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>

3 files changed, 51 insertions, 16 deletions

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 {