| 1 | /* tcp_usrreq.c 1.49 82/01/18 */ |
| 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/in_pcb.h" |
| 11 | #include "../net/in_systm.h" |
| 12 | #include "../net/if.h" |
| 13 | #include "../net/ip.h" |
| 14 | #include "../net/ip_var.h" |
| 15 | #include "../net/tcp.h" |
| 16 | #include "../net/tcp_fsm.h" |
| 17 | #include "../net/tcp_seq.h" |
| 18 | #include "../net/tcp_timer.h" |
| 19 | #include "../net/tcp_var.h" |
| 20 | #include "../net/tcpip.h" |
| 21 | #include "../net/tcp_debug.h" |
| 22 | #include "../errno.h" |
| 23 | |
| 24 | /* |
| 25 | * TCP protocol interface to socket abstraction. |
| 26 | */ |
| 27 | extern char *tcpstates[]; |
| 28 | struct tcpcb *tcp_newtcpcb(); |
| 29 | |
| 30 | /* |
| 31 | * Process a TCP user request for TCP tb. If this is a send request |
| 32 | * then m is the mbuf chain of send data. If this is a timer expiration |
| 33 | * (called from the software clock routine), then timertype tells which timer. |
| 34 | */ |
| 35 | tcp_usrreq(so, req, m, addr) |
| 36 | struct socket *so; |
| 37 | int req; |
| 38 | struct mbuf *m; |
| 39 | caddr_t addr; |
| 40 | { |
| 41 | register struct inpcb *inp = sotoinpcb(so); |
| 42 | register struct tcpcb *tp; |
| 43 | int s = splnet(); |
| 44 | int error = 0; |
| 45 | int ostate; |
| 46 | COUNT(TCP_USRREQ); |
| 47 | |
| 48 | /* |
| 49 | * When a TCP is attached to a socket, then there will be |
| 50 | * a (struct inpcb) pointed at by the socket, and this |
| 51 | * structure will point at a subsidary (struct tcpcb). |
| 52 | * The normal sequence of events is: |
| 53 | * PRU_ATTACH creating these structures |
| 54 | * PRU_CONNECT connecting to a remote peer |
| 55 | * (PRU_SEND|PRU_RCVD)* exchanging data |
| 56 | * PRU_DISCONNECT disconnecting from remote peer |
| 57 | * PRU_DETACH deleting the structures |
| 58 | * With the operations from PRU_CONNECT through PRU_DISCONNECT |
| 59 | * possible repeated several times. |
| 60 | * |
| 61 | * MULTIPLE CONNECTS ARE NOT YET IMPLEMENTED. |
| 62 | */ |
| 63 | if (inp == 0 && req != PRU_ATTACH) { |
| 64 | splx(s); |
| 65 | return (EINVAL); /* XXX */ |
| 66 | } |
| 67 | if (inp) { |
| 68 | tp = intotcpcb(inp); |
| 69 | #ifdef KPROF |
| 70 | tcp_acounts[tp->t_state][req]++; |
| 71 | #endif |
| 72 | ostate = tp->t_state; |
| 73 | } |
| 74 | switch (req) { |
| 75 | |
| 76 | /* |
| 77 | * TCP attaches to socket via PRU_ATTACH, reserving space, |
| 78 | * and internet and TCP control blocks. |
| 79 | * If the socket is to receive connections, |
| 80 | * then the LISTEN state is entered. |
| 81 | */ |
| 82 | case PRU_ATTACH: |
| 83 | if (inp) { |
| 84 | error = EISCONN; |
| 85 | break; |
| 86 | } |
| 87 | error = tcp_attach(so, (struct sockaddr *)addr); |
| 88 | if (error) |
| 89 | break; |
| 90 | if ((so->so_options & SO_DONTLINGER) == 0) |
| 91 | so->so_linger = TCP_LINGERTIME; |
| 92 | tp = sototcpcb(so); |
| 93 | break; |
| 94 | |
| 95 | /* |
| 96 | * PRU_DETACH detaches the TCP protocol from the socket. |
| 97 | * If the protocol state is non-embryonic, then can't |
| 98 | * do this directly: have to initiate a PRU_DISCONNECT, |
| 99 | * which may finish later; embryonic TCB's can just |
| 100 | * be discarded here. |
| 101 | */ |
| 102 | case PRU_DETACH: |
| 103 | if (tp->t_state > TCPS_LISTEN) |
| 104 | tcp_disconnect(tp); |
| 105 | else { |
| 106 | tcp_close(tp); |
| 107 | tp = 0; |
| 108 | } |
| 109 | break; |
| 110 | |
| 111 | /* |
| 112 | * Initiate connection to peer. |
| 113 | * Create a template for use in transmissions on this connection. |
| 114 | * Enter SYN_SENT state, and mark socket as connecting. |
| 115 | * Start keep-alive timer, and seed output sequence space. |
