/**
* Allocate memory: determine the smallest pool that is big enough
* to contain an element of 'size' and get an element from that pool.
*
* @param size the size in bytes of the memory needed
* @return a pointer to the allocated memory or NULL if the pool is empty
*/
void *
mem_malloc(mem_size_t size)
{
void *ret;
struct memp_malloc_helper *element;
memp_t poolnr;
mem_size_t required_size = size + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
#if MEM_USE_POOLS_TRY_BIGGER_POOL
again:
#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
/* is this pool big enough to hold an element of the required size
plus a struct memp_malloc_helper that saves the pool this element came from? */
if (required_size <= memp_pools[poolnr]->size) {
break;
}
}
if (poolnr > MEMP_POOL_LAST) {
LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
MEM_STATS_INC(err);
return NULL;
}
element = (struct memp_malloc_helper*)memp_malloc(poolnr);
if (element == NULL) {
/* No need to DEBUGF or ASSERT: This error is already
taken care of in memp.c */
#if MEM_USE_POOLS_TRY_BIGGER_POOL
/** Try a bigger pool if this one is empty! */
if (poolnr < MEMP_POOL_LAST) {
poolnr++;
goto again;
}
#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
MEM_STATS_INC(err);
return NULL;
}
/* save the pool number this element came from */
element->poolnr = poolnr;
/* and return a pointer to the memory directly after the struct memp_malloc_helper */
ret = (u8_t*)element + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
#if MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS)
/* truncating to u16_t is safe because struct memp_desc::size is u16_t */
element->size = (u16_t)size;
MEM_STATS_INC_USED(used, element->size);
#endif /* MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS) */
#if MEMP_OVERFLOW_CHECK
/* initialize unused memory (diff between requested size and selected pool's size) */
memset((u8_t*)ret + size, 0xcd, memp_pools[poolnr]->size - size);
#endif /* MEMP_OVERFLOW_CHECK */
return ret;
}
/**
* @ingroup pbuf
* Initialize a custom pbuf (already allocated).
*
* @param l flag to define header size
* @param length size of the pbuf's payload
* @param type type of the pbuf (only used to treat the pbuf accordingly, as
* this function allocates no memory)
* @param p pointer to the custom pbuf to initialize (already allocated)
* @param payload_mem pointer to the buffer that is used for payload and headers,
* must be at least big enough to hold 'length' plus the header size,
* may be NULL if set later.
* ATTENTION: The caller is responsible for correct alignment of this buffer!!
* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
* big enough to hold 'length' plus the header size
*/
struct pbuf*
pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
void *payload_mem, u16_t payload_mem_len)
{
u16_t offset;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
/* determine header offset */
switch (l) {
case PBUF_TRANSPORT:
/* add room for transport (often TCP) layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN;
break;
case PBUF_IP:
/* add room for IP layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN;
break;
case PBUF_LINK:
/* add room for link layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN;
break;
case PBUF_RAW_TX:
/* add room for encapsulating link layer headers (e.g. 802.11) */
offset = PBUF_LINK_ENCAPSULATION_HLEN;
break;
case PBUF_RAW:
offset = 0;
break;
default:
LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
return NULL;
}
if (LWIP_MEM_ALIGN_SIZE(offset) + length > payload_mem_len) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
return NULL;
}
p->pbuf.next = NULL;
if (payload_mem != NULL) {
p->pbuf.payload = (u8_t *)payload_mem + LWIP_MEM_ALIGN_SIZE(offset);
} else {
p->pbuf.payload = NULL;
}
p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
p->pbuf.len = p->pbuf.tot_len = length;
p->pbuf.type = type;
p->pbuf.ref = 1;
return &p->pbuf;
}
struct pbuf *
pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
{
struct pbuf *p;
u16_t offset = 0;
offset += 16;
/* If pbuf is to be allocated in RAM, allocate memory for it. */
p = (struct pbuf*)rt_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
if (p == RT_NULL) return RT_NULL;
/* Set up internal structure of the pbuf. */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
p->len = length;
return p;
}
/**
* Free memory previously allocated by mem_malloc. Loads the pool number
* and calls memp_free with that pool number to put the element back into
* its pool
*
* @param rmem the memory element to free
*/
void
mem_free(void *rmem)
{
struct memp_malloc_helper *hmem;
LWIP_ASSERT("rmem != NULL", (rmem != NULL));
LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
/* get the original struct memp_malloc_helper */
/* cast through void* to get rid of alignment warnings */
hmem = (struct memp_malloc_helper*)(void*)((u8_t*)rmem - LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)));
LWIP_ASSERT("hmem != NULL", (hmem != NULL));
LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
MEM_STATS_DEC_USED(used, hmem->size);
#if MEMP_OVERFLOW_CHECK
{
u16_t i;
LWIP_ASSERT("MEM_USE_POOLS: invalid chunk size",
hmem->size <= memp_pools[hmem->poolnr]->size);
/* check that unused memory remained untouched (diff between requested size and selected pool's size) */
for (i = hmem->size; i < memp_pools[hmem->poolnr]->size; i++) {
u8_t data = *((u8_t*)rmem + i);
LWIP_ASSERT("MEM_USE_POOLS: mem overflow detected", data == 0xcd);
}
}
#endif /* MEMP_OVERFLOW_CHECK */
/* and put it in the pool we saved earlier */
memp_free(hmem->poolnr, hmem);
}
/**
* Free memory previously allocated by mem_malloc. Loads the pool number
* and calls memp_free with that pool number to put the element back into
* its pool
*
* @param rmem the memory element to free
*/
void
mem_free(void *rmem)
{
struct memp_malloc_helper *hmem;
LWIP_ASSERT("rmem != NULL", (rmem != NULL));
LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
/* get the original struct memp_malloc_helper */
hmem = (struct memp_malloc_helper*)(void*)((u8_t*)rmem - LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)));
LWIP_ASSERT("hmem != NULL", (hmem != NULL));
LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
#if MEMP_OVERFLOW_CHECK
{
u16_t i;
LWIP_ASSERT("MEM_USE_POOLS: invalid chunk size",
hmem->size <= memp_sizes[hmem->poolnr]);
/* check that unused memory remained untouched */
for (i = hmem->size; i < memp_sizes[hmem->poolnr]; i++) {
u8_t data = *((u8_t*)rmem + i);
LWIP_ASSERT("MEM_USE_POOLS: mem overflow detected", data == 0xcd);
}
}
#endif /* MEMP_OVERFLOW_CHECK */
/* and put it in the pool we saved earlier */
memp_free(hmem->poolnr, hmem);
}
/**
* Allocate memory: determine the smallest pool that is big enough
* to contain an element of 'size' and get an element from that pool.
*
* @param size the size in bytes of the memory needed
* @return a pointer to the allocated memory or NULL if the pool is empty
*/
void *mem_malloc(mem_size_t size) {
void *ret;
struct memp_malloc_helper *element;
memp_t poolnr;
mem_size_t required_size =
size + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST;
poolnr = (memp_t)(poolnr + 1)) {
#if MEM_USE_POOLS_TRY_BIGGER_POOL
again:
#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
/* is this pool big enough to hold an element of the required size
plus a struct memp_malloc_helper that saves the pool this element came
from? */
if (required_size <= memp_sizes[poolnr]) {
break;
}
}
if (poolnr > MEMP_POOL_LAST) {
LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
return NULL;
}
element = (struct memp_malloc_helper *) memp_malloc(poolnr);
if (element == NULL) {
/* No need to DEBUGF or ASSERT: This error is already
taken care of in memp.c */
#if MEM_USE_POOLS_TRY_BIGGER_POOL
/** Try a bigger pool if this one is empty! */
if (poolnr < MEMP_POOL_LAST) {
poolnr++;
goto again;
}
#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
return NULL;
}
/* save the pool number this element came from */
element->poolnr = poolnr;
/* and return a pointer to the memory directly after the struct
* memp_malloc_helper */
ret =
(u8_t *) element + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
return ret;
}
//lwip内核部分,内存申请
//返回值:0,成功;
// 其他,失败
u8 lwip_comm_mem_malloc(void)
{
u32 mempsize;
u32 ramheapsize;
mempsize=memp_get_memorysize(); //得到memp_memory数组大小
memp_memory=mymalloc(SRAMIN,mempsize); //为memp_memory申请内存
ramheapsize=LWIP_MEM_ALIGN_SIZE(MEM_SIZE)+2*LWIP_MEM_ALIGN_SIZE(4*3)+MEM_ALIGNMENT;//得到ram heap大小
ram_heap=mymalloc(SRAMIN,ramheapsize); //为ram_heap申请内存
TCPIP_THREAD_TASK_STK=mymalloc(SRAMIN,TCPIP_THREAD_STACKSIZE*4);//给内核任务申请堆栈
LWIP_DHCP_TASK_STK=mymalloc(SRAMIN,LWIP_DHCP_STK_SIZE*4); //给dhcp任务堆栈申请内存空间
if(!memp_memory||!ram_heap||!TCPIP_THREAD_TASK_STK||!LWIP_DHCP_TASK_STK)//有申请失败的
{
lwip_comm_mem_free();
return 1;
}
return 0;
}
/**
* @ingroup pbuf
* Initialize a custom pbuf (already allocated).
