• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1  /*
2   * Copyright (c) 2017 Mellanox Technologies Inc.  All rights reserved.
3   * Copyright (c) 2010 Voltaire Inc.  All rights reserved.
4   *
5   * This software is available to you under a choice of one of two
6   * licenses.  You may choose to be licensed under the terms of the GNU
7   * General Public License (GPL) Version 2, available from the file
8   * COPYING in the main directory of this source tree, or the
9   * OpenIB.org BSD license below:
10   *
11   *     Redistribution and use in source and binary forms, with or
12   *     without modification, are permitted provided that the following
13   *     conditions are met:
14   *
15   *      - Redistributions of source code must retain the above
16   *        copyright notice, this list of conditions and the following
17   *        disclaimer.
18   *
19   *      - Redistributions in binary form must reproduce the above
20   *        copyright notice, this list of conditions and the following
21   *        disclaimer in the documentation and/or other materials
22   *        provided with the distribution.
23   *
24   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31   * SOFTWARE.
32   */
33  
34  #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
35  
36  #include <linux/export.h>
37  #include <net/netlink.h>
38  #include <net/net_namespace.h>
39  #include <net/netns/generic.h>
40  #include <net/sock.h>
41  #include <rdma/rdma_netlink.h>
42  #include <linux/module.h>
43  #include "core_priv.h"
44  
45  static struct {
46  	const struct rdma_nl_cbs *cb_table;
47  	/* Synchronizes between ongoing netlink commands and netlink client
48  	 * unregistration.
49  	 */
50  	struct rw_semaphore sem;
51  } rdma_nl_types[RDMA_NL_NUM_CLIENTS];
52  
rdma_nl_chk_listeners(unsigned int group)53  bool rdma_nl_chk_listeners(unsigned int group)
54  {
55  	struct rdma_dev_net *rnet = rdma_net_to_dev_net(&init_net);
56  
57  	return netlink_has_listeners(rnet->nl_sock, group);
58  }
59  EXPORT_SYMBOL(rdma_nl_chk_listeners);
60  
is_nl_msg_valid(unsigned int type,unsigned int op)61  static bool is_nl_msg_valid(unsigned int type, unsigned int op)
62  {
63  	static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS] = {
64  		[RDMA_NL_IWCM] = RDMA_NL_IWPM_NUM_OPS,
65  		[RDMA_NL_LS] = RDMA_NL_LS_NUM_OPS,
66  		[RDMA_NL_NLDEV] = RDMA_NLDEV_NUM_OPS,
67  	};
68  
69  	/*
70  	 * This BUILD_BUG_ON is intended to catch addition of new
71  	 * RDMA netlink protocol without updating the array above.
72  	 */
73  	BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);
74  
75  	if (type >= RDMA_NL_NUM_CLIENTS)
76  		return false;
77  
78  	return (op < max_num_ops[type]) ? true : false;
79  }
80  
81  static const struct rdma_nl_cbs *
get_cb_table(const struct sk_buff * skb,unsigned int type,unsigned int op)82  get_cb_table(const struct sk_buff *skb, unsigned int type, unsigned int op)
83  {
84  	const struct rdma_nl_cbs *cb_table;
85  
86  	/*
87  	 * Currently only NLDEV client is supporting netlink commands in
88  	 * non init_net net namespace.
89  	 */
90  	if (sock_net(skb->sk) != &init_net && type != RDMA_NL_NLDEV)
91  		return NULL;
92  
93  	cb_table = READ_ONCE(rdma_nl_types[type].cb_table);
94  	if (!cb_table) {
95  		/*
96  		 * Didn't get valid reference of the table, attempt module
97  		 * load once.
