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1 | /** @file\r |
2 | Routines to process TCP option.\r | |
3 | \r | |
4 | Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>\r | |
5 | \r | |
6 | This program and the accompanying materials\r | |
7 | are licensed and made available under the terms and conditions of the BSD License\r | |
8 | which accompanies this distribution. The full text of the license may be found at\r | |
9 | http://opensource.org/licenses/bsd-license.php.\r | |
10 | \r | |
11 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
12 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
13 | \r | |
14 | **/\r | |
15 | \r | |
16 | #include "TcpMain.h"\r | |
17 | \r | |
18 | /**\r | |
19 | Get a UINT16 value from buffer.\r | |
20 | \r | |
21 | @param[in] Buf Pointer to input buffer.\r | |
22 | \r | |
23 | @return The UINT16 value obtained from the buffer.\r | |
24 | \r | |
25 | **/\r | |
26 | UINT16\r | |
27 | TcpGetUint16 (\r | |
28 | IN UINT8 *Buf\r | |
29 | )\r | |
30 | {\r | |
31 | UINT16 Value;\r | |
32 | CopyMem (&Value, Buf, sizeof (UINT16));\r | |
33 | return NTOHS (Value);\r | |
34 | }\r | |
35 | \r | |
36 | /**\r | |
37 | Get a UINT32 value from buffer.\r | |
38 | \r | |
39 | @param[in] Buf Pointer to input buffer.\r | |
40 | \r | |
41 | @return The UINT32 value obtained from the buffer.\r | |
42 | \r | |
43 | **/\r | |
44 | UINT32\r | |
45 | TcpGetUint32 (\r | |
46 | IN UINT8 *Buf\r | |
47 | )\r | |
48 | {\r | |
49 | UINT32 Value;\r | |
50 | CopyMem (&Value, Buf, sizeof (UINT32));\r | |
51 | return NTOHL (Value);\r | |
52 | }\r | |
53 | \r | |
54 | /**\r | |
55 | Put a UINT32 value in buffer.\r | |
56 | \r | |
57 | @param[out] Buf Pointer to the buffer.\r | |
58 | @param[in] Data The UINT32 Date to put in the buffer.\r | |
59 | \r | |
60 | **/\r | |
61 | VOID\r | |
62 | TcpPutUint32 (\r | |
63 | OUT UINT8 *Buf,\r | |
64 | IN UINT32 Data\r | |
65 | )\r | |
66 | {\r | |
67 | Data = HTONL (Data);\r | |
68 | CopyMem (Buf, &Data, sizeof (UINT32));\r | |
69 | }\r | |
70 | \r | |
71 | /**\r | |
72 | Compute the window scale value according to the given buffer size.\r | |
73 | \r | |
74 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
75 | \r | |
76 | @return The scale value.\r | |
77 | \r | |
78 | **/\r | |
79 | UINT8\r | |
80 | TcpComputeScale (\r | |
81 | IN TCP_CB *Tcb\r | |
82 | )\r | |
83 | {\r | |
84 | UINT8 Scale;\r | |
85 | UINT32 BufSize;\r | |
86 | \r | |
87 | ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));\r | |
88 | \r | |
89 | BufSize = GET_RCV_BUFFSIZE (Tcb->Sk);\r | |
90 | \r | |
91 | Scale = 0;\r | |
92 | while ((Scale < TCP_OPTION_MAX_WS) && ((UINT32) (TCP_OPTION_MAX_WIN << Scale) < BufSize)) {\r | |
93 | \r | |
94 | Scale++;\r | |
95 | }\r | |
96 | \r | |
97 | return Scale;\r | |
