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 static struct fw3_option forward_opts[] = {
  23         FW3_OPT("name",                string,   forward,     name),
  24         FW3_OPT("family",              family,   forward,     family),
  25
  26         FW3_OPT("src",                 device,   forward,     src),
  27         FW3_OPT("dest",                device,   forward,     dest),
  28 };
  29
  30
  31 void
  32 fw3_load_forwards(struct fw3_state *state, struct uci_package *p)
  33 {
  34         struct uci_section *s;
  35         struct uci_element *e;
  36         struct fw3_forward *forward;
  37
  38         INIT_LIST_HEAD(&state->forwards);
  39
  40         uci_foreach_element(&p->sections, e)
  41         {
  42                 s = uci_to_section(e);
  43
  44                 if (strcmp(s->type, "forwarding"))
  45                         continue;
  46
  47                 forward = malloc(sizeof(*forward));
  48
  49                 if (!forward)
  50                         continue;
  51
  52                 memset(forward, 0, sizeof(*forward));
  53
  54                 fw3_parse_options(forward, forward_opts, ARRAY_SIZE(forward_opts), s);
  55
  56                 if (forward->src.invert || forward->dest.invert)
  57                 {
  58                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
  59                         fw3_free_forward(forward);
  60                         continue;
  61                 }
  62                 else if (forward->src.set && !forward->src.any &&
  63                          !(forward->_src = fw3_lookup_zone(state, forward->src.name, false)))
  64                 {
  65                         warn_elem(e, "refers to not existing zone '%s'", forward->src.name);
  66                         fw3_free_forward(forward);
  67                         continue;
  68                 }
  69                 else if (forward->dest.set && !forward->dest.any &&
  70                          !(forward->_dest = fw3_lookup_zone(state, forward->dest.name, false)))
  71                 {
  72                         warn_elem(e, "refers to not existing zone '%s'", forward->dest.name);
  73                         fw3_free_forward(forward);
  74                         continue;
  75                 }
  76
  77                 if (forward->_dest)
  78                 {
  79                         setbit(forward->_dest->dst_flags, FW3_TARGET_ACCEPT);
  80
  81                         if (forward->_src &&
  82                             (forward->_src->conntrack || forward->_dest->conntrack))
  83                         {
  84                                 forward->_src->conntrack = forward->_dest->conntrack = true;
  85                         }
  86                 }
  87
  88                 list_add_tail(&forward->list, &state->forwards);
  89                 continue;
  90         }
  91 }
  92
  93
  94 static void
  95 print_chain(struct fw3_forward *forward)
  96 {
  97         if (forward->src.any || !forward->src.set)
  98                 fw3_pr("-A delegate_forward");
  99         else
 100                 fw3_pr("-A zone_%s_forward", forward->src.name);
 101 }
 102
 103 static void print_target(struct fw3_forward *forward)
 104 {
 105         if (forward->dest.any || !forward->dest.set)
 106                 fw3_pr(" -j ACCEPT\n");
 107         else
 108                 fw3_pr(" -j zone_%s_dest_ACCEPT\n", forward->dest.name);
 109 }
 110
 111 static void
 112 print_forward(enum fw3_table table, enum fw3_family family,
 113               struct fw3_forward *forward)
 114 {
 115         const char *s, *d;
 116
 117         if (table != FW3_TABLE_FILTER)
 118                 return;
 119
 120         if (!fw3_is_family(forward, family))
 121                 return;
 122
 123         s = forward->_src  ? forward->_src->name  : "*";
 124         d = forward->_dest ? forward->_dest->name : "*";
 125
 126         if (forward->name)
 127                 info("   * Forward '%s'", forward->name);
 128         else
 129                 info("   * Forward %s->%s", s, d);
 130
 131         if (!fw3_is_family(forward->_src, family) ||
 132             !fw3_is_family(forward->_dest, family))
 133         {
 134                 info("     ! Skipping due to different family of zone");
 135                 return;
 136         }
 137
 138         print_chain(forward);
 139         fw3_format_comment("forwarding ", s, "->", d);
 140         print_target(forward);
 141 }
 142
 143 void
 144 fw3_print_forwards(enum fw3_table table, enum fw3_family family,
 145                    struct fw3_state *state)
 146 {
 147         struct fw3_forward *forward;
 148
 149         list_for_each_entry(forward, &state->forwards, list)
 150                 print_forward(table, family, forward);
 151 }