mdw@git.distorted.org.uk Git - fwd/blob - un.c

   1 /* -*-c-*-
   2  *
   3  * $Id: un.c,v 1.7 2003/11/29 20:36:07 mdw Exp $
   4  *
   5  * Protocol specific definitions for Unix-domain sockets
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: un.c,v $
  32  * Revision 1.7  2003/11/29 20:36:07  mdw
  33  * Privileged outgoing connections.
  34  *
  35  * Revision 1.6  2003/11/25 14:08:23  mdw
  36  * Debianization.  Socket target options.  Internet binding.
  37  *
  38  * Revision 1.5  2002/02/22 23:43:32  mdw
  39  * Call @xfree@ rather than @free@.
  40  *
  41  * Revision 1.4  2000/08/01 17:59:56  mdw
  42  * Switch over to using `size_t' for socket address lengths.
  43  *
  44  * Revision 1.3  2000/08/01 17:58:32  mdw
  45  * Remove unnecessary <ctype.h> header.
  46  *
  47  * Revision 1.2  1999/07/27 18:30:53  mdw
  48  * Various minor portability fixes.
  49  *
  50  * Revision 1.1  1999/07/26 23:34:11  mdw
  51  * New socket address types.
  52  *
  53  */
  54
  55 /*----- Header files ------------------------------------------------------*/
  56
  57 #include "config.h"
  58 #undef sun /* Cretins */
  59
  60 #include <errno.h>
  61 #include <limits.h>
  62 #include <stddef.h>
  63 #include <stdio.h>
  64 #include <stdlib.h>
  65 #include <string.h>
  66
  67 #include <sys/types.h>
  68 #include <unistd.h>
  69
  70 #include <sys/socket.h>
  71 #include <sys/un.h>
  72 #include <arpa/inet.h>
  73 #include <netdb.h>
  74
  75 #include <mLib/alloc.h>
  76 #include <mLib/dstr.h>
  77 #include <mLib/report.h>
  78 #include <mLib/sub.h>
  79
  80 #include "addr.h"
  81 #include "conf.h"
  82 #include "fattr.h"
  83 #include "fw.h"
  84 #include "reffd.h"
  85 #include "scan.h"
  86 #include "socket.h"
  87 #include "un.h"
  88
  89 /*----- Data structures ---------------------------------------------------*/
  90
  91 typedef struct un_addr {
  92   addr a;
  93   struct sockaddr_un sun;
  94 } un_addr;
  95
  96 typedef struct un_opts {
  97   addr_opts ao;
  98   fattr f;
  99 } un_opts;
 100
 101 /*----- Protocol operations -----------------------------------------------*/
 102
 103 /* --- @read@ --- */
 104
 105 static addr *un_read(scanner *sc, unsigned type)
 106 {
 107   dstr d = DSTR_INIT;
 108   un_addr *ua;
 109
 110   conf_name(sc, '/', &d);
 111   ua = xmalloc(sizeof(addr) +
 112                offsetof(struct sockaddr_un, sun_path) +
 113                d.len + 1);
 114   ua->a.ops = &un_ops;
 115   ua->a.sz = offsetof(struct sockaddr_un, sun_path) + d.len + 1;
 116   memset(&ua->sun, 0, ua->a.sz);
 117   ua->sun.sun_family = AF_UNIX;
 118   memcpy(ua->sun.sun_path, d.buf, d.len + 1);
 119   dstr_destroy(&d);
 120   return (&ua->a);
 121 }
 122
 123 /* --- @destroy@ --- */
 124
 125 static void un_destroy(addr *a)
 126 {
 127   un_addr *ua = (un_addr *)a;
 128   xfree(ua);
 129 }
 130
 131 /* --- @print@ --- */
 132
 133 static void un_print(addr *a, unsigned type, dstr *d)
 134 {
 135   un_addr *ua = (un_addr *)a;
 136   dstr_puts(d, "unix:");
 137   dstr_puts(d, ua->sun.sun_path);
 138 }
 139
 140 /* --- @initopts@ --- */
