1 /**
2  * @file
3  * Sequential API Main thread module
4  *
5  */
6 
7 /*
8  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without modification,
12  * are permitted provided that the following conditions are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright notice,
15  *    this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright notice,
17  *    this list of conditions and the following disclaimer in the documentation
18  *    and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31  * OF SUCH DAMAGE.
32  *
33  * This file is part of the lwIP TCP/IP stack.
34  *
35  * Author: Adam Dunkels <adam@sics.se>
36  *
37  */
38 
39 #include "lwip/opt.h"
40 
41 #if !NO_SYS /* don't build if not configured for use in lwipopts.h */
42 
43 #include "lwip/priv/tcpip_priv.h"
44 #include "lwip/sys.h"
45 #include "lwip/memp.h"
46 #include "lwip/mem.h"
47 #include "lwip/init.h"
48 #include "lwip/ip.h"
49 #include "lwip/pbuf.h"
50 #include "lwip/etharp.h"
51 #include "netif/ethernet.h"
52 #if LWIP_PACKET
53 #include "lwip/af_packet.h"
54 #endif
55 
56 #define TCPIP_MSG_VAR_REF(name)     API_VAR_REF(name)
57 #define TCPIP_MSG_VAR_DECLARE(name) API_VAR_DECLARE(struct tcpip_msg, name)
58 #define TCPIP_MSG_VAR_ALLOC(name)   API_VAR_ALLOC(struct tcpip_msg, MEMP_TCPIP_MSG_API, name, ERR_MEM)
59 #define TCPIP_MSG_VAR_FREE(name)    API_VAR_FREE(MEMP_TCPIP_MSG_API, name)
60 
61 /* global variables */
62 static tcpip_init_done_fn tcpip_init_done;
63 static void *tcpip_init_done_arg;
64 static sys_mbox_t mbox;
65 
66 #if LWIP_TCPIP_CORE_LOCKING
67 /** The global semaphore to lock the stack. */
68 sys_mutex_t lock_tcpip_core;
69 #endif /* LWIP_TCPIP_CORE_LOCKING */
70 
71 #if LWIP_TIMERS
72 /* wait for a message, timeouts are processed while waiting */
73 #define TCPIP_MBOX_FETCH(mbox, msg) sys_timeouts_mbox_fetch(mbox, msg)
74 #else /* LWIP_TIMERS */
75 /* wait for a message with timers disabled (e.g. pass a timer-check trigger into tcpip_thread) */
76 #define TCPIP_MBOX_FETCH(mbox, msg) sys_mbox_fetch(mbox, msg)
77 #endif /* LWIP_TIMERS */
78 
79 /**
80  * The main lwIP thread. This thread has exclusive access to lwIP core functions
81  * (unless access to them is not locked). Other threads communicate with this
82  * thread using message boxes.
83  *
84  * It also starts all the timers to make sure they are running in the right
85  * thread context.
86  *
87  * @param arg unused argument
88  */
89 static void
tcpip_thread(void * arg)90 tcpip_thread(void *arg)
91 {
92   struct tcpip_msg *msg;
93   LWIP_UNUSED_ARG(arg);
94 
95   if (tcpip_init_done != NULL) {
96     tcpip_init_done(tcpip_init_done_arg);
97   }
98 
99   LOCK_TCPIP_CORE();
100   while (1) {                          /* MAIN Loop */
101     UNLOCK_TCPIP_CORE();
102     LWIP_TCPIP_THREAD_ALIVE();
103     /* wait for a message, timeouts are processed while waiting */
104     TCPIP_MBOX_FETCH(&mbox, (void **)&msg);
105     LOCK_TCPIP_CORE();
106     if (msg == NULL) {
107       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: invalid message: NULL\n"));
108       LWIP_ASSERT("tcpip_thread: invalid message", 0);
109       continue;
110     }
111     switch (msg->type) {
112 #if !LWIP_TCPIP_CORE_LOCKING
113     case TCPIP_MSG_API:
114       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API message %p\n", (void *)msg));
115       msg->msg.api_msg.function(msg->msg.api_msg.msg);
116       break;
117     case TCPIP_MSG_API_CALL:
118       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API CALL message %p\n", (void *)msg));
119       msg->msg.api_call.arg->err = msg->msg.api_call.function(msg->msg.api_call.arg);
120       sys_sem_signal(msg->msg.api_call.sem);
121       break;
122 #endif /* !LWIP_TCPIP_CORE_LOCKING */
123 
124 #if !LWIP_TCPIP_CORE_LOCKING_INPUT
125     case TCPIP_MSG_INPKT:
126       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: PACKET %p\n", (void *)msg));
127       msg->msg.inp.input_fn(msg->msg.inp.p, msg->msg.inp.netif);
128       memp_free(MEMP_TCPIP_MSG_INPKT, msg);
129       break;
130 #endif /* !LWIP_TCPIP_CORE_LOCKING_INPUT */
