[IPSEC] Add complete xfrm event notification

Heres the final patch.
What this patch provides

- netlink xfrm events
- ability to have events generated by netlink propagated to pfkey
  and vice versa.
- fixes the acquire lets-be-happy-with-one-success issue

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 321 insertions, 25 deletions

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index d11747c2a763..918a94c552a5 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -50,7 +50,7 @@ static DEFINE_SPINLOCK(xfrm_state_gc_lock);
 
 static int xfrm_state_gc_flush_bundles;
 
-static void __xfrm_state_delete(struct xfrm_state *x);
+static int __xfrm_state_delete(struct xfrm_state *x);
 
 static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family);
 static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
@@ -215,8 +215,10 @@ void __xfrm_state_destroy(struct xfrm_state *x)
 }
 EXPORT_SYMBOL(__xfrm_state_destroy);
 
-static void __xfrm_state_delete(struct xfrm_state *x)
+static int __xfrm_state_delete(struct xfrm_state *x)
 {
+        int err = -ESRCH;
+
         if (x->km.state != XFRM_STATE_DEAD) {
                 x->km.state = XFRM_STATE_DEAD;
                 spin_lock(&xfrm_state_lock);
@@ -245,14 +247,21 @@ static void __xfrm_state_delete(struct xfrm_state *x)
                  * is what we are dropping here.
                  */
                 atomic_dec(&x->refcnt);
+                err = 0;
         }
+
+        return err;
 }
 
-void xfrm_state_delete(struct xfrm_state *x)
+int xfrm_state_delete(struct xfrm_state *x)
 {
+        int err;
+
         spin_lock_bh(&x->lock);
-        __xfrm_state_delete(x);
+        err = __xfrm_state_delete(x);
         spin_unlock_bh(&x->lock);
+
+        return err;
 }
 EXPORT_SYMBOL(xfrm_state_delete);
 
@@ -796,34 +805,60 @@ EXPORT_SYMBOL(xfrm_replay_advance);
 static struct list_head xfrm_km_list = LIST_HEAD_INIT(xfrm_km_list);
 static DEFINE_RWLOCK(xfrm_km_lock);
 
-static void km_state_expired(struct xfrm_state *x, int hard)
+void km_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
 {
         struct xfrm_mgr *km;
 
-        if (hard)
-                x->km.state = XFRM_STATE_EXPIRED;
-        else
-                x->km.dying = 1;
+        read_lock(&xfrm_km_lock);
+        list_for_each_entry(km, &xfrm_km_list, list)
+                if (km->notify_policy)
+                        km->notify_policy(xp, dir, c);
+        read_unlock(&xfrm_km_lock);
+}
 
+void km_state_notify(struct xfrm_state *x, struct km_event *c)
+{
+        struct xfrm_mgr *km;
         read_lock(&xfrm_km_lock);
         list_for_each_entry(km, &xfrm_km_list, list)
-                km->notify(x, hard);
+                if (km->notify)
+                        km->notify(x, c);
         read_unlock(&xfrm_km_lock);
+}
+
+EXPORT_SYMBOL(km_policy_notify);
+EXPORT_SYMBOL(km_state_notify);
+
+static void km_state_expired(struct xfrm_state *x, int hard)
+{
+        struct km_event c;
+
+        if (hard)
+                x->km.state = XFRM_STATE_EXPIRED;
+        else
+                x->km.dying = 1;
+        c.data = hard;
+        c.event = XFRM_SAP_EXPIRED;
+        km_state_notify(x, &c);
 
         if (hard)
                 wake_up(&km_waitq);
 }
 
+/*
+ * We send to all registered managers regardless of failure
+ * We are happy with one success
+*/
 static int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
 {
-        int err = -EINVAL;
+        int err = -EINVAL, acqret;
         struct xfrm_mgr *km;
 
         read_lock(&xfrm_km_lock);
         list_for_each_entry(km, &xfrm_km_list, list) {
-                err = km->acquire(x, t, pol, XFRM_POLICY_OUT);
-                if (!err)
-                        break;
+                acqret = km->acquire(x, t, pol, XFRM_POLICY_OUT);
+                if (!acqret)
+                        err = acqret;
         }
         read_unlock(&xfrm_km_lock);
         return err;
@@ -848,13 +883,12 @@ EXPORT_SYMBOL(km_new_mapping);
 
 void km_policy_expired(struct xfrm_policy *pol, int dir, int hard)
 {
-        struct xfrm_mgr *km;
+        struct km_event c;
 
