diff options
Diffstat (limited to 'net/ipv6/ipcomp6.c')
| -rw-r--r-- | net/ipv6/ipcomp6.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/net/ipv6/ipcomp6.c b/net/ipv6/ipcomp6.c new file mode 100644 index 000000000..72d4858de --- /dev/null +++ b/net/ipv6/ipcomp6.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173 + * + * Copyright (C)2003 USAGI/WIDE Project + * + * Author Mitsuru KANDA <mk@linux-ipv6.org> + */ +/* + * [Memo] + * + * Outbound: + * The compression of IP datagram MUST be done before AH/ESP processing, + * fragmentation, and the addition of Hop-by-Hop/Routing header. + * + * Inbound: + * The decompression of IP datagram MUST be done after the reassembly, + * AH/ESP processing. + */ + +#define pr_fmt(fmt) "IPv6: " fmt + +#include <linux/module.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/ipcomp.h> +#include <linux/crypto.h> +#include <linux/err.h> +#include <linux/pfkeyv2.h> +#include <linux/random.h> +#include <linux/percpu.h> +#include <linux/smp.h> +#include <linux/list.h> +#include <linux/vmalloc.h> +#include <linux/rtnetlink.h> +#include <net/ip6_route.h> +#include <net/icmp.h> +#include <net/ipv6.h> +#include <net/protocol.h> +#include <linux/ipv6.h> +#include <linux/icmpv6.h> +#include <linux/mutex.h> + +static int ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + struct net *net = dev_net(skb->dev); + __be32 spi; + const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; + struct ip_comp_hdr *ipcomph = + (struct ip_comp_hdr *)(skb->data + offset); + struct xfrm_state *x; + + if (type != ICMPV6_PKT_TOOBIG && + type != NDISC_REDIRECT) + return 0; + + spi = htonl(ntohs(ipcomph->cpi)); + x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, + spi, IPPROTO_COMP, AF_INET6); + if (!x) + return 0; + + if (type == NDISC_REDIRECT) + ip6_redirect(skb, net, skb->dev->ifindex, 0, + sock_net_uid(net, NULL)); + else + ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); + xfrm_state_put(x); + + return 0; +} + +static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) +{ + struct net *net = xs_net(x); + struct xfrm_state *t = NULL; + + t = xfrm_state_alloc(net); + if (!t) + goto out; + + t->id.proto = IPPROTO_IPV6; + t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr); + if (!t->id.spi) + goto error; + + memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); + memcpy(&t->sel, &x->sel, sizeof(t->sel)); + t->props.family = AF_INET6; + t->props.mode = x->props.mode; + memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); + memcpy(&t->mark, &x->mark, sizeof(t->mark)); + t->if_id = x->if_id; + + if (xfrm_init_state(t)) + goto error; + + atomic_set(&t->tunnel_users, 1); + +out: + return t; + +error: + t->km.state = XFRM_STATE_DEAD; + xfrm_state_put(t); + t = NULL; + goto out; +} + +static int ipcomp6_tunnel_attach(struct xfrm_state *x) +{ + struct net *net = xs_net(x); + int err = 0; + struct xfrm_state *t = NULL; + __be32 spi; + u32 mark = x->mark.m & x->mark.v; + + spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr); + if (spi) + t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr, + spi, IPPROTO_IPV6, AF_INET6); + if (!t) { + t = ipcomp6_tunnel_create(x); + if (!t) { + err = -EINVAL; + goto out; + } + xfrm_state_insert(t); + xfrm_state_hold(t); + } + x->tunnel = t; + atomic_inc(&t->tunnel_users); + +out: + return err; +} + +static int ipcomp6_init_state(struct xfrm_state *x, + struct netlink_ext_ack *extack) +{ + int err = -EINVAL; + + x->props.header_len = 0; + switch (x->props.mode) { + case XFRM_MODE_TRANSPORT: + break; + case XFRM_MODE_TUNNEL: + x->props.header_len += sizeof(struct ipv6hdr); + break; + default: + NL_SET_ERR_MSG(extack, "Unsupported XFRM mode for IPcomp"); + goto out; + } + + err = ipcomp_init_state(x, extack); + if (err) + goto out; + + if (x->props.mode == XFRM_MODE_TUNNEL) { + err = ipcomp6_tunnel_attach(x); + if (err) { + NL_SET_ERR_MSG(extack, "Kernel error: failed to initialize the associated state"); + goto out; + } + } + + err = 0; +out: + return err; +} + +static int ipcomp6_rcv_cb(struct sk_buff *skb, int err) +{ + return 0; +} + +static const struct xfrm_type ipcomp6_type = { + .owner = THIS_MODULE, + .proto = IPPROTO_COMP, + .init_state = ipcomp6_init_state, + .destructor = ipcomp_destroy, + .input = ipcomp_input, + .output = ipcomp_output, +}; + +static struct xfrm6_protocol ipcomp6_protocol = { + .handler = xfrm6_rcv, + .input_handler = xfrm_input, + .cb_handler = ipcomp6_rcv_cb, + .err_handler = ipcomp6_err, + .priority = 0, +}; + +static int __init ipcomp6_init(void) +{ + if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { + pr_info("%s: can't add xfrm type\n", __func__); + return -EAGAIN; + } + if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) { + pr_info("%s: can't add protocol\n", __func__); + xfrm_unregister_type(&ipcomp6_type, AF_INET6); + return -EAGAIN; + } + return 0; +} + +static void __exit ipcomp6_fini(void) +{ + if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0) + pr_info("%s: can't remove protocol\n", __func__); + xfrm_unregister_type(&ipcomp6_type, AF_INET6); +} + +module_init(ipcomp6_init); +module_exit(ipcomp6_fini); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); +MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); + +MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); |