mv643xx_eth: deal with unexpected ethernet header sizes

[linux-2.6-omap-h63xx.git] / drivers / net / mv643xx_eth.c

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 94c13be292a30a80e8c26f519588a82aee202998..9522c449ccea2e92940fcaab928ad739e15963ee 100644 (file)
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -699,79 +699,74 @@ static inline __be16 sum16_as_be(__sum16 sum)
        return (__force __be16)sum;
 }
 
-static void txq_submit_skb(struct tx_queue *txq, struct sk_buff *skb)
+static int txq_submit_skb(struct tx_queue *txq, struct sk_buff *skb)
 {
        struct mv643xx_eth_private *mp = txq_to_mp(txq);
        int nr_frags = skb_shinfo(skb)->nr_frags;
        int tx_index;
        struct tx_desc *desc;
        u32 cmd_sts;
+       u16 l4i_chk;
        int length;
 
        cmd_sts = TX_FIRST_DESC | GEN_CRC | BUFFER_OWNED_BY_DMA;
-
-       tx_index = txq_alloc_desc_index(txq);
-       desc = &txq->tx_desc_area[tx_index];
-
-       if (nr_frags) {
-               txq_submit_frag_skb(txq, skb);
-               length = skb_headlen(skb);
-       } else {
-               cmd_sts |= ZERO_PADDING | TX_LAST_DESC | TX_ENABLE_INTERRUPT;
-               length = skb->len;
-       }
-
-       desc->byte_cnt = length;
-       desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);
+       l4i_chk = 0;
 
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
-               int mac_hdr_len;
+               int tag_bytes;
 
                BUG_ON(skb->protocol != htons(ETH_P_IP) &&
                       skb->protocol != htons(ETH_P_8021Q));
 
-               cmd_sts |= GEN_TCP_UDP_CHECKSUM |
-                          GEN_IP_V4_CHECKSUM   |
-                          ip_hdr(skb)->ihl << TX_IHL_SHIFT;
+               tag_bytes = (void *)ip_hdr(skb) - (void *)skb->data - ETH_HLEN;
+               if (unlikely(tag_bytes & ~12)) {
+                       if (skb_checksum_help(skb) == 0)
+                               goto no_csum;
+                       kfree_skb(skb);
+                       return 1;
+               }
 
-               mac_hdr_len = (void *)ip_hdr(skb) - (void *)skb->data;
-               switch (mac_hdr_len - ETH_HLEN) {
-               case 0:
-                       break;
-               case 4:
-                       cmd_sts |= MAC_HDR_EXTRA_4_BYTES;
-                       break;
-               case 8:
-                       cmd_sts |= MAC_HDR_EXTRA_8_BYTES;
-                       break;
-               case 12:
+               if (tag_bytes & 4)
                        cmd_sts |= MAC_HDR_EXTRA_4_BYTES;
+               if (tag_bytes & 8)
                        cmd_sts |= MAC_HDR_EXTRA_8_BYTES;
-                       break;
-               default:
-                       if (net_ratelimit())
-                               dev_printk(KERN_ERR, &txq_to_mp(txq)->dev->dev,
-                                  "mac header length is %d?!\n", mac_hdr_len);
-                       break;
-               }
+
+               cmd_sts |= GEN_TCP_UDP_CHECKSUM |
+                          GEN_IP_V4_CHECKSUM   |
+                          ip_hdr(skb)->ihl << TX_IHL_SHIFT;
 
                switch (ip_hdr(skb)->protocol) {
                case IPPROTO_UDP:
                        cmd_sts |= UDP_FRAME;
-                       desc->l4i_chk = ntohs(sum16_as_be(udp_hdr(skb)->check));
+                       l4i_chk = ntohs(sum16_as_be(udp_hdr(skb)->check));
                        break;
                case IPPROTO_TCP:
-                       desc->l4i_chk = ntohs(sum16_as_be(tcp_hdr(skb)->check));
+                       l4i_chk = ntohs(sum16_as_be(tcp_hdr(skb)->check));
                        break;
                default:
                        BUG();
                }
        } else {
+no_csum:
                /* Errata BTS #50, IHL must be 5 if no HW checksum */
                cmd_sts |= 5 << TX_IHL_SHIFT;
-               desc->l4i_chk = 0;
        }
 
+       tx_index = txq_alloc_desc_index(txq);
+       desc = &txq->tx_desc_area[tx_index];
+
+       if (nr_frags) {
+               txq_submit_frag_skb(txq, skb);
+               length = skb_headlen(skb);
+       } else {
+               cmd_sts |= ZERO_PADDING | TX_LAST_DESC | TX_ENABLE_INTERRUPT;
+               length = skb->len;
+       }
+
+       desc->l4i_chk = l4i_chk;
+       desc->byte_cnt = length;
+       desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);
+
        __skb_queue_tail(&txq->tx_skb, skb);
 
        /* ensure all other descriptors are written before first cmd_sts */
@@ -786,6 +781,8 @@ static void txq_submit_skb(struct tx_queue *txq, struct sk_buff *skb)
        txq_enable(txq);
 
        txq->tx_desc_count += nr_frags + 1;
+
+       return 0;
 }
 
 static int mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -794,7 +791,6 @@ static int mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
        int queue;
        struct tx_queue *txq;
        struct netdev_queue *nq;
-       int entries_left;
 
        queue = skb_get_queue_mapping(skb);
        txq = mp->txq + queue;
@@ -815,14 +811,17 @@ static int mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
                return NETDEV_TX_OK;
        }
 
-       txq_submit_skb(txq, skb);
-       txq->tx_bytes += skb->len;
-       txq->tx_packets++;
-       dev->trans_start = jiffies;
+       if (!txq_submit_skb(txq, skb)) {
+               int entries_left;
+
+               txq->tx_bytes += skb->len;
+               txq->tx_packets++;
+               dev->trans_start = jiffies;
 
-       entries_left = txq->tx_ring_size - txq->tx_desc_count;
-       if (entries_left < MAX_SKB_FRAGS + 1)
-               netif_tx_stop_queue(nq);
+               entries_left = txq->tx_ring_size - txq->tx_desc_count;
+               if (entries_left < MAX_SKB_FRAGS + 1)
+                       netif_tx_stop_queue(nq);
+       }
 
        return NETDEV_TX_OK;
 }