xref: /nrf52832-nimble/rt-thread/components/net/uip/uip/uip.h (revision 104654410c56c573564690304ae786df310c91fc)
1 
2 /**
3  * \addtogroup uip
4  * @{
5  */
6 
7 /**
8  * \file
9  * Header file for the uIP TCP/IP stack.
10  * \author Adam Dunkels <[email protected]>
11  *
12  * The uIP TCP/IP stack header file contains definitions for a number
13  * of C macros that are used by uIP programs as well as internal uIP
14  * structures, TCP/IP header structures and function declarations.
15  *
16  */
17 
18 
19 /*
20  * Copyright (c) 2001-2003, Adam Dunkels.
21  * All rights reserved.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the above copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. The name of the author may not be used to endorse or promote
32  *    products derived from this software without specific prior
33  *    written permission.
34  *
35  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
36  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
37  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
38  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
39  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
40  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
41  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
42  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
43  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
44  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
45  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
46  *
47  * This file is part of the uIP TCP/IP stack.
48  *
49  * $Id: uip.h,v 1.40 2006/06/08 07:12:07 adam Exp $
50  *
51  */
52 
53 #ifndef __UIP_H__
54 #define __UIP_H__
55 
56 #include "uipopt.h"
57 
58 /**
59  * Repressentation of an IP address.
60  *
61  */
62 typedef u16_t uip_ip4addr_t[2];
63 typedef u16_t uip_ip6addr_t[8];
64 #if UIP_CONF_IPV6
65 typedef uip_ip6addr_t uip_ipaddr_t;
66 #else /* UIP_CONF_IPV6 */
67 typedef uip_ip4addr_t uip_ipaddr_t;
68 #endif /* UIP_CONF_IPV6 */
69 
70 /*---------------------------------------------------------------------------*/
71 /* First, the functions that should be called from the
72  * system. Initialization, the periodic timer and incoming packets are
73  * handled by the following three functions.
74  */
75 
76 /**
77  * \defgroup uipconffunc uIP configuration functions
78  * @{
79  *
80  * The uIP configuration functions are used for setting run-time
81  * parameters in uIP such as IP addresses.
82  */
83 
84 /**
85  * Set the IP address of this host.
86  *
87  * The IP address is represented as a 4-byte array where the first
88  * octet of the IP address is put in the first member of the 4-byte
89  * array.
90  *
91  * Example:
92  \code
93 
94  uip_ipaddr_t addr;
95 
96  uip_ipaddr(&addr, 192,168,1,2);
97  uip_sethostaddr(&addr);
98 
99  \endcode
100  * \param addr A pointer to an IP address of type uip_ipaddr_t;
101  *
102  * \sa uip_ipaddr()
103  *
104  * \hideinitializer
105  */
106 #define uip_sethostaddr(addr) uip_ipaddr_copy(uip_hostaddr, (addr))
107 
108 /**
109  * Get the IP address of this host.
110  *
111  * The IP address is represented as a 4-byte array where the first
112  * octet of the IP address is put in the first member of the 4-byte
113  * array.
114  *
115  * Example:
116  \code
117  uip_ipaddr_t hostaddr;
118 
119  uip_gethostaddr(&hostaddr);
120  \endcode
121  * \param addr A pointer to a uip_ipaddr_t variable that will be
122  * filled in with the currently configured IP address.
123  *
124  * \hideinitializer
125  */
126 #define uip_gethostaddr(addr) uip_ipaddr_copy((addr), uip_hostaddr)
127 
128 /**
129  * Set the default router's IP address.
130  *
131  * \param addr A pointer to a uip_ipaddr_t variable containing the IP
132  * address of the default router.
133  *
134  * \sa uip_ipaddr()
135  *
136  * \hideinitializer
137  */
138 #define uip_setdraddr(addr) uip_ipaddr_copy(uip_draddr, (addr))
139 
140 /**
141  * Set the netmask.
142  *
143  * \param addr A pointer to a uip_ipaddr_t variable containing the IP
144  * address of the netmask.
145  *
146  * \sa uip_ipaddr()
147  *
148  * \hideinitializer
149  */
150 #define uip_setnetmask(addr) uip_ipaddr_copy(uip_netmask, (addr))
151 
152 
153 /**
154  * Get the default router's IP address.
155  *
156  * \param addr A pointer to a uip_ipaddr_t variable that will be
157  * filled in with the IP address of the default router.
158  *
159  * \hideinitializer
160  */
161 #define uip_getdraddr(addr) uip_ipaddr_copy((addr), uip_draddr)
162 
163 /**
164  * Get the netmask.
165  *
166  * \param addr A pointer to a uip_ipaddr_t variable that will be
167  * filled in with the value of the netmask.
168  *
169  * \hideinitializer
170  */
171 #define uip_getnetmask(addr) uip_ipaddr_copy((addr), uip_netmask)
172 
173 /** @} */
174 
175 /**
176  * \defgroup uipinit uIP initialization functions
177  * @{
178  *
179  * The uIP initialization functions are used for booting uIP.
180  */
181 
182 /**
183  * uIP initialization function.
184  *
185  * This function should be called at boot up to initilize the uIP
186  * TCP/IP stack.
187  */
188 void uip_init(void);
189 
190 /**
191  * uIP initialization function.
192  *
193  * This function may be used at boot time to set the initial ip_id.
194  */
195 void uip_setipid(u16_t id);
196 
197 /** @} */
198 
199 /**
200  * \defgroup uipdevfunc uIP device driver functions
201  * @{
202  *
203  * These functions are used by a network device driver for interacting
204  * with uIP.
205  */
206 
207 /**
208  * Process an incoming packet.
209  *
210  * This function should be called when the device driver has received
211  * a packet from the network. The packet from the device driver must
212  * be present in the uip_buf buffer, and the length of the packet
213  * should be placed in the uip_len variable.
214  *
215  * When the function returns, there may be an outbound packet placed
216  * in the uip_buf packet buffer. If so, the uip_len variable is set to
217  * the length of the packet. If no packet is to be sent out, the
218  * uip_len variable is set to 0.
219  *
220  * The usual way of calling the function is presented by the source
221  * code below.
222  \code
223   uip_len = devicedriver_poll();
224   if(uip_len > 0) {
225     uip_input();
226     if(uip_len > 0) {
227       devicedriver_send();
228     }
229   }
230  \endcode
231  *
232  * \note If you are writing a uIP device driver that needs ARP
233  * (Address Resolution Protocol), e.g., when running uIP over
234  * Ethernet, you will need to call the uIP ARP code before calling
235  * this function:
236  \code
237   #define BUF ((struct uip_eth_hdr *)&uip_buf[0])
238   uip_len = ethernet_devicedrver_poll();
239   if(uip_len > 0) {
240     if(BUF->type == HTONS(UIP_ETHTYPE_IP)) {
241       uip_arp_ipin();
242       uip_input();
243       if(uip_len > 0) {
244         uip_arp_out();
245 	ethernet_devicedriver_send();
246       }
247     } else if(BUF->type == HTONS(UIP_ETHTYPE_ARP)) {
248       uip_arp_arpin();
249       if(uip_len > 0) {
250 	ethernet_devicedriver_send();
251       }
252     }
253  \endcode
254  *
255  * \hideinitializer
256  */
257 #define uip_input()        uip_process(UIP_DATA)
258 
259 /**
260  * Periodic processing for a connection identified by its number.
