From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Mon, 11 Sep 2023 18:00:48 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qfjLF-00BfSm-BA for lore@lore.pengutronix.de; Mon, 11 Sep 2023 18:00:48 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qfjLC-0004Md-UD for lore@pengutronix.de; Mon, 11 Sep 2023 18:00:47 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=xTet5CbSDnZkFakQkw1/yY9vXOwhHuikG2/jsqUvrgQ=; b=eOhdLIV+BKGOgYjaK4hEtRUT8Y I8gNQzOkT+1UD5+YWNJQo538mAiycy/DviqcjHsBwVdO90oIyVYoKNU2V2f7nZW2lsCawnpkktJ8z t6VzYdrCDfnLDsEUvlxxP5B69UhEbMfseJryLoObPkZenv277L+6qB8z0PNDOcLh0sW/Dcc4n9ExB yNyFFirk+64bcmFQwZdggggg9JawlZzqHta/uuA+OPLS5JnqmIQKG0LxIRCy4hOOyekDpSktVdqLt UYvYDUx7enc87jXV0E3G2MiqkDBbmXTU5bESDULcFgrT+xLABlMMJzhG6+vZ5GFUVeBI9yT6l/4VA 5loiqwlw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qfjK7-000xLb-39; Mon, 11 Sep 2023 15:59:39 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qfjK1-000xIU-1w for barebox@lists.infradead.org; Mon, 11 Sep 2023 15:59:36 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qfjK0-0003yh-3O; Mon, 11 Sep 2023 17:59:32 +0200 Received: from [2a0a:edc0:0:1101:1d::54] (helo=dude05.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1qfjJz-005aH5-DW; Mon, 11 Sep 2023 17:59:31 +0200 Received: from afa by dude05.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1qfjJy-00Ft0W-2k; Mon, 11 Sep 2023 17:59:30 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Alexander Shiyan , Ahmad Fatoum Date: Mon, 11 Sep 2023 17:59:27 +0200 Message-Id: <20230911155927.3786335-3-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230911155927.3786335-1-a.fatoum@pengutronix.de> References: <20230911155927.3786335-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230911_085933_641515_C55F7069 X-CRM114-Status: GOOD ( 18.80 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.9 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 3/3] net: add generic MAC address derivation from machine ID X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) From: Ahmad Fatoum Especially during development, devices often lack a MAC address. While a MAC address can be easily added to the environment: nv dev.eth0.ethaddr="aa:bb:cc:dd:ee:ff" It's easily lost when flashing complete new images, e.g. from CI. Make the development experience neater by deriving a stable MAC address if possible. Signed-off-by: Ahmad Fatoum --- include/net.h | 2 ++ net/Kconfig | 17 +++++++++++++++++ net/eth.c | 11 ++++++++++- net/net.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-- 4 files changed, 76 insertions(+), 3 deletions(-) diff --git a/include/net.h b/include/net.h index a0ef8bee0404..de43c29f74ac 100644 --- a/include/net.h +++ b/include/net.h @@ -418,6 +418,8 @@ static inline int is_broadcast_ether_addr(const u8 *addr) #define ETH_ALEN 6 /* Octets in an Ethernet address */ #define ETH_HLEN 14 /* Total octets in header.*/ +int generate_ether_addr(u8 *addr, int ethid); + /** * random_ether_addr - Generate software assigned random Ethernet address * @addr: Pointer to a six-byte array containing the Ethernet address diff --git a/net/Kconfig b/net/Kconfig index 59f14c23cba2..04fcdcbe5bd5 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -6,6 +6,23 @@ menuconfig NET if NET +config NET_ETHADDR_FROM_MACHINE_ID + bool + prompt "generate stable Ethernet address" + depends on MACHINE_ID && HAVE_DIGEST_SHA256 && HAVE_DIGEST_HMAC + help + By default, barebox will generate random Ethernet addresses for + interfaces that