net/tap: Set locally administered bit with a fixed MAC address
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Commit Message
When the tap driver is loaded and the user selects the optional
"mac=fixed" setting, the tap driver incorrectly uses a globally
unique EUI-48 identifier (as documented in RFC 7042) of
00:64:74:61:70:<iface_idx>. Since this is a locally generated ID,
the Local bit in the MAC address should be set to 1, resulting in
the new address 02:64:74:61:70:<iface_idx>.
Bugzilla ID: 1198
Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
---
doc/guides/nics/tap.rst | 8 ++++----
drivers/net/tap/rte_eth_tap.c | 4 ++--
examples/ipsec-secgw/test/common_defs.sh | 2 +-
3 files changed, 7 insertions(+), 7 deletions(-)
Comments
On Tue, 25 Apr 2023 16:58:06 -0400
David Christensen <drc@linux.vnet.ibm.com> wrote:
> When the tap driver is loaded and the user selects the optional
> "mac=fixed" setting, the tap driver incorrectly uses a globally
> unique EUI-48 identifier (as documented in RFC 7042) of
> 00:64:74:61:70:<iface_idx>. Since this is a locally generated ID,
> the Local bit in the MAC address should be set to 1, resulting in
> the new address 02:64:74:61:70:<iface_idx>.
>
> Bugzilla ID: 1198
>
> Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
On 4/26/2023 1:39 AM, Stephen Hemminger wrote:
> On Tue, 25 Apr 2023 16:58:06 -0400
> David Christensen <drc@linux.vnet.ibm.com> wrote:
>
>> When the tap driver is loaded and the user selects the optional
>> "mac=fixed" setting, the tap driver incorrectly uses a globally
>> unique EUI-48 identifier (as documented in RFC 7042) of
>> 00:64:74:61:70:<iface_idx>. Since this is a locally generated ID,
>> the Local bit in the MAC address should be set to 1, resulting in
>> the new address 02:64:74:61:70:<iface_idx>.
>>
>> Bugzilla ID: 1198
>>
>> Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
>
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
>
Bugzilla ID: 1198
Fixes: f6921783fee6 ("net/tap: add support for fixed MAC addresses")
Cc: stable@dpdk.org
Acked-by: Ferruh Yigit <ferruh.yigit@amd.com>
Applied to dpdk-next-net/main, thanks.
Dropped 'examples/ipsec-secgw/test/common_defs.sh' change while merging,
although it is a minor change can you please send a separate patch for it?
@@ -34,14 +34,14 @@ Using the option ``mac=fixed`` you can create a fixed known MAC address::
The MAC address will have a fixed value with the last octet incrementing by one
for each interface string containing ``mac=fixed``. The MAC address is formatted
-as 00:'d':'t':'a':'p':[00-FF]. Convert the characters to hex and you get the
-actual MAC address: ``00:64:74:61:70:[00-FF]``.
+as 02:'d':'t':'a':'p':[00-FF]. Convert the characters to hex and you get the
+actual MAC address: ``02:64:74:61:70:[00-FF]``.
- --vdev=net_tap0,mac="00:64:74:61:70:11"
+ --vdev=net_tap0,mac="02:64:74:61:70:11"
The MAC address will have a user value passed as string. The MAC address is in
format with delimiter ``:``. The string is byte converted to hex and you get
-the actual MAC address: ``00:64:74:61:70:11``.
+the actual MAC address: ``02:64:74:61:70:11``.
It is possible to specify a remote netdevice to capture packets from by adding
``remote=foo1``, for example::
@@ -2303,8 +2303,8 @@ set_mac_type(const char *key __rte_unused,
if (!strncasecmp(ETH_TAP_MAC_FIXED, value, strlen(ETH_TAP_MAC_FIXED))) {
static int iface_idx;
- /* fixed mac = 00:64:74:61:70:<iface_idx> */
- memcpy((char *)user_mac->addr_bytes, "\0dtap",
+ /* fixed mac = 02:64:74:61:70:<iface_idx> */
+ memcpy((char *)user_mac->addr_bytes, "\002dtap",
RTE_ETHER_ADDR_LEN);
user_mac->addr_bytes[RTE_ETHER_ADDR_LEN - 1] =
iface_idx++ + '0';
@@ -26,7 +26,7 @@ fi
LOCAL_IFACE=dtap0
-LOCAL_MAC="00:64:74:61:70:30"
+LOCAL_MAC="02:64:74:61:70:30"
REMOTE_IPV4=192.168.31.14
LOCAL_IPV4=192.168.31.92