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> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 26 | #include <net/sock.h> |
| 27 | #include <linux/init.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 28 | |
Hong zhi guo | 573ce26 | 2013-03-27 06:47:04 +0000 | [diff] [blame] | 29 | #include <net/netlink.h> |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 30 | #include <linux/netfilter/nfnetlink.h> |
| 31 | |
| 32 | MODULE_LICENSE("GPL"); |
Harald Welte | 4fdb3bb | 2005-08-09 19:40:55 -0700 | [diff] [blame] | 33 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| 34 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 35 | |
| 36 | static char __initdata nfversion[] = "0.30"; |
| 37 | |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 38 | static struct { |
| 39 | struct mutex mutex; |
| 40 | const struct nfnetlink_subsystem __rcu *subsys; |
| 41 | } table[NFNL_SUBSYS_COUNT]; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 42 | |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 43 | static const int nfnl_group2type[NFNLGRP_MAX+1] = { |
| 44 | [NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK, |
| 45 | [NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK, |
| 46 | [NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK, |
| 47 | [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, |
| 48 | [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, |
| 49 | [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, |
| 50 | }; |
| 51 | |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 52 | void nfnl_lock(__u8 subsys_id) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 53 | { |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 54 | mutex_lock(&table[subsys_id].mutex); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 55 | } |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 56 | EXPORT_SYMBOL_GPL(nfnl_lock); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 57 | |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 58 | void nfnl_unlock(__u8 subsys_id) |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 59 | { |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 60 | mutex_unlock(&table[subsys_id].mutex); |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 61 | } |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 62 | EXPORT_SYMBOL_GPL(nfnl_unlock); |
Patrick McHardy | a3c5029 | 2007-03-14 16:39:25 -0700 | [diff] [blame] | 63 | |
Patrick McHardy | 0eb5db7 | 2014-02-18 18:06:48 +0000 | [diff] [blame] | 64 | #ifdef CONFIG_PROVE_LOCKING |
| 65 | int lockdep_nfnl_is_held(u8 subsys_id) |
| 66 | { |
| 67 | return lockdep_is_held(&table[subsys_id].mutex); |
| 68 | } |
| 69 | EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held); |
| 70 | #endif |
| 71 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 72 | int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 73 | { |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 74 | nfnl_lock(n->subsys_id); |
| 75 | if (table[n->subsys_id].subsys) { |
| 76 | nfnl_unlock(n->subsys_id); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 77 | return -EBUSY; |
| 78 | } |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 79 | rcu_assign_pointer(table[n->subsys_id].subsys, n); |
| 80 | nfnl_unlock(n->subsys_id); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 81 | |
| 82 | return 0; |
| 83 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 84 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 85 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 86 | int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 87 | { |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 88 | nfnl_lock(n->subsys_id); |
| 89 | table[n->subsys_id].subsys = NULL; |
| 90 | nfnl_unlock(n->subsys_id); |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 91 | synchronize_rcu(); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 92 | return 0; |
| 93 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 94 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 95 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 96 | 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] | 97 | { |
| 98 | u_int8_t subsys_id = NFNL_SUBSYS_ID(type); |
| 99 | |
