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kernel/net/ipv6/ipv6_sockglue.c
David L Stevens c9e3e8b695 [IPV6]: multicast join and misc 
Here is a simplified version of the patch to fix a bug in IPv6
multicasting. It:

1) adds existence check & EADDRINUSE error for regular joins
2) adds an exception for EADDRINUSE in the source-specific multicast
        join (where a prior join is ok)
3) adds a missing/needed read_lock on sock_mc_list; would've raced
        with destroying the socket on interface down without
4) adds a "leave group" in the (INCLUDE, empty) source filter case.
        This frees unneeded socket buffer memory, but also prevents
        an inappropriate interaction among the 8 socket options that
        mess with this. Some would fail as if in the group when you
        aren't really.

Item #4 had a locking bug in the last version of this patch; rather than
removing the idev->lock read lock only, I've simplified it to remove
all lock state in the path and treat it as a direct "leave group" call for
the (INCLUDE,empty) case it covers. Tested on an MP machine. :-)

Much thanks to HoerdtMickael <hoerdt@clarinet.u-strasbg.fr> who
reported the original bug.

Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-21 13:58:25 -07:00

705 lines
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/*
* IPv6 BSD socket options interface
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
*
* Based on linux/net/ipv4/ip_sockglue.c
*
* $Id: ipv6_sockglue.c,v 1.41 2002/02/01 22:01:04 davem Exp $
*
* This program 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 of the License, or (at your option) any later version.
*
* FIXME: Make the setsockopt code POSIX compliant: That is
*
* o Return -EINVAL for setsockopt of short lengths
* o Truncate getsockopt returns
* o Return an optlen of the truncated length if need be
*
* Changes:
* David L Stevens <dlstevens@us.ibm.com>:
* - added multicast source filtering API for MLDv2
*/
#include <linux/module.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/netfilter.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/xfrm.h>
#include <asm/uaccess.h>
DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics);
static struct packet_type ipv6_packet_type = {
.type = __constant_htons(ETH_P_IPV6),
.func = ipv6_rcv,
};
struct ip6_ra_chain *ip6_ra_chain;
DEFINE_RWLOCK(ip6_ra_lock);
int ip6_ra_control(struct sock *sk, int sel, void (*destructor)(struct sock *))
{
struct ip6_ra_chain *ra, *new_ra, **rap;
/* RA packet may be delivered ONLY to IPPROTO_RAW socket */
if (sk->sk_type != SOCK_RAW || inet_sk(sk)->num != IPPROTO_RAW)
return -EINVAL;
new_ra = (sel>=0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
write_lock_bh(&ip6_ra_lock);
for (rap = &ip6_ra_chain; (ra=*rap) != NULL; rap = &ra->next) {
if (ra->sk == sk) {
if (sel>=0) {
write_unlock_bh(&ip6_ra_lock);
if (new_ra)
kfree(new_ra);
return -EADDRINUSE;
}
*rap = ra->next;
write_unlock_bh(&ip6_ra_lock);
if (ra->destructor)
ra->destructor(sk);
sock_put(sk);
kfree(ra);
return 0;
}
}
if (new_ra == NULL) {
write_unlock_bh(&ip6_ra_lock);
return -ENOBUFS;
}
new_ra->sk = sk;
new_ra->sel = sel;
new_ra->destructor = destructor;
new_ra->next = ra;
*rap = new_ra;
sock_hold(sk);
write_unlock_bh(&ip6_ra_lock);
return 0;
}
extern int ip6_mc_source(int add, int omode, struct sock *sk,
struct group_source_req *pgsr);
extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
struct group_filter __user *optval, int __user *optlen);
int ipv6_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
