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linux/net/netlabel/netlabel_mgmt.c
Paul Moore b1edeb1023 netlabel: Replace protocol/NetLabel linking with refrerence counts 
NetLabel has always had a list of backpointers in the CIPSO DOI definition
structure which pointed to the NetLabel LSM domain mapping structures which
referenced the CIPSO DOI struct.  The rationale for this was that when an
administrator removed a CIPSO DOI from the system all of the associated
NetLabel LSM domain mappings should be removed as well; a list of
backpointers made this a simple operation.

Unfortunately, while the backpointers did make the removal easier they were
a bit of a mess from an implementation point of view which was making
further development difficult.  Since the removal of a CIPSO DOI is a
realtively rare event it seems to make sense to remove this backpointer
list as the optimization was hurting us more then it was helping.  However,
we still need to be able to track when a CIPSO DOI definition is being used
so replace the backpointer list with a reference count.  In order to
preserve the current functionality of removing the associated LSM domain
mappings when a CIPSO DOI is removed we walk the LSM domain mapping table,
removing the relevant entries.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:31 -04:00

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/*
* NetLabel Management Support
*
* This file defines the management functions for the NetLabel system. The
* NetLabel system manages static and dynamic label mappings for network
* protocols such as CIPSO and RIPSO.
*
* Author: Paul Moore <paul.moore@hp.com>
*
*/
/*
* (c) Copyright Hewlett-Packard Development Company, L.P., 2006
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 <linux/types.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/atomic.h>
#include "netlabel_domainhash.h"
#include "netlabel_user.h"
#include "netlabel_mgmt.h"
/* NetLabel configured protocol counter */
atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
/* Argument struct for netlbl_domhsh_walk() */
struct netlbl_domhsh_walk_arg {
struct netlink_callback *nl_cb;
struct sk_buff *skb;
u32 seq;
};
/* NetLabel Generic NETLINK CIPSOv4 family */
static struct genl_family netlbl_mgmt_gnl_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
.name = NETLBL_NLTYPE_MGMT_NAME,
.version = NETLBL_PROTO_VERSION,
.maxattr = NLBL_MGMT_A_MAX,
};
/* NetLabel Netlink attribute policy */
static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
};
/*
* NetLabel Command Handlers
*/
/**
* netlbl_mgmt_add - Handle an ADD message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated ADD message and add the domains from the message
* to the hash table. See netlabel.h for a description of the message format.
* Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -EINVAL;
struct netlbl_dom_map *entry = NULL;
size_t tmp_size;
u32 tmp_val;
struct netlbl_audit audit_info;
if (!info->attrs[NLBL_MGMT_A_DOMAIN] ||
!info->attrs[NLBL_MGMT_A_PROTOCOL])
goto add_failure;
netlbl_netlink_auditinfo(skb, &audit_info);
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry == NULL) {
ret_val = -ENOMEM;
goto add_failure;
}
tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
entry->domain = kmalloc(tmp_size, GFP_KERNEL);
if (entry->domain == NULL) {
ret_val = -ENOMEM;
goto add_failure;
}
entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
nla_strlcpy(entry->domain, info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
switch (entry->type) {
case NETLBL_NLTYPE_UNLABELED:
ret_val = netlbl_domhsh_add(entry, &audit_info);
break;
case NETLBL_NLTYPE_CIPSOV4:
if (!info->attrs[NLBL_MGMT_A_CV4DOI])
goto add_failure;
tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
if (entry->type_def.cipsov4 == NULL)
goto add_failure;
ret_val = netlbl_domhsh_add(entry, &audit_info);
if (ret_val != 0)
cipso_v4_doi_putdef(entry->type_def.cipsov4);
break;
default:
goto add_failure;
}
if (ret_val != 0)
goto add_failure;
return 0;
add_failure:
if (entry)
kfree(entry->domain);
kfree(entry);
return ret_val;
}
/**
* netlbl_mgmt_remove - Handle a REMOVE message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated REMOVE message and remove the specified domain
* mappings. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
{
char *domain;
struct netlbl_audit audit_info;
if (!info->attrs[NLBL_MGMT_A_DOMAIN])
return -EINVAL;
netlbl_netlink_auditinfo(skb, &audit_info);
domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
return netlbl_domhsh_remove(domain, &audit_info);
}
/**
* netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
* @entry: the domain mapping hash table entry
* @arg: the netlbl_domhsh_walk_arg structure
*
* Description:
* This function is designed to be used as a callback to the
* netlbl_domhsh_walk() function for use in generating a response for a LISTALL
* message. Returns the size of the message on success, negative values on
* failure.
