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wireshark/epan/emem.h

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/* emem.h
* Definitions for Wireshark memory management and garbage collection
* Ronnie Sahlberg 2005
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* 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.
*/
#ifndef __EMEM_H__
#define __EMEM_H__
#include "gnuc_format_check.h"
/* Functions for handling memory allocation and garbage collection with
* a packet lifetime scope.
* These functions are used to allocate memory that will only remain persistent
* until Wireshark starts dissecting the next packet in the list.
* Everytime Wireshark starts decoding the next packet all memory allocated
* through these functions will be released back to the free pool.
*
* These functions are very fast and offer automatic garbage collection:
* Everytime a new packet is dissected, all memory allocations done in
* the previous packet is freed.
*/
/* Initialize packet-lifetime memory allocation pool. This function is called
* once when [t]Wireshark is initialized to set up the required structures.
*/
void ep_init_chunk(void);
/* Allocate memory with a packet lifetime scope */
void *ep_alloc(size_t size);
#define ep_new(type) ((type*)ep_alloc(sizeof(type)))
/* Allocate memory with a packet lifetime scope and fill it with zeros*/
void* ep_alloc0(size_t size);
#define ep_new0(type) ((type*)ep_alloc0(sizeof(type)))
/* Duplicate a string with a packet lifetime scope */
gchar* ep_strdup(const gchar* src);
/* Duplicate at most n characters of a string with a packet lifetime scope */
gchar* ep_strndup(const gchar* src, size_t len);
/* Duplicate a buffer with a packet lifetime scope */
void* ep_memdup(const void* src, size_t len);
/* Create a formatted string with a packet lifetime scope */
gchar* ep_strdup_vprintf(const gchar* fmt, va_list ap);
gchar* ep_strdup_printf(const gchar* fmt, ...)
GNUC_FORMAT_CHECK(printf, 1, 2);
/* allocates with a packet lifetime scope an array of type made of num elements */
#define ep_alloc_array(type,num) (type*)ep_alloc(sizeof(type)*(num))
/* allocates with a packet lifetime scope an array of type made of num elements,
* initialised to zero.
*/
#define ep_alloc_array0(type,num) (type*)ep_alloc0(sizeof(type)*(num))
/*
* Splits a string into a maximum of max_tokens pieces, using the given
* delimiter. If max_tokens is reached, the remainder of string is appended
* to the last token. Consecutive delimiters are treated as a single delimiter.
*
* the vector and all the strings are allocated with packet lifetime scope
*/
gchar** ep_strsplit(const gchar* string, const gchar* delimiter, int max_tokens);
/* release all memory allocated in the previous packet dissector */
void ep_free_all(void);
/* a stack implemented using ephemeral allocators */
typedef struct _ep_stack_frame_t** ep_stack_t;
struct _ep_stack_frame_t {
void* payload;
struct _ep_stack_frame_t* below;
struct _ep_stack_frame_t* above;
};
/*
* creates an empty stack with a packet lifetime scope
*/
ep_stack_t ep_stack_new(void);
/*
* pushes item into stack, returns item
*/
void* ep_stack_push(ep_stack_t stack, void* item);
/*
* pops an item from the stack
*/
void* ep_stack_pop(ep_stack_t stack);
/*
* returns the item on top of the stack without popping it
*/
#define ep_stack_peek(stack) ((*(stack))->payload)
/* Functions for handling memory allocation and garbage collection with
* a capture lifetime scope.
* These functions are used to allocate memory that will only remain persistent
* until Wireshark opens a new capture or capture file.
* Everytime Wireshark starts a new capture or opens a new capture file
* all the data allocated through these functions will be released back
* to the free pool.
*
* These functions are very fast and offer automatic garbage collection.
*/
/* Initialize capture-lifetime memory allocation pool. This function is called
* once when [t]Wireshark is initialized to set up the required structures.
