[PATCH 18/26] net/ipv6: split up ipv6_flowlabel_opt

[Christoph Hellwig <hch@xxxxxx>]

Split ipv6_flowlabel_opt into a subfunction for each action and a small
wrapper.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 net/ipv6/ip6_flowlabel.c | 311 +++++++++++++++++++++------------------
 1 file changed, 167 insertions(+), 144 deletions(-)

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index ce4fbba4acce7e..27ee6de9beffc4 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -533,187 +533,210 @@ int ipv6_flowlabel_opt_get(struct sock *sk, struct 
in6_flowlabel_req *freq,
        return -ENOENT;
 }
 
-int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
+#define socklist_dereference(__sflp) \
+       rcu_dereference_protected(__sflp, lockdep_is_held(&ip6_sk_fl_lock))
+
+static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq)
 {
-       int uninitialized_var(err);
-       struct net *net = sock_net(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
-       struct in6_flowlabel_req freq;
-       struct ipv6_fl_socklist *sfl1 = NULL;
-       struct ipv6_fl_socklist *sfl;
        struct ipv6_fl_socklist __rcu **sflp;
-       struct ip6_flowlabel *fl, *fl1 = NULL;
-
+       struct ipv6_fl_socklist *sfl;
 
-       if (optlen < sizeof(freq))
-               return -EINVAL;
+       if (freq->flr_flags & IPV6_FL_F_REFLECT) {
+               if (sk->sk_protocol != IPPROTO_TCP)
+                       return -ENOPROTOOPT;
+               if (!np->repflow)
+                       return -ESRCH;
+               np->flow_label = 0;
+               np->repflow = 0;
+               return 0;
+       }
 
-       if (copy_from_user(&freq, optval, sizeof(freq)))
-               return -EFAULT;
+       spin_lock_bh(&ip6_sk_fl_lock);
+       for (sflp = &np->ipv6_fl_list;
+            (sfl = socklist_dereference(*sflp)) != NULL;
+            sflp = &sfl->next) {
+               if (sfl->fl->label == freq->flr_label)
+                       goto found;
+       }
+       spin_unlock_bh(&ip6_sk_fl_lock);
+       return -ESRCH;
+found:
+       if (freq->flr_label == (np->flow_label & IPV6_FLOWLABEL_MASK))
+               np->flow_label &= ~IPV6_FLOWLABEL_MASK;
+       *sflp = sfl->next;
+       spin_unlock_bh(&ip6_sk_fl_lock);
+       fl_release(sfl->fl);
+       kfree_rcu(sfl, rcu);
+       return 0;
+}
+               
+static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req 
*freq)
+{
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct net *net = sock_net(sk);
+       struct ipv6_fl_socklist *sfl;
+       int err;
 
-       switch (freq.flr_action) {
-       case IPV6_FL_A_PUT:
-               if (freq.flr_flags & IPV6_FL_F_REFLECT) {
-                       if (sk->sk_protocol != IPPROTO_TCP)
-                               return -ENOPROTOOPT;
-                       if (!np->repflow)
-                               return -ESRCH;
-                       np->flow_label = 0;
-                       np->repflow = 0;
-                       return 0;
-               }
-               spin_lock_bh(&ip6_sk_fl_lock);
-               for (sflp = &np->ipv6_fl_list;
-                    (sfl = rcu_dereference_protected(*sflp,
-                                                     
lockdep_is_held(&ip6_sk_fl_lock))) != NULL;
-                    sflp = &sfl->next) {
-                       if (sfl->fl->label == freq.flr_label) {
-                               if (freq.flr_label == 
(np->flow_label&IPV6_FLOWLABEL_MASK))
-                                       np->flow_label &= ~IPV6_FLOWLABEL_MASK;
-                               *sflp = sfl->next;
-                               spin_unlock_bh(&ip6_sk_fl_lock);
-                               fl_release(sfl->fl);
-                               kfree_rcu(sfl, rcu);
-                               return 0;
-                       }
+       rcu_read_lock_bh();
+       for_each_sk_fl_rcu(np, sfl) {
+               if (sfl->fl->label == freq->flr_label) {
+                       err = fl6_renew(sfl->fl, freq->flr_linger,
+                                       freq->flr_expires);
+                       rcu_read_unlock_bh();
+                       return err;
                }
-               spin_unlock_bh(&ip6_sk_fl_lock);
-               return -ESRCH;
+       }
+       rcu_read_unlock_bh();
 
