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

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