1b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu/* 2b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * xfrm6_mode_transport.c - Transport mode encapsulation for IPv6. 3b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * 4b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * Copyright (C) 2002 USAGI/WIDE Project 5b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> 6b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu */ 7b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 8b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <linux/init.h> 9b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <linux/kernel.h> 10b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <linux/module.h> 11b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <linux/skbuff.h> 12b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <linux/stringify.h> 13b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <net/dst.h> 14b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <net/ipv6.h> 15b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu#include <net/xfrm.h> 16b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 17b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu/* Add encapsulation header. 18b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * 19b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * The IP header and mutable extension headers will be moved forward to make 20b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu * space for the encapsulation header. 21b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu */ 22eb878e84575fbce21d2edb079eada78bfa27023dJamal Hadi Salimstatic int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb) 23b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu{ 24b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu struct ipv6hdr *iph; 25b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu u8 *prevhdr; 26b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu int hdr_len; 27b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 280660e03f6b18f19b6bbafe7583265a51b90daf36Arnaldo Carvalho de Melo iph = ipv6_hdr(skb); 29b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 30aee5adb4307c4c63a4dc5f3b49984d76f8a71b5bMasahide NAKAMURA hdr_len = x->type->hdr_offset(x, skb, &prevhdr); 31007f0211a8872f32381f5d44becf8eb2f27f3c30Herbert Xu skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); 327b277b1a5fb147cb828e5d8b9780cee60f31a9bfHerbert Xu skb_set_network_header(skb, -x->props.header_len); 3337fedd3aab6517daec628764c5d66dd8761fbe5fHerbert Xu skb->transport_header = skb->network_header + hdr_len; 347b277b1a5fb147cb828e5d8b9780cee60f31a9bfHerbert Xu __skb_pull(skb, hdr_len); 357b277b1a5fb147cb828e5d8b9780cee60f31a9bfHerbert Xu memmove(ipv6_hdr(skb), iph, hdr_len); 36b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu return 0; 37b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu} 38b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 3931a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu/* Remove encapsulation header. 4031a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * 4131a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * The IP header will be moved over the top of the encapsulation header. 4231a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * 4331a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * On entry, skb->h shall point to where the IP header should be and skb->nh 4431a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * shall be set to where the IP header currently is. skb->data shall point 4531a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu * to the start of the payload. 4631a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu */ 47b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xustatic int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb) 48b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu{ 499c70220b73908f64792422a2c39c593c4792f2c5Arnaldo Carvalho de Melo int ihl = skb->data - skb_transport_header(skb); 5031a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu 51b0e380b1d8a8e0aca215df97702f99815f05c094Arnaldo Carvalho de Melo if (skb->transport_header != skb->network_header) { 529c70220b73908f64792422a2c39c593c4792f2c5Arnaldo Carvalho de Melo memmove(skb_transport_header(skb), 539c70220b73908f64792422a2c39c593c4792f2c5Arnaldo Carvalho de Melo skb_network_header(skb), ihl); 54b0e380b1d8a8e0aca215df97702f99815f05c094Arnaldo Carvalho de Melo skb->network_header = skb->transport_header; 55d56f90a7c96da5187f0cdf07ee7434fe6aa78bbcArnaldo Carvalho de Melo } 560660e03f6b18f19b6bbafe7583265a51b90daf36Arnaldo Carvalho de Melo ipv6_hdr(skb)->payload_len = htons(skb->len + ihl - 5731a4ab93025719e62e7cf7ce899f71c34ecde5a0Herbert Xu sizeof(struct ipv6hdr)); 58badff6d01a8589a1c828b0bf118903ca38627f4eArnaldo Carvalho de Melo skb_reset_transport_header(skb); 59b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu return 0; 60b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu} 61b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 62b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xustatic struct xfrm_mode xfrm6_transport_mode = { 63b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu .input = xfrm6_transport_input, 64b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu .output = xfrm6_transport_output, 65b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu .owner = THIS_MODULE, 66b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu .encap = XFRM_MODE_TRANSPORT, 67b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu}; 68b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 69b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xustatic int __init xfrm6_transport_init(void) 70b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu{ 71b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6); 72b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu} 73b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 74b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xustatic void __exit xfrm6_transport_exit(void) 75b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu{ 76b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu int err; 77b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 78b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6); 79b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu BUG_ON(err); 80b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu} 81b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xu 82b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xumodule_init(xfrm6_transport_init); 83b59f45d0b2878ab76f8053b0973654e6621828eeHerbert Xumodule_exit(xfrm6_transport_exit); 84b59f45d0b2878ab76f8053b0973654e6621828eeHerbert XuMODULE_LICENSE("GPL"); 85b59f45d0b2878ab76f8053b0973654e6621828eeHerbert XuMODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT); 86