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eCryptfs: remove netlink transport 

The netlink transport code has not worked for a while and the miscdev
transport is a simpler solution.  This patch removes the netlink code and
makes the miscdev transport the only eCryptfs kernel to userspace
transport.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tyler Hicks 2008-10-15 22:02:51 -07:00 committed by Linus Torvalds
parent 807b7ebe41
commit 624ae52845
6 changed files with 60 additions and 388 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/ecryptfs/Makefile
View File

@ -4,4 +4,4 @@
obj-$(CONFIG_ECRYPT_FS) += ecryptfs.o
ecryptfs-objs := dentry.o file.o inode.o main.o super.o mmap.o read_write.o crypto.o keystore.o messaging.o netlink.o miscdev.o kthread.o debug.o
ecryptfs-objs := dentry.o file.o inode.o main.o super.o mmap.o read_write.o crypto.o keystore.o messaging.o miscdev.o kthread.o debug.o

28
fs/ecryptfs/ecryptfs_kernel.h
View File

@ -79,11 +79,6 @@
#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_TRANSPORT_MISCDEV 3
#define ECRYPTFS_DEFAULT_TRANSPORT ECRYPTFS_TRANSPORT_MISCDEV
#define ECRYPTFS_XATTR_NAME "user.ecryptfs"
#define RFC2440_CIPHER_DES3_EDE 0x02
@ -400,8 +395,6 @@ struct ecryptfs_msg_ctx {
struct mutex mux;
};
extern unsigned int ecryptfs_transport;
struct ecryptfs_daemon;
struct ecryptfs_daemon {
@ -627,31 +620,20 @@ int
ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags);
int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
int ecryptfs_process_helo(unsigned int transport, uid_t euid,
struct user_namespace *user_ns, struct pid *pid);
int ecryptfs_process_helo(uid_t euid, struct user_namespace *user_ns,
struct pid *pid);
int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns,
struct pid *pid);
int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
struct user_namespace *user_ns, struct pid *pid,
u32 seq);
int ecryptfs_send_message(unsigned int transport, char *data, int data_len,
int ecryptfs_send_message(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_init_messaging(void);
void ecryptfs_release_messaging(void);
int ecryptfs_send_netlink(char *data, int data_len,
struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
u16 msg_flags, struct pid *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, u8 msg_type,
u16 msg_flags, struct pid *daemon_pid);
int ecryptfs_init_connector(void);
void ecryptfs_release_connector(void);
void
ecryptfs_write_header_metadata(char *virt,
struct ecryptfs_crypt_stat *crypt_stat,

32
fs/ecryptfs/keystore.c
View File

@ -234,8 +234,8 @@ parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
}
i += data_len;
if (message_len < (i + m_size)) {
ecryptfs_printk(KERN_ERR, "The received netlink message is "
"shorter than expected\n");
ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
"is shorter than expected\n");
rc = -EIO;
goto out;
}
@ -438,8 +438,8 @@ decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_msg_ctx *msg_ctx;
struct ecryptfs_message *msg = NULL;
char *auth_tok_sig;
char *netlink_message;
size_t netlink_message_length;
char *payload;
size_t payload_len;
int rc;
rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
@ -449,15 +449,15 @@ decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
goto out;
}
rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
&netlink_message, &netlink_message_length);
&payload, &payload_len);
if (rc) {
ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
goto out;
}
rc = ecryptfs_send_message(ecryptfs_transport, netlink_message,
netlink_message_length, &msg_ctx);
rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
ecryptfs_printk(KERN_ERR, "Error sending message to "
"ecryptfsd\n");
goto out;
}
rc = ecryptfs_wait_for_response(msg_ctx, &msg);
@ -1333,23 +1333,22 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_key_record *key_rec)
{
struct ecryptfs_msg_ctx *msg_ctx = NULL;
char *netlink_payload;
size_t netlink_payload_length;
char *payload = NULL;
size_t payload_len;
struct ecryptfs_message *msg;
int rc;
rc = write_tag_66_packet(auth_tok->token.private_key.signature,
ecryptfs_code_for_cipher_string(crypt_stat),
crypt_stat, &netlink_payload,
&netlink_payload_length);
crypt_stat, &payload, &payload_len);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
goto out;
}
rc = ecryptfs_send_message(ecryptfs_transport, netlink_payload,
netlink_payload_length, &msg_ctx);
rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
ecryptfs_printk(KERN_ERR, "Error sending message to "
"ecryptfsd\n");
goto out;
}
rc = ecryptfs_wait_for_response(msg_ctx, &msg);
@ -1364,8 +1363,7 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
kfree(msg);
out:
if (netlink_payload)
kfree(netlink_payload);
kfree(payload);
return rc;
}
/**

