iptables: fix regression with unintended free in need_protomatch
[project/firewall3.git] / iptables.c
index 96fba12f0e90fb45baadae7fc597226cafd006ea..d03d1dd2933e8000712a0696c4e0d60fa6142347 100644 (file)
  * 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;
 
@@ -44,12 +141,11 @@ void
 get_kernel_version(void)
 {
        static struct utsname uts;
-       int x = 0, y = 0, z = 0;
+       int x = 3, y = 0, z = 0;
 
-       if (uname(&uts) == -1)
-               sprintf(uts.release, "3.0.0");
+       if (uname(&uts) != -1)
+               sscanf(uts.release, "%d.%d.%d", &x, &y, &z);
 
-       sscanf(uts.release, "%d.%d.%d", &x, &y, &z);
        kernel_version = 0x10000 * x + 0x100 * y + z;
 }
 
@@ -66,12 +162,18 @@ static void fw3_init_extensions(void)
 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
@@ -96,12 +198,21 @@ fw3_ipt_open(enum fw3_family family, enum fw3_table table)
        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;
 }
 
@@ -217,9 +328,61 @@ delete_rules(struct fw3_ipt_handle *h, const char *target)
        }
 }
 
+static bool
+is_referenced(struct fw3_ipt_handle *h, const char *target)
+{
+       const struct ipt_entry *e;
+       const char *chain;
+       const char *t;
+
+#ifndef DISABLE_IPV6
+       if (h->family == FW3_FAMILY_V6)
+       {
+               for (chain = ip6tc_first_chain(h->handle);
+                    chain != NULL;
+                    chain = ip6tc_next_chain(h->handle))
+               {
+                       const struct ip6t_entry *e6;
+                       for (e6 = ip6tc_first_rule(chain, h->handle);
+                            e6 != NULL;
+                            e6 = ip6tc_next_rule(e6, h->handle))
+                       {
+                               t = ip6tc_get_target(e6, h->handle);
+
+                               if (*t && !strcmp(t, target))
+                                       return true;
+                       }
+               }
+       }
+       else
+#endif
+       {
+               for (chain = iptc_first_chain(h->handle);
+                    chain != NULL;
+                    chain = iptc_next_chain(h->handle))
+               {
+                       for (e = iptc_first_rule(chain, h->handle);
+                            e != NULL;
+                            e = iptc_next_rule(e, h->handle))
+                       {
+                               t = iptc_get_target(e, h->handle);
+
+                               if (*t && !strcmp(t, target))
+                                       return true;
+                       }
+               }
+       }
+
+       return false;
+}
+
 void
-fw3_ipt_delete_chain(struct fw3_ipt_handle *h, const char *chain)
+fw3_ipt_delete_chain(struct fw3_ipt_handle *h, bool if_unused,
+                     const char *chain)
 {
+       if (if_unused && is_referenced(h, chain))
+               return;
+
        delete_rules(h, chain);
 
        if (fw3_pr_debug)
@@ -233,10 +396,9 @@ fw3_ipt_delete_chain(struct fw3_ipt_handle *h, const char *chain)
                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;
 
@@ -244,18 +406,14 @@ get_rule_id(const void *base, unsigned int start, unsigned int end)
        {
                em = base + i;
 
-               if (strcmp(em->u.user.name, "id"))
-                       continue;
-
-               memcpy(&id, em->data, sizeof(id));
-
-               if ((id & FW3_ID_MASK) != FW3_ID_MAGIC)
+               if (strcmp(em->u.user.name, "comment"))
                        continue;
 
-               return (id & ~FW3_ID_MASK);
+               if (!memcmp(em->data, "!fw3", 4))
+                       return true;
        }
 
-       return -1;
+       return false;
 }
 
 void
@@ -264,7 +422,6 @@ fw3_ipt_delete_id_rules(struct fw3_ipt_handle *h, const char *chain)
        unsigned int num;
        const struct ipt_entry *e;
        bool found;
-       int id;
 