261  *
262  * This function does the necessary periodic processing (timers,
263  * polling) for a uIP TCP conneciton, and should be called when the
264  * periodic uIP timer goes off. It should be called for every
265  * connection, regardless of whether they are open of closed.
266  *
267  * When the function returns, it may have an outbound packet waiting
268  * for service in the uIP packet buffer, and if so the uip_len
269  * variable is set to a value larger than zero. The device driver
270  * should be called to send out the packet.
271  *
272  * The ususal way of calling the function is through a for() loop like
273  * this:
274  \code
275   for(i = 0; i < UIP_CONNS; ++i) {
276     uip_periodic(i);
277     if(uip_len > 0) {
278       devicedriver_send();
279     }
280   }
281  \endcode
282  *
283  * \note If you are writing a uIP device driver that needs ARP
284  * (Address Resolution Protocol), e.g., when running uIP over
285  * Ethernet, you will need to call the uip_arp_out() function before
286  * calling the device driver:
287  \code
288   for(i = 0; i < UIP_CONNS; ++i) {
289     uip_periodic(i);
290     if(uip_len > 0) {
291       uip_arp_out();
292       ethernet_devicedriver_send();
293     }
294   }
295  \endcode
296  *
297  * \param conn The number of the connection which is to be periodically polled.
298  *
299  * \hideinitializer
300  */
301 #define uip_periodic(conn) do { uip_conn = &uip_conns[conn]; \
302                                 uip_process(UIP_TIMER); } while (0)
303 
304 /**
305  *
306  *
307  */
308 #define uip_conn_active(conn) (uip_conns[conn].tcpstateflags != UIP_CLOSED)
309 
310 /**
311  * Perform periodic processing for a connection identified by a pointer
312  * to its structure.
313  *
314  * Same as uip_periodic() but takes a pointer to the actual uip_conn
315  * struct instead of an integer as its argument. This function can be
316  * used to force periodic processing of a specific connection.
317  *
318  * \param conn A pointer to the uip_conn struct for the connection to
319  * be processed.
320  *
321  * \hideinitializer
322  */
323 #define uip_periodic_conn(conn) do { uip_conn = conn; \
324                                      uip_process(UIP_TIMER); } while (0)
325 
326 /**
327  * Reuqest that a particular connection should be polled.
328  *
329  * Similar to uip_periodic_conn() but does not perform any timer
330  * processing. The application is polled for new data.
331  *
332  * \param conn A pointer to the uip_conn struct for the connection to
333  * be processed.
334  *
335  * \hideinitializer
336  */
337 #define uip_poll_conn(conn) do { uip_conn = conn; \
338                                  uip_process(UIP_POLL_REQUEST); } while (0)
339 
340 
341 #if UIP_UDP
342 /**
343  * Periodic processing for a UDP connection identified by its number.
344  *
345  * This function is essentially the same as uip_periodic(), but for
346  * UDP connections. It is called in a similar fashion as the
347  * uip_periodic() function:
348  \code
349   for(i = 0; i < UIP_UDP_CONNS; i++) {
350     uip_udp_periodic(i);
351     if(uip_len > 0) {
352       devicedriver_send();
353     }
354   }
355  \endcode
356  *
357  * \note As for the uip_periodic() function, special care has to be
358  * taken when using uIP together with ARP and Ethernet:
359  \code
360   for(i = 0; i < UIP_UDP_CONNS; i++) {
361     uip_udp_periodic(i);
362     if(uip_len > 0) {
363       uip_arp_out();
364       ethernet_devicedriver_send();
365     }
366   }
367  \endcode
368  *
369  * \param conn The number of the UDP connection to be processed.
370  *
371  * \hideinitializer
372  */
373 #define uip_udp_periodic(conn) do { uip_udp_conn = &uip_udp_conns[conn]; \
374                                 uip_process(UIP_UDP_TIMER); } while (0)
375 
376 /**
377  * Periodic processing for a UDP connection identified by a pointer to
378  * its structure.
379  *
380  * Same as uip_udp_periodic() but takes a pointer to the actual
381  * uip_conn struct instead of an integer as its argument. This
382  * function can be used to force periodic processing of a specific
383  * connection.
384  *
385  * \param conn A pointer to the uip_udp_conn struct for the connection
386  * to be processed.
387  *
388  * \hideinitializer
389  */
390 #define uip_udp_periodic_conn(conn) do { uip_udp_conn = conn; \
391                                          uip_process(UIP_UDP_TIMER); } while (0)
392 
393 
394 #endif /* UIP_UDP */
395 
396 /**
397  * The uIP packet buffer.
398  *
399  * The uip_buf array is used to hold incoming and outgoing
400  * packets. The device driver should place incoming data into this
401  * buffer. When sending data, the device driver should read the link
402  * level headers and the TCP/IP headers from this buffer. The size of
403  * the link level headers is configured by the UIP_LLH_LEN define.
404  *
405  * \note The application data need not be placed in this buffer, so
406  * the device driver must read it from the place pointed to by the
407  * uip_appdata pointer as illustrated by the following example:
408  \code
409  void
410  devicedriver_send(void)
411  {
412     hwsend(&uip_buf[0], UIP_LLH_LEN);
413     if(uip_len <= UIP_LLH_LEN + UIP_TCPIP_HLEN) {
414       hwsend(&uip_buf[UIP_LLH_LEN], uip_len - UIP_LLH_LEN);
415     } else {
416       hwsend(&uip_buf[UIP_LLH_LEN], UIP_TCPIP_HLEN);
417       hwsend(uip_appdata, uip_len - UIP_TCPIP_HLEN - UIP_LLH_LEN);
418     }
419  }
420  \endcode
421  */
422 extern u8_t uip_buf[UIP_BUFSIZE+2];
423 
424 /** @} */
425 
426 /*---------------------------------------------------------------------------*/
427 /* Functions that are used by the uIP application program. Opening and
428  * closing connections, sending and receiving data, etc. is all
429  * handled by the functions below.
430 */
431 /**
432  * \defgroup uipappfunc uIP application functions
433  * @{
434  *
435  * Functions used by an application running of top of uIP.
436  */
437 
438 /**
439  * Start listening to the specified port.
440  *
441  * \note Since this function expects the port number in network byte
442  * order, a conversion using HTONS() or uip_htons() is necessary.
443  *
444  \code
445  uip_listen(HTONS(80));
446  \endcode
447  *
448  * \param port A 16-bit port number in network byte order.
