Dominick Meglio's new ares_expand_string() function

* March 30, 2004

- Dominick Meglio's new ares_expand_string. A helper function when decoding

  incoming DNS packages.

- Daniel Stenberg modified the Makefile.in to use a for loop for the man page

  installation to improve overview and make it easier to add man pages.

* March 9, 2004

- Gisle Vanem improved build on Windows.

	ares_free_hostent.o ares_free_string.o ares_gethostbyaddr.o \

	ares_gethostbyname.o ares_init.o ares_mkquery.o ares_parse_a_reply.o \

	ares_parse_ptr_reply.o ares_process.o ares_query.o ares_search.o \

	ares_send.o ares_strerror.o ares_timeout.o ares_version.o

	ares_send.o ares_strerror.o ares_timeout.o ares_version.o \

	ares_expand_string.o

MANPAGES= ares_destroy.3 ares_expand_name.3 ares_expand_string.3 ares_fds.3   \

        ares_free_hostent.3 ares_free_string.3 ares_gethostbyaddr.3	      \

        ares_gethostbyname.3 ares_init.3 ares_init_options.3 ares_mkquery.3   \

        ares_parse_a_reply.3 ares_parse_ptr_reply.3 ares_process.3	      \

        ares_query.3 ares_search.3 ares_send.3 ares_strerror.3 ares_timeout.3 \

        ares_version.3

$(LIB): ${OBJS}

	ar cru $@ ${OBJS}

	chmod u-w ${DESTDIR}${libdir}/$(LIB)

	${INSTALL} -m 444 ${srcdir}/ares.h ${DESTDIR}${includedir}

	${INSTALL} -m 444 ${srcdir}/ares_version.h ${DESTDIR}${includedir}

	${INSTALL} -m 444 ${srcdir}/ares_destroy.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_expand_name.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_fds.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_free_hostent.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_free_string.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_gethostbyaddr.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_gethostbyname.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_init.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_init_options.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_mkquery.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_parse_a_reply.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_parse_ptr_reply.3 \

		${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_process.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_query.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_search.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_send.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_strerror.3 ${DESTDIR}${mandir}/man3

	${INSTALL} -m 444 ${srcdir}/ares_timeout.3 ${DESTDIR}${mandir}/man3

	(for man in $(MANPAGES); do \

	   ${INSTALL} -m 444 ${srcdir}/$${man} ${DESTDIR}${mandir}/man3; \

	done)

clean:

	rm -f ${OBJS} $(LIB) adig.o adig ahost.o ahost

#define ARES_EFILE		14

#define ARES_ENOMEM		15

#define ARES_EDESTRUCTION	16

#define ARES_EBADSTR		17

/* Flag values */

#define ARES_FLAG_USEVC		(1 << 0)

		 int rd, unsigned char **buf, int *buflen);

int ares_expand_name(const unsigned char *encoded, const unsigned char *abuf,

		     int alen, char **s, long *enclen);

int ares_expand_string(const unsigned char *encoded, const unsigned char *abuf,

		     int alen, unsigned char **s, long *enclen);

int ares_parse_a_reply(const unsigned char *abuf, int alen,

		       struct hostent **host);

int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr,

.\" $Id$

.\"

.\" Copyright 1998 by the Massachusetts Institute of Technology.

.\"

.\" Permission to use, copy, modify, and distribute this

.\" software and its documentation for any purpose and without

.\" fee is hereby granted, provided that the above copyright

.\" notice appear in all copies and that both that copyright

.\" notice and this permission notice appear in supporting

.\" documentation, and that the name of M.I.T. not be used in

.\" advertising or publicity pertaining to distribution of the

.\" software without specific, written prior permission.

.\" M.I.T. makes no representations about the suitability of

.\" this software for any purpose.  It is provided "as is"

.\" without express or implied warranty.

.\"

.TH ARES_EXPAND_NAME 3 "23 July 1998"

.SH NAME

ares_expand_string \- Expand a length encoded string

.SH SYNOPSIS

.nf

.B #include <ares.h>

.PP

.B int ares_expand_string(const unsigned char *\fIencoded\fP,

.B      const unsigned char *\fIabuf\fP, int \fIalen\fP, unsigned char **\fIs\fP,

.B 	int *\fIenclen\fP)

.fi

.SH DESCRIPTION

The

.B ares_expand_string

function converts a length encoded string to a NULL terminated C

string.  The argument

.I encoded

gives the beginning of the encoded string, and the arguments

.I abuf

and

.I alen

give the containing message buffer (necessary for the processing of

indirection pointers within the encoded domain name).  The result is

placed in a NUL-terminated allocated buffer, a pointer to which is

stored in the variable pointed to by

.IR s .

The length of the encoded string is stored in the variable pointed to by

.I enclen

so that the caller can advance past the encoded string to read

further data in the message.

.SH RETURN VALUES

.B ares_expand_string

can return any of the following values:

.TP 15

.B ARES_SUCCESS

Expansion of the encoded string succeeded.

.TP 15

.B ARES_EBADSTR

The encoded string was malformed and could not be expanded.

.TP 15

.B ARES_ENOMEM

Memory was exhausted.

.SH SEE ALSO

.BR ares_free_string (3)

.SH AUTHOR

Dominick Meglio

/* Copyright 1998 by the Massachusetts Institute of Technology.

 *

 * Permission to use, copy, modify, and distribute this

 * software and its documentation for any purpose and without

 * fee is hereby granted, provided that the above copyright

 * notice appear in all copies and that both that copyright

 * notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in

 * advertising or publicity pertaining to distribution of the

 * software without specific, written prior permission.

 * M.I.T. makes no representations about the suitability of

 * this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include <sys/types.h>

#ifdef WIN32

#include "nameser.h"

#else

#include <netinet/in.h>

#include <arpa/nameser.h>

#endif

#include <string.h>

#include <stdlib.h>

#include "ares.h"

#include "ares_private.h" /* for the memdebug */

/* Simply decodes a length-encoded character string. The first byte of the

 * input is the length of the string to be returned and the bytes thereafter

 * are the characters of the string. The returned result will be NULL

 * terminated.

 */

int ares_expand_string(const unsigned char *encoded,

                       const unsigned char *abuf,

                       int alen,

                       unsigned char **s,

                       long *enclen)

{

  unsigned char *q;

  long len;

  if (encoded == abuf+alen)

    return ARES_EBADSTR;

  len = *encoded;

  if (encoded+len+1 > abuf+alen)

    return ARES_EBADSTR;

  encoded++;

  *s = malloc(len+1);

  if (*s == NULL)

    return ARES_ENOMEM;

  q = *s; 

  strncpy((char *)q, (char *)encoded, len);

  q[len] = '\0';

  *s = q;

  *enclen = len+1; 

  return ARES_SUCCESS;

}