Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * netfilter module for userspace bridged Ethernet frames logging daemons | |
3 | * | |
4 | * Authors: | |
5 | * Bart De Schuymer <bdschuym@pandora.be> | |
d5228a4f | 6 | * Harald Welte <laforge@netfilter.org> |
1da177e4 LT |
7 | * |
8 | * November, 2004 | |
9 | * | |
10 | * Based on ipt_ULOG.c, which is | |
11 | * (C) 2000-2002 by Harald Welte <laforge@netfilter.org> | |
12 | * | |
9d6f229f YH |
13 | * This module accepts two parameters: |
14 | * | |
1da177e4 LT |
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 | */ | |
ff67e4e4 | 30 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 31 | #include <linux/module.h> |
5a0e3ad6 | 32 | #include <linux/slab.h> |
1da177e4 LT |
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> | |
18219d3f | 40 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
41 | #include <linux/netfilter_bridge/ebtables.h> |
42 | #include <linux/netfilter_bridge/ebt_ulog.h> | |
f01ffbd6 | 43 | #include <net/netfilter/nf_log.h> |
1da177e4 LT |
44 | #include <net/sock.h> |
45 | #include "../br_private.h" | |
46 | ||
c2db2924 | 47 | static unsigned int nlbufsiz = NLMSG_GOODSIZE; |
1da177e4 LT |
48 | module_param(nlbufsiz, uint, 0600); |
49 | MODULE_PARM_DESC(nlbufsiz, "netlink buffer size (number of bytes) " | |
9d6f229f | 50 | "(defaults to 4096)"); |
1da177e4 LT |
51 | |
52 | static unsigned int flushtimeout = 10; | |
53 | module_param(flushtimeout, uint, 0600); | |
54 | MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths ofa second) " | |
9d6f229f | 55 | "(defaults to 10)"); |
1da177e4 LT |
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 | ||
dcb7cd97 MH |
76 | if (!ub->skb) |
77 | return; | |
78 | ||
1da177e4 LT |
79 | /* last nlmsg needs NLMSG_DONE */ |
80 | if (ub->qlen > 1) | |
81 | ub->lastnlh->nlmsg_type = NLMSG_DONE; | |
82 | ||
ac6d439d PM |
83 | NETLINK_CB(ub->skb).dst_group = nlgroup + 1; |
84 | netlink_broadcast(ebtulognl, ub->skb, 0, nlgroup + 1, GFP_ATOMIC); | |
1da177e4 LT |
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; | |
ad2ad0f9 | 102 | unsigned int n; |
1da177e4 | 103 | |
ad2ad0f9 PM |
104 | n = max(size, nlbufsiz); |
105 | skb = alloc_skb(n, GFP_ATOMIC); | |
1da177e4 | 106 | if (!skb) { |
ff67e4e4 | 107 | pr_debug("cannot alloc whole buffer of size %ub!\n", n); |
ad2ad0f9 | 108 | if (n > size) { |
1da177e4 LT |
109 | /* try to allocate only as much as we need for |
110 | * current packet */ | |
111 | skb = alloc_skb(size, GFP_ATOMIC); | |
112 | if (!skb) | |
ff67e4e4 JE |
113 | pr_debug("cannot even allocate " |
114 | "buffer of size %ub\n", size); | |
1da177e4 LT |
115 | } |
116 | } | |
117 | ||
118 | return skb; | |
119 | } | |
120 | ||
d5228a4f | 121 | static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb, |
1da177e4 | 122 | const struct net_device *in, const struct net_device *out, |
d5228a4f | 123 | const struct ebt_ulog_info *uloginfo, const char *prefix) |
1da177e4 LT |
124 | { |
125 | ebt_ulog_packet_msg_t *pm; | |
126 | size_t size, copy_len; | |
127 | struct nlmsghdr *nlh; | |
1da177e4 LT |
128 | unsigned int group = uloginfo->nlgroup; |
129 | ebt_ulog_buff_t *ub = &ulog_buffers[group]; | |
130 | spinlock_t *lock = &ub->lock; | |
b7aa0bf7 | 131 | ktime_t kt; |
1da177e4 LT |
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) { | |
