ipsec: add support of limited SA dump
The goal of this patch is to allow userland to dump only a part of SA by
specifying a filter during the dump.
The kernel is in charge to filter SA, this avoids to generate useless netlink
traffic (it save also some cpu cycles). This is particularly useful when there
is a big number of SA set on the system.
Note that I removed the union in struct xfrm_state_walk to fix a problem on arm.
struct netlink_callback->args is defined as a array of 6 long and the first long
is used in xfrm code to flag the cb as initialized. Hence, we must have:
sizeof(struct xfrm_state_walk) <= sizeof(long) * 5.
With the union, it was false on arm (sizeof(struct xfrm_state_walk) was
sizeof(long) * 7), due to the padding.
In fact, whatever the arch is, this union seems useless, there will be always
padding after it. Removing it will not increase the size of this struct (and
reduce it on arm).
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 5313ccf..45332ac 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -118,11 +118,10 @@
struct xfrm_state_walk {
struct list_head all;
u8 state;
- union {
- u8 dying;
- u8 proto;
- };
+ u8 dying;
+ u8 proto;
u32 seq;
+ struct xfrm_filter *filter;
};
/* Full description of state of transformer. */
@@ -1406,7 +1405,8 @@
}
#endif
-void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto);
+void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
+ struct xfrm_filter *filter);
int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
int (*func)(struct xfrm_state *, int, void*), void *);
void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net);
diff --git a/include/uapi/linux/pfkeyv2.h b/include/uapi/linux/pfkeyv2.h
index 0b80c80..ada7f01 100644
--- a/include/uapi/linux/pfkeyv2.h
+++ b/include/uapi/linux/pfkeyv2.h
@@ -235,6 +235,18 @@
} __attribute__((packed));
/* sizeof(struct sadb_x_kmaddress) == 8 */
+/* To specify the SA dump filter */
+struct sadb_x_filter {
+ __u16 sadb_x_filter_len;
+ __u16 sadb_x_filter_exttype;
+ __u32 sadb_x_filter_saddr[4];
+ __u32 sadb_x_filter_daddr[4];
+ __u16 sadb_x_filter_family;
+ __u8 sadb_x_filter_splen;
+ __u8 sadb_x_filter_dplen;
+} __attribute__((packed));
+/* sizeof(struct sadb_x_filter) == 40 */
+
/* Message types */
#define SADB_RESERVED 0
#define SADB_GETSPI 1
@@ -358,7 +370,8 @@
#define SADB_X_EXT_SEC_CTX 24
/* Used with MIGRATE to pass @ to IKE for negotiation */
#define SADB_X_EXT_KMADDRESS 25
-#define SADB_EXT_MAX 25
+#define SADB_X_EXT_FILTER 26
+#define SADB_EXT_MAX 26
/* Identity Extension values */
#define SADB_IDENTTYPE_RESERVED 0
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index a8cd6a4..6550c67 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -298,6 +298,8 @@
XFRMA_TFCPAD, /* __u32 */
XFRMA_REPLAY_ESN_VAL, /* struct xfrm_replay_esn */
XFRMA_SA_EXTRA_FLAGS, /* __u32 */
+ XFRMA_PROTO, /* __u8 */
+ XFRMA_FILTER, /* struct xfrm_filter */
__XFRMA_MAX
#define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -474,6 +476,14 @@
__be16 new_sport;
};
+struct xfrm_filter {
+ xfrm_address_t saddr;
+ xfrm_address_t daddr;
+ __u16 family;
+ __u8 splen;
+ __u8 dplen;
+};
+
#ifndef __KERNEL__
/* backwards compatibility for userspace */
#define XFRMGRP_ACQUIRE 1
diff --git a/net/key/af_key.c b/net/key/af_key.c
index e1c69d0..f0879c1 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1798,6 +1798,7 @@
static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
{
u8 proto;
+ struct xfrm_filter *filter = NULL;
struct pfkey_sock *pfk = pfkey_sk(sk);
if (pfk->dump.dump != NULL)
@@ -1807,11 +1808,27 @@