* Example of custom pbuf usage: @ref zerocopyrx
*
* @param l header size
* @param length size of the pbuf's payload
* @param type type of the pbuf (only used to treat the pbuf accordingly, as
* this function allocates no memory)
* @param p pointer to the custom pbuf to initialize (already allocated)
* @param payload_mem pointer to the buffer that is used for payload and headers,
* must be at least big enough to hold 'length' plus the header size,
* may be NULL if set later.
* ATTENTION: The caller is responsible for correct alignment of this buffer!!
* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
* big enough to hold 'length' plus the header size
*/
struct pbuf *
pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
void *payload_mem, u16_t payload_mem_len)
{
u16_t offset = (u16_t)l;
void *payload;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
if (LWIP_MEM_ALIGN_SIZE(offset) + length > payload_mem_len) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
return NULL;
}
if (payload_mem != NULL) {
payload = (u8_t *)payload_mem + LWIP_MEM_ALIGN_SIZE(offset);
} else {
payload = NULL;
}
pbuf_init_alloced_pbuf(&p->pbuf, payload, length, length, type, PBUF_FLAG_IS_CUSTOM);
return &p->pbuf;
}
//lwip内核部分,内存申请
//返回值:0,成功;
// 其他,失败
uint8_t lwip_comm_mem_malloc(void)
{
uint32_t mempsize;
uint32_t ramheapsize;
mempsize=memp_get_memorysize(); //得到memp_memory数组大小
memp_memory=mymalloc(SRAMEX,mempsize); //为memp_memory申请内存
printf("memp_memory内存大小为:%d\r\n",mempsize);
ramheapsize=LWIP_MEM_ALIGN_SIZE(MEM_SIZE)+2*LWIP_MEM_ALIGN_SIZE(4*3)+MEM_ALIGNMENT;//得到ram heap大小
ram_heap=mymalloc(SRAMEX,ramheapsize); //为ram_heap申请内存
printf("ram_heap内存大小为:%d\r\n",ramheapsize);
TCPIP_THREAD_TASK_STK=mymalloc(SRAMEX,TCPIP_THREAD_STACKSIZE*4); //给内核任务申请堆栈
//LWIP_DHCP_TASK_STK=mymalloc(SRAMEX,LWIP_DHCP_STK_SIZE*4); //给dhcp任务申请堆栈
if(!memp_memory) {
lwip_comm_mem_free();
return 1;
}
if(!ram_heap) {
lwip_comm_mem_free();
return 1;
}
if(!TCPIP_THREAD_TASK_STK) {
lwip_comm_mem_free();
return 1;
}
// if((!memp_memory)||(!ram_heap)||(!TCPIP_THREAD_TASK_STK));//||!LWIP_DHCP_TASK_STK) //有申请失败的
// {
// lwip_comm_mem_free();
// return 1;
// }
return 0;
}
static struct pbuf *ICACHE_FLASH_ATTR
tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags,
u8_t first_seg)
{
struct pbuf *p;
u16_t alloc = length;
#if LWIP_NETIF_TX_SINGLE_PBUF
LWIP_UNUSED_ARG(max_length);
LWIP_UNUSED_ARG(pcb);
LWIP_UNUSED_ARG(apiflags);
LWIP_UNUSED_ARG(first_seg);
/* always create MSS-sized pbufs */
alloc = TCP_MSS;
#else /* LWIP_NETIF_TX_SINGLE_PBUF */
if (length < max_length) {
/* Should we allocate an oversized pbuf, or just the minimum
* length required? If tcp_write is going to be called again
* before this segment is transmitted, we want the oversized
* buffer. If the segment will be transmitted immediately, we can
* save memory by allocating only length. We use a simple
* heuristic based on the following information:
*
* Did the user set TCP_WRITE_FLAG_MORE?
*
* Will the Nagle algorithm defer transmission of this segment?
*/
if ((apiflags & TCP_WRITE_FLAG_MORE) ||
(!(pcb->flags & TF_NODELAY) &&
(!first_seg ||
pcb->unsent != NULL ||
pcb->unacked != NULL))) {
alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
}
}
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
p = pbuf_alloc(layer, alloc, PBUF_RAM);
if (p == NULL) {
return NULL;
}
LWIP_ASSERT("need unchained pbuf", p->next == NULL);
*oversize = p->len - length;
/* trim p->len to the currently used size */
p->len = p->tot_len = length;
return p;
}
/**
* Free memory previously allocated by mem_malloc. Loads the pool number
* and calls memp_free with that pool number to put the element back into
* its pool
*
* @param rmem the memory element to free
*/
void
mem_free(void *rmem)
{
struct memp_malloc_helper *hmem;
LWIP_ASSERT("rmem != NULL", (rmem != NULL));
LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
/* get the original struct memp_malloc_helper */
hmem = (struct memp_malloc_helper*)(void*)((u8_t*)rmem - LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)));
LWIP_ASSERT("hmem != NULL", (hmem != NULL));
LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
/* and put it in the pool we saved earlier */
memp_free(hmem->poolnr, hmem);
}
/**
* Zero the heap and initialize start, end and lowest-free
*/
void
mem_init(LWIP_MEM_CFG *mem_cfg)
{
struct mem *mem;
BOOL en = mem_cfg->enable;
UINT8 *start = mem_cfg->start;
UINT32 length = LWIP_MEM_ALIGN_SIZE(mem_cfg->length);
LWIP_ASSERT("Sanity check alignment",
(SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
if(en == TRUE)
{
ram_heap = (UINT8 *)start;
MEM_SIZE_ALIGNED = (length - (2*SIZEOF_STRUCT_MEM) - MEM_ALIGNMENT);
}
else
{
ram_heap = (UINT8 *)MALLOC(MEM_SIZE);
MEM_SIZE_ALIGNED = (MEM_SIZE - (2*SIZEOF_STRUCT_MEM) - MEM_ALIGNMENT);
}
/* align the heap */
ram = LWIP_MEM_ALIGN(ram_heap);
/* initialize the start of the heap */
mem = (struct mem *)ram;
mem->next = MEM_SIZE_ALIGNED;
mem->prev = 0;
mem->used = 0;
/* initialize the end of the heap */
ram_end = (struct mem *)&ram[MEM_SIZE_ALIGNED];
ram_end->used = 1;
ram_end->next = MEM_SIZE_ALIGNED;
ram_end->prev = MEM_SIZE_ALIGNED;
mem_sem = sys_sem_new(1);
/* initialize the lowest-free pointer to the start of the heap */
lfree = (struct mem *)ram;
#if MEM_STATS
lwip_stats.mem.avail = MEM_SIZE_ALIGNED;
#endif /* MEM_STATS */
}
/**
* @ingroup pbuf
* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
*
* The actual memory allocated for the pbuf is determined by the
* layer at which the pbuf is allocated and the requested size
* (from the size parameter).
*
* @param layer flag to define header size
* @param length size of the pbuf's payload
* @param type this parameter decides how and where the pbuf
* should be allocated as follows:
*
* - PBUF_RAM: buffer memory for pbuf is allocated as one large
* chunk. This includes protocol headers as well.
* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
* protocol headers. Additional headers must be prepended
* by allocating another pbuf and chain in to the front of
* the ROM pbuf. It is assumed that the memory used is really
* similar to ROM in that it is immutable and will not be
* changed. Memory which is dynamic should generally not
* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
* protocol headers. It is assumed that the pbuf is only
* being used in a single thread. If the pbuf gets queued,
* then pbuf_take should be called to copy the buffer.
* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
* the pbuf pool that is allocated during pbuf_init().
*
* @return the allocated pbuf. If multiple pbufs where allocated, this
* is the first pbuf of a pbuf chain.