 141
 142 static addr_opts *un_initopts(void)
 143 {
 144   un_opts *uo = CREATE(un_opts);
 145   uo->f = fattr_global;
 146   return (&uo->ao);
 147 }
 148
 149 /* --- @option@ --- */
 150
 151 static int srcopt(scanner *sc, addr_opts *ao)
 152 {
 153   un_opts *uo = (un_opts *)ao;
 154   CONF_BEGIN(sc, "unix", "Unix domain socket")
 155
 156   if (fattr_option(sc, uo ? &uo->f : &fattr_global))
 157     CONF_ACCEPT;
 158
 159   CONF_END;
 160 }
 161
 162 static int un_option(scanner *sc, addr_opts *ao, unsigned type)
 163 {
 164   CONF_BEGIN(sc, "unix", "Unix domain socket");
 165   if (type != ADDR_DEST && srcopt(sc, ao))
 166     CONF_ACCEPT;
 167   CONF_END;
 168 }
 169
 170 /* --- @accept@ --- */
 171
 172 static reffd *un_accept(int fd, addr_opts *ao, const char *desc)
 173 {
 174   int nfd;
 175   un_opts *uo = (un_opts *)ao;
 176
 177   /* --- Accept the new connection --- */
 178
 179   {
 180     char buf[PATH_MAX + sizeof(struct sockaddr)];
 181     struct sockaddr_un *sun = (struct sockaddr_un *)buf;
 182     size_t sunsz = sizeof(buf);
 183
 184     if ((nfd = accept(fd, (struct sockaddr *)sun, &sunsz)) < 0)
 185       return (0);
 186   }
 187
 188   /* --- Log the connection --- *
 189    *
 190    * It'd be really nice if I could find out who the user is, but I can't in
 191    * anything like a portable way.
 192    */
 193
 194   if (!(uo->ao.f & ADDRF_NOLOG))
 195     fw_log(-1, "[%s] accepted", desc);
 196   return (reffd_init(nfd));
 197 }
 198
 199 /* --- @freeopts@ --- */
 200
 201 static void un_freeopts(addr_opts *ao)
 202 {
 203   un_opts *uo = (un_opts *)ao;
 204   DESTROY(uo);
 205 }
 206
 207 /* --- @bind@ --- */
 208
 209 static int un_bind(addr *a, addr_opts *ao)
 210 {
 211   un_addr *ua = (un_addr *)a;
 212   un_opts *uo = (un_opts *)ao;
 213   int fd;
 214
 215   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 216     goto fail_0;
 217   if (bind(fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun)))
 218     goto fail_1;
 219   if (fattr_apply(ua->sun.sun_path, &uo->f))
 220     goto fail_1;
 221   return (fd);
 222
 223 fail_1:
 224   close(fd);
 225 fail_0:
 226   return (-1);
 227 }
 228
 229 /* --- @unbind@ --- */
 230
 231 static void un_unbind(addr *a)
 232 {
 233   un_addr *ua = (un_addr *)a;
 234   unlink(ua->sun.sun_path);
 235 }
 236
 237 /* --- @connect@ --- */
 238
 239 static int un_connect(addr *a, addr_opts *ao, conn *c, endpt *e)
 240 {
 241   un_addr *ua = (un_addr *)a;
 242   int fd;
 243
 244   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 245     goto fail_0;
 246   return (conn_init(c, sel, fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun),
 247                     starget_connected, e));
 248 fail_0:
 249   return (-1);
 250 }
 251
 252 /* --- Protocol definition --- */
 253
 254 addr_ops un_ops = {
 255   "unix",
 256   un_read, un_destroy, un_print,
 257   un_initopts, un_option, 0, un_freeopts, un_bind, un_unbind, un_accept,
 258   0, 0, un_connect
 259 };
 260
 261 /*----- That's all, folks -------------------------------------------------*/