| 1 | /* tcp_usrreq.c 1.57 82/04/30 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/mbuf.h" |
| 6 | #include "../h/socket.h" |
| 7 | #include "../h/socketvar.h" |
| 8 | #include "../h/protosw.h" |
| 9 | #include "../net/in.h" |
| 10 | #include "../net/route.h" |
| 11 | #include "../net/in_pcb.h" |
| 12 | #include "../net/in_systm.h" |
| 13 | #include "../net/if.h" |
| 14 | #include "../net/ip.h" |
| 15 | #include "../net/ip_var.h" |
| 16 | #include "../net/tcp.h" |
| 17 | #include "../net/tcp_fsm.h" |
| 18 | #include "../net/tcp_seq.h" |
| 19 | #include "../net/tcp_timer.h" |
| 20 | #include "../net/tcp_var.h" |
| 21 | #include "../net/tcpip.h" |
| 22 | #include "../net/tcp_debug.h" |
| 23 | #include <errno.h> |
| 24 | |
| 25 | /* |
| 26 | * TCP protocol interface to socket abstraction. |
| 27 | */ |
| 28 | extern char *tcpstates[]; |
| 29 | struct tcpcb *tcp_newtcpcb(); |
| 30 | |
| 31 | /* |
| 32 | * Process a TCP user request for TCP tb. If this is a send request |
| 33 | * then m is the mbuf chain of send data. If this is a timer expiration |
| 34 | * (called from the software clock routine), then timertype tells which timer. |
| 35 | */ |
| 36 | tcp_usrreq(so, req, m, addr) |
| 37 | struct socket *so; |
| 38 | int req; |
| 39 | struct mbuf *m; |
| 40 | caddr_t addr; |
| 41 | { |
| 42 | register struct inpcb *inp = sotoinpcb(so); |
| 43 | register struct tcpcb *tp; |
| 44 | int s = splnet(); |
| 45 | int error = 0; |
| 46 | int ostate; |
| 47 | COUNT(TCP_USRREQ); |
| 48 | |
| 49 | /* |
| 50 | * When a TCP is attached to a socket, then there will be |
| 51 | * a (struct inpcb) pointed at by the socket, and this |
| 52 | * structure will point at a subsidary (struct tcpcb). |
| 53 | * The normal sequence of events is: |
| 54 | * PRU_ATTACH creating these structures |
| 55 | * PRU_CONNECT connecting to a remote peer |
| 56 | * (PRU_SEND|PRU_RCVD)* exchanging data |
| 57 | * PRU_DISCONNECT disconnecting from remote peer |
| 58 | * PRU_DETACH deleting the structures |
| 59 | * With the operations from PRU_CONNECT through PRU_DISCONNECT |
| 60 | * possible repeated several times. |
| 61 | * |
| 62 | * MULTIPLE CONNECTS ARE NOT YET IMPLEMENTED. |
| 63 | */ |
| 64 | if (inp == 0 && req != PRU_ATTACH) { |
| 65 | splx(s); |
| 66 | return (EINVAL); /* XXX */ |
| 67 | } |
| 68 | if (inp) { |
| 69 | tp = intotcpcb(inp); |
| 70 | #ifdef KPROF |
| 71 | tcp_acounts[tp->t_state][req]++; |
| 72 | #endif |
| 73 | ostate = tp->t_state; |
| 74 | } |
| 75 | switch (req) { |
| 76 | |
| 77 | /* |
| 78 | * TCP attaches to socket via PRU_ATTACH, reserving space, |
| 79 | * and internet and TCP control blocks. |
| 80 | * If the socket is to receive connections, |
| 81 | * then the LISTEN state is entered. |
| 82 | */ |
| 83 | case PRU_ATTACH: |
| 84 | if (inp) { |
| 85 | error = EISCONN; |
| 86 | break; |
| 87 | } |
| 88 | error = tcp_attach(so, (struct sockaddr *)addr); |
| 89 | if (error) |
| 90 | break; |
| 91 | if ((so->so_options & SO_DONTLINGER) == 0) |
