/*
* firewall3 - 3rd OpenWrt UCI firewall implementation
*
- * Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
+ * Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
+#define _GNU_SOURCE /* RTLD_NEXT */
+
+/* include userspace headers */
+#include <dlfcn.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <sys/utsname.h>
+#include <sys/socket.h>
+
+/* prevent indirect inclusion of kernel headers */
+#define _LINUX_IF_H
+#define _LINUX_IN_H
+#define _LINUX_IN6_H
+
+/* prevent libiptc from including kernel headers */
+#define _FWCHAINS_KERNEL_HEADERS_H
+
+/* finally include libiptc and xtables */
+#include <libiptc/libiptc.h>
+#include <libiptc/libip6tc.h>
+#include <xtables.h>
+
+#include <setjmp.h>
+
+#include "options.h"
+
+/* xtables interface */
+#if (XTABLES_VERSION_CODE >= 10)
+# include "xtables-10.h"
+#elif (XTABLES_VERSION_CODE == 5)
+# include "xtables-5.h"
+#else
+# error "Unsupported xtables version"
+#endif
+
#include "iptables.h"
+#define XT_LOCK_NAME "/var/run/xtables.lock"
+static int xt_lock_fd = -1;
+
+struct fw3_ipt_rule {
+ struct fw3_ipt_handle *h;
+
+ union {
+ struct ipt_entry e;
+ struct ip6t_entry e6;
+ };
+
+ struct xtables_rule_match *matches;
+ struct xtables_target *target;
+
+ int argc;
+ char **argv;
+
+ uint32_t protocol;
+ bool protocol_loaded;
+};
static struct option base_opts[] = {
- { .name = "match", .has_arg = 1, .val = 'm' },
- { .name = "jump", .has_arg = 1, .val = 'j' },
+ { .name = "match", .has_arg = 1, .val = 'm' },
+ { .name = "jump", .has_arg = 1, .val = 'j' },
+ { .name = "in-interface", .has_arg = 1, .val = 'i' },
+ { .name = "out-interface", .has_arg = 1, .val = 'o' },
+ { .name = "source", .has_arg = 1, .val = 's' },
+ { .name = "destination", .has_arg = 1, .val = 'd' },
{ NULL }
};
+
+static jmp_buf fw3_ipt_error_jmp;
+
+static __attribute__((noreturn))
+void fw3_ipt_error_handler(enum xtables_exittype status,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ fprintf(stderr, " ! Exception: ");
+
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+
+ longjmp(fw3_ipt_error_jmp, status);
+}
+
static struct xtables_globals xtg = {
.option_offset = 0,
.program_version = "4",
.orig_opts = base_opts,
+ .exit_err = fw3_ipt_error_handler,
+#if XTABLES_VERSION_CODE > 10
+ .compat_rev = xtables_compatible_revision,
+#endif
};
static struct xtables_globals xtg6 = {
.option_offset = 0,
.program_version = "6",
.orig_opts = base_opts,
+ .exit_err = fw3_ipt_error_handler,
+#if XTABLES_VERSION_CODE > 10
+ .compat_rev = xtables_compatible_revision,
+#endif
};
+static struct {
+ bool retain;
+ int mcount, tcount;
+ struct xtables_match **matches;
+ struct xtables_target **targets;
+ void (*register_match)(struct xtables_match *);
+ void (*register_target)(struct xtables_target *);
+} xext;
+
+
/* Required by certain extensions like SNAT and DNAT */
int kernel_version = 0;
struct fw3_ipt_handle *
fw3_ipt_open(enum fw3_family family, enum fw3_table table)
{
+ int i;
struct fw3_ipt_handle *h;
h = fw3_alloc(sizeof(*h));
xtables_init();
+ while (!fw3_lock_path(&xt_lock_fd, XT_LOCK_NAME)) {