449  */
450 void uip_listen(u16_t port);
451 
452 /**
453  * Stop listening to the specified port.
454  *
455  * \note Since this function expects the port number in network byte
456  * order, a conversion using HTONS() or uip_htons() is necessary.
457  *
458  \code
459  uip_unlisten(HTONS(80));
460  \endcode
461  *
462  * \param port A 16-bit port number in network byte order.
463  */
464 void uip_unlisten(u16_t port);
465 
466 /**
467  * Connect to a remote host using TCP.
468  *
469  * This function is used to start a new connection to the specified
470  * port on the specied host. It allocates a new connection identifier,
471  * sets the connection to the SYN_SENT state and sets the
472  * retransmission timer to 0. This will cause a TCP SYN segment to be
473  * sent out the next time this connection is periodically processed,
474  * which usually is done within 0.5 seconds after the call to
475  * uip_connect().
476  *
477  * \note This function is avaliable only if support for active open
478  * has been configured by defining UIP_ACTIVE_OPEN to 1 in uipopt.h.
479  *
480  * \note Since this function requires the port number to be in network
481  * byte order, a conversion using HTONS() or uip_htons() is necessary.
482  *
483  \code
484  uip_ipaddr_t ipaddr;
485 
486  uip_ipaddr(&ipaddr, 192,168,1,2);
487  uip_connect(&ipaddr, HTONS(80));
488  \endcode
489  *
490  * \param ripaddr The IP address of the remote hot.
491  *
492  * \param port A 16-bit port number in network byte order.
493  *
494  * \return A pointer to the uIP connection identifier for the new connection,
495  * or NULL if no connection could be allocated.
496  *
497  */
498 struct uip_conn *uip_connect(uip_ipaddr_t *ripaddr, u16_t port);
499 
500 
501 
502 /**
503  * \internal
504  *
505  * Check if a connection has outstanding (i.e., unacknowledged) data.
506  *
507  * \param conn A pointer to the uip_conn structure for the connection.
508  *
509  * \hideinitializer
510  */
511 #define uip_outstanding(conn) ((conn)->len)
512 
513 /**
514  * Send data on the current connection.
515  *
516  * This function is used to send out a single segment of TCP
517  * data. Only applications that have been invoked by uIP for event
518  * processing can send data.
519  *
520  * The amount of data that actually is sent out after a call to this
521  * funcion is determined by the maximum amount of data TCP allows. uIP
522  * will automatically crop the data so that only the appropriate
523  * amount of data is sent. The function uip_mss() can be used to query
524  * uIP for the amount of data that actually will be sent.
525  *
526  * \note This function does not guarantee that the sent data will
527  * arrive at the destination. If the data is lost in the network, the
528  * application will be invoked with the uip_rexmit() event being
529  * set. The application will then have to resend the data using this
530  * function.
531  *
532  * \param data A pointer to the data which is to be sent.
533  *
534  * \param len The maximum amount of data bytes to be sent.
535  *
536  * \hideinitializer
537  */
538 void uip_send(const void *data, int len);
539 
540 /**
541  * The length of any incoming data that is currently avaliable (if avaliable)
542  * in the uip_appdata buffer.
543  *
544  * The test function uip_data() must first be used to check if there
545  * is any data available at all.
546  *
547  * \hideinitializer
548  */
549 /*void uip_datalen(void);*/
550 #define uip_datalen()       uip_len
551 
552 /**
553  * The length of any out-of-band data (urgent data) that has arrived
554  * on the connection.
555  *
556  * \note The configuration parameter UIP_URGDATA must be set for this
557  * function to be enabled.
558  *
559  * \hideinitializer
560  */
561 #define uip_urgdatalen()    uip_urglen
562 
563 /**
564  * Close the current connection.
565  *
566  * This function will close the current connection in a nice way.
567  *
568  * \hideinitializer
569  */
570 #define uip_close()         (uip_flags = UIP_CLOSE)
571 
572 /**
573  * Abort the current connection.
574  *
575  * This function will abort (reset) the current connection, and is
576  * usually used when an error has occured that prevents using the
577  * uip_close() function.
578  *
579  * \hideinitializer
580  */
581 #define uip_abort()         (uip_flags = UIP_ABORT)
582 
583 /**
584  * Tell the sending host to stop sending data.
585  *
586  * This function will close our receiver's window so that we stop
587  * receiving data for the current connection.
588  *
589  * \hideinitializer
590  */
591 #define uip_stop()          (uip_conn->tcpstateflags |= UIP_STOPPED)
592 
593 /**
594  * Find out if the current connection has been previously stopped with
595  * uip_stop().
596  *
597  * \hideinitializer
598  */
599 #define uip_stopped(conn)   ((conn)->tcpstateflags & UIP_STOPPED)
600 
601 /**
602  * Restart the current connection, if is has previously been stopped
603  * with uip_stop().
604  *
605  * This function will open the receiver's window again so that we
606  * start receiving data for the current connection.
607  *
608  * \hideinitializer
609  */
610 #define uip_restart()         do { uip_flags |= UIP_NEWDATA; \
611                                    uip_conn->tcpstateflags &= ~UIP_STOPPED; \
612                               } while(0)
613 
614 
615 /* uIP tests that can be made to determine in what state the current
616    connection is, and what the application function should do. */
617 
618 /**
619  * Is the current connection a UDP connection?
620  *
621  * This function checks whether the current connection is a UDP connection.
622  *
623  * \hideinitializer
624  *
625  */
626 #define uip_udpconnection() (uip_conn == NULL)
627 
628 /**
629  * Is new incoming data available?
630  *
631  * Will reduce to non-zero if there is new data for the application
632  * present at the uip_appdata pointer. The size of the data is
633  * avaliable through the uip_len variable.
634  *
635  * \hideinitializer
636  */
637 #define uip_newdata()   (uip_flags & UIP_NEWDATA)
638 
639 /**
640  * Has previously sent data been acknowledged?
641  *
642  * Will reduce to non-zero if the previously sent data has been
643  * acknowledged by the remote host. This means that the application
644  * can send new data.
645  *
646  * \hideinitializer
647  */
648 #define uip_acked()   (uip_flags & UIP_ACKDATA)
649 
650 /**
651  * Has the connection just been connected?
652  *
653  * Reduces to non-zero if the current connection has been connected to
654  * a remote host. This will happen both if the connection has been
655  * actively opened (with uip_connect()) or passively opened (with
656  * uip_listen()).
657  *
658  * \hideinitializer
659  */
660 #define uip_connected() (uip_flags & UIP_CONNECTED)
661 
662 /**
663  * Has the connection been closed by the other end?
664  *
665  * Is non-zero if the connection has been closed by the remote
666  * host. The application may then do the necessary clean-ups.
667  *
668  * \hideinitializer
669  */
670 #define uip_closed()    (uip_flags & UIP_CLOSE)
671 
672 /**
673  * Has the connection been aborted by the other end?
