diff options
Diffstat (limited to 'net/sctp/ipv6.c')
| -rw-r--r-- | net/sctp/ipv6.c | 1217 |
1 files changed, 1217 insertions, 0 deletions
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c new file mode 100644 index 000000000..d081858c2 --- /dev/null +++ b/net/sctp/ipv6.c @@ -0,0 +1,1217 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* SCTP kernel implementation + * (C) Copyright IBM Corp. 2002, 2004 + * Copyright (c) 2001 Nokia, Inc. + * Copyright (c) 2001 La Monte H.P. Yarroll + * Copyright (c) 2002-2003 Intel Corp. + * + * This file is part of the SCTP kernel implementation + * + * SCTP over IPv6. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <linux-sctp@vger.kernel.org> + * + * Written or modified by: + * Le Yanqun <yanqun.le@nokia.com> + * Hui Huang <hui.huang@nokia.com> + * La Monte H.P. Yarroll <piggy@acm.org> + * Sridhar Samudrala <sri@us.ibm.com> + * Jon Grimm <jgrimm@us.ibm.com> + * Ardelle Fan <ardelle.fan@intel.com> + * + * Based on: + * linux/net/ipv6/tcp_ipv6.c + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/netdevice.h> +#include <linux/init.h> +#include <linux/ipsec.h> +#include <linux/slab.h> + +#include <linux/ipv6.h> +#include <linux/icmpv6.h> +#include <linux/random.h> +#include <linux/seq_file.h> + +#include <net/protocol.h> +#include <net/ndisc.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <net/transp_v6.h> +#include <net/addrconf.h> +#include <net/ip6_route.h> +#include <net/inet_common.h> +#include <net/inet_ecn.h> +#include <net/sctp/sctp.h> +#include <net/udp_tunnel.h> + +#include <linux/uaccess.h> + +static inline int sctp_v6_addr_match_len(union sctp_addr *s1, + union sctp_addr *s2); +static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, + __be16 port); +static int sctp_v6_cmp_addr(const union sctp_addr *addr1, + const union sctp_addr *addr2); + +/* Event handler for inet6 address addition/deletion events. + * The sctp_local_addr_list needs to be protocted by a spin lock since + * multiple notifiers (say IPv4 and IPv6) may be running at the same + * time and thus corrupt the list. + * The reader side is protected with RCU. + */ +static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, + void *ptr) +{ + struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; + struct sctp_sockaddr_entry *addr = NULL; + struct sctp_sockaddr_entry *temp; + struct net *net = dev_net(ifa->idev->dev); + int found = 0; + + switch (ev) { + case NETDEV_UP: + addr = kzalloc(sizeof(*addr), GFP_ATOMIC); + if (addr) { + addr->a.v6.sin6_family = AF_INET6; + addr->a.v6.sin6_addr = ifa->addr; + addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex; + addr->valid = 1; + spin_lock_bh(&net->sctp.local_addr_lock); + list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list); + sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW); + spin_unlock_bh(&net->sctp.local_addr_lock); + } + break; + case NETDEV_DOWN: + spin_lock_bh(&net->sctp.local_addr_lock); + list_for_each_entry_safe(addr, temp, + &net->sctp.local_addr_list, list) { + if (addr->a.sa.sa_family == AF_INET6 && + ipv6_addr_equal(&addr->a.v6.sin6_addr, + &ifa->addr) && + addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) { + sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); + found = 1; + addr->valid = 0; + list_del_rcu(&addr->list); + break; + } + } + spin_unlock_bh(&net->sctp.local_addr_lock); + if (found) + kfree_rcu(addr, rcu); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block sctp_inet6addr_notifier = { + .notifier_call = sctp_inet6addr_event, +}; + +static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb, + __u8 type, __u8 code, __u32 info) +{ + struct sctp_association *asoc = t->asoc; + struct sock *sk = asoc->base.sk; + struct ipv6_pinfo *np; + int err = 0; + + switch (type) { + case ICMPV6_PKT_TOOBIG: + if (ip6_sk_accept_pmtu(sk)) + sctp_icmp_frag_needed(sk, asoc, t, info); + return; + case ICMPV6_PARAMPROB: + if (ICMPV6_UNK_NEXTHDR == code) { + sctp_icmp_proto_unreachable(sk, asoc, t); + return; + } + break; + case