From 37355565ba57fd45f78f0934305be2761b641f8f Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 16 Mar 2015 15:56:05 +0100 Subject: [PATCH] ip6_tunnel: fix error code when tunnel exists After commit 2b0bb01b6edb, the kernel returns -ENOBUFS when user tries to add an existing tunnel with ioctl API: $ ip -6 tunnel add ip6tnl1 mode ip6ip6 dev eth1 add tunnel "ip6tnl0" failed: No buffer space available It's confusing, the right error is EEXIST. This patch also change a bit the code returned: - ENOBUFS -> ENOMEM - ENOENT -> ENODEV Fixes: 2b0bb01b6edb ("ip6_tunnel: Return an error when adding an existing tunnel.") CC: Steffen Klassert Reported-by: Pierre Cheynier Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv6/ip6_tunnel.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 266a264ec212..ddd94eca19b3 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -314,7 +314,7 @@ out: * Create tunnel matching given parameters. * * Return: - * created tunnel or NULL + * created tunnel or error pointer **/ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) @@ -322,7 +322,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) struct net_device *dev; struct ip6_tnl *t; char name[IFNAMSIZ]; - int err; + int err = -ENOMEM; if (p->name[0]) strlcpy(name, p->name, IFNAMSIZ); @@ -348,7 +348,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) failed_free: ip6_dev_free(dev); failed: - return NULL; + return ERR_PTR(err); } /** @@ -362,7 +362,7 @@ failed: * tunnel device is created and registered for use. * * Return: - * matching tunnel or NULL + * matching tunnel or error pointer **/ static struct ip6_tnl *ip6_tnl_locate(struct net *net, @@ -380,13 +380,13 @@ static struct ip6_tnl *ip6_tnl_locate(struct net *net, if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr)) { if (create) - return NULL; + return ERR_PTR(-EEXIST); return t; } } if (!create) - return NULL; + return ERR_PTR(-ENODEV); return ip6_tnl_create(net, p); } @@ -1420,7 +1420,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) } ip6_tnl_parm_from_user(&p1, &p); t = ip6_tnl_locate(net, &p1, 0); - if (t == NULL) + if (IS_ERR(t)) t = netdev_priv(dev); } else { memset(&p, 0, sizeof(p)); @@ -1445,7 +1445,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) ip6_tnl_parm_from_user(&p1, &p); t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); if (cmd == SIOCCHGTUNNEL) { - if (t != NULL) { + if (!IS_ERR(t)) { if (t->dev != dev) { err = -EEXIST; break; @@ -1457,14 +1457,15 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) else err = ip6_tnl_update(t, &p1); } - if (t) { + if (!IS_ERR(t)) { err = 0; ip6_tnl_parm_to_user(&p, &t->parms); if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) err = -EFAULT; - } else - err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); + } else { + err = PTR_ERR(t); + } break; case SIOCDELTUNNEL: err = -EPERM; @@ -1478,7 +1479,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) err = -ENOENT; ip6_tnl_parm_from_user(&p1, &p); t = ip6_tnl_locate(net, &p1, 0); - if (t == NULL) + if (IS_ERR(t)) break; err = -EPERM; if (t->dev == ip6n->fb_tnl_dev) @@ -1672,12 +1673,13 @@ static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct net *net = dev_net(dev); - struct ip6_tnl *nt; + struct ip6_tnl *nt, *t; nt = netdev_priv(dev); ip6_tnl_netlink_parms(data, &nt->parms); - if (ip6_tnl_locate(net, &nt->parms, 0)) + t = ip6_tnl_locate(net, &nt->parms, 0); + if (!IS_ERR(t)) return -EEXIST; return ip6_tnl_create2(dev); @@ -1697,8 +1699,7 @@ static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[], ip6_tnl_netlink_parms(data, &p); t = ip6_tnl_locate(net, &p, 0); - - if (t) { + if (!IS_ERR(t)) { if (t->dev != dev) return -EEXIST; } else -- 2.20.1