*
*/
static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
{
int ret_val = -ENOMEM;
struct netlbl_domhsh_walk_arg *cb_arg = arg;
void *data;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
cb_arg->seq, &netlbl_mgmt_gnl_family,
NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
if (data == NULL)
goto listall_cb_failure;
ret_val = nla_put_string(cb_arg->skb,
NLBL_MGMT_A_DOMAIN,
entry->domain);
if (ret_val != 0)
goto listall_cb_failure;
ret_val = nla_put_u32(cb_arg->skb, NLBL_MGMT_A_PROTOCOL, entry->type);
if (ret_val != 0)
goto listall_cb_failure;
switch (entry->type) {
case NETLBL_NLTYPE_CIPSOV4:
ret_val = nla_put_u32(cb_arg->skb,
NLBL_MGMT_A_CV4DOI,
entry->type_def.cipsov4->doi);
if (ret_val != 0)
goto listall_cb_failure;
break;
}
cb_arg->seq++;
return genlmsg_end(cb_arg->skb, data);
listall_cb_failure:
genlmsg_cancel(cb_arg->skb, data);
return ret_val;
}
/**
* netlbl_mgmt_listall - Handle a LISTALL message
* @skb: the NETLINK buffer
* @cb: the NETLINK callback
*
* Description:
* Process a user generated LISTALL message and dumps the domain hash table in
* a form suitable for use in a kernel generated LISTALL message. Returns zero
* on success, negative values on failure.
*
*/
static int netlbl_mgmt_listall(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct netlbl_domhsh_walk_arg cb_arg;
u32 skip_bkt = cb->args[0];
u32 skip_chain = cb->args[1];
cb_arg.nl_cb = cb;
cb_arg.skb = skb;
cb_arg.seq = cb->nlh->nlmsg_seq;
netlbl_domhsh_walk(&skip_bkt,
&skip_chain,
netlbl_mgmt_listall_cb,
&cb_arg);
cb->args[0] = skip_bkt;
cb->args[1] = skip_chain;
return skb->len;
}
/**
* netlbl_mgmt_adddef - Handle an ADDDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated ADDDEF message and respond accordingly. Returns
* zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -EINVAL;
struct netlbl_dom_map *entry = NULL;
u32 tmp_val;
struct netlbl_audit audit_info;
if (!info->attrs[NLBL_MGMT_A_PROTOCOL])
goto adddef_failure;
netlbl_netlink_auditinfo(skb, &audit_info);
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry == NULL) {
ret_val = -ENOMEM;
goto adddef_failure;
}
entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
switch (entry->type) {
case NETLBL_NLTYPE_UNLABELED:
ret_val = netlbl_domhsh_add_default(entry, &audit_info);
break;
case NETLBL_NLTYPE_CIPSOV4:
if (!info->attrs[NLBL_MGMT_A_CV4DOI])
goto adddef_failure;
tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
if (entry->type_def.cipsov4 == NULL)
goto adddef_failure;
ret_val = netlbl_domhsh_add_default(entry, &audit_info);
if (ret_val != 0)
cipso_v4_doi_putdef(entry->type_def.cipsov4);
break;
default:
goto adddef_failure;
}
if (ret_val != 0)
goto adddef_failure;
return 0;
adddef_failure:
kfree(entry);
return ret_val;
}
/**
* netlbl_mgmt_removedef - Handle a REMOVEDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated REMOVEDEF message and remove the default domain
* mapping. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
{
struct netlbl_audit audit_info;
netlbl_netlink_auditinfo(skb, &audit_info);
return netlbl_domhsh_remove_default(&audit_info);
}
/**
* netlbl_mgmt_listdef - Handle a LISTDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated LISTDEF message and dumps the default domain
* mapping in a form suitable for use in a kernel generated LISTDEF message.
* Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -ENOMEM;
struct sk_buff *ans_skb = NULL;
void *data;
struct netlbl_dom_map *entry;
ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (ans_skb == NULL)
return -ENOMEM;
data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
0, NLBL_MGMT_C_LISTDEF);
if (data == NULL)
goto listdef_failure;
rcu_read_lock();
entry = netlbl_domhsh_getentry(NULL);
if (entry == NULL) {
ret_val = -ENOENT;
goto listdef_failure_lock;
}
ret_val = nla_put_u32(ans_skb, NLBL_MGMT_A_PROTOCOL, entry->type);
if (ret_val != 0)
goto listdef_failure_lock;
switch (entry->type) {
case NETLBL_NLTYPE_CIPSOV4:
ret_val = nla_put_u32(ans_skb,
NLBL_MGMT_A_CV4DOI,
entry->type_def.cipsov4->doi);
if (ret_val != 0)
goto listdef_failure_lock;
break;
}
rcu_read_unlock();
genlmsg_end(ans_skb, data);
return genlmsg_reply(ans_skb, info);
listdef_failure_lock:
rcu_read_unlock();
listdef_failure:
kfree_skb(ans_skb);
return ret_val;
}
/**
* netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
* @skb: the skb to write to
* @seq: the NETLINK sequence number
* @cb: the NETLINK callback
* @protocol: the NetLabel protocol to use in the message
*
* Description:
* This function is to be used in conjunction with netlbl_mgmt_protocols() to
* answer a application's PROTOCOLS message. Returns the size of the message
* on success, negative values on failure.
*
*/
static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
struct netlink_callback *cb,
u32 protocol)
{
int ret_val = -ENOMEM;
void *data;
data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
&netlbl_mgmt_gnl_family, NLM_F_MULTI,
NLBL_MGMT_C_PROTOCOLS);
if (data == NULL)
goto protocols_cb_failure;
ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
if (ret_val != 0)
goto protocols_cb_failure;
return genlmsg_end(skb, data);
protocols_cb_failure:
genlmsg_cancel(skb, data);
return ret_val;
}
/**
* netlbl_mgmt_protocols - Handle a PROTOCOLS message
* @skb: the NETLINK buffer
* @cb: the NETLINK callback
*
* Description:
* Process a user generated PROTOCOLS message and respond accordingly.
*
*/
static int netlbl_mgmt_protocols(struct sk_buff *skb,
struct netlink_callback *cb)
{
u32 protos_sent = cb->args[0];
if (protos_sent == 0) {
if (netlbl_mgmt_protocols_cb(skb,
cb,
NETLBL_NLTYPE_UNLABELED) < 0)
goto protocols_return;
protos_sent++;
}
if (protos_sent == 1) {
if (netlbl_mgmt_protocols_cb(skb,
cb,
NETLBL_NLTYPE_CIPSOV4) < 0)
goto protocols_return;
protos_sent++;
}
protocols_return:
cb->args[0] = protos_sent;
return skb->len;
}
/**
* netlbl_mgmt_version - Handle a VERSION message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated VERSION message and respond accordingly. Returns
* zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -ENOMEM;
struct sk_buff *ans_skb = NULL;
void *data;
ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (ans_skb == NULL)
return -ENOMEM;
data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
0, NLBL_MGMT_C_VERSION);
if (data == NULL)
goto version_failure;
ret_val = nla_put_u32(ans_skb,
NLBL_MGMT_A_VERSION,
NETLBL_PROTO_VERSION);
if (ret_val != 0)
goto version_failure;
genlmsg_end(ans_skb, data);
return genlmsg_reply(ans_skb, info);
version_failure:
kfree_skb(ans_skb);
return ret_val;
}
/*
* NetLabel Generic NETLINK Command Definitions
*/
static struct genl_ops netlbl_mgmt_genl_ops[] = {
{
.cmd = NLBL_MGMT_C_ADD,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_add,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_REMOVE,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_remove,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_LISTALL,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = NULL,
.dumpit = netlbl_mgmt_listall,
},
{
.cmd = NLBL_MGMT_C_ADDDEF,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_adddef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_REMOVEDEF,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_removedef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_LISTDEF,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_listdef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_PROTOCOLS,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = NULL,
.dumpit = netlbl_mgmt_protocols,
},
{
.cmd = NLBL_MGMT_C_VERSION,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_version,
.dumpit = NULL,
},
};
/*
* NetLabel Generic NETLINK Protocol Functions
*/
/**
* netlbl_mgmt_genl_init - Register the NetLabel management component
*
* Description:
* Register the NetLabel management component with the Generic NETLINK
* mechanism. Returns zero on success, negative values on failure.
*
*/
int __init netlbl_mgmt_genl_init(void)
{
int ret_val, i;
ret_val = genl_register_family(&netlbl_mgmt_gnl_family);
if (ret_val != 0)
return ret_val;
for (i = 0; i < ARRAY_SIZE(netlbl_mgmt_genl_ops); i++) {
ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
&netlbl_mgmt_genl_ops[i]);
if (ret_val != 0)
return ret_val;
}
return 0;
}
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