[PATCH v2] net: igmp: use IS_ENABLED(CONFIG_IP_MULTICAST) instead of ifdef

From: Arnd Bergmann
Date: Tue Feb 16 2016 - 11:33:09 EST

A recent change to use correct network namespace in net/ipv4/igmp.c
caused a couple of harmless build warnings when CONFIG_MULTICAST is
disabled:

net/ipv4/igmp.c: In function 'igmp_group_added':
net/ipv4/igmp.c:1227:14: error: unused variable 'net' [-Werror=unused-variable]
net/ipv4/igmp.c: In function 'ip_mc_inc_group':
net/ipv4/igmp.c:1319:14: error: unused variable 'net' [-Werror=unused-variable]
net/ipv4/igmp.c: In function 'ip_mc_init_dev':
net/ipv4/igmp.c:1646:14: error: unused variable 'net' [-Werror=unused-variable]
net/ipv4/igmp.c: In function 'ip_mc_up':
net/ipv4/igmp.c:1665:14: error: unused variable 'net' [-Werror=unused-variable]

This reworks the entire file to change each instance if '#ifdef
CONFIG_IP_MULTICAST' to 'if (IS_ENABLED(CONFIG_IP_MULTICAST)', which
should avoid these problems forever, and makes the whole file more
readable.

Build-tested only.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Nikolay Borisov <kernel@xxxxxxxx>
Fixes: 87a8a2ae65b7 ("igmp: Namespaceify igmp_llm_reports sysctl knob")
---
net/ipv4/igmp.c | 142 ++++++++++++++++++++++++++------------------------------
1 file changed, 66 insertions(+), 76 deletions(-)

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 7c95335bf85e..2b6dd53adaa4 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -107,7 +107,6 @@
#include <linux/seq_file.h>
#endif

-#ifdef CONFIG_IP_MULTICAST
/* Parameter names and values are taken from igmp-v2-06 draft */

#define IGMP_V1_ROUTER_PRESENT_TIMEOUT (400*HZ)
@@ -166,7 +165,6 @@ static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
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);
@@ -189,8 +187,6 @@ static void ip_ma_put(struct ip_mc_list *im)
pmc != NULL; \
pmc = rtnl_dereference(pmc->next_rcu))

-#ifdef CONFIG_IP_MULTICAST
-
/*
* Timer management
*/
@@ -763,7 +759,9 @@ static void igmp_ifc_timer_expire(unsigned long data)
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))
+
+ if (!IS_ENABLED(CONFIG_IP_MULTICAST) ||
+ IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
return;
in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
igmp_ifc_start_timer(in_dev, 1);
@@ -1044,9 +1042,6 @@ drop:
return 0;
}

-#endif
-
-
/*
* Add a filter to a device
*/
@@ -1080,7 +1075,6 @@ static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
dev_mc_del(dev, buf);
}

-#ifdef CONFIG_IP_MULTICAST
/*
* deleted ip_mc_list manipulation
*/
@@ -1181,22 +1175,20 @@ static void igmpv3_clear_delrec(struct in_device *in_dev)
}
rcu_read_unlock();
}
-#endif

static void igmp_group_dropped(struct ip_mc_list *im)
{
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 (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ return;
if (im->multiaddr == IGMP_ALL_HOSTS)
return;
if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
@@ -1218,7 +1210,6 @@ static void igmp_group_dropped(struct ip_mc_list *im)

igmp_ifc_event(in_dev);
}
-#endif
}

static void igmp_group_added(struct ip_mc_list *im)
@@ -1231,7 +1222,9 @@ static void igmp_group_added(struct ip_mc_list *im)
ip_mc_filter_add(in_dev, im->multiaddr);
}

-#ifdef CONFIG_IP_MULTICAST
+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ return;
+
if (im->multiaddr == IGMP_ALL_HOSTS)
return;
if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
@@ -1249,7 +1242,6 @@ static void igmp_group_added(struct ip_mc_list *im)

im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
igmp_ifc_event(in_dev);
-#endif
}


@@ -1341,10 +1333,10 @@ void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
im->sfcount[MCAST_EXCLUDE] = 1;
atomic_set(&im->refcnt, 1);
spin_lock_init(&im->lock);
-#ifdef CONFIG_IP_MULTICAST
- setup_timer(&im->timer, igmp_timer_expire, (unsigned long)im);
- im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
-#endif
+ if (IS_ENABLED(CONFIG_IP_MULTICAST)) {
+ setup_timer(&im->timer, igmp_timer_expire, (unsigned long)im);
+ im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
+ }

im->next_rcu = in_dev->mc_list;
in_dev->mc_count++;
@@ -1352,9 +1344,9 @@ void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)

ip_mc_hash_add(in_dev, im);

-#ifdef CONFIG_IP_MULTICAST
- igmpv3_del_delrec(in_dev, im->multiaddr);
-#endif
+ if (IS_ENABLED(CONFIG_IP_MULTICAST))
+ igmpv3_del_delrec(in_dev, im->multiaddr);
+
igmp_group_added(im);
if (!in_dev->dead)
ip_rt_multicast_event(in_dev);
@@ -1533,11 +1525,13 @@ EXPORT_SYMBOL(ip_mc_check_igmp);
*/
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);

