BSD 4.4 Lite Libexec Sources

7 files changed, 907 insertions, 0 deletions

diff --git a/libexec/talkd/Makefile b/libexec/talkd/Makefile
new file mode 100644
index 0000000..51f6806
--- /dev/null
+++ b/libexec/talkd/Makefile
@@ -0,0 +1,8 @@
+#	@(#)Makefile	8.1 (Berkeley) 6/4/93
+
+PROG=	ntalkd
+SRCS=	talkd.c announce.c process.c table.c print.c ttymsg.c
+.PATH:  ${.CURDIR}/../../usr.bin/wall
+MAN8=	talkd.0
+
+.include <bsd.prog.mk>
diff --git a/libexec/talkd/announce.c b/libexec/talkd/announce.c
new file mode 100644
index 0000000..e8c9915
--- /dev/null
+++ b/libexec/talkd/announce.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)announce.c	8.2 (Berkeley) 1/7/94";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <protocols/talkd.h>
+#include <sgtty.h>
+#include <errno.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <paths.h>
+
+extern char hostname[];
+
+/*
+ * Announce an invitation to talk.
+ */
+	
+/*
+ * See if the user is accepting messages. If so, announce that 
+ * a talk is requested.
+ */
+announce(request, remote_machine)
+	CTL_MSG *request;
+	char *remote_machine;
+{
+	char full_tty[32];
+	FILE *tf;
+	struct stat stbuf;
+
+	(void)snprintf(full_tty, sizeof(full_tty),
+	    "%s%s", _PATH_DEV, request->r_tty);
+	if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
+		return (PERMISSION_DENIED);
+	return (print_mesg(request->r_tty, tf, request, remote_machine));
+}
+
+#define max(a,b) ( (a) > (b) ? (a) : (b) )
+#define N_LINES 5
+#define N_CHARS 120
+
+/*
+ * Build a block of characters containing the message. 
+ * It is sent blank filled and in a single block to
+ * try to keep the message in one piece if the recipient
+ * in in vi at the time
+ */
+print_mesg(tty, tf, request, remote_machine)
+	char *tty;
+	FILE *tf;
+	CTL_MSG *request;
+	char *remote_machine;
+{
+	struct timeval clock;
+	struct timezone zone;
+	struct tm *localtime();
+	struct tm *localclock;
+	struct iovec iovec;
+	char line_buf[N_LINES][N_CHARS];
+	int sizes[N_LINES];
+	char big_buf[N_LINES*N_CHARS];
+	char *bptr, *lptr, *ttymsg();
+	int i, j, max_size;
+
+	i = 0;
+	max_size = 0;
+	gettimeofday(&clock, &zone);
+	localclock = localtime( &clock.tv_sec );
+	(void)sprintf(line_buf[i], " ");
+	sizes[i] = strlen(line_buf[i]);
+	max_size = max(max_size, sizes[i]);
+	i++;
+	(void)sprintf(line_buf[i], "Message from Talk_Daemon@%s at %d:%02d ...",
+	hostname, localclock->tm_hour , localclock->tm_min );
+	sizes[i] = strlen(line_buf[i]);
+	max_size = max(max_size, sizes[i]);
+	i++;
+	(void)sprintf(line_buf[i], "talk: connection requested by %s@%s",
+		request->l_name, remote_machine);
+	sizes[i] = strlen(line_buf[i]);
+	max_size = max(max_size, sizes[i]);
+	i++;
+	(void)sprintf(line_buf[i], "talk: respond with:  talk %s@%s",
+		request->l_name, remote_machine);
+	sizes[i] = strlen(line_buf[i]);
+	max_size = max(max_size, sizes[i]);
+	i++;
+	(void)sprintf(line_buf[i], " ");
+	sizes[i] = strlen(line_buf[i]);
+	max_size = max(max_size, sizes[i]);
+	i++;
+	bptr = big_buf;
+	*bptr++ = ''; /* send something to wake them up */
+	*bptr++ = '\r';	/* add a \r in case of raw mode */
+	*bptr++ = '\n';
+	for (i = 0; i < N_LINES; i++) {
+		/* copy the line into the big buffer */
+		lptr = line_buf[i];
+		while (*lptr != '\0')
+			*(bptr++) = *(lptr++);
+		/* pad out the rest of the lines with blanks */
+		for (j = sizes[i]; j < max_size + 2; j++)
+			*(bptr++) = ' ';
+		*(bptr++) = '\r';	/* add a \r in case of raw mode */
+		*(bptr++) = '\n';
+	}
+	*bptr = '\0';
+	iovec.iov_base = big_buf;
+	iovec.iov_len = bptr - big_buf;
+	/*
+	 * we choose a timeout of RING_WAIT-5 seconds so that we don't
+	 * stack up processes trying to write messages to a tty
+	 * that is permanently blocked.