19
fs/ecryptfs/main.c
View File

@ -30,7 +30,6 @@
#include <linux/namei.h>
#include <linux/skbuff.h>
#include <linux/crypto.h>
#include <linux/netlink.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/key.h>
@ -49,8 +48,7 @@ MODULE_PARM_DESC(ecryptfs_verbosity,
"0, which is Quiet)");
/**
* Module parameter that defines the number of netlink message buffer
* elements
* Module parameter that defines the number of message buffer elements
*/
unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
@ -60,9 +58,9 @@ MODULE_PARM_DESC(ecryptfs_message_buf_len,
/**
* Module parameter that defines the maximum guaranteed amount of time to wait
* for a response through netlink. The actual sleep time will be, more than
* for a response from ecryptfsd. The actual sleep time will be, more than
* likely, a small amount greater than this specified value, but only less if
* the netlink message successfully arrives.
* the message successfully arrives.
*/
signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
@ -83,8 +81,6 @@ module_param(ecryptfs_number_of_users, uint, 0);
MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
"concurrent users of eCryptfs");
unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;
void __ecryptfs_printk(const char *fmt, ...)
{
va_list args;
@ -779,10 +775,11 @@ static int __init ecryptfs_init(void)
"rc = [%d]\n", __func__, rc);
goto out_do_sysfs_unregistration;
}
rc = ecryptfs_init_messaging(ecryptfs_transport);
rc = ecryptfs_init_messaging();
if (rc) {
printk(KERN_ERR "Failure occured while attempting to "
"initialize the eCryptfs netlink socket\n");
"initialize the communications channel to "
"ecryptfsd\n");
goto out_destroy_kthread;
}
rc = ecryptfs_init_crypto();
@ -797,7 +794,7 @@ static int __init ecryptfs_init(void)
goto out;
out_release_messaging:
ecryptfs_release_messaging(ecryptfs_transport);
ecryptfs_release_messaging();
out_destroy_kthread:
ecryptfs_destroy_kthread();
out_do_sysfs_unregistration:
@ -818,7 +815,7 @@ static void __exit ecryptfs_exit(void)
if (rc)
printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
"rc = [%d]\n", rc);
ecryptfs_release_messaging(ecryptfs_transport);
ecryptfs_release_messaging();
ecryptfs_destroy_kthread();
do_sysfs_unregistration();
unregister_filesystem(&ecryptfs_fs_type);

94
fs/ecryptfs/messaging.c
View File

@ -134,12 +134,11 @@ out:
}
static int
ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx);
ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
struct ecryptfs_msg_ctx **msg_ctx);
/**
* ecryptfs_send_raw_message
* @transport: Transport type
* @msg_type: Message type
* @daemon: Daemon struct for recipient of message
*
@ -150,38 +149,25 @@ ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
*
* Returns zero on success; non-zero otherwise
*/
static int ecryptfs_send_raw_message(unsigned int transport, u8 msg_type,
static int ecryptfs_send_raw_message(u8 msg_type,
struct ecryptfs_daemon *daemon)
{
struct ecryptfs_msg_ctx *msg_ctx;
int rc;
switch(transport) {
case ECRYPTFS_TRANSPORT_NETLINK:
rc = ecryptfs_send_netlink(NULL, 0, NULL, msg_type, 0,
daemon->pid);
break;
case ECRYPTFS_TRANSPORT_MISCDEV:
rc = ecryptfs_send_message_locked(transport, NULL, 0, msg_type,
&msg_ctx);
rc = ecryptfs_send_message_locked(NULL, 0, msg_type, &msg_ctx);
if (rc) {
printk(KERN_ERR "%s: Error whilst attempting to send "
"message via procfs; rc = [%d]\n", __func__, rc);
"message to ecryptfsd; rc = [%d]\n", __func__, rc);
goto out;
}
/* Raw messages are logically context-free (e.g., no
* reply is expected), so we set the state of the
* ecryptfs_msg_ctx object to indicate that it should
* be freed as soon as the transport sends out the message. */
* be freed as soon as the message is sent. */
mutex_lock(&msg_ctx->mux);
msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_NO_REPLY;
mutex_unlock(&msg_ctx->mux);
break;
case ECRYPTFS_TRANSPORT_CONNECTOR:
case ECRYPTFS_TRANSPORT_RELAYFS:
default:
rc = -ENOSYS;
}
out:
return rc;
}
@ -227,7 +213,6 @@ out:
/**
* ecryptfs_process_helo
* @transport: The underlying transport (netlink, etc.)
* @euid: The user ID owner of the message
* @user_ns: The namespace in which @euid applies
* @pid: The process ID for the userspace program that sent the
@ -239,8 +224,8 @@ out:
* Returns zero after adding a new daemon to the hash list;
* non-zero otherwise.
*/
int ecryptfs_process_helo(unsigned int transport, uid_t euid,
struct user_namespace *user_ns, struct pid *pid)
int ecryptfs_process_helo(uid_t euid, struct user_namespace *user_ns,
struct pid *pid)
{
struct ecryptfs_daemon *new_daemon;
struct ecryptfs_daemon *old_daemon;
@ -252,8 +237,7 @@ int ecryptfs_process_helo(unsigned int transport, uid_t euid,
printk(KERN_WARNING "Received request from user [%d] "
"to register daemon [0x%p]; unregistering daemon "
"[0x%p]\n", euid, pid, old_daemon->pid);
rc = ecryptfs_send_raw_message(transport, ECRYPTFS_MSG_QUIT,
old_daemon);
rc = ecryptfs_send_raw_message(ECRYPTFS_MSG_QUIT, old_daemon);
if (rc)
printk(KERN_WARNING "Failed to send QUIT "
"message to daemon [0x%p]; rc = [%d]\n",
@ -467,8 +451,6 @@ out:
/**
* ecryptfs_send_message_locked
* @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
@ -478,8 +460,8 @@ out:
* Returns zero on success; non-zero otherwise
*/
static int
ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx)
ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
struct ecryptfs_msg_ctx **msg_ctx)
{
struct ecryptfs_daemon *daemon;
int rc;
@ -503,20 +485,8 @@ ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
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, msg_type,
0, daemon->pid);
break;
case ECRYPTFS_TRANSPORT_MISCDEV:
rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type,
0, daemon);
break;
case ECRYPTFS_TRANSPORT_CONNECTOR:
case ECRYPTFS_TRANSPORT_RELAYFS:
default:
rc = -ENOSYS;
}
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);
@ -526,8 +496,6 @@ out:
/**
* 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
@ -536,14 +504,14 @@ out:
*
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_send_message(unsigned int transport, char *data, int data_len,
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(transport, data, data_len,
ECRYPTFS_MSG_REQUEST, msg_ctx);
rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST,
msg_ctx);
mutex_unlock(&ecryptfs_daemon_hash_mux);
return rc;
}
@ -586,7 +554,7 @@ sleep:
return rc;
}
int ecryptfs_init_messaging(unsigned int transport)
int ecryptfs_init_messaging(void)
{
int i;
int rc = 0;
@ -639,27 +607,14 @@ int ecryptfs_init_messaging(unsigned int transport)
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_MISCDEV:
rc = ecryptfs_init_ecryptfs_miscdev();
if (rc)
ecryptfs_release_messaging(transport);
break;
case ECRYPTFS_TRANSPORT_CONNECTOR:
case ECRYPTFS_TRANSPORT_RELAYFS:
default:
rc = -ENOSYS;
}
ecryptfs_release_messaging();
out:
return rc;
}
void ecryptfs_release_messaging(unsigned int transport)
void ecryptfs_release_messaging(void)
{
if (ecryptfs_msg_ctx_arr) {
int i;
@ -698,17 +653,6 @@ void ecryptfs_release_messaging(unsigned int transport)
kfree(ecryptfs_daemon_hash);
mutex_unlock(&ecryptfs_daemon_hash_mux);
}
switch(transport) {
case ECRYPTFS_TRANSPORT_NETLINK:
ecryptfs_release_netlink();
break;
case ECRYPTFS_TRANSPORT_MISCDEV:
ecryptfs_destroy_ecryptfs_miscdev();
break;
case ECRYPTFS_TRANSPORT_CONNECTOR:
case ECRYPTFS_TRANSPORT_RELAYFS:
default:
break;
}
return;
}