98  		 */
99  		up_read(&rdma_nl_types[type].sem);
100  
101  		request_module("rdma-netlink-subsys-%u", type);
102  
103  		down_read(&rdma_nl_types[type].sem);
104  		cb_table = READ_ONCE(rdma_nl_types[type].cb_table);
105  	}
106  	if (!cb_table || (!cb_table[op].dump && !cb_table[op].doit))
107  		return NULL;
108  	return cb_table;
109  }
110  
rdma_nl_register(unsigned int index,const struct rdma_nl_cbs cb_table[])111  void rdma_nl_register(unsigned int index,
112  		      const struct rdma_nl_cbs cb_table[])
113  {
114  	if (WARN_ON(!is_nl_msg_valid(index, 0)) ||
115  	    WARN_ON(READ_ONCE(rdma_nl_types[index].cb_table)))
116  		return;
117  
118  	/* Pairs with the READ_ONCE in is_nl_valid() */
119  	smp_store_release(&rdma_nl_types[index].cb_table, cb_table);
120  }
121  EXPORT_SYMBOL(rdma_nl_register);
122  
rdma_nl_unregister(unsigned int index)123  void rdma_nl_unregister(unsigned int index)
124  {
125  	down_write(&rdma_nl_types[index].sem);
126  	rdma_nl_types[index].cb_table = NULL;
127  	up_write(&rdma_nl_types[index].sem);
128  }
129  EXPORT_SYMBOL(rdma_nl_unregister);
130  
ibnl_put_msg(struct sk_buff * skb,struct nlmsghdr ** nlh,int seq,int len,int client,int op,int flags)131  void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
132  		   int len, int client, int op, int flags)
133  {
134  	*nlh = nlmsg_put(skb, 0, seq, RDMA_NL_GET_TYPE(client, op), len, flags);
135  	if (!*nlh)
136  		return NULL;
137  	return nlmsg_data(*nlh);
138  }
139  EXPORT_SYMBOL(ibnl_put_msg);
140  
ibnl_put_attr(struct sk_buff * skb,struct nlmsghdr * nlh,int len,void * data,int type)141  int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
142  		  int len, void *data, int type)
143  {
144  	if (nla_put(skb, type, len, data)) {
145  		nlmsg_cancel(skb, nlh);
146  		return -EMSGSIZE;
147  	}
148  	return 0;
149  }
150  EXPORT_SYMBOL(ibnl_put_attr);
151  
rdma_nl_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)152  static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
153  			   struct netlink_ext_ack *extack)
154  {
155  	int type = nlh->nlmsg_type;
156  	unsigned int index = RDMA_NL_GET_CLIENT(type);
157  	unsigned int op = RDMA_NL_GET_OP(type);
158  	const struct rdma_nl_cbs *cb_table;
159  	int err = -EINVAL;
160  
161  	if (!is_nl_msg_valid(index, op))
162  		return -EINVAL;
163  
164  	down_read(&rdma_nl_types[index].sem);
165  	cb_table = get_cb_table(skb, index, op);
166  	if (!cb_table)
167  		goto done;
168  
169  	if ((cb_table[op].flags & RDMA_NL_ADMIN_PERM) &&
170  	    !netlink_capable(skb, CAP_NET_ADMIN)) {
171  		err = -EPERM;
172  		goto done;
173  	}
174  
175  	/*
176  	 * LS responses overload the 0x100 (NLM_F_ROOT) flag.  Don't
177  	 * mistakenly call the .dump() function.
178  	 */
179  	if (index == RDMA_NL_LS) {
180  		if (cb_table[op].doit)
181  			err = cb_table[op].doit(skb, nlh, extack);
182  		goto done;
183  	}
184  	/* FIXME: Convert IWCM to properly handle doit callbacks */
185  	if ((nlh->nlmsg_flags & NLM_F_DUMP) || index == RDMA_NL_IWCM) {
186  		struct netlink_dump_control c = {
187  			.dump = cb_table[op].dump,
188  		};
189  		if (c.dump)
190  			err = netlink_dump_start(skb->sk, skb, nlh, &c);
191  		goto done;
192  	}
193  
194  	if (cb_table[op].doit)
195  		err = cb_table[op].doit(skb, nlh, extack);
196  done:
197  	up_read(&rdma_nl_types[index].sem);
198  	return err;
199  }
200  
201  /*
202   * This function is similar to netlink_rcv_skb with one exception:
203   * It calls to the callback for the netlink messages without NLM_F_REQUEST
204   * flag. These messages are intended for RDMA_NL_LS consumer, so it is allowed
205   * for that consumer only.
206   */
rdma_nl_rcv_skb(struct sk_buff * skb,int (* cb)(struct sk_buff *,struct nlmsghdr *,struct netlink_ext_ack *))207  static int rdma_nl_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
208  						   struct nlmsghdr *,
209  						   struct netlink_ext_ack *))
210  {
211  	struct netlink_ext_ack extack = {};
212  	struct nlmsghdr *nlh;
213  	int err;
214  
215  	while (skb->len >= nlmsg_total_size(0)) {
216  		int msglen;
217  
218  		nlh = nlmsg_hdr(skb);
219  		err = 0;
220  
221  		if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
222  			return 0;
223  
224  		/*
225  		 * Generally speaking, the only requests are handled
226  		 * by the kernel, but RDMA_NL_LS is different, because it
227  		 * runs backward netlink scheme. Kernel initiates messages
228  		 * and waits for reply with data to keep pathrecord cache
229  		 * in sync.
