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https://github.com/lwip-tcpip/lwip.git
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Added pbuf_get_contiguous() to get data in one piece (either zero copy from pbuf or memcpied into a supplied buffer)
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@ -1056,6 +1056,47 @@ pbuf_copy_partial(const struct pbuf *buf, void *dataptr, u16_t len, u16_t offset
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return copied_total;
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return copied_total;
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}
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}
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/** Get part of a pbuf's payload as contiguous memory. The returned memory is
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* either a pointer into the pbuf's payload or, if split over multiple pbufs,
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* a copy into the user-supplied buffer.
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*
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* @param p the pbuf from which to copy data
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* @param dataptr the application supplied buffer
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* @param len length of data to copy (dataptr must be big enough). No more
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* than buf->tot_len will be copied, irrespective of len
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* @param offset offset into the packet buffer from where to begin copying len bytes
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* @return the number of bytes copied, or 0 on failure
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*/
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void *
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pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset)
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{
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const struct pbuf *q;
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LWIP_ERROR("pbuf_get_contiguous: invalid buf", (p != NULL), return NULL;);
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LWIP_ERROR("pbuf_get_contiguous: invalid dataptr", (buffer != NULL), return NULL;);
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LWIP_ERROR("pbuf_get_contiguous: invalid dataptr", (bufsize >= len), return NULL;);
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for (q = p; q != NULL; q = q->next) {
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if ((offset != 0) && (offset >= q->len)) {
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/* don't copy from this buffer -> on to the next */
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offset -= q->len;
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} else {
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if (q->len >= (offset + len)) {
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/* all data in this pbuf, return zero-copy */
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return (u8_t*)q->payload + offset;
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}
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/* need to copy */
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if (pbuf_copy_partial(q, buffer, len, offset) != len) {
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/* copying failed: pbuf is too short */
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return NULL;
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}
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return buffer;
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}
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}
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/* pbuf is too short (offset does not fit in) */
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return NULL;
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}
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#if LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE
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#if LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE
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/**
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/**
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* This method modifies a 'pbuf chain', so that its total length is
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* This method modifies a 'pbuf chain', so that its total length is
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@ -240,6 +240,7 @@ void pbuf_chain(struct pbuf *head, struct pbuf *tail);
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struct pbuf *pbuf_dechain(struct pbuf *p);
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struct pbuf *pbuf_dechain(struct pbuf *p);
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err_t pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from);
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err_t pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from);
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u16_t pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
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u16_t pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
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void *pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset);
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err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
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err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
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err_t pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset);
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err_t pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset);
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struct pbuf *pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset);
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struct pbuf *pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset);
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