+ warn("Currently busy xtables.lock - wait 1 second");
+ sleep(1);
+ }
+
if (family == FW3_FAMILY_V6)
{
#ifndef DISABLE_IPV6
if (!h->handle)
{
free(h);
+ fw3_unlock_path(&xt_lock_fd, XT_LOCK_NAME);
return NULL;
}
fw3_xt_reset();
fw3_init_extensions();
+ if (xext.register_match)
+ for (i = 0; i < xext.mcount; i++)
+ xext.register_match(xext.matches[i]);
+
+ if (xext.register_target)
+ for (i = 0; i < xext.tcount; i++)
+ xext.register_target(xext.targets[i]);
+
return h;
}
iptc_delete_chain(chain, h->handle);
}
-static int
-get_rule_id(const void *base, unsigned int start, unsigned int end)
+static bool
+has_rule_tag(const void *base, unsigned int start, unsigned int end)
{
- uint32_t id;
unsigned int i;
const struct xt_entry_match *em;
{
em = base + i;
- if (strcmp(em->u.user.name, "id"))
+ if (strcmp(em->u.user.name, "comment"))
continue;
- memcpy(&id, em->data, sizeof(id));
-
- if ((id & FW3_ID_MASK) != FW3_ID_MAGIC)
- continue;
-
- return (id & ~FW3_ID_MASK);
+ if (!memcmp(em->data, "!fw3", 4))
+ return true;
}
- return -1;
+ return false;
}
void
unsigned int num;
const struct ipt_entry *e;
bool found;
- int id;
#ifndef DISABLE_IPV6
if (h->family == FW3_FAMILY_V6)
e6 != NULL;
num++, e6 = ip6tc_next_rule(e6, h->handle))
{
- id = get_rule_id(e6, sizeof(*e6), e6->target_offset);
-
- if (id >= 0)
+ if (has_rule_tag(e6, sizeof(*e6), e6->target_offset))
{
if (fw3_pr_debug)
debug(h, "-D %s %u\n", chain, num + 1);
e != NULL;
num++, e = iptc_next_rule(e, h->handle))
{
- id = get_rule_id(e, sizeof(*e), e->target_offset);
-
- if (id >= 0)
+ if (has_rule_tag(e, sizeof(*e), e->target_offset))
{
if (fw3_pr_debug)
debug(h, "-D %s %u\n", chain, num + 1);
void
fw3_ipt_close(struct fw3_ipt_handle *h)
{
- if (h->libv)
- {
- while (h->libc > 0)
- {
- h->libc--;
- dlclose(h->libv[h->libc]);
- }
-
- free(h->libv);
- }
-
+ fw3_unlock_path(&xt_lock_fd, XT_LOCK_NAME);
free(h);
}
r = fw3_alloc(sizeof(*r));
r->h = h;
- r->id = 0;
r->argv = fw3_alloc(sizeof(char *));
r->argv[r->argc++] = "fw3";
return NULL;
}
-static bool
-load_extension(struct fw3_ipt_handle *h, const char *name)
-{
- char path[256];
- void *lib, **tmp;
- const char *pfx = (h->family == FW3_FAMILY_V6) ? "libip6t" : "libipt";
-
- snprintf(path, sizeof(path), "/usr/lib/iptables/libxt_%s.so", name);
- if (!(lib = dlopen(path, RTLD_NOW)))
- {
- snprintf(path, sizeof(path), "/usr/lib/iptables/%s_%s.so", pfx, name);
- lib = dlopen(path, RTLD_NOW);
- }
-
- if (!lib)
- return false;
-
- tmp = realloc(h->libv, sizeof(lib) * (h->libc + 1));
-
- if (!tmp)
- return false;
-
- h->libv = tmp;
- h->libv[h->libc++] = lib;
-
- return true;
-}
-
static struct xtables_match *
find_match(struct fw3_ipt_rule *r, const char *name)
{
struct xtables_match *m;
- m = xtables_find_match(name, XTF_DONT_LOAD, &r->matches);
-
- if (!m && load_extension(r->h, name))
- m = xtables_find_match(name, XTF_DONT_LOAD, &r->matches);
+ xext.retain = true;
+ m = xtables_find_match(name, XTF_TRY_LOAD, &r->matches);
+ xext.retain = false;
return m;
}
{
struct xtables_target *t;
- if (is_chain(r->h, name))