+	 */
+	if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
+		return (FAILED);
+
+	return (SUCCESS);
+}
diff --git a/libexec/talkd/print.c b/libexec/talkd/print.c
new file mode 100644
index 0000000..9c0085b
--- /dev/null
+++ b/libexec/talkd/print.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)print.c	8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+/* debug print routines */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <protocols/talkd.h>
+#include <syslog.h>
+#include <stdio.h>
+
+static	char *types[] =
+    { "leave_invite", "look_up", "delete", "announce" };
+#define	NTYPES	(sizeof (types) / sizeof (types[0]))
+static	char *answers[] = 
+    { "success", "not_here", "failed", "machine_unknown", "permission_denied",
+      "unknown_request", "badversion", "badaddr", "badctladdr" };
+#define	NANSWERS	(sizeof (answers) / sizeof (answers[0]))
+
+print_request(cp, mp)
+	char *cp;
+	register CTL_MSG *mp;
+{
+	char tbuf[80], *tp;
+	
+	if (mp->type > NTYPES) {
+		(void)sprintf(tbuf, "type %d", mp->type);
+		tp = tbuf;
+	} else
+		tp = types[mp->type];
+	syslog(LOG_DEBUG, "%s: %s: id %d, l_user %s, r_user %s, r_tty %s",
+	    cp, tp, mp->id_num, mp->l_name, mp->r_name, mp->r_tty);
+}
+
+print_response(cp, rp)
+	char *cp;
+	register CTL_RESPONSE *rp;
+{
+	char tbuf[80], *tp, abuf[80], *ap;
+	
+	if (rp->type > NTYPES) {
+		(void)sprintf(tbuf, "type %d", rp->type);
+		tp = tbuf;
+	} else
+		tp = types[rp->type];
+	if (rp->answer > NANSWERS) {
+		(void)sprintf(abuf, "answer %d", rp->answer);
+		ap = abuf;
+	} else
+		ap = answers[rp->answer];
+	syslog(LOG_DEBUG, "%s: %s: %s, id %d", cp, tp, ap, ntohl(rp->id_num));
+}
diff --git a/libexec/talkd/process.c b/libexec/talkd/process.c
new file mode 100644
index 0000000..dd05e6b
--- /dev/null
+++ b/libexec/talkd/process.c
@@ -0,0 +1,219 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)process.c	8.2 (Berkeley) 11/16/93";
+#endif /* not lint */
+
+/*
+ * process.c handles the requests, which can be of three types:
+ *	ANNOUNCE - announce to a user that a talk is wanted
+ *	LEAVE_INVITE - insert the request into the table
+ *	LOOK_UP - look up to see if a request is waiting in
+ *		  in the table for the local user
+ *	DELETE - delete invitation
+ */
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <protocols/talkd.h>
+#include <netdb.h>
+#include <syslog.h>
+#include <stdio.h>
+#include <string.h>
+#include <paths.h>
+
+CTL_MSG *find_request();
+CTL_MSG *find_match();
+
+process_request(mp, rp)
+	register CTL_MSG *mp;
+	register CTL_RESPONSE *rp;
+{
+	register CTL_MSG *ptr;
+	extern int debug;
+
+	rp->vers = TALK_VERSION;
+	rp->type = mp->type;
+	rp->id_num = htonl(0);
+	if (mp->vers != TALK_VERSION) {
+		syslog(LOG_WARNING, "Bad protocol version %d", mp->vers);
+		rp->answer = BADVERSION;
+		return;
+	}
+	mp->id_num = ntohl(mp->id_num);
+	mp->addr.sa_family = ntohs(mp->addr.sa_family);
+	if (mp->addr.sa_family != AF_INET) {
+		syslog(LOG_WARNING, "Bad address, family %d",
+		    mp->addr.sa_family);
+		rp->answer = BADADDR;
+		return;
+	}
+	mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
+	if (mp->ctl_addr.sa_family != AF_INET) {
+		syslog(LOG_WARNING, "Bad control address, family %d",
+		    mp->ctl_addr.sa_family);
+		rp->answer = BADCTLADDR;
+		return;
+	}
+	mp->pid = ntohl(mp->pid);
+	if (debug)
+		print_request("process_request", mp);
+	switch (mp->type) {
+
