forwards.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
   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 = calloc(1, sizeof(*forward));
  52                 if (!forward)
  53                         continue;
  54
  55                 forward->enabled = true;
  56
  57                 fw3_parse_options(forward, fw3_forward_opts, s);
  58
  59                 if (!forward->enabled)
  60                 {
  61                         fw3_free_forward(forward);
  62                         continue;
  63                 }
  64
  65                 if (forward->src.invert || forward->dest.invert)
  66                 {
  67                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
  68                         fw3_free_forward(forward);
  69                         continue;
  70                 }
  71                 else if (forward->src.set && !forward->src.any &&
  72                          !(forward->_src = fw3_lookup_zone(state, forward->src.name)))
  73                 {
  74                         warn_elem(e, "refers to not existing zone '%s'", forward->src.name);
  75                         fw3_free_forward(forward);
  76                         continue;
  77                 }
  78                 else if (forward->dest.set && !forward->dest.any &&
  79                          !(forward->_dest = fw3_lookup_zone(state, forward->dest.name)))
  80                 {
  81                         warn_elem(e, "refers to not existing zone '%s'", forward->dest.name);
  82                         fw3_free_forward(forward);
  83                         continue;
  84                 }
  85
  86                 /* NB: forward family... */
  87                 if (forward->_dest)
  88                 {
  89                         setbit(forward->_dest->flags[0], FW3_FLAG_ACCEPT);
  90                         setbit(forward->_dest->flags[1], FW3_FLAG_ACCEPT);
  91
  92                         if (forward->_src &&
  93                             (forward->_src->conntrack || forward->_dest->conntrack))
  94                         {
  95                                 forward->_src->conntrack = forward->_dest->conntrack = true;
  96                         }
  97                 }
  98
  99                 list_add_tail(&forward->list, &state->forwards);
 100                 continue;
 101         }
 102 }
 103
 104
 105 static void
 106 append_chain(struct fw3_ipt_rule *r, struct fw3_forward *forward)
 107 {
 108         if (forward->src.any || !forward->src.set)
 109                 fw3_ipt_rule_append(r, "FORWARD");
 110         else
 111                 fw3_ipt_rule_append(r, "zone_%s_forward", forward->src.name);
 112 }
 113
 114 static void set_target(struct fw3_ipt_rule *r, struct fw3_forward *forward)
 115 {
 116         if (forward->dest.any || !forward->dest.set)
 117                 fw3_ipt_rule_target(r, "ACCEPT");
 118         else
 119                 fw3_ipt_rule_target(r, "zone_%s_dest_ACCEPT", forward->dest.name);
 120 }
 121
 122 static void
 123 print_forward(struct fw3_ipt_handle *handle, struct fw3_forward *forward)
 124 {
 125         const char *s, *d;
 126         struct fw3_ipt_rule *r;
 127
 128         if (handle->table != FW3_TABLE_FILTER)
 129                 return;
 130
 131         if (!fw3_is_family(forward, handle->family))
 132                 return;
 133
 134         s = forward->_src  ? forward->_src->name  : "*";
 135         d = forward->_dest ? forward->_dest->name : "*";
 136
 137         info("   * Forward '%s' -> '%s'", s, d);
 138
 139         if (!fw3_is_family(forward->_src, handle->family) ||
 140             !fw3_is_family(forward->_dest, handle->family))
 141         {
 142                 info("     ! Skipping due to different family of zone");
 143                 return;
 144         }
 145
 146         r = fw3_ipt_rule_new(handle);
 147         fw3_ipt_rule_comment(r, "forwarding %s -> %s", s, d);
 148         set_target(r, forward);
 149         append_chain(r, forward);
 150 }
 151
 152 void
 153 fw3_print_forwards(struct fw3_ipt_handle *handle, struct fw3_state *state)
 154 {
 155         struct fw3_forward *forward;
 156
 157         list_for_each_entry(forward, &state->forwards, list)
 158                 print_forward(handle, forward);
 159 }