Date: Thu, 4 Aug 2016 09:26:15 +0000 From: "sepherosa_gmail.com (Sepherosa Ziehau)" <phabric-noreply@FreeBSD.org> To: freebsd-net@freebsd.org Subject: [Differential] D7415: tcp/lro: If timestamps mismatch or it's a FIN, force flush. Message-ID: <b3b8064c155f5f5ec9704d8b57ce9e8c@localhost.localdomain> In-Reply-To: <differential-rev-PHID-DREV-nxbjynsxkd5zh6l3wyn3-req@FreeBSD.org> References: <differential-rev-PHID-DREV-nxbjynsxkd5zh6l3wyn3-req@FreeBSD.org>
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[-- Attachment #1 --] sepherosa_gmail.com updated this revision to Diff 19032. sepherosa_gmail.com added a comment. Don't create entry for segments cant be further aggregated/delayed. Noticed-by: hps CHANGES SINCE LAST UPDATE https://reviews.freebsd.org/D7415?vs=19031&id=19032 REVISION DETAIL https://reviews.freebsd.org/D7415 AFFECTED FILES sys/netinet/tcp_lro.c EMAIL PREFERENCES https://reviews.freebsd.org/settings/panel/emailpreferences/ To: sepherosa_gmail.com, rrs, gallatin, hselasky, np, glebius, hiren, bz, #transport Cc: freebsd-net-list [-- Attachment #2 --] diff --git a/sys/netinet/tcp_lro.c b/sys/netinet/tcp_lro.c --- a/sys/netinet/tcp_lro.c +++ b/sys/netinet/tcp_lro.c @@ -603,6 +603,7 @@ int error, ip_len, l; uint16_t eh_type, tcp_data_len; struct lro_head *bucket; + int force_flush = 0; /* We expect a contiguous header [eh, ip, tcp]. */ @@ -669,8 +670,15 @@ * Check TCP header constraints. */ /* Ensure no bits set besides ACK or PSH. */ - if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) - return (TCP_LRO_CANNOT); + if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) { + if (th->th_flags & TH_SYN) + return (TCP_LRO_CANNOT); + /* + * Make sure that previously seen segements/ACKs are delivered + * before this segement, e.g. FIN. + */ + force_flush = 1; + } /* XXX-BZ We lose a ACK|PUSH flag concatenating multiple segments. */ /* XXX-BZ Ideally we'd flush on PUSH? */ @@ -686,8 +694,13 @@ ts_ptr = (uint32_t *)(th + 1); if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) || (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16| - TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) - return (TCP_LRO_CANNOT); + TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) { + /* + * Make sure that previously seen segements/ACKs are delivered + * before this segement. + */ + force_flush = 1; + } /* If the driver did not pass in the checksum, set it now. */ if (csum == 0x0000) @@ -754,6 +767,13 @@ #endif } + if (force_flush) { + /* Timestamps mismatch; this is a FIN, etc */ + tcp_lro_active_remove(le); + tcp_lro_flush(lc, le); + return (TCP_LRO_CANNOT); + } + /* Flush now if appending will result in overflow. */ if (le->p_len > (lc->lro_length_lim - tcp_data_len)) { tcp_lro_active_remove(le); @@ -830,6 +850,14 @@ return (0); } + if (force_flush) { + /* + * Nothing to flush, but this segment can not be further + * aggregated/delayed. + */ + return (TCP_LRO_CANNOT); + } + /* Try to find an empty slot. */ if (LIST_EMPTY(&lc->lro_free)) return (TCP_LRO_NO_ENTRIES);
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