summaryrefslogtreecommitdiffstats
path: root/net/ipv4/geneve.c
blob: e64f8e9785d184cd033d23682691b397adc65f1e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
/*
 * Geneve: Generic Network Virtualization Encapsulation
 *
 * Copyright (c) 2014 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/igmp.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/ethtool.h>
#include <linux/mutex.h>
#include <net/arp.h>
#include <net/ndisc.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/rtnetlink.h>
#include <net/route.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/geneve.h>
#include <net/protocol.h>
#include <net/udp_tunnel.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip6_tunnel.h>
#include <net/ip6_checksum.h>
#endif

/* Protects sock_list and refcounts. */
static DEFINE_MUTEX(geneve_mutex);

/* per-network namespace private data for this module */
struct geneve_net {
	struct list_head	sock_list;
};

static int geneve_net_id;

static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
{
	return (struct genevehdr *)(udp_hdr(skb) + 1);
}

static struct geneve_sock *geneve_find_sock(struct net *net,
					    sa_family_t family, __be16 port)
{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_sock *gs;

	list_for_each_entry(gs, &gn->sock_list, list) {
		if (inet_sk(gs->sock->sk)->inet_sport == port &&
		    inet_sk(gs->sock->sk)->sk.sk_family == family)
			return gs;
	}

	return NULL;
}

static void geneve_build_header(struct genevehdr *geneveh,
				__be16 tun_flags, u8 vni[3],
				u8 options_len, u8 *options)
{
	geneveh->ver = GENEVE_VER;
	geneveh->opt_len = options_len / 4;
	geneveh->oam = !!(tun_flags & TUNNEL_OAM);
	geneveh->critical = !!(tun_flags & TUNNEL_CRIT_OPT);
	geneveh->rsvd1 = 0;
	memcpy(geneveh->vni, vni, 3);
	geneveh->proto_type = htons(ETH_P_TEB);
	geneveh->rsvd2 = 0;

	memcpy(geneveh->options, options, options_len);
}

/* Transmit a fully formatted Geneve frame.
 *
 * When calling this function. The skb->data should point
 * to the geneve header which is fully formed.
 *
 * This function will add other UDP tunnel headers.
 */
int geneve_xmit_skb(struct geneve_sock *gs, struct rtable *rt,
		    struct sk_buff *skb, __be32 src, __be32 dst, __u8 tos,
		    __u8 ttl, __be16 df, __be16 src_port, __be16 dst_port,
		    __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
		    bool csum, bool xnet)
{
	struct genevehdr *gnvh;
	int min_headroom;
	int err;

	skb = udp_tunnel_handle_offloads(skb, csum);
	if (IS_ERR(skb))
		return PTR_ERR(skb);

	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
			+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

	err = skb_cow_head(skb, min_headroom);
	if (unlikely(err)) {
		kfree_skb(skb);
		return err;
	}

	skb = vlan_hwaccel_push_inside(skb);
	if (unlikely(!skb))
		return -ENOMEM;

	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);

	skb_set_inner_protocol(skb, htons(ETH_P_TEB));

	return udp_tunnel_xmit_skb(rt, skb, src, dst,
				   tos, ttl, df, src_port, dst_port, xnet,
				   !csum);
}
EXPORT_SYMBOL_GPL(geneve_xmit_skb);

static int geneve_hlen(struct genevehdr *gh)
{
	return sizeof(*gh) + gh->opt_len * 4;
}

static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
					   struct sk_buff *skb,
					   struct udp_offload *uoff)
{
	struct sk_buff *p, **pp = NULL;
	struct genevehdr *gh, *gh2;
	unsigned int hlen, gh_len, off_gnv;
	const struct packet_offload *ptype;
	__be16 type;
	int flush = 1;

