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ipv6: mcast: RCU conversions

- ipv6_sock_mc_join() : doesnt touch dev refcount

- ipv6_sock_mc_drop() : doesnt touch dev/idev refcounts

- ip6_mc_find_dev() becomes ip6_mc_find_dev_rcu() (called from rcu),
                    and doesnt touch dev/idev refcounts

- ipv6_sock_mc_close() : doesnt touch dev/idev refcounts

- ip6_mc_source() uses ip6_mc_find_dev_rcu()

- ip6_mc_msfilter() uses ip6_mc_find_dev_rcu()

- ip6_mc_msfget() uses ip6_mc_find_dev_rcu()

- ipv6_dev_mc_dec(), ipv6_chk_mcast_addr(),
  igmp6_event_query(), igmp6_event_report(),
  mld_sendpack(), igmp6_send() dont touch idev refcount

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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commit 96b52e61be1ad4d4f8de39b9deaf253da804ea3b 1 parent 9785916
Eric Dumazet authored davem330 committed
Showing with 87 additions and 96 deletions.
  1. +87 −96 net/ipv6/mcast.c
View
183 net/ipv6/mcast.c
@@ -152,18 +152,19 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
mc_lst->next = NULL;
ipv6_addr_copy(&mc_lst->addr, addr);
+ rcu_read_lock();
if (ifindex == 0) {
struct rt6_info *rt;
rt = rt6_lookup(net, addr, NULL, 0, 0);
if (rt) {
dev = rt->rt6i_dev;
- dev_hold(dev);
dst_release(&rt->u.dst);
}
} else
- dev = dev_get_by_index(net, ifindex);
+ dev = dev_get_by_index_rcu(net, ifindex);
if (dev == NULL) {
+ rcu_read_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
return -ENODEV;
}
@@ -180,8 +181,8 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
err = ipv6_dev_mc_inc(dev, addr);
if (err) {
+ rcu_read_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
- dev_put(dev);
return err;
}
@@ -190,7 +191,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
np->ipv6_mc_list = mc_lst;
write_unlock_bh(&ipv6_sk_mc_lock);
- dev_put(dev);
+ rcu_read_unlock();
return 0;
}
@@ -213,18 +214,17 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
*lnk = mc_lst->next;
write_unlock_bh(&ipv6_sk_mc_lock);
- dev = dev_get_by_index(net, mc_lst->ifindex);
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(net, mc_lst->ifindex);
if (dev != NULL) {
- struct inet6_dev *idev = in6_dev_get(dev);
+ struct inet6_dev *idev = __in6_dev_get(dev);
(void) ip6_mc_leave_src(sk, mc_lst, idev);
- if (idev) {
+ if (idev)
__ipv6_dev_mc_dec(idev, &mc_lst->addr);
- in6_dev_put(idev);
- }
- dev_put(dev);
} else
(void) ip6_mc_leave_src(sk, mc_lst, NULL);
+ rcu_read_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
return 0;
}
@@ -234,43 +234,36 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
return -EADDRNOTAVAIL;
}
-static struct inet6_dev *ip6_mc_find_dev(struct net *net,
- struct in6_addr *group,
- int ifindex)
+/* called with rcu_read_lock() */
+static struct inet6_dev *ip6_mc_find_dev_rcu(struct net *net,
+ struct in6_addr *group,
+ int ifindex)
{
struct net_device *dev = NULL;
struct inet6_dev *idev = NULL;
if (ifindex == 0) {
- struct rt6_info *rt;
+ struct rt6_info *rt = rt6_lookup(net, group, NULL, 0, 0);
- rt = rt6_lookup(net, group, NULL, 0, 0);
if (rt) {
dev = rt->rt6i_dev;
dev_hold(dev);
dst_release(&rt->u.dst);
}
} else
- dev = dev_get_by_index(net, ifindex);
+ dev = dev_get_by_index_rcu(net, ifindex);
if (!dev)
- goto nodev;
- idev = in6_dev_get(dev);