| 116 | * Send initial segment on connection. |
| 117 | */ |
| 118 | case PRU_CONNECT: |
| 119 | error = in_pcbconnect(inp, (struct sockaddr_in *)addr); |
| 120 | if (error) |
| 121 | break; |
| 122 | tp->t_template = tcp_template(tp); |
| 123 | if (tp->t_template == 0) { |
| 124 | in_pcbdisconnect(inp); |
| 125 | error = ENOBUFS; |
| 126 | break; |
| 127 | } |
| 128 | soisconnecting(so); |
| 129 | tp->t_state = TCPS_SYN_SENT; |
| 130 | tp->t_timer[TCPT_KEEP] = TCPTV_KEEP; |
| 131 | tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; |
| 132 | tcp_sendseqinit(tp); |
| 133 | (void) tcp_output(tp); |
| 134 | break; |
| 135 | |
| 136 | /* |
| 137 | * Initiate disconnect from peer. |
| 138 | * If connection never passed embryonic stage, just drop; |
| 139 | * else if don't need to let data drain, then can just drop anyways, |
| 140 | * else have to begin TCP shutdown process: mark socket disconnecting, |
| 141 | * drain unread data, state switch to reflect user close, and |
| 142 | * send segment (e.g. FIN) to peer. Socket will be really disconnected |
| 143 | * when peer sends FIN and acks ours. |
| 144 | * |
| 145 | * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB. |
| 146 | */ |
| 147 | case PRU_DISCONNECT: |
| 148 | tcp_disconnect(tp); |
| 149 | break; |
| 150 | |
| 151 | /* |
| 152 | * Accept a connection. Essentially all the work is |
| 153 | * done at higher levels; just return the address |
| 154 | * of the peer, storing through addr. |
| 155 | */ |
| 156 | case PRU_ACCEPT: |
| 157 | in_pcbconnaddr(inp, (struct sockaddr *)addr); |
| 158 | break; |
| 159 | |
| 160 | /* |
| 161 | * Mark the connection as being incapable of further output. |
| 162 | */ |
| 163 | case PRU_SHUTDOWN: |
| 164 | socantsendmore(so); |
| 165 | tcp_usrclosed(tp); |
| 166 | (void) tcp_output(tp); |
| 167 | break; |
| 168 | |
| 169 | /* |
| 170 | * After a receive, possibly send window update to peer. |
| 171 | */ |
| 172 | case PRU_RCVD: |
| 173 | (void) tcp_output(tp); |
| 174 | break; |
| 175 | |
| 176 | /* |
| 177 | * Do a send by putting data in output queue and updating urgent |
| 178 | * marker if URG set. Possibly send more data. |
| 179 | */ |
| 180 | case PRU_SEND: |
| 181 | sbappend(&so->so_snd, m); |
| 182 | /* |
| 183 | if (tp->t_flags & TF_PUSH) |
| 184 | tp->snd_end = tp->snd_una + so->so_snd.sb_cc; |
| 185 | */ |
| 186 | (void) tcp_output(tp); |
| 187 | break; |
| 188 | |
| 189 | /* |
| 190 | * Abort the TCP. |
| 191 | */ |
| 192 | case PRU_ABORT: |
| 193 | tcp_drop(tp, ECONNABORTED); |
| 194 | break; |
| 195 | |
| 196 | /* SOME AS YET UNIMPLEMENTED HOOKS */ |
| 197 | case PRU_CONTROL: |
| 198 | error = EOPNOTSUPP; |
| 199 | break; |
| 200 | |
| 201 | case PRU_SENSE: |
| 202 | error = EOPNOTSUPP; |
| 203 | break; |
| 204 | /* END UNIMPLEMENTED HOOKS */ |
| 205 | |
| 206 | case PRU_RCVOOB: |
| 207 | if (so->so_oobmark == 0 && |
| 208 | (so->so_state & SS_RCVATMARK) == 0) { |
| 209 | error = EINVAL; |
| 210 | break; |
| 211 | } |
| 212 | if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { |
| 213 | error = EWOULDBLOCK; |
| 214 | break; |
| 215 | } |
| 216 | *mtod(m, caddr_t) = tp->t_iobc; |
| 217 | break; |
| 218 | |
| 219 | case PRU_SENDOOB: |
| 220 | #ifdef TCPTRUEOOB |
| 221 | if (tp->t_flags & TF_DOOOB) { |
| 222 | tp->t_oobseq++; |
| 223 | tp->t_oobc = *mtod(m, caddr_t); |
| 224 | tp->t_oobmark = tp->snd_una + so->so_snd.sb_cc; |
| 225 | printf("sendoob seq now %x oobc %x\n", tp->t_oobseq, tp->t_oobc); |
| 226 | tp->t_oobflags |= TCPOOB_NEEDACK; |
| 227 | (void) tcp_output(tp); |
| 228 | } |
| 229 | #endif |
| 230 | if (sbspace(&so->so_snd) < -512) { |
| 231 | error = ENOBUFS; |