674  *
675  * Non-zero if the current connection has been aborted (reset) by the
676  * remote host.
677  *
678  * \hideinitializer
679  */
680 #define uip_aborted()    (uip_flags & UIP_ABORT)
681 
682 /**
683  * Has the connection timed out?
684  *
685  * Non-zero if the current connection has been aborted due to too many
686  * retransmissions.
687  *
688  * \hideinitializer
689  */
690 #define uip_timedout()    (uip_flags & UIP_TIMEDOUT)
691 
692 /**
693  * Do we need to retransmit previously data?
694  *
695  * Reduces to non-zero if the previously sent data has been lost in
696  * the network, and the application should retransmit it. The
697  * application should send the exact same data as it did the last
698  * time, using the uip_send() function.
699  *
700  * \hideinitializer
701  */
702 #define uip_rexmit()     (uip_flags & UIP_REXMIT)
703 
704 /**
705  * Is the connection being polled by uIP?
706  *
707  * Is non-zero if the reason the application is invoked is that the
708  * current connection has been idle for a while and should be
709  * polled.
710  *
711  * The polling event can be used for sending data without having to
712  * wait for the remote host to send data.
713  *
714  * \hideinitializer
715  */
716 #define uip_poll()       (uip_flags & UIP_POLL)
717 
718 /**
719  * Get the initial maxium segment size (MSS) of the current
720  * connection.
721  *
722  * \hideinitializer
723  */
724 #define uip_initialmss()             (uip_conn->initialmss)
725 
726 /**
727  * Get the current maxium segment size that can be sent on the current
728  * connection.
729  *
730  * The current maxiumum segment size that can be sent on the
731  * connection is computed from the receiver's window and the MSS of
732  * the connection (which also is available by calling
733  * uip_initialmss()).
734  *
735  * \hideinitializer
736  */
737 #define uip_mss()             (uip_conn->mss)
738 
739 /**
740  * Set up a new UDP connection.
741  *
742  * This function sets up a new UDP connection. The function will
743  * automatically allocate an unused local port for the new
744  * connection. However, another port can be chosen by using the
745  * uip_udp_bind() call, after the uip_udp_new() function has been
746  * called.
747  *
748  * Example:
749  \code
750  uip_ipaddr_t addr;
751  struct uip_udp_conn *c;
752 
753  uip_ipaddr(&addr, 192,168,2,1);
754  c = uip_udp_new(&addr, HTONS(12345));
755  if(c != NULL) {
756    uip_udp_bind(c, HTONS(12344));
757  }
758  \endcode
759  * \param ripaddr The IP address of the remote host.
760  *
761  * \param rport The remote port number in network byte order.
762  *
763  * \return The uip_udp_conn structure for the new connection or NULL
764  * if no connection could be allocated.
765  */
766 struct uip_udp_conn *uip_udp_new(uip_ipaddr_t *ripaddr, u16_t rport);
767 
768 /**
769  * Removed a UDP connection.
770  *
771  * \param conn A pointer to the uip_udp_conn structure for the connection.
772  *
773  * \hideinitializer
774  */
775 #define uip_udp_remove(conn) (conn)->lport = 0
776 
777 /**
778  * Bind a UDP connection to a local port.
779  *
780  * \param conn A pointer to the uip_udp_conn structure for the
781  * connection.
782  *
783  * \param port The local port number, in network byte order.
784  *
785  * \hideinitializer
786  */
787 #define uip_udp_bind(conn, port) (conn)->lport = port
788 
789 /**
790  * Send a UDP datagram of length len on the current connection.
791  *
792  * This function can only be called in response to a UDP event (poll
793  * or newdata). The data must be present in the uip_buf buffer, at the
794  * place pointed to by the uip_appdata pointer.
795  *
796  * \param len The length of the data in the uip_buf buffer.
797  *
798  * \hideinitializer
799  */
800 #define uip_udp_send(len) uip_send((char *)uip_appdata, len)
801 
802 /** @} */
803 
804 /* uIP convenience and converting functions. */
805 
806 /**
807  * \defgroup uipconvfunc uIP conversion functions
808  * @{
809  *
810  * These functions can be used for converting between different data
811  * formats used by uIP.
812  */
813 
814 /**
815  * Construct an IP address from four bytes.
816  *
817  * This function constructs an IP address of the type that uIP handles
818  * internally from four bytes. The function is handy for specifying IP
819  * addresses to use with e.g. the uip_connect() function.
820  *
821  * Example:
822  \code
823  uip_ipaddr_t ipaddr;
824  struct uip_conn *c;
825 
826  uip_ipaddr(&ipaddr, 192,168,1,2);
827  c = uip_connect(&ipaddr, HTONS(80));
828  \endcode
829  *
830  * \param addr A pointer to a uip_ipaddr_t variable that will be
831  * filled in with the IP address.
832  *
833  * \param addr0 The first octet of the IP address.
834  * \param addr1 The second octet of the IP address.
835  * \param addr2 The third octet of the IP address.
836  * \param addr3 The forth octet of the IP address.
837  *
838  * \hideinitializer
839  */
840 #define uip_ipaddr(addr, addr0,addr1,addr2,addr3) do { \
841                      ((u16_t *)(addr))[0] = HTONS(((addr0) << 8) | (addr1)); \
842                      ((u16_t *)(addr))[1] = HTONS(((addr2) << 8) | (addr3)); \
843                   } while(0)
844 
845 /**
846  * Construct an IPv6 address from eight 16-bit words.
847  *
848  * This function constructs an IPv6 address.
849  *
850  * \hideinitializer
851  */
852 #define uip_ip6addr(addr, addr0,addr1,addr2,addr3,addr4,addr5,addr6,addr7) do { \
853                      ((u16_t *)(addr))[0] = HTONS((addr0)); \
854                      ((u16_t *)(addr))[1] = HTONS((addr1)); \
855                      ((u16_t *)(addr))[2] = HTONS((addr2)); \
856                      ((u16_t *)(addr))[3] = HTONS((addr3)); \
857                      ((u16_t *)(addr))[4] = HTONS((addr4)); \
858                      ((u16_t *)(addr))[5] = HTONS((addr5)); \
859                      ((u16_t *)(addr))[6] = HTONS((addr6)); \
860                      ((u16_t *)(addr))[7] = HTONS((addr7)); \
861                   } while(0)
862 
863 /**
864  * Copy an IP address to another IP address.
865  *
866  * Copies an IP address from one place to another.
867  *
868  * Example:
869  \code
870  uip_ipaddr_t ipaddr1, ipaddr2;
871 
872  uip_ipaddr(&ipaddr1, 192,16,1,2);
873  uip_ipaddr_copy(&ipaddr2, &ipaddr1);
874  \endcode
875  *
876  * \param dest The destination for the copy.
877  * \param src The source from where to copy.