Pablo Neira Ayuso | ac0f1d9 | 2007-03-14 16:41:28 -0700 | [diff] [blame] | 100 | if (subsys_id >= NFNL_SUBSYS_COUNT) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 101 | return NULL; |
| 102 | |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 103 | return rcu_dereference(table[subsys_id].subsys); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 104 | } |
| 105 | |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 106 | static inline const struct nfnl_callback * |
| 107 | nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 108 | { |
| 109 | u_int8_t cb_id = NFNL_MSG_TYPE(type); |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 110 | |
Pablo Neira Ayuso | 67ca396 | 2007-03-14 16:40:38 -0700 | [diff] [blame] | 111 | if (cb_id >= ss->cb_count) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 112 | return NULL; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 113 | |
| 114 | return &ss->cb[cb_id]; |
| 115 | } |
| 116 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 117 | int nfnetlink_has_listeners(struct net *net, unsigned int group) |
Patrick McHardy | a242769 | 2006-03-20 18:03:59 -0800 | [diff] [blame] | 118 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 119 | return netlink_has_listeners(net->nfnl, group); |
Patrick McHardy | a242769 | 2006-03-20 18:03:59 -0800 | [diff] [blame] | 120 | } |
| 121 | EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); |
| 122 | |
Patrick McHardy | 3ab1f68 | 2013-04-17 06:47:09 +0000 | [diff] [blame] | 123 | struct sk_buff *nfnetlink_alloc_skb(struct net *net, unsigned int size, |
| 124 | u32 dst_portid, gfp_t gfp_mask) |
| 125 | { |
| 126 | return netlink_alloc_skb(net->nfnl, size, dst_portid, gfp_mask); |
| 127 | } |
| 128 | EXPORT_SYMBOL_GPL(nfnetlink_alloc_skb); |
| 129 | |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 130 | int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 131 | unsigned int group, int echo, gfp_t flags) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 132 | { |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 133 | return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 134 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 135 | EXPORT_SYMBOL_GPL(nfnetlink_send); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 136 | |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 137 | int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) |
Pablo Neira Ayuso | dd5b6ce | 2009-03-23 13:21:06 +0100 | [diff] [blame] | 138 | { |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 139 | return netlink_set_err(net->nfnl, portid, group, error); |
Pablo Neira Ayuso | dd5b6ce | 2009-03-23 13:21:06 +0100 | [diff] [blame] | 140 | } |
| 141 | EXPORT_SYMBOL_GPL(nfnetlink_set_err); |
| 142 | |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 143 | int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid, |
| 144 | int flags) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 145 | { |
Patrick McHardy | ec464e5 | 2013-04-17 06:47:08 +0000 | [diff] [blame] | 146 | return netlink_unicast(net->nfnl, skb, portid, flags); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 147 | } |
Pablo Neira Ayuso | f4bc177 | 2007-03-14 16:42:11 -0700 | [diff] [blame] | 148 | EXPORT_SYMBOL_GPL(nfnetlink_unicast); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 149 | |
| 150 | /* Process one complete nfnetlink message. */ |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 151 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 152 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 153 | struct net *net = sock_net(skb->sk); |
Patrick McHardy | 7c8d4cb | 2007-09-28 14:15:45 -0700 | [diff] [blame] | 154 | const struct nfnl_callback *nc; |
| 155 | const struct nfnetlink_subsystem *ss; |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 156 | int type, err; |
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 | /* All the messages must at least contain nfgenmsg */ |
Hong zhi guo | 573ce26 | 2013-03-27 06:47:04 +0000 | [diff] [blame] | 159 | if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 160 | return 0; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 161 | |
| 162 | type = nlh->nlmsg_type; |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 163 | replay: |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 164 | rcu_read_lock(); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 165 | ss = nfnetlink_get_subsys(type); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 166 | if (!ss) { |
