Commit | Line | Data |
---|---|---|
b11be056 | 1 | /* tcp_input.c 6.1 83/07/29 */ |
87e78f19 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
dad64fdf | 5 | #include "../h/mbuf.h" |
8a13b737 | 6 | #include "../h/protosw.h" |
dad64fdf | 7 | #include "../h/socket.h" |
d52566dd | 8 | #include "../h/socketvar.h" |
f4d55810 SL |
9 | #include "../h/errno.h" |
10 | ||
11 | #include "../net/if.h" | |
c124e997 | 12 | #include "../net/route.h" |
f4d55810 SL |
13 | |
14 | #include "../netinet/in.h" | |
fcfe450e BJ |
15 | #include "../netinet/in_pcb.h" |
16 | #include "../netinet/in_systm.h" | |
fcfe450e BJ |
17 | #include "../netinet/ip.h" |
18 | #include "../netinet/ip_var.h" | |
19 | #include "../netinet/tcp.h" | |
20 | #include "../netinet/tcp_fsm.h" | |
21 | #include "../netinet/tcp_seq.h" | |
22 | #include "../netinet/tcp_timer.h" | |
23 | #include "../netinet/tcp_var.h" | |
24 | #include "../netinet/tcpip.h" | |
25 | #include "../netinet/tcp_debug.h" | |
87e78f19 | 26 | |
22856bb8 | 27 | int tcpprintfs = 0; |
60b16fa9 | 28 | int tcpcksum = 1; |
4b935108 | 29 | struct tcpiphdr tcp_saveti; |
8b5a83bb | 30 | extern tcpnodelack; |
87e78f19 | 31 | |
4b935108 | 32 | struct tcpcb *tcp_newtcpcb(); |
2ff61f9d BJ |
33 | /* |
34 | * TCP input routine, follows pages 65-76 of the | |
35 | * protocol specification dated September, 1981 very closely. | |
36 | */ | |
2b4b57cd BJ |
37 | tcp_input(m0) |
38 | struct mbuf *m0; | |
87e78f19 | 39 | { |
2b4b57cd | 40 | register struct tcpiphdr *ti; |
53a5409e | 41 | struct inpcb *inp; |
2b4b57cd | 42 | register struct mbuf *m; |
8b5a83bb | 43 | struct mbuf *om = 0; |
2b4b57cd | 44 | int len, tlen, off; |
8e65fd66 | 45 | register struct tcpcb *tp = 0; |
2b4b57cd | 46 | register int tiflags; |
d52566dd | 47 | struct socket *so; |
f1b2fa5b | 48 | int todrop, acked; |
4b935108 | 49 | short ostate; |
ebcadd38 | 50 | struct in_addr laddr; |
7aa16f99 | 51 | int dropsocket = 0; |
87e78f19 BJ |
52 | |
53 | /* | |
4aed14e3 BJ |
54 | * Get IP and TCP header together in first mbuf. |
55 | * Note: IP leaves IP header in first mbuf. | |
87e78f19 | 56 | */ |
2b4b57cd | 57 | m = m0; |
20790db4 | 58 | ti = mtod(m, struct tcpiphdr *); |
4aed14e3 | 59 | if (((struct ip *)ti)->ip_hl > (sizeof (struct ip) >> 2)) |
d63599ac | 60 | ip_stripoptions((struct ip *)ti, (struct mbuf *)0); |
6703c41f BJ |
61 | if (m->m_off > MMAXOFF || m->m_len < sizeof (struct tcpiphdr)) { |
62 | if ((m = m_pullup(m, sizeof (struct tcpiphdr))) == 0) { | |
8a13b737 | 63 | tcpstat.tcps_hdrops++; |
6703c41f | 64 | return; |
8a13b737 BJ |
65 | } |
66 | ti = mtod(m, struct tcpiphdr *); | |
67 | } | |
87e78f19 | 68 | |
2b4b57cd | 69 | /* |
4aed14e3 | 70 | * Checksum extended TCP header and data. |
2b4b57cd BJ |
71 | */ |
72 | tlen = ((struct ip *)ti)->ip_len; | |
73 | len = sizeof (struct ip) + tlen; | |
60b16fa9 | 74 | if (tcpcksum) { |
2b4b57cd BJ |
75 | ti->ti_next = ti->ti_prev = 0; |
76 | ti->ti_x1 = 0; | |
ac83b17a | 77 | ti->ti_len = (u_short)tlen; |
668cc26d | 78 | ti->ti_len = htons((u_short)ti->ti_len); |
4b6b94ca | 79 | if (ti->ti_sum = in_cksum(m, len)) { |
ee954ff1 SL |
80 | if (tcpprintfs) |
81 | printf("tcp sum: src %x\n", ti->ti_src); | |
2b4b57cd | 82 | tcpstat.tcps_badsum++; |
8a13b737 | 83 | goto drop; |
87e78f19 BJ |
84 | } |
85 | } | |
86 | ||
87 | /* | |
4aed14e3 | 88 | * Check that TCP offset makes sense, |
8b5a83bb | 89 | * pull out TCP options and adjust length. |
87e78f19 | 90 | */ |
2b4b57cd | 91 | off = ti->ti_off << 2; |
4b6b94ca | 92 | if (off < sizeof (struct tcphdr) || off > tlen) { |
ee954ff1 SL |
93 | if (tcpprintfs) |
94 | printf("tcp off: src %x off %d\n", ti->ti_src, off); | |
2b4b57cd | 95 | tcpstat.tcps_badoff++; |
8a13b737 | 96 | goto drop; |
2b4b57cd | 97 | } |
1e977657 BJ |
98 | tlen -= off; |
99 | ti->ti_len = tlen; | |
8b5a83bb BJ |
100 | if (off > sizeof (struct tcphdr)) { |
101 | if ((m = m_pullup(m, sizeof (struct ip) + off)) == 0) { | |
102 | tcpstat.tcps_hdrops++; | |
01b1394e | 103 | return; |
8b5a83bb BJ |
104 | } |
105 | ti = mtod(m, struct tcpiphdr *); | |
cce93e4b | 106 | om = m_get(M_DONTWAIT, MT_DATA); |
8b5a83bb BJ |
107 | if (om == 0) |
108 | goto drop; | |
8b5a83bb BJ |
109 | om->m_len = off - sizeof (struct tcphdr); |
110 | { caddr_t op = mtod(m, caddr_t) + sizeof (struct tcpiphdr); | |
668cc26d | 111 | bcopy(op, mtod(om, caddr_t), (unsigned)om->m_len); |
8b5a83bb | 112 | m->m_len -= om->m_len; |
