cfg80211: Support multiple CSA counters

Change the type of NL80211_ATTR_CSA_C_OFF_BEACON and
NL80211_ATTR_CSA_C_OFF_PRESP to be NLA_BINARY which allows
userspace to use beacons and probe responses with
multiple CSA counters.
This isn't breaking the API since userspace can
continue to use nla_put_u16 for this attributes, which
is equivalent to a single element u16 array.
In addition advertise max number of supported CSA counters.
This is needed when using CSA and eCSA IEs together.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 66 insertions, 23 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 39788711ce6e..d03d8bdb29ca 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -402,6 +402,8 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
         rdev->wiphy.rts_threshold = (u32) -1;
         rdev->wiphy.coverage_class = 0;
 
+        rdev->wiphy.max_num_csa_counters = 1;
+
         return &rdev->wiphy;
 }
 EXPORT_SYMBOL(wiphy_new);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4c0ca40ef90e..ca19b1520389 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -371,8 +371,8 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
         [NL80211_ATTR_CH_SWITCH_COUNT] = { .type = NLA_U32 },
         [NL80211_ATTR_CH_SWITCH_BLOCK_TX] = { .type = NLA_FLAG },
         [NL80211_ATTR_CSA_IES] = { .type = NLA_NESTED },
-        [NL80211_ATTR_CSA_C_OFF_BEACON] = { .type = NLA_U16 },
-        [NL80211_ATTR_CSA_C_OFF_PRESP] = { .type = NLA_U16 },
+        [NL80211_ATTR_CSA_C_OFF_BEACON] = { .type = NLA_BINARY },
+        [NL80211_ATTR_CSA_C_OFF_PRESP] = { .type = NLA_BINARY },
         [NL80211_ATTR_STA_SUPPORTED_CHANNELS] = { .type = NLA_BINARY },
         [NL80211_ATTR_STA_SUPPORTED_OPER_CLASSES] = { .type = NLA_BINARY },
         [NL80211_ATTR_HANDLE_DFS] = { .type = NLA_FLAG },
@@ -1670,6 +1670,13 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
                         }
                         nla_nest_end(msg, nested);
                 }
+                state->split_start++;
+                break;
+        case 12:
+                if (rdev->wiphy.flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH &&
+                    nla_put_u8(msg, NL80211_ATTR_MAX_CSA_COUNTERS,
+                               rdev->wiphy.max_num_csa_counters))
+                        goto nla_put_failure;
 
                 /* done */
                 state->split_start = 0;
@@ -5864,6 +5871,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
         u8 radar_detect_width = 0;
         int err;
         bool need_new_beacon = false;
+        int len, i;
 
         if (!rdev->ops->channel_switch ||
             !(rdev->wiphy.flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
@@ -5922,26 +5930,55 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
         if (!csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON])
                 return -EINVAL;
 
-        params.counter_offset_beacon =
-                nla_get_u16(csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON]);
-        if (params.counter_offset_beacon >= params.beacon_csa.tail_len)
+        len = nla_len(csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON]);
+        if (!len || (len % sizeof(u16)))
                 return -EINVAL;
 
-        /* sanity check - counters should be the same */
-        if (params.beacon_csa.tail[params.counter_offset_beacon] !=
-            params.count)
+        params.n_counter_offsets_beacon = len / sizeof(u16);
+        if (rdev->wiphy.max_num_csa_counters &&
+            (params.n_counter_offsets_beacon >
+             rdev->wiphy.max_num_csa_counters))
                 return -EINVAL;
 