if (proto == 0)
return -EINVAL;
+ if (ext_hdrs[SADB_X_EXT_FILTER - 1]) {
+ struct sadb_x_filter *xfilter = ext_hdrs[SADB_X_EXT_FILTER - 1];
+
+ filter = kmalloc(sizeof(*filter), GFP_KERNEL);
+ if (filter == NULL)
+ return -ENOMEM;
+
+ memcpy(&filter->saddr, &xfilter->sadb_x_filter_saddr,
+ sizeof(xfrm_address_t));
+ memcpy(&filter->daddr, &xfilter->sadb_x_filter_daddr,
+ sizeof(xfrm_address_t));
+ filter->family = xfilter->sadb_x_filter_family;
+ filter->splen = xfilter->sadb_x_filter_splen;
+ filter->dplen = xfilter->sadb_x_filter_dplen;
+ }
+
pfk->dump.msg_version = hdr->sadb_msg_version;
pfk->dump.msg_portid = hdr->sadb_msg_pid;
pfk->dump.dump = pfkey_dump_sa;
pfk->dump.done = pfkey_dump_sa_done;
- xfrm_state_walk_init(&pfk->dump.u.state, proto);
+ xfrm_state_walk_init(&pfk->dump.u.state, proto, filter);
return pfkey_do_dump(pfk);
}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 0bf12f6..a750901 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1603,6 +1603,23 @@
}
EXPORT_SYMBOL(xfrm_alloc_spi);
+static bool __xfrm_state_filter_match(struct xfrm_state *x,
+ struct xfrm_filter *filter)
+{
+ if (filter) {
+ if ((filter->family == AF_INET ||
+ filter->family == AF_INET6) &&
+ x->props.family != filter->family)
+ return false;
+
+ return addr_match(&x->props.saddr, &filter->saddr,
+ filter->splen) &&
+ addr_match(&x->id.daddr, &filter->daddr,
+ filter->dplen);
+ }
+ return true;
+}
+
int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
int (*func)(struct xfrm_state *, int, void*),
void *data)
@@ -1625,6 +1642,8 @@
state = container_of(x, struct xfrm_state, km);
if (!xfrm_id_proto_match(state->id.proto, walk->proto))
continue;
+ if (!__xfrm_state_filter_match(state, walk->filter))
+ continue;
err = func(state, walk->seq, data);
if (err) {
list_move_tail(&walk->all, &x->all);
@@ -1643,17 +1662,21 @@
}
EXPORT_SYMBOL(xfrm_state_walk);
-void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto)
+void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
+ struct xfrm_filter *filter)
{
INIT_LIST_HEAD(&walk->all);
walk->proto = proto;
walk->state = XFRM_STATE_DEAD;
walk->seq = 0;
+ walk->filter = filter;
}
EXPORT_SYMBOL(xfrm_state_walk_init);
void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net)
{
+ kfree(walk->filter);
+
if (list_empty(&walk->all))
return;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d7694f2..023e5e7 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -887,6 +887,7 @@
return 0;
}
+static const struct nla_policy xfrma_policy[XFRMA_MAX+1];
static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
@@ -902,8 +903,31 @@
info.nlmsg_flags = NLM_F_MULTI;
if (!cb->args[0]) {
+ struct nlattr *attrs[XFRMA_MAX+1];
+ struct xfrm_filter *filter = NULL;
+ u8 proto = 0;
+ int err;
+
cb->args[0] = 1;
- xfrm_state_walk_init(walk, 0);
+
+ err = nlmsg_parse(cb->nlh, 0, attrs, XFRMA_MAX,
+ xfrma_policy);
+ if (err < 0)
+ return err;
+
+ if (attrs[XFRMA_FILTER]) {
+ filter = kmalloc(sizeof(*filter), GFP_KERNEL);
+ if (filter == NULL)
+ return -ENOMEM;
+
+ memcpy(filter, nla_data(attrs[XFRMA_FILTER]),
+ sizeof(*filter));
+ }
+
+ if (attrs[XFRMA_PROTO])
+ proto = nla_get_u8(attrs[XFRMA_PROTO]);
+
+ xfrm_state_walk_init(walk, proto, filter);
}
(void) xfrm_state_walk(net, walk, dump_one_state, &info);
@@ -2309,6 +2333,8 @@
[XFRMA_TFCPAD] = { .type = NLA_U32 },
[XFRMA_REPLAY_ESN_VAL] = { .len = sizeof(struct xfrm_replay_state_esn) },
[XFRMA_SA_EXTRA_FLAGS] = { .type = NLA_U32 },
+ [XFRMA_PROTO] = { .type = NLA_U8 },
+ [XFRMA_FILTER] = { .len = sizeof(struct xfrm_filter) },
};
static const struct xfrm_link {