1 #include <linux/skbuff.h> 2 #include <linux/netdevice.h> 3 #include <linux/if_vlan.h> 4 #include <linux/netpoll.h> 5 #include <linux/export.h> 6 #include "vlan.h" 7 8 bool vlan_do_receive(struct sk_buff **skbp, bool last_handler) 9 { 10 struct sk_buff *skb = *skbp; 11 u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK; 12 struct net_device *vlan_dev; 13 struct vlan_pcpu_stats *rx_stats; 14 15 vlan_dev = vlan_find_dev(skb->dev, vlan_id); 16 if (!vlan_dev) { 17 /* Only the last call to vlan_do_receive() should change 18 * pkt_type to PACKET_OTHERHOST 19 */ 20 if (vlan_id && last_handler) 21 skb->pkt_type = PACKET_OTHERHOST; 22 return false; 23 } 24 25 skb = *skbp = skb_share_check(skb, GFP_ATOMIC); 26 if (unlikely(!skb)) 27 return false; 28 29 skb->dev = vlan_dev; 30 if (skb->pkt_type == PACKET_OTHERHOST) { 31 /* Our lower layer thinks this is not local, let's make sure. 32 * This allows the VLAN to have a different MAC than the 33 * underlying device, and still route correctly. */ 34 if (!compare_ether_addr(eth_hdr(skb)->h_dest, 35 vlan_dev->dev_addr)) 36 skb->pkt_type = PACKET_HOST; 37 } 38 39 if (!(vlan_dev_info(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) { 40 unsigned int offset = skb->data - skb_mac_header(skb); 41 42 /* 43 * vlan_insert_tag expect skb->data pointing to mac header. 44 * So change skb->data before calling it and change back to 45 * original position later 46 */ 47 skb_push(skb, offset); 48 skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci); 49 if (!skb) 50 return false; 51 skb_pull(skb, offset + VLAN_HLEN); 52 skb_reset_mac_len(skb); 53 } 54 55 skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci); 56 skb->vlan_tci = 0; 57 58 rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_pcpu_stats); 59 60 u64_stats_update_begin(&rx_stats->syncp); 61 rx_stats->rx_packets++; 62 rx_stats->rx_bytes += skb->len; 63 if (skb->pkt_type == PACKET_MULTICAST) 64 rx_stats->rx_multicast++; 65 u64_stats_update_end(&rx_stats->syncp); 66 67 return true; 68 } 69 70 /* Must be invoked with rcu_read_lock or with RTNL. */ 71 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, 72 u16 vlan_id) 73 { 74 struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp); 75 76 if (grp) { 77 return vlan_group_get_device(grp, vlan_id); 78 } else { 79 /* 80 * Bonding slaves do not have grp assigned to themselves. 81 * Grp is assigned to bonding master instead. 82 */ 83 if (netif_is_bond_slave(real_dev)) 84 return __vlan_find_dev_deep(real_dev->master, vlan_id); 85 } 86 87 return NULL; 88 } 89 EXPORT_SYMBOL(__vlan_find_dev_deep); 90 91 struct net_device *vlan_dev_real_dev(const struct net_device *dev) 92 { 93 return vlan_dev_info(dev)->real_dev; 94 } 95 EXPORT_SYMBOL(vlan_dev_real_dev); 96 97 u16 vlan_dev_vlan_id(const struct net_device *dev) 98 { 99 return vlan_dev_info(dev)->vlan_id; 100 } 101 EXPORT_SYMBOL(vlan_dev_vlan_id); 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 skb_reset_network_header(skb); 175 skb_reset_transport_header(skb); 176 return skb; 177 178 err_free: 179 kfree_skb(skb); 180 return NULL; 181 } 182