NDISC_REDIRECT: + sctp_icmp_redirect(sk, t, skb); + return; + default: + break; + } + + np = inet6_sk(sk); + icmpv6_err_convert(type, code, &err); + if (!sock_owned_by_user(sk) && np->recverr) { + sk->sk_err = err; + sk_error_report(sk); + } else { + sk->sk_err_soft = err; + } +} + +/* ICMP error handler. */ +static int sctp_v6_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); + struct sctp_transport *transport; + struct sctp_association *asoc; + __u16 saveip, savesctp; + struct sock *sk; + + /* Fix up skb to look at the embedded net header. */ + saveip = skb->network_header; + savesctp = skb->transport_header; + skb_reset_network_header(skb); + skb_set_transport_header(skb, offset); + sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); + /* Put back, the original pointers. */ + skb->network_header = saveip; + skb->transport_header = savesctp; + if (!sk) { + __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); + return -ENOENT; + } + + sctp_v6_err_handle(transport, skb, type, code, ntohl(info)); + sctp_err_finish(sk, transport); + + return 0; +} + +int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + struct sctp_association *asoc; + struct sctp_transport *t; + struct icmp6hdr *hdr; + __u32 info = 0; + + skb->transport_header += sizeof(struct udphdr); + sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t); + if (!sk) { + __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); + return -ENOENT; + } + + skb->transport_header -= sizeof(struct udphdr); + hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr)); + if (hdr->icmp6_type == NDISC_REDIRECT) { + /* can't be handled without outer ip6hdr known, leave it to udpv6_err */ + sctp_err_finish(sk, t); + return 0; + } + if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG) + info = ntohl(hdr->icmp6_mtu); + sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info); + + sctp_err_finish(sk, t); + return 1; +} + +static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t) +{ + struct dst_entry *dst = dst_clone(t->dst); + struct flowi6 *fl6 = &t->fl.u.ip6; + struct sock *sk = skb->sk; + struct ipv6_pinfo *np = inet6_sk(sk); + __u8 tclass = np->tclass; + __be32 label; + + pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, + skb->len, &fl6->saddr, &fl6->daddr); + + if (t->dscp & SCTP_DSCP_SET_MASK) + tclass = t->dscp & SCTP_DSCP_VAL_MASK; + + if (INET_ECN_is_capable(tclass)) + IP6_ECN_flow_xmit(sk, fl6->flowlabel); + + if (!(t->param_flags & SPP_PMTUD_ENABLE)) + skb->ignore_df = 1; + + SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); + + if (!t->encap_port || !sctp_sk(sk)->udp_port) { + int res; + + skb_dst_set(skb, dst); + rcu_read_lock(); + res = ip6_xmit(sk, skb, fl6, sk->sk_mark, + rcu_dereference(np->opt), + tclass, sk->sk_priority); + rcu_read_unlock(); + return res; + } + + if (skb_is_gso(skb)) + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; + + skb->encapsulation = 1; + skb_reset_inner_mac_header(skb); + skb_reset_inner_transport_header(skb); + skb_set_inner_ipproto(skb, IPPROTO_SCTP); + label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6); + + return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, + &fl6->daddr, tclass, ip6_dst_hoplimit(dst), + label, sctp_sk(sk)->udp_port, t->encap_port, false); +} + +/* Returns the dst cache entry for the given source and destination ip + * addresses. + */ +static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, + struct flowi *fl, struct sock *sk) +{ + struct sctp_association *asoc = t->asoc; + struct dst_entry *dst = NULL; + struct flowi _fl; + struct flowi6 *fl6 = &_fl.u.ip6; + struct sctp_bind_addr *bp; + struct ipv6_pinfo *np = inet6_sk(sk); + struct sctp_sockaddr_entry *laddr; + union sctp_addr *daddr = &t->ipaddr; + union sctp_addr dst_saddr; + struct in6_addr *final_p, final; + enum sctp_scope scope; + __u8 matchlen = 0; + + memset(&_fl, 0, sizeof(_fl)); + fl6->daddr = daddr->v6.sin6_addr; + fl6->fl6_dport = daddr->v6.sin6_port; + fl6->flowi6_proto = IPPROTO_SCTP; + if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) + fl6->flowi6_oif = daddr->v6.sin6_scope_id; + else if (asoc) + fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; + if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) + fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); + + if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { + struct ip6_flowlabel *flowlabel; + + flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); + if (IS_ERR(flowlabel)) + goto out; + fl6_sock_release(flowlabel); + } + + pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); + + if (asoc) + fl6->fl6_sport = htons(asoc->base.bind_addr.port); + + if (saddr) { + fl6->saddr = saddr->v6.sin6_addr; + if (!fl6->fl6_sport) + fl6->fl6_sport = saddr->v6.sin6_port; + + pr_debug("src=%pI6 - ", &fl6->saddr); + } + + rcu_read_lock(); + final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); + rcu_read_unlock(); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); + if (!asoc || saddr) { + t->dst = dst; + memcpy(fl, &_fl, sizeof(_fl)); + goto out; + } + + bp = &asoc->base.bind_addr; + scope = sctp_scope(daddr); + /* ip6_dst_lookup has filled in the fl6->saddr for us. Check + * to see if we can use it. + */ + if (!IS_ERR(dst)) { + /* Walk through the bind address list and look for a bind + * address that matches the source address of the returned dst. + */ + sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); + rcu_read_lock(); + list_for_each_entry_rcu(laddr, &bp->address_list, list) { + if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || + (laddr->state != SCTP_ADDR_SRC && + !asoc->src_out_of_asoc_ok)) + continue; + + /* Do not compare against v4 addrs */ + if ((laddr->a.sa.sa_family == AF_INET6) && + (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { + rcu_read_unlock(); + t->dst = dst; + memcpy(fl, &_fl, sizeof(_fl)); + goto out; + } + } + rcu_read_unlock(); + /* None of the bound addresses match the source address of the + * dst. So release it. + */ + dst_release(dst); + dst = NULL; + } + + /* Walk through the bind address list and try to get the + * best source address for a given destination. + */ + rcu_read_lock(); + list_for_each_entry_rcu(laddr, &bp->address_list, list) { + struct dst_entry *bdst; + __u8 bmatchlen; + + if (!laddr->valid || + laddr->state != SCTP_ADDR_SRC || + laddr->a.sa.sa_family != AF_INET6 || + scope > sctp_scope(&laddr->a)) + continue; + + fl6->saddr = laddr->a.v6.sin6_addr; + fl6->fl6_sport = laddr->a.v6.sin6_port; + final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); + bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); + + if (IS_ERR(bdst)) + continue; + + if (ipv6_chk_addr(dev_net(bdst->dev), + &laddr->a.v6.sin6_addr, bdst->dev, 1)) { + if (!IS_ERR_OR_NULL(dst)) + dst_release(dst); + dst = bdst; + t->dst = dst; + memcpy(fl, &_fl, sizeof(_fl)); + break; + } + + bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); + if (matchlen > bmatchlen) { + dst_release(bdst); + continue; + } + + if (!IS_ERR_OR_NULL(dst)) + dst_release(dst); + dst = bdst; + matchlen = bmatchlen; + t->dst = dst; + memcpy(fl, &_fl, sizeof(_fl)); + } + rcu_read_unlock(); + +out: + if (!IS_ERR_OR_NULL(dst)) { + struct rt6_info *rt; + + rt = (struct rt6_info *)dst; + t->dst_cookie = rt6_get_cookie(rt); + pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", + &rt->rt6i_dst.addr, rt->rt6i_dst.plen, + &fl->u.ip6.saddr); + } else { + t->dst = NULL; + pr_debug("no route\n"); + } +} + +/* Returns the number of consecutive initial bits that match in the 2 ipv6 + * addresses. + */ +static inline int sctp_v6_addr_match_len(union sctp_addr *s1, + union sctp_addr *s2) +{ + return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); +} + +/* Fills in the source address(saddr) based on the destination address(daddr) + * and asoc's bind address list. + */ +static void sctp_v6_get_saddr(struct sctp_sock *sk, + struct sctp_transport *t, + struct flowi *fl) +{ + struct flowi6 *fl6 = &fl->u.ip6; + union sctp_addr *saddr = &t->saddr; + + pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); + + if (t->dst) { + saddr->v6.sin6_family = AF_INET6; + saddr->v6.sin6_addr = fl6->saddr; + } +} + +/* Make a copy of all potential local addresses. */ +static void sctp_v6_copy_addrlist(struct list_head *addrlist, + struct net_device *dev) +{ + struct inet6_dev *in6_dev; + struct inet6_ifaddr *ifp; + struct sctp_sockaddr_entry *addr; + + rcu_read_lock(); + if ((in6_dev = __in6_dev_get(dev)) == NULL) { + rcu_read_unlock(); + return; + } + + read_lock_bh(&in6_dev->lock); + list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { + /* Add the address to the local list. */ + addr = kzalloc(sizeof(*addr), GFP_ATOMIC); + if (addr) { + addr->a.v6.sin6_family = AF_INET6; + addr->a.v6.sin6_addr = ifp->addr; + addr->a.v6.sin6_scope_id = dev->ifindex; + addr->valid = 1; + INIT_LIST_HEAD(&addr->list); + list_add_tail(&addr->list, addrlist); + } + } + + read_unlock_bh(&in6_dev->lock); + rcu_read_unlock(); +} + +/* Copy over any ip options */ +static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) +{ + struct ipv6_pinfo *newnp, *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + + newnp = inet6_sk(newsk); + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) { + opt = ipv6_dup_options(newsk, opt); + if (!opt) + pr_err("%s: Failed to copy ip options\n", __func__); + } + RCU_INIT_POINTER(newnp->opt, opt); + rcu_read_unlock(); +} + +/* Account for the IP options */ +static int sctp_v6_ip_options_len(struct sock *sk) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + int len = 0; + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) + len = opt->opt_flen + opt->opt_nflen; + + rcu_read_unlock(); + return len; +} + +/* Initialize a sockaddr_storage from in incoming skb. */ +static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, + int is_saddr) +{ + /* Always called on head skb, so this is safe */ + struct sctphdr *sh = sctp_hdr(skb); + struct sockaddr_in6 *sa = &addr->v6; + + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_flowinfo = 0; /* FIXME */ + addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; + + if (is_saddr) { + sa->sin6_port = sh->source; + sa->sin6_addr = ipv6_hdr(skb)->saddr; + } else { + sa->sin6_port = sh->dest; + sa->sin6_addr = ipv6_hdr(skb)->daddr; + } +} + +/* Initialize an sctp_addr from a socket. */ +static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) +{ + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_port = 0; + addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; +} + +/* Initialize sk->sk_rcv_saddr from sctp_addr. */ +static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) +{ + if (addr->sa.sa_family == AF_INET) { + sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; + sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; + sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); + sk->sk_v6_rcv_saddr.s6_addr32[3] = + addr->v4.sin_addr.s_addr; + } else { + sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; + } +} + +/* Initialize sk->sk_daddr from sctp_addr. */ +static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) +{ + if (addr->sa.sa_family == AF_INET) { + sk->sk_v6_daddr.s6_addr32[0] = 0; + sk->sk_v6_daddr.s6_addr32[1] = 0; + sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); + sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; + } else { + sk->sk_v6_daddr = addr->v6.sin6_addr; + } +} + +/* Initialize a sctp_addr from an address parameter. */ +static bool sctp_v6_from_addr_param(union sctp_addr *addr, + union sctp_addr_param *param, + __be16 port, int iif) +{ + if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) + return false; + + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_port = port; + addr->v6.sin6_flowinfo = 0; /* BUG */ + addr->v6.sin6_addr = param->v6.addr; + addr->v6.sin6_scope_id = iif; + + return true; +} + +/* Initialize an address parameter from a sctp_addr and return the length + * of the address parameter. + */ +static int sctp_v6_to_addr_param(const