#if !defined(lint) && !defined(SABER) && !defined(GCC_WALL)
static char XRNrcsid[] = "$Id: clientlib.c,v 1.14 1995/05/04 21:00:42 jik Exp $";
#endif

/* #define DEBUG */

/*
 * nntp client interface
 *
 * Copyright (c) 1988-1993, The Regents of the University of California.
 *
 * 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 the University of California not
 * be used in advertising or publicity pertaining to distribution of 
 * the software without specific, written prior permission.  The University
 * of California makes no representations about the suitability of this
 * software for any purpose.  It is provided "as is" without express or
 * implied warranty.
 *
 * THE UNIVERSITY OF CALIFORNIA DISCLAIMS ALL WARRANTIES WITH REGARD TO 
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND 
 * FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE FOR
 * ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
 * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "config.h"
#include "utils.h"
#include <X11/Xos.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#ifdef notdef
#if defined(AF_DECnet) && defined(ultrix)
# ifndef DECNET
#  define DECNET
# endif
#endif
#endif /* notdef */

#ifdef DECNET
#include <netdnet/dn.h>
#include <netdnet/dnetdb.h>
#endif

#include "codes.h"
#include "news.h"
#include "server.h"
#include "internals.h"
#include "clientlib.h"

#ifdef BSD_BFUNCS
#define memset(_Str_, _Chr_, _Len_) bzero(_Str_, _Len_)
#define memcpy(_To_, _From_, _Len_) bcopy(_From_, _To_, _Len_)
#endif

FILE	*ser_rd_fp = NULL;
FILE	*ser_wr_fp = NULL;

char	*server_init_msg = NULL;

#ifdef DECNET
static int get_dnet_socket _ARGUMENTS((char *));
#endif

static int get_tcp_socket _ARGUMENTS((char *));
int get_server_init_msg _ARGUMENTS((char **));

/*
 * getserverbyfile	Get the name of a server from a named file.
 *			Handle white space and comments.
 *			Use NNTPSERVER environment variable if set.
 *
 *	Parameters:	"file" is the name of the file to read.
 *
 *	Returns:	Pointer to static data area containing the
 *			first non-ws/comment line in the file.
 *			NULL on error (or lack of entry in file).
 *
 *	Side effects:	None.
 */

char * getserverbyfile(file)
    char *file;
{
    char *cp;
    static char	buf[256];

    if ((cp = getenv("NNTPSERVER")) != 0) {
	(void) strcpy(buf, cp);
    } else {
	cp = getinfofromfile(file);
	if (cp == NULL) {
	    return(NULL);
	} else {
	    (void) strcpy(buf, cp);
	}
    }
    return (buf);
}

/*
 * server_init  Get a connection to the remote news server.
 *
 *	Parameters:	"machine" is the machine to connect to.
 *
 *	Returns:	-1 on error
 *			server's initial response code on success.
 *
 *	Side effects:	Connects to server.
 *			"ser_rd_fp" and "ser_wr_fp" are fp's
 *			for reading and writing to server.
 */

int server_init(machine)
    char *machine;
{
#ifdef NNTPVIATIP
	char	line[256];
#else
	int	sockt_rd, sockt_wr;
#endif
	int 	retval, retval2;
	char 	*mode_init_msg;
#ifdef DECNET
	char	*cp;
#endif /* DECNET */

#ifdef NNTPVIATIP
	ser_rd_fp = fdopen(3, "r"); /* 3 is dictated by tip(1) ~C command */
	ser_wr_fp = fdopen(4, "r"); /* 4 is dictated by tip(1) ~C command */
	(void) sprintf(line, "telnet %s %d", machine, 119);
	put_server(line);
	get_server(line, sizeof(line)); /* Trying ... */
	get_server(line, sizeof(line)); /* Connected to ... */
	get_server(line, sizeof(line)); /* Escape character is ... */
#else /* NNTPVIATIP */

#ifdef DECNET

	cp = index(machine, ':');

	if (cp && cp[1] == ':') {
		*cp = '\0';
		sockt_rd = get_dnet_socket(machine);
	} else
		sockt_rd = get_tcp_socket(machine);

#else  /* DECNET */

	sockt_rd = get_tcp_socket(machine);

