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linux-next/net/sctp/ipv6.c
David Howells cdfbabfb2f net: Work around lockdep limitation in sockets that use sockets 
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to ->accept() that is analogous to the one
     passed in to ->create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:23:27 -08:00

1095 lines
29 KiB
C
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/* 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.
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* 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 <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 = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
if (addr) {
addr->a.v6.sin6_family = AF_INET6;
addr->a.v6.sin6_port = 0;
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)) {
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,
};
/* ICMP error handler. */
static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct inet6_dev *idev;
struct sock *sk;
struct sctp_association *asoc;
struct sctp_transport *transport;
struct ipv6_pinfo *np;
__u16 saveip, savesctp;
int err;
struct net *net = dev_net(skb->dev);
idev = in6_dev_get(skb->dev);
/* 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, idev, ICMP6_MIB_INERRORS);
goto out;
}
/* Warning: The sock lock is held. Remember to call
* sctp_err_finish!
*/
switch (type) {
case ICMPV6_PKT_TOOBIG:
if (ip6_sk_accept_pmtu(sk))
sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
goto out_unlock;
case ICMPV6_PARAMPROB:
if (ICMPV6_UNK_NEXTHDR == code) {
sctp_icmp_proto_unreachable(sk, asoc, transport);
goto out_unlock;
}
break;
case NDISC_REDIRECT:
sctp_icmp_redirect(sk, transport, skb);
goto out_unlock;
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->sk_error_report(sk);
} else { /* Only an error on timeout */
sk->sk_err_soft = err;
}
out_unlock:
sctp_err_finish(sk, transport);
out:
if (likely(idev != NULL))
in6_dev_put(idev);
}
static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
{
struct sock *sk = skb->sk;
struct ipv6_pinfo *np = inet6_sk(sk);
struct flowi6 *fl6 = &transport->fl.u.ip6;
int res;
pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
skb->len, &fl6->saddr, &fl6->daddr);
IP6_ECN_flow_xmit(sk, fl6->flowlabel);
if (!(transport->param_flags & SPP_PMTUD_ENABLE))
skb->ignore_df = 1;
SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
rcu_read_lock();
res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
np->tclass);
rcu_read_unlock();
return res;
}
/* 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 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 *baddr = NULL;
union sctp_addr *daddr = &t->ipaddr;
union sctp_addr dst_saddr;
struct in6_addr *final_p, final;
__u8 matchlen = 0;
__u8 bmatchlen;
sctp_scope_t scope;
memset(fl6, 0, sizeof(struct flowi6));
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;
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;
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(sk, fl6, final_p);
if (!asoc || saddr)
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();
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) {
if (!laddr->valid)
continue;
if ((laddr->state == SCTP_ADDR_SRC) &&
(laddr->a.sa.sa_family == AF_INET6) &&
(scope <= sctp_scope(&laddr->a))) {
bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
if (!baddr || (matchlen < bmatchlen)) {
baddr = &laddr->a;
matchlen = bmatchlen;
}
}
}
if (baddr) {
fl6->saddr = baddr->v6.sin6_addr;
fl6->fl6_sport = baddr->v6.sin6_port;
final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
dst = ip6_dst_lookup_flow(sk, fl6, final_p);
}
rcu_read_unlock();
out:
if (!IS_ERR_OR_NULL(dst)) {
struct rt6_info *rt;
rt = (struct rt6_info *)dst;
t->dst = 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,
&fl6->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_port = 0;
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();
}
/* 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 void sctp_v6_from_addr_param(union sctp_addr *addr,
union sctp_addr_param *param,
__be16 port, int iif)
{
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;
}
/* 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(sctp_ipv6addr_param_t);
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_addr = *saddr;
}
/* 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)
{
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)) {
if (addr2->v6.sin6_port == addr1->v4.sin_port &&
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)) {
if (addr1->v6.sin6_port == addr2->v4.sin_port &&
addr1->v6.sin6_addr.s6_addr32[3] ==
addr2->v4.sin_addr.s_addr)
return 1;
}
return 0;
}
if (addr1->v6.sin6_port != addr2->v6.sin6_port)
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) {
if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
(addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
return 0;
}
}
return 1;
}
/* 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 sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
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 sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
{
int v6scope;
sctp_scope_t retval;
/* 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;
struct ipv6_txoptions *opt;
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));
rcu_read_lock();
opt = rcu_dereference(np->opt);
if (opt)
opt = ipv6_dup_options(newsk, opt);
RCU_INIT_POINTER(newnp->opt, opt);
rcu_read_unlock();
/* 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)
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))) & 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);
}
}
*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;
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 sctp_af *af1, *af2;
struct sock *sk = sctp_opt2sk(opt);
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 != addr2->sa.sa_family)
return 0;
return af1->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_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 *uaddr_len, int peer)
{
int rc;
rc = inet6_getname(sock, uaddr, uaddr_len, peer);
if (rc != 0)
return rc;
*uaddr_len = 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 = inet_dgram_connect,
.socketpair = sock_no_socketpair,
.accept = inet_accept,
.getname = sctp_getname,
.poll = sctp_poll,
.ioctl = inet6_ioctl,
.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_setsockopt = compat_sock_common_setsockopt,
.compat_getsockopt = compat_sock_common_getsockopt,
#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)
{
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),
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_ipv6_setsockopt,
.compat_getsockopt = compat_ipv6_getsockopt,
#endif
};
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,
.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);
}
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