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linux/net/ipv4/igmp.c
Guillaume Nault ec20b28300 ipv4: Set scope explicitly in ip_route_output(). 
Add a "scope" parameter to ip_route_output() so that callers don't have
to override the tos parameter with the RTO_ONLINK flag if they want a
local scope.

This will allow converting flowi4_tos to dscp_t in the future, thus
allowing static analysers to flag invalid interactions between
"tos" (the DSCP bits) and ECN.

Only three users ask for local scope (bonding, arp and atm). The others
continue to use RT_SCOPE_UNIVERSE. While there, add a comment to warn
users about the limitations of ip_route_output().

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Leon Romanovsky <leonro@nvidia.com> # infiniband
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-08 13:20:51 +01:00

3110 lines
74 KiB
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Linux NET3: Internet Group Management Protocol [IGMP]
*
* This code implements the IGMP protocol as defined in RFC1112. There has
* been a further revision of this protocol since which is now supported.
*
* If you have trouble with this module be careful what gcc you have used,
* the older version didn't come out right using gcc 2.5.8, the newer one
* seems to fall out with gcc 2.6.2.
*
* Authors:
* Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Fixes:
*
* Alan Cox : Added lots of __inline__ to optimise
* the memory usage of all the tiny little
* functions.
* Alan Cox : Dumped the header building experiment.
* Alan Cox : Minor tweaks ready for multicast routing
* and extended IGMP protocol.
* Alan Cox : Removed a load of inline directives. Gcc 2.5.8
* writes utterly bogus code otherwise (sigh)
* fixed IGMP loopback to behave in the manner
* desired by mrouted, fixed the fact it has been
* broken since 1.3.6 and cleaned up a few minor
* points.
*
* Chih-Jen Chang : Tried to revise IGMP to Version 2
* Tsu-Sheng Tsao E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
* The enhancements are mainly based on Steve Deering's
* ipmulti-3.5 source code.
* Chih-Jen Chang : Added the igmp_get_mrouter_info and
* Tsu-Sheng Tsao igmp_set_mrouter_info to keep track of
* the mrouted version on that device.
* Chih-Jen Chang : Added the max_resp_time parameter to
* Tsu-Sheng Tsao igmp_heard_query(). Using this parameter
* to identify the multicast router version
* and do what the IGMP version 2 specified.
* Chih-Jen Chang : Added a timer to revert to IGMP V2 router
* Tsu-Sheng Tsao if the specified time expired.
* Alan Cox : Stop IGMP from 0.0.0.0 being accepted.
* Alan Cox : Use GFP_ATOMIC in the right places.
* Christian Daudt : igmp timer wasn't set for local group
* memberships but was being deleted,
* which caused a "del_timer() called
* from %p with timer not initialized\n"
* message (960131).
* Christian Daudt : removed del_timer from
* igmp_timer_expire function (960205).
* Christian Daudt : igmp_heard_report now only calls
* igmp_timer_expire if tm->running is
* true (960216).
* Malcolm Beattie : ttl comparison wrong in igmp_rcv made
* igmp_heard_query never trigger. Expiry
* miscalculation fixed in igmp_heard_query
* and random() made to return unsigned to
* prevent negative expiry times.
* Alexey Kuznetsov: Wrong group leaving behaviour, backport
* fix from pending 2.1.x patches.
* Alan Cox: Forget to enable FDDI support earlier.
* Alexey Kuznetsov: Fixed leaving groups on device down.
* Alexey Kuznetsov: Accordance to igmp-v2-06 draft.
* David L Stevens: IGMPv3 support, with help from
* Vinay Kulkarni
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <linux/times.h>
#include <linux/pkt_sched.h>
#include <linux/byteorder/generic.h>
#include <net/net_namespace.h>
#include <net/arp.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/inet_common.h>
#include <linux/netfilter_ipv4.h>
#ifdef CONFIG_IP_MROUTE
#include <linux/mroute.h>
#endif
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#endif
#ifdef CONFIG_IP_MULTICAST
/* Parameter names and values are taken from igmp-v2-06 draft */
#define IGMP_QUERY_INTERVAL (125*HZ)
#define IGMP_QUERY_RESPONSE_INTERVAL (10*HZ)
#define IGMP_INITIAL_REPORT_DELAY (1)
/* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
* IGMP specs require to report membership immediately after
* joining a group, but we delay the first report by a
* small interval. It seems more natural and still does not
* contradict to specs provided this delay is small enough.
*/
#define IGMP_V1_SEEN(in_dev) \
(IPV4_DEVCONF_ALL_RO(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
((in_dev)->mr_v1_seen && \
time_before(jiffies, (in_dev)->mr_v1_seen)))
#define IGMP_V2_SEEN(in_dev) \
(IPV4_DEVCONF_ALL_RO(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
((in_dev)->mr_v2_seen && \
time_before(jiffies, (in_dev)->mr_v2_seen)))
static int unsolicited_report_interval(struct in_device *in_dev)
{
int interval_ms, interval_jiffies;
if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
interval_ms = IN_DEV_CONF_GET(
in_dev,
IGMPV2_UNSOLICITED_REPORT_INTERVAL);
else /* v3 */
interval_ms = IN_DEV_CONF_GET(
in_dev,
IGMPV3_UNSOLICITED_REPORT_INTERVAL);
interval_jiffies = msecs_to_jiffies(interval_ms);
/* _timer functions can't handle a delay of 0 jiffies so ensure
* we always return a positive value.
*/
if (interval_jiffies <= 0)
interval_jiffies = 1;
return interval_jiffies;
}
static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
gfp_t gfp);
static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
static void igmpv3_clear_delrec(struct in_device *in_dev);
static int sf_setstate(struct ip_mc_list *pmc);
static void sf_markstate(struct ip_mc_list *pmc);
#endif
static void ip_mc_clear_src(struct ip_mc_list *pmc);
static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
int sfcount, __be32 *psfsrc, int delta);
static void ip_ma_put(struct ip_mc_list *im)
{
if (refcount_dec_and_test(&im->refcnt)) {
in_dev_put(im->interface);
kfree_rcu(im, rcu);
}
}
#define for_each_pmc_rcu(in_dev, pmc) \
for (pmc = rcu_dereference(in_dev->mc_list); \
pmc != NULL; \
pmc = rcu_dereference(pmc->next_rcu))
#define for_each_pmc_rtnl(in_dev, pmc) \
for (pmc = rtnl_dereference(in_dev->mc_list); \
pmc != NULL; \
pmc = rtnl_dereference(pmc->next_rcu))
static void ip_sf_list_clear_all(struct ip_sf_list *psf)
{
struct ip_sf_list *next;
while (psf) {
next = psf->sf_next;
kfree(psf);
psf = next;
}
}
#ifdef CONFIG_IP_MULTICAST
/*
* Timer management
*/
static void igmp_stop_timer(struct ip_mc_list *im)
{
spin_lock_bh(&im->lock);
if (del_timer(&im->timer))
refcount_dec(&im->refcnt);
im->tm_running = 0;
im->reporter = 0;
im->unsolicit_count = 0;
spin_unlock_bh(&im->lock);
}
/* It must be called with locked im->lock */
static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
{
int tv = get_random_u32_below(max_delay);
im->tm_running = 1;
if (refcount_inc_not_zero(&im->refcnt)) {
if (mod_timer(&im->timer, jiffies + tv + 2))
ip_ma_put(im);
}
}
static void igmp_gq_start_timer(struct in_device *in_dev)
{
int tv = get_random_u32_below(in_dev->mr_maxdelay);
unsigned long exp = jiffies + tv + 2;
if (in_dev->mr_gq_running &&
time_after_eq(exp, (in_dev->mr_gq_timer).expires))
return;
in_dev->mr_gq_running = 1;
if (!mod_timer(&in_dev->mr_gq_timer, exp))
in_dev_hold(in_dev);
}
static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
{
int tv = get_random_u32_below(delay);
if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
in_dev_hold(in_dev);
}
static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
{
spin_lock_bh(&im->lock);
im->unsolicit_count = 0;
if (del_timer(&im->timer)) {
if ((long)(im->timer.expires-jiffies) < max_delay) {
add_timer(&im->timer);
im->tm_running = 1;
spin_unlock_bh(&im->lock);
return;
}
refcount_dec(&im->refcnt);
}
igmp_start_timer(im, max_delay);
spin_unlock_bh(&im->lock);
}
/*
* Send an IGMP report.