	off_gnv = skb_gro_offset(skb);
	hlen = off_gnv + sizeof(*gh);
	gh = skb_gro_header_fast(skb, off_gnv);
	if (skb_gro_header_hard(skb, hlen)) {
		gh = skb_gro_header_slow(skb, hlen, off_gnv);
		if (unlikely(!gh))
			goto out;
	}

	if (gh->ver != GENEVE_VER || gh->oam)
		goto out;
	gh_len = geneve_hlen(gh);

	hlen = off_gnv + gh_len;
	if (skb_gro_header_hard(skb, hlen)) {
		gh = skb_gro_header_slow(skb, hlen, off_gnv);
		if (unlikely(!gh))
			goto out;
	}

	flush = 0;

	for (p = *head; p; p = p->next) {
		if (!NAPI_GRO_CB(p)->same_flow)
			continue;

		gh2 = (struct genevehdr *)(p->data + off_gnv);
		if (gh->opt_len != gh2->opt_len ||
		    memcmp(gh, gh2, gh_len)) {
			NAPI_GRO_CB(p)->same_flow = 0;
			continue;
		}
	}

	type = gh->proto_type;

	rcu_read_lock();
	ptype = gro_find_receive_by_type(type);
	if (!ptype) {
		flush = 1;
		goto out_unlock;
	}

	skb_gro_pull(skb, gh_len);
	skb_gro_postpull_rcsum(skb, gh, gh_len);
	pp = ptype->callbacks.gro_receive(head, skb);

out_unlock:
	rcu_read_unlock();
out:
	NAPI_GRO_CB(skb)->flush |= flush;

	return pp;
}

static int geneve_gro_complete(struct sk_buff *skb, int nhoff,
			       struct udp_offload *uoff)
{
	struct genevehdr *gh;
	struct packet_offload *ptype;
	__be16 type;
	int gh_len;
	int err = -ENOSYS;

	udp_tunnel_gro_complete(skb, nhoff);

	gh = (struct genevehdr *)(skb->data + nhoff);
	gh_len = geneve_hlen(gh);
	type = gh->proto_type;

	rcu_read_lock();
	ptype = gro_find_complete_by_type(type);
	if (ptype)
		err = ptype->callbacks.gro_complete(skb, nhoff + gh_len);

	rcu_read_unlock();
	return err;
}

static void geneve_notify_add_rx_port(struct geneve_sock *gs)
{
	struct sock *sk = gs->sock->sk;
	sa_family_t sa_family = sk->sk_family;
	int err;

	if (sa_family == AF_INET) {
		err = udp_add_offload(&gs->udp_offloads);
		if (err)
			pr_warn("geneve: udp_add_offload failed with status %d\n",
				err);
	}
}

static void geneve_notify_del_rx_port(struct geneve_sock *gs)
{
	struct sock *sk = gs->sock->sk;
	sa_family_t sa_family = sk->sk_family;

	if (sa_family == AF_INET)
		udp_del_offload(&gs->udp_offloads);
}

/* Callback from net/ipv4/udp.c to receive packets */
static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
	struct genevehdr *geneveh;
	struct geneve_sock *gs;
	int opts_len;

	/* Need Geneve and inner Ethernet header to be present */
	if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
		goto error;

	/* Return packets with reserved bits set */
	geneveh = geneve_hdr(skb);

	if (unlikely(geneveh->ver != GENEVE_VER))
		goto error;

	if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
		goto error;

	opts_len = geneveh->opt_len * 4;
	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
				 htons(ETH_P_TEB)))
		goto drop;

	gs = rcu_dereference_sk_user_data(sk);
	if (!gs)
		goto drop;

	gs->rcv(gs, skb);
	return 0;

drop:
	/* Consume bad packet */
	kfree_skb(skb);
	return 0;

error:
	/* Let the UDP layer deal with the skb */
	return 1;
}

static struct socket *geneve_create_sock(struct net *net, bool ipv6,
					 __be16 port)
{
	struct socket *sock;
	struct udp_port_cfg udp_conf;
	int err;

	memset(&udp_conf, 0, sizeof(udp_conf));

	if (ipv6) {
		udp_conf.family = AF_INET6;
	} else {
		udp_conf.family = AF_INET;
		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
	}

	udp_conf.local_udp_port = port;

