[PATCH 1/9] ipv4: streamline ipmr_new_tunnel

From: Christoph Hellwig
Date: Tue May 19 2020 - 09:04:43 EST


Reduce a few level of indentation to simplify the function.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
net/ipv4/ipmr.c | 73 ++++++++++++++++++++++++-------------------------
1 file changed, 36 insertions(+), 37 deletions(-)

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 5c218db2dede7..a1169b6941134 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -471,50 +471,49 @@ static bool ipmr_init_vif_indev(const struct net_device *dev)

static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
{
- struct net_device *dev;
+ struct net_device *tunnel_dev, *new_dev;
+ struct ip_tunnel_parm p = { };
+ mm_segment_t oldfs = get_fs();
+ struct ifreq ifr;
+ int err;

- dev = __dev_get_by_name(net, "tunl0");
+ tunnel_dev = __dev_get_by_name(net, "tunl0");
+ if (!tunnel_dev)
+ goto out;

- if (dev) {
- const struct net_device_ops *ops = dev->netdev_ops;
- int err;
- struct ifreq ifr;
- struct ip_tunnel_parm p;
+ p.iph.daddr = v->vifc_rmt_addr.s_addr;
+ p.iph.saddr = v->vifc_lcl_addr.s_addr;
+ p.iph.version = 4;
+ p.iph.ihl = 5;
+ p.iph.protocol = IPPROTO_IPIP;
+ sprintf(p.name, "dvmrp%d", v->vifc_vifi);
+ ifr.ifr_ifru.ifru_data = (__force void __user *)&p;

- memset(&p, 0, sizeof(p));
- p.iph.daddr = v->vifc_rmt_addr.s_addr;
- p.iph.saddr = v->vifc_lcl_addr.s_addr;
- p.iph.version = 4;
- p.iph.ihl = 5;
- p.iph.protocol = IPPROTO_IPIP;
- sprintf(p.name, "dvmrp%d", v->vifc_vifi);
- ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
+ if (!tunnel_dev->netdev_ops->ndo_do_ioctl)
+ goto out;

- if (ops->ndo_do_ioctl) {
- mm_segment_t oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = tunnel_dev->netdev_ops->ndo_do_ioctl(tunnel_dev, &ifr,
+ SIOCADDTUNNEL);
+ set_fs(oldfs);
+ if (err)
+ goto out;

- set_fs(KERNEL_DS);
- err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
- set_fs(oldfs);
- } else {
- err = -EOPNOTSUPP;
- }
- dev = NULL;
+ new_dev = __dev_get_by_name(net, p.name);
+ if (!new_dev)
+ goto out;

- if (err == 0 &&
- (dev = __dev_get_by_name(net, p.name)) != NULL) {
- dev->flags |= IFF_MULTICAST;
- if (!ipmr_init_vif_indev(dev))
- goto failure;
- if (dev_open(dev, NULL))
- goto failure;
- dev_hold(dev);
- }
- }
- return dev;
+ new_dev->flags |= IFF_MULTICAST;
+ if (!ipmr_init_vif_indev(new_dev))
+ goto out_unregister;
+ if (dev_open(new_dev, NULL))
+ goto out_unregister;
+ dev_hold(new_dev);
+ return new_dev;

-failure:
- unregister_netdevice(dev);
+out_unregister:
+ unregister_netdevice(new_dev);
+out:
return NULL;
}

--
2.26.2