xfrm: Move IPsec replay detection functions to a separate file
To support multiple versions of replay detection, we move the replay
detection functions to a separate file and make them accessible
via function pointers contained in the struct xfrm_replay.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index c631047..aa429ee 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -4,7 +4,7 @@
obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
xfrm_input.o xfrm_output.o xfrm_algo.o \
- xfrm_sysctl.o
+ xfrm_sysctl.o xfrm_replay.o
obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
obj-$(CONFIG_XFRM_USER) += xfrm_user.o
obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index b173b7f..55d5f5c 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -172,7 +172,7 @@
goto drop_unlock;
}
- if (x->props.replay_window && xfrm_replay_check(x, skb, seq)) {
+ if (x->props.replay_window && x->repl->check(x, skb, seq)) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
goto drop_unlock;
}
@@ -206,8 +206,7 @@
/* only the first xfrm gets the encap type */
encap_type = 0;
- if (x->props.replay_window)
- xfrm_replay_advance(x, seq);
+ x->repl->advance(x, seq);
x->curlft.bytes += skb->len;
x->curlft.packets++;
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 4b63776..1aba03f 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -67,17 +67,10 @@
goto error;
}
- if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
- XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
- if (unlikely(x->replay.oseq == 0)) {
- XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
- x->replay.oseq--;
- xfrm_audit_state_replay_overflow(x, skb);
- err = -EOVERFLOW;
- goto error;
- }
- if (xfrm_aevent_is_on(net))
- xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
+ err = x->repl->overflow(x, skb);
+ if (err) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
+ goto error;
}
x->curlft.bytes += skb->len;
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
new file mode 100644
index 0000000..42d68f3
--- /dev/null
+++ b/net/xfrm/xfrm_replay.c
@@ -0,0 +1,141 @@
+/*
+ * xfrm_replay.c - xfrm replay detection, derived from xfrm_state.c.
+ */
+
+#include <net/xfrm.h>
+
+static void xfrm_replay_notify(struct xfrm_state *x, int event)
+{
+ struct km_event c;
+ /* we send notify messages in case
+ * 1. we updated on of the sequence numbers, and the seqno difference
+ * is at least x->replay_maxdiff, in this case we also update the
+ * timeout of our timer function
+ * 2. if x->replay_maxage has elapsed since last update,
+ * and there were changes
+ *
+ * The state structure must be locked!
+ */
+
+ switch (event) {
+ case XFRM_REPLAY_UPDATE:
+ if (x->replay_maxdiff &&
+ (x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
+ (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff)) {
+ if (x->xflags & XFRM_TIME_DEFER)
+ event = XFRM_REPLAY_TIMEOUT;
+ else
+ return;
+ }
+
+ break;
+
+ case XFRM_REPLAY_TIMEOUT:
+ if (memcmp(&x->replay, &x->preplay,
+ sizeof(struct xfrm_replay_state)) == 0) {
+ x->xflags |= XFRM_TIME_DEFER;
+ return;
+ }
+
+ break;
+ }
+
+ memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state));
+ c.event = XFRM_MSG_NEWAE;
+ c.data.aevent = event;
+ km_state_notify(x, &c);
+
+ if (x->replay_maxage &&
+ !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
+ x->xflags &= ~XFRM_TIME_DEFER;
+}
+
+static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err = 0;
+ struct net *net = xs_net(x);
+
+ if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
+ XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
+ if (unlikely(x->replay.oseq == 0)) {
+ x->replay.oseq--;
+ xfrm_audit_state_replay_overflow(x, skb);
+ err = -EOVERFLOW;
+
+ return err;
+ }
+ if (xfrm_aevent_is_on(net))
+ x->repl->notify(x, XFRM_REPLAY_UPDATE);
+ }
+
+ return err;
+}
+
+static int xfrm_replay_check(struct xfrm_state *x,
+ struct sk_buff *skb, __be32 net_seq)
+{
+ u32 diff;
+ u32 seq = ntohl(net_seq);
+
+ if (unlikely(seq == 0))
+ goto err;
+
+ if (likely(seq > x->replay.seq))
+ return 0;
+
+ diff = x->replay.seq - seq;
+ if (diff >= min_t(unsigned int, x->props.replay_window,
+ sizeof(x->replay.bitmap) * 8)) {
+ x->stats.replay_window++;
+ goto err;
+ }
+
+ if (x->replay.bitmap & (1U << diff)) {
+ x->stats.replay++;
+ goto err;
+ }
+ return 0;
+
+err:
+ xfrm_audit_state_replay(x, skb, net_seq);
+ return -EINVAL;
+}
+
+static void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
+{
+ u32 diff;
+ u32 seq = ntohl(net_seq);
+
+ if (!x->props.replay_window)
+ return;
+
+ if (seq > x->replay.seq) {
+ diff = seq - x->replay.seq;
+ if (diff < x->props.replay_window)
+ x->replay.bitmap = ((x->replay.bitmap) << diff) | 1;
+ else
+ x->replay.bitmap = 1;
+ x->replay.seq = seq;
+ } else {
+ diff = x->replay.seq - seq;
+ x->replay.bitmap |= (1U << diff);
+ }
+
+ if (xfrm_aevent_is_on(xs_net(x)))
+ xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
+}
+
+static struct xfrm_replay xfrm_replay_legacy = {
+ .advance = xfrm_replay_advance,
+ .check = xfrm_replay_check,
+ .notify = xfrm_replay_notify,
+ .overflow = xfrm_replay_overflow,
+};
+
+int xfrm_init_replay(struct xfrm_state *x)
+{
+ x->repl = &xfrm_replay_legacy;
+
+ return 0;
+}
+EXPORT_SYMBOL(xfrm_init_replay);
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index cd6be49..23779d1 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -42,13 +42,6 @@
static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family);
static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
-#ifdef CONFIG_AUDITSYSCALL
-static void xfrm_audit_state_replay(struct xfrm_state *x,
- struct sk_buff *skb, __be32 net_seq);
-#else
-#define xfrm_audit_state_replay(x, s, sq) do { ; } while (0)
-#endif /* CONFIG_AUDITSYSCALL */
-
static inline unsigned int xfrm_dst_hash(struct net *net,
const xfrm_address_t *daddr,
const xfrm_address_t *saddr,
@@ -1619,54 +1612,6 @@
}
EXPORT_SYMBOL(xfrm_state_walk_done);
-
-void xfrm_replay_notify(struct xfrm_state *x, int event)
-{
- struct km_event c;
- /* we send notify messages in case
- * 1. we updated on of the sequence numbers, and the seqno difference
- * is at least x->replay_maxdiff, in this case we also update the
- * timeout of our timer function
- * 2. if x->replay_maxage has elapsed since last update,
- * and there were changes
- *
- * The state structure must be locked!
