Bug Summary

File:netinet/tcp_output.c
Warning:line 1073, column 6
Branch condition evaluates to a garbage value

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name tcp_output.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -D CONFIG_DRM_AMD_DC_DCN3_0 -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -o /usr/obj/sys/arch/amd64/compile/GENERIC.MP/scan-build/2022-01-12-131800-47421-1 -x c /usr/src/sys/netinet/tcp_output.c
1/* $OpenBSD: tcp_output.c,v 1.131 2021/11/25 13:46:02 bluhm Exp $ */
2/* $NetBSD: tcp_output.c,v 1.16 1997/06/03 16:17:09 kml Exp $ */
3
4/*
5 * Copyright (c) 1982, 1986, 1988, 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995
33 *
34 * NRL grants permission for redistribution and use in source and binary
35 * forms, with or without modification, of the software and documentation
36 * created at NRL provided that the following conditions are met:
37 *
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 * 3. All advertising materials mentioning features or use of this software
44 * must display the following acknowledgements:
45 * This product includes software developed by the University of
46 * California, Berkeley and its contributors.
47 * This product includes software developed at the Information
48 * Technology Division, US Naval Research Laboratory.
49 * 4. Neither the name of the NRL nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR
57 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64 *
65 * The views and conclusions contained in the software and documentation
66 * are those of the authors and should not be interpreted as representing
67 * official policies, either expressed or implied, of the US Naval
68 * Research Laboratory (NRL).
69 */
70
71#include "pf.h"
72#include "stoeplitz.h"
73
74#include <sys/param.h>
75#include <sys/systm.h>
76#include <sys/mbuf.h>
77#include <sys/protosw.h>
78#include <sys/socket.h>
79#include <sys/socketvar.h>
80#include <sys/kernel.h>
81
82#include <net/if.h>
83#include <net/route.h>
84#if NPF1 > 0
85#include <net/pfvar.h>
86#endif
87
88#include <netinet/in.h>
89#include <netinet/ip.h>
90#include <netinet/in_pcb.h>
91#include <netinet/ip_var.h>
92#include <netinet/tcp.h>
93#define TCPOUTFLAGS
94#include <netinet/tcp_fsm.h>
95#include <netinet/tcp_seq.h>
96#include <netinet/tcp_timer.h>
97#include <netinet/tcp_var.h>
98#include <netinet/tcp_debug.h>
99
100#ifdef notyet
101extern struct mbuf *m_copypack();
102#endif
103
104extern int tcprexmtthresh;
105
106#ifdef TCP_SACK_DEBUG
107void tcp_print_holes(struct tcpcb *tp);
108
109void
110tcp_print_holes(struct tcpcb *tp)
111{
112 struct sackhole *p = tp->snd_holes;
113 if (p == NULL((void *)0))
114 return;
115 printf("Hole report: start--end dups rxmit\n");
116 while (p) {
117 printf("%x--%x d %d r %x\n", p->start, p->end, p->dups,
118 p->rxmit);
119 p = p->next;
120 }
121 printf("\n");
122}
123#endif /* TCP_SACK_DEBUG */
124
125/*
126 * Returns pointer to a sackhole if there are any pending retransmissions;
127 * NULL otherwise.
128 */
129struct sackhole *
130tcp_sack_output(struct tcpcb *tp)
131{
132 struct sackhole *p;
133
134 if (!tp->sack_enable)
135 return (NULL((void *)0));
136 p = tp->snd_holes;
137 while (p) {
138 if (p->dups >= tcprexmtthresh && SEQ_LT(p->rxmit, p->end)((int)((p->rxmit)-(p->end)) < 0)) {
139 if (SEQ_LT(p->rxmit, tp->snd_una)((int)((p->rxmit)-(tp->snd_una)) < 0)) {/* old SACK hole */
140 p = p->next;
141 continue;
142 }
143#ifdef TCP_SACK_DEBUG
144 if (p)
145 tcp_print_holes(tp);
146#endif
147 return (p);
148 }
149 p = p->next;
150 }
151 return (NULL((void *)0));
152}
153
154/*
155 * After a timeout, the SACK list may be rebuilt. This SACK information
156 * should be used to avoid retransmitting SACKed data. This function
157 * traverses the SACK list to see if snd_nxt should be moved forward.
158 */
159
160void
161tcp_sack_adjust(struct tcpcb *tp)
162{
163 struct sackhole *cur = tp->snd_holes;
164 if (cur == NULL((void *)0))
165 return; /* No holes */
166 if (SEQ_GEQ(tp->snd_nxt, tp->rcv_lastsack)((int)((tp->snd_nxt)-(tp->rcv_lastsack)) >= 0))
167 return; /* We're already beyond any SACKed blocks */
168 /*
169 * Two cases for which we want to advance snd_nxt:
170 * i) snd_nxt lies between end of one hole and beginning of another
171 * ii) snd_nxt lies between end of last hole and rcv_lastsack
172 */
173 while (cur->next) {
174 if (SEQ_LT(tp->snd_nxt, cur->end)((int)((tp->snd_nxt)-(cur->end)) < 0))
175 return;
176 if (SEQ_GEQ(tp->snd_nxt, cur->next->start)((int)((tp->snd_nxt)-(cur->next->start)) >= 0))
177 cur = cur->next;
178 else {
179 tp->snd_nxt = cur->next->start;
180 return;
181 }
182 }
183 if (SEQ_LT(tp->snd_nxt, cur->end)((int)((tp->snd_nxt)-(cur->end)) < 0))
184 return;
185 tp->snd_nxt = tp->rcv_lastsack;
186 return;
187}
188
189/*
190 * Tcp output routine: figure out what should be sent and send it.
191 */
192int
193tcp_output(struct tcpcb *tp)
194{
195 struct socket *so = tp->t_inpcb->inp_socket;
196 long len, win, txmaxseg;
197 int off, flags, error;
1
'error' declared without an initial value
→
198 struct mbuf *m;
199 struct tcphdr *th;
200 u_int32_t optbuf[howmany(MAX_TCPOPTLEN, sizeof(u_int32_t))(((40) + ((sizeof(u_int32_t)) - 1)) / (sizeof(u_int32_t)))];
201 u_char *opt = (u_char *)optbuf;
202 unsigned int optlen, hdrlen, packetlen;
203 int idle, sendalot = 0;
204 int i, sack_rxmit = 0;
205 struct sackhole *p;
206#ifdef TCP_SIGNATURE1
207 unsigned int sigoff;
208#endif /* TCP_SIGNATURE */
209#ifdef TCP_ECN1
210 int needect;
211#endif
212
213 if (tp->t_flags & TF_BLOCKOUTPUT0x01000000) {
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
214 tp->t_flags |= TF_NEEDOUTPUT0x00800000;
215 return (0);
216 } else
217 tp->t_flags &= ~TF_NEEDOUTPUT0x00800000;
218
219#if defined(TCP_SIGNATURE1) && defined(DIAGNOSTIC1)
220 if (tp->sack_enable && (tp->t_flags & TF_SIGNATURE0x0400))
4
←
Assuming field 'sack_enable' is 0
→
221 return (EINVAL22);
222#endif /* defined(TCP_SIGNATURE) && defined(DIAGNOSTIC) */
223
224 /*
225 * Determine length of data that should be transmitted,
226 * and flags that will be used.
227 * If there is some data or critical controls (SYN, RST)
228 * to send, then transmit; otherwise, investigate further.
229 */
230 idle = (tp->t_flags & TF_LASTIDLE0x00100000) || (tp->snd_max == tp->snd_una);
5
←
Assuming the condition is false
→
6
←
Assuming field 'snd_max' is not equal to field 'snd_una'
→
231 if (idle
6.1
'idle' is 0
 && (tcp_now - tp->t_rcvtime) >= tp->t_rxtcur)
232 /*
233 * We have been idle for "a while" and no acks are
234 * expected to clock out any data we send --
235 * slow start to get ack "clock" running again.