+        params.counter_offsets_beacon =
+                nla_data(csa_attrs[NL80211_ATTR_CSA_C_OFF_BEACON]);
+
+        /* sanity checks - counters should fit and be the same */
+        for (i = 0; i < params.n_counter_offsets_beacon; i++) {
+                u16 offset = params.counter_offsets_beacon[i];
+
+                if (offset >= params.beacon_csa.tail_len)
+                        return -EINVAL;
+
+                if (params.beacon_csa.tail[offset] != params.count)
+                        return -EINVAL;
+        }
+
         if (csa_attrs[NL80211_ATTR_CSA_C_OFF_PRESP]) {
-                params.counter_offset_presp =
-                        nla_get_u16(csa_attrs[NL80211_ATTR_CSA_C_OFF_PRESP]);
-                if (params.counter_offset_presp >=
-                    params.beacon_csa.probe_resp_len)
+                len = nla_len(csa_attrs[NL80211_ATTR_CSA_C_OFF_PRESP]);
+                if (!len || (len % sizeof(u16)))
                         return -EINVAL;
 
-                if (params.beacon_csa.probe_resp[params.counter_offset_presp] !=
-                    params.count)
+                params.n_counter_offsets_presp = len / sizeof(u16);
+                if (rdev->wiphy.max_num_csa_counters &&
+                    (params.n_counter_offsets_beacon >
+                     rdev->wiphy.max_num_csa_counters))
                         return -EINVAL;
+
+                params.counter_offsets_presp =
+                        nla_data(csa_attrs[NL80211_ATTR_CSA_C_OFF_PRESP]);
+
+                /* sanity checks - counters should fit and be the same */
+                for (i = 0; i < params.n_counter_offsets_presp; i++) {
+                        u16 offset = params.counter_offsets_presp[i];
+
+                        if (offset >= params.beacon_csa.probe_resp_len)
+                                return -EINVAL;
+
+                        if (params.beacon_csa.probe_resp[offset] !=
+                            params.count)
+                                return -EINVAL;
+                }
         }
 
 skip_beacons:
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index cdfbb00e1b37..560ed77084e9 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1876,29 +1876,33 @@ TRACE_EVENT(rdev_channel_switch,
                 WIPHY_ENTRY
                 NETDEV_ENTRY
                 CHAN_DEF_ENTRY
-                __field(u16, counter_offset_beacon)
-                __field(u16, counter_offset_presp)
                 __field(bool, radar_required)
                 __field(bool, block_tx)
                 __field(u8, count)
+                __dynamic_array(u16, bcn_ofs, params->n_counter_offsets_beacon)
+                __dynamic_array(u16, pres_ofs, params->n_counter_offsets_presp)
         ),
         TP_fast_assign(
                 WIPHY_ASSIGN;
                 NETDEV_ASSIGN;
                 CHAN_DEF_ASSIGN(&params->chandef);
-                __entry->counter_offset_beacon = params->counter_offset_beacon;
-                __entry->counter_offset_presp = params->counter_offset_presp;
                 __entry->radar_required = params->radar_required;
                 __entry->block_tx = params->block_tx;
                 __entry->count = params->count;
+                memcpy(__get_dynamic_array(bcn_ofs),
+                       params->counter_offsets_beacon,
+                       params->n_counter_offsets_beacon * sizeof(u16));
+
+                /* probe response offsets are optional */
+                if (params->n_counter_offsets_presp)
+                        memcpy(__get_dynamic_array(pres_ofs),
+                               params->counter_offsets_presp,
+                               params->n_counter_offsets_presp * sizeof(u16));
         ),
         TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " CHAN_DEF_PR_FMT
-                  ", block_tx: %d, count: %u, radar_required: %d"
-                  ", counter offsets (beacon/presp): %u/%u",
+                  ", block_tx: %d, count: %u, radar_required: %d",
                   WIPHY_PR_ARG, NETDEV_PR_ARG, CHAN_DEF_PR_ARG,
-                  __entry->block_tx, __entry->count, __entry->radar_required,
-                  __entry->counter_offset_beacon,
-                  __entry->counter_offset_presp)
+                  __entry->block_tx, __entry->count, __entry->radar_required)
 );
 
 TRACE_EVENT(rdev_set_qos_map,