Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 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> |
Pablo Neira Ayuso | 67ca396 | 2007-03-14 16:40:38 -0700 | [diff] [blame] | 6 | * (C) 2005,2007 by Pablo Neira Ayuso <pablo@netfilter.org> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 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 | |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/socket.h> |
| 20 | #include <linux/kernel.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 21 | #include <linux/string.h> |
| 22 | #include <linux/sockios.h> |
| 23 | #include <linux/net.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 24 | #include <linux/skbuff.h> |
| 25 | #include <asm/uaccess.h> |
| 26 | #include <asm/system.h> |
| 27 | #include <net/sock.h> |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 28 | #include <net/netlink.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 29 | #include <linux/init.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 30 | |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 31 | #include <linux/netlink.h> |
| 32 | #include <linux/netfilter/nfnetlink.h> |
| 33 | |
| 34 | MODULE_LICENSE("GPL"); |
Harald Welte | 4fdb3bb | 2005-08-09 19:40:55 -0700 | [diff] [blame] | 35 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| 36 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 37 | |
| 38 | static char __initdata nfversion[] = "0.30"; |
| 39 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 40 | static const struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT]; |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 41 | static DEFINE_MUTEX(nfnl_mutex); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 42 | |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 43 | void nfnl_lock(void) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 44 | { |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 45 | mutex_lock(&nfnl_mutex); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 46 | } |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 47 | EXPORT_SYMBOL_GPL(nfnl_lock); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 48 | |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 49 | void nfnl_unlock(void) |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 50 | { |
| 51 | mutex_unlock(&nfnl_mutex); |
| 52 | } |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 53 | EXPORT_SYMBOL_GPL(nfnl_unlock); |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 54 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 55 | int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 56 | { |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 57 | nfnl_lock(); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 58 | if (subsys_table[n->subsys_id]) { |
| 59 | nfnl_unlock(); |
| 60 | return -EBUSY; |
| 61 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 62 | subsys_table[n->subsys_id] = n; |
| 63 | nfnl_unlock(); |
| 64 | |
| 65 | return 0; |
| 66 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 67 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 68 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 69 | int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 70 | { |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 71 | nfnl_lock(); |
| 72 | subsys_table[n->subsys_id] = NULL; |
| 73 | nfnl_unlock(); |
| 74 | |
| 75 | return 0; |
| 76 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 77 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 78 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 79 | static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 80 | { |
| 81 | u_int8_t subsys_id = NFNL_SUBSYS_ID(type); |
| 82 | |
Pablo Neira Ayuso | ac0f1d9 | 2007-03-14 16:41:28 -0700 | [diff] [blame] | 83 | if (subsys_id >= NFNL_SUBSYS_COUNT) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 84 | return NULL; |
| 85 | |
| 86 | return subsys_table[subsys_id]; |
| 87 | } |
| 88 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 89 | static inline const struct nfnl_callback * |
| 90 | nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 91 | { |
| 92 | u_int8_t cb_id = NFNL_MSG_TYPE(type); |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 93 | |
Pablo Neira Ayuso | 67ca396 | 2007-03-14 16:40:38 -0700 | [diff] [blame] | 94 | if (cb_id >= ss->cb_count) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 95 | return NULL; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 96 | |
| 97 | return &ss->cb[cb_id]; |
| 98 | } |
| 99 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 100 | int nfnetlink_has_listeners(struct net *net, unsigned int group) |
Patrick McHardy | a242769 | 2006-03-20 18:03:59 -0800 | [diff] [blame] | 101 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 102 | return netlink_has_listeners(net->nfnl, group); |
Patrick McHardy | a242769 | 2006-03-20 18:03:59 -0800 | [diff] [blame] | 103 | } |
| 104 | EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); |
| 105 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 106 | int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 107 | unsigned group, int echo, gfp_t flags) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 108 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 109 | return nlmsg_notify(net->nfnl, skb, pid, group, echo, flags); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 110 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 111 | EXPORT_SYMBOL_GPL(nfnetlink_send); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 112 | |
Pablo Neira Ayuso | 37b7ef7 | 2010-03-16 13:30:21 +0000 | [diff] [blame] | 113 | int nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error) |
Pablo Neira Ayuso | dd5b6ce | 2009-03-23 13:21:06 +0100 | [diff] [blame] | 114 | { |
Pablo Neira Ayuso | 37b7ef7 | 2010-03-16 13:30:21 +0000 | [diff] [blame] | 115 | return netlink_set_err(net->nfnl, pid, group, error); |
Pablo Neira Ayuso | dd5b6ce | 2009-03-23 13:21:06 +0100 | [diff] [blame] | 116 | } |
