[PATCH libnetfilter_queue 1/3] pktbuff: add pktb_alloc_head() and pktb_build_data()

[Pablo Neira Ayuso <pablo@netfilter.org>]

Add two new helper functions to skip memcpy()'ing the payload from the
netlink message.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/libnetfilter_queue/pktbuff.h |  3 +++
 src/extra/pktbuff.c                  | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/libnetfilter_queue/pktbuff.h b/include/libnetfilter_queue/pktbuff.h
index 42bc153ec337..f9bddaf072fb 100644
--- a/include/libnetfilter_queue/pktbuff.h
+++ b/include/libnetfilter_queue/pktbuff.h
@@ -4,8 +4,11 @@
 struct pkt_buff;
 
 struct pkt_buff *pktb_alloc(int family, void *data, size_t len, size_t extra);
+struct pkt_buff *pktb_alloc_head(void);
 void pktb_free(struct pkt_buff *pktb);
 
+void pktb_build_data(struct pkt_buff *pktb, uint8_t *payload, uint32_t len);
+
 uint8_t *pktb_data(struct pkt_buff *pktb);
 uint32_t pktb_len(struct pkt_buff *pktb);
 
diff --git a/src/extra/pktbuff.c b/src/extra/pktbuff.c
index 6dd0ca98aff2..a93e72ac7795 100644
--- a/src/extra/pktbuff.c
+++ b/src/extra/pktbuff.c
@@ -93,6 +93,26 @@ struct pkt_buff *pktb_alloc(int family, void *data, size_t len, size_t extra)
 	return pktb;
 }
 
+EXPORT_SYMBOL
+struct pkt_buff *pktb_alloc_head(void)
+{
+	struct pkt_buff *pktb;
+
+	pktb = calloc(1, sizeof(struct pkt_buff));
+	if (pktb == NULL)
+		return NULL;
+
+	return pktb;
+}
+
+EXPORT_SYMBOL
+void pktb_build_data(struct pkt_buff *pktb, uint8_t *payload, uint32_t len)
+{
+	pktb->len = len;
+	pktb->data_len = len;
+	pktb->data = payload;
+}
+
 /**
  * pktb_data - get pointer to network packet
  * \param pktb Pointer to userspace packet buffer
-- 
2.20.1