236 */
237 tp->snd_cwnd = 2 * tp->t_maxseg;
238
239 /* remember 'idle' for next invocation of tcp_output */
240 if (idle
6.2
'idle' is 0
 && soissending(so)((so)->so_state & 0x2000)) {
241 tp->t_flags |= TF_LASTIDLE0x00100000;
242 idle = 0;
243 } else
244 tp->t_flags &= ~TF_LASTIDLE0x00100000;
245
246again:
247 /*
248 * If we've recently taken a timeout, snd_max will be greater than
249 * snd_nxt. There may be SACK information that allows us to avoid
250 * resending already delivered data. Adjust snd_nxt accordingly.
251 */
252 if (tp->sack_enable
6.3
Field 'sack_enable' is 0
 && SEQ_LT(tp->snd_nxt, tp->snd_max)((int)((tp->snd_nxt)-(tp->snd_max)) < 0))
253 tcp_sack_adjust(tp);
254 off = tp->snd_nxt - tp->snd_una;
255 win = ulmin(tp->snd_wnd, tp->snd_cwnd);
256
257 flags = tcp_outflags[tp->t_state];
258
259 /*
260 * Send any SACK-generated retransmissions. If we're explicitly trying
261 * to send out new data (when sendalot is 1), bypass this function.
262 * If we retransmit in fast recovery mode, decrement snd_cwnd, since
263 * we're replacing a (future) new transmission with a retransmission
264 * now, and we previously incremented snd_cwnd in tcp_input().
265 */
266 if (tp->sack_enable
6.4
Field 'sack_enable' is 0
 && !sendalot) {
267 if (tp->t_dupacks >= tcprexmtthresh &&
268 (p = tcp_sack_output(tp))) {
269 off = p->rxmit - tp->snd_una;
270 sack_rxmit = 1;
271 /* Coalesce holes into a single retransmission */
272 len = min(tp->t_maxseg, p->end - p->rxmit);
273 if (SEQ_LT(tp->snd_una, tp->snd_last)((int)((tp->snd_una)-(tp->snd_last)) < 0))
274 tp->snd_cwnd -= tp->t_maxseg;
275 }
276 }
277
278 sendalot = 0;
279 /*
280 * If in persist timeout with window of 0, send 1 byte.
281 * Otherwise, if window is small but nonzero
282 * and timer expired, we will send what we can
283 * and go to transmit state.
284 */
285 if (tp->t_force) {
7
←
Assuming field 't_force' is 0
→
8
←
Taking false branch
→
286 if (win == 0) {
287 /*
288 * If we still have some data to send, then
289 * clear the FIN bit. Usually this would
290 * happen below when it realizes that we
291 * aren't sending all the data. However,
292 * if we have exactly 1 byte of unset data,
293 * then it won't clear the FIN bit below,
294 * and if we are in persist state, we wind
295 * up sending the packet without recording
296 * that we sent the FIN bit.
297 *
298 * We can't just blindly clear the FIN bit,
299 * because if we don't have any more data
300 * to send then the probe will be the FIN
301 * itself.
302 */
303 if (off < so->so_snd.sb_cc)
304 flags &= ~TH_FIN0x01;
305 win = 1;
306 } else {
307 TCP_TIMER_DISARM(tp, TCPT_PERSIST)do { (((tp)->t_flags) &= ~(0x04000000 << (1))); timeout_del
(&(tp)->t_timer[(1)]); } while (0);
308 tp->t_rxtshift = 0;
309 }
310 }
311
312 if (!sack_rxmit
8.1
'sack_rxmit' is 0
) {
9
←
Taking true branch
→
313 len = ulmin(so->so_snd.sb_cc, win) - off;
314 }
315
316 if (len
9.1
'len' is >= 0
 < 0) {
10
←
Taking false branch
→
317 /*
318 * If FIN has been sent but not acked,
319 * but we haven't been called to retransmit,
320 * len will be -1. Otherwise, window shrank
321 * after we sent into it. If window shrank to 0,
322 * cancel pending retransmit, pull snd_nxt back
323 * to (closed) window, and set the persist timer
324 * if it isn't already going. If the window didn't
325 * close completely, just wait for an ACK.
326 */
327 len = 0;
328 if (win == 0) {
329 TCP_TIMER_DISARM(tp, TCPT_REXMT)do { (((tp)->t_flags) &= ~(0x04000000 << (0))); timeout_del
(&(tp)->t_timer[(0)]); } while (0);
330 tp->t_rxtshift = 0;
331 tp->snd_nxt = tp->snd_una;
332 if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))) == 0)
333 tcp_setpersist(tp);
334 }
335 }
336
337 /*
338 * Never send more than half a buffer full. This insures that we can
339 * always keep 2 packets on the wire, no matter what SO_SNDBUF is, and
340 * therefore acks will never be delayed unless we run out of data to
341 * transmit.
342 */
343 txmaxseg = ulmin(so->so_snd.sb_hiwat / 2, tp->t_maxseg);
344
345 if (len > txmaxseg) {
11
←
Assuming 'len' is <= 'txmaxseg'
→
12
←
Taking false branch
→
346 len = txmaxseg;
347 sendalot = 1;
348 }
349 if (off + len < so->so_snd.sb_cc)
13
←
Assuming the condition is false
→
14
←
Taking false branch
→
350 flags &= ~TH_FIN0x01;
351
352 win = sbspace(so, &so->so_rcv);
353
354 /*
355 * Sender silly window avoidance. If connection is idle
356 * and can send all data, a maximum segment,
357 * at least a maximum default-size segment do it,
358 * or are forced, do it; otherwise don't bother.
359 * If peer's buffer is tiny, then send
360 * when window is at least half open.
361 * If retransmitting (possibly after persist timer forced us
362 * to send into a small window), then must resend.
363 */
364 if (len) {
15
←
Assuming 'len' is 0
→
16
←
Taking false branch
→
365 if (len == txmaxseg)
366 goto send;
367 if ((idle || (tp->t_flags & TF_NODELAY0x0004)) &&
368 len + off >= so->so_snd.sb_cc && !soissending(so)((so)->so_state & 0x2000) &&
369 (tp->t_flags & TF_NOPUSH0x02000000) == 0)
370 goto send;
371 if (tp->t_force)
372 goto send;
373 if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0)
374 goto send;
375 if (SEQ_LT(tp->snd_nxt, tp->snd_max)((int)((tp->snd_nxt)-(tp->snd_max)) < 0))
376 goto send;
377 if (sack_rxmit)
378 goto send;
379 }
380
381 /*
382 * Compare available window to amount of window
383 * known to peer (as advertised window less
384 * next expected input). If the difference is at least two
385 * max size segments, or at least 50% of the maximum possible
386 * window, then want to send a window update to peer.
387 */
388 if (win > 0) {
17
←
Assuming 'win' is <= 0
→
18
←
Taking false branch
→
389 /*
390 * "adv" is the amount we can increase the window,
391 * taking into account that we are limited by
392 * TCP_MAXWIN << tp->rcv_scale.
393 */
394 long adv = lmin(win, (long)TCP_MAXWIN65535 << tp->rcv_scale) -
395 (tp->rcv_adv - tp->rcv_nxt);
396
397 if (adv >= (long) (2 * tp->t_maxseg))
398 goto send;
399 if (2 * adv >= (long) so->so_rcv.sb_hiwat)
400 goto send;
401 }
402
403 /*
404 * Send if we owe peer an ACK.
405 */
406 if (tp->t_flags & TF_ACKNOW0x0001)
19
←
Assuming the condition is false
→
20
←
Taking false branch
→
407 goto send;
408 if (flags & (TH_SYN0x02|TH_RST0x04))
21
←
Assuming the condition is false
→
22
←
Taking false branch
→
409 goto send;
410 if (SEQ_GT(tp->snd_up, tp->snd_una)((int)((tp->snd_up)-(tp->snd_una)) > 0))
23
←
Assuming the condition is false
→
24
←
Taking false branch
→
411 goto send;
412 /*
413 * If our state indicates that FIN should be sent
414 * and we have not yet done so, or we're retransmitting the FIN,
415 * then we need to send.
