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>

7 files changed, 154 insertions, 37 deletions

diff --git a/include/linux/pfkeyv2.h b/include/linux/pfkeyv2.h
index 700725ddcaae..01b262959f2e 100644
--- a/include/linux/pfkeyv2.h
+++ b/include/linux/pfkeyv2.h
@@ -226,6 +226,15 @@ struct sadb_x_sec_ctx {
 } __attribute__((packed));
 /* sizeof(struct sadb_sec_ctx) = 8 */
 
+/* Used by MIGRATE to pass addresses IKE will use to perform
+ * negotiation with the peer */
+struct sadb_x_kmaddress {
+        uint16_t        sadb_x_kmaddress_len;
+        uint16_t        sadb_x_kmaddress_exttype;
+        uint32_t        sadb_x_kmaddress_reserved;
+} __attribute__((packed));
+/* sizeof(struct sadb_x_kmaddress) == 8 */
+
 /* Message types */
 #define SADB_RESERVED           0
 #define SADB_GETSPI             1
@@ -346,7 +355,9 @@ struct sadb_x_sec_ctx {
 #define SADB_X_EXT_NAT_T_DPORT          22
 #define SADB_X_EXT_NAT_T_OA             23
 #define SADB_X_EXT_SEC_CTX              24
-#define SADB_EXT_MAX                    24
+/* Used with MIGRATE to pass @ to IKE for negotiation */
+#define SADB_X_EXT_KMADDRESS            25
+#define SADB_EXT_MAX                    25
 
 /* Identity Extension values */
 #define SADB_IDENTTYPE_RESERVED 0
diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index fb0c215a3051..4bc1e6b86cb2 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -279,6 +279,7 @@ enum xfrm_attr_type_t {
         XFRMA_POLICY_TYPE,      /* struct xfrm_userpolicy_type */
         XFRMA_MIGRATE,
         XFRMA_ALG_AEAD,         /* struct xfrm_algo_aead */
+        XFRMA_KMADDRESS,        /* struct xfrm_user_kmaddress */
         __XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -415,6 +416,15 @@ struct xfrm_user_report {
         struct xfrm_selector            sel;
 };
 
+/* Used by MIGRATE to pass addresses IKE should use to perform
+ * SA negotiation with the peer */
+struct xfrm_user_kmaddress {
+        xfrm_address_t                  local;
+        xfrm_address_t                  remote;
+        __u32                           reserved;
+        __u16                           family;
+};
+
 struct xfrm_user_migrate {
         xfrm_address_t                  old_daddr;
         xfrm_address_t                  old_saddr;
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index b98d2056f27f..11c890ad8ebb 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -492,6 +492,13 @@ struct xfrm_policy
         struct xfrm_tmpl        xfrm_vec[XFRM_MAX_DEPTH];
 };
 
+struct xfrm_kmaddress {
+        xfrm_address_t          local;
+        xfrm_address_t          remote;
+        u32                     reserved;
+        u16                     family;
+};
+
 struct xfrm_migrate {
         xfrm_address_t          old_daddr;
         xfrm_address_t          old_saddr;
@@ -531,7 +538,7 @@ struct xfrm_mgr
         int                     (*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
         int                     (*notify_policy)(struct xfrm_policy *x, int dir, struct km_event *c);
         int                     (*report)(u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
-        int                     (*migrate)(struct xfrm_selector *sel, u8 dir, u8 type, struct xfrm_migrate *m, int num_bundles);
+        int                     (*migrate)(struct xfrm_selector *sel, u8 dir, u8 type, struct xfrm_migrate *m, int num_bundles, struct xfrm_kmaddress *k);
 };
 
 extern int xfrm_register_km(struct xfrm_mgr *km);
@@ -1432,12 +1439,14 @@ extern int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *xdst,
 
