1 /* 2 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)tcp_usrreq.c 7.15 (Berkeley) 6/28/90 34 * $Id: tcp_usrreq.c,v 1.4 1993/06/15 02:25:26 cgd Exp $ 35 */ 36 37 #include "param.h" 38 #include "systm.h" 39 #include "malloc.h" 40 #include "mbuf.h" 41 #include "socket.h" 42 #include "socketvar.h" 43 #include "protosw.h" 44 #include "errno.h" 45 #include "stat.h" 46 47 #include "../net/if.h" 48 #include "../net/route.h" 49 50 #include "in.h" 51 #include "in_systm.h" 52 #include "ip.h" 53 #include "in_pcb.h" 54 #include "ip_var.h" 55 #include "tcp.h" 56 #include "tcp_fsm.h" 57 #include "tcp_seq.h" 58 #include "tcp_timer.h" 59 #include "tcp_var.h" 60 #include "tcpip.h" 61 #include "tcp_debug.h" 62 63 /* 64 * TCP protocol interface to socket abstraction. 65 */ 66 extern char *tcpstates[]; 67 struct tcpcb *tcp_newtcpcb(); 68 69 /* 70 * Process a TCP user request for TCP tb. If this is a send request 71 * then m is the mbuf chain of send data. If this is a timer expiration 72 * (called from the software clock routine), then timertype tells which timer. 73 */ 74 /*ARGSUSED*/ 75 tcp_usrreq(so, req, m, nam, control) 76 struct socket *so; 77 int req; 78 struct mbuf *m, *nam, *control; 79 { 80 register struct inpcb *inp; 81 register struct tcpcb *tp; 82 int s; 83 int error = 0; 84 int ostate; 85 86 if (req == PRU_CONTROL) 87 return (in_control(so, (int)m, (caddr_t)nam, 88 (struct ifnet *)control)); 89 if (control && control->m_len) { 90 m_freem(control); 91 if (m) 92 m_freem(m); 93 return (EINVAL); 94 } 95 96 s = splnet(); 97 inp = sotoinpcb(so); 98 /* 99 * When a TCP is attached to a socket, then there will be 100 * a (struct inpcb) pointed at by the socket, and this 101 * structure will point at a subsidary (struct tcpcb). 102 */ 103 if (inp == 0 && req != PRU_ATTACH) { 104 splx(s); 105 return (EINVAL); /* XXX */ 106 } 107 if (inp) { 108 tp = intotcpcb(inp); 109 /* WHAT IF TP IS 0? */ 110 #ifdef KPROF 111 tcp_acounts[tp->t_state][req]++; 112 #endif 113 ostate = tp->t_state; 114 } else 115 ostate = 0; 116 switch (req) { 117 118 /* 119 * TCP attaches to socket via PRU_ATTACH, reserving space, 120 * and an internet control block. 121 */ 122 case PRU_ATTACH: 123 if (inp) { 124 error = EISCONN; 125 break; 126 } 127 error = tcp_attach(so); 128 if (error) 129 break; 130 if ((so->so_options & SO_LINGER) && so->so_linger == 0) 131 so->so_linger = TCP_LINGERTIME; 132 tp = sototcpcb(so); 133 break; 134 135 /* 136 * PRU_DETACH detaches the TCP protocol from the socket. 137 * If the protocol state is non-embryonic, then can't 138 * do this directly: have to initiate a PRU_DISCONNECT, 139 * which may finish later; embryonic TCB's can just 140 * be discarded here. 141 */ 142 case PRU_DETACH: 143 if (tp->t_state > TCPS_LISTEN) 144 tp = tcp_disconnect(tp); 145 else 146 tp = tcp_close(tp); 147 break; 148 149 /* 150 * Give the socket an address. 151 */ 152 case PRU_BIND: 153 error = in_pcbbind(inp, nam); 154 if (error) 155 break; 156 break; 157 158 /* 159 * Prepare to accept connections. 160 */ 161 case PRU_LISTEN: 162 if (inp->inp_lport == 0) 163 error = in_pcbbind(inp, (struct mbuf *)0); 164 if (error == 0) 165 tp->t_state = TCPS_LISTEN; 166 break; 167 168 /* 169 * Initiate connection to peer. 170 * Create a template for use in transmissions on this connection. 171 * Enter SYN_SENT state, and mark socket as connecting. 172 * Start keep-alive timer, and seed output sequence space. 173 * Send initial segment on connection. 174 */ 175 case PRU_CONNECT: 176 if (inp->inp_lport == 0) { 177 error = in_pcbbind(inp, (struct mbuf *)0); 178 if (error) 179 break; 180 } 181 error = in_pcbconnect(inp, nam); 182 if (error) 183 break; 184 tp->t_template = tcp_template(tp); 185 if (tp->t_template == 0) { 186 in_pcbdisconnect(inp); 187 error = ENOBUFS; 188 break; 189 } 190 soisconnecting(so); 191 tcpstat.tcps_connattempt++; 192 tp->t_state = TCPS_SYN_SENT; 193 tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; 194 tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; 195 tcp_sendseqinit(tp); 196 error = tcp_output(tp); 197 break; 198 199 /* 200 * Create a TCP connection between two sockets. 