*/
#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
int gdeleted, int sdeleted)
{
switch (type) {
case IGMPV3_MODE_IS_INCLUDE:
case IGMPV3_MODE_IS_EXCLUDE:
if (gdeleted || sdeleted)
return 0;
if (!(pmc->gsquery && !psf->sf_gsresp)) {
if (pmc->sfmode == MCAST_INCLUDE)
return 1;
/* don't include if this source is excluded
* in all filters
*/
if (psf->sf_count[MCAST_INCLUDE])
return type == IGMPV3_MODE_IS_INCLUDE;
return pmc->sfcount[MCAST_EXCLUDE] ==
psf->sf_count[MCAST_EXCLUDE];
}
return 0;
case IGMPV3_CHANGE_TO_INCLUDE:
if (gdeleted || sdeleted)
return 0;
return psf->sf_count[MCAST_INCLUDE] != 0;
case IGMPV3_CHANGE_TO_EXCLUDE:
if (gdeleted || sdeleted)
return 0;
if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
psf->sf_count[MCAST_INCLUDE])
return 0;
return pmc->sfcount[MCAST_EXCLUDE] ==
psf->sf_count[MCAST_EXCLUDE];
case IGMPV3_ALLOW_NEW_SOURCES:
if (gdeleted || !psf->sf_crcount)
return 0;
return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
case IGMPV3_BLOCK_OLD_SOURCES:
if (pmc->sfmode == MCAST_INCLUDE)
return gdeleted || (psf->sf_crcount && sdeleted);
return psf->sf_crcount && !gdeleted && !sdeleted;
}
return 0;
}
static int
igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
{
struct ip_sf_list *psf;
int scount = 0;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (!is_in(pmc, psf, type, gdeleted, sdeleted))
continue;
scount++;
}
return scount;
}
/* source address selection per RFC 3376 section 4.2.13 */
static __be32 igmpv3_get_srcaddr(struct net_device *dev,
const struct flowi4 *fl4)
{
struct in_device *in_dev = __in_dev_get_rcu(dev);
const struct in_ifaddr *ifa;
if (!in_dev)
return htonl(INADDR_ANY);
in_dev_for_each_ifa_rcu(ifa, in_dev) {
if (fl4->saddr == ifa->ifa_local)
return fl4->saddr;
}
return htonl(INADDR_ANY);
}
static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
{
struct sk_buff *skb;
struct rtable *rt;
struct iphdr *pip;
struct igmpv3_report *pig;
struct net *net = dev_net(dev);
struct flowi4 fl4;
int hlen = LL_RESERVED_SPACE(dev);
int tlen = dev->needed_tailroom;
unsigned int size;
size = min(mtu, IP_MAX_MTU);
while (1) {
skb = alloc_skb(size + hlen + tlen,
GFP_ATOMIC | __GFP_NOWARN);
if (skb)
break;
size >>= 1;
if (size < 256)
return NULL;
}
skb->priority = TC_PRIO_CONTROL;
rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
0, 0,
IPPROTO_IGMP, 0, dev->ifindex);
if (IS_ERR(rt)) {
kfree_skb(skb);
return NULL;
}
skb_dst_set(skb, &rt->dst);
skb->dev = dev;
skb_reserve(skb, hlen);
skb_tailroom_reserve(skb, mtu, tlen);
skb_reset_network_header(skb);
pip = ip_hdr(skb);
skb_put(skb, sizeof(struct iphdr) + 4);
pip->version = 4;
pip->ihl = (sizeof(struct iphdr)+4)>>2;
pip->tos = 0xc0;
pip->frag_off = htons(IP_DF);
pip->ttl = 1;
pip->daddr = fl4.daddr;
rcu_read_lock();
pip->saddr = igmpv3_get_srcaddr(dev, &fl4);
rcu_read_unlock();
pip->protocol = IPPROTO_IGMP;
pip->tot_len = 0; /* filled in later */
ip_select_ident(net, skb, NULL);
((u8 *)&pip[1])[0] = IPOPT_RA;
((u8 *)&pip[1])[1] = 4;
((u8 *)&pip[1])[2] = 0;
((u8 *)&pip[1])[3] = 0;
skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
skb_put(skb, sizeof(*pig));
pig = igmpv3_report_hdr(skb);
pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
pig->resv1 = 0;
pig->csum = 0;
pig->resv2 = 0;
pig->ngrec = 0;
return skb;
}
static int igmpv3_sendpack(struct sk_buff *skb)
{
struct igmphdr *pig = igmp_hdr(skb);
const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
}
static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
{
return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
}
static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
int type, struct igmpv3_grec **ppgr, unsigned int mtu)
{
struct net_device *dev = pmc->interface->dev;
struct igmpv3_report *pih;
struct igmpv3_grec *pgr;
if (!skb) {
skb = igmpv3_newpack(dev, mtu);
if (!skb)
return NULL;
}
pgr = skb_put(skb, sizeof(struct igmpv3_grec));
pgr->grec_type = type;
pgr->grec_auxwords = 0;
pgr->grec_nsrcs = 0;
pgr->grec_mca = pmc->multiaddr;
pih = igmpv3_report_hdr(skb);
pih->ngrec = htons(ntohs(pih->ngrec)+1);
*ppgr = pgr;
return skb;
}
#define AVAILABLE(skb) ((skb) ? skb_availroom(skb) : 0)
static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
int type, int gdeleted, int sdeleted)
{
struct net_device *dev = pmc->interface->dev;
struct net *net = dev_net(dev);
struct igmpv3_report *pih;
struct igmpv3_grec *pgr = NULL;
struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
int scount, stotal, first, isquery, truncate;
unsigned int mtu;
if (pmc->multiaddr == IGMP_ALL_HOSTS)
return skb;
if (ipv4_is_local_multicast(pmc->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
return skb;
mtu = READ_ONCE(dev->mtu);
if (mtu < IPV4_MIN_MTU)
return skb;
isquery = type == IGMPV3_MODE_IS_INCLUDE ||
type == IGMPV3_MODE_IS_EXCLUDE;
truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
type == IGMPV3_CHANGE_TO_EXCLUDE;
stotal = scount = 0;
psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
if (!*psf_list)
goto empty_source;
pih = skb ? igmpv3_report_hdr(skb) : NULL;
/* EX and TO_EX get a fresh packet, if needed */
if (truncate) {
if (pih && pih->ngrec &&
AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
if (skb)
igmpv3_sendpack(skb);
skb = igmpv3_newpack(dev, mtu);
}
}
first = 1;
psf_prev = NULL;
for (psf = *psf_list; psf; psf = psf_next) {
__be32 *psrc;
psf_next = psf->sf_next;
if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
psf_prev = psf;
continue;
}
/* Based on RFC3376 5.1. Should not send source-list change
* records when there is a filter mode change.
*/
if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
(!gdeleted && pmc->crcount)) &&
(type == IGMPV3_ALLOW_NEW_SOURCES ||
type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
goto decrease_sf_crcount;
/* clear marks on query responses */
if (isquery)
psf->sf_gsresp = 0;
if (AVAILABLE(skb) < sizeof(__be32) +
first*sizeof(struct igmpv3_grec)) {
if (truncate && !first)
break; /* truncate these */
if (pgr)
pgr->grec_nsrcs = htons(scount);
if (skb)
igmpv3_sendpack(skb);
skb = igmpv3_newpack(dev, mtu);
first = 1;
scount = 0;
}
if (first) {
skb = add_grhead(skb, pmc, type, &pgr, mtu);
first = 0;
}
if (!skb)
return NULL;
psrc = skb_put(skb, sizeof(__be32));
*psrc = psf->sf_inaddr;
scount++; stotal++;
if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
decrease_sf_crcount:
psf->sf_crcount--;
if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
if (psf_prev)
psf_prev->sf_next = psf->sf_next;
else
*psf_list = psf->sf_next;
kfree(psf);
continue;
}
}
psf_prev = psf;
}
empty_source:
if (!stotal) {
if (type == IGMPV3_ALLOW_NEW_SOURCES ||
type == IGMPV3_BLOCK_OLD_SOURCES)
return skb;
if (pmc->crcount || isquery) {
/* make sure we have room for group header */
if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
igmpv3_sendpack(skb);
skb = NULL; /* add_grhead will get a new one */
}
skb = add_grhead(skb, pmc, type, &pgr, mtu);
}
}
if (pgr)
pgr->grec_nsrcs = htons(scount);
if (isquery)
pmc->gsquery = 0; /* clear query state on report */
return skb;
}
static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
{
struct sk_buff *skb = NULL;
struct net *net = dev_net(in_dev->dev);
int type;
if (!pmc) {
rcu_read_lock();
for_each_pmc_rcu(in_dev, pmc) {
if (pmc->multiaddr == IGMP_ALL_HOSTS)
continue;
if (ipv4_is_local_multicast(pmc->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
continue;
spin_lock_bh(&pmc->lock);
if (pmc->sfcount[MCAST_EXCLUDE])
type = IGMPV3_MODE_IS_EXCLUDE;
else
type = IGMPV3_MODE_IS_INCLUDE;
skb = add_grec(skb, pmc, type, 0, 0);
spin_unlock_bh(&pmc->lock);
}
rcu_read_unlock();
} else {
spin_lock_bh(&pmc->lock);
if (pmc->sfcount[MCAST_EXCLUDE])
type = IGMPV3_MODE_IS_EXCLUDE;
else
type = IGMPV3_MODE_IS_INCLUDE;
skb = add_grec(skb, pmc, type, 0, 0);
spin_unlock_bh(&pmc->lock);
}
if (!skb)
return 0;
return igmpv3_sendpack(skb);
}
/*
* remove zero-count source records from a source filter list
*/
static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
{
struct ip_sf_list *psf_prev, *psf_next, *psf;
psf_prev = NULL;
for (psf = *ppsf; psf; psf = psf_next) {
psf_next = psf->sf_next;
if (psf->sf_crcount == 0) {
if (psf_prev)
psf_prev->sf_next = psf->sf_next;
else
*ppsf = psf->sf_next;
kfree(psf);
} else
psf_prev = psf;
}
}
static void kfree_pmc(struct ip_mc_list *pmc)
{
ip_sf_list_clear_all(pmc->sources);
ip_sf_list_clear_all(pmc->tomb);
kfree(pmc);
}
static void igmpv3_send_cr(struct in_device *in_dev)
{
struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
struct sk_buff *skb = NULL;
int type, dtype;
rcu_read_lock();
spin_lock_bh(&in_dev->mc_tomb_lock);
/* deleted MCA's */
pmc_prev = NULL;
for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
pmc_next = pmc->next;
if (pmc->sfmode == MCAST_INCLUDE) {
type = IGMPV3_BLOCK_OLD_SOURCES;
