4 files changed, 467 insertions, 0 deletions

diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 9529ea1ae392..15ca89e9961b 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -178,6 +178,9 @@ enum {
         XFRM_MSG_REPORT,
 #define XFRM_MSG_REPORT XFRM_MSG_REPORT
 
+        XFRM_MSG_MIGRATE,
+#define XFRM_MSG_MIGRATE XFRM_MSG_MIGRATE
+
         __XFRM_MSG_MAX
 };
 #define XFRM_MSG_MAX (__XFRM_MSG_MAX - 1)
@@ -256,6 +259,7 @@ enum xfrm_attr_type_t {
         XFRMA_COADDR,           /* xfrm_address_t */
         XFRMA_LASTUSED,
         XFRMA_POLICY_TYPE,      /* struct xfrm_userpolicy_type */
+        XFRMA_MIGRATE,
         __XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -351,6 +355,19 @@ struct xfrm_user_report {
         struct xfrm_selector            sel;
 };
 
+struct xfrm_user_migrate {
+        xfrm_address_t                  old_daddr;
+        xfrm_address_t                  old_saddr;
+        xfrm_address_t                  new_daddr;
+        xfrm_address_t                  new_saddr;
+        __u8                            proto;
+        __u8                            mode;
+        __u16                           reserved;
+        __u32                           reqid;
+        __u16                           old_family;
+        __u16                           new_family;
+};
+
 #ifndef __KERNEL__
 /* backwards compatibility for userspace */
 #define XFRMGRP_ACQUIRE         1
@@ -375,6 +392,8 @@ enum xfrm_nlgroups {
 #define XFRMNLGRP_AEVENTS       XFRMNLGRP_AEVENTS
         XFRMNLGRP_REPORT,
 #define XFRMNLGRP_REPORT        XFRMNLGRP_REPORT
+        XFRMNLGRP_MIGRATE,
+#define XFRMNLGRP_MIGRATE       XFRMNLGRP_MIGRATE
         __XFRMNLGRP_MAX
 };
 #define XFRMNLGRP_MAX   (__XFRMNLGRP_MAX - 1)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index bf91d632901d..16924cb772c9 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -362,6 +362,19 @@ struct xfrm_policy
         struct xfrm_tmpl        xfrm_vec[XFRM_MAX_DEPTH];
 };
 
+struct xfrm_migrate {
+        xfrm_address_t          old_daddr;
+        xfrm_address_t          old_saddr;
+        xfrm_address_t          new_daddr;
+        xfrm_address_t          new_saddr;
+        u8                      proto;
+        u8                      mode;
+        u16                     reserved;
+        u32                     reqid;
+        u16                     old_family;
+        u16                     new_family;
+};
+
 #define XFRM_KM_TIMEOUT                30
 /* which seqno */
 #define XFRM_REPLAY_SEQ         1
@@ -388,6 +401,7 @@ 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);
 };
 
 extern int xfrm_register_km(struct xfrm_mgr *km);
@@ -988,6 +1002,16 @@ extern int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *xdst,
                           struct flowi *fl, int family, int strict);
 extern void xfrm_init_pmtu(struct dst_entry *dst);
 
+#ifdef CONFIG_XFRM_MIGRATE
+extern int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
+                      struct xfrm_migrate *m, int num_bundles);
+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);
+#endif
+
 extern wait_queue_head_t km_waitq;
 extern int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
 extern void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 pid);
@@ -1053,5 +1077,25 @@ static inline void xfrm_aevent_doreplay(struct xfrm_state *x)
                 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
 }
 
+#ifdef CONFIG_XFRM_MIGRATE
+static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
+{
+        return (struct xfrm_algo *)kmemdup(orig, sizeof(*orig) + orig->alg_key_len, GFP_KERNEL);
+}
+
+static inline void xfrm_states_put(struct xfrm_state **states, int n)
+{
+        int i;
+        for (i = 0; i < n; i++)
+                xfrm_state_put(*(states + i));
+}
+
+static inline void xfrm_states_delete(struct xfrm_state **states, int n)
+{
+        int i;
+        for (i = 0; i < n; i++)
+                xfrm_state_delete(*(states + i));
+}
+#endif
 
