nspawn-network.c revision 07630cea1f3a845c09309f197ac7c4f11edd3b62
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2015 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <linux/veth.h>
#include <net/if.h>
#include "libudev.h"
#include "sd-id128.h"
#include "sd-netlink.h"
#include "ether-addr-util.h"
#include "netlink-util.h"
#include "siphash24.h"
#include "string-util.h"
#include "udev-util.h"
#include "util.h"
#include "nspawn-network.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 MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
static int generate_mac(
const char *machine_name,
struct ether_addr *mac,
sd_id128_t hash_key,
uint64_t idx) {
uint8_t result[8];
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 = alloca(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. */
siphash24(result, 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;
}
int setup_veth(const char *machine_name,
pid_t pid,
char iface_name[IFNAMSIZ],
bool bridge) {
_cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
_cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
struct ether_addr mac_host, mac_container;
int r, i;
/* 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 = 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, iface_name);
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, "host0");
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 (host0, %s): %m", iface_name);
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_bridge(const char *veth_name, const char *bridge_name) {
_cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
_cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
int r, bridge_ifi;
assert(veth_name);
assert(bridge_name);
bridge_ifi = (int) if_nametoindex(bridge_name);
if (bridge_ifi <= 0)
return log_error_errno(errno, "Failed to resolve interface %s: %m", bridge_name);
r = sd_netlink_open(&rtnl);
if (r < 0)
return log_error_errno(r, "Failed to connect to netlink: %m");
r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
if (r < 0)
return log_error_errno(r, "Failed to allocate netlink message: %m");
r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
if (r < 0)
return log_error_errno(r, "Failed to set IFF_UP flag: %m");
r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
if (r < 0)
return log_error_errno(r, "Failed to add netlink interface name field: %m");
r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
if (r < 0)
return log_error_errno(r, "Failed to add netlink master field: %m");
r = sd_netlink_call(rtnl, m, 0, NULL);
if (r < 0)
return log_error_errno(r, "Failed to add veth interface to bridge: %m");
return bridge_ifi;
}
static int parse_interface(struct udev *udev, const char *name) {
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
char ifi_str[2 + DECIMAL_STR_MAX(int)];
int ifi;
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);
d = udev_device_new_from_device_id(udev, ifi_str);
if (!d)
return log_error_errno(errno, "Failed to get udev device for interface %s: %m", name);
if (udev_device_get_is_initialized(d) <= 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_udev_unref_ struct udev *udev = NULL;
_cleanup_netlink_unref_ 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");
udev = udev_new();
if (!udev) {
log_error("Failed to connect to udev.");
return -ENOMEM;
}
STRV_FOREACH(i, ifaces) {
_cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
int ifi;
ifi = parse_interface(udev, *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_udev_unref_ struct udev *udev = NULL;
_cleanup_netlink_unref_ 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");
udev = udev_new();
if (!udev) {
log_error("Failed to connect to udev.");
return -ENOMEM;
}
STRV_FOREACH(i, ifaces) {
_cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
_cleanup_free_ char *n = NULL;
struct ether_addr mac;
int ifi;
ifi = parse_interface(udev, *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_udev_unref_ struct udev *udev = NULL;
_cleanup_netlink_unref_ 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");
udev = udev_new();
if (!udev) {
log_error("Failed to connect to udev.");
return -ENOMEM;
}
STRV_FOREACH(i, ifaces) {
_cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
_cleanup_free_ char *n = NULL;
int ifi;
ifi = parse_interface(udev, *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;
}