249
fs/ecryptfs/netlink.c
View File

@ -1,249 +0,0 @@
/**
* 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, u8 msg_type,
u16 msg_flags, struct pid *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, pid_nr(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, pid_nr(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 = nlmsg_hdr(skb);
struct ecryptfs_message *msg = NLMSG_DATA(nlh);
struct pid *pid;
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;
}
pid = find_get_pid(NETLINK_CREDS(skb)->pid);
rc = ecryptfs_process_response(msg, NETLINK_CREDS(skb)->uid, NULL,
pid, nlh->nlmsg_seq);
put_pid(pid);
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)
{
struct pid *pid;
int rc;
pid = find_get_pid(NETLINK_CREDS(skb)->pid);
rc = ecryptfs_process_helo(ECRYPTFS_TRANSPORT_NETLINK,
NETLINK_CREDS(skb)->uid, NULL, pid);
put_pid(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)
{
struct pid *pid;
int rc;
pid = find_get_pid(NETLINK_CREDS(skb)->pid);
rc = ecryptfs_process_quit(NETLINK_CREDS(skb)->uid, NULL, pid);
put_pid(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 sk_buff *skb)
{
struct nlmsghdr *nlh;
nlh = nlmsg_hdr(skb);
if (!NLMSG_OK(nlh, skb->len)) {
ecryptfs_printk(KERN_ERR, "Received corrupt netlink "
"message\n");
goto free;
}
switch (nlh->nlmsg_type) {
case ECRYPTFS_MSG_RESPONSE:
if (ecryptfs_process_nl_response(skb)) {
ecryptfs_printk(KERN_WARNING, "Failed to "
"deliver netlink response to "
"requesting operation\n");
}
break;
case ECRYPTFS_MSG_HELO:
if (ecryptfs_process_nl_helo(skb)) {
ecryptfs_printk(KERN_WARNING, "Failed to "
"fulfill HELO request\n");
}
break;
case ECRYPTFS_MSG_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(&init_net, NETLINK_ECRYPTFS, 0,
ecryptfs_receive_nl_message,
NULL, 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)
{
netlink_kernel_release(ecryptfs_nl_sock);
ecryptfs_nl_sock = NULL;
}