wireless: Use first phyX name available when registering phy devices.

Choose first available phyX name when creating phy devices.  This
means that reloading a wifi driver will not cause a change in the
name of it's phy device.

Also, allow users to rename a phy to any un-used name, including
phy%d.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 30 insertions, 24 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 9c21ebf9780e..1684ad91763c 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -178,26 +178,10 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
                         char *newname)
 {
         struct cfg80211_registered_device *rdev2;
-        int wiphy_idx, taken = -1, result, digits;
+        int result;
 
         assert_cfg80211_lock();
 
-        /* prohibit calling the thing phy%d when %d is not its number */
-        sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
-        if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
-                /* count number of places needed to print wiphy_idx */
-                digits = 1;
-                while (wiphy_idx /= 10)
-                        digits++;
-                /*
-                 * deny the name if it is phy<idx> where <idx> is printed
-                 * without leading zeroes. taken == strlen(newname) here
-                 */
-                if (taken == strlen(PHY_NAME) + digits)
-                        return -EINVAL;
-        }
-
-
         /* Ignore nop renames */
         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
                 return 0;
@@ -205,7 +189,7 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
         /* Ensure another device does not already have this name. */
         list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
                 if (strcmp(newname, dev_name(&rdev2->wiphy.dev)) == 0)
-                        return -EINVAL;
+                        return -EEXIST;
 
         result = device_rename(&rdev->wiphy.dev, newname);
         if (result)
@@ -320,9 +304,11 @@ static void cfg80211_event_work(struct work_struct *work)
 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 {
         static int wiphy_counter;
-
-        struct cfg80211_registered_device *rdev;
+        int i;
+        struct cfg80211_registered_device *rdev, *rdev2;
         int alloc_size;
+        char nname[IFNAMSIZ + 1];
+        bool found = false;
 
         WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
         WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
@@ -346,16 +332,36 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 
         if (unlikely(!wiphy_idx_valid(rdev->wiphy_idx))) {
                 wiphy_counter--;
+                goto too_many_devs;
+        }
+
+        /* 64k wiphy devices is enough for anyone! */
+        for (i = 0; i < 0xFFFF; i++) {
+                found = false;
+                snprintf(nname, sizeof(nname)-1, PHY_NAME "%d", i);
+                nname[sizeof(nname)-1] = 0;
+                list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
+                        if (strcmp(nname, dev_name(&rdev2->wiphy.dev)) == 0) {
+                                found = true;
+                                break;
+                        }
+
+                if (!found)
+                        break;
+        }
+
+        if (unlikely(found)) {
+too_many_devs:
                 mutex_unlock(&cfg80211_mutex);
-                /* ugh, wrapped! */
+                /* ugh, too many devices already! */
                 kfree(rdev);
                 return NULL;
         }
 
-        mutex_unlock(&cfg80211_mutex);
-
         /* give it a proper name */
-        dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+        dev_set_name(&rdev->wiphy.dev, "%s", nname);
+
+        mutex_unlock(&cfg80211_mutex);
 
         mutex_init(&rdev->mtx);
         mutex_init(&rdev->devlist_mtx);