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-rw-r--r--src/nspawn/nspawn-network.c661
1 files changed, 661 insertions, 0 deletions
diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c
new file mode 100644
index 0000000..c028b57
--- /dev/null
+++ b/src/nspawn/nspawn-network.c
@@ -0,0 +1,661 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <linux/veth.h>
+#include <net/if.h>
+#include <sys/file.h>
+
+#include "sd-device.h"
+#include "sd-id128.h"
+#include "sd-netlink.h"
+
+#include "alloc-util.h"
+#include "ether-addr-util.h"
+#include "lockfile-util.h"
+#include "missing_network.h"
+#include "netlink-util.h"
+#include "nspawn-network.h"
+#include "siphash24.h"
+#include "socket-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "util.h"
+
+#define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1)
+#define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
+#define VETH_EXTRA_HOST_HASH_KEY SD_ID128_MAKE(48,c7,f6,b7,ea,9d,4c,9e,b7,28,d4,de,91,d5,bf,66)
+#define VETH_EXTRA_CONTAINER_HASH_KEY SD_ID128_MAKE(af,50,17,61,ce,f9,4d,35,84,0d,2b,20,54,be,ce,59)
+#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
+
+static int remove_one_link(sd_netlink *rtnl, const char *name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ if (isempty(name))
+ return 0;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r == -ENODEV) /* Already gone */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Failed to remove interface %s: %m", name);
+
+ return 1;
+}
+
+static int generate_mac(
+ const char *machine_name,
+ struct ether_addr *mac,
+ sd_id128_t hash_key,
+ uint64_t idx) {
+
+ uint64_t result;
+ size_t l, sz;
+ uint8_t *v, *i;
+ int r;
+
+ l = strlen(machine_name);
+ sz = sizeof(sd_id128_t) + l;
+ if (idx > 0)
+ sz += sizeof(idx);
+
+ v = newa(uint8_t, sz);
+
+ /* fetch some persistent data unique to the host */
+ r = sd_id128_get_machine((sd_id128_t*) v);
+ if (r < 0)
+ return r;
+
+ /* combine with some data unique (on this host) to this
+ * container instance */
+ i = mempcpy(v + sizeof(sd_id128_t), machine_name, l);
+ if (idx > 0) {
+ idx = htole64(idx);
+ memcpy(i, &idx, sizeof(idx));
+ }
+
+ /* Let's hash the host machine ID plus the container name. We
+ * use a fixed, but originally randomly created hash key here. */
+ result = htole64(siphash24(v, sz, hash_key.bytes));
+
+ assert_cc(ETH_ALEN <= sizeof(result));
+ memcpy(mac->ether_addr_octet, &result, ETH_ALEN);
+
+ /* see eth_random_addr in the kernel */
+ mac->ether_addr_octet[0] &= 0xfe; /* clear multicast bit */
+ mac->ether_addr_octet[0] |= 0x02; /* set local assignment bit (IEEE802) */
+
+ return 0;
+}
+
+static int add_veth(
+ sd_netlink *rtnl,
+ pid_t pid,
+ const char *ifname_host,
+ const struct ether_addr *mac_host,
+ const char *ifname_container,
+ const struct ether_addr *mac_container) {
+
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ assert(rtnl);
+ assert(ifname_host);
+ assert(mac_host);
+ assert(ifname_container);
+ assert(mac_container);
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_host);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_host);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "veth");
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_open_container(m, VETH_INFO_PEER);
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_container);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_container);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add new veth interfaces (%s:%s): %m", ifname_host, ifname_container);
+
+ return 0;
+}
+
+int setup_veth(const char *machine_name,
+ pid_t pid,
+ char iface_name[IFNAMSIZ],
+ bool bridge) {
+
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ struct ether_addr mac_host, mac_container;
+ int r, i;
+
+ assert(machine_name);
+ assert(pid > 0);
+ assert(iface_name);
+
+ /* Use two different interface name prefixes depending whether
+ * we are in bridge mode or not. */
+ snprintf(iface_name, IFNAMSIZ - 1, "%s-%s",
+ bridge ? "vb" : "ve", machine_name);
+
+ r = generate_mac(machine_name, &mac_container, CONTAINER_HASH_KEY, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate predictable MAC address for container side: %m");
+
