1 files changed, 269 insertions, 0 deletions
diff --git a/src/util/mymalloc.c b/src/util/mymalloc.c
new file mode 100644
index 0000000..1c8199e
--- /dev/null
+++ b/src/util/mymalloc.c
@@ -0,0 +1,269 @@
+/*++
+/* NAME
+/*	mymalloc 3
+/* SUMMARY
+/*	memory management wrappers
+/* SYNOPSIS
+/*	#include <mymalloc.h>
+/*
+/*	void	*mymalloc(len)
+/*	ssize_t	len;
+/*
+/*	void	*myrealloc(ptr, len)
+/*	void	*ptr;
+/*	ssize_t	len;
+/*
+/*	void	myfree(ptr)
+/*	void	*ptr;
+/*
+/*	char	*mystrdup(str)
+/*	const char *str;
+/*
+/*	char	*mystrndup(str, len)
+/*	const char *str;
+/*	ssize_t	len;
+/*
+/*	char	*mymemdup(ptr, len)
+/*	const char *ptr;
+/*	ssize_t	len;
+/* DESCRIPTION
+/*	This module performs low-level memory management with error
+/*	handling. A call of these functions either succeeds or it does
+/*	not return at all.
+/*
+/*	To save memory, zero-length strings are shared and read-only.
+/*	The caller must not attempt to modify the null terminator.
+/*	This code is enabled unless NO_SHARED_EMPTY_STRINGS is
+/*	defined at compile time (for example, you have an sscanf()
+/*	routine that pushes characters back into its input).
+/*
+/*	mymalloc() allocates the requested amount of memory. The memory
+/*	is not set to zero.
+/*
+/*	myrealloc() resizes memory obtained from mymalloc() or myrealloc()
+/*	to the requested size. The result pointer value may differ from
+/*	that given via the \fIptr\fR argument.
+/*
+/*	myfree() takes memory obtained from mymalloc() or myrealloc()
+/*	and makes it available for other use.
+/*
+/*	mystrdup() returns a dynamic-memory copy of its null-terminated
+/*	argument. This routine uses mymalloc().
+/*
+/*	mystrndup() returns a dynamic-memory copy of at most \fIlen\fR
+/*	leading characters of its null-terminated
+/*	argument. The result is null-terminated. This routine uses mymalloc().
+/*
+/*	mymemdup() makes a copy of the memory pointed to by \fIptr\fR
+/*	with length \fIlen\fR. The result is NOT null-terminated.
+/*	This routine uses mymalloc().
+/* SEE ALSO
+/*	msg(3) diagnostics interface
+/* DIAGNOSTICS
+/*	Problems are reported via the msg(3) diagnostics routines:
+/*	the requested amount of memory is not available; improper use
+/*	is detected; other fatal errors.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+/* System libraries. */
+
+#include "sys_defs.h"
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+
+/* Application-specific. */
+
+#include "msg.h"
+#include "mymalloc.h"
+
+ /*
+  * Structure of an annotated memory block. In order to detect spurious
+  * free() calls we prepend a signature to memory given to the application.
+  * In order to detect access to free()d blocks, overwrite each block as soon
+  * as it is passed to myfree(). With the code below, the user data has
+  * integer alignment or better.
+  */
+typedef struct MBLOCK {
+    int     signature;			/* set when block is active */
+    ssize_t length;			/* user requested length */
+    union {
+	ALIGN_TYPE align;
+	char    payload[1];		/* actually a bunch of bytes */
+    }       u;
+} MBLOCK;
+
+#define SIGNATURE	0xdead
+#define FILLER		0xff
+
+#define CHECK_IN_PTR(ptr, real_ptr, len, fname) { \
+    if (ptr == 0) \
+	msg_panic("%s: null pointer input", fname); \
+    real_ptr = (MBLOCK *) (ptr - offsetof(MBLOCK, u.payload[0])); \
+    if (real_ptr->signature != SIGNATURE) \
+	msg_panic("%s: corrupt or unallocated memory block", fname); \
+    real_ptr->signature = 0; \
+    if ((len = real_ptr->length) < 1) \
+	msg_panic("%s: corrupt memory block length", fname); \
+}
+
+#define CHECK_OUT_PTR(ptr, real_ptr, len) { \
+    real_ptr->signature = SIGNATURE; \
+    real_ptr->length = len; \
+    ptr = real_ptr->u.payload; \
+}
+
+#define SPACE_FOR(len)	(offsetof(MBLOCK, u.payload[0]) + len)
+
+ /*
+  * Optimization for short strings. We share one copy with multiple callers.