*/
struct pbuf *
pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
{
struct pbuf *p, *q, *r;
u16_t offset;
s32_t rem_len; /* remaining length */
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
/* determine header offset */
switch (layer) {
case PBUF_TRANSPORT:
/* add room for transport (often TCP) layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN;
break;
case PBUF_IP:
/* add room for IP layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN;
break;
case PBUF_LINK:
/* add room for link layer header */
offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN;
break;
case PBUF_RAW_TX:
/* add room for encapsulating link layer headers (e.g. 802.11) */
offset = PBUF_LINK_ENCAPSULATION_HLEN;
break;
case PBUF_RAW:
/* no offset (e.g. RX buffers or chain successors) */
offset = 0;
break;
default:
LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
return NULL;
}
switch (type) {
case PBUF_POOL:
/* allocate head of pbuf chain into p */
p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
if (p == NULL) {
PBUF_POOL_IS_EMPTY();
return NULL;
}
p->type = type;
p->next = NULL;
p->if_idx = NETIF_NO_INDEX;
/* make the payload pointer point 'offset' bytes into pbuf data memory */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
/* the total length of the pbuf chain is the requested size */
p->tot_len = length;
/* set the length of the first pbuf in the chain */
p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
/* set reference count (needed here in case we fail) */
p->ref = 1;
/* now allocate the tail of the pbuf chain */
/* remember first pbuf for linkage in next iteration */
r = p;
/* remaining length to be allocated */
rem_len = length - p->len;
/* any remaining pbufs to be allocated? */
while (rem_len > 0) {
q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
if (q == NULL) {
PBUF_POOL_IS_EMPTY();
/* free chain so far allocated */
pbuf_free(p);
/* bail out unsuccessfully */
return NULL;
}
q->type = type;
q->flags = 0;
q->next = NULL;
/* make previous pbuf point to this pbuf */
r->next = q;
/* set total length of this pbuf and next in chain */
LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
q->tot_len = (u16_t)rem_len;
/* this pbuf length is pool size, unless smaller sized tail */
q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
q->ref = 1;
/* calculate remaining length to be allocated */
rem_len -= q->len;
/* remember this pbuf for linkage in next iteration */
r = q;
}
/* end of chain */
/*r->next = NULL;*/
break;
case PBUF_RAM:
{
mem_size_t alloc_len = LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length);
/* bug #50040: Check for integer overflow when calculating alloc_len */
if (alloc_len < LWIP_MEM_ALIGN_SIZE(length)) {
return NULL;
}
/* If pbuf is to be allocated in RAM, allocate memory for it. */
p = (struct pbuf*)mem_malloc(alloc_len);
}
if (p == NULL) {
return NULL;
}
/* Set up internal structure of the pbuf. */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
break;
/* pbuf references existing (non-volatile static constant) ROM payload? */
case PBUF_ROM:
/* pbuf references existing (externally allocated) RAM payload? */
case PBUF_REF:
/* only allocate memory for the pbuf structure */
p = (struct pbuf *)memp_malloc(MEMP_PBUF);
if (p == NULL) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
(type == PBUF_ROM) ? "ROM" : "REF"));
return NULL;
}
/* caller must set this field properly, afterwards */
p->payload = NULL;
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
break;
default:
LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
return NULL;
}
/* set reference count */
p->ref = 1;
/* set flags */
p->flags = 0;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
return p;
}
/**
* Adam's mem_malloc() plus solution for bug #17922
* Allocate a block of memory with a minimum of 'size' bytes.
*
* @param size is the minimum size of the requested block in bytes.
* @return pointer to allocated memory or NULL if no free memory was found.
*
* Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
*/
void *
mem_malloc(mem_size_t size)
{
mem_size_t ptr, ptr2;
struct mem *mem, *mem2;
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
u8_t local_mem_free_count = 0;
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
LWIP_MEM_ALLOC_DECL_PROTECT();
if (size == 0) {
return NULL;
}
/* Expand the size of the allocated memory region so that we can
adjust for alignment. */
size = LWIP_MEM_ALIGN_SIZE(size);
if(size < MIN_SIZE_ALIGNED) {
/* every data block must be at least MIN_SIZE_ALIGNED long */
size = MIN_SIZE_ALIGNED;
}
if (size > MEM_SIZE_ALIGNED) {
return NULL;
}
/* protect the heap from concurrent access */
sys_mutex_lock(&mem_mutex);
LWIP_MEM_ALLOC_PROTECT();
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
/* run as long as a mem_free disturbed mem_malloc or mem_trim */
do {
local_mem_free_count = 0;
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
/* Scan through the heap searching for a free block that is big enough,
* beginning with the lowest free block.
*/
for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
ptr = ((struct mem *)(void *)&ram[ptr])->next) {
mem = (struct mem *)(void *)&ram[ptr];
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mem_free_count = 0;
LWIP_MEM_ALLOC_UNPROTECT();
/* allow mem_free or mem_trim to run */
LWIP_MEM_ALLOC_PROTECT();
if (mem_free_count != 0) {
/* If mem_free or mem_trim have run, we have to restart since they
could have altered our current struct mem. */
local_mem_free_count = 1;
break;
}
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
if ((!mem->used) &&
(mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
/* mem is not used and at least perfect fit is possible:
* mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
/* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
* at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
* -> split large block, create empty remainder,
* remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
* mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
* struct mem would fit in but no data between mem2 and mem2->next
* @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
* region that couldn't hold data, but when mem->next gets freed,
* the 2 regions would be combined, resulting in more free memory
*/
ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
/* create mem2 struct */
mem2 = (struct mem *)(void *)&ram[ptr2];
mem2->used = 0;
mem2->next = mem->next;
mem2->prev = ptr;
/* and insert it between mem and mem->next */
mem->next = ptr2;
mem->used = 1;
if (mem2->next != MEM_SIZE_ALIGNED) {
((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
}
MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
} else {
/* (a mem2 struct does no fit into the user data space of mem and mem->next will always
* be used at this point: if not we have 2 unused structs in a row, plug_holes should have
* take care of this).
* -> near fit or excact fit: do not split, no mem2 creation
* also can't move mem->next directly behind mem, since mem->next
* will always be used at this point!
*/
mem->used = 1;
MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
}
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mem_malloc_adjust_lfree:
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
if (mem == lfree) {
struct mem *cur = lfree;
/* Find next free block after mem and update lowest free pointer */
while (cur->used && cur != ram_end) {
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mem_free_count = 0;
LWIP_MEM_ALLOC_UNPROTECT();
/* prevent high interrupt latency... */
LWIP_MEM_ALLOC_PROTECT();
if (mem_free_count != 0) {
/* If mem_free or mem_trim have run, we have to restart since they
could have altered our current struct mem or lfree. */
goto mem_malloc_adjust_lfree;
}
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
cur = (struct mem *)(void *)&ram[cur->next];
}
lfree = cur;
LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
}
LWIP_MEM_ALLOC_UNPROTECT();
sys_mutex_unlock(&mem_mutex);
LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
(mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
LWIP_ASSERT("mem_malloc: sanity check alignment",
(((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
return (u8_t *)mem + SIZEOF_STRUCT_MEM;
}
}
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
/* if we got interrupted by a mem_free, try again */
} while(local_mem_free_count != 0);
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
MEM_STATS_INC(err);
LWIP_MEM_ALLOC_UNPROTECT();
sys_mutex_unlock(&mem_mutex);
return NULL;
}
/**
* Shrink memory returned by mem_malloc().
*
* @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
* @param newsize required size after shrinking (needs to be smaller than or
* equal to the previous size)
* @return for compatibility reasons: is always == rmem, at the moment
* or NULL if newsize is > old size, in which case rmem is NOT touched
* or freed!
*/
void *
mem_trim(void *rmem, mem_size_t newsize)
{
mem_size_t size;
mem_size_t ptr, ptr2;
struct mem *mem, *mem2;
/* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
LWIP_MEM_FREE_DECL_PROTECT();
/* Expand the size of the allocated memory region so that we can
adjust for alignment. */
newsize = LWIP_MEM_ALIGN_SIZE(newsize);
if(newsize < MIN_SIZE_ALIGNED) {
/* every data block must be at least MIN_SIZE_ALIGNED long */
newsize = MIN_SIZE_ALIGNED;
}
if (newsize > MEM_SIZE_ALIGNED) {
return NULL;
}
LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
(u8_t *)rmem < (u8_t *)ram_end);
if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
SYS_ARCH_DECL_PROTECT(lev);
LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
/* protect mem stats from concurrent access */
SYS_ARCH_PROTECT(lev);
MEM_STATS_INC(illegal);
SYS_ARCH_UNPROTECT(lev);
return rmem;
}
/* Get the corresponding struct mem ... */
mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
/* ... and its offset pointer */
ptr = (mem_size_t)((u8_t *)mem - ram);
size = mem->next - ptr - SIZEOF_STRUCT_MEM;
LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
if (newsize > size) {
/* not supported */
return NULL;
}
if (newsize == size) {
/* No change in size, simply return */
return rmem;
}
/* protect the heap from concurrent access */
LWIP_MEM_FREE_PROTECT();
mem2 = (struct mem *)(void *)&ram[mem->next];
if(mem2->used == 0) {
/* The next struct is unused, we can simply move it at little */
mem_size_t next;
/* remember the old next pointer */
next = mem2->next;
/* create new struct mem which is moved directly after the shrinked mem */
ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
if (lfree == mem2) {
lfree = (struct mem *)(void *)&ram[ptr2];
}
mem2 = (struct mem *)(void *)&ram[ptr2];
mem2->used = 0;
/* restore the next pointer */
mem2->next = next;
/* link it back to mem */
mem2->prev = ptr;
/* link mem to it */
mem->next = ptr2;
/* last thing to restore linked list: as we have moved mem2,
* let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
* the end of the heap */
if (mem2->next != MEM_SIZE_ALIGNED) {
((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
}
MEM_STATS_DEC_USED(used, (size - newsize));
/* no need to plug holes, we've already done that */
} else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
/* Next struct is used but there's room for another struct mem with
* at least MIN_SIZE_ALIGNED of data.
* Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
* ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
* @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
* region that couldn't hold data, but when mem->next gets freed,
* the 2 regions would be combined, resulting in more free memory */
ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
mem2 = (struct mem *)(void *)&ram[ptr2];
if (mem2 < lfree) {
lfree = mem2;
}
mem2->used = 0;
mem2->next = mem->next;
mem2->prev = ptr;
mem->next = ptr2;
if (mem2->next != MEM_SIZE_ALIGNED) {
((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
}
MEM_STATS_DEC_USED(used, (size - newsize));
/* the original mem->next is used, so no need to plug holes! */
}
/* else {
next struct mem is used but size between mem and mem2 is not big enough
to create another struct mem
-> don't do anyhting.
