From: Steffen Klassert Subject: [RFC v2 PATCH 6/9] xfrm: Move IPsec replay detection functions to a separate file Date: Tue, 8 Mar 2011 11:08:32 +0100 Message-ID: <20110308100832.GH31402@secunet.com> References: <20110308100407.GB31402@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alex Badea , Andreas Gruenbacher , netdev@vger.kernel.org, linux-crypto@vger.kernel.org To: Herbert Xu , David Miller Return-path: Content-Disposition: inline In-Reply-To: <20110308100407.GB31402@secunet.com> Sender: netdev-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org 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 --- include/net/xfrm.h | 24 +++++++-- net/xfrm/Makefile | 2 +- net/xfrm/xfrm_input.c | 5 +- net/xfrm/xfrm_output.c | 15 ++---- net/xfrm/xfrm_replay.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++ net/xfrm/xfrm_state.c | 111 +------------------------------------ net/xfrm/xfrm_user.c | 4 +- 7 files changed, 174 insertions(+), 128 deletions(-) create mode 100644 net/xfrm/xfrm_replay.c diff --git a/include/net/xfrm.h b/include/net/xfrm.h index d546d81..570eb77 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -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); 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 @@ 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++; 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 @@ 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; 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 + +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 81221d9..104cddf 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -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) { 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 @@ 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; -- 1.7.0.4