*/
void se_init_chunk(void);
/* Allocate memory with a capture lifetime scope */
void *se_alloc(size_t size);
/* Allocate memory with a capture lifetime scope and fill it with zeros*/
void* se_alloc0(size_t size);
/* Duplicate a string with a capture lifetime scope */
gchar* se_strdup(const gchar* src);
/* Duplicate at most n characters of a string with a capture lifetime scope */
gchar* se_strndup(const gchar* src, size_t len);
/* Duplicate a buffer with a capture lifetime scope */
void* se_memdup(const void* src, size_t len);
/* Create a formatted string with a capture lifetime scope */
gchar* se_strdup_vprintf(const gchar* fmt, va_list ap);
gchar* se_strdup_printf(const gchar* fmt, ...)
GNUC_FORMAT_CHECK(printf, 1, 2);
/* allocates with a capture lifetime scope an array of type made of num elements */
#define se_alloc_array(type,num) (type*)se_alloc(sizeof(type)*(num))
/* release all memory allocated */
void se_free_all(void);
/**************************************************************
* binary trees
**************************************************************/
typedef struct _emem_tree_node_t {
struct _emem_tree_node_t *parent;
struct _emem_tree_node_t *left;
struct _emem_tree_node_t *right;
struct {
#define EMEM_TREE_RB_COLOR_RED 0
#define EMEM_TREE_RB_COLOR_BLACK 1
guint32 rb_color:1;
#define EMEM_TREE_NODE_IS_DATA 0
#define EMEM_TREE_NODE_IS_SUBTREE 1
guint32 is_subtree:1;
} u;
guint32 key32;
void *data;
} emem_tree_node_t;
/* Right now we only do basic red/black trees but in the future we might want
* to try something different, such as a tree where each node keeps track
* of how many times it has been looked up, and letting often looked up
* nodes bubble upwards in the tree using rotate_right/left.
* That would probably be good for things like nfs filehandles
*/
#define EMEM_TREE_TYPE_RED_BLACK 1
typedef struct _emem_tree_t {
struct _emem_tree_t *next;
int type;
const char *name; /* just a string to make debugging easier */
emem_tree_node_t *tree;
void *(*malloc)(size_t);
} emem_tree_t;
/* list of all trees with se allocation scope so that they can all be reset
* automatically when we free all se memory
*/
extern emem_tree_t *se_trees;
/* *******************************************************************
* Tree functions for SE memory allocation scope
* ******************************************************************* */
/* This function is used to create a se based tree with monitoring.
* When the SE heap is released back to the system the pointer to the
* tree is automatically reset to NULL.
*
* type is : EMEM_TREE_TYPE_RED_BLACK for a standard red/black tree.
*/
emem_tree_t *se_tree_create(int type, const char *name);
/* This function is similar to the se_tree_create() call but with the
* difference that when the se memory is release everything including the
* pointer to the tree itself will be released.
* This tree will not be just reset to zero it will be completely forgotten
* by the allocator.
* Use this function for when you want to store the pointer to a tree inside
* another structure that is also se allocated so that when the structure is
* released, the tree will be completely released as well.
*/
emem_tree_t *se_tree_create_non_persistent(int type, const char *name);
/* se_tree_insert32
* Insert data into the tree and key it by a 32bit integer value
*/
#define se_tree_insert32 emem_tree_insert32
/* se_tree_lookup32
* Retrieve the data at the search key. the search key is a 32bit integer value
*/
#define se_tree_lookup32 emem_tree_lookup32
/* se_tree_lookup32_le
* Retrieve the data for the largest key that is less than or equal
* to the search key.