-> the remaining space stays unused since it is too small
} */
#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mem_free_count = 1;
#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
LWIP_MEM_FREE_UNPROTECT();
return rmem;
}
}
/* the datagram is not (yet?) reassembled completely */
LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
return NULL;
nullreturn:
LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
IPFRAG_STATS_INC(ip_frag.drop);
pbuf_free(p);
return NULL;
}
#endif /* IP_REASSEMBLY */
#if IP_FRAG
#if IP_FRAG_USES_STATIC_BUF
static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
#else /* IP_FRAG_USES_STATIC_BUF */
#if !LWIP_NETIF_TX_SINGLE_PBUF
/** Allocate a new struct pbuf_custom_ref */
static struct pbuf_custom_ref*
ip_frag_alloc_pbuf_custom_ref(void)
{
return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
}
/** Free a struct pbuf_custom_ref */
static void
ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
{
LWIP_ASSERT("p != NULL", p != NULL);
/**
* Adam's mem_malloc() plus solution for bug #17922
* Allocate a block of memory with a minimum of 'size' bytes.
*
* @param size is the minimum size of the requested block in bytes.
* @return pointer to allocated memory or NULL if no free memory was found.
*
* Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
*/
void *
mem_malloc(mem_size_t size)
{
mem_size_t ptr, ptr2;
struct mem *mem, *mem2;
if (size == 0) {
return NULL;
}
/* Expand the size of the allocated memory region so that we can
adjust for alignment. */
size = LWIP_MEM_ALIGN_SIZE(size);
if(size < MIN_SIZE_ALIGNED) {
/* every data block must be at least MIN_SIZE_ALIGNED long */
size = MIN_SIZE_ALIGNED;
}
if (size > MEM_SIZE_ALIGNED) {
return NULL;
}
/* protect the heap from concurrent access */
sys_arch_sem_wait(mem_sem, 0);
/* Scan through the heap searching for a free block that is big enough,
* beginning with the lowest free block.
*/
for (ptr = (u8_t *)lfree - ram; ptr < MEM_SIZE_ALIGNED - size;
ptr = ((struct mem *)&ram[ptr])->next) {
mem = (struct mem *)&ram[ptr];
if ((!mem->used) &&
(mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
/* mem is not used and at least perfect fit is possible:
* mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
/* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
* at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
* -> split large block, create empty remainder,
* remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
* mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
* struct mem would fit in but no data between mem2 and mem2->next
* @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
* region that couldn't hold data, but when mem->next gets freed,
* the 2 regions would be combined, resulting in more free memory
*/
ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
/* create mem2 struct */
mem2 = (struct mem *)&ram[ptr2];
mem2->used = 0;
mem2->next = mem->next;
mem2->prev = ptr;
/* and insert it between mem and mem->next */
mem->next = ptr2;
mem->used = 1;
if (mem2->next != MEM_SIZE_ALIGNED) {
((struct mem *)&ram[mem2->next])->prev = ptr2;
}
#if MEM_STATS
lwip_stats.mem.used += (size + SIZEOF_STRUCT_MEM);
if (lwip_stats.mem.max < lwip_stats.mem.used) {
lwip_stats.mem.max = lwip_stats.mem.used;
}
#endif /* MEM_STATS */
} else {
/* (a mem2 struct does no fit into the user data space of mem and mem->next will always
* be used at this point: if not we have 2 unused structs in a row, plug_holes should have
* take care of this).
* -> near fit or excact fit: do not split, no mem2 creation
* also can't move mem->next directly behind mem, since mem->next
* will always be used at this point!
*/
mem->used = 1;
#if MEM_STATS
lwip_stats.mem.used += mem->next - ((u8_t *)mem - ram);
if (lwip_stats.mem.max < lwip_stats.mem.used) {
lwip_stats.mem.max = lwip_stats.mem.used;
}
#endif /* MEM_STATS */
}
if (mem == lfree) {
/* Find next free block after mem and update lowest free pointer */
while (lfree->used && lfree != ram_end) {
lfree = (struct mem *)&ram[lfree->next];
}
LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
}
sys_sem_signal(mem_sem);
LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
(mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
(unsigned long)((u8_t *)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
LWIP_ASSERT("mem_malloc: sanity check alignment",
(((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
return (u8_t *)mem + SIZEOF_STRUCT_MEM;
}
}
LWIP_DEBUGF(MEM_DEBUG | 2, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
#if MEM_STATS
++lwip_stats.mem.err;
#endif /* MEM_STATS */
sys_sem_signal(mem_sem);
return NULL;
}
/**
* Create a TCP segment with prefilled header.
*
* Called by tcp_write and tcp_enqueue_flags.
*
* @param pcb Protocol control block for the TCP connection.
* @param p pbuf that is used to hold the TCP header.
* @param flags TCP flags for header.
* @param seqno TCP sequence number of this packet
* @param optflags options to include in TCP header
* @return a new tcp_seg pointing to p, or NULL.
* The TCP header is filled in except ackno and wnd.
* p is freed on failure.
*/
static struct tcp_seg *
tcp_create_segment(struct tcp_pcb *pcb, struct pbuf *p, u8_t flags, u32_t seqno, u8_t optflags)
{
struct tcp_seg *seg;
u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags);
#if LWIP_3RD_PARTY_BUFS
if ((seg = external_tcp_seg_alloc(pcb)) == NULL) {
#else
if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) {
#endif
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no memory.\n"));
tcp_tx_pbuf_free(pcb, p);
return NULL;
}
seg->flags = optflags;
seg->next = NULL;
seg->p = p;
seg->dataptr = p->payload;
seg->len = p->tot_len - optlen;
#if TCP_OVERSIZE_DBGCHECK
seg->oversize_left = 0;
#endif /* TCP_OVERSIZE_DBGCHECK */
#if TCP_CHECKSUM_ON_COPY
seg->chksum = 0;
seg->chksum_swapped = 0;
/* check optflags */
LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED",
(optflags & TF_SEG_DATA_CHECKSUMMED) == 0);
#endif /* TCP_CHECKSUM_ON_COPY */
seg->seqno = seqno;
/* build TCP header */
if (pbuf_header(p, TCP_HLEN)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no room for TCP header in pbuf.\n"));
TCP_STATS_INC(tcp.err);
tcp_tx_seg_free(pcb, seg);
return NULL;
}
seg->tcphdr = (struct tcp_hdr *)seg->p->payload;
seg->tcphdr->src = htons(pcb->local_port);
seg->tcphdr->dest = htons(pcb->remote_port);
seg->tcphdr->seqno = htonl(seqno);
/* ackno is set in tcp_output */
TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags);
/* wnd and chksum are set in tcp_output */
seg->tcphdr->urgp = 0;
return seg;
}
/**
* Allocate a PBUF_RAM pbuf, perhaps with extra space at the end.
*
* This function is like pbuf_alloc(layer, length, PBUF_RAM) except
* there may be extra bytes available at the end.
*
* @param layer flag to define header size.
* @param length size of the pbuf's payload.
* @param max_length maximum usable size of payload+oversize.
* @param oversize pointer to a u16_t that will receive the number of usable tail bytes.
* @param pcb The TCP connection that willo enqueue the pbuf.
* @param apiflags API flags given to tcp_write.
* @param first_seg true when this pbuf will be used in the first enqueued segment.
* @param
*/
static struct pbuf *
tcp_pbuf_prealloc(u16_t length, u16_t max_length,
u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags,
u8_t first_seg)
{
struct pbuf *p;
u16_t alloc = length;
if (length < max_length) {
/* Should we allocate an oversized pbuf, or just the minimum
* length required? If tcp_write is going to be called again
* before this segment is transmitted, we want the oversized
* buffer. If the segment will be transmitted immediately, we can
* save memory by allocating only length. We use a simple
* heuristic based on the following information:
*
* Did the user set TCP_WRITE_FLAG_MORE?
*
* Will the Nagle algorithm defer transmission of this segment?
*/
if ((apiflags & TCP_WRITE_FLAG_MORE) ||
(!(pcb->flags & TF_NODELAY) &&
(!first_seg ||
pcb->unsent != NULL ||
pcb->unacked != NULL))) {
alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + pcb->tcp_oversize_val));
}
}
p = tcp_tx_pbuf_alloc(pcb, alloc, PBUF_RAM);
if (p == NULL) {
return NULL;
}
LWIP_ASSERT("need unchained pbuf", p->next == NULL);
*oversize = p->len - length;
/* trim p->len to the currently used size */
p->len = p->tot_len = length;
return p;
}
/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
*
* @param pcb the tcp pcb to check for
* @param len length of data to send (checked agains snd_buf)
* @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
*/
static err_t
tcp_write_checks(struct tcp_pcb *pcb, u32_t len)
{
/* connection is in invalid state for data transmission? */
if ((get_tcp_state(pcb) != ESTABLISHED) &&
(get_tcp_state(pcb) != CLOSE_WAIT) &&
(get_tcp_state(pcb) != SYN_SENT) &&
(get_tcp_state(pcb) != SYN_RCVD)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
return ERR_CONN;
} else if (len == 0) {
return ERR_OK;
}
/* fail on too much data */
if (len > pcb->snd_buf) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U32_F" > snd_buf=%"U32_F")\n",
len, pcb->snd_buf));
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U32_F"\n", (u32_t)pcb->snd_queuelen));
/* If total number of pbufs on the unsent/unacked queues exceeds the
* configured maximum, return an error */
/* check for configured max queuelen and possible overflow */
if ((pcb->snd_queuelen >= pcb->max_unsent_len) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U32_F" (max %"U32_F")\n",
pcb->snd_queuelen, pcb->max_unsent_len));
TCP_STATS_INC(tcp.memerr);
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
if (pcb->snd_queuelen != 0) {
} else {
LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
pcb->unacked == NULL && pcb->unsent == NULL);
}
return ERR_OK;
}
/**
* Write data for sending (but does not send it immediately).