Johannes Berg | 95a5afc | 2008-10-16 15:24:51 -0700 | [diff] [blame] | 167 | #ifdef CONFIG_MODULES |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 168 | rcu_read_unlock(); |
Harald Welte | 37d2e7a | 2005-11-14 15:24:59 -0800 | [diff] [blame] | 169 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 170 | rcu_read_lock(); |
Harald Welte | 37d2e7a | 2005-11-14 15:24:59 -0800 | [diff] [blame] | 171 | ss = nfnetlink_get_subsys(type); |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 172 | if (!ss) |
| 173 | #endif |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 174 | { |
| 175 | rcu_read_unlock(); |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 176 | return -EINVAL; |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 177 | } |
Harald Welte | 0ab43f8 | 2005-08-09 19:43:44 -0700 | [diff] [blame] | 178 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 179 | |
| 180 | nc = nfnetlink_find_client(type, ss); |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 181 | if (!nc) { |
| 182 | rcu_read_unlock(); |
Thomas Graf | 1d00a4e | 2007-03-22 23:30:12 -0700 | [diff] [blame] | 183 | return -EINVAL; |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 184 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 185 | |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 186 | { |
Hong zhi guo | 573ce26 | 2013-03-27 06:47:04 +0000 | [diff] [blame] | 187 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
Patrick McHardy | e373057 | 2007-09-28 14:38:52 -0700 | [diff] [blame] | 188 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 189 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
| 190 | struct nlattr *attr = (void *)nlh + min_len; |
| 191 | int attrlen = nlh->nlmsg_len - min_len; |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 192 | __u8 subsys_id = NFNL_SUBSYS_ID(type); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 193 | |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 194 | err = nla_parse(cda, ss->cb[cb_id].attr_count, |
| 195 | attr, attrlen, ss->cb[cb_id].policy); |
Tomasz Bursztyka | 4009e18 | 2012-06-28 02:57:49 +0000 | [diff] [blame] | 196 | if (err < 0) { |
| 197 | rcu_read_unlock(); |
Pablo Neira Ayuso | f49c857 | 2009-06-02 20:03:33 +0200 | [diff] [blame] | 198 | return err; |
Tomasz Bursztyka | 4009e18 | 2012-06-28 02:57:49 +0000 | [diff] [blame] | 199 | } |
Patrick McHardy | e373057 | 2007-09-28 14:38:52 -0700 | [diff] [blame] | 200 | |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 201 | if (nc->call_rcu) { |
| 202 | err = nc->call_rcu(net->nfnl, skb, nlh, |
| 203 | (const struct nlattr **)cda); |
| 204 | rcu_read_unlock(); |
| 205 | } else { |
| 206 | rcu_read_unlock(); |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 207 | nfnl_lock(subsys_id); |
| 208 | if (rcu_dereference_protected(table[subsys_id].subsys, |
Paul Bolle | 9df9e783 | 2013-03-04 02:45:41 +0000 | [diff] [blame] | 209 | lockdep_is_held(&table[subsys_id].mutex)) != ss || |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 210 | nfnetlink_find_client(type, ss) != nc) |
| 211 | err = -EAGAIN; |
Tomasz Bursztyka | 59560a3 | 2012-06-28 02:57:47 +0000 | [diff] [blame] | 212 | else if (nc->call) |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 213 | err = nc->call(net->nfnl, skb, nlh, |
| 214 | (const struct nlattr **)cda); |
Tomasz Bursztyka | 59560a3 | 2012-06-28 02:57:47 +0000 | [diff] [blame] | 215 | else |
| 216 | err = -EINVAL; |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 217 | nfnl_unlock(subsys_id); |
Eric Dumazet | 6b75e3e | 2011-07-18 16:08:07 +0200 | [diff] [blame] | 218 | } |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 219 | if (err == -EAGAIN) |
| 220 | goto replay; |
| 221 | return err; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 222 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 223 | } |
| 224 | |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 225 | struct nfnl_err { |
| 226 | struct list_head head; |
| 227 | struct nlmsghdr *nlh; |
| 228 | int err; |
| 229 | }; |
| 230 | |
| 231 | static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err) |
| 232 | { |
