// SPDX-License-Identifier: GPL-2.0-only/* * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 2004-2008 International Business Machines Corp. * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> * Tyler Hicks <code@tyhicks.com> */#include <linux/overflow.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/user_namespace.h>#include <linux/nsproxy.h>#include "ecryptfs_kernel.h" static LIST_HEAD(ecryptfs_msg_ctx_free_list);static LIST_HEAD(ecryptfs_msg_ctx_alloc_list);static DEFINE_MUTEX(ecryptfs_msg_ctx_lists_mux); static struct hlist_head *ecryptfs_daemon_hash;DEFINE_MUTEX(ecryptfs_daemon_hash_mux);static int ecryptfs_hash_bits;#define ecryptfs_current_euid_hash(uid) \ hash_long((unsigned long)from_kuid(&init_user_ns, current_euid()), ecryptfs_hash_bits) static u32 ecryptfs_msg_counter;static 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. Sets the msg_ctx task to current. Returns zero on * success; non-zero on error or upon failure to acquire a free * context element. Must be called with ecryptfs_msg_ctx_lists_mux * held. */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)) { printk(KERN_WARNING "%s: 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", __func__, 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 * * Must be called with ecryptfs_msg_ctx_lists_mux held. */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 * * Must be called with ecryptfs_msg_ctx_lists_mux held. */void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx){ list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); kfree(msg_ctx->msg); msg_ctx->msg = NULL; msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE;} /** * ecryptfs_find_daemon_by_euid * @daemon: If return value is zero, points to the desired daemon pointer * * Must be called with ecryptfs_daemon_hash_mux held. * * Search the hash list for the current effective user id. * * Returns zero if the user id exists in the list; non-zero otherwise. */int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon){ int rc; hlist_for_each_entry(*daemon, &ecryptfs_daemon_hash[ecryptfs_current_euid_hash()], euid_chain) { if (uid_eq((*daemon)->file->f_cred->euid, current_euid())) { rc = 0; goto out; } } rc = -EINVAL;out: return rc;} /** * ecryptfs_spawn_daemon - Create and initialize a new daemon struct * @daemon: Pointer to set to newly allocated daemon struct * @file: File used when opening /dev/ecryptfs * * Must be called ceremoniously while in possession of * ecryptfs_sacred_daemon_hash_mux * * Returns zero on success; non-zero otherwise */intecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file){ int rc = 0; (*daemon) = kzalloc_obj(**daemon); if (!(*daemon)) { rc = -ENOMEM; goto out; } (*daemon)->file = file; mutex_init(&(*daemon)->mux); INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue); init_waitqueue_head(&(*daemon)->wait); (*daemon)->num_queued_msg_ctx = 0; hlist_add_head(&(*daemon)->euid_chain, &ecryptfs_daemon_hash[ecryptfs_current_euid_hash()]);out: return rc;} /* * ecryptfs_exorcise_daemon - Destroy the daemon struct * * Must be called ceremoniously while in possession of * ecryptfs_daemon_hash_mux and the daemon's own mux. */int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon){ struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp; int rc = 0; mutex_lock(&daemon->mux); if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ) || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) { rc = -EBUSY; mutex_unlock(&daemon->mux); goto out; } mutex_lock(&ecryptfs_msg_ctx_lists_mux); list_for_each_entry_safe(msg_ctx, msg_ctx_tmp, &daemon->msg_ctx_out_queue, daemon_out_list) { list_del(&msg_ctx->daemon_out_list); daemon->num_queued_msg_ctx--; printk(KERN_WARNING "%s: Warning: dropping message that is in " "the out queue of a dying daemon\n", __func__); ecryptfs_msg_ctx_alloc_to_free(msg_ctx); } mutex_unlock(&ecryptfs_msg_ctx_lists_mux); hlist_del(&daemon->euid_chain); mutex_unlock(&daemon->mux); kfree_sensitive(daemon);out: return