[PATCH v2 2/2] mac80211_hwsim: allow configurable cipher types

[James Prestwood]

The mac80211_hwsim driver does not specify supported cipher types, which
in turn enables all ciphers to be supported in software. (see
net/mac80211/main.c:ieee80211_init_cipher_suites). Allowing ciphers
to be configurable is valuable for simulating older drivers that may
not support all ciphers.

This patch adds a new attribute:

 - HWSIM_ATTR_CIPHER_SUPPORT
        A u32 array/list of supported cipher types

This only allows enabling/disabling cipher types listed in the (new)
"hwsim_ciphers" array in mac80211_hwsim.c. Any unknown cipher type
will result in -EINVAL.

Signed-off-by: James Prestwood <james.prestw...@linux.intel.com>
---
 drivers/net/wireless/mac80211_hwsim.c | 64 +++++++++++++++++++++++++++
 drivers/net/wireless/mac80211_hwsim.h |  2 +
 2 files changed, 66 insertions(+)

diff --git a/drivers/net/wireless/mac80211_hwsim.c 
b/drivers/net/wireless/mac80211_hwsim.c
index 2e4dac2de187..b6b832a41286 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -371,6 +371,20 @@ static const struct ieee80211_rate hwsim_rates[] = {
        { .bitrate = 540 }
 };
 
+static const u32 hwsim_ciphers[] = {
+       WLAN_CIPHER_SUITE_WEP40,
+       WLAN_CIPHER_SUITE_WEP104,
+       WLAN_CIPHER_SUITE_TKIP,
+       WLAN_CIPHER_SUITE_CCMP,
+       WLAN_CIPHER_SUITE_CCMP_256,
+       WLAN_CIPHER_SUITE_GCMP,
+       WLAN_CIPHER_SUITE_GCMP_256,
+       WLAN_CIPHER_SUITE_AES_CMAC,
+       WLAN_CIPHER_SUITE_BIP_CMAC_256,
+       WLAN_CIPHER_SUITE_BIP_GMAC_128,
+       WLAN_CIPHER_SUITE_BIP_GMAC_256,
+};
+
 #define OUI_QCA 0x001374
 #define QCA_NL80211_SUBCMD_TEST 1
 enum qca_nl80211_vendor_subcmds {
@@ -474,6 +488,8 @@ struct mac80211_hwsim_data {
        struct ieee80211_iface_limit if_limits[3];
        int n_if_limits;
 
+       u32 ciphers[ARRAY_SIZE(hwsim_ciphers)];
+
        struct mac_address addresses[2];
        int channels, idx;
        bool use_chanctx;
@@ -602,6 +618,7 @@ static const struct nla_policy 
hwsim_genl_policy[HWSIM_ATTR_MAX + 1] = {
        [HWSIM_ATTR_FREQ] = { .type = NLA_U32 },
        [HWSIM_ATTR_PERM_ADDR] = { .type = NLA_UNSPEC, .len = ETH_ALEN },
        [HWSIM_ATTR_IFTYPE_SUPPORT] = { .type = NLA_U32 },
+       [HWSIM_ATTR_CIPHER_SUPPORT] = { .type = NLA_BINARY },
 };
 
 static void mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
@@ -2375,6 +2392,8 @@ struct hwsim_new_radio_params {
        bool no_vif;
        const u8 *perm_addr;
        u32 iftypes;
+       u32 *ciphers;
+       u8 n_ciphers;
 };
 
 static void hwsim_mcast_config_msg(struct sk_buff *mcast_skb,
@@ -2637,6 +2656,13 @@ static int mac80211_hwsim_new_radio(struct genl_info 
*info,
        hw->wiphy->iface_combinations = &data->if_combination;
        hw->wiphy->n_iface_combinations = 1;
 
+       if (param->ciphers) {
+               memcpy(data->ciphers, param->ciphers,
+                               param->n_ciphers * sizeof(u32));
+               hw->wiphy->cipher_suites = data->ciphers;
+               hw->wiphy->n_cipher_suites = param->n_ciphers;
+       }
+
        INIT_DELAYED_WORK(&data->roc_start, hw_roc_start);
        INIT_DELAYED_WORK(&data->roc_done, hw_roc_done);
        INIT_DELAYED_WORK(&data->hw_scan, hw_scan_work);
@@ -3184,6 +3210,29 @@ static int hwsim_register_received_nl(struct sk_buff 
*skb_2,
        return 0;
 }
 
+/* ensures ciphers only include ciphers listed in 'hwsim_ciphers' array */
+static int hwsim_validate_ciphers(const u32 *ciphers, int n_ciphers)
+{
+       int i;
+
+       for (i = 0; i < n_ciphers; i++) {
+               int j;
+               int found = 0;
+
+               for (j = 0; j < ARRAY_SIZE(hwsim_ciphers); j++) {
+                       if (ciphers[i] == hwsim_ciphers[j]) {
+                               found = 1;
+                               break;
+                       }
+               }
+
+               if (!found)
+                       return -1;
+       }
+
+       return 0;
+}
+
 static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info)
 {
        struct hwsim_new_radio_params param = { 0 };
@@ -3266,6 +3315,21 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, 
struct genl_info *info)
                param.p2p_device = true;
        }
 
+       if (info->attrs[HWSIM_ATTR_CIPHER_SUPPORT]) {
+               param.ciphers = nla_data(
+                                       info->attrs[HWSIM_ATTR_CIPHER_SUPPORT]);
+               param.n_ciphers = nla_len(
+                                       info->attrs[HWSIM_ATTR_CIPHER_SUPPORT]);
+
+               if (param.n_ciphers > sizeof(hwsim_ciphers))
+                       return -EINVAL;
+
+               param.n_ciphers /= sizeof(u32);
+
+               if (hwsim_validate_ciphers(param.ciphers, param.n_ciphers))
+                       return -EINVAL;
+       }
+
        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 3f6b670116d0..a1ef8457fad4 100644
--- a/drivers/net/wireless/mac80211_hwsim.h
+++ b/drivers/net/wireless/mac80211_hwsim.h
@@ -133,6 +133,7 @@ enum {
  *     rates of %HWSIM_ATTR_TX_INFO
  * @HWSIM_ATTR_PERM_ADDR: permanent mac address of new radio
  * @HWSIM_ATTR_IFTYPE_SUPPORT: u32 attribute of supported interface types bits
+ * @HWSIM_ATTR_CIPHER_SUPPORT: u32 array of supported cipher types
  * @__HWSIM_ATTR_MAX: enum limit
  */
 
@@ -162,6 +163,7 @@ enum {
        HWSIM_ATTR_TX_INFO_FLAGS,
        HWSIM_ATTR_PERM_ADDR,
        HWSIM_ATTR_IFTYPE_SUPPORT,
+       HWSIM_ATTR_CIPHER_SUPPORT,
        __HWSIM_ATTR_MAX,
 };
 #define HWSIM_ATTR_MAX (__HWSIM_ATTR_MAX - 1)
-- 
2.17.1