From 36cf9acf93e8561d9faec24849e57688a81eb9c5 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 13 Nov 2007 21:40:52 -0800 Subject: [IPSEC]: Separate inner/outer mode processing on output With inter-family transforms the inner mode differs from the outer mode. Attempting to handle both sides from the same function means that it needs to handle both IPv4 and IPv6 which creates duplication and confusion. This patch separates the two parts on the output path so that each function deals with one family only. In particular, the functions xfrm4_extract_output/xfrm6_extract_output moves the pertinent fields from the IPv4/IPv6 IP headers into a neutral format stored in skb->cb. This is then used by the outer mode output functions to write the outer IP header. In this way the output function no longer has to know about the inner address family. Since the extract functions are only called by tunnel modes (the only modes that can support inter-family transforms), I've also moved the xfrm*_tunnel_check_size calls into them. This allows the correct ICMP message to be sent as opposed to now where you might call icmp_send with an IPv6 packet and vice versa. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/xfrm4_mode_beet.c | 15 +++++++++++++-- net/ipv4/xfrm4_mode_tunnel.c | 37 +++++++++++-------------------------- net/ipv4/xfrm4_output.c | 41 ++++++++++++++++++++++++++++++----------- net/ipv4/xfrm4_state.c | 17 +++++++++++++++++ 4 files changed, 71 insertions(+), 39 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c index e42e122414be..94842adce144 100644 --- a/net/ipv4/xfrm4_mode_beet.c +++ b/net/ipv4/xfrm4_mode_beet.c @@ -43,7 +43,17 @@ static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb) ph = (struct ip_beet_phdr *)__skb_pull(skb, sizeof(*iph) - hdrlen); top_iph = ip_hdr(skb); - memmove(top_iph, iph, sizeof(*iph)); + + top_iph->ihl = 5; + top_iph->version = 4; + + top_iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol; + top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos; + + top_iph->id = XFRM_MODE_SKB_CB(skb)->id; + top_iph->frag_off = XFRM_MODE_SKB_CB(skb)->frag_off; + top_iph->ttl = XFRM_MODE_SKB_CB(skb)->ttl; + if (unlikely(optlen)) { BUG_ON(optlen < 0); @@ -111,7 +121,8 @@ out: static struct xfrm_mode xfrm4_beet_mode = { .input = xfrm4_beet_input, - .output = xfrm4_beet_output, + .output2 = xfrm4_beet_output, + .output = xfrm4_prepare_output, .owner = THIS_MODULE, .encap = XFRM_MODE_BEET, .flags = XFRM_MODE_FLAG_TUNNEL, diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c index 68a9f56ff09f..cc8bbb274e37 100644 --- a/net/ipv4/xfrm4_mode_tunnel.c +++ b/net/ipv4/xfrm4_mode_tunnel.c @@ -36,53 +36,37 @@ static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) static int xfrm4_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) { struct dst_entry *dst = skb->dst; - struct xfrm_dst *xdst = (struct xfrm_dst*)dst; - struct iphdr *iph, *top_iph; + struct iphdr *top_iph; int flags; - iph = ip_hdr(skb); - skb_set_network_header(skb, -x->props.header_len); skb->mac_header = skb->network_header + offsetof(struct iphdr, protocol); - skb->transport_header = skb->network_header + sizeof(*iph); + skb->transport_header = skb->network_header + sizeof(*top_iph); top_iph = ip_hdr(skb); top_iph->ihl = 5; top_iph->version = 4; - flags = x->props.flags; + top_iph->protocol = x->inner_mode->afinfo->proto; /* DS disclosed */ - if (xdst->route->ops->family == AF_INET) { - top_iph->protocol = IPPROTO_IPIP; - top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos); - top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? - 0 : (iph->frag_off & htons(IP_DF)); - } -#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) - else { - struct ipv6hdr *ipv6h = (struct ipv6hdr*)iph; - top_iph->protocol = IPPROTO_IPV6; - top_iph->tos = INET_ECN_encapsulate(iph->tos, ipv6_get_dsfield(ipv6h)); - top_iph->frag_off = 0; - } -#endif + top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos, + XFRM_MODE_SKB_CB(skb)->tos); + flags = x->props.flags; if (flags & XFRM_STATE_NOECN) IP_ECN_clear(top_iph); - if (!top_iph->frag_off) - __ip_select_ident(top_iph, dst->child, 0); + top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? + 0 : XFRM_MODE_SKB_CB(skb)->frag_off; + ip_select_ident(top_iph, dst->child, NULL); top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT); top_iph->saddr = x->props.saddr.a4; top_iph->daddr = x->id.daddr.a4; - skb->protocol = htons(ETH_P_IP); - - memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); return 0; } @@ -136,7 +120,8 @@ out: static struct xfrm_mode xfrm4_tunnel_mode = { .input = xfrm4_tunnel_input, - .output = xfrm4_tunnel_output, + .output2 = xfrm4_tunnel_output, + .output = xfrm4_prepare_output, .owner = THIS_MODULE, .encap = XFRM_MODE_TUNNEL, .flags = XFRM_MODE_FLAG_TUNNEL, diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index c4a7156962bd..13fd11335e28 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -8,11 +8,12 @@ * 2 of the License, or (at your option) any later version. */ -#include #include #include +#include #include #include +#include #include #include #include @@ -25,8 +26,6 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb) if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE) goto out; - IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE; - if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df) goto out; @@ -40,19 +39,39 @@ out: return ret; } +int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb) +{ + int err; + + err = xfrm4_tunnel_check_size(skb); + if (err) + return err; + + return xfrm4_extract_header(skb); +} + +int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb) +{ + int err; + + err = x->inner_mode->afinfo->extract_output(x, skb); + if (err) + return err; + + memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE; + + skb->protocol = htons(ETH_P_IP); + + return x->outer_mode->output2(x, skb); +} +EXPORT_SYMBOL(xfrm4_prepare_output); + static inline int xfrm4_output_one(struct sk_buff *skb) { - struct dst_entry *dst = skb->dst; - struct xfrm_state *x = dst->xfrm; struct iphdr *iph; int err; - if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) { - err = xfrm4_tunnel_check_size(skb); - if (err) - goto error_nolock; - } - err = xfrm_output(skb); if (err) goto error_nolock; diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c index 13d54a1c3337..e6030e74ff65 100644 --- a/net/ipv4/xfrm4_state.c +++ b/net/ipv4/xfrm4_state.c @@ -47,12 +47,29 @@ __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl, x->props.family = AF_INET; } +int xfrm4_extract_header(struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + + XFRM_MODE_SKB_CB(skb)->id = iph->id; + XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off; + XFRM_MODE_SKB_CB(skb)->tos = iph->tos; + XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl; + XFRM_MODE_SKB_CB(skb)->protocol = iph->protocol; + memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0, + sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl)); + + return 0; +} + static struct xfrm_state_afinfo xfrm4_state_afinfo = { .family = AF_INET, + .proto = IPPROTO_IPIP, .owner = THIS_MODULE, .init_flags = xfrm4_init_flags, .init_tempsel = __xfrm4_init_tempsel, .output = xfrm4_output, + .extract_output = xfrm4_extract_output, }; void __init xfrm4_state_init(void) -- cgit v1.2.3-59-g8ed1b