131 
132 #if LWIP_TCPIP_TIMEOUT && LWIP_TIMERS
133     case TCPIP_MSG_TIMEOUT:
134       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: TIMEOUT %p\n", (void *)msg));
135       sys_timeout(msg->msg.tmo.msecs, msg->msg.tmo.h, msg->msg.tmo.arg);
136       memp_free(MEMP_TCPIP_MSG_API, msg);
137       break;
138     case TCPIP_MSG_UNTIMEOUT:
139       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: UNTIMEOUT %p\n", (void *)msg));
140       sys_untimeout(msg->msg.tmo.h, msg->msg.tmo.arg);
141       memp_free(MEMP_TCPIP_MSG_API, msg);
142       break;
143 #endif /* LWIP_TCPIP_TIMEOUT && LWIP_TIMERS */
144 
145     case TCPIP_MSG_CALLBACK:
146       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK %p\n", (void *)msg));
147       msg->msg.cb.function(msg->msg.cb.ctx);
148       memp_free(MEMP_TCPIP_MSG_API, msg);
149       break;
150 
151     case TCPIP_MSG_CALLBACK_STATIC:
152       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK_STATIC %p\n", (void *)msg));
153       msg->msg.cb.function(msg->msg.cb.ctx);
154       break;
155 #ifdef LWIP_NETIF_DRV
156     case TCPIP_MSG_DRV:
157       LWIP_DEBUGF(NETIF_DEBUG, ("tcpip_thread: DRV %p\n", (void *)msg));
158       msg->msg.drv.drv_fn(msg->msg.drv.netif, msg->msg.drv.event);
159       memp_free(MEMP_NETIF_DRV_MSG, msg);
160       break;
161 #endif
162     default:
163       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: invalid message: %d\n", msg->type));
164       LWIP_ASSERT("tcpip_thread: invalid message", 0);
165       break;
166     }
167   }
168 }
169 
170 #ifdef LWIP_NETIF_DRV
171 /**
172  * Pass a received packet to tcpip_thread for input processing
173  *
174  * @param p the received packet
175  * @param inp the network interface on which the packet was received
176  * @param input_fn input function to call
177  */
178 err_t
tcpip_signal_netif_event(struct netif * inp,u32_t event,netif_drv_fn drv_fn)179 tcpip_signal_netif_event(struct netif *inp, u32_t event, netif_drv_fn drv_fn)
180 {
181   struct tcpip_msg *msg;
182 
183   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
184 
185   msg = (struct tcpip_msg *)memp_malloc(MEMP_NETIF_DRV_MSG);
186   if (msg == NULL) {
187     return ERR_MEM;
188   }
189 
190   msg->type = TCPIP_MSG_DRV;
191   //msg->msg.inp.p = p;
192   msg->msg.drv.netif = inp;
193   msg->msg.drv.event = event;
194   msg->msg.drv.drv_fn = drv_fn;
195   if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
196     memp_free(MEMP_NETIF_DRV_MSG, msg);
197     return ERR_MEM;
198   }
199   return ERR_OK;
200 }
201 #endif
202 
203 /**
204  * Pass a received packet to tcpip_thread for input processing
205  *
206  * @param p the received packet
207  * @param inp the network interface on which the packet was received
208  * @param input_fn input function to call
209  */
210 err_t
tcpip_inpkt(struct pbuf * p,struct netif * inp,netif_input_fn input_fn)211 tcpip_inpkt(struct pbuf *p, struct netif *inp, netif_input_fn input_fn)
212 {
213 #if LWIP_TCPIP_CORE_LOCKING_INPUT
214   err_t ret;
215   LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_inpkt: PACKET %p/%p\n", (void *)p, (void *)inp));
216   LOCK_TCPIP_CORE();
217   ret = input_fn(p, inp);
218   UNLOCK_TCPIP_CORE();
219   return ret;
220 #else /* LWIP_TCPIP_CORE_LOCKING_INPUT */
221   struct tcpip_msg *msg;
222 
223   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
224 
225   msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_INPKT);
226   if (msg == NULL) {
227     return ERR_MEM;
228   }
229 
230   msg->type = TCPIP_MSG_INPKT;
231   msg->msg.inp.p = p;
232   msg->msg.inp.netif = inp;
233   msg->msg.inp.input_fn = input_fn;
234   if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
235     memp_free(MEMP_TCPIP_MSG_INPKT, msg);
236     return ERR_MEM;
237   }
238   return ERR_OK;
239 #endif /* LWIP_TCPIP_CORE_LOCKING_INPUT */
240 }
241 
242 /**
243  * @ingroup lwip_os
244  * Pass a received packet to tcpip_thread for input processing with
245  * ethernet_input or ip_input. Don't call directly, pass to netif_add()
246  * and call netif->input().
