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GUI: Fix Tomato RAF theme for all builds. Compilation typo.
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / net / bridge / netfilter / ebt_ulog.c
blob26377e96fa1cf129d2b495c872647ca74281b5fd
1 /*
2 * netfilter module for userspace bridged Ethernet frames logging daemons
3 *
4 * Authors:
5 * Bart De Schuymer <bdschuym@pandora.be>
6 * Harald Welte <laforge@netfilter.org>
7 *
8 * November, 2004
9 *
10 * Based on ipt_ULOG.c, which is
11 * (C) 2000-2002 by Harald Welte <laforge@netfilter.org>
12 *
13 * This module accepts two parameters:
14 *
15 * nlbufsiz:
16 * The parameter specifies how big the buffer for each netlink multicast
17 * group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
18 * get accumulated in the kernel until they are sent to userspace. It is
19 * NOT possible to allocate more than 128kB, and it is strongly discouraged,
20 * because atomically allocating 128kB inside the network rx softirq is not
21 * reliable. Please also keep in mind that this buffer size is allocated for
22 * each nlgroup you are using, so the total kernel memory usage increases
23 * by that factor.
24 *
25 * flushtimeout:
26 * Specify, after how many hundredths of a second the queue should be
27 * flushed even if it is not full yet.
28 *
29 */
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 #include <linux/module.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34 #include <linux/socket.h>
35 #include <linux/skbuff.h>
36 #include <linux/kernel.h>
37 #include <linux/timer.h>
38 #include <linux/netlink.h>
39 #include <linux/netdevice.h>
40 #include <linux/netfilter/x_tables.h>
41 #include <linux/netfilter_bridge/ebtables.h>
42 #include <linux/netfilter_bridge/ebt_ulog.h>
43 #include <net/netfilter/nf_log.h>
44 #include <net/sock.h>
45 #include "../br_private.h"
46
47 static unsigned int nlbufsiz = NLMSG_GOODSIZE;
48 module_param(nlbufsiz, uint, 0600);
49 MODULE_PARM_DESC(nlbufsiz, "netlink buffer size (number of bytes) "
50 "(defaults to 4096)");
51
52 static unsigned int flushtimeout = 10;
53 module_param(flushtimeout, uint, 0600);
54 MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths ofa second) "
55 "(defaults to 10)");
56
57 typedef struct {
58 unsigned int qlen; /* number of nlmsgs' in the skb */
59 struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
60 struct sk_buff *skb; /* the pre-allocated skb */
61 struct timer_list timer; /* the timer function */
62 spinlock_t lock; /* the per-queue lock */
63 } ebt_ulog_buff_t;
64
65 static ebt_ulog_buff_t ulog_buffers[EBT_ULOG_MAXNLGROUPS];
66 static struct sock *ebtulognl;
67
68 /* send one ulog_buff_t to userspace */
69 static void ulog_send(unsigned int nlgroup)
70 {
71 ebt_ulog_buff_t *ub = &ulog_buffers[nlgroup];
72
73 if (timer_pending(&ub->timer))
74 del_timer(&ub->timer);
75
76 if (!ub->skb)
77 return;
78
79 /* last nlmsg needs NLMSG_DONE */
80 if (ub->qlen > 1)
81 ub->lastnlh->nlmsg_type = NLMSG_DONE;
82
83 NETLINK_CB(ub->skb).dst_group = nlgroup + 1;
84 netlink_broadcast(ebtulognl, ub->skb, 0, nlgroup + 1, GFP_ATOMIC);
85
86 ub->qlen = 0;
87 ub->skb = NULL;
88 }
89
90 /* timer function to flush queue in flushtimeout time */
91 static void ulog_timer(unsigned long data)
92 {
93 spin_lock_bh(&ulog_buffers[data].lock);
94 if (ulog_buffers[data].skb)
95 ulog_send(data);
