diff options
| -rw-r--r-- | fs/Kconfig | 2 | ||||
| -rw-r--r-- | fs/ecryptfs/ecryptfs_kernel.h | 101 | ||||
| -rw-r--r-- | fs/ecryptfs/messaging.c | 505 | ||||
| -rw-r--r-- | fs/ecryptfs/netlink.c | 255 | ||||
| -rw-r--r-- | include/linux/netlink.h | 1 |
5 files changed, 860 insertions, 4 deletions
@@ -1088,7 +1088,7 @@ config AFFS_FS config ECRYPT_FS tristate "eCrypt filesystem layer support (EXPERIMENTAL)" - depends on EXPERIMENTAL && KEYS && CRYPTO + depends on EXPERIMENTAL && KEYS && CRYPTO && NET help Encrypted filesystem that operates on the VFS layer. See <file:Documentation/ecryptfs.txt> to learn more about diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 0f89710..508648e 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -6,6 +6,8 @@ * Copyright (C) 2001-2003 Stony Brook University * Copyright (C) 2004-2006 International Business Machines Corp. * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> + * Trevor S. Highland <trevor.highland@gmail.com> + * Tyler Hicks <tyhicks@ou.edu> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as @@ -35,7 +37,7 @@ /* Version verification for shared data structures w/ userspace */ #define ECRYPTFS_VERSION_MAJOR 0x00 #define ECRYPTFS_VERSION_MINOR 0x04 -#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x01 +#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x02 /* These flags indicate which features are supported by the kernel * module; userspace tools such as the mount helper read * ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine @@ -60,10 +62,24 @@ #define ECRYPTFS_MAX_KEY_BYTES 64 #define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512 #define ECRYPTFS_DEFAULT_IV_BYTES 16 -#define ECRYPTFS_FILE_VERSION 0x01 +#define ECRYPTFS_FILE_VERSION 0x02 #define ECRYPTFS_DEFAULT_HEADER_EXTENT_SIZE 8192 #define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096 #define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192 +#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32 +#define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ +#define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3) +#define ECRYPTFS_NLMSG_HELO 100 +#define ECRYPTFS_NLMSG_QUIT 101 +#define ECRYPTFS_NLMSG_REQUEST 102 +#define ECRYPTFS_NLMSG_RESPONSE 103 +#define ECRYPTFS_MAX_PKI_NAME_BYTES 16 +#define ECRYPTFS_DEFAULT_NUM_USERS 4 +#define ECRYPTFS_MAX_NUM_USERS 32768 +#define ECRYPTFS_TRANSPORT_NETLINK 0 +#define ECRYPTFS_TRANSPORT_CONNECTOR 1 +#define ECRYPTFS_TRANSPORT_RELAYFS 2 +#define ECRYPTFS_DEFAULT_TRANSPORT ECRYPTFS_TRANSPORT_NETLINK #define RFC2440_CIPHER_DES3_EDE 0x02 #define RFC2440_CIPHER_CAST_5 0x03 @@ -77,6 +93,7 @@ #define ECRYPTFS_SET_FLAG(flag_bit_vector, flag) (flag_bit_vector |= (flag)) #define ECRYPTFS_CLEAR_FLAG(flag_bit_vector, flag) (flag_bit_vector &= ~(flag)) #define ECRYPTFS_CHECK_FLAG(flag_bit_vector, flag) (flag_bit_vector & (flag)) +#define RFC2440_CIPHER_RSA 0x01 /** * For convenience, we may need to pass around the encrypted session @@ -114,6 +131,14 @@ struct ecryptfs_password { enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY}; +struct ecryptfs_private_key { + u32 key_size; + u32 data_len; + u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1]; + char pki_type[ECRYPTFS_MAX_PKI_NAME_BYTES + 1]; + u8 data[]; +}; + /* May be a password or a private key */ struct ecryptfs_auth_tok { u16 version; /* 8-bit major and 8-bit minor */ @@ -123,7 +148,7 @@ struct ecryptfs_auth_tok { u8 reserved[32]; union { struct ecryptfs_password password; - /* Private key is in future eCryptfs releases */ + struct ecryptfs_private_key