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pbuf: Add pbuf_copy_partial_pbuf library function

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Like pbuf_copy, but can copy part of a pbuf to an offset in another.
pbuf_copy now uses this function internally.

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>
This commit is contained in:
Erik Ekman 2020-07-03 18:55:02 +02:00 committed by Simon Goldschmidt
parent 1c6202c414
commit 843a116155
2 changed files with 46 additions and 11 deletions
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56
src/core/pbuf.c
View File

@ -960,54 +960,88 @@ pbuf_dechain(struct pbuf *p)
err_t
pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from)
{
size_t offset_to = 0, offset_from = 0, len;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
(const void *)p_to, (const void *)p_from));
LWIP_ERROR("pbuf_copy: invalid source", p_from != NULL, return ERR_ARG;);
return pbuf_copy_partial_pbuf(p_to, p_from, p_from->tot_len, 0);
}
/**
* @ingroup pbuf
* Copy part or all of one packet buffer into another, to a specified offset.
*
* @note Only data in one packet is copied, no packet queue!
* @note Argument order is shared with pbuf_copy, but different than pbuf_copy_partial.
*
* @param p_to pbuf destination of the copy
* @param p_from pbuf source of the copy
* @param copy_len number of bytes to copy
* @param offset offset in destination pbuf where to copy to
*
* @return ERR_OK if copy_len bytes were copied
* ERR_ARG if one of the pbufs is NULL or p_from is shorter than copy_len
* or p_to is not big enough to hold copy_len at offset
* ERR_VAL if any of the pbufs are part of a queue
*/
err_t
pbuf_copy_partial_pbuf(struct pbuf *p_to, const struct pbuf *p_from, u16_t copy_len, u16_t offset)
{
size_t offset_to = offset, offset_from = 0, len_calc;
u16_t len;
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy_partial_pbuf(%p, %p, %"U16_F", %"U16_F")\n",
(const void *)p_to, (const void *)p_from, copy_len, offset));
/* is the copy_len in range? */
LWIP_ERROR("pbuf_copy_partial_pbuf: copy_len bigger than source", ((p_from != NULL) &&
(p_from->tot_len >= copy_len)), return ERR_ARG;);
/* is the target big enough to hold the source? */
LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
LWIP_ERROR("pbuf_copy_partial_pbuf: target not big enough", ((p_to != NULL) &&
(p_to->tot_len >= (offset + copy_len))), return ERR_ARG;);
/* iterate through pbuf chain */
do {
/* copy one part of the original chain */
if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
/* complete current p_from fits into current p_to */
len = p_from->len - offset_from;
len_calc = p_from->len - offset_from;
} else {
/* current p_from does not fit into current p_to */
len = p_to->len - offset_to;
len_calc = p_to->len - offset_to;
}
len = (u16_t)LWIP_MIN(copy_len, len_calc);
MEMCPY((u8_t *)p_to->payload + offset_to, (u8_t *)p_from->payload + offset_from, len);
offset_to += len;
offset_from += len;
copy_len -= len;
LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
if (offset_from >= p_from->len) {
/* on to next p_from (if any) */
offset_from = 0;
p_from = p_from->next;
LWIP_ERROR("p_from != NULL", (p_from != NULL) || (copy_len == 0), return ERR_ARG;);
}
if (offset_to == p_to->len) {
/* on to next p_to (if any) */
offset_to = 0;
p_to = p_to->next;
LWIP_ERROR("p_to != NULL", (p_to != NULL) || (p_from == NULL), return ERR_ARG;);
LWIP_ERROR("p_to != NULL", (p_to != NULL) || (copy_len == 0), return ERR_ARG;);
}
if ((p_from != NULL) && (p_from->len == p_from->tot_len)) {
/* don't copy more than one packet! */
LWIP_ERROR("pbuf_copy() does not allow packet queues!",
LWIP_ERROR("pbuf_copy_partial_pbuf() does not allow packet queues!",
(p_from->next == NULL), return ERR_VAL;);
}
if ((p_to != NULL) && (p_to->len == p_to->tot_len)) {
/* don't copy more than one packet! */
LWIP_ERROR("pbuf_copy() does not allow packet queues!",
LWIP_ERROR("pbuf_copy_partial_pbuf() does not allow packet queues!",
(p_to->next == NULL), return ERR_VAL;);
}
} while (p_from);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
} while (copy_len);
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy_partial_pbuf: copy complete.\n"));
return ERR_OK;
}

1
src/include/lwip/pbuf.h
View File

@ -296,6 +296,7 @@ void pbuf_cat(struct pbuf *head, struct pbuf *tail);
void pbuf_chain(struct pbuf *head, struct pbuf *tail);
struct pbuf *pbuf_dechain(struct pbuf *p);
err_t pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from);
err_t pbuf_copy_partial_pbuf(struct pbuf *p_to, const struct pbuf *p_from, u16_t copy_len, u16_t offset);
u16_t pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
void *pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset);
err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);