+ r = generate_mac(machine_name, &mac_host, HOST_HASH_KEY, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate predictable MAC address for host side: %m");
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ r = add_veth(rtnl, pid, iface_name, &mac_host, "host0", &mac_container);
+ if (r < 0)
+ return r;
+
+ i = (int) if_nametoindex(iface_name);
+ if (i <= 0)
+ return log_error_errno(errno, "Failed to resolve interface %s: %m", iface_name);
+
+ return i;
+}
+
+int setup_veth_extra(
+ const char *machine_name,
+ pid_t pid,
+ char **pairs) {
+
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ uint64_t idx = 0;
+ char **a, **b;
+ int r;
+
+ assert(machine_name);
+ assert(pid > 0);
+
+ if (strv_isempty(pairs))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ STRV_FOREACH_PAIR(a, b, pairs) {
+ struct ether_addr mac_host, mac_container;
+
+ r = generate_mac(machine_name, &mac_container, VETH_EXTRA_CONTAINER_HASH_KEY, idx);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate predictable MAC address for container side of extra veth link: %m");
+
+ r = generate_mac(machine_name, &mac_host, VETH_EXTRA_HOST_HASH_KEY, idx);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate predictable MAC address for container side of extra veth link: %m");
+
+ r = add_veth(rtnl, pid, *a, &mac_host, *b, &mac_container);
+ if (r < 0)
+ return r;
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static int join_bridge(sd_netlink *rtnl, const char *veth_name, const char *bridge_name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r, bridge_ifi;
+
+ assert(rtnl);
+ assert(veth_name);
+ assert(bridge_name);
+
+ bridge_ifi = (int) if_nametoindex(bridge_name);
+ if (bridge_ifi <= 0)
+ return -errno;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
+ if (r < 0)
+ return r;
+
+ r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return r;
+
+ return bridge_ifi;
+}
+
+static int create_bridge(sd_netlink *rtnl, const char *bridge_name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, bridge_name);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "bridge");
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create) {
+ _cleanup_(release_lock_file) LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ int r, bridge_ifi;
+ unsigned n = 0;
+
+ assert(veth_name);
+ assert(bridge_name);
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ if (create) {
+ /* We take a system-wide lock here, so that we can safely check whether there's still a member in the
+ * bridge before removing it, without risking interference from other nspawn instances. */
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+ }
+
+ for (;;) {
+ bridge_ifi = join_bridge(rtnl, veth_name, bridge_name);
+ if (bridge_ifi >= 0)
+ return bridge_ifi;
+ if (bridge_ifi != -ENODEV || !create || n > 10)
+ return log_error_errno(bridge_ifi, "Failed to add interface %s to bridge %s: %m", veth_name, bridge_name);
+
+ /* Count attempts, so that we don't enter an endless loop here. */
+ n++;
+
+ /* The bridge doesn't exist yet. Let's create it */
+ r = create_bridge(rtnl, bridge_name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create bridge interface %s: %m", bridge_name);
+
+ /* Try again, now that the bridge exists */
+ }
+}
+
+int remove_bridge(const char *bridge_name) {
+ _cleanup_(release_lock_file) LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ const char *path;
+ int r;
+
+ /* Removes the specified bridge, but only if it is currently empty */
+
+ if (isempty(bridge_name))
+ return 0;
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+
+ path = strjoina("/sys/class/net/", bridge_name, "/brif");
+
+ r = dir_is_empty(path);
+ if (r == -ENOENT) /* Already gone? */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Can't detect if bridge %s is empty: %m", bridge_name);
+ if (r == 0) /* Still populated, leave it around */
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ return remove_one_link(rtnl, bridge_name);
+}
+
+static int parse_interface(const char *name) {
+ _cleanup_(sd_device_unrefp) sd_device *d = NULL;
+ char ifi_str[2 + DECIMAL_STR_MAX(int)];
+ int ifi, r;
+
+ ifi = (int) if_nametoindex(name);
+ if (ifi <= 0)
+ return log_error_errno(errno, "Failed to resolve interface %s: %m", name);
+
+ sprintf(ifi_str, "n%i", ifi);
