[XFRM] STATE: Search by address using source address list.

This is a support to search transformation states by its addresses
by using source address list for Mobile IPv6 usage.
To use it from user-space, it is also added a message type for
source address as a xfrm state option.
Based on MIPL2 kernel patch.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 119 insertions, 10 deletions

diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 5154064b6d95..66343d3d4b91 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -234,6 +234,7 @@ enum xfrm_attr_type_t {
         XFRMA_REPLAY_VAL,
         XFRMA_REPLAY_THRESH,
         XFRMA_ETIMER_THRESH,
+        XFRMA_SRCADDR,          /* xfrm_address_t */
         __XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 88145e3348d0..d9c40e713184 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -244,6 +244,7 @@ struct xfrm_state_afinfo {
                                                 struct xfrm_tmpl *tmpl,
                                                 xfrm_address_t *daddr, xfrm_address_t *saddr);
         struct xfrm_state       *(*state_lookup)(xfrm_address_t *daddr, u32 spi, u8 proto);
+        struct xfrm_state       *(*state_lookup_byaddr)(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto);
         struct xfrm_state       *(*find_acq)(u8 mode, u32 reqid, u8 proto, 
                                              xfrm_address_t *daddr, xfrm_address_t *saddr, 
                                              int create);
@@ -937,6 +938,7 @@ extern void xfrm_state_insert(struct xfrm_state *x);
 extern int xfrm_state_add(struct xfrm_state *x);
 extern int xfrm_state_update(struct xfrm_state *x);
 extern struct xfrm_state *xfrm_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto, unsigned short family);
+extern struct xfrm_state *xfrm_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto, unsigned short family);
 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
 extern int xfrm_state_delete(struct xfrm_state *x);
 extern void xfrm_state_flush(u8 proto);
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index c56b258fad73..616be131b4e3 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -80,6 +80,14 @@ __xfrm4_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto)
         return NULL;
 }
 
+/* placeholder until ipv4's code is written */
+static struct xfrm_state *
+__xfrm4_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr,
+                            u8 proto)
+{
+        return NULL;
+}
+
 static struct xfrm_state *
 __xfrm4_find_acq(u8 mode, u32 reqid, u8 proto, 
                  xfrm_address_t *daddr, xfrm_address_t *saddr, 
@@ -137,6 +145,7 @@ static struct xfrm_state_afinfo xfrm4_state_afinfo = {
         .init_flags             = xfrm4_init_flags,
         .init_tempsel           = __xfrm4_init_tempsel,
         .state_lookup           = __xfrm4_state_lookup,
+        .state_lookup_byaddr    = __xfrm4_state_lookup_byaddr,
         .find_acq               = __xfrm4_find_acq,
 };
 
diff --git a/net/ipv6/xfrm6_state.c b/net/ipv6/xfrm6_state.c
index 2fb07850449f..9c95b9d3e110 100644
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -64,6 +64,26 @@ __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
 }
 
 static struct xfrm_state *
+__xfrm6_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr,
+                            u8 proto)
+{
+        struct xfrm_state *x = NULL;
+        unsigned h;
+
+        h = __xfrm6_src_hash(saddr);
+        list_for_each_entry(x, xfrm6_state_afinfo.state_bysrc+h, bysrc) {
+                if (x->props.family == AF_INET6 &&
+                    ipv6_addr_equal((struct in6_addr *)daddr, (struct in6_addr *)x->id.daddr.a6) &&
+                    ipv6_addr_equal((struct in6_addr *)saddr, (struct in6_addr *)x->props.saddr.a6) &&
+                    proto == x->id.proto) {
+                        xfrm_state_hold(x);
+                        return x;
+                }
+        }
+        return NULL;
+}
+
+static struct xfrm_state *
 __xfrm6_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto)
 {
         unsigned h = __xfrm6_spi_hash(daddr, spi, proto);
@@ -140,6 +160,7 @@ static struct xfrm_state_afinfo xfrm6_state_afinfo = {
         .family                 = AF_INET6,
         .init_tempsel           = __xfrm6_init_tempsel,
         .state_lookup           = __xfrm6_state_lookup,
+        .state_lookup_byaddr    = __xfrm6_state_lookup_byaddr,
         .find_acq               = __xfrm6_find_acq,
 };
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 2a9992894e69..11f480b12952 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -487,6 +487,16 @@ void xfrm_state_insert(struct xfrm_state *x)
 }
 EXPORT_SYMBOL(xfrm_state_insert);
 
+static inline struct xfrm_state *
+__xfrm_state_locate(struct xfrm_state_afinfo *afinfo, struct xfrm_state *x,
+                    int use_spi)
+{
+        if (use_spi)
+                return afinfo->state_lookup(&x->id.daddr, x->id.spi, x->id.proto);
+        else
+                return afinfo->state_lookup_byaddr(&x->id.daddr, &x->props.saddr, x->id.proto);
+}
+
 static struct xfrm_state *__xfrm_find_acq_byseq(u32 seq);
 
 int xfrm_state_add(struct xfrm_state *x)
@@ -495,6 +505,7 @@ int xfrm_state_add(struct xfrm_state *x)
         struct xfrm_state *x1;
         int family;
         int err;
+        int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);
 
         family = x->props.family;
         afinfo = xfrm_state_get_afinfo(family);
@@ -503,7 +514,7 @@ int xfrm_state_add(struct xfrm_state *x)
 
         spin_lock_bh(&xfrm_state_lock);
 
