diff options
| -rw-r--r-- | sys/net80211/ieee80211_input.c | 82 |
1 files changed, 47 insertions, 35 deletions
diff --git a/sys/net80211/ieee80211_input.c b/sys/net80211/ieee80211_input.c index d6161a5e6fa..2457e44d962 100644 --- a/sys/net80211/ieee80211_input.c +++ b/sys/net80211/ieee80211_input.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ieee80211_input.c,v 1.173 2016/04/28 13:58:00 stsp Exp $ */ +/* $OpenBSD: ieee80211_input.c,v 1.174 2016/04/28 15:00:27 stsp Exp $ */ /*- * Copyright (c) 2001 Atsushi Onoe @@ -67,6 +67,8 @@ void ieee80211_input_ba_flush(struct ieee80211com *, struct ieee80211_node *, void ieee80211_input_ba_gap_timeout(void *arg); void ieee80211_ba_move_window(struct ieee80211com *, struct ieee80211_node *, u_int8_t, u_int16_t); +void ieee80211_input_ba_seq(struct ieee80211com *, + struct ieee80211_node *, uint8_t, uint16_t); struct mbuf *ieee80211_align_mbuf(struct mbuf *); void ieee80211_decap(struct ieee80211com *, struct mbuf *, struct ieee80211_node *, int); @@ -712,26 +714,13 @@ ieee80211_input_ba(struct ieee80211com *ic, struct mbuf *m, return; } if (SEQ_LT(ba->ba_winend, sn)) { /* WinEndB < SN */ - /* - * If this frame would move the window outside the range of - * winend + winsize, drop it. This is likely a fluke and the - * next frame will fit into the window again. Allowing the - * window to be moved too far ahead makes us drop frames - * until their sequence numbers catch up with the new window. - * - * However, if the window really did move arbitrarily, we must - * allow it to move forward. We try to detect this condition - * by counting missed consecutive frames. - */ - count = (sn - ba->ba_winend) & 0xfff; -#ifdef DIAGNOSTIC - if ((ifp->if_flags & IFF_DEBUG) && count > 1) - printf("%s: received frame with bad sequence number " - "%d, expecting %d:%d\n", __func__, - sn, ba->ba_winstart, ba->ba_winend); -#endif ic->ic_stats.is_ht_rx_frame_above_ba_winend++; + count = (sn - ba->ba_winend) & 0xfff; if (count > ba->ba_winsize) { + /* + * Check whether we're consistently behind the window, + * and let the window move forward if neccessary. + */ if (ba->ba_winmiss < IEEE80211_BA_MAX_WINMISS) { if (ba->ba_missedsn == sn - 1) ba->ba_winmiss++; @@ -747,23 +736,13 @@ ieee80211_input_ba(struct ieee80211com *ic, struct mbuf *m, ic->ic_stats.is_ht_rx_ba_window_jump++; ba->ba_winmiss = 0; ba->ba_missedsn = 0; - - count = ba->ba_winsize; /* no overlap */ - } - while (count-- > 0) { - /* gaps may exist */ - if (ba->ba_buf[ba->ba_head].m != NULL) { - ieee80211_input(ifp, ba->ba_buf[ba->ba_head].m, - ni, &ba->ba_buf[ba->ba_head].rxi); - ba->ba_buf[ba->ba_head].m = NULL; - } else - ic->ic_stats.is_ht_rx_ba_frame_lost++; - ba->ba_head = (ba->ba_head + 1) % - IEEE80211_BA_MAX_WINSZ; + ieee80211_ba_move_window(ic, ni, tid, sn); + } else { + ic->ic_stats.is_ht_rx_ba_window_slide++; + ieee80211_input_ba_seq(ic, ni, tid, + ba->ba_winstart + count); + ieee80211_input_ba_flush(ic, ni, ba); } - /* move window forward */ - ba->ba_winend = sn; - ba->ba_winstart = (sn - ba->ba_winsize + 1) & 0xfff; } /* WinStartB <= SN <= WinEndB */ @@ -791,6 +770,39 @@ ieee80211_input_ba(struct ieee80211com *ic, struct mbuf *m, ieee80211_input_ba_flush(ic, ni, ba); } +/* + * Forward buffered frames with sequence number lower than max_seq. + * See 802.11-2012 9.21.7.6.2 b. + */ +void +ieee80211_input_ba_seq(struct ieee80211com *ic, struct ieee80211_node *ni, + uint8_t tid, uint16_t max_seq) +{ + struct ifnet *ifp = &ic->ic_if; + struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid]; + struct ieee80211_frame *wh; + uint16_t seq; + int i = 0; + + while (i++ < ba->ba_winsize) { + /* gaps may exist */ + if (ba->ba_buf[ba->ba_head].m != NULL) { + wh = mtod(ba->ba_buf[ba->ba_head].m, + struct ieee80211_frame *); + KASSERT(ieee80211_has_seq(wh)); + seq = letoh16(*(u_int16_t *)wh->i_seq) >> + IEEE80211_SEQ_SEQ_SHIFT; + if (!SEQ_LT(seq, max_seq)) + return; + ieee80211_input(ifp, ba->ba_buf[ba->ba_head].m, + ni, &ba->ba_buf[ba->ba_head].rxi); + ba->ba_buf[ba->ba_head].m = NULL; + } else + ic->ic_stats.is_ht_rx_ba_frame_lost++; + ba->ba_head = (ba->ba_head + 1) % IEEE80211_BA_MAX_WINSZ; + } +} + /* Flush a consecutive sequence of frames from the reorder buffer. */ void ieee80211_input_ba_flush(struct ieee80211com *ic, struct ieee80211_node *ni, |