simon Pendry |
| 3 | * Copyright (c) 1993 |
| 4 | * The Regents of the University of California. All rights reserved. |
| 5 | * |
| 6 | * This code is derived from software contributed to Berkeley by |
| 7 | * Jan-Simon Pendry. |
| 8 | * |
| 9 | * %sccs.include.redist.c% |
| 10 | * |
| 11 | * @(#)procfs_subr.c 8.5 (Berkeley) %G% |
| 12 | * |
| 13 | * From: |
| 14 | * $Id: procfs_subr.c,v 3.2 1993/12/15 09:40:17 jsp Exp $ |
| 15 | */ |
| 16 | |
| 17 | #include <sys/param.h> |
| 18 | #include <sys/systm.h> |
| 19 | #include <sys/time.h> |
| 20 | #include <sys/kernel.h> |
| 21 | #include <sys/proc.h> |
| 22 | #include <sys/vnode.h> |
| 23 | #include <sys/malloc.h> |
| 24 | #include <miscfs/procfs/procfs.h> |
| 25 | |
| 26 | static struct pfsnode *pfshead; |
| 27 | static int pfsvplock; |
| 28 | |
| 29 | /* |
| 30 | * allocate a pfsnode/vnode pair. the vnode is |
| 31 | * referenced, but not locked. |
| 32 | * |
| 33 | * the pid, pfs_type, and mount point uniquely |
| 34 | * identify a pfsnode. the mount point is needed |
| 35 | * because someone might mount this filesystem |
| 36 | * twice. |
| 37 | * |
| 38 | * all pfsnodes are maintained on a singly-linked |
| 39 | * list. new nodes are only allocated when they cannot |
| 40 | * be found on this list. entries on the list are |
| 41 | * removed when the vfs reclaim entry is called. |
| 42 | * |
| 43 | * a single lock is kept for the entire list. this is |
| 44 | * needed because the getnewvnode() function can block |
| 45 | * waiting for a vnode to become free, in which case there |
| 46 | * may be more than one process trying to get the same |
| 47 | * vnode. this lock is only taken if we are going to |
| 48 | * call getnewvnode, since the kernel itself is single-threaded. |
| 49 | * |
| 50 | * if an entry is found on the list, then call vget() to |
| 51 | * take a reference. this is done because there may be |
| 52 | * zero references to it and so it needs to removed from |
| 53 | * the vnode free list. |
| 54 | */ |
| 55 | int |
| 56 | procfs_allocvp(mp, vpp, pid, pfs_type) |
| 57 | struct mount *mp; |
| 58 | struct vnode **vpp; |
| 59 | long pid; |
| 60 | pfstype pfs_type; |
| 61 | { |
| 62 | struct pfsnode *pfs; |
| 63 | struct vnode *vp; |
| 64 | struct pfsnode **pp; |
| 65 | int error; |
| 66 | |
| 67 | loop: |
| 68 | for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { |
| 69 | vp = PFSTOV(pfs); |
| 70 | if (pfs->pfs_pid == pid && |
| 71 | pfs->pfs_type == pfs_type && |
| 72 | vp->v_mount == mp) { |
| 73 | if (vget(vp, 0)) |
| 74 | goto loop; |
| 75 | *vpp = vp; |
| 76 | return (0); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * otherwise lock the vp list while we call getnewvnode |
| 82 | * since that can block. |
| 83 | */ |
| 84 | if (pfsvplock & PROCFS_LOCKED) { |
| 85 | pfsvplock |= PROCFS_WANT; |
| 86 | sleep((caddr_t) &pfsvplock, PINOD); |
| 87 | goto loop; |
| 88 | } |
| 89 | pfsvplock |= PROCFS_LOCKED; |
| 90 | |
| 91 | if (error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) |
| 92 | goto out; |
| 93 | vp = *vpp; |
| 94 | |
| 95 | MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); |
| 96 | vp->v_data = pfs; |
| 97 | |
| 98 | pfs->pfs_next = 0; |
| 99 | pfs->pfs_pid = (pid_t) pid; |
| 100 | pfs->pfs_type = pfs_type; |
| 101 | pfs->pfs_vnode = vp; |
| 102 | pfs->pfs_flags = 0; |
| 103 | pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); |
| 104 | |
| 105 | switch (pfs_type) { |
| 106 | case Proot: /* /proc = dr-xr-xr-x */ |
| 107 | pfs->pfs_mode = (VREAD|VEXEC) | |
| 108 | (VREAD|VEXEC) >> 3 | |
| 109 | (VREAD|VEXEC) >> 6; |
| 110 | vp->v_type = VDIR; |
| 111 | vp->v_flag = VROOT; |
| 112 | break; |
| 113 | |
| 114 | case Pcurproc: /* /proc/curproc = lr--r--r-- */ |
| 115 | pfs->pfs_mode = (VREAD) | |
| 116 | (VREAD >> 3) | |
| 117 | (VREAD >> 6); |
| 118 | vp->v_type = VLNK; |
| 119 | break; |
| 120 | |
| 121 | case Pproc: |
| 122 | pfs->pfs_mode = (VREAD|VEXEC) | |
| 123 | (VREAD|VEXEC) >> 3 | |
| 124 | (VREAD|VEXEC) >> 6; |
| 125 | vp->v_type = VDIR; |
| 126 | break; |
| 127 | |
| 128 | case Pfile: |
| 129 | case Pmem: |
| 130 | case Pregs: |
| 131 | case Pfpregs: |
| 132 | pfs->pfs_mode = (VREAD|VWRITE); |
