vlan: fix device vlan alias handling

A recent commit changed the vlan chain handling to not treat devices with
non-digit characters after "." as vlan devices. This broke aliases, which
rely on names after the "." component.
Fix dealing with both cases by first trying to set up a vlan regardless
of the non-digit characters, but for the first component allow falling back
to treating the first two parts as a full device name

Fixes: 013a1171e9b0 ("device: do not treat devices with non-digit characters after . as vlan devices")
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/vlan.c b/vlan.c
index 401cc94b7808d629211e3429eac2dc83f8e4e302..23b20a954a7be058412c15cb59f0cb7175cd5551 100644 (file)
--- a/vlan.c
+++ b/vlan.c
@@ -239,16 +239,10 @@ error:
 
 static char *split_vlan(char *s)
 {
-retry:
        s = strchr(s, '.');
        if (!s)
                return NULL;
 
-       if (!isdigit(s[1])) {
-               s++;
-               goto retry;
-       }
-
        *s = 0;
        s++;
 
@@ -257,7 +251,7 @@ retry:
 
 struct device *get_vlan_device_chain(const char *ifname, int create)
 {
-       struct device *dev = NULL;
+       struct device *dev = NULL, *vldev;
        char *buf, *s, *next;
 
        buf = strdup(ifname);
@@ -266,9 +260,30 @@ struct device *get_vlan_device_chain(const char *ifname, int create)
 
        s = split_vlan(buf);
        dev = __device_get(buf, create, false);
-       if (!dev)
+       if (!dev || !s)
                goto out;
 
+       /* for the first split, we need to check if we're using an alias or
+        * if the . separator isn't being used as a vlan separator (e.g. for
+        * AP WDS VLANs */
+       if (!isdigit(s[0])) {
+               next = split_vlan(s);
+               vldev = get_vlan_device(dev, s, create);
+               if (!vldev) {
+                       s[-1] = '.';
+                       dev = __device_get(buf, create, false);
+                       if (!dev)
+                               goto out;
+
+                       if (next)
+                               next[-1] = '.';
+               } else {
+                       dev = vldev;
+                       s = next;
+               }
+       }
+
+
        while (s) {
                next = split_vlan(s);
                dev = get_vlan_device(dev, s, create);