1 /*
2 * Copyright (c) 1980 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1980 Regents of the University of California.\n\
37 All rights reserved.\n";
38 #endif /* not lint */
39
40 #ifndef lint
41 static char sccsid[] = "@(#)comsat.c 5.24 (Berkeley) 2/25/91";
42 #endif /* not lint */
43
44 #include <sys/param.h>
45 #include <sys/socket.h>
46 #include <sys/stat.h>
47 #include <sys/file.h>
48 #include <sys/wait.h>
49
50 #include <netinet/in.h>
51
52 #include <stdio.h>
53 #include <sgtty.h>
54 #include <utmp.h>
55 #include <signal.h>
56 #include <errno.h>
57 #include <netdb.h>
58 #include <syslog.h>
59 #include <ctype.h>
60 #include <string.h>
61 #include <paths.h>
62
63 int debug = 0;
64 #define dsyslog if (debug) syslog
65
66 #define MAXIDLE 120
67
68 char hostname[MAXHOSTNAMELEN];
69 struct utmp *utmp = NULL;
70 time_t lastmsgtime, time();
71 int nutmp, uf;
72
73 /* ARGSUSED */
main(argc,argv)74 main(argc, argv)
75 int argc;
76 char **argv;
77 {
78 extern int errno;
79 register int cc;
80 char msgbuf[100];
81 struct sockaddr_in from;
82 int fromlen;
83 void onalrm(), reapchildren();
84
85 /* verify proper invocation */
86 fromlen = sizeof(from);
87 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) {
88 (void)fprintf(stderr,
89 "comsat: getsockname: %s.\n", strerror(errno));
90 exit(1);
91 }
92 openlog("comsat", LOG_PID, LOG_DAEMON);
93 if (chdir(_PATH_MAILDIR)) {
94 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR);
95 exit(1);
96 }
97 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
98 syslog(LOG_ERR, ".main: %s: %m", _PATH_UTMP);
99 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
100 exit(1);
101 }
102 (void)time(&lastmsgtime);
103 (void)gethostname(hostname, sizeof(hostname));
104 onalrm();
105 (void)signal(SIGALRM, onalrm);
106 (void)signal(SIGTTOU, SIG_IGN);
107 (void)signal(SIGCHLD, reapchildren);
108 for (;;) {
109 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
110 if (cc <= 0) {
111 if (errno != EINTR)
112 sleep(1);
113 errno = 0;
114 continue;
115 }
116 if (!nutmp) /* no one has logged in yet */
117 continue;
118 sigblock(sigmask(SIGALRM));
119 msgbuf[cc] = 0;
120 (void)time(&lastmsgtime);
121 mailfor(msgbuf);
122 sigsetmask(0L);
123 }
124 }
125
126 void
reapchildren()127 reapchildren()
128 {
129 while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
130 }
131
132 void
onalrm()133 onalrm()
134 {
135 static u_int utmpsize; /* last malloced size for utmp */
136 static u_int utmpmtime; /* last modification time for utmp */
137 struct stat statbf;
138 off_t lseek();
139 char *malloc(), *realloc();
140
141 if (time((time_t *)NULL) - lastmsgtime >= MAXIDLE)
142 exit(0);
143 (void)alarm((u_int)15);
144 (void)fstat(uf, &statbf);
145 if (statbf.st_mtime > utmpmtime) {
146 utmpmtime = statbf.st_mtime;
147 if (statbf.st_size > utmpsize) {
148 utmpsize = statbf.st_size + 10 * sizeof(struct utmp);
149 if (utmp)
150 utmp = (struct utmp *)realloc((char *)utmp, utmpsize);
151 else
152 utmp = (struct utmp *)malloc(utmpsize);
153 if (!utmp) {
154 syslog(LOG_ERR, "malloc failed");
155 exit(1);
156 }
157 }
158 (void)lseek(uf, 0L, L_SET);
159 nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp);
160 }
161 }
162
mailfor(name)163 mailfor(name)
164 char *name;
165 {
166 register struct utmp *utp = &utmp[nutmp];
167 register char *cp;
168 off_t offset;
169
170 if (!(cp = index(name, '@')))
171 return;
172 *cp = '\0';
173 offset = atoi(cp + 1);
174 while (--utp >= utmp)
175 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name)))
176 notify(utp, offset);
177 }
178
179 static char *cr;
180
notify(utp,offset)181 notify(utp, offset)
182 register struct utmp *utp;
183 off_t offset;
184 {
185 static char tty[20] = _PATH_DEV;
186 struct sgttyb gttybuf;
187 struct stat stb;
188 FILE *tp;
189 char name[sizeof(utmp[0].ut_name) + 1];
190
191 (void)strncpy(tty + sizeof(_PATH_DEV) - 1, utp->ut_line,
192 sizeof(utp->ut_line));
193 if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) {
194 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty);
195 return;
196 }
197 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty);
198 if (fork())
199 return;
200 (void)signal(SIGALRM, SIG_DFL);
201 (void)alarm((u_int)30);
202 if ((tp = fopen(tty, "w")) == NULL) {
203 dsyslog(LOG_ERR, "fopen of tty %s failed", tty);
204 _exit(-1);
205 }
206 (void)ioctl(fileno(tp), TIOCGETP, >tybuf);
207 cr = (gttybuf.sg_flags&CRMOD) && !(gttybuf.sg_flags&RAW) ?
208 "\n" : "\n\r";
209 (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name));
210 name[sizeof(name) - 1] = '\0';
211 (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived:%s----%s",
212 cr, name, sizeof(hostname), hostname, cr, cr);
213 jkfprintf(tp, name, offset);
214 (void)fclose(tp);
215 _exit(0);
216 }
217
jkfprintf(tp,name,offset)218 jkfprintf(tp, name, offset)
219 register FILE *tp;
220 char name[];
221 off_t offset;
222 {
223 register char *cp, ch;
224 register FILE *fi;
225 register int linecnt, charcnt, inheader;
226 char line[BUFSIZ];
227
228 if ((fi = fopen(name, "r")) == NULL)
229 return;
230 (void)fseek(fi, offset, L_SET);
231 /*
232 * Print the first 7 lines or 560 characters of the new mail
233 * (whichever comes first). Skip header crap other than
234 * From, Subject, To, and Date.
235 */
236 linecnt = 7;
237 charcnt = 560;
238 inheader = 1;
239 while (fgets(line, sizeof(line), fi) != NULL) {
240 if (inheader) {
241 if (line[0] == '\n') {
242 inheader = 0;
243 continue;
244 }
245 if (line[0] == ' ' || line[0] == '\t' ||
246 strncmp(line, "From:", 5) &&
247 strncmp(line, "Subject:", 8))
248 continue;
249 }
250 if (linecnt <= 0 || charcnt <= 0) {
251 (void)fprintf(tp, "...more...%s", cr);
252 return;
253 }
254 /* strip weird stuff so can't trojan horse stupid terminals */
255 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) {
256 ch = toascii(ch);
257 if (!isprint(ch) && !isspace(ch))
258 ch |= 0x40;
259 (void)fputc(ch, tp);
260 }
261 (void)fputs(cr, tp);
262 --linecnt;
263 }
264 (void)fprintf(tp, "----%s\n", cr);
265 }
266