usr/src/cmd/smbsrv/bind-helper/bind-helper.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  14  */
  15
  16 /*
  17  * This program is installed with an RBAC exec_attr
  18  * that allows it to bind a reserved address.
  19  * (Or just make it setuid root.)
  20  *
  21  * To grant privileges to the program using RBAC,
  22  * add the following line to /etc/security/exec_attr
  23  *      Forced Privilege:solaris:cmd:::\
  24  *      /usr/lib/smbsrv/bind-helper:\
  25  *      privs=net_privaddr,sys_smb\
  26  *
  27  * Args: family address port
  28  * Does a bind on fileno(stdin)
  29  */
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <unistd.h>
  34 #include <string.h>
  35 #include <errno.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <netinet/in.h>
  39 #include <arpa/inet.h>
  40
  41 int
  42 main(int argc, char **argv)
  43 {
  44         struct sockaddr sa;
  45         /* LINTED E_BAD_PTR_CAST_ALIGN */
  46         struct sockaddr_in  *sin  = (struct sockaddr_in *)&sa;
  47         /* LINTED E_BAD_PTR_CAST_ALIGN */
  48         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa;
  49         int rc, err = 0;
  50
  51         if (argc < 4) {
  52                 (void) fprintf(stderr, "usage: %s family address port\n",
  53                     argv[0]);
  54                 exit(1);
  55         }
  56
  57         (void) memset(&sa, 0, sizeof (sa));
  58         sa.sa_family = atoi(argv[1]);
  59         switch (sa.sa_family) {
  60         case AF_INET:
  61                 rc = inet_pton(AF_INET, argv[2], &sin->sin_addr);
  62                 sin->sin_port = htons(atoi(argv[3]));
  63                 break;
  64         case AF_INET6:
  65                 rc = inet_pton(AF_INET6, argv[2], &sin6->sin6_addr);
  66                 sin6->sin6_port = htons(atoi(argv[3]));
  67                 break;
  68         default:
  69                 rc = 0;
  70                 break;
  71         }
  72
  73         if (rc > 0)
  74                 err = 0;
  75         else if (rc == 0)
  76                 err = EINVAL;
  77         else if (rc < 0)
  78                 err = errno;
  79         if (err != 0) {
  80                 (void) fprintf(stderr, "%s: bad proto addr %s %s %s\n",
  81                     argv[0], argv[1], argv[2], argv[3]);
  82                 exit(1);
  83         }
  84
  85         if (bind(0, &sa, sizeof (sa)) < 0) {
  86                 err = errno;
  87                 (void) fprintf(stderr, "%s: bind: %s\n",
  88                     argv[0], strerror(err));
  89                 exit(2);
  90         }
  91         exit(0);
  92 }