 #endif  /* _NET_XFRM_H */
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index b7e537fe2d75..825c60af7723 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2236,3 +2236,233 @@ void __init xfrm_init(void)
         xfrm_input_init();
 }
 
+#ifdef CONFIG_XFRM_MIGRATE
+static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
+                                       struct xfrm_selector *sel_tgt)
+{
+        if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
+                if (sel_tgt->family == sel_cmp->family &&
+                    xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
+                                  sel_cmp->family) == 0 &&
+                    xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
+                                  sel_cmp->family) == 0 &&
+                    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
+                    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
+                        return 1;
+                }
+        } else {
+                if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
+                        return 1;
+                }
+        }
+        return 0;
+}
+
+static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
+                                                     u8 dir, u8 type)
+{
+        struct xfrm_policy *pol, *ret = NULL;
+        struct hlist_node *entry;
+        struct hlist_head *chain;
+        u32 priority = ~0U;
+
+        read_lock_bh(&xfrm_policy_lock);
+        chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
+        hlist_for_each_entry(pol, entry, chain, bydst) {
+                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
+                    pol->type == type) {
+                        ret = pol;
+                        priority = ret->priority;
+                        break;
+                }
+        }
+        chain = &xfrm_policy_inexact[dir];
+        hlist_for_each_entry(pol, entry, chain, bydst) {
+                if (xfrm_migrate_selector_match(sel, &pol->selector) &&
+                    pol->type == type &&
+                    pol->priority < priority) {
+                        ret = pol;
+                        break;
+                }
+        }
+
+        if (ret)
+                xfrm_pol_hold(ret);
+
+        read_unlock_bh(&xfrm_policy_lock);
+
+        return ret;
+}
+
+static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
+{
+        int match = 0;
+
+        if (t->mode == m->mode && t->id.proto == m->proto &&
+            (m->reqid == 0 || t->reqid == m->reqid)) {
+                switch (t->mode) {
+                case XFRM_MODE_TUNNEL:
+                case XFRM_MODE_BEET:
+                        if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
+                                          m->old_family) == 0 &&
+                            xfrm_addr_cmp(&t->saddr, &m->old_saddr,
+                                          m->old_family) == 0) {
+                                match = 1;
+                        }
+                        break;
+                case XFRM_MODE_TRANSPORT:
+                        /* in case of transport mode, template does not store
+                           any IP addresses, hence we just compare mode and
+                           protocol */
+                        match = 1;
+                        break;
+                default:
+                        break;
+                }
+        }
+        return match;
+}
+
+/* update endpoint address(es) of template(s) */
+static int xfrm_policy_migrate(struct xfrm_policy *pol,
+                               struct xfrm_migrate *m, int num_migrate)
+{
+        struct xfrm_migrate *mp;
+        struct dst_entry *dst;
+        int i, j, n = 0;
+
+        write_lock_bh(&pol->lock);
+        if (unlikely(pol->dead)) {
+                /* target policy has been deleted */
+                write_unlock_bh(&pol->lock);
+                return -ENOENT;
+        }
+
+        for (i = 0; i < pol->xfrm_nr; i++) {
+                for (j = 0, mp = m; j < num_migrate; j++, mp++) {
+                        if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
+                                continue;
+                        n++;
+                        if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL)
+                                continue;
+                        /* update endpoints */
