sys/netinet/tcp_output.c

137 #define TCP_XMIT_TIMER_ASSERT(tp, len, th_flags)			\
138 	KASSERT(((len) == 0 && ((th_flags) & (TH_SYN | TH_FIN)) == 0) ||\
145 			    long len, int tso);
153     struct tcpopt *to, long len, int tso)
161 		hhook_data.len = len;
188 	long len, recwin, sendwin;
276 	len = 0;
303 				len = ((long)ulmin(cwin,
306 			len = ((long)ulmin(cwin, p->end - p->rxmit));
310 		if (len > 0) {
315 			    min(len, tp->t_maxseg));
375 	 * in which case len is already set.
379 			len = ((long)ulmin(sbavail(&so->so_snd), sendwin) -
389 			len = ((long)ulmin(sbavail(&so->so_snd), tp->snd_wnd) -
392 			 * Don't remove this (len > 0) check !
393 			 * We explicitly check for len > 0 here (although it
396 			 * len above. Without this check, the computation
397 			 * of len is bungled by the optimizer.
399 			if (len > 0) {
405 				len = lmin(len, cwin);
427 		off--, len++;
436 		len = 0;
449 		len = 0;
451 	if (len <= 0) {
455 		 * len will be < 0.  Otherwise, window shrank
468 		len = 0;
479 	/* len will be >= 0 after this point. */
480 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
550 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > tp->t_maxseg &&
561 		if (SEQ_LT(p->rxmit + len, tp->snd_una + sbused(&so->so_snd)))
564 		if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
573 	 * conditions when len is non-zero:
583 	if (len) {
584 		if (len >= tp->t_maxseg)
591 		 * note: the len + off check is almost certainly unnecessary.
595 		    len + off >= sbavail(&so->so_snd) &&
601 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0)
738 	if (len > 0) {
739 		if (len >= tp->t_maxseg)
848 	if (len + optlen + ipoptlen > tp->t_maxseg) {
881 					len = 0;
882 				} else if (len > max_len) {
884 					len = max_len;
906 				while (mb != NULL && max_len < len) {
939 					len = 0;
940 				} else if (len > max_len) {
942 					len = max_len;
952 			if ((off + len) < sbavail(&so->so_snd)) {
953 				moff = len % max_len;
955 					len -= moff;
964 			if (len <= max_len) {
965 				len = max_len;
981 			len = tp->t_maxseg - optlen - ipoptlen;
987 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
988 	    ("%s: len > IP_MAXPACKET", __func__));
1003 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
1010 	if (len) {
1014 		if ((tp->t_flags & TF_FORCEDATA) && len == 1)
1019 			TCPSTAT_ADD(tcps_sndrexmitbyte, len);
1022 			TCPSTAT_ADD(tcps_sndbyte, len);
1045 		mb = sbsndptr(&so->so_snd, off, len, &moff);
1047 		if (len <= MHLEN - hdrlen - max_linkhdr) {
1048 			m_copydata(mb, moff, (int)len,
1050 			m->m_len += len;
1052 			m->m_next = m_copy(mb, moff, (int)len);
1068 		if ((off + len == sbused(&so->so_snd)) && !(flags & TH_SYN))
1145 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
1146 		    !((tp->t_flags & TF_FORCEDATA) && len == 1)) {
1181 		if (len || (flags & (TH_SYN|TH_FIN)) ||
1188 		p->rxmit += len;
1189 		tp->sackhint.sack_bytes_rexmit += len;
1249 		tcp_signature_compute(m, 0, len, optlen,
1258 	m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
1268 		    optlen + len, IPPROTO_TCP, 0);
1278 		    htons(sizeof(struct tcphdr) + IPPROTO_TCP + len + optlen));
1291 		KASSERT(len > tp->t_maxseg - optlen,
1292 		    ("%s: len <= tso_segsz", __func__));
1298 	KASSERT(len + hdrlen + ipoptlen - ipsec_optlen == m_length(m, NULL),
1300 	    __func__, len, hdrlen, ipoptlen, ipsec_optlen, m_length(m, NULL)));
1302 	KASSERT(len + hdrlen + ipoptlen == m_length(m, NULL),
1304 	    __func__, len, hdrlen, ipoptlen, m_length(m, NULL)));
1308 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
1321 			ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen + (th->th_off << 2) */);
1339 	 * m->m_pkthdr.len should have been set before checksum calculation,
1360 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
1392 	ip->ip_len = htons(m->m_pkthdr.len);
1453 		tp->snd_nxt += len;
1484 		} else if (len == 0 && sbavail(&so->so_snd) &&
1493 			 * 3) A -> B: ACK for #2, 0 len packet
1514 		int xlen = len;
1522 			tp->snd_max = tp->snd_nxt + len;
1545 				p->rxmit -= len;
1546 				tp->sackhint.sack_bytes_rexmit -= len;
1550 				tp->snd_nxt -= len;
1558 			TCP_XMIT_TIMER_ASSERT(tp, len, flags);