net: Implement random ethaddr fallback in eth.c
Implement the random ethaddr fallback in eth.c so it is in a common
place and not reimplemented in each board or driver that wants this
behavior.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index 1ea397a..5cbb39b 100644
--- a/README
+++ b/README
@@ -5623,7 +5623,8 @@
warning is printed.
o If neither SROM nor the environment contain a MAC address, an error
- is raised.
+ is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
+ a random, locally-assigned MAC is used.
If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
will be programmed into hardware as part of the initialization process. This
diff --git a/doc/README.enetaddr b/doc/README.enetaddr
index 0fafd2c..82c9cd5 100644
--- a/doc/README.enetaddr
+++ b/doc/README.enetaddr
@@ -37,6 +37,8 @@
environment variable will be used unchanged.
If the environment variable is not set, it will be initialized from
eth_device->enetaddr, and a warning will be printed.
+ If both are invalid and CONFIG_NET_RANDOM_ETHADDR is defined, a random,
+ locally-assigned MAC is written to eth_device->enetaddr.
4. Program the address into hardware if the following conditions are met:
a) The relevant driver has a 'write_addr' function
b) The user hasn't set an 'ethmacskip' environment variable
diff --git a/net/Kconfig b/net/Kconfig
index 22b9eaa..a2bd4fe 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -7,4 +7,12 @@
if NET
+config NET_RANDOM_ETHADDR
+ bool "Random ethaddr if unset"
+ help
+ Selecting this will allow the Ethernet interface to function
+ even when the ethaddr variable for that interface is unset.
+ A new MAC address will be generated on every boot and it will
+ not be added to the environment.
+
endif # if NET
diff --git a/net/eth.c b/net/eth.c
index 04a544c..6c49db5 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -538,9 +538,15 @@
printf("\nWarning: %s using MAC address from ROM\n",
dev->name);
} else if (is_zero_ethaddr(pdata->enetaddr)) {
+#ifdef CONFIG_NET_RANDOM_ETHADDR
+ net_random_ethaddr(pdata->enetaddr);
+ printf("\nWarning: %s (eth%d) using random MAC address - %pM\n",
+ dev->name, dev->seq, pdata->enetaddr);
+#else
printf("\nError: %s address not set.\n",
dev->name);
return -EINVAL;
+#endif
}
return 0;
@@ -666,9 +672,15 @@
printf("\nWarning: %s using MAC address from net device\n",
dev->name);
} else if (is_zero_ethaddr(dev->enetaddr)) {
+#ifdef CONFIG_NET_RANDOM_ETHADDR
+ net_random_ethaddr(dev->enetaddr);
+ printf("\nWarning: %s (eth%d) using random MAC address - %pM\n",
+ dev->name, eth_number, dev->enetaddr);
+#else
printf("\nError: %s address not set.\n",
dev->name);
return -EINVAL;
+#endif
}
if (dev->write_hwaddr && !eth_mac_skip(eth_number)) {