summaryrefslogtreecommitdiff
path: root/net/8021q/vlan_core.c
blob: 5940366fac4870b85c442ab02c38e6637707a022 (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
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/netpoll.h>
#include "vlan.h"

bool vlan_do_receive(struct sk_buff **skbp)
{
	struct sk_buff *skb = *skbp;
	u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
	struct net_device *vlan_dev;
	struct vlan_pcpu_stats *rx_stats;

	vlan_dev = vlan_find_dev(skb->dev, vlan_id);
	if (!vlan_dev) {
		if (vlan_id)
			skb->pkt_type = PACKET_OTHERHOST;
		return false;
	}

	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
	if (unlikely(!skb))
		return false;

	skb->dev = vlan_dev;
	if (skb->pkt_type == PACKET_OTHERHOST) {
		/* Our lower layer thinks this is not local, let's make sure.
		 * This allows the VLAN to have a different MAC than the
		 * underlying device, and still route correctly. */
		if (!compare_ether_addr(eth_hdr(skb)->h_dest,
					vlan_dev->dev_addr))
			skb->pkt_type = PACKET_HOST;
	}

	if (!(vlan_dev_info(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
		unsigned int offset = skb->data - skb_mac_header(skb);

		/*
		 * vlan_insert_tag expect skb->data pointing to mac header.
		 * So change skb->data before calling it and change back to
		 * original position later
		 */
		skb_push(skb, offset);
		skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
		if (!skb)
			return false;
		skb_pull(skb, offset + VLAN_HLEN);
		skb_reset_mac_len(skb);
	}

	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
	skb->vlan_tci = 0;

	rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_pcpu_stats);

	u64_stats_update_begin(&rx_stats->syncp);
	rx_stats->rx_packets++;
	rx_stats->rx_bytes += skb->len;
	if (skb->pkt_type == PACKET_MULTICAST)
		rx_stats->rx_multicast++;
	u64_stats_update_end(&rx_stats->syncp);

	return true;
}

/* Must be invoked with rcu_read_lock or with RTNL. */
struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
					u16 vlan_id)
{
	struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);

	if (grp) {
		return vlan_group_get_device(grp, vlan_id);
	} else {
		/*
		 * Bonding slaves do not have grp assigned to themselves.
		 * Grp is assigned to bonding master instead.
		 */
		if (netif_is_bond_slave(real_dev))
			return __vlan_find_dev_deep(real_dev->master, vlan_id);
	}

	return NULL;
}
EXPORT_SYMBOL(__vlan_find_dev_deep);

struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
	return vlan_dev_info(dev)->real_dev;
}
EXPORT_SYMBOL(vlan_dev_real_dev);

u16 vlan_dev_vlan_id(const struct net_device *dev)
{
	return vlan_dev_info(dev)->vlan_id;
}
EXPORT_SYMBOL(vlan_dev_vlan_id);

/* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
		      u16 vlan_tci, int polling)
{
	__vlan_hwaccel_put_tag(skb, vlan_tci);
	return polling ? netif_receive_skb(skb) : netif_rx(skb);
}
EXPORT_SYMBOL(__vlan_hwaccel_rx);

gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
			      unsigned int vlan_tci, struct sk_buff *skb)
{
	__vlan_hwaccel_put_tag(skb, vlan_tci);
	return napi_gro_receive(napi, skb);
}
EXPORT_SYMBOL(vlan_gro_receive);

gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
			    unsigned int vlan_tci)
{
	__vlan_hwaccel_put_tag(napi->skb, vlan_tci);
	return napi_gro_frags(napi);
}
EXPORT_SYMBOL(vlan_gro_frags);

static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
{
	if (skb_cow(skb, skb_headroom(skb)) < 0)
		return NULL;
	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
	skb->mac_header += VLAN_HLEN;
	skb_reset_mac_len(skb);
	return skb;
}

static void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr)
{
	__be16 proto;
	unsigned char *rawp;

	/*
	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
	 * three protocols care about.
	 */

	proto = vhdr->h_vlan_encapsulated_proto;
	if (ntohs(proto) >= 1536) {
		skb->protocol = proto;
		return;
	}

	rawp = skb->data;
	if (*(unsigned short *) rawp == 0xFFFF)
		/*
		 * This is a magic hack to spot IPX packets. Older Novell
		 * breaks the protocol design and runs IPX over 802.3 without
		 * an 802.2 LLC layer. We look for FFFF which isn't a used
		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
		 * but does for the rest.
		 */
		skb->protocol = htons(ETH_P_802_3);
	else
		/*
		 * Real 802.2 LLC
		 */
		skb->protocol = htons(ETH_P_802_2);
}

struct sk_buff *vlan_untag(struct sk_buff *skb)
{
	struct vlan_hdr *vhdr;
	u16 vlan_tci;

	if (unlikely(vlan_tx_tag_present(skb))) {
		/* vlan_tci is already set-up so leave this for another time */
		return skb;
	}

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (unlikely(!skb))
		goto err_free;

	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
		goto err_free;

	vhdr = (struct vlan_hdr *) skb->data;
	vlan_tci = ntohs(vhdr->h_vlan_TCI);
	__vlan_hwaccel_put_tag(skb, vlan_tci);

	skb_pull_rcsum(skb, VLAN_HLEN);
	vlan_set_encap_proto(skb, vhdr);

	skb = vlan_reorder_header(skb);
	if (unlikely(!skb))
		goto err_free;

	return skb;

err_free:
	kfree_skb(skb);
	return NULL;
}