openwrt/target/linux/uml/patches-5.15/102-pseudo-random-mac.patch
John Audia dee4e7b40c kernel: bump 5.15 to 5.15.132
Changelog: https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.132

Removed upstreamed:
	bcm53xx/patches-5.15/037-v6.6-0006-ARM-dts-BCM53573-Add-cells-sizes-to-PCIe-node.patch[1]
	bcm53xx/patches-5.15/037-v6.6-0007-ARM-dts-BCM53573-Use-updated-spi-gpio-binding-proper.patch[2]
	bcm53xx/patches-5.15/037-v6.6-0008-ARM-dts-BCM5301X-Extend-RAM-to-full-256MB-for-Linksy.patch[3]

All other patches automatically rebased.

1. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.15.132&id=b35f3ca1877e024887df205ede952863d65dad36
2. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.15.132&id=2840d9b9c8750be270fb1153ccd5b983cbb5d592
3. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.15.132&id=f086e859ddc252c32f0438edff241859c0f022ce

Build system: x86_64
Build-tested: ramips/tplink_archer-a6-v3
Run-tested: ramips/tplink_archer-a6-v3

Signed-off-by: John Audia <therealgraysky@proton.me>
(cherry picked from commit ac422c9788)
[Refresh on top of OpenWrt 23.05]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2023-09-25 23:04:37 +02:00

152 lines
4.1 KiB
Diff

===============================================================================
This patch makes MAC addresses of network interfaces predictable. In
particular, it adds a small routine that computes MAC addresses of based on
a SHA1 hash of the virtual machine name and interface ID.
TECHNICAL INFORMATION:
Applies to vanilla kernel 3.9.4.
===============================================================================
--- a/arch/um/drivers/Kconfig
+++ b/arch/um/drivers/Kconfig
@@ -136,6 +136,20 @@ config UML_NET
enable at least one of the following transport options to actually
make use of UML networking.
+config UML_NET_DETERMINISTIC_MAC
+ bool "Use deterministic MAC addresses for network interfaces"
+ default y
+ depends on UML_NET
+ select CRYPTO_SHA1
+ help
+ Virtual network devices inside a User-Mode Linux instance must be
+ assigned a MAC (Ethernet) address. If none is specified on the UML
+ command line, one must be automatically computed. If this option is
+ enabled, a randomly generated address is used. Otherwise, if this
+ option is disabled, the address is generated from a SHA1 hash of
+ the umid of the UML instance and the interface name. The latter choice
+ is useful to make MAC addresses predictable.
+
config UML_NET_ETHERTAP
bool "Ethertap transport (obsolete)"
depends on UML_NET
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -25,6 +25,14 @@
#include <net_kern.h>
#include <net_user.h>
+#include <crypto/sha1.h>
+#include <crypto/hash.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/scatterlist.h>
+#include "os.h"
+
#define DRIVER_NAME "uml-netdev"
static DEFINE_SPINLOCK(opened_lock);
@@ -274,9 +282,55 @@ static const struct ethtool_ops uml_net_
.get_ts_info = ethtool_op_get_ts_info,
};
+#ifdef CONFIG_UML_NET_DETERMINISTIC_MAC
+
+/* Compute a SHA1 hash of the UML instance's id and
+ * * an interface name. */
+static int compute_hash(const char *umid, const char *ifname, char *hash)
+{
+ struct ahash_request *desc = NULL;
+ struct crypto_ahash *tfm = NULL;
+ struct scatterlist sg;
+ char *vmif = NULL;
+ int ret = -ENOMEM;
+
+ vmif = kmalloc(1024, GFP_KERNEL);
+ if (!vmif)
+ goto out;
+
+ strcpy (vmif, umid);
+ strcat (vmif, ifname);
+
+ tfm = crypto_alloc_ahash("sha1", 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(tfm))
+ goto out;
+
+ desc = ahash_request_alloc(tfm, GFP_KERNEL);
+ if (!desc)
+ goto out;
+
+ crypto_ahash_clear_flags(tfm, ~0);
+
+ sg_init_table(&sg, 1);
+ sg_set_buf(&sg, vmif, strlen(vmif));
+
+ ahash_request_set_crypt(desc, &sg, hash, strlen(vmif));
+
+ ret = crypto_ahash_digest(desc);
+out:
+ crypto_free_ahash(tfm);
+ ahash_request_free(desc);
+ kfree(vmif);
+
+ return ret;
+}
+
+#endif
+
void uml_net_setup_etheraddr(struct net_device *dev, char *str)
{
unsigned char *addr = dev->dev_addr;
+ u8 hash[SHA1_DIGEST_SIZE];
char *end;
int i;
@@ -319,9 +373,26 @@ void uml_net_setup_etheraddr(struct net_
return;
random:
+#ifndef CONFIG_UML_NET_DETERMINISTIC_MAC
printk(KERN_INFO
"Choosing a random ethernet address for device %s\n", dev->name);
eth_hw_addr_random(dev);
+#else
+ printk(KERN_INFO
+ "Computing a digest to use as ethernet address for device %s\n", dev->name);
+ if (compute_hash(get_umid(), dev->name, hash) < 0) {
+ printk(KERN_WARNING
+ "Could not compute digest to use as ethernet address for device %s. "
+ "Using random address instead.\n", dev->name);
+ random_ether_addr(addr);
+ }
+ else {
+ for (i=0; i < 6; i++)
+ addr[i] = (hash[i] + hash[i+6]) % 0x100;
+ }
+ addr [0] &= 0xfe; /* clear multicast bit */
+ addr [0] |= 0x02; /* set local assignment bit (IEEE802) */
+#endif
}
static DEFINE_SPINLOCK(devices_lock);
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -356,12 +356,12 @@ static void helper_unlock(void)
}
int call_usermodehelper_stdoutpipe(struct subprocess_info *sub_info,
- struct file **filp)
+ struct file **filp)
{
struct file *f[2];
if (create_pipe_files(f, 0) < 0)
- return PTR_ERR(f);
+ return PTR_ERR(f);
sub_info->stdout = f[1];
*filp = f[0];