From fb6d2270ab7809e7e36dcf56e1d7975bad658504 Mon Sep 17 00:00:00 2001
From: kkrentz <konrad.krentz@googlemail.com>
Date: Wed, 19 Jun 2013 04:58:48 -0700
Subject: [PATCH] framer-802154: Simplification of frame802154_create

---
 core/net/mac/frame802154.c           | 41 ++++++++++------------------
 core/net/mac/frame802154.h           |  2 +-
 core/net/mac/framer-802154.c         |  2 +-
 core/net/mac/sicslowmac/sicslowmac.c |  2 +-
 4 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/core/net/mac/frame802154.c b/core/net/mac/frame802154.c
index eb39e62c3..83b162dcd 100644
--- a/core/net/mac/frame802154.c
+++ b/core/net/mac/frame802154.c
@@ -172,70 +172,59 @@ frame802154_hdrlen(frame802154_t *p)
  *
  *   \param buf Pointer to the buffer to use for the frame.
  *
- *   \param buf_len The length of the buffer to use for the frame.
- *
- *   \return The length of the frame header or 0 if there was
- *   insufficient space in the buffer for the frame headers.
+ *   \return The length of the frame header
 */
 int
-frame802154_create(frame802154_t *p, uint8_t *buf, int buf_len)
+frame802154_create(frame802154_t *p, uint8_t *buf)
 {
   int c;
   field_length_t flen;
-  uint8_t *tx_frame_buffer;
   uint8_t pos;
 
   field_len(p, &flen);
-
-  if(3 + flen.dest_pid_len + flen.dest_addr_len +
-     flen.src_pid_len + flen.src_addr_len + flen.aux_sec_len > buf_len) {
-    /* Too little space for headers. */
-    return 0;
-  }
-
+  
   /* OK, now we have field lengths.  Time to actually construct */
-  /* the outgoing frame, and store it in tx_frame_buffer */
-  tx_frame_buffer = buf;
-  tx_frame_buffer[0] = (p->fcf.frame_type & 7) |
+  /* the outgoing frame, and store it in buf */
+  buf[0] = (p->fcf.frame_type & 7) |
     ((p->fcf.security_enabled & 1) << 3) |
     ((p->fcf.frame_pending & 1) << 4) |
     ((p->fcf.ack_required & 1) << 5) |
     ((p->fcf.panid_compression & 1) << 6);
-  tx_frame_buffer[1] = ((p->fcf.dest_addr_mode & 3) << 2) |
+  buf[1] = ((p->fcf.dest_addr_mode & 3) << 2) |
     ((p->fcf.frame_version & 3) << 4) |
     ((p->fcf.src_addr_mode & 3) << 6);
 
   /* sequence number */
-  tx_frame_buffer[2] = p->seq;
+  buf[2] = p->seq;
   pos = 3;
 
   /* Destination PAN ID */
   if(flen.dest_pid_len == 2) {
-    tx_frame_buffer[pos++] = p->dest_pid & 0xff;
-    tx_frame_buffer[pos++] = (p->dest_pid >> 8) & 0xff;
+    buf[pos++] = p->dest_pid & 0xff;
+    buf[pos++] = (p->dest_pid >> 8) & 0xff;
   }
 
   /* Destination address */
   for(c = flen.dest_addr_len; c > 0; c--) {
-    tx_frame_buffer[pos++] = p->dest_addr[c - 1];
+    buf[pos++] = p->dest_addr[c - 1];
   }
 
   /* Source PAN ID */
   if(flen.src_pid_len == 2) {
-    tx_frame_buffer[pos++] = p->src_pid & 0xff;
-    tx_frame_buffer[pos++] = (p->src_pid >> 8) & 0xff;
+    buf[pos++] = p->src_pid & 0xff;
+    buf[pos++] = (p->src_pid >> 8) & 0xff;
   }
 
   /* Source address */
   for(c = flen.src_addr_len; c > 0; c--) {
-    tx_frame_buffer[pos++] = p->src_addr[c - 1];
+    buf[pos++] = p->src_addr[c - 1];
   }
 
   /* Aux header */
   if(flen.aux_sec_len) {
     /* TODO Support key identifier mode !=0 */
-    tx_frame_buffer[pos++] = p->aux_hdr.security_control.security_level;
-    memcpy(tx_frame_buffer + pos, p->aux_hdr.frame_counter.u8, 4);
+    buf[pos++] = p->aux_hdr.security_control.security_level;
+    memcpy(buf + pos, p->aux_hdr.frame_counter.u8, 4);
     pos += 4;
   }
 
diff --git a/core/net/mac/frame802154.h b/core/net/mac/frame802154.h
index 27d2041fa..925c2bfdc 100644
--- a/core/net/mac/frame802154.h
+++ b/core/net/mac/frame802154.h
@@ -172,7 +172,7 @@ typedef struct {
 /* Prototypes */
 
 int frame802154_hdrlen(frame802154_t *p);
-int frame802154_create(frame802154_t *p, uint8_t *buf, int buf_len);
+int frame802154_create(frame802154_t *p, uint8_t *buf);
 int frame802154_parse(uint8_t *data, int length, frame802154_t *pf);
 
 /** @} */
diff --git a/core/net/mac/framer-802154.c b/core/net/mac/framer-802154.c
index 7451db13d..48231035d 100644
--- a/core/net/mac/framer-802154.c
+++ b/core/net/mac/framer-802154.c
@@ -189,7 +189,7 @@ create_frame(int type, int do_create)
     return hdr_len;
 
   } else if(packetbuf_hdralloc(hdr_len)) {
-    frame802154_create(&params, packetbuf_hdrptr(), hdr_len);
+    frame802154_create(&params, packetbuf_hdrptr());
 
     PRINTF("15.4-OUT: %2X", params.fcf.frame_type);
     PRINTADDR(params.dest_addr);
diff --git a/core/net/mac/sicslowmac/sicslowmac.c b/core/net/mac/sicslowmac/sicslowmac.c
index 2c7562f29..56db88ff5 100644
--- a/core/net/mac/sicslowmac/sicslowmac.c
+++ b/core/net/mac/sicslowmac/sicslowmac.c
@@ -157,7 +157,7 @@ send_packet(mac_callback_t sent, void *ptr)
   len = frame802154_hdrlen(&params);
   if(packetbuf_hdralloc(len)) {
     int ret;
-    frame802154_create(&params, packetbuf_hdrptr(), len);
+    frame802154_create(&params, packetbuf_hdrptr());
 
     PRINTF("6MAC-UT: %2X", params.fcf.frame_type);
     PRINTADDR(params.dest_addr);