struct ipv6_pinfo *np = inet6_sk(sk);
int val, valbool;
int retv = -ENOPROTOOPT;
if (level == SOL_IP && sk->sk_type != SOCK_RAW)
return udp_prot.setsockopt(sk, level, optname, optval, optlen);
if(level!=SOL_IPV6)
goto out;
if (optval == NULL)
val=0;
else if (get_user(val, (int __user *) optval))
return -EFAULT;
valbool = (val!=0);
lock_sock(sk);
switch (optname) {
case IPV6_ADDRFORM:
if (val == PF_INET) {
struct ipv6_txoptions *opt;
struct sk_buff *pktopt;
if (sk->sk_protocol != IPPROTO_UDP &&
sk->sk_protocol != IPPROTO_TCP)
break;
if (sk->sk_state != TCP_ESTABLISHED) {
retv = -ENOTCONN;
break;
}
if (ipv6_only_sock(sk) ||
!(ipv6_addr_type(&np->daddr) & IPV6_ADDR_MAPPED)) {
retv = -EADDRNOTAVAIL;
break;
}
fl6_free_socklist(sk);
ipv6_sock_mc_close(sk);
if (sk->sk_protocol == IPPROTO_TCP) {
struct tcp_sock *tp = tcp_sk(sk);
local_bh_disable();
sock_prot_dec_use(sk->sk_prot);
sock_prot_inc_use(&tcp_prot);
local_bh_enable();
sk->sk_prot = &tcp_prot;
tp->af_specific = &ipv4_specific;
sk->sk_socket->ops = &inet_stream_ops;
sk->sk_family = PF_INET;
tcp_sync_mss(sk, tp->pmtu_cookie);
} else {
local_bh_disable();
sock_prot_dec_use(sk->sk_prot);
sock_prot_inc_use(&udp_prot);
local_bh_enable();
sk->sk_prot = &udp_prot;
sk->sk_socket->ops = &inet_dgram_ops;
sk->sk_family = PF_INET;
}
opt = xchg(&np->opt, NULL);
if (opt)
sock_kfree_s(sk, opt, opt->tot_len);
pktopt = xchg(&np->pktoptions, NULL);
if (pktopt)
kfree_skb(pktopt);
sk->sk_destruct = inet_sock_destruct;
#ifdef INET_REFCNT_DEBUG
atomic_dec(&inet6_sock_nr);
#endif
module_put(THIS_MODULE);
retv = 0;
break;
}
goto e_inval;
case IPV6_V6ONLY:
if (inet_sk(sk)->num)
goto e_inval;
np->ipv6only = valbool;
retv = 0;
break;
case IPV6_PKTINFO:
np->rxopt.bits.rxinfo = valbool;
retv = 0;
break;
case IPV6_HOPLIMIT:
np->rxopt.bits.rxhlim = valbool;
retv = 0;
break;
case IPV6_RTHDR:
if (val < 0 || val > 2)
goto e_inval;
np->rxopt.bits.srcrt = val;
retv = 0;
break;
case IPV6_HOPOPTS:
np->rxopt.bits.hopopts = valbool;
retv = 0;
break;
case IPV6_DSTOPTS:
np->rxopt.bits.dstopts = valbool;
retv = 0;
break;
case IPV6_FLOWINFO:
np->rxopt.bits.rxflow = valbool;
retv = 0;
break;
case IPV6_PKTOPTIONS:
{
struct ipv6_txoptions *opt = NULL;
struct msghdr msg;
struct flowi fl;
int junk;
fl.fl6_flowlabel = 0;
fl.oif = sk->sk_bound_dev_if;
if (optlen == 0)
goto update;
/* 1K is probably excessive
* 1K is surely not enough, 2K per standard header is 16K.
*/
retv = -EINVAL;
if (optlen > 64*1024)
break;
opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
retv = -ENOBUFS;
if (opt == NULL)
break;
memset(opt, 0, sizeof(*opt));
opt->tot_len = sizeof(*opt) + optlen;
retv = -EFAULT;
if (copy_from_user(opt+1, optval, optlen))
goto done;
msg.msg_controllen = optlen;
msg.msg_control = (void*)(opt+1);
retv = datagram_send_ctl(&msg, &fl, opt, &junk);
if (retv)
goto done;
update:
retv = 0;
if (sk->sk_type == SOCK_STREAM) {
if (opt) {
struct tcp_sock *tp = tcp_sk(sk);
if (!((1 << sk->sk_state) &
(TCPF_LISTEN | TCPF_CLOSE))
&& inet_sk(sk)->daddr != LOOPBACK4_IPV6) {
tp->ext_header_len = opt->opt_flen + opt->opt_nflen;
tcp_sync_mss(sk, tp->pmtu_cookie);
}
}
opt = xchg(&np->opt, opt);
sk_dst_reset(sk);
} else {
write_lock(&sk->sk_dst_lock);
opt = xchg(&np->opt, opt);
write_unlock(&sk->sk_dst_lock);
sk_dst_reset(sk);
}
done:
if (opt)
sock_kfree_s(sk, opt, opt->tot_len);
break;
}
case IPV6_UNICAST_HOPS:
if (val > 255 || val < -1)
goto e_inval;
np->hop_limit = val;
retv = 0;
break;
case IPV6_MULTICAST_HOPS:
if (sk->sk_type == SOCK_STREAM)
goto e_inval;
if (val > 255 || val < -1)
goto e_inval;
np->mcast_hops = val;