- */
-
- switch (event) {
- case XFRM_REPLAY_UPDATE:
- if (x->replay_maxdiff &&
- (x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
- (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff)) {
- if (x->xflags & XFRM_TIME_DEFER)
- event = XFRM_REPLAY_TIMEOUT;
- else
- return;
- }
-
- break;
-
- case XFRM_REPLAY_TIMEOUT:
- if ((x->replay.seq == x->preplay.seq) &&
- (x->replay.bitmap == x->preplay.bitmap) &&
- (x->replay.oseq == x->preplay.oseq)) {
- x->xflags |= XFRM_TIME_DEFER;
- return;
- }
-
- break;
- }
-
- memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state));
- c.event = XFRM_MSG_NEWAE;
- c.data.aevent = event;
- km_state_notify(x, &c);
-
- if (x->replay_maxage &&
- !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
- x->xflags &= ~XFRM_TIME_DEFER;
-}
-
static void xfrm_replay_timer_handler(unsigned long data)
{
struct xfrm_state *x = (struct xfrm_state*)data;
@@ -1675,7 +1620,7 @@
if (x->km.state == XFRM_STATE_VALID) {
if (xfrm_aevent_is_on(xs_net(x)))
- xfrm_replay_notify(x, XFRM_REPLAY_TIMEOUT);
+ x->repl->notify(x, XFRM_REPLAY_TIMEOUT);
else
x->xflags |= XFRM_TIME_DEFER;
}
@@ -1683,57 +1628,6 @@
spin_unlock(&x->lock);
}
-int xfrm_replay_check(struct xfrm_state *x,
- struct sk_buff *skb, __be32 net_seq)
-{
- u32 diff;
- u32 seq = ntohl(net_seq);
-
- if (unlikely(seq == 0))
- goto err;
-
- if (likely(seq > x->replay.seq))
- return 0;
-
- diff = x->replay.seq - seq;
- if (diff >= min_t(unsigned int, x->props.replay_window,
- sizeof(x->replay.bitmap) * 8)) {
- x->stats.replay_window++;
- goto err;
- }
-
- if (x->replay.bitmap & (1U << diff)) {
- x->stats.replay++;
- goto err;
- }
- return 0;
-
-err:
- xfrm_audit_state_replay(x, skb, net_seq);
- return -EINVAL;
-}
-
-void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
-{
- u32 diff;
- u32 seq = ntohl(net_seq);
-
- if (seq > x->replay.seq) {
- diff = seq - x->replay.seq;
- if (diff < x->props.replay_window)
- x->replay.bitmap = ((x->replay.bitmap) << diff) | 1;
- else
- x->replay.bitmap = 1;
- x->replay.seq = seq;
- } else {
- diff = x->replay.seq - seq;
- x->replay.bitmap |= (1U << diff);
- }
-
- if (xfrm_aevent_is_on(xs_net(x)))
- xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
-}
-
static LIST_HEAD(xfrm_km_list);
static DEFINE_RWLOCK(xfrm_km_lock);
@@ -2246,7 +2140,7 @@
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_replay_overflow);
-static void xfrm_audit_state_replay(struct xfrm_state *x,
+void xfrm_audit_state_replay(struct xfrm_state *x,
struct sk_buff *skb, __be32 net_seq)
{
struct audit_buffer *audit_buf;
@@ -2261,6 +2155,7 @@
spi, spi, ntohl(net_seq));
audit_log_end(audit_buf);
}
+EXPORT_SYMBOL_GPL(xfrm_audit_state_replay);
void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
{
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 468ab60..f7b3c85 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -475,8 +475,10 @@
x->preplay.seq = x->replay.seq+x->replay_maxdiff;
x->preplay.oseq = x->replay.oseq +x->replay_maxdiff;
- /* override default values from above */
+ if ((err = xfrm_init_replay(x)))
+ goto error;
+ /* override default values from above */
xfrm_update_ae_params(x, attrs);
return x;