From 16a6677fdf1d1194f688f8291b06fbaff248c353 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Fri, 6 Jan 2006 23:01:48 -0800 Subject: [PATCH] [XFRM]: Netfilter IPsec output hooks Call netfilter hooks before IPsec transforms. Packets visit the FORWARD/LOCAL_OUT and POST_ROUTING hook before the first encapsulation and the LOCAL_OUT and POST_ROUTING hook before each following tunnel mode transform. Patch from Herbert Xu : Move the loop from dst_output into xfrm4_output/xfrm6_output since they're the only ones who need to it. xfrm{4,6}_output_one() processes the first SA all subsequent transport mode SAs and is called in a loop that calls the netfilter hooks between each two calls. In order to avoid the tail call issue, I've added the inline function nf_hook which is nf_hook_slow plus the empty list check. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter.h | 61 ++++++++++++++++++------------- include/net/dst.h | 11 +----- net/ipv4/xfrm4_output.c | 71 +++++++++++++++++++++++++++--------- net/ipv6/xfrm6_output.c | 75 +++++++++++++++++++++++++++++---------- 4 files changed, 148 insertions(+), 70 deletions(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index be365e70ee99..79bb977afeac 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -168,6 +168,37 @@ void nf_log_packet(int pf, const struct net_device *out, struct nf_loginfo *li, const char *fmt, ...); + +int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, + struct net_device *indev, struct net_device *outdev, + int (*okfn)(struct sk_buff *), int thresh); + +/** + * nf_hook_thresh - call a netfilter hook + * + * Returns 1 if the hook has allowed the packet to pass. The function + * okfn must be invoked by the caller in this case. Any other return + * value indicates the packet has been consumed by the hook. + */ +static inline int nf_hook_thresh(int pf, unsigned int hook, + struct sk_buff **pskb, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sk_buff *), int thresh) +{ +#ifndef CONFIG_NETFILTER_DEBUG + if (list_empty(&nf_hooks[pf][hook])) + return 1; +#endif + return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh); +} + +static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb, + struct net_device *indev, struct net_device *outdev, + int (*okfn)(struct sk_buff *)) +{ + return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN); +} /* Activate hook; either okfn or kfree_skb called, unless a hook returns NF_STOLEN (in which case, it's up to the hook to deal with @@ -188,35 +219,17 @@ void nf_log_packet(int pf, /* This is gross, but inline doesn't cut it for avoiding the function call in fast path: gcc doesn't inline (needs value tracking?). --RR */ -#ifdef CONFIG_NETFILTER_DEBUG -#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ -({int __ret; \ -if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ - __ret = (okfn)(skb); \ -__ret;}) -#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ -({int __ret; \ -if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ - __ret = (okfn)(skb); \ -__ret;}) -#else -#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ -({int __ret; \ -if (list_empty(&nf_hooks[pf][hook]) || \ - (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ - __ret = (okfn)(skb); \ -__ret;}) + +/* HX: It's slightly less gross now. */ + #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ ({int __ret; \ -if (list_empty(&nf_hooks[pf][hook]) || \ - (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ +if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1)\ __ret = (okfn)(skb); \ __ret;}) -#endif -int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, - struct net_device *indev, struct net_device *outdev, - int (*okfn)(struct sk_buff *), int thresh); +#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ + NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN) /* Call setsockopt() */ int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, diff --git a/include/net/dst.h b/include/net/dst.h index bee8b84d329d..5161e89017f9 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -225,16 +225,7 @@ static inline void dst_set_expires(struct dst_entry *dst, int timeout) /* Output packet to network from transport. */ static inline int dst_output(struct sk_buff *skb) { - int err; - - for (;;) { - err = skb->dst->output(skb); - - if (likely(err == 0)) - return