dtype = IGMPV3_BLOCK_OLD_SOURCES;
skb = add_grec(skb, pmc, type, 1, 0);
skb = add_grec(skb, pmc, dtype, 1, 1);
}
if (pmc->crcount) {
if (pmc->sfmode == MCAST_EXCLUDE) {
type = IGMPV3_CHANGE_TO_INCLUDE;
skb = add_grec(skb, pmc, type, 1, 0);
}
pmc->crcount--;
if (pmc->crcount == 0) {
igmpv3_clear_zeros(&pmc->tomb);
igmpv3_clear_zeros(&pmc->sources);
}
}
if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
if (pmc_prev)
pmc_prev->next = pmc_next;
else
in_dev->mc_tomb = pmc_next;
in_dev_put(pmc->interface);
kfree_pmc(pmc);
} else
pmc_prev = pmc;
}
spin_unlock_bh(&in_dev->mc_tomb_lock);
/* change recs */
for_each_pmc_rcu(in_dev, pmc) {
spin_lock_bh(&pmc->lock);
if (pmc->sfcount[MCAST_EXCLUDE]) {
type = IGMPV3_BLOCK_OLD_SOURCES;
dtype = IGMPV3_ALLOW_NEW_SOURCES;
} else {
type = IGMPV3_ALLOW_NEW_SOURCES;
dtype = IGMPV3_BLOCK_OLD_SOURCES;
}
skb = add_grec(skb, pmc, type, 0, 0);
skb = add_grec(skb, pmc, dtype, 0, 1); /* deleted sources */
/* filter mode changes */
if (pmc->crcount) {
if (pmc->sfmode == MCAST_EXCLUDE)
type = IGMPV3_CHANGE_TO_EXCLUDE;
else
type = IGMPV3_CHANGE_TO_INCLUDE;
skb = add_grec(skb, pmc, type, 0, 0);
pmc->crcount--;
}
spin_unlock_bh(&pmc->lock);
}
rcu_read_unlock();
if (!skb)
return;
(void) igmpv3_sendpack(skb);
}
static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
int type)
{
struct sk_buff *skb;
struct iphdr *iph;
struct igmphdr *ih;
struct rtable *rt;
struct net_device *dev = in_dev->dev;
struct net *net = dev_net(dev);
__be32 group = pmc ? pmc->multiaddr : 0;
struct flowi4 fl4;
__be32 dst;
int hlen, tlen;
if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
return igmpv3_send_report(in_dev, pmc);
if (ipv4_is_local_multicast(group) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
return 0;
if (type == IGMP_HOST_LEAVE_MESSAGE)
dst = IGMP_ALL_ROUTER;
else
dst = group;
rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
0, 0,
IPPROTO_IGMP, 0, dev->ifindex);
if (IS_ERR(rt))
return -1;
hlen = LL_RESERVED_SPACE(dev);
tlen = dev->needed_tailroom;
skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
if (!skb) {
ip_rt_put(rt);
return -1;
}
skb->priority = TC_PRIO_CONTROL;
skb_dst_set(skb, &rt->dst);
skb_reserve(skb, hlen);
skb_reset_network_header(skb);
iph = ip_hdr(skb);
skb_put(skb, sizeof(struct iphdr) + 4);
iph->version = 4;
iph->ihl = (sizeof(struct iphdr)+4)>>2;
iph->tos = 0xc0;
iph->frag_off = htons(IP_DF);
iph->ttl = 1;
iph->daddr = dst;
iph->saddr = fl4.saddr;
iph->protocol = IPPROTO_IGMP;
ip_select_ident(net, skb, NULL);
((u8 *)&iph[1])[0] = IPOPT_RA;
((u8 *)&iph[1])[1] = 4;
((u8 *)&iph[1])[2] = 0;
((u8 *)&iph[1])[3] = 0;
ih = skb_put(skb, sizeof(struct igmphdr));
ih->type = type;
ih->code = 0;
ih->csum = 0;
ih->group = group;
ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
return ip_local_out(net, skb->sk, skb);
}
static void igmp_gq_timer_expire(struct timer_list *t)
{
struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer);
in_dev->mr_gq_running = 0;
igmpv3_send_report(in_dev, NULL);
in_dev_put(in_dev);
}
static void igmp_ifc_timer_expire(struct timer_list *t)
{
struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer);
u32 mr_ifc_count;
igmpv3_send_cr(in_dev);
restart:
mr_ifc_count = READ_ONCE(in_dev->mr_ifc_count);
if (mr_ifc_count) {
if (cmpxchg(&in_dev->mr_ifc_count,
mr_ifc_count,
mr_ifc_count - 1) != mr_ifc_count)
goto restart;
igmp_ifc_start_timer(in_dev,
unsolicited_report_interval(in_dev));
}
in_dev_put(in_dev);
}
static void igmp_ifc_event(struct in_device *in_dev)
{
struct net *net = dev_net(in_dev->dev);
if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
return;
WRITE_ONCE(in_dev->mr_ifc_count, in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv));
igmp_ifc_start_timer(in_dev, 1);
}
static void igmp_timer_expire(struct timer_list *t)
{
struct ip_mc_list *im = from_timer(im, t, timer);
struct in_device *in_dev = im->interface;
spin_lock(&im->lock);
im->tm_running = 0;
if (im->unsolicit_count && --im->unsolicit_count)
igmp_start_timer(im, unsolicited_report_interval(in_dev));
im->reporter = 1;
spin_unlock(&im->lock);
if (IGMP_V1_SEEN(in_dev))
igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
else if (IGMP_V2_SEEN(in_dev))
igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
else
igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
ip_ma_put(im);
}
/* mark EXCLUDE-mode sources */
static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
{
struct ip_sf_list *psf;
int i, scount;
scount = 0;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (scount == nsrcs)
break;
for (i = 0; i < nsrcs; i++) {
/* skip inactive filters */
if (psf->sf_count[MCAST_INCLUDE] ||
pmc->sfcount[MCAST_EXCLUDE] !=
psf->sf_count[MCAST_EXCLUDE])
break;
if (srcs[i] == psf->sf_inaddr) {
scount++;
break;
}
}
}
pmc->gsquery = 0;
if (scount == nsrcs) /* all sources excluded */
return 0;
return 1;
}
static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
{
struct ip_sf_list *psf;
int i, scount;
if (pmc->sfmode == MCAST_EXCLUDE)
return igmp_xmarksources(pmc, nsrcs, srcs);
/* mark INCLUDE-mode sources */
scount = 0;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (scount == nsrcs)
break;
for (i = 0; i < nsrcs; i++)
if (srcs[i] == psf->sf_inaddr) {
psf->sf_gsresp = 1;
scount++;
break;
}
}
if (!scount) {
pmc->gsquery = 0;
return 0;
}
pmc->gsquery = 1;
return 1;
}
/* return true if packet was dropped */
static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
{
struct ip_mc_list *im;
struct net *net = dev_net(in_dev->dev);
/* Timers are only set for non-local groups */
if (group == IGMP_ALL_HOSTS)
return false;
if (ipv4_is_local_multicast(group) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
return false;
rcu_read_lock();
for_each_pmc_rcu(in_dev, im) {
if (im->multiaddr == group) {
igmp_stop_timer(im);
break;
}
}
rcu_read_unlock();
return false;
}
/* return true if packet was dropped */
static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
int len)
{
struct igmphdr *ih = igmp_hdr(skb);
struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
struct ip_mc_list *im;
__be32 group = ih->group;
int max_delay;
int mark = 0;
struct net *net = dev_net(in_dev->dev);
if (len == 8) {
if (ih->code == 0) {
/* Alas, old v1 router presents here. */
max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
in_dev->mr_v1_seen = jiffies +
(in_dev->mr_qrv * in_dev->mr_qi) +
in_dev->mr_qri;
group = 0;
} else {
/* v2 router present */
max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
in_dev->mr_v2_seen = jiffies +
(in_dev->mr_qrv * in_dev->mr_qi) +
in_dev->mr_qri;
}
/* cancel the interface change timer */
WRITE_ONCE(in_dev->mr_ifc_count, 0);
if (del_timer(&in_dev->mr_ifc_timer))
__in_dev_put(in_dev);
/* clear deleted report items */
igmpv3_clear_delrec(in_dev);
} else if (len < 12) {
return true; /* ignore bogus packet; freed by caller */
} else if (IGMP_V1_SEEN(in_dev)) {
/* This is a v3 query with v1 queriers present */
max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
group = 0;
} else if (IGMP_V2_SEEN(in_dev)) {
/* this is a v3 query with v2 queriers present;
* Interpretation of the max_delay code is problematic here.
* A real v2 host would use ih_code directly, while v3 has a
* different encoding. We use the v3 encoding as more likely
* to be intended in a v3 query.
*/
max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
if (!max_delay)
max_delay = 1; /* can't mod w/ 0 */
} else { /* v3 */
if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
return true;
ih3 = igmpv3_query_hdr(skb);
if (ih3->nsrcs) {
if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
+ ntohs(ih3->nsrcs)*sizeof(__be32)))
return true;
ih3 = igmpv3_query_hdr(skb);
}
max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
if (!max_delay)
max_delay = 1; /* can't mod w/ 0 */
in_dev->mr_maxdelay = max_delay;
/* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently
* received value was zero, use the default or statically
* configured value.
*/
in_dev->mr_qrv = ih3->qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL;
/* RFC3376, 8.3. Query Response Interval:
* The number of seconds represented by the [Query Response
* Interval] must be less than the [Query Interval].
*/
if (in_dev->mr_qri >= in_dev->mr_qi)
in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ;
if (!group) { /* general query */
if (ih3->nsrcs)
return true; /* no sources allowed */
igmp_gq_start_timer(in_dev);
return false;
}
/* mark sources to include, if group & source-specific */
mark = ih3->nsrcs != 0;
}
/*
* - Start the timers in all of our membership records
* that the query applies to for the interface on
* which the query arrived excl. those that belong
* to a "local" group (224.0.0.X)
* - For timers already running check if they need to
* be reset.
