ia64/linux-2.6.18-xen.hg

view net/netfilter/nfnetlink.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
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>
6 * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
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 */
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/socket.h>
20 #include <linux/kernel.h>
21 #include <linux/major.h>
22 #include <linux/sched.h>
23 #include <linux/timer.h>
24 #include <linux/string.h>
25 #include <linux/sockios.h>
26 #include <linux/net.h>
27 #include <linux/fcntl.h>
28 #include <linux/skbuff.h>
29 #include <asm/uaccess.h>
30 #include <asm/system.h>
31 #include <net/sock.h>
32 #include <linux/init.h>
33 #include <linux/spinlock.h>
35 #include <linux/netfilter.h>
36 #include <linux/netlink.h>
37 #include <linux/netfilter/nfnetlink.h>
39 MODULE_LICENSE("GPL");
40 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
41 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
43 static char __initdata nfversion[] = "0.30";
45 #if 0
46 #define DEBUGP(format, args...) \
47 printk(KERN_DEBUG "%s(%d):%s(): " format, __FILE__, \
48 __LINE__, __FUNCTION__, ## args)
49 #else
50 #define DEBUGP(format, args...)
51 #endif
53 static struct sock *nfnl = NULL;
54 static struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
55 DECLARE_MUTEX(nfnl_sem);
57 void nfnl_lock(void)
58 {
59 nfnl_shlock();
60 }
62 void nfnl_unlock(void)
63 {
64 nfnl_shunlock();
65 }
67 int nfnetlink_subsys_register(struct nfnetlink_subsystem *n)
68 {
69 DEBUGP("registering subsystem ID %u\n", n->subsys_id);
71 nfnl_lock();
72 if (subsys_table[n->subsys_id]) {
73 nfnl_unlock();
74 return -EBUSY;
75 }
76 subsys_table[n->subsys_id] = n;
77 nfnl_unlock();
79 return 0;
80 }
82 int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n)
83 {
84 DEBUGP("unregistering subsystem ID %u\n", n->subsys_id);
86 nfnl_lock();
87 subsys_table[n->subsys_id] = NULL;
88 nfnl_unlock();
90 return 0;
91 }
93 static inline struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type)
94 {
95 u_int8_t subsys_id = NFNL_SUBSYS_ID(type);
97 if (subsys_id >= NFNL_SUBSYS_COUNT
98 || subsys_table[subsys_id] == NULL)
99 return NULL;
101 return subsys_table[subsys_id];
102 }
104 static inline struct nfnl_callback *
105 nfnetlink_find_client(u_int16_t type, struct nfnetlink_subsystem *ss)
106 {
107 u_int8_t cb_id = NFNL_MSG_TYPE(type);
109 if (cb_id >= ss->cb_count) {
110 DEBUGP("msgtype %u >= %u, returning\n", type, ss->cb_count);
111 return NULL;
112 }
114 return &ss->cb[cb_id];
115 }
117 void __nfa_fill(struct sk_buff *skb, int attrtype, int attrlen,
118 const void *data)
119 {
120 struct nfattr *nfa;
121 int size = NFA_LENGTH(attrlen);
123 nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
124 nfa->nfa_type = attrtype;
125 nfa->nfa_len = size;
126 memcpy(NFA_DATA(nfa), data, attrlen);
127 memset(NFA_DATA(nfa) + attrlen, 0, NFA_ALIGN(size) - size);
128 }
130 void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len)
131 {
132 memset(tb, 0, sizeof(struct nfattr *) * maxattr);
134 while (NFA_OK(nfa, len)) {
135 unsigned flavor = NFA_TYPE(nfa);
136 if (flavor && flavor <= maxattr)
137 tb[flavor-1] = nfa;
138 nfa = NFA_NEXT(nfa, len);
139 }
140 }
142 /**
143 * nfnetlink_check_attributes - check and parse nfnetlink attributes
144 *
145 * subsys: nfnl subsystem for which this message is to be parsed
146 * nlmsghdr: netlink message to be checked/parsed
147 * cda: array of pointers, needs to be at least subsys->attr_count big
148 *
149 */
150 static int
151 nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
152 struct nlmsghdr *nlh, struct nfattr *cda[])
153 {
154 int min_len;
155 u_int16_t attr_count;
156 u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
158 if (unlikely(cb_id >= subsys->cb_count)) {
159 DEBUGP("msgtype %u >= %u, returning\n",
160 cb_id, subsys->cb_count);
161 return -EINVAL;
162 }
164 min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
165 if (unlikely(nlh->nlmsg_len < min_len))
166 return -EINVAL;
168 attr_count = subsys->cb[cb_id].attr_count;
169 memset(cda, 0, sizeof(struct nfattr *) * attr_count);
171 /* check attribute lengths. */
172 if (likely(nlh->nlmsg_len > min_len)) {
173 struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
174 int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
176 while (NFA_OK(attr, attrlen)) {
177 unsigned flavor = NFA_TYPE(attr);
178 if (flavor) {
179 if (flavor > attr_count)
180 return -EINVAL;
181 cda[flavor - 1] = attr;
182 }
183 attr = NFA_NEXT(attr, attrlen);
184 }
185 }
187 /* implicit: if nlmsg_len == min_len, we return 0, and an empty