private_key; } token; } __attribute__ ((packed)); @@ -177,8 +202,13 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_DEFAULT_CIPHER "aes" #define ECRYPTFS_DEFAULT_KEY_BYTES 16 #define ECRYPTFS_DEFAULT_HASH "md5" +#define ECRYPTFS_TAG_1_PACKET_TYPE 0x01 #define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C #define ECRYPTFS_TAG_11_PACKET_TYPE 0xED +#define ECRYPTFS_TAG_64_PACKET_TYPE 0x40 +#define ECRYPTFS_TAG_65_PACKET_TYPE 0x41 +#define ECRYPTFS_TAG_66_PACKET_TYPE 0x42 +#define ECRYPTFS_TAG_67_PACKET_TYPE 0x43 #define MD5_DIGEST_SIZE 16 /** @@ -271,6 +301,45 @@ struct ecryptfs_auth_tok_list_item { struct ecryptfs_auth_tok auth_tok; }; +struct ecryptfs_message { + u32 index; + u32 data_len; + u8 data[]; +}; + +struct ecryptfs_msg_ctx { +#define ECRYPTFS_MSG_CTX_STATE_FREE 0x0001 +#define ECRYPTFS_MSG_CTX_STATE_PENDING 0x0002 +#define ECRYPTFS_MSG_CTX_STATE_DONE 0x0003 + u32 state; + unsigned int index; + unsigned int counter; + struct ecryptfs_message *msg; + struct task_struct *task; + struct list_head node; + struct mutex mux; +}; + +extern struct list_head ecryptfs_msg_ctx_free_list; +extern struct list_head ecryptfs_msg_ctx_alloc_list; +extern struct mutex ecryptfs_msg_ctx_lists_mux; + +#define ecryptfs_uid_hash(uid) \ + hash_long((unsigned long)uid, ecryptfs_hash_buckets) +extern struct hlist_head *ecryptfs_daemon_id_hash; +extern struct mutex ecryptfs_daemon_id_hash_mux; +extern int ecryptfs_hash_buckets; + +extern unsigned int ecryptfs_msg_counter; +extern struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; +extern unsigned int ecryptfs_transport; + +struct ecryptfs_daemon_id { + pid_t pid; + uid_t uid; + struct hlist_node id_chain; +}; + static inline struct ecryptfs_file_info * ecryptfs_file_to_private(struct file *file) { @@ -391,6 +460,9 @@ extern struct super_operations ecryptfs_sops; extern struct dentry_operations ecryptfs_dops; extern struct address_space_operations ecryptfs_aops; extern int ecryptfs_verbosity; +extern unsigned int ecryptfs_message_buf_len; +extern signed long ecryptfs_message_wait_timeout; +extern unsigned int ecryptfs_number_of_users; extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache; extern struct kmem_cache *ecryptfs_file_info_cache; @@ -484,4 +556,27 @@ int ecryptfs_open_lower_file(struct file **lower_file, struct vfsmount *lower_mnt, int flags); int ecryptfs_close_lower_file(struct file *lower_file); +int ecryptfs_process_helo(unsigned int transport, uid_t uid, pid_t pid); +int ecryptfs_process_quit(uid_t uid, pid_t pid); +int ecryptfs_process_response(struct ecryptfs_message *msg, pid_t pid, u32 seq); +int ecryptfs_send_message(unsigned int transport, char *data, int data_len, + struct ecryptfs_msg_ctx **msg_ctx); +int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, + struct ecryptfs_message **emsg); +int ecryptfs_init_messaging(unsigned int transport); +void ecryptfs_release_messaging(unsigned int transport); + +int ecryptfs_send_netlink(char *data, int data_len, + struct ecryptfs_msg_ctx *msg_ctx, u16 msg_type, + u16 msg_flags, pid_t daemon_pid); +int ecryptfs_init_netlink(void); +void ecryptfs_release_netlink(void); + +int ecryptfs_send_connector(char *data, int data_len, + struct ecryptfs_msg_ctx *msg_ctx, u16 msg_type, + u16 msg_flags, pid_t daemon_pid); +int ecryptfs_init_connector(void); +void ecryptfs_release_connector(void); + + #endif /* #ifndef ECRYPTFS_KERNEL_H */ diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c new file mode 100644 index 0000000..c22b32f --- /dev/null +++ b/fs/ecryptfs/messaging.c @@ -0,0 +1,505 @@ +/** + * eCryptfs: Linux filesystem