| 1 | /* $NetBSD: ptyfs_subr.c,v 1.33 2014/10/15 15:00:03 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1993 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to Berkeley by |
| 8 | * Jan-Simon Pendry. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * 3. Neither the name of the University nor the names of its contributors |
| 19 | * may be used to endorse or promote products derived from this software |
| 20 | * without specific prior written permission. |
| 21 | * |
| 22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | * |
| 34 | * @(#)ptyfs_subr.c 8.6 (Berkeley) 5/14/95 |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * Copyright (c) 1994 Christopher G. Demetriou. All rights reserved. |
| 39 | * Copyright (c) 1993 Jan-Simon Pendry |
| 40 | * |
| 41 | * This code is derived from software contributed to Berkeley by |
| 42 | * Jan-Simon Pendry. |
| 43 | * |
| 44 | * Redistribution and use in source and binary forms, with or without |
| 45 | * modification, are permitted provided that the following conditions |
| 46 | * are met: |
| 47 | * 1. Redistributions of source code must retain the above copyright |
| 48 | * notice, this list of conditions and the following disclaimer. |
| 49 | * 2. Redistributions in binary form must reproduce the above copyright |
| 50 | * notice, this list of conditions and the following disclaimer in the |
| 51 | * documentation and/or other materials provided with the distribution. |
| 52 | * 3. All advertising materials mentioning features or use of this software |
| 53 | * must display the following acknowledgement: |
| 54 | * This product includes software developed by the University of |
| 55 | * California, Berkeley and its contributors. |
| 56 | * 4. Neither the name of the University nor the names of its contributors |
| 57 | * may be used to endorse or promote products derived from this software |
| 58 | * without specific prior written permission. |
| 59 | * |
| 60 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 61 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 62 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 63 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 64 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 65 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 66 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 67 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 68 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 69 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 70 | * SUCH DAMAGE. |
| 71 | * |
| 72 | * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95 |
| 73 | */ |
| 74 | |
| 75 | #include <sys/cdefs.h> |
| 76 | __KERNEL_RCSID(0, "$NetBSD: ptyfs_subr.c,v 1.33 2014/10/15 15:00:03 christos Exp $" ); |
| 77 | |
| 78 | #include <sys/param.h> |
| 79 | #include <sys/systm.h> |
| 80 | #include <sys/time.h> |
| 81 | #include <sys/kernel.h> |
| 82 | #include <sys/vnode.h> |
| 83 | #include <sys/stat.h> |
| 84 | #include <sys/malloc.h> |
| 85 | #include <sys/file.h> |
| 86 | #include <sys/namei.h> |
| 87 | #include <sys/filedesc.h> |
| 88 | #include <sys/select.h> |
| 89 | #include <sys/tty.h> |
| 90 | #include <sys/pty.h> |
| 91 | #include <sys/kauth.h> |
| 92 | #include <sys/lwp.h> |
| 93 | |
| 94 | #include <fs/ptyfs/ptyfs.h> |
| 95 | |
| 96 | static kmutex_t ptyfs_hashlock; |
| 97 | |
| 98 | static SLIST_HEAD(ptyfs_hashhead, ptyfsnode) *ptyfs_node_tbl; |
| 99 | static u_long ptyfs_node_mask; /* size of hash table - 1 */ |
| 100 | |
| 101 | /* |
| 102 | * allocate a ptyfsnode/vnode pair. the vnode is referenced. |
| 103 | * |
| 104 | * the pty, ptyfs_type, and mount point uniquely |
| 105 | * identify a ptyfsnode. the mount point is needed |
| 106 | * because someone might mount this filesystem |
| 107 | * twice. |
| 108 | */ |
| 109 | int |
| 110 | ptyfs_allocvp(struct mount *mp, struct vnode **vpp, ptyfstype type, int pty) |
| 111 | { |
| 112 | struct ptyfskey key; |
| 113 | |
| 114 | memset(&key, 0, sizeof(key)); |
| 115 | key.ptk_pty = pty; |
| 116 | key.ptk_type = type; |
| 117 | return vcache_get(mp, &key, sizeof(key), vpp); |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * Initialize ptyfsnode hash table. |
| 122 | */ |
| 123 | void |
| 124 | ptyfs_hashinit(void) |
| 125 | { |
| 126 | |
| 127 | ptyfs_node_tbl = hashinit(16, HASH_SLIST, true, &ptyfs_node_mask); |
| 128 | mutex_init(&ptyfs_hashlock, MUTEX_DEFAULT, IPL_NONE); |
| 129 | } |
| 130 | |
| 131 | /* |
