Commit | Line | Data |
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f9e815b3 HW |
1 | /* Netfilter messages via netlink socket. Allows for user space |
2 | * protocol helpers and general trouble making from userspace. | |
3 | * | |
4 | * (C) 2001 by Jay Schulist <jschlst@samba.org>, | |
5 | * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org> | |
67ca3966 | 6 | * (C) 2005,2007 by Pablo Neira Ayuso <pablo@netfilter.org> |
f9e815b3 HW |
7 | * |
8 | * Initial netfilter messages via netlink development funded and | |
9 | * generally made possible by Network Robots, Inc. (www.networkrobots.com) | |
10 | * | |
11 | * Further development of this code funded by Astaro AG (http://www.astaro.com) | |
12 | * | |
13 | * This software may be used and distributed according to the terms | |
14 | * of the GNU General Public License, incorporated herein by reference. | |
15 | */ | |
16 | ||
f9e815b3 HW |
17 | #include <linux/module.h> |
18 | #include <linux/types.h> | |
19 | #include <linux/socket.h> | |
20 | #include <linux/kernel.h> | |
f9e815b3 HW |
21 | #include <linux/string.h> |
22 | #include <linux/sockios.h> | |
23 | #include <linux/net.h> | |
f9e815b3 HW |
24 | #include <linux/skbuff.h> |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/system.h> | |
27 | #include <net/sock.h> | |
a3c5029c | 28 | #include <net/netlink.h> |
f9e815b3 | 29 | #include <linux/init.h> |
f9e815b3 | 30 | |
f9e815b3 HW |
31 | #include <linux/netlink.h> |
32 | #include <linux/netfilter/nfnetlink.h> | |
33 | ||
34 | MODULE_LICENSE("GPL"); | |
4fdb3bb7 HW |
35 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
36 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); | |
f9e815b3 HW |
37 | |
38 | static char __initdata nfversion[] = "0.30"; | |
39 | ||
7c8d4cb4 | 40 | static const struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT]; |
a3c5029c | 41 | static DEFINE_MUTEX(nfnl_mutex); |
f9e815b3 | 42 | |
e6a7d3c0 | 43 | void nfnl_lock(void) |
f9e815b3 | 44 | { |
a3c5029c | 45 | mutex_lock(&nfnl_mutex); |
f9e815b3 | 46 | } |
e6a7d3c0 | 47 | EXPORT_SYMBOL_GPL(nfnl_lock); |
f9e815b3 | 48 | |
e6a7d3c0 | 49 | void nfnl_unlock(void) |
a3c5029c PM |
50 | { |
51 | mutex_unlock(&nfnl_mutex); | |
f9e815b3 | 52 | } |
e6a7d3c0 | 53 | EXPORT_SYMBOL_GPL(nfnl_unlock); |
f9e815b3 | 54 | |
7c8d4cb4 | 55 | int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) |
f9e815b3 | 56 | { |
f9e815b3 | 57 | nfnl_lock(); |
0ab43f84 HW |
58 | if (subsys_table[n->subsys_id]) { |
59 | nfnl_unlock(); | |
60 | return -EBUSY; | |
61 | } | |
f9e815b3 HW |
62 | subsys_table[n->subsys_id] = n; |
63 | nfnl_unlock(); | |
64 | ||
65 | return 0; | |
66 | } | |
f4bc177f | 67 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); |
f9e815b3 | 68 | |
7c8d4cb4 | 69 | int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) |
f9e815b3 | 70 | { |
f9e815b3 HW |
71 | nfnl_lock(); |
72 | subsys_table[n->subsys_id] = NULL; | |
73 | nfnl_unlock(); | |
74 | ||
75 | return 0; | |
76 | } | |
f4bc177f | 77 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); |
f9e815b3 | 78 | |
7c8d4cb4 | 79 | static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type) |
f9e815b3 HW |
80 | { |
81 | u_int8_t subsys_id = NFNL_SUBSYS_ID(type); | |
82 | ||
ac0f1d98 | 83 | if (subsys_id >= NFNL_SUBSYS_COUNT) |
f9e815b3 HW |
84 | return NULL; |
85 | ||
86 | return subsys_table[subsys_id]; | |
87 | } | |
88 | ||
7c8d4cb4 PM |
89 | static inline const struct nfnl_callback * |
90 | nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss) | |
f9e815b3 HW |
91 | { |
92 | u_int8_t cb_id = NFNL_MSG_TYPE(type); | |
601e68e1 | 93 | |
67ca3966 | 94 | if (cb_id >= ss->cb_count) |
f9e815b3 | 95 | return NULL; |
f9e815b3 HW |
96 | |
97 | return &ss->cb[cb_id]; | |
98 | } | |
99 | ||
cd8c20b6 | 100 | int nfnetlink_has_listeners(struct net *net, unsigned int group) |
a2427692 | 101 | { |
cd8c20b6 | 102 | return netlink_has_listeners(net->nfnl, group); |
a2427692 PM |
103 | } |
104 | EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); | |
105 | ||
cd8c20b6 | 106 | int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, |
e34d5c1a | 107 | unsigned group, int echo, gfp_t flags) |
f9e815b3 | 108 | { |
cd8c20b6 | 109 | return nlmsg_notify(net->nfnl, skb, pid, group, echo, flags); |
f9e815b3 | 110 | } |
f4bc177f | 111 | EXPORT_SYMBOL_GPL(nfnetlink_send); |
f9e815b3 | 112 | |