416 */
417 if (flags & TH_FIN0x01 &&
25
←
Assuming the condition is true
→
28
←
Taking true branch
→
418 ((tp->t_flags & TF_SENTFIN0x0010) == 0 || tp->snd_nxt == tp->snd_una))
26
←
Assuming the condition is false
→
27
←
Assuming field 'snd_nxt' is equal to field 'snd_una'
→
419 goto send;
29
←
Control jumps to line 475
→
420 /*
421 * In SACK, it is possible for tcp_output to fail to send a segment
422 * after the retransmission timer has been turned off. Make sure
423 * that the retransmission timer is set.
424 */
425 if (SEQ_GT(tp->snd_max, tp->snd_una)((int)((tp->snd_max)-(tp->snd_una)) > 0) &&
426 TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))) == 0 &&
427 TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))) == 0) {
428 TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur)do { (((tp)->t_flags) |= (0x04000000 << (0))); timeout_add_msec
(&(tp)->t_timer[(0)], (tp->t_rxtcur) * 500); } while
(0);
429 return (0);
430 }
431
432 /*
433 * TCP window updates are not reliable, rather a polling protocol
434 * using ``persist'' packets is used to insure receipt of window
435 * updates. The three ``states'' for the output side are:
436 * idle not doing retransmits or persists
437 * persisting to move a small or zero window
438 * (re)transmitting and thereby not persisting
439 *
440 * tp->t_timer[TCPT_PERSIST]
441 * is set when we are in persist state.
442 * tp->t_force
443 * is set when we are called to send a persist packet.
444 * tp->t_timer[TCPT_REXMT]
445 * is set when we are retransmitting
446 * The output side is idle when both timers are zero.
447 *
448 * If send window is too small, there is data to transmit, and no
449 * retransmit or persist is pending, then go to persist state.
450 * If nothing happens soon, send when timer expires:
451 * if window is nonzero, transmit what we can,
452 * otherwise force out a byte.
453 */
454 if (so->so_snd.sb_cc && TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))) == 0 &&
455 TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))) == 0) {
456 tp->t_rxtshift = 0;
457 tcp_setpersist(tp);
458 }
459
460 /*
461 * No reason to send a segment, just return.
462 */
463 return (0);
464
465send:
466 /*
467 * Before ESTABLISHED, force sending of initial options
468 * unless TCP set not to do any options.
469 * NOTE: we assume that the IP/TCP header plus TCP options
470 * always fit in a single mbuf, leaving room for a maximum
471 * link header, i.e.
472 * max_linkhdr + sizeof(network header) + sizeof(struct tcphdr +
473 * optlen <= MHLEN
474 */
475 optlen = 0;
476
477 switch (tp->pf) {
30
←
Control jumps to 'case 24:' at line 483
→
478 case 0: /*default to PF_INET*/
479 case PF_INET2:
480 hdrlen = sizeof(struct ip) + sizeof(struct tcphdr);
481 break;
482#ifdef INET61
483 case PF_INET624:
484 hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
485 break;
31
←
 Execution continues on line 491
→
486#endif /* INET6 */
487 default:
488 return (EPFNOSUPPORT46);
489 }
490
491 if (flags & TH_SYN0x02) {
32
←
Assuming the condition is false
→
33
←
Taking false branch
→
492 tp->snd_nxt = tp->iss;
493 if ((tp->t_flags & TF_NOOPT0x0008) == 0) {
494 u_int16_t mss;
495
496 opt[0] = TCPOPT_MAXSEG2;
497 opt[1] = 4;
498 mss = htons((u_int16_t) tcp_mss(tp, 0))(__uint16_t)(__builtin_constant_p((u_int16_t) tcp_mss(tp, 0))
? (__uint16_t)(((__uint16_t)((u_int16_t) tcp_mss(tp, 0)) &
0xffU) << 8 | ((__uint16_t)((u_int16_t) tcp_mss(tp, 0)
) & 0xff00U) >> 8) : __swap16md((u_int16_t) tcp_mss
(tp, 0)));
499 memcpy(opt + 2, &mss, sizeof(mss))__builtin_memcpy((opt + 2), (&mss), (sizeof(mss)));
500 optlen = 4;
501
502 if (flags & TH_ACK0x10)
503 tcp_mss_update(tp);
504 /*
505 * If this is the first SYN of connection (not a SYN
506 * ACK), include SACK_PERMIT_HDR option. If this is a
507 * SYN ACK, include SACK_PERMIT_HDR option if peer has
508 * already done so.
509 */
510 if (tp->sack_enable && ((flags & TH_ACK0x10) == 0 ||
511 (tp->t_flags & TF_SACK_PERMIT0x0200))) {
512 *((u_int32_t *) (opt + optlen)) =
513 htonl(TCPOPT_SACK_PERMIT_HDR)(__uint32_t)(__builtin_constant_p((1<<24|1<<16|4<<
8|2)) ? (__uint32_t)(((__uint32_t)((1<<24|1<<16|4
<<8|2)) & 0xff) << 24 | ((__uint32_t)((1<<
24|1<<16|4<<8|2)) & 0xff00) << 8 | ((__uint32_t
)((1<<24|1<<16|4<<8|2)) & 0xff0000) >>
8 | ((__uint32_t)((1<<24|1<<16|4<<8|2)) &
0xff000000) >> 24) : __swap32md((1<<24|1<<
16|4<<8|2)));
514 optlen += 4;
515 }
516 if ((tp->t_flags & TF_REQ_SCALE0x0020) &&
517 ((flags & TH_ACK0x10) == 0 ||
518 (tp->t_flags & TF_RCVD_SCALE0x0040))) {
519 *((u_int32_t *) (opt + optlen)) = htonl((__uint32_t)(__builtin_constant_p(1 << 24 | 3 << 16
| 3 << 8 | tp->request_r_scale) ? (__uint32_t)(((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff) << 24 | ((__uint32_t)(1 << 24 | 3 <<
16 | 3 << 8 | tp->request_r_scale) & 0xff00) <<
8 | ((__uint32_t)(1 << 24 | 3 << 16 | 3 <<
8 | tp->request_r_scale) & 0xff0000) >> 8 | ((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff000000) >> 24) : __swap32md(1 << 24 |
3 << 16 | 3 << 8 | tp->request_r_scale))
520 TCPOPT_NOP << 24 |(__uint32_t)(__builtin_constant_p(1 << 24 | 3 << 16
| 3 << 8 | tp->request_r_scale) ? (__uint32_t)(((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff) << 24 | ((__uint32_t)(1 << 24 | 3 <<
16 | 3 << 8 | tp->request_r_scale) & 0xff00) <<
8 | ((__uint32_t)(1 << 24 | 3 << 16 | 3 <<
8 | tp->request_r_scale) & 0xff0000) >> 8 | ((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff000000) >> 24) : __swap32md(1 << 24 |
3 << 16 | 3 << 8 | tp->request_r_scale))
521 TCPOPT_WINDOW << 16 |(__uint32_t)(__builtin_constant_p(1 << 24 | 3 << 16
| 3 << 8 | tp->request_r_scale) ? (__uint32_t)(((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff) << 24 | ((__uint32_t)(1 << 24 | 3 <<
16 | 3 << 8 | tp->request_r_scale) & 0xff00) <<
8 | ((__uint32_t)(1 << 24 | 3 << 16 | 3 <<
8 | tp->request_r_scale) & 0xff0000) >> 8 | ((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff000000) >> 24) : __swap32md(1 << 24 |
3 << 16 | 3 << 8 | tp->request_r_scale))
522 TCPOLEN_WINDOW << 8 |(__uint32_t)(__builtin_constant_p(1 << 24 | 3 << 16
| 3 << 8 | tp->request_r_scale) ? (__uint32_t)(((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff) << 24 | ((__uint32_t)(1 << 24 | 3 <<
16 | 3 << 8 | tp->request_r_scale) & 0xff00) <<
8 | ((__uint32_t)(1 << 24 | 3 << 16 | 3 <<
8 | tp->request_r_scale) & 0xff0000) >> 8 | ((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff000000) >> 24) : __swap32md(1 << 24 |
3 << 16 | 3 << 8 | tp->request_r_scale))
523 tp->request_r_scale)(__uint32_t)(__builtin_constant_p(1 << 24 | 3 << 16
| 3 << 8 | tp->request_r_scale) ? (__uint32_t)(((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff) << 24 | ((__uint32_t)(1 << 24 | 3 <<
16 | 3 << 8 | tp->request_r_scale) & 0xff00) <<
8 | ((__uint32_t)(1 << 24 | 3 << 16 | 3 <<
8 | tp->request_r_scale) & 0xff0000) >> 8 | ((__uint32_t
)(1 << 24 | 3 << 16 | 3 << 8 | tp->request_r_scale
) & 0xff000000) >> 24) : __swap32md(1 << 24 |
3 << 16 | 3 << 8 | tp->request_r_scale));
524 optlen += 4;
525 }
526 }
527 }
528
529 /*
530 * Send a timestamp and echo-reply if this is a SYN and our side
531 * wants to use timestamps (TF_REQ_TSTMP is set) or both our side
532 * and our peer have sent timestamps in our SYN's.
