poslib/domainfn.h File Reference

domain-name manipulation More...

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Classes
class	domainname
	class representing a domain name More...
struct	dom_compr_info
	internal domain name compression structure More...
Defines
#define	DOM_LEN   255
	Maximum length of binary domain name.
#define	DOMLABEL_LEN   63
	Maximum length of domain name label.
#define	tocstr()   tostring().c_str()
	convert to human-readable character array
Typedefs
typedef char	_sdomain [DOM_LEN]
	static binary domain name
Functions
void *	memdup (const void *src, int len)
	dump memory
int	dom_comprlen (message_buff &buff, int ix)
	compressed length
_domain	dom_uncompress (message_buff &buff, int ix)
	uncompress domain name
void	dom_write (stl_string &ret, _domain dom, stl_slist(dom_compr_info)&compr)
	compress domain name
_domain	domfrom (_domain dom, int ix)
	domain name portion pointer
bool	domisparent (_domain parent, _domain child)
	test for parent<->child relationship
int	domlen (const _domain dom)
	length of binary domain name
_domain	domdup (const _domain dom)
	dynamic copy of binary domain name
bool	domlcmp (const _domain dom1, const _domain dom2)
	compare binary domain labels
bool	domcmp (const _domain dom1, const _domain dom2)
	compare binary domain names
void	domcat (_domain target, const _domain src)
	domain name concatenation
void	domcpy (_domain res, const _domain src)
	static copy of binary domain name
void	domfromlabel (_domain dom, const char *label, int len=-1)
	create domain name from label
stl_string	dom_tostring (const _domain dom)
	to-string conversion
int	dom_nlabels (const _domain dom)
	number of labels
stl_string	dom_label (const _domain dom, int label)
	label of domain name
const _domain	dom_plabel (const _domain dom, int label)
	label of domain name
int	domncommon (const _domain dom1, const _domain dom2)
	check label match count
int	domccmp (const _domain _dom1, const _domain _dom2)
	compare domain names
void	domto (_domain ret, const _domain src, int labels)
	return domain name portion

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Detailed Description

domain-name manipulation

This source file offers various functions for domain-name manipulation. Firstly, it offers the domainname class, which is a C++ class representing a domain name. Secondly, it offers various functions for reading and writing domain names from and to DNS messages, and thirdly, it offers functions which can be used to manipulate domain names as they would appear in DNS messages. These functions use the _domain typedef to represent such a domain name. Usually you will not need to call these yourself.

Definition in file domainfn.h.

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Define Documentation

#define DOM_LEN   255

Maximum length of binary domain name. This is the maximum length of a decompressed binary domain name. Definition at line 47 of file domainfn.h.

#define DOMLABEL_LEN   63

Maximum length of domain name label. This is the maximum length of a domain name label, not including the length byte (in binary data), or the trailing ' ' label. Definition at line 55 of file domainfn.h.

#define tocstr (   )     tostring().c_str()

convert to human-readable character array Converts the domain name to a human-readable character array. It will also have a trailing dot. This is static data, so if you want a copy, use a strdup(). See also: tostring() Definition at line 256 of file domainfn.h.

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Typedef Documentation

typedef char _sdomain[DOM_LEN]

static binary domain name Use this typedef if you want to declare a static _domain variable. Definition at line 334 of file domainfn.h.

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Function Documentation

int dom_comprlen (  message_buff &  buff, int  ix )

compressed length This function returns the compressed length - that is, the length the domain takes up in the DNS message - of a domain name. Parameters: buff  A DNS messagee ix  Index of the domain name Returns: Length in bytes the domain name takes up.

stl_string dom_label (  const _domain  dom, int  label )

label of domain name Returns a label of the domain name in human-readable form. Parameters: dom  The domain name label  Label index (0 <= label < #dom_nlabels(dom)) Returns: The label See also: dom_nlabels()

int dom_nlabels (  const _domain  dom  )

number of labels Returns the number of labels, also counting the empty ' ' label, of the domain name. Parameters: dom  The domain name Returns: Number of labels

const _domain dom_plabel (  const _domain  dom, int  label )

label of domain name Returns a label of the domain name as a pointer to the position in the domain. Parameters: dom  The domain name label  Label index (0 < label < #dom_nlabels(dom)) Returns: The label See also: dom_nlabels()

stl_string dom_tostring (  const _domain  dom  )

to-string conversion Converts the domain name to a human-readable string. Contains the trailing dot. Parameters: dom  The domain name Returns: Human-readable string.

