From 29e97d214509ef4977838e073d30f6b16f75c6d5 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Sat, 21 Nov 2015 15:57:31 +0100 Subject: [PATCH] net: ipmr: rearrange and cleanup setsockopt Take rtnl in the beginning unconditionally as most options already need it (one exception - MRT_DONE, see the comment inside), make the lock/unlock places central and move out the switch() local variables. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- net/ipv4/ipmr.c | 191 +++++++++++++++++++++++++++--------------------- 1 file changed, 107 insertions(+), 84 deletions(-) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 50aec313119d..e384f39202cb 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1276,38 +1276,45 @@ static void mrtsock_destruct(struct sock *sk) * MOSPF/PIM router set up we can clean this up. */ -int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen) +int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, + unsigned int optlen) { - int ret, parent = 0; - struct vifctl vif; - struct mfcctl mfc; struct net *net = sock_net(sk); + int val, ret = 0, parent = 0; struct mr_table *mrt; + struct vifctl vif; + struct mfcctl mfc; + u32 uval; + /* There's one exception to the lock - MRT_DONE which needs to unlock */ + rtnl_lock(); if (sk->sk_type != SOCK_RAW || - inet_sk(sk)->inet_num != IPPROTO_IGMP) - return -EOPNOTSUPP; + inet_sk(sk)->inet_num != IPPROTO_IGMP) { + ret = -EOPNOTSUPP; + goto out_unlock; + } mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); - if (!mrt) - return -ENOENT; - + if (!mrt) { + ret = -ENOENT; + goto out_unlock; + } if (optname != MRT_INIT) { if (sk != rcu_access_pointer(mrt->mroute_sk) && - !ns_capable(net->user_ns, CAP_NET_ADMIN)) - return -EACCES; + !ns_capable(net->user_ns, CAP_NET_ADMIN)) { + ret = -EACCES; + goto out_unlock; + } } switch (optname) { case MRT_INIT: if (optlen != sizeof(int)) - return -EINVAL; - - rtnl_lock(); - if (rtnl_dereference(mrt->mroute_sk)) { - rtnl_unlock(); - return -EADDRINUSE; - } + ret = -EINVAL; + if (rtnl_dereference(mrt->mroute_sk)) + ret = -EADDRINUSE; + if (ret) + break; ret = ip_ra_control(sk, 1, mrtsock_destruct); if (ret == 0) { @@ -1317,30 +1324,41 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsi NETCONFA_IFINDEX_ALL, net->ipv4.devconf_all); } - rtnl_unlock(); - return ret; + break; case MRT_DONE: - if (sk != rcu_access_pointer(mrt->mroute_sk)) - return -EACCES; - return ip_ra_control(sk, 0, NULL); + if (sk != rcu_access_pointer(mrt->mroute_sk)) { + ret = -EACCES; + } else { + /* We need to unlock here because mrtsock_destruct takes + * care of rtnl itself and we can't change that due to + * the IP_ROUTER_ALERT setsockopt which runs without it. + */ + rtnl_unlock(); + ret = ip_ra_control(sk, 0, NULL); + goto out; + } + break; case MRT_ADD_VIF: case MRT_DEL_VIF: - if (optlen != sizeof(vif)) - return -EINVAL; - if (copy_from_user(&vif, optval, sizeof(vif))) - return -EFAULT; - if (vif.vifc_vifi >= MAXVIFS) - return -ENFILE; - rtnl_lock(); + if (optlen != sizeof(vif)) { + ret = -EINVAL; + break; + } + if (copy_from_user(&vif, optval, sizeof(vif))) { + ret = -EFAULT; + break; + } + if (vif.vifc_vifi >= MAXVIFS) { + ret = -ENFILE; + break; + } if (optname == MRT_ADD_VIF) { ret = vif_add(net, mrt, &vif, sk == rtnl_dereference(mrt->mroute_sk)); } else { ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL); } - rtnl_unlock(); - return ret; - + break; /* Manipulate the forwarding caches. These live * in a sort of kernel/user symbiosis. */ @@ -1349,82 +1367,87 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsi parent = -1; case MRT_ADD_MFC_PROXY: case MRT_DEL_MFC_PROXY: - if (optlen != sizeof(mfc)) - return -EINVAL; - if (copy_from_user(&mfc, optval, sizeof(mfc))) - return -EFAULT; + if (optlen != sizeof(mfc)) { + ret = -EINVAL; + break; + } + if (copy_from_user(&mfc, optval, sizeof(mfc))) { + ret = -EFAULT; + break; + } if (parent == 0) parent = mfc.mfcc_parent; - rtnl_lock(); if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY) ret = ipmr_mfc_delete(mrt, &mfc, parent); else ret = ipmr_mfc_add(net, mrt, &mfc, sk == rtnl_dereference(mrt->mroute_sk), parent); - rtnl_unlock(); - return ret; + break; /* Control PIM assert. */ case MRT_ASSERT: - { - int v; - if (optlen != sizeof(v)) - return -EINVAL; - if (get_user(v, (int __user *)optval)) - return -EFAULT; - mrt->mroute_do_assert = v; - return 0; - } + if (optlen != sizeof(val)) { + ret = -EINVAL; + break; + } + if (get_user(val, (int __user *)optval)) { + ret = -EFAULT; + break; + } + mrt->mroute_do_assert = val; + break; case MRT_PIM: - { - int v; - - if (!pimsm_enabled()) - return -ENOPROTOOPT; - if (optlen != sizeof(v)) - return -EINVAL; - if (get_user(v, (int __user *)optval)) - return -EFAULT; - v = !!v; + if (!pimsm_enabled()) { + ret = -ENOPROTOOPT; + break; + } + if (optlen != sizeof(val)) { + ret = -EINVAL; + break; + } + if (get_user(val, (int __user *)optval)) { + ret = -EFAULT; + break; + } - rtnl_lock(); - ret = 0; - if (v != mrt->mroute_do_pim) { - mrt->mroute_do_pim = v; - mrt->mroute_do_assert = v; + val = !!val; + if (val != mrt->mroute_do_pim) { + mrt->mroute_do_pim = val; + mrt->mroute_do_assert = val; } - rtnl_unlock(); - return ret; - } + break; case MRT_TABLE: - { - u32 v; - - if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) - return -ENOPROTOOPT; - if (optlen != sizeof(u32)) - return -EINVAL; - if (get_user(v, (u32 __user *)optval)) - return -EFAULT; + if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) { + ret = -ENOPROTOOPT; + break; + } + if (optlen != sizeof(uval)) { + ret = -EINVAL; + break; + } + if (get_user(uval, (u32 __user *)optval)) { + ret = -EFAULT; + break; + } - rtnl_lock(); - ret = 0; if (sk == rtnl_dereference(mrt->mroute_sk)) { ret = -EBUSY; } else { - mrt = ipmr_new_table(net, v); + mrt = ipmr_new_table(net, uval); if (IS_ERR(mrt)) ret = PTR_ERR(mrt); else - raw_sk(sk)->ipmr_table = v; + raw_sk(sk)->ipmr_table = uval; } - rtnl_unlock(); - return ret; - } + break; /* Spurious command, or MRT_VERSION which you cannot set. */ default: - return -ENOPROTOOPT; + ret = -ENOPROTOOPT; } +out_unlock: + rtnl_unlock(); +out: + return ret; } /* Getsock opt support for the multicast routing system. */ -- GitLab