encryption layer + * + * Copyright (C) 2004-2006 International Business Machines Corp. + * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + */ + +#include "ecryptfs_kernel.h" + +LIST_HEAD(ecryptfs_msg_ctx_free_list); +LIST_HEAD(ecryptfs_msg_ctx_alloc_list); +struct mutex ecryptfs_msg_ctx_lists_mux; + +struct hlist_head *ecryptfs_daemon_id_hash; +struct mutex ecryptfs_daemon_id_hash_mux; +int ecryptfs_hash_buckets; + +unsigned int ecryptfs_msg_counter; +struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; + +/** + * ecryptfs_acquire_free_msg_ctx + * @msg_ctx: The context that was acquired from the free list + * + * Acquires a context element from the free list and locks the mutex + * on the context. Returns zero on success; non-zero on error or upon + * failure to acquire a free context element. Be sure to lock the + * list mutex before calling. + */ +static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx) +{ + struct list_head *p; + int rc; + + if (list_empty(&ecryptfs_msg_ctx_free_list)) { + ecryptfs_printk(KERN_WARNING, "The eCryptfs free " + "context list is empty. It may be helpful to " + "specify the ecryptfs_message_buf_len " + "parameter to be greater than the current " + "value of [%d]\n", ecryptfs_message_buf_len); + rc = -ENOMEM; + goto out; + } + list_for_each(p, &ecryptfs_msg_ctx_free_list) { + *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node); + if (mutex_trylock(&(*msg_ctx)->mux)) { + (*msg_ctx)->task = current; + rc = 0; + goto out; + } + } + rc = -ENOMEM; +out: + return rc; +} + +/** + * ecryptfs_msg_ctx_free_to_alloc + * @msg_ctx: The context to move from the free list to the alloc list + * + * Be sure to lock the list mutex and the context mutex before + * calling. + */ +static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx) +{ + list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list); + msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING; + msg_ctx->counter = ++ecryptfs_msg_counter; +} + +/** + * ecryptfs_msg_ctx_alloc_to_free + * @msg_ctx: The context to move from the alloc list to the free list + * + * Be sure to lock the list mutex and the context mutex before + * calling. + */ +static void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx) +{ + list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); + if (msg_ctx->msg) + kfree(msg_ctx->msg); + msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE; +} + +/** + * ecryptfs_find_daemon_id + * @uid: The user id which maps to the desired daemon id + * @id: If return value is zero, points to the desired daemon id + * pointer + * + * Search the hash list for the given user id. Returns zero if the + * user id exists in the list; non-zero otherwise. The daemon id hash + * mutex should be held before calling this function. + */ +static int ecryptfs_find_daemon_id(uid_t uid, struct ecryptfs_daemon_id **id) +{ + struct hlist_node *elem; + int rc; + + hlist_for_each_entry(*id, elem, + &ecryptfs_daemon_id_hash[ecryptfs_uid_hash(uid)], + id_chain) { + if ((*id)->uid == uid) { + rc = 0; + goto out; + } + } + rc = -EINVAL; +out: + return rc; +} + +static int ecryptfs_send_raw_message(unsigned int transport, u16 msg_type, + pid_t pid) +{ + int rc; + + switch(transport) { + case ECRYPTFS_TRANSPORT_NETLINK: + rc = ecryptfs_send_netlink(NULL, 0, NULL, msg_type, 0, pid); + break; + case ECRYPTFS_TRANSPORT_CONNECTOR: + case ECRYPTFS_TRANSPORT_RELAYFS: + default: + rc = -ENOSYS; + } + return rc; +} + +/** + * ecryptfs_process_helo + * @transport: The underlying transport (netlink, etc.) + * @uid: The user ID owner of