- return xtables_find_target(XT_STANDARD_TARGET, XTF_LOAD_MUST_SUCCEED);
+ xext.retain = true;
- t = xtables_find_target(name, XTF_DONT_LOAD);
+ if (is_chain(r->h, name))
+ t = xtables_find_target(XT_STANDARD_TARGET, XTF_TRY_LOAD);
+ else
+ t = xtables_find_target(name, XTF_TRY_LOAD);
- if (!t && load_extension(r->h, name))
- t = xtables_find_target(name, XTF_DONT_LOAD);
+ xext.retain = false;
return t;
}
if (sp->port_min == sp->port_max)
sprintf(buf, "%u", sp->port_min);
else
- sprintf(buf, "%u:%u", sp->port_min, sp->port_max);
+ snprintf(buf, sizeof(buf), "%u:%u", sp->port_min, sp->port_max);
fw3_ipt_rule_addarg(r, sp->invert, "--sport", buf);
}
if (dp->port_min == dp->port_max)
sprintf(buf, "%u", dp->port_min);
else
- sprintf(buf, "%u:%u", dp->port_min, dp->port_max);
+ snprintf(buf, sizeof(buf), "%u:%u", dp->port_min, dp->port_max);
fw3_ipt_rule_addarg(r, dp->invert, "--dport", buf);
}
if (icmp->code6_min == 0 && icmp->code6_max == 0xFF)
sprintf(buf, "%u", icmp->type6);
else
- sprintf(buf, "%u/%u", icmp->type6, icmp->code6_min);
+ snprintf(buf, sizeof(buf), "%u/%u", icmp->type6, icmp->code6_min);
fw3_ipt_rule_addarg(r, icmp->invert, "--icmpv6-type", buf);
}
if (icmp->code_min == 0 && icmp->code_max == 0xFF)
sprintf(buf, "%u", icmp->type);
else
- sprintf(buf, "%u/%u", icmp->type, icmp->code_min);
+ snprintf(buf, sizeof(buf), "%u/%u", icmp->type, icmp->code_min);
fw3_ipt_rule_addarg(r, icmp->invert, "--icmp-type", buf);
}
fw3_ipt_rule_addarg(r, false, buf, NULL);
}
+void
+fw3_ipt_rule_helper(struct fw3_ipt_rule *r, struct fw3_cthelpermatch *match)
+{
+ if (!match || !match->set || !match->ptr)
+ return;
+
+ fw3_ipt_rule_addarg(r, false, "-m", "helper");
+ fw3_ipt_rule_addarg(r, match->invert, "--helper", match->ptr->name);
+}
+
void
fw3_ipt_rule_time(struct fw3_ipt_rule *r, struct fw3_time *time)
{
fw3_ipt_rule_addarg(r, false, "-m", "time");
- if (time->utc)
- fw3_ipt_rule_addarg(r, false, "--utc", NULL);
+ if (!time->utc)
+ fw3_ipt_rule_addarg(r, false, "--kerneltz", NULL);
if (d1)
{
{
for (i = 1, p = buf; i < 32; i++)
{
- if (hasbit(time->monthdays, i))
+ if (fw3_hasbit(time->monthdays, i))
{
if (p > buf)
*p++ = ',';
}
}
- fw3_ipt_rule_addarg(r, hasbit(time->monthdays, 0), "--monthdays", buf);
+ fw3_ipt_rule_addarg(r, fw3_hasbit(time->monthdays, 0), "--monthdays", buf);
}
if (time->weekdays & 0xFE)
{
for (i = 1, p = buf; i < 8; i++)
{
- if (hasbit(time->weekdays, i))
+ if (fw3_hasbit(time->weekdays, i))
{
if (p > buf)
*p++ = ',';
}
}
- fw3_ipt_rule_addarg(r, hasbit(time->weekdays, 0), "--weekdays", buf);
+ fw3_ipt_rule_addarg(r, fw3_hasbit(time->weekdays, 0), "--weekdays", buf);
}
}
fw3_ipt_rule_addarg(r, mark->invert, "--mark", buf);
}
+void
+fw3_ipt_rule_dscp(struct fw3_ipt_rule *r, struct fw3_dscp *dscp)
+{
+ char buf[sizeof("0xFF\0")];
+
+ if (!dscp || !dscp->set)
+ return;
+
+ sprintf(buf, "0x%x", dscp->dscp);
+
+ fw3_ipt_rule_addarg(r, false, "-m", "dscp");
+ fw3_ipt_rule_addarg(r, dscp->invert, "--dscp", buf);
+}
+
void
fw3_ipt_rule_comment(struct fw3_ipt_rule *r, const char *fmt, ...)