| 233 | struct nfnl_err *nfnl_err; |
| 234 | |
| 235 | nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); |
| 236 | if (nfnl_err == NULL) |
| 237 | return -ENOMEM; |
| 238 | |
| 239 | nfnl_err->nlh = nlh; |
| 240 | nfnl_err->err = err; |
| 241 | list_add_tail(&nfnl_err->head, list); |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | static void nfnl_err_del(struct nfnl_err *nfnl_err) |
| 247 | { |
| 248 | list_del(&nfnl_err->head); |
| 249 | kfree(nfnl_err); |
| 250 | } |
| 251 | |
| 252 | static void nfnl_err_reset(struct list_head *err_list) |
| 253 | { |
| 254 | struct nfnl_err *nfnl_err, *next; |
| 255 | |
| 256 | list_for_each_entry_safe(nfnl_err, next, err_list, head) |
| 257 | nfnl_err_del(nfnl_err); |
| 258 | } |
| 259 | |
| 260 | static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) |
| 261 | { |
| 262 | struct nfnl_err *nfnl_err, *next; |
| 263 | |
| 264 | list_for_each_entry_safe(nfnl_err, next, err_list, head) { |
| 265 | netlink_ack(skb, nfnl_err->nlh, nfnl_err->err); |
| 266 | nfnl_err_del(nfnl_err); |
| 267 | } |
| 268 | } |
| 269 | |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 270 | static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, |
| 271 | u_int16_t subsys_id) |
| 272 | { |
| 273 | struct sk_buff *nskb, *oskb = skb; |
| 274 | struct net *net = sock_net(skb->sk); |
| 275 | const struct nfnetlink_subsystem *ss; |
| 276 | const struct nfnl_callback *nc; |
| 277 | bool success = true, done = false; |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 278 | static LIST_HEAD(err_list); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 279 | int err; |
| 280 | |
| 281 | if (subsys_id >= NFNL_SUBSYS_COUNT) |
| 282 | return netlink_ack(skb, nlh, -EINVAL); |
| 283 | replay: |
| 284 | nskb = netlink_skb_clone(oskb, GFP_KERNEL); |
| 285 | if (!nskb) |
| 286 | return netlink_ack(oskb, nlh, -ENOMEM); |
| 287 | |
| 288 | nskb->sk = oskb->sk; |
| 289 | skb = nskb; |
| 290 | |
| 291 | nfnl_lock(subsys_id); |
| 292 | ss = rcu_dereference_protected(table[subsys_id].subsys, |
| 293 | lockdep_is_held(&table[subsys_id].mutex)); |
| 294 | if (!ss) { |
| 295 | #ifdef CONFIG_MODULES |
| 296 | nfnl_unlock(subsys_id); |
| 297 | request_module("nfnetlink-subsys-%d", subsys_id); |
| 298 | nfnl_lock(subsys_id); |
| 299 | ss = rcu_dereference_protected(table[subsys_id].subsys, |
| 300 | lockdep_is_held(&table[subsys_id].mutex)); |
| 301 | if (!ss) |
| 302 | #endif |
| 303 | { |
| 304 | nfnl_unlock(subsys_id); |
Denys Fedoryshchenko | ecd15dd | 2014-05-04 13:35:37 +0200 | [diff] [blame] | 305 | netlink_ack(skb, nlh, -EOPNOTSUPP); |
| 306 | return kfree_skb(nskb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 307 | } |
| 308 | } |
| 309 | |
| 310 | if (!ss->commit || !ss->abort) { |
| 311 | nfnl_unlock(subsys_id); |
Denys Fedoryshchenko | ecd15dd | 2014-05-04 13:35:37 +0200 | [diff] [blame] | 312 | netlink_ack(skb, nlh, -EOPNOTSUPP); |
| 313 | return kfree_skb(skb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 314 | } |
| 315 | |
| 316 | while (skb->len >= nlmsg_total_size(0)) { |
| 317 | int msglen, type; |
| 318 | |
| 319 | nlh = nlmsg_hdr(skb); |
| 320 | err = 0; |
| 321 | |
| 322 | if (nlh->nlmsg_len < NLMSG_HDRLEN) { |
| 323 | err = -EINVAL; |
| 324 | goto ack; |
| 325 | } |
| 326 | |
| 327 | /* Only requests are handled by the kernel */ |
| 328 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { |
| 329 | err = -EINVAL; |
| 330 | goto ack; |
| 331 | } |
| 332 | |
| 333 | type = nlh->nlmsg_type; |
| 334 | if (type == NFNL_MSG_BATCH_BEGIN) { |
| 335 | /* Malformed: Batch begin twice */ |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 336 | nfnl_err_reset(&err_list); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 337 | success = false; |
| 338 | goto done; |
| 339 | } else if (type == NFNL_MSG_BATCH_END) { |
| 340 | done = true; |
| 341 | goto done; |
| 342 | } else if (type < NLMSG_MIN_TYPE) { |
| 343 | err = -EINVAL; |
| 344 | goto ack; |
| 345 | } |
| 346 | |
| 347 | /* We only accept a batch with messages for the same |
| 348 | * subsystem. |
| 349 | */ |
| 350 | if (NFNL_SUBSYS_ID(type) != subsys_id) { |
| 351 | err = -EINVAL; |
| 352 | goto ack; |
| 353 | } |
| 354 | |
| 355 | nc = nfnetlink_find_client(type, ss); |
| 356 | if (!nc) { |
| 357 | err = -EINVAL; |
