linux/net/sctp/ipv6.c
Eric Dumazet 2f2d9972af net: annotate lockless accesses to sk->sk_err_soft
This field can be read/written without lock synchronization.

tcp and dccp have been handled in different patches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-17 08:25:05 +00:00

1230 lines
32 KiB
C

// 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 {
WRITE_ONCE(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)
{
const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
struct sock *sk = &sp->inet.sk;
struct net *net = sock_net(sk);
struct net_device *dev = NULL;
int type;
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;
if (sk->sk_bound_dev_if) {
dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
if (!dev)
return 0;
}
return ipv6_can_nonlocal_bind(net, &sp->inet) ||
ipv6_chk_addr(net, in6, dev, 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;
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 inet6_iif(skb);
}
static int sctp_v6_skb_sdif(const struct sk_buff *skb)
{
return inet6_sdif(skb);
}
/* 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,
.skb_sdif = sctp_v6_skb_sdif,
.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);
}