| 117 | EXPORT_SYMBOL_GPL(nfnetlink_set_err); |
| 118 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 119 | int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 120 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 121 | return netlink_unicast(net->nfnl, skb, pid, flags); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 122 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 123 | EXPORT_SYMBOL_GPL(nfnetlink_unicast); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 124 | |
| 125 | /* Process one complete nfnetlink message. */ |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 126 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 127 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 128 | struct net *net = sock_net(skb->sk); |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 129 | const struct nfnl_callback *nc; |
| 130 | const struct nfnetlink_subsystem *ss; |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 131 | int type, err; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 132 | |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 133 | if (security_netlink_recv(skb, CAP_NET_ADMIN)) |
| 134 | return -EPERM; |
Harald Welte | 37d2e7a | 2005-11-14 15:24:59 -0800 | [diff] [blame] | 135 | |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 136 | /* All the messages must at least contain nfgenmsg */ |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 137 | if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct nfgenmsg))) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 138 | return 0; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 139 | |
| 140 | type = nlh->nlmsg_type; |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 141 | replay: |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 142 | ss = nfnetlink_get_subsys(type); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 143 | if (!ss) { |
Johannes Berg | 95a5afc | 2008-10-16 15:24:51 -0700 | [diff] [blame] | 144 | #ifdef CONFIG_MODULES |
Denis V. Lunev | 3b71535 | 2007-10-10 21:13:32 -0700 | [diff] [blame] | 145 | nfnl_unlock(); |
Harald Welte | 37d2e7a | 2005-11-14 15:24:59 -0800 | [diff] [blame] | 146 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 147 | nfnl_lock(); |
Harald Welte | 37d2e7a | 2005-11-14 15:24:59 -0800 | [diff] [blame] | 148 | ss = nfnetlink_get_subsys(type); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 149 | if (!ss) |
| 150 | #endif |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 151 | return -EINVAL; |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 152 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 153 | |
| 154 | nc = nfnetlink_find_client(type, ss); |
Pablo Neira Ayuso | 67ca396 | 2007-03-14 16:40:38 -0700 | [diff] [blame] | 155 | if (!nc) |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 156 | return -EINVAL; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 157 | |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 158 | { |
Patrick McHardy | e373057 | 2007-09-28 14:38:52 -0700 | [diff] [blame] | 159 | int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg)); |
| 160 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 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; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 164 | |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 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; |
Patrick McHardy | e373057 | 2007-09-28 14:38:52 -0700 | [diff] [blame] | 169 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 170 | err = nc->call(net->nfnl, skb, nlh, (const struct nlattr **)cda); |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 171 | if (err == -EAGAIN) |
| 172 | goto replay; |
| 173 | return err; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 174 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 175 | } |
| 176 | |
Denis V. Lunev | cd40b7d | 2007-10-10 21:15:29 -0700 | [diff] [blame] | 177 | static void nfnetlink_rcv(struct sk_buff *skb) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 178 | { |
Denis V. Lunev | cd40b7d | 2007-10-10 21:15:29 -0700 | [diff] [blame] | 179 | nfnl_lock(); |
| 180 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); |
| 181 | nfnl_unlock(); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 182 | } |
| 183 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 184 | static int __net_init nfnetlink_net_init(struct net *net) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 185 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 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; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 195 | } |
| 196 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 197 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
| 198 | { |
| 199 | struct net *net; |
| 200 | |
| 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 | } |
| 207 | |
| 208 | static struct pernet_operations nfnetlink_net_ops = { |
| 209 | .init = nfnetlink_net_init, |
| 210 | .exit_batch = nfnetlink_net_exit_batch, |
| 211 | }; |
| 212 | |
Adrian Bunk | 395dde2 | 2005-09-05 18:06:45 -0700 | [diff] [blame] | 213 | static int __init nfnetlink_init(void) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 214 | { |
Stephen Hemminger | 654d0fb | 2010-05-13 15:02:08 +0200 | [diff] [blame] | 215 | pr_info("Netfilter messages via NETLINK v%s.\n", nfversion); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 216 | return register_pernet_subsys(&nfnetlink_net_ops); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 217 | } |
| 218 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 219 | static void __exit nfnetlink_exit(void) |
| 220 | { |
Stephen Hemminger | 654d0fb | 2010-05-13 15:02:08 +0200 | [diff] [blame] | 221 | pr_info("Removing netfilter NETLINK layer.\n"); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 222 | unregister_pernet_subsys(&nfnetlink_net_ops); |
| 223 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 224 | module_init(nfnetlink_init); |
| 225 | module_exit(nfnetlink_exit); |