From 843a1161552dc3ead6e5518690828c99a7969ccf Mon Sep 17 00:00:00 2001 From: Erik Ekman Date: Fri, 3 Jul 2020 18:55:02 +0200 Subject: [PATCH] pbuf: Add pbuf_copy_partial_pbuf library function 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 --- src/core/pbuf.c | 56 +++++++++++++++++++++++++++++++++-------- src/include/lwip/pbuf.h | 1 + 2 files changed, 46 insertions(+), 11 deletions(-) diff --git a/src/core/pbuf.c b/src/core/pbuf.c index da2934fe..7638dfda 100644 --- a/src/core/pbuf.c +++ b/src/core/pbuf.c @@ -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; } diff --git a/src/include/lwip/pbuf.h b/src/include/lwip/pbuf.h index 1f520f03..e5daf968 100644 --- a/src/include/lwip/pbuf.h +++ b/src/include/lwip/pbuf.h @@ -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);