1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1980, 1993\n\
35 The Regents of the University of California. All rights reserved.\n";
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93";
41 #endif
42 static const char rcsid[] =
43 "$FreeBSD$";
44 #endif /* not lint */
45
46 #include <sys/param.h>
47 #include <sys/socket.h>
48 #include <sys/stat.h>
49 #include <sys/file.h>
50 #include <sys/wait.h>
51
52 #include <netinet/in.h>
53
54 #include <ctype.h>
55 #include <err.h>
56 #include <errno.h>
57 #include <netdb.h>
58 #include <paths.h>
59 #include <pwd.h>
60 #include <termios.h>
61 #include <signal.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <syslog.h>
66 #include <unistd.h>
67 #include <utmpx.h>
68
69 static int debug = 0;
70 #define dsyslog if (debug) syslog
71
72 #define MAXIDLE 120
73
74 static char hostname[MAXHOSTNAMELEN];
75
76 static void jkfprintf(FILE *, char[], char[], off_t);
77 static void mailfor(char *);
78 static void notify(struct utmpx *, char[], off_t, int);
79 static void reapchildren(int);
80
81 int
main(int argc __unused,char * argv[]__unused)82 main(int argc __unused, char *argv[] __unused)
83 {
84 struct sockaddr_in from;
85 socklen_t fromlen;
86 int cc;
87 char msgbuf[256];
88
89 /* verify proper invocation */
90 fromlen = sizeof(from);
91 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0)
92 err(1, "getsockname");
93 openlog("comsat", LOG_PID, LOG_DAEMON);
94 if (chdir(_PATH_MAILDIR)) {
95 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR);
96 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
97 exit(1);
98 }
99 (void)gethostname(hostname, sizeof(hostname));
100 (void)signal(SIGTTOU, SIG_IGN);
101 (void)signal(SIGCHLD, reapchildren);
102 for (;;) {
103 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
104 if (cc <= 0) {
105 if (errno != EINTR)
106 sleep(1);
107 errno = 0;
108 continue;
109 }
110 msgbuf[cc] = '\0';
111 mailfor(msgbuf);
112 sigsetmask(0L);
113 }
114 }
115
116 static void
reapchildren(int signo __unused)117 reapchildren(int signo __unused)
118 {
119 while (wait3(NULL, WNOHANG, NULL) > 0);
120 }
121
122 static void
mailfor(char * name)123 mailfor(char *name)
124 {
125 struct utmpx *utp;
126 char *cp;
127 char *file;
128 off_t offset;
129 int folder;
130 char buf[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1];
131 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1];
132
133 if (!(cp = strchr(name, '@')))
134 return;
135 *cp = '\0';
136 offset = strtoll(cp + 1, NULL, 10);
137 if (!(cp = strchr(cp + 1, ':')))
138 file = name;
139 else
140 file = cp + 1;
141 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utp->ut_user),
142 name);
143 if (*file != '/') {
144 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR,
145 (int)sizeof(utp->ut_user), file);
146 file = buf2;
147 }
148 folder = strcmp(buf, file);
149 setutxent();
150 while ((utp = getutxent()) != NULL)
151 if (utp->ut_type == USER_PROCESS && !strcmp(utp->ut_user, name))
152 notify(utp, file, offset, folder);
153 endutxent();
154 }
155
156 static const char *cr;
157
158 static void
notify(struct utmpx * utp,char file[],off_t offset,int folder)159 notify(struct utmpx *utp, char file[], off_t offset, int folder)
160 {
161 FILE *tp;
162 struct stat stb;
163 struct termios tio;
164 char tty[20];
165 const char *s = utp->ut_line;
