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

   1 /* -*-c-*-
   2  *
   3  * $Id: un.c,v 1.8 2003/11/30 00:25:27 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 1.8  2003/11/30 00:25:27  mdw
  33  * Fix source option prefix.
  34  *
  35  * Revision 1.7  2003/11/29 20:36:07  mdw
  36  * Privileged outgoing connections.
  37  *
  38  * Revision 1.6  2003/11/25 14:08:23  mdw
  39  * Debianization.  Socket target options.  Internet binding.
  40  *
  41  * Revision 1.5  2002/02/22 23:43:32  mdw
  42  * Call @xfree@ rather than @free@.
  43  *
  44  * Revision 1.4  2000/08/01 17:59:56  mdw
  45  * Switch over to using `size_t' for socket address lengths.
  46  *
  47  * Revision 1.3  2000/08/01 17:58:32  mdw
  48  * Remove unnecessary <ctype.h> header.
  49  *
  50  * Revision 1.2  1999/07/27 18:30:53  mdw
  51  * Various minor portability fixes.
  52  *
  53  * Revision 1.1  1999/07/26 23:34:11  mdw
  54  * New socket address types.
  55  *
  56  */
  57
  58 /*----- Header files ------------------------------------------------------*/
  59
  60 #include "config.h"
  61 #undef sun /* Cretins */
  62
  63 #include <errno.h>
  64 #include <limits.h>
  65 #include <stddef.h>
  66 #include <stdio.h>
  67 #include <stdlib.h>
  68 #include <string.h>
  69
  70 #include <sys/types.h>
  71 #include <unistd.h>
  72
  73 #include <sys/socket.h>
  74 #include <sys/un.h>
  75 #include <arpa/inet.h>
  76 #include <netdb.h>
  77
  78 #include <mLib/alloc.h>
  79 #include <mLib/dstr.h>
  80 #include <mLib/report.h>
  81 #include <mLib/sub.h>
  82
  83 #include "addr.h"
  84 #include "conf.h"
  85 #include "fattr.h"
  86 #include "fw.h"
  87 #include "reffd.h"
  88 #include "scan.h"
  89 #include "socket.h"
  90 #include "un.h"
  91
  92 /*----- Data structures ---------------------------------------------------*/
  93
  94 typedef struct un_addr {
  95   addr a;
  96   struct sockaddr_un sun;
  97 } un_addr;
  98
  99 typedef struct un_opts {
 100   addr_opts ao;
 101   fattr f;
 102 } un_opts;
 103
 104 /*----- Protocol operations -----------------------------------------------*/
 105
 106 /* --- @read@ --- */
 107
 108 static addr *un_read(scanner *sc, unsigned type)
 109 {
 110   dstr d = DSTR_INIT;
 111   un_addr *ua;
 112
 113   conf_name(sc, '/', &d);
 114   ua = xmalloc(sizeof(addr) +
 115                offsetof(struct sockaddr_un, sun_path) +
 116                d.len + 1);
 117   ua->a.ops = &un_ops;
 118   ua->a.sz = offsetof(struct sockaddr_un, sun_path) + d.len + 1;
 119   memset(&ua->sun, 0, ua->a.sz);
 120   ua->sun.sun_family = AF_UNIX;
 121   memcpy(ua->sun.sun_path, d.buf, d.len + 1);
 122   dstr_destroy(&d);
 123   return (&ua->a);
 124 }
 125
 126 /* --- @destroy@ --- */
 127
 128 static void un_destroy(addr *a)
 129 {
 130   un_addr *ua = (un_addr *)a;
 131   xfree(ua);
 132 }
 133
 134 /* --- @print@ --- */
 135
 136 static void un_print(addr *a, unsigned type, dstr *d)
 137 {
 138   un_addr *ua = (un_addr *)a;
 139   dstr_puts(d, "unix:");
 140   dstr_puts(d, ua->sun.sun_path);
 141 }
 142
 143 /* --- @initopts@ --- */
