| 8a67d61d |
1 | /** @file\r |
| 2 | \r |
| 3 | Copyright (c) 2005 - 2006, Intel Corporation\r |
| 4 | All rights reserved. This program and the accompanying materials\r |
| 5 | are licensed and made available under the terms and conditions of the BSD License\r |
| 6 | which accompanies this distribution. The full text of the license may be found at\r |
| 7 | http://opensource.org/licenses/bsd-license.php\r |
| 8 | \r |
| 9 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
| 10 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
| 11 | \r |
| 12 | Module Name:\r |
| 13 | \r |
| 14 | Tcp4Output.c\r |
| 15 | \r |
| 16 | Abstract:\r |
| 17 | \r |
| 18 | TCP output process routines.\r |
| 19 | \r |
| 20 | \r |
| 21 | **/\r |
| 22 | \r |
| 23 | #include "Tcp4Main.h"\r |
| 24 | \r |
| 25 | STATIC UINT8 mTcpOutFlag[] = {\r |
| 26 | 0, // TCP_CLOSED\r |
| 27 | 0, // TCP_LISTEN\r |
| 28 | TCP_FLG_SYN, // TCP_SYN_SENT\r |
| 29 | TCP_FLG_SYN | TCP_FLG_ACK, // TCP_SYN_RCVD\r |
| 30 | TCP_FLG_ACK, // TCP_ESTABLISHED\r |
| 31 | TCP_FLG_FIN | TCP_FLG_ACK, // TCP_FIN_WAIT_1\r |
| 32 | TCP_FLG_ACK, // TCP_FIN_WAIT_2\r |
| 33 | TCP_FLG_ACK | TCP_FLG_FIN, // TCP_CLOSING\r |
| 34 | TCP_FLG_ACK, // TCP_TIME_WAIT\r |
| 35 | TCP_FLG_ACK, // TCP_CLOSE_WAIT\r |
| 36 | TCP_FLG_FIN | TCP_FLG_ACK // TCP_LAST_ACK\r |
| 37 | };\r |
| 38 | \r |
| 39 | \r |
| 40 | /**\r |
| 41 | Compute the sequence space left in the old receive window.\r |
| 42 | \r |
| 43 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 44 | \r |
| 45 | @return The sequence space left in the old receive window.\r |
| 46 | \r |
| 47 | **/\r |
| 48 | UINT32\r |
| 49 | TcpRcvWinOld (\r |
| 50 | IN TCP_CB *Tcb\r |
| 51 | )\r |
| 52 | {\r |
| 53 | UINT32 OldWin;\r |
| 54 | \r |
| 55 | OldWin = 0;\r |
| 56 | \r |
| 57 | if (TCP_SEQ_GT (Tcb->RcvWl2 + Tcb->RcvWnd, Tcb->RcvNxt)) {\r |
| 58 | \r |
| 59 | OldWin = TCP_SUB_SEQ (\r |
| 60 | Tcb->RcvWl2 + Tcb->RcvWnd,\r |
| 61 | Tcb->RcvNxt\r |
| 62 | );\r |
| 63 | }\r |
| 64 | \r |
| 65 | return OldWin;\r |
| 66 | }\r |
| 67 | \r |
| 68 | \r |
| 69 | /**\r |
| 70 | Compute the current receive window.\r |
| 71 | \r |
| 72 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 73 | \r |
| 74 | @return The size of the current receive window, in bytes.\r |
| 75 | \r |
| 76 | **/\r |
| 77 | UINT32\r |
| 78 | TcpRcvWinNow (\r |
| 79 | IN TCP_CB *Tcb\r |
| 80 | )\r |
| 81 | {\r |
| 82 | SOCKET *Sk;\r |
| 83 | UINT32 Win;\r |
| 84 | UINT32 Increase;\r |
| 85 | UINT32 OldWin;\r |
| 86 | \r |
| 87 | Sk = Tcb->Sk;\r |
| 88 | ASSERT (Sk);\r |
| 89 | \r |
| 90 | OldWin = TcpRcvWinOld (Tcb);\r |
| 91 | \r |
| 92 | Win = SockGetFreeSpace (Sk, SOCK_RCV_BUF);\r |
| 93 | \r |
| 94 | Increase = 0;\r |
| 95 | if (Win > OldWin) {\r |
| 96 | Increase = Win - OldWin;\r |
| 97 | }\r |
| 98 | \r |
| 99 | //\r |
| 100 | // Receiver's SWS: don't advertise a bigger window\r |
| 101 | // unless it can be increased by at least one Mss or\r |
| 102 | // half of the receive buffer.\r |
| 103 | //\r |
| 104 | if ((Increase > Tcb->SndMss) ||\r |
| 105 | (2 * Increase >= GET_RCV_BUFFSIZE (Sk))) {\r |
| 106 | \r |
| 107 | return Win;\r |
| 108 | }\r |
| 109 | \r |
| 110 | return OldWin;\r |
| 111 | }\r |
| 112 | \r |
| 113 | \r |
| 114 | /**\r |
| 115 | Compute the value to fill in the window size field\r |
| 116 | of the outgoing segment.\r |
| 117 | \r |
| 118 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 119 | @param Syn The flag to indicate whether the outgoing segment is a SYN\r |
| 120 | segment.\r |
| 121 | \r |
| 122 | @return The value of the local receive window size used to fill the outing segment.\r |
| 123 | \r |
| 124 | **/\r |
| 125 | STATIC\r |
| 126 | UINT16\r |
| 127 | TcpComputeWnd (\r |
| 128 | IN TCP_CB *Tcb,\r |
| 129 | IN BOOLEAN Syn\r |
| 130 | )\r |
| 131 | {\r |
| 132 | UINT32 Wnd;\r |
| 133 | \r |
| 134 | //\r |
| 135 | // RFC requires that initial window not be scaled\r |
| 136 | //\r |
| 137 | if (Syn) {\r |
| 138 | \r |
| 139 | Wnd = GET_RCV_BUFFSIZE (Tcb->Sk);\r |
| 140 | } else {\r |
| 141 | \r |
| 142 | Wnd = TcpRcvWinNow (Tcb);\r |
| 143 | \r |
| 144 | Tcb->RcvWnd = Wnd;\r |
| 145 | }\r |
| 146 | \r |
| 147 | Wnd = NET_MIN (Wnd >> Tcb->RcvWndScale, 0xffff);\r |
| 148 | return NTOHS ((UINT16) Wnd);\r |
| 149 | }\r |
| 150 | \r |
| 151 | \r |
| 152 | /**\r |
| 153 | Get the maximum SndNxt.\r |
| 154 | \r |
| 155 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 156 | \r |
| 157 | @return The sequence number of the maximum SndNxt.\r |
| 158 | \r |
| 159 | **/\r |