union sctp_addr *addr, + union sctp_addr_param *param) +{ + int length = sizeof(struct sctp_ipv6addr_param); + + param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; + param->v6.param_hdr.length = htons(length); + param->v6.addr = addr->v6.sin6_addr; + + return length; +} + +/* Initialize a sctp_addr from struct in6_addr. */ +static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, + __be16 port) +{ + addr->sa.sa_family = AF_INET6; + addr->v6.sin6_port = port; + addr->v6.sin6_flowinfo = 0; + addr->v6.sin6_addr = *saddr; + addr->v6.sin6_scope_id = 0; +} + +static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, + const union sctp_addr *addr2) +{ + if (addr1->sa.sa_family != addr2->sa.sa_family) { + if (addr1->sa.sa_family == AF_INET && + addr2->sa.sa_family == AF_INET6 && + ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && + addr2->v6.sin6_addr.s6_addr32[3] == + addr1->v4.sin_addr.s_addr) + return 1; + + if (addr2->sa.sa_family == AF_INET && + addr1->sa.sa_family == AF_INET6 && + ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && + addr1->v6.sin6_addr.s6_addr32[3] == + addr2->v4.sin_addr.s_addr) + return 1; + + return 0; + } + + if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) + return 0; + + /* If this is a linklocal address, compare the scope_id. */ + if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && + addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && + addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) + return 0; + + return 1; +} + +/* Compare addresses exactly. + * v4-mapped-v6 is also in consideration. + */ +static int sctp_v6_cmp_addr(const union sctp_addr *addr1, + const union sctp_addr *addr2) +{ + return __sctp_v6_cmp_addr(addr1, addr2) && + addr1->v6.sin6_port == addr2->v6.sin6_port; +} + +/* Initialize addr struct to INADDR_ANY. */ +static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) +{ + memset(addr, 0x00, sizeof(union sctp_addr)); + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_port = port; +} + +/* Is this a wildcard address? */ +static int sctp_v6_is_any(const union sctp_addr *addr) +{ + return ipv6_addr_any(&addr->v6.sin6_addr); +} + +/* Should this be available for binding? */ +static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) +{ + int type; + struct net *net = sock_net(&sp->inet.sk); + const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; + + type = ipv6_addr_type(in6); + if (IPV6_ADDR_ANY == type) + return 1; + if (type == IPV6_ADDR_MAPPED) { + if (sp && ipv6_only_sock(sctp_opt2sk(sp))) + return 0; + sctp_v6_map_v4(addr); + return sctp_get_af_specific(AF_INET)->available(addr, sp); + } + if (!(type & IPV6_ADDR_UNICAST)) + return 0; + + return ipv6_can_nonlocal_bind(net, &sp->inet) || + ipv6_chk_addr(net, in6, NULL, 0); +} + +/* This function checks if the address is a valid address to be used for + * SCTP. + * + * Output: + * Return 0 - If the address is a non-unicast or an illegal address. + * Return 1 - If the address is a unicast. + */ +static int sctp_v6_addr_valid(union sctp_addr *addr, + struct sctp_sock *sp, + const struct sk_buff *skb) +{ + int ret = ipv6_addr_type(&addr->v6.sin6_addr); + + /* Support v4-mapped-v6 address. */ + if (ret == IPV6_ADDR_MAPPED) { + /* Note: This routine is used in input, so v4-mapped-v6 + * are disallowed here when there is no sctp_sock. + */ + if (sp && ipv6_only_sock(sctp_opt2sk(sp))) + return 0; + sctp_v6_map_v4(addr); + return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); + } + + /* Is this a non-unicast address */ + if (!