98 | }\r | |
99 | \r | |
100 | /**\r | |
101 | Build the TCP option in three-way handshake.\r | |
102 | \r | |
103 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
104 | @param[in] Nbuf Pointer to the buffer to store the options.\r | |
105 | \r | |
106 | @return The total length of the TCP option field.\r | |
107 | \r | |
108 | **/\r | |
109 | UINT16\r | |
110 | TcpSynBuildOption (\r | |
111 | IN TCP_CB *Tcb,\r | |
112 | IN NET_BUF *Nbuf\r | |
113 | )\r | |
114 | {\r | |
115 | UINT8 *Data;\r | |
116 | UINT16 Len;\r | |
117 | \r | |
118 | ASSERT ((Tcb != NULL) && (Nbuf != NULL) && (Nbuf->Tcp == NULL));\r | |
119 | \r | |
120 | Len = 0;\r | |
121 | \r | |
122 | //\r | |
123 | // Add a timestamp option if not disabled by the application\r | |
124 | // and it is the first SYN segment, or the peer has sent\r | |
125 | // us its timestamp.\r | |
126 | //\r | |
127 | if (!TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_NO_TS) &&\r | |
128 | (!TCP_FLG_ON (TCPSEG_NETBUF (Nbuf)->Flag, TCP_FLG_ACK) ||\r | |
129 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_TS))\r | |
130 | ) {\r | |
131 | \r | |
132 | Data = NetbufAllocSpace (\r | |
133 | Nbuf,\r | |
134 | TCP_OPTION_TS_ALIGNED_LEN,\r | |
135 | NET_BUF_HEAD\r | |
136 | );\r | |
137 | \r | |
138 | ASSERT (Data != NULL);\r | |
139 | Len += TCP_OPTION_TS_ALIGNED_LEN;\r | |
140 | \r | |
141 | TcpPutUint32 (Data, TCP_OPTION_TS_FAST);\r | |
142 | TcpPutUint32 (Data + 4, mTcpTick);\r | |
143 | TcpPutUint32 (Data + 8, 0);\r | |
144 | }\r | |
145 | \r | |
146 | //\r | |
147 | // Build window scale option, only when configured\r | |
148 | // to send WS option, and either we are doing active\r | |
149 | // open or we have received WS option from peer.\r | |
150 | //\r | |
151 | if (!TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_NO_WS) &&\r | |
152 | (!TCP_FLG_ON (TCPSEG_NETBUF (Nbuf)->Flag, TCP_FLG_ACK) ||\r | |
153 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_WS))\r | |
154 | ) {\r | |
155 | \r | |
156 | Data = NetbufAllocSpace (\r | |
157 | Nbuf,\r | |
158 | TCP_OPTION_WS_ALIGNED_LEN,\r | |
159 | NET_BUF_HEAD\r | |
160 | );\r | |
161 | \r | |
162 | ASSERT (Data != NULL);\r | |
163 | \r | |
164 | Len += TCP_OPTION_WS_ALIGNED_LEN;\r | |
165 | TcpPutUint32 (Data, TCP_OPTION_WS_FAST | TcpComputeScale (Tcb));\r | |
166 | }\r | |
167 | \r | |
168 | //\r | |
169 | // Build the MSS option.\r | |
170 | //\r | |
171 | Data = NetbufAllocSpace (Nbuf, TCP_OPTION_MSS_LEN, 1);\r | |
172 | ASSERT (Data != NULL);\r | |
173 | \r | |
174 | Len += TCP_OPTION_MSS_LEN;\r | |
175 | TcpPutUint32 (Data, TCP_OPTION_MSS_FAST | Tcb->RcvMss);\r | |
176 | \r | |
177 | return Len;\r | |
178 | }\r | |
179 | \r | |
180 | /**\r | |
181 | Build the TCP option in synchronized states.\r | |