-        read_lock(&xfrm_km_lock);
-        list_for_each_entry(km, &xfrm_km_list, list)
-                if (km->notify_policy)
-                        km->notify_policy(pol, dir, hard);
-        read_unlock(&xfrm_km_lock);
+        c.data = hard;
+        c.data = hard;
+        c.event = XFRM_SAP_EXPIRED;
+        km_policy_notify(pol, dir, &c);
 
         if (hard)
                 wake_up(&km_waitq);
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 97509011c274..bd8e6882c083 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -277,6 +277,7 @@ static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
         struct xfrm_usersa_info *p = NLMSG_DATA(nlh);
         struct xfrm_state *x;
         int err;
+        struct km_event c;
 
         err = verify_newsa_info(p, (struct rtattr **) xfrma);
         if (err)
@@ -286,6 +287,7 @@ static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
         if (!x)
                 return err;
 
+        xfrm_state_hold(x);
         if (nlh->nlmsg_type == XFRM_MSG_NEWSA)
                 err = xfrm_state_add(x);
         else
@@ -294,14 +296,27 @@ static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
         if (err < 0) {
                 x->km.state = XFRM_STATE_DEAD;
                 xfrm_state_put(x);
+                return err;
         }
 
+        c.seq = nlh->nlmsg_seq;
+        c.pid = nlh->nlmsg_pid;
+        if (nlh->nlmsg_type == XFRM_MSG_NEWSA)
+                c.event = XFRM_SAP_ADDED;
+        else
+                c.event = XFRM_SAP_UPDATED;
+
+        km_state_notify(x, &c);
+        xfrm_state_put(x);
+
         return err;
 }
 
 static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 {
         struct xfrm_state *x;
+        int err;
+        struct km_event c;
         struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
 
         x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
@@ -313,10 +328,19 @@ static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
                 return -EPERM;
         }
 
-        xfrm_state_delete(x);
+        err = xfrm_state_delete(x);
+        if (err < 0) {
+                xfrm_state_put(x);
+                return err;
+        }
+
+        c.seq = nlh->nlmsg_seq;
+        c.pid = nlh->nlmsg_pid;
+        c.event = XFRM_SAP_DELETED;
+        km_state_notify(x, &c);
         xfrm_state_put(x);
 
-        return 0;
+        return err;
 }
 
 static void copy_to_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
@@ -681,6 +705,7 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
 {
         struct xfrm_userpolicy_info *p = NLMSG_DATA(nlh);
         struct xfrm_policy *xp;
+        struct km_event c;
         int err;
         int excl;
 
@@ -692,6 +717,10 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
         if (!xp)
                 return err;
 
+        /* shouldnt excl be based on nlh flags??
+         * Aha! this is anti-netlink really i.e  more pfkey derived
+         * in netlink excl is a flag and you wouldnt need
+         * a type XFRM_MSG_UPDPOLICY - JHS */
         excl = nlh->nlmsg_type == XFRM_MSG_NEWPOLICY;
         err = xfrm_policy_insert(p->dir, xp, excl);
         if (err) {
@@ -699,6 +728,15 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
                 return err;
         }
 
+        if (!excl)
+                c.event = XFRM_SAP_UPDATED;
+        else
+                c.event = XFRM_SAP_ADDED;
+
+        c.seq = nlh->nlmsg_seq;
+        c.pid = nlh->nlmsg_pid;
+        km_policy_notify(xp, p->dir, &c);
+
         xfrm_pol_put(xp);
 
         return 0;
@@ -816,6 +854,7 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
         struct xfrm_policy *xp;
         struct xfrm_userpolicy_id *p;
         int err;
+        struct km_event c;
         int delete;
 
         p = NLMSG_DATA(nlh);
@@ -843,6 +882,11 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
                                               NETLINK_CB(skb).pid,
                                               MSG_DONTWAIT);
                 }
+        } else {
+                c.event = XFRM_SAP_DELETED;
+                c.seq = nlh->nlmsg_seq;
+                c.pid = nlh->nlmsg_pid;
+                km_policy_notify(xp, p->dir, &c);
         }
 
         xfrm_pol_put(xp);
@@ -852,15 +896,28 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfr
 
 static int xfrm_flush_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 {
+        struct km_event c;
         struct xfrm_usersa_flush *p = NLMSG_DATA(nlh);
 
         xfrm_state_flush(p->proto);
+        c.data = p->proto;
+        c.event = XFRM_SAP_FLUSHED;
+        c.seq = nlh->nlmsg_seq;
+        c.pid = nlh->nlmsg_pid;
+        km_state_notify(NULL, &c);
+
         return 0;
 }
 
 static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 {
+        struct km_event c;
+
         xfrm_policy_flush();
+        c.event = XFRM_SAP_FLUSHED;
+        c.seq = nlh->nlmsg_seq;
+        c.pid = nlh->nlmsg_pid;
+        km_policy_notify(NULL, 0, &c);
         return 0;
 }
 