+	case ANNOUNCE:
+		do_announce(mp, rp);
+		break;
+
+	case LEAVE_INVITE:
+		ptr = find_request(mp);
+		if (ptr != (CTL_MSG *)0) {
+			rp->id_num = htonl(ptr->id_num);
+			rp->answer = SUCCESS;
+		} else
+			insert_table(mp, rp);
+		break;
+
+	case LOOK_UP:
+		ptr = find_match(mp);
+		if (ptr != (CTL_MSG *)0) {
+			rp->id_num = htonl(ptr->id_num);
+			rp->addr = ptr->addr;
+			rp->addr.sa_family = htons(ptr->addr.sa_family);
+			rp->answer = SUCCESS;
+		} else
+			rp->answer = NOT_HERE;
+		break;
+
+	case DELETE:
+		rp->answer = delete_invite(mp->id_num);
+		break;
+
+	default:
+		rp->answer = UNKNOWN_REQUEST;
+		break;
+	}
+	if (debug)
+		print_response("process_request", rp);
+}
+
+do_announce(mp, rp)
+	register CTL_MSG *mp;
+	CTL_RESPONSE *rp;
+{
+	struct hostent *hp;
+	CTL_MSG *ptr;
+	int result;
+
+	/* see if the user is logged */
+	result = find_user(mp->r_name, mp->r_tty);
+	if (result != SUCCESS) {
+		rp->answer = result;
+		return;
+	}
+#define	satosin(sa)	((struct sockaddr_in *)(sa))
+	hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr,
+		sizeof (struct in_addr), AF_INET);
+	if (hp == (struct hostent *)0) {
+		rp->answer = MACHINE_UNKNOWN;
+		return;
+	}
+	ptr = find_request(mp);
+	if (ptr == (CTL_MSG *) 0) {
+		insert_table(mp, rp);
+		rp->answer = announce(mp, hp->h_name);
+		return;
+	}
+	if (mp->id_num > ptr->id_num) {
+		/*
+		 * This is an explicit re-announce, so update the id_num
+		 * field to avoid duplicates and re-announce the talk.
+		 */
+		ptr->id_num = new_id();
+		rp->id_num = htonl(ptr->id_num);
+		rp->answer = announce(mp, hp->h_name);
+	} else {
+		/* a duplicated request, so ignore it */
+		rp->id_num = htonl(ptr->id_num);
+		rp->answer = SUCCESS;
+	}
+}
+
+#include <utmp.h>
+
+/*
+ * Search utmp for the local user
+ */
+find_user(name, tty)
+	char *name, *tty;
+{
+	struct utmp ubuf;
+	int status;
+	FILE *fd;
+	struct stat statb;
+	char line[sizeof(ubuf.ut_line) + 1];
+	char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)];
+
+	if ((fd = fopen(_PATH_UTMP, "r")) == NULL) {
+		fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP);
+		return (FAILED);
+	}
+#define SCMPN(a, b)	strncmp(a, b, sizeof (a))
+	status = NOT_HERE;
+	(void) strcpy(ftty, _PATH_DEV);
+	while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
+		if (SCMPN(ubuf.ut_name, name) == 0) {
+			strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line));
+			line[sizeof(ubuf.ut_line)] = '\0';
+			if (*tty == '\0') {
+				status = PERMISSION_DENIED;
+				/* no particular tty was requested */
+				(void) strcpy(ftty + sizeof(_PATH_DEV) - 1,
+				    line);
+				if (stat(ftty, &statb) == 0) {
+					if (!(statb.st_mode & 020))
+						continue;
+					(void) strcpy(tty, line);
+					status = SUCCESS;
+					break;
+				}
+			}
+			if (strcmp(line, tty) == 0) {
+				status = SUCCESS;
+				break;
+			}
+		}
+	fclose(fd);
+	return (status);
+}
diff --git a/libexec/talkd/table.c b/libexec/talkd/table.c
new file mode 100644
index 0000000..cc8cb66
--- /dev/null
+++ b/libexec/talkd/table.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)table.c	8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+/*
+ * Routines to handle insertion, deletion, etc on the table
+ * of requests kept by the daemon. Nothing fancy here, linear
+ * search on a double-linked list. A time is kept with each 
+ * entry so that overly old invitations can be eliminated.