* - Use the igmp->igmp_code field as the maximum
* delay possible
*/
rcu_read_lock();
for_each_pmc_rcu(in_dev, im) {
int changed;
if (group && group != im->multiaddr)
continue;
if (im->multiaddr == IGMP_ALL_HOSTS)
continue;
if (ipv4_is_local_multicast(im->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
continue;
spin_lock_bh(&im->lock);
if (im->tm_running)
im->gsquery = im->gsquery && mark;
else
im->gsquery = mark;
changed = !im->gsquery ||
igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
spin_unlock_bh(&im->lock);
if (changed)
igmp_mod_timer(im, max_delay);
}
rcu_read_unlock();
return false;
}
/* called in rcu_read_lock() section */
int igmp_rcv(struct sk_buff *skb)
{
/* This basically follows the spec line by line -- see RFC1112 */
struct igmphdr *ih;
struct net_device *dev = skb->dev;
struct in_device *in_dev;
int len = skb->len;
bool dropped = true;
if (netif_is_l3_master(dev)) {
dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
if (!dev)
goto drop;
}
in_dev = __in_dev_get_rcu(dev);
if (!in_dev)
goto drop;
if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
goto drop;
if (skb_checksum_simple_validate(skb))
goto drop;
ih = igmp_hdr(skb);
switch (ih->type) {
case IGMP_HOST_MEMBERSHIP_QUERY:
dropped = igmp_heard_query(in_dev, skb, len);
break;
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
/* Is it our report looped back? */
if (rt_is_output_route(skb_rtable(skb)))
break;
/* don't rely on MC router hearing unicast reports */
if (skb->pkt_type == PACKET_MULTICAST ||
skb->pkt_type == PACKET_BROADCAST)
dropped = igmp_heard_report(in_dev, ih->group);
break;
case IGMP_PIM:
#ifdef CONFIG_IP_PIMSM_V1
return pim_rcv_v1(skb);
#endif
case IGMPV3_HOST_MEMBERSHIP_REPORT:
case IGMP_DVMRP:
case IGMP_TRACE:
case IGMP_HOST_LEAVE_MESSAGE:
case IGMP_MTRACE:
case IGMP_MTRACE_RESP:
break;
default:
break;
}
drop:
if (dropped)
kfree_skb(skb);
else
consume_skb(skb);
return 0;
}
#endif
/*
* Add a filter to a device
*/
static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
{
char buf[MAX_ADDR_LEN];
struct net_device *dev = in_dev->dev;
/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
We will get multicast token leakage, when IFF_MULTICAST
is changed. This check should be done in ndo_set_rx_mode
routine. Something sort of:
if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
--ANK
*/
if (arp_mc_map(addr, buf, dev, 0) == 0)
dev_mc_add(dev, buf);
}
/*
* Remove a filter from a device
*/
static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
{
char buf[MAX_ADDR_LEN];
struct net_device *dev = in_dev->dev;
if (arp_mc_map(addr, buf, dev, 0) == 0)
dev_mc_del(dev, buf);
}
#ifdef CONFIG_IP_MULTICAST
/*
* deleted ip_mc_list manipulation
*/
static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
gfp_t gfp)
{
struct ip_mc_list *pmc;
struct net *net = dev_net(in_dev->dev);
/* this is an "ip_mc_list" for convenience; only the fields below
* are actually used. In particular, the refcnt and users are not
* used for management of the delete list. Using the same structure
* for deleted items allows change reports to use common code with
* non-deleted or query-response MCA's.
*/
pmc = kzalloc(sizeof(*pmc), gfp);
if (!pmc)
return;
spin_lock_init(&pmc->lock);
spin_lock_bh(&im->lock);
pmc->interface = im->interface;
in_dev_hold(in_dev);
pmc->multiaddr = im->multiaddr;
pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
pmc->sfmode = im->sfmode;
if (pmc->sfmode == MCAST_INCLUDE) {
struct ip_sf_list *psf;
pmc->tomb = im->tomb;
pmc->sources = im->sources;
im->tomb = im->sources = NULL;
for (psf = pmc->sources; psf; psf = psf->sf_next)
psf->sf_crcount = pmc->crcount;
}
spin_unlock_bh(&im->lock);
spin_lock_bh(&in_dev->mc_tomb_lock);
pmc->next = in_dev->mc_tomb;
in_dev->mc_tomb = pmc;
spin_unlock_bh(&in_dev->mc_tomb_lock);
}
/*
* restore ip_mc_list deleted records
*/
static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
{
struct ip_mc_list *pmc, *pmc_prev;
struct ip_sf_list *psf;
struct net *net = dev_net(in_dev->dev);
__be32 multiaddr = im->multiaddr;
spin_lock_bh(&in_dev->mc_tomb_lock);
pmc_prev = NULL;
for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
if (pmc->multiaddr == multiaddr)
break;
pmc_prev = pmc;
}
if (pmc) {
if (pmc_prev)
pmc_prev->next = pmc->next;
else
in_dev->mc_tomb = pmc->next;
}
spin_unlock_bh(&in_dev->mc_tomb_lock);
spin_lock_bh(&im->lock);
if (pmc) {
im->interface = pmc->interface;
if (im->sfmode == MCAST_INCLUDE) {
swap(im->tomb, pmc->tomb);
swap(im->sources, pmc->sources);
for (psf = im->sources; psf; psf = psf->sf_next)
psf->sf_crcount = in_dev->mr_qrv ?:
READ_ONCE(net->ipv4.sysctl_igmp_qrv);
} else {
im->crcount = in_dev->mr_qrv ?:
READ_ONCE(net->ipv4.sysctl_igmp_qrv);
}
in_dev_put(pmc->interface);
kfree_pmc(pmc);
}
spin_unlock_bh(&im->lock);
}
/*
* flush ip_mc_list deleted records
*/
static void igmpv3_clear_delrec(struct in_device *in_dev)
{
struct ip_mc_list *pmc, *nextpmc;
spin_lock_bh(&in_dev->mc_tomb_lock);
pmc = in_dev->mc_tomb;
in_dev->mc_tomb = NULL;
spin_unlock_bh(&in_dev->mc_tomb_lock);
for (; pmc; pmc = nextpmc) {
nextpmc = pmc->next;
ip_mc_clear_src(pmc);
in_dev_put(pmc->interface);
kfree_pmc(pmc);
}
/* clear dead sources, too */
rcu_read_lock();
for_each_pmc_rcu(in_dev, pmc) {
struct ip_sf_list *psf;
spin_lock_bh(&pmc->lock);
psf = pmc->tomb;
pmc->tomb = NULL;
spin_unlock_bh(&pmc->lock);
ip_sf_list_clear_all(psf);
}
rcu_read_unlock();
}
#endif
static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp)
{
struct in_device *in_dev = im->interface;
#ifdef CONFIG_IP_MULTICAST
struct net *net = dev_net(in_dev->dev);
int reporter;
#endif
if (im->loaded) {
im->loaded = 0;
ip_mc_filter_del(in_dev, im->multiaddr);
}
#ifdef CONFIG_IP_MULTICAST
if (im->multiaddr == IGMP_ALL_HOSTS)
return;
if (ipv4_is_local_multicast(im->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
return;
reporter = im->reporter;
igmp_stop_timer(im);
if (!in_dev->dead) {
if (IGMP_V1_SEEN(in_dev))
return;
if (IGMP_V2_SEEN(in_dev)) {
if (reporter)
igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
return;
}
/* IGMPv3 */
igmpv3_add_delrec(in_dev, im, gfp);
igmp_ifc_event(in_dev);
}
#endif
}
static void igmp_group_dropped(struct ip_mc_list *im)
{
__igmp_group_dropped(im, GFP_KERNEL);
}
static void igmp_group_added(struct ip_mc_list *im)
{
struct in_device *in_dev = im->interface;
#ifdef CONFIG_IP_MULTICAST
struct net *net = dev_net(in_dev->dev);
#endif
if (im->loaded == 0) {
im->loaded = 1;
ip_mc_filter_add(in_dev, im->multiaddr);
}
#ifdef CONFIG_IP_MULTICAST
if (im->multiaddr == IGMP_ALL_HOSTS)
return;
if (ipv4_is_local_multicast(im->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
return;
if (in_dev->dead)
return;
im->unsolicit_count = READ_ONCE(net->ipv4.sysctl_igmp_qrv);
if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
spin_lock_bh(&im->lock);
igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
spin_unlock_bh(&im->lock);
return;
}
/* else, v3 */
/* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should
* not send filter-mode change record as the mode should be from
* IN() to IN(A).
*/
if (im->sfmode == MCAST_EXCLUDE)
im->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
igmp_ifc_event(in_dev);
#endif
}
/*
* Multicast list managers
*/
static u32 ip_mc_hash(const struct ip_mc_list *im)
{
return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
}
static void ip_mc_hash_add(struct in_device *in_dev,
struct ip_mc_list *im)
{
struct ip_mc_list __rcu **mc_hash;
u32 hash;
mc_hash = rtnl_dereference(in_dev->mc_hash);
if (mc_hash) {
hash = ip_mc_hash(im);
im->next_hash = mc_hash[hash];
rcu_assign_pointer(mc_hash[hash], im);
return;
}
/* do not use a hash table for small number of items */
if (in_dev->mc_count < 4)
return;
mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
GFP_KERNEL);
if (!mc_hash)
return;
for_each_pmc_rtnl(in_dev, im) {
hash = ip_mc_hash(im);
im->next_hash = mc_hash[hash];
RCU_INIT_POINTER(mc_hash[hash], im);
}
rcu_assign_pointer(in_dev->mc_hash, mc_hash);
}
static void ip_mc_hash_remove(struct in_device *in_dev,
struct ip_mc_list *im)
{
struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
struct ip_mc_list *aux;
if (!mc_hash)
return;
mc_hash += ip_mc_hash(im);
while ((aux = rtnl_dereference(*mc_hash)) != im)
mc_hash = &aux->next_hash;
*mc_hash = im->next_hash;
}
/*
* A socket has joined a multicast group on device dev.
