[PATCH 5/9] sit: refactor ipip6_tunnel_ioctl

From: Christoph Hellwig
Date: Mon May 18 2020 - 07:48:10 EST


Split the ioctl handler into one function per command instead of having
a all the logic sit in one giant switch statement.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
net/ipv6/sit.c | 368 ++++++++++++++++++++++++++++---------------------
1 file changed, 210 insertions(+), 158 deletions(-)

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 98954830c40ba..2909b2c53eaad 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -83,6 +83,13 @@ struct sit_net {
struct net_device *fb_tunnel_dev;
};

+static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ return net_generic(t->net, sit_net_id);
+}
+
/*
* Must be invoked with rcu_read_lock
*/
@@ -291,14 +298,18 @@ __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)

}

-static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
- struct ip_tunnel_prl __user *a)
+static int ipip6_tunnel_get_prl(struct net_device *dev, struct ifreq *ifr)
{
+ struct ip_tunnel_prl __user *a = ifr->ifr_ifru.ifru_data;
+ struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_prl kprl, *kp;
struct ip_tunnel_prl_entry *prl;
unsigned int cmax, c = 0, ca, len;
int ret = 0;

+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
+ return -EINVAL;
+
if (copy_from_user(&kprl, a, sizeof(kprl)))
return -EFAULT;
cmax = kprl.datalen / sizeof(kprl);
@@ -441,6 +452,35 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
return err;
}

+static int ipip6_tunnel_prl_ctl(struct net_device *dev, struct ifreq *ifr,
+ int cmd)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_prl prl;
+ int err;
+
+ if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
+ return -EINVAL;
+
+ if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
+ return -EFAULT;
+
+ switch (cmd) {
+ case SIOCDELPRL:
+ err = ipip6_tunnel_del_prl(t, &prl);
+ break;
+ case SIOCADDPRL:
+ case SIOCCHGPRL:
+ err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
+ break;
+ }
+ dst_cache_reset(&t->dst_cache);
+ netdev_state_change(dev);
+ return 0;
+}
+
static int
isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
{
@@ -1151,7 +1191,53 @@ static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
netdev_state_change(t->dev);
return 0;
}
-#endif
+
+static int
+ipip6_tunnel_get6rd(struct net_device *dev, struct ifreq *ifr)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_6rd ip6rd;
+ struct ip_tunnel_parm p;
+
+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ return -EFAULT;
+ t = ipip6_tunnel_locate(t->net, &p, 0);
+ }
+ if (!t)
+ t = netdev_priv(dev);
+
+ ip6rd.prefix = t->ip6rd.prefix;
+ ip6rd.relay_prefix = t->ip6rd.relay_prefix;
+ ip6rd.prefixlen = t->ip6rd.prefixlen;
+ ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, sizeof(ip6rd)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+ipip6_tunnel_6rdctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_6rd ip6rd;
+ int err;
+
+ if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, sizeof(ip6rd)))
+ return -EFAULT;
+
+ if (cmd != SIOCDEL6RD) {
+ err = ipip6_tunnel_update_6rd(t, &ip6rd);
+ if (err < 0)
+ return err;
+ } else
+ ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
+ return 0;
+}
+
+#endif /* CONFIG_IPV6_SIT_6RD */

static bool ipip6_valid_ip_proto(u8 ipproto)
{
@@ -1164,185 +1250,151 @@ static bool ipip6_valid_ip_proto(u8 ipproto)
}

static int
-ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
{
- int err = 0;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (!ipip6_valid_ip_proto(p->iph.protocol))
+ return -EINVAL;
+ if (p->iph.version != 4 ||
+ p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
+ return -EINVAL;
+
+ if (p->iph.ttl)
+ p->iph.frag_off |= htons(IP_DF);
+ return 0;
+}
+
+static int
+ipip6_tunnel_get(struct net_device *dev, struct ifreq *ifr)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_parm p;
- struct ip_tunnel_prl prl;
+
+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ return -EFAULT;
+ t = ipip6_tunnel_locate(t->net, &p, 0);
+ }
+ if (!t)
+ t = netdev_priv(dev);
+
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+ipip6_tunnel_add(struct net_device *dev, struct ifreq *ifr)
+{
struct ip_tunnel *t = netdev_priv(dev);
- struct net *net = t->net;
- struct sit_net *sitn = net_generic(net, sit_net_id);
-#ifdef CONFIG_IPV6_SIT_6RD
- struct ip_tunnel_6rd ip6rd;
-#endif
+ struct ip_tunnel_parm p;
+ int err;

- switch (cmd) {
- case SIOCGETTUNNEL:
-#ifdef CONFIG_IPV6_SIT_6RD
- case SIOCGET6RD:
-#endif
- if (dev == sitn->fb_tunnel_dev) {
- if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
- err = -EFAULT;
- break;
- }
- t = ipip6_tunnel_locate(net, &p, 0);
- if (!t)
- t = netdev_priv(dev);
- }
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ return -EFAULT;
+ err = __ipip6_tunnel_ioctl_validate(t->net, &p);
+ if (err)
+ return err;

