nl80211: add packet offset information for wowlan pattern

If user knows the location of a wowlan pattern to be matched in
Rx packet, he can provide an offset with the pattern. This will
help drivers to ignore initial bytes and match the pattern
efficiently.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
[refactor pattern sending]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 60 insertions, 30 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 77686ca28948..d3a73818e44c 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1576,6 +1576,7 @@ struct cfg80211_pmksa {
  *      one bit per byte, in same format as nl80211
  * @pattern: bytes to match where bitmask is 1
  * @pattern_len: length of pattern (in bytes)
+ * @pkt_offset: packet offset (in bytes)
  *
  * Internal note: @mask and @pattern are allocated in one chunk of
  * memory, free @mask only!
@@ -1583,6 +1584,7 @@ struct cfg80211_pmksa {
 struct cfg80211_wowlan_trig_pkt_pattern {
         u8 *mask, *pattern;
         int pattern_len;
+        int pkt_offset;
 };
 
 /**
@@ -2290,12 +2292,14 @@ enum wiphy_wowlan_support_flags {
  *      (see nl80211.h for the pattern definition)
  * @pattern_max_len: maximum length of each pattern
  * @pattern_min_len: minimum length of each pattern
+ * @max_pkt_offset: maximum Rx packet offset
  */
 struct wiphy_wowlan_support {
         u32 flags;
         int n_patterns;
         int pattern_max_len;
         int pattern_min_len;
+        int max_pkt_offset;
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index b23321154e8b..eb7b32247ec5 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2910,6 +2910,8 @@ enum nl80211_tx_power_setting {
  *      Note that the pattern matching is done as though frames were not
  *      802.11 frames but 802.3 frames, i.e. the frame is fully unpacked
  *      first (including SNAP header unpacking) and then matched.
+ * @NL80211_WOWLAN_PKTPAT_OFFSET: packet offset, pattern is matched after
+ *      these fixed number of bytes of received packet
  * @NUM_NL80211_WOWLAN_PKTPAT: number of attributes
  * @MAX_NL80211_WOWLAN_PKTPAT: max attribute number
  */
@@ -2917,6 +2919,7 @@ enum nl80211_wowlan_packet_pattern_attr {
         __NL80211_WOWLAN_PKTPAT_INVALID,
         NL80211_WOWLAN_PKTPAT_MASK,
         NL80211_WOWLAN_PKTPAT_PATTERN,
+        NL80211_WOWLAN_PKTPAT_OFFSET,
 
         NUM_NL80211_WOWLAN_PKTPAT,
         MAX_NL80211_WOWLAN_PKTPAT = NUM_NL80211_WOWLAN_PKTPAT - 1,
@@ -2927,6 +2930,7 @@ enum nl80211_wowlan_packet_pattern_attr {
  * @max_patterns: maximum number of patterns supported
  * @min_pattern_len: minimum length of each pattern
  * @max_pattern_len: maximum length of each pattern
+ * @max_pkt_offset: maximum Rx packet offset
  *
  * This struct is carried in %NL80211_WOWLAN_TRIG_PKT_PATTERN when
  * that is part of %NL80211_ATTR_WOWLAN_TRIGGERS_SUPPORTED in the
@@ -2936,6 +2940,7 @@ struct nl80211_wowlan_pattern_support {
         __u32 max_patterns;
         __u32 min_pattern_len;
         __u32 max_pattern_len;
+        __u32 max_pkt_offset;
 } __attribute__((packed));
 
 /**
@@ -2951,9 +2956,10 @@ struct nl80211_wowlan_pattern_support {
  * @NL80211_WOWLAN_TRIG_PKT_PATTERN: wake up on the specified packet patterns
  *      which are passed in an array of nested attributes, each nested attribute
  *      defining a with attributes from &struct nl80211_wowlan_trig_pkt_pattern.
- *      Each pattern defines a wakeup packet. The matching is done on the MSDU,
- *      i.e. as though the packet was an 802.3 packet, so the pattern matching
- *      is done after the packet is converted to the MSDU.
+ *      Each pattern defines a wakeup packet. Packet offset is associated with
+ *      each pattern which is used while matching the pattern. The matching is
+ *      done on the MSDU, i.e. as though the packet was an 802.3 packet, so the
+ *      pattern matching is done after the packet is converted to the MSDU.
  *
  *      In %NL80211_ATTR_WOWLAN_TRIGGERS_SUPPORTED, it is a binary attribute
  *      carrying a &struct nl80211_wowlan_pattern_support.
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 93bc63eae076..cc0fad30b8c9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1238,6 +1238,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 portid, u32 seq, int flag
                                         dev->wiphy.wowlan.pattern_min_len,
                                 .max_pattern_len =
                                         dev->wiphy.wowlan.pattern_max_len,
+                                .max_pkt_offset =
+                                        dev->wiphy.wowlan.max_pkt_offset,
                         };
                         if (nla_put(msg, NL80211_WOWLAN_TRIG_PKT_PATTERN,
                                     sizeof(pat), &pat))
@@ -6895,6 +6897,39 @@ static int nl80211_leave_mesh(struct sk_buff *skb, struct genl_info *info)
 }
 
