Date: Wed, 15 Dec 2010 10:15:13 +0100 From: =?iso-8859-1?Q?Michael_T=FCxen?= <Michael.Tuexen@lurchi.franken.de> To: =?utf-8?B?572X6ZKw?= <blade_ly@yahoo.com.cn> Cc: freebsd-net@freebsd.org Subject: Re: [SCTP] last_sequence_delivered in sctp_process_a_data_chunk question Message-ID: <AD3C54B2-0378-4D70-81FE-F7F014703293@lurchi.franken.de> In-Reply-To: <173127.17301.qm@web15007.mail.cnb.yahoo.com> References: <173127.17301.qm@web15007.mail.cnb.yahoo.com>
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On Dec 15, 2010, at 8:46 AM, =E7=BD=97=E9=92=B0 wrote: > Hi, all experts: I find a suspect point in function of = sctp_process_a_data_chunk in all FreeBSD branches.for example:Line 1900 = of sctp_indata: (asoc->strmin[strmno].last_sequence_delivered + 1) =3D=3D = strmseqThis is a logical judgement sentence.last_sequence_delivered is = unsigned short type, strmseq is also.there is a problem: if = last_sequence_delivered equal 0xffff, and the result of = last_sequence_delivered + 1 must be 0x10000, rather than 0x0000, and if = strmseq is also be 0x0, then this judgement will give you wrong value. > so i think put a (uint16_t) before this sentence will be more secure. = so how do you think?like this: = (uint16_t)(asoc->strmin[strmno].last_sequence_delivered + 1) =3D=3D = strmseqThanks and i hope your response. In head and FreeBSD 8.0 and 8.1 sctp_structs.h contains: struct sctp_stream_in { struct sctp_readhead inqueue; uint16_t stream_no; uint16_t last_sequence_delivered; /* used for re-order */ uint8_t delivery_started; }; Furthermore sctp_process_a_data_chunk() contains: uint16_t strmno, strmseq; So I do not think the problem "is in all branches". Can you be more = specific, which version your are talking about? Best regards Michael >=20 >=20 >=20 > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >=20
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