96 spin_unlock_bh(&ulog_buffers[data].lock);
97 }
98
99 static struct sk_buff *ulog_alloc_skb(unsigned int size)
100 {
101 struct sk_buff *skb;
102 unsigned int n;
103
104 n = max(size, nlbufsiz);
105 skb = alloc_skb(n, GFP_ATOMIC);
106 if (!skb) {
107 pr_debug("cannot alloc whole buffer of size %ub!\n", n);
108 if (n > size) {
109 /* try to allocate only as much as we need for
110 * current packet */
111 skb = alloc_skb(size, GFP_ATOMIC);
112 if (!skb)
113 pr_debug("cannot even allocate "
114 "buffer of size %ub\n", size);
115 }
116 }
117
118 return skb;
119 }
120
121 static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
122 const struct net_device *in, const struct net_device *out,
123 const struct ebt_ulog_info *uloginfo, const char *prefix)
124 {
125 ebt_ulog_packet_msg_t *pm;
126 size_t size, copy_len;
127 struct nlmsghdr *nlh;
128 unsigned int group = uloginfo->nlgroup;
129 ebt_ulog_buff_t *ub = &ulog_buffers[group];
130 spinlock_t *lock = &ub->lock;
131 ktime_t kt;
132
133 if ((uloginfo->cprange == 0) ||
134 (uloginfo->cprange > skb->len + ETH_HLEN))
135 copy_len = skb->len + ETH_HLEN;
136 else
137 copy_len = uloginfo->cprange;
138
139 size = NLMSG_SPACE(sizeof(*pm) + copy_len);
140 if (size > nlbufsiz) {
141 pr_debug("Size %Zd needed, but nlbufsiz=%d\n", size, nlbufsiz);
142 return;
143 }
144
145 spin_lock_bh(lock);
146
147 if (!ub->skb) {
148 if (!(ub->skb = ulog_alloc_skb(size)))
149 goto alloc_failure;
150 } else if (size > skb_tailroom(ub->skb)) {
151 ulog_send(group);
152
153 if (!(ub->skb = ulog_alloc_skb(size)))
154 goto alloc_failure;
155 }
156
157 nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, 0,
158 size - NLMSG_ALIGN(sizeof(*nlh)));
159 ub->qlen++;
160
161 pm = NLMSG_DATA(nlh);
162
163 /* Fill in the ulog data */
164 pm->version = EBT_ULOG_VERSION;
165 kt = ktime_get_real();
166 pm->stamp = ktime_to_timeval(kt);
167 if (ub->qlen == 1)
168 ub->skb->tstamp = kt;
169 pm->data_len = copy_len;
170 pm->mark = skb->mark;
171 pm->hook = hooknr;
172 if (uloginfo->prefix != NULL)
173 strcpy(pm->prefix, uloginfo->prefix);
174 else
175 *(pm->prefix) = '\0';
176
177 if (in) {
178 strcpy(pm->physindev, in->name);
179 /* If in isn't a bridge, then physindev==indev */
180 if (br_port_exists(in))
181 /* rcu_read_lock()ed by nf_hook_slow */
182 strcpy(pm->indev, br_port_get_rcu(in)->br->dev->name);
183 else
184 strcpy(pm->indev, in->name);
185 } else
186 pm->indev[0] = pm->physindev[0] = '\0';
187
188 if (out) {
189 /* If out exists, then out is a bridge port */
190 strcpy(pm->physoutdev, out->name);
191 /* rcu_read_lock()ed by nf_hook_slow */
192 strcpy(pm->outdev, br_port_get_rcu(out)->br->dev->name);
193 } else
194 pm->outdev[0] = pm->physoutdev[0] = '\0';
195
196 if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0)
197 BUG();
198
199 if (ub->qlen > 1)
200 ub->lastnlh->nlmsg_flags |= NLM_F_MULTI;
201
202 ub->lastnlh = nlh;
203
204 if (ub->qlen >= uloginfo->qthreshold)
205 ulog_send(group);
206 else if (!timer_pending(&ub->timer)) {
207 ub->timer.expires = jiffies + flushtimeout * HZ / 100;
208 add_timer(&ub->timer);
209 }
210
211 unlock:
212 spin_unlock_bh(lock);
213
214 return;
215
216 nlmsg_failure:
217 pr_debug("error during NLMSG_PUT. This should "
218 "not happen, please report to author.\n");
219 goto unlock;
220 alloc_failure:
221 goto unlock;
222 }
223
224 /* this function is registered with the netfilter core */
