/*
* 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
#include "utils.h"
#include "options.h"
+#include "zones.h"
+#include "ipsets.h"
+
+
static int lock_fd = -1;
static pid_t pipe_pid = -1;
static FILE *pipe_fd = NULL;
+bool fw3_pr_debug = false;
+
+
static void
warn_elem_section_name(struct uci_section *s, bool find_name)
{
fprintf(stderr, "\n");
}
+void *
+fw3_alloc(size_t size)
+{
+ void *mem;
+
+ mem = calloc(1, size);
+
+ if (!mem)
+ error("Out of memory while allocating %d bytes", size);
+
+ return mem;
+}
+
+char *
+fw3_strdup(const char *s)
+{
+ char *ns;
+
+ ns = strdup(s);
+
+ if (!ns)
+ error("Out of memory while duplicating string '%s'", s);
+
+ return ns;
+}
+
const char *
fw3_find_command(const char *cmd)
{
return false;
argn = 2;
- args = malloc(argn * sizeof(arg));
+ args = calloc(argn, sizeof(arg));
if (!args)
return false;
switch ((pid = fork()))
{
case -1:
+ free(args);
return false;
case 0:
signal(SIGPIPE, SIG_IGN);
pipe_pid = pid;
close(pfds[0]);
+ fcntl(pfds[1], F_SETFD, fcntl(pfds[1], F_GETFD) | FD_CLOEXEC);
}
pipe_fd = fdopen(pfds[1], "w");
+ free(args);
return true;
}
void
fw3_pr(const char *fmt, ...)
{
- va_list args;
- va_start(args, fmt);
- vfprintf(pipe_fd, fmt, args);
- va_end(args);
+ va_list args;
+
+ if (fw3_pr_debug && pipe_fd != stdout)
+ {
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+ }
+
+ va_start(args, fmt);
+ vfprintf(pipe_fd, fmt, args);
+ va_end(args);
}
void
return seen;
}
+
bool
-fw3_check_statefile(bool test_exists)
+fw3_lock(void)
{
- struct stat s;
+ lock_fd = open(FW3_LOCKFILE, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
- if (!stat(FW3_STATEFILE, &s))
+ if (lock_fd < 0)
{
- if (test_exists)
- return true;
-
- warn("The firewall appears to be started already. "
- "If it is indeed empty, remove the %s file and retry.",
- FW3_STATEFILE);
-
+ warn("Cannot create lock file %s: %s", FW3_LOCKFILE, strerror(errno));
return false;
}
- else if (test_exists)
+
+ if (flock(lock_fd, LOCK_EX))
{
- warn("The firewall appears to stopped already.");
+ warn("Cannot acquire exclusive lock: %s", strerror(errno));
return false;
}
- lock_fd = open(FW3_STATEFILE, O_CREAT | O_RDWR);
+ return true;
+}
+void
+fw3_unlock(void)
+{
if (lock_fd < 0)
+ return;
+
+ if (flock(lock_fd, LOCK_UN))
+ warn("Cannot release exclusive lock: %s", strerror(errno));
+
+ close(lock_fd);
+ unlink(FW3_LOCKFILE);
+
+ lock_fd = -1;
+}
+
+
+static void
+write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
+ struct uci_package *dest)
+{
+ char buf[sizeof("0xffffffff\0")];
+ struct uci_ptr ptr = { .p = dest };
+
+ uci_add_section(ctx, dest, "defaults", &ptr.s);
+
+ ptr.o = NULL;
+ ptr.option = "input";
+ ptr.value = fw3_flag_names[d->policy_input];
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "output";
+ ptr.value = fw3_flag_names[d->policy_output];
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "forward";
+ ptr.value = fw3_flag_names[d->policy_forward];
+ uci_set(ctx, &ptr);
+
+ sprintf(buf, "0x%x", d->flags[0]);
+ ptr.o = NULL;
+ ptr.option = "__flags_v4";
+ ptr.value = buf;
+ uci_set(ctx, &ptr);
+
+ sprintf(buf, "0x%x", d->flags[1]);
+ ptr.o = NULL;
+ ptr.option = "__flags_v6";
+ ptr.value = buf;
+ uci_set(ctx, &ptr);
+}
+
+static void
+write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
+ struct uci_package *dest, struct ifaddrs *ifaddr)
+{
+ struct fw3_device *dev;
