usr/src/cmd/ssh/libopenbsd-compat/common/bindresvport.c

   1 /* This file has be modified from the original OpenBSD source */
   2
   3 /*
   4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   5  * unrestricted use provided that this legend is included on all tape
   6  * media and as a part of the software program in whole or part.  Users
   7  * may copy or modify Sun RPC without charge, but are not authorized
   8  * to license or distribute it to anyone else except as part of a product or
   9  * program developed by the user.
  10  *
  11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  14  *
  15  * Sun RPC is provided with no support and without any obligation on the
  16  * part of Sun Microsystems, Inc. to assist in its use, correction,
  17  * modification or enhancement.
  18  *
  19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  21  * OR ANY PART THEREOF.
  22  *
  23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  24  * or profits or other special, indirect and consequential damages, even if
  25  * Sun has been advised of the possibility of such damages.
  26  *
  27  * Sun Microsystems, Inc.
  28  * 2550 Garcia Avenue
  29  * Mountain View, California  94043
  30  */
  31
  32 #include "includes.h"
  33
  34 #ifndef HAVE_BINDRESVPORT_SA
  35
  36 #if defined(LIBC_SCCS) && !defined(lint)
  37 static char *rcsid = "$OpenBSD: bindresvport.c,v 1.13 2000/01/26 03:43:21 deraadt Exp $";
  38 #endif /* LIBC_SCCS and not lint */
  39
  40 /*
  41  * Copyright (c) 1987 by Sun Microsystems, Inc.
  42  *
  43  * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
  44  */
  45
  46 #include "includes.h"
  47
  48 #define STARTPORT 600
  49 #define ENDPORT (IPPORT_RESERVED - 1)
  50 #define NPORTS  (ENDPORT - STARTPORT + 1)
  51
  52 /*
  53  * Bind a socket to a privileged IP port
  54  */
  55 int
  56 bindresvport_sa(sd, sa)
  57         int sd;
  58         struct sockaddr *sa;
  59 {
  60         int error, af;
  61         struct sockaddr_storage myaddr;
  62         struct sockaddr_in *sin;
  63         struct sockaddr_in6 *sin6;
  64         u_int16_t *portp;
  65         u_int16_t port;
  66         socklen_t salen;
  67         int i;
  68
  69         if (sa == NULL) {
  70                 memset(&myaddr, 0, sizeof(myaddr));
  71                 sa = (struct sockaddr *)&myaddr;
  72
  73                 if (getsockname(sd, sa, &salen) == -1)
  74                         return -1;      /* errno is correctly set */
  75
  76                 af = sa->sa_family;
  77                 memset(&myaddr, 0, salen);
  78         } else
  79                 af = sa->sa_family;
  80
  81         if (af == AF_INET) {
  82                 /* LINTED */
  83                 sin = (struct sockaddr_in *)sa;
  84                 salen = sizeof(struct sockaddr_in);
  85                 portp = &sin->sin_port;
  86         } else if (af == AF_INET6) {
  87                 /* LINTED */
  88                 sin6 = (struct sockaddr_in6 *)sa;
  89                 salen = sizeof(struct sockaddr_in6);
  90                 portp = &sin6->sin6_port;
  91         } else {
  92                 errno = EPFNOSUPPORT;
  93                 return (-1);
  94         }
  95         sa->sa_family = af;
  96
  97         port = ntohs(*portp);
  98         if (port == 0)
  99                 port = (arc4random() % NPORTS) + STARTPORT;
 100
 101         /* Avoid warning */
 102         error = -1;
 103
 104         for(i = 0; i < NPORTS; i++) {
 105                 *portp = htons(port);
 106
 107                 error = bind(sd, sa, salen);
 108
 109                 /* Terminate on success */
 110                 if (error == 0)
 111                         break;
 112
 113                 /* Terminate on errors, except "address already in use" */
 114                 if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL)))
 115                         break;
 116
 117                 port++;
 118                 if (port > ENDPORT)
 119                         port = STARTPORT;
 120         }
 121
 122         return (error);
 123 }
 124
 125 #endif /* HAVE_BINDRESVPORT_SA */
 126
 127 #pragma ident   "%Z%%M% %I%     %E% SMI"