[RANDOM]: Introduce secure_dccp_sequence_number

Code contributed by Stephen Hemminger.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 6b11d6b2129f08cb9a800292f05f409e0b70835d..7999da25fe40afb035c4342cd1f227f0b4d21078 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1589,6 +1589,40 @@ u32 secure_tcpv6_port_ephemeral(const __u32 *saddr, const __u32 *daddr, __u16 dp
 EXPORT_SYMBOL(secure_tcpv6_port_ephemeral);
 #endif
 
+#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
+/* Similar to secure_tcp_sequence_number but generate a 48 bit value
+ * bit's 32-47 increase every key exchange
+ *       0-31  hash(source, dest)
+ */
+u64 secure_dccp_sequence_number(__u32 saddr, __u32 daddr,
+                               __u16 sport, __u16 dport)
+{
+       struct timeval tv;
+       u64 seq;
+       __u32 hash[4];
+       struct keydata *keyptr = get_keyptr();
+
+       hash[0] = saddr;
+       hash[1] = daddr;
+       hash[2] = (sport << 16) + dport;
+       hash[3] = keyptr->secret[11];
+
+       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 &= (1ull << 48) - 1;
+#if 0
+       printk("dccp init_seq(%lx, %lx, %d, %d) = %d\n",
+              saddr, daddr, sport, dport, seq);
+#endif
+       return seq;
+}
+
+EXPORT_SYMBOL(secure_dccp_sequence_number);
+#endif
+
 #endif /* CONFIG_INET */
 
 

diff --git a/include/linux/random.h b/include/linux/random.h
index cc670344991606d5d23f94c8f23068528b951f51..7b2adb3322d5a6052504058e152cc0f94828c06e 100644 (file)
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -59,6 +59,8 @@ extern __u32 secure_tcp_sequence_number(__u32 saddr, __u32 daddr,
                                        __u16 sport, __u16 dport);
 extern __u32 secure_tcpv6_sequence_number(__u32 *saddr, __u32 *daddr,
                                          __u16 sport, __u16 dport);
+extern u64 secure_dccp_sequence_number(__u32 saddr, __u32 daddr,
+                                      __u16 sport, __u16 dport);
 
 #ifndef MODULE
 extern struct file_operations random_fops, urandom_fops;