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 `fwd' port forwarder.
  11  *
  12  * `fwd' 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  * `fwd' 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 `fwd'; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #include "fwd.h"
  28
  29 /*----- Data structures ---------------------------------------------------*/
  30
  31 typedef struct un_addr {
  32   addr a;
  33   struct sockaddr_un sun;
  34 } un_addr;
  35
  36 typedef struct un_opts {
  37   addr_opts ao;
  38   fattr f;
  39 } un_opts;
  40
  41 /*----- Protocol operations -----------------------------------------------*/
  42
  43 /* --- @read@ --- */
  44
  45 static addr *un_read(scanner *sc, unsigned type)
  46 {
  47   dstr d = DSTR_INIT;
  48   un_addr *ua;
  49
  50   conf_fname(sc, &d);
  51   ua = xmalloc(sizeof(addr) +
  52                offsetof(struct sockaddr_un, sun_path) +
  53                d.len + 1);
  54   ua->a.ops = &un_ops;
  55   ua->a.sz = offsetof(struct sockaddr_un, sun_path) + d.len + 1;
  56   memset(&ua->sun, 0, ua->a.sz);
  57   ua->sun.sun_family = AF_UNIX;
  58   memcpy(ua->sun.sun_path, d.buf, d.len + 1);
  59   dstr_destroy(&d);
  60   return (&ua->a);
  61 }
  62
  63 /* --- @destroy@ --- */
  64
  65 static void un_destroy(addr *a)
  66 {
  67   un_addr *ua = (un_addr *)a;
  68   xfree(ua);
  69 }
  70
  71 /* --- @print@ --- */
  72
  73 static void un_print(addr *a, unsigned type, dstr *d)
  74 {
  75   un_addr *ua = (un_addr *)a;
  76   dstr_puts(d, "unix:");
  77   dstr_puts(d, ua->sun.sun_path);
  78 }
  79
  80 /* --- @initopts@ --- */
  81
  82 static addr_opts *un_initopts(void)
  83 {
  84   un_opts *uo = CREATE(un_opts);
  85   uo->f = fattr_global;
  86   return (&uo->ao);
  87 }
  88
  89 /* --- @option@ --- */
  90
  91 static int srcopt(scanner *sc, addr_opts *ao)
  92 {
  93   un_opts *uo = (un_opts *)ao;
  94   CONF_BEGIN(sc, "source", "Unix domain socket source")
  95
  96   if (fattr_option(sc, uo ? &uo->f : &fattr_global))
  97     CONF_ACCEPT;
  98
  99   CONF_END;
 100 }
 101
 102 static int un_option(scanner *sc, addr_opts *ao, unsigned type)
 103 {
 104   CONF_BEGIN(sc, "unix", "Unix domain socket");
 105   if (type != ADDR_DEST && srcopt(sc, ao))
 106     CONF_ACCEPT;
 107   CONF_END;
 108 }
 109
 110 /* --- @accept@ --- */
 111
 112 static reffd *un_accept(int fd, addr_opts *ao, const char *desc)
 113 {
 114   int nfd;
 115   un_opts *uo = (un_opts *)ao;
 116
 117   /* --- Accept the new connection --- */
 118
 119   {
 120     char buf[PATH_MAX + sizeof(struct sockaddr)];
 121     struct sockaddr_un *sun = (struct sockaddr_un *)buf;
 122     size_t sunsz = sizeof(buf);
 123
 124     if ((nfd = accept(fd, (struct sockaddr *)sun, &sunsz)) < 0)
 125       return (0);
 126   }
 127
 128   /* --- Log the connection --- *
 129    *
 130    * It'd be really nice if I could find out who the user is, but I can't in
 131    * anything like a portable way.
 132    */
 133
 134   if (!(uo->ao.f & ADDRF_NOLOG))
 135     fw_log(-1, "[%s] accepted", desc);
 136   return (reffd_init(nfd));
 137 }
 138
 139 /* --- @freeopts@ --- */
 140
 141 static void un_freeopts(addr_opts *ao)
 142 {
 143   un_opts *uo = (un_opts *)ao;
 144   DESTROY(uo);
 145 }
 146
 147 /* --- @bind@ --- */
 148
 149 static int un_bind(addr *a, addr_opts *ao)
 150 {
 151   un_addr *ua = (un_addr *)a;
 152   un_opts *uo = (un_opts *)ao;
 153   int fd;
 154
 155   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 156     goto fail_0;
 157   if (bind(fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun)))
 158     goto fail_1;
 159   if (fattr_apply(ua->sun.sun_path, &uo->f))
 160     goto fail_1;
 161   return (fd);
 162
 163 fail_1:
 164   close(fd);
 165 fail_0:
 166   return (-1);
 167 }
 168
 169 /* --- @unbind@ --- */
 170
 171 static void un_unbind(addr *a)
 172 {
 173   un_addr *ua = (un_addr *)a;
 174   unlink(ua->sun.sun_path);
 175 }
 176
 177 /* --- @connect@ --- */
 178
 179 static int un_connect(addr *a, addr_opts *ao, conn *c, endpt *e)
 180 {
 181   un_addr *ua = (un_addr *)a;
 182   int fd;
 183
 184   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 185     goto fail_0;
 186   return (conn_init(c, sel, fd, (struct sockaddr *)&ua->sun, sizeof(ua->sun),
 187                     starget_connected, e));
 188 fail_0:
 189   return (-1);
 190 }
 191
 192 /* --- Protocol definition --- */
 193
 194 addr_ops un_ops = {
 195   "unix",
 196   un_read, un_destroy, un_print,
 197   un_initopts, un_option, 0, un_freeopts, un_bind, un_unbind, un_accept,
 198   0, 0, un_connect
 199 };
 200
 201 /*----- That's all, folks -------------------------------------------------*/