lib/roken/mini_inetd.c

   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