 #ifndef DISABLE_IPV6
        if (h->family == FW3_FAMILY_V6)
@@ -280,9 +437,7 @@ fw3_ipt_delete_id_rules(struct fw3_ipt_handle *h, const char *chain)
                                 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);
@@ -307,9 +462,7 @@ fw3_ipt_delete_id_rules(struct fw3_ipt_handle *h, const char *chain)
                                 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);
@@ -323,20 +476,29 @@ fw3_ipt_delete_id_rules(struct fw3_ipt_handle *h, const char *chain)
        }
 }
 
-void
-fw3_ipt_create_chain(struct fw3_ipt_handle *h, const char *fmt, ...)
+
+static bool
+is_chain(struct fw3_ipt_handle *h, const char *name)
 {
-       char buf[32];
-       va_list ap;
+#ifndef DISABLE_IPV6
+       if (h->family == FW3_FAMILY_V6)
+               return ip6tc_is_chain(name, h->handle);
+       else
+#endif
+               return iptc_is_chain(name, h->handle);
+}
 
-       va_start(ap, fmt);
-       vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
-       va_end(ap);
+void
+fw3_ipt_create_chain(struct fw3_ipt_handle *h, bool ignore_existing,
+                     const char *chain)
+{
+       if (ignore_existing && is_chain(h, chain))
+               return;
 
        if (fw3_pr_debug)
-               debug(h, "-N %s\n", buf);
+               debug(h, "-N %s\n", chain);
 
-       iptc_create_chain(buf, h->handle);
+       iptc_create_chain(chain, h->handle);
 }
 
 void
@@ -412,7 +574,7 @@ fw3_ipt_gc(struct fw3_ipt_handle *h)
                                if (!chain_is_empty(h, chain))
                                        continue;
 
-                               fw3_ipt_delete_chain(h, chain);
+                               fw3_ipt_delete_chain(h, false, chain);
                                found = true;
                                break;
                        }
@@ -435,7 +597,7 @@ fw3_ipt_gc(struct fw3_ipt_handle *h)
 
                                warn("D=%s\n", chain);
 
-                               fw3_ipt_delete_chain(h, chain);
+                               fw3_ipt_delete_chain(h, false, chain);
                                found = true;
                                break;
                        }
@@ -467,17 +629,7 @@ fw3_ipt_commit(struct fw3_ipt_handle *h)
 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);
 }
 
@@ -489,7 +641,6 @@ fw3_ipt_rule_new(struct fw3_ipt_handle *h)
        r = fw3_alloc(sizeof(*r));
 
        r->h = h;
-       r->id = 0;
        r->argv = fw3_alloc(sizeof(char *));
        r->argv[r->argc++] = "fw3";
 
@@ -497,17 +648,6 @@ fw3_ipt_rule_new(struct fw3_ipt_handle *h)
 }
 
 
-static bool
-is_chain(struct fw3_ipt_handle *h, const char *name)
-{
-#ifndef DISABLE_IPV6
-       if (h->family == FW3_FAMILY_V6)
-               return ip6tc_is_chain(name, h->handle);
-       else
-#endif
-               return iptc_is_chain(name, h->handle);
-}
-
 static char *
 get_protoname(struct fw3_ipt_rule *r)
 {
@@ -521,43 +661,14 @@ get_protoname(struct fw3_ipt_rule *r)
        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;
 }
@@ -598,12 +709,18 @@ init_match(struct fw3_ipt_rule *r, struct xtables_match *m, bool no_clone)
 static bool
 need_protomatch(struct fw3_ipt_rule *r, const char *pname)
 {
+       struct xtables_match *match;
+
        if (!pname)
                return false;
 
-       if (!xtables_find_match(pname, XTF_DONT_LOAD, NULL))
+       match = xtables_find_match(pname, XTF_DONT_LOAD, NULL);
+       if (!match)
                return true;
 
+       /* Free any kind of clone from xtables_find_match */
+       if (match == match->next)
+               free(match);
        return !r->protocol_loaded;
 }
 
