1 files changed, 459 insertions, 0 deletions
diff --git a/src/libstrongswan/utils/leak_detective.c b/src/libstrongswan/utils/leak_detective.c
new file mode 100644
index 000000000..b8a023270
--- /dev/null
+++ b/src/libstrongswan/utils/leak_detective.c
@@ -0,0 +1,459 @@
+/**
+ * @file leak_detective.c
+ * 
+ * @brief Allocation hooks to find memory leaks.
+ */
+
+/*
+ * Copyright (C) 2006 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <malloc.h>
+#include <signal.h> 
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <dlfcn.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <pthread.h>
+#include <netdb.h>
+#include <printf.h>
+#ifdef HAVE_BACKTRACE
+# include <execinfo.h>
+#endif /* HAVE_BACKTRACE */
+
+#include "leak_detective.h"
+
+#include <library.h>
+#include <debug.h>
+
+#ifdef LEAK_DETECTIVE
+
+/**
+ * Magic value which helps to detect memory corruption. Yummy!
+ */
+#define MEMORY_HEADER_MAGIC 0x7ac0be11
+
+/**
+ * Pattern which is filled in memory before freeing it
+ */
+#define MEMORY_FREE_PATTERN 0xFF
+
+/**
+ * Pattern which is filled in newly allocated memory
+ */
+#define MEMORY_ALLOC_PATTERN 0xEE
+
+
+static void install_hooks(void);
+static void uninstall_hooks(void);
+static void *malloc_hook(size_t, const void *);
+static void *realloc_hook(void *, size_t, const void *);
+static void free_hook(void*, const void *);
+
+static u_int count_malloc = 0;
+static u_int count_free = 0;
+static u_int count_realloc = 0;
+
+typedef struct memory_header_t memory_header_t;
+
+/**
+ * Header which is prepended to each allocated memory block
+ */
+struct memory_header_t {
+	/**
+	 * Magci byte which must(!) hold MEMORY_HEADER_MAGIC
+	 */
+	u_int32_t magic;
+	
+	/**
+	 * Number of bytes following after the header
+	 */
+	size_t bytes;
+	
+	/**
+	 * Stack frames at the time of allocation
+	 */
+	void *stack_frames[STACK_FRAMES_COUNT];
+	
+	/**
+	 * Number of stacks frames obtained in stack_frames
+	 */
+	int stack_frame_count;
+	
+	/**
+	 * Pointer to previous entry in linked list
+	 */
+	memory_header_t *previous;
+	
+	/**
+	 * Pointer to next entry in linked list
+	 */
+	memory_header_t *next;
+};
+
+/**
+ * first mem header is just a dummy to chain 
+ * the others on it...
+ */
+static memory_header_t first_header = {
+	magic: MEMORY_HEADER_MAGIC,
+	bytes: 0,
+	stack_frame_count: 0,
+	previous: NULL,
+	next: NULL
+};
+
+/**
+ * standard hooks, used to temparily remove hooking
+ */
+static void *old_malloc_hook, *old_realloc_hook, *old_free_hook;
+
+/**
+ * are the hooks currently installed? 
+ */
+static bool installed = FALSE;
+
+/**
+ * Mutex to exclusivly uninstall hooks, access heap list
+ */
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+
+/**
+ * log stack frames queried by backtrace()
+ * TODO: Dump symbols of static functions. This could be done with
+ * the addr2line utility or the GNU BFD Library...
+ */
+static void log_stack_frames(void **stack_frames, int stack_frame_count)
+{
+#ifdef HAVE_BACKTRACE
+	char **strings;
+	size_t i;
+
+	strings = backtrace_symbols (stack_frames, stack_frame_count);
+
+	DBG1("  dumping %d stack frame addresses", stack_frame_count);
+
+	for (i = 0; i < stack_frame_count; i++)
+	{
+		DBG1("    %s", strings[i]);
+	}
+	free (strings);
+#endif /* HAVE_BACKTRACE */
+}
+
+/**
+ * Whitelist, which contains address ranges in stack frames ignored when leaking.
+ * 
+ * This is necessary, as some function use allocation hacks (static buffers)
+ * and so on, which we want to suppress on leak reports.
+ *
+ * The range_size is calculated using the readelf utility, e.g.:
+ * readelf -s /lib/glibc.so.6
+ * The values are for glibc-2.4 and may or may not be correct on other systems.
