Initial du_buff code

Compiles but untested. Expect bugs.

2 files changed, 334 insertions, 0 deletions

diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index 5c0e6bbe..9a6f1946 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -8,6 +8,7 @@ set(SOURCE_FILES
         # Add source files here
         bitmap.c
         cdap.c
+        du_buff.c
 )
 
 add_library(ouroboros SHARED ${SOURCE_FILES})
diff --git a/src/lib/du_buff.c b/src/lib/du_buff.c
new file mode 100644
index 00000000..1944634d
--- /dev/null
+++ b/src/lib/du_buff.c
@@ -0,0 +1,333 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Data Unit Buffer
+ *
+ *    Dimitri Staessens <[email protected]>
+ *    Sander Vrijders   <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <malloc.h>
+#include <string.h>
+#include <errno.h>
+#include "ouroboros/du_buff.h"
+
+#define OUROBOROS_PREFIX "du_buff"
+
+#include "ouroboros/logs.h"
+
+void buffer_destroy (struct buffer * buf)
+{
+        if (buf == NULL) {
+                LOG_DBG("buffer_destroy: Bogus input, bugging out.");
+                return;
+        }
+
+        list_del(&(buf->list));
+
+        free (&(buf->data));
+
+        free (buf);
+}
+
+
+void buffer_destroy_list(struct buffer * buf)
+{
+        struct list_head * ptr;
+        struct list_head * n;
+
+        if (buf == NULL) {
+                LOG_DBG("buffer_destroy_list: Bogus input, bugging out.");
+                return;
+        }
+
+        list_for_each_safe(ptr, n, &(buf->list)) {
+                struct buffer * tmp = list_entry(ptr, struct buffer, list);
+                list_del(ptr);
+                buffer_destroy(tmp);
+        }
+}
+
+struct buffer * buffer_create (size_t size)
+{
+        struct buffer * head      = NULL;
+        size_t          remaining = size;
+        const size_t    page_size = sysconf(_SC_PAGESIZE);
+
+        while (remaining > 0) {
+                struct buffer * buf;
+                size_t sz = remaining < page_size ? remaining : page_size;
+
+                buf = (struct buffer *)malloc(sizeof(struct buffer));
+                if (buf == NULL) {
+                        LOG_WARN("buffer_create: could not allocate struct.");
+                        return NULL;
+                }
+
+                buf->data=(uint8_t *)malloc(sz);
+                if (buf->data == NULL) {
+                        LOG_WARN("buffer_create: allocate memblock failed.");
+                        buffer_destroy_list(head);
+                        return NULL;
+                }
+
+                buf->size = sz;
+                INIT_LIST_HEAD(&(buf->list));
+
+                if (head == NULL)
+                        head = buf;
+                else
+                        list_add_tail(&(buf->list), &(head->list));
+
+                remaining -= buf->size;
+        }
+
+        return head;
+}
+
+struct buffer * buffer_seek(const struct buffer * head, size_t pos)
+{
+        struct list_head * ptr = NULL;
+        struct buffer    * hit = NULL;
+        size_t cur_buf_start   = 0;
+        size_t cur_buf_end     = 0;
+
+        if (head = NULL) {
+                LOG_DBG("buffer_seek: Bogus input, bugging out.");
+                return NULL;
+        }
+
+        list_for_each(ptr, &(head->list)) {
+                struct buffer * tmp = list_entry(ptr, struct buffer, list);
+
+                cur_buf_end = cur_buf_start + tmp->size;
+
+                if (cur_buf_end > pos)
+                        return tmp;
+
+                cur_buf_start = cur_buf_end;
+        }
+
+        return NULL;
+}
+
+uint8_t * buffer_seek_pos(const struct buffer * head, size_t pos)
+{
+        struct list_head * ptr = NULL;
+        struct buffer    * hit = NULL;
+        size_t cur_buf_start   = 0;
+        size_t cur_buf_end     = 0;
+
+        if (head = NULL) {
+                LOG_DBG("buffer_seek_pos: Bogus input, bugging out.");
+                return NULL;
+        }
+
+        list_for_each(ptr, &(head->list)) {
+                struct buffer * tmp = list_entry(ptr, struct buffer, list);
+
+                cur_buf_end = cur_buf_start + tmp->size;
+
+                if (cur_buf_end > pos)
+                        return tmp->data + (pos - cur_buf_start);
+
+                cur_buf_start = cur_buf_end;
+        }
+
+        return NULL;
+}
+
+int buffer_copy_data(struct buffer * head,
+                     size_t          pos,
+                     const void    * src,
+                     size_t          len)
+{
+        struct list_head * ptr       = NULL;
+        struct buffer    * buf_start = NULL;
+        struct buffer    * buf_end   = NULL;