| 160 | TCP_SEQNO\r |
| 161 | TcpGetMaxSndNxt (\r |
| 162 | IN TCP_CB *Tcb\r |
| 163 | )\r |
| 164 | {\r |
| 165 | NET_LIST_ENTRY *Entry;\r |
| 166 | NET_BUF *Nbuf;\r |
| 167 | \r |
| 168 | if (NetListIsEmpty (&Tcb->SndQue)) {\r |
| 169 | return Tcb->SndNxt;\r |
| 170 | }\r |
| 171 | \r |
| 172 | Entry = Tcb->SndQue.BackLink;\r |
| 173 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r |
| 174 | \r |
| 175 | ASSERT (TCP_SEQ_GEQ (TCPSEG_NETBUF (Nbuf)->End, Tcb->SndNxt));\r |
| 176 | return TCPSEG_NETBUF (Nbuf)->End;\r |
| 177 | }\r |
| 178 | \r |
| 179 | \r |
| 180 | /**\r |
| 181 | Compute how much data to send.\r |
| 182 | \r |
| 183 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 184 | @param Force Whether to ignore the sender's SWS avoidance algorithm and send\r |
| 185 | out data by force.\r |
| 186 | \r |
| 187 | @return The length of the data can be sent, if 0, no data can be sent.\r |
| 188 | \r |
| 189 | **/\r |
| 190 | UINT32\r |
| 191 | TcpDataToSend (\r |
| 192 | IN TCP_CB *Tcb,\r |
| 193 | IN INTN Force\r |
| 194 | )\r |
| 195 | {\r |
| 196 | SOCKET *Sk;\r |
| 197 | UINT32 Win;\r |
| 198 | UINT32 Len;\r |
| 199 | UINT32 Left;\r |
| 200 | UINT32 Limit;\r |
| 201 | \r |
| 202 | Sk = Tcb->Sk;\r |
| 203 | ASSERT (Sk);\r |
| 204 | \r |
| 205 | //\r |
| 206 | // TCP should NOT send data beyond the send window\r |
| 207 | // and congestion window. The right edge of send\r |
| 208 | // window is defined as SND.WL2 + SND.WND. The right\r |
| 209 | // edge of congestion window is defined as SND.UNA +\r |
| 210 | // CWND.\r |
| 211 | //\r |
| 212 | Win = 0;\r |
| 213 | Limit = Tcb->SndWl2 + Tcb->SndWnd;\r |
| 214 | \r |
| 215 | if (TCP_SEQ_GT (Limit, Tcb->SndUna + Tcb->CWnd)) {\r |
| 216 | \r |
| 217 | Limit = Tcb->SndUna + Tcb->CWnd;\r |
| 218 | }\r |
| 219 | \r |
| 220 | if (TCP_SEQ_GT (Limit, Tcb->SndNxt)) {\r |
| 221 | Win = TCP_SUB_SEQ (Limit, Tcb->SndNxt);\r |
| 222 | }\r |
| 223 | \r |
| 224 | //\r |
| 225 | // The data to send contains two parts: the data on the\r |
| 226 | // socket send queue, and the data on the TCB's send\r |
| 227 | // buffer. The later can be non-zero if the peer shrinks\r |
| 228 | // its advertised window.\r |
| 229 | //\r |
| 230 | Left = GET_SND_DATASIZE (Sk) +\r |
| 231 | TCP_SUB_SEQ (TcpGetMaxSndNxt (Tcb), Tcb->SndNxt);\r |
| 232 | \r |
| 233 | Len = NET_MIN (Win, Left);\r |
| 234 | \r |
| 235 | if (Len > Tcb->SndMss) {\r |
| 236 | Len = Tcb->SndMss;\r |
| 237 | }\r |
| 238 | \r |
| 239 | if (Force || (Len == 0 && Left == 0)) {\r |
| 240 | return Len;\r |
| 241 | }\r |
| 242 | \r |
| 243 | if (Len == 0 && Left != 0) {\r |
| 244 | goto SetPersistTimer;\r |
| 245 | }\r |
| 246 | \r |
| 247 | //\r |
| 248 | // Sender's SWS avoidance: Don't send a small segment unless\r |
| 249 | // a)A full-sized segment can be sent,\r |
| 250 | // b)at least one-half of the maximum sized windows that\r |
| 251 | // the other end has ever advertised.\r |
| 252 | // c)It can send everything it has and either it isn't\r |
| 253 | // expecting an ACK or the Nagle algorithm is disabled.\r |
| 254 | //\r |
| 255 | if ((Len == Tcb->SndMss) || (2 * Len >= Tcb->SndWndMax)) {\r |
| 256 | \r |
| 257 | return Len;\r |
| 258 | }\r |
| 259 | \r |
| 260 | if ((Len == Left) &&\r |
| 261 | ((Tcb->SndNxt == Tcb->SndUna) ||\r |
| 262 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_NO_NAGLE))) {\r |
| 263 | \r |
| 264 | return Len;\r |
| 265 | }\r |
| 266 | \r |
| 267 | //\r |
| 268 | // RFC1122 suggests to set a timer when SWSA forbids TCP\r |
| 269 | // sending more data, and combine it with probe timer.\r |
| 270 | //\r |
| 271 | SetPersistTimer:\r |
| 272 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r |
| 273 | \r |
| 274 | TCP4_DEBUG_WARN (\r |
| 275 | ("TcpDataToSend: enter persistent state for TCB %x\n",\r |
| 276 | Tcb)\r |
| 277 | );\r |
| 278 | \r |
| 279 | TcpSetProbeTimer (Tcb);\r |
| 280 | }\r |
| 281 | \r |
| 282 | return 0;\r |
| 283 | }\r |
| 284 | \r |
| 285 | \r |
| 286 | /**\r |
| 287 | Build the TCP header of the TCP segment and transmit the\r |
| 288 | segment by IP.\r |
| 289 | \r |
| 290 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 291 | @param Nbuf Pointer to the buffer containing the segment to be sent out.\r |
| 292 | \r |
| 293 | @retval 0 The segment is sent out successfully.\r |
| 294 | @retval other Error condition occurred.\r |
| 295 | \r |
| 296 | **/\r |
| 297 | STATIC\r |
| 298 | INTN\r |
| 299 | TcpTransmitSegment (\r |
| 300 | IN TCP_CB *Tcb,\r |
| 301 | IN NET_BUF *Nbuf\r |
| 302 | )\r |
| 303 | {\r |
