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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>
This commit is contained in:
Steffen Klassert 2011-03-08 00:08:32 +00:00 committed by David S. Miller
parent d212a4c290
commit 9fdc4883d9
7 changed files with 174 additions and 128 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
include/net/xfrm.h
View File

@ -192,6 +192,9 @@ struct xfrm_state {
struct xfrm_replay_state preplay;
struct xfrm_replay_state_esn *preplay_esn;
/* The functions for replay detection. */
struct xfrm_replay *repl;
/* internal flag that only holds state for delayed aevent at the
* moment
*/
@ -261,6 +264,15 @@ struct km_event {
struct net *net;
};
struct xfrm_replay {
void (*advance)(struct xfrm_state *x, __be32 net_seq);
int (*check)(struct xfrm_state *x,
struct sk_buff *skb,
__be32 net_seq);
void (*notify)(struct xfrm_state *x, int event);
int (*overflow)(struct xfrm_state *x, struct sk_buff *skb);
};
struct net_device;
struct xfrm_type;
struct xfrm_dst;
@ -693,6 +705,8 @@ extern void xfrm_audit_state_delete(struct xfrm_state *x, int result,
u32 auid, u32 ses, u32 secid);
extern void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
struct sk_buff *skb);
extern void xfrm_audit_state_replay(struct xfrm_state *x,
struct sk_buff *skb, __be32 net_seq);
extern void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family);
extern void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
__be32 net_spi, __be32 net_seq);
@ -725,6 +739,11 @@ static inline void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
{
}
static inline void xfrm_audit_state_replay(struct xfrm_state *x,
struct sk_buff *skb, __be32 net_seq)
{
}
static inline void xfrm_audit_state_notfound_simple(struct sk_buff *skb,
u16 family)
{
@ -1408,10 +1427,7 @@ extern int xfrm_state_delete(struct xfrm_state *x);
extern int xfrm_state_flush(struct net *net, u8 proto, struct xfrm_audit *audit_info);
extern void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
extern void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
extern int xfrm_replay_check(struct xfrm_state *x,
struct sk_buff *skb, __be32 seq);
extern void xfrm_replay_advance(struct xfrm_state *x, __be32 seq);
extern void xfrm_replay_notify(struct xfrm_state *x, int event);
extern int xfrm_init_replay(struct xfrm_state *x);
extern int xfrm_state_mtu(struct xfrm_state *x, int mtu);
extern int xfrm_init_state(struct xfrm_state *x);
extern int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);

2
net/xfrm/Makefile
View File

@ -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

5
net/xfrm/xfrm_input.c
View File

@ -172,7 +172,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
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 @@ resume:
/* 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++;

15
net/xfrm/xfrm_output.c
View File

@ -67,17 +67,10 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
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;

141
net/xfrm/xfrm_replay.c Normal file
View File

@ -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);

111
net/xfrm/xfrm_state.c
View File

@ -42,13 +42,6 @@ static unsigned int xfrm_state_hashmax __read_mostly = 1 * 1024 * 1024;
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 @@ void xfrm_state_walk_done(struct xfrm_state_walk *walk)
}
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 @@ static void xfrm_replay_timer_handler(unsigned long data)
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 @@ static void xfrm_replay_timer_handler(unsigned long data)
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 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
}
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 @@ static void xfrm_audit_state_replay(struct xfrm_state *x,
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)
{

4
net/xfrm/xfrm_user.c
View File

@ -475,8 +475,10 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
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;