*/
static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
unsigned int mode, gfp_t gfp)
{
struct ip_mc_list *im;
ASSERT_RTNL();
for_each_pmc_rtnl(in_dev, im) {
if (im->multiaddr == addr) {
im->users++;
ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0);
goto out;
}
}
im = kzalloc(sizeof(*im), gfp);
if (!im)
goto out;
im->users = 1;
im->interface = in_dev;
in_dev_hold(in_dev);
im->multiaddr = addr;
/* initial mode is (EX, empty) */
im->sfmode = mode;
im->sfcount[mode] = 1;
refcount_set(&im->refcnt, 1);
spin_lock_init(&im->lock);
#ifdef CONFIG_IP_MULTICAST
timer_setup(&im->timer, igmp_timer_expire, 0);
#endif
im->next_rcu = in_dev->mc_list;
in_dev->mc_count++;
rcu_assign_pointer(in_dev->mc_list, im);
ip_mc_hash_add(in_dev, im);
#ifdef CONFIG_IP_MULTICAST
igmpv3_del_delrec(in_dev, im);
#endif
igmp_group_added(im);
if (!in_dev->dead)
ip_rt_multicast_event(in_dev);
out:
return;
}
void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
{
____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp);
}
EXPORT_SYMBOL(__ip_mc_inc_group);
void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
{
__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);
}
EXPORT_SYMBOL(ip_mc_inc_group);
static int ip_mc_check_iphdr(struct sk_buff *skb)
{
const struct iphdr *iph;
unsigned int len;
unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
if (!pskb_may_pull(skb, offset))
return -EINVAL;
iph = ip_hdr(skb);
if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
return -EINVAL;
offset += ip_hdrlen(skb) - sizeof(*iph);
if (!pskb_may_pull(skb, offset))
return -EINVAL;
iph = ip_hdr(skb);
if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
return -EINVAL;
len = skb_network_offset(skb) + ntohs(iph->tot_len);
if (skb->len < len || len < offset)
return -EINVAL;
skb_set_transport_header(skb, offset);
return 0;
}
static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
{
unsigned int len = skb_transport_offset(skb);
len += sizeof(struct igmpv3_report);
return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
}
static int ip_mc_check_igmp_query(struct sk_buff *skb)
{
unsigned int transport_len = ip_transport_len(skb);
unsigned int len;
/* IGMPv{1,2}? */
if (transport_len != sizeof(struct igmphdr)) {
/* or IGMPv3? */
if (transport_len < sizeof(struct igmpv3_query))
return -EINVAL;
len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
if (!ip_mc_may_pull(skb, len))
return -EINVAL;
}
/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
* all-systems destination addresses (224.0.0.1) for general queries
*/
if (!igmp_hdr(skb)->group &&
ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
return -EINVAL;
return 0;
}
static int ip_mc_check_igmp_msg(struct sk_buff *skb)
{
switch (igmp_hdr(skb)->type) {
case IGMP_HOST_LEAVE_MESSAGE:
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
return 0;
case IGMPV3_HOST_MEMBERSHIP_REPORT:
return ip_mc_check_igmp_reportv3(skb);
case IGMP_HOST_MEMBERSHIP_QUERY:
return ip_mc_check_igmp_query(skb);
default:
return -ENOMSG;
}
}
static __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
{
return skb_checksum_simple_validate(skb);
}
static int ip_mc_check_igmp_csum(struct sk_buff *skb)
{
unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
unsigned int transport_len = ip_transport_len(skb);
struct sk_buff *skb_chk;
if (!ip_mc_may_pull(skb, len))
return -EINVAL;
skb_chk = skb_checksum_trimmed(skb, transport_len,
ip_mc_validate_checksum);
if (!skb_chk)
return -EINVAL;
if (skb_chk != skb)
kfree_skb(skb_chk);
return 0;
}
/**
* ip_mc_check_igmp - checks whether this is a sane IGMP packet
* @skb: the skb to validate
*
* Checks whether an IPv4 packet is a valid IGMP packet. If so sets
* skb transport header accordingly and returns zero.
*
* -EINVAL: A broken packet was detected, i.e. it violates some internet
* standard
* -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
* -ENOMEM: A memory allocation failure happened.
*
* Caller needs to set the skb network header and free any returned skb if it
* differs from the provided skb.
*/
int ip_mc_check_igmp(struct sk_buff *skb)
{
int ret = ip_mc_check_iphdr(skb);
if (ret < 0)
return ret;
if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
return -ENOMSG;
ret = ip_mc_check_igmp_csum(skb);
if (ret < 0)
return ret;
return ip_mc_check_igmp_msg(skb);
}
EXPORT_SYMBOL(ip_mc_check_igmp);
/*
* Resend IGMP JOIN report; used by netdev notifier.
*/
static void ip_mc_rejoin_groups(struct in_device *in_dev)
{
#ifdef CONFIG_IP_MULTICAST
struct ip_mc_list *im;
int type;
struct net *net = dev_net(in_dev->dev);
ASSERT_RTNL();
for_each_pmc_rtnl(in_dev, im) {
if (im->multiaddr == IGMP_ALL_HOSTS)
continue;
if (ipv4_is_local_multicast(im->multiaddr) &&
!READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
continue;
/* a failover is happening and switches
* must be notified immediately
*/
if (IGMP_V1_SEEN(in_dev))
type = IGMP_HOST_MEMBERSHIP_REPORT;
else if (IGMP_V2_SEEN(in_dev))
type = IGMPV2_HOST_MEMBERSHIP_REPORT;
else
type = IGMPV3_HOST_MEMBERSHIP_REPORT;
igmp_send_report(in_dev, im, type);
}
#endif
}
/*
* A socket has left a multicast group on device dev
*/
void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
{
struct ip_mc_list *i;
struct ip_mc_list __rcu **ip;
ASSERT_RTNL();
for (ip = &in_dev->mc_list;
(i = rtnl_dereference(*ip)) != NULL;
ip = &i->next_rcu) {
if (i->multiaddr == addr) {
if (--i->users == 0) {
ip_mc_hash_remove(in_dev, i);
*ip = i->next_rcu;
in_dev->mc_count--;
__igmp_group_dropped(i, gfp);
ip_mc_clear_src(i);
if (!in_dev->dead)
ip_rt_multicast_event(in_dev);
ip_ma_put(i);
return;
}
break;
}
}
}
EXPORT_SYMBOL(__ip_mc_dec_group);
/* Device changing type */
void ip_mc_unmap(struct in_device *in_dev)
{
struct ip_mc_list *pmc;
ASSERT_RTNL();
for_each_pmc_rtnl(in_dev, pmc)
igmp_group_dropped(pmc);
}
void ip_mc_remap(struct in_device *in_dev)
{
struct ip_mc_list *pmc;
ASSERT_RTNL();
for_each_pmc_rtnl(in_dev, pmc) {
#ifdef CONFIG_IP_MULTICAST
igmpv3_del_delrec(in_dev, pmc);
#endif
igmp_group_added(pmc);
}
}
/* Device going down */
void ip_mc_down(struct in_device *in_dev)
{
struct ip_mc_list *pmc;
ASSERT_RTNL();
for_each_pmc_rtnl(in_dev, pmc)
igmp_group_dropped(pmc);
#ifdef CONFIG_IP_MULTICAST
WRITE_ONCE(in_dev->mr_ifc_count, 0);
if (del_timer(&in_dev->mr_ifc_timer))
__in_dev_put(in_dev);
in_dev->mr_gq_running = 0;
if (del_timer(&in_dev->mr_gq_timer))
__in_dev_put(in_dev);
#endif
ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}
#ifdef CONFIG_IP_MULTICAST
static void ip_mc_reset(struct in_device *in_dev)
{
struct net *net = dev_net(in_dev->dev);
in_dev->mr_qi = IGMP_QUERY_INTERVAL;
in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL;
in_dev->mr_qrv = READ_ONCE(net->ipv4.sysctl_igmp_qrv);
}
#else
static void ip_mc_reset(struct in_device *in_dev)
{
}
#endif
void ip_mc_init_dev(struct in_device *in_dev)
{
ASSERT_RTNL();
#ifdef CONFIG_IP_MULTICAST
timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0);
timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0);
#endif
ip_mc_reset(in_dev);
spin_lock_init(&in_dev->mc_tomb_lock);
}
/* Device going up */
void ip_mc_up(struct in_device *in_dev)
{
struct ip_mc_list *pmc;
ASSERT_RTNL();
ip_mc_reset(in_dev);
ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
for_each_pmc_rtnl(in_dev, pmc) {
#ifdef CONFIG_IP_MULTICAST
igmpv3_del_delrec(in_dev, pmc);
#endif
igmp_group_added(pmc);
}
}
/*
* Device is about to be destroyed: clean up.
