From b59f45d0b2878ab76f8053b0973654e6621828ee Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 27 May 2006 23:05:54 -0700 Subject: [IPSEC] xfrm: Abstract out encapsulation modes This patch adds the structure xfrm_mode. It is meant to represent the operations carried out by transport/tunnel modes. By doing this we allow additional encapsulation modes to be added without clogging up the xfrm_input/xfrm_output paths. Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and BEET modes. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/Kconfig | 18 ++++++ net/ipv4/Makefile | 2 + net/ipv4/xfrm4_input.c | 28 +-------- net/ipv4/xfrm4_mode_transport.c | 69 ++++++++++++++++++++++ net/ipv4/xfrm4_mode_tunnel.c | 125 ++++++++++++++++++++++++++++++++++++++++ net/ipv4/xfrm4_output.c | 61 +------------------- 6 files changed, 219 insertions(+), 84 deletions(-) create mode 100644 net/ipv4/xfrm4_mode_transport.c create mode 100644 net/ipv4/xfrm4_mode_tunnel.c (limited to 'net/ipv4') diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig index e40f75322377..35eb70b1448d 100644 --- a/net/ipv4/Kconfig +++ b/net/ipv4/Kconfig @@ -414,6 +414,24 @@ config INET_TUNNEL tristate default n +config INET_XFRM_MODE_TRANSPORT + tristate "IP: IPsec transport mode" + default y + select XFRM + ---help--- + Support for IPsec transport mode. + + If unsure, say Y. + +config INET_XFRM_MODE_TUNNEL + tristate "IP: IPsec tunnel mode" + default y + select XFRM + ---help--- + Support for IPsec tunnel mode. + + If unsure, say Y. + config INET_DIAG tristate "INET: socket monitoring interface" default y diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index 9ef50a0b9d2c..4cc94482eacc 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -24,6 +24,8 @@ obj-$(CONFIG_INET_ESP) += esp4.o obj-$(CONFIG_INET_IPCOMP) += ipcomp.o obj-$(CONFIG_INET_XFRM_TUNNEL) += xfrm4_tunnel.o obj-$(CONFIG_INET_TUNNEL) += tunnel4.o +obj-$(CONFIG_INET_XFRM_MODE_TRANSPORT) += xfrm4_mode_transport.o +obj-$(CONFIG_INET_XFRM_MODE_TUNNEL) += xfrm4_mode_tunnel.o obj-$(CONFIG_IP_PNP) += ipconfig.o obj-$(CONFIG_IP_ROUTE_MULTIPATH_RR) += multipath_rr.o obj-$(CONFIG_IP_ROUTE_MULTIPATH_RANDOM) += multipath_random.o diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c index 3e174c83bfe7..817ed84511a6 100644 --- a/net/ipv4/xfrm4_input.c +++ b/net/ipv4/xfrm4_input.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include @@ -24,15 +23,6 @@ int xfrm4_rcv(struct sk_buff *skb) EXPORT_SYMBOL(xfrm4_rcv); -static inline void ipip_ecn_decapsulate(struct sk_buff *skb) -{ - struct iphdr *outer_iph = skb->nh.iph; - struct iphdr *inner_iph = skb->h.ipiph; - - if (INET_ECN_is_ce(outer_iph->tos)) - IP_ECN_set_ce(inner_iph); -} - static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq) { switch (nexthdr) { @@ -113,24 +103,10 @@ int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) xfrm_vec[xfrm_nr++] = x; - iph = skb->nh.iph; + if (x->mode->input(x, skb)) + goto drop; if (x->props.mode) { - if (iph->protocol != IPPROTO_IPIP) - goto drop; - if (!pskb_may_pull(skb, sizeof(struct iphdr))) - goto drop; - if (skb_cloned(skb) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) - goto drop; - if (x->props.flags & XFRM_STATE_DECAP_DSCP) - ipv4_copy_dscp(iph, skb->h.ipiph); - if (!(x->props.flags & XFRM_STATE_NOECN)) - ipip_ecn_decapsulate(skb); - skb->mac.raw = memmove(skb->data - skb->mac_len, - skb->mac.raw, skb->mac_len); - skb->nh.raw = skb->data; - memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); decaps = 1; break; } diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c new file mode 100644 index 000000000000..e46d9a4ccc55 --- /dev/null +++ b/net/ipv4/xfrm4_mode_transport.c @@ -0,0 +1,69 @@ +/* + * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4. + * + * Copyright (c) 2004-2006 Herbert Xu + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* Add encapsulation header. + * + * The IP header will be moved forward to make space for the encapsulation + * header. + * + * On exit, skb->h will be set to the start of the payload to be processed + * by x->type->output and skb->nh will be set to the top IP header. + */ +static int xfrm4_transport_output(struct sk_buff *skb) +{ + struct xfrm_state *x; + struct iphdr *iph; + int ihl; + + iph = skb->nh.iph; + skb->h.ipiph = iph; + + ihl = iph->ihl * 4; + skb->h.raw += ihl; + + x = skb->dst->xfrm; + skb->nh.raw = memmove(skb_push(skb, x->props.header_len), iph, ihl); + return 0; +} + +static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb) +{ + return 0; +} + +static struct xfrm_mode xfrm4_transport_mode = { + .input = xfrm4_transport_input, + .output = xfrm4_transport_output, + .owner = THIS_MODULE, + .encap = XFRM_MODE_TRANSPORT, +}; + +static int __init xfrm4_transport_init(void) +{ + return xfrm_register_mode(&xfrm4_transport_mode, AF_INET); +} + +static void __exit xfrm4_transport_exit(void) +{ + int err; + + err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET); + BUG_ON(err); +} + +module_init(xfrm4_transport_init); +module_exit(xfrm4_transport_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT); diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c