Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 1 | /** |
| 2 | * eCryptfs: Linux filesystem encryption layer |
| 3 | * |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 4 | * Copyright (C) 2004-2008 International Business Machines Corp. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 5 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> |
| 6 | * Tyler Hicks <tyhicks@ou.edu> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License version |
| 10 | * 2 as published by the Free Software Foundation. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, but |
| 13 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 20 | * 02111-1307, USA. |
| 21 | */ |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 22 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Michael Halcrow | 6a3fd92 | 2008-04-29 00:59:52 -0700 | [diff] [blame] | 24 | #include <linux/user_namespace.h> |
| 25 | #include <linux/nsproxy.h> |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 26 | #include "ecryptfs_kernel.h" |
| 27 | |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 28 | static LIST_HEAD(ecryptfs_msg_ctx_free_list); |
| 29 | static LIST_HEAD(ecryptfs_msg_ctx_alloc_list); |
| 30 | static struct mutex ecryptfs_msg_ctx_lists_mux; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 31 | |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 32 | static struct hlist_head *ecryptfs_daemon_hash; |
| 33 | struct mutex ecryptfs_daemon_hash_mux; |
Andre Osterhues | a6f80fb | 2010-07-13 15:59:17 -0500 | [diff] [blame] | 34 | static int ecryptfs_hash_bits; |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 35 | #define ecryptfs_current_euid_hash(uid) \ |
Eric W. Biederman | cdf8c58 | 2012-02-07 16:24:33 -0800 | [diff] [blame] | 36 | hash_long((unsigned long)from_kuid(&init_user_ns, current_euid()), ecryptfs_hash_bits) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 37 | |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 38 | static u32 ecryptfs_msg_counter; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 39 | static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 40 | |
| 41 | /** |
| 42 | * ecryptfs_acquire_free_msg_ctx |
| 43 | * @msg_ctx: The context that was acquired from the free list |
| 44 | * |
| 45 | * Acquires a context element from the free list and locks the mutex |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 46 | * on the context. Sets the msg_ctx task to current. Returns zero on |
| 47 | * success; non-zero on error or upon failure to acquire a free |
| 48 | * context element. Must be called with ecryptfs_msg_ctx_lists_mux |
| 49 | * held. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 50 | */ |
| 51 | static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx) |
| 52 | { |
| 53 | struct list_head *p; |
| 54 | int rc; |
| 55 | |
| 56 | if (list_empty(&ecryptfs_msg_ctx_free_list)) { |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 57 | printk(KERN_WARNING "%s: The eCryptfs free " |
| 58 | "context list is empty. It may be helpful to " |
| 59 | "specify the ecryptfs_message_buf_len " |
| 60 | "parameter to be greater than the current " |
| 61 | "value of [%d]\n", __func__, ecryptfs_message_buf_len); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 62 | rc = -ENOMEM; |
| 63 | goto out; |
| 64 | } |
| 65 | list_for_each(p, &ecryptfs_msg_ctx_free_list) { |
| 66 | *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node); |
| 67 | if (mutex_trylock(&(*msg_ctx)->mux)) { |
| 68 | (*msg_ctx)->task = current; |
| 69 | rc = 0; |
| 70 | goto out; |
| 71 | } |
| 72 | } |
| 73 | rc = -ENOMEM; |
| 74 | out: |
| 75 | return rc; |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | * ecryptfs_msg_ctx_free_to_alloc |
| 80 | * @msg_ctx: The context to move from the free list to the alloc list |
| 81 | * |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 82 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 83 | */ |
| 84 | static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx) |
| 85 | { |
| 86 | list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list); |
| 87 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING; |
| 88 | msg_ctx->counter = ++ecryptfs_msg_counter; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * ecryptfs_msg_ctx_alloc_to_free |
| 93 | * @msg_ctx: The context to move from the alloc list to the free list |
| 94 | * |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 95 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 96 | */ |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 97 | void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 98 | { |
| 99 | list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); |
Tim Gardner | 1101d58 | 2013-02-12 11:03:49 -0700 | [diff] [blame] | 100 | kfree(msg_ctx->msg); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 101 | msg_ctx->msg = NULL; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 102 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE; |
