Memory-allocation abstraction layer and buffer-based allocator added
diff --git a/library/memory_buffer_alloc.c b/library/memory_buffer_alloc.c
new file mode 100644
index 0000000..c7df7b4
--- /dev/null
+++ b/library/memory_buffer_alloc.c
@@ -0,0 +1,376 @@
+/*
+ * Buffer-based memory allocator
+ *
+ * Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ * This file is part of PolarSSL (http://www.polarssl.org)
+ * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ * All rights reserved.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_MEMORY_C) && defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+
+#include "polarssl/memory.h"
+
+#include <string.h>
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+#include <stdio.h>
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+#include <execinfo.h>
+#endif
+#endif
+
+#define MAGIC1 0xFF00AA55
+#define MAGIC2 0xEE119966
+#define MAX_BT 20
+
+typedef struct _memory_header memory_header;
+struct _memory_header
+{
+ size_t magic1;
+ size_t size;
+ size_t alloc;
+ memory_header *prev;
+ memory_header *next;
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ char **trace;
+ size_t trace_count;
+#endif
+ size_t magic2;
+};
+
+typedef struct
+{
+ unsigned char *buf;
+ size_t len;
+ memory_header *first;
+ size_t largest_free;
+ size_t current_alloc_size;
+ int verify;
+}
+buffer_alloc_ctx;
+
+static buffer_alloc_ctx heap;
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+static void debug_header( memory_header *hdr )
+{
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ size_t i;
+#endif
+
+ fprintf(stderr, "HDR: PTR(%10u), PREV(%10u), NEXT(%10u), ALLOC(%u), SIZE(%10u)\n",
+ (size_t) hdr, (size_t) hdr->prev, (size_t) hdr->next,
+ hdr->alloc, hdr->size );
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ fprintf(stderr, "TRACE: \n");
+ for( i = 0; i < hdr->trace_count; i++ )
+ fprintf(stderr, "%s\n", hdr->trace[i]);
+#endif
+}
+
+static void debug_chain()
+{
+ memory_header *cur = heap.first;
+
+ while( cur != NULL )
+ {
+ debug_header( cur );
+ fprintf(stderr, "\n");
+ cur = cur->next;
+ }
+}
+#endif /* POLARSSL_MEMORY_DEBUG */
+
+static int verify_header( memory_header *hdr )
+{
+ if( hdr->magic1 != MAGIC1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: MAGIC1 mismatch\n");
+#endif
+ return( 1 );
+ }
+
+ if( hdr->magic2 != MAGIC2 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: MAGIC2 mismatch\n");
+#endif
+ return( 1 );
+ }
+
+ if( hdr->alloc > 1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: alloc has illegal value\n");
+#endif
+ return( 1 );
+ }
+
+ return( 0 );
+}
+
+static int verify_chain()
+{
+ memory_header *prv = heap.first, *cur = heap.first->next;
+
+ if( verify_header( heap.first ) != 0 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: verification of first header failed\n");
+#endif
+ return( 1 );
+ }
+
+ if( heap.first->prev != NULL )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: verification failed: first->prev != NULL\n");
+#endif
+ return( 1 );
+ }
+
+ while( cur != NULL )
+ {
+ if( verify_header( cur ) != 0 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: verification of header failed\n");
+#endif
+ return( 1 );
+ }
+
+ if( cur->prev != prv )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: verification failed: cur->prev != prv\n");
+#endif
+ return( 1 );
+ }
+
+ prv = cur;
+ cur = cur->next;
+ }
+
+ return( 0 );
+}
+
+static void *buffer_alloc_malloc( size_t len )
+{
+ memory_header *new, *cur = heap.first;
+ unsigned char *p;
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ void *trace_buffer[MAX_BT];
+ size_t trace_cnt;
+#endif
+
+ if( heap.buf == NULL || heap.first == NULL )
+ return( NULL );
+
+ if( len % POLARSSL_MEMORY_ALIGN_MULTIPLE )
+ {
+ len -= len % POLARSSL_MEMORY_ALIGN_MULTIPLE;
+ len += POLARSSL_MEMORY_ALIGN_MULTIPLE;
+ }
+
+ // Find block that fits
+ //
+ while( cur != NULL )
+ {
+ if( cur->alloc == 0 && cur->size >= len )
+ break;
+
+ cur = cur->next;