*/
void ip_mc_destroy_dev(struct in_device *in_dev)
{
struct ip_mc_list *i;
ASSERT_RTNL();
/* Deactivate timers */
ip_mc_down(in_dev);
#ifdef CONFIG_IP_MULTICAST
igmpv3_clear_delrec(in_dev);
#endif
while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
in_dev->mc_list = i->next_rcu;
in_dev->mc_count--;
ip_mc_clear_src(i);
ip_ma_put(i);
}
}
/* RTNL is locked */
static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
{
struct net_device *dev = NULL;
struct in_device *idev = NULL;
if (imr->imr_ifindex) {
idev = inetdev_by_index(net, imr->imr_ifindex);
return idev;
}
if (imr->imr_address.s_addr) {
dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
if (!dev)
return NULL;
}
if (!dev) {
struct rtable *rt = ip_route_output(net,
imr->imr_multiaddr.s_addr,
0, 0, 0,
RT_SCOPE_UNIVERSE);
if (!IS_ERR(rt)) {
dev = rt->dst.dev;
ip_rt_put(rt);
}
}
if (dev) {
imr->imr_ifindex = dev->ifindex;
idev = __in_dev_get_rtnl(dev);
}
return idev;
}
/*
* Join a socket to a group
*/
static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
__be32 *psfsrc)
{
struct ip_sf_list *psf, *psf_prev;
int rv = 0;
psf_prev = NULL;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (psf->sf_inaddr == *psfsrc)
break;
psf_prev = psf;
}
if (!psf || psf->sf_count[sfmode] == 0) {
/* source filter not found, or count wrong => bug */
return -ESRCH;
}
psf->sf_count[sfmode]--;
if (psf->sf_count[sfmode] == 0) {
ip_rt_multicast_event(pmc->interface);
}
if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
struct in_device *in_dev = pmc->interface;
struct net *net = dev_net(in_dev->dev);
#endif
/* no more filters for this source */
if (psf_prev)
psf_prev->sf_next = psf->sf_next;
else
pmc->sources = psf->sf_next;
#ifdef CONFIG_IP_MULTICAST
if (psf->sf_oldin &&
!IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
psf->sf_crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
psf->sf_next = pmc->tomb;
pmc->tomb = psf;
rv = 1;
} else
#endif
kfree(psf);
}
return rv;
}
#ifndef CONFIG_IP_MULTICAST
#define igmp_ifc_event(x) do { } while (0)
#endif
static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
int sfcount, __be32 *psfsrc, int delta)
{
struct ip_mc_list *pmc;
int changerec = 0;
int i, err;
if (!in_dev)
return -ENODEV;
rcu_read_lock();
for_each_pmc_rcu(in_dev, pmc) {
if (*pmca == pmc->multiaddr)
break;
}
if (!pmc) {
/* MCA not found?? bug */
rcu_read_unlock();
return -ESRCH;
}
spin_lock_bh(&pmc->lock);
rcu_read_unlock();
#ifdef CONFIG_IP_MULTICAST
sf_markstate(pmc);
#endif
if (!delta) {
err = -EINVAL;
if (!pmc->sfcount[sfmode])
goto out_unlock;
pmc->sfcount[sfmode]--;
}
err = 0;
for (i = 0; i < sfcount; i++) {
int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
changerec |= rv > 0;
if (!err && rv < 0)
err = rv;
}
if (pmc->sfmode == MCAST_EXCLUDE &&
pmc->sfcount[MCAST_EXCLUDE] == 0 &&
pmc->sfcount[MCAST_INCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
struct ip_sf_list *psf;
struct net *net = dev_net(in_dev->dev);
#endif
/* filter mode change */
pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount);
for (psf = pmc->sources; psf; psf = psf->sf_next)
psf->sf_crcount = 0;
igmp_ifc_event(pmc->interface);
} else if (sf_setstate(pmc) || changerec) {
igmp_ifc_event(pmc->interface);
#endif
}
out_unlock:
spin_unlock_bh(&pmc->lock);
return err;
}
/*
* Add multicast single-source filter to the interface list
*/
static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
__be32 *psfsrc)
{
struct ip_sf_list *psf, *psf_prev;
psf_prev = NULL;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (psf->sf_inaddr == *psfsrc)
break;
psf_prev = psf;
}
if (!psf) {
psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
if (!psf)
return -ENOBUFS;
psf->sf_inaddr = *psfsrc;
if (psf_prev) {
psf_prev->sf_next = psf;
} else
pmc->sources = psf;
}
psf->sf_count[sfmode]++;
if (psf->sf_count[sfmode] == 1) {
ip_rt_multicast_event(pmc->interface);
}
return 0;
}
#ifdef CONFIG_IP_MULTICAST
static void sf_markstate(struct ip_mc_list *pmc)
{
struct ip_sf_list *psf;
int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
for (psf = pmc->sources; psf; psf = psf->sf_next)
if (pmc->sfcount[MCAST_EXCLUDE]) {
psf->sf_oldin = mca_xcount ==
psf->sf_count[MCAST_EXCLUDE] &&
!psf->sf_count[MCAST_INCLUDE];
} else
psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
}
static int sf_setstate(struct ip_mc_list *pmc)
{
struct ip_sf_list *psf, *dpsf;
int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
int qrv = pmc->interface->mr_qrv;
int new_in, rv;
rv = 0;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (pmc->sfcount[MCAST_EXCLUDE]) {
new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
!psf->sf_count[MCAST_INCLUDE];
} else
new_in = psf->sf_count[MCAST_INCLUDE] != 0;
if (new_in) {
if (!psf->sf_oldin) {
struct ip_sf_list *prev = NULL;
for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
if (dpsf->sf_inaddr == psf->sf_inaddr)
break;
prev = dpsf;
}
if (dpsf) {
if (prev)
prev->sf_next = dpsf->sf_next;
else
pmc->tomb = dpsf->sf_next;
kfree(dpsf);
}
psf->sf_crcount = qrv;
rv++;
}
} else if (psf->sf_oldin) {
psf->sf_crcount = 0;
/*
* add or update "delete" records if an active filter
* is now inactive
*/
for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
if (dpsf->sf_inaddr == psf->sf_inaddr)
break;
if (!dpsf) {
dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
if (!dpsf)
continue;
*dpsf = *psf;
/* pmc->lock held by callers */
dpsf->sf_next = pmc->tomb;
pmc->tomb = dpsf;
}
dpsf->sf_crcount = qrv;
rv++;
}
}
return rv;
}
#endif
/*
* Add multicast source filter list to the interface list
*/
static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
int sfcount, __be32 *psfsrc, int delta)
{
struct ip_mc_list *pmc;
int isexclude;
int i, err;
if (!in_dev)
return -ENODEV;
rcu_read_lock();
for_each_pmc_rcu(in_dev, pmc) {
if (*pmca == pmc->multiaddr)
break;
}
if (!pmc) {
/* MCA not found?? bug */
rcu_read_unlock();
return -ESRCH;
}
spin_lock_bh(&pmc->lock);
rcu_read_unlock();
#ifdef CONFIG_IP_MULTICAST
sf_markstate(pmc);
#endif
isexclude = pmc->sfmode == MCAST_EXCLUDE;
if (!delta)
pmc->sfcount[sfmode]++;
err = 0;
for (i = 0; i < sfcount; i++) {
err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
if (err)
break;
}
if (err) {
int j;
if (!delta)
pmc->sfcount[sfmode]--;
for (j = 0; j < i; j++)
(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
#ifdef CONFIG_IP_MULTICAST
struct ip_sf_list *psf;
struct net *net = dev_net(pmc->interface->dev);
in_dev = pmc->interface;
#endif
/* filter mode change */
if (pmc->sfcount[MCAST_EXCLUDE])
pmc->sfmode = MCAST_EXCLUDE;
else if (pmc->sfcount[MCAST_INCLUDE])
pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
/* else no filters; keep old mode for reports */
pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount);
for (psf = pmc->sources; psf; psf = psf->sf_next)
psf->sf_crcount = 0;
igmp_ifc_event(in_dev);
} else if (sf_setstate(pmc)) {
igmp_ifc_event(in_dev);
#endif
}
spin_unlock_bh(&pmc->lock);
return err;
}
static void ip_mc_clear_src(struct ip_mc_list *pmc)
{
struct ip_sf_list *tomb, *sources;
spin_lock_bh(&pmc->lock);
tomb = pmc->tomb;
pmc->tomb = NULL;
sources = pmc->sources;
pmc->sources = NULL;
pmc->sfmode = MCAST_EXCLUDE;
pmc->sfcount[MCAST_INCLUDE] = 0;
pmc->sfcount[MCAST_EXCLUDE] = 1;
spin_unlock_bh(&pmc->lock);
ip_sf_list_clear_all(tomb);
ip_sf_list_clear_all(sources);
}
/* Join a multicast group
*/
static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
unsigned int mode)
{
__be32 addr = imr->imr_multiaddr.s_addr;
struct ip_mc_socklist *iml, *i;
struct in_device *in_dev;
struct inet_sock *inet = inet_sk(sk);
struct net *net = sock_net(sk);
int ifindex;
int count = 0;
int err;
ASSERT_RTNL();
if (!ipv4_is_multicast(addr))
return -EINVAL;
in_dev = ip_mc_find_dev(net, imr);
if (!in_dev) {
err = -ENODEV;
goto done;
}
err = -EADDRINUSE;
ifindex = imr->imr_ifindex;
for_each_pmc_rtnl(inet, i) {
if (i->multi.imr_multiaddr.s_addr == addr &&
i->multi.imr_ifindex == ifindex)
goto done;
count++;
}
err = -ENOBUFS;
if (count >= READ_ONCE(net->ipv4.sysctl_igmp_max_memberships))
goto done;
iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
if (!iml)
goto done;
memcpy(&iml->multi, imr, sizeof(*imr));
iml->next_rcu = inet->mc_list;
iml->sflist = NULL;
iml->sfmode = mode;
rcu_assign_pointer(inet->mc_list, iml);
____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
err = 0;
done:
return err;
}
/* Join ASM (Any-Source Multicast) group
*/
int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
{
return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
}
EXPORT_SYMBOL(ip_mc_join_group);
/* Join SSM (Source-Specific Multicast) group
*/
int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
unsigned int mode)
{
return __ip_mc_join_group(sk, imr, mode);
}
static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
struct in_device *in_dev)
{
struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
int err;
if (!psf) {
/* any-source empty exclude case */
return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
iml->sfmode, 0, NULL, 0);
}
err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
iml->sfmode, psf->sl_count, psf->sl_addr, 0);
RCU_INIT_POINTER(iml->sflist, NULL);
/* decrease mem now to avoid the memleak warning */
atomic_sub(struct_size(psf, sl_addr, psf->sl_max), &sk->sk_omem_alloc);
kfree_rcu(psf, rcu);
return err;
}
int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
struct inet_sock *inet = inet_sk(sk);
struct ip_mc_socklist *iml;
struct ip_mc_socklist __rcu **imlp;
struct in_device *in_dev;
struct net *net = sock_net(sk);
__be32 group = imr->imr_multiaddr.s_addr;
u32 ifindex;
int ret = -EADDRNOTAVAIL;