- err = -EFAULT;
- if (cmd == SIOCGETTUNNEL) {
- memcpy(&p, &t->parms, sizeof(p));
- if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
- sizeof(p)))
- goto done;
-#ifdef CONFIG_IPV6_SIT_6RD
+ t = ipip6_tunnel_locate(t->net, &p, 1);
+ if (!t)
+ return -ENOBUFS;
+
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+ipip6_tunnel_change(struct net_device *dev, struct ifreq *ifr)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_parm p;
+ int err;
+
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ return -EFAULT;
+ err = __ipip6_tunnel_ioctl_validate(t->net, &p);
+ if (err)
+ return err;
+
+ t = ipip6_tunnel_locate(t->net, &p, 0);
+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
+ if (!t)
+ return -ENOENT;
+ } else {
+ if (t) {
+ if (t->dev != dev)
+ return -EEXIST;
} else {
- ip6rd.prefix = t->ip6rd.prefix;
- ip6rd.relay_prefix = t->ip6rd.relay_prefix;
- ip6rd.prefixlen = t->ip6rd.prefixlen;
- ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
- if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
- sizeof(ip6rd)))
- goto done;
-#endif
+ if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
+ (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
+ return -EINVAL;
+ t = netdev_priv(dev);
}
- err = 0;
- break;

- case SIOCADDTUNNEL:
- case SIOCCHGTUNNEL:
- err = -EPERM;
- if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
- goto done;
+ ipip6_tunnel_update(t, &p, t->fwmark);
+ }

- err = -EFAULT;
- if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
- goto done;
-
- err = -EINVAL;
- if (!ipip6_valid_ip_proto(p.iph.protocol))
- goto done;
- if (p.iph.version != 4 ||
- p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
- goto done;
- if (p.iph.ttl)
- p.iph.frag_off |= htons(IP_DF);
-
- t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
-
- if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
- if (t) {
- if (t->dev != dev) {
- err = -EEXIST;
- break;
- }
- } else {
- if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
- (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
- err = -EINVAL;
- break;
- }
- t = netdev_priv(dev);
- }
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+ return -EFAULT;
+ return 0;
+}

- ipip6_tunnel_update(t, &p, t->fwmark);
- }
+static int
+ipip6_tunnel_del(struct net_device *dev, struct ifreq *ifr)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_parm p;

- if (t) {
- err = 0;
- if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
- err = -EFAULT;
- } else
- err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
- break;
+ if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;

- case SIOCDELTUNNEL:
- err = -EPERM;
- if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
- goto done;
-
- if (dev == sitn->fb_tunnel_dev) {
- err = -EFAULT;
- if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
- goto done;
- err = -ENOENT;
- t = ipip6_tunnel_locate(net, &p, 0);
- if (!t)
- goto done;
- err = -EPERM;
- if (t == netdev_priv(sitn->fb_tunnel_dev))
- goto done;
- dev = t->dev;
- }
- unregister_netdevice(dev);
- err = 0;
- break;
+ if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ return -EFAULT;
+ t = ipip6_tunnel_locate(t->net, &p, 0);
+ if (!t)
+ return -ENOENT;
+ if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
+ return -EPERM;
+ dev = t->dev;
+ }
+ unregister_netdevice(dev);
+ return 0;
+}

+static int
+ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ switch (cmd) {
+ case SIOCGETTUNNEL:
+ return ipip6_tunnel_get(dev, ifr);
+ case SIOCADDTUNNEL:
+ return ipip6_tunnel_add(dev, ifr);
+ case SIOCCHGTUNNEL:
+ return ipip6_tunnel_change(dev, ifr);
+ case SIOCDELTUNNEL:
+ return ipip6_tunnel_del(dev, ifr);
case SIOCGETPRL:
- err = -EINVAL;
- if (dev == sitn->fb_tunnel_dev)
- goto done;
- err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
- break;
-
+ return ipip6_tunnel_get_prl(dev, ifr);
case SIOCADDPRL:
case SIOCDELPRL:
case SIOCCHGPRL:
- err = -EPERM;
- if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
- goto done;
- err = -EINVAL;
- if (dev == sitn->fb_tunnel_dev)
- goto done;
- err = -EFAULT;
- if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
- goto done;
-
- switch (cmd) {
- case SIOCDELPRL:
- err = ipip6_tunnel_del_prl(t, &prl);
- break;
- case SIOCADDPRL:
- case SIOCCHGPRL:
- err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
- break;
- }
- dst_cache_reset(&t->dst_cache);
- netdev_state_change(dev);
- break;
-
+ return ipip6_tunnel_prl_ctl(dev, ifr, cmd);
#ifdef CONFIG_IPV6_SIT_6RD
+ case SIOCGET6RD:
+ return ipip6_tunnel_get6rd(dev, ifr);
case SIOCADD6RD:
case SIOCCHG6RD:
case SIOCDEL6RD:
- err = -EPERM;
- if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
- goto done;
-
- err = -EFAULT;
- if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
- sizeof(ip6rd)))
- goto done;
-
- if (cmd != SIOCDEL6RD) {
- err = ipip6_tunnel_update_6rd(t, &ip6rd);
- if (err < 0)
- goto done;
- } else
- ipip6_tunnel_clone_6rd(dev, sitn);
-
- err = 0;
- break;
+ return ipip6_tunnel_6rdctl(dev, ifr, cmd);
#endif
-
default:
- err = -EINVAL;
+ return -EINVAL;
}
-
-done:
- return err;
}

static const struct net_device_ops ipip6_netdev_ops = {
--
2.26.2