-       case IPV6_FL_A_RENEW:
-               rcu_read_lock_bh();
-               for_each_sk_fl_rcu(np, sfl) {
-                       if (sfl->fl->label == freq.flr_label) {
-                               err = fl6_renew(sfl->fl, freq.flr_linger, 
freq.flr_expires);
-                               rcu_read_unlock_bh();
-                               return err;
-                       }
-               }
-               rcu_read_unlock_bh();
+       if (freq->flr_share == IPV6_FL_S_NONE &&
+           ns_capable(net->user_ns, CAP_NET_ADMIN)) {
+               struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
 
-               if (freq.flr_share == IPV6_FL_S_NONE &&
-                   ns_capable(net->user_ns, CAP_NET_ADMIN)) {
-                       fl = fl_lookup(net, freq.flr_label);
-                       if (fl) {
-                               err = fl6_renew(fl, freq.flr_linger, 
freq.flr_expires);
-                               fl_release(fl);
-                               return err;
-                       }
+               if (fl) {
+                       err = fl6_renew(fl, freq->flr_linger,
+                                       freq->flr_expires);
+                       fl_release(fl);
+                       return err;
                }
-               return -ESRCH;
-
-       case IPV6_FL_A_GET:
-               if (freq.flr_flags & IPV6_FL_F_REFLECT) {
-                       struct net *net = sock_net(sk);
-                       if (net->ipv6.sysctl.flowlabel_consistency) {
-                               net_info_ratelimited("Can not set 
IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
-                               return -EPERM;
-                       }
+       }
+       return -ESRCH;
+}
 
-                       if (sk->sk_protocol != IPPROTO_TCP)
-                               return -ENOPROTOOPT;
+static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
+               void __user *optval, int optlen)
+{
+       struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
+       struct ip6_flowlabel *fl, *fl1 = NULL;
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct net *net = sock_net(sk);
+       int uninitialized_var(err);
 
-                       np->repflow = 1;
-                       return 0;
+       if (freq->flr_flags & IPV6_FL_F_REFLECT) {
+               if (net->ipv6.sysctl.flowlabel_consistency) {
+                       net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if 
flowlabel_consistency sysctl is enable\n");
+                       return -EPERM;
                }
 
-               if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
-                       return -EINVAL;
+               if (sk->sk_protocol != IPPROTO_TCP)
+                       return -ENOPROTOOPT;
+               np->repflow = 1;
+               return 0;
+       }
 
-               if (net->ipv6.sysctl.flowlabel_state_ranges &&
-                   (freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
-                       return -ERANGE;
+       if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
+               return -EINVAL;
+       if (net->ipv6.sysctl.flowlabel_state_ranges &&
+           (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
+               return -ERANGE;
 
-               fl = fl_create(net, sk, &freq, optval, optlen, &err);
-               if (!fl)
-                       return err;
-               sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
+       fl = fl_create(net, sk, freq, optval, optlen, &err);
+       if (!fl)
+               return err;
 
-               if (freq.flr_label) {
-                       err = -EEXIST;
-                       rcu_read_lock_bh();
-                       for_each_sk_fl_rcu(np, sfl) {
-                               if (sfl->fl->label == freq.flr_label) {
-                                       if (freq.flr_flags&IPV6_FL_F_EXCL) {
-                                               rcu_read_unlock_bh();
-                                               goto done;
-                                       }
-                                       fl1 = sfl->fl;
-                                       if (!atomic_inc_not_zero(&fl1->users))
-                                               fl1 = NULL;
-                                       break;
+       sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
+
+       if (freq->flr_label) {
+               err = -EEXIST;
+               rcu_read_lock_bh();
+               for_each_sk_fl_rcu(np, sfl) {
+                       if (sfl->fl->label == freq->flr_label) {
+                               if (freq->flr_flags & IPV6_FL_F_EXCL) {
+                                       rcu_read_unlock_bh();
+                                       goto done;
                                }
+                               fl1 = sfl->fl;
+                               if (!atomic_inc_not_zero(&fl1->users))
+                                       fl1 = NULL;
+                               break;
                        }
-                       rcu_read_unlock_bh();
+               }
+               rcu_read_unlock_bh();
 