*
* It waits in the expectation of more data being sent soon (as
* it can send them more efficiently by combining them together).
* To prompt the system to send data now, call tcp_output() after
* calling tcp_write().
*
* @param pcb Protocol control block for the TCP connection to enqueue data for.
* @param arg Pointer to the data to be enqueued for sending.
* @param len Data length in bytes
* @param apiflags combination of following flags :
* - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack
* - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent,
* @return ERR_OK if enqueued, another err_t on error
*/
err_t
tcp_write(struct tcp_pcb *pcb, const void *arg, u32_t len, u8_t apiflags)
{
struct pbuf *concat_p = NULL;
struct tcp_seg *seg = NULL, *prev_seg = NULL, *queue = NULL;
u32_t pos = 0; /* position in 'arg' data */
u32_t queuelen;
u8_t optlen = 0;
u8_t optflags = 0;
#if TCP_OVERSIZE
u16_t oversize = 0;
u16_t oversize_used = 0;
#endif /* TCP_OVERSIZE */
#if TCP_CHECKSUM_ON_COPY
u16_t concat_chksum = 0;
u8_t concat_chksum_swapped = 0;
u16_t concat_chksummed = 0;
#endif /* TCP_CHECKSUM_ON_COPY */
err_t err;
/* don't allocate segments bigger than half the maximum window we ever received */
u16_t mss_local = LWIP_MIN(pcb->mss, pcb->snd_wnd_max/2);
mss_local = mss_local ? mss_local : pcb->mss;
int byte_queued = pcb->snd_nxt - pcb->lastack;
if ( len < pcb->mss)
pcb->snd_sml_add = (pcb->unacked ? pcb->unacked->len : 0) + byte_queued;
#if LWIP_NETIF_TX_SINGLE_PBUF
/* Always copy to try to create single pbufs for TX */
apiflags |= TCP_WRITE_FLAG_COPY;
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
(void *)pcb, arg, len, (u16_t)apiflags));
LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
arg != NULL, return ERR_ARG;);
err = tcp_write_checks(pcb, len);
if (err != ERR_OK) {
return err;
}
queuelen = pcb->snd_queuelen;
#if LWIP_TCP_TIMESTAMPS
if ((pcb->flags & TF_TIMESTAMP)) {
optflags = TF_SEG_OPTS_TS;
/* ensure that segments can hold at least one data byte... */
mss_local = LWIP_MAX(mss_local, LWIP_TCP_OPT_LEN_TS + 1);
}
#endif /* LWIP_TCP_TIMESTAMPS */
optlen = LWIP_TCP_OPT_LENGTH( optflags );
/*
* TCP segmentation is done in three phases with increasing complexity:
*
* 1. Copy data directly into an oversized pbuf.
* 2. Chain a new pbuf to the end of pcb->unsent.
* 3. Create new segments.
*
* We may run out of memory at any point. In that case we must
* return ERR_MEM and not change anything in pcb. Therefore, all
* changes are recorded in local variables and committed at the end
* of the function. Some pcb fields are maintained in local copies:
*
* queuelen = pcb->snd_queuelen
* oversize = pcb->unsent_oversize
*
* These variables are set consistently by the phases:
*
* seg points to the last segment tampered with.
*
* pos records progress as data is segmented.
*/
/* Find the tail of the unsent queue. */
if (pcb->unsent != NULL) {
u16_t space;
u16_t unsent_optlen;
if (!pcb->last_unsent || pcb->last_unsent->next) {
/* @todo: this could be sped up by keeping last_unsent in the pcb */
for (pcb->last_unsent = pcb->unsent; pcb->last_unsent->next != NULL;
pcb->last_unsent = pcb->last_unsent->next);
}
/* Usable space at the end of the last unsent segment */
unsent_optlen = LWIP_TCP_OPT_LENGTH(pcb->last_unsent->flags);
LWIP_ASSERT("mss_local is too small", mss_local >= pcb->last_unsent->len + unsent_optlen);
space = mss_local - (pcb->last_unsent->len + unsent_optlen);
/*
* Phase 1: Copy data directly into an oversized pbuf.
*
* The number of bytes copied is recorded in the oversize_used
* variable. The actual copying is done at the bottom of the
* function.
*/
#if TCP_OVERSIZE
#if TCP_OVERSIZE_DBGCHECK
/* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
pcb->unsent_oversize == pcb->last_unsent->oversize_left);
#endif /* TCP_OVERSIZE_DBGCHECK */
oversize = pcb->unsent_oversize;
if (oversize > 0) {
LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
seg = pcb->last_unsent;
oversize_used = oversize < len ? oversize : len;
pos += oversize_used;
oversize -= oversize_used;
space -= oversize_used;
}
/* now we are either finished or oversize is zero */
LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len));
#endif /* TCP_OVERSIZE */
/*
* Phase 2: Chain a new pbuf to the end of pcb->unsent.
*
* We don't extend segments containing SYN/FIN flags or options
* (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at
* the end.
*/
if ((pos < len) && (space > 0) && (pcb->last_unsent->len > 0)) {
u16_t seglen = space < len - pos ? space : len - pos;
seg = pcb->last_unsent;
/* Create a pbuf with a copy or reference to seglen bytes. We
* can use PBUF_RAW here since the data appears in the middle of
* a segment. A header will never be prepended. */
if (apiflags & TCP_WRITE_FLAG_COPY) {
/* Data is copied */
if ((concat_p = tcp_pbuf_prealloc(seglen, space, &oversize, pcb, apiflags, 1)) == NULL) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n",
seglen));
goto memerr;
}
#if TCP_OVERSIZE_DBGCHECK
pcb->last_unsent->oversize_left += oversize;
#endif /* TCP_OVERSIZE_DBGCHECK */
TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
#if TCP_CHECKSUM_ON_COPY
concat_chksummed += seglen;
#endif /* TCP_CHECKSUM_ON_COPY */
} else {
LWIP_ASSERT("tcp_write : we are never here", 0);
goto memerr;
}
pos += seglen;
queuelen += pbuf_clen(concat_p);
}
} else {
#if TCP_OVERSIZE
pcb->last_unsent = NULL;
LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)",
pcb->unsent_oversize == 0);
#endif /* TCP_OVERSIZE */
}
/*
* Phase 3: Create new segments.
*
* The new segments are chained together in the local 'queue'
* variable, ready to be appended to pcb->unsent.
*/
while (pos < len) {
struct pbuf *p;
u32_t left = len - pos;
u16_t max_len = mss_local - optlen;
u16_t seglen = left > max_len ? max_len : left;
if (apiflags & TCP_WRITE_FLAG_COPY) {
/* If copy is set, memory should be allocated and data copied
* into pbuf */
if ((p = tcp_pbuf_prealloc(seglen + optlen, mss_local, &oversize, pcb, apiflags, queue == NULL)) == NULL) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen));
goto memerr;
}
LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen",
(p->len >= seglen));
TCP_DATA_COPY2((char *)p->payload + optlen, (u8_t*)arg + pos, seglen, &chksum, &chksum_swapped);
} else {
LWIP_ASSERT("tcp_write: we are never here",0);
goto memerr;
}
queuelen += pbuf_clen(p);
/* Now that there are more segments queued, we check again if the
* length of the queue exceeds the configured maximum or
* overflows. */
if ((queuelen > pcb->max_unsent_len) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: queue too long %"U32_F" (%"U32_F")\n", queuelen, pcb->max_unsent_len));
tcp_tx_pbuf_free(pcb, p);
goto memerr;
}
if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) {
goto memerr;
}
#if TCP_OVERSIZE_DBGCHECK
seg->oversize_left = oversize;
#endif /* TCP_OVERSIZE_DBGCHECK */
#if TCP_CHECKSUM_ON_COPY
seg->chksum = chksum;
seg->chksum_swapped = chksum_swapped;
seg->flags |= TF_SEG_DATA_CHECKSUMMED;
#endif /* TCP_CHECKSUM_ON_COPY */
/* Fix dataptr for the nocopy case */
if ((apiflags & TCP_WRITE_FLAG_COPY) == 0) {
seg->dataptr = (u8_t*)arg + pos;
}
/* first segment of to-be-queued data? */
if (queue == NULL) {
queue = seg;
} else {
/* Attach the segment to the end of the queued segments */
LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL);
prev_seg->next = seg;
}
/* remember last segment of to-be-queued data for next iteration */
prev_seg = seg;
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n",
ntohl(seg->tcphdr->seqno),
ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
pos += seglen;
}
/*
* All three segmentation phases were successful. We can commit the
* transaction.