 #ifdef CONFIG_XFRM_MIGRATE
 extern int km_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);
 extern struct xfrm_state * xfrm_migrate_state_find(struct xfrm_migrate *m);
 extern struct xfrm_state * xfrm_state_migrate(struct xfrm_state *x,
                                               struct xfrm_migrate *m);
 extern int xfrm_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);
 #endif
 
 extern wait_queue_head_t km_waitq;
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;
 }
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index b7ec08025ffb..832b47c1de80 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2679,7 +2679,8 @@ static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
 }
 
 int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-                 struct xfrm_migrate *m, int num_migrate)
+                 struct xfrm_migrate *m, int num_migrate,
+                 struct xfrm_kmaddress *k)
 {
         int i, err, nx_cur = 0, nx_new = 0;
         struct xfrm_policy *pol = NULL;
@@ -2723,7 +2724,7 @@ int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
         }
 
         /* Stage 5 - announce */
-        km_migrate(sel, dir, type, m, num_migrate);
+        km_migrate(sel, dir, type, m, num_migrate, k);
 
         xfrm_pol_put(pol);
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 747fd8c291a7..508337f97249 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1814,7 +1814,8 @@ EXPORT_SYMBOL(km_policy_expired);
 
 #ifdef CONFIG_XFRM_MIGRATE
 int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-               struct xfrm_migrate *m, int num_migrate)
+               struct xfrm_migrate *m, int num_migrate,
+               struct xfrm_kmaddress *k)
 {
         int err = -EINVAL;
         int ret;
@@ -1823,7 +1824,7 @@ int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
         read_lock(&xfrm_km_lock);
         list_for_each_entry(km, &xfrm_km_list, list) {
                 if (km->migrate) {
-                        ret = km->migrate(sel, dir, type, m, num_migrate);
+                        ret = km->migrate(sel, dir, type, m, num_migrate, k);
                         if (!ret)
                                 err = ret;
                 }
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 76f75df21e15..4a8a1abb59ee 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1710,12 +1710,23 @@ static int xfrm_add_acquire(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 #ifdef CONFIG_XFRM_MIGRATE
 static int copy_from_user_migrate(struct xfrm_migrate *ma,
+                                  struct xfrm_kmaddress *k,
                                   struct nlattr **attrs, int *num)
 {
         struct nlattr *rt = attrs[XFRMA_MIGRATE];
         struct xfrm_user_migrate *um;
         int i, num_migrate;
 
+        if (k != NULL) {
+                struct xfrm_user_kmaddress *uk;
+
+                uk = nla_data(attrs[XFRMA_KMADDRESS]);
+                memcpy(&k->local, &uk->local, sizeof(k->local));
+                memcpy(&k->remote, &uk->remote, sizeof(k->remote));
+                k->family = uk->family;
+                k->reserved = uk->reserved;
+        }
+
         um = nla_data(rt);
         num_migrate = nla_len(rt) / sizeof(*um);
 
@@ -1745,6 +1756,7 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
         struct xfrm_userpolicy_id *pi = nlmsg_data(nlh);
         struct xfrm_migrate m[XFRM_MAX_DEPTH];
+        struct xfrm_kmaddress km, *kmp;
         u8 type;
         int err;
         int n = 0;
@@ -1752,19 +1764,20 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (attrs[XFRMA_MIGRATE] == NULL)
                 return -EINVAL;
 
+        kmp = attrs[XFRMA_KMADDRESS] ? &km : NULL;
+
         err = copy_from_user_policy_type(&type, attrs);
         if (err)
                 return err;
 
-        err = copy_from_user_migrate((struct xfrm_migrate *)m,
-                                     attrs, &n);
+        err = copy_from_user_migrate((struct xfrm_migrate *)m, kmp, attrs, &n);
         if (err)
                 return err;
 
         if (!n)
                 return 0;
 
-        xfrm_migrate(&pi->sel, pi->dir, type, m, n);
+        xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp);
 
         return 0;
 }
@@ -1795,16 +1808,30 @@ static int copy_to_user_migrate(struct xfrm_migrate *m, struct sk_buff *skb)
         return nla_put(skb, XFRMA_MIGRATE, sizeof(um), &um);
 }
 
