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