| 304 | UINT16 Len;\r |
| 305 | TCP_HEAD *Head;\r |
| 306 | TCP_SEG *Seg;\r |
| 307 | BOOLEAN Syn;\r |
| 308 | UINT32 DataLen;\r |
| 309 | \r |
| 310 | ASSERT (Nbuf && (Nbuf->Tcp == NULL) && TcpVerifySegment (Nbuf));\r |
| 311 | \r |
| 312 | DataLen = Nbuf->TotalSize;\r |
| 313 | \r |
| 314 | Seg = TCPSEG_NETBUF (Nbuf);\r |
| 315 | Syn = TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN);\r |
| 316 | \r |
| 317 | if (Syn) {\r |
| 318 | \r |
| 319 | Len = TcpSynBuildOption (Tcb, Nbuf);\r |
| 320 | } else {\r |
| 321 | \r |
| 322 | Len = TcpBuildOption (Tcb, Nbuf);\r |
| 323 | }\r |
| 324 | \r |
| 325 | ASSERT ((Len % 4 == 0) && (Len <= 40));\r |
| 326 | \r |
| 327 | Len += sizeof (TCP_HEAD);\r |
| 328 | \r |
| 329 | Head = (TCP_HEAD *) NetbufAllocSpace (\r |
| 330 | Nbuf,\r |
| 331 | sizeof (TCP_HEAD),\r |
| 332 | NET_BUF_HEAD\r |
| 333 | );\r |
| 334 | \r |
| 335 | ASSERT (Head != NULL);\r |
| 336 | \r |
| 337 | Nbuf->Tcp = Head;\r |
| 338 | \r |
| 339 | Head->SrcPort = Tcb->LocalEnd.Port;\r |
| 340 | Head->DstPort = Tcb->RemoteEnd.Port;\r |
| 341 | Head->Seq = NTOHL (Seg->Seq);\r |
| 342 | Head->Ack = NTOHL (Tcb->RcvNxt);\r |
| 343 | Head->HeadLen = (UINT8) (Len >> 2);\r |
| 344 | Head->Res = 0;\r |
| 345 | Head->Wnd = TcpComputeWnd (Tcb, Syn);\r |
| 346 | Head->Checksum = 0;\r |
| 347 | \r |
| 348 | //\r |
| 349 | // Check whether to set the PSH flag.\r |
| 350 | //\r |
| 351 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_PSH);\r |
| 352 | \r |
| 353 | if (DataLen != 0) {\r |
| 354 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_PSH) &&\r |
| 355 | TCP_SEQ_BETWEEN (Seg->Seq, Tcb->SndPsh, Seg->End)) {\r |
| 356 | \r |
| 357 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r |
| 358 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_PSH);\r |
| 359 | \r |
| 360 | } else if ((Seg->End == Tcb->SndNxt) &&\r |
| 361 | (GET_SND_DATASIZE (Tcb->Sk) == 0)) {\r |
| 362 | \r |
| 363 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r |
| 364 | }\r |
| 365 | }\r |
| 366 | \r |
| 367 | //\r |
| 368 | // Check whether to set the URG flag and the urgent pointer.\r |
| 369 | //\r |
| 370 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);\r |
| 371 | \r |
| 372 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&\r |
| 373 | TCP_SEQ_LEQ (Seg->Seq, Tcb->SndUp)) {\r |
| 374 | \r |
| 375 | TCP_SET_FLG (Seg->Flag, TCP_FLG_URG);\r |
| 376 | \r |
| 377 | if (TCP_SEQ_LT (Tcb->SndUp, Seg->End)) {\r |
| 378 | \r |
| 379 | Seg->Urg = (UINT16) TCP_SUB_SEQ (Tcb->SndUp, Seg->Seq);\r |
| 380 | } else {\r |
| 381 | \r |
| 382 | Seg->Urg = (UINT16) NET_MIN (\r |
| 383 | TCP_SUB_SEQ (Tcb->SndUp,\r |
| 384 | Seg->Seq),\r |
| 385 | 0xffff\r |
| 386 | );\r |
| 387 | }\r |
| 388 | }\r |
| 389 | \r |
| 390 | Head->Flag = Seg->Flag;\r |
| 391 | Head->Urg = NTOHS (Seg->Urg);\r |
| 392 | Head->Checksum = TcpChecksum (Nbuf, Tcb->HeadSum);\r |
| 393 | \r |
| 394 | //\r |
| 395 | // update the TCP session's control information\r |
| 396 | //\r |
| 397 | Tcb->RcvWl2 = Tcb->RcvNxt;\r |
| 398 | if (Syn) {\r |
| 399 | Tcb->RcvWnd = NTOHS (Head->Wnd);\r |
| 400 | }\r |
| 401 | \r |
| 402 | //\r |
| 403 | // clear delayedack flag\r |
| 404 | //\r |
| 405 | Tcb->DelayedAck = 0;\r |
| 406 | \r |
| 407 | return TcpSendIpPacket (Tcb, Nbuf, Tcb->LocalEnd.Ip, Tcb->RemoteEnd.Ip);\r |
| 408 | }\r |
| 409 | \r |
| 410 | \r |
| 411 | /**\r |
| 412 | Get a segment from the Tcb's SndQue.\r |
| 413 | \r |
| 414 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 415 | @param Seq The sequence number of the segment.\r |
| 416 | @param Len The maximum length of the segment.\r |
| 417 | \r |
| 418 | @return Pointer to the segment, if NULL some error occurred.\r |
| 419 | \r |
| 420 | **/\r |
| 421 | NET_BUF *\r |
| 422 | TcpGetSegmentSndQue (\r |
| 423 | IN TCP_CB *Tcb,\r |
| 424 | IN TCP_SEQNO Seq,\r |
| 425 | IN UINT32 Len\r |
| 426 | )\r |
| 427 | {\r |
| 428 | NET_LIST_ENTRY *Head;\r |
| 429 | NET_LIST_ENTRY *Cur;\r |
| 430 | NET_BUF *Node;\r |
| 431 | TCP_SEG *Seg;\r |
| 432 | NET_BUF *Nbuf;\r |
| 433 | TCP_SEQNO End;\r |
| 434 | UINT8 *Data;\r |
| 435 | UINT8 Flag;\r |
| 436 | INT32 Offset;\r |
| 437 | INT32 CopyLen;\r |
| 438 | \r |
| 439 | ASSERT (Tcb && TCP_SEQ_LEQ (Seq, Tcb->SndNxt) && (Len > 0));\r |
| 440 | \r |
| 441 | //\r |
| 442 | // Find the segment that contains the Seq.\r |
| 443 | //\r |
| 444 | Head = &Tcb->SndQue;\r |
| 445 | \r |
| 446 | Node = NULL;\r |
| 447 | Seg = NULL;\r |
| 448 | \r |
| 449 | NET_LIST_FOR_EACH (Cur, Head) {\r |
