1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 char copyright[] =
10 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
11  All rights reserved.\n";
12 #endif /* not lint */
13 
14 #ifndef lint
15 static char sccsid[] = "@(#)mail.local.c	5.8 (Berkeley) 06/22/92";
16 #endif /* not lint */
17 
18 #include <sys/param.h>
19 #include <sys/stat.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <syslog.h>
23 #include <fcntl.h>
24 #include <netdb.h>
25 #include <pwd.h>
26 #include <time.h>
27 #include <unistd.h>
28 #include <errno.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include "pathnames.h"
33 
34 #define	FATAL		1
35 #define	NOTFATAL	0
36 
37 int	deliver __P((int, char *));
38 void	err __P((int, const char *, ...));
39 void	notifybiff __P((char *));
40 int	store __P((char *));
41 void	usage __P((void));
42 
43 main(argc, argv)
44 	int argc;
45 	char **argv;
46 {
47 	struct passwd *pw;
48 	int ch, fd, eval;
49 	uid_t uid;
50 	char *from;
51 
52 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
53 
54 	from = NULL;
55 	while ((ch = getopt(argc, argv, "df:r:")) != EOF)
56 		switch(ch) {
57 		case 'd':		/* backward compatible */
58 			break;
59 		case 'f':
60 		case 'r':		/* backward compatible */
61 			if (from)
62 			    err(FATAL, "multiple -f options");
63 			from = optarg;
64 			break;
65 		case '?':
66 		default:
67 			usage();
68 		}
69 	argc -= optind;
70 	argv += optind;
71 
72 	if (!*argv)
73 		usage();
74 
75 	/*
76 	 * If from not specified, use the name from getlogin() if the
77 	 * uid matches, otherwise, use the name from the password file
78 	 * corresponding to the uid.
79 	 */
80 	uid = getuid();
81 	if (!from && (!(from = getlogin()) ||
82 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
83 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
84 
85 	fd = store(from);
86 	for (eval = 0; *argv; ++argv)
87 		eval |= deliver(fd, *argv);
88 	exit(eval);
89 }
90 
91 store(from)
92 	char *from;
93 {
94 	FILE *fp;
95 	time_t tval;
96 	int fd, eline;
97 	char *tn, line[2048];
98 
99 	tn = strdup(_PATH_LOCTMP);
100 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
101 		err(FATAL, "unable to open temporary file");
102 	(void)unlink(tn);
103 	free(tn);
104 
105 	(void)time(&tval);
106 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
107 
108 	line[0] = '\0';
109 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
110 		if (line[0] == '\n')
111 			eline = 1;
112 		else {
113 			if (eline && line[0] == 'F' && !bcmp(line, "From ", 5))
114 				(void)putc('>', fp);
115 			eline = 0;
116 		}
117 		(void)fprintf(fp, "%s", line);
118 		if (ferror(fp))
119 			break;
120 	}
121 
122 	/* If message not newline terminated, need an extra. */
123 	if (!index(line, '\n'))
124 		(void)putc('\n', fp);
125 	/* Output a newline; note, empty messages are allowed. */
126 	(void)putc('\n', fp);
127 
128 	(void)fflush(fp);
129 	if (ferror(fp))
130 		err(FATAL, "temporary file write error");
131 	return(fd);
132 }
133 
134 deliver(fd, name)
135 	int fd;
136 	char *name;
137 {
138 	struct stat sb;
139 	struct passwd *pw;
140 	int created, mbfd, nr, nw, off, rval;
141 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN];
142 	off_t curoff;
143 
144 	/*
145 	 * Disallow delivery to unknown names -- special mailboxes can be
146 	 * handled in the sendmail aliases file.
