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s390/qeth: improve fallback to random MAC address

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If READ MAC fails to fetch a valid MAC address, allow some more device
types (IQD and z/VM OSD) to fall back to a random address.
Also use eth_hw_addr_random(), for indicating to userspace that the
address type is NET_ADDR_RANDOM.

Note that while z/VM has various protection schemes to prohibit
custom addresses on its NICs, they are all optional. So we should at
least give it a try.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Wiedmann 2018-04-26 09:42:24 +02:00 committed by David S. Miller
parent d7e6ed97b5
commit 21b1702af1
1 changed files with 13 additions and 10 deletions
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23
drivers/s390/net/qeth_l2_main.c
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@ -439,7 +439,6 @@ static int qeth_l2_process_inbound_buffer(struct qeth_card *card,
static int qeth_l2_request_initial_mac(struct qeth_card *card)
{
int rc = 0;
char vendor_pre[] = {0x02, 0x00, 0x00};
QETH_DBF_TEXT(SETUP, 2, "l2reqmac");
QETH_DBF_TEXT_(SETUP, 2, "doL2%s", CARD_BUS_ID(card));
@ -459,16 +458,20 @@ static int qeth_l2_request_initial_mac(struct qeth_card *card)
card->info.type == QETH_CARD_TYPE_OSX ||
card->info.guestlan) {
rc = qeth_setadpparms_change_macaddr(card);
if (rc) {
QETH_DBF_MESSAGE(2, "couldn't get MAC address on "
"device %s: x%x\n", CARD_BUS_ID(card), rc);
QETH_DBF_TEXT_(SETUP, 2, "1err%04x", rc);
return rc;
}
} else {
eth_random_addr(card->dev->dev_addr);
memcpy(card->dev->dev_addr, vendor_pre, 3);
if (!rc)
goto out;
QETH_DBF_MESSAGE(2, "READ_MAC Assist failed on device %s: x%x\n",
CARD_BUS_ID(card), rc);
QETH_DBF_TEXT_(SETUP, 2, "1err%04x", rc);
/* fall back once more: */
}
/* some devices don't support a custom MAC address: */
if (card->info.type == QETH_CARD_TYPE_OSM ||
card->info.type == QETH_CARD_TYPE_OSX)
return (rc) ? rc : -EADDRNOTAVAIL;
eth_hw_addr_random(card->dev);
out:
QETH_DBF_HEX(SETUP, 2, card->dev->dev_addr, card->dev->addr_len);
return 0;