| 450 | Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);\r |
| 451 | Seg = TCPSEG_NETBUF (Node);\r |
| 452 | \r |
| 453 | if (TCP_SEQ_LT (Seq, Seg->End) && TCP_SEQ_LEQ (Seg->Seq, Seq)) {\r |
| 454 | \r |
| 455 | break;\r |
| 456 | }\r |
| 457 | }\r |
| 458 | \r |
| 459 | ASSERT (Cur != Head);\r |
| 460 | \r |
| 461 | //\r |
| 462 | // Return the buffer if it can be returned without\r |
| 463 | // adjustment:\r |
| 464 | //\r |
| 465 | if ((Seg->Seq == Seq) &&\r |
| 466 | TCP_SEQ_LEQ (Seg->End, Seg->Seq + Len) &&\r |
| 467 | !NET_BUF_SHARED (Node)) {\r |
| 468 | \r |
| 469 | NET_GET_REF (Node);\r |
| 470 | return Node;\r |
| 471 | }\r |
| 472 | \r |
| 473 | //\r |
| 474 | // Create a new buffer and copy data there.\r |
| 475 | //\r |
| 476 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r |
| 477 | \r |
| 478 | if (Nbuf == NULL) {\r |
| 479 | return NULL;\r |
| 480 | }\r |
| 481 | \r |
| 482 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r |
| 483 | \r |
| 484 | Flag = Seg->Flag;\r |
| 485 | End = Seg->End;\r |
| 486 | \r |
| 487 | if (TCP_SEQ_LT (Seq + Len, Seg->End)) {\r |
| 488 | End = Seq + Len;\r |
| 489 | }\r |
| 490 | \r |
| 491 | CopyLen = TCP_SUB_SEQ (End, Seq);\r |
| 492 | Offset = TCP_SUB_SEQ (Seq, Seg->Seq);\r |
| 493 | \r |
| 494 | //\r |
| 495 | // If SYN is set and out of the range, clear the flag.\r |
| 496 | // Becuase the sequence of the first byte is SEG.SEQ+1,\r |
| 497 | // adjust Offset by -1. If SYN is in the range, copy\r |
| 498 | // one byte less.\r |
| 499 | //\r |
| 500 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r |
| 501 | \r |
| 502 | if (TCP_SEQ_LT (Seg->Seq, Seq)) {\r |
| 503 | \r |
| 504 | TCP_CLEAR_FLG (Flag, TCP_FLG_SYN);\r |
| 505 | Offset--;\r |
| 506 | } else {\r |
| 507 | \r |
| 508 | CopyLen--;\r |
| 509 | }\r |
| 510 | }\r |
| 511 | \r |
| 512 | //\r |
| 513 | // If FIN is set and in the range, copy one byte less,\r |
| 514 | // and if it is out of the range, clear the flag.\r |
| 515 | //\r |
| 516 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r |
| 517 | \r |
| 518 | if (Seg->End == End) {\r |
| 519 | \r |
| 520 | CopyLen--;\r |
| 521 | } else {\r |
| 522 | \r |
| 523 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r |
| 524 | }\r |
| 525 | }\r |
| 526 | \r |
| 527 | ASSERT (CopyLen >= 0);\r |
| 528 | \r |
| 529 | //\r |
| 530 | // copy data to the segment\r |
| 531 | //\r |
| 532 | if (CopyLen) {\r |
| 533 | Data = NetbufAllocSpace (Nbuf, CopyLen, NET_BUF_TAIL);\r |
| 534 | ASSERT (Data);\r |
| 535 | \r |
| 536 | if ((INT32) NetbufCopy (Node, Offset, CopyLen, Data) != CopyLen) {\r |
| 537 | goto OnError;\r |
| 538 | }\r |
| 539 | }\r |
| 540 | \r |
| 541 | NetCopyMem (TCPSEG_NETBUF (Nbuf), Seg, sizeof (TCP_SEG));\r |
| 542 | \r |
| 543 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r |
| 544 | TCPSEG_NETBUF (Nbuf)->End = End;\r |
| 545 | TCPSEG_NETBUF (Nbuf)->Flag = Flag;\r |
| 546 | \r |
| 547 | return Nbuf;\r |
| 548 | \r |
| 549 | OnError:\r |
| 550 | NetbufFree (Nbuf);\r |
| 551 | return NULL;\r |
| 552 | }\r |
| 553 | \r |
| 554 | \r |
| 555 | /**\r |
| 556 | Get a segment from the Tcb's socket buffer.\r |
| 557 | \r |
| 558 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 559 | @param Seq The sequence number of the segment.\r |
| 560 | @param Len The maximum length of the segment.\r |
| 561 | \r |
| 562 | @return Pointer to the segment, if NULL some error occurred.\r |
| 563 | \r |
| 564 | **/\r |
| 565 | NET_BUF *\r |
| 566 | TcpGetSegmentSock (\r |
| 567 | IN TCP_CB *Tcb,\r |
| 568 | IN TCP_SEQNO Seq,\r |
| 569 | IN UINT32 Len\r |
| 570 | )\r |
| 571 | {\r |
| 572 | NET_BUF *Nbuf;\r |
| 573 | UINT8 *Data;\r |
| 574 | UINT32 DataGet;\r |
| 575 | \r |
| 576 | ASSERT (Tcb && Tcb->Sk);\r |
| 577 | \r |
| 578 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r |
| 579 | \r |
| 580 | if (Nbuf == NULL) {\r |
| 581 | TCP4_DEBUG_ERROR (("TcpGetSegmentSock: failed to allocate "\r |
| 582 | "a netbuf for TCB %x\n",Tcb));\r |
| 583 | \r |
| 584 | return NULL;\r |
| 585 | }\r |
| 586 | \r |
| 587 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r |
| 588 | \r |
| 589 | DataGet = 0;\r |
| 590 | \r |
| 591 | if (Len) {\r |
| 592 | //\r |
| 593 | // copy data to the segment.\r |
| 594 | //\r |
| 595 | Data = NetbufAllocSpace (Nbuf, Len, NET_BUF_TAIL);\r |
| 596 | ASSERT (Data);\r |
| 597 | \r |
| 598 | DataGet = SockGetDataToSend (Tcb->Sk, 0, Len, Data);\r |
| 599 | }\r |
| 600 | \r |
| 601 | NET_GET_REF (Nbuf);\r |
| 602 | \r |
| 603 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r |