668cc26d SL |
113 | bcopy(op+om->m_len, op, |
114 | (unsigned)(m->m_len-sizeof (struct tcpiphdr))); | |
8b5a83bb BJ |
115 | } |
116 | } | |
2ff61f9d | 117 | tiflags = ti->ti_flags; |
2b4b57cd | 118 | |
795e0416 | 119 | /* |
1e977657 | 120 | * Drop TCP and IP headers. |
795e0416 BJ |
121 | */ |
122 | off += sizeof (struct ip); | |
123 | m->m_off += off; | |
124 | m->m_len -= off; | |
125 | ||
8a13b737 | 126 | /* |
4aed14e3 | 127 | * Convert TCP protocol specific fields to host format. |
8a13b737 BJ |
128 | */ |
129 | ti->ti_seq = ntohl(ti->ti_seq); | |
130 | ti->ti_ack = ntohl(ti->ti_ack); | |
131 | ti->ti_win = ntohs(ti->ti_win); | |
132 | ti->ti_urp = ntohs(ti->ti_urp); | |
133 | ||
2b4b57cd | 134 | /* |
8075bb0e | 135 | * Locate pcb for segment. |
2b4b57cd | 136 | */ |
2ff61f9d | 137 | inp = in_pcblookup |
ebcadd38 BJ |
138 | (&tcb, ti->ti_src, ti->ti_sport, ti->ti_dst, ti->ti_dport, |
139 | INPLOOKUP_WILDCARD); | |
2ff61f9d BJ |
140 | |
141 | /* | |
142 | * If the state is CLOSED (i.e., TCB does not exist) then | |
4aed14e3 | 143 | * all data in the incoming segment is discarded. |
2ff61f9d | 144 | */ |
22856bb8 | 145 | if (inp == 0) |
8a13b737 | 146 | goto dropwithreset; |
2ff61f9d | 147 | tp = intotcpcb(inp); |
22856bb8 | 148 | if (tp == 0) |
8a13b737 | 149 | goto dropwithreset; |
f1b2fa5b | 150 | so = inp->inp_socket; |
4b935108 BJ |
151 | if (so->so_options & SO_DEBUG) { |
152 | ostate = tp->t_state; | |
153 | tcp_saveti = *ti; | |
154 | } | |
ebf42a75 BJ |
155 | if (so->so_options & SO_ACCEPTCONN) { |
156 | so = sonewconn(so); | |
157 | if (so == 0) | |
158 | goto drop; | |
7aa16f99 SL |
159 | /* |
160 | * This is ugly, but .... | |
161 | * | |
162 | * Mark socket as temporary until we're | |
163 | * committed to keeping it. The code at | |
164 | * ``drop'' and ``dropwithreset'' check the | |
165 | * flag dropsocket to see if the temporary | |
166 | * socket created here should be discarded. | |
167 | * We mark the socket as discardable until | |
168 | * we're committed to it below in TCPS_LISTEN. | |
169 | */ | |
170 | dropsocket++; | |
ebf42a75 BJ |
171 | inp = (struct inpcb *)so->so_pcb; |
172 | inp->inp_laddr = ti->ti_dst; | |
173 | inp->inp_lport = ti->ti_dport; | |
174 | tp = intotcpcb(inp); | |
175 | tp->t_state = TCPS_LISTEN; | |
176 | } | |
87e78f19 | 177 | |
405c9168 BJ |
178 | /* |
179 | * Segment received on connection. | |
180 | * Reset idle time and keep-alive timer. | |
181 | */ | |
182 | tp->t_idle = 0; | |
183 | tp->t_timer[TCPT_KEEP] = TCPTV_KEEP; | |
184 | ||
8b5a83bb BJ |
185 | /* |
186 | * Process options. | |
187 | */ | |
188 | if (om) { | |
189 | tcp_dooptions(tp, om); | |
190 | om = 0; | |
191 | } | |
192 | ||
87e78f19 | 193 | /* |
8a13b737 BJ |
194 | * Calculate amount of space in receive window, |
195 | * and then do TCP input processing. | |
87e78f19 | 196 | */ |
8a13b737 | 197 | tp->rcv_wnd = sbspace(&so->so_rcv); |
4b6b94ca BJ |
198 | if (tp->rcv_wnd < 0) |
199 | tp->rcv_wnd = 0; | |
2ff61f9d | 200 | |
87e78f19 BJ |
201 | switch (tp->t_state) { |
202 | ||
2ff61f9d BJ |
203 | /* |
204 | * If the state is LISTEN then ignore segment if it contains an RST. | |
205 | * If the segment contains an ACK then it is bad and send a RST. | |
206 | * If it does not contain a SYN then it is not interesting; drop it. | |
8a13b737 | 207 | * Otherwise initialize tp->rcv_nxt, and tp->irs, select an initial |
2ff61f9d | 208 | * tp->iss, and send a segment: |
8a13b737 | 209 | * <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK> |
2ff61f9d BJ |
210 | * Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss. |
211 | * Fill in remote peer address fields if not previously specified. | |
212 | * Enter SYN_RECEIVED state, and process any other fields of this | |
4aed14e3 | 213 | * segment in this state. |
2ff61f9d | 214 | */ |
8075bb0e | 215 | case TCPS_LISTEN: { |
789d2a39 | 216 | struct mbuf *am; |
8075bb0e BJ |
217 | register struct sockaddr_in *sin; |
218 | ||
2ff61f9d BJ |
219 | if (tiflags & TH_RST) |
220 | goto drop; | |
22856bb8 | 221 | if (tiflags & TH_ACK) |
8a13b737 | 222 | goto dropwithreset; |
22856bb8 | 223 | if ((tiflags & TH_SYN) == 0) |
2ff61f9d | 224 | goto drop; |
789d2a39 SL |
225 | am = m_get(M_DONTWAIT, MT_SONAME); |
226 | if (am == NULL) | |
227 | goto drop; | |
228 | am->m_len = sizeof (struct sockaddr_in); | |
a8d3bf7f | 229 | sin = mtod(am, struct sockaddr_in *); |
8075bb0e BJ |