#endif /* DECNET */

	if (sockt_rd < 0)
		return (-1);

	/*
	 * Now we'll make file pointers (i.e., buffered I/O) out of
	 * the socket file descriptor.  Note that we can't just
	 * open a fp for reading and writing -- we have to open
	 * up two separate fp's, one for reading, one for writing.
	 */

	if ((ser_rd_fp = fdopen(sockt_rd, "r")) == NULL) {
		perror("server_init: fdopen #1");
		return (-1);
	}

	sockt_wr = dup(sockt_rd);
	if ((ser_wr_fp = fdopen(sockt_wr, "w")) == NULL) {
		perror("server_init: fdopen #2");
		(void) fclose(ser_rd_fp);
		ser_rd_fp = NULL;		/* from above */
		return (-1);
	}
#endif /* NNTPVIATIP */

	if (server_init_msg) {
	    XtFree(server_init_msg);
	    server_init_msg = 0;
	}

	if ((retval = get_server_init_msg(&server_init_msg)) < 0) {
	    return (retval);
	}

	/*
	  Make sure we're in READER mode.  Now, you may be saying to
	  yourself, "Why is this necessary?  The only news server that
	  supports the MODE command is INN, and if the person
	  compiling this program is using INN, he's going to link
	  against the INN client libraries anyway, so this function
	  won't ever be used."  Well, first of all, other news servers
	  are probably going to support the MODE command at some point
	  in the future.  Second, someone may want to compile XRN
	  without access to the INN client libraries and still talk to
	  an INN server.

	  In any case, it doesn't hurt to send the MODE command and
	  see what happens.
	  */

	put_server("MODE READER");

	if ((retval2 = get_server_init_msg(&mode_init_msg)) < 0) {
	    XtFree(server_init_msg);
	    server_init_msg = 0;
	    return (retval2);
	}

	if ((*mode_init_msg == CHAR_OK) || (retval2 == ERR_ACCESS)) {
	    XtFree(server_init_msg);
	    server_init_msg = mode_init_msg;
	    return (retval2);
	}
	else {
	    XtFree(mode_init_msg);
	    return (retval);
	}
}

/*
 * get_server_init_msg - get a banner message from the server.
 *
 *	Parameters:	"msg" a pointer into which the message will be
 *			placed.  It should be freed when it is no
 *			longer needed.
 *
 *	Returns:	-1 on error or the server response code.
 *
 *	Side effects:	Reads data from server, closes server
 *			connection on error.
 *
 *	Errors:		Printed to stderr.
 */

int get_server_init_msg(in_msg)
    char **in_msg;
{
    char line[256];
    int length;
    char *msg;

    msg = XtMalloc(1024);
    *msg = '\0';
    length = 1024;

    do {
	if (get_server(line, sizeof(line)) == -1) {
	    if (feof(ser_rd_fp)) {
		fprintf(stderr, "Unexpected EOF on NNTP server socket -- server is probably malfunctioning.\n");
	    }
	    else {
		perror("reading from server");
	    }
	    XtFree(msg);
	    (void) fclose(ser_rd_fp);
	    (void) fclose(ser_wr_fp);
	    ser_rd_fp = ser_wr_fp = NULL;
	    return (-1);
	}
	while (strlen(line)+strlen(msg)+1 >= (unsigned) length) {
	    length += 1024;
	    msg = XtRealloc(msg, length);
	}
	strcat(msg, line);
	strcat(msg, "\n");
    } while (line[3] == '-');

    *in_msg = msg;
    return (atoi(line));
}

/*
 * get_tcp_socket -- get us a socket connected to the news server.
 *
 *	Parameters:	"machine" is the machine the server is running on.
 *
 *	Returns:	Socket connected to the news server if
 *			all is ok, else -1 on error.
 *
 *	Side effects:	Connects to server.
 *
 *	Errors:		Printed via perror.
 *
 *  This is a rewrite of the original get_tcp_socket.  This rewrite was
 *  supplied by Casey Leedom <casey@gauss.llnl.gov>
 */
static int get_tcp_socket1 _ARGUMENTS((struct sockaddr_in *));

static int get_tcp_socket(machine)
    char *machine;
{
	int	s;
#ifdef h_addr
	register char **cp;
#endif /* h_addr */
	struct	sockaddr_in sin;
	struct servent *getservbyname _ARGUMENTS((CONST char *, CONST char *));
        struct servent *sp;
	struct hostent *gethostbyname _ARGUMENTS((CONST char *)), *hp;