retv = 0;
break;
case IPV6_MULTICAST_LOOP:
np->mc_loop = valbool;
retv = 0;
break;
case IPV6_MULTICAST_IF:
if (sk->sk_type == SOCK_STREAM)
goto e_inval;
if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val)
goto e_inval;
if (__dev_get_by_index(val) == NULL) {
retv = -ENODEV;
break;
}
np->mcast_oif = val;
retv = 0;
break;
case IPV6_ADD_MEMBERSHIP:
case IPV6_DROP_MEMBERSHIP:
{
struct ipv6_mreq mreq;
retv = -EFAULT;
if (copy_from_user(&mreq, optval, sizeof(struct ipv6_mreq)))
break;
if (optname == IPV6_ADD_MEMBERSHIP)
retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
else
retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
break;
}
case IPV6_JOIN_ANYCAST:
case IPV6_LEAVE_ANYCAST:
{
struct ipv6_mreq mreq;
if (optlen != sizeof(struct ipv6_mreq))
goto e_inval;
retv = -EFAULT;
if (copy_from_user(&mreq, optval, sizeof(struct ipv6_mreq)))
break;
if (optname == IPV6_JOIN_ANYCAST)
retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
else
retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
break;
}
case MCAST_JOIN_GROUP:
case MCAST_LEAVE_GROUP:
{
struct group_req greq;
struct sockaddr_in6 *psin6;
retv = -EFAULT;
if (copy_from_user(&greq, optval, sizeof(struct group_req)))
break;
if (greq.gr_group.ss_family != AF_INET6) {
retv = -EADDRNOTAVAIL;
break;
}
psin6 = (struct sockaddr_in6 *)&greq.gr_group;
if (optname == MCAST_JOIN_GROUP)
retv = ipv6_sock_mc_join(sk, greq.gr_interface,
&psin6->sin6_addr);
else
retv = ipv6_sock_mc_drop(sk, greq.gr_interface,
&psin6->sin6_addr);
break;
}
case MCAST_JOIN_SOURCE_GROUP:
case MCAST_LEAVE_SOURCE_GROUP:
case MCAST_BLOCK_SOURCE:
case MCAST_UNBLOCK_SOURCE:
{
struct group_source_req greqs;
int omode, add;
if (optlen != sizeof(struct group_source_req))
goto e_inval;
if (copy_from_user(&greqs, optval, sizeof(greqs))) {
retv = -EFAULT;
break;
}
if (greqs.gsr_group.ss_family != AF_INET6 ||
greqs.gsr_source.ss_family != AF_INET6) {
retv = -EADDRNOTAVAIL;
break;
}
if (optname == MCAST_BLOCK_SOURCE) {
omode = MCAST_EXCLUDE;
add = 1;
} else if (optname == MCAST_UNBLOCK_SOURCE) {
omode = MCAST_EXCLUDE;
add = 0;
} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
struct sockaddr_in6 *psin6;
psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
retv = ipv6_sock_mc_join(sk, greqs.gsr_interface,
&psin6->sin6_addr);
/* prior join w/ different source is ok */
if (retv && retv != -EADDRINUSE)
break;
omode = MCAST_INCLUDE;
add = 1;
} else /* MCAST_LEAVE_SOURCE_GROUP */ {
omode = MCAST_INCLUDE;
add = 0;
}
retv = ip6_mc_source(add, omode, sk, &greqs);
break;
}
case MCAST_MSFILTER:
{
extern int sysctl_optmem_max;
extern int sysctl_mld_max_msf;
struct group_filter *gsf;
if (optlen < GROUP_FILTER_SIZE(0))
goto e_inval;
if (optlen > sysctl_optmem_max) {
retv = -ENOBUFS;
break;
}
gsf = (struct group_filter *)kmalloc(optlen,GFP_KERNEL);
if (gsf == 0) {
retv = -ENOBUFS;
break;
}
retv = -EFAULT;
if (copy_from_user(gsf, optval, optlen)) {
kfree(gsf);
break;
}
/* numsrc >= (4G-140)/128 overflow in 32 bits */
if (gsf->gf_numsrc >= 0x1ffffffU ||
gsf->gf_numsrc > sysctl_mld_max_msf) {
kfree(gsf);
retv = -ENOBUFS;
break;
}
if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
kfree(gsf);
retv = -EINVAL;
break;
}
retv = ip6_mc_msfilter(sk, gsf);
kfree(gsf);
break;
}
case IPV6_ROUTER_ALERT:
retv = ip6_ra_control(sk, val, NULL);
break;
case IPV6_MTU_DISCOVER:
if (val<0 || val>2)
goto e_inval;
np->pmtudisc = val;
retv = 0;
break;
case IPV6_MTU:
if (val && val < IPV6_MIN_MTU)
goto e_inval;
np->frag_size = val;
retv = 0;
break;
case IPV6_RECVERR:
np->recverr = valbool;
if (!val)