230 | sin->sin_family = AF_INET; |
231 | sin->sin_addr = ti->ti_src; | |
232 | sin->sin_port = ti->ti_sport; | |
ebcadd38 | 233 | laddr = inp->inp_laddr; |
789d2a39 | 234 | if (inp->inp_laddr.s_addr == INADDR_ANY) |
ebcadd38 | 235 | inp->inp_laddr = ti->ti_dst; |
a8d3bf7f | 236 | if (in_pcbconnect(inp, am)) { |
ebcadd38 | 237 | inp->inp_laddr = laddr; |
5a1f132a | 238 | (void) m_free(am); |
4aed14e3 | 239 | goto drop; |
ebcadd38 | 240 | } |
5a1f132a | 241 | (void) m_free(am); |
4aed14e3 BJ |
242 | tp->t_template = tcp_template(tp); |
243 | if (tp->t_template == 0) { | |
244 | in_pcbdisconnect(inp); | |
ebcadd38 | 245 | inp->inp_laddr = laddr; |
93f92b1d | 246 | tp = 0; |
4aed14e3 BJ |
247 | goto drop; |
248 | } | |
8a13b737 | 249 | tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; |
2ff61f9d | 250 | tp->irs = ti->ti_seq; |
8a13b737 BJ |
251 | tcp_sendseqinit(tp); |
252 | tcp_rcvseqinit(tp); | |
2ff61f9d | 253 | tp->t_state = TCPS_SYN_RECEIVED; |
4aed14e3 | 254 | tp->t_timer[TCPT_KEEP] = TCPTV_KEEP; |
7aa16f99 | 255 | dropsocket = 0; /* committed to socket */ |
8a13b737 | 256 | goto trimthenstep6; |
8075bb0e | 257 | } |
87e78f19 | 258 | |
2ff61f9d BJ |
259 | /* |
260 | * If the state is SYN_SENT: | |
261 | * if seg contains an ACK, but not for our SYN, drop the input. | |
262 | * if seg contains a RST, then drop the connection. | |
263 | * if seg does not contain SYN, then drop it. | |
264 | * Otherwise this is an acceptable SYN segment | |
265 | * initialize tp->rcv_nxt and tp->irs | |
266 | * if seg contains ack then advance tp->snd_una | |
267 | * if SYN has been acked change to ESTABLISHED else SYN_RCVD state | |
268 | * arrange for segment to be acked (eventually) | |
269 | * continue processing rest of data/controls, beginning with URG | |
270 | */ | |
271 | case TCPS_SYN_SENT: | |
272 | if ((tiflags & TH_ACK) && | |
22856bb8 BJ |
273 | /* this should be SEQ_LT; is SEQ_LEQ for BBN vax TCP only */ |
274 | (SEQ_LT(ti->ti_ack, tp->iss) || | |
4b6b94ca | 275 | SEQ_GT(ti->ti_ack, tp->snd_max))) |
8a13b737 | 276 | goto dropwithreset; |
2ff61f9d | 277 | if (tiflags & TH_RST) { |
0e3936fa SL |
278 | if (tiflags & TH_ACK) |
279 | tp = tcp_drop(tp, ECONNREFUSED); | |
2ff61f9d | 280 | goto drop; |
87e78f19 | 281 | } |
2ff61f9d BJ |
282 | if ((tiflags & TH_SYN) == 0) |
283 | goto drop; | |
4b6b94ca | 284 | tp->snd_una = ti->ti_ack; |
b8977237 BJ |
285 | if (SEQ_LT(tp->snd_nxt, tp->snd_una)) |
286 | tp->snd_nxt = tp->snd_una; | |
4aed14e3 | 287 | tp->t_timer[TCPT_REXMT] = 0; |
2ff61f9d | 288 | tp->irs = ti->ti_seq; |
8a13b737 BJ |
289 | tcp_rcvseqinit(tp); |
290 | tp->t_flags |= TF_ACKNOW; | |
405c9168 | 291 | if (SEQ_GT(tp->snd_una, tp->iss)) { |
4aed14e3 | 292 | soisconnected(so); |
2ff61f9d | 293 | tp->t_state = TCPS_ESTABLISHED; |
405c9168 BJ |
294 | (void) tcp_reass(tp, (struct tcpiphdr *)0); |
295 | } else | |
8a13b737 BJ |
296 | tp->t_state = TCPS_SYN_RECEIVED; |
297 | goto trimthenstep6; | |
298 | ||
299 | trimthenstep6: | |
300 | /* | |
4b6b94ca | 301 | * Advance ti->ti_seq to correspond to first data byte. |
8a13b737 BJ |
302 | * If data, trim to stay within window, |
303 | * dropping FIN if necessary. | |
304 | */ | |
4b6b94ca | 305 | ti->ti_seq++; |
8a13b737 BJ |
306 | if (ti->ti_len > tp->rcv_wnd) { |
307 | todrop = ti->ti_len - tp->rcv_wnd; | |
308 | m_adj(m, -todrop); | |
309 | ti->ti_len = tp->rcv_wnd; | |
310 | ti->ti_flags &= ~TH_FIN; | |
87e78f19 | 311 | } |
e832edbc | 312 | tp->snd_wl1 = ti->ti_seq - 1; |
8a13b737 | 313 | goto step6; |
2ff61f9d | 314 | } |
87e78f19 | 315 | |
2ff61f9d BJ |
316 | /* |
317 | * States other than LISTEN or SYN_SENT. | |
318 | * First check that at least some bytes of segment are within | |
319 | * receive window. | |
320 | */ | |
321 | if (tp->rcv_wnd == 0) { | |
322 | /* | |
323 | * If window is closed can only take segments at | |
4b6b94ca | 324 | * window edge, and have to drop data and PUSH from |
2ff61f9d BJ |
325 | * incoming segments. |
326 | */ | |
22856bb8 | 327 | if (tp->rcv_nxt != ti->ti_seq) |
2ff61f9d | 328 | goto dropafterack; |
8a13b737 | 329 | if (ti->ti_len > 0) { |
fd5dc5f0 | 330 | m_adj(m, ti->ti_len); |
8a13b737 BJ |
331 | ti->ti_len = 0; |
332 | ti->ti_flags &= ~(TH_PUSH|TH_FIN); | |
87e78f19 | 333 | } |
2ff61f9d BJ |
334 | } else { |
335 | /* | |
4b6b94ca | 336 | * If segment begins before rcv_nxt, drop leading |
2ff61f9d BJ |
337 | * data (and SYN); if nothing left, just ack. |