+ return NULL;
+ idev = __in6_dev_get(dev);
if (!idev)
- goto release;
+ return NULL;;
read_lock_bh(&idev->lock);
- if (idev->dead)
- goto unlock_release;
-
+ if (idev->dead) {
+ read_unlock_bh(&idev->lock);
+ return NULL;
+ }
return idev;
-
-unlock_release:
- read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
-release:
- dev_put(dev);
-nodev:
- return NULL;
}
void ipv6_sock_mc_close(struct sock *sk)
@@ -286,19 +279,17 @@ void ipv6_sock_mc_close(struct sock *sk)
np->ipv6_mc_list = mc_lst->next;
write_unlock_bh(&ipv6_sk_mc_lock);
- dev = dev_get_by_index(net, mc_lst->ifindex);
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(net, mc_lst->ifindex);
if (dev) {
- struct inet6_dev *idev = in6_dev_get(dev);
+ struct inet6_dev *idev = __in6_dev_get(dev);
(void) ip6_mc_leave_src(sk, mc_lst, idev);
- if (idev) {
+ if (idev)
__ipv6_dev_mc_dec(idev, &mc_lst->addr);
- in6_dev_put(idev);
- }
- dev_put(dev);
} else
(void) ip6_mc_leave_src(sk, mc_lst, NULL);
-
+ rcu_read_unlock();
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
write_lock_bh(&ipv6_sk_mc_lock);
@@ -327,14 +318,17 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
if (!ipv6_addr_is_multicast(group))
return -EINVAL;
- idev = ip6_mc_find_dev(net, group, pgsr->gsr_interface);
- if (!idev)
+ rcu_read_lock();
+ idev = ip6_mc_find_dev_rcu(net, group, pgsr->gsr_interface);
+ if (!idev) {
+ rcu_read_unlock();
return -ENODEV;
+ }
dev = idev->dev;
err = -EADDRNOTAVAIL;
- read_lock_bh(&ipv6_sk_mc_lock);
+ read_lock(&ipv6_sk_mc_lock);
for (pmc=inet6->ipv6_mc_list; pmc; pmc=pmc->next) {
if (pgsr->gsr_interface && pmc->ifindex != pgsr->gsr_interface)
continue;
@@ -358,7 +352,7 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
pmc->sfmode = omode;
}
- write_lock_bh(&pmc->sflock);
+ write_lock(&pmc->sflock);
pmclocked = 1;
psl = pmc->sflist;
@@ -433,11 +427,10 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
ip6_mc_add_src(idev, group, omode, 1, source, 1);
done:
if (pmclocked)
- write_unlock_bh(&pmc->sflock);
- read_unlock_bh(&ipv6_sk_mc_lock);
+ write_unlock(&pmc->sflock);
+ read_unlock(&ipv6_sk_mc_lock);
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
- dev_put(dev);
+ rcu_read_unlock();
if (leavegroup)
return ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
return err;
@@ -463,14 +456,17 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
gsf->gf_fmode != MCAST_EXCLUDE)
return -EINVAL;
- idev = ip6_mc_find_dev(net, group, gsf->gf_interface);
+ rcu_read_lock();
+ idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
- if (!idev)
+ if (!idev) {
+ rcu_read_unlock();
return -ENODEV;
+ }
dev = idev->dev;
err = 0;
- read_lock_bh(&ipv6_sk_mc_lock);
+ read_lock(&ipv6_sk_mc_lock);
if (gsf->gf_fmode == MCAST_INCLUDE && gsf->gf_numsrc == 0) {
leavegroup = 1;
@@ -512,7 +508,7 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
(void) ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
}
- write_lock_bh(&pmc->sflock);
+ write_lock(&pmc->sflock);
psl = pmc->sflist;
if (psl) {
(void) ip6_mc_del_src(idev, group, pmc->sfmode,
@@ -522,13 +518,12 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
(void) ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
pmc->sflist = newpsl;
pmc->sfmode = gsf->gf_fmode;
- write_unlock_bh(&pmc->sflock);
