mac80211_hwsim: add permanent mac address option for new radios

If simulation needs predictable permanent mac addresses of hwsim wireless
phy, this patch add the ability to create a new radio with a user defined
permanent mac address. Allowed mac addresses needs to be locally
administrated mac addresses (as also the former fixed 42:* and 02:* were).

To do not break the operation with legacy software using hwsim, the new
address is set twice. The problem here is, the netlink call backs use
wiphy->addresses[1] as identification of a radio and not the proposed
permanent address (wiphy->addresses[0]). This design decision is not
documented in the kernel repo, therefore this patch simply reproduces this,
but with the same address.

Signed-off-by: Benjamin Beichler <benjamin.beichler@uni-rostock.de>
[make pointer const]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 1cf22e62e3dddafcbf3136f8ba07aa397b9bb088..12b727ba9dec6b973298743404d00e1da0f7aa4a 100644 (file)
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -637,6 +637,7 @@ static const struct nla_policy hwsim_genl_policy[HWSIM_ATTR_MAX + 1] = {
        [HWSIM_ATTR_RADIO_NAME] = { .type = NLA_STRING },
        [HWSIM_ATTR_NO_VIF] = { .type = NLA_FLAG },
        [HWSIM_ATTR_FREQ] = { .type = NLA_U32 },
+       [HWSIM_ATTR_PERM_ADDR] = { .type = NLA_UNSPEC, .len = ETH_ALEN },
 };
 
 static void mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
@@ -2408,6 +2409,7 @@ struct hwsim_new_radio_params {
        bool destroy_on_close;
        const char *hwname;
        bool no_vif;
+       const u8 *perm_addr;
 };
 
 static void hwsim_mcast_config_msg(struct sk_buff *mcast_skb,
@@ -2572,15 +2574,25 @@ static int mac80211_hwsim_new_radio(struct genl_info *info,
        skb_queue_head_init(&data->pending);
 
        SET_IEEE80211_DEV(hw, data->dev);
-       eth_zero_addr(addr);
-       addr[0] = 0x02;
-       addr[3] = idx >> 8;
-       addr[4] = idx;
-       memcpy(data->addresses[0].addr, addr, ETH_ALEN);
-       memcpy(data->addresses[1].addr, addr, ETH_ALEN);
-       data->addresses[1].addr[0] |= 0x40;
-       hw->wiphy->n_addresses = 2;
-       hw->wiphy->addresses = data->addresses;
+       if (!param->perm_addr) {
+               eth_zero_addr(addr);
+               addr[0] = 0x02;
+               addr[3] = idx >> 8;
+               addr[4] = idx;
+               memcpy(data->addresses[0].addr, addr, ETH_ALEN);
+               /* Why need here second address ? */
+               data->addresses[1].addr[0] |= 0x40;
+               memcpy(data->addresses[1].addr, addr, ETH_ALEN);
+               hw->wiphy->n_addresses = 2;
+               hw->wiphy->addresses = data->addresses;
+               /* possible address clash is checked at hash table insertion */
+       } else {
+               memcpy(data->addresses[0].addr, param->perm_addr, ETH_ALEN);
+               /* compatibility with automatically generated mac addr */
+               memcpy(data->addresses[1].addr, param->perm_addr, ETH_ALEN);
+               hw->wiphy->n_addresses = 2;
+               hw->wiphy->addresses = data->addresses;
+       }
 
        data->channels = param->channels;
        data->use_chanctx = param->use_chanctx;
@@ -3210,6 +3222,19 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info)
                param.regd = hwsim_world_regdom_custom[idx];
        }
 
+       if (info->attrs[HWSIM_ATTR_PERM_ADDR]) {
+               if (!is_valid_ether_addr(
+                               nla_data(info->attrs[HWSIM_ATTR_PERM_ADDR]))) {
+                       GENL_SET_ERR_MSG(info,"MAC is no valid source addr");
+                       NL_SET_BAD_ATTR(info->extack,
+                                       info->attrs[HWSIM_ATTR_PERM_ADDR]);
+                       return -EINVAL;
+               }
+
+
+               param.perm_addr = nla_data(info->attrs[HWSIM_ATTR_PERM_ADDR]);
+       }
+
        ret = mac80211_hwsim_new_radio(info, &param);
        kfree(hwname);
        return ret;

diff --git a/drivers/net/wireless/mac80211_hwsim.h b/drivers/net/wireless/mac80211_hwsim.h
index a96a79c1eff5d4c6d4f615b075a6cfb6a5e0c991..0fe3199f8c72f832da345fe11ba76d7d081ad41d 100644 (file)
--- a/drivers/net/wireless/mac80211_hwsim.h
+++ b/drivers/net/wireless/mac80211_hwsim.h
@@ -68,7 +68,12 @@ enum hwsim_tx_control_flags {
  *     %HWSIM_ATTR_SIGNAL, %HWSIM_ATTR_COOKIE
  * @HWSIM_CMD_NEW_RADIO: create a new radio with the given parameters,
  *     returns the radio ID (>= 0) or negative on errors, if successful
- *     then multicast the result
+ *     then multicast the result, uses optional parameter:
+ *     %HWSIM_ATTR_REG_STRICT_REG, %HWSIM_ATTR_SUPPORT_P2P_DEVICE,
+ *     %HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE, %HWSIM_ATTR_CHANNELS,
+ *     %HWSIM_ATTR_NO_VIF, %HWSIM_ATTR_RADIO_NAME, %HWSIM_ATTR_USE_CHANCTX,
+ *     %HWSIM_ATTR_REG_HINT_ALPHA2, %HWSIM_ATTR_REG_CUSTOM_REG,
+ *     %HWSIM_ATTR_PERM_ADDR
  * @HWSIM_CMD_DEL_RADIO: destroy a radio, reply is multicasted
  * @HWSIM_CMD_GET_RADIO: fetch information about existing radios, uses:
  *     %HWSIM_ATTR_RADIO_ID
@@ -126,6 +131,7 @@ enum {
  * @HWSIM_ATTR_FREQ: Frequency at which packet is transmitted or received.
  * @HWSIM_ATTR_TX_INFO_FLAGS: additional flags for corresponding
  *     rates of %HWSIM_ATTR_TX_INFO
+ * @HWSIM_ATTR_PERM_ADDR: permanent mac address of new radio
  * @__HWSIM_ATTR_MAX: enum limit
  */
 
@@ -153,6 +159,7 @@ enum {
        HWSIM_ATTR_FREQ,
        HWSIM_ATTR_PAD,
        HWSIM_ATTR_TX_INFO_FLAGS,
+       HWSIM_ATTR_PERM_ADDR,
        __HWSIM_ATTR_MAX,
 };
 #define HWSIM_ATTR_MAX (__HWSIM_ATTR_MAX - 1)