the message + * @pid: The process ID for the userspace program that sent the + * message + * + * Adds the uid and pid values to the daemon id hash. If a uid + * already has a daemon pid registered, the daemon will be + * unregistered before the new daemon id is put into the hash list. + * Returns zero after adding a new daemon id to the hash list; + * non-zero otherwise. + */ +int ecryptfs_process_helo(unsigned int transport, uid_t uid, pid_t pid) +{ + struct ecryptfs_daemon_id *new_id; + struct ecryptfs_daemon_id *old_id; + int rc; + + mutex_lock(&ecryptfs_daemon_id_hash_mux); + new_id = kmalloc(sizeof(*new_id), GFP_KERNEL); + if (!new_id) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Failed to allocate memory; unable " + "to register daemon [%d] for user\n", pid, uid); + goto unlock; + } + if (!ecryptfs_find_daemon_id(uid, &old_id)) { + printk(KERN_WARNING "Received request from user [%d] " + "to register daemon [%d]; unregistering daemon " + "[%d]\n", uid, pid, old_id->pid); + hlist_del(&old_id->id_chain); + rc = ecryptfs_send_raw_message(transport, ECRYPTFS_NLMSG_QUIT, + old_id->pid); + if (rc) + printk(KERN_WARNING "Failed to send QUIT " + "message to daemon [%d]; rc = [%d]\n", + old_id->pid, rc); + kfree(old_id); + } + new_id->uid = uid; + new_id->pid = pid; + hlist_add_head(&new_id->id_chain, + &ecryptfs_daemon_id_hash[ecryptfs_uid_hash(uid)]); + rc = 0; +unlock: + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + return rc; +} + +/** + * ecryptfs_process_quit + * @uid: The user ID owner of the message + * @pid: The process ID for the userspace program that sent the + * message + * + * Deletes the corresponding daemon id for the given uid and pid, if + * it is the registered that is requesting the deletion. Returns zero + * after deleting the desired daemon id; non-zero otherwise. + */ +int ecryptfs_process_quit(uid_t uid, pid_t pid) +{ + struct ecryptfs_daemon_id *id; + int rc; + + mutex_lock(&ecryptfs_daemon_id_hash_mux); + if (ecryptfs_find_daemon_id(uid, &id)) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "Received request from user [%d] to " + "unregister unrecognized daemon [%d]\n", uid, + pid); + goto unlock; + } + if (id->pid != pid) { + rc = -EINVAL; + ecryptfs_printk(KERN_WARNING, "Received request from user [%d] " + "with pid [%d] to unregister daemon [%d]\n", + uid, pid, id->pid); + goto unlock; + } + hlist_del(&id->id_chain); + kfree(id); + rc = 0; +unlock: + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + return rc; +} + +/** + * ecryptfs_process_reponse + * @msg: The ecryptfs message received; the caller should sanity check + * msg->data_len + * @pid: The process ID of the userspace application that sent the + * message + * @seq: The sequence number of the message + * + * Processes a response message after sending a operation request to + * userspace. Returns zero upon delivery to desired context element; + * non-zero upon delivery failure or error. + */ +int ecryptfs_process_response(struct ecryptfs_message *msg, pid_t pid, u32 seq) +{ + struct ecryptfs_daemon_id *id; + struct ecryptfs_msg_ctx *msg_ctx; + int msg_size; + int rc; + + if (msg->index >= ecryptfs_message_buf_len) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "Attempt to reference " + "context buffer at index [%d]; maximum " + "allowable is [%d]\n", msg->index, + (ecryptfs_message_buf_len - 1)); + goto out; + } + msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; + mutex_lock(&msg_ctx->mux); + if (ecryptfs_find_daemon_id(msg_ctx->task->euid, &id)) { + rc = -EBADMSG; + ecryptfs_printk(KERN_WARNING, "User [%d] received a " + "message response from process [%d] but does " + "not have a registered daemon\n", + msg_ctx->task->euid, pid); + goto wake_up; + } + if (id->pid != pid) { + rc = -EBADMSG; + ecryptfs_printk(KERN_ERR, "User [%d] received a " + "message response from an unrecognized " + "process [%d]\n", msg_ctx->task->euid, pid); + goto unlock; + } + if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { + rc = -EINVAL; + ecryptfs_printk(KERN_WARNING, "Desired context element is not " + "pending a response\n"); + goto unlock; + } else if (msg_ctx->counter != seq) { + rc = -EINVAL; + ecryptfs_printk(KERN_WARNING, "Invalid message sequence; " + "expected [%d]; received [%d]\n", + msg_ctx->counter, seq); + goto unlock; + } + msg_size = sizeof(*msg) + msg->data_len; + msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL); + if (!msg_ctx->msg) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Failed to allocate memory\n"); + goto unlock; + } + memcpy(msg_ctx->msg, msg, msg_size); + msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; + rc = 0; +wake_up: + wake_up_process(msg_ctx->task); +unlock: + mutex_unlock(&msg_ctx->mux); +out: + return rc; +} + +/** + * ecryptfs_send_message + * @transport: The transport over which to send the message (i.e., + * netlink) + * @data: The data to send + * @data_len: The length of data + * @msg_ctx: The message context allocated for the send + */ +int ecryptfs_send_message(unsigned int transport, char *data, int data_len, + struct ecryptfs_msg_ctx **msg_ctx) +{ + struct ecryptfs_daemon_id *id; + int rc; + + mutex_lock(&ecryptfs_daemon_id_hash_mux); + if (ecryptfs_find_daemon_id(current->euid, &id)) { + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + rc = -ENOTCONN; + ecryptfs_printk(KERN_ERR, "User [%d] does not have a daemon " + "registered\n", current->euid); + goto out; + } + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + mutex_lock(&ecryptfs_msg_ctx_lists_mux); + rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); + if (rc) { + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + ecryptfs_printk(KERN_WARNING, "Could not claim a free " + "context element\n"); + goto out; + } + ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); + mutex_unlock(&(*msg_ctx)->mux); + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + switch (transport) { + case ECRYPTFS_TRANSPORT_NETLINK: + rc = ecryptfs_send_netlink(data, data_len, *msg_ctx, + ECRYPTFS_NLMSG_REQUEST, 0, id->pid); + break; + case ECRYPTFS_TRANSPORT_CONNECTOR: + case ECRYPTFS_TRANSPORT_RELAYFS: + default: + rc = -ENOSYS; + } + if (rc) { + printk(KERN_ERR "Error attempting to send message to userspace " + "daemon; rc = [%d]\n", rc); + } +out: + return rc; +} + +/** + * ecryptfs_wait_for_response + * @msg_ctx: The context that was assigned when sending a message + * @msg: The incoming message from userspace; not set if rc != 0 + * + * Sleeps until awaken by ecryptfs_receive_message or until the amount + * of time exceeds ecryptfs_message_wait_timeout. If zero is + * returned, msg will point to a valid message from userspace; a + * non-zero value is returned upon failure to receive a message or an + * error occurs. + */ +int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, + struct ecryptfs_message **msg) +{ + signed long timeout = ecryptfs_message_wait_timeout * HZ; + int rc = 0; + +sleep: + timeout = schedule_timeout_interruptible(timeout); + mutex_lock(&ecryptfs_msg_ctx_lists_mux); + mutex_lock(&msg_ctx->mux); + if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) { + if (timeout) { + mutex_unlock(&msg_ctx->mux); + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + goto sleep; + } + rc = -ENOMSG; + } else { + *msg = msg_ctx->msg; + msg_ctx->msg = NULL; + } + ecryptfs_msg_ctx_alloc_to_free(msg_ctx); + mutex_unlock(&msg_ctx->mux); + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + return rc; +} + +int ecryptfs_init_messaging(unsigned int transport) +{ + int i; + int rc = 0; + + if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { + ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; + ecryptfs_printk(KERN_WARNING, "Specified number of users is " + "too large, defaulting to [%d] users\n", + ecryptfs_number_of_users); + } + mutex_init(&ecryptfs_daemon_id_hash_mux); + mutex_lock(&ecryptfs_daemon_id_hash_mux); + ecryptfs_hash_buckets = 0; + while (ecryptfs_number_of_users >> ++ecryptfs_hash_buckets); + ecryptfs_daemon_id_hash = kmalloc(sizeof(struct hlist_head) + * ecryptfs_hash_buckets, GFP_KERNEL); + if (!ecryptfs_daemon_id_hash) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Failed to allocate memory\n"); + goto out; + } + for (i = 0; i < ecryptfs_hash_buckets; i++) + INIT_HLIST_HEAD(&ecryptfs_daemon_id_hash[i]); + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + + ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) + * ecryptfs_message_buf_len), GFP_KERNEL); + if (!ecryptfs_msg_ctx_arr) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Failed to allocate memory\n"); + goto out; + } + mutex_init(&ecryptfs_msg_ctx_lists_mux); + mutex_lock(&ecryptfs_msg_ctx_lists_mux); + ecryptfs_msg_counter = 0; + for (i = 0; i < ecryptfs_message_buf_len; i++) { + INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node); + mutex_init(&ecryptfs_msg_ctx_arr[i].mux); + mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); + ecryptfs_msg_ctx_arr[i].index = i; + ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE; + ecryptfs_msg_ctx_arr[i].counter = 0; + ecryptfs_msg_ctx_arr[i].task = NULL; + ecryptfs_msg_ctx_arr[i].msg = NULL; + list_add_tail(&ecryptfs_msg_ctx_arr[i].node, + &ecryptfs_msg_ctx_free_list); + mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); + } + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + switch(transport) { + case ECRYPTFS_TRANSPORT_NETLINK: + rc = ecryptfs_init_netlink(); + if (rc) + ecryptfs_release_messaging(transport); + break; + case ECRYPTFS_TRANSPORT_CONNECTOR: + case ECRYPTFS_TRANSPORT_RELAYFS: + default: + rc = -ENOSYS; + } +out: + return rc; +} + +void ecryptfs_release_messaging(unsigned int transport) +{ + if (ecryptfs_msg_ctx_arr) { + int i; + + mutex_lock(&ecryptfs_msg_ctx_lists_mux); + for (i = 0; i < ecryptfs_message_buf_len; i++) { + mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); + if (ecryptfs_msg_ctx_arr[i].msg) + kfree(ecryptfs_msg_ctx_arr[i].msg); + mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); + } + kfree(ecryptfs_msg_ctx_arr); + mutex_unlock(&ecryptfs_msg_ctx_lists_mux); + } + if (ecryptfs_daemon_id_hash) { + struct hlist_node *elem; + struct ecryptfs_daemon_id *id; + int i; + + mutex_lock(&ecryptfs_daemon_id_hash_mux); + for (i = 0; i < ecryptfs_hash_buckets; i++) { + hlist_for_each_entry(id, elem, + &ecryptfs_daemon_id_hash[i], + id_chain) { + hlist_del(elem); + kfree(id); + } + } + kfree(ecryptfs_daemon_id_hash); + mutex_unlock(&ecryptfs_daemon_id_hash_mux); + } + switch(transport) { + case ECRYPTFS_TRANSPORT_NETLINK: + ecryptfs_release_netlink(); + break; + case ECRYPTFS_TRANSPORT_CONNECTOR: + case ECRYPTFS_TRANSPORT_RELAYFS: + default: + break; + } + return; +} diff --git a/fs/ecryptfs/netlink.c b/fs/ecryptfs/netlink.c new file mode 