147 	 */
148 	if (!(pw = getpwnam(name))) {
149 		err(NOTFATAL, "unknown name: %s", name);
150 		return(1);
151 	}
152 
153 	(void)sprintf(path, "%s/%s", _PATH_MAILDIR, name);
154 
155 	if (!(created = lstat(path, &sb)) &&
156 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
157 		err(NOTFATAL, "%s: linked file", path);
158 		return(1);
159 	}
160 
161 	/*
162 	 * There's a race here -- two processes think they both created
163 	 * the file.  This means the file cannot be unlinked.
164 	 */
165 	if ((mbfd =
166 	    open(path, O_APPEND|O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR)) < 0) {
167 		err(NOTFATAL, "%s: %s", path, strerror(errno));
168 		return(1);
169 	}
170 
171 	rval = 0;
172 	/* XXX: Open should allow flock'ing the file; see 4.4BSD. */
173 	if (flock(mbfd, LOCK_EX)) {
174 		err(NOTFATAL, "%s: %s", path, strerror(errno));
175 		rval = 1;
176 		goto bad;
177 	}
178 
179 	curoff = lseek(mbfd, (off_t)0, SEEK_END);
180 	(void)sprintf(biffmsg, "%s@%qd\n", name, curoff);
181 	if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
182 		err(FATAL, "temporary file: %s", strerror(errno));
183 		rval = 1;
184 		goto bad;
185 	}
186 
187 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
188 		for (off = 0; off < nr; nr -= nw, off += nw)
189 			if ((nw = write(mbfd, buf + off, nr)) < 0) {
190 				err(NOTFATAL, "%s: %s", path, strerror(errno));
191 				goto trunc;
192 			}
193 	if (nr < 0) {
194 		err(FATAL, "temporary file: %s", strerror(errno));
195 trunc:		(void)ftruncate(mbfd, curoff);
196 		rval = 1;
197 	}
198 
199 	/*
200 	 * Set the owner and group.  Historically, binmail repeated this at
201 	 * each mail delivery.  We no longer do this, assuming that if the
202 	 * ownership or permissions were changed there was a reason for doing
203 	 * so.
204 	 */
205 bad:	if (created)
206 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
207 
208 	(void)fsync(mbfd);		/* Don't wait for update. */
209 	(void)close(mbfd);		/* Implicit unlock. */
210 
211 	if (!rval)
212 		notifybiff(biffmsg);
213 	return(rval);
214 }
215 
216 void
217 notifybiff(msg)
218 	char *msg;
219 {
220 	static struct sockaddr_in addr;
221 	static int f = -1;
222 	struct hostent *hp;
223 	struct servent *sp;
224 	int len;
225 
226 	if (!addr.sin_family) {
227 		/* Be silent if biff service not available. */
228 		if (!(sp = getservbyname("biff", "udp")))
229 			return;
230 		if (!(hp = gethostbyname("localhost"))) {
231 			err(NOTFATAL, "localhost: %s", strerror(errno));
232 			return;
233 		}
234 		addr.sin_family = hp->h_addrtype;
235 		bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
236 		addr.sin_port = sp->s_port;
237 	}
238 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
239 		err(NOTFATAL, "socket: %s", strerror(errno));
240 		return;
241 	}
242 	len = strlen(msg) + 1;
243 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
244 	    != len)
245 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
246 }
247 
248 void
249 usage()
250 {
251 	err(FATAL, "usage: mail.local [-f from] user ...");
252 }
253 
254 #if __STDC__
255 #include <stdarg.h>
256 #else
257 #include <varargs.h>
258 #endif
259 
260 void
261 #if __STDC__
262 err(int isfatal, const char *fmt, ...)
263 #else
264 err(isfatal, fmt, va_alist)
265 	int isfatal;
266 	char *fmt;
267 	va_dcl
268 #endif
269 {
270 	va_list ap;
271 #if __STDC__
272 	va_start(ap, fmt);
273 #else
274 	va_start(ap);
275 #endif
276 	vsyslog(LOG_ERR, fmt, ap);
277 	va_end(ap);
278 	if (isfatal)
279 		exit(1);
280 }
281