878  *
879  * \hideinitializer
880  */
881 #if !UIP_CONF_IPV6
882 #define uip_ipaddr_copy(dest, src) do { \
883                      ((u16_t *)dest)[0] = ((u16_t *)src)[0]; \
884                      ((u16_t *)dest)[1] = ((u16_t *)src)[1]; \
885                   } while(0)
886 #else /* !UIP_CONF_IPV6 */
887 #define uip_ipaddr_copy(dest, src) memcpy(dest, src, sizeof(uip_ip6addr_t))
888 #endif /* !UIP_CONF_IPV6 */
889 
890 /**
891  * Compare two IP addresses
892  *
893  * Compares two IP addresses.
894  *
895  * Example:
896  \code
897  uip_ipaddr_t ipaddr1, ipaddr2;
898 
899  uip_ipaddr(&ipaddr1, 192,16,1,2);
900  if(uip_ipaddr_cmp(&ipaddr2, &ipaddr1)) {
901     printf("They are the same");
902  }
903  \endcode
904  *
905  * \param addr1 The first IP address.
906  * \param addr2 The second IP address.
907  *
908  * \hideinitializer
909  */
910 #if !UIP_CONF_IPV6
911 #define uip_ipaddr_cmp(addr1, addr2) (((u16_t *)addr1)[0] == ((u16_t *)addr2)[0] && \
912 				      ((u16_t *)addr1)[1] == ((u16_t *)addr2)[1])
913 #else /* !UIP_CONF_IPV6 */
914 #define uip_ipaddr_cmp(addr1, addr2) (memcmp(addr1, addr2, sizeof(uip_ip6addr_t)) == 0)
915 #endif /* !UIP_CONF_IPV6 */
916 
917 /**
918  * Compare two IP addresses with netmasks
919  *
920  * Compares two IP addresses with netmasks. The masks are used to mask
921  * out the bits that are to be compared.
922  *
923  * Example:
924  \code
925  uip_ipaddr_t ipaddr1, ipaddr2, mask;
926 
927  uip_ipaddr(&mask, 255,255,255,0);
928  uip_ipaddr(&ipaddr1, 192,16,1,2);
929  uip_ipaddr(&ipaddr2, 192,16,1,3);
930  if(uip_ipaddr_maskcmp(&ipaddr1, &ipaddr2, &mask)) {
931     printf("They are the same");
932  }
933  \endcode
934  *
935  * \param addr1 The first IP address.
936  * \param addr2 The second IP address.
937  * \param mask The netmask.
938  *
939  * \hideinitializer
940  */
941 #define uip_ipaddr_maskcmp(addr1, addr2, mask) \
942                           (((((u16_t *)addr1)[0] & ((u16_t *)mask)[0]) == \
943                             (((u16_t *)addr2)[0] & ((u16_t *)mask)[0])) && \
944                            ((((u16_t *)addr1)[1] & ((u16_t *)mask)[1]) == \
945                             (((u16_t *)addr2)[1] & ((u16_t *)mask)[1])))
946 
947 
948 /**
949  * Mask out the network part of an IP address.
950  *
951  * Masks out the network part of an IP address, given the address and
952  * the netmask.
953  *
954  * Example:
955  \code
956  uip_ipaddr_t ipaddr1, ipaddr2, netmask;
957 
958  uip_ipaddr(&ipaddr1, 192,16,1,2);
959  uip_ipaddr(&netmask, 255,255,255,0);
960  uip_ipaddr_mask(&ipaddr2, &ipaddr1, &netmask);
961  \endcode
962  *
963  * In the example above, the variable "ipaddr2" will contain the IP
964  * address 192.168.1.0.
965  *
966  * \param dest Where the result is to be placed.
967  * \param src The IP address.
968  * \param mask The netmask.
969  *
970  * \hideinitializer
971  */
972 #define uip_ipaddr_mask(dest, src, mask) do { \
973                      ((u16_t *)dest)[0] = ((u16_t *)src)[0] & ((u16_t *)mask)[0]; \
974                      ((u16_t *)dest)[1] = ((u16_t *)src)[1] & ((u16_t *)mask)[1]; \
975                   } while(0)
976 
977 /**
978  * Pick the first octet of an IP address.
979  *
980  * Picks out the first octet of an IP address.
981  *
982  * Example:
983  \code
984  uip_ipaddr_t ipaddr;
985  u8_t octet;
986 
987  uip_ipaddr(&ipaddr, 1,2,3,4);
988  octet = uip_ipaddr1(&ipaddr);
989  \endcode
990  *
991  * In the example above, the variable "octet" will contain the value 1.
992  *
993  * \hideinitializer
994  */
995 #define uip_ipaddr1(addr) (uip_htons(((u16_t *)(addr))[0]) >> 8)
996 
997 /**
998  * Pick the second octet of an IP address.
999  *
1000  * Picks out the second octet of an IP address.
1001  *
1002  * Example:
1003  \code
1004  uip_ipaddr_t ipaddr;
1005  u8_t octet;
1006 
1007  uip_ipaddr(&ipaddr, 1,2,3,4);
1008  octet = uip_ipaddr2(&ipaddr);
1009  \endcode
1010  *
1011  * In the example above, the variable "octet" will contain the value 2.
1012  *
1013  * \hideinitializer
1014  */
1015 #define uip_ipaddr2(addr) (uip_htons(((u16_t *)(addr))[0]) & 0xff)
1016 
1017 /**
1018  * Pick the third octet of an IP address.
1019  *
1020  * Picks out the third octet of an IP address.
1021  *
1022  * Example:
1023  \code
1024  uip_ipaddr_t ipaddr;
1025  u8_t octet;
1026 
1027  uip_ipaddr(&ipaddr, 1,2,3,4);
1028  octet = uip_ipaddr3(&ipaddr);
1029  \endcode
1030  *
1031  * In the example above, the variable "octet" will contain the value 3.
1032  *
1033  * \hideinitializer
1034  */
1035 #define uip_ipaddr3(addr) (uip_htons(((u16_t *)(addr))[1]) >> 8)
1036 
1037 /**
1038  * Pick the fourth octet of an IP address.
1039  *
1040  * Picks out the fourth octet of an IP address.
1041  *
1042  * Example:
1043  \code
1044  uip_ipaddr_t ipaddr;
1045  u8_t octet;
1046 
1047  uip_ipaddr(&ipaddr, 1,2,3,4);
1048  octet = uip_ipaddr4(&ipaddr);
1049  \endcode
1050  *
1051  * In the example above, the variable "octet" will contain the value 4.
1052  *
1053  * \hideinitializer
1054  */
1055 #define uip_ipaddr4(addr) (uip_htons(((u16_t *)(addr))[1]) & 0xff)
1056 
1057 /**
1058  * Convert 16-bit quantity from host byte order to network byte order.
1059  *
1060  * This macro is primarily used for converting constants from host
1061  * byte order to network byte order. For converting variables to
1062  * network byte order, use the uip_htons() function instead.