ASSERT_RTNL();
in_dev = ip_mc_find_dev(net, imr);
if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
ret = -ENODEV;
goto out;
}
ifindex = imr->imr_ifindex;
for (imlp = &inet->mc_list;
(iml = rtnl_dereference(*imlp)) != NULL;
imlp = &iml->next_rcu) {
if (iml->multi.imr_multiaddr.s_addr != group)
continue;
if (ifindex) {
if (iml->multi.imr_ifindex != ifindex)
continue;
} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
iml->multi.imr_address.s_addr)
continue;
(void) ip_mc_leave_src(sk, iml, in_dev);
*imlp = iml->next_rcu;
if (in_dev)
ip_mc_dec_group(in_dev, group);
/* decrease mem now to avoid the memleak warning */
atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
kfree_rcu(iml, rcu);
return 0;
}
out:
return ret;
}
EXPORT_SYMBOL(ip_mc_leave_group);
int ip_mc_source(int add, int omode, struct sock *sk, struct
ip_mreq_source *mreqs, int ifindex)
{
int err;
struct ip_mreqn imr;
__be32 addr = mreqs->imr_multiaddr;
struct ip_mc_socklist *pmc;
struct in_device *in_dev = NULL;
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *psl;
struct net *net = sock_net(sk);
int leavegroup = 0;
int i, j, rv;
if (!ipv4_is_multicast(addr))
return -EINVAL;
ASSERT_RTNL();
imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
imr.imr_address.s_addr = mreqs->imr_interface;
imr.imr_ifindex = ifindex;
in_dev = ip_mc_find_dev(net, &imr);
if (!in_dev) {
err = -ENODEV;
goto done;
}
err = -EADDRNOTAVAIL;
for_each_pmc_rtnl(inet, pmc) {
if ((pmc->multi.imr_multiaddr.s_addr ==
imr.imr_multiaddr.s_addr) &&
(pmc->multi.imr_ifindex == imr.imr_ifindex))
break;
}
if (!pmc) { /* must have a prior join */
err = -EINVAL;
goto done;
}
/* if a source filter was set, must be the same mode as before */
if (pmc->sflist) {
if (pmc->sfmode != omode) {
err = -EINVAL;
goto done;
}
} else if (pmc->sfmode != omode) {
/* allow mode switches for empty-set filters */
ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
NULL, 0);
pmc->sfmode = omode;
}
psl = rtnl_dereference(pmc->sflist);
if (!add) {
if (!psl)
goto done; /* err = -EADDRNOTAVAIL */
rv = !0;
for (i = 0; i < psl->sl_count; i++) {
rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
sizeof(__be32));
if (rv == 0)
break;
}
if (rv) /* source not found */
goto done; /* err = -EADDRNOTAVAIL */
/* special case - (INCLUDE, empty) == LEAVE_GROUP */
if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
leavegroup = 1;
goto done;
}
/* update the interface filter */
ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
&mreqs->imr_sourceaddr, 1);
for (j = i+1; j < psl->sl_count; j++)
psl->sl_addr[j-1] = psl->sl_addr[j];
psl->sl_count--;
err = 0;
goto done;
}
/* else, add a new source to the filter */
if (psl && psl->sl_count >= READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) {
err = -ENOBUFS;
goto done;
}
if (!psl || psl->sl_count == psl->sl_max) {
struct ip_sf_socklist *newpsl;
int count = IP_SFBLOCK;
if (psl)
count += psl->sl_max;
newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr, count),
GFP_KERNEL);
if (!newpsl) {
err = -ENOBUFS;
goto done;
}
newpsl->sl_max = count;
newpsl->sl_count = count - IP_SFBLOCK;
if (psl) {
for (i = 0; i < psl->sl_count; i++)
newpsl->sl_addr[i] = psl->sl_addr[i];
/* decrease mem now to avoid the memleak warning */
atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
&sk->sk_omem_alloc);
}
rcu_assign_pointer(pmc->sflist, newpsl);
if (psl)
kfree_rcu(psl, rcu);
psl = newpsl;
}
rv = 1; /* > 0 for insert logic below if sl_count is 0 */
for (i = 0; i < psl->sl_count; i++) {
rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
sizeof(__be32));
if (rv == 0)
break;
}
if (rv == 0) /* address already there is an error */
goto done;
for (j = psl->sl_count-1; j >= i; j--)
psl->sl_addr[j+1] = psl->sl_addr[j];
psl->sl_addr[i] = mreqs->imr_sourceaddr;
psl->sl_count++;
err = 0;
/* update the interface list */
ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
&mreqs->imr_sourceaddr, 1);
done:
if (leavegroup)
err = ip_mc_leave_group(sk, &imr);
return err;
}
int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
{
int err = 0;
struct ip_mreqn imr;
__be32 addr = msf->imsf_multiaddr;
struct ip_mc_socklist *pmc;
struct in_device *in_dev;
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *newpsl, *psl;
struct net *net = sock_net(sk);
int leavegroup = 0;
if (!ipv4_is_multicast(addr))
return -EINVAL;
if (msf->imsf_fmode != MCAST_INCLUDE &&
msf->imsf_fmode != MCAST_EXCLUDE)
return -EINVAL;
ASSERT_RTNL();
imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
imr.imr_address.s_addr = msf->imsf_interface;
imr.imr_ifindex = ifindex;
in_dev = ip_mc_find_dev(net, &imr);
if (!in_dev) {
err = -ENODEV;
goto done;
}
/* special case - (INCLUDE, empty) == LEAVE_GROUP */
if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
leavegroup = 1;
goto done;
}
for_each_pmc_rtnl(inet, pmc) {
if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
pmc->multi.imr_ifindex == imr.imr_ifindex)
break;
}
if (!pmc) { /* must have a prior join */
err = -EINVAL;
goto done;
}
if (msf->imsf_numsrc) {
newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr,
msf->imsf_numsrc),
GFP_KERNEL);
if (!newpsl) {
err = -ENOBUFS;
goto done;
}
newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
memcpy(newpsl->sl_addr, msf->imsf_slist_flex,
flex_array_size(msf, imsf_slist_flex, msf->imsf_numsrc));
err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
if (err) {
sock_kfree_s(sk, newpsl,
struct_size(newpsl, sl_addr,
newpsl->sl_max));
goto done;
}
} else {
newpsl = NULL;
(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
msf->imsf_fmode, 0, NULL, 0);
}
psl = rtnl_dereference(pmc->sflist);
if (psl) {
(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
psl->sl_count, psl->sl_addr, 0);
/* decrease mem now to avoid the memleak warning */
atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
&sk->sk_omem_alloc);
} else {
(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
0, NULL, 0);
}
rcu_assign_pointer(pmc->sflist, newpsl);
if (psl)
kfree_rcu(psl, rcu);
pmc->sfmode = msf->imsf_fmode;
err = 0;
done:
if (leavegroup)
err = ip_mc_leave_group(sk, &imr);
return err;
}
int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
sockptr_t optval, sockptr_t optlen)
{
int err, len, count, copycount, msf_size;
struct ip_mreqn imr;
__be32 addr = msf->imsf_multiaddr;
struct ip_mc_socklist *pmc;
struct in_device *in_dev;
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *psl;
struct net *net = sock_net(sk);
ASSERT_RTNL();
if (!ipv4_is_multicast(addr))
return -EINVAL;
imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
imr.imr_address.s_addr = msf->imsf_interface;
imr.imr_ifindex = 0;
in_dev = ip_mc_find_dev(net, &imr);
if (!in_dev) {
err = -ENODEV;
goto done;
}
err = -EADDRNOTAVAIL;
for_each_pmc_rtnl(inet, pmc) {
if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
pmc->multi.imr_ifindex == imr.imr_ifindex)
break;
}
if (!pmc) /* must have a prior join */
goto done;
msf->imsf_fmode = pmc->sfmode;
psl = rtnl_dereference(pmc->sflist);
if (!psl) {
count = 0;
} else {
count = psl->sl_count;
}
copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
len = flex_array_size(psl, sl_addr, copycount);
msf->imsf_numsrc = count;
msf_size = IP_MSFILTER_SIZE(copycount);
if (copy_to_sockptr(optlen, &msf_size, sizeof(int)) ||
copy_to_sockptr(optval, msf, IP_MSFILTER_SIZE(0))) {
return -EFAULT;
}
if (len &&
copy_to_sockptr_offset(optval,
offsetof(struct ip_msfilter, imsf_slist_flex),
psl->sl_addr, len))
return -EFAULT;
return 0;
done:
return err;
}
int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
sockptr_t optval, size_t ss_offset)
{
int i, count, copycount;
struct sockaddr_in *psin;
__be32 addr;
struct ip_mc_socklist *pmc;
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *psl;
ASSERT_RTNL();
psin = (struct sockaddr_in *)&gsf->gf_group;
if (psin->sin_family != AF_INET)
return -EINVAL;
addr = psin->sin_addr.s_addr;
if (!ipv4_is_multicast(addr))
return -EINVAL;
for_each_pmc_rtnl(inet, pmc) {
if (pmc->multi.imr_multiaddr.s_addr == addr &&
pmc->multi.imr_ifindex == gsf->gf_interface)
break;
}
if (!pmc) /* must have a prior join */
return -EADDRNOTAVAIL;
gsf->gf_fmode = pmc->sfmode;
psl = rtnl_dereference(pmc->sflist);
count = psl ? psl->sl_count : 0;
copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
gsf->gf_numsrc = count;
for (i = 0; i < copycount; i++) {
struct sockaddr_storage ss;
psin = (struct sockaddr_in *)&ss;
memset(&ss, 0, sizeof(ss));
psin->sin_family = AF_INET;
psin->sin_addr.s_addr = psl->sl_addr[i];
if (copy_to_sockptr_offset(optval, ss_offset,
&ss, sizeof(ss)))
return -EFAULT;
ss_offset += sizeof(ss);
}
return 0;
}
/*
* check if a multicast source filter allows delivery for a given <src,dst,intf>
*/
int ip_mc_sf_allow(const struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
int dif, int sdif)
{
const struct inet_sock *inet = inet_sk(sk);
struct ip_mc_socklist *pmc;
struct ip_sf_socklist *psl;
int i;
int ret;
ret = 1;
if (!ipv4_is_multicast(loc_addr))
goto out;
rcu_read_lock();
for_each_pmc_rcu(inet, pmc) {
if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
(pmc->multi.imr_ifindex == dif ||
(sdif && pmc->multi.imr_ifindex == sdif)))
break;
}
ret = inet_test_bit(MC_ALL, sk);
if (!pmc)
goto unlock;
psl = rcu_dereference(pmc->sflist);
ret = (pmc->sfmode == MCAST_EXCLUDE);
if (!psl)
goto unlock;
for (i = 0; i < psl->sl_count; i++) {
if (psl->sl_addr[i] == rmt_addr)
break;
}
ret = 0;
if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
goto unlock;
if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
goto unlock;
ret = 1;
unlock:
rcu_read_unlock();
out:
return ret;
}
/*
* A socket is closing.