-static inline size_t xfrm_migrate_msgsize(int num_migrate)
+static int copy_to_user_kmaddress(struct xfrm_kmaddress *k, struct sk_buff *skb)
+{
+        struct xfrm_user_kmaddress uk;
+
+        memset(&uk, 0, sizeof(uk));
+        uk.family = k->family;
+        uk.reserved = k->reserved;
+        memcpy(&uk.local, &k->local, sizeof(uk.local));
+        memcpy(&uk.remote, &k->local, sizeof(uk.remote));
+
+        return nla_put(skb, XFRMA_KMADDRESS, sizeof(uk), &uk);
+}
+
+static inline size_t xfrm_migrate_msgsize(int num_migrate, int with_kma)
 {
         return NLMSG_ALIGN(sizeof(struct xfrm_userpolicy_id))
-               + nla_total_size(sizeof(struct xfrm_user_migrate) * num_migrate)
-               + userpolicy_type_attrsize();
+              + (with_kma ? nla_total_size(sizeof(struct xfrm_kmaddress)) : 0)
+              + nla_total_size(sizeof(struct xfrm_user_migrate) * num_migrate)
+              + userpolicy_type_attrsize();
 }
 
 static int build_migrate(struct sk_buff *skb, struct xfrm_migrate *m,
-                         int num_migrate, struct xfrm_selector *sel,
-                         u8 dir, u8 type)
+                         int num_migrate, struct xfrm_kmaddress *k,
+                         struct xfrm_selector *sel, u8 dir, u8 type)
 {
         struct xfrm_migrate *mp;
         struct xfrm_userpolicy_id *pol_id;
@@ -1821,6 +1848,9 @@ static int build_migrate(struct sk_buff *skb, struct xfrm_migrate *m,
         memcpy(&pol_id->sel, sel, sizeof(pol_id->sel));
         pol_id->dir = dir;
 
+        if (k != NULL && (copy_to_user_kmaddress(k, skb) < 0))
+                        goto nlmsg_failure;
+
         if (copy_to_user_policy_type(type, skb) < 0)
                 goto nlmsg_failure;
 
@@ -1836,23 +1866,25 @@ nlmsg_failure:
 }
 
 static int xfrm_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-                             struct xfrm_migrate *m, int num_migrate)
+                             struct xfrm_migrate *m, int num_migrate,
+                             struct xfrm_kmaddress *k)
 {
         struct sk_buff *skb;
 
-        skb = nlmsg_new(xfrm_migrate_msgsize(num_migrate), GFP_ATOMIC);
+        skb = nlmsg_new(xfrm_migrate_msgsize(num_migrate, !!k), GFP_ATOMIC);
         if (skb == NULL)
                 return -ENOMEM;
 
         /* build migrate */
-        if (build_migrate(skb, m, num_migrate, sel, dir, type) < 0)
+        if (build_migrate(skb, m, num_migrate, k, sel, dir, type) < 0)
                 BUG();
 
         return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_MIGRATE, GFP_ATOMIC);
 }
 #else
 static int xfrm_send_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
-                             struct xfrm_migrate *m, int num_migrate)
+                             struct xfrm_migrate *m, int num_migrate,
+                             struct xfrm_kmaddress *k)
 {
         return -ENOPROTOOPT;
 }
@@ -1901,6 +1933,7 @@ static const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
         [XFRMA_COADDR]          = { .len = sizeof(xfrm_address_t) },
         [XFRMA_POLICY_TYPE]     = { .len = sizeof(struct xfrm_userpolicy_type)},
         [XFRMA_MIGRATE]         = { .len = sizeof(struct xfrm_user_migrate) },
+        [XFRMA_KMADDRESS]       = { .len = sizeof(struct xfrm_user_kmaddress) },
 };
 
 static struct xfrm_link {