NAME
libinn - InterNetNews library routines
SYNOPSIS
#include "inn/libinn.h"
char *
GenerateMessageID(domain)
char *domain;
void
HeaderCleanFrom(from)
char *from;
char *
HeaderFind(Article, Header, size)
char *Article;
char *Header;
int size;
FILE *
CAopen(FromServer, ToServer)
FILE *FromServer;
FILE *ToServer;
FILE *
CAlistopen(FromServer, ToServer, request)
FILE *FromServer;
FILE *ToServer;
char *request;
void
CAclose()
struct _DDHANDLE *
DDstart(FromServer, ToServer)
FILE *FromServer;
FILE *ToServer;
void
DDcheck(h, group)
DDHANDLE *h;
char *group;
char *
DDend(h)
DDHANDLE *h;
void
close_on_exec(fd, flag)
int fd;
bool flag;
int
nonblocking(fd, flag)
int fd;
bool flag;
bool
inn_lock_file(fd, type, flag)
int fd;
LOCKTYPE type;
bool block;
char *
GetFQDN(domain)
char *domain;
char *
GetModeratorAddress(FromServer, ToServer, group, moderatormailer)
FILE *FromServer;
FILE *ToServer;
char *group;
char *moderatormailer;
int
GetResourceUsage(usertime, systime)
double *usertime;
double *systime;
int
NNTPlocalopen(FromServerp, ToServerp, errbuff, len)
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
size_t len;
int
NNTPremoteopen(port, FromServerp, ToServerp, errbuff, len)
int port;
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
size_t len;
int
NNTPconnect(host, port, FromServerp, ToServerp, errbuff, len)
char *host;
int port;
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
size_t len;
int
NNTPsendarticle(text, ToServer, Terminate)
char *text;
FILE *ToServer;
int Terminate;
int
NNTPsendpassword(server, FromServer, ToServer)
char *server;
FILE *FromServer;
FILE *ToServer;
void
Radix32(value, p)
unsigned long value;
char *p;
char *
ReadInFile(name, Sbp)
char *name;
struct stat *Sbp;
char *
ReadInDescriptor(fd, Sbp)
int fd;
struct stat *Sbp;
HASH
HashMessageID(MessageID)
const char *MessageID;
DESCRIPTION
Libinn is a library of utility routines for manipulating Usenet
articles and related data.
GenerateMessageID uses the current time, process-ID, and fully-
qualified domain name, which is passed as an argument and used if local
host can not be resolved or it is different from ‘‘domain’’ set in
inn.conf, to create a Message-ID header that is highly likely to be
unique. The returned value points to static space that is reused on
subsequent calls.
HeaderCleanFrom removes the extraneous information from the value of a
‘‘From’’ or ‘‘Reply-To’’ header and leaves just the official mailing
address. In particular, the following transformations are made to the
from parameter:
address --> address
address (stuff) --> address
stuff <address> --> address
The transformations are simple, based on RFC 5536 which limits the
format of the header.
HeaderFind searches through Article looking for the specified Header.
Size should be the length of the header name. It returns a pointer to
the value of the header, skipping leading whitespace, or NULL if the
header cannot be found. Article should be a standard C string
containing the text of the article; the end of the headers is indicated
by a blank line — two consecutive \n characters.
CAopen and CAclose provide news clients with access to the active file;
the ‘‘CA’’ stands for Client Active. CAopen opens the active file for
reading. It returns a pointer to an open FILE, or NULL on error. If a
local or NFS-mounted copy exists, CAopen will use that file. The
FromServer and ToServer parameters should be FILE’s connected to the
NNTP server for input and output, respectively. See NNTPremoteopen or
NNTPlocalopen, below. If either parameter is NULL, then CAopen will
just return NULL if the file is not locally available. If they are not
NULL, CAopen will use them to query the NNTP server using the ‘‘list’’
command to make a local temporary copy.
The CAlistopen sends a ‘‘list’’ command to the server and returns a
temporary file containing the results. The request parameter, if not
NULL, will be sent as an argument to the command. Unlike CAopen, this
routine will never use a locally-available copy of the active file.
CAclose closes the active file and removes any temporary file that
might have been created by CAopen or CAlistopen.
CloseOnExec can make a descriptor ‘‘close-on-exec’’ so that it is not
shared with any child processes. If the flag is non-zero, the file is
so marked; if zero, the ‘‘close-on-exec’’ mode is cleared.
DDstart, DDcheck, and DDend are used to set the Distribution header;
the ‘‘DD’’ stands for Default Distribution. The distrib.pats file is
consulted to determine the proper value for the Distribution header
after all newsgroups have been checked. DDstart begins the parsing.
It returns a pointer to an opaque handle that should be used on
subsequent calls. The FromServer and ToServer parameters should be
FILE’s connected to the NNTP server for input and output, respectively.
If either parameter is NULL, then an empty default will ultimately be
returned if the file is not locally available.
DDcheck should be called with the handle, h, returned by DDstart and a
newgroups, group, to check. It can be called as often as necessary.