@@ -623,13 +740,14 @@ find_target(struct fw3_ipt_rule *r, const char *name)
 {
        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;
 }
@@ -832,7 +950,7 @@ void
 fw3_ipt_rule_sport_dport(struct fw3_ipt_rule *r,
                          struct fw3_port *sp, struct fw3_port *dp)
 {
-       char buf[sizeof("65535:65535\0")];
+       char buf[sizeof("65535:65535")];
 
        if ((!sp || !sp->set) && (!dp || !dp->set))
                return;
@@ -843,9 +961,9 @@ fw3_ipt_rule_sport_dport(struct fw3_ipt_rule *r,
        if (sp && sp->set)
        {
                if (sp->port_min == sp->port_max)
-                       sprintf(buf, "%u", sp->port_min);
+                       snprintf(buf, sizeof(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);
        }
@@ -853,9 +971,9 @@ fw3_ipt_rule_sport_dport(struct fw3_ipt_rule *r,
        if (dp && dp->set)
        {
                if (dp->port_min == dp->port_max)
-                       sprintf(buf, "%u", dp->port_min);
+                       snprintf(buf, sizeof(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);
        }
@@ -864,9 +982,10 @@ fw3_ipt_rule_sport_dport(struct fw3_ipt_rule *r,
 void
 fw3_ipt_rule_device(struct fw3_ipt_rule *r, const char *device, bool out)
 {
+       struct fw3_device dev = { .any = false };
+
        if (device) {
-               struct fw3_device dev = { .any = false };
-               strncpy(dev.name, device, sizeof(dev.name) - 1);
+               snprintf(dev.name, sizeof(dev.name), "%s", device);
                fw3_ipt_rule_in_out(r, (out) ? NULL : &dev, (out) ? &dev : NULL);
        }
 }
@@ -874,14 +993,14 @@ fw3_ipt_rule_device(struct fw3_ipt_rule *r, const char *device, bool out)
 void
 fw3_ipt_rule_mac(struct fw3_ipt_rule *r, struct fw3_mac *mac)
 {
-       char buf[sizeof("ff:ff:ff:ff:ff:ff\0")];
+       char buf[sizeof("ff:ff:ff:ff:ff:ff")];
        uint8_t *addr = mac->mac.ether_addr_octet;
 
        if (!mac)
                return;
 
-       sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x",
-               addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+       snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
+                addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
 
        fw3_ipt_rule_addarg(r, false, "-m", "mac");
        fw3_ipt_rule_addarg(r, mac->invert, "--mac-source", buf);
@@ -890,7 +1009,7 @@ fw3_ipt_rule_mac(struct fw3_ipt_rule *r, struct fw3_mac *mac)
 void
 fw3_ipt_rule_icmptype(struct fw3_ipt_rule *r, struct fw3_icmptype *icmp)
 {
-       char buf[sizeof("255/255\0")];
+       char buf[sizeof("255/255")];
 
        if (!icmp)
                return;
@@ -899,9 +1018,9 @@ fw3_ipt_rule_icmptype(struct fw3_ipt_rule *r, struct fw3_icmptype *icmp)
        if (r->h->family == FW3_FAMILY_V6)
        {
                if (icmp->code6_min == 0 && icmp->code6_max == 0xFF)
-                       sprintf(buf, "%u", icmp->type6);
+                       snprintf(buf, sizeof(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);
        }
@@ -909,9 +1028,9 @@ fw3_ipt_rule_icmptype(struct fw3_ipt_rule *r, struct fw3_icmptype *icmp)
 #endif
        {
                if (icmp->code_min == 0 && icmp->code_max == 0xFF)
-                       sprintf(buf, "%u", icmp->type);
+                       snprintf(buf, sizeof(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);
        }
@@ -920,19 +1039,19 @@ fw3_ipt_rule_icmptype(struct fw3_ipt_rule *r, struct fw3_icmptype *icmp)
 void
 fw3_ipt_rule_limit(struct fw3_ipt_rule *r, struct fw3_limit *limit)
 {
-       char buf[sizeof("-4294967296/second\0")];
+       char buf[sizeof("-4294967296/second")];
 
        if (!limit || limit->rate <= 0)
                return;
 
        fw3_ipt_rule_addarg(r, false, "-m", "limit");
 
