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;
 }