+ struct fw3_address *sub;
+ struct ifaddrs *ifa;
+ enum fw3_family fam = FW3_FAMILY_ANY;
+
+ char *p, buf[INET6_ADDRSTRLEN];
+
+ struct uci_ptr ptr = { .p = dest };
+
+ if (!z->enabled)
+ return;
+
+ if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
+ fam = FW3_FAMILY_V6;
+ else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
+ fam = FW3_FAMILY_V4;
+ else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
+ return;
+
+ uci_add_section(ctx, dest, "zone", &ptr.s);
+
+ ptr.o = NULL;
+ ptr.option = "name";
+ ptr.value = z->name;
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "input";
+ ptr.value = fw3_flag_names[z->policy_input];
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "output";
+ ptr.value = fw3_flag_names[z->policy_output];
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "forward";
+ ptr.value = fw3_flag_names[z->policy_forward];
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "masq";
+ ptr.value = z->masq ? "1" : "0";
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "mtu_fix";
+ ptr.value = z->mtu_fix ? "1" : "0";
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "custom_chains";
+ ptr.value = z->custom_chains ? "1" : "0";
+ uci_set(ctx, &ptr);
+
+ if (fam != FW3_FAMILY_ANY)
{
- warn("Unable to create %s file", FW3_STATEFILE);
- goto fail;
+ ptr.o = NULL;
+ ptr.option = "family";
+ ptr.value = fw3_flag_names[fam];
+ uci_set(ctx, &ptr);
}
- if (flock(lock_fd, LOCK_EX))
+ ptr.o = NULL;
+ ptr.option = "device";
+
+ fw3_foreach(dev, &z->devices)
{
- warn("Unable to acquire exclusive lock on %s file", FW3_STATEFILE);
- goto fail;
+ char *ep;
+
+ if (!dev)
+ continue;
+ p = buf;
+ ep = buf + sizeof(buf);
+
+ if (dev->invert)
+ p += snprintf(p, ep - p, "!");
+
+ if (*dev->network)
+ p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
+ else
+ p += snprintf(p, ep - p, "%s", dev->name);
+
+ ptr.value = buf;
+ uci_add_list(ctx, &ptr);
}
- return true;
+ ptr.o = NULL;
+ ptr.option = "subnet";
-fail:
- if (lock_fd > -1)
+ fw3_foreach(sub, &z->subnets)
{
- close(lock_fd);
- lock_fd = -1;
+ if (!sub)
+ continue;
+
+ ptr.value = fw3_address_to_string(sub, true, false);
+ uci_add_list(ctx, &ptr);
}
- return false;
+ ptr.o = NULL;
+ ptr.option = "__addrs";
+
+ fw3_foreach(dev, &z->devices)
+ {
+ if (!dev)
+ continue;
+
+ for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
+ {
+ if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
+ continue;
+
+ if (ifa->ifa_addr->sa_family == AF_INET)
+ inet_ntop(AF_INET,
+ &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
+ buf, sizeof(buf));
+ else if (ifa->ifa_addr->sa_family == AF_INET6)
+ inet_ntop(AF_INET6,
+ &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
+ buf, sizeof(buf));
+ else
+ continue;
+
+ ptr.value = buf;
+ uci_add_list(ctx, &ptr);
+ }
+ }
+
+ sprintf(buf, "0x%x", z->flags[0]);
+ ptr.o = NULL;
+ ptr.option = "__flags_v4";
+ ptr.value = buf;
+ uci_set(ctx, &ptr);
+
+ sprintf(buf, "0x%x", z->flags[1]);
+ ptr.o = NULL;
+ ptr.option = "__flags_v6";
+ ptr.value = buf;
+ uci_set(ctx, &ptr);
+}
+
+static void
+write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
+ struct uci_package *dest)
+{
+ struct fw3_ipset_datatype *type;
+
+ char buf[sizeof("65535-65535\0")];
+
+ struct uci_ptr ptr = { .p = dest };
+
+ if (!s->enabled || s->external)
+ return;
+
+ uci_add_section(ctx, dest, "ipset", &ptr.s);
+
+ ptr.o = NULL;