rc;} /** * ecryptfs_process_response * @daemon: eCryptfs daemon object * @msg: The ecryptfs message received; the caller should sanity check * msg->data_len and free the memory * @seq: The sequence number of the message; must match the sequence * number for the existing message context waiting for this * response * * Processes a response message after sending an operation request to * userspace. Some other process is awaiting this response. Before * sending out its first communications, the other process allocated a * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The * response message contains this index so that we can copy over the * response message into the msg_ctx that the process holds a * reference to. The other process is going to wake up, check to see * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then * proceed to read off and process the response message. Returns zero * upon delivery to desired context element; non-zero upon delivery * failure or error. * * Returns zero on success; non-zero otherwise */int ecryptfs_process_response(struct ecryptfs_daemon *daemon, struct ecryptfs_message *msg, u32 seq){ struct ecryptfs_msg_ctx *msg_ctx; size_t msg_size; int rc; if (msg->index >= ecryptfs_message_buf_len) { rc = -EINVAL; printk(KERN_ERR "%s: Attempt to reference " "context buffer at index [%d]; maximum " "allowable is [%d]\n", __func__, msg->index, (ecryptfs_message_buf_len - 1)); goto out; } msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; mutex_lock(&msg_ctx->mux); if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { rc = -EINVAL; printk(KERN_WARNING "%s: Desired context element is not " "pending a response\n", __func__); goto unlock; } else if (msg_ctx->counter != seq) { rc = -EINVAL; printk(KERN_WARNING "%s: Invalid message sequence; " "expected [%d]; received [%d]\n", __func__, msg_ctx->counter, seq); goto unlock; } msg_size = struct_size(msg, data, msg->data_len); msg_ctx->msg = kmemdup(msg, msg_size, GFP_KERNEL); if (!msg_ctx->msg) { rc = -ENOMEM; goto unlock; } msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; wake_up_process(msg_ctx->task); rc = 0;unlock: mutex_unlock(&msg_ctx->mux);out: return rc;} /** * ecryptfs_send_message_locked * @data: The data to send * @data_len: The length of data * @msg_type: Type of message * @msg_ctx: The message context allocated for the send * * Must be called with ecryptfs_daemon_hash_mux held. * * Returns zero on success; non-zero otherwise */static intecryptfs_send_message_locked(char *data, int data_len, u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx){ struct ecryptfs_daemon *daemon; int rc; rc = ecryptfs_find_daemon_by_euid(&daemon); if (rc) { rc = -ENOTCONN; goto out; } mutex_lock(&ecryptfs_msg_ctx_lists_mux); rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); if (rc) { mutex_unlock(&ecryptfs_msg_ctx_lists_mux); printk(KERN_WARNING "%s: Could not claim a free " "context element\n", __func__); goto out; } ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); mutex_unlock(&(*msg_ctx)->mux); mutex_unlock(&ecryptfs_msg_ctx_lists_mux); rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0, daemon); if (rc) { printk(KERN_ERR "%s: Error attempting to send message to " "userspace daemon; rc = [%d]\n", __func__, rc); mutex_lock(&ecryptfs_msg_ctx_lists_mux); mutex_lock(&(*msg_ctx)->mux); ecryptfs_msg_ctx_alloc_to_free(*msg_ctx); mutex_unlock(&(*msg_ctx)->mux); mutex_unlock(&ecryptfs_msg_ctx_lists_mux); *msg_ctx = NULL; }out: return rc;} /** * ecryptfs_send_message * @data: The data to send * @data_len: The length of data * @msg_ctx: The message context allocated for the send * * Grabs ecryptfs_daemon_hash_mux. * * Returns zero on success; non-zero otherwise */int ecryptfs_send_message(char *data, int data_len, struct ecryptfs_msg_ctx **msg_ctx){ int rc; mutex_lock(&ecryptfs_daemon_hash_mux); rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST, msg_ctx); mutex_unlock(&ecryptfs_daemon_hash_mux); 