| 103 | } |
| 104 | |
| 105 | /** |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 106 | * ecryptfs_find_daemon_by_euid |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 107 | * @daemon: If return value is zero, points to the desired daemon pointer |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 108 | * |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 109 | * Must be called with ecryptfs_daemon_hash_mux held. |
| 110 | * |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 111 | * Search the hash list for the current effective user id. |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 112 | * |
| 113 | * Returns zero if the user id exists in the list; non-zero otherwise. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 114 | */ |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 115 | int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 116 | { |
| 117 | struct hlist_node *elem; |
| 118 | int rc; |
| 119 | |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 120 | hlist_for_each_entry(*daemon, elem, |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 121 | &ecryptfs_daemon_hash[ecryptfs_current_euid_hash()], |
| 122 | euid_chain) { |
Eric W. Biederman | cdf8c58 | 2012-02-07 16:24:33 -0800 | [diff] [blame] | 123 | if (uid_eq((*daemon)->file->f_cred->euid, current_euid())) { |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 124 | rc = 0; |
| 125 | goto out; |
| 126 | } |
| 127 | } |
| 128 | rc = -EINVAL; |
| 129 | out: |
| 130 | return rc; |
| 131 | } |
| 132 | |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 133 | /** |
| 134 | * ecryptfs_spawn_daemon - Create and initialize a new daemon struct |
| 135 | * @daemon: Pointer to set to newly allocated daemon struct |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 136 | * @file: File used when opening /dev/ecryptfs |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 137 | * |
| 138 | * Must be called ceremoniously while in possession of |
| 139 | * ecryptfs_sacred_daemon_hash_mux |
| 140 | * |
| 141 | * Returns zero on success; non-zero otherwise |
| 142 | */ |
| 143 | int |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 144 | ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file) |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 145 | { |
| 146 | int rc = 0; |
| 147 | |
| 148 | (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL); |
| 149 | if (!(*daemon)) { |
| 150 | rc = -ENOMEM; |
Michael Halcrow | df261c5 | 2009-01-06 14:42:02 -0800 | [diff] [blame] | 151 | printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of " |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 152 | "GFP_KERNEL memory\n", __func__, sizeof(**daemon)); |
| 153 | goto out; |
| 154 | } |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 155 | (*daemon)->file = file; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 156 | mutex_init(&(*daemon)->mux); |
| 157 | INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue); |
| 158 | init_waitqueue_head(&(*daemon)->wait); |
| 159 | (*daemon)->num_queued_msg_ctx = 0; |
| 160 | hlist_add_head(&(*daemon)->euid_chain, |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 161 | &ecryptfs_daemon_hash[ecryptfs_current_euid_hash()]); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 162 | out: |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 163 | return rc; |
| 164 | } |
| 165 | |
| 166 | /** |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 167 | * ecryptfs_exorcise_daemon - Destroy the daemon struct |
| 168 | * |
| 169 | * Must be called ceremoniously while in possession of |
| 170 | * ecryptfs_daemon_hash_mux and the daemon's own mux. |
| 171 | */ |
| 172 | int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon) |
| 173 | { |
| 174 | struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp; |
| 175 | int rc = 0; |
| 176 | |
| 177 | mutex_lock(&daemon->mux); |
| 178 | if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ) |
| 179 | || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) { |
| 180 | rc = -EBUSY; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 181 | mutex_unlock(&daemon->mux); |
| 182 | goto out; |
| 183 | } |
| 184 | list_for_each_entry_safe(msg_ctx, msg_ctx_tmp, |
| 185 | &daemon->msg_ctx_out_queue, daemon_out_list) { |
| 186 | list_del(&msg_ctx->daemon_out_list); |
| 187 | daemon->num_queued_msg_ctx--; |
| 188 | printk(KERN_WARNING "%s: Warning: dropping message that is in " |
| 189 | "the out queue of a dying daemon\n", __func__); |
| 190 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); |
| 191 | } |
| 192 | hlist_del(&daemon->euid_chain); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 193 | mutex_unlock(&daemon->mux); |
Johannes Weiner | 00fcf2c | 2009-03-31 15:24:42 -0700 | [diff] [blame] | 194 | kzfree(daemon); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 195 | out: |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 196 | return rc; |
| 197 | } |
