diff --git a/src/core/pbuf.c b/src/core/pbuf.c index a209e0ca8fce45940c981897f1b919ef910306b7..db8064c8061d5c22181e4bd1fc7d53a4abdf960f 100644 --- a/src/core/pbuf.c +++ b/src/core/pbuf.c @@ -1011,6 +1011,83 @@ pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from) return ERR_OK; } +/** + * @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; + + 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_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; + } else { + /* current p_from does not fit into current p_to */ + len = p_to->len - offset_to; + } + len = LWIP_MIN(copy_len, len); + 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) || (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_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_partial_pbuf() does not allow packet queues!", + (p_to->next == NULL), return ERR_VAL;); + } + } while (copy_len); + LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy_partial_pbuf: copy complete.\n")); + return ERR_OK; +} + /** * @ingroup pbuf * Copy (part of) the contents of a packet buffer diff --git a/src/include/lwip/pbuf.h b/src/include/lwip/pbuf.h index 82902a4e9812c42f9f92feb11986f2b36c20bd5a..de1a0e24418faa6969a37a10e6f850ada1734bb5 100644 --- a/src/include/lwip/pbuf.h +++ b/src/include/lwip/pbuf.h @@ -293,6 +293,7 @@ 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); diff --git a/src/netif/zepif.c b/src/netif/zepif.c index b4033030bf98361b995c0b3dd40309926c0986e8..de43b99b539eee5f0e4327053ac100a68f40fd93 100644 --- a/src/netif/zepif.c +++ b/src/netif/zepif.c @@ -201,7 +201,7 @@ zepif_linkoutput(struct netif *netif, struct pbuf *p) state->seqno++; zep->len = (u8_t)p->tot_len; - err = pbuf_take_at(q, p->payload, p->tot_len, sizeof(struct zep_hdr)); + err = pbuf_copy_partial_pbuf(q, p, p->tot_len, sizeof(struct zep_hdr)); if (err == ERR_OK) { #if ZEPIF_LOOPBACK zepif_udp_recv(netif, state->pcb, pbuf_clone(PBUF_RAW, PBUF_RAM, q), NULL, 0);