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. Callee must free @msg on success. */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 __init ecryptfs_init_messaging(void){ int i; int rc = 0; if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; printk(KERN_WARNING "%s: Specified number of users is " "too large, defaulting to [%d] users\n", __func__, ecryptfs_number_of_users); } mutex_lock(&ecryptfs_daemon_hash_mux); ecryptfs_hash_bits = 1; while (ecryptfs_number_of_users >> ecryptfs_hash_bits) ecryptfs_hash_bits++; ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head) * (1 << ecryptfs_hash_bits)), GFP_KERNEL); if (!ecryptfs_daemon_hash) { rc = -ENOMEM; mutex_unlock(&ecryptfs_daemon_hash_mux); goto out; } for (i = 0; i < (1 << ecryptfs_hash_bits); i++) INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]); mutex_unlock(&ecryptfs_daemon_hash_mux); ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) * ecryptfs_message_buf_len), GFP_KERNEL); if (!ecryptfs_msg_ctx_arr) { kfree(ecryptfs_daemon_hash); rc = -ENOMEM; goto out; } 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); INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list); 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); rc = ecryptfs_init_ecryptfs_miscdev(); if (rc) ecryptfs_release_messaging();out: return rc;} void ecryptfs_release_messaging(void){ 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); 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_hash) { struct ecryptfs_daemon *daemon; struct hlist_node *n; int i; mutex_lock(&ecryptfs_daemon_hash_mux); for (i = 0; i < (1 << ecryptfs_hash_bits); i++) { int rc; hlist_for_each_entry_safe(daemon, n, &ecryptfs_daemon_hash[i], euid_chain) { rc = ecryptfs_exorcise_daemon(daemon); if (rc) printk(KERN_ERR "%s: Error whilst " "attempting to destroy daemon; " "rc = [%d]. Dazed and confused, " "but trying to continue.\n", __func__, rc); } } kfree(ecryptfs_daemon_hash); mutex_unlock(&ecryptfs_daemon_hash_mux); } ecryptfs_destroy_ecryptfs_miscdev(); return;}
// SPDX-License-Identifier: GPL-2.0-only
/*
* eCryptfs: Linux filesystem encryption layer
*
* Copyright (C) 2004-2008 International Business Machines Corp.
* Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
* Tyler Hicks <code@tyhicks.com>
*/
#include <linux/overflow.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/user_namespace.h>
#include <linux/nsproxy.h>
#include "ecryptfs_kernel.h"
static LIST_HEAD(ecryptfs_msg_ctx_free_list);
static LIST_HEAD(ecryptfs_msg_ctx_alloc_list);
static DEFINE_MUTEX(ecryptfs_msg_ctx_lists_mux);
static struct hlist_head *ecryptfs_daemon_hash;
DEFINE_MUTEX(ecryptfs_daemon_hash_mux);
static int ecryptfs_hash_bits;
#define ecryptfs_current_euid_hash(uid) \
hash_long((unsigned long)from_kuid(&init_user_ns, current_euid()), ecryptfs_hash_bits)
static u32 ecryptfs_msg_counter;
static 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. Sets the msg_ctx task to current. Returns zero on
* success; non-zero on error or upon failure to acquire a free
* context element. Must be called with ecryptfs_msg_ctx_lists_mux
* held.
*/
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)) {
printk(KERN_WARNING "%s: 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", __func__, 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
*
* Must be called with ecryptfs_msg_ctx_lists_mux held.
*/
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
*
* Must be called with ecryptfs_msg_ctx_lists_mux held.
*/
void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx)
{
list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list);
kfree(msg_ctx->msg);
msg_ctx->msg = NULL;
msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE;
}
/**
* ecryptfs_find_daemon_by_euid
* @daemon: If return value is zero, points to the desired daemon pointer
*
* Must be called with ecryptfs_daemon_hash_mux held.
*
* Search the hash list for the current effective user id.
*
* Returns zero if the user id exists in the list; non-zero otherwise.