+ *
+ * Consider this a mis-guided attempt at modularity
+ */
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <protocols/talkd.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX_ID 16000	/* << 2^15 so I don't have sign troubles */
+
+#define NIL ((TABLE_ENTRY *)0)
+
+extern	int debug;
+struct	timeval tp;
+struct	timezone txp;
+
+typedef struct table_entry TABLE_ENTRY;
+
+struct table_entry {
+	CTL_MSG request;
+	long	time;
+	TABLE_ENTRY *next;
+	TABLE_ENTRY *last;
+};
+
+TABLE_ENTRY *table = NIL;
+CTL_MSG *find_request();
+CTL_MSG *find_match();
+
+/*
+ * Look in the table for an invitation that matches the current
+ * request looking for an invitation
+ */
+CTL_MSG *
+find_match(request)
+	register CTL_MSG *request;
+{
+	register TABLE_ENTRY *ptr;
+	time_t current_time;
+
+	gettimeofday(&tp, &txp);
+	current_time = tp.tv_sec;
+	if (debug)
+		print_request("find_match", request);
+	for (ptr = table; ptr != NIL; ptr = ptr->next) {
+		if ((ptr->time - current_time) > MAX_LIFE) {
+			/* the entry is too old */
+			if (debug)
+				print_request("deleting expired entry",
+				    &ptr->request);
+			delete(ptr);
+			continue;
+		}
+		if (debug)
+			print_request("", &ptr->request);
+		if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
+		    strcmp(request->r_name, ptr->request.l_name) == 0 &&
+		     ptr->request.type == LEAVE_INVITE)
+			return (&ptr->request);
+	}
+	return ((CTL_MSG *)0);
+}
+
+/*
+ * Look for an identical request, as opposed to a complimentary
+ * one as find_match does 
+ */
+CTL_MSG *
+find_request(request)
+	register CTL_MSG *request;
+{
+	register TABLE_ENTRY *ptr;
+	time_t current_time;
+
+	gettimeofday(&tp, &txp);
+	current_time = tp.tv_sec;
+	/*
+	 * See if this is a repeated message, and check for
+	 * out of date entries in the table while we are it.
+	 */
+	if (debug)
+		print_request("find_request", request);
+	for (ptr = table; ptr != NIL; ptr = ptr->next) {
+		if ((ptr->time - current_time) > MAX_LIFE) {
+			/* the entry is too old */
+			if (debug)
+				print_request("deleting expired entry",
+				    &ptr->request);
+			delete(ptr);
+			continue;
+		}
+		if (debug)
+			print_request("", &ptr->request);
+		if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
+		    strcmp(request->l_name, ptr->request.l_name) == 0 &&
+		    request->type == ptr->request.type &&
+		    request->pid == ptr->request.pid) {
+			/* update the time if we 'touch' it */
+			ptr->time = current_time;
+			return (&ptr->request);
+		}
+	}
+	return ((CTL_MSG *)0);
+}
+
+insert_table(request, response)
+	CTL_MSG *request;
+	CTL_RESPONSE *response;
+{
+	register TABLE_ENTRY *ptr;
+	time_t current_time;
+
+	gettimeofday(&tp, &txp);
+	current_time = tp.tv_sec;
+	request->id_num = new_id();
+	response->id_num = htonl(request->id_num);
+	/* insert a new entry into the top of the list */
+	ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
+	if (ptr == NIL) {
+		syslog(LOG_ERR, "insert_table: Out of memory");
+		_exit(1);
+	}
+	ptr->time = current_time;
+	ptr->request = *request;
+	ptr->next = table;
+	if (ptr->next != NIL)
+		ptr->next->last = ptr;
+	ptr->last = NIL;
+	table = ptr;
+}
+
+/*
+ * Generate a unique non-zero sequence number
+ */
+new_id()
+{
+	static int current_id = 0;
+
+	current_id = (current_id + 1) % MAX_ID;
+	/* 0 is reserved, helps to pick up bugs */
+	if (current_id == 0)
+		current_id = 1;
+	return (current_id);
+}
+
+/*
+ * Delete the invitation with id 'id_num'
+ */
+delete_invite(id_num)
+	int id_num;
+{
+	register TABLE_ENTRY *ptr;
+
+	ptr = table;
+	if (debug)
+		syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
+	for (ptr = table; ptr != NIL; ptr = ptr->next) {
+		if (ptr->request.id_num == id_num)
+			break;
+		if (debug)
+			print_request("", &ptr->request);
+	}
+	if (ptr != NIL) {
+		delete(ptr);
+		return (SUCCESS);
+	}
+	return (NOT_HERE);
+}
+
+/*
+ * Classic delete from a double-linked list
+ */
+delete(ptr)
+	register TABLE_ENTRY *ptr;
+{
+
+	if (debug)
+		print_request("delete", &ptr->request);
+	if (table == ptr)
+		table = ptr->next;
+	else if (ptr->last != NIL)
+		ptr->last->next = ptr->next;
+	if (ptr->next != NIL)
+		ptr->next->last = ptr->last;
+	free((char *)ptr);
+}
diff --git a/libexec/talkd/talkd.8 b/libexec/talkd/talkd.8
new file mode 100644
index 0000000..36dfb28
--- /dev/null
+++ b/libexec/talkd/talkd.8
@@ -0,0 +1,75 @@
+.\" Copyright (c) 1983, 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)talkd.8	8.2 (Berkeley) 12/11/93
+.\"
+.Dd December 11, 1993
+.Dt TALKD 8
+.Os BSD 4.3
+.Sh NAME
+.Nm talkd
+.Nd remote user communication server
+.Sh SYNOPSIS
+.Nm talkd
+.Sh DESCRIPTION
+.Nm Talkd
+is the server that notifies a user that someone else wants to
+initiate a conversation.
