From 330f4032e32741f7f604d742616e4aad86452f4d Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 18 Jul 2020 14:26:07 +0200 Subject: [PATCH] vlan: initialize device ifname earlier at creation time Avoids attempting to add the device with an empty string as ifname Signed-off-by: Felix Fietkau --- vlan.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/vlan.c b/vlan.c index 8748b30..6270d95 100644 --- a/vlan.c +++ b/vlan.c @@ -61,19 +61,9 @@ static int vlan_set_device_state(struct device *dev, bool up) return ret; } -static int vlan_dev_set_name(struct vlan_device *vldev, struct device *dev) -{ - char *name; - - name = alloca(strlen(dev->ifname) + sizeof(".2147483647\0")); - vldev->dev.hidden = dev->hidden; - sprintf(name, "%s.%d", dev->ifname, vldev->id); - - return device_set_ifname(&vldev->dev, name); -} - static void vlan_dev_cb(struct device_user *dep, enum device_event ev) { + char name[IFNAMSIZ + 1]; struct vlan_device *vldev; vldev = container_of(dep, struct vlan_device, dep); @@ -85,7 +75,10 @@ static void vlan_dev_cb(struct device_user *dep, enum device_event ev) device_set_present(&vldev->dev, false); break; case DEV_EVENT_UPDATE_IFNAME: - if (vlan_dev_set_name(vldev, dep->dev) < 0) + vldev->dev.hidden = dep->dev->hidden; + if (snprintf(name, sizeof(name), "%s.%d", dep->dev->ifname, + vldev->id) >= sizeof(name) - 1 || + device_set_ifname(&vldev->dev, name)) free_vlan_if(&vldev->dev); break; case DEV_EVENT_TOPO_CHANGE: @@ -106,6 +99,7 @@ static struct device *get_vlan_device(struct device *dev, int id, bool create) }; struct vlan_device *vldev; struct device_user *dep; + char name[IFNAMSIZ + 1]; /* look for an existing interface before creating a new one */ list_for_each_entry(dep, &dev->users.list, list.list) { @@ -122,20 +116,22 @@ static struct device *get_vlan_device(struct device *dev, int id, bool create) if (!create) return NULL; - D(DEVICE, "Create vlan device '%s.%d'\n", dev->ifname, id); + if (snprintf(name, sizeof(name), "%s.%d", dev->ifname, id) >= sizeof(name) - 1) + return NULL; + + D(DEVICE, "Create vlan device '%s'\n", name); vldev = calloc(1, sizeof(*vldev)); if (!vldev) return NULL; vldev->id = id; + vldev->dev.hidden = dev->hidden; + strcpy(vldev->dev.ifname, name); if (device_init(&vldev->dev, &vlan_type, NULL) < 0) goto error; - if (vlan_dev_set_name(vldev, dev) < 0) - goto error; - vldev->dev.default_config = true; vldev->set_state = vldev->dev.set_state; -- 2.30.2