*/
int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon)
{
int rc;
hlist_for_each_entry(*daemon,
&ecryptfs_daemon_hash[ecryptfs_current_euid_hash()],
euid_chain) {
if (uid_eq((*daemon)->file->f_cred->euid, current_euid())) {
rc = 0;
goto out;
}
}
rc = -EINVAL;
out:
return rc;
}
/**
* ecryptfs_spawn_daemon - Create and initialize a new daemon struct
* @daemon: Pointer to set to newly allocated daemon struct
* @file: File used when opening /dev/ecryptfs
*
* Must be called ceremoniously while in possession of
* ecryptfs_sacred_daemon_hash_mux
*
* Returns zero on success; non-zero otherwise
*/
int
ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file)
{
int rc = 0;
(*daemon) = kzalloc_obj(**daemon);
if (!(*daemon)) {
rc = -ENOMEM;
goto out;
}
(*daemon)->file = file;
mutex_init(&(*daemon)->mux);
INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue);
init_waitqueue_head(&(*daemon)->wait);
(*daemon)->num_queued_msg_ctx = 0;
hlist_add_head(&(*daemon)->euid_chain,
&ecryptfs_daemon_hash[ecryptfs_current_euid_hash()]);
out:
return rc;
}
/*
* ecryptfs_exorcise_daemon - Destroy the daemon struct
*
* Must be called ceremoniously while in possession of
* ecryptfs_daemon_hash_mux and the daemon's own mux.
*/
int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon)
{
struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp;
int rc = 0;
mutex_lock(&daemon->mux);
if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ)
|| (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) {
rc = -EBUSY;
mutex_unlock(&daemon->mux);
goto out;
}
mutex_lock(&ecryptfs_msg_ctx_lists_mux);
list_for_each_entry_safe(msg_ctx, msg_ctx_tmp,
&daemon->msg_ctx_out_queue, daemon_out_list) {
list_del(&msg_ctx->daemon_out_list);
daemon->num_queued_msg_ctx--;
printk(KERN_WARNING "%s: Warning: dropping message that is in "
"the out queue of a dying daemon\n", __func__);
ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
}
mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
hlist_del(&daemon->euid_chain);
mutex_unlock(&daemon->mux);
kfree_sensitive(daemon);
out:
return rc;
}
/**
* ecryptfs_process_response
* @daemon: eCryptfs daemon object
* @msg: The ecryptfs message received; the caller should sanity check
* msg->data_len and free the memory
* @seq: The sequence number of the message; must match the sequence
* number for the existing message context waiting for this
* response
*
* Processes a response message after sending an operation request to
* userspace. Some other process is awaiting this response. Before
* sending out its first communications, the other process allocated a
* msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The
* response message contains this index so that we can copy over the
* response message into the msg_ctx that the process holds a
* reference to. The other process is going to wake up, check to see
* that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then
* proceed to read off and process the response message. Returns zero
* upon delivery to desired context element; non-zero upon delivery
* failure or error.
*
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
struct ecryptfs_message *msg, u32 seq)
{
struct ecryptfs_msg_ctx *msg_ctx;
size_t msg_size;
int rc;
if (msg->index >= ecryptfs_message_buf_len) {
rc = -EINVAL;
printk(KERN_ERR "%s: Attempt to reference "
"context buffer at index [%d]; maximum "
"allowable is [%d]\n", __func__, msg->index,
(ecryptfs_message_buf_len - 1));
goto out;
}
msg_ctx = &ecryptfs_msg_ctx_arr[msg->index];
mutex_lock(&msg_ctx->mux);
if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) {
rc = -EINVAL;
printk(KERN_WARNING "%s: Desired context element is not "
"pending a response\n", __func__);
goto unlock;
} else if (msg_ctx->counter != seq) {
rc = -EINVAL;
printk(KERN_WARNING "%s: Invalid message sequence; "
"expected [%d]; received [%d]\n", __func__,
msg_ctx->counter, seq);
goto unlock;
}
msg_size = struct_size(msg, data, msg->data_len);
msg_ctx->msg = kmemdup(msg, msg_size, GFP_KERNEL);
if (!msg_ctx->msg) {
rc = -ENOMEM;
goto unlock;
}
msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE;
wake_up_process(msg_ctx->task);
rc = 0;
unlock:
mutex_unlock(&msg_ctx->mux);
out:
return rc;
}
/**
* ecryptfs_send_message_locked
* @data: The data to send
* @data_len: The length of data
* @msg_type: Type of message
* @msg_ctx: The message context allocated for the send
*
* Must be called with ecryptfs_daemon_hash_mux held.
