// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C)2003,2004 USAGI/WIDE Project * * Authors Mitsuru KANDA <mk@linux-ipv6.org> * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> * * Based on net/ipv4/xfrm4_tunnel.c */ #include <linux/module.h> #include <linux/xfrm.h> #include <linux/slab.h> #include <linux/rculist.h> #include <net/ip.h> #include <net/xfrm.h> #include <net/ipv6.h> #include <linux/ipv6.h> #include <linux/icmpv6.h> #include <linux/mutex.h> #include <net/netns/generic.h> #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256 #define XFRM6_TUNNEL_SPI_MIN 1 #define XFRM6_TUNNEL_SPI_MAX 0xffffffff struct xfrm6_tunnel_net { struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE]; struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE]; u32 spi; }; static unsigned int xfrm6_tunnel_net_id __read_mostly; static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net) { return net_generic(net, xfrm6_tunnel_net_id); } /* * xfrm_tunnel_spi things are for allocating unique id ("spi") * per xfrm_address_t. */ struct xfrm6_tunnel_spi { struct hlist_node list_byaddr; struct hlist_node list_byspi; xfrm_address_t addr; u32 spi; refcount_t refcnt; struct rcu_head rcu_head; }; static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock); static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly; static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr) { unsigned int h; h = ipv6_addr_hash((const struct in6_addr *)addr); h ^= h >> 16; h ^= h >> 8; h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1; return h; } static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi) { return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE; } static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); struct xfrm6_tunnel_spi *x6spi; hlist_for_each_entry_rcu(x6spi, &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], list_byaddr, lockdep_is_held(&xfrm6_tunnel_spi_lock)) { if (xfrm6_addr_equal(&x6spi->addr, saddr)) return x6spi; } return NULL; } __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr) { struct xfrm6_tunnel_spi *x6spi; u32 spi; rcu_read_lock_bh(); x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); spi = x6spi ? x6spi->spi : 0; rcu_read_unlock_bh(); return htonl(spi); } EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); struct xfrm6_tunnel_spi *x6spi; int index = xfrm6_tunnel_spi_hash_byspi(spi); hlist_for_each_entry(x6spi, &xfrm6_tn->spi_byspi[index], list_byspi) { if (x6spi->spi == spi) return -1; } return index; } static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); u32 spi; struct xfrm6_tunnel_spi *x6spi; int index; if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN || xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN; else xfrm6_tn->spi++; for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { index = __xfrm6_tunnel_spi_check(net, spi); if (index >= 0) goto alloc_spi; if (spi == XFRM6_TUNNEL_SPI_MAX) break; } for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { index = __xfrm6_tunnel_spi_check(net, spi); if (index >= 0) goto alloc_spi; } spi = 0; goto out; alloc_spi: xfrm6_tn->spi = spi; x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); if (!x6spi) goto out; memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); x6spi->spi = spi; refcount_set(&x6spi->refcnt, 1); hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); index = xfrm6_tunnel_spi_hash_byaddr(saddr); hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); out: return spi; } __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) { struct xfrm6_tunnel_spi *x6spi; u32 spi; spin_lock_bh(&xfrm6_tunnel_spi_lock); x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); if (x6spi) { refcount_inc(&x6spi->refcnt); spi = x6spi->spi; } else spi = __xfrm6_tunnel_alloc_spi(net, saddr); spin_unlock_bh(&xfrm6_tunnel_spi_lock); return htonl(spi); } EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); static void x6spi_destroy_rcu(struct rcu_head *head) { kmem_cache_free(xfrm6_tunnel_spi_kmem, container_of(head, struct xfrm6_tunnel_spi, rcu_head)); } static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); struct xfrm6_tunnel_spi *x6spi; struct hlist_node *n; spin_lock_bh(&xfrm6_tunnel_spi_lock); hlist_for_each_entry_safe(x6spi, n, &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], list_byaddr) { if (xfrm6_addr_equal(&x6spi->addr, saddr)) { if (refcount_dec_and_test(&x6spi->refcnt)) { hlist_del_rcu(&x6spi->list_byaddr); hlist_del_rcu(&x6spi->list_byspi); call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu); break; } } } spin_unlock_bh(&xfrm6_tunnel_spi_lock); } static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) { skb_push(skb, -skb_network_offset(skb)); return 0; } static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) { return skb_network_header(skb)[IP6CB(skb)->nhoff]; } static int xfrm6_tunnel_rcv(struct sk_buff *skb) { struct net *net = dev_net(skb->dev); const struct ipv6hdr *iph = ipv6_hdr(skb); __be32 spi; spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr); return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi, NULL); } static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info) { /* xfrm6_tunnel native err handling */ switch (type) { case ICMPV6_DEST_UNREACH: switch (code) { case ICMPV6_NOROUTE: case ICMPV6_ADM_PROHIBITED: case ICMPV6_NOT_NEIGHBOUR: case ICMPV6_ADDR_UNREACH: case ICMPV6_PORT_UNREACH: default: break; } break; case ICMPV6_PKT_TOOBIG: break; case ICMPV6_TIME_EXCEED: switch (code) { case ICMPV6_EXC_HOPLIMIT: break; case ICMPV6_EXC_FRAGTIME: default: break; } break; case ICMPV6_PARAMPROB: switch (code) { case ICMPV6_HDR_FIELD: break; case ICMPV6_UNK_NEXTHDR: break; case ICMPV6_UNK_OPTION: break; } break; default: break; } return 0; } static int xfrm6_tunnel_init_state(struct xfrm_state *x) { if (x->props.mode != XFRM_MODE_TUNNEL) return -EINVAL; if (x->encap) return -EINVAL; x->props.header_len = sizeof(struct ipv6hdr); return 0; } static void xfrm6_tunnel_destroy(struct xfrm_state *x) { struct net *net = xs_net(x); xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr); } static const struct xfrm_type xfrm6_tunnel_type = { .description = "IP6IP6", .owner = THIS_MODULE, .proto = IPPROTO_IPV6, .init_state = xfrm6_tunnel_init_state, .destructor = xfrm6_tunnel_destroy, .input = xfrm6_tunnel_input, .output = xfrm6_tunnel_output, }; static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = { .handler = xfrm6_tunnel_rcv, .err_handler = xfrm6_tunnel_err, .priority = 2, }; static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = { .handler = xfrm6_tunnel_rcv, .err_handler = xfrm6_tunnel_err, .priority = 2, }; static int __net_init xfrm6_tunnel_net_init(struct net *net) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); unsigned int i; for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]); for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]); xfrm6_tn->spi = 0; return 0; } static void __net_exit xfrm6_tunnel_net_exit(struct net *net) { struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); unsigned int i; xfrm_flush_gc(); xfrm_state_flush(net, 0, false, true); for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byaddr[i])); for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byspi[i])); } static struct pernet_operations xfrm6_tunnel_net_ops = { .init = xfrm6_tunnel_net_init, .exit = xfrm6_tunnel_net_exit, .id = &xfrm6_tunnel_net_id, .size = sizeof(struct xfrm6_tunnel_net), }; static int __init xfrm6_tunnel_init(void) { int rv; xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", sizeof(struct xfrm6_tunnel_spi), 0, SLAB_HWCACHE_ALIGN, NULL); if (!xfrm6_tunnel_spi_kmem) return -ENOMEM; rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); if (rv < 0) goto out_pernet; rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); if (rv < 0) goto out_type; rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); if (rv < 0) goto out_xfrm6; rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); if (rv < 0) goto out_xfrm46; return 0; out_xfrm46: xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); out_xfrm6: xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); out_type: unregister_pernet_subsys(&xfrm6_tunnel_net_ops); out_pernet: kmem_cache_destroy(xfrm6_tunnel_spi_kmem); return rv; } static void __exit xfrm6_tunnel_fini(void) { xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); unregister_pernet_subsys(&xfrm6_tunnel_net_ops); /* Someone maybe has gotten the xfrm6_tunnel_spi. * So need to wait it. */ rcu_barrier(); kmem_cache_destroy(xfrm6_tunnel_spi_kmem); } module_init(xfrm6_tunnel_init); module_exit(xfrm6_tunnel_fini); MODULE_LICENSE("GPL"); MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);