+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ return;
+
ASSERT_RTNL();

for_each_pmc_rtnl(in_dev, im) {
@@ -1558,7 +1552,6 @@ static void ip_mc_rejoin_groups(struct in_device *in_dev)
type = IGMPV3_HOST_MEMBERSHIP_REPORT;
igmp_send_report(in_dev, im, type);
}
-#endif
}

/*
@@ -1628,15 +1621,15 @@ void ip_mc_down(struct in_device *in_dev)
for_each_pmc_rtnl(in_dev, pmc)
igmp_group_dropped(pmc);

-#ifdef CONFIG_IP_MULTICAST
- 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);
- igmpv3_clear_delrec(in_dev);
-#endif
+ if (IS_ENABLED(CONFIG_IP_MULTICAST)) {
+ 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);
+ igmpv3_clear_delrec(in_dev);
+ }

ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}
@@ -1646,13 +1639,13 @@ void ip_mc_init_dev(struct in_device *in_dev)
struct net *net = dev_net(in_dev->dev);
ASSERT_RTNL();

-#ifdef CONFIG_IP_MULTICAST
- setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
- (unsigned long)in_dev);
- setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
- (unsigned long)in_dev);
- in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
-#endif
+ if (IS_ENABLED(CONFIG_IP_MULTICAST)) {
+ setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
+ (unsigned long)in_dev);
+ setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
+ (unsigned long)in_dev);
+ in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
+ }

spin_lock_init(&in_dev->mc_tomb_lock);
}
@@ -1666,9 +1659,9 @@ void ip_mc_up(struct in_device *in_dev)

ASSERT_RTNL();

-#ifdef CONFIG_IP_MULTICAST
- in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
-#endif
+ if (IS_ENABLED(CONFIG_IP_MULTICAST))
+ in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
+
ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);

for_each_pmc_rtnl(in_dev, pmc)
@@ -1755,34 +1748,27 @@ static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
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 &&
+ if (IS_ENABLED(CONFIG_IP_MULTICAST) && psf->sf_oldin &&
!IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
psf->sf_next = pmc->tomb;
pmc->tomb = psf;
rv = 1;
- } else
-#endif
+ } else {
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)
{
@@ -1804,9 +1790,9 @@ static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
}
spin_lock_bh(&pmc->lock);
rcu_read_unlock();
-#ifdef CONFIG_IP_MULTICAST
+
sf_markstate(pmc);
-#endif
+
if (!delta) {
err = -EINVAL;
if (!pmc->sfcount[sfmode])
@@ -1824,14 +1810,15 @@ static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
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
+
+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ goto out_unlock;
+
pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
in_dev->mr_ifc_count = pmc->crcount;
for (psf = pmc->sources; psf; psf = psf->sf_next)
@@ -1839,7 +1826,6 @@ static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
igmp_ifc_event(pmc->interface);
} else if (sf_setstate(pmc) || changerec) {
igmp_ifc_event(pmc->interface);
-#endif
}
out_unlock:
spin_unlock_bh(&pmc->lock);
@@ -1877,11 +1863,15 @@ static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
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];
+ int mca_xcount;
+
+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ return;
+
+ mca_xcount = pmc->sfcount[MCAST_EXCLUDE];

for (psf = pmc->sources; psf; psf = psf->sf_next)
if (pmc->sfcount[MCAST_EXCLUDE]) {
@@ -1895,10 +1885,15 @@ static void sf_markstate(struct ip_mc_list *pmc)
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 mca_xcount;
+ int qrv;
int new_in, rv;

+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ return 0;
+
+ mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
+ qrv = pmc->interface->mr_qrv;
rv = 0;
for (psf = pmc->sources; psf; psf = psf->sf_next) {
if (pmc->sfcount[MCAST_EXCLUDE]) {
@@ -1950,7 +1945,6 @@ static int sf_setstate(struct ip_mc_list *pmc)
}
return rv;
}
-#endif

/*
* Add multicast source filter list to the interface list
@@ -1977,9 +1971,7 @@ static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
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]++;
@@ -1997,18 +1989,19 @@ static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int 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
+
+ if (!IS_ENABLED(CONFIG_IP_MULTICAST))
+ goto out_unlock;
+
/* else no filters; keep old mode for reports */

pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
@@ -2018,8 +2011,8 @@ static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
igmp_ifc_event(in_dev);
} else if (sf_setstate(pmc)) {
igmp_ifc_event(in_dev);
-#endif
}
+out_unlock:
spin_unlock_bh(&pmc->lock);
return err;
}
@@ -2711,13 +2704,10 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v)
char *querier;
long delta;

-#ifdef CONFIG_IP_MULTICAST
- querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
+ querier = !IS_ENABLED(CONFIG_IP_MULTICAST) ? "NONE" :
+ 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",
--
2.7.0