	/* Open UDP socket */
	err = udp_sock_create(net, &udp_conf, &sock);
	if (err < 0)
		return ERR_PTR(err);

	return sock;
}

/* Create new listen socket if needed */
static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
						geneve_rcv_t *rcv, void *data,
						bool ipv6)
{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_sock *gs;
	struct socket *sock;
	struct udp_tunnel_sock_cfg tunnel_cfg;

	gs = kzalloc(sizeof(*gs), GFP_KERNEL);
	if (!gs)
		return ERR_PTR(-ENOMEM);

	sock = geneve_create_sock(net, ipv6, port);
	if (IS_ERR(sock)) {
		kfree(gs);
		return ERR_CAST(sock);
	}

	gs->sock = sock;
	gs->refcnt = 1;
	gs->rcv = rcv;
	gs->rcv_data = data;

	/* Initialize the geneve udp offloads structure */
	gs->udp_offloads.port = port;
	gs->udp_offloads.callbacks.gro_receive  = geneve_gro_receive;
	gs->udp_offloads.callbacks.gro_complete = geneve_gro_complete;
	geneve_notify_add_rx_port(gs);

	/* Mark socket as an encapsulation socket */
	tunnel_cfg.sk_user_data = gs;
	tunnel_cfg.encap_type = 1;
	tunnel_cfg.encap_rcv = geneve_udp_encap_recv;
	tunnel_cfg.encap_destroy = NULL;
	setup_udp_tunnel_sock(net, sock, &tunnel_cfg);

	list_add(&gs->list, &gn->sock_list);

	return gs;
}

struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
				    geneve_rcv_t *rcv, void *data,
				    bool no_share, bool ipv6)
{
	struct geneve_sock *gs;

	mutex_lock(&geneve_mutex);

	gs = geneve_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port);
	if (gs) {
		if (!no_share && gs->rcv == rcv)
			gs->refcnt++;
		else
			gs = ERR_PTR(-EBUSY);
	} else {
		gs = geneve_socket_create(net, port, rcv, data, ipv6);
	}

	mutex_unlock(&geneve_mutex);

	return gs;
}
EXPORT_SYMBOL_GPL(geneve_sock_add);

void geneve_sock_release(struct geneve_sock *gs)
{
	mutex_lock(&geneve_mutex);

	if (--gs->refcnt)
		goto unlock;

	list_del(&gs->list);
	geneve_notify_del_rx_port(gs);
	udp_tunnel_sock_release(gs->sock);
	kfree_rcu(gs, rcu);

unlock:
	mutex_unlock(&geneve_mutex);
}
EXPORT_SYMBOL_GPL(geneve_sock_release);

static __net_init int geneve_init_net(struct net *net)
{
	struct geneve_net *gn = net_generic(net, geneve_net_id);

	INIT_LIST_HEAD(&gn->sock_list);

	return 0;
}

static struct pernet_operations geneve_net_ops = {
	.init = geneve_init_net,
	.id   = &geneve_net_id,
	.size = sizeof(struct geneve_net),
};

static int __init geneve_init_module(void)
{
	int rc;

	rc = register_pernet_subsys(&geneve_net_ops);
	if (rc)
		return rc;

	pr_info("Geneve driver\n");

	return 0;
}
module_init(geneve_init_module);

static void __exit geneve_cleanup_module(void)
{
	unregister_pernet_subsys(&geneve_net_ops);
}
module_exit(geneve_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jesse Gross <jesse@nicira.com>");
MODULE_DESCRIPTION("Driver for GENEVE encapsulated traffic");
MODULE_ALIAS_RTNL_LINK("geneve");
OpenPOWER on IntegriCloud