1/*
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
| 1/*
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
|
50
51#include <sys/param.h>
52#include <sys/signal.h>
53#include <sys/stat.h>
54#include <sys/file.h>
55#include <sys/time.h>
56#include <ctype.h>
57#include <err.h>
58#include <locale.h>
59#include <paths.h>
60#include <pwd.h>
61#include <stdio.h>
62#include <string.h>
63#include <unistd.h>
64#include <utmp.h>
65
66void done __P((int));
67void do_write __P((char *, char *, uid_t));
68static void usage __P((void));
69int term_chk __P((char *, int *, time_t *, int));
70void wr_fputs __P((unsigned char *s));
71void search_utmp __P((char *, char *, char *, uid_t));
72int utmp_chk __P((char *, char *));
73
74int
75main(argc, argv)
76 int argc;
77 char **argv;
78{
79 register char *cp;
80 time_t atime;
81 uid_t myuid;
82 int msgsok, myttyfd;
83 char tty[MAXPATHLEN], *mytty;
84
85 (void)setlocale(LC_CTYPE, "");
86
87 /* check that sender has write enabled */
88 if (isatty(fileno(stdin)))
89 myttyfd = fileno(stdin);
90 else if (isatty(fileno(stdout)))
91 myttyfd = fileno(stdout);
92 else if (isatty(fileno(stderr)))
93 myttyfd = fileno(stderr);
94 else
95 errx(1, "can't find your tty");
96 if (!(mytty = ttyname(myttyfd)))
97 errx(1, "can't find your tty's name");
98 if ((cp = rindex(mytty, '/')))
99 mytty = cp + 1;
100 if (term_chk(mytty, &msgsok, &atime, 1))
101 exit(1);
102 if (!msgsok)
103 errx(1, "you have write permission turned off");
104
105 myuid = getuid();
106
107 /* check args */
108 switch (argc) {
109 case 2:
110 search_utmp(argv[1], tty, mytty, myuid);
111 do_write(tty, mytty, myuid);
112 break;
113 case 3:
114 if (!strncmp(argv[2], _PATH_DEV, strlen(_PATH_DEV)))
115 argv[2] += strlen(_PATH_DEV);
116 if (utmp_chk(argv[1], argv[2]))
117 errx(1, "%s is not logged in on %s", argv[1], argv[2]);
118 if (term_chk(argv[2], &msgsok, &atime, 1))
119 exit(1);
120 if (myuid && !msgsok)
121 errx(1, "%s has messages disabled on %s", argv[1], argv[2]);
122 do_write(argv[2], mytty, myuid);
123 break;
124 default:
125 usage();
126 }
127 done(0);
128 return (0);
129}
130
131static void
132usage()
133{
134 (void)fprintf(stderr, "usage: write user [tty]\n");
135 exit(1);
136}
137
138/*
139 * utmp_chk - checks that the given user is actually logged in on
140 * the given tty
141 */
142int
143utmp_chk(user, tty)
144 char *user, *tty;
145{
146 struct utmp u;
147 int ufd;
148
149 if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
150 return(0); /* ignore error, shouldn't happen anyway */
151
152 while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
153 if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0 &&
154 strncmp(tty, u.ut_line, sizeof(u.ut_line)) == 0) {
155 (void)close(ufd);
156 return(0);
157 }
158
159 (void)close(ufd);
160 return(1);
161}
162
163/*
164 * search_utmp - search utmp for the "best" terminal to write to
165 *
166 * Ignores terminals with messages disabled, and of the rest, returns
167 * the one with the most recent access time. Returns as value the number
168 * of the user's terminals with messages enabled, or -1 if the user is
169 * not logged in at all.
170 *
171 * Special case for writing to yourself - ignore the terminal you're
172 * writing from, unless that's the only terminal with messages enabled.
