/* * Copyright (c) 2009 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Alex Hornung * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name of The DragonFly Project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific, prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include MALLOC_DECLARE(M_DEVFS); static d_open_t devfs_dev_open; static d_close_t devfs_dev_close; static d_ioctl_t devfs_dev_ioctl; static struct devfs_rule *devfs_rule_alloc(struct devfs_rule_ioctl *); static void devfs_rule_free(struct devfs_rule *); static int devfs_rule_insert(struct devfs_rule_ioctl *); static void devfs_rule_remove(struct devfs_rule *); static int devfs_rule_clear(struct devfs_rule_ioctl *); static void devfs_rule_create_link(struct devfs_node *, struct devfs_rule *); static int devfs_rule_checkname(struct devfs_rule *, struct devfs_node *); static struct objcache *devfs_rule_cache; static struct lock devfs_rule_lock; static struct objcache_malloc_args devfs_rule_malloc_args = { sizeof(struct devfs_rule), M_DEVFS }; static cdev_t devfs_dev; static struct devfs_rule_head devfs_rule_list = TAILQ_HEAD_INITIALIZER(devfs_rule_list); static struct dev_ops devfs_dev_ops = { { "devfs", 0, 0 }, .d_open = devfs_dev_open, .d_close = devfs_dev_close, .d_ioctl = devfs_dev_ioctl }; static struct devfs_rule * devfs_rule_alloc(struct devfs_rule_ioctl *templ) { struct devfs_rule *rule; size_t len; rule = objcache_get(devfs_rule_cache, M_WAITOK); memset(rule, 0, sizeof(struct devfs_rule)); if (templ->mntpoint == NULL) goto error_out; /* NOTREACHED */ len = strlen(templ->mntpoint); if (len == 0) goto error_out; /* NOTREACHED */ rule->mntpoint = kstrdup(templ->mntpoint, M_DEVFS); rule->mntpointlen = len; if (templ->rule_type & DEVFS_RULE_NAME) { if (templ->name == NULL) goto error_out; /* NOTREACHED */ len = strlen(templ->name); if (len == 0) goto error_out; /* NOTREACHED */ rule->name = kstrdup(templ->name, M_DEVFS); rule->namlen = len; } if (templ->rule_cmd & DEVFS_RULE_LINK) { if (templ->linkname == NULL) goto error_out; /* NOTREACHED */ len = strlen(templ->linkname); if (len == 0) goto error_out; /* NOTREACHED */ rule->linkname = kstrdup(templ->linkname, M_DEVFS); rule->linknamlen = len; } rule->rule_type = templ->rule_type; rule->rule_cmd = templ->rule_cmd; rule->dev_type = templ->dev_type; rule->mode = templ->mode; rule->uid = templ->uid; rule->gid = templ->gid; return rule; error_out: devfs_rule_free(rule); return NULL; } static void devfs_rule_free(struct devfs_rule *rule) { if (rule->mntpoint != NULL) { kfree(rule->mntpoint, M_DEVFS); } if (rule->name != NULL) { kfree(rule->name, M_DEVFS); } if (rule->linkname != NULL) { kfree(rule->linkname, M_DEVFS); } objcache_put(devfs_rule_cache, rule); } static int devfs_rule_insert(struct devfs_rule_ioctl *templ) { struct devfs_rule *rule; rule = devfs_rule_alloc(templ); if (rule == NULL) return EINVAL; lockmgr(&devfs_rule_lock, LK_EXCLUSIVE); TAILQ_INSERT_TAIL(&devfs_rule_list, rule, link); lockmgr(&devfs_rule_lock, LK_RELEASE); return 0; } static void devfs_rule_remove(struct devfs_rule *rule) { TAILQ_REMOVE(&devfs_rule_list, rule, link); devfs_rule_free(rule); } static int devfs_rule_clear(struct devfs_rule_ioctl *templ) { struct devfs_rule *rule1, *rule2; size_t mntpointlen; if (templ->mntpoint == NULL) return EINVAL; mntpointlen = strlen(templ->mntpoint); if (mntpointlen == 0) return EINVAL; lockmgr(&devfs_rule_lock, LK_EXCLUSIVE); TAILQ_FOREACH_MUTABLE(rule1, &devfs_rule_list, link, rule2) { if ((templ->mntpoint[0] == '*') || ( (mntpointlen == rule1->mntpointlen) && (!memcmp(templ->mntpoint, rule1->mntpoint, mntpointlen)) )) { devfs_rule_remove(rule1); } } lockmgr(&devfs_rule_lock, LK_RELEASE); return 0; } void * devfs_rule_reset_node(struct devfs_node *node, void *unused) { /* * Don't blindly unhide all devices, some, like unix98 pty masters, * haven't been hidden by a rule. */ if (node->flags & DEVFS_RULE_HIDDEN) node->flags &= ~(DEVFS_HIDDEN | DEVFS_RULE_HIDDEN); if ((node->node_type == Nlink) && (node->flags & DEVFS_RULE_CREATED)) { KKASSERT(node->link_target); node->flags &= ~DEVFS_RULE_CREATED; --node->link_target->nlinks; devfs_gc(node); } else if ((node->node_type == Ndev) && (node->d_dev)) { node->uid = node->d_dev->si_uid; node->gid = node->d_dev->si_gid; node->mode = node->d_dev->si_perms; } return NULL; } static void devfs_rule_create_link(struct devfs_node *node, struct devfs_rule *rule) { size_t len = 0; char *path = NULL; char *name, name_buf[PATH_MAX], buf[PATH_MAX]; if (rule->name[rule->namlen-1] == '*') { devfs_resolve_name_path(rule->name, name_buf, &path, &name); len = strlen(name); --len; ksnprintf(buf, sizeof(buf), "%s%s", rule->linkname, node->d_dir.d_name+len); devfs_alias_create(buf, node, 1); } else { devfs_alias_create(rule->linkname, node, 1); } } void * devfs_rule_check_apply(struct devfs_node *node, void *unused) { struct devfs_rule *rule; struct mount *mp = node->mp; int locked = 0; /* Check if it is locked already. if not, we acquire the devfs lock */ if ((lockstatus(&devfs_rule_lock, curthread)) != LK_EXCLUSIVE) { lockmgr(&devfs_rule_lock, LK_EXCLUSIVE); locked = 1; } TAILQ_FOREACH(rule, &devfs_rule_list, link) { /* * Skip this rule if it is only intended for jailed mount points * and the current mount point isn't jailed */ if ((rule->rule_type & DEVFS_RULE_JAIL) && (!(DEVFS_MNTDATA(mp)->jailed)) ) continue; /* * Skip this rule if it is not intended for jailed mount points * and the current mount point is jailed. */ if (!(rule->rule_type & DEVFS_RULE_JAIL) && (DEVFS_MNTDATA(mp)->jailed)) continue; /* * Skip this rule if the mount point specified in the rule doesn't * match the mount point of the node */ if ((rule->mntpoint[0] != '*') && (strcmp(rule->mntpoint, mp->mnt_stat.f_mntonname))) continue; /* * Skip this rule if this is a by-type rule and the device flags * don't match the specified device type in the rule */ if ((rule->rule_type & DEVFS_RULE_TYPE) && ( (rule->dev_type == 0) || (!dev_is_good(node->d_dev)) || (!(dev_dflags(node->d_dev) & rule->dev_type))) ) continue; /* * Skip this rule if this is a by-name rule and the node name * doesn't match the wildcard string in the rule */ if ((rule->rule_type & DEVFS_RULE_NAME) && (!devfs_rule_checkname(rule, node)) ) continue; if (rule->rule_cmd & DEVFS_RULE_HIDE) { /* * If we should hide the device, we just apply the relevant * hide flag to the node and let devfs do the rest in the * vnops */ if ((node->d_dir.d_namlen == 5) && (!memcmp(node->d_dir.d_name, "devfs", 5))) { /* * Magically avoid /dev/devfs from