| 132 | * Free ptyfsnode hash table. |
| 133 | */ |
| 134 | void |
| 135 | ptyfs_hashdone(void) |
| 136 | { |
| 137 | |
| 138 | mutex_destroy(&ptyfs_hashlock); |
| 139 | hashdone(ptyfs_node_tbl, HASH_SLIST, ptyfs_node_mask); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * Get a ptyfsnode from the hash table, or allocate one. |
| 144 | */ |
| 145 | struct ptyfsnode * |
| 146 | ptyfs_get_node(ptyfstype type, int pty) |
| 147 | { |
| 148 | struct ptyfs_hashhead *ppp; |
| 149 | struct ptyfsnode *pp; |
| 150 | |
| 151 | ppp = &ptyfs_node_tbl[PTYFS_FILENO(type, pty) & ptyfs_node_mask]; |
| 152 | |
| 153 | mutex_enter(&ptyfs_hashlock); |
| 154 | SLIST_FOREACH(pp, ppp, ptyfs_hash) { |
| 155 | if (pty == pp->ptyfs_pty && pp->ptyfs_type == type) { |
| 156 | mutex_exit(&ptyfs_hashlock); |
| 157 | return pp; |
| 158 | } |
| 159 | } |
| 160 | mutex_exit(&ptyfs_hashlock); |
| 161 | |
| 162 | pp = malloc(sizeof(struct ptyfsnode), M_TEMP, M_WAITOK); |
| 163 | pp->ptyfs_pty = pty; |
| 164 | pp->ptyfs_type = type; |
| 165 | pp->ptyfs_fileno = PTYFS_FILENO(pty, type); |
| 166 | if (pp->ptyfs_type == PTYFSroot) |
| 167 | pp->ptyfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP| |
| 168 | S_IROTH|S_IXOTH; |
| 169 | else |
| 170 | pp->ptyfs_mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP| |
| 171 | S_IROTH|S_IWOTH; |
| 172 | |
| 173 | pp->ptyfs_uid = pp->ptyfs_gid = 0; |
| 174 | pp->ptyfs_status = PTYFS_CHANGE; |
| 175 | PTYFS_ITIMES(pp, NULL, NULL, NULL); |
| 176 | pp->ptyfs_birthtime = pp->ptyfs_mtime = |
| 177 | pp->ptyfs_atime = pp->ptyfs_ctime; |
| 178 | pp->ptyfs_flags = 0; |
| 179 | mutex_enter(&ptyfs_hashlock); |
| 180 | /* |
| 181 | * XXX We have minimum race condition when opening master side |
| 182 | * first time, if other threads through other mount points, trying |
| 183 | * opening the same device. As follow we have little chance have |
| 184 | * unused list entries. |
| 185 | */ |
| 186 | SLIST_INSERT_HEAD(ppp, pp, ptyfs_hash); |
| 187 | mutex_exit(&ptyfs_hashlock); |
| 188 | return pp; |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Mark this controlling pty as active. |
| 193 | */ |
| 194 | void |
| 195 | ptyfs_set_active(struct mount *mp, int pty) |
| 196 | { |
| 197 | struct ptyfsmount *pmnt = VFSTOPTY(mp); |
| 198 | |
| 199 | KASSERT(pty >= 0); |
| 200 | /* Reallocate map if needed. */ |
| 201 | if (pty >= pmnt->pmnt_bitmap_size * NBBY) { |
| 202 | int osize, nsize; |
| 203 | uint8_t *obitmap, *nbitmap; |
| 204 | |
| 205 | nsize = roundup(howmany(pty + 1, NBBY), 64); |
| 206 | nbitmap = kmem_alloc(nsize, KM_SLEEP); |
| 207 | mutex_enter(&pmnt->pmnt_lock); |
| 208 | if (pty < pmnt->pmnt_bitmap_size * NBBY) { |
| 209 | mutex_exit(&pmnt->pmnt_lock); |
| 210 | kmem_free(nbitmap, nsize); |
| 211 | } else { |
| 212 | osize = pmnt->pmnt_bitmap_size; |
| 213 | obitmap = pmnt->pmnt_bitmap; |
| 214 | pmnt->pmnt_bitmap_size = nsize; |
| 215 | pmnt->pmnt_bitmap = nbitmap; |
| 216 | if (osize > 0) |
| 217 | memcpy(pmnt->pmnt_bitmap, obitmap, osize); |
| 218 | memset(pmnt->pmnt_bitmap + osize, 0, nsize - osize); |
| 219 | mutex_exit(&pmnt->pmnt_lock); |
| 220 | if (osize > 0) |
| 221 | kmem_free(obitmap, osize); |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | mutex_enter(&pmnt->pmnt_lock); |
| 226 | setbit(pmnt->pmnt_bitmap, pty); |
| 227 | mutex_exit(&pmnt->pmnt_lock); |
| 228 | } |
| 229 | |
| 230 | /* |
| 231 | * Mark this controlling pty as inactive. |
| 232 | */ |
| 233 | void |
| 234 | ptyfs_clr_active(struct mount *mp, int pty) |
| 235 | { |
| 236 | struct ptyfsmount *pmnt = VFSTOPTY(mp); |
| 237 | |
| 238 | KASSERT(pty >= 0); |
| 239 | mutex_enter(&pmnt->pmnt_lock); |
| 240 | if (pty >= 0 && pty < pmnt->pmnt_bitmap_size * NBBY) |
| 241 | clrbit(pmnt->pmnt_bitmap, pty); |
| 242 | mutex_exit(&pmnt->pmnt_lock); |
| 243 | } |
| 244 | |
| 245 | /* |
| 246 | * Lookup the next active controlling pty greater or equal "pty". |
| 247 | * Return -1 if not found. |
| 248 | */ |
| 249 | int |
| 250 | ptyfs_next_active(struct mount *mp, int pty) |
| 251 | { |
| 252 | struct ptyfsmount *pmnt = VFSTOPTY(mp); |
| 253 | |
| 254 | KASSERT(pty >= 0); |
| 255 | mutex_enter(&pmnt->pmnt_lock); |
| 256 | while (pty < pmnt->pmnt_bitmap_size * NBBY) { |
| 257 | if (isset(pmnt->pmnt_bitmap, pty)) { |
| 258 | mutex_exit(&pmnt->pmnt_lock); |
| 259 | return pty; |
| 260 | } |
| 261 | pty++; |
| 262 | } |
| 263 | mutex_exit(&pmnt->pmnt_lock); |
| 264 | return -1; |
| 265 | } |
| 266 | |