+                        memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
+                               sizeof(pol->xfrm_vec[i].id.daddr));
+                        memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
+                               sizeof(pol->xfrm_vec[i].saddr));
+                        pol->xfrm_vec[i].encap_family = mp->new_family;
+                        /* flush bundles */
+                        while ((dst = pol->bundles) != NULL) {
+                                pol->bundles = dst->next;
+                                dst_free(dst);
+                        }
+                }
+        }
+
+        write_unlock_bh(&pol->lock);
+
+        if (!n)
+                return -ENODATA;
+
+        return 0;
+}
+
+static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
+{
+        int i, j;
+
+        if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
+                return -EINVAL;
+
+        for (i = 0; i < num_migrate; i++) {
+                if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
+                                   m[i].old_family) == 0) &&
+                    (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
+                                   m[i].old_family) == 0))
+                        return -EINVAL;
+                if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
+                    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
+                        return -EINVAL;
+
+                /* check if there is any duplicated entry */
+                for (j = i + 1; j < num_migrate; j++) {
+                        if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
+                                    sizeof(m[i].old_daddr)) &&
+                            !memcmp(&m[i].old_saddr, &m[j].old_saddr,
+                                    sizeof(m[i].old_saddr)) &&
+                            m[i].proto == m[j].proto &&
+                            m[i].mode == m[j].mode &&
+                            m[i].reqid == m[j].reqid &&
+                            m[i].old_family == m[j].old_family)
+                                return -EINVAL;
+                }
+        }
+
+        return 0;
+}
+
+int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
+                 struct xfrm_migrate *m, int num_migrate)
+{
+        int i, err, nx_cur = 0, nx_new = 0;
+        struct xfrm_policy *pol = NULL;
+        struct xfrm_state *x, *xc;
+        struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
+        struct xfrm_state *x_new[XFRM_MAX_DEPTH];
+        struct xfrm_migrate *mp;
+
+        if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
+                goto out;
+
+        /* Stage 1 - find policy */
+        if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
+                err = -ENOENT;
+                goto out;
+        }
+
+        /* Stage 2 - find and update state(s) */
+        for (i = 0, mp = m; i < num_migrate; i++, mp++) {
+                if ((x = xfrm_migrate_state_find(mp))) {
+                        x_cur[nx_cur] = x;
+                        nx_cur++;
+                        if ((xc = xfrm_state_migrate(x, mp))) {
+                                x_new[nx_new] = xc;
+                                nx_new++;
+                        } else {
+                                err = -ENODATA;
+                                goto restore_state;
+                        }
+                }
+        }
+
+        /* Stage 3 - update policy */
+        if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
+                goto restore_state;
+
+        /* Stage 4 - delete old state(s) */
+        if (nx_cur) {
+                xfrm_states_put(x_cur, nx_cur);
+                xfrm_states_delete(x_cur, nx_cur);
+        }
+
+        /* Stage 5 - announce */
+        km_migrate(sel, dir, type, m, num_migrate);
+
+        xfrm_pol_put(pol);
+
+        return 0;
+out:
+        return err;
+
+restore_state:
+        if (pol)
+                xfrm_pol_put(pol);
+        if (nx_cur)
+                xfrm_states_put(x_cur, nx_cur);
+        if (nx_new)
+                xfrm_states_delete(x_new, nx_new);
+
+        return err;
+}
+#endif
+
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 24f7bfd07af2..91b02687db52 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -828,6 +828,160 @@ out:
 }
 EXPORT_SYMBOL(xfrm_state_add);
 
