update erp information element in the beacon frame to reflect

changes in the bss

Reviewed by:	avatar
Obtained from:	atheros
MFC after:	2 weeks

4 files changed, 21 insertions, 4 deletions

diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c
index 254317ca..a26f860 100644
--- a/sys/net80211/ieee80211_node.c
+++ b/sys/net80211/ieee80211_node.c
@@ -2028,6 +2028,8 @@ ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
 			ic->ic_flags |= IEEE80211_F_USEBARKER;
 			ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
 		}
+		if (ic->ic_nonerpsta == 1)
+			ic->ic_flags_ext |= IEEE80211_FEXT_ERPUPDATE;
 	} else
 		ni->ni_flags |= IEEE80211_NODE_ERP;
 }
@@ -2143,6 +2145,7 @@ ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
 				ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
 				ic->ic_flags &= ~IEEE80211_F_USEBARKER;
 			}
+			ic->ic_flags_ext |= IEEE80211_FEXT_ERPUPDATE;
 		}
 	}
 }
diff --git a/sys/net80211/ieee80211_output.c b/sys/net80211/ieee80211_output.c
index ebcf6ec..fa2d529 100644
--- a/sys/net80211/ieee80211_output.c
+++ b/sys/net80211/ieee80211_output.c
@@ -1490,8 +1490,10 @@ ieee80211_beacon_alloc(struct ieee80211com *ic, struct ieee80211_node *ni,
 	}
 	if (ic->ic_flags & IEEE80211_F_WPA)
 		frm = ieee80211_add_wpa(frm, ic);
-	if (ic->ic_curmode == IEEE80211_MODE_11G)
+	if (ic->ic_curmode == IEEE80211_MODE_11G) {
+		bo->bo_erp = frm;
 		frm = ieee80211_add_erp(frm, ic);
+	}
 	efrm = ieee80211_add_xrates(frm, rs);
 	bo->bo_trailer_len = efrm - bo->bo_trailer;
 	m->m_pkthdr.len = m->m_len = efrm - mtod(m, u_int8_t *);
@@ -1616,10 +1618,13 @@ ieee80211_beacon_update(struct ieee80211com *ic, struct ieee80211_node *ni,
 			}
 			if (timlen != bo->bo_tim_len) {
 				/* copy up/down trailer */
-				ovbcopy(bo->bo_trailer, tie->tim_bitmap+timlen,
+				int adjust = tie->tim_bitmap+timlen
+					   - bo->bo_trailer;
+				ovbcopy(bo->bo_trailer, bo->bo_trailer+adjust,
 					bo->bo_trailer_len);
-				bo->bo_trailer = tie->tim_bitmap+timlen;
-				bo->bo_wme = bo->bo_trailer;
+				bo->bo_trailer += adjust;
+				bo->bo_wme += adjust;
+				bo->bo_erp += adjust;
 				bo->bo_tim_len = timlen;
 
 				/* update information element */
@@ -1646,6 +1651,13 @@ ieee80211_beacon_update(struct ieee80211com *ic, struct ieee80211_node *ni,
 			tie->tim_bitctl |= 1;
 		else
 			tie->tim_bitctl &= ~1;
+		if (ic->ic_flags_ext & IEEE80211_FEXT_ERPUPDATE) {
+			/*
+			 * ERP element needs updating.
+			 */
+			(void) ieee80211_add_erp(bo->bo_erp, ic);
+			ic->ic_flags_ext &= ~IEEE80211_FEXT_ERPUPDATE;
+		}
 	}
 	IEEE80211_BEACON_UNLOCK(ic);
 
diff --git a/sys/net80211/ieee80211_proto.h b/sys/net80211/ieee80211_proto.h
index ea05da8..4b8f6b4 100644
--- a/sys/net80211/ieee80211_proto.h
+++ b/sys/net80211/ieee80211_proto.h
@@ -237,6 +237,7 @@ struct ieee80211_beacon_offsets {
 	u_int8_t	*bo_trailer;	/* start of fixed-size trailer */
 	u_int16_t	bo_tim_len;	/* atim/dtim length in bytes */
 	u_int16_t	bo_trailer_len;	/* trailer length in bytes */
+	u_int8_t	*bo_erp;	/* start of ERP element */
 };
 struct mbuf *ieee80211_beacon_alloc(struct ieee80211com *,
 		struct ieee80211_node *, struct ieee80211_beacon_offsets *);
diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h
index aecde3c..11aaacf 100644
--- a/sys/net80211/ieee80211_var.h
+++ b/sys/net80211/ieee80211_var.h
@@ -246,6 +246,7 @@ struct ieee80211com {
 #define	IEEE80211_FEXT_WDS	0x00000001	/* CONF: 4 addr allowed */
 /* 0x00000006 reserved */
 #define	IEEE80211_FEXT_BGSCAN	0x00000008	/* STATUS: enable full bgscan completion */
+#define	IEEE80211_FEXT_ERPUPDATE 0x00000200	/* STATUS: update ERP element */
 
 /* ic_caps */
 #define	IEEE80211_C_WEP		0x00000001	/* CAPABILITY: WEP available */