| 358 | goto ack; |
| 359 | } |
| 360 | |
| 361 | { |
| 362 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
| 363 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
| 364 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
| 365 | struct nlattr *attr = (void *)nlh + min_len; |
| 366 | int attrlen = nlh->nlmsg_len - min_len; |
| 367 | |
| 368 | err = nla_parse(cda, ss->cb[cb_id].attr_count, |
| 369 | attr, attrlen, ss->cb[cb_id].policy); |
| 370 | if (err < 0) |
| 371 | goto ack; |
| 372 | |
| 373 | if (nc->call_batch) { |
| 374 | err = nc->call_batch(net->nfnl, skb, nlh, |
| 375 | (const struct nlattr **)cda); |
| 376 | } |
| 377 | |
| 378 | /* The lock was released to autoload some module, we |
| 379 | * have to abort and start from scratch using the |
| 380 | * original skb. |
| 381 | */ |
| 382 | if (err == -EAGAIN) { |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 383 | nfnl_err_reset(&err_list); |
Pablo Neira Ayuso | fc04733 | 2014-09-11 14:53:17 +0200 | [diff] [blame] | 384 | ss->abort(oskb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 385 | nfnl_unlock(subsys_id); |
| 386 | kfree_skb(nskb); |
| 387 | goto replay; |
| 388 | } |
| 389 | } |
| 390 | ack: |
| 391 | if (nlh->nlmsg_flags & NLM_F_ACK || err) { |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 392 | /* Errors are delivered once the full batch has been |
| 393 | * processed, this avoids that the same error is |
| 394 | * reported several times when replaying the batch. |
| 395 | */ |
| 396 | if (nfnl_err_add(&err_list, nlh, err) < 0) { |
| 397 | /* We failed to enqueue an error, reset the |
| 398 | * list of errors and send OOM to userspace |
| 399 | * pointing to the batch header. |
| 400 | */ |
| 401 | nfnl_err_reset(&err_list); |
| 402 | netlink_ack(skb, nlmsg_hdr(oskb), -ENOMEM); |
| 403 | success = false; |
| 404 | goto done; |
| 405 | } |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 406 | /* We don't stop processing the batch on errors, thus, |
| 407 | * userspace gets all the errors that the batch |
| 408 | * triggers. |
| 409 | */ |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 410 | if (err) |
| 411 | success = false; |
| 412 | } |
| 413 | |
| 414 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
| 415 | if (msglen > skb->len) |
| 416 | msglen = skb->len; |
| 417 | skb_pull(skb, msglen); |
| 418 | } |
| 419 | done: |
| 420 | if (success && done) |
Pablo Neira Ayuso | fc04733 | 2014-09-11 14:53:17 +0200 | [diff] [blame] | 421 | ss->commit(oskb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 422 | else |
Pablo Neira Ayuso | fc04733 | 2014-09-11 14:53:17 +0200 | [diff] [blame] | 423 | ss->abort(oskb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 424 | |
Pablo Neira Ayuso | cbb8125 | 2014-09-02 18:04:53 +0200 | [diff] [blame] | 425 | nfnl_err_deliver(&err_list, oskb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 426 | nfnl_unlock(subsys_id); |
| 427 | kfree_skb(nskb); |
| 428 | } |
| 429 | |
Denis V. Lunev | cd40b7d | 2007-10-10 21:15:29 -0700 | [diff] [blame] | 430 | static void nfnetlink_rcv(struct sk_buff *skb) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 431 | { |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 432 | struct nlmsghdr *nlh = nlmsg_hdr(skb); |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 433 | int msglen; |
| 434 | |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 435 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
| 436 | skb->len < nlh->nlmsg_len) |
| 437 | return; |
| 438 | |
Eric W. Biederman | 90f62cf3 | 2014-04-23 14:29:27 -0700 | [diff] [blame] | 439 | if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { |
Jiri Benc | cdbe7c2 | 2013-11-07 19:59:19 +0100 | [diff] [blame] | 440 | netlink_ack(skb, nlh, -EPERM); |
| 441 | return; |
| 442 | } |
| 443 | |
Pablo Neira Ayuso | 0628b12 | 2013-10-14 11:05:33 +0200 | [diff] [blame] | 444 | if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) { |
| 445 | struct nfgenmsg *nfgenmsg; |
| 446 | |
| 447 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
| 448 | if (msglen > skb->len) |
| 449 | msglen = skb->len; |
| 450 | |
| 451 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
| 452 | skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) |
| 453 | return; |
| 454 | |