 #ifdef CONFIG_PM
+static int nl80211_send_wowlan_patterns(struct sk_buff *msg,
+                                        struct cfg80211_registered_device *rdev)
+{
+        struct nlattr *nl_pats, *nl_pat;
+        int i, pat_len;
+
+        if (!rdev->wowlan->n_patterns)
+                return 0;
+
+        nl_pats = nla_nest_start(msg, NL80211_WOWLAN_TRIG_PKT_PATTERN);
+        if (!nl_pats)
+                return -ENOBUFS;
+
+        for (i = 0; i < rdev->wowlan->n_patterns; i++) {
+                nl_pat = nla_nest_start(msg, i + 1);
+                if (!nl_pat)
+                        return -ENOBUFS;
+                pat_len = rdev->wowlan->patterns[i].pattern_len;
+                if (nla_put(msg, NL80211_WOWLAN_PKTPAT_MASK,
+                            DIV_ROUND_UP(pat_len, 8),
+                            rdev->wowlan->patterns[i].mask) ||
+                    nla_put(msg, NL80211_WOWLAN_PKTPAT_PATTERN,
+                            pat_len, rdev->wowlan->patterns[i].pattern) ||
+                    nla_put_u32(msg, NL80211_WOWLAN_PKTPAT_OFFSET,
+                                rdev->wowlan->patterns[i].pkt_offset))
+                        return -ENOBUFS;
+                nla_nest_end(msg, nl_pat);
+        }
+        nla_nest_end(msg, nl_pats);
+
+        return 0;
+}
+
 static int nl80211_get_wowlan(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -6935,32 +6970,8 @@ static int nl80211_get_wowlan(struct sk_buff *skb, struct genl_info *info)
                     (rdev->wowlan->rfkill_release &&
                      nla_put_flag(msg, NL80211_WOWLAN_TRIG_RFKILL_RELEASE)))
                         goto nla_put_failure;
-                if (rdev->wowlan->n_patterns) {
-                        struct nlattr *nl_pats, *nl_pat;
-                        int i, pat_len;
-
-                        nl_pats = nla_nest_start(msg,
-                                        NL80211_WOWLAN_TRIG_PKT_PATTERN);
-                        if (!nl_pats)
-                                goto nla_put_failure;
-
-                        for (i = 0; i < rdev->wowlan->n_patterns; i++) {
-                                nl_pat = nla_nest_start(msg, i + 1);
-                                if (!nl_pat)
-                                        goto nla_put_failure;
-                                pat_len = rdev->wowlan->patterns[i].pattern_len;
-                                if (nla_put(msg, NL80211_WOWLAN_PKTPAT_MASK,
-                                            DIV_ROUND_UP(pat_len, 8),
-                                            rdev->wowlan->patterns[i].mask) ||
-                                    nla_put(msg, NL80211_WOWLAN_PKTPAT_PATTERN,
-                                            pat_len,
-                                            rdev->wowlan->patterns[i].pattern))
-                                        goto nla_put_failure;
-                                nla_nest_end(msg, nl_pat);
-                        }
-                        nla_nest_end(msg, nl_pats);
-                }
-
+                if (nl80211_send_wowlan_patterns(msg, rdev))
+                        goto nla_put_failure;
                 nla_nest_end(msg, nl_wowlan);
         }
 
@@ -7046,7 +7057,7 @@ static int nl80211_set_wowlan(struct sk_buff *skb, struct genl_info *info)
         if (tb[NL80211_WOWLAN_TRIG_PKT_PATTERN]) {
                 struct nlattr *pat;
                 int n_patterns = 0;
-                int rem, pat_len, mask_len;
+                int rem, pat_len, mask_len, pkt_offset;
                 struct nlattr *pat_tb[NUM_NL80211_WOWLAN_PKTPAT];
 
                 nla_for_each_nested(pat, tb[NL80211_WOWLAN_TRIG_PKT_PATTERN],
@@ -7081,6 +7092,15 @@ static int nl80211_set_wowlan(struct sk_buff *skb, struct genl_info *info)
                             pat_len < wowlan->pattern_min_len)
                                 goto error;
 
+                        if (!pat_tb[NL80211_WOWLAN_PKTPAT_OFFSET])
+                                pkt_offset = 0;
+                        else
+                                pkt_offset = nla_get_u32(
+                                        pat_tb[NL80211_WOWLAN_PKTPAT_OFFSET]);
+                        if (pkt_offset > wowlan->max_pkt_offset)
+                                goto error;
+                        new_triggers.patterns[i].pkt_offset = pkt_offset;
+
                         new_triggers.patterns[i].mask =
                                 kmalloc(mask_len + pat_len, GFP_KERNEL);
                         if (!new_triggers.patterns[i].mask) {