had no explicit Ethernet address set via + either board code or NVMEM properties in device tree. + + Say y here, to randomize Ethernet addresses only if no machine ID + is available. Should barebox have a machine ID, it will be used + alonside the hostname to generate MAC addresses that are unlikely + to change between subsequent runs of barebox. + + This is not recommended for use in production as it may leak + information about the machine ID. + config NET_NFS bool prompt "nfs support" diff --git a/net/eth.c b/net/eth.c index ccac5e2a6488..e74c00e74a9a 100644 --- a/net/eth.c +++ b/net/eth.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -558,6 +559,7 @@ static int of_populate_ethaddr(void) { char str[sizeof("xx:xx:xx:xx:xx:xx")]; struct eth_device *edev; + bool generated = false; int ret; list_for_each_entry(edev, &netdev_list, list) { @@ -566,11 +568,18 @@ static int of_populate_ethaddr(void) ret = of_get_mac_addr_nvmem(edev->parent->of_node, edev->ethaddr); + if (ret && IS_ENABLED(CONFIG_NET_ETHADDR_FROM_MACHINE_ID)) { + ret = generate_ether_addr(edev->ethaddr, edev->dev.id); + generated = true; + } if (ret) continue; ethaddr_to_string(edev->ethaddr, str); - dev_info(&edev->dev, "Got preset MAC address from device tree: %s\n", str); + if (generated) + dev_notice(&edev->dev, "Generated MAC address from unique id: %s\n", str); + else + dev_info(&edev->dev, "Got preset MAC address from NVMEM: %s\n", str); eth_set_ethaddr(edev, edev->ethaddr); } diff --git a/net/net.c b/net/net.c index bf2117ff7ec2..e38179491d7a 100644 --- a/net/net.c +++ b/net/net.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -365,6 +366,43 @@ IPaddr_t net_get_gateway(void) static LIST_HEAD(connection_list); +/** + * generate_ether_addr - Generates stable software assigned Ethernet address + * @addr: Pointer to a six-byte array to contain the Ethernet address + * @ethid: index of the Ethernet interface + * + * Derives an Ethernet address (MAC) from the machine ID, that's stable + * per board that is not multicast and has the local assigned bit set. + * + * Return 0 if an address could be generated or a negative error code otherwise. + */ +int generate_ether_addr(u8 *ethaddr, int ethid) +{ + const char *hostname; + uuid_t id; + int ret; + + if (!IS_ENABLED(CONFIG_NET_ETHADDR_FROM_MACHINE_ID)) + return -ENOSYS; + + hostname = barebox_get_hostname(); + if (!hostname) + return -EINVAL; + + ret = machine_id_get_app_specific(&id, ARRAY_AND_SIZE("barebox-macaddr:"), + hostname, strlen(hostname), NULL); + if (ret) + return ret; + + memcpy(ethaddr, &id.b, ETH_ALEN); + eth_addr_add(ethaddr, ethid); + + ethaddr[0] &= 0xfe; /* clear multicast bit */ + ethaddr[0] |= 0x02; /* set local assignment bit (IEEE802) */ + + return 0; +} + static struct net_connection *net_new(struct eth_device *edev, IPaddr_t dest, rx_handler_f *handler, void *ctx) { @@ -381,9 +419,16 @@ static struct net_connection *net_new(struct eth_device *edev, IPaddr_t dest, if (!is_valid_ether_addr(edev->ethaddr)) { char str[sizeof("xx:xx:xx:xx:xx:xx")]; - random_ether_addr(edev->ethaddr); + + ret = generate_ether_addr(edev->ethaddr, edev->dev.id); + if (ret) + random_ether_addr(edev->ethaddr); + ethaddr_to_string(edev->ethaddr, str); - dev_warn(&edev->dev, "No MAC address set. Using random address %s\n", str); + + dev_warn(&edev->dev, "No MAC address set. Using %s %s\n", + ret == 1 ? "address computed from unique ID" : "random address", + str); eth_set_ethaddr(edev, edev->ethaddr); } -- 2.39.2