+ ptr.option = "name";
+ ptr.value = s->name;
+ uci_set(ctx, &ptr);
+
+ ptr.o = NULL;
+ ptr.option = "storage";
+ ptr.value = fw3_ipset_method_names[s->method];
+ uci_set(ctx, &ptr);
+
+ list_for_each_entry(type, &s->datatypes, list)
+ {
+ sprintf(buf, "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
+ ptr.o = NULL;
+ ptr.option = "match";
+ ptr.value = buf;
+ uci_add_list(ctx, &ptr);
+ }
+
+ if (s->iprange.set)
+ {
+ ptr.o = NULL;
+ ptr.option = "iprange";
+ ptr.value = fw3_address_to_string(&s->iprange, false, false);
+ uci_set(ctx, &ptr);
+ }
+
+ if (s->portrange.set)
+ {
+ sprintf(buf, "%u-%u", s->portrange.port_min, s->portrange.port_max);
+ ptr.o = NULL;
+ ptr.option = "portrange";
+ ptr.value = buf;
+ uci_set(ctx, &ptr);
+ }
}
void
-fw3_remove_statefile(void)
+fw3_write_statefile(void *state)
{
- if (lock_fd > -1)
- fw3_close_statefile();
+ FILE *sf;
+ struct fw3_state *s = state;
+ struct fw3_zone *z;
+ struct fw3_ipset *i;
+ struct ifaddrs *ifaddr;
+
+ struct uci_package *p;
+
+ if (fw3_no_family(s->defaults.flags[0]) &&
+ fw3_no_family(s->defaults.flags[1]))
+ {
+ unlink(FW3_STATEFILE);
+ }
+ else
+ {
+ sf = fopen(FW3_STATEFILE, "w+");
- if (unlink(FW3_STATEFILE))
- warn("Unable to delete %s file", FW3_STATEFILE);
+ if (!sf)
+ {
+ warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
+ return;
+ }
+
+ if (getifaddrs(&ifaddr))
+ {
+ warn("Cannot get interface addresses: %s", strerror(errno));
+ ifaddr = NULL;
+ }
+
+ if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
+ uci_unload(s->uci, p);
+
+ uci_import(s->uci, sf, "fw3_state", NULL, true);
+
+ if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
+ {
+ write_defaults_uci(s->uci, &s->defaults, p);
+
+ list_for_each_entry(z, &s->zones, list)
+ write_zone_uci(s->uci, z, p, ifaddr);
+
+ list_for_each_entry(i, &s->ipsets, list)
+ write_ipset_uci(s->uci, i, p);
+
+ uci_export(s->uci, sf, p, true);
+ uci_unload(s->uci, p);
+ }
+
+ fsync(fileno(sf));
+ fclose(sf);
+
+ if (ifaddr)
+ freeifaddrs(ifaddr);
+ }
}
+
void
-fw3_close_statefile(void)
+fw3_free_object(void *obj, const void *opts)
{
- flock(lock_fd, LOCK_UN);
- close(lock_fd);
+ const struct fw3_option *ol;
+ struct list_head *list, *cur, *tmp;
- lock_fd = -1;
+ for (ol = opts; ol->name; ol++)
+ {
+ if (!ol->elem_size)
+ continue;
+
+ list = (struct list_head *)((char *)obj + ol->offset);
+ list_for_each_safe(cur, tmp, list)
+ {
+ list_del(cur);
+ free(cur);
+ }
+ }
+
+ free(obj);
+}
+
+void
+fw3_free_list(struct list_head *head)
+{
+ struct list_head *entry, *tmp;
+
+ if (!head)
+ return;
+
+ list_for_each_safe(entry, tmp, head)
+ {
+ list_del(entry);
+ free(entry);
+ }
+
+ free(head);
+}
+
+bool
+fw3_hotplug(bool add, void *zone, void *device)
+{
+ struct fw3_zone *z = zone;
+ struct fw3_device *d = device;
+
+ if (!*d->network)
+ return false;
+
+ switch (fork())
+ {
+ case -1:
+ warn("Unable to fork(): %s\n", strerror(errno));
+ return false;
+
+ case 0:
+ break;
+
+ default:
+ return true;
+ }
+
+ close(0);
+ close(1);
+ close(2);
+ if (chdir("/")) {};
+
+ clearenv();
+ setenv("ACTION", add ? "add" : "remove", 1);
+ setenv("ZONE", z->name, 1);
+ setenv("INTERFACE", d->network, 1);
+ setenv("DEVICE", d->name, 1);
+
+ execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
+
+ /* unreached */
+ return false;
+}
+
+int
+fw3_netmask2bitlen(int family, void *mask)
+{