1063  *
1064  * \hideinitializer
1065  */
1066 #ifndef HTONS
1067 #   if UIP_BYTE_ORDER == UIP_BIG_ENDIAN
1068 #      define HTONS(n) (n)
1069 #   else /* UIP_BYTE_ORDER == UIP_BIG_ENDIAN */
1070 #      define HTONS(n) (u16_t)((((u16_t) (n)) << 8) | (((u16_t) (n)) >> 8))
1071 #   endif /* UIP_BYTE_ORDER == UIP_BIG_ENDIAN */
1072 #else
1073 #error "HTONS already defined!"
1074 #endif /* HTONS */
1075 
1076 /**
1077  * Convert 16-bit quantity from host byte order to network byte order.
1078  *
1079  * This function is primarily used for converting variables from host
1080  * byte order to network byte order. For converting constants to
1081  * network byte order, use the HTONS() macro instead.
1082  */
1083 
1084 #ifndef uip_htons
1085 u16_t uip_htons(u16_t val);
1086 #endif /* uip_htons */
1087 #ifndef ntohs
1088 #define ntohs uip_htons
1089 #endif
1090 
1091 /** @} */
1092 
1093 /**
1094  * Pointer to the application data in the packet buffer.
1095  *
1096  * This pointer points to the application data when the application is
1097  * called. If the application wishes to send data, the application may
1098  * use this space to write the data into before calling uip_send().
1099  */
1100 extern volatile u8_t *uip_appdata;
1101 
1102 #if UIP_URGDATA > 0
1103 /* u8_t *uip_urgdata:
1104  *
1105  * This pointer points to any urgent data that has been received. Only
1106  * present if compiled with support for urgent data (UIP_URGDATA).
1107  */
1108 extern void *uip_urgdata;
1109 #endif /* UIP_URGDATA > 0 */
1110 
1111 
1112 /**
1113  * \defgroup uipdrivervars Variables used in uIP device drivers
1114  * @{
1115  *
1116  * uIP has a few global variables that are used in device drivers for
1117  * uIP.
1118  */
1119 
1120 /**
1121  * The length of the packet in the uip_buf buffer.
1122  *
1123  * The global variable uip_len holds the length of the packet in the
1124  * uip_buf buffer.
1125  *
1126  * When the network device driver calls the uIP input function,
1127  * uip_len should be set to the length of the packet in the uip_buf
1128  * buffer.
1129  *
1130  * When sending packets, the device driver should use the contents of
1131  * the uip_len variable to determine the length of the outgoing
1132  * packet.
1133  *
1134  */
1135 extern u16_t uip_len;
1136 
1137 /** @} */
1138 
1139 #if UIP_URGDATA > 0
1140 extern u16_t uip_urglen, uip_surglen;
1141 #endif /* UIP_URGDATA > 0 */
1142 
1143 
1144 /**
1145  * Representation of a uIP TCP connection.
1146  *
1147  * The uip_conn structure is used for identifying a connection. All
1148  * but one field in the structure are to be considered read-only by an
1149  * application. The only exception is the appstate field whos purpose
1150  * is to let the application store application-specific state (e.g.,
1151  * file pointers) for the connection. The type of this field is
1152  * configured in the "uipopt.h" header file.
1153  */
1154 struct uip_conn {
1155   uip_ipaddr_t ripaddr;   /**< The IP address of the remote host. */
1156 
1157   u16_t lport;        /**< The local TCP port, in network byte order. */
1158   u16_t rport;        /**< The local remote TCP port, in network byte
1159 			 order. */
1160 
1161   u8_t rcv_nxt[4];    /**< The sequence number that we expect to
1162 			 receive next. */
1163   u8_t snd_nxt[4];    /**< The sequence number that was last sent by
1164                          us. */
1165   u16_t len;          /**< Length of the data that was previously sent. */
1166   u16_t mss;          /**< Current maximum segment size for the
1167 			 connection. */
1168   u16_t initialmss;   /**< Initial maximum segment size for the
1169 			 connection. */
1170   u8_t sa;            /**< Retransmission time-out calculation state
1171 			 variable. */
1172   u8_t sv;            /**< Retransmission time-out calculation state
1173 			 variable. */
1174   u8_t rto;           /**< Retransmission time-out. */
1175   u8_t tcpstateflags; /**< TCP state and flags. */
1176   u8_t timer;         /**< The retransmission timer. */
1177   u8_t nrtx;          /**< The number of retransmissions for the last
1178 			 segment sent. */
1179 
1180   /** The application state. */
1181   uip_tcp_appstate_t appstate;
1182 };
1183 
1184 
1185 /**
1186  * Pointer to the current TCP connection.
1187  *
1188  * The uip_conn pointer can be used to access the current TCP
1189  * connection.
1190  */
1191 extern struct uip_conn *uip_conn;
1192 /* The array containing all uIP connections. */
1193 extern struct uip_conn uip_conns[UIP_CONNS];
1194 /**
1195  * \addtogroup uiparch
1196  * @{
1197  */
1198 
1199 /**
1200  * 4-byte array used for the 32-bit sequence number calculations.
1201  */
1202 extern u8_t uip_acc32[4];
1203 
1204 /** @} */
1205 
1206 
1207 #if UIP_UDP
1208 /**
1209  * Representation of a uIP UDP connection.
1210  */
1211 struct uip_udp_conn {
1212   uip_ipaddr_t ripaddr;   /**< The IP address of the remote peer. */
1213   u16_t lport;        /**< The local port number in network byte order. */
1214   u16_t rport;        /**< The remote port number in network byte order. */
1215   u8_t  ttl;          /**< Default time-to-live. */
1216 
1217   /** The application state. */
1218   uip_udp_appstate_t appstate;
1219 };
1220 
1221 /**
1222  * The current UDP connection.
1223  */
1224 extern struct uip_udp_conn *uip_udp_conn;
1225 extern struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
1226 #endif /* UIP_UDP */
1227 
1228 /**
1229  * The structure holding the TCP/IP statistics that are gathered if
1230  * UIP_STATISTICS is set to 1.