533 */
534 if ((tp->t_flags & (TF_REQ_TSTMP0x0080|TF_NOOPT0x0008)) == TF_REQ_TSTMP0x0080 &&
34
←
Assuming the condition is false
→
535 (flags & TH_RST0x04) == 0 &&
536 ((flags & (TH_SYN0x02|TH_ACK0x10)) == TH_SYN0x02 ||
537 (tp->t_flags & TF_RCVD_TSTMP0x0100))) {
538 u_int32_t *lp = (u_int32_t *)(opt + optlen);
539
540 /* Form timestamp option as shown in appendix A of RFC 1323. */
541 *lp++ = htonl(TCPOPT_TSTAMP_HDR)(__uint32_t)(__builtin_constant_p((1<<24|1<<16|8<<
8|10)) ? (__uint32_t)(((__uint32_t)((1<<24|1<<16|
8<<8|10)) & 0xff) << 24 | ((__uint32_t)((1<<
24|1<<16|8<<8|10)) & 0xff00) << 8 | ((__uint32_t
)((1<<24|1<<16|8<<8|10)) & 0xff0000) >>
8 | ((__uint32_t)((1<<24|1<<16|8<<8|10)) &
0xff000000) >> 24) : __swap32md((1<<24|1<<
16|8<<8|10)));
542 *lp++ = htonl(tcp_now + tp->ts_modulate)(__uint32_t)(__builtin_constant_p(tcp_now + tp->ts_modulate
) ? (__uint32_t)(((__uint32_t)(tcp_now + tp->ts_modulate) &
0xff) << 24 | ((__uint32_t)(tcp_now + tp->ts_modulate
) & 0xff00) << 8 | ((__uint32_t)(tcp_now + tp->ts_modulate
) & 0xff0000) >> 8 | ((__uint32_t)(tcp_now + tp->
ts_modulate) & 0xff000000) >> 24) : __swap32md(tcp_now
+ tp->ts_modulate));
543 *lp = htonl(tp->ts_recent)(__uint32_t)(__builtin_constant_p(tp->ts_recent) ? (__uint32_t
)(((__uint32_t)(tp->ts_recent) & 0xff) << 24 | (
(__uint32_t)(tp->ts_recent) & 0xff00) << 8 | ((__uint32_t
)(tp->ts_recent) & 0xff0000) >> 8 | ((__uint32_t
)(tp->ts_recent) & 0xff000000) >> 24) : __swap32md
(tp->ts_recent));
544 optlen += TCPOLEN_TSTAMP_APPA(10 +2);
545
546 /* Set receive buffer autosizing timestamp. */
547 if (tp->rfbuf_ts == 0)
548 tp->rfbuf_ts = tcp_now;
549
550 }
551
552#ifdef TCP_SIGNATURE1
553 if (tp->t_flags & TF_SIGNATURE0x0400) {
35
←
Assuming the condition is false
→
36
←
Taking false branch
→
554 u_int8_t *bp = (u_int8_t *)(opt + optlen);
555
556 /* Send signature option */
557 *(bp++) = TCPOPT_SIGNATURE19;
558 *(bp++) = TCPOLEN_SIGNATURE18;
559 sigoff = optlen + 2;
560
561 {
562 unsigned int i;
563
564 for (i = 0; i < 16; i++)
565 *(bp++) = 0;
566 }
567
568
569 /* Pad options list to the next 32 bit boundary and
570 * terminate it.
571 */
572 *bp++ = TCPOPT_NOP1;
573 *bp++ = TCPOPT_NOP1;
574
575 optlen += TCPOLEN_SIGLEN(18 +2);
576 }
577#endif /* TCP_SIGNATURE */
578
579 /*
580 * Send SACKs if necessary. This should be the last option processed.
581 * Only as many SACKs are sent as are permitted by the maximum options
582 * size. No more than three SACKs are sent.
583 */
584 if (tp->sack_enable
36.1
Field 'sack_enable' is 0
 && tp->t_state == TCPS_ESTABLISHED4 &&
585 (tp->t_flags & (TF_SACK_PERMIT0x0200|TF_NOOPT0x0008)) == TF_SACK_PERMIT0x0200 &&
586 tp->rcv_numsacks) {
587 u_int32_t *lp = (u_int32_t *)(opt + optlen);
588 u_int32_t *olp = lp++;
589 int count = 0; /* actual number of SACKs inserted */
590 int maxsack = (MAX_TCPOPTLEN40 - (optlen + 4))/TCPOLEN_SACK8;
591
592 tcpstat_inc(tcps_sack_snd_opts);
593 maxsack = min(maxsack, TCP_MAX_SACK3);
594 for (i = 0; (i < tp->rcv_numsacks && count < maxsack); i++) {
595 struct sackblk sack = tp->sackblks[i];
596 if (sack.start == 0 && sack.end == 0)
597 continue;
598 *lp++ = htonl(sack.start)(__uint32_t)(__builtin_constant_p(sack.start) ? (__uint32_t)(
((__uint32_t)(sack.start) & 0xff) << 24 | ((__uint32_t
)(sack.start) & 0xff00) << 8 | ((__uint32_t)(sack.start
) & 0xff0000) >> 8 | ((__uint32_t)(sack.start) &
0xff000000) >> 24) : __swap32md(sack.start));
599 *lp++ = htonl(sack.end)(__uint32_t)(__builtin_constant_p(sack.end) ? (__uint32_t)(((
__uint32_t)(sack.end) & 0xff) << 24 | ((__uint32_t)
(sack.end) & 0xff00) << 8 | ((__uint32_t)(sack.end)
& 0xff0000) >> 8 | ((__uint32_t)(sack.end) & 0xff000000
) >> 24) : __swap32md(sack.end));
600 count++;
601 }
602 *olp = htonl(TCPOPT_SACK_HDR|(TCPOLEN_SACK*count+2))(__uint32_t)(__builtin_constant_p((1<<24|1<<16|5<<
8)|(8*count+2)) ? (__uint32_t)(((__uint32_t)((1<<24|1<<
16|5<<8)|(8*count+2)) & 0xff) << 24 | ((__uint32_t
)((1<<24|1<<16|5<<8)|(8*count+2)) & 0xff00
) << 8 | ((__uint32_t)((1<<24|1<<16|5<<
8)|(8*count+2)) & 0xff0000) >> 8 | ((__uint32_t)((1
<<24|1<<16|5<<8)|(8*count+2)) & 0xff000000
) >> 24) : __swap32md((1<<24|1<<16|5<<
8)|(8*count+2)));
603 optlen += TCPOLEN_SACK8*count + 4; /* including leading NOPs */
604 }
605
606#ifdef DIAGNOSTIC1
607 if (optlen
36.2
'optlen' is <= MAX_TCPOPTLEN
 > MAX_TCPOPTLEN40)
37
←
Taking false branch
→
608 panic("tcp_output: options too long");
609#endif /* DIAGNOSTIC */
610
611 hdrlen += optlen;
612
613 /*
614 * Adjust data length if insertion of options will
615 * bump the packet length beyond the t_maxopd length.