DDend releases any state maintained in the handle and returns an
allocated copy of the text that should be used for the Distribution
header.
SetNonBlocking enables (if flag is non-zero) or disables (if flag is
zero) non-blocking I/O on the indicated descriptor. It returns -1 on
failure or zero on success.
inn_lock_file tries to lock the file descriptor fd. If block is true
it will block until the lock can be made, otherwise it will return
false if the file cannot be locked. type is one of: INN_LOCK_READ,
INN_LOCK_WRITE, or INN_LOCK_UNLOCK. It returns false on failure or
true on success.
GetFQDN returns the fully-qualified domain name of the local host.
Domain is used if local host can not be resolved. The returned value
points to static space that is reused on subsequent calls, or NULL on
error.
GetModeratorAddress returns the mailing address of the moderator for
specified group or NULL on error. Moderatormailer is used as its
address, if there is no matched moderator. See moderators(5) for
details on how the address is determined. GetModeratorAddress does no
checking to see if the specified group is actually moderated. The
returned value points to static space that is reused on subsequent
calls. The FromServer and ToServer parameters should be FILE’s
connected to the NNTP server for input and output, respectively. If
either of these parameters is NULL, then an attempt to get the list
from a local copy is made.
GetResourceUsage fills in the usertime and systime parameters with the
total user and system time used by the current process and any children
it may have spawned. If <HAVE_GETRUSAGE in include/config.h> is
defined, it gets the values by doing a getrusage(2) system call;
otherwise it calls times(2). It returns -1 on failure, or zero on
success.
NNTPlocalopen opens a connection to the private port of an InterNetNews
server running on the local host, if <HAVE_UNIX_DOMAIN_SOCKETS in
include/config.h> is defined. It returns -1 on failure, or zero on
success. FromServerp and ToServerp will be filled in with FILE’s which
can be used to communicate with the server. Errbuff can either be NULL
or a pointer to a buffer at least 512 bytes long. If not NULL, and the
server refuses the connection, then it will be filled in with the text
of the server’s reply. Len should be the length of the buffer. This
routine is not for general use. If <HAVE_UNIX_DOMAIN_SOCKETS in
include/config.h> is not defined, this is a stub routine, for
compatibility with systems that have Unix-domain stream sockets. It
always returns -1.
NNTPremoteopen does the same except that it uses ‘‘innconf->server’’ as
the local server, and opens a connection to the port. Any client
program can use this routine. It returns -1 on failure, or zero on
success.
NNTPconnect is the same as NNTPremoteopen except that the desired host
is given as the host parameter.
NNTPsendarticle writes text on ToServer using NNTP conventions for line
termination. The text should consist of one or more lines ending with
a newline. If Terminate is non-zero, then the routine will also write
the NNTP data-termination marker on the stream. It returns -1 on
failure, or zero on success.
NNTPsendpassword sends authentication information to an NNTP server by
finding the appropriate entry in the passwd.nntp file. Server contains
the name of the host; ‘‘innconf->server’’ will be used if server is
NULL. FromServer and ToServer should be FILE’s that are connected to
the server. No action is taken if the specified host is not listed in
the password file.
Radix32 converts the number in value into a radix-32 string into the
buffer pointed to by p. The number is split into five-bit pieces and
each pieces is converted into a character using the alphabet 0..9a..v
to represent the numbers 0..32. Only the lowest 32 bits of value are
used, so p need only point to a buffer of eight bytes (seven characters
and the trailing \0).
ReadInFile reads the file named name into allocated memory, appending a
terminating \0 byte. It returns a pointer to the space, or NULL on
error. If Sbp is not NULL, it is taken as the address of a place to
store the results of a stat(2) call.
ReadInDescriptor performs the same function as ReadInFile except that
fd refers to an already-open file.
HashMessageID returns hashed message-id using MD5.
EXAMPLES
char *p;
char *Article;
char buff[256], errbuff[256];
FILE *F;
FILE *ToServer;
FILE *FromServer;
int port = 119;
if ((p = HeaderFind(Article, "From", 4)) == NULL)
Fatal("Can’t find From line");
(void)strcpy(buff, p);
HeaderCleanFrom(buff);
if ((F = CAopen(FromServer, ToServer)) == NULL)
Fatal("Can’t open active file");
/* Don’t pass the file on to our children. */
CloseOnExec(fileno(F), 1);
/* Make a local copy. */
p = ReadInDescriptor(fileno(F), (struct stat *)NULL);
/* Close the file. */
CAclose();
if (NNTPremoteopen(port, &FromServer, &ToServer, errbuff) < 0)
Fatal("Can’t connect to server");
if ((p = GetModeratorAddress("comp.sources.unix")) == NULL)
Fatal("Can’t find moderator’s address");
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. This is
revision 8894, dated 2010-01-17.
SEE ALSO
active(5), dbz(3z), inn.conf(5), inndcomm(3), moderators(5),
passwd.nntp(5).