| 604 | TCPSEG_NETBUF (Nbuf)->End = Seq + Len;\r |
| 605 | \r |
| 606 | NetListInsertTail (&(Tcb->SndQue), &(Nbuf->List));\r |
| 607 | \r |
| 608 | if (DataGet != 0) {\r |
| 609 | \r |
| 610 | SockDataSent (Tcb->Sk, DataGet);\r |
| 611 | }\r |
| 612 | \r |
| 613 | return Nbuf;\r |
| 614 | }\r |
| 615 | \r |
| 616 | \r |
| 617 | /**\r |
| 618 | Get a segment starting from sequence Seq of a maximum\r |
| 619 | length of Len.\r |
| 620 | \r |
| 621 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 622 | @param Seq The sequence number of the segment.\r |
| 623 | @param Len The maximum length of the segment.\r |
| 624 | \r |
| 625 | @return Pointer to the segment, if NULL some error occurred.\r |
| 626 | \r |
| 627 | **/\r |
| 628 | NET_BUF *\r |
| 629 | TcpGetSegment (\r |
| 630 | IN TCP_CB *Tcb,\r |
| 631 | IN TCP_SEQNO Seq,\r |
| 632 | IN UINT32 Len\r |
| 633 | )\r |
| 634 | {\r |
| 635 | NET_BUF *Nbuf;\r |
| 636 | \r |
| 637 | ASSERT (Tcb);\r |
| 638 | \r |
| 639 | //\r |
| 640 | // Compare the SndNxt with the max sequence number sent.\r |
| 641 | //\r |
| 642 | if ((Len != 0) && TCP_SEQ_LT (Seq, TcpGetMaxSndNxt (Tcb))) {\r |
| 643 | \r |
| 644 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r |
| 645 | } else {\r |
| 646 | \r |
| 647 | Nbuf = TcpGetSegmentSock (Tcb, Seq, Len);\r |
| 648 | }\r |
| 649 | \r |
| 650 | ASSERT (TcpVerifySegment (Nbuf));\r |
| 651 | return Nbuf;\r |
| 652 | }\r |
| 653 | \r |
| 654 | \r |
| 655 | /**\r |
| 656 | Retransmit the segment from sequence Seq.\r |
| 657 | \r |
| 658 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 659 | @param Seq The sequence number of the segment to be retransmitted.\r |
| 660 | \r |
| 661 | @retval 0 Retransmission succeeded.\r |
| 662 | @retval -1 Error condition occurred.\r |
| 663 | \r |
| 664 | **/\r |
| 665 | INTN\r |
| 666 | TcpRetransmit (\r |
| 667 | IN TCP_CB *Tcb,\r |
| 668 | IN TCP_SEQNO Seq\r |
| 669 | )\r |
| 670 | {\r |
| 671 | NET_BUF *Nbuf;\r |
| 672 | UINT32 Len;\r |
| 673 | \r |
| 674 | //\r |
| 675 | // Compute the maxium length of retransmission. It is\r |
| 676 | // limited by three factors:\r |
| 677 | // 1. Less than SndMss\r |
| 678 | // 2. must in the current send window\r |
| 679 | // 3. will not change the boundaries of queued segments.\r |
| 680 | //\r |
| 681 | if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r |
| 682 | TCP4_DEBUG_WARN (("TcpRetransmit: retransmission cancelled "\r |
| 683 | "because send window too small for TCB %x\n", Tcb));\r |
| 684 | \r |
| 685 | return 0;\r |
| 686 | }\r |
| 687 | \r |
| 688 | Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r |
| 689 | Len = NET_MIN (Len, Tcb->SndMss);\r |
| 690 | \r |
| 691 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r |
| 692 | if (Nbuf == NULL) {\r |
| 693 | return -1;\r |
| 694 | }\r |
| 695 | \r |
| 696 | ASSERT (TcpVerifySegment (Nbuf));\r |
| 697 | \r |
| 698 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r |
| 699 | goto OnError;\r |
| 700 | }\r |
| 701 | \r |
| 702 | //\r |
| 703 | // The retransmitted buffer may be on the SndQue,\r |
| 704 | // trim TCP head because all the buffer on SndQue\r |
| 705 | // are headless.\r |
| 706 | //\r |
| 707 | ASSERT (Nbuf->Tcp);\r |
| 708 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r |
| 709 | Nbuf->Tcp = NULL;\r |
| 710 | \r |
| 711 | NetbufFree (Nbuf);\r |
| 712 | return 0;\r |
| 713 | \r |
| 714 | OnError:\r |
| 715 | if (Nbuf != NULL) {\r |
| 716 | NetbufFree (Nbuf);\r |
| 717 | }\r |
| 718 | \r |
| 719 | return -1;\r |
| 720 | }\r |
| 721 | \r |
| 722 | \r |
| 723 | /**\r |
| 724 | Check whether to send data/SYN/FIN and piggy back an ACK.\r |
| 725 | \r |
| 726 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 727 | @param Force Whether to ignore the sender's SWS avoidance algorithm and send\r |
| 728 | out data by force.\r |
| 729 | \r |
| 730 | @return The number of bytes sent.\r |
| 731 | \r |
| 732 | **/\r |
| 733 | INTN\r |
| 734 | TcpToSendData (\r |
| 735 | IN TCP_CB *Tcb,\r |
| 736 | IN INTN Force\r |
| 737 | )\r |
| 738 | {\r |
| 739 | UINT32 Len;\r |
| 740 | INTN Sent;\r |
| 741 | UINT8 Flag;\r |
| 742 | NET_BUF *Nbuf;\r |
| 743 | TCP_SEG *Seg;\r |
| 744 | TCP_SEQNO Seq;\r |
| 745 | TCP_SEQNO End;\r |
| 746 | \r |
| 747 | ASSERT (Tcb && Tcb->Sk && (Tcb->State != TCP_LISTEN));\r |
| 748 | \r |
| 749 | Sent = 0;\r |
| 750 | \r |
| 751 | if ((Tcb->State == TCP_CLOSED) ||\r |
| 752 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT)) {\r |
| 753 | \r |
| 754 | return 0;\r |
| 755 | }\r |
| 756 | \r |