616 */
617 if (len > tp->t_maxopd - optlen) {
38
←
Taking false branch
→
618 len = tp->t_maxopd - optlen;
619 sendalot = 1;
620 flags &= ~TH_FIN0x01;
621 }
622
623#ifdef DIAGNOSTIC1
624 if (max_linkhdr + hdrlen > MCLBYTES(1 << 11))
39
←
Assuming the condition is false
→
40
←
Taking false branch
→
625 panic("tcphdr too big");
626#endif
627
628 /*
629 * Grab a header mbuf, attaching a copy of data to
630 * be transmitted, and initialize the header from
631 * the template for sends on this connection.
632 */
633 if (len
40.1
'len' is 0
) {
41
←
Taking false branch
→
634 if (tp->t_force && len == 1)
635 tcpstat_inc(tcps_sndprobe);
636 else if (SEQ_LT(tp->snd_nxt, tp->snd_max)((int)((tp->snd_nxt)-(tp->snd_max)) < 0)) {
637 tcpstat_pkt(tcps_sndrexmitpack, tcps_sndrexmitbyte,
638 len);
639 } else {
640 tcpstat_pkt(tcps_sndpack, tcps_sndbyte, len);
641 }
642#ifdef notyet
643 if ((m = m_copypack(so->so_snd.sb_mb, off,
644 (int)len, max_linkhdr + hdrlen)) == 0) {
645 error = ENOBUFS55;
646 goto out;
647 }
648 /*
649 * m_copypack left space for our hdr; use it.
650 */
651 m->m_lenm_hdr.mh_len += hdrlen;
652 m->m_datam_hdr.mh_data -= hdrlen;
653#else
654 MGETHDR(m, M_DONTWAIT, MT_HEADER)m = m_gethdr((0x0002), (2));
655 if (m != NULL((void *)0) && max_linkhdr + hdrlen > MHLEN((256 - sizeof(struct m_hdr)) - sizeof(struct pkthdr))) {
656 MCLGET(m, M_DONTWAIT)(void) m_clget((m), (0x0002), (1 << 11));
657 if ((m->m_flagsm_hdr.mh_flags & M_EXT0x0001) == 0) {
658 m_freem(m);
659 m = NULL((void *)0);
660 }
661 }
662 if (m == NULL((void *)0)) {
663 error = ENOBUFS55;
664 goto out;
665 }
666 m->m_datam_hdr.mh_data += max_linkhdr;
667 m->m_lenm_hdr.mh_len = hdrlen;
668 if (len <= m_trailingspace(m)) {
669 m_copydata(so->so_snd.sb_mb, off, (int) len,
670 mtod(m, caddr_t)((caddr_t)((m)->m_hdr.mh_data)) + hdrlen);
671 m->m_lenm_hdr.mh_len += len;
672 } else {
673 m->m_nextm_hdr.mh_next = m_copym(so->so_snd.sb_mb, off, (int) len,
674 M_NOWAIT0x0002);
675 if (m->m_nextm_hdr.mh_next == 0) {
676 (void) m_free(m);
677 error = ENOBUFS55;
678 goto out;
679 }
680 }
681 if (so->so_snd.sb_mb->m_flagsm_hdr.mh_flags & M_PKTHDR0x0002)
682 m->m_pkthdrM_dat.MH.MH_pkthdr.ph_loopcnt =
683 so->so_snd.sb_mb->m_pkthdrM_dat.MH.MH_pkthdr.ph_loopcnt;
684#endif
685 /*
686 * If we're sending everything we've got, set PUSH.
687 * (This will keep happy those implementations which only
688 * give data to the user when a buffer fills or
689 * a PUSH comes in.)
690 */
691 if (off + len == so->so_snd.sb_cc && !soissending(so)((so)->so_state & 0x2000))
692 flags |= TH_PUSH0x08;
693 } else {
694 if (tp->t_flags & TF_ACKNOW0x0001)
42
←
Taking false branch
→
695 tcpstat_inc(tcps_sndacks);
696 else if (flags & (TH_SYN0x02|TH_FIN0x01|TH_RST0x04))
43
←
Assuming the condition is false
→
44
←
Taking false branch
→
697 tcpstat_inc(tcps_sndctrl);
698 else if (SEQ_GT(tp->snd_up, tp->snd_una)((int)((tp->snd_up)-(tp->snd_una)) > 0))
45
←
Taking false branch
→
699 tcpstat_inc(tcps_sndurg);
700 else
701 tcpstat_inc(tcps_sndwinup);
702
703 MGETHDR(m, M_DONTWAIT, MT_HEADER)m = m_gethdr((0x0002), (2));
704 if (m != NULL((void *)0) && max_linkhdr + hdrlen > MHLEN((256 - sizeof(struct m_hdr)) - sizeof(struct pkthdr))) {
46
←
Assuming 'm' is not equal to NULL
→
47
←
Assuming the condition is false
→
48
←
Taking false branch
→
705 MCLGET(m, M_DONTWAIT)(void) m_clget((m), (0x0002), (1 << 11));
706 if ((m->m_flagsm_hdr.mh_flags & M_EXT0x0001) == 0) {
707 m_freem(m);
708 m = NULL((void *)0);
709 }
710 }
711 if (m
48.1
'm' is not equal to NULL
 == NULL((void *)0)) {
49
←
Taking false branch
→
712 error = ENOBUFS55;
713 goto out;
714 }
715 m->m_datam_hdr.mh_data += max_linkhdr;
716 m->m_lenm_hdr.mh_len = hdrlen;
717 }
718 m->m_pkthdrM_dat.MH.MH_pkthdr.ph_ifidx = 0;
719 m->m_pkthdrM_dat.MH.MH_pkthdr.len = hdrlen + len;
720
721 if (!tp->t_template)
50
←
Assuming field 't_template' is non-null
→
51
←
Taking false branch
→
722 panic("tcp_output");
723#ifdef DIAGNOSTIC1
724 if (tp->t_template->m_lenm_hdr.mh_len != hdrlen - optlen)
52
←
Assuming the condition is false
→
53
←
Taking false branch
→
725 panic("tcp_output: template len != hdrlen - optlen");
726#endif /* DIAGNOSTIC */
727 memcpy(mtod(m, caddr_t), mtod(tp->t_template, caddr_t),__builtin_memcpy((((caddr_t)((m)->m_hdr.mh_data))), (((caddr_t
)((tp->t_template)->m_hdr.mh_data))), (tp->t_template
->m_hdr.mh_len))
728 tp->t_template->m_len)__builtin_memcpy((((caddr_t)((m)->m_hdr.mh_data))), (((caddr_t
)((tp->t_template)->m_hdr.mh_data))), (tp->t_template
->m_hdr.mh_len));
729 th = (struct tcphdr *)(mtod(m, caddr_t)((caddr_t)((m)->m_hdr.mh_data)) + tp->t_template->m_lenm_hdr.mh_len -
730 sizeof(struct tcphdr));
731
732 /*
733 * Fill in fields, remembering maximum advertised
734 * window for use in delaying messages about window sizes.
735 * If resending a FIN, be sure not to use a new sequence number.
736 */
737 if ((flags & TH_FIN0x01) && (tp->t_flags & TF_SENTFIN0x0010) &&
54
←
Taking false branch
→
738 (tp->snd_nxt
53.1
Field 'snd_nxt' is not equal to field 'snd_max'
 == tp->snd_max))
739 tp->snd_nxt--;
740 /*
741 * If we are doing retransmissions, then snd_nxt will
742 * not reflect the first unsent octet. For ACK only
743 * packets, we do not want the sequence number of the
744 * retransmitted packet, we want the sequence number
745 * of the next unsent octet. So, if there is no data
746 * (and no SYN or FIN), use snd_max instead of snd_nxt
747 * when filling in ti_seq. But if we are in persist
748 * state, snd_max might reflect one byte beyond the
749 * right edge of the window, so use snd_nxt in that
750 * case, since we know we aren't doing a retransmission.
751 * (retransmit and persist are mutually exclusive...)
