From 96b52e61be1ad4d4f8de39b9deaf253da804ea3b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 7 Jun 2010 21:05:02 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv6/mcast.c | 183 ++++++++++++++++++++++------------------------- 1 file changed, 87 insertions(+), 96 deletions(-) diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 8752e8084806..3e36d1538b6e 100644 --- a/net/ipv6/mcast.c +++ b/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 @@ out: } 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 @@ out: } else IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); - if (likely(idev != NULL)) - in6_dev_put(idev); + rcu_read_unlock(); return; err_out: -- 2.20.1