-       sprintf(buf, "%u/%s", limit->rate, fw3_limit_units[limit->unit]);
+       snprintf(buf, sizeof(buf), "%u/%s", limit->rate, fw3_limit_units[limit->unit]);
        fw3_ipt_rule_addarg(r, limit->invert, "--limit", buf);
 
        if (limit->burst > 0)
        {
-               sprintf(buf, "%u", limit->burst);
+               snprintf(buf, sizeof(buf), "%u", limit->burst);
                fw3_ipt_rule_addarg(r, limit->invert, "--limit-burst", buf);
        }
 }
@@ -940,9 +1059,10 @@ fw3_ipt_rule_limit(struct fw3_ipt_rule *r, struct fw3_limit *limit)
 void
 fw3_ipt_rule_ipset(struct fw3_ipt_rule *r, struct fw3_setmatch *match)
 {
-       char buf[sizeof("dst,dst,dst\0")];
+       char buf[sizeof("dst,dst,dst")];
        char *p = buf;
-       int i = 0;
+       int i = 0, len;
+       size_t rem = sizeof(buf);
 
        struct fw3_ipset *set;
        struct fw3_ipset_datatype *type;
@@ -956,10 +1076,23 @@ fw3_ipt_rule_ipset(struct fw3_ipt_rule *r, struct fw3_setmatch *match)
                if (i >= 3)
                        break;
 
-               if (p > buf)
+               if (p > buf) {
+                       if (rem <= 1)
+                               break;
+
                        *p++ = ',';
+                       *p = 0;
+                       rem--;
+               }
+
+               len = snprintf(p, rem, "%s", match->dir[i] ? match->dir[i] : type->dir);
+
+               if (len < 0 || len >= rem)
+                       break;
+
+               rem -= len;
+               p += len;
 
-               p += sprintf(p, "%s", match->dir[i] ? match->dir[i] : type->dir);
                i++;
        }
 
@@ -971,18 +1104,30 @@ fw3_ipt_rule_ipset(struct fw3_ipt_rule *r, struct fw3_setmatch *match)
        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)
 {
-       int i;
+       int i, len;
        struct tm empty = { 0 };
 
-       char buf[84]; /* sizeof("1,2,3,...,30,31\0") */
+       char buf[84]; /* sizeof("1,2,3,...,30,31") */
        char *p;
 
        bool d1 = memcmp(&time->datestart, &empty, sizeof(empty));
        bool d2 = memcmp(&time->datestop, &empty, sizeof(empty));
 
+       size_t rem;
+
        if (!d1 && !d2 && !time->timestart && !time->timestop &&
            !(time->monthdays & 0xFFFFFFFE) && !(time->weekdays & 0xFE))
        {
@@ -991,8 +1136,8 @@ 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)
        {
@@ -1008,7 +1153,7 @@ fw3_ipt_rule_time(struct fw3_ipt_rule *r, struct fw3_time *time)
 
        if (time->timestart)
        {
-               sprintf(buf, "%02d:%02d:%02d",
+               snprintf(buf, sizeof(buf), "%02d:%02d:%02d",
                        time->timestart / 3600,
                        time->timestart % 3600 / 60,
                        time->timestart % 60);
@@ -1018,7 +1163,7 @@ fw3_ipt_rule_time(struct fw3_ipt_rule *r, struct fw3_time *time)
 
        if (time->timestop)
        {
-               sprintf(buf, "%02d:%02d:%02d",
+               snprintf(buf, sizeof(buf), "%02d:%02d:%02d",
                        time->timestop / 3600,
                        time->timestop % 3600 / 60,
                        time->timestop % 60);
@@ -1028,54 +1173,92 @@ fw3_ipt_rule_time(struct fw3_ipt_rule *r, struct fw3_time *time)
 
        if (time->monthdays & 0xFFFFFFFE)
        {
-               for (i = 1, p = buf; i < 32; i++)
+               for (i = 1, p = buf, rem = sizeof(buf); i < 32; i++)
                {
-                       if (hasbit(time->monthdays, i))
+                       if (fw3_hasbit(time->monthdays, i))
                        {
-                               if (p > buf)
+                               if (p > buf) {
+                                       if (rem <= 1)
+                                               break;
+
                                        *p++ = ',';
+                                       *p = 0;
+                                       rem--;
+                               }
+
+                               len = snprintf(p, rem, "%u", i);
 