| 133 | vp->v_type = VREG; |
| 134 | break; |
| 135 | |
| 136 | case Pctl: |
| 137 | case Pnote: |
| 138 | case Pnotepg: |
| 139 | pfs->pfs_mode = (VWRITE); |
| 140 | vp->v_type = VREG; |
| 141 | break; |
| 142 | |
| 143 | case Pstatus: |
| 144 | pfs->pfs_mode = (VREAD) | |
| 145 | (VREAD >> 3) | |
| 146 | (VREAD >> 6); |
| 147 | vp->v_type = VREG; |
| 148 | break; |
| 149 | |
| 150 | default: |
| 151 | panic("procfs_allocvp"); |
| 152 | } |
| 153 | |
| 154 | /* add to procfs vnode list */ |
| 155 | for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) |
| 156 | continue; |
| 157 | *pp = pfs; |
| 158 | |
| 159 | out: |
| 160 | pfsvplock &= ~PROCFS_LOCKED; |
| 161 | |
| 162 | if (pfsvplock & PROCFS_WANT) { |
| 163 | pfsvplock &= ~PROCFS_WANT; |
| 164 | wakeup((caddr_t) &pfsvplock); |
| 165 | } |
| 166 | |
| 167 | return (error); |
| 168 | } |
| 169 | |
| 170 | int |
| 171 | procfs_freevp(vp) |
| 172 | struct vnode *vp; |
| 173 | { |
| 174 | struct pfsnode **pfspp; |
| 175 | struct pfsnode *pfs = VTOPFS(vp); |
| 176 | |
| 177 | for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { |
| 178 | if (*pfspp == pfs) { |
| 179 | *pfspp = pfs->pfs_next; |
| 180 | break; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | FREE(vp->v_data, M_TEMP); |
| 185 | vp->v_data = 0; |
| 186 | return (0); |
| 187 | } |
| 188 | |
| 189 | int |
| 190 | procfs_rw(ap) |
| 191 | struct vop_read_args *ap; |
| 192 | { |
| 193 | struct vnode *vp = ap->a_vp; |
| 194 | struct uio *uio = ap->a_uio; |
| 195 | struct proc *curp = uio->uio_procp; |
| 196 | struct pfsnode *pfs = VTOPFS(vp); |
| 197 | struct proc *p; |
| 198 | |
| 199 | p = PFIND(pfs->pfs_pid); |
| 200 | if (p == 0) |
| 201 | return (EINVAL); |
| 202 | |
| 203 | switch (pfs->pfs_type) { |
| 204 | case Pnote: |
| 205 | case Pnotepg: |
| 206 | return (procfs_donote(curp, p, pfs, uio)); |
| 207 | |
| 208 | case Pregs: |
| 209 | return (procfs_doregs(curp, p, pfs, uio)); |
| 210 | |
| 211 | case Pfpregs: |
| 212 | return (procfs_dofpregs(curp, p, pfs, uio)); |
| 213 | |
| 214 | case Pctl: |
| 215 | return (procfs_doctl(curp, p, pfs, uio)); |
| 216 | |
| 217 | case Pstatus: |
| 218 | return (procfs_dostatus(curp, p, pfs, uio)); |
| 219 | |
| 220 | case Pmem: |
| 221 | return (procfs_domem(curp, p, pfs, uio)); |
| 222 | |
| 223 | default: |
| 224 | return (EOPNOTSUPP); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * Get a string from userland into (buf). Strip a trailing |
| 230 | * nl character (to allow easy access from the shell). |
| 231 | * The buffer should be *buflenp + 1 chars long. vfs_getuserstr |
| 232 | * will automatically add a nul char at the end. |
| 233 | * |
| 234 | * Returns 0 on success or the following errors |
| 235 | * |
| 236 | * EINVAL: file offset is non-zero. |
| 237 | * EMSGSIZE: message is longer than kernel buffer |
| 238 | * EFAULT: user i/o buffer is not addressable |
| 239 | */ |
| 240 | int |
| 241 | vfs_getuserstr(uio, buf, buflenp) |
| 242 | struct uio *uio; |
| 243 | char *buf; |
| 244 | int *buflenp; |
| 245 | { |
| 246 | int xlen; |
| 247 | int error; |
| 248 | |
| 249 | if (uio->uio_offset != 0) |
| 250 | return (EINVAL); |
| 251 | |
| 252 | xlen = *buflenp; |
| 253 | |
| 254 | /* must be able to read the whole string in one go */ |
| 255 | if (xlen < uio->uio_resid) |
| 256 | return (EMSGSIZE); |
| 257 | xlen = uio->uio_resid; |
| 258 | |
| 259 | if (error = uiomove(buf, xlen, uio)) |
| 260 | return (error); |
| 261 | |
| 262 | /* allow multiple writes without seeks */ |
| 263 | uio->uio_offset = 0; |
| 264 | |
| 265 | /* cleanup string and remove trailing newline */ |
| 266 | buf[xlen] = '\0'; |
| 267 | xlen = strlen(buf); |
| 268 | if (xlen > 0 && buf[xlen-1] == '\n') |
| 269 | buf[--xlen] = '\0'; |
| 270 | *buflenp = xlen; |
| 271 | |
| 272 | return (0); |
| 273 | } |
| 274 | |
| 275 | vfs_namemap_t * |
| 276 | vfs_findname(nm, buf, buflen) |
| 277 | vfs_namemap_t *nm; |
| 278 | char *buf; |
| 279 | int buflen; |
| 280 | { |
| 281 | |
| 282 | for (; nm->nm_name; nm++) |
| 283 | if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0) |
| 284 | return (nm); |
| 285 | |
| 286 | return (0); |
| 287 | } |