338 | */ | |
fd5dc5f0 BJ |
339 | todrop = tp->rcv_nxt - ti->ti_seq; |
340 | if (todrop > 0) { | |
8a13b737 | 341 | if (tiflags & TH_SYN) { |
22856bb8 | 342 | tiflags &= ~TH_SYN; |
fd5dc5f0 | 343 | ti->ti_flags &= ~TH_SYN; |
8a13b737 BJ |
344 | ti->ti_seq++; |
345 | if (ti->ti_urp > 1) | |
346 | ti->ti_urp--; | |
347 | else | |
348 | tiflags &= ~TH_URG; | |
349 | todrop--; | |
350 | } | |
1e977657 BJ |
351 | if (todrop > ti->ti_len || |
352 | todrop == ti->ti_len && (tiflags&TH_FIN) == 0) | |
2ff61f9d BJ |
353 | goto dropafterack; |
354 | m_adj(m, todrop); | |
355 | ti->ti_seq += todrop; | |
356 | ti->ti_len -= todrop; | |
8a13b737 BJ |
357 | if (ti->ti_urp > todrop) |
358 | ti->ti_urp -= todrop; | |
359 | else { | |
360 | tiflags &= ~TH_URG; | |
fd5dc5f0 BJ |
361 | ti->ti_flags &= ~TH_URG; |
362 | ti->ti_urp = 0; | |
8a13b737 | 363 | } |
2ff61f9d BJ |
364 | } |
365 | /* | |
366 | * If segment ends after window, drop trailing data | |
8a13b737 | 367 | * (and PUSH and FIN); if nothing left, just ACK. |
2ff61f9d | 368 | */ |
fd5dc5f0 BJ |
369 | todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd); |
370 | if (todrop > 0) { | |
1e977657 | 371 | if (todrop >= ti->ti_len) |
2ff61f9d BJ |
372 | goto dropafterack; |
373 | m_adj(m, -todrop); | |
374 | ti->ti_len -= todrop; | |
8a13b737 | 375 | ti->ti_flags &= ~(TH_PUSH|TH_FIN); |
87e78f19 | 376 | } |
87e78f19 | 377 | } |
87e78f19 | 378 | |
dd020fc8 | 379 | /* |
6fed2989 | 380 | * If data is received on a connection after the |
dd020fc8 BJ |
381 | * user processes are gone, then RST the other end. |
382 | */ | |
0e3936fa | 383 | if ((so->so_state & SS_NOFDREF) && tp->t_state > TCPS_CLOSE_WAIT && |
c9f1e449 | 384 | ti->ti_len) { |
0e3936fa | 385 | tp = tcp_close(tp); |
dd020fc8 BJ |
386 | goto dropwithreset; |
387 | } | |
388 | ||
87e78f19 | 389 | /* |
2ff61f9d BJ |
390 | * If the RST bit is set examine the state: |
391 | * SYN_RECEIVED STATE: | |
392 | * If passive open, return to LISTEN state. | |
393 | * If active open, inform user that connection was refused. | |
394 | * ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT STATES: | |
395 | * Inform user that connection was reset, and close tcb. | |
396 | * CLOSING, LAST_ACK, TIME_WAIT STATES | |
397 | * Close the tcb. | |
87e78f19 | 398 | */ |
2ff61f9d | 399 | if (tiflags&TH_RST) switch (tp->t_state) { |
4b935108 | 400 | |
2ff61f9d | 401 | case TCPS_SYN_RECEIVED: |
0e3936fa | 402 | tp = tcp_drop(tp, ECONNREFUSED); |
2ff61f9d BJ |
403 | goto drop; |
404 | ||
405 | case TCPS_ESTABLISHED: | |
406 | case TCPS_FIN_WAIT_1: | |
407 | case TCPS_FIN_WAIT_2: | |
408 | case TCPS_CLOSE_WAIT: | |
0e3936fa | 409 | tp = tcp_drop(tp, ECONNRESET); |
2ff61f9d BJ |
410 | goto drop; |
411 | ||
412 | case TCPS_CLOSING: | |
413 | case TCPS_LAST_ACK: | |
414 | case TCPS_TIME_WAIT: | |
0e3936fa | 415 | tp = tcp_close(tp); |
2ff61f9d | 416 | goto drop; |
87e78f19 | 417 | } |
87e78f19 BJ |
418 | |
419 | /* | |
2ff61f9d BJ |
420 | * If a SYN is in the window, then this is an |
421 | * error and we send an RST and drop the connection. | |
422 | */ | |
423 | if (tiflags & TH_SYN) { | |
0e3936fa | 424 | tp = tcp_drop(tp, ECONNRESET); |
8a13b737 | 425 | goto dropwithreset; |
2ff61f9d BJ |
426 | } |
427 | ||
428 | /* | |
429 | * If the ACK bit is off we drop the segment and return. | |
430 | */ | |
8a13b737 | 431 | if ((tiflags & TH_ACK) == 0) |
2ff61f9d BJ |
432 | goto drop; |
433 | ||
434 | /* | |
435 | * Ack processing. | |
87e78f19 | 436 | */ |
87e78f19 BJ |
437 | switch (tp->t_state) { |
438 | ||
2ff61f9d BJ |
439 | /* |
440 | * In SYN_RECEIVED state if the ack ACKs our SYN then enter | |
441 | * ESTABLISHED state and continue processing, othewise | |
442 | * send an RST. | |
443 | */ | |
444 | case TCPS_SYN_RECEIVED: | |
8a13b737 | 445 | if (SEQ_GT(tp->snd_una, ti->ti_ack) || |
4b6b94ca | 446 | SEQ_GT(ti->ti_ack, tp->snd_max)) |
8a13b737 | 447 | goto dropwithreset; |
4aed14e3 | 448 | tp->snd_una++; /* SYN acked */ |
b8977237 BJ |
449 | if (SEQ_LT(tp->snd_nxt, tp->snd_una)) |
450 | tp->snd_nxt = tp->snd_una; | |
4aed14e3 | 451 | tp->t_timer[TCPT_REXMT] = 0; |
8a13b737 BJ |
452 | soisconnected(so); |
453 | tp->t_state = TCPS_ESTABLISHED; | |
405c9168 | 454 | (void) tcp_reass(tp, (struct tcpiphdr *)0); |
4aed14e3 | 455 | tp->snd_wl1 = ti->ti_seq - 1; |
8a13b737 | 456 | /* fall into ... */ |
87e78f19 | 457 | |
2ff61f9d BJ |
458 | /* |