{
if (e->ipv6.flags & IP6T_F_PROTO)
{
- if (e->ipv6.flags & XT_INV_PROTO)
+ if (e->ipv6.invflags & XT_INV_PROTO)
printf(" !");
pname = get_protoname(container_of(e, struct fw3_ipt_rule, e6));
if (e->ipv6.iniface[0])
{
- if (e->ipv6.flags & IP6T_INV_VIA_IN)
+ if (e->ipv6.invflags & IP6T_INV_VIA_IN)
printf(" !");
printf(" -i %s", e->ipv6.iniface);
if (e->ipv6.outiface[0])
{
- if (e->ipv6.flags & IP6T_INV_VIA_OUT)
+ if (e->ipv6.invflags & IP6T_INV_VIA_OUT)
printf(" !");
printf(" -o %s", e->ipv6.outiface);
if (memcmp(&e->ipv6.src, &in6addr_any, sizeof(struct in6_addr)))
{
- if (e->ipv6.flags & IP6T_INV_SRCIP)
+ if (e->ipv6.invflags & IP6T_INV_SRCIP)
printf(" !");
printf(" -s %s/%s",
if (memcmp(&e->ipv6.dst, &in6addr_any, sizeof(struct in6_addr)))
{
- if (e->ipv6.flags & IP6T_INV_DSTIP)
+ if (e->ipv6.invflags & IP6T_INV_DSTIP)
printf(" !");
printf(" -d %s/%s",
if (e->ip.proto)
{
- if (e->ip.flags & XT_INV_PROTO)
+ if (e->ip.invflags & XT_INV_PROTO)
printf(" !");
pname = get_protoname(container_of(e, struct fw3_ipt_rule, e));
if (e->ip.iniface[0])
{
- if (e->ip.flags & IPT_INV_VIA_IN)
+ if (e->ip.invflags & IPT_INV_VIA_IN)
printf(" !");
printf(" -i %s", e->ip.iniface);
if (e->ip.outiface[0])
{
- if (e->ip.flags & IPT_INV_VIA_OUT)
+ if (e->ip.invflags & IPT_INV_VIA_OUT)
printf(" !");
printf(" -o %s", e->ip.outiface);
if (memcmp(&e->ip.src, &in_zero, sizeof(struct in_addr)))
{
- if (e->ip.flags & IPT_INV_SRCIP)
+ if (e->ip.invflags & IPT_INV_SRCIP)
printf(" !");
printf(" -s %s/%s",
if (memcmp(&e->ip.dst, &in_zero, sizeof(struct in_addr)))
{
- if (e->ip.flags & IPT_INV_DSTIP)
+ if (e->ip.invflags & IPT_INV_DSTIP)
printf(" !");
printf(" -d %s/%s",
p += SZ(ip6t_entry_match) + m->match->size;
}
- memset(p, 0xFF, SZ(ip6t_entry_target) + (r->target) ? r->target->userspacesize : 0);
+ memset(p, 0xFF, SZ(ip6t_entry_target) + (r->target ? r->target->userspacesize : 0));
}
else
#endif
p += SZ(ipt_entry_match) + m->match->size;
}
- memset(p, 0xFF, SZ(ipt_entry_target) + (r->target) ? r->target->userspacesize : 0);
+ memset(p, 0xFF, SZ(ipt_entry_target) + (r->target ? r->target->userspacesize : 0));
}
return mask;
}
}
+static void
+set_rule_tag(struct fw3_ipt_rule *r)
+{
+ int i;
+ char *p, **tmp;
+ const char *tag = "!fw3";
+
+ for (i = 0; i < r->argc; i++)
+ if (!strcmp(r->argv[i], "--comment") && (i + 1) < r->argc)
+ if (asprintf(&p, "%s: %s", tag, r->argv[i + 1]) > 0)
+ {
+ free(r->argv[i + 1]);
+ r->argv[i + 1] = p;
+ return;
+ }
+
+ tmp = realloc(r->argv, (r->argc + 4) * sizeof(*r->argv));
+
+ if (tmp)
+ {
+ r->argv = tmp;
+ r->argv[r->argc++] = fw3_strdup("-m");
+ r->argv[r->argc++] = fw3_strdup("comment");
+ r->argv[r->argc++] = fw3_strdup("--comment");
+ r->argv[r->argc++] = fw3_strdup(tag);