	(void) memset((char *) &sin, 0, sizeof(sin));
	if ((sp = getservbyname("nntp", "tcp")) ==  NULL) {
		(void) fprintf(stderr, "nntp/tcp: Unknown service.\n");
		return (-1);
	}
	sin.sin_port = sp->s_port;
	if ((sin.sin_addr.s_addr = inet_addr(machine)) != -1) {
	    sin.sin_family = AF_INET;
	    return(get_tcp_socket1(&sin));
	} else {
	    if ((hp = gethostbyname(machine)) == NULL) {
		    (void) fprintf(stderr, "%s: Unknown host.\n", machine);
		    return (-1);
	    }
	    sin.sin_family = hp->h_addrtype;
	}

	/*
	 * The following is kinda gross.  The 4.3BSD hostent structure
	 * contains a list of addresses, each of which should be tried in
	 * turn if the previous one fails.  However, 4.2 hostent structure
	 * doesn't have this list of addresses.  Under 4.3, h_addr is a
	 * #define to h_addr_list[0].  We use this to figure out whether to
	 * include the NS specific code ...
	 */

#ifdef	h_addr

	/* attempt multiple addresses */

	for (s = 0, cp = hp->h_addr_list; *cp; cp++) {
		if (s < 0)
			(void) fprintf(stderr,
				       "trying alternate address for %s\n",
				       machine);
		(void) memcpy((char *) &sin.sin_addr, *cp, hp->h_length);
		s = get_tcp_socket1(&sin);
		if (s >= 0)
			return(s);
	}
	(void) fprintf(stderr, "giving up ...\n");
	return(-1);

#else	/* 4.2BSD hostent structure */

	(void) memcpy((char *) &sin.sin_addr, hp->h_addr, hp->h_length);
	return(get_tcp_socket1(&sin));

#endif
}

static int get_tcp_socket1(sp)
    struct sockaddr_in *sp;
{
	int s;

	s = socket(sp->sin_family, SOCK_STREAM, 0);
	if (s < 0) {
		(void) perror("socket");
		return (-1);
	}
	if (connect(s, (struct sockaddr *)sp, sizeof (*sp)) < 0) {
		(void) perror("connect");
		(void) close(s);
		return(-1);
	}
	return(s);
}


#ifdef DECNET
/*
 * get_dnet_socket -- get us a socket connected to the news server.
 *
 *	Parameters:	"machine" is the machine the server is running on.
 *
 *	Returns:	Socket connected to the news server if
 *			all is ok, else -1 on error.
 *
 *	Side effects:	Connects to server.
 *
 *	Errors:		Printed via nerror.
 */

static int get_dnet_socket(machine)
    char *machine;
{
	int	s, area, node;
	struct	sockaddr_dn sdn;
	struct	nodeent *getnodebyname(), *np;

	(void) memset((char *) &sdn, 0, sizeof(sdn));

	switch (s = sscanf( machine, "%d%*[.]%d", &area, &node )) {
		case 1: 
			node = area;
			area = 0;
		case 2: 
			node += area*1024;
			sdn.sdn_add.a_len = 2;
			sdn.sdn_family = AF_DECnet;
			sdn.sdn_add.a_addr[0] = node % 256;
			sdn.sdn_add.a_addr[1] = node / 256;
			break;
		default:
			if ((np = getnodebyname(machine)) == NULL) {
			    (void) fprintf(stderr, 
				    "%s: Unknown host.\n", machine);
			    return (-1);
			} else {
			    (void) memcpy((char *) sdn.sdn_add.a_addr, 
					  np->n_addr, 
					  np->n_length);
			    sdn.sdn_add.a_len = np->n_length;
			    sdn.sdn_family = np->n_addrtype;
			}
			break;
	}
	sdn.sdn_objnum = 0;
	sdn.sdn_flags = 0;
	sdn.sdn_objnamel = strlen("NNTP");
	(void) memcpy(&sdn.sdn_objname[0], "NNTP", sdn.sdn_objnamel);

	if ((s = socket(AF_DECnet, SOCK_SEQPACKET, 0)) < 0) {
		nerror("socket");
		return (-1);
	}