 144
 145 static addr_opts *un_initopts(void)
 146 {
 147   un_opts *uo = CREATE(un_opts);
 148   uo->f = fattr_global;
 149   return (&uo->ao);
 150 }
 151
 152 /* --- @option@ --- */
 153
 154 static int srcopt(scanner *sc, addr_opts *ao)
 155 {
 156   un_opts *uo = (un_opts *)ao;
 157   CONF_BEGIN(sc, "source", "Unix domain socket source")
 158
 159   if (fattr_option(sc, uo ? &uo->f : &fattr_global))
 160     CONF_ACCEPT;
 161
 162   CONF_END;
 163 }
 164
 165 static int un_option(scanner *sc, addr_opts *ao, unsigned type)
 166 {
 167   CONF_BEGIN(sc, "unix", "Unix domain socket");
 168   if (type != ADDR_DEST && srcopt(sc, ao))
 169     CONF_ACCEPT;
 170   CONF_END;
 171 }
 172
 173 /* --- @accept@ --- */
 174
 175 static reffd *un_accept(int fd, addr_opts *ao, const char *desc)
 176 {
 177   int nfd;
 178   un_opts *uo = (un_opts *)ao;
 179
 180   /* --- Accept the new connection --- */
 181
 182   {
 183     char buf[PATH_MAX + sizeof(struct sockaddr)];
 184     struct sockaddr_un *sun = (struct sockaddr_un *)buf;
 185     size_t sunsz = sizeof(buf);
 186
 187     if ((nfd = accept(fd, (struct sockaddr *)sun, &sunsz)) < 0)
 188       return (0);
 189   }
 190
 191   /* --- Log the connection --- *
 192    *
 193    * It'd be really nice if I could find out who the user is, but I can't in
 194    * anything like a portable way.
 195    */
 196
 197   if (!(uo->ao.f & ADDRF_NOLOG))
 198     fw_log(-1, "[%s] accepted", desc);
 199   return (reffd_init(nfd));
 200 }
 201
 202 /* --- @freeopts@ --- */
 203
 204 static void un_freeopts(addr_opts *ao)
 205 {
 206   un_opts *uo = (un_opts *)ao;
 207   DESTROY(uo);
 208 }
 209
 210 /* --- @bind@ --- */
 211
 212 static int un_bind(addr *a, addr_opts *ao)
 213 {
 214   un_addr *ua = (un_addr *)a;
 215   un_opts *uo = (un_opts *)ao;
 216   int fd;
 217
 218   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 219     goto fail_0;
 220   if (bind(fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun)))
 221     goto fail_1;
 222   if (fattr_apply(ua->sun.sun_path, &uo->f))
 223     goto fail_1;
 224   return (fd);
 225
 226 fail_1:
 227   close(fd);
 228 fail_0:
 229   return (-1);
 230 }
 231
 232 /* --- @unbind@ --- */
 233
 234 static void un_unbind(addr *a)
 235 {
 236   un_addr *ua = (un_addr *)a;
 237   unlink(ua->sun.sun_path);
 238 }
 239
 240 /* --- @connect@ --- */
 241
 242 static int un_connect(addr *a, addr_opts *ao, conn *c, endpt *e)
 243 {
 244   un_addr *ua = (un_addr *)a;
 245   int fd;
 246
 247   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 248     goto fail_0;
 249   return (conn_init(c, sel, fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun),
 250                     starget_connected, e));
 251 fail_0:
 252   return (-1);
 253 }
 254
 255 /* --- Protocol definition --- */
 256
 257 addr_ops un_ops = {
 258   "unix",
 259   un_read, un_destroy, un_print,
 260   un_initopts, un_option, 0, un_freeopts, un_bind, un_unbind, un_accept,
 261   0, 0, un_connect
 262 };
 263
 264 /*----- That's all, folks -------------------------------------------------*/