182 | \r | |
183 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
184 | @param[in] Nbuf Pointer to the buffer to store the options.\r | |
185 | \r | |
186 | @return The total length of the TCP option field.\r | |
187 | \r | |
188 | **/\r | |
189 | UINT16\r | |
190 | TcpBuildOption (\r | |
191 | IN TCP_CB *Tcb,\r | |
192 | IN NET_BUF *Nbuf\r | |
193 | )\r | |
194 | {\r | |
195 | UINT8 *Data;\r | |
196 | UINT16 Len;\r | |
197 | \r | |
198 | ASSERT ((Tcb != NULL) && (Nbuf != NULL) && (Nbuf->Tcp == NULL));\r | |
199 | Len = 0;\r | |
200 | \r | |
201 | //\r | |
202 | // Build the Timestamp option.\r | |
203 | //\r | |
204 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_TS) &&\r | |
205 | !TCP_FLG_ON (TCPSEG_NETBUF (Nbuf)->Flag, TCP_FLG_RST)\r | |
206 | ) {\r | |
207 | \r | |
208 | Data = NetbufAllocSpace (\r | |
209 | Nbuf,\r | |
210 | TCP_OPTION_TS_ALIGNED_LEN,\r | |
211 | NET_BUF_HEAD\r | |
212 | );\r | |
213 | \r | |
214 | ASSERT (Data != NULL);\r | |
215 | Len += TCP_OPTION_TS_ALIGNED_LEN;\r | |
216 | \r | |
217 | TcpPutUint32 (Data, TCP_OPTION_TS_FAST);\r | |
218 | TcpPutUint32 (Data + 4, mTcpTick);\r | |
219 | TcpPutUint32 (Data + 8, Tcb->TsRecent);\r | |
220 | }\r | |
221 | \r | |
222 | return Len;\r | |
223 | }\r | |
224 | \r | |
225 | /**\r | |
226 | Parse the supported options.\r | |
227 | \r | |
228 | @param[in] Tcp Pointer to the TCP_CB of this TCP instance.\r | |
229 | @param[in, out] Option Pointer to the TCP_OPTION used to store the\r | |
230 | successfully pasrsed options.\r | |
231 | \r | |
232 | @retval 0 The options are successfully pasrsed.\r | |
233 | @retval -1 Ilegal option was found.\r | |
234 | \r | |
235 | **/\r | |
236 | INTN\r | |
237 | TcpParseOption (\r | |
238 | IN TCP_HEAD *Tcp,\r | |
239 | IN OUT TCP_OPTION *Option\r | |
240 | )\r | |
241 | {\r | |
242 | UINT8 *Head;\r | |
243 | UINT8 TotalLen;\r | |
244 | UINT8 Cur;\r | |
245 | UINT8 Type;\r | |
246 | UINT8 Len;\r | |
247 | \r | |
248 | ASSERT ((Tcp != NULL) && (Option != NULL));\r | |
249 | \r | |
250 | Option->Flag = 0;\r | |
251 | \r | |
252 | TotalLen = (UINT8) ((Tcp->HeadLen << 2) - sizeof (TCP_HEAD));\r | |
253 | if (TotalLen <= 0) {\r | |
254 | return 0;\r | |
255 | }\r | |
256 | \r | |
257 | Head = (UINT8 *) (Tcp + 1);\r | |
258 | \r | |
259 | //\r | |
260 | // Fast process of the timestamp option.\r | |
261 | //\r | |
262 | if ((TotalLen == TCP_OPTION_TS_ALIGNED_LEN) && (TcpGetUint32 (Head) == TCP_OPTION_TS_FAST)) {\r | |
263 | \r | |
264 | Option->TSVal = TcpGetUint32 (Head + 4);\r | |
265 | Option->TSEcr = TcpGetUint32 (Head + 8);\r | |
266 | Option->Flag = TCP_OPTION_RCVD_TS;\r | |
267 | \r | |
268 | return 0;\r | |
269 | }\r | |
270 | //\r | |
271 | // Slow path to process the options.\r | |
272 | //\r | |
273 | Cur = 0;\r | |