@@ -1069,10 +1126,12 @@ nlmsg_failure:
         return -1;
 }
 
-static int xfrm_send_state_notify(struct xfrm_state *x, int hard)
+static int xfrm_exp_state_notify(struct xfrm_state *x, struct km_event *c)
 {
         struct sk_buff *skb;
+        int hard = c ->data;
 
+        /* fix to do alloc using NLM macros */
         skb = alloc_skb(sizeof(struct xfrm_user_expire) + 16, GFP_ATOMIC);
         if (skb == NULL)
                 return -ENOMEM;
@@ -1085,6 +1144,122 @@ static int xfrm_send_state_notify(struct xfrm_state *x, int hard)
         return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
 }
 
+static int xfrm_notify_sa_flush(struct km_event *c)
+{
+        struct xfrm_usersa_flush *p;
+        struct nlmsghdr *nlh;
+        struct sk_buff *skb;
+        unsigned char *b;
+        int len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_flush));
+
+        skb = alloc_skb(len, GFP_ATOMIC);
+        if (skb == NULL)
+                return -ENOMEM;
+        b = skb->tail;
+
+        nlh = NLMSG_PUT(skb, c->pid, c->seq,
+                        XFRM_MSG_FLUSHSA, sizeof(*p));
+        nlh->nlmsg_flags = 0;
+
+        p = NLMSG_DATA(nlh);
+        p->proto = c->data;
+
+        nlh->nlmsg_len = skb->tail - b;
+
+        return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_SA, GFP_ATOMIC);
+
+nlmsg_failure:
+        kfree_skb(skb);
+        return -1;
+}
+
+static int inline xfrm_sa_len(struct xfrm_state *x)
+{
+        int l = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info));
+        if (x->aalg)
+                l += RTA_SPACE(sizeof(*x->aalg) + (x->aalg->alg_key_len+7)/8);
+        if (x->ealg)
+                l += RTA_SPACE(sizeof(*x->ealg) + (x->ealg->alg_key_len+7)/8);
+        if (x->calg)
+                l += RTA_SPACE(sizeof(*x->calg));
+        if (x->encap)
+                l += RTA_SPACE(sizeof(*x->encap));
+
+        return l;
+}
+
+static int xfrm_notify_sa(struct xfrm_state *x, struct km_event *c)
+{
+        struct xfrm_usersa_info *p;
+        struct nlmsghdr *nlh;
+        struct sk_buff *skb;
+        u32 nlt;
+        unsigned char *b;
+        int len = xfrm_sa_len(x);
+
+        skb = alloc_skb(len, GFP_ATOMIC);
+        if (skb == NULL)
+                return -ENOMEM;
+        b = skb->tail;
+
+        if (c->event == XFRM_SAP_ADDED)
+                nlt = XFRM_MSG_NEWSA;
+        else if (c->event == XFRM_SAP_UPDATED)
+                nlt = XFRM_MSG_UPDSA;
+        else if (c->event == XFRM_SAP_DELETED)
+                nlt = XFRM_MSG_DELSA;
+        else
+                goto nlmsg_failure;
+
+        nlh = NLMSG_PUT(skb, c->pid, c->seq, nlt, sizeof(*p));
+        nlh->nlmsg_flags = 0;
+
+        p = NLMSG_DATA(nlh);
+        copy_to_user_state(x, p);
+
+        if (x->aalg)
+                RTA_PUT(skb, XFRMA_ALG_AUTH,
+                        sizeof(*(x->aalg))+(x->aalg->alg_key_len+7)/8, x->aalg);
+        if (x->ealg)
+                RTA_PUT(skb, XFRMA_ALG_CRYPT,
+                        sizeof(*(x->ealg))+(x->ealg->alg_key_len+7)/8, x->ealg);
+        if (x->calg)
+                RTA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
+
+        if (x->encap)
+                RTA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
+
+        nlh->nlmsg_len = skb->tail - b;
+
+        return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_SA, GFP_ATOMIC);
+
+nlmsg_failure:
+rtattr_failure:
+        kfree_skb(skb);
+        return -1;
+}
+
+static int xfrm_send_state_notify(struct xfrm_state *x, struct km_event *c)
+{
+
+        switch (c->event) {
+        case XFRM_SAP_EXPIRED:
+                return xfrm_exp_state_notify(x, c);
+        case XFRM_SAP_DELETED:
+        case XFRM_SAP_UPDATED:
+        case XFRM_SAP_ADDED:
+                return xfrm_notify_sa(x, c);
+        case XFRM_SAP_FLUSHED:
+                return xfrm_notify_sa_flush(c);
+        default:
+                 printk("xfrm_user: Unknown SA event %d\n", c->event);
+                 break;
+        }
+
+        return 0;
+
+}
+
 static int build_acquire(struct sk_buff *skb, struct xfrm_state *x,
                          struct xfrm_tmpl *xt, struct xfrm_policy *xp,
                          int dir)
@@ -1218,7 +1393,7 @@ nlmsg_failure:
         return -1;
 }
 