err; - if (unlikely(err != NET_XMIT_BYPASS)) - return err; - } + return skb->dst->output(skb); } /* Input packet from network to transport. */ diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index 66620a95942a..51fabb8f7c54 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -8,8 +8,10 @@ * 2 of the License, or (at your option) any later version. */ +#include #include #include +#include #include #include #include @@ -95,7 +97,7 @@ out: return ret; } -int xfrm4_output(struct sk_buff *skb) +static int xfrm4_output_one(struct sk_buff *skb) { struct dst_entry *dst = skb->dst; struct xfrm_state *x = dst->xfrm; @@ -113,27 +115,32 @@ int xfrm4_output(struct sk_buff *skb) goto error_nolock; } - spin_lock_bh(&x->lock); - err = xfrm_state_check(x, skb); - if (err) - goto error; + do { + spin_lock_bh(&x->lock); + err = xfrm_state_check(x, skb); + if (err) + goto error; - xfrm4_encap(skb); + xfrm4_encap(skb); - err = x->type->output(x, skb); - if (err) - goto error; + err = x->type->output(x, skb); + if (err) + goto error; - x->curlft.bytes += skb->len; - x->curlft.packets++; + x->curlft.bytes += skb->len; + x->curlft.packets++; - spin_unlock_bh(&x->lock); + spin_unlock_bh(&x->lock); - if (!(skb->dst = dst_pop(dst))) { - err = -EHOSTUNREACH; - goto error_nolock; - } - err = NET_XMIT_BYPASS; + if (!(skb->dst = dst_pop(dst))) { + err = -EHOSTUNREACH; + goto error_nolock; + } + dst = skb->dst; + x = dst->xfrm; + } while (x && !x->props.mode); + + err = 0; out_exit: return err; @@ -143,3 +150,33 @@ error_nolock: kfree_skb(skb); goto out_exit; } + +static int xfrm4_output_finish(struct sk_buff *skb) +{ + int err; + + while (likely((err = xfrm4_output_one(skb)) == 0)) { + nf_reset(skb); + + err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL, + skb->dst->dev, dst_output); + if (unlikely(err != 1)) + break; + + if (!skb->dst->xfrm) + return dst_output(skb); + + err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL, + skb->dst->dev, xfrm4_output_finish); + if (unlikely(err != 1)) + break; + } + + return err; +} + +int xfrm4_output(struct sk_buff *skb) +{ + return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev, + xfrm4_output_finish); +} diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index 6b9867717d11..fc0ea38953c4 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -9,9 +9,11 @@ * 2 of the License, or (at your option) any later version. */ +#include #include #include #include +#include #include #include #include @@ -92,7 +94,7 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb) return ret; } -int xfrm6_output(struct sk_buff *skb) +static int xfrm6_output_one(struct sk_buff *skb) { struct dst_entry *dst = skb->dst; struct xfrm_state *x = dst->xfrm; @@ -110,29 +112,34 @@ int xfrm6_output(struct sk_buff *skb) goto error_nolock; } - spin_lock_bh(&x->lock); - err = xfrm_state_check(x, skb); - if (err) - goto error; + do { + spin_lock_bh(&x->lock); + err = xfrm_state_check(x, skb); + if (err) + goto error; - xfrm6_encap(skb); + xfrm6_encap(skb); - err = x->type->output(x, skb); - if (err) - goto error; + err = x->type->output(x, skb); + if (err) + goto error; - x->curlft.bytes += skb->len; - x->curlft.packets++; + x->curlft.bytes += skb->len; + x->curlft.packets++; - spin_unlock_bh(&x->lock); + spin_unlock_bh(&x->lock); - skb->nh.raw = skb->data; - - if (!(skb->dst = dst_pop(dst))) { - err = -EHOSTUNREACH; - goto error_nolock; - } - err = NET_XMIT_BYPASS; + skb->nh.raw = skb->data; + + if (!(skb->dst = dst_pop(dst))) { + err = -EHOSTUNREACH; + goto error_nolock; + } + dst = skb->dst; + x = dst->xfrm; + } while (x && !x->props.mode); + + err = 0; out_exit: return err; @@ -142,3 +149,33 @@ error_nolock: kfree_skb(skb); goto out_exit; } + +static int xfrm6_output_finish(struct sk_buff *skb) +{ + int err; + + while (likely((err = xfrm6_output_one(skb)) == 0)) { + nf_reset(skb); + + err = nf_hook(PF_INET6, NF_IP6_LOCAL_OUT, &skb, NULL, + skb->dst->dev, dst_output); + if (unlikely(err != 1)) + break; + + if (!skb->dst->xfrm) + return dst_output(skb); + + err = nf_hook(PF_INET6, NF_IP6_POST_ROUTING, &skb, NULL, + skb->dst->dev, xfrm6_output_finish); + if (unlikely(err != 1)) + break; + } + + return err; +} + +int xfrm6_output(struct sk_buff *skb) +{ + return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev, + xfrm6_output_finish); +} -- 2.20.1