+#ifdef CONFIG_XFRM_MIGRATE
+struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig, int *errp)
+{
+        int err = -ENOMEM;
+        struct xfrm_state *x = xfrm_state_alloc();
+        if (!x)
+                goto error;
+
+        memcpy(&x->id, &orig->id, sizeof(x->id));
+        memcpy(&x->sel, &orig->sel, sizeof(x->sel));
+        memcpy(&x->lft, &orig->lft, sizeof(x->lft));
+        x->props.mode = orig->props.mode;
+        x->props.replay_window = orig->props.replay_window;
+        x->props.reqid = orig->props.reqid;
+        x->props.family = orig->props.family;
+        x->props.saddr = orig->props.saddr;
+
+        if (orig->aalg) {
+                x->aalg = xfrm_algo_clone(orig->aalg);
+                if (!x->aalg)
+                        goto error;
+        }
+        x->props.aalgo = orig->props.aalgo;
+
+        if (orig->ealg) {
+                x->ealg = xfrm_algo_clone(orig->ealg);
+                if (!x->ealg)
+                        goto error;
+        }
+        x->props.ealgo = orig->props.ealgo;
+
+        if (orig->calg) {
+                x->calg = xfrm_algo_clone(orig->calg);
+                if (!x->calg)
+                        goto error;
+        }
+        x->props.calgo = orig->props.calgo;
+
+        if (orig->encap) {
+                x->encap = kmemdup(orig->encap, sizeof(*x->encap), GFP_KERNEL);
+                if (!x->encap)
+                        goto error;
+        }
+
+        if (orig->coaddr) {
+                x->coaddr = kmemdup(orig->coaddr, sizeof(*x->coaddr),
+                                    GFP_KERNEL);
+                if (!x->coaddr)
+                        goto error;
+        }
+
+        err = xfrm_init_state(x);
+        if (err)
+                goto error;
+
+        x->props.flags = orig->props.flags;
+
+        x->curlft.add_time = orig->curlft.add_time;
+        x->km.state = orig->km.state;
+        x->km.seq = orig->km.seq;
+
+        return x;
+
+ error:
+        if (errp)
+                *errp = err;
+        if (x) {
+                kfree(x->aalg);
+                kfree(x->ealg);
+                kfree(x->calg);
+                kfree(x->encap);
+                kfree(x->coaddr);
+        }
+        kfree(x);
+        return NULL;
+}
+EXPORT_SYMBOL(xfrm_state_clone);
+
+/* xfrm_state_lock is held */
+struct xfrm_state * xfrm_migrate_state_find(struct xfrm_migrate *m)
+{
+        unsigned int h;
+        struct xfrm_state *x;
+        struct hlist_node *entry;
+
+        if (m->reqid) {
+                h = xfrm_dst_hash(&m->old_daddr, &m->old_saddr,
+                                  m->reqid, m->old_family);
+                hlist_for_each_entry(x, entry, xfrm_state_bydst+h, bydst) {
+                        if (x->props.mode != m->mode ||
+                            x->id.proto != m->proto)
+                                continue;
+                        if (m->reqid && x->props.reqid != m->reqid)
+                                continue;
+                        if (xfrm_addr_cmp(&x->id.daddr, &m->old_daddr,
+                                          m->old_family) ||
+                            xfrm_addr_cmp(&x->props.saddr, &m->old_saddr,
+                                          m->old_family))
+                                continue;
+                        xfrm_state_hold(x);
+                        return x;
+                }
+        } else {
+                h = xfrm_src_hash(&m->old_daddr, &m->old_saddr,
+                                  m->old_family);
+                hlist_for_each_entry(x, entry, xfrm_state_bysrc+h, bysrc) {
+                        if (x->props.mode != m->mode ||
+                            x->id.proto != m->proto)
+                                continue;
+                        if (xfrm_addr_cmp(&x->id.daddr, &m->old_daddr,
+                                          m->old_family) ||
+                            xfrm_addr_cmp(&x->props.saddr, &m->old_saddr,
+                                          m->old_family))
+                                continue;
+                        xfrm_state_hold(x);
+                        return x;
+                }
+        }
+
+        return NULL;
+}
+EXPORT_SYMBOL(xfrm_migrate_state_find);
+
+struct xfrm_state * xfrm_state_migrate(struct xfrm_state *x,
+                                       struct xfrm_migrate *m)
+{
+        struct xfrm_state *xc;
+        int err;
+
+        xc = xfrm_state_clone(x, &err);
+        if (!xc)
+                return NULL;
+
+        memcpy(&xc->id.daddr, &m->new_daddr, sizeof(xc->id.daddr));
+        memcpy(&xc->props.saddr, &m->new_saddr, sizeof(xc->props.saddr));
+
+        /* add state */
+        if (!xfrm_addr_cmp(&x->id.daddr, &m->new_daddr, m->new_family)) {
+                /* a care is needed when the destination address of the
+                   state is to be updated as it is a part of triplet */
+                xfrm_state_insert(xc);
+        } else {
+                if ((err = xfrm_state_add(xc)) < 0)
+                        goto error;
+        }
+
+        return xc;
+error:
+        kfree(xc);
+        return NULL;
+}
+EXPORT_SYMBOL(xfrm_state_migrate);
+#endif
+
 int xfrm_state_update(struct xfrm_state *x)
 {
         struct xfrm_state *x1;
@@ -1342,6 +1496,26 @@ void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 pid)
 }
 EXPORT_SYMBOL(km_policy_expired);
 
+int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
+               struct xfrm_migrate *m, int num_migrate)
+{
+        int err = -EINVAL;
+        int ret;
+        struct xfrm_mgr *km;
+
+        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);
+                        if (!ret)
+                                err = ret;
+                }
+        }
+        read_unlock(&xfrm_km_lock);
+        return err;
+}
+EXPORT_SYMBOL(km_migrate);
+
 int km_report(u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr)
 {
         int err = -EINVAL;