[PATCH v2 1/6] cfg80211: support creating wiphy with suggested name.

[greearb-my8/4N5VtI7c+]

From: Ben Greear <greearb-my8/4N5VtI7c+***@public.gmane.org>

Kernel will attempt to use the name if it is supplied,
but if name cannot be used for some reason, the default
phyX name will be used instead.

Signed-off-by: Ben Greear <greearb-my8/4N5VtI7c+***@public.gmane.org>
---
include/net/cfg80211.h | 22 +++++++++++++++++++++-
net/wireless/core.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ed896c0..5252f80 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3193,6 +3193,7 @@ static inline const char *wiphy_name(const struct wiphy *wiphy)
*
* @ops: The configuration operations for this device
* @sizeof_priv: The size of the private area to allocate
+ * @requested_name Request a particular name.
*
* Create a new wiphy and associate the given operations with it.
* @sizeof_priv bytes are allocated for private use.
@@ -3200,7 +3201,26 @@ static inline const char *wiphy_name(const struct wiphy *wiphy)
* Return: A pointer to the new wiphy. This pointer must be
* assigned to each netdev's ieee80211_ptr for proper operation.
*/
-struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv);
+struct wiphy *wiphy_new_nm(const struct cfg80211_ops *ops, int sizeof_priv,
+ const char *requested_name);
+
+/**
+ * wiphy_new - create a new wiphy for use with cfg80211
+ *
+ * @ops: The configuration operations for this device
+ * @sizeof_priv: The size of the private area to allocate
+ *
+ * Create a new wiphy and associate the given operations with it.
+ * @sizeof_priv bytes are allocated for private use.
+ *
+ * Return: A pointer to the new wiphy. This pointer must be
+ * assigned to each netdev's ieee80211_ptr for proper operation.
+ */
+static inline struct wiphy *wiphy_new(const struct cfg80211_ops *ops,
+ int sizeof_priv)
+{
+ return wiphy_new_nm(ops, sizeof_priv, NULL);
+}

/**
* wiphy_register - register a wiphy with cfg80211
diff --git a/net/wireless/core.c b/net/wireless/core.c
index f52a4cd..2013edb 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -309,7 +309,8 @@ static void cfg80211_destroy_iface_wk(struct work_struct *work)

/* exported functions */

-struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
+struct wiphy *wiphy_new_nm(const struct cfg80211_ops *ops, int sizeof_priv,
+ const char *requested_name)
{
static atomic_t wiphy_counter = ATOMIC_INIT(0);

@@ -336,6 +337,7 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
rdev->wiphy_idx = atomic_inc_return(&wiphy_counter);

if (unlikely(rdev->wiphy_idx < 0)) {
+ /* TODO: Fix this someday. */
/* ugh, wrapped! */
atomic_dec(&wiphy_counter);
kfree(rdev);
@@ -346,7 +348,44 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
rdev->wiphy_idx--;

/* give it a proper name */
- dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+ if (requested_name && requested_name[0]) {
+ struct cfg80211_registered_device *rdev2;
+ int wiphy_idx, taken = -1, result, digits;
+
+ /* Code below is from cfg80211_dev_rename */
+ /* prohibit calling the thing phy%d when %d is not its number */
+ sscanf(requested_name, PHY_NAME "%d%n", &wiphy_idx, &taken);
+ if (taken == strlen(requested_name) &&
+ wiphy_idx != rdev->wiphy_idx) {
+ /* count number of places needed to print wiphy_idx */
+ digits = 1;
+ while (wiphy_idx /= 10)
+ digits++;
+ /*
+ * deny name if it is phy<idx> where <idx> is printed
+ * without leading zeroes. taken == strlen(newname) here
+ */
+ if (taken == strlen(PHY_NAME) + digits)
+ goto use_default_name;
+ }
+
+ rtnl_lock();
+ /* Ensure another device does not already have this name. */
+ list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
+ if (strcmp(requested_name, dev_name(&rdev2->wiphy.dev))
+ == 0) {
+ rtnl_unlock();
+ goto use_default_name;
+ }
+
+ result = dev_set_name(&rdev->wiphy.dev, requested_name);
+ rtnl_unlock();
+ if (result)
+ goto use_default_name;
+ } else {
+use_default_name:
+ dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+ }

INIT_LIST_HEAD(&rdev->wdev_list);
INIT_LIST_HEAD(&rdev->beacon_registrations);
@@ -406,7 +445,7 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)

return &rdev->wiphy;
}
-EXPORT_SYMBOL(wiphy_new);
+EXPORT_SYMBOL(wiphy_new_nm);

static int wiphy_verify_combinations(struct wiphy *wiphy)
{