| 198 | |
| 199 | /** |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 200 | * ecryptfs_process_reponse |
| 201 | * @msg: The ecryptfs message received; the caller should sanity check |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 202 | * msg->data_len and free the memory |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 203 | * @seq: The sequence number of the message; must match the sequence |
| 204 | * number for the existing message context waiting for this |
| 205 | * response |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 206 | * |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 207 | * Processes a response message after sending an operation request to |
| 208 | * userspace. Some other process is awaiting this response. Before |
| 209 | * sending out its first communications, the other process allocated a |
| 210 | * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The |
| 211 | * response message contains this index so that we can copy over the |
| 212 | * response message into the msg_ctx that the process holds a |
| 213 | * reference to. The other process is going to wake up, check to see |
| 214 | * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then |
| 215 | * proceed to read off and process the response message. Returns zero |
| 216 | * upon delivery to desired context element; non-zero upon delivery |
| 217 | * failure or error. |
| 218 | * |
| 219 | * Returns zero on success; non-zero otherwise |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 220 | */ |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 221 | int ecryptfs_process_response(struct ecryptfs_daemon *daemon, |
| 222 | struct ecryptfs_message *msg, u32 seq) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 223 | { |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 224 | struct ecryptfs_msg_ctx *msg_ctx; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 225 | size_t msg_size; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 226 | int rc; |
| 227 | |
| 228 | if (msg->index >= ecryptfs_message_buf_len) { |
| 229 | rc = -EINVAL; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 230 | printk(KERN_ERR "%s: Attempt to reference " |
| 231 | "context buffer at index [%d]; maximum " |
| 232 | "allowable is [%d]\n", __func__, msg->index, |
| 233 | (ecryptfs_message_buf_len - 1)); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 234 | goto out; |
| 235 | } |
| 236 | msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; |
| 237 | mutex_lock(&msg_ctx->mux); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 238 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { |
| 239 | rc = -EINVAL; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 240 | printk(KERN_WARNING "%s: Desired context element is not " |
| 241 | "pending a response\n", __func__); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 242 | goto unlock; |
| 243 | } else if (msg_ctx->counter != seq) { |
| 244 | rc = -EINVAL; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 245 | printk(KERN_WARNING "%s: Invalid message sequence; " |
| 246 | "expected [%d]; received [%d]\n", __func__, |
| 247 | msg_ctx->counter, seq); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 248 | goto unlock; |
| 249 | } |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 250 | msg_size = (sizeof(*msg) + msg->data_len); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 251 | msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL); |
| 252 | if (!msg_ctx->msg) { |
| 253 | rc = -ENOMEM; |
Michael Halcrow | df261c5 | 2009-01-06 14:42:02 -0800 | [diff] [blame] | 254 | printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of " |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 255 | "GFP_KERNEL memory\n", __func__, msg_size); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 256 | goto unlock; |
| 257 | } |
| 258 | memcpy(msg_ctx->msg, msg, msg_size); |
| 259 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 260 | wake_up_process(msg_ctx->task); |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 261 | rc = 0; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 262 | unlock: |
| 263 | mutex_unlock(&msg_ctx->mux); |
| 264 | out: |
| 265 | return rc; |
| 266 | } |
| 267 | |
| 268 | /** |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 269 | * ecryptfs_send_message_locked |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 270 | * @data: The data to send |
| 271 | * @data_len: The length of data |
| 272 | * @msg_ctx: The message context allocated for the send |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 273 | * |
| 274 | * Must be called with ecryptfs_daemon_hash_mux held. |
| 275 | * |
| 276 | * Returns zero on success; non-zero otherwise |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 277 | */ |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 278 | static int |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 279 | ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type, |