+ }
+}
+
void
__fw3_ipt_rule_append(struct fw3_ipt_rule *r, bool repl, const char *fmt, ...)
{
struct xtables_target *et;
struct xtables_globals *g;
+ struct fw3_device dev;
+ struct fw3_address addr;
+
+ enum xtables_exittype status;
+
int i, optc;
- uint32_t id;
bool inv = false;
char buf[32];
va_list ap;
optind = 0;
opterr = 0;
- if (r->id >= 0)
- {
- em = find_match(r, "id");
-
- if (!em)
- {
- warn("fw3_ipt_rule_append(): Can't find match '%s'", "id");
- goto free;
- }
-
- init_match(r, em, true);
-
- id = FW3_ID_MAGIC | (r->id & ~FW3_ID_MASK);
- memcpy(em->m->data, &id, sizeof(id));
+ status = setjmp(fw3_ipt_error_jmp);
- em->mflags = 1;
+ if (status > 0)
+ {
+ info(" ! Skipping due to previous exception (code %u)", status);
+ goto free;
}
- while ((optc = getopt_long(r->argc, r->argv, "-:m:j:", g->opts,
+ set_rule_tag(r);
+
+ while ((optc = getopt_long(r->argc, r->argv, "-:m:j:i:o:s:d:", g->opts,
NULL)) != -1)
{
switch (optc)
break;
+ case 'i':
+ case 'o':
+ if (!fw3_parse_device(&dev, optarg, false) ||
+ dev.any || dev.invert || *dev.network)
+ {
+ warn("fw3_ipt_rule_append(): Bad argument '%s'", optarg);
+ goto free;
+ }
+
+ dev.invert = inv;
+ fw3_ipt_rule_in_out(r, (optc == 'i') ? &dev : NULL,
+ (optc == 'o') ? &dev : NULL);
+ break;
+
+ case 's':
+ case 'd':
+ if (!fw3_parse_address(&addr, optarg, false) ||
+ addr.range || addr.invert)
+ {
+ warn("fw3_ipt_rule_append(): Bad argument '%s'", optarg);
+ goto free;
+ }
+
+ addr.invert = inv;
+ fw3_ipt_rule_src_dest(r, (optc == 's') ? &addr : NULL,
+ (optc == 'd') ? &addr : NULL);
+ break;
+
case 1:
if ((optarg[0] == '!') && (optarg[1] == '\0'))
{
return r;
}
+
+void
+xtables_register_match(struct xtables_match *me)
+{
+ int i;
+ static struct xtables_match **tmp;
+
+ if (!xext.register_match)
+ xext.register_match = dlsym(RTLD_NEXT, "xtables_register_match");
+
+ if (!xext.register_match)
+ return;
+
+ xext.register_match(me);
+
+ if (xext.retain)
+ {
+ for (i = 0; i < xext.mcount; i++)
+ if (xext.matches[i] == me)
+ return;
+
+ tmp = realloc(xext.matches, sizeof(me) * (xext.mcount + 1));
+
+ if (!tmp)
+ return;
+
+ xext.matches = tmp;
+ xext.matches[xext.mcount++] = me;
+ }
+}
+
+void
+xtables_register_target(struct xtables_target *me)
+{
+ int i;
+ static struct xtables_target **tmp;
+
+ if (!xext.register_target)
+ xext.register_target = dlsym(RTLD_NEXT, "xtables_register_target");
+
+ if (!xext.register_target)
+ return;
+
+ xext.register_target(me);
+
+ if (xext.retain)
+ {
+ for (i = 0; i < xext.tcount; i++)
+ if (xext.targets[i] == me)
+ return;
+
+ tmp = realloc(xext.targets, sizeof(me) * (xext.tcount + 1));
+
+ if (!tmp)
+ return;
+
+ xext.targets = tmp;
+ xext.targets[xext.tcount++] = me;
+ }
+}