100644 index 0000000..aba061d --- /dev/null +++ b/fs/ecryptfs/netlink.c @@ -0,0 +1,255 @@ +/** + * eCryptfs: Linux filesystem encryption layer + * + * Copyright (C) 2004-2006 International Business Machines Corp. + * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + */ + +#include <net/sock.h> +#include <linux/hash.h> +#include <linux/random.h> +#include "ecryptfs_kernel.h" + +static struct sock *ecryptfs_nl_sock; + +/** + * ecryptfs_send_netlink + * @data: The data to include as the payload + * @data_len: The byte count of the data + * @msg_ctx: The netlink context that will be used to handle the + * response message + * @msg_type: The type of netlink message to send + * @msg_flags: The flags to include in the netlink header + * @daemon_pid: The process id of the daemon to send the message to + * + * Sends the data to the specified daemon pid and uses the netlink + * context element to store the data needed for validation upon + * receiving the response. The data and the netlink context can be + * null if just sending a netlink header is sufficient. Returns zero + * upon sending the message; non-zero upon error. + */ +int ecryptfs_send_netlink(char *data, int data_len, + struct ecryptfs_msg_ctx *msg_ctx, u16 msg_type, + u16 msg_flags, pid_t daemon_pid) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + struct ecryptfs_message *msg; + size_t payload_len; + int rc; + + payload_len = ((data && data_len) ? (sizeof(*msg) + data_len) : 0); + skb = alloc_skb(NLMSG_SPACE(payload_len), GFP_KERNEL); + if (!skb) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Failed to allocate socket buffer\n"); + goto out; + } + nlh = NLMSG_PUT(skb, daemon_pid, msg_ctx ? msg_ctx->counter : 0, + msg_type, payload_len); + nlh->nlmsg_flags = msg_flags; + if (msg_ctx && payload_len) { + msg = (struct ecryptfs_message *)NLMSG_DATA(nlh); + msg->index = msg_ctx->index; + msg->data_len = data_len; + memcpy(msg->data, data, data_len); + } + rc = netlink_unicast(ecryptfs_nl_sock, skb, daemon_pid, 0); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, "Failed to send eCryptfs netlink " + "message; rc = [%d]\n", rc); + goto out; + } + rc = 0; + goto out; +nlmsg_failure: + rc = -EMSGSIZE; + kfree_skb(skb); +out: + return rc; +} + +/** + * ecryptfs_process_nl_reponse + * @skb: The socket buffer containing the netlink message of state + * RESPONSE + * + * Processes a response message after sending a operation request to + * userspace. Attempts to assign the msg to a netlink context element + * at the index specified in the msg. The sk_buff and nlmsghdr must + * be validated before this function. Returns zero upon delivery to + * desired context element; non-zero upon delivery failure or error. + */ +static int ecryptfs_process_nl_response(struct sk_buff *skb) +{ + struct nlmsghdr *nlh = (struct nlmsghdr*)skb->data; + struct ecryptfs_message *msg = NLMSG_DATA(nlh); + int rc; + + if (skb->len - NLMSG_HDRLEN - sizeof(*msg) != msg->data_len) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "Received netlink message with " + "incorrectly specified data length\n"); + goto out; + } + rc = ecryptfs_process_response(msg, NETLINK_CREDS(skb)->pid, + nlh->nlmsg_seq); + if (rc) + printk(KERN_ERR + "Error processing response message; rc = [%d]\n", rc); +out: + return rc; +} + +/** + * ecryptfs_process_nl_helo + * @skb: The socket buffer containing the nlmsghdr in HELO state + * + * Gets uid and pid of the skb and adds the values to the daemon id + * hash. Returns zero after adding a new daemon id to the hash list; + * non-zero otherwise. + */ +static int