230  		 */
231  		if (!(nlh->nlmsg_flags & NLM_F_REQUEST) &&
232  		    (RDMA_NL_GET_CLIENT(nlh->nlmsg_type) != RDMA_NL_LS))
233  			goto ack;
234  
235  		/* Skip control messages */
236  		if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
237  			goto ack;
238  
239  		err = cb(skb, nlh, &extack);
240  		if (err == -EINTR)
241  			goto skip;
242  
243  ack:
244  		if (nlh->nlmsg_flags & NLM_F_ACK || err)
245  			netlink_ack(skb, nlh, err, &extack);
246  
247  skip:
248  		msglen = NLMSG_ALIGN(nlh->nlmsg_len);
249  		if (msglen > skb->len)
250  			msglen = skb->len;
251  		skb_pull(skb, msglen);
252  	}
253  
254  	return 0;
255  }
256  
rdma_nl_rcv(struct sk_buff * skb)257  static void rdma_nl_rcv(struct sk_buff *skb)
258  {
259  	rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg);
260  }
261  
rdma_nl_unicast(struct net * net,struct sk_buff * skb,u32 pid)262  int rdma_nl_unicast(struct net *net, struct sk_buff *skb, u32 pid)
263  {
264  	struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
265  	int err;
266  
267  	err = netlink_unicast(rnet->nl_sock, skb, pid, MSG_DONTWAIT);
268  	return (err < 0) ? err : 0;
269  }
270  EXPORT_SYMBOL(rdma_nl_unicast);
271  
rdma_nl_unicast_wait(struct net * net,struct sk_buff * skb,__u32 pid)272  int rdma_nl_unicast_wait(struct net *net, struct sk_buff *skb, __u32 pid)
273  {
274  	struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
275  	int err;
276  
277  	err = netlink_unicast(rnet->nl_sock, skb, pid, 0);
278  	return (err < 0) ? err : 0;
279  }
280  EXPORT_SYMBOL(rdma_nl_unicast_wait);
281  
rdma_nl_multicast(struct net * net,struct sk_buff * skb,unsigned int group,gfp_t flags)282  int rdma_nl_multicast(struct net *net, struct sk_buff *skb,
283  		      unsigned int group, gfp_t flags)
284  {
285  	struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
286  
287  	return nlmsg_multicast(rnet->nl_sock, skb, 0, group, flags);
288  }
289  EXPORT_SYMBOL(rdma_nl_multicast);
290  
rdma_nl_init(void)291  void rdma_nl_init(void)
292  {
293  	int idx;
294  
295  	for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)
296  		init_rwsem(&rdma_nl_types[idx].sem);
297  }
298  
rdma_nl_exit(void)299  void rdma_nl_exit(void)
300  {
301  	int idx;
302  
303  	for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)
304  		WARN(rdma_nl_types[idx].cb_table,
305  		     "Netlink client %d wasn't released prior to unloading %s\n",
306  		     idx, KBUILD_MODNAME);
307  }
308  
rdma_nl_net_init(struct rdma_dev_net * rnet)309  int rdma_nl_net_init(struct rdma_dev_net *rnet)
310  {
311  	struct net *net = read_pnet(&rnet->net);
312  	struct netlink_kernel_cfg cfg = {
313  		.input	= rdma_nl_rcv,
314  	};
315  	struct sock *nls;
316  
317  	nls = netlink_kernel_create(net, NETLINK_RDMA, &cfg);
318  	if (!nls)
319  		return -ENOMEM;
320  
321  	nls->sk_sndtimeo = 10 * HZ;
322  	rnet->nl_sock = nls;
323  	return 0;
324  }
325  
rdma_nl_net_exit(struct rdma_dev_net * rnet)326  void rdma_nl_net_exit(struct rdma_dev_net *rnet)
327  {
328  	netlink_kernel_release(rnet->nl_sock);
329  }
330  
331  MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_RDMA);
332