166
167 if (strncmp(s, "pts/", 4) == 0)
168 s += 4;
169 if (strchr(s, '/')) {
170 /* A slash is an attempt to break security... */
171 syslog(LOG_AUTH | LOG_NOTICE, "Unexpected `/' in `%s'",
172 utp->ut_line);
173 return;
174 }
175 (void)snprintf(tty, sizeof(tty), "%s%.*s",
176 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line);
177 if (stat(tty, &stb) == -1 || !(stb.st_mode & (S_IXUSR | S_IXGRP))) {
178 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_user, tty);
179 return;
180 }
181 dsyslog(LOG_DEBUG, "notify %s on %s", utp->ut_user, tty);
182 switch (fork()) {
183 case -1:
184 syslog(LOG_NOTICE, "fork failed (%m)");
185 return;
186 case 0:
187 break;
188 default:
189 return;
190 }
191 if ((tp = fopen(tty, "w")) == NULL) {
192 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno));
193 _exit(1);
194 }
195 (void)tcgetattr(fileno(tp), &tio);
196 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r";
197 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) {
198 case S_IXUSR:
199 case (S_IXUSR | S_IXGRP):
200 (void)fprintf(tp,
201 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s",
202 cr, utp->ut_user, (int)sizeof(hostname), hostname,
203 folder ? cr : "", folder ? "to " : "", folder ? file : "",
204 cr, cr);
205 jkfprintf(tp, utp->ut_user, file, offset);
206 break;
207 case S_IXGRP:
208 (void)fprintf(tp, "\007");
209 (void)fflush(tp);
210 (void)sleep(1);
211 (void)fprintf(tp, "\007");
212 break;
213 default:
214 break;
215 }
216 (void)fclose(tp);
217 _exit(0);
218 }
219
220 static void
jkfprintf(FILE * tp,char user[],char file[],off_t offset)221 jkfprintf(FILE *tp, char user[], char file[], off_t offset)
222 {
223 unsigned char *cp, ch;
224 FILE *fi;
225 int linecnt, charcnt, inheader;
226 struct passwd *p;
227 unsigned char line[BUFSIZ];
228
229 /* Set effective uid to user in case mail drop is on nfs */
230 if ((p = getpwnam(user)) != NULL)
231 (void) setuid(p->pw_uid);
232
233 if ((fi = fopen(file, "r")) == NULL)
234 return;
235
236 (void)fseeko(fi, offset, SEEK_CUR);
237 /*
238 * Print the first 7 lines or 560 characters of the new mail
239 * (whichever comes first). Skip header crap other than
240 * From, Subject, To, and Date.
241 */
242 linecnt = 7;
243 charcnt = 560;
244 inheader = 1;
245 while (fgets(line, sizeof(line), fi) != NULL) {
246 if (inheader) {
247 if (line[0] == '\n') {
248 inheader = 0;
249 continue;
250 }
251 if (line[0] == ' ' || line[0] == '\t' ||
252 (strncmp(line, "From:", 5) &&
253 strncmp(line, "Subject:", 8)))
254 continue;
255 }
256 if (linecnt <= 0 || charcnt <= 0) {
257 (void)fprintf(tp, "...more...%s", cr);
258 (void)fclose(fi);
259 return;
260 }
261 /* strip weird stuff so can't trojan horse stupid terminals */
262 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) {
263 /* disable upper controls and enable all other
264 8bit codes due to lack of locale knowledge
265 */
266 if (((ch & 0x80) && ch < 0xA0) ||
267 (!(ch & 0x80) && !isprint(ch) &&
268 !isspace(ch) && ch != '\a' && ch != '\b')
269 ) {
270 if (ch & 0x80) {
271 ch &= ~0x80;
272 (void)fputs("M-", tp);
273 }
274 if (iscntrl(ch)) {
275 ch ^= 0x40;
276 (void)fputc('^', tp);
277 }
278 }
279 (void)fputc(ch, tp);
280 }
281 (void)fputs(cr, tp);
282 --linecnt;
283 }
284 (void)fprintf(tp, "----%s\n", cr);
285 (void)fclose(fi);
286 }
287