s390/qeth: drop unwanted packets earlier in RX path

Packets with an unexpected HW format are currently first extracted from
the RX buffer, passed upwards to the layer-specific driver and only then
finally dropped.

Enhance the RX path so that we can drop such packets before even
allocating an skb. For this, add some additional logic so that when a
packet is meant to be dropped, we can still walk along the packet's data
chunks in the RX buffer. This allows us to extract the following
packet(s) from the buffer.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Wiedmann
2019-11-14 11:19:16 +01:00
committed by David S. Miller
parent 5fd3fcbb8a
commit 7d4faee7c6
3 changed files with 44 additions and 41 deletions

View File

@@ -315,30 +315,19 @@ static int qeth_l2_process_inbound_buffer(struct qeth_card *card,
*done = 1;
break;
}
switch (hdr->hdr.l2.id) {
case QETH_HEADER_TYPE_LAYER2:
if (hdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
skb->protocol = eth_type_trans(skb, skb->dev);
qeth_rx_csum(card, skb, hdr->hdr.l2.flags[1]);
len = skb->len;
napi_gro_receive(&card->napi, skb);
break;
case QETH_HEADER_TYPE_OSN:
if (IS_OSN(card)) {
skb_push(skb, sizeof(struct qeth_hdr));
skb_copy_to_linear_data(skb, hdr,
sizeof(struct qeth_hdr));
len = skb->len;
card->osn_info.data_cb(skb);
break;
}
/* Else, fall through */
default:
dev_kfree_skb_any(skb);
QETH_CARD_TEXT(card, 3, "inbunkno");
QETH_DBF_HEX(CTRL, 3, hdr, sizeof(*hdr));
QETH_CARD_STAT_INC(card, rx_dropped_notsupp);
continue;
} else {
skb_push(skb, sizeof(*hdr));
skb_copy_to_linear_data(skb, hdr, sizeof(*hdr));
len = skb->len;
card->osn_info.data_cb(skb);
}
work_done++;
budget--;
QETH_CARD_STAT_INC(card, rx_packets);