188 * (zeroed) cda[] array. The message is valid, but empty. */
190 return 0;
191 }
193 int nfnetlink_has_listeners(unsigned int group)
194 {
195 return netlink_has_listeners(nfnl, group);
196 }
197 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
199 int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
200 {
201 gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
202 int err = 0;
204 NETLINK_CB(skb).dst_group = group;
205 if (echo)
206 atomic_inc(&skb->users);
207 netlink_broadcast(nfnl, skb, pid, group, allocation);
208 if (echo)
209 err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT);
211 return err;
212 }
214 int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags)
215 {
216 return netlink_unicast(nfnl, skb, pid, flags);
217 }
219 /* Process one complete nfnetlink message. */
220 static int nfnetlink_rcv_msg(struct sk_buff *skb,
221 struct nlmsghdr *nlh, int *errp)
222 {
223 struct nfnl_callback *nc;
224 struct nfnetlink_subsystem *ss;
225 int type, err = 0;
227 DEBUGP("entered; subsys=%u, msgtype=%u\n",
228 NFNL_SUBSYS_ID(nlh->nlmsg_type),
229 NFNL_MSG_TYPE(nlh->nlmsg_type));
231 if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
232 DEBUGP("missing CAP_NET_ADMIN\n");
233 *errp = -EPERM;
234 return -1;
235 }
237 /* Only requests are handled by kernel now. */
238 if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) {
239 DEBUGP("received non-request message\n");
240 return 0;
241 }
243 /* All the messages must at least contain nfgenmsg */
244 if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg))) {
245 DEBUGP("received message was too short\n");
246 return 0;
247 }
249 type = nlh->nlmsg_type;
250 ss = nfnetlink_get_subsys(type);
251 if (!ss) {
252 #ifdef CONFIG_KMOD
253 /* don't call nfnl_shunlock, since it would reenter
254 * with further packet processing */
255 up(&nfnl_sem);
256 request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
257 nfnl_shlock();
258 ss = nfnetlink_get_subsys(type);
259 if (!ss)
260 #endif
261 goto err_inval;
262 }
264 nc = nfnetlink_find_client(type, ss);
265 if (!nc) {
266 DEBUGP("unable to find client for type %d\n", type);
267 goto err_inval;
268 }
270 {
271 u_int16_t attr_count =
272 ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count;
273 struct nfattr *cda[attr_count];
275 memset(cda, 0, sizeof(struct nfattr *) * attr_count);
277 err = nfnetlink_check_attributes(ss, nlh, cda);
278 if (err < 0)
279 goto err_inval;
281 DEBUGP("calling handler\n");
282 err = nc->call(nfnl, skb, nlh, cda, errp);
283 *errp = err;
284 return err;
285 }
287 err_inval:
288 DEBUGP("returning -EINVAL\n");
289 *errp = -EINVAL;
290 return -1;
291 }
293 /* Process one packet of messages. */
294 static inline int nfnetlink_rcv_skb(struct sk_buff *skb)
295 {
296 int err;
297 struct nlmsghdr *nlh;
299 while (skb->len >= NLMSG_SPACE(0)) {
300 u32 rlen;
302 nlh = (struct nlmsghdr *)skb->data;
303 if (nlh->nlmsg_len < sizeof(struct nlmsghdr)
304 || skb->len < nlh->nlmsg_len)
305 return 0;
306 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
307 if (rlen > skb->len)
308 rlen = skb->len;
309 if (nfnetlink_rcv_msg(skb, nlh, &err)) {
310 if (!err)
311 return -1;
312 netlink_ack(skb, nlh, err);
313 } else
314 if (nlh->nlmsg_flags & NLM_F_ACK)
315 netlink_ack(skb, nlh, 0);
316 skb_pull(skb, rlen);
317 }
319 return 0;
320 }
322 static void nfnetlink_rcv(struct sock *sk, int len)
323 {
324 do {
325 struct sk_buff *skb;
327 if (nfnl_shlock_nowait())
328 return;
330 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
331 if (nfnetlink_rcv_skb(skb)) {
332 if (skb->len)
333 skb_queue_head(&sk->sk_receive_queue,
334 skb);
335 else
336 kfree_skb(skb);
337 break;
338 }
339 kfree_skb(skb);
340 }
342 /* don't call nfnl_shunlock, since it would reenter
343 * with further packet processing */
344 up(&nfnl_sem);
345 } while(nfnl && nfnl->sk_receive_queue.qlen);
346 }
348 static void __exit nfnetlink_exit(void)
349 {
350 printk("Removing netfilter NETLINK layer.\n");
351 sock_release(nfnl->sk_socket);
352 return;
353 }
355 static int __init nfnetlink_init(void)
356 {
357 printk("Netfilter messages via NETLINK v%s.\n", nfversion);
359 nfnl = netlink_kernel_create(NETLINK_NETFILTER, NFNLGRP_MAX,
360 nfnetlink_rcv, THIS_MODULE);
361 if (!nfnl) {
362 printk(KERN_ERR "cannot initialize nfnetlink!\n");
363 return -1;
364 }
366 return 0;
367 }
369 module_init(nfnetlink_init);
370 module_exit(nfnetlink_exit);
372 EXPORT_SYMBOL_GPL(nfnetlink_subsys_register);
373 EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister);
374 EXPORT_SYMBOL_GPL(nfnetlink_send);
375 EXPORT_SYMBOL_GPL(nfnetlink_unicast);
376 EXPORT_SYMBOL_GPL(nfattr_parse);
377 EXPORT_SYMBOL_GPL(__nfa_fill);