| 757 | SEND_AGAIN:\r |
| 758 | //\r |
| 759 | // compute how much data can be sent\r |
| 760 | //\r |
| 761 | Len = TcpDataToSend (Tcb, Force);\r |
| 762 | Seq = Tcb->SndNxt;\r |
| 763 | \r |
| 764 | Flag = mTcpOutFlag[Tcb->State];\r |
| 765 | \r |
| 766 | if (Flag & TCP_FLG_SYN) {\r |
| 767 | \r |
| 768 | Seq = Tcb->Iss;\r |
| 769 | Len = 0;\r |
| 770 | }\r |
| 771 | \r |
| 772 | //\r |
| 773 | // only send a segment without data if SYN or\r |
| 774 | // FIN is set.\r |
| 775 | //\r |
| 776 | if ((Len == 0) && !(Flag & (TCP_FLG_SYN | TCP_FLG_FIN))) {\r |
| 777 | return Sent;\r |
| 778 | }\r |
| 779 | \r |
| 780 | Nbuf = TcpGetSegment (Tcb, Seq, Len);\r |
| 781 | \r |
| 782 | if (Nbuf == NULL) {\r |
| 783 | TCP4_DEBUG_ERROR (\r |
| 784 | ("TcpToSendData: failed to get a segment for TCB %x\n",\r |
| 785 | Tcb)\r |
| 786 | );\r |
| 787 | \r |
| 788 | goto OnError;\r |
| 789 | }\r |
| 790 | \r |
| 791 | Seg = TCPSEG_NETBUF (Nbuf);\r |
| 792 | \r |
| 793 | //\r |
| 794 | // Set the TcpSeg in Nbuf.\r |
| 795 | //\r |
| 796 | Len = Nbuf->TotalSize;\r |
| 797 | End = Seq + Len;\r |
| 798 | if (TCP_FLG_ON (Flag, TCP_FLG_SYN)) {\r |
| 799 | End++;\r |
| 800 | }\r |
| 801 | \r |
| 802 | if (Flag & TCP_FLG_FIN) {\r |
| 803 | //\r |
| 804 | // Send FIN if all data is sent, and FIN is\r |
| 805 | // in the window\r |
| 806 | //\r |
| 807 | if ((TcpGetMaxSndNxt (Tcb) == Tcb->SndNxt) &&\r |
| 808 | (GET_SND_DATASIZE (Tcb->Sk) == 0) &&\r |
| 809 | TCP_SEQ_LT (End + 1, Tcb->SndWnd + Tcb->SndWl2)\r |
| 810 | ) {\r |
| 811 | \r |
| 812 | TCP4_DEBUG_TRACE (("TcpToSendData: send FIN "\r |
| 813 | "to peer for TCB %x in state %d\n", Tcb, Tcb->State));\r |
| 814 | \r |
| 815 | End++;\r |
| 816 | } else {\r |
| 817 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r |
| 818 | }\r |
| 819 | }\r |
| 820 | \r |
| 821 | Seg->Seq = Seq;\r |
| 822 | Seg->End = End;\r |
| 823 | Seg->Flag = Flag;\r |
| 824 | \r |
| 825 | ASSERT (TcpVerifySegment (Nbuf));\r |
| 826 | ASSERT (TcpCheckSndQue (&Tcb->SndQue));\r |
| 827 | \r |
| 828 | //\r |
| 829 | // don't send an empty segment here.\r |
| 830 | //\r |
| 831 | if (Seg->End == Seg->Seq) {\r |
| 832 | TCP4_DEBUG_WARN (("TcpToSendData: created a empty"\r |
| 833 | " segment for TCB %x, free it now\n", Tcb));\r |
| 834 | \r |
| 835 | NetbufFree (Nbuf);\r |
| 836 | return Sent;\r |
| 837 | }\r |
| 838 | \r |
| 839 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r |
| 840 | //\r |
| 841 | // TODO: double check this\r |
| 842 | //\r |
| 843 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r |
| 844 | Nbuf->Tcp = NULL;\r |
| 845 | \r |
| 846 | if (Flag & TCP_FLG_FIN) {\r |
| 847 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r |
| 848 | }\r |
| 849 | \r |
| 850 | goto OnError;\r |
| 851 | }\r |
| 852 | \r |
| 853 | Sent += TCP_SUB_SEQ (End, Seq);\r |
| 854 | \r |
| 855 | //\r |
| 856 | // All the buffer in the SndQue is headless\r |
| 857 | //\r |
| 858 | ASSERT (Nbuf->Tcp);\r |
| 859 | \r |
| 860 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r |
| 861 | Nbuf->Tcp = NULL;\r |
| 862 | \r |
| 863 | NetbufFree (Nbuf);\r |
| 864 | \r |
| 865 | //\r |
| 866 | // update status in TCB\r |
| 867 | //\r |
| 868 | Tcb->DelayedAck = 0;\r |
| 869 | \r |
| 870 | if (Flag & TCP_FLG_FIN) {\r |
| 871 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r |
| 872 | }\r |
| 873 | \r |
| 874 | if (TCP_SEQ_GT (End, Tcb->SndNxt)) {\r |
| 875 | Tcb->SndNxt = End;\r |
| 876 | }\r |
| 877 | \r |
| 878 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r |
| 879 | TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);\r |
| 880 | }\r |
| 881 | \r |
| 882 | //\r |
| 883 | // Enable RTT measurement only if not in retransmit.\r |
| 884 | // Karn's algorithm reqires not to update RTT when in loss.\r |
| 885 | //\r |
| 886 | if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&\r |
| 887 | !TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {\r |
| 888 | \r |
| 889 | TCP4_DEBUG_TRACE (("TcpToSendData: set RTT measure "\r |
| 890 | "sequence %d for TCB %x\n", Seq, Tcb));\r |
| 891 | \r |
| 892 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);\r |
| 893 | Tcb->RttSeq = Seq;\r |
| 894 | Tcb->RttMeasure = 0;\r |
| 895 | }\r |
| 896 | \r |
| 897 | if (Len == Tcb->SndMss) {\r |
| 898 | goto SEND_AGAIN;\r |
| 899 | }\r |
| 900 | \r |
| 901 | return Sent;\r |
| 902 | \r |
| 903 | OnError:\r |
| 904 | if (Nbuf != NULL) {\r |
| 905 | NetbufFree (Nbuf);\r |
| 906 | }\r |
| 907 | \r |
| 908 | return Sent;\r |
| 909 | }\r |
| 910 | \r |
| 911 | \r |
| 912 | /**\r |