ff67e4e4 | 141 | pr_debug("Size %Zd needed, but nlbufsiz=%d\n", size, nlbufsiz); |
1da177e4 LT |
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, | |
9d6f229f | 158 | size - NLMSG_ALIGN(sizeof(*nlh))); |
1da177e4 LT |
159 | ub->qlen++; |
160 | ||
161 | pm = NLMSG_DATA(nlh); | |
162 | ||
163 | /* Fill in the ulog data */ | |
164 | pm->version = EBT_ULOG_VERSION; | |
b7aa0bf7 ED |
165 | kt = ktime_get_real(); |
166 | pm->stamp = ktime_to_timeval(kt); | |
1da177e4 | 167 | if (ub->qlen == 1) |
b7aa0bf7 | 168 | ub->skb->tstamp = kt; |
1da177e4 | 169 | pm->data_len = copy_len; |
82e91ffe | 170 | pm->mark = skb->mark; |
1da177e4 LT |
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 (in->br_port) | |
181 | strcpy(pm->indev, in->br_port->br->dev->name); | |
182 | else | |
183 | strcpy(pm->indev, in->name); | |
184 | } else | |
185 | pm->indev[0] = pm->physindev[0] = '\0'; | |
186 | ||
187 | if (out) { | |
188 | /* If out exists, then out is a bridge port */ | |
189 | strcpy(pm->physoutdev, out->name); | |
190 | strcpy(pm->outdev, out->br_port->br->dev->name); | |
191 | } else | |
192 | pm->outdev[0] = pm->physoutdev[0] = '\0'; | |
193 | ||
194 | if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0) | |
195 | BUG(); | |
196 | ||
197 | if (ub->qlen > 1) | |
198 | ub->lastnlh->nlmsg_flags |= NLM_F_MULTI; | |
199 | ||
200 | ub->lastnlh = nlh; | |
201 | ||
202 | if (ub->qlen >= uloginfo->qthreshold) | |
203 | ulog_send(group); | |
204 | else if (!timer_pending(&ub->timer)) { | |
205 | ub->timer.expires = jiffies + flushtimeout * HZ / 100; | |
206 | add_timer(&ub->timer); | |
207 | } | |
208 | ||
209 | unlock: | |
210 | spin_unlock_bh(lock); | |
211 | ||
212 | return; | |
213 | ||
214 | nlmsg_failure: | |
ff67e4e4 JE |
215 | pr_debug("error during NLMSG_PUT. This should " |
216 | "not happen, please report to author.\n"); | |
1da177e4 LT |
217 | goto unlock; |
218 | alloc_failure: | |
219 | goto unlock; | |
220 | } | |
221 | ||
d5228a4f | 222 | /* this function is registered with the netfilter core */ |
76108cea | 223 | static void ebt_log_packet(u_int8_t pf, unsigned int hooknum, |
d5228a4f BDS |
224 | const struct sk_buff *skb, const struct net_device *in, |
225 | const struct net_device *out, const struct nf_loginfo *li, | |
226 | const char *prefix) | |
227 | { | |
228 | struct ebt_ulog_info loginfo; | |
229 | ||
230 | if (!li || li->type != NF_LOG_TYPE_ULOG) { | |
231 | loginfo.nlgroup = EBT_ULOG_DEFAULT_NLGROUP; | |
232 | loginfo.cprange = 0; | |
233 | loginfo.qthreshold = EBT_ULOG_DEFAULT_QTHRESHOLD; | |
234 | loginfo.prefix[0] = '\0'; | |
235 | } else { | |
236 | loginfo.nlgroup = li->u.ulog.group; | |
237 | loginfo.cprange = li->u.ulog.copy_len; | |
238 | loginfo.qthreshold = li->u.ulog.qthreshold; | |
239 | strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix)); | |
240 | } | |
241 | ||
242 | ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix); | |
243 | } | |
244 | ||
2d06d4a5 | 245 | static unsigned int |
4b560b44 | 246 | ebt_ulog_tg(struct sk_buff *skb, const struct xt_action_param *par) |
d5228a4f | 247 | { |
7eb35586 JE |
248 | ebt_ulog_packet(par->hooknum, skb, par->in, par->out, |
249 | par->targinfo, NULL); | |
0ac6ab1f | 250 | return EBT_CONTINUE; |
d5228a4f BDS |
251 | } |
252 | ||