skb_queue_purge(&sk->sk_error_queue);
retv = 0;
break;
case IPV6_FLOWINFO_SEND:
np->sndflow = valbool;
retv = 0;
break;
case IPV6_FLOWLABEL_MGR:
retv = ipv6_flowlabel_opt(sk, optval, optlen);
break;
case IPV6_IPSEC_POLICY:
case IPV6_XFRM_POLICY:
retv = xfrm_user_policy(sk, optname, optval, optlen);
break;
#ifdef CONFIG_NETFILTER
default:
retv = nf_setsockopt(sk, PF_INET6, optname, optval,
optlen);
break;
#endif
}
release_sock(sk);
out:
return retv;
e_inval:
release_sock(sk);
return -EINVAL;
}
int ipv6_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
struct ipv6_pinfo *np = inet6_sk(sk);
int len;
int val;
if (level == SOL_IP && sk->sk_type != SOCK_RAW)
return udp_prot.getsockopt(sk, level, optname, optval, optlen);
if(level!=SOL_IPV6)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
switch (optname) {
case IPV6_ADDRFORM:
if (sk->sk_protocol != IPPROTO_UDP &&
sk->sk_protocol != IPPROTO_TCP)
return -EINVAL;
if (sk->sk_state != TCP_ESTABLISHED)
return -ENOTCONN;
val = sk->sk_family;
break;
case MCAST_MSFILTER:
{
struct group_filter gsf;
int err;
if (len < GROUP_FILTER_SIZE(0))
return -EINVAL;
if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0)))
return -EFAULT;
lock_sock(sk);
err = ip6_mc_msfget(sk, &gsf,
(struct group_filter __user *)optval, optlen);
release_sock(sk);
return err;
}
case IPV6_PKTOPTIONS:
{
struct msghdr msg;
struct sk_buff *skb;
if (sk->sk_type != SOCK_STREAM)
return -ENOPROTOOPT;
msg.msg_control = optval;
msg.msg_controllen = len;
msg.msg_flags = 0;
lock_sock(sk);
skb = np->pktoptions;
if (skb)
atomic_inc(&skb->users);
release_sock(sk);
if (skb) {
int err = datagram_recv_ctl(sk, &msg, skb);
kfree_skb(skb);
if (err)
return err;
} else {
if (np->rxopt.bits.rxinfo) {
struct in6_pktinfo src_info;
src_info.ipi6_ifindex = np->mcast_oif;
ipv6_addr_copy(&src_info.ipi6_addr, &np->daddr);
put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
}
if (np->rxopt.bits.rxhlim) {
int hlim = np->mcast_hops;
put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
}
}
len -= msg.msg_controllen;
return put_user(len, optlen);
}
case IPV6_MTU:
{
struct dst_entry *dst;
val = 0;
lock_sock(sk);
dst = sk_dst_get(sk);
if (dst) {
val = dst_mtu(dst);
dst_release(dst);
}
release_sock(sk);
if (!val)
return -ENOTCONN;
break;
}
case IPV6_V6ONLY:
val = np->ipv6only;
break;
case IPV6_PKTINFO:
val = np->rxopt.bits.rxinfo;
break;
case IPV6_HOPLIMIT:
val = np->rxopt.bits.rxhlim;
break;
case IPV6_RTHDR:
val = np->rxopt.bits.srcrt;
break;
case IPV6_HOPOPTS:
val = np->rxopt.bits.hopopts;
break;
case IPV6_DSTOPTS:
val = np->rxopt.bits.dstopts;
break;
case IPV6_FLOWINFO:
val = np->rxopt.bits.rxflow;
break;
case IPV6_UNICAST_HOPS:
val = np->hop_limit;
break;
case IPV6_MULTICAST_HOPS:
val = np->mcast_hops;
break;
case IPV6_MULTICAST_LOOP:
val = np->mc_loop;
break;
case IPV6_MULTICAST_IF:
val = np->mcast_oif;
break;
case IPV6_MTU_DISCOVER:
val = np->pmtudisc;
break;
case IPV6_RECVERR:
val = np->recverr;
break;
case IPV6_FLOWINFO_SEND:
val = np->sndflow;
break;
default:
#ifdef CONFIG_NETFILTER
lock_sock(sk);
val = nf_getsockopt(sk, PF_INET6, optname, optval,
&len);
release_sock(sk);
if (val >= 0)
val = put_user(len, optlen);
return val;
#else
return -EINVAL;
#endif
}
len = min_t(unsigned int, sizeof(int), len);
if(put_user(len, optlen))
return -EFAULT;
if(copy_to_user(optval,&val,len))
return -EFAULT;
return 0;
}
void __init ipv6_packet_init(void)
{
dev_add_pack(&ipv6_packet_type);
}
void ipv6_packet_cleanup(void)
{
dev_remove_pack(&ipv6_packet_type);
}
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