*/
/*
* Phase 1: If data has been added to the preallocated tail of
* last_unsent, we update the length fields of the pbuf chain.
*/
#if TCP_OVERSIZE
if (oversize_used > 0) {
struct pbuf *p;
/* Bump tot_len of whole chain, len of tail */
for (p = pcb->last_unsent->p; p; p = p->next) {
p->tot_len += oversize_used;
if (p->next == NULL) {
TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, pcb->last_unsent);
p->len += oversize_used;
}
}
pcb->last_unsent->len += oversize_used;
#if TCP_OVERSIZE_DBGCHECK
pcb->last_unsent->oversize_left -= oversize_used;
#endif /* TCP_OVERSIZE_DBGCHECK */
}
pcb->unsent_oversize = oversize;
#endif /* TCP_OVERSIZE */
/*
* Phase 2: concat_p can be concatenated onto pcb->last_unsent->p
*/
if (concat_p != NULL) {
LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty",
(pcb->last_unsent != NULL));
pbuf_cat(pcb->last_unsent->p, concat_p);
pcb->last_unsent->len += concat_p->tot_len;
#if TCP_CHECKSUM_ON_COPY
if (concat_chksummed) {
tcp_seg_add_chksum(concat_chksum, concat_chksummed, &pcb->last_unsent->chksum,
&pcb->last_unsent->chksum_swapped);
pcb->last_unsent->flags |= TF_SEG_DATA_CHECKSUMMED;
}
#endif /* TCP_CHECKSUM_ON_COPY */
}
/*
* Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that
* is harmless
*/
if (pcb->last_unsent == NULL) {
pcb->unsent = queue;
} else {
pcb->last_unsent->next = queue;
}
pcb->last_unsent = seg;
/*
* Finally update the pcb state.
*/
pcb->snd_lbb += len;
pcb->snd_buf -= len;
pcb->snd_queuelen = queuelen;
LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n",
pcb->snd_queuelen));
if (pcb->snd_queuelen != 0) {
LWIP_ASSERT("tcp_write: valid queue length",
pcb->unacked != NULL || pcb->unsent != NULL);
}
/* Set the PSH flag in the last segment that we enqueued. */
if (seg != NULL && seg->tcphdr != NULL) {
TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
}
return ERR_OK;
memerr:
pcb->flags |= TF_NAGLEMEMERR;
TCP_STATS_INC(tcp.memerr);
if (concat_p != NULL) {
tcp_tx_pbuf_free(pcb, concat_p);
}
if (queue != NULL) {
tcp_tx_segs_free(pcb, queue);
}
if (pcb->snd_queuelen != 0) {
LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL ||
pcb->unsent != NULL);
}
LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen));
return ERR_MEM;
}
static struct pbuf* low_level_input(struct netif *netif) {
u16_t l, temp_l;
struct pbuf *first_pbuf, *next_pbuf, *q;
u16_t len;
#ifdef ENET_LITTLE_ENDIAN
u8_t *data_temp;
#endif
u8_t more_pkts = 1, processing_error = 0;
(void)netif;
/* initial pkt handling */
if (!(rx_bd[rx_next_buf].status & ENET_RX_BD_E)) { /* if pkt is filled */
if (rx_bd[rx_next_buf].status & ENET_RX_BD_L) {
more_pkts = 0;
if (rx_bd[rx_next_buf].status & (ENET_RX_BD_LG | ENET_RX_BD_NO | ENET_RX_BD_CR | ENET_RX_BD_OV)) {
/* bad packet */
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
goto EXIT_RX_PKT;
}
else {
#ifdef ENET_LITTLE_ENDIAN
len = __REVSH(rx_bd[rx_next_buf].length);
#else
len = rx_bd[rx_next_buf].length;
#endif
LINK_STATS_INC(link.recv);
}
}
else /* if not L bit, then buffer's length */
len = ENET_RX_BUF_SIZE;
if ((first_pbuf = pbuf_alloc(PBUF_RAW, len, PBUF_POOL)) != NULL) {
/* get data */
l = 0;
temp_l = 0;
/* We iterate over the pbuf chain until we have read the entire
* packet into the pbuf. */
for (q = first_pbuf; q != NULL; q = q->next) {
/* Read enough bytes to fill this pbuf in the chain. The
* available data in the pbuf is given by the q->len
* variable.
* This does not necessarily have to be a memcpy, you can also preallocate
* pbufs for a DMA-enabled MAC and after receiving truncate it to the
* actually received size. In this case, ensure the tot_len member of the
* pbuf is the sum of the chained pbuf len members.
*/
temp_l = LWIP_MIN(len, LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE));
#ifdef ENET_LITTLE_ENDIAN
data_temp = (u8_t *)__REV((u32_t)rx_bd[ rx_next_buf ].data);
memcpy((u8_t*)q->payload, &( data_temp[l] ), temp_l);
#else
memcpy((u8_t*)q->payload, &( rx_bd[ rx_next_buf ].data[l] ), temp_l);
#endif
l += temp_l;
len -= temp_l;
}
}
else {
/* bad buffers */
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
processing_error = 1;
}
EXIT_RX_PKT:
rx_bd[rx_next_buf++].status |= ENET_RX_BD_E; /* consumed pkt */
ENET_RDAR = ENET_RDAR_RDAR_MASK;
if (rx_next_buf >= NUM_ENET_RX_BUFS)
rx_next_buf = 0;
}
else
return (struct pbuf*)NULL; /* special NULL case */
/* more pkts handling */
while (more_pkts) {
//if(!(rx_bd[ rx_next_buf ].status & RX_BD_E) )
///*if pkt is filled*/
//{
if (rx_bd[rx_next_buf].status & ENET_RX_BD_L) {
more_pkts = 0;
if (rx_bd[rx_next_buf].status & (ENET_RX_BD_LG | ENET_RX_BD_NO | ENET_RX_BD_CR | ENET_RX_BD_OV)) {
/* bad packet */
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
goto EXIT_RX_PKT2;
}
else {
#ifdef ENET_LITTLE_ENDIAN
len = __REVSH(rx_bd[rx_next_buf].length);
#else
len = rx_bd[rx_next_buf].length;
#endif
/* buffer with L bit has total frame's length instead of remaining bytes from frame's lenght */
len %= ENET_RX_BUF_SIZE;
LINK_STATS_INC(link.recv);
}
}
else /* if not L bit, then buffer's length */
len = ENET_RX_BUF_SIZE;
if (((next_pbuf = pbuf_alloc(PBUF_RAW, len, PBUF_POOL)) != NULL) && (!processing_error)) {
/* get data */
l = 0;
temp_l = 0;
/* We iterate over the pbuf chain until we have read the entire
* packet into the pbuf. */
for (q = next_pbuf; q != NULL; q = q->next) {
/* Read enough bytes to fill this pbuf in the chain. The
* available data in the pbuf is given by the q->len
* variable.
* This does not necessarily have to be a memcpy, you can also preallocate
* pbufs for a DMA-enabled MAC and after receiving truncate it to the
* actually received size. In this case, ensure the tot_len member of the
* pbuf is the sum of the chained pbuf len members.
*/
temp_l = LWIP_MIN(len, LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE));
#ifdef ENET_LITTLE_ENDIAN
data_temp = (u8_t *)__REV((u32_t)rx_bd[rx_next_buf].data);
memcpy((u8_t*)q->payload, &(data_temp[l]), temp_l);
#else
memcpy((u8_t*)q->payload, &(rx_bd[rx_next_buf].data[l] ), temp_l);
#endif
l += temp_l;
len -= temp_l;
}
/* link pbufs */
pbuf_cat(first_pbuf, next_pbuf);
}
else {
/* bad buffer - out of lwip buffers */
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
processing_error = 1;
}
EXIT_RX_PKT2:
rx_bd[rx_next_buf++].status |= ENET_RX_BD_E; /* consumed pkt */
ENET_RDAR = ENET_RDAR_RDAR_MASK;
if (rx_next_buf >= NUM_ENET_RX_BUFS)
rx_next_buf = 0;
}
return first_pbuf;
}
/**
* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
*
* The actual memory allocated for the pbuf is determined by the
* layer at which the pbuf is allocated and the requested size
* (from the size parameter).
*
* @param layer flag to define header size
* @param length size of the pbuf's payload
* @param type this parameter decides how and where the pbuf
* should be allocated as follows:
*
* - PBUF_RAM: buffer memory for pbuf is allocated as one large
* chunk. This includes protocol headers as well.
* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
* protocol headers. Additional headers must be prepended
* by allocating another pbuf and chain in to the front of
* the ROM pbuf. It is assumed that the memory used is really
* similar to ROM in that it is immutable and will not be
* changed. Memory which is dynamic should generally not
* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
* protocol headers. It is assumed that the pbuf is only
* being used in a single thread. If the pbuf gets queued,
* then pbuf_take should be called to copy the buffer.
* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
* the pbuf pool that is allocated during pbuf_init().
*
* @return the allocated pbuf. If multiple pbufs where allocated, this
* is the first pbuf of a pbuf chain.
