fcc684678af67e644c6cc043dacee9f4159fb5b4
[linux-2.6.git] / net / 8021q / vlan_core.c
1 #include <linux/skbuff.h>
2 #include <linux/netdevice.h>
3 #include <linux/if_vlan.h>
4 #include <linux/netpoll.h>
5 #include "vlan.h"
6
7 bool vlan_do_receive(struct sk_buff **skbp)
8 {
9         struct sk_buff *skb = *skbp;
10         u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
11         struct net_device *vlan_dev;
12         struct vlan_pcpu_stats *rx_stats;
13
14         vlan_dev = vlan_find_dev(skb->dev, vlan_id);
15         if (!vlan_dev) {
16                 if (vlan_id)
17                         skb->pkt_type = PACKET_OTHERHOST;
18                 return false;
19         }
20
21         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
22         if (unlikely(!skb))
23                 return false;
24
25         skb->dev = vlan_dev;
26         if (skb->pkt_type == PACKET_OTHERHOST) {
27                 /* Our lower layer thinks this is not local, let's make sure.
28                  * This allows the VLAN to have a different MAC than the
29                  * underlying device, and still route correctly. */
30                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
31                                         vlan_dev->dev_addr))
32                         skb->pkt_type = PACKET_HOST;
33         }
34
35         if (!(vlan_dev_info(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
36                 unsigned int offset = skb->data - skb_mac_header(skb);
37
38                 /*
39                  * vlan_insert_tag expect skb->data pointing to mac header.
40                  * So change skb->data before calling it and change back to
41                  * original position later
42                  */
43                 skb_push(skb, offset);
44                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
45                 if (!skb)
46                         return false;
47                 skb_pull(skb, offset + VLAN_HLEN);
48                 skb_reset_mac_len(skb);
49         }
50
51         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
52         skb->vlan_tci = 0;
53
54         rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_pcpu_stats);
55
56         u64_stats_update_begin(&rx_stats->syncp);
57         rx_stats->rx_packets++;
58         rx_stats->rx_bytes += skb->len;
59         if (skb->pkt_type == PACKET_MULTICAST)
60                 rx_stats->rx_multicast++;
61         u64_stats_update_end(&rx_stats->syncp);
62
63         return true;
64 }
65
66 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
67 {
68         return vlan_dev_info(dev)->real_dev;
69 }
70 EXPORT_SYMBOL(vlan_dev_real_dev);
71
72 u16 vlan_dev_vlan_id(const struct net_device *dev)
73 {
74         return vlan_dev_info(dev)->vlan_id;
75 }
76 EXPORT_SYMBOL(vlan_dev_vlan_id);
77
78 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
79 int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
80                       u16 vlan_tci, int polling)
81 {
82         __vlan_hwaccel_put_tag(skb, vlan_tci);
83         return polling ? netif_receive_skb(skb) : netif_rx(skb);
84 }
85 EXPORT_SYMBOL(__vlan_hwaccel_rx);
86
87 gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
88                               unsigned int vlan_tci, struct sk_buff *skb)
89 {
90         __vlan_hwaccel_put_tag(skb, vlan_tci);
91         return napi_gro_receive(napi, skb);
92 }
93 EXPORT_SYMBOL(vlan_gro_receive);
94
95 gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
96                             unsigned int vlan_tci)
97 {
98         __vlan_hwaccel_put_tag(napi->skb, vlan_tci);
99         return napi_gro_frags(napi);
100 }
101 EXPORT_SYMBOL(vlan_gro_frags);
102
103 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
104 {
105         if (skb_cow(skb, skb_headroom(skb)) < 0)
106                 return NULL;
107         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
108         skb->mac_header += VLAN_HLEN;
109         skb_reset_mac_len(skb);
110         return skb;
111 }
112
113 static void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr)
114 {
115         __be16 proto;
116         unsigned char *rawp;
117
118         /*
119          * Was a VLAN packet, grab the encapsulated protocol, which the layer
120          * three protocols care about.
121          */
122
123         proto = vhdr->h_vlan_encapsulated_proto;
124         if (ntohs(proto) >= 1536) {
125                 skb->protocol = proto;
126                 return;
127         }
128
129         rawp = skb->data;
130         if (*(unsigned short *) rawp == 0xFFFF)
131                 /*
132                  * This is a magic hack to spot IPX packets. Older Novell
133                  * breaks the protocol design and runs IPX over 802.3 without
134                  * an 802.2 LLC layer. We look for FFFF which isn't a used
135                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
136                  * but does for the rest.
137                  */
138                 skb->protocol = htons(ETH_P_802_3);
139         else
140                 /*
141                  * Real 802.2 LLC
142                  */
143                 skb->protocol = htons(ETH_P_802_2);
144 }
145
146 struct sk_buff *vlan_untag(struct sk_buff *skb)
147 {
148         struct vlan_hdr *vhdr;
149         u16 vlan_tci;
150
151         if (unlikely(vlan_tx_tag_present(skb))) {
152                 /* vlan_tci is already set-up so leave this for another time */
153                 return skb;
154         }
155
156         skb = skb_share_check(skb, GFP_ATOMIC);
157         if (unlikely(!skb))
158                 goto err_free;
159
160         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
161                 goto err_free;
162
163         vhdr = (struct vlan_hdr *) skb->data;
164         vlan_tci = ntohs(vhdr->h_vlan_TCI);
165         __vlan_hwaccel_put_tag(skb, vlan_tci);
166
167         skb_pull_rcsum(skb, VLAN_HLEN);
168         vlan_set_encap_proto(skb, vhdr);
169
170         skb = vlan_reorder_header(skb);
171         if (unlikely(!skb))
172                 goto err_free;
173
174         return skb;
175
176 err_free:
177         kfree_skb(skb);
178         return NULL;
179 }