135367b8 | 253 | static int ebt_ulog_tg_check(const struct xt_tgchk_param *par) |
1da177e4 | 254 | { |
af5d6dc2 | 255 | struct ebt_ulog_info *uloginfo = par->targinfo; |
1da177e4 | 256 | |
18219d3f | 257 | if (uloginfo->nlgroup > 31) |
d6b00a53 | 258 | return -EINVAL; |
1da177e4 LT |
259 | |
260 | uloginfo->prefix[EBT_ULOG_PREFIX_LEN - 1] = '\0'; | |
261 | ||
262 | if (uloginfo->qthreshold > EBT_ULOG_MAX_QLEN) | |
263 | uloginfo->qthreshold = EBT_ULOG_MAX_QLEN; | |
264 | ||
d6b00a53 | 265 | return 0; |
1da177e4 LT |
266 | } |
267 | ||
043ef46c JE |
268 | static struct xt_target ebt_ulog_tg_reg __read_mostly = { |
269 | .name = "ulog", | |
001a18d3 JE |
270 | .revision = 0, |
271 | .family = NFPROTO_BRIDGE, | |
2d06d4a5 JE |
272 | .target = ebt_ulog_tg, |
273 | .checkentry = ebt_ulog_tg_check, | |
fc0e3df4 | 274 | .targetsize = sizeof(struct ebt_ulog_info), |
1da177e4 LT |
275 | .me = THIS_MODULE, |
276 | }; | |
277 | ||
704b3ea3 | 278 | static struct nf_logger ebt_ulog_logger __read_mostly = { |
7249dee5 | 279 | .name = "ebt_ulog", |
d5228a4f BDS |
280 | .logfn = &ebt_log_packet, |
281 | .me = THIS_MODULE, | |
282 | }; | |
283 | ||
65b4b4e8 | 284 | static int __init ebt_ulog_init(void) |
1da177e4 | 285 | { |
3b334d42 | 286 | int ret; |
19eda879 | 287 | int i; |
1da177e4 LT |
288 | |
289 | if (nlbufsiz >= 128*1024) { | |
ff67e4e4 JE |
290 | pr_warning("Netlink buffer has to be <= 128kB," |
291 | " please try a smaller nlbufsiz parameter.\n"); | |
3b334d42 | 292 | return -EINVAL; |
1da177e4 LT |
293 | } |
294 | ||
295 | /* initialize ulog_buffers */ | |
296 | for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) { | |
e6f689db | 297 | setup_timer(&ulog_buffers[i].timer, ulog_timer, i); |
1da177e4 LT |
298 | spin_lock_init(&ulog_buffers[i].lock); |
299 | } | |
300 | ||
b4b51029 EB |
301 | ebtulognl = netlink_kernel_create(&init_net, NETLINK_NFLOG, |
302 | EBT_ULOG_MAXNLGROUPS, NULL, NULL, | |
303 | THIS_MODULE); | |
85bc3f38 | 304 | if (!ebtulognl) |
3b334d42 | 305 | ret = -ENOMEM; |
85bc3f38 | 306 | else if ((ret = xt_register_target(&ebt_ulog_tg_reg)) != 0) |
b7c6ba6e | 307 | netlink_kernel_release(ebtulognl); |
1da177e4 | 308 | |
3b334d42 | 309 | if (ret == 0) |
ee999d8b | 310 | nf_log_register(NFPROTO_BRIDGE, &ebt_ulog_logger); |
d5228a4f | 311 | |
1da177e4 LT |
312 | return ret; |
313 | } | |
314 | ||
65b4b4e8 | 315 | static void __exit ebt_ulog_fini(void) |
1da177e4 LT |
316 | { |
317 | ebt_ulog_buff_t *ub; | |
318 | int i; | |
319 | ||
e92ad99c | 320 | nf_log_unregister(&ebt_ulog_logger); |
043ef46c | 321 | xt_unregister_target(&ebt_ulog_tg_reg); |
1da177e4 LT |
322 | for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) { |
323 | ub = &ulog_buffers[i]; | |
324 | if (timer_pending(&ub->timer)) | |
325 | del_timer(&ub->timer); | |
326 | spin_lock_bh(&ub->lock); | |
327 | if (ub->skb) { | |
328 | kfree_skb(ub->skb); | |
329 | ub->skb = NULL; | |
330 | } | |
331 | spin_unlock_bh(&ub->lock); | |
332 | } | |
b7c6ba6e | 333 | netlink_kernel_release(ebtulognl); |
1da177e4 LT |
334 | } |
335 | ||
65b4b4e8 AM |
336 | module_init(ebt_ulog_init); |
337 | module_exit(ebt_ulog_fini); | |
1da177e4 LT |
338 | MODULE_LICENSE("GPL"); |
339 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); | |
f776c4cd | 340 | MODULE_DESCRIPTION("Ebtables: Packet logging to netlink using ULOG"); |