+ */
+typedef struct whitelist_t whitelist_t;
+
+struct whitelist_t {
+	void* range_start;
+	size_t range_size;
+};
+
+#ifdef LIBCURL
+/* dummy declaration for whitelisting */
+void *Curl_getaddrinfo(void);
+#endif /* LIBCURL */
+
+whitelist_t whitelist[] = {
+	{pthread_create,			2542},
+	{pthread_setspecific,		 217},
+	{mktime,					  60},
+	{tzset,						 123},
+	{inet_ntoa,					 249},
+	{strerror,					 180},
+	{getprotobynumber,			 291},
+	{getservbyport,				 311},
+	{register_printf_function,	 159},
+	{syslog,					  45},
+	{dlopen,					 109},
+#	ifdef LIBCURL
+	/* from /usr/lib/libcurl.so.3 */
+	{Curl_getaddrinfo,			 480},
+#	endif /* LIBCURL */
+};
+
+/**
+ * Check if this stack frame is whitelisted.
+ */
+static bool is_whitelisted(void **stack_frames, int stack_frame_count)
+{
+	int i, j;
+	
+	for (i=0; i< stack_frame_count; i++)
+	{
+		for (j=0; j<sizeof(whitelist)/sizeof(whitelist_t); j++)
+		{
+			if (stack_frames[i] >= whitelist[j].range_start &&
+				stack_frames[i] <= (whitelist[j].range_start + whitelist[j].range_size))
+			{
+				return TRUE;
+			}
+		}
+	}
+	return FALSE;
+}
+
+/**
+ * Report leaks at library destruction
+ */
+void report_leaks()
+{
+	memory_header_t *hdr;
+	int leaks = 0;
+	
+	for (hdr = first_header.next; hdr != NULL; hdr = hdr->next)
+	{
+		if (!is_whitelisted(hdr->stack_frames, hdr->stack_frame_count))
+		{
+			DBG1("Leak (%d bytes at %p):", hdr->bytes, hdr + 1);
+			log_stack_frames(hdr->stack_frames, hdr->stack_frame_count);
+			leaks++;
+		}
+	}
+		
+	switch (leaks)
+	{
+		case 0:
+			DBG1("No leaks detected");
+			break;
+		case 1:
+			DBG1("One leak detected");
+			break;
+		default:
+			DBG1("%d leaks detected", leaks);
+			break;
+	}
+}
+
+/**
+ * Installs the malloc hooks, enables leak detection
+ */
+static void install_hooks()
+{
+	if (!installed)
+	{
+		old_malloc_hook = __malloc_hook;
+		old_realloc_hook = __realloc_hook;
+		old_free_hook = __free_hook;
+		__malloc_hook = malloc_hook;
+		__realloc_hook = realloc_hook;
+		__free_hook = free_hook;
+		installed = TRUE;
+	}
+}
+
+/**
+ * Uninstalls the malloc hooks, disables leak detection
+ */
+static void uninstall_hooks()
+{
+	if (installed)
+	{
+		__malloc_hook = old_malloc_hook;
+		__free_hook = old_free_hook;
+		__realloc_hook = old_realloc_hook;
+		installed = FALSE;
+	}
+}
+
+/**
+ * Hook function for malloc()
+ */
+void *malloc_hook(size_t bytes, const void *caller)
+{
+	memory_header_t *hdr;
+	
+	pthread_mutex_lock(&mutex);
+	count_malloc++;
+	uninstall_hooks();
+	hdr = malloc(bytes + sizeof(memory_header_t));
+	/* set to something which causes crashes */
+	memset(hdr, MEMORY_ALLOC_PATTERN, bytes + sizeof(memory_header_t));
+	
+	hdr->magic = MEMORY_HEADER_MAGIC;
+	hdr->bytes = bytes;
+	hdr->stack_frame_count = backtrace(hdr->stack_frames, STACK_FRAMES_COUNT);
+	install_hooks();
+	
+	/* insert at the beginning of the list */
+	hdr->next = first_header.next;
+	if (hdr->next)
+	{
+		hdr->next->previous = hdr;
+	}
+	hdr->previous = &first_header;
+	first_header.next = hdr;
+	pthread_mutex_unlock(&mutex);
+	return hdr + 1;
+}
+
+/**
+ * Hook function for free()
+ */