| 913 | Send an ACK immediately.\r |
| 914 | \r |
| 915 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 916 | \r |
| 917 | @return None.\r |
| 918 | \r |
| 919 | **/\r |
| 920 | VOID\r |
| 921 | TcpSendAck (\r |
| 922 | IN TCP_CB *Tcb\r |
| 923 | )\r |
| 924 | {\r |
| 925 | NET_BUF *Nbuf;\r |
| 926 | TCP_SEG *Seg;\r |
| 927 | \r |
| 928 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r |
| 929 | \r |
| 930 | if (Nbuf == NULL) {\r |
| 931 | return;\r |
| 932 | }\r |
| 933 | \r |
| 934 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r |
| 935 | \r |
| 936 | Seg = TCPSEG_NETBUF (Nbuf);\r |
| 937 | Seg->Seq = Tcb->SndNxt;\r |
| 938 | Seg->End = Tcb->SndNxt;\r |
| 939 | Seg->Flag = TCP_FLG_ACK;\r |
| 940 | \r |
| 941 | if (TcpTransmitSegment (Tcb, Nbuf) == 0) {\r |
| 942 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);\r |
| 943 | Tcb->DelayedAck = 0;\r |
| 944 | }\r |
| 945 | \r |
| 946 | NetbufFree (Nbuf);\r |
| 947 | }\r |
| 948 | \r |
| 949 | \r |
| 950 | /**\r |
| 951 | Send a zero probe segment. It can be used by keepalive\r |
| 952 | and zero window probe.\r |
| 953 | \r |
| 954 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 955 | \r |
| 956 | @retval 0 The zero probe segment was sent out successfully.\r |
| 957 | @retval other Error condition occurred.\r |
| 958 | \r |
| 959 | **/\r |
| 960 | INTN\r |
| 961 | TcpSendZeroProbe (\r |
| 962 | IN TCP_CB *Tcb\r |
| 963 | )\r |
| 964 | {\r |
| 965 | NET_BUF *Nbuf;\r |
| 966 | TCP_SEG *Seg;\r |
| 967 | INTN Result;\r |
| 968 | \r |
| 969 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r |
| 970 | \r |
| 971 | if (Nbuf == NULL) {\r |
| 972 | return -1;\r |
| 973 | }\r |
| 974 | \r |
| 975 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r |
| 976 | \r |
| 977 | //\r |
| 978 | // SndNxt-1 is out of window. The peer should respond\r |
| 979 | // with an ACK.\r |
| 980 | //\r |
| 981 | Seg = TCPSEG_NETBUF (Nbuf);\r |
| 982 | Seg->Seq = Tcb->SndNxt - 1;\r |
| 983 | Seg->End = Tcb->SndNxt - 1;\r |
| 984 | Seg->Flag = TCP_FLG_ACK;\r |
| 985 | \r |
| 986 | Result = TcpTransmitSegment (Tcb, Nbuf);\r |
| 987 | NetbufFree (Nbuf);\r |
| 988 | \r |
| 989 | return Result;\r |
| 990 | }\r |
| 991 | \r |
| 992 | \r |
| 993 | /**\r |
| 994 | Check whether to send an ACK or delayed ACK.\r |
| 995 | \r |
| 996 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r |
| 997 | \r |
| 998 | @return None.\r |
| 999 | \r |
| 1000 | **/\r |
| 1001 | VOID\r |
| 1002 | TcpToSendAck (\r |
| 1003 | IN TCP_CB *Tcb\r |
| 1004 | )\r |
| 1005 | {\r |
| 1006 | //\r |
| 1007 | // Generally, TCP should send a delayed ACK unless:\r |
| 1008 | // 1. ACK at least every other FULL sized segment received,\r |
| 1009 | // 2. Packets received out of order\r |
| 1010 | // 3. Receiving window is open\r |
| 1011 | //\r |
| 1012 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) ||\r |
| 1013 | (Tcb->DelayedAck >= 1) ||\r |
| 1014 | (TcpRcvWinNow (Tcb) > TcpRcvWinOld (Tcb))\r |
| 1015 | ) {\r |
| 1016 | TcpSendAck (Tcb);\r |
| 1017 | return;\r |
| 1018 | }\r |
| 1019 | \r |
| 1020 | TCP4_DEBUG_TRACE (("TcpToSendAck: scheduled a delayed"\r |
| 1021 | " ACK for TCB %x\n", Tcb));\r |
| 1022 | \r |
| 1023 | //\r |
| 1024 | // schedule a delayed ACK\r |
| 1025 | //\r |
| 1026 | Tcb->DelayedAck++;\r |
| 1027 | }\r |
| 1028 | \r |
| 1029 | \r |
| 1030 | /**\r |
| 1031 | Send a RESET segment in response to the segment received.\r |
| 1032 | \r |
| 1033 | @param Tcb Pointer to the TCP_CB of this TCP instance, may be NULL.\r |
| 1034 | @param Head TCP header of the segment that triggers the reset.\r |
| 1035 | @param Len Length of the segment that triggers the reset.\r |
| 1036 | @param Local Local IP address.\r |
| 1037 | @param Remote Remote peer's IP address.\r |
| 1038 | \r |
| 1039 | @retval 0 A reset is sent or no need to send it.\r |
| 1040 | @retval -1 No reset is sent.\r |
| 1041 | \r |
| 1042 | **/\r |
| 1043 | INTN\r |
| 1044 | TcpSendReset (\r |
| 1045 | IN TCP_CB *Tcb,\r |
| 1046 | IN TCP_HEAD *Head,\r |
| 1047 | IN INT32 Len,\r |
| 1048 | IN UINT32 Local,\r |
| 1049 | IN UINT32 Remote\r |
| 1050 | )\r |
| 1051 | {\r |
| 1052 | NET_BUF *Nbuf;\r |
| 1053 | TCP_HEAD *Nhead;\r |
| 1054 | UINT16 HeadSum;\r |
| 1055 | \r |
| 1056 | //\r |
| 1057 | // Don't respond to a Reset with reset\r |
| 1058 | //\r |
| 1059 | if (Head->Flag & TCP_FLG_RST) {\r |
| 1060 | return 0;\r |
| 1061 | }\r |
| 1062 | \r |
| 1063 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r |
| 1064 | \r |
| 1065 | if (Nbuf == NULL) {\r |