-static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, int hard)
+static int xfrm_exp_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
 {
         struct sk_buff *skb;
         size_t len;
@@ -1229,7 +1404,7 @@ static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, int hard)
         if (skb == NULL)
                 return -ENOMEM;
 
-        if (build_polexpire(skb, xp, dir, hard) < 0)
+        if (build_polexpire(skb, xp, dir, c->data) < 0)
                 BUG();
 
         NETLINK_CB(skb).dst_groups = XFRMGRP_EXPIRE;
@@ -1237,6 +1412,93 @@ static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, int hard)
         return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
 }
 
+static int xfrm_notify_policy(struct xfrm_policy *xp, int dir, struct km_event *c)
+{
+        struct xfrm_userpolicy_info *p;
+        struct nlmsghdr *nlh;
+        struct sk_buff *skb;
+        u32 nlt = 0 ;
+        unsigned char *b;
+        int len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
+        len += NLMSG_SPACE(sizeof(struct xfrm_userpolicy_info));
+
+        skb = alloc_skb(len, GFP_ATOMIC);
+        if (skb == NULL)
+                return -ENOMEM;
+        b = skb->tail;
+
+        if (c->event == XFRM_SAP_ADDED)
+                nlt = XFRM_MSG_NEWPOLICY;
+        else if (c->event == XFRM_SAP_UPDATED)
+                nlt = XFRM_MSG_UPDPOLICY;
+        else if (c->event == XFRM_SAP_DELETED)
+                nlt = XFRM_MSG_DELPOLICY;
+        else
+                goto nlmsg_failure;
+
+        nlh = NLMSG_PUT(skb, c->pid, c->seq, nlt, sizeof(*p));
+
+        p = NLMSG_DATA(nlh);
+
+        nlh->nlmsg_flags = 0;
+
+        copy_to_user_policy(xp, p, dir);
+        if (copy_to_user_tmpl(xp, skb) < 0)
+                goto nlmsg_failure;
+
+        nlh->nlmsg_len = skb->tail - b;
+
+        return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_POLICY, GFP_ATOMIC);
+
+nlmsg_failure:
+        kfree_skb(skb);
+        return -1;
+}
+
+static int xfrm_notify_policy_flush(struct km_event *c)
+{
+        struct nlmsghdr *nlh;
+        struct sk_buff *skb;
+        unsigned char *b;
+        int len = NLMSG_LENGTH(0);
+
+        skb = alloc_skb(len, GFP_ATOMIC);
+        if (skb == NULL)
+                return -ENOMEM;
+        b = skb->tail;
+
+
+        nlh = NLMSG_PUT(skb, c->pid, c->seq, XFRM_MSG_FLUSHPOLICY, 0);
+
+        nlh->nlmsg_len = skb->tail - b;
+
+        return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_POLICY, GFP_ATOMIC);
+
+nlmsg_failure:
+        kfree_skb(skb);
+        return -1;
+}
+
+static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
+{
+
+        switch (c->event) {
+        case XFRM_SAP_ADDED:
+        case XFRM_SAP_UPDATED:
+        case XFRM_SAP_DELETED:
+                return xfrm_notify_policy(xp, dir, c);
+        case XFRM_SAP_FLUSHED:
+                return xfrm_notify_policy_flush(c);
+        case XFRM_SAP_EXPIRED:
+                return xfrm_exp_policy_notify(xp, dir, c);
+        default:
+                printk("xfrm_user: Unknown Policy event %d\n", c->event);
+        }
+
+        return 0;
+
+}
+
 static struct xfrm_mgr netlink_mgr = {
         .id             = "netlink",
         .notify         = xfrm_send_state_notify,