| 280 | struct ecryptfs_msg_ctx **msg_ctx) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 281 | { |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 282 | struct ecryptfs_daemon *daemon; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 283 | int rc; |
| 284 | |
Tyler Hicks | 2ecaf55 | 2012-06-11 09:47:47 -0700 | [diff] [blame] | 285 | rc = ecryptfs_find_daemon_by_euid(&daemon); |
Tyler Hicks | 1111eae | 2013-02-27 11:37:48 -0800 | [diff] [blame^] | 286 | if (rc) { |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 287 | rc = -ENOTCONN; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 288 | goto out; |
| 289 | } |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 290 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
| 291 | rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); |
| 292 | if (rc) { |
| 293 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 294 | printk(KERN_WARNING "%s: Could not claim a free " |
| 295 | "context element\n", __func__); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 296 | goto out; |
| 297 | } |
| 298 | ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); |
| 299 | mutex_unlock(&(*msg_ctx)->mux); |
| 300 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 301 | rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0, |
| 302 | daemon); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 303 | if (rc) |
| 304 | printk(KERN_ERR "%s: Error attempting to send message to " |
| 305 | "userspace daemon; rc = [%d]\n", __func__, rc); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 306 | out: |
| 307 | return rc; |
| 308 | } |
| 309 | |
| 310 | /** |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 311 | * ecryptfs_send_message |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 312 | * @data: The data to send |
| 313 | * @data_len: The length of data |
| 314 | * @msg_ctx: The message context allocated for the send |
| 315 | * |
| 316 | * Grabs ecryptfs_daemon_hash_mux. |
| 317 | * |
| 318 | * Returns zero on success; non-zero otherwise |
| 319 | */ |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 320 | int ecryptfs_send_message(char *data, int data_len, |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 321 | struct ecryptfs_msg_ctx **msg_ctx) |
| 322 | { |
| 323 | int rc; |
| 324 | |
| 325 | mutex_lock(&ecryptfs_daemon_hash_mux); |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 326 | rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST, |
| 327 | msg_ctx); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 328 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
| 329 | return rc; |
| 330 | } |
| 331 | |
| 332 | /** |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 333 | * ecryptfs_wait_for_response |
| 334 | * @msg_ctx: The context that was assigned when sending a message |
| 335 | * @msg: The incoming message from userspace; not set if rc != 0 |
| 336 | * |
| 337 | * Sleeps until awaken by ecryptfs_receive_message or until the amount |
| 338 | * of time exceeds ecryptfs_message_wait_timeout. If zero is |
| 339 | * returned, msg will point to a valid message from userspace; a |
| 340 | * non-zero value is returned upon failure to receive a message or an |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 341 | * error occurs. Callee must free @msg on success. |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 342 | */ |
| 343 | int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, |
| 344 | struct ecryptfs_message **msg) |
| 345 | { |
| 346 | signed long timeout = ecryptfs_message_wait_timeout * HZ; |
| 347 | int rc = 0; |
| 348 | |
| 349 | sleep: |
| 350 | timeout = schedule_timeout_interruptible(timeout); |
| 351 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
| 352 | mutex_lock(&msg_ctx->mux); |
| 353 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) { |
| 354 | if (timeout) { |
| 355 | mutex_unlock(&msg_ctx->mux); |
| 356 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
| 357 | goto sleep; |
| 358 | } |
| 359 | rc = -ENOMSG; |
| 360 | } else { |
| 361 | *msg = msg_ctx->msg; |
| 362 | msg_ctx->msg = NULL; |
| 363 | } |
| 364 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); |
| 365 | mutex_unlock(&msg_ctx->mux); |
| 366 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
| 367 | return rc; |
| 368 | } |
| 369 | |
Jerome Marchand | 7371a38 | 2010-08-17 17:24:05 +0200 | [diff] [blame] | 370 | int __init ecryptfs_init_messaging(void) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 371 | { |
| 372 | int i; |
| 373 | int rc = 0; |
| 374 | |
| 375 | if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { |
| 376 | ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 377 | printk(KERN_WARNING "%s: Specified number of users is " |
| 378 | "too large, defaulting to [%d] users\n", __func__, |
| 379 | ecryptfs_number_of_users); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 380 | } |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 381 | mutex_init(&ecryptfs_daemon_hash_mux); |