| 92 | so->so_linger = TCP_LINGERTIME; |
| 93 | tp = sototcpcb(so); |
| 94 | break; |
| 95 | |
| 96 | /* |
| 97 | * PRU_DETACH detaches the TCP protocol from the socket. |
| 98 | * If the protocol state is non-embryonic, then can't |
| 99 | * do this directly: have to initiate a PRU_DISCONNECT, |
| 100 | * which may finish later; embryonic TCB's can just |
| 101 | * be discarded here. |
| 102 | */ |
| 103 | case PRU_DETACH: |
| 104 | if (tp->t_state > TCPS_LISTEN) |
| 105 | tcp_disconnect(tp); |
| 106 | else { |
| 107 | tcp_close(tp); |
| 108 | tp = 0; |
| 109 | } |
| 110 | break; |
| 111 | |
| 112 | /* |
| 113 | * Initiate connection to peer. |
| 114 | * Create a template for use in transmissions on this connection. |
| 115 | * Enter SYN_SENT state, and mark socket as connecting. |
| 116 | * Start keep-alive timer, and seed output sequence space. |
| 117 | * Send initial segment on connection. |
| 118 | */ |
| 119 | case PRU_CONNECT: |
| 120 | error = in_pcbconnect(inp, (struct sockaddr_in *)addr); |
| 121 | if (error) |
| 122 | break; |
| 123 | tp->t_template = tcp_template(tp); |
| 124 | if (tp->t_template == 0) { |
| 125 | in_pcbdisconnect(inp); |
| 126 | error = ENOBUFS; |
| 127 | break; |
| 128 | } |
| 129 | soisconnecting(so); |
| 130 | tp->t_state = TCPS_SYN_SENT; |
| 131 | tp->t_timer[TCPT_KEEP] = TCPTV_KEEP; |
| 132 | tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; |
| 133 | tcp_sendseqinit(tp); |
| 134 | error = tcp_output(tp); |
| 135 | break; |
| 136 | |
| 137 | /* |
| 138 | * Initiate disconnect from peer. |
| 139 | * If connection never passed embryonic stage, just drop; |
| 140 | * else if don't need to let data drain, then can just drop anyways, |
| 141 | * else have to begin TCP shutdown process: mark socket disconnecting, |
| 142 | * drain unread data, state switch to reflect user close, and |
| 143 | * send segment (e.g. FIN) to peer. Socket will be really disconnected |
| 144 | * when peer sends FIN and acks ours. |
| 145 | * |
| 146 | * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB. |
| 147 | */ |
| 148 | case PRU_DISCONNECT: |
| 149 | tcp_disconnect(tp); |
| 150 | break; |
| 151 | |
| 152 | /* |
| 153 | * Accept a connection. Essentially all the work is |
| 154 | * done at higher levels; just return the address |
| 155 | * of the peer, storing through addr. |
| 156 | */ |
| 157 | case PRU_ACCEPT: { |
| 158 | struct sockaddr_in *sin = (struct sockaddr_in *)addr; |
| 159 | |
| 160 | if (sin) { |
| 161 | bzero((caddr_t)sin, sizeof (*sin)); |
| 162 | sin->sin_family = AF_INET; |
| 163 | sin->sin_port = inp->inp_fport; |
| 164 | sin->sin_addr = inp->inp_faddr; |
| 165 | } |
| 166 | } |
| 167 | break; |
| 168 | |
| 169 | /* |
| 170 | * Mark the connection as being incapable of further output. |
| 171 | */ |
| 172 | case PRU_SHUTDOWN: |
| 173 | socantsendmore(so); |
| 174 | tcp_usrclosed(tp); |
| 175 | error = tcp_output(tp); |
| 176 | break; |
| 177 | |
| 178 | /* |