+ write_unlock(&pmc->sflock);
err = 0;
done:
- read_unlock_bh(&ipv6_sk_mc_lock);
+ read_unlock(&ipv6_sk_mc_lock);
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
- dev_put(dev);
+ rcu_read_unlock();
if (leavegroup)
err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
return err;
@@ -551,11 +546,13 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
if (!ipv6_addr_is_multicast(group))
return -EINVAL;
- idev = ip6_mc_find_dev(net, group, gsf->gf_interface);
+ rcu_read_lock();
+ idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
- if (!idev)
+ if (!idev) {
+ rcu_read_unlock();
return -ENODEV;
-
+ }
dev = idev->dev;
err = -EADDRNOTAVAIL;
@@ -577,8 +574,7 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
psl = pmc->sflist;
count = psl ? psl->sl_count : 0;
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
- dev_put(dev);
+ rcu_read_unlock();
copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
gsf->gf_numsrc = count;
@@ -604,8 +600,7 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
return 0;
done:
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
- dev_put(dev);
+ rcu_read_unlock();
return err;
}
@@ -822,6 +817,7 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
struct ifmcaddr6 *mc;
struct inet6_dev *idev;
+ /* we need to take a reference on idev */
idev = in6_dev_get(dev);
if (idev == NULL)
@@ -860,7 +856,7 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
setup_timer(&mc->mca_timer, igmp6_timer_handler, (unsigned long)mc);
ipv6_addr_copy(&mc->mca_addr, addr);
- mc->idev = idev;
+ mc->idev = idev; /* (reference taken) */
mc->mca_users = 1;
/* mca_stamp should be updated upon changes */
mc->mca_cstamp = mc->mca_tstamp = jiffies;
@@ -915,16 +911,18 @@ int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
int ipv6_dev_mc_dec(struct net_device *dev, const struct in6_addr *addr)
{
- struct inet6_dev *idev = in6_dev_get(dev);
+ struct inet6_dev *idev;
int err;
- if (!idev)
- return -ENODEV;
-
- err = __ipv6_dev_mc_dec(idev, addr);
+ rcu_read_lock();
- in6_dev_put(idev);
+ idev = __in6_dev_get(dev);
+ if (!idev)
+ err = -ENODEV;
+ else
+ err = __ipv6_dev_mc_dec(idev, addr);
+ rcu_read_unlock();
return err;
}
@@ -965,7 +963,8 @@ int ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
struct ifmcaddr6 *mc;
int rv = 0;
- idev = in6_dev_get(dev);
+ rcu_read_lock();
+ idev = __in6_dev_get(dev);
if (idev) {
read_lock_bh(&idev->lock);
for (mc = idev->mc_list; mc; mc=mc->next) {
@@ -992,8 +991,8 @@ int ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
rv = 1; /* don't filter unspecified source */
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
+ rcu_read_unlock();
return rv;
}
@@ -1104,6 +1103,7 @@ static int mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
return 1;
}
+/* called with rcu_read_lock() */
int igmp6_event_query(struct sk_buff *skb)
{
struct mld2_query *mlh2 = NULL;
@@ -1127,7 +1127,7 @@ int igmp6_event_query(struct sk_buff *skb)
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
return -EINVAL;
- idev = in6_dev_get(skb->dev);
+ idev = __in6_dev_get(skb->dev);
if (idev == NULL)
return 0;
@@ -1137,10 +1137,8 @@ int igmp6_event_query(struct sk_buff *skb)
group_type = ipv6_addr_type(group);
if (group_type != IPV6_ADDR_ANY &&