752 */
753 if (len
54.1
'len' is 0
 || (flags & (TH_SYN0x02|TH_FIN0x01)) || TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))))
55
←
Assuming the condition is false
→
56
←
Assuming the condition is false
→
57
←
Taking false branch
→
754 th->th_seq = htonl(tp->snd_nxt)(__uint32_t)(__builtin_constant_p(tp->snd_nxt) ? (__uint32_t
)(((__uint32_t)(tp->snd_nxt) & 0xff) << 24 | ((__uint32_t
)(tp->snd_nxt) & 0xff00) << 8 | ((__uint32_t)(tp
->snd_nxt) & 0xff0000) >> 8 | ((__uint32_t)(tp->
snd_nxt) & 0xff000000) >> 24) : __swap32md(tp->snd_nxt
));
755 else
756 th->th_seq = htonl(tp->snd_max)(__uint32_t)(__builtin_constant_p(tp->snd_max) ? (__uint32_t
)(((__uint32_t)(tp->snd_max) & 0xff) << 24 | ((__uint32_t
)(tp->snd_max) & 0xff00) << 8 | ((__uint32_t)(tp
->snd_max) & 0xff0000) >> 8 | ((__uint32_t)(tp->
snd_max) & 0xff000000) >> 24) : __swap32md(tp->snd_max
));
58
←
'?' condition is false
→
757
758 if (sack_rxmit
58.1
'sack_rxmit' is 0
) {
59
←
Taking false branch
→
759 /*
760 * If sendalot was turned on (due to option stuffing), turn it
761 * off. Properly set th_seq field. Advance the ret'x pointer
762 * by len.
763 */
764 if (sendalot)
765 sendalot = 0;
766 th->th_seq = htonl(p->rxmit)(__uint32_t)(__builtin_constant_p(p->rxmit) ? (__uint32_t)
(((__uint32_t)(p->rxmit) & 0xff) << 24 | ((__uint32_t
)(p->rxmit) & 0xff00) << 8 | ((__uint32_t)(p->
rxmit) & 0xff0000) >> 8 | ((__uint32_t)(p->rxmit
) & 0xff000000) >> 24) : __swap32md(p->rxmit));
767 p->rxmit += len;
768 tcpstat_pkt(tcps_sack_rexmits, tcps_sack_rexmit_bytes, len);
769 }
770
771 th->th_ack = htonl(tp->rcv_nxt)(__uint32_t)(__builtin_constant_p(tp->rcv_nxt) ? (__uint32_t
)(((__uint32_t)(tp->rcv_nxt) & 0xff) << 24 | ((__uint32_t
)(tp->rcv_nxt) & 0xff00) << 8 | ((__uint32_t)(tp
->rcv_nxt) & 0xff0000) >> 8 | ((__uint32_t)(tp->
rcv_nxt) & 0xff000000) >> 24) : __swap32md(tp->rcv_nxt
));
60
←
'?' condition is false
→
772 if (optlen
60.1
'optlen' is 0
) {
61
←
Taking false branch
→
773 memcpy(th + 1, opt, optlen)__builtin_memcpy((th + 1), (opt), (optlen));
774 th->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
775 }
776#ifdef TCP_ECN1
777 if (tcp_do_ecn) {
62
←
Assuming 'tcp_do_ecn' is 0
→
63
←
Taking false branch
→
778 /*
779 * if we have received congestion experienced segs,
780 * set ECE bit.
781 */
782 if (tp->t_flags & TF_RCVD_CE0x00010000) {
783 flags |= TH_ECE0x40;
784 tcpstat_inc(tcps_ecn_sndece);
785 }
786 if (!(tp->t_flags & TF_DISABLE_ECN0x00040000)) {
787 /*
788 * if this is a SYN seg, set ECE and CWR.
789 * set only ECE for SYN-ACK if peer supports ECN.
790 */
791 if ((flags & (TH_SYN0x02|TH_ACK0x10)) == TH_SYN0x02)
792 flags |= (TH_ECE0x40|TH_CWR0x80);
793 else if ((tp->t_flags & TF_ECN_PERMIT0x00008000) &&
794 (flags & (TH_SYN0x02|TH_ACK0x10)) == (TH_SYN0x02|TH_ACK0x10))
795 flags |= TH_ECE0x40;
796 }
797 /*
798 * if we have reduced the congestion window, notify
799 * the peer by setting CWR bit.
800 */
801 if ((tp->t_flags & TF_ECN_PERMIT0x00008000) &&
802 (tp->t_flags & TF_SEND_CWR0x00020000)) {
803 flags |= TH_CWR0x80;
804 tp->t_flags &= ~TF_SEND_CWR0x00020000;
805 tcpstat_inc(tcps_ecn_sndcwr);
806 }
807 }
808#endif
809 th->th_flags = flags;
810
811 /*
812 * Calculate receive window. Don't shrink window,
813 * but avoid silly window syndrome.
814 */
815 if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)tp->t_maxseg)
64
←
Assuming the condition is false
→
816 win = 0;
817 if (win > (long)TCP_MAXWIN65535 << tp->rcv_scale)
65
←
Assuming the condition is false
→
66
←
Taking false branch
→
818 win = (long)TCP_MAXWIN65535 << tp->rcv_scale;
819 if (win < (long)(int32_t)(tp->rcv_adv - tp->rcv_nxt))
67
←
Assuming the condition is false
→
68
←
Taking false branch
→
820 win = (long)(int32_t)(tp->rcv_adv - tp->rcv_nxt);
821 if (flags & TH_RST0x04)
69
←
Assuming the condition is false
→
70
←
Taking false branch
→
822 win = 0;
823 th->th_win = htons((u_int16_t) (win>>tp->rcv_scale))(__uint16_t)(__builtin_constant_p((u_int16_t) (win>>tp->
rcv_scale)) ? (__uint16_t)(((__uint16_t)((u_int16_t) (win>>
tp->rcv_scale)) & 0xffU) << 8 | ((__uint16_t)((u_int16_t
) (win>>tp->rcv_scale)) & 0xff00U) >> 8) :
__swap16md((u_int16_t) (win>>tp->rcv_scale)));
71
←
'?' condition is false
→
824 if (SEQ_GT(tp->snd_up, tp->snd_nxt)((int)((tp->snd_up)-(tp->snd_nxt)) > 0)) {
72
←
Taking false branch
→
825 u_int32_t urp = tp->snd_up - tp->snd_nxt;
826 if (urp > IP_MAXPACKET65535)
827 urp = IP_MAXPACKET65535;
828 th->th_urp = htons((u_int16_t)urp)(__uint16_t)(__builtin_constant_p((u_int16_t)urp) ? (__uint16_t
)(((__uint16_t)((u_int16_t)urp) & 0xffU) << 8 | ((__uint16_t
)((u_int16_t)urp) & 0xff00U) >> 8) : __swap16md((u_int16_t
)urp));
829 th->th_flags |= TH_URG0x20;
830 } else
831 /*
832 * If no urgent pointer to send, then we pull
833 * the urgent pointer to the left edge of the send window
834 * so that it doesn't drift into the send window on sequence
835 * number wraparound.
