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

   1 /* -*-c-*-
   2  *
   3  * $Id: un.c,v 1.9 2004/04/08 01:36:25 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 /*----- Header files ------------------------------------------------------*/
  30
  31 #include "config.h"
  32 #undef sun /* Cretins */
  33
  34 #include <errno.h>
  35 #include <limits.h>
  36 #include <stddef.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include <sys/types.h>
  42 #include <unistd.h>
  43
  44 #include <sys/socket.h>
  45 #include <sys/un.h>
  46 #include <arpa/inet.h>
  47 #include <netdb.h>
  48
  49 #include <mLib/alloc.h>
  50 #include <mLib/dstr.h>
  51 #include <mLib/report.h>
  52 #include <mLib/sub.h>
  53
  54 #include "addr.h"
  55 #include "conf.h"
  56 #include "fattr.h"
  57 #include "fw.h"
  58 #include "reffd.h"
  59 #include "scan.h"
  60 #include "socket.h"
  61 #include "un.h"
  62
  63 /*----- Data structures ---------------------------------------------------*/
  64
  65 typedef struct un_addr {
  66   addr a;
  67   struct sockaddr_un sun;
  68 } un_addr;
  69
  70 typedef struct un_opts {
  71   addr_opts ao;
  72   fattr f;
  73 } un_opts;
  74
  75 /*----- Protocol operations -----------------------------------------------*/
  76
  77 /* --- @read@ --- */
  78
  79 static addr *un_read(scanner *sc, unsigned type)
  80 {
  81   dstr d = DSTR_INIT;
  82   un_addr *ua;
  83
  84   conf_name(sc, '/', &d);
  85   ua = xmalloc(sizeof(addr) +
  86                offsetof(struct sockaddr_un, sun_path) +
  87                d.len + 1);
  88   ua->a.ops = &un_ops;
  89   ua->a.sz = offsetof(struct sockaddr_un, sun_path) + d.len + 1;
  90   memset(&ua->sun, 0, ua->a.sz);
  91   ua->sun.sun_family = AF_UNIX;
  92   memcpy(ua->sun.sun_path, d.buf, d.len + 1);
  93   dstr_destroy(&d);
  94   return (&ua->a);
  95 }
  96
  97 /* --- @destroy@ --- */
  98
  99 static void un_destroy(addr *a)
 100 {
 101   un_addr *ua = (un_addr *)a;
 102   xfree(ua);
 103 }
 104
 105 /* --- @print@ --- */
 106
 107 static void un_print(addr *a, unsigned type, dstr *d)
 108 {
 109   un_addr *ua = (un_addr *)a;
 110   dstr_puts(d, "unix:");
 111   dstr_puts(d, ua->sun.sun_path);
 112 }
 113
 114 /* --- @initopts@ --- */
 115
 116 static addr_opts *un_initopts(void)
 117 {
 118   un_opts *uo = CREATE(un_opts);
 119   uo->f = fattr_global;
 120   return (&uo->ao);
 121 }
 122
 123 /* --- @option@ --- */
 124
 125 static int srcopt(scanner *sc, addr_opts *ao)
 126 {
 127   un_opts *uo = (un_opts *)ao;
 128   CONF_BEGIN(sc, "source", "Unix domain socket source")
 129
 130   if (fattr_option(sc, uo ? &uo->f : &fattr_global))
 131     CONF_ACCEPT;
 132
 133   CONF_END;
 134 }
 135
 136 static int un_option(scanner *sc, addr_opts *ao, unsigned type)
 137 {
 138   CONF_BEGIN(sc, "unix", "Unix domain socket");
 139   if (type != ADDR_DEST && srcopt(sc, ao))
 140     CONF_ACCEPT;
 141   CONF_END;
 142 }
 143
 144 /* --- @accept@ --- */
 145
 146 static reffd *un_accept(int fd, addr_opts *ao, const char *desc)
 147 {
 148   int nfd;
 149   un_opts *uo = (un_opts *)ao;
 150
 151   /* --- Accept the new connection --- */
 152
 153   {
 154     char buf[PATH_MAX + sizeof(struct sockaddr)];
 155     struct sockaddr_un *sun = (struct sockaddr_un *)buf;
 156     size_t sunsz = sizeof(buf);
 157
 158     if ((nfd = accept(fd, (struct sockaddr *)sun, &sunsz)) < 0)
 159       return (0);
 160   }
 161
 162   /* --- Log the connection --- *
 163    *
 164    * It'd be really nice if I could find out who the user is, but I can't in
 165    * anything like a portable way.
 166    */
 167
 168   if (!(uo->ao.f & ADDRF_NOLOG))
 169     fw_log(-1, "[%s] accepted", desc);
 170   return (reffd_init(nfd));
 171 }
 172
 173 /* --- @freeopts@ --- */
 174
 175 static void un_freeopts(addr_opts *ao)
 176 {
 177   un_opts *uo = (un_opts *)ao;
 178   DESTROY(uo);
 179 }
 180
 181 /* --- @bind@ --- */
 182
 183 static int un_bind(addr *a, addr_opts *ao)
 184 {
 185   un_addr *ua = (un_addr *)a;
 186   un_opts *uo = (un_opts *)ao;
 187   int fd;
 188
 189   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 190     goto fail_0;
 191   if (bind(fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun)))
 192     goto fail_1;
 193   if (fattr_apply(ua->sun.sun_path, &uo->f))
 194     goto fail_1;
 195   return (fd);
 196
 197 fail_1:
 198   close(fd);
 199 fail_0:
 200   return (-1);
 201 }
 202
 203 /* --- @unbind@ --- */
 204
 205 static void un_unbind(addr *a)
 206 {
 207   un_addr *ua = (un_addr *)a;
 208   unlink(ua->sun.sun_path);
 209 }
 210
 211 /* --- @connect@ --- */
 212
 213 static int un_connect(addr *a, addr_opts *ao, conn *c, endpt *e)
 214 {
 215   un_addr *ua = (un_addr *)a;
 216   int fd;
 217
 218   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 219     goto fail_0;
 220   return (conn_init(c, sel, fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun),
 221                     starget_connected, e));
 222 fail_0:
 223   return (-1);
 224 }
 225
 226 /* --- Protocol definition --- */
 227
 228 addr_ops un_ops = {
 229   "unix",
 230   un_read, un_destroy, un_print,
 231   un_initopts, un_option, 0, un_freeopts, un_bind, un_unbind, un_accept,
 232   0, 0, un_connect
 233 };
 234
 235 /*----- That's all, folks -------------------------------------------------*/