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linux/net/ipv4/igmp.c
Kuniyuki Iwashima 8ebcc62c73 igmp: Fix data-races around sysctl_igmp_qrv. 
While reading sysctl_igmp_qrv, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

This test can be packed into a helper, so such changes will be in the
follow-up series after net is merged into net-next.

  qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);

Fixes: a9fe8e2994 ("ipv4: implement igmp_qrv sysctl to tune igmp robustness variable")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 12:21:54 +01:00

3104 lines
73 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(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(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 = prandom_u32() % max_delay;
im->tm_running = 1;
if (!mod_timer(&im->timer, jiffies+tv+2))
refcount_inc(&im->refcnt);
}
static void igmp_gq_start_timer(struct in_device *in_dev)
{
int tv = prandom_u32() % 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 = prandom_u32() % 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 = 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);
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,
struct ip_msfilter __user *optval, int __user *optlen)
{
int err, len, count, copycount;
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;
if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
return -EFAULT;
}
if (len &&
copy_to_user(&optval->imsf_slist_flex[0], psl->sl_addr, len))
return -EFAULT;
return 0;
done:
return err;
}
int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
struct sockaddr_storage __user *p)
{
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++, p++) {
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_user(p, &ss, sizeof(ss)))
return -EFAULT;
}
return 0;
}
/*
* check if a multicast source filter allows delivery for a given <src,dst,intf>
*/
int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
int dif, int sdif)
{
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->mc_all;
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);
}
if (!state->im)
break;
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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