*/
#define se_tree_lookup32_le emem_tree_lookup32_le
/* se_tree_insert32_array
* Insert data into the tree and key it by a 32bit integer value
*/
#define se_tree_insert32_array emem_tree_insert32_array
/* se_tree_lookup32_array
* Lookup data from the tree that is index by an array
*/
#define se_tree_lookup32_array emem_tree_lookup32_array
/* Create a new string based hash table */
#define se_tree_create_string() se_tree_create(SE_TREE_TYPE_RED_BLACK)
/* Insert a new value under a string key */
#define se_tree_insert_string emem_tree_insert_string
/* Lookup the value under a string key */
#define se_tree_lookup_string emem_tree_lookup_string
/* Traverse a tree */
#define se_tree_foreach emem_tree_foreach
/* *******************************************************************
* Tree functions for PE memory allocation scope
* ******************************************************************* */
/* These trees have PErmanent allocation scope and will never be released
*/
emem_tree_t *pe_tree_create(int type, const char *name);
#define pe_tree_insert32 emem_tree_insert32
#define pe_tree_lookup32 emem_tree_lookup32
#define pe_tree_lookup32_le emem_tree_lookup32_le
#define pe_tree_insert32_array emem_tree_insert32_array
#define pe_tree_lookup32_array emem_tree_lookup32_array
#define pe_tree_insert_string emem_tree_insert_string
#define pe_tree_lookup_string emem_tree_lookup_string
#define pe_tree_foreach emem_tree_foreach
/* ******************************************************************
* Real tree functions
* ****************************************************************** */
/* This function is used to insert a node indexed by a guint32 key value.
* The data pointer should be allocated by the appropriate storage scope
* so that it will be released at the same time as the tree itself is
* destroyed.
*/
void emem_tree_insert32(emem_tree_t *se_tree, guint32 key, void *data);
/* This function will look up a node in the tree indexed by a guint32 integer
* value.
*/
void *emem_tree_lookup32(emem_tree_t *se_tree, guint32 key);
/* This function will look up a node in the tree indexed by a guint32 integer
* value.
* The function will return the node that has the largest key that is
* equal to or smaller than the search key, or NULL if no such key was
* found.
*/
void *emem_tree_lookup32_le(emem_tree_t *se_tree, guint32 key);
typedef struct _emem_tree_key_t {
guint32 length; /*length in guint32 words */
guint32 *key;
} emem_tree_key_t;
/* This function is used to insert a node indexed by a sequence of guint32
* key values.
* The data pointer should be allocated by SE allocators so that the
* data will be released at the same time as the tree itself is destroyed.
*
* Note: all the "key" members of the "key" argument MUST be aligned on
* 32-bit boundaries; otherwise, this code will crash on platforms such
* as SPARC that require aligned pointers.
*
* If you use ...32_array() calls you MUST make sure that every single node
* you add to a specific tree always has a key of exactly the same number of
* keylen words or things will most likely crash. Or at least that every single
* item that sits behind the same top level node always have exactly the same
* number of words.
*
* One way to guarantee this is the way that NFS does this for the
* nfs_name_snoop_known tree which holds filehandles for both v2 and v3.
* v2 filehandles are always 32 bytes (8 words) while v3 filehandles can have
* any length (though 32bytes are most common).
* The NFS dissector handles this by providing a guint32 containing the length
* as the very first item in this vector :
*
* emem_tree_key_t fhkey[3];
*
* fhlen=nns->fh_length;
* fhkey[0].length=1;
* fhkey[0].key=&fhlen;
* fhkey[1].length=fhlen/4;
* fhkey[1].key=nns->fh;
* fhkey[2].length=0;
*/
void emem_tree_insert32_array(emem_tree_t *se_tree, emem_tree_key_t *key, void *data);
/* This function will look up a node in the tree indexed by a sequence of
* guint32 integer values.
*/
void *emem_tree_lookup32_array(emem_tree_t *se_tree, emem_tree_key_t *key);
/* case insensitive strings as keys */
#define EMEM_TREE_STRING_NOCASE 0x00000001
/* Insert a new value under a string key */
void emem_tree_insert_string(emem_tree_t* h, const gchar* k, void* v, guint32 flags);
/* Lookup the value under a string key */
void* emem_tree_lookup_string(emem_tree_t* h, const gchar* k, guint32 flags);
/* traverse a tree. if the callback returns TRUE the traversal will end */
typedef gboolean (*tree_foreach_func)(void *value, void *userdata);
gboolean emem_tree_foreach(emem_tree_t* emem_tree, tree_foreach_func callback, void *user_data);
/* ******************************************************************
* String buffers - Growable strings similar to GStrings
* ****************************************************************** */
typedef struct _emem_strbuf_t {
gchar *str; /* points to the character data. It may move as text is */
/* added. The str field is nul-terminated and so can */
/* be used as an ordinary C string. */
gsize len; /* strlen: ie: length of str not including trailing '\0' */
gsize alloc_len; /* num bytes curently allocated for str: 1 .. MAX_STRBUF_LEN */
gsize max_alloc_len; /* max num bytes to allocate for str: 1 .. MAX_STRBUF_LEN */
} emem_strbuf_t;
/*
* The maximum length is limited to 64K. If you need something bigger, you
* should probably use an actual GString or GByteArray.