+        uint8_t          * ptr_start = NULL;
+        size_t             space_in_buf;
+        size_t             bytes_remaining;
+        uint8_t          * copy_pos  = NULL;
+
+        if (head == NULL || src == NULL) {
+                LOG_DBG("buffer_copy_data: Bogus input, bugging out.");
+                return -EINVAL;
+        }
+
+        buf_start = buffer_seek(head, pos);
+        buf_end   = buffer_seek(head, pos + len);
+
+        if (buf_start == NULL || buf_end == NULL) {
+                LOG_DBG("buffer_copy_data: Index out of bounds %d, %d",
+                        pos,
+                        pos+len);
+                return -EINVAL;
+        }
+
+        ptr_start = buffer_seek_pos(head, pos);
+
+        if (buf_start == buf_end) {
+                memcpy(ptr_start, src, len);
+                return 0;
+        }
+
+        copy_pos = (uint8_t *)src;
+        bytes_remaining = len;
+        list_for_each(ptr, &(buf_start->list)) {
+                struct buffer * tmp = list_entry(ptr, struct buffer, list);
+                space_in_buf = tmp->data + tmp->size - ptr_start;
+                if (space_in_buf >= bytes_remaining) {
+                        memcpy(ptr_start, copy_pos, bytes_remaining);
+                        return 0;
+                }
+                else
+                        memcpy(ptr_start, copy_pos, space_in_buf);
+                bytes_remaining -= space_in_buf;
+        }
+
+        return 0;
+}
+
+du_buff_t * du_buff_create(size_t size)
+{
+        du_buff_t * dub = (du_buff_t *)malloc(sizeof(du_buff_t));
+
+        if (dub == NULL) {
+                LOG_DBG("create: Bogus input, bugging out.");
+                return NULL;
+        }
+
+        dub->buffer = buffer_create(size);
+        if (dub->buffer == NULL) {
+                free (dub);
+                return NULL;
+        }
+
+        dub->size     = size;
+        dub->du_start = 0;
+        dub->du_end   = 0;
+
+        INIT_LIST_HEAD(&(dub->list));
+
+        return dub;
+}
+
+void du_buff_destroy(du_buff_t * dub)
+{
+        if (dub == NULL) {
+                LOG_DBG("destroy: Bogus input, bugging out.");
+                return;
+        }
+        buffer_destroy_list(dub->buffer);
+
+        list_del(&(dub->list));
+
+        free (dub);
+}
+
+int du_buff_init(du_buff_t * dub,
+                 size_t      start,
+                 uint8_t *   data,
+                 size_t      len)
+{
+        if (dub == NULL || data == NULL) {
+                LOG_DBG("init: Bogus input, bugging out.");
+                return -EINVAL;
+        }
+
+        if (start + len > dub->size) {
+                LOG_DBG("init: Index out of bounds %d", start);
+                return -EINVAL;
+        }
+
+        dub->du_start = start;
+        dub->du_end = start + len;
+
+        return buffer_copy_data(dub->buffer, start, data, len);
+
+}
+
+uint8_t * du_buff_data_ptr_start(du_buff_t * dub)
+{
+        if (dub == NULL) {
+                LOG_DBG("data_ptr_start: Bogus input, bugging out.");
+                return NULL;
+        }
+        return buffer_seek_pos(dub->buffer, dub->du_start);
+}
+
+uint8_t * du_buff_data_ptr_end(du_buff_t * dub)
+{
+        if (dub == NULL) {
+                LOG_DBG("data_ptr_end: Bogus input, bugging out.");
+                return NULL;
+        }
+        return buffer_seek_pos(dub->buffer, dub->du_end);
+}
+
+int du_buff_head_alloc(du_buff_t * dub, size_t size)
+{
+        if (dub->du_start - size < 0) {
+                LOG_WARN("head_alloc: failed to allocate PCI headspace");
+                return -1;
+        }
+
+        dub->du_start -= size;
+
+        return 0;
+}
+int du_buff_tail_alloc(du_buff_t * dub, size_t size)
+{
+        if (dub->du_end + size >= dub->size) {
+                LOG_WARN("tail_alloc: failed to allocate PCI tailspace");
+                return -1;
+        }
+
+        dub->du_end += size;
+
+        return 0;
+
+}
+
+int du_buff_head_release(du_buff_t * dub, size_t size)
+{
+        if (size > dub->du_end - dub->du_start) {
+                LOG_WARN("head_release: tried to release beyond sdu boundary");
+                return -1;
+        }
+
+        dub->du_start += size;
+
+        /* FIXME: copy some random crap to the buffer for security */
+
+        return 0;
+}
+
+int du_buff_tail_release(du_buff_t * dub, size_t size)
+{
+        if (size > dub->du_end - dub->du_start) {
+                LOG_WARN("tail_release: tried to release beyond sdu boundary");
+                return -1;
+        }
+
+        dub->du_end -= size;
+
+        /* FIXME: copy some random crap to the buffer for security */
+
+        return 0;
+}