xref: /original-bsd/libexec/fingerd/fingerd.c (revision c3e32dec)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char copyright[] =
10 "@(#) Copyright (c) 1983, 1993\n\
11 	The Regents of the University of California.  All rights reserved.\n";
12 #endif /* not lint */
13 
14 #ifndef lint
15 static char sccsid[] = "@(#)fingerd.c	8.1 (Berkeley) 06/04/93";
16 #endif /* not lint */
17 
18 #include <sys/types.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
21 #include <arpa/inet.h>
22 #include <errno.h>
23 
24 #include <unistd.h>
25 #include <syslog.h>
26 #include <netdb.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <strings.h>
30 #include "pathnames.h"
31 
32 void err __P((const char *, ...));
33 
34 int
35 main(argc, argv)
36 	int argc;
37 	char *argv[];
38 {
39 	register FILE *fp;
40 	register int ch;
41 	register char *lp;
42 	struct hostent *hp;
43 	struct sockaddr_in sin;
44 	int p[2], logging, secure, sval;
45 #define	ENTRIES	50
46 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
47 
48 	prog = _PATH_FINGER;
49 	logging = secure = 0;
50 	openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
51 	opterr = 0;
52 	while ((ch = getopt(argc, argv, "slp:")) != EOF)
53 		switch (ch) {
54 		case 'l':
55 			logging = 1;
56 			break;
57 		case 'p':
58 			prog = optarg;
59 			break;
60 		case 's':
61 			secure = 1;
62 			break;
63 		case '?':
64 		default:
65 			err("illegal option -- %c", ch);
66 		}
67 
68 	if (logging) {
69 		sval = sizeof(sin);
70 		if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
71 			err("getpeername: %s", strerror(errno));
72 		if (hp = gethostbyaddr((char *)&sin.sin_addr.s_addr,
73 		    sizeof(sin.sin_addr.s_addr), AF_INET))
74 			lp = hp->h_name;
75 		else
76 			lp = inet_ntoa(sin.sin_addr);
77 		syslog(LOG_NOTICE, "query from %s", lp);
78 	}
79 
80 	if (!fgets(line, sizeof(line), stdin))
81 		exit(1);
82 
83 	comp = &av[1];
84 	for (lp = line, ap = &av[2];;) {
85 		*ap = strtok(lp, " \t\r\n");
86 		if (!*ap) {
87 			if (secure && ap == &av[2]) {
88 				puts("must provide username\r\n");
89 				exit(1);
90 			}
91 			break;
92 		}
93 		if (secure && strchr(*ap, '@')) {
94 			puts("fowarding service denied\r\n");
95 			exit(1);
96 		}
97 
98 		/* RFC742: "/[Ww]" == "-l" */
99 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
100 			av[1] = "-l";
101 			comp = &av[0];
102 		}
103 		else if (++ap == av + ENTRIES)
104 			break;
105 		lp = NULL;
106 	}
107 
108 	if (lp = strrchr(prog, '/'))
109 		*comp = ++lp;
110 	else
111 		*comp = prog;
112 	if (pipe(p) < 0)
113 		err("pipe: %s", strerror(errno));
114 
115 	switch(vfork()) {
116 	case 0:
117 		(void)close(p[0]);
118 		if (p[1] != 1) {
119 			(void)dup2(p[1], 1);
120 			(void)close(p[1]);
121 		}
122 		execv(prog, comp);
123 		err("execv: %s: %s", prog, strerror(errno));
124 		_exit(1);
125 	case -1:
126 		err("fork: %s", strerror(errno));
127 	}
128 	(void)close(p[1]);
129 	if (!(fp = fdopen(p[0], "r")))
130 		err("fdopen: %s", strerror(errno));
131 	while ((ch = getc(fp)) != EOF) {
132 		if (ch == '\n')
133 			putchar('\r');
134 		putchar(ch);
135 	}
136 	exit(0);
137 }
138 
139 #if __STDC__
140 #include <stdarg.h>
141 #else
142 #include <varargs.h>
143 #endif
144 
145 void
146 #if __STDC__
147 err(const char *fmt, ...)
148 #else
149 err(fmt, va_alist)
150 	char *fmt;
151         va_dcl
152 #endif
153 {
154 	va_list ap;
155 #if __STDC__
156 	va_start(ap, fmt);
157 #else
158 	va_start(ap);
159 #endif
160 	(void)vsyslog(LOG_ERR, fmt, ap);
161 	va_end(ap);
162 	exit(1);
163 	/* NOTREACHED */
164 }
165