[PATCH net-next 2/2] afs: Use core kernel UUID generation

From: David Howells
Date: Fri Feb 10 2017 - 11:48:40 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

AFS uses a time based UUID to identify the host itself. This requires
getting a timestamp which is currently done through the getnstimeofday()
interface that we want to eventually get rid of.

Instead of replacing it with a ktime-based interface, simply remove the
entire function and use generate_random_uuid() instead, which has a v4
("completely random") UUID instead of the time-based one.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/afs/internal.h | 11 +++++------
fs/afs/main.c | 48 +-----------------------------------------------
fs/afs/netdevices.c | 21 ---------------------
3 files changed, 6 insertions(+), 74 deletions(-)

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 79061fa17168..8acf3670e756 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -561,6 +561,11 @@ extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
extern void afs_mntpt_kill_timer(void);

/*
+ * netdevices.c
+ */
+extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);
+
+/*
* proc.c
*/
extern int afs_proc_init(void);
@@ -624,12 +629,6 @@ extern int afs_fs_init(void);
extern void afs_fs_exit(void);

/*
- * use-rtnetlink.c
- */
-extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);
-extern int afs_get_MAC_address(u8 *, size_t);
-
-/*
* vlclient.c
*/
extern int afs_vl_get_entry_by_name(struct in_addr *, struct key *,
diff --git a/fs/afs/main.c b/fs/afs/main.c
index a07c14df3fd1..51d7d17bca57 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -35,50 +35,6 @@ struct uuid_v1 afs_uuid;
struct workqueue_struct *afs_wq;

/*
- * get a client UUID
- */
-static int __init afs_get_client_UUID(void)
-{
- struct timespec ts;
- u64 uuidtime;
- u16 clockseq, hi_v;
- int ret;
-
- /* read the MAC address of one of the external interfaces and construct
- * a UUID from it */
- ret = afs_get_MAC_address(afs_uuid.node, sizeof(afs_uuid.node));
- if (ret < 0)
- return ret;
-
- getnstimeofday(&ts);
- uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10;
- uuidtime += ts.tv_nsec / 100;
- uuidtime += UUID_TO_UNIX_TIME;
- afs_uuid.time_low = htonl(uuidtime);
- afs_uuid.time_mid = htons(uuidtime >> 32);
- hi_v = (uuidtime >> 48) & UUID_TIMEHI_MASK;
- hi_v |= UUID_VERSION_TIME;
- afs_uuid.time_hi_and_version = htons(hi_v);
-
- get_random_bytes(&clockseq, 2);
- afs_uuid.clock_seq_low = clockseq;
- afs_uuid.clock_seq_hi_and_reserved =
- (clockseq >> 8) & UUID_CLOCKHI_MASK;
- afs_uuid.clock_seq_hi_and_reserved |= UUID_VARIANT_STD;
-
- _debug("AFS UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
- ntohl(afs_uuid.time_low),
- ntohs(afs_uuid.time_mid),
- ntohs(afs_uuid.time_hi_and_version),
- afs_uuid.clock_seq_hi_and_reserved,
- afs_uuid.clock_seq_low,
- afs_uuid.node[0], afs_uuid.node[1], afs_uuid.node[2],
- afs_uuid.node[3], afs_uuid.node[4], afs_uuid.node[5]);
-
- return 0;
-}
-
-/*
* initialise the AFS client FS module
*/
static int __init afs_init(void)
@@ -87,9 +43,7 @@ static int __init afs_init(void)

printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n");

- ret = afs_get_client_UUID();
- if (ret < 0)
- return ret;
+ generate_random_uuid((unsigned char *)&afs_uuid);

/* create workqueue */
ret = -ENOMEM;
diff --git a/fs/afs/netdevices.c b/fs/afs/netdevices.c
index 7ad36506c256..40b2bab3e401 100644
--- a/fs/afs/netdevices.c
+++ b/fs/afs/netdevices.c
@@ -12,27 +12,6 @@
#include "internal.h"

/*
- * get a MAC address from a random ethernet interface that has a real one
- * - the buffer will normally be 6 bytes in size
- */
-int afs_get_MAC_address(u8 *mac, size_t maclen)
-{
- struct net_device *dev;
- int ret = -ENODEV;
-
- BUG_ON(maclen != ETH_ALEN);
-
- rtnl_lock();
- dev = __dev_getfirstbyhwtype(&init_net, ARPHRD_ETHER);
- if (dev) {
- memcpy(mac, dev->dev_addr, maclen);
- ret = 0;
- }
- rtnl_unlock();
- return ret;
-}
-
-/*
* get a list of this system's interface IPv4 addresses, netmasks and MTUs
* - maxbufs must be at least 1
* - returns the number of interface records in the buffer