173 */
174void
175search_utmp(user, tty, mytty, myuid)
176 char *user, *tty, *mytty;
177 uid_t myuid;
178{
179 struct utmp u;
180 time_t bestatime, atime;
181 int ufd, nloggedttys, nttys, msgsok, user_is_me;
182 char atty[UT_LINESIZE + 1];
183
184 if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
185 err(1, "utmp");
186
187 nloggedttys = nttys = 0;
188 bestatime = 0;
189 user_is_me = 0;
190 while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
191 if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0) {
192 ++nloggedttys;
193 (void)strncpy(atty, u.ut_line, UT_LINESIZE);
194 atty[UT_LINESIZE] = '\0';
195 if (term_chk(atty, &msgsok, &atime, 0))
196 continue; /* bad term? skip */
197 if (myuid && !msgsok)
198 continue; /* skip ttys with msgs off */
199 if (strcmp(atty, mytty) == 0) {
200 user_is_me = 1;
201 continue; /* don't write to yourself */
202 }
203 ++nttys;
204 if (atime > bestatime) {
205 bestatime = atime;
206 (void)strcpy(tty, atty);
207 }
208 }
209
210 (void)close(ufd);
211 if (nloggedttys == 0)
212 errx(1, "%s is not logged in", user);
213 if (nttys == 0) {
214 if (user_is_me) { /* ok, so write to yourself! */
215 (void)strcpy(tty, mytty);
216 return;
217 }
218 errx(1, "%s has messages disabled", user);
219 } else if (nttys > 1) {
220 warnx("%s is logged in more than once; writing to %s", user, tty);
221 }
222}
223
224/*
225 * term_chk - check that a terminal exists, and get the message bit
226 * and the access time
227 */
228int
229term_chk(tty, msgsokP, atimeP, showerror)
230 char *tty;
231 int *msgsokP, showerror;
232 time_t *atimeP;
233{
234 struct stat s;
235 char path[MAXPATHLEN];
236
237 (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
238 if (stat(path, &s) < 0) {
239 if (showerror)
240 warn("%s", path);
241 return(1);
242 }
243 *msgsokP = (s.st_mode & (S_IWRITE >> 3)) != 0; /* group write bit */
244 *atimeP = s.st_atime;
245 return(0);
246}
247
248/*
249 * do_write - actually make the connection
250 */
251void
252do_write(tty, mytty, myuid)
253 char *tty, *mytty;
254 uid_t myuid;
255{
| 50
51#include <sys/param.h>
52#include <sys/signal.h>
53#include <sys/stat.h>
54#include <sys/file.h>
55#include <sys/time.h>
56#include <ctype.h>
57#include <err.h>
58#include <locale.h>
59#include <paths.h>
60#include <pwd.h>
61#include <stdio.h>
62#include <string.h>
63#include <unistd.h>
64#include <utmp.h>
65
66void done __P((int));
67void do_write __P((char *, char *, uid_t));
68static void usage __P((void));
69int term_chk __P((char *, int *, time_t *, int));
70void wr_fputs __P((unsigned char *s));
71void search_utmp __P((char *, char *, char *, uid_t));
72int utmp_chk __P((char *, char *));
73
74int
75main(argc, argv)
76 int argc;
77 char **argv;
78{
79 register char *cp;
80 time_t atime;
81 uid_t myuid;
82 int msgsok, myttyfd;
83 char tty[MAXPATHLEN], *mytty;
84
85 (void)setlocale(LC_CTYPE, "");
86
87 /* check that sender has write enabled */
88 if (isatty(fileno(stdin)))
89 myttyfd = fileno(stdin);
90 else if (isatty(fileno(stdout)))
91 myttyfd = fileno(stdout);
92 else if (isatty(fileno(stderr)))
93 myttyfd = fileno(stderr);
94 else
95 errx(1, "can't find your tty");
96 if (!(mytty = ttyname(myttyfd)))
97 errx(1, "can't find your tty's name");
98 if ((cp = rindex(mytty, '/')))
99 mytty = cp + 1;
100 if (term_chk(mytty, &msgsok, &atime, 1))
101 exit(1);
102 if (!msgsok)
103 errx(1, "you have write permission turned off");
104
105 myuid = getuid();
106
107 /* check args */
108 switch (argc) {
109 case 2:
110 search_utmp(argv[1], tty, mytty, myuid);
111 do_write(tty, mytty, myuid);
112 break;
113 case 3:
114 if (!strncmp(argv[2], _PATH_DEV, strlen(_PATH_DEV)))
115 argv[2] += strlen(_PATH_DEV);
116 if (utmp_chk(argv[1], argv[2]))
117 errx(1, "%s is not logged in on %s", argv[1], argv[2]);
118 if (term_chk(argv[2], &msgsok, &atime, 1))
119 exit(1);
120 if (myuid && !msgsok)
121 errx(1, "%s has messages disabled on %s", argv[1], argv[2]);
122 do_write(argv[2], mytty, myuid);
123 break;
124 default:
125 usage();
126 }
127 done(0);
128 return (0);
129}
130
131static void
132usage()
133{
134 (void)fprintf(stderr, "usage: write user [tty]\n");
135 exit(1);
136}
137
138/*
139 * utmp_chk - checks that the given user is actually logged in on
140 * the given tty
141 */
142int
143utmp_chk(user, tty)
144 char *user, *tty;
145{
146 struct utmp u;
147 int ufd;
148
149 if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
150 return(0); /* ignore error, shouldn't happen anyway */
151
152 while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
153 if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0 &&
154 strncmp(tty, u.ut_line, sizeof(u.ut_line)) == 0) {
155 (void)close(ufd);
156 return(0);
157 }
158
159 (void)close(ufd);
160 return(1);
161}
162
163/*
164 * search_utmp - search utmp for the "best" terminal to write to
165 *
166 * Ignores terminals with messages disabled, and of the rest, returns
167 * the one with the most recent access time. Returns as value the number
168 * of the user's terminals with messages enabled, or -1 if the user is
169 * not logged in at all.
