diff options
Diffstat (limited to 'drivers/net/usb/ax88179_178a.c')
| -rw-r--r-- | drivers/net/usb/ax88179_178a.c | 101 |
1 files changed, 76 insertions, 25 deletions
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c index 4704ed6f00ef..ac2d400d1d6c 100644 --- a/drivers/net/usb/ax88179_178a.c +++ b/drivers/net/usb/ax88179_178a.c @@ -1472,6 +1472,42 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb) * are bundled into this buffer and where we can find an array of * per-packet metadata (which contains elements encoded into u16). */ + + /* SKB contents for current firmware: + * <packet 1> <padding> + * ... + * <packet N> <padding> + * <per-packet metadata entry 1> <dummy header> + * ... + * <per-packet metadata entry N> <dummy header> + * <padding2> <rx_hdr> + * + * where: + * <packet N> contains pkt_len bytes: + * 2 bytes of IP alignment pseudo header + * packet received + * <per-packet metadata entry N> contains 4 bytes: + * pkt_len and fields AX_RXHDR_* + * <padding> 0-7 bytes to terminate at + * 8 bytes boundary (64-bit). + * <padding2> 4 bytes to make rx_hdr terminate at + * 8 bytes boundary (64-bit) + * <dummy-header> contains 4 bytes: + * pkt_len=0 and AX_RXHDR_DROP_ERR + * <rx-hdr> contains 4 bytes: + * pkt_cnt and hdr_off (offset of + * <per-packet metadata entry 1>) + * + * pkt_cnt is number of entrys in the per-packet metadata. + * In current firmware there is 2 entrys per packet. + * The first points to the packet and the + * second is a dummy header. + * This was done probably to align fields in 64-bit and + * maintain compatibility with old firmware. + * This code assumes that <dummy header> and <padding2> are + * optional. + */ + if (skb->len < 4) return 0; skb_trim(skb, skb->len - 4); @@ -1485,51 +1521,66 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb) /* Make sure that the bounds of the metadata array are inside the SKB * (and in front of the counter at the end). */ - if (pkt_cnt * 2 + hdr_off > skb->len) + if (pkt_cnt * 4 + hdr_off > skb->len) return 0; pkt_hdr = (u32 *)(skb->data + hdr_off); /* Packets must not overlap the metadata array */ skb_trim(skb, hdr_off); - for (; ; pkt_cnt--, pkt_hdr++) { + for (; pkt_cnt > 0; pkt_cnt--, pkt_hdr++) { + u16 pkt_len_plus_padd; u16 pkt_len; le32_to_cpus(pkt_hdr); pkt_len = (*pkt_hdr >> 16) & 0x1fff; + pkt_len_plus_padd = (pkt_len + 7) & 0xfff8; - if (pkt_len > skb->len) + /* Skip dummy header used for alignment + */ + if (pkt_len == 0) + continue; + + if (pkt_len_plus_padd > skb->len) return 0; /* Check CRC or runt packet */ - if (((*pkt_hdr & (AX_RXHDR_CRC_ERR | AX_RXHDR_DROP_ERR)) == 0) && - pkt_len >= 2 + ETH_HLEN) { - bool last = (pkt_cnt == 0); - - if (last) { - ax_skb = skb; - } else { - ax_skb = skb_clone(skb, GFP_ATOMIC); - if (!ax_skb) - return 0; - } - ax_skb->len = pkt_len; - /* Skip IP alignment pseudo header */ - skb_pull(ax_skb, 2); - skb_set_tail_pointer(ax_skb, ax_skb->len); - ax_skb->truesize = pkt_len + sizeof(struct sk_buff); - ax88179_rx_checksum(ax_skb, pkt_hdr); + if ((*pkt_hdr & (AX_RXHDR_CRC_ERR | AX_RXHDR_DROP_ERR)) || + pkt_len < 2 + ETH_HLEN) { + dev->net->stats.rx_errors++; + skb_pull(skb, pkt_len_plus_padd); + continue; + } - if (last) - return 1; + /* last packet */ + if (pkt_len_plus_padd == skb->len) { + skb_trim(skb, pkt_len); - usbnet_skb_return(dev, ax_skb); + /* Skip IP alignment pseudo header */ + skb_pull(skb, 2); + + skb->truesize = SKB_TRUESIZE(pkt_len_plus_padd); + ax88179_rx_checksum(skb, pkt_hdr); + return 1; } - /* Trim this packet away from the SKB */ - if (!skb_pull(skb, (pkt_len + 7) & 0xFFF8)) + ax_skb = skb_clone(skb, GFP_ATOMIC); + if (!ax_skb) return 0; + skb_trim(ax_skb, pkt_len); + + /* Skip IP alignment pseudo header */ + skb_pull(ax_skb, 2); + + skb->truesize = pkt_len_plus_padd + + SKB_DATA_ALIGN(sizeof(struct sk_buff)); + ax88179_rx_checksum(ax_skb, pkt_hdr); + usbnet_skb_return(dev, ax_skb); + + skb_pull(skb, pkt_len_plus_padd); } + + return 0; } static struct sk_buff * |