| 382 | mutex_lock(&ecryptfs_daemon_hash_mux); |
Andre Osterhues | a6f80fb | 2010-07-13 15:59:17 -0500 | [diff] [blame] | 383 | ecryptfs_hash_bits = 1; |
| 384 | while (ecryptfs_number_of_users >> ecryptfs_hash_bits) |
| 385 | ecryptfs_hash_bits++; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 386 | ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head) |
Andre Osterhues | a6f80fb | 2010-07-13 15:59:17 -0500 | [diff] [blame] | 387 | * (1 << ecryptfs_hash_bits)), |
| 388 | GFP_KERNEL); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 389 | if (!ecryptfs_daemon_hash) { |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 390 | rc = -ENOMEM; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 391 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
| 392 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 393 | goto out; |
| 394 | } |
Andre Osterhues | a6f80fb | 2010-07-13 15:59:17 -0500 | [diff] [blame] | 395 | for (i = 0; i < (1 << ecryptfs_hash_bits); i++) |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 396 | INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]); |
| 397 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 398 | ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 399 | * ecryptfs_message_buf_len), |
| 400 | GFP_KERNEL); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 401 | if (!ecryptfs_msg_ctx_arr) { |
| 402 | rc = -ENOMEM; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 403 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 404 | goto out; |
| 405 | } |
| 406 | mutex_init(&ecryptfs_msg_ctx_lists_mux); |
| 407 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
| 408 | ecryptfs_msg_counter = 0; |
| 409 | for (i = 0; i < ecryptfs_message_buf_len; i++) { |
| 410 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node); |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 411 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 412 | mutex_init(&ecryptfs_msg_ctx_arr[i].mux); |
| 413 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); |
| 414 | ecryptfs_msg_ctx_arr[i].index = i; |
| 415 | ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE; |
| 416 | ecryptfs_msg_ctx_arr[i].counter = 0; |
| 417 | ecryptfs_msg_ctx_arr[i].task = NULL; |
| 418 | ecryptfs_msg_ctx_arr[i].msg = NULL; |
| 419 | list_add_tail(&ecryptfs_msg_ctx_arr[i].node, |
| 420 | &ecryptfs_msg_ctx_free_list); |
| 421 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); |
| 422 | } |
| 423 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 424 | rc = ecryptfs_init_ecryptfs_miscdev(); |
| 425 | if (rc) |
| 426 | ecryptfs_release_messaging(); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 427 | out: |
| 428 | return rc; |
| 429 | } |
| 430 | |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 431 | void ecryptfs_release_messaging(void) |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 432 | { |
| 433 | if (ecryptfs_msg_ctx_arr) { |
| 434 | int i; |
| 435 | |
| 436 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
| 437 | for (i = 0; i < ecryptfs_message_buf_len; i++) { |
| 438 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); |
| 439 | if (ecryptfs_msg_ctx_arr[i].msg) |
| 440 | kfree(ecryptfs_msg_ctx_arr[i].msg); |
| 441 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); |
| 442 | } |
| 443 | kfree(ecryptfs_msg_ctx_arr); |
| 444 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); |
| 445 | } |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 446 | if (ecryptfs_daemon_hash) { |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 447 | struct hlist_node *elem; |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 448 | struct ecryptfs_daemon *daemon; |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 449 | int i; |
| 450 | |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 451 | mutex_lock(&ecryptfs_daemon_hash_mux); |
Andre Osterhues | a6f80fb | 2010-07-13 15:59:17 -0500 | [diff] [blame] | 452 | for (i = 0; i < (1 << ecryptfs_hash_bits); i++) { |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 453 | int rc; |
| 454 | |
| 455 | hlist_for_each_entry(daemon, elem, |
| 456 | &ecryptfs_daemon_hash[i], |
| 457 | euid_chain) { |
| 458 | rc = ecryptfs_exorcise_daemon(daemon); |
| 459 | if (rc) |
| 460 | printk(KERN_ERR "%s: Error whilst " |
| 461 | "attempting to destroy daemon; " |
| 462 | "rc = [%d]. Dazed and confused, " |
| 463 | "but trying to continue.\n", |
| 464 | __func__, rc); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 465 | } |
| 466 | } |
Michael Halcrow | f66e883 | 2008-04-29 00:59:51 -0700 | [diff] [blame] | 467 | kfree(ecryptfs_daemon_hash); |
| 468 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 469 | } |
Tyler Hicks | 624ae52 | 2008-10-15 22:02:51 -0700 | [diff] [blame] | 470 | ecryptfs_destroy_ecryptfs_miscdev(); |
Michael Halcrow | 88b4a07 | 2007-02-12 00:53:43 -0800 | [diff] [blame] | 471 | return; |
| 472 | } |