-                               p += sprintf(p, "%u", i);
+                               if (len < 0 || len >= rem)
+                                       break;
+
+                               rem -= len;
+                               p += len;
                        }
                }
 
-               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++)
+               for (i = 1, p = buf, rem = sizeof(buf); i < 8; i++)
                {
-                       if (hasbit(time->weekdays, i))
+                       if (fw3_hasbit(time->weekdays, i))
                        {
-                               if (p > buf)
+                               if (p > buf) {
+                                       if (rem <= 1)
+                                               break;
+
                                        *p++ = ',';
+                                       *p = 0;
+                                       rem--;
+                               }
+
+                               len = snprintf(p, rem, "%u", i);
+
+                               if (len < 0 || len >= rem)
+                                       break;
 
-                               p += sprintf(p, "%u", i);
+                               rem -= len;
+                               p += len;
                        }
                }
 
-               fw3_ipt_rule_addarg(r, hasbit(time->weekdays, 0), "--weekdays", buf);
+               fw3_ipt_rule_addarg(r, fw3_hasbit(time->weekdays, 0), "--weekdays", buf);
        }
 }
 
 void
 fw3_ipt_rule_mark(struct fw3_ipt_rule *r, struct fw3_mark *mark)
 {
-       char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
+       char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF")];
 
        if (!mark || !mark->set)
                return;
 
        if (mark->mask < 0xFFFFFFFF)
-               sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
+               snprintf(buf, sizeof(buf), "0x%x/0x%x", mark->mark, mark->mask);
        else
-               sprintf(buf, "0x%x", mark->mark);
+               snprintf(buf, sizeof(buf), "0x%x", mark->mark);
 
        fw3_ipt_rule_addarg(r, false, "-m", "mark");
        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")];
+
+       if (!dscp || !dscp->set)
+               return;
+
+       snprintf(buf, sizeof(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, ...)
 {
@@ -1086,7 +1269,7 @@ fw3_ipt_rule_comment(struct fw3_ipt_rule *r, const char *fmt, ...)
                return;
 
        va_start(ap, fmt);
-       vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
+       vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
 
        fw3_ipt_rule_addarg(r, false, "-m", "comment");
@@ -1179,7 +1362,7 @@ static void
 rule_print4(struct ipt_entry *e)
 {
        struct in_addr in_zero = { 0 };
-       char buf1[sizeof("255.255.255.255\0")], buf2[sizeof("255.255.255.255\0")];
+       char buf1[sizeof("255.255.255.255")], buf2[sizeof("255.255.255.255")];
        char *pname;
 
        if (e->ip.proto)
@@ -1359,7 +1542,7 @@ rule_mask(struct fw3_ipt_rule *r)
                        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
@@ -1383,7 +1566,7 @@ rule_mask(struct fw3_ipt_rule *r)
                        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;
@@ -1457,6 +1640,34 @@ rule_build(struct fw3_ipt_rule *r)
        }
 }
 
+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, ...)
 {
@@ -1468,8 +1679,12 @@ __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;
@@ -1484,25 +1699,17 @@ __fw3_ipt_rule_append(struct fw3_ipt_rule *r, bool repl, const char *fmt, ...)
        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;
-               }
+       status = setjmp(fw3_ipt_error_jmp);
 
-               init_match(r, em, true);
-
-               id = FW3_ID_MAGIC | (r->id & ~FW3_ID_MASK);
-               memcpy(em->m->data, &id, sizeof(id));
-
-               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)
@@ -1530,6 +1737,34 @@ __fw3_ipt_rule_append(struct fw3_ipt_rule *r, bool repl, const char *fmt, ...)
 
                        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'))
                        {
@@ -1642,3 +1877,63 @@ fw3_ipt_rule_create(struct fw3_ipt_handle *handle, struct fw3_protocol *proto,
 
        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;
+       }
+}