201 */ 202 case PRU_CONNECT2: 203 error = EOPNOTSUPP; 204 break; 205 206 /* 207 * Initiate disconnect from peer. 208 * If connection never passed embryonic stage, just drop; 209 * else if don't need to let data drain, then can just drop anyways, 210 * else have to begin TCP shutdown process: mark socket disconnecting, 211 * drain unread data, state switch to reflect user close, and 212 * send segment (e.g. FIN) to peer. Socket will be really disconnected 213 * when peer sends FIN and acks ours. 214 * 215 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB. 216 */ 217 case PRU_DISCONNECT: 218 tp = tcp_disconnect(tp); 219 break; 220 221 /* 222 * Accept a connection. Essentially all the work is 223 * done at higher levels; just return the address 224 * of the peer, storing through addr. 225 */ 226 case PRU_ACCEPT: { 227 struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *); 228 229 nam->m_len = sizeof (struct sockaddr_in); 230 sin->sin_family = AF_INET; 231 sin->sin_len = sizeof(*sin); 232 sin->sin_port = inp->inp_fport; 233 sin->sin_addr = inp->inp_faddr; 234 break; 235 } 236 237 /* 238 * Mark the connection as being incapable of further output. 239 */ 240 case PRU_SHUTDOWN: 241 socantsendmore(so); 242 tp = tcp_usrclosed(tp); 243 if (tp) 244 error = tcp_output(tp); 245 break; 246 247 /* 248 * After a receive, possibly send window update to peer. 249 */ 250 case PRU_RCVD: 251 (void) tcp_output(tp); 252 break; 253 254 /* 255 * Do a send by putting data in output queue and updating urgent 256 * marker if URG set. Possibly send more data. 257 */ 258 case PRU_SEND: 259 sbappend(&so->so_snd, m); 260 error = tcp_output(tp); 261 break; 262 263 /* 264 * Abort the TCP. 265 */ 266 case PRU_ABORT: 267 tp = tcp_drop(tp, ECONNABORTED); 268 break; 269 270 case PRU_SENSE: 271 ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; 272 (void) splx(s); 273 return (0); 274 275 case PRU_RCVOOB: 276 if ((so->so_oobmark == 0 && 277 (so->so_state & SS_RCVATMARK) == 0) || 278 so->so_options & SO_OOBINLINE || 279 tp->t_oobflags & TCPOOB_HADDATA) { 280 error = EINVAL; 281 break; 282 } 283 if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { 284 error = EWOULDBLOCK; 285 break; 286 } 287 m->m_len = 1; 288 *mtod(m, caddr_t) = tp->t_iobc; 289 if (((int)nam & MSG_PEEK) == 0) 290 tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA); 291 break; 292 293 case PRU_SENDOOB: 294 if (sbspace(&so->so_snd) < -512) { 295 m_freem(m); 296 error = ENOBUFS; 297 break; 298 } 299 /* 300 * According to RFC961 (Assigned Protocols), 301 * the urgent pointer points to the last octet 302 * of urgent data. We continue, however, 303 * to consider it to indicate the first octet 304 * of data past the urgent section. 305 * Otherwise, snd_up should be one lower. 306 */ 307 sbappend(&so->so_snd, m); 308 tp->snd_up = tp->snd_una + so->so_snd.sb_cc; 309 tp->t_force = 1; 310 error = tcp_output(tp); 311 tp->t_force = 0; 312 break; 313 314 case PRU_SOCKADDR: 315 in_setsockaddr(inp, nam); 316 break; 317 318 case PRU_PEERADDR: 319 in_setpeeraddr(inp, nam); 320 break; 321 322 /* 323 * TCP slow timer went off; going through this 324 * routine for tracing's sake. 325 */ 326 case PRU_SLOWTIMO: 327 tp = tcp_timers(tp, (int)nam); 328 req |= (int)nam << 8; /* for debug's sake */ 329 break; 330 331 default: 332 panic("tcp_usrreq"); 333 } 334 if (tp && (so->so_options & SO_DEBUG)) 335 tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req); 336 splx(s); 337 return (error); 338 } 339 340 tcp_ctloutput(op, so, level, optname, mp) 341 int op; 342 struct socket *so; 343 int level, optname; 344 