xfrm: MIGRATE enhancements (draft-ebalard-mext-pfkey-enhanced-migrate)

Provides implementation of the enhancements of XFRM/PF_KEY MIGRATE mechanism
specified in draft-ebalard-mext-pfkey-enhanced-migrate-00. Defines associated
PF_KEY SADB_X_EXT_KMADDRESS extension and XFRM/netlink XFRMA_KMADDRESS
attribute.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 17 deletions

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 7ae641df70bd..362fe317e1f3 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -398,6 +398,7 @@ static u8 sadb_ext_min_len[] = {
         [SADB_X_EXT_NAT_T_DPORT]        = (u8) sizeof(struct sadb_x_nat_t_port),
         [SADB_X_EXT_NAT_T_OA]           = (u8) sizeof(struct sadb_address),
         [SADB_X_EXT_SEC_CTX]            = (u8) sizeof(struct sadb_x_sec_ctx),
+        [SADB_X_EXT_KMADDRESS]          = (u8) sizeof(struct sadb_x_kmaddress),
 };
 
 /* Verify sadb_address_{len,prefixlen} against sa_family.  */
@@ -2384,24 +2385,21 @@ static int pfkey_sockaddr_pair_size(sa_family_t family)
         return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
 }
 
-static int parse_sockaddr_pair(struct sadb_x_ipsecrequest *rq,
+static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
                                xfrm_address_t *saddr, xfrm_address_t *daddr,
                                u16 *family)
 {
-        u8 *sa = (u8 *) (rq + 1);
         int af, socklen;
 
-        if (rq->sadb_x_ipsecrequest_len <
-            pfkey_sockaddr_pair_size(((struct sockaddr *)sa)->sa_family))
+        if (ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
                 return -EINVAL;
 
-        af = pfkey_sockaddr_extract((struct sockaddr *) sa,
-                                    saddr);
+        af = pfkey_sockaddr_extract(sa, saddr);
         if (!af)
                 return -EINVAL;
 
         socklen = pfkey_sockaddr_len(af);
-        if (pfkey_sockaddr_extract((struct sockaddr *) (sa + socklen),
+        if (pfkey_sockaddr_extract((struct sockaddr *) (((u8 *)sa) + socklen),
                                    daddr) != af)
                 return -EINVAL;
 
@@ -2421,7 +2419,9 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
                 return -EINVAL;
 
         /* old endoints */
-        err = parse_sockaddr_pair(rq1, &m->old_saddr, &m->old_daddr,
+        err = parse_sockaddr_pair((struct sockaddr *)(rq1 + 1),
+                                  rq1->sadb_x_ipsecrequest_len,
+                                  &m->old_saddr, &m->old_daddr,
                                   &m->old_family);
         if (err)
                 return err;
@@ -2434,7 +2434,9 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
                 return -EINVAL;
 
         /* new endpoints */
-        err = parse_sockaddr_pair(rq2, &m->new_saddr, &m->new_daddr,
+        err = parse_sockaddr_pair((struct sockaddr *)(rq2 + 1),
+                                  rq2->sadb_x_ipsecrequest_len,
+                                  &m->new_saddr, &m->new_daddr,
                                   &m->new_family);
         if (err)
                 return err;
@@ -2460,29 +2462,40 @@ static int pfkey_migrate(struct sock *sk, struct sk_buff *skb,
         int i, len, ret, err = -EINVAL;
         u8 dir;
         struct sadb_address *sa;
+        struct sadb_x_kmaddress *kma;
         struct sadb_x_policy *pol;
         struct sadb_x_ipsecrequest *rq;
         struct xfrm_selector sel;
         struct xfrm_migrate m[XFRM_MAX_DEPTH];
+        struct xfrm_kmaddress k;
 
         if (!present_and_same_family(ext_hdrs[SADB_EXT_ADDRESS_SRC - 1],
-            ext_hdrs[SADB_EXT_ADDRESS_DST - 1]) ||
+                                     ext_hdrs[SADB_EXT_ADDRESS_DST - 1]) ||
             !ext_hdrs[SADB_X_EXT_POLICY - 1]) {
                 err = -EINVAL;
                 goto out;
         }
 
+        kma = ext_hdrs[SADB_X_EXT_KMADDRESS - 1];
         pol = ext_hdrs[SADB_X_EXT_POLICY - 1];
-        if (!pol) {
-                err = -EINVAL;
-                goto out;
-        }
 
         if (pol->sadb_x_policy_dir >= IPSEC_DIR_MAX) {
                 err = -EINVAL;
                 goto out;
         }
 
