diff options
Diffstat (limited to 'sys/dev/ic/atw.c')
| -rw-r--r-- | sys/dev/ic/atw.c | 172 |
1 files changed, 170 insertions, 2 deletions
diff --git a/sys/dev/ic/atw.c b/sys/dev/ic/atw.c index 02bdc497f9e..a6a42f15b75 100644 --- a/sys/dev/ic/atw.c +++ b/sys/dev/ic/atw.c @@ -1,4 +1,4 @@ -/* $OpenBSD: atw.c,v 1.52 2007/02/14 04:49:43 jsg Exp $ */ +/* $OpenBSD: atw.c,v 1.53 2007/06/07 20:20:15 damien Exp $ */ /* $NetBSD: atw.c,v 1.69 2004/07/23 07:07:55 dyoung Exp $ */ /*- @@ -255,6 +255,9 @@ void atw_node_free(struct ieee80211com *, struct ieee80211_node *); static __inline uint32_t atw_last_even_tsft(uint32_t, uint32_t, uint32_t); uint64_t atw_get_tsft(struct atw_softc *sc); void atw_change_ibss(struct atw_softc *); +int atw_compute_duration1(int, int, uint32_t, int, struct atw_duration *); +int atw_compute_duration(struct ieee80211_frame *, int, uint32_t, int, + int, struct atw_duration *, struct atw_duration *, int *, int); /* * Tuner/transceiver/modem @@ -3410,6 +3413,171 @@ atw_watchdog(struct ifnet *ifp) ieee80211_watchdog(ifp); } +/* + * Arguments in: + * + * paylen: payload length (no FCS, no WEP header) + * + * hdrlen: header length + * + * rate: MSDU speed, units 500kb/s + * + * flags: IEEE80211_F_SHPREAMBLE (use short preamble), + * IEEE80211_F_SHSLOT (use short slot length) + * + * Arguments out: + * + * d: 802.11 Duration field for RTS, + * 802.11 Duration field for data frame, + * PLCP Length for data frame, + * residual octets at end of data slot + */ +int +atw_compute_duration1(int len, int use_ack, uint32_t flags, int rate, + struct atw_duration *d) +{ + int pre, ctsrate; + int ack, bitlen, data_dur, remainder; + + /* RTS reserves medium for SIFS | CTS | SIFS | (DATA) | SIFS | ACK + * DATA reserves medium for SIFS | ACK + * + * XXXMYC: no ACK on multicast/broadcast or control packets + */ + + bitlen = len * 8; + + pre = IEEE80211_DUR_DS_SIFS; + if ((flags & IEEE80211_F_SHPREAMBLE) != 0) + pre += IEEE80211_DUR_DS_SHORT_PREAMBLE + + IEEE80211_DUR_DS_FAST_PLCPHDR; + else + pre += IEEE80211_DUR_DS_LONG_PREAMBLE + + IEEE80211_DUR_DS_SLOW_PLCPHDR; + + d->d_residue = 0; + data_dur = (bitlen * 2) / rate; + remainder = (bitlen * 2) % rate; + if (remainder != 0) { + d->d_residue = (rate - remainder) / 16; + data_dur++; + } + + switch (rate) { + case 2: /* 1 Mb/s */ + case 4: /* 2 Mb/s */ + /* 1 - 2 Mb/s WLAN: send ACK/CTS at 1 Mb/s */ + ctsrate = 2; + break; + case 11: /* 5.5 Mb/s */ + case 22: /* 11 Mb/s */ + case 44: /* 22 Mb/s */ + /* 5.5 - 11 Mb/s WLAN: send ACK/CTS at 2 Mb/s */ + ctsrate = 4; + break; + default: + /* TBD */ + return -1; + } + + d->d_plcp_len = data_dur; + + ack = (use_ack) ? pre + (IEEE80211_DUR_DS_SLOW_ACK * 2) / ctsrate : 0; + + d->d_rts_dur = + pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate + + pre + data_dur + + ack; + + d->d_data_dur = ack; + + return 0; +} + +/* + * Arguments in: + * + * wh: 802.11 header + * + * len: packet length + * + * rate: MSDU speed, units 500kb/s + * + * fraglen: fragment length, set to maximum (or higher) for no + * fragmentation + * + * flags: IEEE80211_F_WEPON (hardware adds WEP), + * IEEE80211_F_SHPREAMBLE (use short preamble), + * IEEE80211_F_SHSLOT (use short slot length) + * + * Arguments out: + * + * d0: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields + * of first/only fragment + * + * dn: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields + * of first/only fragment + */ +int +atw_compute_duration(struct ieee80211_frame *wh, int len, uint32_t flags, + int fraglen, int rate, struct atw_duration *d0, struct atw_duration *dn, + int *npktp, int debug) +{ + int ack, rc; + int firstlen, hdrlen, lastlen, lastlen0, npkt, overlen, paylen; + + if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) + hdrlen = sizeof(struct ieee80211_frame_addr4); + else + hdrlen = sizeof(struct ieee80211_frame); + + paylen = len - hdrlen; + + if ((flags & IEEE80211_F_WEPON) != 0) + overlen = IEEE80211_WEP_TOTLEN + IEEE80211_CRC_LEN; + else + overlen = IEEE80211_CRC_LEN; + + npkt = paylen / fraglen; + lastlen0 = paylen % fraglen; + + if (npkt == 0) /* no fragments */ + lastlen = paylen + overlen; + else if (lastlen0 != 0) { /* a short "tail" fragment */ + lastlen = lastlen0 + overlen; + npkt++; + } else /* full-length "tail" fragment */ + lastlen = fraglen + overlen; + + if (npktp != NULL) + *npktp = npkt; + + if (npkt > 1) + firstlen = fraglen + overlen; + else + firstlen = paylen + overlen; + + if (debug) { + printf("%s: npkt %d firstlen %d lastlen0 %d lastlen %d " + "fraglen %d overlen %d len %d rate %d flags %08x\n", + __func__, npkt, firstlen, lastlen0, lastlen, fraglen, + overlen, len, rate, flags); + } + + ack = !IEEE80211_IS_MULTICAST(wh->i_addr1) && + (wh->i_fc[1] & IEEE80211_FC0_TYPE_MASK) != IEEE80211_FC0_TYPE_CTL; + + rc = atw_compute_duration1(firstlen + hdrlen, ack, flags, rate, d0); + if (rc == -1) + return rc; + + if (npkt <= 1) { + *dn = *d0; + return 0; + } + return atw_compute_duration1(lastlen + hdrlen, ack, flags, rate, dn); +} + #ifdef ATW_DEBUG void atw_dump_pkt(struct ifnet *ifp, struct mbuf *m0) @@ -3520,7 +3688,7 @@ atw_start(struct ifnet *ifp) else rate = MAX(2, ieee80211_get_rate(ic)); - if (ieee80211_compute_duration(wh, m0->m_pkthdr.len, + if (atw_compute_duration(wh, m0->m_pkthdr.len, ic->ic_flags & ~IEEE80211_F_WEPON, ic->ic_fragthreshold, rate, &txs->txs_d0, &txs->txs_dn, &npkt, (sc->sc_if.if_flags & (IFF_DEBUG|IFF_LINK2)) == |