459 | * In ESTABLISHED state: drop duplicate ACKs; ACK out of range | |
460 | * ACKs. If the ack is in the range | |
4b6b94ca | 461 | * tp->snd_una < ti->ti_ack <= tp->snd_max |
2ff61f9d BJ |
462 | * then advance tp->snd_una to ti->ti_ack and drop |
463 | * data from the retransmission queue. If this ACK reflects | |
464 | * more up to date window information we update our window information. | |
465 | */ | |
466 | case TCPS_ESTABLISHED: | |
467 | case TCPS_FIN_WAIT_1: | |
468 | case TCPS_FIN_WAIT_2: | |
469 | case TCPS_CLOSE_WAIT: | |
470 | case TCPS_CLOSING: | |
4aed14e3 BJ |
471 | case TCPS_LAST_ACK: |
472 | case TCPS_TIME_WAIT: | |
8a13b737 BJ |
473 | #define ourfinisacked (acked > 0) |
474 | ||
4aed14e3 | 475 | if (SEQ_LEQ(ti->ti_ack, tp->snd_una)) |
2ff61f9d | 476 | break; |
22856bb8 | 477 | if (SEQ_GT(ti->ti_ack, tp->snd_max)) |
2ff61f9d | 478 | goto dropafterack; |
8a13b737 | 479 | acked = ti->ti_ack - tp->snd_una; |
dd020fc8 BJ |
480 | |
481 | /* | |
482 | * If transmit timer is running and timed sequence | |
483 | * number was acked, update smoothed round trip time. | |
484 | */ | |
485 | if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq)) { | |
486 | if (tp->t_srtt == 0) | |
487 | tp->t_srtt = tp->t_rtt; | |
488 | else | |
489 | tp->t_srtt = | |
490 | tcp_alpha * tp->t_srtt + | |
491 | (1 - tcp_alpha) * tp->t_rtt; | |
dd020fc8 BJ |
492 | tp->t_rtt = 0; |
493 | } | |
494 | ||
6703c41f | 495 | if (ti->ti_ack == tp->snd_max) |
4aed14e3 | 496 | tp->t_timer[TCPT_REXMT] = 0; |
6703c41f | 497 | else { |
4aed14e3 BJ |
498 | TCPT_RANGESET(tp->t_timer[TCPT_REXMT], |
499 | tcp_beta * tp->t_srtt, TCPTV_MIN, TCPTV_MAX); | |
dd020fc8 | 500 | tp->t_rtt = 1; |
22856bb8 | 501 | tp->t_rxtshift = 0; |
8a13b737 | 502 | } |
6703c41f BJ |
503 | if (acked > so->so_snd.sb_cc) { |
504 | sbdrop(&so->so_snd, so->so_snd.sb_cc); | |
505 | tp->snd_wnd -= so->so_snd.sb_cc; | |
506 | } else { | |
668cc26d | 507 | sbdrop(&so->so_snd, acked); |
6703c41f BJ |
508 | tp->snd_wnd -= acked; |
509 | acked = 0; | |
510 | } | |
5744ed2b | 511 | if ((so->so_snd.sb_flags & SB_WAIT) || so->so_snd.sb_sel) |
22856bb8 | 512 | sowwakeup(so); |
4b6b94ca | 513 | tp->snd_una = ti->ti_ack; |
b8977237 BJ |
514 | if (SEQ_LT(tp->snd_nxt, tp->snd_una)) |
515 | tp->snd_nxt = tp->snd_una; | |
405c9168 | 516 | |
87e78f19 BJ |
517 | switch (tp->t_state) { |
518 | ||
2ff61f9d BJ |
519 | /* |
520 | * In FIN_WAIT_1 STATE in addition to the processing | |
521 | * for the ESTABLISHED state if our FIN is now acknowledged | |
8a13b737 | 522 | * then enter FIN_WAIT_2. |
2ff61f9d BJ |
523 | */ |
524 | case TCPS_FIN_WAIT_1: | |
fdae4427 BJ |
525 | if (ourfinisacked) { |
526 | /* | |
527 | * If we can't receive any more | |
528 | * data, then closing user can proceed. | |
529 | */ | |
530 | if (so->so_state & SS_CANTRCVMORE) | |
531 | soisdisconnected(so); | |
8a13b737 | 532 | tp->t_state = TCPS_FIN_WAIT_2; |
fdae4427 | 533 | } |
87e78f19 BJ |
534 | break; |
535 | ||
2ff61f9d BJ |
536 | /* |
537 | * In CLOSING STATE in addition to the processing for | |
538 | * the ESTABLISHED state if the ACK acknowledges our FIN | |
539 | * then enter the TIME-WAIT state, otherwise ignore | |
540 | * the segment. | |
541 | */ | |
542 | case TCPS_CLOSING: | |
4aed14e3 | 543 | if (ourfinisacked) { |
2ff61f9d | 544 | tp->t_state = TCPS_TIME_WAIT; |
4aed14e3 BJ |
545 | tcp_canceltimers(tp); |
546 | tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; | |
547 | soisdisconnected(so); | |
548 | } | |
549 | break; | |
87e78f19 | 550 | |
2ff61f9d | 551 | /* |
8a13b737 BJ |
552 | * The only thing that can arrive in LAST_ACK state |
553 | * is an acknowledgment of our FIN. If our FIN is now | |
554 | * acknowledged, delete the TCB, enter the closed state | |
555 | * and return. | |
2ff61f9d BJ |
556 | */ |
557 | case TCPS_LAST_ACK: | |
0e3936fa SL |
558 | if (ourfinisacked) |
559 | tp = tcp_close(tp); | |
2ff61f9d | 560 | goto drop; |
87e78f19 | 561 | |
2ff61f9d BJ |
562 | /* |
563 | * In TIME_WAIT state the only thing that should arrive | |
564 | * is a retransmission of the remote FIN. Acknowledge | |
565 | * it and restart the finack timer. | |
566 | */ | |
567 | case TCPS_TIME_WAIT: | |
405c9168 | 568 | tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; |
2ff61f9d | 569 | goto dropafterack; |
87e78f19 | 570 | } |
8a13b737 BJ |
571 | #undef ourfinisacked |
572 | } | |
87e78f19 | 573 | |
2ff61f9d | 574 | step6: |
