[porthole] added memory copy utility functions

porthole/CMakeLists.txt

@@ -7,6 +7,7 @@ include_directories(
 
 add_library(porthole STATIC
   src/porthole.c
+  src/util.c
 )
 
 if(WIN32)

porthole/include/porthole/client.h

@@ -17,27 +17,10 @@ this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place, Suite 330, Boston, MA 02111-1307 USA
 */
 
-#include <stdbool.h>
-#include <stdint.h>
+#include "types.h"
 
 typedef struct PortholeClient *PortholeClient;
 
-typedef struct
-{
-  unsigned int   size;
-  void         * data;
-}
-PortholeSegment;
-
-typedef struct
-{
-  uint32_t        id;
-  unsigned int    size;
-  unsigned int    num_segments;
-  PortholeSegment segments[0];
-}
-PortholeMap;
-
 /**
  * Memory map event callback.
  *

porthole/include/porthole/util.h

@@ -0,0 +1,52 @@
+/*
+Looking Glass - KVM FrameRelay (KVMFR) Client
+Copyright (C) 2017-2019 Geoffrey McRae <geoff@hostfission.com>
+https://looking-glass.hostfission.com
+
+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., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "types.h"
+#include <sys/types.h>
+
+/**
+ * Copy from memory to a PortholeMap
+ *
+ * @param src The source buffer
+ * @param dst The destination map
+ * @param len The data length to copy
+ * @param off The offset into the dst PortholeMap
+ */
+void porthole_copy_mem_to_map(void * src, PortholeMap * dst, size_t len, off_t off);
+
+/**
+ * Copy from a PortholeMap to memory
+ *
+ * @param src The source buffer
+ * @param dst The destination buffer
+ * @param len The data length to copy
+ * @param off The offset into the src PortholeMap
+ */
+void porthole_copy_map_to_mem(PortholeMap * src, void * dst, size_t len, off_t off);
+
+/**
+ * Copy from a PortholeMap to a PortholeMap
+ *
+ * @param src     The source buffer
+ * @param dst     The destination buffer
+ * @param len     The data length to copy
+ * @param src_off The offset into the src PortholeMap
+ * @param dst_off The offset into the dst PortholeMap
+ */
+void porthole_copy_map_to_map(PortholeMap * src, PortholeMap * dst, size_t len, off_t src_off, off_t dst_off);

porthole/src/util.c

@@ -0,0 +1,152 @@
+/*
+Looking Glass - KVM FrameRelay (KVMFR) Client
+Copyright (C) 2017-2019 Geoffrey McRae <geoff@hostfission.com>
+https://looking-glass.hostfission.com
+
+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., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "porthole/util.h"
+#include "common/debug.h"
+
+#include <string.h>
+
+void porthole_copy_mem_to_map(void * src, PortholeMap * dst, size_t len, off_t off)
+{
+  if (off + len > dst->size)
+    DEBUG_FATAL("Attempt to write beyond the length of destination mapping");
+
+  /* find the start segment */
+  PortholeSegment * seg = &dst->segments[0];
+  while(off)
+  {
+    if (seg->size > off)
+      break;
+
+    off -= seg->size;
+    ++seg;
+  }
+
+  /* copy into each segment until the length has been satisfied */
+  while(len)
+  {
+    char * buf   = (char *)seg->data + off;
+    size_t avail = seg->size - off;
+    off = 0;
+
+    if (avail > len)
+      avail = len;
+
+    memcpy(buf, src, avail);
+
+    src = (char *)src + avail;
+    len -= avail;
+    ++seg;
+  }
+}
+
+void porthole_copy_map_to_mem(PortholeMap * src, void * dst, size_t len, off_t off)
+{
+  if (off + len > src->size)
+    DEBUG_FATAL("Attempt to read beyond the length of the source mapping");
+
+  /* find the start segment */
+  PortholeSegment * seg = &src->segments[0];
+  while(off)
+  {
+    if (seg->size > off)
+      break;
+
+    off -= seg->size;
+    ++seg;
+  }
+
+  /* copy from each segment until the length has been satisfied */
+  while(len)
+  {
+    char * buf = (char *)seg->data + off;
+    size_t avail = seg->size - off;
+    off = 0;
+
+    if (avail > len)
+      avail = len;
+
+    memcpy(dst, buf, avail);
+
+    dst  = (char *)dst + avail;
+    len -= avail;
+    ++seg;
+  }
+}
+
+void porthole_copy_map_to_map(PortholeMap * src, PortholeMap * dst, size_t len, off_t src_off, off_t dst_off)
+{
+  if (src_off + len > src->size)
+    DEBUG_FATAL("Attempt to read beyond th elength of the source mapping");
+
+  if (dst_off + len > dst->size)
+    DEBUG_FATAL("Attempt to write beyond the length of the destination mapping");
+
+  /* find the start segments */
+  PortholeSegment * src_seg = &src->segments[0];
+  while(src_off)
+  {
+    if (src_seg->size > src_off)
+      break;
+
+    src_off -= src_seg->size;
+    ++src_seg;
+  }
+
+  PortholeSegment * dst_seg = &dst->segments[0];
+  while(dst_off)
+  {
+    if (dst_seg->size > dst_off)
+      break;
+
+    dst_off -= dst_seg->size;
+    ++dst_seg;
+  }
+
+  while(len)
+  {
+    char * src_buf   = (char *)src_seg->data + src_off;
+    char * dst_buf   = (char *)dst_seg->data + dst_off;
+    size_t src_avail = src_seg->size - src_off;
+    size_t dst_avail = dst_seg->size - dst_off;
+    src_off = 0;
+    dst_off = 0;
+
+    size_t avail = src_avail > dst_avail ? dst_avail : src_avail;
+    if (avail > len)
+      avail = len;
+
+    memcpy(dst_buf, src_buf, avail);
+
+    src_avail -= avail;
+    dst_avail -= avail;
+
+    if (src_avail == 0)
+      ++src_seg;
+    else
+      src_off = src_avail;
+
+    if (dst_avail == 0)
+      ++dst_seg;
+    else
+      dst_off = dst_avail;
+
+    len -= avail;
+  }
+}