*/
/**
* Allocate an ephemeral string buffer with "unlimited" size.
*
* @param init The initial string for the buffer, or NULL to allocate an initial zero-length string.
*
* @return A newly-allocated string buffer.
*/
emem_strbuf_t *ep_strbuf_new(const gchar *init);
/**
* Allocate an ephemeral string buffer suitable for the protocol tree.
* The string will never grow beyond the maximum tree item length.
*
* @param init The initial string for the buffer, or NULL to allocate an initial zero-length string.
*
* @return A newly-allocated string buffer.
*/
emem_strbuf_t *ep_strbuf_new_label(const gchar *init);
/**
* Allocate an ephemeral string buffer with enough initial space for @alloc_len bytes
* and a maximum of @max_alloc_len bytes.
*
* @param alloc_len The initial size of the buffer. This value can be 0, but a nonzero
* value is recommended.
* @param max_alloc_len The maximum size of the buffer. 0 means "unlimited" (within
* reason).
*
* @return A newly-allocated string buffer. @str will be empty.
*/
emem_strbuf_t *ep_strbuf_sized_new(gsize alloc_len, gsize max_alloc_len);
/**
* Append vprintf-style formatted text to a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to append to.
* @param format A printf-style string format.
* @param args The list of arguments to append.
*/
void ep_strbuf_append_vprintf(emem_strbuf_t *strbuf, const gchar *format, va_list ap);
/**
* Apply printf-style formatted text to a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to set to.
* @param format A printf-style string format.
*/
void ep_strbuf_printf(emem_strbuf_t *strbuf, const gchar *format, ...)
GNUC_FORMAT_CHECK(printf, 2, 3);
/**
* Append printf-style formatted text to a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to append to.
* @param format A printf-style string format.
*/
void ep_strbuf_append_printf(emem_strbuf_t *strbuf, const gchar *format, ...)
GNUC_FORMAT_CHECK(printf, 2, 3);
/**
* Append a string to a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to append to.
* @param str A null-terminated string.
*
* @return strbuf
*/
emem_strbuf_t *ep_strbuf_append(emem_strbuf_t *strbuf, const gchar *str);
/**
* Append a character to a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to append to.
* @param c The character to append.
*
* @return strbuf
*/
emem_strbuf_t *ep_strbuf_append_c(emem_strbuf_t *strbuf, const gchar c);
/**
* Chop off the end of a string buffer.
*
* @param strbuf The ep_strbuf-allocated string buffer to append to.
* @param len The new string length.
*
* @return strbuf
*/
emem_strbuf_t *ep_strbuf_truncate(emem_strbuf_t *strbuf, gsize len);
/* #define DEBUG_INTENSE_CANARY_CHECKS */
/* Helper to troubleshoot ep memory corruption
* if compiled and the environment variable WIRESHARK_DEBUG_EP_INTENSE_CANARY exists
* it will check the canaries and when found corrupt stop there in the hope
* the corruptor is still there in the stack.
* Some checkpoints are already set in packet.c in strategic points
* before and after dissection of a frame or a dissector call.
*/
#ifdef DEBUG_INTENSE_CANARY_CHECKS
void ep_check_canary_integrity(const char* fmt, ...);
#define EP_CHECK_CANARY(sprintf_args) ep_check_canary_integrity sprintf_args
#else
#define EP_CHECK_CANARY(dummy)
#endif
void emem_print_tree(emem_tree_t* emem_tree);
#endif /* emem.h */
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