+ int bits;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (family == FW3_FAMILY_V6)
+ for (bits = 0, v6 = mask;
+ bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
+ bits++);
+ else
+ for (bits = 0, v4 = mask;
+ bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
+ bits++);
+
+ return bits;
+}
+
+bool
+fw3_bitlen2netmask(int family, int bits, void *mask)
+{
+ int i;
+ uint8_t rem, b;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (family == FW3_FAMILY_V6)
+ {
+ if (bits < -128 || bits > 128)
+ return false;
+
+ v6 = mask;
+ rem = abs(bits);
+
+ for (i = 0; i < sizeof(v6->s6_addr); i++)
+ {
+ b = (rem > 8) ? 8 : rem;
+ v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
+ rem -= b;
+ }
+
+ if (bits < 0)
+ for (i = 0; i < sizeof(v6->s6_addr); i++)
+ v6->s6_addr[i] = ~v6->s6_addr[i];
+ }
+ else
+ {
+ if (bits < -32 || bits > 32)
+ return false;
+
+ v4 = mask;
+ v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
+
+ if (bits < 0)
+ v4->s_addr = ~v4->s_addr;
+ }
+
+ return true;
+}
+
+void
+fw3_flush_conntrack(void *state)
+{
+ bool found;
+ struct fw3_state *s = state;
+ struct fw3_address *addr;
+ struct fw3_device *dev;
+ struct fw3_zone *zone;
+ struct ifaddrs *ifaddr, *ifa;
+ struct sockaddr_in *sin;
+ struct sockaddr_in6 *sin6;
+ char buf[INET6_ADDRSTRLEN];
+ FILE *ct;
+
+ if (!state)
+ {
+ if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
+ {
+ info(" * Flushing conntrack table ...");
+
+ fwrite("f\n", 1, 2, ct);
+ fclose(ct);
+ }
+
+ return;
+ }
+
+ if (getifaddrs(&ifaddr))
+ {
+ warn("Cannot get interface addresses: %s", strerror(errno));
+ return;
+ }
+
+ if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
+ {
+ list_for_each_entry(zone, &s->zones, list)
+ list_for_each_entry(addr, &zone->old_addrs, list)
+ {
+ found = false;
+
+ list_for_each_entry(dev, &zone->devices, list)
+ {
+ for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
+ {
+ if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
+ continue;
+
+ sin = (struct sockaddr_in *)ifa->ifa_addr;
+ sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
+
+ if (addr->family == FW3_FAMILY_V4 &&
+ sin->sin_family == AF_INET)
+ {
+ found = !memcmp(&addr->address.v4, &sin->sin_addr,
+ sizeof(sin->sin_addr));
+ }
+ else if (addr->family == FW3_FAMILY_V6 &&
+ sin6->sin6_family == AF_INET6)
+ {
+ found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
+ sizeof(sin6->sin6_addr));
+ }
+ }
+
+ if (found)
+ break;
+ }
+
+ if (!found)
+ {
+ inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
+ &addr->address.v4, buf, sizeof(buf));
+
+ info(" * Flushing conntrack: %s", buf);
+ fprintf(ct, "%s\n", buf);
+ }
+ }
+
+ fclose(ct);
+ }
+
+ freeifaddrs(ifaddr);
+}
+
+bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
+{
+ struct blob_attr *opt;
+ unsigned orem;
+
+ if (!type || !name)
+ return false;
+
+ *type = NULL;
+
+ blobmsg_for_each_attr(opt, entry, orem)
+ if (!strcmp(blobmsg_name(opt), "type"))
+ *type = blobmsg_get_string(opt);
+ else if (!strcmp(blobmsg_name(opt), "name"))
+ *name = blobmsg_get_string(opt);
+
+ return *type != NULL ? true : false;
+}
+
+const char *
+fw3_protoname(void *proto)
+{
+ static char buf[sizeof("4294967295")];
+ struct fw3_protocol *p = proto;
+ struct protoent *pe;
+
+ if (!p)
+ return "?";
+
+ pe = getprotobynumber(p->protocol);
+
+ if (!pe)
+ {
+ snprintf(buf, sizeof(buf), "%u", p->protocol);
+ return buf;
+ }
+
+ return pe->p_name;
}