| 232 | break; |
| 233 | } |
| 234 | tp->snd_up = tp->snd_una + so->so_snd.sb_cc + 1; |
| 235 | sbappend(&so->so_snd, m); |
| 236 | /* |
| 237 | if (tp->t_flags & TF_PUSH) |
| 238 | tp->snd_end = tp->snd_una + so->so_snd.sb_cc; |
| 239 | */ |
| 240 | tp->t_force = 1; |
| 241 | (void) tcp_output(tp); |
| 242 | tp->t_force = 0; |
| 243 | break; |
| 244 | |
| 245 | /* |
| 246 | * TCP slow timer went off; going through this |
| 247 | * routine for tracing's sake. |
| 248 | */ |
| 249 | case PRU_SLOWTIMO: |
| 250 | tcp_timers(tp, (int)addr); |
| 251 | req |= (int)addr << 8; /* for debug's sake */ |
| 252 | break; |
| 253 | |
| 254 | default: |
| 255 | panic("tcp_usrreq"); |
| 256 | } |
| 257 | if (tp && (so->so_options & SO_DEBUG)) |
| 258 | tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req); |
| 259 | splx(s); |
| 260 | return (error); |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * Attach TCP protocol to socket, allocating |
| 265 | * internet protocol control block, tcp control block, |
| 266 | * bufer space, and entering LISTEN state if to accept connections. |
| 267 | */ |
| 268 | tcp_attach(so, sa) |
| 269 | struct socket *so; |
| 270 | struct sockaddr *sa; |
| 271 | { |
| 272 | register struct tcpcb *tp; |
| 273 | struct inpcb *inp; |
| 274 | int error; |
| 275 | |
| 276 | error = in_pcbattach(so, &tcb, 2048, 2048, (struct sockaddr_in *)sa); |
| 277 | if (error) |
| 278 | return (error); |
| 279 | inp = (struct inpcb *)so->so_pcb; |
| 280 | tp = tcp_newtcpcb(inp); |
| 281 | if (so->so_options & SO_ACCEPTCONN) { |
| 282 | if (tp == 0) { |
| 283 | in_pcbdetach(inp); |
| 284 | return (ENOBUFS); |
| 285 | } |
| 286 | tp->t_state = TCPS_LISTEN; |
| 287 | } else |
| 288 | tp->t_state = TCPS_CLOSED; |
| 289 | return (0); |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * Initiate (or continue) disconnect. |
| 294 | * If embryonic state, just send reset (once). |
| 295 | * If not in ``let data drain'' option, just drop. |
| 296 | * Otherwise (hard), mark socket disconnecting and drop |
| 297 | * current input data; switch states based on user close, and |
| 298 | * send segment to peer (with FIN). |
| 299 | */ |
| 300 | tcp_disconnect(tp) |
| 301 | struct tcpcb *tp; |
| 302 | { |
| 303 | struct socket *so = tp->t_inpcb->inp_socket; |
| 304 | |
| 305 | if (tp->t_state < TCPS_ESTABLISHED) |
| 306 | tcp_close(tp); |
| 307 | else if (so->so_linger == 0) |
| 308 | tcp_drop(tp, 0); |
| 309 | else { |
| 310 | soisdisconnecting(so); |
| 311 | sbflush(&so->so_rcv); |
| 312 | tcp_usrclosed(tp); |
| 313 | (void) tcp_output(tp); |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * User issued close, and wish to trail through shutdown states: |
| 319 | * if never received SYN, just forget it. If got a SYN from peer, |
| 320 | * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN. |
| 321 | * If already got a FIN from peer, then almost done; go to LAST_ACK |
| 322 | * state. In all other cases, have already sent FIN to peer (e.g. |
| 323 | * after PRU_SHUTDOWN), and just have to play tedious game waiting |
| 324 | * for peer to send FIN or not respond to keep-alives, etc. |
| 325 | */ |
| 326 | tcp_usrclosed(tp) |
| 327 | struct tcpcb *tp; |
| 328 | { |
| 329 | |
| 330 | switch (tp->t_state) { |
| 331 | |
| 332 | case TCPS_LISTEN: |
| 333 | case TCPS_SYN_SENT: |
| 334 | tp->t_state = TCPS_CLOSED; |
| 335 | tcp_close(tp); |
| 336 | break; |
| 337 | |
| 338 | case TCPS_SYN_RECEIVED: |
| 339 | case TCPS_ESTABLISHED: |
| 340 | tp->t_state = TCPS_FIN_WAIT_1; |
| 341 | break; |
| 342 | |
| 343 | case TCPS_CLOSE_WAIT: |
| 344 | tp->t_state = TCPS_LAST_ACK; |
| 345 | break; |
| 346 | } |
| 347 | } |