247  *
248  * @param p the received packet, p->payload pointing to the Ethernet header or
249  *          to an IP header (if inp doesn't have NETIF_FLAG_ETHARP or
250  *          NETIF_FLAG_ETHERNET flags)
251  * @param inp the network interface on which the packet was received
252  */
253 err_t
tcpip_input(struct pbuf * p,struct netif * inp)254 tcpip_input(struct pbuf *p, struct netif *inp)
255 {
256 #if LWIP_PACKET
257   /* packet type data just return ok. */
258   if(!packet_input_hook(p, inp))
259   {
260     pbuf_free(p);
261     return 0;
262   }
263   else
264 #endif
265 #if LWIP_ETHERNET
266   if (inp->flags & (NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET)) {
267     return tcpip_inpkt(p, inp, ethernet_input);
268   } else
269 #endif /* LWIP_ETHERNET */
270   return tcpip_inpkt(p, inp, ip_input);
271 }
272 
273 /**
274  * Call a specific function in the thread context of
275  * tcpip_thread for easy access synchronization.
276  * A function called in that way may access lwIP core code
277  * without fearing concurrent access.
278  *
279  * @param function the function to call
280  * @param ctx parameter passed to f
281  * @param block 1 to block until the request is posted, 0 to non-blocking mode
282  * @return ERR_OK if the function was called, another err_t if not
283  */
284 err_t
tcpip_callback_with_block(tcpip_callback_fn function,void * ctx,u8_t block)285 tcpip_callback_with_block(tcpip_callback_fn function, void *ctx, u8_t block)
286 {
287   struct tcpip_msg *msg;
288 
289   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
290 
291   msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
292   if (msg == NULL) {
293     return ERR_MEM;
294   }
295 
296   msg->type = TCPIP_MSG_CALLBACK;
297   msg->msg.cb.function = function;
298   msg->msg.cb.ctx = ctx;
299   if (block) {
300     sys_mbox_post(&mbox, msg);
301   } else {
302     if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
303       memp_free(MEMP_TCPIP_MSG_API, msg);
304       return ERR_MEM;
305     }
306   }
307   return ERR_OK;
308 }
309 
310 #if LWIP_TCPIP_TIMEOUT && LWIP_TIMERS
311 /**
312  * call sys_timeout in tcpip_thread
313  *
314  * @param msecs time in milliseconds for timeout
315  * @param h function to be called on timeout
316  * @param arg argument to pass to timeout function h
317  * @return ERR_MEM on memory error, ERR_OK otherwise
318  */
319 err_t
tcpip_timeout(u32_t msecs,sys_timeout_handler h,void * arg)320 tcpip_timeout(u32_t msecs, sys_timeout_handler h, void *arg)
321 {
322   struct tcpip_msg *msg;
323 
324   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
325 
326   msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
327   if (msg == NULL) {
328     return ERR_MEM;
329   }
330 
331   msg->type = TCPIP_MSG_TIMEOUT;
332   msg->msg.tmo.msecs = msecs;
333   msg->msg.tmo.h = h;
334   msg->msg.tmo.arg = arg;
335   sys_mbox_post(&mbox, msg);
336   return ERR_OK;
337 }
338 
339 /**
340  * call sys_untimeout in tcpip_thread
341  *
342  * @param h function to be called on timeout
343  * @param arg argument to pass to timeout function h
344  * @return ERR_MEM on memory error, ERR_OK otherwise
345  */
346 err_t
tcpip_untimeout(sys_timeout_handler h,void * arg)347 tcpip_untimeout(sys_timeout_handler h, void *arg)
348 {
349   struct tcpip_msg *msg;
350 
351   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
352 
353   msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
354   if (msg == NULL) {
355     return ERR_MEM;
356   }
357 
358   msg->type = TCPIP_MSG_UNTIMEOUT;
359   msg->msg.tmo.h = h;
360   msg->msg.tmo.arg = arg;
361   sys_mbox_post(&mbox, msg);
362   return ERR_OK;
363 }
364 #endif /* LWIP_TCPIP_TIMEOUT && LWIP_TIMERS */
365 
366 
367 /**
368  * Sends a message to TCPIP thread to call a function. Caller thread blocks on
369  * on a provided semaphore, which ist NOT automatically signalled by TCPIP thread,
370  * this has to be done by the user.
