From 3d126890dd67beffec27c1b6f51c040fc8d0b526 Mon Sep 17 00:00:00 2001 From: Noriaki TAKAMIYA Date: Wed, 23 Aug 2006 20:32:34 -0700 Subject: [PATCH] [IPV6] MIP6: Add destination options header transformation. Add destination options header transformation for Mobile IPv6. Based on MIPL2 kernel patch. This patch was also written by: Ville Nuorvala Signed-off-by: Noriaki TAKAMIYA Signed-off-by: Masahide NAKAMURA Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- include/net/mip6.h | 3 + net/ipv6/mip6.c | 167 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 170 insertions(+) diff --git a/include/net/mip6.h b/include/net/mip6.h index 644b8b67304..42b65bace12 100644 --- a/include/net/mip6.h +++ b/include/net/mip6.h @@ -25,6 +25,9 @@ #ifndef _NET_MIP6_H #define _NET_MIP6_H +#define MIP6_OPT_PAD_1 0 +#define MIP6_OPT_PAD_N 1 + extern int mip6_init(void); extern void mip6_fini(void); diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c index 63e548b6f81..a8adf891fe0 100644 --- a/net/ipv6/mip6.c +++ b/net/ipv6/mip6.c @@ -35,6 +35,165 @@ static xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr return x->coaddr; } +static inline unsigned int calc_padlen(unsigned int len, unsigned int n) +{ + return (n - len + 16) & 0x7; +} + +static inline void *mip6_padn(__u8 *data, __u8 padlen) +{ + if (!data) + return NULL; + if (padlen == 1) { + data[0] = MIP6_OPT_PAD_1; + } else if (padlen > 1) { + data[0] = MIP6_OPT_PAD_N; + data[1] = padlen - 2; + if (padlen > 2) + memset(data+2, 0, data[1]); + } + return data + padlen; +} + +static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ipv6hdr *iph = skb->nh.ipv6h; + struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data; + + if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) && + !ipv6_addr_any((struct in6_addr *)x->coaddr)) + return -ENOENT; + + return destopt->nexthdr; +} + +/* Destination Option Header is inserted. + * IP Header's src address is replaced with Home Address Option in + * Destination Option Header. + */ +static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ipv6hdr *iph; + struct ipv6_destopt_hdr *dstopt; + struct ipv6_destopt_hao *hao; + u8 nexthdr; + int len; + + iph = (struct ipv6hdr *)skb->data; + iph->payload_len = htons(skb->len - sizeof(*iph)); + + nexthdr = *skb->nh.raw; + *skb->nh.raw = IPPROTO_DSTOPTS; + + dstopt = (struct ipv6_destopt_hdr *)skb->h.raw; + dstopt->nexthdr = nexthdr; + + hao = mip6_padn((char *)(dstopt + 1), + calc_padlen(sizeof(*dstopt), 6)); + + hao->type = IPV6_TLV_HAO; + hao->length = sizeof(*hao) - 2; + BUG_TRAP(hao->length == 16); + + len = ((char *)hao - (char *)dstopt) + sizeof(*hao); + + memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr)); + memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr)); + + BUG_TRAP(len == x->props.header_len); + dstopt->hdrlen = (x->props.header_len >> 3) - 1; + + return 0; +} + +static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb, + u8 **nexthdr) +{ + u16 offset = sizeof(struct ipv6hdr); + struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1); + unsigned int packet_len = skb->tail - skb->nh.raw; + int found_rhdr = 0; + + *nexthdr = &skb->nh.ipv6h->nexthdr; + + while (offset + 1 <= packet_len) { + + switch (**nexthdr) { + case NEXTHDR_HOP: + break; + case NEXTHDR_ROUTING: + found_rhdr = 1; + break; + case NEXTHDR_DEST: + /* + * HAO MUST NOT appear more than once. + * XXX: It is better to try to find by the end of + * XXX: packet if HAO exists. + */ + if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) { + LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n"); + return offset; + } + + if (found_rhdr) + return offset; + + break; + default: + return offset; + } + + offset += ipv6_optlen(exthdr); + *nexthdr = &exthdr->nexthdr; + exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); + } + + return offset; +} + +static int mip6_destopt_init_state(struct xfrm_state *x) +{ + if (x->id.spi) { + printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__, + x->id.spi); + return -EINVAL; + } + if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) { + printk(KERN_INFO "%s: state's mode is not %u: %u\n", + __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode); + return -EINVAL; + } + + x->props.header_len = sizeof(struct ipv6_destopt_hdr) + + calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) + + sizeof(struct ipv6_destopt_hao); + BUG_TRAP(x->props.header_len == 24); + + return 0; +} + +/* + * Do nothing about destroying since it has no specific operation for + * destination options header unlike IPsec protocols. + */ +static void mip6_destopt_destroy(struct xfrm_state *x) +{ +} + +static struct xfrm_type mip6_destopt_type = +{ + .description = "MIP6DESTOPT", + .owner = THIS_MODULE, + .proto = IPPROTO_DSTOPTS, + .flags = XFRM_TYPE_NON_FRAGMENT, + .init_state = mip6_destopt_init_state, + .destructor = mip6_destopt_destroy, + .input = mip6_destopt_input, + .output = mip6_destopt_output, + .hdr_offset = mip6_destopt_offset, + .local_addr = mip6_xfrm_addr, +}; + static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb) { struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data; @@ -164,6 +323,10 @@ int __init mip6_init(void) { printk(KERN_INFO "Mobile IPv6\n"); + if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) { + printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__); + goto mip6_destopt_xfrm_fail; + } if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) { printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__); goto mip6_rthdr_xfrm_fail; @@ -171,6 +334,8 @@ int __init mip6_init(void) return 0; mip6_rthdr_xfrm_fail: + xfrm_unregister_type(&mip6_destopt_type, AF_INET6); + mip6_destopt_xfrm_fail: return -EAGAIN; } @@ -178,4 +343,6 @@ void __exit mip6_fini(void) { if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0) printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__); + if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0) + printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__); } -- 2.32.0.93.g670b81a890