836 */
837 tp->snd_up = tp->snd_una; /* drag it along */
838
839#ifdef TCP_SIGNATURE1
840 if (tp->t_flags & TF_SIGNATURE0x0400) {
73
←
Taking false branch
→
841 int iphlen;
842 union sockaddr_union src, dst;
843 struct tdb *tdb;
844
845 bzero(&src, sizeof(union sockaddr_union))__builtin_bzero((&src), (sizeof(union sockaddr_union)));
846 bzero(&dst, sizeof(union sockaddr_union))__builtin_bzero((&dst), (sizeof(union sockaddr_union)));
847
848 switch (tp->pf) {
849 case 0: /*default to PF_INET*/
850 case AF_INET2:
851 iphlen = sizeof(struct ip);
852 src.sa.sa_len = sizeof(struct sockaddr_in);
853 src.sa.sa_family = AF_INET2;
854 src.sin.sin_addr = mtod(m, struct ip *)((struct ip *)((m)->m_hdr.mh_data))->ip_src;
855 dst.sa.sa_len = sizeof(struct sockaddr_in);
856 dst.sa.sa_family = AF_INET2;
857 dst.sin.sin_addr = mtod(m, struct ip *)((struct ip *)((m)->m_hdr.mh_data))->ip_dst;
858 break;
859#ifdef INET61
860 case AF_INET624:
861 iphlen = sizeof(struct ip6_hdr);
862 src.sa.sa_len = sizeof(struct sockaddr_in6);
863 src.sa.sa_family = AF_INET624;
864 src.sin6.sin6_addr = mtod(m, struct ip6_hdr *)((struct ip6_hdr *)((m)->m_hdr.mh_data))->ip6_src;
865 dst.sa.sa_len = sizeof(struct sockaddr_in6);
866 dst.sa.sa_family = AF_INET624;
867 dst.sin6.sin6_addr = mtod(m, struct ip6_hdr *)((struct ip6_hdr *)((m)->m_hdr.mh_data))->ip6_dst;
868 break;
869#endif /* INET6 */
870 }
871
872 tdb = gettdbbysrcdst(rtable_l2(tp->t_inpcb->inp_rtableid),gettdbbysrcdst_dir((rtable_l2(tp->t_inpcb->inp_rtableid
)),(0),(&src),(&dst),(6),0)
873 0, &src, &dst, IPPROTO_TCP)gettdbbysrcdst_dir((rtable_l2(tp->t_inpcb->inp_rtableid
)),(0),(&src),(&dst),(6),0);
874 if (tdb == NULL((void *)0)) {
875 m_freem(m);
876 return (EPERM1);
877 }
878
879 if (tcp_signature(tdb, tp->pf, m, th, iphlen, 0,
880 mtod(m, caddr_t)((caddr_t)((m)->m_hdr.mh_data)) + hdrlen - optlen + sigoff) < 0) {
881 m_freem(m);
882 tdb_unref(tdb);
883 return (EINVAL22);
884 }
885 tdb_unref(tdb);
886 }
887#endif /* TCP_SIGNATURE */
888
889 /* Defer checksumming until later (ip_output() or hardware) */
890 m->m_pkthdrM_dat.MH.MH_pkthdr.csum_flags |= M_TCP_CSUM_OUT0x0002;
891
892 /*
893 * In transmit state, time the transmission and arrange for
894 * the retransmit. In persist state, just set snd_max.
895 */
896 if (tp->t_force
73.1
Field 't_force' is equal to 0
 == 0 || TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))) == 0) {
897 tcp_seq startseq = tp->snd_nxt;
898
899 /*
900 * Advance snd_nxt over sequence space of this segment.
901 */
902 if (flags & (TH_SYN0x02|TH_FIN0x01)) {
74
←
Taking false branch
→
903 if (flags & TH_SYN0x02)
904 tp->snd_nxt++;
905 if (flags & TH_FIN0x01) {
906 tp->snd_nxt++;
907 tp->t_flags |= TF_SENTFIN0x0010;
908 }
909 }
910 if (tp->sack_enable
74.1
Field 'sack_enable' is 0
) {
75
←
Taking false branch
→
911 if (sack_rxmit && (p->rxmit != tp->snd_nxt)) {
912 goto timer;
913 }
914 }
915 tp->snd_nxt += len;
916 if (SEQ_GT(tp->snd_nxt, tp->snd_max)((int)((tp->snd_nxt)-(tp->snd_max)) > 0)) {
76
←
Taking true branch
→
917 tp->snd_max = tp->snd_nxt;
918 /*
919 * Time this transmission if not a retransmission and
920 * not currently timing anything.
921 */
922 if (tp->t_rtttime == 0) {
77
←
Assuming field 't_rtttime' is not equal to 0
→
78
←
Taking false branch
→
923 tp->t_rtttime = tcp_now;
924 tp->t_rtseq = startseq;
925 tcpstat_inc(tcps_segstimed);
926 }
927 }
928
929 /*
930 * Set retransmit timer if not currently set,
931 * and not doing an ack or a keep-alive probe.
932 * Initial value for retransmit timer is smoothed
933 * round-trip time + 2 * round-trip time variance.
934 * Initialize shift counter which is used for backoff
935 * of retransmit time.
936 */
937 timer:
938 if (tp->sack_enable
78.1
Field 'sack_enable' is 0
 && sack_rxmit &&
939 TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))) == 0 &&
940 tp->snd_nxt != tp->snd_max) {
941 TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur)do { (((tp)->t_flags) |= (0x04000000 << (0))); timeout_add_msec
(&(tp)->t_timer[(0)], (tp->t_rxtcur) * 500); } while
(0);
942 if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1)))) {
943 TCP_TIMER_DISARM(tp, TCPT_PERSIST)do { (((tp)->t_flags) &= ~(0x04000000 << (1))); timeout_del
(&(tp)->t_timer[(1)]); } while (0);
944 tp->t_rxtshift = 0;
945 }
946 }
947
948 if (TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))) == 0 &&
79
←
Assuming the condition is false
→
949 tp->snd_nxt != tp->snd_una) {
950 TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur)do { (((tp)->t_flags) |= (0x04000000 << (0))); timeout_add_msec
(&(tp)->t_timer[(0)], (tp->t_rxtcur) * 500); } while
(0);
951 if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1)))) {
952 TCP_TIMER_DISARM(tp, TCPT_PERSIST)do { (((tp)->t_flags) &= ~(0x04000000 << (1))); timeout_del
(&(tp)->t_timer[(1)]); } while (0);
953 tp->t_rxtshift = 0;
954 }
955 }
956
957 if (len
79.1
'len' is equal to 0
 == 0 && so->so_snd.sb_cc &&
80
←
Assuming field 'sb_cc' is 0
→
958 TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))) == 0 &&
959 TCP_TIMER_ISARMED(tp, TCPT_PERSIST)(((tp)->t_flags) & (0x04000000 << (1))) == 0) {
960 /*
961 * Avoid a situation where we do not set persist timer
962 * after a zero window condition. For example:
963 * 1) A -> B: packet with enough data to fill the window
964 * 2) B -> A: ACK for #1 + new data (0 window
965 * advertisement)
966 * 3) A -> B: ACK for #2, 0 len packet
967 *
968 * In this case, A will not activate the persist timer,
969 * because it chose to send a packet. Unless tcp_output
970 * is called for some other reason (delayed ack timer,
971 * another input packet from B, socket syscall), A will
972 * not send zero window probes.
973 *
974 * So, if you send a 0-length packet, but there is data
975 * in the socket buffer, and neither the rexmt or
976 * persist timer is already set, then activate the
977 * persist timer.
978 */
979 tp->t_rxtshift = 0;
980 tcp_setpersist(tp);
981 }
982 } else
983 if (SEQ_GT(tp->snd_nxt + len, tp->snd_max)((int)((tp->snd_nxt + len)-(tp->snd_max)) > 0))
984 tp->snd_max = tp->snd_nxt + len;
985
986 tcp_update_sndspace(tp);
987
988 /*
989 * Trace.
990 */
991 if (so->so_options & SO_DEBUG0x0001)
81
←
Assuming the condition is false
→
82
←
Taking false branch
→
992 tcp_trace(TA_OUTPUT1, tp->t_state, tp, tp, mtod(m, caddr_t)((caddr_t)((m)->m_hdr.mh_data)), 0,
993 len);
994
995 /*
996 * Fill in IP length and desired time to live and
997 * send to IP level. There should be a better way
998 * to handle ttl and tos; we could keep them in
999 * the template, but need a way to checksum without them.
1000 */
1001
1002#ifdef TCP_ECN1
1003 /*
1004 * if peer is ECN capable, set the ECT bit in the IP header.
1005 * but don't set ECT for a pure ack, a retransmit or a window probe.