225 static void ebt_log_packet(u_int8_t pf, unsigned int hooknum,
226 const struct sk_buff *skb, const struct net_device *in,
227 const struct net_device *out, const struct nf_loginfo *li,
228 const char *prefix)
229 {
230 struct ebt_ulog_info loginfo;
231
232 if (!li || li->type != NF_LOG_TYPE_ULOG) {
233 loginfo.nlgroup = EBT_ULOG_DEFAULT_NLGROUP;
234 loginfo.cprange = 0;
235 loginfo.qthreshold = EBT_ULOG_DEFAULT_QTHRESHOLD;
236 loginfo.prefix[0] = '\0';
237 } else {
238 loginfo.nlgroup = li->u.ulog.group;
239 loginfo.cprange = li->u.ulog.copy_len;
240 loginfo.qthreshold = li->u.ulog.qthreshold;
241 strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
242 }
243
244 ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
245 }
246
247 static unsigned int
248 ebt_ulog_tg(struct sk_buff *skb, const struct xt_action_param *par)
249 {
250 ebt_ulog_packet(par->hooknum, skb, par->in, par->out,
251 par->targinfo, NULL);
252 return EBT_CONTINUE;
253 }
254
255 static int ebt_ulog_tg_check(const struct xt_tgchk_param *par)
256 {
257 struct ebt_ulog_info *uloginfo = par->targinfo;
258
259 if (uloginfo->nlgroup > 31)
260 return -EINVAL;
261
262 uloginfo->prefix[EBT_ULOG_PREFIX_LEN - 1] = '\0';
263
264 if (uloginfo->qthreshold > EBT_ULOG_MAX_QLEN)
265 uloginfo->qthreshold = EBT_ULOG_MAX_QLEN;
266
267 return 0;
268 }
269
270 static struct xt_target ebt_ulog_tg_reg __read_mostly = {
271 .name = "ulog",
272 .revision = 0,
273 .family = NFPROTO_BRIDGE,
274 .target = ebt_ulog_tg,
275 .checkentry = ebt_ulog_tg_check,
276 .targetsize = sizeof(struct ebt_ulog_info),
277 .me = THIS_MODULE,
278 };
279
280 static struct nf_logger ebt_ulog_logger __read_mostly = {
281 .name = "ebt_ulog",
282 .logfn = &ebt_log_packet,
283 .me = THIS_MODULE,
284 };
285
286 static int __init ebt_ulog_init(void)
287 {
288 int ret;
289 int i;
290
291 if (nlbufsiz >= 128*1024) {
292 pr_warning("Netlink buffer has to be <= 128kB,"
293 " please try a smaller nlbufsiz parameter.\n");
294 return -EINVAL;
295 }
296
297 /* initialize ulog_buffers */
298 for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
299 setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
300 spin_lock_init(&ulog_buffers[i].lock);
301 }
302
303 ebtulognl = netlink_kernel_create(&init_net, NETLINK_NFLOG,
304 EBT_ULOG_MAXNLGROUPS, NULL, NULL,
305 THIS_MODULE);
306 if (!ebtulognl)
307 ret = -ENOMEM;
308 else if ((ret = xt_register_target(&ebt_ulog_tg_reg)) != 0)
309 netlink_kernel_release(ebtulognl);
310
311 if (ret == 0)
312 nf_log_register(NFPROTO_BRIDGE, &ebt_ulog_logger);
313
314 return ret;
315 }
316
317 static void __exit ebt_ulog_fini(void)
318 {
319 ebt_ulog_buff_t *ub;
320 int i;
321
322 nf_log_unregister(&ebt_ulog_logger);
323 xt_unregister_target(&ebt_ulog_tg_reg);
324 for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
325 ub = &ulog_buffers[i];
326 if (timer_pending(&ub->timer))
327 del_timer(&ub->timer);
328 spin_lock_bh(&ub->lock);
329 if (ub->skb) {
330 kfree_skb(ub->skb);
331 ub->skb = NULL;
332 }
333 spin_unlock_bh(&ub->lock);
334 }
335 netlink_kernel_release(ebtulognl);
336 }
337
338 module_init(ebt_ulog_init);
339 module_exit(ebt_ulog_fini);
340 MODULE_LICENSE("GPL");
341 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
342 MODULE_DESCRIPTION("Ebtables: Packet logging to netlink using ULOG");
Tomato firmware and modifications.