4aed14e3 BJ |
575 | /* |
576 | * Update window information. | |
577 | */ | |
22856bb8 | 578 | if (SEQ_LT(tp->snd_wl1, ti->ti_seq) || tp->snd_wl1 == ti->ti_seq && |
8e65fd66 | 579 | (SEQ_LT(tp->snd_wl2, ti->ti_ack) || |
22856bb8 | 580 | tp->snd_wl2 == ti->ti_ack && ti->ti_win > tp->snd_wnd)) { |
4aed14e3 BJ |
581 | tp->snd_wnd = ti->ti_win; |
582 | tp->snd_wl1 = ti->ti_seq; | |
583 | tp->snd_wl2 = ti->ti_ack; | |
a8d3bf7f | 584 | if (tp->snd_wnd != 0) |
4aed14e3 BJ |
585 | tp->t_timer[TCPT_PERSIST] = 0; |
586 | } | |
4aed14e3 | 587 | |
2ff61f9d | 588 | /* |
b2db9217 | 589 | * Process segments with URG. |
2ff61f9d | 590 | */ |
9c811062 BJ |
591 | if ((tiflags & TH_URG) && ti->ti_urp && |
592 | TCPS_HAVERCVDFIN(tp->t_state) == 0) { | |
f4be5024 | 593 | /* |
a5d9c993 SL |
594 | * This is a kludge, but if we receive accept |
595 | * random urgent pointers, we'll crash in | |
596 | * soreceive. It's hard to imagine someone | |
597 | * actually wanting to send this much urgent data. | |
f4be5024 SL |
598 | */ |
599 | if (ti->ti_urp > tp->t_maxseg) { /* XXX */ | |
600 | ti->ti_urp = 0; /* XXX */ | |
601 | tiflags &= ~TH_URG; /* XXX */ | |
602 | ti->ti_flags &= ~TH_URG; /* XXX */ | |
a5d9c993 | 603 | goto badurp; /* XXX */ |
f4be5024 | 604 | } |
b2db9217 BJ |
605 | /* |
606 | * If this segment advances the known urgent pointer, | |
607 | * then mark the data stream. This should not happen | |
608 | * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since | |
609 | * a FIN has been received from the remote side. | |
610 | * In these states we ignore the URG. | |
611 | */ | |
612 | if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) { | |
613 | tp->rcv_up = ti->ti_seq + ti->ti_urp; | |
614 | so->so_oobmark = so->so_rcv.sb_cc + | |
615 | (tp->rcv_up - tp->rcv_nxt) - 1; | |
616 | if (so->so_oobmark == 0) | |
617 | so->so_state |= SS_RCVATMARK; | |
77a4e3ca | 618 | sohasoutofband(so); |
b2db9217 BJ |
619 | tp->t_oobflags &= ~TCPOOB_HAVEDATA; |
620 | } | |
621 | /* | |
622 | * Remove out of band data so doesn't get presented to user. | |
623 | * This can happen independent of advancing the URG pointer, | |
624 | * but if two URG's are pending at once, some out-of-band | |
625 | * data may creep in... ick. | |
626 | */ | |
ebf42a75 | 627 | if (ti->ti_urp <= ti->ti_len) |
b2db9217 | 628 | tcp_pulloutofband(so, ti); |
5e74df82 | 629 | } |
a5d9c993 | 630 | badurp: /* XXX */ |
87e78f19 BJ |
631 | |
632 | /* | |
2ff61f9d BJ |
633 | * Process the segment text, merging it into the TCP sequencing queue, |
634 | * and arranging for acknowledgment of receipt if necessary. | |
635 | * This process logically involves adjusting tp->rcv_wnd as data | |
636 | * is presented to the user (this happens in tcp_usrreq.c, | |
637 | * case PRU_RCVD). If a FIN has already been received on this | |
638 | * connection then we just ignore the text. | |
87e78f19 | 639 | */ |
e832edbc BJ |
640 | if ((ti->ti_len || (tiflags&TH_FIN)) && |
641 | TCPS_HAVERCVDFIN(tp->t_state) == 0) { | |
2ff61f9d | 642 | tiflags = tcp_reass(tp, ti); |
8b5a83bb BJ |
643 | if (tcpnodelack == 0) |
644 | tp->t_flags |= TF_DELACK; | |
645 | else | |
646 | tp->t_flags |= TF_ACKNOW; | |
4aed14e3 | 647 | } else { |
2b4b57cd | 648 | m_freem(m); |
e832edbc | 649 | tiflags &= ~TH_FIN; |
4aed14e3 | 650 | } |
87e78f19 BJ |
651 | |
652 | /* | |
e832edbc BJ |
653 | * If FIN is received ACK the FIN and let the user know |
654 | * that the connection is closing. | |
87e78f19 | 655 | */ |
e832edbc | 656 | if (tiflags & TH_FIN) { |
4aed14e3 BJ |
657 | if (TCPS_HAVERCVDFIN(tp->t_state) == 0) { |
658 | socantrcvmore(so); | |
659 | tp->t_flags |= TF_ACKNOW; | |
660 | tp->rcv_nxt++; | |
661 | } | |
2ff61f9d | 662 | switch (tp->t_state) { |
87e78f19 | 663 | |
2ff61f9d BJ |
664 | /* |
665 | * In SYN_RECEIVED and ESTABLISHED STATES | |
666 | * enter the CLOSE_WAIT state. | |
53a5409e | 667 | */ |
2ff61f9d BJ |
668 | case TCPS_SYN_RECEIVED: |
669 | case TCPS_ESTABLISHED: | |
670 | tp->t_state = TCPS_CLOSE_WAIT; | |
671 | break; | |
53a5409e | 672 | |
2ff61f9d | 673 | /* |
8a13b737 BJ |
674 | * If still in FIN_WAIT_1 STATE FIN has not been acked so |
675 | * enter the CLOSING state. | |
53a5409e | 676 | */ |
2ff61f9d | 677 | case TCPS_FIN_WAIT_1: |
8a13b737 | 678 | tp->t_state = TCPS_CLOSING; |
2ff61f9d | 679 | break; |
87e78f19 | 680 | |
2ff61f9d BJ |
681 | /* |
682 | * In FIN_WAIT_2 state enter the TIME_WAIT state, | |