| 1066 | return -1;\r |
| 1067 | }\r |
| 1068 | \r |
| 1069 | Nhead = (TCP_HEAD *) NetbufAllocSpace (\r |
| 1070 | Nbuf,\r |
| 1071 | sizeof (TCP_HEAD),\r |
| 1072 | NET_BUF_TAIL\r |
| 1073 | );\r |
| 1074 | \r |
| 1075 | ASSERT (Nhead != NULL);\r |
| 1076 | \r |
| 1077 | Nbuf->Tcp = Nhead;\r |
| 1078 | Nhead->Flag = TCP_FLG_RST;\r |
| 1079 | \r |
| 1080 | //\r |
| 1081 | // Derive Seq/ACK from the segment if no TCB\r |
| 1082 | // associated with it, otherwise from the Tcb\r |
| 1083 | //\r |
| 1084 | if (Tcb == NULL) {\r |
| 1085 | \r |
| 1086 | if (TCP_FLG_ON (Head->Flag, TCP_FLG_ACK)) {\r |
| 1087 | Nhead->Seq = Head->Ack;\r |
| 1088 | Nhead->Ack = 0;\r |
| 1089 | } else {\r |
| 1090 | Nhead->Seq = 0;\r |
| 1091 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r |
| 1092 | Nhead->Ack = HTONL (NTOHL (Head->Seq) + Len);\r |
| 1093 | }\r |
| 1094 | } else {\r |
| 1095 | \r |
| 1096 | Nhead->Seq = HTONL (Tcb->SndNxt);\r |
| 1097 | Nhead->Ack = HTONL (Tcb->RcvNxt);\r |
| 1098 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r |
| 1099 | }\r |
| 1100 | \r |
| 1101 | Nhead->SrcPort = Head->DstPort;\r |
| 1102 | Nhead->DstPort = Head->SrcPort;\r |
| 1103 | Nhead->HeadLen = (sizeof (TCP_HEAD) >> 2);\r |
| 1104 | Nhead->Res = 0;\r |
| 1105 | Nhead->Wnd = HTONS (0xFFFF);\r |
| 1106 | Nhead->Checksum = 0;\r |
| 1107 | Nhead->Urg = 0;\r |
| 1108 | \r |
| 1109 | HeadSum = NetPseudoHeadChecksum (Local, Remote, 6, 0);\r |
| 1110 | Nhead->Checksum = TcpChecksum (Nbuf, HeadSum);\r |
| 1111 | \r |
| 1112 | TcpSendIpPacket (Tcb, Nbuf, Local, Remote);\r |
| 1113 | \r |
| 1114 | NetbufFree (Nbuf);\r |
| 1115 | return 0;\r |
| 1116 | }\r |
| 1117 | \r |
| 1118 | \r |
| 1119 | /**\r |
| 1120 | Verify that the segment is in good shape.\r |
| 1121 | \r |
| 1122 | @param Nbuf Buffer that contains the segment to be checked.\r |
| 1123 | \r |
| 1124 | @retval 0 The segment is broken.\r |
| 1125 | @retval 1 The segment is in good shape.\r |
| 1126 | \r |
| 1127 | **/\r |
| 1128 | INTN\r |
| 1129 | TcpVerifySegment (\r |
| 1130 | IN NET_BUF *Nbuf\r |
| 1131 | )\r |
| 1132 | {\r |
| 1133 | TCP_HEAD *Head;\r |
| 1134 | TCP_SEG *Seg;\r |
| 1135 | UINT32 Len;\r |
| 1136 | \r |
| 1137 | if (Nbuf == NULL) {\r |
| 1138 | return 1;\r |
| 1139 | }\r |
| 1140 | \r |
| 1141 | NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);\r |
| 1142 | \r |
| 1143 | Seg = TCPSEG_NETBUF (Nbuf);\r |
| 1144 | Len = Nbuf->TotalSize;\r |
| 1145 | Head = Nbuf->Tcp;\r |
| 1146 | \r |
| 1147 | if (Head != NULL) {\r |
| 1148 | if (Head->Flag != Seg->Flag) {\r |
| 1149 | return 0;\r |
| 1150 | }\r |
| 1151 | \r |
| 1152 | Len -= (Head->HeadLen << 2);\r |
| 1153 | }\r |
| 1154 | \r |
| 1155 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r |
| 1156 | Len++;\r |
| 1157 | }\r |
| 1158 | \r |
| 1159 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r |
| 1160 | Len++;\r |
| 1161 | }\r |
| 1162 | \r |
| 1163 | if (Seg->Seq + Len != Seg->End) {\r |
| 1164 | return 0;\r |
| 1165 | }\r |
| 1166 | \r |
| 1167 | return 1;\r |
| 1168 | }\r |
| 1169 | \r |
| 1170 | \r |
| 1171 | /**\r |
| 1172 | Verify that all the segments in SndQue are in good shape.\r |
| 1173 | \r |
| 1174 | @param Head Pointer to the head node of the SndQue.\r |
| 1175 | \r |
| 1176 | @retval 0 At least one segment is broken.\r |
| 1177 | @retval 1 All segments in the specific queue are in good shape.\r |
| 1178 | \r |
| 1179 | **/\r |
| 1180 | INTN\r |
| 1181 | TcpCheckSndQue (\r |
| 1182 | IN NET_LIST_ENTRY *Head\r |
| 1183 | )\r |
| 1184 | {\r |
| 1185 | NET_LIST_ENTRY *Entry;\r |
| 1186 | NET_BUF *Nbuf;\r |
| 1187 | TCP_SEQNO Seq;\r |
| 1188 | \r |
| 1189 | if (NetListIsEmpty (Head)) {\r |
| 1190 | return 1;\r |
| 1191 | }\r |
| 1192 | //\r |
| 1193 | // Initialize the Seq\r |
| 1194 | //\r |
| 1195 | Entry = Head->ForwardLink;\r |
| 1196 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r |
| 1197 | Seq = TCPSEG_NETBUF (Nbuf)->Seq;\r |
| 1198 | \r |
| 1199 | NET_LIST_FOR_EACH (Entry, Head) {\r |
| 1200 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r |
| 1201 | \r |
| 1202 | if (TcpVerifySegment (Nbuf) == 0) {\r |
| 1203 | return 0;\r |
| 1204 | }\r |
| 1205 | \r |
| 1206 | //\r |
| 1207 | // All the node in the SndQue should has:\r |
| 1208 | // SEG.SEQ = LAST_SEG.END\r |
| 1209 | //\r |
| 1210 | if (Seq != TCPSEG_NETBUF (Nbuf)->Seq) {\r |
| 1211 | return 0;\r |
| 1212 | }\r |
| 1213 | \r |
| 1214 | Seq = TCPSEG_NETBUF (Nbuf)->End;\r |
| 1215 | }\r |
| 1216 | \r |
| 1217 | return 1;\r |
| 1218 | }\r |
projects / mirror_edk2.git / blame