struct mbuf **mp; 345 { 346 int error = 0; 347 struct inpcb *inp = sotoinpcb(so); 348 register struct tcpcb *tp = intotcpcb(inp); 349 register struct mbuf *m; 350 351 if (level != IPPROTO_TCP) 352 return (ip_ctloutput(op, so, level, optname, mp)); 353 354 switch (op) { 355 356 case PRCO_SETOPT: 357 m = *mp; 358 switch (optname) { 359 360 case TCP_NODELAY: 361 if (m == NULL || m->m_len < sizeof (int)) 362 error = EINVAL; 363 else if (*mtod(m, int *)) 364 tp->t_flags |= TF_NODELAY; 365 else 366 tp->t_flags &= ~TF_NODELAY; 367 break; 368 369 case TCP_MAXSEG: /* not yet */ 370 default: 371 error = EINVAL; 372 break; 373 } 374 if (m) 375 (void) m_free(m); 376 break; 377 378 case PRCO_GETOPT: 379 *mp = m = m_get(M_WAIT, MT_SOOPTS); 380 m->m_len = sizeof(int); 381 382 switch (optname) { 383 case TCP_NODELAY: 384 *mtod(m, int *) = tp->t_flags & TF_NODELAY; 385 break; 386 case TCP_MAXSEG: 387 *mtod(m, int *) = tp->t_maxseg; 388 break; 389 default: 390 error = EINVAL; 391 break; 392 } 393 break; 394 } 395 return (error); 396 } 397 398 u_long tcp_sendspace = 1024*8; 399 u_long tcp_recvspace = 1024*8; 400 401 /* 402 * Attach TCP protocol to socket, allocating 403 * internet protocol control block, tcp control block, 404 * bufer space, and entering LISTEN state if to accept connections. 405 */ 406 tcp_attach(so) 407 struct socket *so; 408 { 409 register struct tcpcb *tp; 410 struct inpcb *inp; 411 int error; 412 413 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 414 error = soreserve(so, tcp_sendspace, tcp_recvspace); 415 if (error) 416 return (error); 417 } 418 error = in_pcballoc(so, &tcb); 419 if (error) 420 return (error); 421 inp = sotoinpcb(so); 422 tp = tcp_newtcpcb(inp); 423 if (tp == 0) { 424 int nofd = so->so_state & SS_NOFDREF; /* XXX */ 425 426 so->so_state &= ~SS_NOFDREF; /* don't free the socket yet */ 427 in_pcbdetach(inp); 428 so->so_state |= nofd; 429 return (ENOBUFS); 430 } 431 tp->t_state = TCPS_CLOSED; 432 return (0); 433 } 434 435 /* 436 * Initiate (or continue) disconnect. 437 * If embryonic state, just send reset (once). 438 * If in ``let data drain'' option and linger null, just drop. 439 * Otherwise (hard), mark socket disconnecting and drop 440 * current input data; switch states based on user close, and 441 * send segment to peer (with FIN). 442 */ 443 struct tcpcb * 444 tcp_disconnect(tp) 445 register struct tcpcb *tp; 446 { 447 struct socket *so = tp->t_inpcb->inp_socket; 448 449 if (tp->t_state < TCPS_ESTABLISHED) 450 tp = tcp_close(tp); 451 else if ((so->so_options & SO_LINGER) && so->so_linger == 0) 452 tp = tcp_drop(tp, 0); 453 else { 454 soisdisconnecting(so); 455 sbflush(&so->so_rcv); 456 tp = tcp_usrclosed(tp); 457 if (tp) 458 (void) tcp_output(tp); 459 } 460 return (tp); 461 } 462 463 /* 464 * User issued close, and wish to trail through shutdown states: 465 * if never received SYN, just forget it. If got a SYN from peer, 466 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN. 467 * If already got a FIN from peer, then almost done; go to LAST_ACK 468 * state. In all other cases, have already sent FIN to peer (e.g. 469 * after PRU_SHUTDOWN), and just have to play tedious game waiting 470 * for peer to send FIN or not respond to keep-alives, etc. 471 * We can let the user exit from the close as soon as the FIN is acked. 472 */ 473 struct tcpcb * 474 tcp_usrclosed(tp) 475 register struct tcpcb *tp; 476 { 477 478 switch (tp->t_state) { 479 480 case TCPS_CLOSED: 481 case TCPS_LISTEN: 482 case TCPS_SYN_SENT: 483 tp->t_state = TCPS_CLOSED; 484 tp = tcp_close(tp); 485 break; 486 487 case TCPS_SYN_RECEIVED: 488 case TCPS_ESTABLISHED: 489 tp->t_state = TCPS_FIN_WAIT_1; 490 break; 491 492 case TCPS_CLOSE_WAIT: 493 tp->t_state = TCPS_LAST_ACK; 494 break; 495 } 496 if (tp && tp->t_state >= TCPS_FIN_WAIT_2) 497 soisdisconnected(tp->t_inpcb->inp_socket); 498 return (tp); 499 } 500