1 /* $NetBSD: mini_inetd.c,v 1.2 2017/01/28 21:31:50 christos Exp $ */
2
3 /*
4 * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #include <err.h>
39 #include <krb5/roken.h>
40
41 /*
42 * accept a connection on `s' and pretend it's served by inetd.
43 */
44
45 static void
accept_it(rk_socket_t s,rk_socket_t * ret_socket)46 accept_it (rk_socket_t s, rk_socket_t *ret_socket)
47 {
48 rk_socket_t as;
49
50 as = accept(s, NULL, NULL);
51 if(rk_IS_BAD_SOCKET(as))
52 err (1, "accept");
53
54 if (ret_socket) {
55
56 *ret_socket = as;
57
58 } else {
59 int fd = socket_to_fd(as, 0);
60
61 /* We would use _O_RDONLY for the socket_to_fd() call for
62 STDIN, but there are instances where we assume that STDIN
63 is a r/w socket. */
64
65 dup2(fd, STDIN_FILENO);
66 dup2(fd, STDOUT_FILENO);
67
68 rk_closesocket(as);
69 }
70 }
71
72 /**
73 * Listen on a specified addresses
74 *
75 * Listens on the specified addresses for incoming connections. If
76 * the \a ret_socket parameter is \a NULL, on return STDIN and STDOUT
77 * will be connected to an accepted socket. If the \a ret_socket
78 * parameter is non-NULL, the accepted socket will be returned in
79 * *ret_socket. In the latter case, STDIN and STDOUT will be left
80 * unmodified.
81 *
82 * This function does not return if there is an error or if no
83 * connection is established.
84 *
85 * @param[in] ai Addresses to listen on
86 * @param[out] ret_socket If non-NULL receives the accepted socket.
87 *
88 * @see mini_inetd()
89 */
90 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
mini_inetd_addrinfo(struct addrinfo * ai,rk_socket_t * ret_socket)91 mini_inetd_addrinfo (struct addrinfo *ai, rk_socket_t *ret_socket)
92 {
93 int ret;
94 struct addrinfo *a;
95 int n, nalloc, i;
96 rk_socket_t *fds;
97 fd_set orig_read_set, read_set;
98 rk_socket_t max_fd = (rk_socket_t)-1;
99
100 for (nalloc = 0, a = ai; a != NULL; a = a->ai_next)
101 ++nalloc;
102
103 fds = malloc (nalloc * sizeof(*fds));
104 if (fds == NULL) {
105 errx (1, "mini_inetd: out of memory");
106 UNREACHABLE(return);
107 }
108
109 FD_ZERO(&orig_read_set);
110
111 for (i = 0, a = ai; a != NULL; a = a->ai_next) {
112 fds[i] = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
113 if (rk_IS_BAD_SOCKET(fds[i]))
114 continue;
115 socket_set_reuseaddr (fds[i], 1);
116 socket_set_ipv6only(fds[i], 1);
117 if (rk_IS_SOCKET_ERROR(bind (fds[i], a->ai_addr, a->ai_addrlen))) {
118 warn ("bind af = %d", a->ai_family);
119 rk_closesocket(fds[i]);
120 fds[i] = rk_INVALID_SOCKET;
121 continue;
122 }
123 if (rk_IS_SOCKET_ERROR(listen (fds[i], SOMAXCONN))) {
124 warn ("listen af = %d", a->ai_family);
125 rk_closesocket(fds[i]);
126 fds[i] = rk_INVALID_SOCKET;
127 continue;
128 }
129 #ifndef NO_LIMIT_FD_SETSIZE
130 if (fds[i] >= FD_SETSIZE)
131 errx (1, "fd too large");
132 #endif
133 FD_SET(fds[i], &orig_read_set);
134 max_fd = max(max_fd, fds[i]);
135 ++i;
136 }
137 if (i == 0)
138 errx (1, "no sockets");
139 n = i;
140
141 do {
142 read_set = orig_read_set;
143
144 ret = select (max_fd + 1, &read_set, NULL, NULL, NULL);
145 if (rk_IS_SOCKET_ERROR(ret) && rk_SOCK_ERRNO != EINTR)
146 err (1, "select");
147 } while (ret <= 0);
148
149 for (i = 0; i < n; ++i)
150 if (FD_ISSET (fds[i], &read_set)) {
151 accept_it (fds[i], ret_socket);
152 for (i = 0; i < n; ++i)
153 rk_closesocket(fds[i]);
154 free(fds);
155 return;
156 }
157 abort ();
158 }
159
160 /**
161 * Listen on a specified port
162 *
163 * Listens on the specified port for incoming connections. If the \a
164 * ret_socket parameter is \a NULL, on return STDIN and STDOUT will be
165 * connected to an accepted socket. If the \a ret_socket parameter is
166 * non-NULL, the accepted socket will be returned in *ret_socket. In
167 * the latter case, STDIN and STDOUT will be left unmodified.
168 *
169 * This function does not return if there is an error or if no
170 * connection is established.
171 *
172 * @param[in] port Port to listen on
173 * @param[out] ret_socket If non-NULL receives the accepted socket.
174 *
175 * @see mini_inetd_addrinfo()
176 */
177 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
mini_inetd(int port,rk_socket_t * ret_socket)178 mini_inetd(int port, rk_socket_t * ret_socket)
179 {
180 int error;
181 struct addrinfo *ai, hints;
182 char portstr[NI_MAXSERV];
183
184 memset (&hints, 0, sizeof(hints));
185 hints.ai_flags = AI_PASSIVE;
186 hints.ai_socktype = SOCK_STREAM;
187 hints.ai_family = PF_UNSPEC;
188
189 snprintf (portstr, sizeof(portstr), "%d", ntohs(port));
190
191 error = getaddrinfo (NULL, portstr, &hints, &ai);
192 if (error)
193 errx (1, "getaddrinfo: %s", gai_strerror (error));
194
195 mini_inetd_addrinfo(ai, ret_socket);
196
197 freeaddrinfo(ai);
198 }
199
200