+ r = sd_device_new_from_device_id(&d, ifi_str);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get device for interface %s: %m", name);
+
+ r = sd_device_get_is_initialized(d);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine whether interface %s is initialized or not: %m", name);
+ if (r == 0) {
+ log_error("Network interface %s is not initialized yet.", name);
+ return -EBUSY;
+ }
+
+ return ifi;
+}
+
+int move_network_interfaces(pid_t pid, char **ifaces) {
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ char **i;
+ int r;
+
+ if (strv_isempty(ifaces))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ STRV_FOREACH(i, ifaces) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int ifi;
+
+ ifi = parse_interface(*i);
+ if (ifi < 0)
+ return ifi;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, ifi);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to append namespace PID to netlink message: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to move interface %s to namespace: %m", *i);
+ }
+
+ return 0;
+}
+
+int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) {
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ unsigned idx = 0;
+ char **i;
+ int r;
+
+ if (strv_isempty(ifaces))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ STRV_FOREACH(i, ifaces) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ _cleanup_free_ char *n = NULL;
+ struct ether_addr mac;
+ int ifi;
+
+ ifi = parse_interface(*i);
+ if (ifi < 0)
+ return ifi;
+
+ r = generate_mac(machine_name, &mac, MACVLAN_HASH_KEY, idx++);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create MACVLAN MAC address: %m");
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface index: %m");
+
+ n = strappend("mv-", *i);
+ if (!n)
+ return log_oom();
+
+ strshorten(n, IFNAMSIZ-1);
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, n);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, &mac);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "macvlan");
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_MACVLAN_MODE, MACVLAN_MODE_BRIDGE);
+ if (r < 0)
+ return log_error_errno(r, "Failed to append macvlan mode: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add new macvlan interfaces: %m");
+ }
+
+ return 0;
+}
+
+int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) {
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ char **i;
+ int r;
+
+ if (strv_isempty(ifaces))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ STRV_FOREACH(i, ifaces) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ _cleanup_free_ char *n = NULL;
+ int ifi;
+
+ ifi = parse_interface(*i);
+ if (ifi < 0)
+ return ifi;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface index: %m");
+
+ n = strappend("iv-", *i);
+ if (!n)
+ return log_oom();
+
+ strshorten(n, IFNAMSIZ-1);
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, n);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "ipvlan");
+ if (r < 0)
+ return log_error_errno(r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_append_u16(m, IFLA_IPVLAN_MODE, IPVLAN_MODE_L2);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add ipvlan mode: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add new ipvlan interfaces: %m");
+ }
+
+ return 0;
+}
+
+int veth_extra_parse(char ***l, const char *p) {
+ _cleanup_free_ char *a = NULL, *b = NULL;
+ int r;
+
+ r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (r == 0 || !ifname_valid(a))
+ return -EINVAL;
+
+ r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (r == 0 || !ifname_valid(b)) {
+ free(b);
+ b = strdup(a);
+ if (!b)
+ return -ENOMEM;
+ }
+
+ if (p)
+ return -EINVAL;
+
+ r = strv_push_pair(l, a, b);
+ if (r < 0)
+ return -ENOMEM;
+
+ a = b = NULL;
+ return 0;
+}
+
+int remove_veth_links(const char *primary, char **pairs) {
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ char **a, **b;
+ int r;
+
+ /* In some cases the kernel might pin the veth links between host and container even after the namespace
+ * died. Hence, let's better remove them explicitly too. */
+
+ if (isempty(primary) && strv_isempty(pairs))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ remove_one_link(rtnl, primary);
+
+ STRV_FOREACH_PAIR(a, b, pairs)
+ remove_one_link(rtnl, *a);
+
+ return 0;
+}