| 179 | * After a receive, possibly send window update to peer. |
| 180 | */ |
| 181 | case PRU_RCVD: |
| 182 | (void) tcp_output(tp); |
| 183 | break; |
| 184 | |
| 185 | /* |
| 186 | * Do a send by putting data in output queue and updating urgent |
| 187 | * marker if URG set. Possibly send more data. |
| 188 | */ |
| 189 | case PRU_SEND: |
| 190 | sbappend(&so->so_snd, m); |
| 191 | #ifdef notdef |
| 192 | if (tp->t_flags & TF_PUSH) |
| 193 | tp->snd_end = tp->snd_una + so->so_snd.sb_cc; |
| 194 | #endif |
| 195 | error = tcp_output(tp); |
| 196 | break; |
| 197 | |
| 198 | /* |
| 199 | * Abort the TCP. |
| 200 | */ |
| 201 | case PRU_ABORT: |
| 202 | tcp_drop(tp, ECONNABORTED); |
| 203 | break; |
| 204 | |
| 205 | /* SOME AS YET UNIMPLEMENTED HOOKS */ |
| 206 | case PRU_CONTROL: |
| 207 | error = EOPNOTSUPP; |
| 208 | break; |
| 209 | |
| 210 | case PRU_SENSE: |
| 211 | error = EOPNOTSUPP; |
| 212 | break; |
| 213 | /* END UNIMPLEMENTED HOOKS */ |
| 214 | |
| 215 | case PRU_RCVOOB: |
| 216 | if (so->so_oobmark == 0 && |
| 217 | (so->so_state & SS_RCVATMARK) == 0) { |
| 218 | error = EINVAL; |
| 219 | break; |
| 220 | } |
| 221 | if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { |
| 222 | error = EWOULDBLOCK; |
| 223 | break; |
| 224 | } |
| 225 | *mtod(m, caddr_t) = tp->t_iobc; |
| 226 | break; |
| 227 | |
| 228 | case PRU_SENDOOB: |
| 229 | #ifdef TCPTRUEOOB |
| 230 | if (tp->t_flags & TF_DOOOB) { |
| 231 | tp->t_oobseq++; |
| 232 | tp->t_oobc = *mtod(m, caddr_t); |
| 233 | tp->t_oobmark = tp->snd_una + so->so_snd.sb_cc; |
| 234 | printf("sendoob seq now %x oobc %x\n", tp->t_oobseq, tp->t_oobc); |
| 235 | tp->t_oobflags |= TCPOOB_NEEDACK; |
| 236 | /* what to do ...? */ |
| 237 | if (error = tcp_output(tp)) |
| 238 | break; |
| 239 | } |
| 240 | #endif |
| 241 | if (sbspace(&so->so_snd) < -512) { |
| 242 | error = ENOBUFS; |
| 243 | break; |
| 244 | } |
| 245 | tp->snd_up = tp->snd_una + so->so_snd.sb_cc + 1; |
| 246 | sbappend(&so->so_snd, m); |
| 247 | #ifdef notdef |
| 248 | if (tp->t_flags & TF_PUSH) |
| 249 | tp->snd_end = tp->snd_una + so->so_snd.sb_cc; |
| 250 | #endif |
| 251 | tp->t_force = 1; |
| 252 | error = tcp_output(tp); |
| 253 | tp->t_force = 0; |
| 254 | break; |
| 255 | |
| 256 | case PRU_SOCKADDR: |
| 257 | in_setsockaddr((struct sockaddr_in *)addr, inp); |
| 258 | break; |
| 259 | |
| 260 | /* |
| 261 | * TCP slow timer went off; going through this |
| 262 | * routine for tracing's sake. |
| 263 | */ |
| 264 | case PRU_SLOWTIMO: |
| 265 | tcp_timers(tp, (int)addr); |
| 266 | req |= (int)addr << 8; /* for debug's sake */ |
| 267 | break; |
| 268 | |
| 269 | default: |
| 270 | panic("tcp_usrreq"); |
| 271 | } |
| 272 | if (tp && (so->so_options & SO_DEBUG)) |
| 273 | tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req); |
| 274 | splx(s); |
| 275 | return (error); |
| 276 | } |
| 277 | |
| 278 | int tcp_sendspace = 1024*2; |
| 279 | int tcp_recvspace = 1024*2; |
| 280 | /* |