371  * It is recommended to use LWIP_TCPIP_CORE_LOCKING since this is the way
372  * with least runtime overhead.
373  *
374  * @param fn function to be called from TCPIP thread
375  * @param apimsg argument to API function
376  * @param sem semaphore to wait on
377  * @return ERR_OK if the function was called, another err_t if not
378  */
379 err_t
tcpip_send_msg_wait_sem(tcpip_callback_fn fn,void * apimsg,sys_sem_t * sem)380 tcpip_send_msg_wait_sem(tcpip_callback_fn fn, void *apimsg, sys_sem_t* sem)
381 {
382 #if LWIP_TCPIP_CORE_LOCKING
383   LWIP_UNUSED_ARG(sem);
384   LOCK_TCPIP_CORE();
385   fn(apimsg);
386   UNLOCK_TCPIP_CORE();
387   return ERR_OK;
388 #else /* LWIP_TCPIP_CORE_LOCKING */
389   TCPIP_MSG_VAR_DECLARE(msg);
390 
391   LWIP_ASSERT("semaphore not initialized", sys_sem_valid(sem));
392   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
393 
394   TCPIP_MSG_VAR_ALLOC(msg);
395   TCPIP_MSG_VAR_REF(msg).type = TCPIP_MSG_API;
396   TCPIP_MSG_VAR_REF(msg).msg.api_msg.function = fn;
397   TCPIP_MSG_VAR_REF(msg).msg.api_msg.msg = apimsg;
398   sys_mbox_post(&mbox, &TCPIP_MSG_VAR_REF(msg));
399   sys_arch_sem_wait(sem, 0);
400   TCPIP_MSG_VAR_FREE(msg);
401   return ERR_OK;
402 #endif /* LWIP_TCPIP_CORE_LOCKING */
403 }
404 
405 /**
406  * Synchronously calls function in TCPIP thread and waits for its completion.
407  * It is recommended to use LWIP_TCPIP_CORE_LOCKING (preferred) or
408  * LWIP_NETCONN_SEM_PER_THREAD.
409  * If not, a semaphore is created and destroyed on every call which is usually
410  * an expensive/slow operation.
411  * @param fn Function to call
412  * @param call Call parameters
413  * @return Return value from tcpip_api_call_fn
414  */
415 err_t
tcpip_api_call(tcpip_api_call_fn fn,struct tcpip_api_call_data * call)416 tcpip_api_call(tcpip_api_call_fn fn, struct tcpip_api_call_data *call)
417 {
418 #if LWIP_TCPIP_CORE_LOCKING
419   err_t err;
420   LOCK_TCPIP_CORE();
421   err = fn(call);
422   UNLOCK_TCPIP_CORE();
423   return err;
424 #else /* LWIP_TCPIP_CORE_LOCKING */
425   TCPIP_MSG_VAR_DECLARE(msg);
426 
427 #if !LWIP_NETCONN_SEM_PER_THREAD
428   err_t err = sys_sem_new(&call->sem, 0);
429   if (err != ERR_OK) {
430     return err;
431   }
432 #endif /* LWIP_NETCONN_SEM_PER_THREAD */
433 
434   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
435 
436   TCPIP_MSG_VAR_ALLOC(msg);
437   TCPIP_MSG_VAR_REF(msg).type = TCPIP_MSG_API_CALL;
438   TCPIP_MSG_VAR_REF(msg).msg.api_call.arg = call;
439   TCPIP_MSG_VAR_REF(msg).msg.api_call.function = fn;
440 #if LWIP_NETCONN_SEM_PER_THREAD
441   TCPIP_MSG_VAR_REF(msg).msg.api_call.sem = LWIP_NETCONN_THREAD_SEM_GET();
442 #else /* LWIP_NETCONN_SEM_PER_THREAD */
443   TCPIP_MSG_VAR_REF(msg).msg.api_call.sem = &call->sem;
444 #endif /* LWIP_NETCONN_SEM_PER_THREAD */
445   sys_mbox_post(&mbox, &TCPIP_MSG_VAR_REF(msg));
446   sys_arch_sem_wait(TCPIP_MSG_VAR_REF(msg).msg.api_call.sem, 0);
447   TCPIP_MSG_VAR_FREE(msg);
448 
449 #if !LWIP_NETCONN_SEM_PER_THREAD
450   sys_sem_free(&call->sem);
451 #endif /* LWIP_NETCONN_SEM_PER_THREAD */
452 
453   return call->err;
454 #endif /* LWIP_TCPIP_CORE_LOCKING */
455 }
456 
457 /**
458  * Allocate a structure for a static callback message and initialize it.