| 455 | nfgenmsg = nlmsg_data(nlh); |
| 456 | skb_pull(skb, msglen); |
| 457 | nfnetlink_rcv_batch(skb, nlh, nfgenmsg->res_id); |
| 458 | } else { |
| 459 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); |
| 460 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 461 | } |
| 462 | |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 463 | #ifdef CONFIG_MODULES |
Richard Guy Briggs | 4f52090 | 2014-04-22 21:31:54 -0400 | [diff] [blame] | 464 | static int nfnetlink_bind(int group) |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 465 | { |
| 466 | const struct nfnetlink_subsystem *ss; |
| 467 | int type = nfnl_group2type[group]; |
| 468 | |
| 469 | rcu_read_lock(); |
| 470 | ss = nfnetlink_get_subsys(type); |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 471 | rcu_read_unlock(); |
Richard Guy Briggs | bfe4bc7 | 2014-04-22 21:31:53 -0400 | [diff] [blame] | 472 | if (!ss) |
| 473 | request_module("nfnetlink-subsys-%d", type); |
Richard Guy Briggs | 4f52090 | 2014-04-22 21:31:54 -0400 | [diff] [blame] | 474 | return 0; |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 475 | } |
| 476 | #endif |
| 477 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 478 | static int __net_init nfnetlink_net_init(struct net *net) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 479 | { |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 480 | struct sock *nfnl; |
Pablo Neira Ayuso | a31f2d1 | 2012-06-29 06:15:21 +0000 | [diff] [blame] | 481 | struct netlink_kernel_cfg cfg = { |
| 482 | .groups = NFNLGRP_MAX, |
| 483 | .input = nfnetlink_rcv, |
Pablo Neira Ayuso | 0329274 | 2012-06-29 06:15:22 +0000 | [diff] [blame] | 484 | #ifdef CONFIG_MODULES |
| 485 | .bind = nfnetlink_bind, |
| 486 | #endif |
Pablo Neira Ayuso | a31f2d1 | 2012-06-29 06:15:21 +0000 | [diff] [blame] | 487 | }; |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 488 | |
Pablo Neira Ayuso | 9f00d97 | 2012-09-08 02:53:54 +0000 | [diff] [blame] | 489 | nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 490 | if (!nfnl) |
| 491 | return -ENOMEM; |
| 492 | net->nfnl_stash = nfnl; |
Eric Dumazet | cf778b0 | 2012-01-12 04:41:32 +0000 | [diff] [blame] | 493 | rcu_assign_pointer(net->nfnl, nfnl); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 494 | return 0; |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 495 | } |
| 496 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 497 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
| 498 | { |
| 499 | struct net *net; |
| 500 | |
| 501 | list_for_each_entry(net, net_exit_list, exit_list) |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 502 | RCU_INIT_POINTER(net->nfnl, NULL); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 503 | synchronize_net(); |
| 504 | list_for_each_entry(net, net_exit_list, exit_list) |
| 505 | netlink_kernel_release(net->nfnl_stash); |
| 506 | } |
| 507 | |
| 508 | static struct pernet_operations nfnetlink_net_ops = { |
| 509 | .init = nfnetlink_net_init, |
| 510 | .exit_batch = nfnetlink_net_exit_batch, |
| 511 | }; |
| 512 | |
Adrian Bunk | 395dde2 | 2005-09-05 18:06:45 -0700 | [diff] [blame] | 513 | static int __init nfnetlink_init(void) |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 514 | { |
Pablo Neira Ayuso | c14b78e | 2013-02-05 01:50:26 +0100 | [diff] [blame] | 515 | int i; |
| 516 | |
| 517 | for (i=0; i<NFNL_SUBSYS_COUNT; i++) |
| 518 | mutex_init(&table[i].mutex); |
| 519 | |
Stephen Hemminger | 654d0fb | 2010-05-13 15:02:08 +0200 | [diff] [blame] | 520 | pr_info("Netfilter messages via NETLINK v%s.\n", nfversion); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 521 | return register_pernet_subsys(&nfnetlink_net_ops); |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 522 | } |
| 523 | |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 524 | static void __exit nfnetlink_exit(void) |
| 525 | { |
Stephen Hemminger | 654d0fb | 2010-05-13 15:02:08 +0200 | [diff] [blame] | 526 | pr_info("Removing netfilter NETLINK layer.\n"); |
Alexey Dobriyan | cd8c20b | 2010-01-13 16:02:14 +0100 | [diff] [blame] | 527 | unregister_pernet_subsys(&nfnetlink_net_ops); |
| 528 | } |
Harald Welte | f9e815b | 2005-08-09 19:30:24 -0700 | [diff] [blame] | 529 | module_init(nfnetlink_init); |
| 530 | module_exit(nfnetlink_exit); |