forwards.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include "forwards.h"
  20
  21
  22 const struct fw3_option fw3_forward_opts[] = {
  23         FW3_OPT("enabled",             bool,     forward,     enabled),
  24
  25         FW3_OPT("name",                string,   forward,     name),
  26         FW3_OPT("family",              family,   forward,     family),
  27
  28         FW3_OPT("src",                 device,   forward,     src),
  29         FW3_OPT("dest",                device,   forward,     dest),
  30
  31         { }
  32 };
  33
  34
  35 void
  36 fw3_load_forwards(struct fw3_state *state, struct uci_package *p)
  37 {
  38         struct uci_section *s;
  39         struct uci_element *e;
  40         struct fw3_forward *forward;
  41
  42         INIT_LIST_HEAD(&state->forwards);
  43
  44         uci_foreach_element(&p->sections, e)
  45         {
  46                 s = uci_to_section(e);
  47
  48                 if (strcmp(s->type, "forwarding"))
  49                         continue;
  50
  51                 forward = malloc(sizeof(*forward));
  52
  53                 if (!forward)
  54                         continue;
  55
  56                 memset(forward, 0, sizeof(*forward));
  57
  58                 forward->enabled = true;
  59
  60                 fw3_parse_options(forward, fw3_forward_opts, s);
  61
  62                 if (!forward->enabled)
  63                 {
  64                         fw3_free_forward(forward);
  65                         continue;
  66                 }
  67
  68                 if (forward->src.invert || forward->dest.invert)
  69                 {
  70                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
  71                         fw3_free_forward(forward);
  72                         continue;
  73                 }
  74                 else if (forward->src.set && !forward->src.any &&
  75                          !(forward->_src = fw3_lookup_zone(state, forward->src.name)))
  76                 {
  77                         warn_elem(e, "refers to not existing zone '%s'", forward->src.name);
  78                         fw3_free_forward(forward);
  79                         continue;
  80                 }
  81                 else if (forward->dest.set && !forward->dest.any &&
  82                          !(forward->_dest = fw3_lookup_zone(state, forward->dest.name)))
  83                 {
  84                         warn_elem(e, "refers to not existing zone '%s'", forward->dest.name);
  85                         fw3_free_forward(forward);
  86                         continue;
  87                 }
  88
  89                 /* NB: forward family... */
  90                 if (forward->_dest)
  91                 {
  92                         setbit(forward->_dest->flags[0], FW3_FLAG_ACCEPT);
  93                         setbit(forward->_dest->flags[1], FW3_FLAG_ACCEPT);
  94
  95                         if (forward->_src &&
  96                             (forward->_src->conntrack || forward->_dest->conntrack))
  97                         {
  98                                 forward->_src->conntrack = forward->_dest->conntrack = true;
  99                         }
 100                 }
 101
 102                 list_add_tail(&forward->list, &state->forwards);
 103                 continue;
 104         }
 105 }
 106
 107
 108 static void
 109 append_chain(struct fw3_ipt_rule *r, struct fw3_forward *forward)
 110 {
 111         if (forward->src.any || !forward->src.set)
 112                 fw3_ipt_rule_append(r, "delegate_forward");
 113         else
 114                 fw3_ipt_rule_append(r, "zone_%s_forward", forward->src.name);
 115 }
 116
 117 static void set_target(struct fw3_ipt_rule *r, struct fw3_forward *forward)
 118 {
 119         if (forward->dest.any || !forward->dest.set)
 120                 fw3_ipt_rule_target(r, "ACCEPT");
 121         else
 122                 fw3_ipt_rule_target(r, "zone_%s_dest_ACCEPT", forward->dest.name);
 123 }
 124
 125 static void
 126 print_forward(struct fw3_ipt_handle *handle, struct fw3_forward *forward)
 127 {
 128         const char *s, *d;
 129         struct fw3_ipt_rule *r;
 130
 131         if (handle->table != FW3_TABLE_FILTER)
 132                 return;
 133
 134         if (!fw3_is_family(forward, handle->family))
 135                 return;
 136
 137         s = forward->_src  ? forward->_src->name  : "*";
 138         d = forward->_dest ? forward->_dest->name : "*";
 139
 140         info("   * Forward '%s' -> '%s'", s, d);
 141
 142         if (!fw3_is_family(forward->_src, handle->family) ||
 143             !fw3_is_family(forward->_dest, handle->family))
 144         {
 145                 info("     ! Skipping due to different family of zone");
 146                 return;
 147         }
 148
 149         r = fw3_ipt_rule_new(handle);
 150         fw3_ipt_rule_comment(r, "forwarding %s -> %s", s, d);
 151         set_target(r, forward);
 152         append_chain(r, forward);
 153 }
 154
 155 void
 156 fw3_print_forwards(struct fw3_ipt_handle *handle, struct fw3_state *state)
 157 {
 158         struct fw3_forward *forward;
 159
 160         list_for_each_entry(forward, &state->forwards, list)
 161                 print_forward(handle, forward);
 162 }