*
* Returns zero on success; non-zero otherwise
*/
static int
ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
struct ecryptfs_msg_ctx **msg_ctx)
{
struct ecryptfs_daemon *daemon;
int rc;
rc = ecryptfs_find_daemon_by_euid(&daemon);
if (rc) {
rc = -ENOTCONN;
goto out;
}
mutex_lock(&ecryptfs_msg_ctx_lists_mux);
rc = ecryptfs_acquire_free_msg_ctx(msg_ctx);
if (rc) {
mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
printk(KERN_WARNING "%s: Could not claim a free "
"context element\n", __func__);
goto out;
}
ecryptfs_msg_ctx_free_to_alloc(*msg_ctx);
mutex_unlock(&(*msg_ctx)->mux);
mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0,
daemon);
if (rc) {
printk(KERN_ERR "%s: Error attempting to send message to "
"userspace daemon; rc = [%d]\n", __func__, rc);
mutex_lock(&ecryptfs_msg_ctx_lists_mux);
mutex_lock(&(*msg_ctx)->mux);
ecryptfs_msg_ctx_alloc_to_free(*msg_ctx);
mutex_unlock(&(*msg_ctx)->mux);
mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
*msg_ctx = NULL;
}
out:
return rc;
}
/**
* ecryptfs_send_message
* @data: The data to send
* @data_len: The length of data
* @msg_ctx: The message context allocated for the send
*
* Grabs ecryptfs_daemon_hash_mux.
*
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_send_message(char *data, int data_len,
struct ecryptfs_msg_ctx **msg_ctx)
{
int rc;
mutex_lock(&ecryptfs_daemon_hash_mux);
rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST,
msg_ctx);
mutex_unlock(&ecryptfs_daemon_hash_mux);
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. Callee must free @msg on success.
*/
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 __init ecryptfs_init_messaging(void)
{
int i;
int rc = 0;
if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) {
ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS;
printk(KERN_WARNING "%s: Specified number of users is "
"too large, defaulting to [%d] users\n", __func__,
ecryptfs_number_of_users);
}
mutex_lock(&ecryptfs_daemon_hash_mux);
ecryptfs_hash_bits = 1;
while (ecryptfs_number_of_users >> ecryptfs_hash_bits)
ecryptfs_hash_bits++;
ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head)
* (1 << ecryptfs_hash_bits)),
GFP_KERNEL);
if (!ecryptfs_daemon_hash) {
rc = -ENOMEM;
mutex_unlock(&ecryptfs_daemon_hash_mux);
goto out;
}
for (i = 0; i < (1 << ecryptfs_hash_bits); i++)
INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]);
mutex_unlock(&ecryptfs_daemon_hash_mux);
ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx)
* ecryptfs_message_buf_len),
GFP_KERNEL);
if (!ecryptfs_msg_ctx_arr) {
kfree(ecryptfs_daemon_hash);
rc = -ENOMEM;
goto out;
}
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);
INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list);
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);
rc = ecryptfs_init_ecryptfs_miscdev();
if (rc)
ecryptfs_release_messaging();
out:
return rc;
}
void ecryptfs_release_messaging(void)
{
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);
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_hash) {
struct ecryptfs_daemon *daemon;
struct hlist_node *n;
int i;
mutex_lock(&ecryptfs_daemon_hash_mux);
for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
int rc;
hlist_for_each_entry_safe(daemon, n,
&ecryptfs_daemon_hash[i],
euid_chain) {
rc = ecryptfs_exorcise_daemon(daemon);
if (rc)
printk(KERN_ERR "%s: Error whilst "
"attempting to destroy daemon; "
"rc = [%d]. Dazed and confused, "
"but trying to continue.\n",
__func__, rc);
}
}
kfree(ecryptfs_daemon_hash);
mutex_unlock(&ecryptfs_daemon_hash_mux);
}
ecryptfs_destroy_ecryptfs_miscdev();
return;
}