new file mode 100644 index 000000000000..f8d880beb12f --- /dev/null +++ b/net/ipv4/xfrm4_mode_tunnel.c @@ -0,0 +1,125 @@ +/* + * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4. + * + * Copyright (c) 2004-2006 Herbert Xu + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static inline void ipip_ecn_decapsulate(struct sk_buff *skb) +{ + struct iphdr *outer_iph = skb->nh.iph; + struct iphdr *inner_iph = skb->h.ipiph; + + if (INET_ECN_is_ce(outer_iph->tos)) + IP_ECN_set_ce(inner_iph); +} + +/* Add encapsulation header. + * + * The top IP header will be constructed per RFC 2401. The following fields + * in it shall be filled in by x->type->output: + * tot_len + * check + * + * On exit, skb->h will be set to the start of the payload to be processed + * by x->type->output and skb->nh will be set to the top IP header. + */ +static int xfrm4_tunnel_output(struct sk_buff *skb) +{ + struct dst_entry *dst = skb->dst; + struct xfrm_state *x = dst->xfrm; + struct iphdr *iph, *top_iph; + int flags; + + iph = skb->nh.iph; + skb->h.ipiph = iph; + + skb->nh.raw = skb_push(skb, x->props.header_len); + top_iph = skb->nh.iph; + + top_iph->ihl = 5; + top_iph->version = 4; + + /* DS disclosed */ + top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos); + + flags = x->props.flags; + if (flags & XFRM_STATE_NOECN) + IP_ECN_clear(top_iph); + + top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? + 0 : (iph->frag_off & htons(IP_DF)); + if (!top_iph->frag_off) + __ip_select_ident(top_iph, dst->child, 0); + + top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT); + + top_iph->saddr = x->props.saddr.a4; + top_iph->daddr = x->id.daddr.a4; + top_iph->protocol = IPPROTO_IPIP; + + memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); + return 0; +} + +static int xfrm4_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) +{ + struct iphdr *iph = skb->nh.iph; + int err = -EINVAL; + + if (iph->protocol != IPPROTO_IPIP) + goto out; + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto out; + + if (skb_cloned(skb) && + (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) + goto out; + + if (x->props.flags & XFRM_STATE_DECAP_DSCP) + ipv4_copy_dscp(iph, skb->h.ipiph); + if (!(x->props.flags & XFRM_STATE_NOECN)) + ipip_ecn_decapsulate(skb); + skb->mac.raw = memmove(skb->data - skb->mac_len, + skb->mac.raw, skb->mac_len); + skb->nh.raw = skb->data; + memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); + err = 0; + +out: + return err; +} + +static struct xfrm_mode xfrm4_tunnel_mode = { + .input = xfrm4_tunnel_input, + .output = xfrm4_tunnel_output, + .owner = THIS_MODULE, + .encap = XFRM_MODE_TUNNEL, +}; + +static int __init xfrm4_tunnel_init(void) +{ + return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET); +} + +static void __exit xfrm4_tunnel_exit(void) +{ + int err; + + err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET); + BUG_ON(err); +} + +module_init(xfrm4_tunnel_init); +module_exit(xfrm4_tunnel_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL); diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index 4ef8efaf6a67..ac9d91d4bb05 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -12,67 +12,10 @@ #include #include #include -#include #include #include #include -/* Add encapsulation header. - * - * In transport mode, the IP header will be moved forward to make space - * for the encapsulation header. - * - * In tunnel mode, the top IP header will be constructed per RFC 2401. - * The following fields in it shall be filled in by x->type->output: - * tot_len - * check - * - * On exit, skb->h will be set to the start of the payload to be processed - * by x->type->output and skb->nh will be set to the top IP header. - */ -static void xfrm4_encap(struct sk_buff *skb) -{ - struct dst_entry *dst = skb->dst; - struct xfrm_state *x = dst->xfrm; - struct iphdr *iph, *top_iph; - int flags; - - iph = skb->nh.iph; - skb->h.ipiph = iph; - - skb->nh.raw = skb_push(skb, x->props.header_len); - top_iph = skb->nh.iph; - - if (!x->props.mode) { - skb->h.raw += iph->ihl*4; - memmove(top_iph, iph, iph->ihl*4); - return; - } - - top_iph->ihl = 5; - top_iph->version = 4; - - /* DS disclosed */ - top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos); - - flags = x->props.flags; - if (flags & XFRM_STATE_NOECN) - IP_ECN_clear(top_iph); - - top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? - 0 : (iph->frag_off & htons(IP_DF)); - if (!top_iph->frag_off) - __ip_select_ident(top_iph, dst->child, 0); - - top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT); - - top_iph->saddr = x->props.saddr.a4; - top_iph->daddr = x->id.daddr.a4; - top_iph->protocol = IPPROTO_IPIP; - - memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); -} - static int xfrm4_tunnel_check_size(struct sk_buff *skb) { int mtu, ret = 0; @@ -121,7 +64,9 @@ static int xfrm4_output_one(struct sk_buff *skb) if (err) goto error; - xfrm4_encap(skb); + err = x->mode->output(skb); + if (err) + goto error; err = x->type->output(x, skb); if (err) -- cgit v1.2.3