+  * This differs from normal heap memory in two ways, because the memory is
+  * shared:
+  * 
+  * -  It must be read-only to avoid horrible bugs. This is OK because there is
+  * no legitimate reason to modify the null terminator.
+  * 
+  * - myfree() cannot overwrite the memory with a filler pattern like it can do
+  * with heap memory. Therefore, some dangling pointer bugs will be masked.
+  */
+#ifndef NO_SHARED_EMPTY_STRINGS
+static const char empty_string[] = "";
+
+#endif
+
+/* mymalloc - allocate memory or bust */
+
+void   *mymalloc(ssize_t len)
+{
+    void   *ptr;
+    MBLOCK *real_ptr;
+
+    /*
+     * Note: for safety reasons the request length is a signed type. This
+     * allows us to catch integer overflow problems that weren't already
+     * caught up-stream.
+     */
+    if (len < 1)
+	msg_panic("mymalloc: requested length %ld", (long) len);
+#ifdef MYMALLOC_FUZZ
+    len += MYMALLOC_FUZZ;
+#endif
+    if ((real_ptr = (MBLOCK *) malloc(SPACE_FOR(len))) == 0)
+	msg_fatal("mymalloc: insufficient memory for %ld bytes: %m",
+		  (long) len);
+    CHECK_OUT_PTR(ptr, real_ptr, len);
+    memset(ptr, FILLER, len);
+    return (ptr);
+}
+
+/* myrealloc - reallocate memory or bust */
+
+void   *myrealloc(void *ptr, ssize_t len)
+{
+    MBLOCK *real_ptr;
+    ssize_t old_len;
+
+#ifndef NO_SHARED_EMPTY_STRINGS
+    if (ptr == empty_string)
+	return (mymalloc(len));
+#endif
+
+    /*
+     * Note: for safety reasons the request length is a signed type. This
+     * allows us to catch integer overflow problems that weren't already
+     * caught up-stream.
+     */
+    if (len < 1)
+	msg_panic("myrealloc: requested length %ld", (long) len);
+#ifdef MYMALLOC_FUZZ
+    len += MYMALLOC_FUZZ;
+#endif
+    CHECK_IN_PTR(ptr, real_ptr, old_len, "myrealloc");
+    if ((real_ptr = (MBLOCK *) realloc((void *) real_ptr, SPACE_FOR(len))) == 0)
+	msg_fatal("myrealloc: insufficient memory for %ld bytes: %m",
+		  (long) len);
+    CHECK_OUT_PTR(ptr, real_ptr, len);
+    if (len > old_len)
+	memset(ptr + old_len, FILLER, len - old_len);
+    return (ptr);
+}
+
+/* myfree - release memory */
+
+void    myfree(void *ptr)
+{
+    MBLOCK *real_ptr;
+    ssize_t len;
+
+#ifndef NO_SHARED_EMPTY_STRINGS
+    if (ptr != empty_string) {
+#endif
+	CHECK_IN_PTR(ptr, real_ptr, len, "myfree");
+	memset((void *) real_ptr, FILLER, SPACE_FOR(len));
+	free((void *) real_ptr);
+#ifndef NO_SHARED_EMPTY_STRINGS
+    }
+#endif
+}
+
+/* mystrdup - save string to heap */
+
+char   *mystrdup(const char *str)
+{
+    size_t  len;
+
+    if (str == 0)
+	msg_panic("mystrdup: null pointer argument");
+#ifndef NO_SHARED_EMPTY_STRINGS
+    if (*str == 0)
+	return ((char *) empty_string);
+#endif
+    if ((len = strlen(str) + 1) > SSIZE_T_MAX)
+	msg_panic("mystrdup: string length >= SSIZE_T_MAX");
+    return (strcpy(mymalloc(len), str));
+}
+
+/* mystrndup - save substring to heap */
+
+char   *mystrndup(const char *str, ssize_t len)
+{
+    char   *result;
+    char   *cp;
+
+    if (str == 0)
+	msg_panic("mystrndup: null pointer argument");
+    if (len < 0)
+	msg_panic("mystrndup: requested length %ld", (long) len);
+#ifndef NO_SHARED_EMPTY_STRINGS
+    if (*str == 0)
+	return ((char *) empty_string);
+#endif
+    if ((cp = memchr(str, 0, len)) != 0)
+	len = cp - str;
+    result = memcpy(mymalloc(len + 1), str, len);
+    result[len] = 0;
+    return (result);
+}
+
+/* mymemdup - copy memory */
+
+char   *mymemdup(const void *ptr, ssize_t len)
+{
+    if (ptr == 0)
+	msg_panic("mymemdup: null pointer argument");
+    return (memcpy(mymalloc(len), ptr, len));
+}