-        x1 = afinfo->state_lookup(&x->id.daddr, x->id.spi, x->id.proto);
+        x1 = __xfrm_state_locate(afinfo, x, use_spi);
         if (x1) {
                 xfrm_state_put(x1);
                 x1 = NULL;
@@ -511,7 +522,7 @@ int xfrm_state_add(struct xfrm_state *x)
                 goto out;
         }
 
-        if (x->km.seq) {
+        if (use_spi && x->km.seq) {
                 x1 = __xfrm_find_acq_byseq(x->km.seq);
                 if (x1 && xfrm_addr_cmp(&x1->id.daddr, &x->id.daddr, family)) {
                         xfrm_state_put(x1);
@@ -519,7 +530,7 @@ int xfrm_state_add(struct xfrm_state *x)
                 }
         }
 
-        if (!x1)
+        if (use_spi && !x1)
                 x1 = afinfo->find_acq(
                         x->props.mode, x->props.reqid, x->id.proto,
                         &x->id.daddr, &x->props.saddr, 0);
@@ -548,13 +559,14 @@ int xfrm_state_update(struct xfrm_state *x)
         struct xfrm_state_afinfo *afinfo;
         struct xfrm_state *x1;
         int err;
+        int use_spi = xfrm_id_proto_match(x->id.proto, IPSEC_PROTO_ANY);
 
         afinfo = xfrm_state_get_afinfo(x->props.family);
         if (unlikely(afinfo == NULL))
                 return -EAFNOSUPPORT;
 
         spin_lock_bh(&xfrm_state_lock);
-        x1 = afinfo->state_lookup(&x->id.daddr, x->id.spi, x->id.proto);
+        x1 = __xfrm_state_locate(afinfo, x, use_spi);
 
         err = -ESRCH;
         if (!x1)
@@ -675,6 +687,23 @@ xfrm_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto,
 EXPORT_SYMBOL(xfrm_state_lookup);
 
 struct xfrm_state *
+xfrm_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr,
+                         u8 proto, unsigned short family)
+{
+        struct xfrm_state *x;
+        struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
+        if (!afinfo)
+                return NULL;
+
+        spin_lock_bh(&xfrm_state_lock);
+        x = afinfo->state_lookup_byaddr(daddr, saddr, proto);
+        spin_unlock_bh(&xfrm_state_lock);
+        xfrm_state_put_afinfo(afinfo);
+        return x;
+}
+EXPORT_SYMBOL(xfrm_state_lookup_byaddr);
+
+struct xfrm_state *
 xfrm_find_acq(u8 mode, u32 reqid, u8 proto, 
               xfrm_address_t *daddr, xfrm_address_t *saddr, 
               int create, unsigned short family)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 41f3d51ffc33..b5f8ab71aa54 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -87,6 +87,22 @@ static int verify_encap_tmpl(struct rtattr **xfrma)
         return 0;
 }
 
+static int verify_one_addr(struct rtattr **xfrma, enum xfrm_attr_type_t type,
+                           xfrm_address_t **addrp)
+{
+        struct rtattr *rt = xfrma[type - 1];
+
+        if (!rt)
+                return 0;
+
+        if ((rt->rta_len - sizeof(*rt)) < sizeof(**addrp))
+                return -EINVAL;
+
+        if (addrp)
+                *addrp = RTA_DATA(rt);
+
+        return 0;
+}
 
 static inline int verify_sec_ctx_len(struct rtattr **xfrma)
 {
@@ -418,16 +434,48 @@ out:
         return err;
 }
 
+static struct xfrm_state *xfrm_user_state_lookup(struct xfrm_usersa_id *p,
+                                                 struct rtattr **xfrma,
+                                                 int *errp)
+{
+        struct xfrm_state *x = NULL;
+        int err;
+
+        if (xfrm_id_proto_match(p->proto, IPSEC_PROTO_ANY)) {
+                err = -ESRCH;
+                x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
+        } else {
+                xfrm_address_t *saddr = NULL;
+
+                err = verify_one_addr(xfrma, XFRMA_SRCADDR, &saddr);
+                if (err)
+                        goto out;
+
+                if (!saddr) {
+                        err = -EINVAL;
+                        goto out;
+                }
+
+                x = xfrm_state_lookup_byaddr(&p->daddr, saddr, p->proto,
+                                             p->family);
+        }
+
+ out:
+        if (!x && errp)
+                *errp = err;
+        return x;
+}
+
 static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 {
         struct xfrm_state *x;
-        int err;
+        int err = -ESRCH;
         struct km_event c;
         struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
 
-        x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
+        x = xfrm_user_state_lookup(p, (struct rtattr **)xfrma, &err);
         if (x == NULL)
-                return -ESRCH;
+                return err;
 
         if ((err = security_xfrm_state_delete(x)) != 0)
                 goto out;
@@ -578,10 +626,9 @@ static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
         struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
         struct xfrm_state *x;
         struct sk_buff *resp_skb;
-        int err;
+        int err = -ESRCH;
 
-        x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
-        err = -ESRCH;
+        x = xfrm_user_state_lookup(p, (struct rtattr **)xfrma, &err);
         if (x == NULL)
                 goto out_noput;