- !(group_type&IPV6_ADDR_MULTICAST)) {
- in6_dev_put(idev);
+ !(group_type&IPV6_ADDR_MULTICAST))
return -EINVAL;
- }
if (len == 24) {
int switchback;
@@ -1161,10 +1159,9 @@ int igmp6_event_query(struct sk_buff *skb)
} else if (len >= 28) {
int srcs_offset = sizeof(struct mld2_query) -
sizeof(struct icmp6hdr);
- if (!pskb_may_pull(skb, srcs_offset)) {
- in6_dev_put(idev);
+ if (!pskb_may_pull(skb, srcs_offset))
return -EINVAL;
- }
+
mlh2 = (struct mld2_query *)skb_transport_header(skb);
max_delay = (MLDV2_MRC(ntohs(mlh2->mld2q_mrc))*HZ)/1000;
if (!max_delay)
@@ -1173,28 +1170,23 @@ int igmp6_event_query(struct sk_buff *skb)
if (mlh2->mld2q_qrv)
idev->mc_qrv = mlh2->mld2q_qrv;
if (group_type == IPV6_ADDR_ANY) { /* general query */
- if (mlh2->mld2q_nsrcs) {
- in6_dev_put(idev);
+ if (mlh2->mld2q_nsrcs)
return -EINVAL; /* no sources allowed */
- }
+
mld_gq_start_timer(idev);
- in6_dev_put(idev);
return 0;
}
/* mark sources to include, if group & source-specific */
if (mlh2->mld2q_nsrcs != 0) {
if (!pskb_may_pull(skb, srcs_offset +
- ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr))) {
- in6_dev_put(idev);
+ ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr)))
return -EINVAL;
- }
+
mlh2 = (struct mld2_query *)skb_transport_header(skb);
mark = 1;
}
- } else {
- in6_dev_put(idev);
+ } else
return -EINVAL;
- }
read_lock_bh(&idev->lock);
if (group_type == IPV6_ADDR_ANY) {
@@ -1227,12 +1219,11 @@ int igmp6_event_query(struct sk_buff *skb)
}
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
return 0;
}
-
+/* called with rcu_read_lock() */
int igmp6_event_report(struct sk_buff *skb)
{
struct ifmcaddr6 *ma;
@@ -1260,7 +1251,7 @@ int igmp6_event_report(struct sk_buff *skb)
!(addr_type&IPV6_ADDR_LINKLOCAL))
return -EINVAL;
- idev = in6_dev_get(skb->dev);
+ idev = __in6_dev_get(skb->dev);
if (idev == NULL)
return -ENODEV;
@@ -1280,7 +1271,6 @@ int igmp6_event_report(struct sk_buff *skb)
}
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
return 0;
}
@@ -1396,12 +1386,14 @@ static void mld_sendpack(struct sk_buff *skb)
struct mld2_report *pmr =
(struct mld2_report *)skb_transport_header(skb);
int payload_len, mldlen;
- struct inet6_dev *idev = in6_dev_get(skb->dev);
+ struct inet6_dev *idev;
struct net *net = dev_net(skb->dev);
int err;
struct flowi fl;
struct dst_entry *dst;
+ rcu_read_lock();
+ idev = __in6_dev_get(skb->dev);
IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
payload_len = (skb->tail - skb->network_header) - sizeof(*pip6);
@@ -1441,8 +1433,7 @@ static void mld_sendpack(struct sk_buff *skb)
} else
IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_OUTDISCARDS);
- if (likely(idev != NULL))
- in6_dev_put(idev);
+ rcu_read_unlock();
return;
err_out:
@@ -1779,7 +1770,8 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
IPPROTO_ICMPV6,
csum_partial(hdr, len, 0));
- idev = in6_dev_get(skb->dev);
+ rcu_read_lock();
+ idev = __in6_dev_get(skb->dev);
dst = icmp6_dst_alloc(skb->dev, NULL, &ipv6_hdr(skb)->daddr);
if (!dst) {
@@ -1806,8 +1798,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
} else
IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
- if (likely(idev != NULL))
- in6_dev_put(idev);
+ rcu_read_unlock();
return;
err_out:
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