ecryptfs_process_nl_helo(struct sk_buff *skb) +{ + int rc; + + rc = ecryptfs_process_helo(ECRYPTFS_TRANSPORT_NETLINK, + NETLINK_CREDS(skb)->uid, + NETLINK_CREDS(skb)->pid); + if (rc) + printk(KERN_WARNING "Error processing HELO; rc = [%d]\n", rc); + return rc; +} + +/** + * ecryptfs_process_nl_quit + * @skb: The socket buffer containing the nlmsghdr in QUIT state + * + * Gets uid and pid of the skb and deletes the corresponding daemon + * id, if it is the registered that is requesting the + * deletion. Returns zero after deleting the desired daemon id; + * non-zero otherwise. + */ +static int ecryptfs_process_nl_quit(struct sk_buff *skb) +{ + int rc; + + rc = ecryptfs_process_quit(NETLINK_CREDS(skb)->uid, + NETLINK_CREDS(skb)->pid); + if (rc) + printk(KERN_WARNING + "Error processing QUIT message; rc = [%d]\n", rc); + return rc; +} + +/** + * ecryptfs_receive_nl_message + * + * Callback function called by netlink system when a message arrives. + * If the message looks to be valid, then an attempt is made to assign + * it to its desired netlink context element and wake up the process + * that is waiting for a response. + */ +static void ecryptfs_receive_nl_message(struct sock *sk, int len) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + int rc = 0; /* skb_recv_datagram requires this */ + +receive: + skb = skb_recv_datagram(sk, 0, 0, &rc); + if (rc == -EINTR) + goto receive; + else if (rc < 0) { + ecryptfs_printk(KERN_ERR, "Error occurred while " + "receiving eCryptfs netlink message; " + "rc = [%d]\n", rc); + return; + } + nlh = (struct nlmsghdr *)skb->data; + if (!NLMSG_OK(nlh, skb->len)) { + ecryptfs_printk(KERN_ERR, "Received corrupt netlink " + "message\n"); + goto free; + } + switch (nlh->nlmsg_type) { + case ECRYPTFS_NLMSG_RESPONSE: + if (ecryptfs_process_nl_response(skb)) { + ecryptfs_printk(KERN_WARNING, "Failed to " + "deliver netlink response to " + "requesting operation\n"); + } + break; + case ECRYPTFS_NLMSG_HELO: + if (ecryptfs_process_nl_helo(skb)) { + ecryptfs_printk(KERN_WARNING, "Failed to " + "fulfill HELO request\n"); + } + break; + case ECRYPTFS_NLMSG_QUIT: + if (ecryptfs_process_nl_quit(skb)) { + ecryptfs_printk(KERN_WARNING, "Failed to " + "fulfill QUIT request\n"); + } + break; + default: + ecryptfs_printk(KERN_WARNING, "Dropping netlink " + "message of unrecognized type [%d]\n", + nlh->nlmsg_type); + break; + } +free: + kfree_skb(skb); +} + +/** + * ecryptfs_init_netlink + * + * Initializes the daemon id hash list, netlink context array, and + * necessary locks. Returns zero upon success; non-zero upon error. + */ +int ecryptfs_init_netlink(void) +{ + int rc; + + ecryptfs_nl_sock = netlink_kernel_create(NETLINK_ECRYPTFS, 0, + ecryptfs_receive_nl_message, + THIS_MODULE); + if (!ecryptfs_nl_sock) { + rc = -EIO; + ecryptfs_printk(KERN_ERR, "Failed to create netlink socket\n"); + goto out; + } + ecryptfs_nl_sock->sk_sndtimeo = ECRYPTFS_DEFAULT_SEND_TIMEOUT; + rc = 0; +out: + return rc; +} + +/** + * ecryptfs_release_netlink + * + * Frees all memory used by the netlink context array and releases the + * netlink socket. + */ +void ecryptfs_release_netlink(void) +{ + if (ecryptfs_nl_sock && ecryptfs_nl_sock->sk_socket) + sock_release(ecryptfs_nl_sock->sk_socket); + ecryptfs_nl_sock = NULL; +} diff --git a/include/linux/netlink.h b/include/linux/netlink.h index b3b9b60..2a20f48 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -23,6 +23,7 @@ #define NETLINK_GENERIC 16 /* leave room for NETLINK_DM (DM Events) */ #define NETLINK_SCSITRANSPORT 18 /* SCSI Transports */ +#define NETLINK_ECRYPTFS 19 #define MAX_LINKS 32 |