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 } 180