+ }
+
+ if( cur == NULL )
+ return( NULL );
+
+ // Found location, split block if > memory_header + 4 room left
+ //
+ if( cur->size - len < sizeof(memory_header) + POLARSSL_MEMORY_ALIGN_MULTIPLE )
+ {
+ cur->alloc = 1;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ trace_cnt = backtrace( trace_buffer, MAX_BT );
+ cur->trace = backtrace_symbols( trace_buffer, trace_cnt );
+ cur->trace_count = trace_cnt;
+#endif
+
+ if( ( heap.verify & MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
+ exit( 1 );
+
+ return ( (unsigned char *) cur ) + sizeof(memory_header);
+ }
+
+ p = ( (unsigned char *) cur ) + sizeof(memory_header) + len;
+ new = (memory_header *) p;
+
+ new->size = cur->size - len - sizeof(memory_header);
+ new->alloc = 0;
+ new->prev = cur;
+ new->next = cur->next;
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ new->trace = NULL;
+ new->trace_count = 0;
+#endif
+ new->magic1 = MAGIC1;
+ new->magic2 = MAGIC2;
+
+ if( new->next != NULL )
+ new->next->prev = new;
+
+ cur->alloc = 1;
+ cur->size = len;
+ cur->next = new;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ trace_cnt = backtrace( trace_buffer, MAX_BT );
+ cur->trace = backtrace_symbols( trace_buffer, trace_cnt );
+ cur->trace_count = trace_cnt;
+#endif
+
+ if( ( heap.verify & MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
+ exit( 1 );
+
+ return ( (unsigned char *) cur ) + sizeof(memory_header);
+}
+
+static void buffer_alloc_free( void *ptr )
+{
+ memory_header *hdr, *old;
+ unsigned char *p = (unsigned char *) ptr;
+
+
+ if( ptr == NULL || heap.buf == NULL || heap.first == NULL )
+ return;
+
+ if( p < heap.buf || p > heap.buf + heap.len )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: polarssl_free() outside of managed space\n");
+#endif
+ exit(1);
+ }
+
+ p -= sizeof(memory_header);
+ hdr = (memory_header *) p;
+
+ if( verify_header( hdr ) != 0 )
+ exit( 1 );
+
+ if( hdr->alloc != 1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ fprintf(stderr, "FATAL: polarssl_free() on unallocated data\n");
+#endif
+ exit(1);
+ }
+
+ hdr->alloc = 0;
+
+ // Regroup with block before
+ //
+ if( hdr->prev != NULL && hdr->prev->alloc == 0 )
+ {
+ hdr->prev->size += sizeof(memory_header) + hdr->size;
+ hdr->prev->next = hdr->next;
+ old = hdr;
+ hdr = hdr->prev;
+
+ if( hdr->next != NULL )
+ hdr->next->prev = hdr;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ free( old->trace );
+#endif
+ memset( old, 0, sizeof(memory_header) );
+ }
+
+ // Regroup with block after
+ //
+ if( hdr->next != NULL && hdr->next->alloc == 0 )
+ {
+ hdr->size += sizeof(memory_header) + hdr->next->size;
+ old = hdr->next;
+ hdr->next = hdr->next->next;
+
+ if( hdr->next != NULL )
+ hdr->next->prev = hdr;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ free( old->trace );
+#endif
+ memset( old, 0, sizeof(memory_header) );
+ }
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ hdr->trace = NULL;
+ hdr->trace_count = 0;
+#endif
+
+ if( ( heap.verify & MEMORY_VERIFY_FREE ) && verify_chain() != 0 )
+ exit( 1 );
+}
+
+int memory_buffer_alloc_verify()
+{
+ return verify_chain();
+}
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+void memory_buffer_alloc_status()
+{
+ if( heap.first->next == NULL )
+ fprintf(stderr, "All memory de-allocated in stack buffer\n");
+ else
+ {
+ fprintf(stderr, "Memory currently allocated:\n");
+ debug_chain();
+ }
+}
+#endif /* POLARSSL_MEMORY_BUFFER_ALLOC_DEBUG */
+
+int memory_buffer_alloc_init( unsigned char *buf, size_t len )
+{
+ polarssl_malloc = buffer_alloc_malloc;
+ polarssl_free = buffer_alloc_free;
+
+ memset( &heap, 0, sizeof(buffer_alloc_ctx) );
+ memset( buf, 0, len );
+
+ heap.buf = buf;
+ heap.len = len;
+
+ heap.first = (memory_header *) buf;
+ heap.first->size = len - sizeof(memory_header);
+ heap.first->magic1 = MAGIC1;
+ heap.first->magic2 = MAGIC2;
+
+ heap.largest_free = heap.first->size;
+
+ return( 0 );
+}
+
+#endif /* POLARSSL_MEMORY_C && POLARSSL_MEMORY_BUFFER_ALLOC_C */