274 | \r | |
275 | while (Cur < TotalLen) {\r | |
276 | Type = Head[Cur];\r | |
277 | \r | |
278 | switch (Type) {\r | |
279 | case TCP_OPTION_MSS:\r | |
280 | Len = Head[Cur + 1];\r | |
281 | \r | |
282 | if ((Len != TCP_OPTION_MSS_LEN) || (TotalLen - Cur < TCP_OPTION_MSS_LEN)) {\r | |
283 | \r | |
284 | return -1;\r | |
285 | }\r | |
286 | \r | |
287 | Option->Mss = TcpGetUint16 (&Head[Cur + 2]);\r | |
288 | TCP_SET_FLG (Option->Flag, TCP_OPTION_RCVD_MSS);\r | |
289 | \r | |
290 | Cur += TCP_OPTION_MSS_LEN;\r | |
291 | break;\r | |
292 | \r | |
293 | case TCP_OPTION_WS:\r | |
294 | Len = Head[Cur + 1];\r | |
295 | \r | |
296 | if ((Len != TCP_OPTION_WS_LEN) || (TotalLen - Cur < TCP_OPTION_WS_LEN)) {\r | |
297 | \r | |
298 | return -1;\r | |
299 | }\r | |
300 | \r | |
301 | Option->WndScale = (UINT8) MIN (14, Head[Cur + 2]);\r | |
302 | TCP_SET_FLG (Option->Flag, TCP_OPTION_RCVD_WS);\r | |
303 | \r | |
304 | Cur += TCP_OPTION_WS_LEN;\r | |
305 | break;\r | |
306 | \r | |
307 | case TCP_OPTION_TS:\r | |
308 | Len = Head[Cur + 1];\r | |
309 | \r | |
310 | if ((Len != TCP_OPTION_TS_LEN) || (TotalLen - Cur < TCP_OPTION_TS_LEN)) {\r | |
311 | \r | |
312 | return -1;\r | |
313 | }\r | |
314 | \r | |
315 | Option->TSVal = TcpGetUint32 (&Head[Cur + 2]);\r | |
316 | Option->TSEcr = TcpGetUint32 (&Head[Cur + 6]);\r | |
317 | TCP_SET_FLG (Option->Flag, TCP_OPTION_RCVD_TS);\r | |
318 | \r | |
319 | Cur += TCP_OPTION_TS_LEN;\r | |
320 | break;\r | |
321 | \r | |
322 | case TCP_OPTION_NOP:\r | |
323 | Cur++;\r | |
324 | break;\r | |
325 | \r | |
326 | case TCP_OPTION_EOP:\r | |
327 | Cur = TotalLen;\r | |
328 | break;\r | |
329 | \r | |
330 | default:\r | |
331 | Len = Head[Cur + 1];\r | |
332 | \r | |
333 | if ((TotalLen - Cur) < Len || Len < 2) {\r | |
334 | return -1;\r | |
335 | }\r | |
336 | \r | |
337 | Cur = (UINT8) (Cur + Len);\r | |
338 | break;\r | |
339 | }\r | |
340 | \r | |
341 | }\r | |
342 | \r | |
343 | return 0;\r | |
344 | }\r | |
345 | \r | |
346 | /**\r | |
347 | Check the segment against PAWS.\r | |
348 | \r | |
349 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
350 | @param[in] TSVal The timestamp value.\r | |
351 | \r | |
352 | @retval 1 The segment passed the PAWS check.\r | |
353 | @retval 0 The segment failed to pass the PAWS check.\r | |
354 | \r | |
355 | **/\r | |
356 | UINT32\r | |
357 | TcpPawsOK (\r | |
358 | IN TCP_CB *Tcb,\r | |
359 | IN UINT32 TSVal\r | |
360 | )\r | |
361 | {\r | |
362 | //\r | |
363 | // PAWS as defined in RFC1323, buggy...\r | |
364 | //\r | |
365 | if (TCP_TIME_LT (TSVal, Tcb->TsRecent) &&\r | |
366 | TCP_TIME_LT (Tcb->TsRecentAge + TCP_PAWS_24DAY, mTcpTick)\r | |
367 | ) {\r | |
368 | \r | |
369 | return 0;\r | |
370 | \r | |
371 | }\r | |
372 | \r | |
373 | return 1;\r | |
374 | }\r |