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 /* Must be invoked with rcu_read_lock or with RTNL. */ 67 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, 68 u16 vlan_id) 69 { 70 struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp); 71 72 if (grp) { 73 return vlan_group_get_device(grp, vlan_id); 74 } else { 75 /* 76 * Bonding slaves do not have grp assigned to themselves. 77 * Grp is assigned to bonding master instead. 78 */ 79 if (netif_is_bond_slave(real_dev)) 80 return __vlan_find_dev_deep(real_dev->master, vlan_id); 81 } 82 83 return NULL; 84 } 85 EXPORT_SYMBOL(__vlan_find_dev_deep); 86 87 struct net_device *vlan_dev_real_dev(const struct net_device *dev) 88 { 89 return vlan_dev_info(dev)->real_dev; 90 } 91 EXPORT_SYMBOL(vlan_dev_real_dev); 92 93 u16 vlan_dev_vlan_id(const struct net_device *dev) 94 { 95 return vlan_dev_info(dev)->vlan_id; 96 } 97 EXPORT_SYMBOL(vlan_dev_vlan_id); 98 99 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb) 100 { 101 if (skb_cow(skb, skb_headroom(skb)) < 0) 102 return NULL; 103 memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN); 104 skb->mac_header += VLAN_HLEN; 105 skb_reset_mac_len(skb); 106 return skb; 107 } 108 109 static void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr) 110 { 111 __be16 proto; 112 unsigned char *rawp; 113 114 /* 115 * Was a VLAN packet, grab the encapsulated protocol, which the layer 116 * three protocols care about. 117 */ 118 119 proto = vhdr->h_vlan_encapsulated_proto; 120 if (ntohs(proto) >= 1536) { 121 skb->protocol = proto; 122 return; 123 } 124 125 rawp = skb->data; 126 if (*(unsigned short *) rawp == 0xFFFF) 127 /* 128 * This is a magic hack to spot IPX packets. Older Novell 129 * breaks the protocol design and runs IPX over 802.3 without 130 * an 802.2 LLC layer. We look for FFFF which isn't a used 131 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 132 * but does for the rest. 133 */ 134 skb->protocol = htons(ETH_P_802_3); 135 else 136 /* 137 * Real 802.2 LLC 138 */ 139 skb->protocol = htons(ETH_P_802_2); 140 } 141 142 struct sk_buff *vlan_untag(struct sk_buff *skb) 143 { 144 struct vlan_hdr *vhdr; 145 u16 vlan_tci; 146 147 if (unlikely(vlan_tx_tag_present(skb))) { 148 /* vlan_tci is already set-up so leave this for another time */ 149 return skb; 150 } 151 152 skb = skb_share_check(skb, GFP_ATOMIC); 153 if (unlikely(!skb)) 154 goto err_free; 155 156 if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) 157 goto err_free; 158 159 vhdr = (struct vlan_hdr *) skb->data; 160 vlan_tci = ntohs(vhdr->h_vlan_TCI); 161 __vlan_hwaccel_put_tag(skb, vlan_tci); 162 163 skb_pull_rcsum(skb, VLAN_HLEN); 164 vlan_set_encap_proto(skb, vhdr); 165 166 skb = vlan_reorder_header(skb); 167 if (unlikely(!skb)) 168 goto err_free; 169 170 skb_reset_network_header(skb); 171 skb_reset_transport_header(skb); 172 return skb; 173 174 err_free: 175 kfree_skb(skb); 176 return NULL; 177 } 178