459  * This is intended to be used to send "static" messages from interrupt context.
460  *
461  * @param function the function to call
462  * @param ctx parameter passed to function
463  * @return a struct pointer to pass to tcpip_trycallback().
464  */
465 struct tcpip_callback_msg*
tcpip_callbackmsg_new(tcpip_callback_fn function,void * ctx)466 tcpip_callbackmsg_new(tcpip_callback_fn function, void *ctx)
467 {
468   struct tcpip_msg *msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
469   if (msg == NULL) {
470     return NULL;
471   }
472   msg->type = TCPIP_MSG_CALLBACK_STATIC;
473   msg->msg.cb.function = function;
474   msg->msg.cb.ctx = ctx;
475   return (struct tcpip_callback_msg*)msg;
476 }
477 
478 /**
479  * Free a callback message allocated by tcpip_callbackmsg_new().
480  *
481  * @param msg the message to free
482  */
483 void
tcpip_callbackmsg_delete(struct tcpip_callback_msg * msg)484 tcpip_callbackmsg_delete(struct tcpip_callback_msg* msg)
485 {
486   memp_free(MEMP_TCPIP_MSG_API, msg);
487 }
488 
489 /**
490  * Try to post a callback-message to the tcpip_thread mbox
491  * This is intended to be used to send "static" messages from interrupt context.
492  *
493  * @param msg pointer to the message to post
494  * @return sys_mbox_trypost() return code
495  */
496 err_t
tcpip_trycallback(struct tcpip_callback_msg * msg)497 tcpip_trycallback(struct tcpip_callback_msg* msg)
498 {
499   LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
500   return sys_mbox_trypost(&mbox, msg);
501 }
502 
503 /**
504  * @ingroup lwip_os
505  * Initialize this module:
506  * - initialize all sub modules
507  * - start the tcpip_thread
508  *
509  * @param initfunc a function to call when tcpip_thread is running and finished initializing
510  * @param arg argument to pass to initfunc
511  */
512 void
tcpip_init(tcpip_init_done_fn initfunc,void * arg)513 tcpip_init(tcpip_init_done_fn initfunc, void *arg)
514 {
515   lwip_init();
516 
517   tcpip_init_done = initfunc;
518   tcpip_init_done_arg = arg;
519   if (sys_mbox_new(&mbox, TCPIP_MBOX_SIZE) != ERR_OK) {
520     LWIP_ASSERT("failed to create tcpip_thread mbox", 0);
521   }
522 #if LWIP_TCPIP_CORE_LOCKING
523   if (sys_mutex_new(&lock_tcpip_core) != ERR_OK) {
524     LWIP_ASSERT("failed to create lock_tcpip_core", 0);
525   }
526 #endif /* LWIP_TCPIP_CORE_LOCKING */
527 
528   sys_thread_new(TCPIP_THREAD_NAME, tcpip_thread, NULL, TCPIP_THREAD_STACKSIZE, TCPIP_THREAD_PRIO);
529 }
530 
531 /**
532  * Simple callback function used with tcpip_callback to free a pbuf
533  * (pbuf_free has a wrong signature for tcpip_callback)
534  *
535  * @param p The pbuf (chain) to be dereferenced.
536  */
537 static void
pbuf_free_int(void * p)538 pbuf_free_int(void *p)
539 {
540   struct pbuf *q = (struct pbuf *)p;
541   pbuf_free(q);
542 }
543 
544 /**
545  * A simple wrapper function that allows you to free a pbuf from interrupt context.
546  *
547  * @param p The pbuf (chain) to be dereferenced.
548  * @return ERR_OK if callback could be enqueued, an err_t if not
549  */
550 err_t
pbuf_free_callback(struct pbuf * p)551 pbuf_free_callback(struct pbuf *p)
552 {
553   return tcpip_callback_with_block(pbuf_free_int, p, 0);
554 }
555 
556 /**
557  * A simple wrapper function that allows you to free heap memory from
558  * interrupt context.
559  *
560  * @param m the heap memory to free
561  * @return ERR_OK if callback could be enqueued, an err_t if not
562  */
563 err_t
mem_free_callback(void * m)564 mem_free_callback(void *m)
565 {
566   return tcpip_callback_with_block(mem_free, m, 0);
567 }
568 
569 #endif /* !NO_SYS */
570