*/
struct pbuf *
pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
{
struct pbuf *p, *q, *r;
u16_t offset;
s32_t rem_len; /* remaining length */
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
/* determine header offset */
offset = 0;
switch (layer) {
case PBUF_TRANSPORT:
/* add room for transport (often TCP) layer header */
offset += PBUF_TRANSPORT_HLEN;
/* FALLTHROUGH */
case PBUF_IP:
/* add room for IP layer header */
offset += PBUF_IP_HLEN;
/* FALLTHROUGH */
case PBUF_LINK:
/* add room for link layer header */
offset += PBUF_LINK_HLEN;
#ifdef PBUF_RSV_FOR_WLAN
/*
* 1. LINK_HLEN 14Byte will be remove in WLAN layer
* 2. IEEE80211_HDR_MAX_LEN needs 40 bytes.
* 3. encryption needs exra 4 bytes ahead of actual data payload, and require
* DAddr and SAddr to be 4-byte aligned.
* 4. TRANSPORT and IP are all 20, 4 bytes aligned, nice...
* 5. LCC add 6 bytes more, We don't consider WAPI yet...
* 6. define LWIP_MEM_ALIGN to be 4 Byte aligned, pbuf struct is 16B, Only thing may be
* matter is ether_hdr is not 4B aligned.
*
* So, we need extra (40 + 4 - 14) = 30 and it's happen to be 4-Byte aligned
*
* 1. lwip
* | empty 30B | eth_hdr (14B) | payload ...|
* total: 44B ahead payload
* 2. net80211
* | max 80211 hdr, 32B | ccmp/tkip iv (8B) | sec rsv(4B) | payload ...|
* total: 40B ahead sec_rsv and 44B ahead payload
*
*/
offset += EP_OFFSET; //remove LINK hdr in wlan
#endif /* PBUF_RSV_FOR_WLAN */
break;
case PBUF_RAW:
#ifdef PBUF_RSV_FOR_WLAN
/*
* RAW pbuf suppose
*/
offset += EP_OFFSET; //remove LINK hdr in wlan
#endif /* PBUF_RAW */
break;
default:
LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
return NULL;
}
switch (type) {
case PBUF_POOL:
/* allocate head of pbuf chain into p */
p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
if (p == NULL) {
PBUF_POOL_IS_EMPTY();
return NULL;
}
p->type = type;
p->next = NULL;
/* make the payload pointer point 'offset' bytes into pbuf data memory */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
/* the total length of the pbuf chain is the requested size */
p->tot_len = length;
/* set the length of the first pbuf in the chain */
p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
/* set reference count (needed here in case we fail) */
p->ref = 1;
/* now allocate the tail of the pbuf chain */
/* remember first pbuf for linkage in next iteration */
r = p;
/* remaining length to be allocated */
rem_len = length - p->len;
/* any remaining pbufs to be allocated? */
while (rem_len > 0) {
q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
if (q == NULL) {
PBUF_POOL_IS_EMPTY();
/* free chain so far allocated */
pbuf_free(p);
/* bail out unsuccesfully */
return NULL;
}
q->type = type;
q->flags = 0;
q->next = NULL;
/* make previous pbuf point to this pbuf */
r->next = q;
/* set total length of this pbuf and next in chain */
LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
q->tot_len = (u16_t)rem_len;
/* this pbuf length is pool size, unless smaller sized tail */
q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
q->ref = 1;
/* calculate remaining length to be allocated */
rem_len -= q->len;
/* remember this pbuf for linkage in next iteration */
r = q;
}
/* end of chain */
/*r->next = NULL;*/
break;
case PBUF_RAM:
/* If pbuf is to be allocated in RAM, allocate memory for it. */
p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
if (p == NULL) {
return NULL;
}
/* Set up internal structure of the pbuf. */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
p->eb = NULL;
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
break;
#ifdef EBUF_LWIP
case PBUF_ESF_RX:
#endif /* ESF_LWIP */
/* pbuf references existing (non-volatile static constant) ROM payload? */
case PBUF_ROM:
/* pbuf references existing (externally allocated) RAM payload? */
case PBUF_REF:
/* only allocate memory for the pbuf structure */
p = (struct pbuf *)memp_malloc(MEMP_PBUF);
if (p == NULL) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
(type == PBUF_ROM) ? "ROM" : "REF"));
return NULL;
}
/* caller must set this field properly, afterwards */
p->payload = NULL;
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
break;
default:
LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
return NULL;
}
/* set reference count */
p->ref = 1;
/* set flags */
p->flags = 0;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
return p;
}
/* layer是pbuf_layer类型，预留不同的首部空间。可以是
* PBUF_TRANSPORT,
* PBUF_IP,
* PBUF_LINK,
* PBUF_RAW
* length是要申请的数据区长度
* type是要申请的pbuf类型，可以是
* PBUF_RAM
* PBUF_ROM
* PBUF_REF
* PBUF_POOL
*/
struct pbuf *
pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
{
struct pbuf *p, *q, *r;
u16_t offset;
s32_t rem_len; /* remaining length */
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
/* determine header offset */
offset = 0;
/* 根据申请层次不同，选择不同的预留空间 */
switch (layer) {
/* 传输层预留TCP首部空间，注意这里没有break;，继续累加 */
case PBUF_TRANSPORT:
/* add room for transport (often TCP) layer header */
offset += PBUF_TRANSPORT_HLEN;
/* FALLTHROUGH */
/* 预留网络层首部空间 */
case PBUF_IP:
/* add room for IP layer header */
offset += PBUF_IP_HLEN;
/* FALLTHROUGH */
/* 预留链路层首部空间 */
case PBUF_LINK:
/* add room for link layer header */
offset += PBUF_LINK_HLEN;
break;
/* 不预留首部空间 */
case PBUF_RAW:
break;
/* 层次参数错误，返回错误信息 */
default:
LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
return NULL;
}
/* 根据要申请的type，分配具体类型的pbuf */
switch (type) {
/* 在内存池分配pbuf和数据区
* PBUF_POOL类型可能需要分配多个MEMP_PBUF_POOL，以满足申请的空间
*/
case PBUF_POOL:
/* allocate head of pbuf chain into p */
/* MEMP_PBUF_POOL申请的大小是pbuf结构+PBUF_POOL_BUFSIZE。
* PBUF_POOL_BUFSIZE是1460(TCP的MSS)+20+20+14=1514， */
p = memp_malloc(MEMP_PBUF_POOL);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
/* 分配失败，则返回NULL */
if (p == NULL) {
PBUF_POOL_IS_EMPTY();
return NULL;
}
/* 初始化type和next字段 */
p->type = type;
p->next = NULL;
/* make the payload pointer point 'offset' bytes into pbuf data memory */
/* 设置数据字段指针，预留出pbuf和offset大小 */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
/* the total length of the pbuf chain is the requested size */
/* 设置pbuf链表第一个pbuf中的tot_len字段 */
p->tot_len = length;
/* set the length of the first pbuf in the chain */
/* 第一个pbuf中的数据段长度是PBUF_POOL_BUFSIZE(1514) - 预留大小 */
p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
/* set reference count (needed here in case we fail) */
/* 引用次数设为1 */
p->ref = 1;
/* now allocate the tail of the pbuf chain */
/* 检查分配的第一个pbuf空间是否满足申请的length，不满足则继续申请，构造
* pbuf链表
*/
/* remember first pbuf for linkage in next iteration */
/* r是pbuf上最后一个节点指针，用于把新节点放入链表
* p是pbuf链表头节点指针
*/
r = p;
/* remaining length to be allocated */
/* 还需申请的空间 */
rem_len = length - p->len;
/* any remaining pbufs to be allocated? */
/* 仍然需要申请 */
while (rem_len > 0) {
/* 申请新的pbuf，包括pbuf结构大小+1514 */
q = memp_malloc(MEMP_PBUF_POOL);
/* 申请失败，则释放pbuf链表所有节点 */
if (q == NULL) {
PBUF_POOL_IS_EMPTY();
/* free chain so far allocated */
pbuf_free(p);
/* bail out unsuccesfully */
return NULL;
}
/* 设置新申请节点的类型 */
q->type = type;
q->flags = 0;
/* 新节点next指针设为0 */
q->next = NULL;
/* make previous pbuf point to this pbuf */
/* 新节点放入链表 */
r->next = q;
/* set total length of this pbuf and next in chain */
LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
/* 新节点和后续所有所有节点数据段总长度 */
q->tot_len = (u16_t)rem_len;
/* this pbuf length is pool size, unless smaller sized tail */
/* 新节点本身数据段长度
* 新节点数据段可承载的最大长度可能大于要申请的长度，
* 所以len要设置为实际申请的长度和最大长度的最小值
*/
q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
/* 新节点的数据段指针 */
q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
((u8_t*)p->payload + p->len <=
(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
/* 新节点引用次数 */
q->ref = 1;
/* 还需申请的长度 */
/* calculate remaining length to be allocated */
rem_len -= q->len;
/* remember this pbuf for linkage in next iteration */
/* 保存pbuf最后一个节点指针 */
r = q;
}
/* end of chain */
/*r->next = NULL;*/
break;
/* 在内存堆分配pbuf结构和数据区域 */
case PBUF_RAM:
/* If pbuf is to be allocated in RAM, allocate memory for it. */
/* 申请总大小是pbuf结构大小+offset+数据区域大小 */
p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
if (p == NULL) {
/* 申请失败，则返回NULL */
return NULL;
}
/* Set up internal structure of the pbuf. */
/* 设置pbuf的数据区指针 */
p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
/* 从内存堆分配的pbuf只需要一个，不需要链表。因为第一个节点就可以获得要申请的数据区长度
* 数据区总长度 */
p->len = p->tot_len = length;
/* 仅有一个节点 */
p->next = NULL;
p->type = type;
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
break;
/* pbuf references existing (non-volatile static constant) ROM payload? */
/* PBUF_ROM和PBUF_REF类型，只分配PBUF结构，payload指向的数据区不需申请 */
case PBUF_ROM:
/* pbuf references existing (externally allocated) RAM payload? */
case PBUF_REF:
/* only allocate memory for the pbuf structure */
/* 从内存池中申请MEMP_PBUF类型的内存，详见memp_std.h */
p = memp_malloc(MEMP_PBUF);
/* 申请失败，则返回NULL */
if (p == NULL) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
(type == PBUF_ROM) ? "ROM" : "REF"));
return NULL;
}
/* 设置pbuf结构字段 */
/* caller must set this field properly, afterwards */
/* PBUF_ROM和PBUF_REF类型的pbuf，必须由调用者设置payload字段 */
p->payload = NULL;
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
break;
default:
LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
return NULL;
}
/* set reference count */
/* 除了PBUF_POOL类型，都没有设置ref。在这里同一设置ref */
p->ref = 1;
/* set flags */
p->flags = 0;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
return p;
}
/**
* @ingroup pbuf
* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
*
* The actual memory allocated for the pbuf is determined by the
* layer at which the pbuf is allocated and the requested size
* (from the size parameter).