_domain dom_uncompress (  message_buff &  buff, int  ix )

uncompress domain name This function decompresses a domain name in a DNS message. It returns the binary, decompressed data describing the domain name. Parameters: buff  A DNS message ix  Index of the domain name Returns: Uncompressed binary domain name (dynamically allocated)

void dom_write (  stl_string &  ret, _domain  dom, stl_slist(dom_compr_info)&  compr )

compress domain name This function writes a domain name to the end of a DNS message, compressing it if possible. Parameters: ret  A (partial) DNS message dom  Domain name to write compr  List of earlier compressed domain names

void domcat (  _domain  target, const _domain  src )

domain name concatenation Appends src to target. Since it does not re-allocate memory, Make sure that target can hold at least #DOM_MAX bytes. Parameters: target  Target src  Source

int domccmp (  const _domain  _dom1, const _domain  _dom2 )

compare domain names This function offers a way to compare domain names the way the strcmp do. It operates in such a way that child domains are greater than parent domains, and for for other domains, the first non-matching domain label is compared using strcmpi. For example, www.foo.acdam.net is greater than bar.acdam.net because foo is greater than bar which is the first non-matching label after the common acdam.net part of the domain names. Parameters: dom1  First domain name dom2  Second domain name Returns: <0, 0 or >0 if the first domain name is smaller than, equal to, or larger than the second one, respectively.

bool domcmp (  const _domain  dom1, const _domain  dom2 )

compare binary domain names Checks whether both binary domain names are equal. Parameters: dom1  First domain name dom2  Second domain name Returns: true if the domain names are equal

void domcpy (  _domain  res, const _domain  src )

static copy of binary domain name Makes a static copy of a domain name. Make sure that res can hold at least #DOM_MAX bytes. Parameters: res  Target src  Source See also: domdup()

_domain domdup (  const _domain  dom  )

dynamic copy of binary domain name Makes a dynamically allocated copy of a domain name. Parameters: dom  Domain name Returns: Copy of domain name See also: domcpy()

_domain domfrom (  _domain  dom, int  ix )

domain name portion pointer Returns a pointer to the portion of the domain name from the ix'th label. Parameters: dom  Domain name ix  Index Returns: Domain name portion

void domfromlabel (  _domain  dom, const char *  label, int  len = -1 )

create domain name from label Creates a domain name containing just one label: the string argument given. If a length is given, only the first few characters of the string are used. Make sure that dom can hold at least #DOM_MAX bytes. Parameters: dom  Result label  String label len  If given, length of string label (default: strlen(label)).

bool domisparent (  _domain  parent, _domain  child )

test for parent<->child relationship Tests whether the first domain name is a parent of the second domain name. Parameters: parent  Parent domain child  Child domain Returns: True if parent is indeed a parent of child .

bool domlcmp (  const _domain  dom1, const _domain  dom2 )

compare binary domain labels Checks whether both binary domain name start with the same label. Parameters: dom1  First domain name dom2  Second domain name Returns: true if the domain names start with the same label

int domlen (  const _domain  dom  )

length of binary domain name Returns the length, in bytes, including the trailing ' ' character, of the domain name. Parameters: dom  Domain name Returns: Length of the domain name

int domncommon (  const _domain  dom1, const _domain  dom2 )

check label match count Returns the number of labels the two domain names have in common at their ends; for example this returns 2 for www.acdam.net and www.foo.acdam.net . Parameters: dom  The domain name to check with Returns: Number of common labels See also: nlabels()

void domto (  _domain  ret, const _domain  src, int  labels )

return domain name portion Returns a domain name consisting of the first label labels of the given domain name. The ret buffer should be large enough to hold the result to prevent a buffer overflow. Parameters: ret  Result buffer src  Source domain labels  Number of labels to include

void* memdup (  const void *  src, int  len )

dump memory This is an alternative to the c strdup() function, but instead it can dump any type of memory, as long as you give the right length. Parameters: src  Source memory location len  Length of data Returns: A newly-allocated copy of src.

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