1231  *
1232  */
1233 struct uip_stats {
1234   struct {
1235     uip_stats_t drop;     /**< Number of dropped packets at the IP
1236 			     layer. */
1237     uip_stats_t recv;     /**< Number of received packets at the IP
1238 			     layer. */
1239     uip_stats_t sent;     /**< Number of sent packets at the IP
1240 			     layer. */
1241     uip_stats_t vhlerr;   /**< Number of packets dropped due to wrong
1242 			     IP version or header length. */
1243     uip_stats_t hblenerr; /**< Number of packets dropped due to wrong
1244 			     IP length, high byte. */
1245     uip_stats_t lblenerr; /**< Number of packets dropped due to wrong
1246 			     IP length, low byte. */
1247     uip_stats_t fragerr;  /**< Number of packets dropped since they
1248 			     were IP fragments. */
1249     uip_stats_t chkerr;   /**< Number of packets dropped due to IP
1250 			     checksum errors. */
1251     uip_stats_t protoerr; /**< Number of packets dropped since they
1252 			     were neither ICMP, UDP nor TCP. */
1253   } ip;                   /**< IP statistics. */
1254   struct {
1255     uip_stats_t drop;     /**< Number of dropped ICMP packets. */
1256     uip_stats_t recv;     /**< Number of received ICMP packets. */
1257     uip_stats_t sent;     /**< Number of sent ICMP packets. */
1258     uip_stats_t typeerr;  /**< Number of ICMP packets with a wrong
1259 			     type. */
1260   } icmp;                 /**< ICMP statistics. */
1261   struct {
1262     uip_stats_t drop;     /**< Number of dropped TCP segments. */
1263     uip_stats_t recv;     /**< Number of recived TCP segments. */
1264     uip_stats_t sent;     /**< Number of sent TCP segments. */
1265     uip_stats_t chkerr;   /**< Number of TCP segments with a bad
1266 			     checksum. */
1267     uip_stats_t ackerr;   /**< Number of TCP segments with a bad ACK
1268 			     number. */
1269     uip_stats_t rst;      /**< Number of recevied TCP RST (reset) segments. */
1270     uip_stats_t rexmit;   /**< Number of retransmitted TCP segments. */
1271     uip_stats_t syndrop;  /**< Number of dropped SYNs due to too few
1272 			     connections was avaliable. */
1273     uip_stats_t synrst;   /**< Number of SYNs for closed ports,
1274 			     triggering a RST. */
1275   } tcp;                  /**< TCP statistics. */
1276 #if UIP_UDP
1277   struct {
1278     uip_stats_t drop;     /**< Number of dropped UDP segments. */
1279     uip_stats_t recv;     /**< Number of recived UDP segments. */
1280     uip_stats_t sent;     /**< Number of sent UDP segments. */
1281     uip_stats_t chkerr;   /**< Number of UDP segments with a bad
1282 			     checksum. */
1283   } udp;                  /**< UDP statistics. */
1284 #endif /* UIP_UDP */
1285 };
1286 
1287 /**
1288  * The uIP TCP/IP statistics.
1289  *
1290  * This is the variable in which the uIP TCP/IP statistics are gathered.
1291  */
1292 extern struct uip_stats uip_stat;
1293 
1294 
1295 /*---------------------------------------------------------------------------*/
1296 /* All the stuff below this point is internal to uIP and should not be
1297  * used directly by an application or by a device driver.
1298  */
1299 /*---------------------------------------------------------------------------*/
1300 /* u8_t uip_flags:
1301  *
1302  * When the application is called, uip_flags will contain the flags
1303  * that are defined in this file. Please read below for more
1304  * infomation.
1305  */
1306 extern u8_t uip_flags;
1307 
1308 /* The following flags may be set in the global variable uip_flags
1309    before calling the application callback. The UIP_ACKDATA,
1310    UIP_NEWDATA, and UIP_CLOSE flags may both be set at the same time,
1311    whereas the others are mutualy exclusive. Note that these flags
1312    should *NOT* be accessed directly, but only through the uIP
1313    functions/macros. */
1314 
1315 #define UIP_ACKDATA   1     /* Signifies that the outstanding data was
1316 			       acked and the application should send
1317 			       out new data instead of retransmitting
1318 			       the last data. */
1319 #define UIP_NEWDATA   2     /* Flags the fact that the peer has sent
1320 			       us new data. */
1321 #define UIP_REXMIT    4     /* Tells the application to retransmit the
1322 			       data that was last sent. */
1323 #define UIP_POLL      8     /* Used for polling the application, to
1324 			       check if the application has data that
1325 			       it wants to send. */
1326 #define UIP_CLOSE     16    /* The remote host has closed the
1327 			       connection, thus the connection has
1328 			       gone away. Or the application signals
1329 			       that it wants to close the
1330 			       connection. */
1331 #define UIP_ABORT     32    /* The remote host has aborted the
1332 			       connection, thus the connection has
1333 			       gone away. Or the application signals
1334 			       that it wants to abort the
1335 			       connection. */
1336 #define UIP_CONNECTED 64    /* We have got a connection from a remote
1337                                host and have set up a new connection
1338                                for it, or an active connection has
1339                                been successfully established. */
1340 
1341 #define UIP_TIMEDOUT  128   /* The connection has been aborted due to
1342 			       too many retransmissions. */
1343 
1344 /* uip_process(flag):
1345  *
1346  * The actual uIP function which does all the work.
1347  */
1348 void uip_process(u8_t flag);
1349 
1350 /* The following flags are passed as an argument to the uip_process()
1351    function. They are used to distinguish between the two cases where
1352    uip_process() is called. It can be called either because we have
1353    incoming data that should be processed, or because the periodic
1354    timer has fired. These values are never used directly, but only in
1355    the macrose defined in this file. */
1356 
1357 #define UIP_DATA          1     /* Tells uIP that there is incoming
1358 				   data in the uip_buf buffer. The
1359 				   length of the data is stored in the
1360 				   global variable uip_len. */
1361 #define UIP_TIMER         2     /* Tells uIP that the periodic timer
1362 				   has fired. */
1363 #define UIP_POLL_REQUEST  3     /* Tells uIP that a connection should