-                       if (!fl1)
-                               fl1 = fl_lookup(net, freq.flr_label);
-                       if (fl1) {
+               if (!fl1)
+                       fl1 = fl_lookup(net, freq->flr_label);
+               if (fl1) {
 recheck:
-                               err = -EEXIST;
-                               if (freq.flr_flags&IPV6_FL_F_EXCL)
-                                       goto release;
-                               err = -EPERM;
-                               if (fl1->share == IPV6_FL_S_EXCL ||
-                                   fl1->share != fl->share ||
-                                   ((fl1->share == IPV6_FL_S_PROCESS) &&
-                                    (fl1->owner.pid != fl->owner.pid)) ||
-                                   ((fl1->share == IPV6_FL_S_USER) &&
-                                    !uid_eq(fl1->owner.uid, fl->owner.uid)))
-                                       goto release;
-
-                               err = -ENOMEM;
-                               if (!sfl1)
-                                       goto release;
-                               if (fl->linger > fl1->linger)
-                                       fl1->linger = fl->linger;
-                               if ((long)(fl->expires - fl1->expires) > 0)
-                                       fl1->expires = fl->expires;
-                               fl_link(np, sfl1, fl1);
-                               fl_free(fl);
-                               return 0;
+                       err = -EEXIST;
+                       if (freq->flr_flags&IPV6_FL_F_EXCL)
+                               goto release;
+                       err = -EPERM;
+                       if (fl1->share == IPV6_FL_S_EXCL ||
+                           fl1->share != fl->share ||
+                           ((fl1->share == IPV6_FL_S_PROCESS) &&
+                            (fl1->owner.pid != fl->owner.pid)) ||
+                           ((fl1->share == IPV6_FL_S_USER) &&
+                            !uid_eq(fl1->owner.uid, fl->owner.uid)))
+                               goto release;
+
+                       err = -ENOMEM;
+                       if (!sfl1)
+                               goto release;
+                       if (fl->linger > fl1->linger)
+                               fl1->linger = fl->linger;
+                       if ((long)(fl->expires - fl1->expires) > 0)
+                               fl1->expires = fl->expires;
+                       fl_link(np, sfl1, fl1);
+                       fl_free(fl);
+                       return 0;
 
 release:
-                               fl_release(fl1);
-                               goto done;
-                       }
-               }
-               err = -ENOENT;
-               if (!(freq.flr_flags&IPV6_FL_F_CREATE))
+                       fl_release(fl1);
                        goto done;
+               }
+       }
+       err = -ENOENT;
+       if (!(freq->flr_flags & IPV6_FL_F_CREATE))
+               goto done;
 
-               err = -ENOMEM;
-               if (!sfl1)
-                       goto done;
+       err = -ENOMEM;
+       if (!sfl1)
+               goto done;
 
-               err = mem_check(sk);
-               if (err != 0)
-                       goto done;
+       err = mem_check(sk);
+       if (err != 0)
+               goto done;
 
-               fl1 = fl_intern(net, fl, freq.flr_label);
-               if (fl1)
-                       goto recheck;
+       fl1 = fl_intern(net, fl, freq->flr_label);
+       if (fl1)
+               goto recheck;
 
-               if (!freq.flr_label) {
-                       if (copy_to_user(&((struct in6_flowlabel_req __user *) 
optval)->flr_label,
-                                        &fl->label, sizeof(fl->label))) {
-                               /* Intentionally ignore fault. */
-                       }
+       if (!freq->flr_label) {
+               if (copy_to_user(&((struct in6_flowlabel_req __user *) 
optval)->flr_label,
+                                &fl->label, sizeof(fl->label))) {
+                       /* Intentionally ignore fault. */
                }
-
-               fl_link(np, sfl1, fl);
-               return 0;
-
-       default:
-               return -EINVAL;
        }
 
+       fl_link(np, sfl1, fl);
+       return 0;
 done:
        fl_free(fl);
        kfree(sfl1);
        return err;
 }
 
+int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
+{
+       struct in6_flowlabel_req freq;
+
+       if (optlen < sizeof(freq))
+               return -EINVAL;
+       if (copy_from_user(&freq, optval, sizeof(freq)))
+               return -EFAULT;
+
+       switch (freq.flr_action) {
+       case IPV6_FL_A_PUT:
+               return ipv6_flowlabel_put(sk, &freq);
+       case IPV6_FL_A_RENEW:
+               return ipv6_flowlabel_renew(sk, &freq);
+       case IPV6_FL_A_GET:
+               return ipv6_flowlabel_get(sk, &freq, optval, optlen);
+       default:
+               return -EINVAL;
+       }
+}
+
 #ifdef CONFIG_PROC_FS
 
 struct ip6fl_iter_state {
-- 
2.27.0