From dcb2cb99a1c5bbd9decaab1186f14e5278d316f8 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon@gmx.de>
Date: Tue, 25 Apr 2017 10:07:57 +0200
Subject: [PATCH] Added 'pbuf_alloc_copy' e.g. as a single function for use
 with non scatter-gather drivers

---
 src/core/pbuf.c         | 27 +++++++++++++++++++++++++++
 src/include/lwip/pbuf.h |  1 +
 2 files changed, 28 insertions(+)

diff --git a/src/core/pbuf.c b/src/core/pbuf.c
index b75747a7..202d7de7 100644
--- a/src/core/pbuf.c
+++ b/src/core/pbuf.c
@@ -1319,6 +1319,33 @@ pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
   return q;
 }
 
+/**
+ * @ingroup pbuf
+ * Allocates a new pbuf of same length (via @pbuf_alloc) and copies the source
+ * pbuf into this new pbuf (using @pbuf_copy).
+ *
+ * @param layer pbuf_layer of the new pbuf
+ * @param type this parameter decides how and where the pbuf should be allocated
+ *             (@see pbuf_alloc)
+ * @param p the source pbuf
+ *
+ * @return a new pbuf or NULL if allocation fails
+ */
+struct pbuf *
+pbuf_alloc_copy(pbuf_layer layer, pbuf_type type, struct pbuf *p)
+{
+  struct pbuf *q;
+  err_t err;
+  q = pbuf_alloc(layer, p->tot_len, type);
+  if (q == NULL) {
+    return NULL;
+  }
+  err = pbuf_copy(q, p);
+  LWIP_UNUSED_ARG(err); /* in case of LWIP_NOASSERT */
+  LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
+  return q;
+}
+
 #if LWIP_CHECKSUM_ON_COPY
 /**
  * Copies data into a single pbuf (*not* into a pbuf queue!) and updates
diff --git a/src/include/lwip/pbuf.h b/src/include/lwip/pbuf.h
index 667c2383..52a4f1fe 100644
--- a/src/include/lwip/pbuf.h
+++ b/src/include/lwip/pbuf.h
@@ -262,6 +262,7 @@ err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
 err_t pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset);
 struct pbuf *pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset);
 struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer);
+struct pbuf *pbuf_alloc_copy(pbuf_layer l, pbuf_type type, struct pbuf *p);
 #if LWIP_CHECKSUM_ON_COPY
 err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr,
                        u16_t len, u16_t *chksum);