683 | * starting the time-wait timer, turning off the other | |
684 | * standard timers. | |
685 | */ | |
686 | case TCPS_FIN_WAIT_2: | |
4aed14e3 | 687 | tp->t_state = TCPS_TIME_WAIT; |
a6503abf | 688 | tcp_canceltimers(tp); |
405c9168 | 689 | tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; |
4aed14e3 | 690 | soisdisconnected(so); |
2ff61f9d BJ |
691 | break; |
692 | ||
53a5409e | 693 | /* |
2ff61f9d | 694 | * In TIME_WAIT state restart the 2 MSL time_wait timer. |
53a5409e | 695 | */ |
2ff61f9d | 696 | case TCPS_TIME_WAIT: |
405c9168 | 697 | tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; |
2ff61f9d | 698 | break; |
8a13b737 | 699 | } |
87e78f19 | 700 | } |
4b935108 BJ |
701 | if (so->so_options & SO_DEBUG) |
702 | tcp_trace(TA_INPUT, ostate, tp, &tcp_saveti, 0); | |
8a13b737 BJ |
703 | |
704 | /* | |
705 | * Return any desired output. | |
706 | */ | |
668cc26d | 707 | (void) tcp_output(tp); |
2ff61f9d | 708 | return; |
8a13b737 | 709 | |
2ff61f9d | 710 | dropafterack: |
8a13b737 | 711 | /* |
1e977657 BJ |
712 | * Generate an ACK dropping incoming segment if it occupies |
713 | * sequence space, where the ACK reflects our state. | |
8a13b737 | 714 | */ |
1e977657 BJ |
715 | if ((tiflags&TH_RST) || |
716 | tlen == 0 && (tiflags&(TH_SYN|TH_FIN)) == 0) | |
8a13b737 | 717 | goto drop; |
f3cdd721 BJ |
718 | if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG) |
719 | tcp_trace(TA_RESPOND, ostate, tp, &tcp_saveti, 0); | |
8e65fd66 | 720 | tcp_respond(tp, ti, tp->rcv_nxt, tp->snd_nxt, TH_ACK); |
4b6b94ca | 721 | return; |
8a13b737 BJ |
722 | |
723 | dropwithreset: | |
f37c1c84 | 724 | if (om) { |
668cc26d | 725 | (void) m_free(om); |
f37c1c84 SL |
726 | om = 0; |
727 | } | |
8a13b737 | 728 | /* |
4aed14e3 | 729 | * Generate a RST, dropping incoming segment. |
8a13b737 BJ |
730 | * Make ACK acceptable to originator of segment. |
731 | */ | |
732 | if (tiflags & TH_RST) | |
733 | goto drop; | |
734 | if (tiflags & TH_ACK) | |
8e65fd66 | 735 | tcp_respond(tp, ti, (tcp_seq)0, ti->ti_ack, TH_RST); |
8a13b737 BJ |
736 | else { |
737 | if (tiflags & TH_SYN) | |
738 | ti->ti_len++; | |
1e977657 BJ |
739 | tcp_respond(tp, ti, ti->ti_seq+ti->ti_len, (tcp_seq)0, |
740 | TH_RST|TH_ACK); | |
8a13b737 | 741 | } |
7aa16f99 SL |
742 | /* destroy temporarily created socket */ |
743 | if (dropsocket) | |
744 | (void) soabort(so); | |
4b6b94ca | 745 | return; |
8a13b737 | 746 | |
2ff61f9d | 747 | drop: |
01b1394e SL |
748 | if (om) |
749 | (void) m_free(om); | |
8a13b737 BJ |
750 | /* |
751 | * Drop space held by incoming segment and return. | |
752 | */ | |
f3cdd721 BJ |
753 | if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) |
754 | tcp_trace(TA_DROP, ostate, tp, &tcp_saveti, 0); | |
2ff61f9d | 755 | m_freem(m); |
7aa16f99 SL |
756 | /* destroy temporarily created socket */ |
757 | if (dropsocket) | |
758 | (void) soabort(so); | |
4b935108 | 759 | return; |
2ff61f9d BJ |
760 | } |
761 | ||
8b5a83bb BJ |
762 | tcp_dooptions(tp, om) |
763 | struct tcpcb *tp; | |
764 | struct mbuf *om; | |
5e74df82 | 765 | { |
8b5a83bb BJ |
766 | register u_char *cp; |
767 | int opt, optlen, cnt; | |
768 | ||
769 | cp = mtod(om, u_char *); | |
770 | cnt = om->m_len; | |
771 | for (; cnt > 0; cnt -= optlen, cp += optlen) { | |
772 | opt = cp[0]; | |
773 | if (opt == TCPOPT_EOL) | |
774 | break; | |
775 | if (opt == TCPOPT_NOP) | |
776 | optlen = 1; | |
357b20fc | 777 | else { |
8b5a83bb | 778 | optlen = cp[1]; |
357b20fc SL |
779 | if (optlen <= 0) |
780 | break; | |
781 | } | |
8b5a83bb BJ |
782 | switch (opt) { |
783 | ||
784 | default: | |
785 | break; | |
786 | ||
787 | case TCPOPT_MAXSEG: | |
788 | if (optlen != 4) | |
789 | continue; | |
790 | tp->t_maxseg = *(u_short *)(cp + 2); | |
668cc26d | 791 | tp->t_maxseg = ntohs((u_short)tp->t_maxseg); |
8b5a83bb | 792 | break; |
8b5a83bb | 793 | } |
5e74df82 | 794 | } |
668cc26d | 795 | (void) m_free(om); |
5e74df82 BJ |
796 | } |
797 | ||
b2db9217 BJ |
798 | /* |
799 | * Pull out of band byte out of a segment so | |
800 | * it doesn't appear in the user's data queue. | |
801 | * It is still reflected in the segment length for | |
802 | * sequencing purposes. | |
803 | */ | |
804 | tcp_pulloutofband(so, ti) | |
805 | struct socket *so; | |
806 | struct tcpiphdr *ti; | |
807 | { | |
808 | register struct mbuf *m; | |
1acff8ec | 809 | int cnt = ti->ti_urp - 1; |
b2db9217 BJ |