37b7ef72 | 113 | int nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error) |
dd5b6ce6 | 114 | { |
37b7ef72 | 115 | return netlink_set_err(net->nfnl, pid, group, error); |
dd5b6ce6 PNA |
116 | } |
117 | EXPORT_SYMBOL_GPL(nfnetlink_set_err); | |
118 | ||
cd8c20b6 | 119 | int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags) |
f9e815b3 | 120 | { |
cd8c20b6 | 121 | return netlink_unicast(net->nfnl, skb, pid, flags); |
f9e815b3 | 122 | } |
f4bc177f | 123 | EXPORT_SYMBOL_GPL(nfnetlink_unicast); |
f9e815b3 HW |
124 | |
125 | /* Process one complete nfnetlink message. */ | |
1d00a4eb | 126 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
f9e815b3 | 127 | { |
cd8c20b6 | 128 | struct net *net = sock_net(skb->sk); |
7c8d4cb4 PM |
129 | const struct nfnl_callback *nc; |
130 | const struct nfnetlink_subsystem *ss; | |
1d00a4eb | 131 | int type, err; |
f9e815b3 | 132 | |
1d00a4eb TG |
133 | if (security_netlink_recv(skb, CAP_NET_ADMIN)) |
134 | return -EPERM; | |
37d2e7a2 | 135 | |
f9e815b3 | 136 | /* All the messages must at least contain nfgenmsg */ |
f49c857f | 137 | if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct nfgenmsg))) |
f9e815b3 | 138 | return 0; |
f9e815b3 HW |
139 | |
140 | type = nlh->nlmsg_type; | |
e6a7d3c0 | 141 | replay: |
f9e815b3 | 142 | ss = nfnetlink_get_subsys(type); |
0ab43f84 | 143 | if (!ss) { |
95a5afca | 144 | #ifdef CONFIG_MODULES |
3b71535f | 145 | nfnl_unlock(); |
37d2e7a2 | 146 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
a3c5029c | 147 | nfnl_lock(); |
37d2e7a2 | 148 | ss = nfnetlink_get_subsys(type); |
0ab43f84 HW |
149 | if (!ss) |
150 | #endif | |
1d00a4eb | 151 | return -EINVAL; |
0ab43f84 | 152 | } |
f9e815b3 HW |
153 | |
154 | nc = nfnetlink_find_client(type, ss); | |
67ca3966 | 155 | if (!nc) |
1d00a4eb | 156 | return -EINVAL; |
f9e815b3 | 157 | |
f9e815b3 | 158 | { |
e3730578 PM |
159 | int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg)); |
160 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); | |
f49c857f PNA |
161 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
162 | struct nlattr *attr = (void *)nlh + min_len; | |
163 | int attrlen = nlh->nlmsg_len - min_len; | |
164 | ||
165 | err = nla_parse(cda, ss->cb[cb_id].attr_count, | |
166 | attr, attrlen, ss->cb[cb_id].policy); | |
167 | if (err < 0) | |
168 | return err; | |
601e68e1 | 169 | |
cd8c20b6 | 170 | err = nc->call(net->nfnl, skb, nlh, (const struct nlattr **)cda); |
e6a7d3c0 PNA |
171 | if (err == -EAGAIN) |
172 | goto replay; | |
173 | return err; | |
f9e815b3 | 174 | } |
f9e815b3 HW |
175 | } |
176 | ||
cd40b7d3 | 177 | static void nfnetlink_rcv(struct sk_buff *skb) |
f9e815b3 | 178 | { |
cd40b7d3 DL |
179 | nfnl_lock(); |
180 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); | |
181 | nfnl_unlock(); | |
f9e815b3 HW |
182 | } |
183 | ||
cd8c20b6 | 184 | static int __net_init nfnetlink_net_init(struct net *net) |
f9e815b3 | 185 | { |
cd8c20b6 AD |
186 | struct sock *nfnl; |
187 | ||
188 | nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, NFNLGRP_MAX, | |
189 | nfnetlink_rcv, NULL, THIS_MODULE); | |
190 | if (!nfnl) | |
191 | return -ENOMEM; | |
192 | net->nfnl_stash = nfnl; | |
193 | rcu_assign_pointer(net->nfnl, nfnl); | |
194 | return 0; | |
f9e815b3 HW |
195 | } |
196 | ||
cd8c20b6 | 197 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
f9e815b3 | 198 | { |
cd8c20b6 | 199 | struct net *net; |
f9e815b3 | 200 | |
cd8c20b6 AD |
201 | list_for_each_entry(net, net_exit_list, exit_list) |
202 | rcu_assign_pointer(net->nfnl, NULL); | |
203 | synchronize_net(); | |
204 | list_for_each_entry(net, net_exit_list, exit_list) | |
205 | netlink_kernel_release(net->nfnl_stash); | |
206 | } | |
f9e815b3 | 207 | |
cd8c20b6 AD |
208 | static struct pernet_operations nfnetlink_net_ops = { |
209 | .init = nfnetlink_net_init, | |
210 | .exit_batch = nfnetlink_net_exit_batch, | |
211 | }; | |
212 | ||
213 | static int __init nfnetlink_init(void) | |
214 | { | |
215 | printk("Netfilter messages via NETLINK v%s.\n", nfversion); | |
216 | return register_pernet_subsys(&nfnetlink_net_ops); | |
f9e815b3 HW |
217 | } |
218 | ||
cd8c20b6 AD |
219 | static void __exit nfnetlink_exit(void) |
220 | { | |
221 | printk("Removing netfilter NETLINK layer.\n"); | |
222 | unregister_pernet_subsys(&nfnetlink_net_ops); | |
223 | } | |
f9e815b3 HW |
224 | module_init(nfnetlink_init); |
225 | module_exit(nfnetlink_exit); |