+It acts as a repository of invitations, responding to requests
+by clients wishing to rendezvous to hold a conversation.
+In normal operation, a client, the caller,
+initiates a rendezvous by sending a
+.Tn CTL_MSG
+to the server of
+type
+.Tn LOOK_UP
+(see
+.Aq Pa protocols/talkd.h ) .
+This causes the server to search its invitation
+tables to check if an invitation currently exists for the caller
+(to speak to the callee specified in the message).
+If the lookup fails,
+the caller then sends an
+.Tn ANNOUNCE
+message causing the server to
+broadcast an announcement on the callee's login ports requesting contact.
+When the callee responds, the local server uses the
+recorded invitation to respond with the appropriate rendezvous
+address and the caller and callee client programs establish a
+stream connection through which the conversation takes place.
+.Sh SEE ALSO
+.Xr talk 1 ,
+.Xr write 1
+.Sh HISTORY
+The
+.Nm
+command appeared in
+.Bx 4.3 .
diff --git a/libexec/talkd/talkd.c b/libexec/talkd/talkd.c
new file mode 100644
index 0000000..669931b
--- /dev/null
+++ b/libexec/talkd/talkd.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1983, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)talkd.c	8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+/*
+ * The top level of the daemon, the format is heavily borrowed
+ * from rwhod.c. Basically: find out who and where you are; 
+ * disconnect all descriptors and ttys, and then endless
+ * loop on waiting for and processing requests
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <protocols/talkd.h>
+#include <signal.h>
+#include <syslog.h>
+#include <time.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <paths.h>
+
+CTL_MSG		request;
+CTL_RESPONSE	response;
+
+int	sockt;
+int	debug = 0;
+void	timeout();
+long	lastmsgtime;
+
+char	hostname[32];
+
+#define TIMEOUT 30
+#define MAXIDLE 120
+
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	register CTL_MSG *mp = &request;
+	int cc;
+
+	if (getuid()) {
+		fprintf(stderr, "%s: getuid: not super-user\n", argv[0]);
+		exit(1);
+	}
+	openlog("talkd", LOG_PID, LOG_DAEMON);
+	if (gethostname(hostname, sizeof (hostname) - 1) < 0) {
+		syslog(LOG_ERR, "gethostname: %m");
+		_exit(1);
+	}
+	if (chdir(_PATH_DEV) < 0) {
+		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
+		_exit(1);
+	}
+	if (argc > 1 && strcmp(argv[1], "-d") == 0)
+		debug = 1;
+	signal(SIGALRM, timeout);
+	alarm(TIMEOUT);
+	for (;;) {
+		extern int errno;
+
+		cc = recv(0, (char *)mp, sizeof (*mp), 0);
+		if (cc != sizeof (*mp)) {
+			if (cc < 0 && errno != EINTR)
+				syslog(LOG_WARNING, "recv: %m");
+			continue;
+		}
+		lastmsgtime = time(0);
+		process_request(mp, &response);
+		/* can block here, is this what I want? */
+		cc = sendto(sockt, (char *)&response,
+		    sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
+		    sizeof (mp->ctl_addr));
+		if (cc != sizeof (response))
+			syslog(LOG_WARNING, "sendto: %m");
+	}
+}
+
+void
+timeout()
+{
+
+	if (time(0) - lastmsgtime >= MAXIDLE)
+		_exit(0);
+	alarm(TIMEOUT);
+}