[NET]: random functions can use nsec resolution instead of usec

In order to get more randomness for secure_tcpv6_sequence_number(),
secure_tcp_sequence_number(), secure_dccp_sequence_number() functions,
we can use the high resolution time services, providing nanosec
resolution.

I've also done two kmalloc()/kzalloc() conversions.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 23 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 03af50f900d..46c1b97748b 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -881,15 +881,15 @@ EXPORT_SYMBOL(get_random_bytes);
  */
 static void init_std_data(struct entropy_store *r)
 {
-        struct timeval tv;
+        ktime_t now;
         unsigned long flags;
 
         spin_lock_irqsave(&r->lock, flags);
         r->entropy_count = 0;
         spin_unlock_irqrestore(&r->lock, flags);
 
-        do_gettimeofday(&tv);
-        add_entropy_words(r, (__u32 *)&tv, sizeof(tv)/4);
+        now = ktime_get_real();
+        add_entropy_words(r, (__u32 *)&now, sizeof(now)/4);
         add_entropy_words(r, (__u32 *)utsname(),
                           sizeof(*(utsname()))/4);
 }
@@ -911,14 +911,12 @@ void rand_initialize_irq(int irq)
                 return;
 
         /*
-         * If kmalloc returns null, we just won't use that entropy
+         * If kzalloc returns null, we just won't use that entropy
          * source.
          */
-        state = kmalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
-        if (state) {
-                memset(state, 0, sizeof(struct timer_rand_state));
+        state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
+        if (state)
                 irq_timer_state[irq] = state;
-        }
 }
 
 #ifdef CONFIG_BLOCK
@@ -927,14 +925,12 @@ void rand_initialize_disk(struct gendisk *disk)
         struct timer_rand_state *state;
 
         /*
-         * If kmalloc returns null, we just won't use that entropy
+         * If kzalloc returns null, we just won't use that entropy
          * source.
          */
-        state = kmalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
-        if (state) {
-                memset(state, 0, sizeof(struct timer_rand_state));
+        state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
+        if (state)
                 disk->random = state;
-        }
 }
 #endif
 
@@ -1469,7 +1465,6 @@ late_initcall(seqgen_init);
 __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
                                    __be16 sport, __be16 dport)
 {
-        struct timeval tv;
         __u32 seq;
         __u32 hash[12];
         struct keydata *keyptr = get_keyptr();
@@ -1485,8 +1480,7 @@ __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
         seq = twothirdsMD4Transform((const __u32 *)daddr, hash) & HASH_MASK;
         seq += keyptr->count;
 
-        do_gettimeofday(&tv);
-        seq += tv.tv_usec + tv.tv_sec * 1000000;
+        seq += ktime_get_real().tv64;
 
         return seq;
 }
@@ -1521,7 +1515,6 @@ __u32 secure_ip_id(__be32 daddr)
 __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
                                  __be16 sport, __be16 dport)
 {
-        struct timeval tv;
         __u32 seq;
         __u32 hash[4];
         struct keydata *keyptr = get_keyptr();
@@ -1543,12 +1536,11 @@ __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
          *      As close as possible to RFC 793, which
          *      suggests using a 250 kHz clock.
          *      Further reading shows this assumes 2 Mb/s networks.
-         *      For 10 Mb/s Ethernet, a 1 MHz clock is appropriate.
+         *      For 10 Gb/s Ethernet, a 1 GHz clock is appropriate.
          *      That's funny, Linux has one built in!  Use it!
          *      (Networks are faster now - should this be increased?)
          */
-        do_gettimeofday(&tv);
-        seq += tv.tv_usec + tv.tv_sec * 1000000;
+        seq += ktime_get_real().tv64;
 #if 0
         printk("init_seq(%lx, %lx, %d, %d) = %d\n",
                saddr, daddr, sport, dport, seq);
@@ -1596,7 +1588,6 @@ u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, __be16
 u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
                                 __be16 sport, __be16 dport)
 {
-        struct timeval tv;
         u64 seq;
         __u32 hash[4];
         struct keydata *keyptr = get_keyptr();
@@ -1609,8 +1600,7 @@ u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
         seq = half_md4_transform(hash, keyptr->secret);
         seq |= ((u64)keyptr->count) << (32 - HASH_BITS);
 
-        do_gettimeofday(&tv);
-        seq += tv.tv_usec + tv.tv_sec * 1000000;
+        seq += ktime_get_real().tv64;
         seq &= (1ull << 48) - 1;
 #if 0
         printk("dccp init_seq(%lx, %lx, %d, %d) = %d\n",