being hidden, so that one * can still use the rule system even after a "* hide". */ continue; } node->flags |= (DEVFS_HIDDEN | DEVFS_RULE_HIDDEN); } else if (rule->rule_cmd & DEVFS_RULE_SHOW) { /* * Show rule just means that the node should not be hidden, so * what we do is clear the hide flag from the node. */ node->flags &= ~DEVFS_HIDDEN; } else if (rule->rule_cmd & DEVFS_RULE_LINK) { /* * This is a LINK rule, so we tell devfs to create * a link with the correct name to this node. */ devfs_rule_create_link(node, rule); #if 0 devfs_alias_create(rule->linkname, node, 1); #endif } else if (rule->rule_cmd & DEVFS_RULE_PERM) { /* * This is a normal ownership/permission rule. We * just apply the permissions and ownership and * we are done. */ node->mode = rule->mode; node->uid = rule->uid; node->gid = rule->gid; } } /* If we acquired the lock, we also get rid of it */ if (locked) lockmgr(&devfs_rule_lock, LK_RELEASE); return NULL; } static int devfs_rule_checkname(struct devfs_rule *rule, struct devfs_node *node) { struct devfs_node *parent = DEVFS_MNTDATA(node->mp)->root_node; char *path = NULL; char *name, name_buf[PATH_MAX]; int no_match = 0; devfs_resolve_name_path(rule->name, name_buf, &path, &name); parent = devfs_resolve_or_create_path(parent, path, 0); if (parent == NULL) return 0; /* no match */ /* Check if node is a child of the parent we found */ if (node->parent != parent) return 0; /* no match */ #if 0 if (rule->rule_type & DEVFS_RULE_LINK) no_match = memcmp(name, node->d_dir.d_name, strlen(name)); else #endif no_match = devfs_WildCaseCmp(name, node->d_dir.d_name); return !no_match; } static int devfs_dev_open(struct dev_open_args *ap) { /* * Only allow read-write access. */ if (((ap->a_oflags & FWRITE) == 0) || ((ap->a_oflags & FREAD) == 0)) return(EPERM); /* * We don't allow nonblocking access. */ if ((ap->a_oflags & O_NONBLOCK) != 0) { devfs_debug(DEVFS_DEBUG_SHOW, "devfs_dev: can't do nonblocking access\n"); return(ENODEV); } return 0; } static int devfs_dev_close(struct dev_close_args *ap) { return 0; } static int devfs_dev_ioctl(struct dev_ioctl_args *ap) { int error; struct devfs_rule_ioctl *rule; error = 0; rule = (struct devfs_rule_ioctl *)ap->a_data; switch(ap->a_cmd) { case DEVFS_RULE_ADD: error = devfs_rule_insert(rule); break; case DEVFS_RULE_APPLY: if (rule->mntpoint == NULL) error = EINVAL; else devfs_apply_rules(rule->mntpoint); break; case DEVFS_RULE_CLEAR: error = devfs_rule_clear(rule); break; case DEVFS_RULE_RESET: if (rule->mntpoint == NULL) error = EINVAL; else devfs_reset_rules(rule->mntpoint); break; default: error = ENOTTY; /* Inappropriate ioctl for device */ break; } return(error); } static void devfs_dev_init(void *unused) { lockinit(&devfs_rule_lock, "devfs_rule lock", 0, 0); devfs_rule_cache = objcache_create("devfs-rule-cache", 0, 0, NULL, NULL, NULL, objcache_malloc_alloc, objcache_malloc_free, &devfs_rule_malloc_args ); devfs_dev = make_dev(&devfs_dev_ops, 0, UID_ROOT, GID_WHEEL, 0600, "devfs"); } static void devfs_dev_uninit(void *unused) { /* XXX: destroy all rules first */ destroy_dev(devfs_dev); objcache_destroy(devfs_rule_cache); } SYSINIT(devfsdev,SI_SUB_DRIVERS,SI_ORDER_FIRST,devfs_dev_init,NULL); SYSUNINIT(devfsdev, SI_SUB_DRIVERS,SI_ORDER_FIRST,devfs_dev_uninit, NULL);