1364 				   be polled. */
1365 #define UIP_UDP_SEND_CONN 4     /* Tells uIP that a UDP datagram
1366 				   should be constructed in the
1367 				   uip_buf buffer. */
1368 #if UIP_UDP
1369 #define UIP_UDP_TIMER     5
1370 #endif /* UIP_UDP */
1371 
1372 /* The TCP states used in the uip_conn->tcpstateflags. */
1373 #define UIP_CLOSED      0
1374 #define UIP_SYN_RCVD    1
1375 #define UIP_SYN_SENT    2
1376 #define UIP_ESTABLISHED 3
1377 #define UIP_FIN_WAIT_1  4
1378 #define UIP_FIN_WAIT_2  5
1379 #define UIP_CLOSING     6
1380 #define UIP_TIME_WAIT   7
1381 #define UIP_LAST_ACK    8
1382 #define UIP_TS_MASK     15
1383 
1384 #define UIP_STOPPED      16
1385 
1386 /* The TCP and IP headers. */
1387 struct uip_tcpip_hdr {
1388 #if UIP_CONF_IPV6
1389   /* IPv6 header. */
1390   u8_t vtc,
1391     tcflow;
1392   u16_t flow;
1393   u8_t len[2];
1394   u8_t proto, ttl;
1395   uip_ip6addr_t srcipaddr, destipaddr;
1396 #else /* UIP_CONF_IPV6 */
1397   /* IPv4 header. */
1398   u8_t vhl,
1399     tos,
1400     len[2],
1401     ipid[2],
1402     ipoffset[2],
1403     ttl,
1404     proto;
1405   u16_t ipchksum;
1406   u16_t srcipaddr[2],
1407     destipaddr[2];
1408 #endif /* UIP_CONF_IPV6 */
1409 
1410   /* TCP header. */
1411   u16_t srcport,
1412     destport;
1413   u8_t seqno[4],
1414     ackno[4],
1415     tcpoffset,
1416     flags,
1417     wnd[2];
1418   u16_t tcpchksum;
1419   u8_t urgp[2];
1420   u8_t optdata[4];
1421 };
1422 
1423 /* The ICMP and IP headers. */
1424 struct uip_icmpip_hdr {
1425 #if UIP_CONF_IPV6
1426   /* IPv6 header. */
1427   u8_t vtc,
1428     tcf;
1429   u16_t flow;
1430   u8_t len[2];
1431   u8_t proto, ttl;
1432   uip_ip6addr_t srcipaddr, destipaddr;
1433 #else /* UIP_CONF_IPV6 */
1434   /* IPv4 header. */
1435   u8_t vhl,
1436     tos,
1437     len[2],
1438     ipid[2],
1439     ipoffset[2],
1440     ttl,
1441     proto;
1442   u16_t ipchksum;
1443   u16_t srcipaddr[2],
1444     destipaddr[2];
1445 #endif /* UIP_CONF_IPV6 */
1446 
1447   /* ICMP (echo) header. */
1448   u8_t type, icode;
1449   u16_t icmpchksum;
1450 #if !UIP_CONF_IPV6
1451   u16_t id, seqno;
1452 #else /* !UIP_CONF_IPV6 */
1453   u8_t flags, reserved1, reserved2, reserved3;
1454   u8_t icmp6data[16];
1455   u8_t options[1];
1456 #endif /* !UIP_CONF_IPV6 */
1457 };
1458 
1459 
1460 /* The UDP and IP headers. */
1461 struct uip_udpip_hdr {
1462 #if UIP_CONF_IPV6
1463   /* IPv6 header. */
1464   u8_t vtc,
1465     tcf;
1466   u16_t flow;
1467   u8_t len[2];
1468   u8_t proto, ttl;
1469   uip_ip6addr_t srcipaddr, destipaddr;
1470 #else /* UIP_CONF_IPV6 */
1471   /* IP header. */
1472   u8_t vhl,
1473     tos,
1474     len[2],
1475     ipid[2],
1476     ipoffset[2],
1477     ttl,
1478     proto;
1479   u16_t ipchksum;
1480   u16_t srcipaddr[2],
1481     destipaddr[2];
1482 #endif /* UIP_CONF_IPV6 */
1483 
1484   /* UDP header. */
1485   u16_t srcport,
1486     destport;
1487   u16_t udplen;
1488   u16_t udpchksum;
1489 };
1490 
1491 
1492 
1493 /**
1494  * The buffer size available for user data in the \ref uip_buf buffer.
1495  *
1496  * This macro holds the available size for user data in the \ref
1497  * uip_buf buffer. The macro is intended to be used for checking
1498  * bounds of available user data.
1499  *
1500  * Example:
1501  \code
1502  snprintf(uip_appdata, UIP_APPDATA_SIZE, "%u\n", i);
1503  \endcode
1504  *
1505  * \hideinitializer
1506  */
1507 #define UIP_APPDATA_SIZE (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN)
1508 
1509 
1510 #define UIP_PROTO_ICMP  1
1511 #define UIP_PROTO_TCP   6
1512 #define UIP_PROTO_UDP   17
1513 #define UIP_PROTO_ICMP6 58
1514 
1515 /* Header sizes. */
1516 #if UIP_CONF_IPV6
1517 #define UIP_IPH_LEN    40
1518 #else /* UIP_CONF_IPV6 */
1519 #define UIP_IPH_LEN    20    /* Size of IP header */
1520 #endif /* UIP_CONF_IPV6 */
1521 #define UIP_UDPH_LEN    8    /* Size of UDP header */
1522 #define UIP_TCPH_LEN   20    /* Size of TCP header */
1523 #define UIP_IPUDPH_LEN (UIP_UDPH_LEN + UIP_IPH_LEN)    /* Size of IP +
1524 							  UDP
1525 							  header */
1526 #define UIP_IPTCPH_LEN (UIP_TCPH_LEN + UIP_IPH_LEN)    /* Size of IP +
1527 							  TCP
1528 							  header */
1529 #define UIP_TCPIP_HLEN UIP_IPTCPH_LEN
1530 
1531 
1532 #if UIP_FIXEDADDR
1533 extern const uip_ipaddr_t uip_hostaddr, uip_netmask, uip_draddr;
1534 #else /* UIP_FIXEDADDR */
1535 extern uip_ipaddr_t uip_hostaddr, uip_netmask, uip_draddr;
1536 #endif /* UIP_FIXEDADDR */
1537 
1538 
1539 
1540 /**
1541  * Representation of a 48-bit Ethernet address.
1542  */
1543 struct uip_eth_addr {
1544   u8_t addr[6];
1545 };
1546 
1547 /**
1548  * Calculate the Internet checksum over a buffer.
1549  *
1550  * The Internet checksum is the one's complement of the one's
1551  * complement sum of all 16-bit words in the buffer.
1552  *
1553  * See RFC1071.
1554  *
1555  * \param buf A pointer to the buffer over which the checksum is to be
1556  * computed.
1557  *
1558  * \param len The length of the buffer over which the checksum is to
1559  * be computed.
1560  *
1561  * \return The Internet checksum of the buffer.
1562  */
1563 u16_t uip_chksum(u16_t *buf, u16_t len);
1564 
1565 /**
1566  * Calculate the IP header checksum of the packet header in uip_buf.
1567  *
1568  * The IP header checksum is the Internet checksum of the 20 bytes of
1569  * the IP header.
1570  *
1571  * \return The IP header checksum of the IP header in the uip_buf
1572  * buffer.
1573  */
1574 u16_t uip_ipchksum(void);
1575 
1576 /**
1577  * Calculate the TCP checksum of the packet in uip_buf and uip_appdata.
1578  *
1579  * The TCP checksum is the Internet checksum of data contents of the
1580  * TCP segment, and a pseudo-header as defined in RFC793.
1581  *
1582  * \return The TCP checksum of the TCP segment in uip_buf and pointed
1583  * to by uip_appdata.
1584  */
1585 u16_t uip_tcpchksum(void);
1586 
1587 /**
1588  * Calculate the UDP checksum of the packet in uip_buf and uip_appdata.
1589  *
1590  * The UDP checksum is the Internet checksum of data contents of the
1591  * UDP segment, and a pseudo-header as defined in RFC768.
1592  *
1593  * \return The UDP checksum of the UDP segment in uip_buf and pointed
1594  * to by uip_appdata.
1595  */
1596 u16_t uip_udpchksum(void);
1597 
1598 
1599 #endif /* __UIP_H__ */
1600 
1601 
1602 /** @} */
1603