| 281 | * Attach TCP protocol to socket, allocating |
| 282 | * internet protocol control block, tcp control block, |
| 283 | * bufer space, and entering LISTEN state if to accept connections. |
| 284 | */ |
| 285 | tcp_attach(so, sa) |
| 286 | struct socket *so; |
| 287 | struct sockaddr *sa; |
| 288 | { |
| 289 | register struct tcpcb *tp; |
| 290 | struct inpcb *inp; |
| 291 | int error; |
| 292 | |
| 293 | error = in_pcbattach(so, &tcb, |
| 294 | tcp_sendspace, tcp_recvspace, (struct sockaddr_in *)sa); |
| 295 | if (error) |
| 296 | return (error); |
| 297 | inp = (struct inpcb *)so->so_pcb; |
| 298 | tp = tcp_newtcpcb(inp); |
| 299 | if (so->so_options & SO_ACCEPTCONN) { |
| 300 | if (tp == 0) { |
| 301 | in_pcbdetach(inp); |
| 302 | return (ENOBUFS); |
| 303 | } |
| 304 | tp->t_state = TCPS_LISTEN; |
| 305 | } else |
| 306 | tp->t_state = TCPS_CLOSED; |
| 307 | return (0); |
| 308 | } |
| 309 | |
| 310 | /* |
| 311 | * Initiate (or continue) disconnect. |
| 312 | * If embryonic state, just send reset (once). |
| 313 | * If not in ``let data drain'' option, just drop. |
| 314 | * Otherwise (hard), mark socket disconnecting and drop |
| 315 | * current input data; switch states based on user close, and |
| 316 | * send segment to peer (with FIN). |
| 317 | */ |
| 318 | tcp_disconnect(tp) |
| 319 | struct tcpcb *tp; |
| 320 | { |
| 321 | struct socket *so = tp->t_inpcb->inp_socket; |
| 322 | |
| 323 | if (tp->t_state < TCPS_ESTABLISHED) |
| 324 | tcp_close(tp); |
| 325 | else if (so->so_linger == 0) |
| 326 | tcp_drop(tp, 0); |
| 327 | else { |
| 328 | soisdisconnecting(so); |
| 329 | sbflush(&so->so_rcv); |
| 330 | tcp_usrclosed(tp); |
| 331 | (void) tcp_output(tp); |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | /* |
| 336 | * User issued close, and wish to trail through shutdown states: |
| 337 | * if never received SYN, just forget it. If got a SYN from peer, |
| 338 | * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN. |
| 339 | * If already got a FIN from peer, then almost done; go to LAST_ACK |
| 340 | * state. In all other cases, have already sent FIN to peer (e.g. |
| 341 | * after PRU_SHUTDOWN), and just have to play tedious game waiting |
| 342 | * for peer to send FIN or not respond to keep-alives, etc. |
| 343 | * We can let the user exit from the close as soon as the FIN is acked. |
| 344 | */ |
| 345 | tcp_usrclosed(tp) |
| 346 | struct tcpcb *tp; |
| 347 | { |
| 348 | |
| 349 | switch (tp->t_state) { |
| 350 | |
| 351 | case TCPS_LISTEN: |
| 352 | case TCPS_SYN_SENT: |
| 353 | tp->t_state = TCPS_CLOSED; |
| 354 | tcp_close(tp); |
| 355 | break; |
| 356 | |
| 357 | case TCPS_SYN_RECEIVED: |
| 358 | case TCPS_ESTABLISHED: |
| 359 | tp->t_state = TCPS_FIN_WAIT_1; |
| 360 | break; |
| 361 | |
| 362 | case TCPS_CLOSE_WAIT: |
| 363 | tp->t_state = TCPS_LAST_ACK; |
| 364 | break; |
| 365 | } |
| 366 | if (tp->t_state >= TCPS_FIN_WAIT_2) |
| 367 | soisdisconnected(tp->t_inpcb->inp_socket); |
| 368 | } |