From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- net/ipv6/mip6.c | 511 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 511 insertions(+) create mode 100644 net/ipv6/mip6.c (limited to 'net/ipv6/mip6.c') diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c new file mode 100644 index 000000000..878fcec14 --- /dev/null +++ b/net/ipv6/mip6.c @@ -0,0 +1,511 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C)2003-2006 Helsinki University of Technology + * Copyright (C)2003-2006 USAGI/WIDE Project + */ +/* + * Authors: + * Noriaki TAKAMIYA @USAGI + * Masahide NAKAMURA @USAGI + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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] = IPV6_TLV_PAD1; + } else if (padlen > 1) { + data[0] = IPV6_TLV_PADN; + data[1] = padlen - 2; + if (padlen > 2) + memset(data+2, 0, data[1]); + } + return data + padlen; +} + +static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos) +{ + icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos); +} + +static int mip6_mh_len(int type) +{ + int len = 0; + + switch (type) { + case IP6_MH_TYPE_BRR: + len = 0; + break; + case IP6_MH_TYPE_HOTI: + case IP6_MH_TYPE_COTI: + case IP6_MH_TYPE_BU: + case IP6_MH_TYPE_BACK: + len = 1; + break; + case IP6_MH_TYPE_HOT: + case IP6_MH_TYPE_COT: + case IP6_MH_TYPE_BERROR: + len = 2; + break; + } + return len; +} + +static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb) +{ + struct ip6_mh _hdr; + const struct ip6_mh *mh; + + mh = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (!mh) + return -1; + + if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len) + return -1; + + if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) { + net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n", + mh->ip6mh_hdrlen, + mip6_mh_len(mh->ip6mh_type)); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) + + skb_network_header_len(skb)); + return -1; + } + + if (mh->ip6mh_proto != IPPROTO_NONE) { + net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n", + mh->ip6mh_proto); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) + + skb_network_header_len(skb)); + return -1; + } + + return 0; +} + +struct mip6_report_rate_limiter { + spinlock_t lock; + ktime_t stamp; + int iif; + struct in6_addr src; + struct in6_addr dst; +}; + +static struct mip6_report_rate_limiter mip6_report_rl = { + .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock) +}; + +static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data; + int err = destopt->nexthdr; + + spin_lock(&x->lock); + if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) && + !ipv6_addr_any((struct in6_addr *)x->coaddr)) + err = -ENOENT; + spin_unlock(&x->lock); + + return err; +} + +/* 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; + + skb_push(skb, -skb_network_offset(skb)); + iph = ipv6_hdr(skb); + + nexthdr = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_DSTOPTS; + + dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb); + dstopt->nexthdr = nexthdr; + + hao = mip6_padn((char *)(dstopt + 1), + calc_padlen(sizeof(*dstopt), 6)); + + hao->type = IPV6_TLV_HAO; + BUILD_BUG_ON(sizeof(*hao) != 18); + hao->length = sizeof(*hao) - 2; + + len = ((char *)hao - (char *)dstopt) + sizeof(*hao); + + memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr)); + spin_lock_bh(&x->lock); + memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr)); + spin_unlock_bh(&x->lock); + + WARN_ON(len != x->props.header_len); + dstopt->hdrlen = (x->props.header_len >> 3) - 1; + + return 0; +} + +static inline int mip6_report_rl_allow(ktime_t stamp, + const struct in6_addr *dst, + const struct in6_addr *src, int iif) +{ + int allow = 0; + + spin_lock_bh(&mip6_report_rl.lock); + if (mip6_report_rl.stamp != stamp || + mip6_report_rl.iif != iif || + !ipv6_addr_equal(&mip6_report_rl.src, src) || + !ipv6_addr_equal(&mip6_report_rl.dst, dst)) { + mip6_report_rl.stamp = stamp; + mip6_report_rl.iif = iif; + mip6_report_rl.src = *src; + mip6_report_rl.dst = *dst; + allow = 1; + } + spin_unlock_bh(&mip6_report_rl.lock); + return allow; +} + +static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, + const struct flowi *fl) +{ + struct net *net = xs_net(x); + struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb; + const struct flowi6 *fl6 = &fl->u.ip6; + struct ipv6_destopt_hao *hao = NULL; + struct xfrm_selector sel; + int offset; + ktime_t stamp; + int err = 0; + + if (unlikely(fl6->flowi6_proto == IPPROTO_MH && + fl6->fl6_mh_type <= IP6_MH_TYPE_MAX)) + goto out; + + if (likely(opt->dsthao)) { + offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); + if (likely(offset >= 0)) + hao = (struct ipv6_destopt_hao *) + (skb_network_header(skb) + offset); + } + + stamp = skb_get_ktime(skb); + + if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr, + hao ? &hao->addr : &ipv6_hdr(skb)->saddr, + opt->iif)) + goto out; + + memset(&sel, 0, sizeof(sel)); + memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr, + sizeof(sel.daddr)); + sel.prefixlen_d = 128; + memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr, + sizeof(sel.saddr)); + sel.prefixlen_s = 128; + sel.family = AF_INET6; + sel.proto = fl6->flowi6_proto; + sel.dport = xfrm_flowi_dport(fl, &fl6->uli); + if (sel.dport) + sel.dport_mask = htons(~0); + sel.sport = xfrm_flowi_sport(fl, &fl6->uli); + if (sel.sport) + sel.sport_mask = htons(~0); + sel.ifindex = fl6->flowi6_oif; + + err = km_report(net, IPPROTO_DSTOPTS, &sel, + (hao ? (xfrm_address_t *)&hao->addr : NULL)); + + out: + return err; +} + +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 *)(ipv6_hdr(skb) + 1); + const unsigned char *nh = skb_network_header(skb); + unsigned int packet_len = skb_tail_pointer(skb) - + skb_network_header(skb); + int found_rhdr = 0; + + *nexthdr = &ipv6_hdr(skb)->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) { + net_dbg_ratelimited("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 *)(nh + offset); + } + + return offset; +} + +static int mip6_destopt_init_state(struct xfrm_state *x) +{ + if (x->id.spi) { + pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi); + return -EINVAL; + } + if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) { + pr_info("%s: state's mode is not %u: %u\n", + __func__, 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); + WARN_ON(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 const struct xfrm_type mip6_destopt_type = { + .description = "MIP6DESTOPT", + .owner = THIS_MODULE, + .proto = IPPROTO_DSTOPTS, + .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR, + .init_state = mip6_destopt_init_state, + .destructor = mip6_destopt_destroy, + .input = mip6_destopt_input, + .output = mip6_destopt_output, + .reject = mip6_destopt_reject, + .hdr_offset = mip6_destopt_offset, +}; + +static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data; + int err = rt2->rt_hdr.nexthdr; + + spin_lock(&x->lock); + if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) && + !ipv6_addr_any((struct in6_addr *)x->coaddr)) + err = -ENOENT; + spin_unlock(&x->lock); + + return err; +} + +/* Routing Header type 2 is inserted. + * IP Header's dst address is replaced with Routing Header's Home Address. + */ +static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ipv6hdr *iph; + struct rt2_hdr *rt2; + u8 nexthdr; + + skb_push(skb, -skb_network_offset(skb)); + iph = ipv6_hdr(skb); + + nexthdr = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_ROUTING; + + rt2 = (struct rt2_hdr *)skb_transport_header(skb); + rt2->rt_hdr.nexthdr = nexthdr; + rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1; + rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2; + rt2->rt_hdr.segments_left = 1; + memset(&rt2->reserved, 0, sizeof(rt2->reserved)); + + WARN_ON(rt2->rt_hdr.hdrlen != 2); + + memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr)); + spin_lock_bh(&x->lock); + memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr)); + spin_unlock_bh(&x->lock); + + return 0; +} + +static int mip6_rthdr_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 *)(ipv6_hdr(skb) + 1); + const unsigned char *nh = skb_network_header(skb); + unsigned int packet_len = skb_tail_pointer(skb) - + skb_network_header(skb); + int found_rhdr = 0; + + *nexthdr = &ipv6_hdr(skb)->nexthdr; + + while (offset + 1 <= packet_len) { + + switch (**nexthdr) { + case NEXTHDR_HOP: + break; + case NEXTHDR_ROUTING: + if (offset + 3 <= packet_len) { + struct ipv6_rt_hdr *rt; + rt = (struct ipv6_rt_hdr *)(nh + offset); + if (rt->type != 0) + return offset; + } + found_rhdr = 1; + break; + case NEXTHDR_DEST: + if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) + return offset; + + if (found_rhdr) + return offset; + + break; + default: + return offset; + } + + offset += ipv6_optlen(exthdr); + *nexthdr = &exthdr->nexthdr; + exthdr = (struct ipv6_opt_hdr *)(nh + offset); + } + + return offset; +} + +static int mip6_rthdr_init_state(struct xfrm_state *x) +{ + if (x->id.spi) { + pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi); + return -EINVAL; + } + if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) { + pr_info("%s: state's mode is not %u: %u\n", + __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode); + return -EINVAL; + } + + x->props.header_len = sizeof(struct rt2_hdr); + + return 0; +} + +/* + * Do nothing about destroying since it has no specific operation for routing + * header type 2 unlike IPsec protocols. + */ +static void mip6_rthdr_destroy(struct xfrm_state *x) +{ +} + +static const struct xfrm_type mip6_rthdr_type = { + .description = "MIP6RT", + .owner = THIS_MODULE, + .proto = IPPROTO_ROUTING, + .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR, + .init_state = mip6_rthdr_init_state, + .destructor = mip6_rthdr_destroy, + .input = mip6_rthdr_input, + .output = mip6_rthdr_output, + .hdr_offset = mip6_rthdr_offset, +}; + +static int __init mip6_init(void) +{ + pr_info("Mobile IPv6\n"); + + if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) { + pr_info("%s: can't add xfrm type(destopt)\n", __func__); + goto mip6_destopt_xfrm_fail; + } + if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) { + pr_info("%s: can't add xfrm type(rthdr)\n", __func__); + goto mip6_rthdr_xfrm_fail; + } + if (rawv6_mh_filter_register(mip6_mh_filter) < 0) { + pr_info("%s: can't add rawv6 mh filter\n", __func__); + goto mip6_rawv6_mh_fail; + } + + + return 0; + + mip6_rawv6_mh_fail: + xfrm_unregister_type(&mip6_rthdr_type, AF_INET6); + mip6_rthdr_xfrm_fail: + xfrm_unregister_type(&mip6_destopt_type, AF_INET6); + mip6_destopt_xfrm_fail: + return -EAGAIN; +} + +static void __exit mip6_fini(void) +{ + if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0) + pr_info("%s: can't remove rawv6 mh filter\n", __func__); + xfrm_unregister_type(&mip6_rthdr_type, AF_INET6); + xfrm_unregister_type(&mip6_destopt_type, AF_INET6); +} + +module_init(mip6_init); +module_exit(mip6_fini); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS); +MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING); -- cgit v1.2.3