utils.h

Asterisk-1.4.4最新内核源代码

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <[e-mail]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 * \brief Utility functions
 */

#ifndef _ASTERISK_UTILS_H
#define _ASTERISK_UTILS_H

#include "asterisk/compat.h"

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <netinet/in.h>
#include <arpa/inet.h>	/* we want to override inet_ntoa */
#include <netdb.h>
#include <limits.h>

#include "asterisk/lock.h"
#include "asterisk/time.h"
#include "asterisk/strings.h"
#include "asterisk/logger.h"
#include "asterisk/compiler.h"

/*! \note
 \verbatim
   Note:
   It is very important to use only unsigned variables to hold
   bit flags, as otherwise you can fall prey to the compiler's
   sign-extension antics if you try to use the top two bits in
   your variable.

   The flag macros below use a set of compiler tricks to verify
   that the caller is using an "unsigned int" variable to hold
   the flags, and nothing else. If the caller uses any other
   type of variable, a warning message similar to this:

   warning: comparison of distinct pointer types lacks cast
   will be generated.

   The "dummy" variable below is used to make these comparisons.

   Also note that at -O2 or above, this type-safety checking
   does _not_ produce any additional object code at all.
 \endverbatim
*/

extern unsigned int __unsigned_int_flags_dummy;

#define ast_test_flag(p,flag) 		({ \
					typeof ((p)->flags) __p = (p)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__p == &__x); \
					((p)->flags & (flag)); \
					})

#define ast_set_flag(p,flag) 		do { \
					typeof ((p)->flags) __p = (p)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__p == &__x); \
					((p)->flags |= (flag)); \
					} while(0)

#define ast_clear_flag(p,flag) 		do { \
					typeof ((p)->flags) __p = (p)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__p == &__x); \
					((p)->flags &= ~(flag)); \
					} while(0)

#define ast_copy_flags(dest,src,flagz)	do { \
					typeof ((dest)->flags) __d = (dest)->flags; \
					typeof ((src)->flags) __s = (src)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__d == &__x); \
					(void) (&__s == &__x); \
					(dest)->flags &= ~(flagz); \
					(dest)->flags |= ((src)->flags & (flagz)); \
					} while (0)

#define ast_set2_flag(p,value,flag)	do { \
					typeof ((p)->flags) __p = (p)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__p == &__x); \
					if (value) \
						(p)->flags |= (flag); \
					else \
						(p)->flags &= ~(flag); \
					} while (0)

#define ast_set_flags_to(p,flag,value)	do { \
					typeof ((p)->flags) __p = (p)->flags; \
					typeof (__unsigned_int_flags_dummy) __x = 0; \
					(void) (&__p == &__x); \
					(p)->flags &= ~(flag); \
					(p)->flags |= (value); \
					} while (0)

/* Non-type checking variations for non-unsigned int flags.  You
   should only use non-unsigned int flags where required by 
   protocol etc and if you know what you're doing :)  */
#define ast_test_flag_nonstd(p,flag) \
					((p)->flags & (flag))

#define ast_set_flag_nonstd(p,flag) 		do { \
					((p)->flags |= (flag)); \
					} while(0)

#define ast_clear_flag_nonstd(p,flag) 		do { \
					((p)->flags &= ~(flag)); \
					} while(0)

#define ast_copy_flags_nonstd(dest,src,flagz)	do { \
					(dest)->flags &= ~(flagz); \
					(dest)->flags |= ((src)->flags & (flagz)); \
					} while (0)

#define ast_set2_flag_nonstd(p,value,flag)	do { \
					if (value) \
						(p)->flags |= (flag); \
					else \
						(p)->flags &= ~(flag); \
					} while (0)

#define AST_FLAGS_ALL UINT_MAX

struct ast_flags {
	unsigned int flags;
};

struct ast_hostent {
	struct hostent hp;
	char buf[1024];
};

struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp);

