lib: du_buff alloc API changed to return pointers

du_buff.[c/h]: alloc_head and alloc_tail now return a pointer to the
               start of the PCI for direct read/write access.

2 files changed, 24 insertions, 24 deletions

diff --git a/include/ouroboros/du_buff.h b/include/ouroboros/du_buff.h
index 92d0609d..66904ca7 100644
--- a/include/ouroboros/du_buff.h
+++ b/include/ouroboros/du_buff.h
@@ -39,8 +39,8 @@ int         du_buff_init(du_buff_t * dub,
                          uint8_t   * data,
                          size_t      len);
 
-int         du_buff_head_alloc(du_buff_t * dub, size_t size);
-int         du_buff_tail_alloc(du_buff_t * dub, size_t size);
+uint8_t *   du_buff_head_alloc(du_buff_t * dub, size_t size);
+uint8_t *   du_buff_tail_alloc(du_buff_t * dub, size_t size);
 int         du_buff_head_release(du_buff_t * dub, size_t size);
 int         du_buff_tail_release(du_buff_t * dub, size_t size);
 
diff --git a/src/lib/du_buff.c b/src/lib/du_buff.c
index 324dccc5..3db01831 100644
--- a/src/lib/du_buff.c
+++ b/src/lib/du_buff.c
@@ -43,8 +43,8 @@ struct buffer {
 struct du_buff {
         struct buffer  * buffer;
         size_t           size;
-        size_t           du_start;
-        size_t           du_end;
+        size_t           du_head;
+        size_t           du_tail;
 };
 
 void buffer_destroy(struct buffer * buf)
@@ -253,8 +253,8 @@ du_buff_t * du_buff_create(size_t size)
 
         dub->buffer   = NULL;
         dub->size     = size;
-        dub->du_start = 0;
-        dub->du_end   = 0;
+        dub->du_head = 0;
+        dub->du_tail   = 0;
 
         return dub;
 }
@@ -294,44 +294,44 @@ int du_buff_init(du_buff_t * dub,
         if (dub->buffer == NULL)
                 return -ENOMEM;
 
-        dub->du_start = start;
-        dub->du_end = start + len;
+        dub->du_head = start;
+        dub->du_tail = start + len;
 
         return buffer_copy_data(dub->buffer, start, data, len);
 }
 
-int du_buff_head_alloc(du_buff_t * dub, size_t size)
+uint8_t * du_buff_head_alloc(du_buff_t * dub, size_t size)
 {
         if (dub == NULL) {
                 LOG_DBGF("Bogus input, bugging out.");
-                return -EINVAL;
+                return NULL;
         }
 
-        if (dub->du_start - size < 0) {
+        if (dub->du_head - size < 0) {
                 LOG_WARN("Failed to allocate PCI headspace");
-                return -ENOBUFS;
+                return NULL;
         }
 
-        dub->du_start -= size;
+        dub->du_head -= size;
 
-        return 0;
+        return (buffer_seek_pos(dub->buffer, dub->du_head));
 }
 
-int du_buff_tail_alloc(du_buff_t * dub, size_t size)
+uint8_t * du_buff_tail_alloc(du_buff_t * dub, size_t size)
 {
         if (dub == NULL) {
                 LOG_DBGF("Bogus input, bugging out.");
-                return -EINVAL;
+                return NULL;
         }
 
-        if (dub->du_end + size >= dub->size) {
+        if (dub->du_tail + size >= dub->size) {
                 LOG_WARN("Failed to allocate PCI tailspace");
-                return -ENOBUFS;
+                return NULL;
         }
 
-        dub->du_end += size;
+        dub->du_tail += size;
 
-        return 0;
+        return (buffer_seek_pos(dub->buffer, dub->du_tail));
 }
 
 int du_buff_head_release(du_buff_t * dub, size_t size)
@@ -341,12 +341,12 @@ int du_buff_head_release(du_buff_t * dub, size_t size)
                 return -EINVAL;
         }
 
-        if (size > dub->du_end - dub->du_start) {
+        if (size > dub->du_tail - dub->du_head) {
                 LOG_WARN("Tried to release beyond sdu boundary");
                 return -EOVERFLOW;
         }
 
-        dub->du_start += size;
+        dub->du_head += size;
 
         /* FIXME: copy some random crap to the buffer for security */
 
@@ -360,12 +360,12 @@ int du_buff_tail_release(du_buff_t * dub, size_t size)
                 return -EINVAL;
         }
 
-        if (size > dub->du_end - dub->du_start) {
+        if (size > dub->du_tail - dub->du_head) {
                 LOG_WARN("Tried to release beyond sdu boundary");
                 return -EOVERFLOW;
         }
 
-        dub->du_end -= size;
+        dub->du_tail -= size;
 
         /* FIXME: copy some random crap to the buffer for security */