[XFRM] IPV6: Add sort functions to combine templates/states for IPsec.

Add sort functions to combine templates/states for IPsec.
Think of outbound transformation order we should be careful with transport AH
which must be the last of all transport ones.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 97 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_state.c b/net/ipv6/xfrm6_state.c
index 9c95b9d3e110..e0b8f3c5caa2 100644
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -156,12 +156,109 @@ __xfrm6_find_acq(u8 mode, u32 reqid, u8 proto,
         return x0;
 }
 
+static int
+__xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
+{
+        int i;
+        int j = 0;
+
+        /* Rule 1: select IPsec transport except AH */
+        for (i = 0; i < n; i++) {
+                if (src[i]->props.mode == XFRM_MODE_TRANSPORT &&
+                    src[i]->id.proto != IPPROTO_AH) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+        if (j == n)
+                goto end;
+
+        /* XXX: Rule 2: select MIPv6 RO or inbound trigger */
+
+        /* Rule 3: select IPsec transport AH */
+        for (i = 0; i < n; i++) {
+                if (src[i] &&
+                    src[i]->props.mode == XFRM_MODE_TRANSPORT &&
+                    src[i]->id.proto == IPPROTO_AH) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+        if (j == n)
+                goto end;
+
+        /* Rule 4: select IPsec tunnel */
+        for (i = 0; i < n; i++) {
+                if (src[i] &&
+                    src[i]->props.mode == XFRM_MODE_TUNNEL) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+        if (likely(j == n))
+                goto end;
+
+        /* Final rule */
+        for (i = 0; i < n; i++) {
+                if (src[i]) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+
+ end:
+        return 0;
+}
+
+static int
+__xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
+{
+        int i;
+        int j = 0;
+
+        /* Rule 1: select IPsec transport */
+        for (i = 0; i < n; i++) {
+                if (src[i]->mode == XFRM_MODE_TRANSPORT) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+        if (j == n)
+                goto end;
+
+        /* XXX: Rule 2: select MIPv6 RO or inbound trigger */
+
+        /* Rule 3: select IPsec tunnel */
+        for (i = 0; i < n; i++) {
+                if (src[i] &&
+                    src[i]->mode == XFRM_MODE_TUNNEL) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+        if (likely(j == n))
+                goto end;
+
+        /* Final rule */
+        for (i = 0; i < n; i++) {
+                if (src[i]) {
+                        dst[j++] = src[i];
+                        src[i] = NULL;
+                }
+        }
+
+ end:
+        return 0;
+}
+
 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
         .family                 = AF_INET6,
         .init_tempsel           = __xfrm6_init_tempsel,
         .state_lookup           = __xfrm6_state_lookup,
         .state_lookup_byaddr    = __xfrm6_state_lookup_byaddr,
         .find_acq               = __xfrm6_find_acq,
+        .tmpl_sort              = __xfrm6_tmpl_sort,
+        .state_sort             = __xfrm6_state_sort,
 };
 
 void __init xfrm6_state_init(void)