/* ast_md5_hash 
	\brief Produces MD5 hash based on input string */
void ast_md5_hash(char *output, char *input);
/* ast_sha1_hash
	\brief Produces SHA1 hash based on input string */
void ast_sha1_hash(char *output, char *input);

int ast_base64encode_full(char *dst, const unsigned char *src, int srclen, int max, int linebreaks);
int ast_base64encode(char *dst, const unsigned char *src, int srclen, int max);
int ast_base64decode(unsigned char *dst, const char *src, int max);

/*! ast_uri_encode
	\brief Turn text string to URI-encoded %XX version 
 	At this point, we're converting from ISO-8859-x (8-bit), not UTF8
	as in the SIP protocol spec 
	If doreserved == 1 we will convert reserved characters also.
	RFC 2396, section 2.4
	outbuf needs to have more memory allocated than the instring
	to have room for the expansion. Every char that is converted
	is replaced by three ASCII characters.
	\param string	String to be converted
	\param outbuf	Resulting encoded string
	\param buflen	Size of output buffer
	\param doreserved	Convert reserved characters
*/

char *ast_uri_encode(const char *string, char *outbuf, int buflen, int doreserved);

/*!	\brief Decode URI, URN, URL (overwrite string)
	\param s	String to be decoded 
 */
void ast_uri_decode(char *s);

static force_inline void ast_slinear_saturated_add(short *input, short *value)
{
	int res;

	res = (int) *input + *value;
	if (res > 32767)
		*input = 32767;
	else if (res < -32767)
		*input = -32767;
	else
		*input = (short) res;
}
	
static force_inline void ast_slinear_saturated_multiply(short *input, short *value)
{
	int res;

	res = (int) *input * *value;
	if (res > 32767)
		*input = 32767;
	else if (res < -32767)
		*input = -32767;
	else
		*input = (short) res;
}

static force_inline void ast_slinear_saturated_divide(short *input, short *value)
{
	*input /= *value;
}

int test_for_thread_safety(void);

/*!
 * \brief thread-safe replacement for inet_ntoa().
 *
 * \note It is very important to note that even though this is a thread-safe
 *       replacement for inet_ntoa(), it is *not* reentrant.  In a single
 *       thread, the result from a previous call to this function is no longer
 *       valid once it is called again.  If the result from multiple calls to
 *       this function need to be kept or used at once, then the result must be
 *       copied to a local buffer before calling this function again.
 */
const char *ast_inet_ntoa(struct in_addr ia);

#ifdef inet_ntoa
#undef inet_ntoa
#endif
#define inet_ntoa __dont__use__inet_ntoa__use__ast_inet_ntoa__instead__

int ast_utils_init(void);
int ast_wait_for_input(int fd, int ms);

/*! ast_carefulwrite
	\brief Try to write string, but wait no more than ms milliseconds
	before timing out.

	\note If you are calling ast_carefulwrite, it is assumed that you are calling
	it on a file descriptor that _DOES_ have NONBLOCK set.  This way,
	there is only one system call made to do a write, unless we actually
	have a need to wait.  This way, we get better performance.
*/
int ast_carefulwrite(int fd, char *s, int len, int timeoutms);

/*! Compares the source address and port of two sockaddr_in */
static force_inline int inaddrcmp(const struct sockaddr_in *sin1, const struct sockaddr_in *sin2)
{
	return ((sin1->sin_addr.s_addr != sin2->sin_addr.s_addr) 
		|| (sin1->sin_port != sin2->sin_port));
}

#define AST_STACKSIZE 240 * 1024

#if defined(LOW_MEMORY)
#define AST_BACKGROUND_STACKSIZE 48 * 1024
#else
#define AST_BACKGROUND_STACKSIZE 240 * 1024
#endif

void ast_register_thread(char *name);
void ast_unregister_thread(void *id);

int ast_pthread_create_stack(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine)(void *),
			     void *data, size_t stacksize, const char *file, const char *caller,
			     int line, const char *start_fn);

#define ast_pthread_create(a, b, c, d) ast_pthread_create_stack(a, b, c, d,			\
							        0,				\
	 						        __FILE__, __FUNCTION__,		\
 							        __LINE__, #c)

#define ast_pthread_create_background(a, b, c, d) ast_pthread_create_stack(a, b, c, d,			\
									   AST_BACKGROUND_STACKSIZE,	\