net: sctp: sctp_auth_make_key_vector: remove duplicate ntohs calls

Instead of calling 3 times ntohs(random->param_hdr.length), 2 times
ntohs(hmacs->param_hdr.length), and 3 times ntohs(chunks->param_hdr.length)
within the same function, we only call each once and store it in a
variable.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 9 deletions

diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index 159b9bc5d633..94a12de58691 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -200,10 +200,14 @@ static struct sctp_auth_bytes *sctp_auth_make_key_vector(
         struct sctp_auth_bytes *new;
         __u32   len;
         __u32   offset = 0;
+        __u16   random_len, hmacs_len, chunks_len = 0;
 
-        len = ntohs(random->param_hdr.length) + ntohs(hmacs->param_hdr.length);
-        if (chunks)
-                len += ntohs(chunks->param_hdr.length);
+        random_len = ntohs(random->param_hdr.length);
+        hmacs_len = ntohs(hmacs->param_hdr.length);
+        if (chunks)
+                chunks_len = ntohs(chunks->param_hdr.length);
+
+        len = random_len + hmacs_len + chunks_len;
 
         new = kmalloc(sizeof(struct sctp_auth_bytes) + len, gfp);
         if (!new)
@@ -211,16 +215,15 @@ static struct sctp_auth_bytes *sctp_auth_make_key_vector(
 
         new->len = len;
 
-        memcpy(new->data, random, ntohs(random->param_hdr.length));
-        offset += ntohs(random->param_hdr.length);
+        memcpy(new->data, random, random_len);
+        offset += random_len;
 
         if (chunks) {
-                memcpy(new->data + offset, chunks,
-                        ntohs(chunks->param_hdr.length));
-                offset += ntohs(chunks->param_hdr.length);
+                memcpy(new->data + offset, chunks, chunks_len);
+                offset += chunks_len;
         }
 
-        memcpy(new->data + offset, hmacs, ntohs(hmacs->param_hdr.length));
+        memcpy(new->data + offset, hmacs, hmacs_len);
 
         return new;
 }