170 *
171 * Special case for writing to yourself - ignore the terminal you're
172 * writing from, unless that's the only terminal with messages enabled.
173 */
174void
175search_utmp(user, tty, mytty, myuid)
176 char *user, *tty, *mytty;
177 uid_t myuid;
178{
179 struct utmp u;
180 time_t bestatime, atime;
181 int ufd, nloggedttys, nttys, msgsok, user_is_me;
182 char atty[UT_LINESIZE + 1];
183
184 if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
185 err(1, "utmp");
186
187 nloggedttys = nttys = 0;
188 bestatime = 0;
189 user_is_me = 0;
190 while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
191 if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0) {
192 ++nloggedttys;
193 (void)strncpy(atty, u.ut_line, UT_LINESIZE);
194 atty[UT_LINESIZE] = '\0';
195 if (term_chk(atty, &msgsok, &atime, 0))
196 continue; /* bad term? skip */
197 if (myuid && !msgsok)
198 continue; /* skip ttys with msgs off */
199 if (strcmp(atty, mytty) == 0) {
200 user_is_me = 1;
201 continue; /* don't write to yourself */
202 }
203 ++nttys;
204 if (atime > bestatime) {
205 bestatime = atime;
206 (void)strcpy(tty, atty);
207 }
208 }
209
210 (void)close(ufd);
211 if (nloggedttys == 0)
212 errx(1, "%s is not logged in", user);
213 if (nttys == 0) {
214 if (user_is_me) { /* ok, so write to yourself! */
215 (void)strcpy(tty, mytty);
216 return;
217 }
218 errx(1, "%s has messages disabled", user);
219 } else if (nttys > 1) {
220 warnx("%s is logged in more than once; writing to %s", user, tty);
221 }
222}
223
224/*
225 * term_chk - check that a terminal exists, and get the message bit
226 * and the access time
227 */
228int
229term_chk(tty, msgsokP, atimeP, showerror)
230 char *tty;
231 int *msgsokP, showerror;
232 time_t *atimeP;
233{
234 struct stat s;
235 char path[MAXPATHLEN];
236
237 (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
238 if (stat(path, &s) < 0) {
239 if (showerror)
240 warn("%s", path);
241 return(1);
242 }
243 *msgsokP = (s.st_mode & (S_IWRITE >> 3)) != 0; /* group write bit */
244 *atimeP = s.st_atime;
245 return(0);
246}
247
248/*
249 * do_write - actually make the connection
250 */
251void
252do_write(tty, mytty, myuid)
253 char *tty, *mytty;
254 uid_t myuid;
255{
|
258 time_t now;
259 char path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512];
260
261 /* Determine our login name before the we reopen() stdout */
262 if ((login = getlogin()) == NULL) {
263 if ((pwd = getpwuid(myuid)))
264 login = pwd->pw_name;
265 else
266 login = "???";
267 }
268
269 (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
270 if ((freopen(path, "w", stdout)) == NULL)
271 err(1, "%s", path);
272
273 (void)signal(SIGINT, done);
274 (void)signal(SIGHUP, done);
275
276 /* print greeting */
277 if (gethostname(host, sizeof(host)) < 0)
278 (void)strcpy(host, "???");
279 now = time((time_t *)NULL);
280 nows = ctime(&now);
281 nows[16] = '\0';
282 (void)printf("\r\n\007\007\007Message from %s@%s on %s at %s ...\r\n",
283 login, host, mytty, nows + 11);
284
285 while (fgets(line, sizeof(line), stdin) != NULL)
286 wr_fputs(line);
287}
288
289/*
290 * done - cleanup and exit
291 */
292void
293done(n)
| 259 time_t now;
260 char path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512];
261
262 /* Determine our login name before the we reopen() stdout */
263 if ((login = getlogin()) == NULL) {
264 if ((pwd = getpwuid(myuid)))
265 login = pwd->pw_name;
266 else
267 login = "???";
268 }
269
270 (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
271 if ((freopen(path, "w", stdout)) == NULL)
272 err(1, "%s", path);
273
274 (void)signal(SIGINT, done);
275 (void)signal(SIGHUP, done);
276
277 /* print greeting */
278 if (gethostname(host, sizeof(host)) < 0)
279 (void)strcpy(host, "???");
280 now = time((time_t *)NULL);
281 nows = ctime(&now);
282 nows[16] = '\0';
283 (void)printf("\r\n\007\007\007Message from %s@%s on %s at %s ...\r\n",
284 login, host, mytty, nows + 11);
285
286 while (fgets(line, sizeof(line), stdin) != NULL)
287 wr_fputs(line);
288}
289
290/*
291 * done - cleanup and exit
292 */
293void
294done(n)
|