+        if (kma) {
+                /* convert sadb_x_kmaddress to xfrm_kmaddress */
+                k.reserved = kma->sadb_x_kmaddress_reserved;
+                ret = parse_sockaddr_pair((struct sockaddr *)(kma + 1),
+                                          8*(kma->sadb_x_kmaddress_len) - sizeof(*kma),
+                                          &k.local, &k.remote, &k.family);
+                if (ret < 0) {
+                        err = ret;
+                        goto out;
+                }
+        }
+
         dir = pol->sadb_x_policy_dir - 1;
         memset(&sel, 0, sizeof(sel));
 
@@ -2527,7 +2540,8 @@ static int pfkey_migrate(struct sock *sk, struct sk_buff *skb,
                 goto out;
         }
 
-        return xfrm_migrate(&sel, dir, XFRM_POLICY_TYPE_MAIN, m, i);
+        return xfrm_migrate(&sel, dir, XFRM_POLICY_TYPE_MAIN, m, i,
+                            kma ? &k : NULL);
 
  out:
         return err;
@@ -3319,6 +3333,32 @@ static int set_sadb_address(struct sk_buff *skb, int sasize, int type,
         return 0;
 }
 
+
+static int set_sadb_kmaddress(struct sk_buff *skb, struct xfrm_kmaddress *k)
+{
+        struct sadb_x_kmaddress *kma;
+        u8 *sa;
+        int family = k->family;
+        int socklen = pfkey_sockaddr_len(family);
+        int size_req;
+
+        size_req = (sizeof(struct sadb_x_kmaddress) +
+                    pfkey_sockaddr_pair_size(family));
+
+        kma = (struct sadb_x_kmaddress *)skb_put(skb, size_req);
+        memset(kma, 0, size_req);
+        kma->sadb_x_kmaddress_len = size_req / 8;
+        kma->sadb_x_kmaddress_exttype = SADB_X_EXT_KMADDRESS;
+        kma->sadb_x_kmaddress_reserved = k->reserved;
+
+        sa = (u8 *)(kma + 1);
+        if (!pfkey_sockaddr_fill(&k->local, 0, (struct sockaddr *)sa, family) ||
+            !pfkey_sockaddr_fill(&k->remote, 0, (struct sockaddr *)(sa+socklen), family))
+                return -EINVAL;
+
+        return 0;
+}
+
 static int set_ipsecrequest(struct sk_buff *skb,
                             uint8_t proto, uint8_t mode, int level,
                             uint32_t reqid, uint8_t family,
@@ -3351,7 +3391,8 @@ static int set_ipsecrequest(struct sk_buff *skb,
 
 #ifdef CONFIG_NET_KEY_MIGRATE
 static int pfkey_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-                              struct xfrm_migrate *m, int num_bundles)
+                              struct xfrm_migrate *m, int num_bundles,
+                              struct xfrm_kmaddress *k)
 {
         int i;
         int sasize_sel;
@@ -3368,6 +3409,12 @@ static int pfkey_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
         if (num_bundles <= 0 || num_bundles > XFRM_MAX_DEPTH)
                 return -EINVAL;
 
+        if (k != NULL) {
+                /* addresses for KM */
+                size += PFKEY_ALIGN8(sizeof(struct sadb_x_kmaddress) +
+                                     pfkey_sockaddr_pair_size(k->family));
+        }
+
         /* selector */
         sasize_sel = pfkey_sockaddr_size(sel->family);
         if (!sasize_sel)
@@ -3404,6 +3451,10 @@ static int pfkey_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
         hdr->sadb_msg_seq = 0;
         hdr->sadb_msg_pid = 0;
 
+        /* Addresses to be used by KM for negotiation, if ext is available */
+        if (k != NULL && (set_sadb_kmaddress(skb, k) < 0))
+                return -EINVAL;
+
         /* selector src */
         set_sadb_address(skb, sasize_sel, SADB_EXT_ADDRESS_SRC, sel);
 
@@ -3449,7 +3500,8 @@ err:
 }
 #else
 static int pfkey_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-                              struct xfrm_migrate *m, int num_bundles)
+                              struct xfrm_migrate *m, int num_bundles,
+                              struct xfrm_kmaddress *k)
 {
         return -ENOPROTOOPT;
 }