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xfrm: replay: avoid xfrm replay notify indirection
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replay protection is implemented using a callback structure and then
called via

   x->repl->notify(), x->repl->recheck(), and so on.

all the differect functions are always built-in, so this could be direct
calls instead.

This first patch prepares for removal of the x->repl structure.
Add an enum with the three available replay modes to the xfrm_state
structure and then replace all x->repl->notify() calls by the new
xfrm_replay_notify() helper.

The helper checks the enum internally to adapt behaviour as needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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Florian Westphal authored and Steffen Klassert committed Jun 21, 2021
1 parent 30ad6a8 commit cfc61c5
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Showing 3 changed files with 39 additions and 19 deletions.
11 changes: 10 additions & 1 deletion include/net/xfrm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -145,6 +145,12 @@ enum {
XFRM_MODE_FLAG_TUNNEL = 1,
};

enum xfrm_replay_mode {
XFRM_REPLAY_MODE_LEGACY,
XFRM_REPLAY_MODE_BMP,
XFRM_REPLAY_MODE_ESN,
};

/* Full description of state of transformer. */
struct xfrm_state {
possible_net_t xs_net;
Expand Down Expand Up @@ -218,6 +224,8 @@ struct xfrm_state {
/* The functions for replay detection. */
const struct xfrm_replay *repl;

/* replay detection mode */
enum xfrm_replay_mode repl_mode;
/* internal flag that only holds state for delayed aevent at the
* moment
*/
Expand Down Expand Up @@ -305,7 +313,6 @@ struct xfrm_replay {
int (*recheck)(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);
};

Expand Down Expand Up @@ -1715,6 +1722,8 @@ static inline int xfrm_policy_id2dir(u32 index)
}

#ifdef CONFIG_XFRM
void xfrm_replay_notify(struct xfrm_state *x, int event);

static inline int xfrm_aevent_is_on(struct net *net)
{
struct sock *nlsk;
Expand Down
45 changes: 28 additions & 17 deletions net/xfrm/xfrm_replay.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,8 +34,11 @@ u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq)
return seq_hi;
}
EXPORT_SYMBOL(xfrm_replay_seqhi);
;
static void xfrm_replay_notify(struct xfrm_state *x, int event)

static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event);
static void xfrm_replay_notify_esn(struct xfrm_state *x, int event);

void xfrm_replay_notify(struct xfrm_state *x, int event)
{
struct km_event c;
/* we send notify messages in case
Expand All @@ -48,6 +51,17 @@ static void xfrm_replay_notify(struct xfrm_state *x, int event)
* The state structure must be locked!
*/

switch (x->repl_mode) {
case XFRM_REPLAY_MODE_LEGACY:
break;
case XFRM_REPLAY_MODE_BMP:
xfrm_replay_notify_bmp(x, event);
return;
case XFRM_REPLAY_MODE_ESN:
xfrm_replay_notify_esn(x, event);
return;
}

switch (event) {
case XFRM_REPLAY_UPDATE:
if (!x->replay_maxdiff ||
Expand Down Expand Up @@ -98,7 +112,7 @@ static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
return err;
}
if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand Down Expand Up @@ -157,7 +171,7 @@ static void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
}

if (xfrm_aevent_is_on(xs_net(x)))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
Expand All @@ -178,7 +192,7 @@ static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
return err;
}
if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand Down Expand Up @@ -273,7 +287,7 @@ static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq)
replay_esn->bmp[nr] |= (1U << bitnr);

if (xfrm_aevent_is_on(xs_net(x)))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
Expand Down Expand Up @@ -416,7 +430,7 @@ static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
}
}
if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand Down Expand Up @@ -548,7 +562,7 @@ static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
replay_esn->bmp[nr] |= (1U << bitnr);

if (xfrm_aevent_is_on(xs_net(x)))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

#ifdef CONFIG_XFRM_OFFLOAD
Expand Down Expand Up @@ -585,7 +599,7 @@ static int xfrm_replay_overflow_offload(struct xfrm_state *x, struct sk_buff *sk
x->replay.oseq = oseq;

if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand Down Expand Up @@ -625,7 +639,7 @@ static int xfrm_replay_overflow_offload_bmp(struct xfrm_state *x, struct sk_buff
}

if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand Down Expand Up @@ -674,7 +688,7 @@ static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff
replay_esn->oseq = oseq;

if (xfrm_aevent_is_on(net))
x->repl->notify(x, XFRM_REPLAY_UPDATE);
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}

return err;
Expand All @@ -684,47 +698,41 @@ static const struct xfrm_replay xfrm_replay_legacy = {
.advance = xfrm_replay_advance,
.check = xfrm_replay_check,
.recheck = xfrm_replay_check,
.notify = xfrm_replay_notify,
.overflow = xfrm_replay_overflow_offload,
};

static const struct xfrm_replay xfrm_replay_bmp = {
.advance = xfrm_replay_advance_bmp,
.check = xfrm_replay_check_bmp,
.recheck = xfrm_replay_check_bmp,
.notify = xfrm_replay_notify_bmp,
.overflow = xfrm_replay_overflow_offload_bmp,
};

static const struct xfrm_replay xfrm_replay_esn = {
.advance = xfrm_replay_advance_esn,
.check = xfrm_replay_check_esn,
.recheck = xfrm_replay_recheck_esn,
.notify = xfrm_replay_notify_esn,
.overflow = xfrm_replay_overflow_offload_esn,
};
#else
static const struct xfrm_replay xfrm_replay_legacy = {
.advance = xfrm_replay_advance,
.check = xfrm_replay_check,
.recheck = xfrm_replay_check,
.notify = xfrm_replay_notify,
.overflow = xfrm_replay_overflow,
};

static const struct xfrm_replay xfrm_replay_bmp = {
.advance = xfrm_replay_advance_bmp,
.check = xfrm_replay_check_bmp,
.recheck = xfrm_replay_check_bmp,
.notify = xfrm_replay_notify_bmp,
.overflow = xfrm_replay_overflow_bmp,
};

static const struct xfrm_replay xfrm_replay_esn = {
.advance = xfrm_replay_advance_esn,
.check = xfrm_replay_check_esn,
.recheck = xfrm_replay_recheck_esn,
.notify = xfrm_replay_notify_esn,
.overflow = xfrm_replay_overflow_esn,
};
#endif
Expand All @@ -742,11 +750,14 @@ int xfrm_init_replay(struct xfrm_state *x)
if (replay_esn->replay_window == 0)
return -EINVAL;
x->repl = &xfrm_replay_esn;
x->repl_mode = XFRM_REPLAY_MODE_ESN;
} else {
x->repl = &xfrm_replay_bmp;
x->repl_mode = XFRM_REPLAY_MODE_BMP;
}
} else {
x->repl = &xfrm_replay_legacy;
x->repl_mode = XFRM_REPLAY_MODE_LEGACY;
}

return 0;
Expand Down
2 changes: 1 addition & 1 deletion net/xfrm/xfrm_state.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2177,7 +2177,7 @@ static void xfrm_replay_timer_handler(struct timer_list *t)

if (x->km.state == XFRM_STATE_VALID) {
if (xfrm_aevent_is_on(xs_net(x)))
x->repl->notify(x, XFRM_REPLAY_TIMEOUT);
xfrm_replay_notify(x, XFRM_REPLAY_TIMEOUT);
else
x->xflags |= XFRM_TIME_DEFER;
}
Expand Down

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