(ret & IPV6_ADDR_UNICAST)) + return 0; + + return 1; +} + +/* What is the scope of 'addr'? */ +static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) +{ + enum sctp_scope retval; + int v6scope; + + /* The IPv6 scope is really a set of bit fields. + * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. + */ + + v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); + switch (v6scope) { + case IFA_HOST: + retval = SCTP_SCOPE_LOOPBACK; + break; + case IFA_LINK: + retval = SCTP_SCOPE_LINK; + break; + case IFA_SITE: + retval = SCTP_SCOPE_PRIVATE; + break; + default: + retval = SCTP_SCOPE_GLOBAL; + break; + } + + return retval; +} + +/* Create and initialize a new sk for the socket to be returned by accept(). */ +static struct sock *sctp_v6_create_accept_sk(struct sock *sk, + struct sctp_association *asoc, + bool kern) +{ + struct sock *newsk; + struct ipv6_pinfo *newnp, *np = inet6_sk(sk); + struct sctp6_sock *newsctp6sk; + + newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); + if (!newsk) + goto out; + + sock_init_data(NULL, newsk); + + sctp_copy_sock(newsk, sk, asoc); + sock_reset_flag(sk, SOCK_ZAPPED); + + newsctp6sk = (struct sctp6_sock *)newsk; + inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; + + sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; + + newnp = inet6_sk(newsk); + + memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + newnp->ipv6_mc_list = NULL; + newnp->ipv6_ac_list = NULL; + newnp->ipv6_fl_list = NULL; + + sctp_v6_copy_ip_options(sk, newsk); + + /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() + * and getpeername(). + */ + sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); + + newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; + + sk_refcnt_debug_inc(newsk); + + if (newsk->sk_prot->init(newsk)) { + sk_common_release(newsk); + newsk = NULL; + } + +out: + return newsk; +} + +/* Format a sockaddr for return to user space. This makes sure the return is + * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. + */ +static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) +{ + if (sp->v4mapped) { + if (addr->sa.sa_family == AF_INET) + sctp_v4_map_v6(addr); + } else { + if (addr->sa.sa_family == AF_INET6 && + ipv6_addr_v4mapped(&addr->v6.sin6_addr)) + sctp_v6_map_v4(addr); + } + + if (addr->sa.sa_family == AF_INET) { + memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); + return sizeof(struct sockaddr_in); + } + return sizeof(struct sockaddr_in6); +} + +/* Where did this skb come from? */ +static int sctp_v6_skb_iif(const struct sk_buff *skb) +{ + return IP6CB(skb)->iif; +} + +/* Was this packet marked by Explicit Congestion Notification? */ +static int sctp_v6_is_ce(const struct sk_buff *skb) +{ + return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); +} + +/* Dump the v6 addr to the seq file. */ +static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) +{ + seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); +} + +static void sctp_v6_ecn_capable(struct sock *sk) +{ + inet6_sk(sk)->tclass |= INET_ECN_ECT_0; +} + +/* Initialize a PF_INET msgname from a ulpevent. */ +static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, + char *msgname, int *addrlen) +{ + union sctp_addr *addr; + struct sctp_association *asoc; + union sctp_addr *paddr; + + if (!msgname) + return; + + addr = (union sctp_addr *)msgname; + asoc = event->asoc; + paddr = &asoc->peer.primary_addr; + + if (paddr->sa.sa_family == AF_INET) { + addr->v4.sin_family = AF_INET; + addr->v4.sin_port = htons(asoc->peer.port); + addr->v4.sin_addr = paddr->v4.sin_addr; + } else { + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_flowinfo = 0; + if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) + addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; + else + addr->v6.sin6_scope_id = 0; + addr->v6.sin6_port = htons(asoc->peer.port); + addr->v6.sin6_addr = paddr->v6.sin6_addr; + } + + *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); +} + +/* Initialize a msg_name from an inbound skb. */ +static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, + int *addr_len) +{ + union sctp_addr *addr; + struct sctphdr *sh; + + if (!msgname) + return; + + addr = (union sctp_addr *)msgname; + sh = sctp_hdr(skb); + + if (ip_hdr(skb)->version == 4) { + addr->v4.sin_family = AF_INET; + addr->v4.sin_port = sh->source; + addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; + } else { + addr->v6.sin6_family = AF_INET6; + addr->v6.sin6_flowinfo = 0; + addr->v6.sin6_port = sh->source; + addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; + if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) + addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); + else + addr->v6.sin6_scope_id = 0; + } + + *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); +} + +/* Do we support this AF? */ +static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) +{ + switch (family) { + case AF_INET6: + return 1; + /* v4-mapped-v6 addresses */ + case AF_INET: + if (!ipv6_only_sock(sctp_opt2sk(sp))) + return 1; + fallthrough; + default: + return 0; + } +} + +/* Address matching with wildcards allowed. This extra level + * of indirection lets us choose whether a PF_INET6 should + * disallow any v4 addresses if we so choose. + */ +static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, + const union sctp_addr *addr2, + struct sctp_sock *opt) +{ + struct sock *sk = sctp_opt2sk(opt); + struct sctp_af *af1, *af2; + + af1 = sctp_get_af_specific(addr1->sa.sa_family); + af2 = sctp_get_af_specific(addr2->sa.sa_family); + + if (!af1 || !af2) + return 0; + + /* If the socket is IPv6 only, v4 addrs will not match */ + if (ipv6_only_sock(sk) && af1 != af2) + return 0; + + /* Today, wildcard AF_INET/AF_INET6. */ + if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) + return 1; + + if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) + return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; + + return __sctp_v6_cmp_addr(addr1, addr2); +} + +/* Verify that the provided sockaddr looks bindable. Common verification, + * has already been taken care of. + */ +static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) +{ + struct sctp_af *af; + + /* ASSERT: address family has already been verified. */ + if (addr->sa.sa_family != AF_INET6) + af = sctp_get_af_specific(addr->sa.sa_family); + else { + int type = ipv6_addr_type(&addr->v6.sin6_addr); + struct net_device *dev; + + if (type & IPV6_ADDR_LINKLOCAL) { + struct net *net; + if (!addr->v6.sin6_scope_id) + return 0; + net = sock_net(&opt->inet.sk); + rcu_read_lock(); + dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); + if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || + ipv6_chk_addr(net, &addr->v6.sin6_addr, + dev, 0))) { + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + } + + af = opt->pf->af; + } + return af->available(addr, opt); +} + +/* Verify that the provided sockaddr looks sendable. Common verification, + * has already been taken care of. + */ +static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) +{ + struct sctp_af *af = NULL; + + /* ASSERT: address family has already been verified. */ + if (addr->sa.sa_family != AF_INET6) + af = sctp_get_af_specific(addr->sa.sa_family); + else { + int type = ipv6_addr_type(&addr->v6.sin6_addr); + struct net_device *dev; + + if (type & IPV6_ADDR_LINKLOCAL) { + if (!addr->v6.sin6_scope_id) + return 0; + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), + addr->v6.sin6_scope_id); + rcu_read_unlock(); + if (!dev) + return 0; + } + af = opt->pf->af; + } + + return af != NULL; +} + +/* Fill in Supported Address Type information for INIT and INIT-ACK + * chunks. Note: In the future, we may want to look at sock options + * to determine whether a PF_INET6 socket really wants to have IPV4 + * addresses. + * Returns number of addresses supported. + */ +static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, + __be16 *types) +{ + types[0] = SCTP_PARAM_IPV6_ADDRESS; + if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { + types[1] = SCTP_PARAM_IPV4_ADDRESS; + return 2; + } + return 1; +} + +/* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ +static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + int rc; + + rc = inet6_getname(sock, uaddr, peer); + + if (rc < 0) + return rc; + + rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), + (union sctp_addr *)uaddr); + + return rc; +} + +static const struct proto_ops inet6_seqpacket_ops = { + .family = PF_INET6, + .owner = THIS_MODULE, + .release = inet6_release, + .bind = inet6_bind, + .connect = sctp_inet_connect, + .socketpair = sock_no_socketpair, + .accept = inet_accept, + .getname = sctp_getname, + .poll = sctp_poll, + .ioctl = inet6_ioctl, + .gettstamp = sock_gettstamp, + .listen = sctp_inet_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = inet_recvmsg, + .mmap = sock_no_mmap, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet6_compat_ioctl, +#endif +}; + +static struct inet_protosw sctpv6_seqpacket_protosw = { + .type = SOCK_SEQPACKET, + .protocol = IPPROTO_SCTP, + .prot = &sctpv6_prot, + .ops = &inet6_seqpacket_ops, + .flags = SCTP_PROTOSW_FLAG +}; +static struct inet_protosw sctpv6_stream_protosw = { + .type = SOCK_STREAM, + .protocol = IPPROTO_SCTP, + .prot = &sctpv6_prot, + .ops = &inet6_seqpacket_ops, + .flags = SCTP_PROTOSW_FLAG, +}; + +static int sctp6_rcv(struct sk_buff *skb) +{ + SCTP_INPUT_CB(skb)->encap_port = 0; + return sctp_rcv(skb) ? -1 : 0; +} + +static const struct inet6_protocol sctpv6_protocol = { + .handler = sctp6_rcv, + .err_handler = sctp_v6_err, + .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, +}; + +static struct sctp_af sctp_af_inet6 = { + .sa_family = AF_INET6, + .sctp_xmit = sctp_v6_xmit, + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .get_dst = sctp_v6_get_dst, + .get_saddr = sctp_v6_get_saddr, + .copy_addrlist = sctp_v6_copy_addrlist, + .from_skb = sctp_v6_from_skb, + .from_sk = sctp_v6_from_sk, + .from_addr_param = sctp_v6_from_addr_param, + .to_addr_param = sctp_v6_to_addr_param, + .cmp_addr = sctp_v6_cmp_addr, + .scope = sctp_v6_scope, + .addr_valid = sctp_v6_addr_valid, + .inaddr_any = sctp_v6_inaddr_any, + .is_any = sctp_v6_is_any, + .available = sctp_v6_available, + .skb_iif = sctp_v6_skb_iif, + .is_ce = sctp_v6_is_ce, + .seq_dump_addr = sctp_v6_seq_dump_addr, + .ecn_capable = sctp_v6_ecn_capable, + .net_header_len = sizeof(struct ipv6hdr), + .sockaddr_len = sizeof(struct sockaddr_in6), + .ip_options_len = sctp_v6_ip_options_len, +}; + +static struct sctp_pf sctp_pf_inet6 = { + .event_msgname = sctp_inet6_event_msgname, + .skb_msgname = sctp_inet6_skb_msgname, + .af_supported = sctp_inet6_af_supported, + .cmp_addr = sctp_inet6_cmp_addr, + .bind_verify = sctp_inet6_bind_verify, + .send_verify = sctp_inet6_send_verify, + .supported_addrs = sctp_inet6_supported_addrs, + .create_accept_sk = sctp_v6_create_accept_sk, + .addr_to_user = sctp_v6_addr_to_user, + .to_sk_saddr = sctp_v6_to_sk_saddr, + .to_sk_daddr = sctp_v6_to_sk_daddr, + .copy_ip_options = sctp_v6_copy_ip_options, + .af = &sctp_af_inet6, +}; + +/* Initialize IPv6 support and register with socket layer. */ +void sctp_v6_pf_init(void) +{ + /* Register the SCTP specific PF_INET6 functions. */ + sctp_register_pf(&sctp_pf_inet6, PF_INET6); + + /* Register the SCTP specific AF_INET6 functions. */ + sctp_register_af(&sctp_af_inet6); +} + +void sctp_v6_pf_exit(void) +{ + list_del(&sctp_af_inet6.list); +} + +/* Initialize IPv6 support and register with socket layer. */ +int sctp_v6_protosw_init(void) +{ + int rc; + + rc = proto_register(&sctpv6_prot, 1); + if (rc) + return rc; + + /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ + inet6_register_protosw(&sctpv6_seqpacket_protosw); + inet6_register_protosw(&sctpv6_stream_protosw); + + return 0; +} + +void sctp_v6_protosw_exit(void) +{ + inet6_unregister_protosw(&sctpv6_seqpacket_protosw); + inet6_unregister_protosw(&sctpv6_stream_protosw); + proto_unregister(&sctpv6_prot); +} + + +/* Register with inet6 layer. */ +int sctp_v6_add_protocol(void) +{ + /* Register notifier for inet6 address additions/deletions. */ + register_inet6addr_notifier(&sctp_inet6addr_notifier); + + if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) + return -EAGAIN; + + return 0; +} + +/* Unregister with inet6 layer. */ +void sctp_v6_del_protocol(void) +{ + inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); + unregister_inet6addr_notifier(&sctp_inet6addr_notifier); +} |