810 | |
811 | m = dtom(ti); | |
812 | while (cnt >= 0) { | |
813 | if (m->m_len > cnt) { | |
814 | char *cp = mtod(m, caddr_t) + cnt; | |
815 | struct tcpcb *tp = sototcpcb(so); | |
816 | ||
817 | tp->t_iobc = *cp; | |
818 | tp->t_oobflags |= TCPOOB_HAVEDATA; | |
668cc26d | 819 | bcopy(cp+1, cp, (unsigned)(m->m_len - cnt - 1)); |
b2db9217 BJ |
820 | m->m_len--; |
821 | return; | |
822 | } | |
823 | cnt -= m->m_len; | |
824 | m = m->m_next; | |
825 | if (m == 0) | |
826 | break; | |
827 | } | |
828 | panic("tcp_pulloutofband"); | |
829 | } | |
830 | ||
2ff61f9d BJ |
831 | /* |
832 | * Insert segment ti into reassembly queue of tcp with | |
833 | * control block tp. Return TH_FIN if reassembly now includes | |
834 | * a segment with FIN. | |
835 | */ | |
f1b2fa5b | 836 | tcp_reass(tp, ti) |
2ff61f9d BJ |
837 | register struct tcpcb *tp; |
838 | register struct tcpiphdr *ti; | |
2ff61f9d BJ |
839 | { |
840 | register struct tcpiphdr *q; | |
8a13b737 | 841 | struct socket *so = tp->t_inpcb->inp_socket; |
e832edbc BJ |
842 | struct mbuf *m; |
843 | int flags; | |
2ff61f9d BJ |
844 | |
845 | /* | |
405c9168 BJ |
846 | * Call with ti==0 after become established to |
847 | * force pre-ESTABLISHED data up to user socket. | |
2ff61f9d | 848 | */ |
405c9168 | 849 | if (ti == 0) |
2ff61f9d | 850 | goto present; |
87e78f19 | 851 | |
2ff61f9d BJ |
852 | /* |
853 | * Find a segment which begins after this one does. | |
854 | */ | |
855 | for (q = tp->seg_next; q != (struct tcpiphdr *)tp; | |
856 | q = (struct tcpiphdr *)q->ti_next) | |
857 | if (SEQ_GT(q->ti_seq, ti->ti_seq)) | |
858 | break; | |
859 | ||
860 | /* | |
861 | * If there is a preceding segment, it may provide some of | |
862 | * our data already. If so, drop the data from the incoming | |
863 | * segment. If it provides all of our data, drop us. | |
864 | */ | |
865 | if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) { | |
866 | register int i; | |
fd5dc5f0 | 867 | q = (struct tcpiphdr *)q->ti_prev; |
2ff61f9d BJ |
868 | /* conversion to int (in i) handles seq wraparound */ |
869 | i = q->ti_seq + q->ti_len - ti->ti_seq; | |
870 | if (i > 0) { | |
2b4b57cd | 871 | if (i >= ti->ti_len) |
2ff61f9d | 872 | goto drop; |
4ab1a5c3 | 873 | m_adj(dtom(ti), i); |
2b4b57cd | 874 | ti->ti_len -= i; |
2ff61f9d | 875 | ti->ti_seq += i; |
53a5409e | 876 | } |
2ff61f9d BJ |
877 | q = (struct tcpiphdr *)(q->ti_next); |
878 | } | |
87e78f19 | 879 | |
2ff61f9d BJ |
880 | /* |
881 | * While we overlap succeeding segments trim them or, | |
882 | * if they are completely covered, dequeue them. | |
883 | */ | |
fd5dc5f0 | 884 | while (q != (struct tcpiphdr *)tp) { |
2ff61f9d | 885 | register int i = (ti->ti_seq + ti->ti_len) - q->ti_seq; |
fd5dc5f0 BJ |
886 | if (i <= 0) |
887 | break; | |
2ff61f9d | 888 | if (i < q->ti_len) { |
fd5dc5f0 | 889 | q->ti_seq += i; |
2ff61f9d BJ |
890 | q->ti_len -= i; |
891 | m_adj(dtom(q), i); | |
892 | break; | |
ac5e71a1 | 893 | } |
2ff61f9d | 894 | q = (struct tcpiphdr *)q->ti_next; |
473a17a5 | 895 | m = dtom(q->ti_prev); |
2ff61f9d | 896 | remque(q->ti_prev); |
473a17a5 | 897 | m_freem(m); |
2ff61f9d | 898 | } |
87e78f19 | 899 | |
2ff61f9d BJ |
900 | /* |
901 | * Stick new segment in its place. | |
902 | */ | |
903 | insque(ti, q->ti_prev); | |
2ff61f9d | 904 | |
2ff61f9d BJ |
905 | present: |
906 | /* | |
4aed14e3 BJ |
907 | * Present data to user, advancing rcv_nxt through |
908 | * completed sequence space. | |
2ff61f9d | 909 | */ |
e832edbc | 910 | if (TCPS_HAVERCVDSYN(tp->t_state) == 0) |
4aed14e3 | 911 | return (0); |
2b4b57cd | 912 | ti = tp->seg_next; |
e832edbc BJ |
913 | if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt) |
914 | return (0); | |
915 | if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len) | |
916 | return (0); | |
917 | do { | |
4aed14e3 BJ |
918 | tp->rcv_nxt += ti->ti_len; |
919 | flags = ti->ti_flags & TH_FIN; | |
2b4b57cd | 920 | remque(ti); |
e832edbc | 921 | m = dtom(ti); |
2b4b57cd | 922 | ti = (struct tcpiphdr *)ti->ti_next; |
e832edbc | 923 | if (so->so_state & SS_CANTRCVMORE) |
668cc26d | 924 | m_freem(m); |
789d2a39 | 925 | else |
e832edbc BJ |
926 | sbappend(&so->so_rcv, m); |
927 | } while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt); | |
928 | sorwakeup(so); | |
2ff61f9d BJ |
929 | return (flags); |
930 | drop: | |
931 | m_freem(dtom(ti)); | |
e832edbc | 932 | return (0); |
d52566dd | 933 | } |