xref: /freebsd/crypto/heimdal/lib/roken/mini_inetd.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
1 /*
2  * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
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  *
17  * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 #include <config.h>
35 
36 #include <err.h>
37 #include "roken.h"
38 
39 /*
40  * accept a connection on `s' and pretend it's served by inetd.
41  */
42 
43 static void
44 accept_it (rk_socket_t s, rk_socket_t *ret_socket)
45 {
46     rk_socket_t as;
47 
48     as = accept(s, NULL, NULL);
49     if(rk_IS_BAD_SOCKET(as))
50 	err (1, "accept");
51 
52     if (ret_socket) {
53 
54 	*ret_socket = as;
55 
56     } else {
57 	int fd = socket_to_fd(as, 0);
58 
59 	/* We would use _O_RDONLY for the socket_to_fd() call for
60 	   STDIN, but there are instances where we assume that STDIN
61 	   is a r/w socket. */
62 
63 	dup2(fd, STDIN_FILENO);
64 	dup2(fd, STDOUT_FILENO);
65 
66 	rk_closesocket(as);
67     }
68 }
69 
70 /**
71  * Listen on a specified addresses
72  *
73  * Listens on the specified addresses for incoming connections.  If
74  * the \a ret_socket parameter is \a NULL, on return STDIN and STDOUT
75  * will be connected to an accepted socket.  If the \a ret_socket
76  * parameter is non-NULL, the accepted socket will be returned in
77  * *ret_socket.  In the latter case, STDIN and STDOUT will be left
78  * unmodified.
79  *
80  * This function does not return if there is an error or if no
81  * connection is established.
82  *
83  * @param[in] ai Addresses to listen on
84  * @param[out] ret_socket If non-NULL receives the accepted socket.
85  *
86  * @see mini_inetd()
87  */
88 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
89 mini_inetd_addrinfo (struct addrinfo *ai, rk_socket_t *ret_socket)
90 {
91     int ret;
92     struct addrinfo *a;
93     int n, nalloc, i;
94     rk_socket_t *fds;
95     fd_set orig_read_set, read_set;
96     rk_socket_t max_fd = (rk_socket_t)-1;
97 
98     for (nalloc = 0, a = ai; a != NULL; a = a->ai_next)
99 	++nalloc;
100 
101     fds = malloc (nalloc * sizeof(*fds));
102     if (fds == NULL) {
103 	errx (1, "mini_inetd: out of memory");
104 	UNREACHABLE(return);
105     }
106 
107     FD_ZERO(&orig_read_set);
108 
109     for (i = 0, a = ai; a != NULL; a = a->ai_next) {
110 	fds[i] = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
111 	if (rk_IS_BAD_SOCKET(fds[i]))
112 	    continue;
113 	socket_set_reuseaddr (fds[i], 1);
114 	socket_set_ipv6only(fds[i], 1);
115 	if (rk_IS_SOCKET_ERROR(bind (fds[i], a->ai_addr, a->ai_addrlen))) {
116 	    warn ("bind af = %d", a->ai_family);
117 	    rk_closesocket(fds[i]);
118 	    fds[i] = rk_INVALID_SOCKET;
119 	    continue;
120 	}
121 	if (rk_IS_SOCKET_ERROR(listen (fds[i], SOMAXCONN))) {
122 	    warn ("listen af = %d", a->ai_family);
123 	    rk_closesocket(fds[i]);
124 	    fds[i] = rk_INVALID_SOCKET;
125 	    continue;
126 	}
127 #ifndef NO_LIMIT_FD_SETSIZE
128 	if (fds[i] >= FD_SETSIZE)
129 	    errx (1, "fd too large");
130 #endif
131 	FD_SET(fds[i], &orig_read_set);
132 	max_fd = max(max_fd, fds[i]);
133 	++i;
134     }
135     if (i == 0)
136 	errx (1, "no sockets");
137     n = i;
138 
139     do {
140 	read_set = orig_read_set;
141 
142 	ret = select (max_fd + 1, &read_set, NULL, NULL, NULL);
143 	if (rk_IS_SOCKET_ERROR(ret) && rk_SOCK_ERRNO != EINTR)
144 	    err (1, "select");
145     } while (ret <= 0);
146 
147     for (i = 0; i < n; ++i)
148 	if (FD_ISSET (fds[i], &read_set)) {
149 	    accept_it (fds[i], ret_socket);
150 	    for (i = 0; i < n; ++i)
151 	      rk_closesocket(fds[i]);
152 	    free(fds);
153 	    return;
154 	}
155     abort ();
156 }
157 
158 /**
159  * Listen on a specified port
160  *
161  * Listens on the specified port for incoming connections.  If the \a
162  * ret_socket parameter is \a NULL, on return STDIN and STDOUT will be
163  * connected to an accepted socket.  If the \a ret_socket parameter is
164  * non-NULL, the accepted socket will be returned in *ret_socket.  In
165  * the latter case, STDIN and STDOUT will be left unmodified.
166  *
167  * This function does not return if there is an error or if no
168  * connection is established.
169  *
170  * @param[in] port Port to listen on
171  * @param[out] ret_socket If non-NULL receives the accepted socket.
172  *
173  * @see mini_inetd_addrinfo()
174  */
175 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
176 mini_inetd(int port, rk_socket_t * ret_socket)
177 {
178     int error;
179     struct addrinfo *ai, hints;
180     char portstr[NI_MAXSERV];
181 
182     memset (&hints, 0, sizeof(hints));
183     hints.ai_flags    = AI_PASSIVE;
184     hints.ai_socktype = SOCK_STREAM;
185     hints.ai_family   = PF_UNSPEC;
186 
187     snprintf (portstr, sizeof(portstr), "%d", ntohs(port));
188 
189     error = getaddrinfo (NULL, portstr, &hints, &ai);
190     if (error)
191 	errx (1, "getaddrinfo: %s", gai_strerror (error));
192 
193     mini_inetd_addrinfo(ai, ret_socket);
194 
195     freeaddrinfo(ai);
196 }
197 
198