	/* And then connect */

	if (connect(s, (struct sockaddr *) &sdn, sizeof(sdn)) < 0) {
		nerror("connect");
		close(s);
		return (-1);
	}

	return (s);
}
#endif /* DECNET */

/*
 * handle_server_response
 *
 *	Print some informative messages based on the server's initial
 *	response code.  This is here so inews, rn, etc. can share
 *	the code.
 *
 *	Parameters:	"response" is the response code which the
 *			server sent us, presumably from "server_init",
 *			above.
 *			"server" is the news server we got the
 *			response code from.
 *
 *	Returns:	-1 if the error is fatal (and we should exit).
 *			0 otherwise.
 *
 *	Side effects:	None.
 */

int handle_server_response(response, server)
    int	response;
    char *server;
{
    switch (response) {
	case OK_NOPOST:		/* fall through */
    		printf(
	"NOTE: This machine does not have permission to post articles.\n");
		printf(
	"      Please don't waste your time trying.\n\n");

	case OK_CANPOST:
		return (0);

	case ERR_ACCESS:
		printf(
   "This machine does not have permission to use the %s news server.\n",
		server);
		return (-1);

	case ERR_GOODBYE:
 		printf(
	"The news service is currently not available from %s:\n\n",
		       server);
		fputs(server_init_msg, stdout);
		return(-1);
		break;

  	default:
		printf("Unexpected response code from the %s news server.\n",
			server);
		if (server_init_msg)
		    printf("\n%s", server_init_msg);
		return (-1);
    }
	/*NOTREACHED*/
}

/*
 * put_server -- send a line of text to the server, terminating it
 * with CR and LF, as per ARPA standard.
 *
 *	Parameters:	"string" is the string to be sent to the
 *			server.
 *
 *	Returns:	Nothing.
 *
 *	Side effects:	Talks to the server.
 *
 *	Note:		This routine flushes the buffer each time
 *			it is called.  For large transmissions
 *			(i.e., posting news) don't use it.  Instead,
 *			do the fprintf's yourself, and then a final
 *			fflush.
 */

void put_server(string)
    char *string;
{
#ifdef DEBUG
	(void) fprintf(stderr, ">>> %s\n", string);
#endif
	(void) fprintf(ser_wr_fp, "%s\r\n", string);
	(void) fflush(ser_wr_fp);
#ifdef NNTPVIATIP
	{
	    char line[256];
	    get_server(line, sizeof(line));
	}
#endif
}

/*
 * get_server -- get a line of text from the server.  Strips
 * CR's and LF's.
 *
 *	Parameters:	"string" has the buffer space for the
 *			line received.
 *			"size" is the size of the buffer.
 *
 *	Returns:	-1 on error, 0 otherwise.
 *
 *	Side effects:	Talks to server, changes contents of "string".
 */

int get_server(string, size)
    char *string;
    int size;
{
    register char *cp;

    if (fgets(string, size, ser_rd_fp) == NULL) {
	return (-1);
    }
#ifdef NNTPVIATIP
    for (cp = string; cp < &string[size]; cp++) {
	*cp = *cp & 0x7F;
	if (*cp == '\0') {
	    break;
	}
    }
#endif
    if ((cp = index(string, '\r')) != NULL)
	*cp = '\0';
    else if ((cp = index(string, '\n')) != NULL)
	*cp = '\0';
#ifdef DEBUG
    (void) fprintf(stderr, "<<< %s\n", string);
#endif
    return (0);
}

/*
 * close_server -- close the connection to the server, after sending
 *		the "quit" command.
 *
 *	Parameters:	None.
 *
 *	Returns:	Nothing.
 *
 *	Side effects:	Closes the connection with the server.
 *			You can't use "put_server" or "get_server"
 *			after this routine is called.
 */

void close_server()
{
	char	ser_line[256];

	if (ser_wr_fp == NULL || ser_rd_fp == NULL)
		return;

	put_server("QUIT");
	(void) get_server(ser_line, sizeof(ser_line));

	(void) fclose(ser_wr_fp);
	(void) fclose(ser_rd_fp);
	ser_wr_fp = ser_rd_fp = NULL;
}