1006 */
1007 needect = 0;
1008 if (tcp_do_ecn && (tp->t_flags & TF_ECN_PERMIT0x00008000)) {
83
←
Assuming 'tcp_do_ecn' is 0
→
1009 if (len == 0 || SEQ_LT(tp->snd_nxt, tp->snd_max)((int)((tp->snd_nxt)-(tp->snd_max)) < 0) ||
1010 (tp->t_force && len == 1)) {
1011 /* don't set ECT */
1012 } else {
1013 needect = 1;
1014 tcpstat_inc(tcps_ecn_sndect);
1015 }
1016 }
1017#endif
1018
1019 /* force routing table */
1020 m->m_pkthdrM_dat.MH.MH_pkthdr.ph_rtableid = tp->t_inpcb->inp_rtableid;
1021
1022#if NPF1 > 0
1023 pf_mbuf_link_inpcb(m, tp->t_inpcb);
1024#endif
1025
1026 switch (tp->pf) {
84
←
'Default' branch taken. Execution continues on line 1073
→
1027 case 0: /*default to PF_INET*/
1028 case AF_INET2:
1029 {
1030 struct ip *ip;
1031
1032 ip = mtod(m, struct ip *)((struct ip *)((m)->m_hdr.mh_data));
1033 ip->ip_len = htons(m->m_pkthdr.len)(__uint16_t)(__builtin_constant_p(m->M_dat.MH.MH_pkthdr.len
) ? (__uint16_t)(((__uint16_t)(m->M_dat.MH.MH_pkthdr.len) &
0xffU) << 8 | ((__uint16_t)(m->M_dat.MH.MH_pkthdr.len
) & 0xff00U) >> 8) : __swap16md(m->M_dat.MH.MH_pkthdr
.len));
1034 packetlen = m->m_pkthdrM_dat.MH.MH_pkthdr.len;
1035 ip->ip_ttl = tp->t_inpcb->inp_ipinp_hu.hu_ip.ip_ttl;
1036 ip->ip_tos = tp->t_inpcb->inp_ipinp_hu.hu_ip.ip_tos;
1037#ifdef TCP_ECN1
1038 if (needect)
1039 ip->ip_tos |= IPTOS_ECN_ECT00x02;
1040#endif
1041 }
1042#if NSTOEPLITZ1 > 0
1043 m->m_pkthdrM_dat.MH.MH_pkthdr.ph_flowid = tp->t_inpcb->inp_flowid;
1044 SET(m->m_pkthdr.csum_flags, M_FLOWID)((m->M_dat.MH.MH_pkthdr.csum_flags) |= (0x4000));
1045#endif
1046 error = ip_output(m, tp->t_inpcb->inp_options,
1047 &tp->t_inpcb->inp_routeinp_ru.ru_route,
1048 (ip_mtudisc ? IP_MTUDISC0x0800 : 0), NULL((void *)0), tp->t_inpcb, 0);
1049 break;
1050#ifdef INET61
1051 case AF_INET624:
1052 {
1053 struct ip6_hdr *ip6;
1054
1055 ip6 = mtod(m, struct ip6_hdr *)((struct ip6_hdr *)((m)->m_hdr.mh_data));
1056 ip6->ip6_plenip6_ctlun.ip6_un1.ip6_un1_plen = m->m_pkthdrM_dat.MH.MH_pkthdr.len -
1057 sizeof(struct ip6_hdr);
1058 packetlen = m->m_pkthdrM_dat.MH.MH_pkthdr.len;
1059 ip6->ip6_nxtip6_ctlun.ip6_un1.ip6_un1_nxt = IPPROTO_TCP6;
1060 ip6->ip6_hlimip6_ctlun.ip6_un1.ip6_un1_hlim = in6_selecthlim(tp->t_inpcb);
1061#ifdef TCP_ECN1
1062 if (needect)
1063 ip6->ip6_flowip6_ctlun.ip6_un1.ip6_un1_flow |= htonl(IPTOS_ECN_ECT0 << 20)(__uint32_t)(__builtin_constant_p(0x02 << 20) ? (__uint32_t
)(((__uint32_t)(0x02 << 20) & 0xff) << 24 | (
(__uint32_t)(0x02 << 20) & 0xff00) << 8 | ((__uint32_t
)(0x02 << 20) & 0xff0000) >> 8 | ((__uint32_t
)(0x02 << 20) & 0xff000000) >> 24) : __swap32md
(0x02 << 20));
1064#endif
1065 }
1066 error = ip6_output(m, tp->t_inpcb->inp_outputopts6,
1067 &tp->t_inpcb->inp_route6inp_ru.ru_route6,
1068 0, NULL((void *)0), tp->t_inpcb);
1069 break;
1070#endif /* INET6 */
1071 }
1072
1073 if (error) {
85
←
Branch condition evaluates to a garbage value
1074out:
1075 if (error == ENOBUFS55) {
1076 /*
1077 * If the interface queue is full, or IP cannot
1078 * get an mbuf, trigger TCP slow start.
1079 */
1080 tp->snd_cwnd = tp->t_maxseg;
1081 return (0);
1082 }
1083 if (error == EMSGSIZE40) {
1084 /*
1085 * ip_output() will have already fixed the route
1086 * for us. tcp_mtudisc() will, as its last action,
1087 * initiate retransmission, so it is important to
1088 * not do so here.
1089 */
1090 tcp_mtudisc(tp->t_inpcb, -1);
1091 return (0);
1092 }
1093 if ((error == EHOSTUNREACH65 || error == ENETDOWN50) &&
1094 TCPS_HAVERCVDSYN(tp->t_state)((tp->t_state) >= 3)) {
1095 tp->t_softerror = error;
1096 return (0);
1097 }
1098
1099 /* Restart the delayed ACK timer, if necessary. */
1100 if (TCP_TIMER_ISARMED(tp, TCPT_DELACK)(((tp)->t_flags) & (0x04000000 << (5))))
1101 TCP_TIMER_ARM_MSEC(tp, TCPT_DELACK, tcp_delack_msecs)do { (((tp)->t_flags) |= (0x04000000 << (5))); timeout_add_msec
(&(tp)->t_timer[(5)], (tcp_delack_msecs)); } while (0);
1102
1103 return (error);
1104 }
1105
1106 if (packetlen > tp->t_pmtud_mtu_sent)
1107 tp->t_pmtud_mtu_sent = packetlen;
1108
1109 tcpstat_inc(tcps_sndtotal);
1110 if (TCP_TIMER_ISARMED(tp, TCPT_DELACK)(((tp)->t_flags) & (0x04000000 << (5))))
1111 tcpstat_inc(tcps_delack);
1112
1113 /*
1114 * Data sent (as far as we can tell).
1115 * If this advertises a larger window than any other segment,
1116 * then remember the size of the advertised window.
1117 * Any pending ACK has now been sent.
1118 */
1119 if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv)((int)((tp->rcv_nxt+win)-(tp->rcv_adv)) > 0))
1120 tp->rcv_adv = tp->rcv_nxt + win;
1121 tp->last_ack_sent = tp->rcv_nxt;
1122 tp->t_flags &= ~TF_ACKNOW0x0001;
1123 TCP_TIMER_DISARM(tp, TCPT_DELACK)do { (((tp)->t_flags) &= ~(0x04000000 << (5))); timeout_del
(&(tp)->t_timer[(5)]); } while (0);
1124 if (sendalot)
1125 goto again;
1126 return (0);
1127}
1128
1129void
1130tcp_setpersist(struct tcpcb *tp)
1131{
1132 int t = ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + TCP_RTT_BASE_SHIFT2);
1133 int nticks;
1134
1135 if (TCP_TIMER_ISARMED(tp, TCPT_REXMT)(((tp)->t_flags) & (0x04000000 << (0))))
1136 panic("tcp_output REXMT");
1137 /*
1138 * Start/restart persistence timer.
1139 */
1140 if (t < tp->t_rttmin)
1141 t = tp->t_rttmin;
1142 TCPT_RANGESET(nticks, t * tcp_backoff[tp->t_rxtshift],do { (nticks) = (t * tcp_backoff[tp->t_rxtshift]); if ((nticks
) < (( 5*2))) (nticks) = (( 5*2)); else if ((nticks) > (
( 60*2))) (nticks) = (( 60*2)); } while ( 0)
1143 TCPTV_PERSMIN, TCPTV_PERSMAX)do { (nticks) = (t * tcp_backoff[tp->t_rxtshift]); if ((nticks
) < (( 5*2))) (nticks) = (( 5*2)); else if ((nticks) > (
( 60*2))) (nticks) = (( 60*2)); } while ( 0);
1144 TCP_TIMER_ARM(tp, TCPT_PERSIST, nticks)do { (((tp)->t_flags) |= (0x04000000 << (1))); timeout_add_msec
(&(tp)->t_timer[(1)], (nticks) * 500); } while (0);
1145 if (tp->t_rxtshift < TCP_MAXRXTSHIFT12)
1146 tp->t_rxtshift++;
1147}