*
* @param layer header size
* @param length size of the pbuf's payload
* @param type this parameter decides how and where the pbuf
* should be allocated as follows:
*
* - PBUF_RAM: buffer memory for pbuf is allocated as one large
* chunk. This includes protocol headers as well.
* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
* protocol headers. Additional headers must be prepended
* by allocating another pbuf and chain in to the front of
* the ROM pbuf. It is assumed that the memory used is really
* similar to ROM in that it is immutable and will not be
* changed. Memory which is dynamic should generally not
* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
* protocol headers. It is assumed that the pbuf is only
* being used in a single thread. If the pbuf gets queued,
* then pbuf_take should be called to copy the buffer.
* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
* the pbuf pool that is allocated during pbuf_init().
*
* @return the allocated pbuf. If multiple pbufs where allocated, this
* is the first pbuf of a pbuf chain.
*/
struct pbuf *
pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
{
struct pbuf *p;
u16_t offset = (u16_t)layer;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
switch (type) {
case PBUF_REF: /* fall through */
case PBUF_ROM:
p = pbuf_alloc_reference(NULL, length, type);
break;
case PBUF_POOL: {
struct pbuf *q, *last;
u16_t rem_len; /* remaining length */
p = NULL;
last = NULL;
rem_len = length;
do {
u16_t qlen;
q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
if (q == NULL) {
PBUF_POOL_IS_EMPTY();
/* free chain so far allocated */
if (p) {
pbuf_free(p);
}
/* bail out unsuccessfully */
return NULL;
}
qlen = LWIP_MIN(rem_len, (u16_t)(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)));
pbuf_init_alloced_pbuf(q, LWIP_MEM_ALIGN((void *)((u8_t *)q + SIZEOF_STRUCT_PBUF + offset)),
rem_len, qlen, type, 0);
LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
if (p == NULL) {
/* allocated head of pbuf chain (into p) */
p = q;
} else {
/* make previous pbuf point to this pbuf */
last->next = q;
}
last = q;
rem_len = (u16_t)(rem_len - qlen);
offset = 0;
} while (rem_len > 0);
break;
}
case PBUF_RAM: {
u16_t payload_len = (u16_t)(LWIP_MEM_ALIGN_SIZE(offset) + LWIP_MEM_ALIGN_SIZE(length));
mem_size_t alloc_len = (mem_size_t)(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF) + payload_len);
/* bug #50040: Check for integer overflow when calculating alloc_len */
if ((payload_len < LWIP_MEM_ALIGN_SIZE(length)) ||
(alloc_len < LWIP_MEM_ALIGN_SIZE(length))) {
return NULL;
}
/* If pbuf is to be allocated in RAM, allocate memory for it. */
p = (struct pbuf *)mem_malloc(alloc_len);
if (p == NULL) {
return NULL;
}
pbuf_init_alloced_pbuf(p, LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset)),
length, length, type, 0);
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
break;
}
default:
LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
return NULL;
}
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
return p;
}
/**
* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
*
* The actual memory allocated for the pbuf is determined by the
* layer at which the pbuf is allocated and the requested size
* (from the size parameter).
*
* @param layer flag to define header size
* @param length size of the pbuf's payload
* @param type this parameter decides how and where the pbuf
* should be allocated as follows:
*
* - PBUF_RAM: buffer memory for pbuf is allocated as one large
* chunk. This includes protocol headers as well.
* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
* protocol headers. Additional headers must be prepended
* by allocating another pbuf and chain in to the front of
* the ROM pbuf. It is assumed that the memory used is really
* similar to ROM in that it is immutable and will not be
* changed. Memory which is dynamic should generally not
* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
* protocol headers. It is assumed that the pbuf is only
* being used in a single thread. If the pbuf gets queued,
* then pbuf_take should be called to copy the buffer.
* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
* the pbuf pool that is allocated during pbuf_init().
*
* @return the allocated pbuf. If multiple pbufs where allocated, this
* is the first pbuf of a pbuf chain.
*/
struct pbuf *pbuf_alloc(pbuf_layer layer, uint16_t length, pbuf_type type)
{
struct pbuf *p, *q, *r;
uint16_t offset;
int32_t rem_len; /* remaining length */
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%" U16_F ")\n", length));
/* determine header offset */
switch (layer) {
case PBUF_TRANSPORT:
/* add room for transport (often TCP) layer header */
offset = PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN;
break;
case PBUF_IP:
/* add room for IP layer header */
offset = PBUF_LINK_HLEN + PBUF_IP_HLEN;
break;
case PBUF_LINK:
/* add room for link layer header */
offset = PBUF_LINK_HLEN;
break;
case PBUF_RAW:
offset = 0;
break;
default:
return NULL;
}
switch (type) {
case PBUF_POOL:
/* allocate head of pbuf chain into p */
p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
if (p == NULL) {
PBUF_POOL_IS_EMPTY();
return NULL;
}
p->type = type;
p->next = NULL;
/* make the payload pointer point 'offset' bytes into pbuf data memory */
p->payload = LWIP_MEM_ALIGN((void *)((uint8_t *) p + (SIZEOF_STRUCT_PBUF + offset)));
/* the total length of the pbuf chain is the requested size */
p->tot_len = length;
/* set the length of the first pbuf in the chain */
p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
/* set reference count (needed here in case we fail) */
p->ref = 1;
/* now allocate the tail of the pbuf chain */
/* remember first pbuf for linkage in next iteration */
r = p;
/* remaining length to be allocated */
rem_len = length - p->len;
/* any remaining pbufs to be allocated? */
while (rem_len > 0) {
q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
if (q == NULL) {
PBUF_POOL_IS_EMPTY();
/* free chain so far allocated */
pbuf_free(p);
/* bail out unsuccesfully */
return NULL;
}
q->type = type;
q->flags = 0;
q->next = NULL;
/* make previous pbuf point to this pbuf */
r->next = q;
/* set total length of this pbuf and next in chain */
q->tot_len = (uint16_t) rem_len;
/* this pbuf length is pool size, unless smaller sized tail */
q->len = LWIP_MIN((uint16_t) rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
q->payload = (void *)((uint8_t *) q + SIZEOF_STRUCT_PBUF);
q->ref = 1;
/* calculate remaining length to be allocated */
rem_len -= q->len;
/* remember this pbuf for linkage in next iteration */
r = q;
}
/* end of chain */
/*r->next = NULL; */
break;
case PBUF_RAM:
/* If pbuf is to be allocated in RAM, allocate memory for it. */
p = (struct pbuf *)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
if (p == NULL) {
return NULL;
}
/* Set up internal structure of the pbuf. */
p->payload = LWIP_MEM_ALIGN((void *)((uint8_t *) p + SIZEOF_STRUCT_PBUF + offset));
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
break;
/* pbuf references existing (non-volatile static constant) ROM payload? */
case PBUF_ROM:
/* pbuf references existing (externally allocated) RAM payload? */
case PBUF_REF:
/* only allocate memory for the pbuf structure */
p = (struct pbuf *)memp_malloc(MEMP_PBUF);
if (p == NULL) {
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n", (type == PBUF_ROM) ? "ROM" : "REF"));
return NULL;
}
/* caller must set this field properly, afterwards */
p->payload = NULL;
p->len = p->tot_len = length;
p->next = NULL;
p->type = type;
break;
default:
return NULL;
}
/* set reference count */
p->ref = 1;
/* set flags */
p->flags = 0;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%" U16_F ") == %p\n", length, (void *)p));
return p;
}