+void free_hook(void *ptr, const void *caller)
+{
+	void *stack_frames[STACK_FRAMES_COUNT];
+	int stack_frame_count;
+	memory_header_t *hdr = ptr - sizeof(memory_header_t);
+	
+	/* allow freeing of NULL */
+	if (ptr == NULL)
+	{
+		return;
+	}
+	
+	pthread_mutex_lock(&mutex);
+	count_free++;
+	uninstall_hooks();
+	if (hdr->magic != MEMORY_HEADER_MAGIC)
+	{
+		DBG1("freeing of invalid memory (%p, MAGIC 0x%x != 0x%x):",
+			 ptr, hdr->magic, MEMORY_HEADER_MAGIC);
+		stack_frame_count = backtrace(stack_frames, STACK_FRAMES_COUNT);
+		log_stack_frames(stack_frames, stack_frame_count);
+		install_hooks();
+		pthread_mutex_unlock(&mutex);
+		return;
+	}
+	
+	/* remove item from list */
+	if (hdr->next)
+	{
+		hdr->next->previous = hdr->previous;
+	}
+	hdr->previous->next = hdr->next;
+	
+	/* clear MAGIC, set mem to something remarkable */
+	memset(hdr, MEMORY_FREE_PATTERN, hdr->bytes + sizeof(memory_header_t));
+	
+	free(hdr);
+	install_hooks();
+	pthread_mutex_unlock(&mutex);
+}
+
+/**
+ * Hook function for realloc()
+ */
+void *realloc_hook(void *old, size_t bytes, const void *caller)
+{
+	memory_header_t *hdr;
+	void *stack_frames[STACK_FRAMES_COUNT];
+	int stack_frame_count;
+	
+	/* allow reallocation of NULL */
+	if (old == NULL)
+	{
+		return malloc_hook(bytes, caller);
+	}
+	
+	hdr = old - sizeof(memory_header_t);
+	
+	pthread_mutex_lock(&mutex);
+	count_realloc++;
+	uninstall_hooks();
+	if (hdr->magic != MEMORY_HEADER_MAGIC)
+	{
+		DBG1("reallocation of invalid memory (%p):", old);
+		stack_frame_count = backtrace(stack_frames, STACK_FRAMES_COUNT);
+		log_stack_frames(stack_frames, stack_frame_count);
+		install_hooks();
+		pthread_mutex_unlock(&mutex);
+		raise(SIGKILL);
+		return NULL;
+	}
+	
+	hdr = realloc(hdr, bytes + sizeof(memory_header_t));
+	
+	/* update statistics */
+	hdr->bytes = bytes;
+	hdr->stack_frame_count = backtrace(hdr->stack_frames, STACK_FRAMES_COUNT);
+	
+	/* update header of linked list neighbours */
+	if (hdr->next)
+	{
+		hdr->next->previous = hdr;
+	}
+	hdr->previous->next = hdr;
+	install_hooks();
+	pthread_mutex_unlock(&mutex);
+	return hdr + 1;
+}
+
+/**
+ * Setup leak detective
+ */
+void __attribute__ ((constructor)) leak_detective_init()
+{
+	install_hooks();
+}
+
+/**
+ * Clean up leak detective
+ */
+void __attribute__ ((destructor)) leak_detective_cleanup()
+{
+	uninstall_hooks();
+	report_leaks();
+}
+
+/**
+ * Log memory allocation statistics
+ */
+void leak_detective_status(FILE *stream)
+{
+	u_int blocks = 0;
+	size_t bytes = 0;
+	memory_header_t *hdr = &first_header;
+	
+	pthread_mutex_lock(&mutex);
+	while ((hdr = hdr->next))
+	{
+		blocks++;
+		bytes += hdr->bytes;
+	}
+	pthread_mutex_unlock(&mutex);
+	
+	fprintf(stream, "allocation statistics:\n");
+	fprintf(stream, "  call stats: malloc: %d, free: %d, realloc: %d\n",
+			count_malloc, count_free, count_realloc);
+	fprintf(stream, "  allocated %d blocks, total size %d bytes (avg. %d bytes)\n",
+			blocks, bytes, bytes/blocks);
+}
+
+#else /* !LEAK_DETECTION */
+
+/**
+ * Dummy when !using LEAK_DETECTIVE
+ */
+void leak_detective_status(FILE *stream)
+{
+
+}
+
+#endif /* LEAK_DETECTION */