*/
void ip_mc_drop_socket(struct sock *sk)
{
struct inet_sock *inet = inet_sk(sk);
struct ip_mc_socklist *iml;
struct net *net = sock_net(sk);
if (!inet->mc_list)
return;
rtnl_lock();
while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
struct in_device *in_dev;
inet->mc_list = iml->next_rcu;
in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
(void) ip_mc_leave_src(sk, iml, in_dev);
if (in_dev)
ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
/* decrease mem now to avoid the memleak warning */
atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
kfree_rcu(iml, rcu);
}
rtnl_unlock();
}
/* called with rcu_read_lock() */
int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
{
struct ip_mc_list *im;
struct ip_mc_list __rcu **mc_hash;
struct ip_sf_list *psf;
int rv = 0;
mc_hash = rcu_dereference(in_dev->mc_hash);
if (mc_hash) {
u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
for (im = rcu_dereference(mc_hash[hash]);
im != NULL;
im = rcu_dereference(im->next_hash)) {
if (im->multiaddr == mc_addr)
break;
}
} else {
for_each_pmc_rcu(in_dev, im) {
if (im->multiaddr == mc_addr)
break;
}
}
if (im && proto == IPPROTO_IGMP) {
rv = 1;
} else if (im) {
if (src_addr) {
spin_lock_bh(&im->lock);
for (psf = im->sources; psf; psf = psf->sf_next) {
if (psf->sf_inaddr == src_addr)
break;
}
if (psf)
rv = psf->sf_count[MCAST_INCLUDE] ||
psf->sf_count[MCAST_EXCLUDE] !=
im->sfcount[MCAST_EXCLUDE];
else
rv = im->sfcount[MCAST_EXCLUDE] != 0;
spin_unlock_bh(&im->lock);
} else
rv = 1; /* unspecified source; tentatively allow */
}
return rv;
}
#if defined(CONFIG_PROC_FS)
struct igmp_mc_iter_state {
struct seq_net_private p;
struct net_device *dev;
struct in_device *in_dev;
};
#define igmp_mc_seq_private(seq) ((struct igmp_mc_iter_state *)(seq)->private)
static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct ip_mc_list *im = NULL;
struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
state->in_dev = NULL;
for_each_netdev_rcu(net, state->dev) {
struct in_device *in_dev;
in_dev = __in_dev_get_rcu(state->dev);
if (!in_dev)
continue;
im = rcu_dereference(in_dev->mc_list);
if (im) {
state->in_dev = in_dev;
break;
}
}
return im;
}
static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
{
struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
im = rcu_dereference(im->next_rcu);
while (!im) {
state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->in_dev = NULL;
break;
}
state->in_dev = __in_dev_get_rcu(state->dev);
if (!state->in_dev)
continue;
im = rcu_dereference(state->in_dev->mc_list);
}
return im;
}
static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
{
struct ip_mc_list *im = igmp_mc_get_first(seq);
if (im)
while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
--pos;
return pos ? NULL : im;
}
static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(rcu)
{
rcu_read_lock();
return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ip_mc_list *im;
if (v == SEQ_START_TOKEN)
im = igmp_mc_get_first(seq);
else
im = igmp_mc_get_next(seq, v);
++*pos;
return im;
}
static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
__releases(rcu)
{
struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
state->in_dev = NULL;
state->dev = NULL;
rcu_read_unlock();
}
static int igmp_mc_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_puts(seq,
"Idx\tDevice : Count Querier\tGroup Users Timer\tReporter\n");
else {
struct ip_mc_list *im = v;
struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
char *querier;
long delta;
#ifdef CONFIG_IP_MULTICAST
querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
IGMP_V2_SEEN(state->in_dev) ? "V2" :
"V3";
#else
querier = "NONE";
#endif
if (rcu_access_pointer(state->in_dev->mc_list) == im) {
seq_printf(seq, "%d\t%-10s: %5d %7s\n",
state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
}
delta = im->timer.expires - jiffies;
seq_printf(seq,
"\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
im->multiaddr, im->users,
im->tm_running,
im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
im->reporter);
}
return 0;
}
static const struct seq_operations igmp_mc_seq_ops = {
.start = igmp_mc_seq_start,
.next = igmp_mc_seq_next,
.stop = igmp_mc_seq_stop,
.show = igmp_mc_seq_show,
};
struct igmp_mcf_iter_state {
struct seq_net_private p;
struct net_device *dev;
struct in_device *idev;
struct ip_mc_list *im;
};
#define igmp_mcf_seq_private(seq) ((struct igmp_mcf_iter_state *)(seq)->private)
static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct ip_sf_list *psf = NULL;
struct ip_mc_list *im = NULL;
struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
state->idev = NULL;
state->im = NULL;
for_each_netdev_rcu(net, state->dev) {
struct in_device *idev;
idev = __in_dev_get_rcu(state->dev);
if (unlikely(!idev))
continue;
im = rcu_dereference(idev->mc_list);
if (likely(im)) {
spin_lock_bh(&im->lock);
psf = im->sources;
if (likely(psf)) {
state->im = im;
state->idev = idev;
break;
}
spin_unlock_bh(&im->lock);
}
}
return psf;
}
static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
{
struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
psf = psf->sf_next;
while (!psf) {
spin_unlock_bh(&state->im->lock);
state->im = state->im->next;
while (!state->im) {
state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->idev = NULL;
goto out;
}
state->idev = __in_dev_get_rcu(state->dev);
if (!state->idev)
continue;
state->im = rcu_dereference(state->idev->mc_list);
}
spin_lock_bh(&state->im->lock);
psf = state->im->sources;
}
out:
return psf;
}
static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
{
struct ip_sf_list *psf = igmp_mcf_get_first(seq);
if (psf)
while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
--pos;
return pos ? NULL : psf;
}
static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(rcu)
{
rcu_read_lock();
return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ip_sf_list *psf;
if (v == SEQ_START_TOKEN)
psf = igmp_mcf_get_first(seq);
else
psf = igmp_mcf_get_next(seq, v);
++*pos;
return psf;
}
static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
__releases(rcu)
{
struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
if (likely(state->im)) {
spin_unlock_bh(&state->im->lock);
state->im = NULL;
}
state->idev = NULL;
state->dev = NULL;
rcu_read_unlock();
}
static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
{
struct ip_sf_list *psf = v;
struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
if (v == SEQ_START_TOKEN) {
seq_puts(seq, "Idx Device MCA SRC INC EXC\n");
} else {
seq_printf(seq,
"%3d %6.6s 0x%08x "
"0x%08x %6lu %6lu\n",
state->dev->ifindex, state->dev->name,
ntohl(state->im->multiaddr),
ntohl(psf->sf_inaddr),
psf->sf_count[MCAST_INCLUDE],
psf->sf_count[MCAST_EXCLUDE]);
}
return 0;
}
static const struct seq_operations igmp_mcf_seq_ops = {
.start = igmp_mcf_seq_start,
.next = igmp_mcf_seq_next,
.stop = igmp_mcf_seq_stop,
.show = igmp_mcf_seq_show,
};
static int __net_init igmp_net_init(struct net *net)
{
struct proc_dir_entry *pde;
int err;
pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
sizeof(struct igmp_mc_iter_state));
if (!pde)
goto out_igmp;
pde = proc_create_net("mcfilter", 0444, net->proc_net,
&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
if (!pde)
goto out_mcfilter;
err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
SOCK_DGRAM, 0, net);
if (err < 0) {
pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
err);
goto out_sock;
}
return 0;
out_sock:
remove_proc_entry("mcfilter", net->proc_net);
out_mcfilter:
remove_proc_entry("igmp", net->proc_net);
out_igmp:
return -ENOMEM;
}
static void __net_exit igmp_net_exit(struct net *net)
{
remove_proc_entry("mcfilter", net->proc_net);
remove_proc_entry("igmp", net->proc_net);
inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
}
static struct pernet_operations igmp_net_ops = {
.init = igmp_net_init,
.exit = igmp_net_exit,
};
#endif
static int igmp_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct in_device *in_dev;
switch (event) {
case NETDEV_RESEND_IGMP:
in_dev = __in_dev_get_rtnl(dev);
if (in_dev)
ip_mc_rejoin_groups(in_dev);
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block igmp_notifier = {
.notifier_call = igmp_netdev_event,
};
int __init igmp_mc_init(void)
{
#if defined(CONFIG_PROC_FS)
int err;
err = register_pernet_subsys(&igmp_net_ops);
if (err)
return err;
err = register_netdevice_notifier(&igmp_notifier);
if (err)
goto reg_notif_fail;
return 0;
reg_notif_fail:
unregister_pernet_subsys(&igmp_net_ops);
return err;
#else
return register_netdevice_notifier(&igmp_notifier);
#endif
}
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