1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #include <linux/veth.h>
9 #include "sd-netlink.h"
11 #include "alloc-util.h"
12 #include "ether-addr-util.h"
13 #include "lockfile-util.h"
14 #include "missing_network.h"
15 #include "netlink-util.h"
16 #include "nspawn-network.h"
17 #include "siphash24.h"
18 #include "socket-util.h"
19 #include "stat-util.h"
20 #include "string-util.h"
24 #define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1)
25 #define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
26 #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)
27 #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)
28 #define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
30 static int remove_one_link(sd_netlink
*rtnl
, const char *name
) {
31 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
37 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_DELLINK
, 0);
39 return log_error_errno(r
, "Failed to allocate netlink message: %m");
41 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, name
);
43 return log_error_errno(r
, "Failed to add netlink interface name: %m");
45 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
46 if (r
== -ENODEV
) /* Already gone */
49 return log_error_errno(r
, "Failed to remove interface %s: %m", name
);
54 static int generate_mac(
55 const char *machine_name
,
56 struct ether_addr
*mac
,
65 l
= strlen(machine_name
);
66 sz
= sizeof(sd_id128_t
) + l
;
72 /* fetch some persistent data unique to the host */
73 r
= sd_id128_get_machine((sd_id128_t
*) v
);
77 /* combine with some data unique (on this host) to this
78 * container instance */
79 i
= mempcpy(v
+ sizeof(sd_id128_t
), machine_name
, l
);
82 memcpy(i
, &idx
, sizeof(idx
));
85 /* Let's hash the host machine ID plus the container name. We
86 * use a fixed, but originally randomly created hash key here. */
87 result
= htole64(siphash24(v
, sz
, hash_key
.bytes
));
89 assert_cc(ETH_ALEN
<= sizeof(result
));
90 memcpy(mac
->ether_addr_octet
, &result
, ETH_ALEN
);
92 /* see eth_random_addr in the kernel */
93 mac
->ether_addr_octet
[0] &= 0xfe; /* clear multicast bit */
94 mac
->ether_addr_octet
[0] |= 0x02; /* set local assignment bit (IEEE802) */
102 const char *ifname_host
,
103 const struct ether_addr
*mac_host
,
104 const char *ifname_container
,
105 const struct ether_addr
*mac_container
) {
107 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
113 assert(ifname_container
);
114 assert(mac_container
);
116 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_NEWLINK
, 0);
118 return log_error_errno(r
, "Failed to allocate netlink message: %m");
120 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, ifname_host
);
122 return log_error_errno(r
, "Failed to add netlink interface name: %m");
124 r
= sd_netlink_message_append_ether_addr(m
, IFLA_ADDRESS
, mac_host
);
126 return log_error_errno(r
, "Failed to add netlink MAC address: %m");
128 r
= sd_netlink_message_open_container(m
, IFLA_LINKINFO
);
130 return log_error_errno(r
, "Failed to open netlink container: %m");
132 r
= sd_netlink_message_open_container_union(m
, IFLA_INFO_DATA
, "veth");
134 return log_error_errno(r
, "Failed to open netlink container: %m");
136 r
= sd_netlink_message_open_container(m
, VETH_INFO_PEER
);
138 return log_error_errno(r
, "Failed to open netlink container: %m");
140 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, ifname_container
);
142 return log_error_errno(r
, "Failed to add netlink interface name: %m");
144 r
= sd_netlink_message_append_ether_addr(m
, IFLA_ADDRESS
, mac_container
);
146 return log_error_errno(r
, "Failed to add netlink MAC address: %m");
148 r
= sd_netlink_message_append_u32(m
, IFLA_NET_NS_PID
, pid
);
150 return log_error_errno(r
, "Failed to add netlink namespace field: %m");
152 r
= sd_netlink_message_close_container(m
);
154 return log_error_errno(r
, "Failed to close netlink container: %m");
156 r
= sd_netlink_message_close_container(m
);
158 return log_error_errno(r
, "Failed to close netlink container: %m");
160 r
= sd_netlink_message_close_container(m
);
162 return log_error_errno(r
, "Failed to close netlink container: %m");
164 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
166 return log_error_errno(r
, "Failed to add new veth interfaces (%s:%s): %m", ifname_host
, ifname_container
);
171 int setup_veth(const char *machine_name
,
173 char iface_name
[IFNAMSIZ
],
176 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
177 struct ether_addr mac_host
, mac_container
;
180 assert(machine_name
);
184 /* Use two different interface name prefixes depending whether
185 * we are in bridge mode or not. */
186 snprintf(iface_name
, IFNAMSIZ
- 1, "%s-%s",
187 bridge
? "vb" : "ve", machine_name
);
189 r
= generate_mac(machine_name
, &mac_container
, CONTAINER_HASH_KEY
, 0);
191 return log_error_errno(r
, "Failed to generate predictable MAC address for container side: %m");
193 r
= generate_mac(machine_name
, &mac_host
, HOST_HASH_KEY
, 0);
195 return log_error_errno(r
, "Failed to generate predictable MAC address for host side: %m");
197 r
= sd_netlink_open(&rtnl
);
199 return log_error_errno(r
, "Failed to connect to netlink: %m");
201 r
= add_veth(rtnl
, pid
, iface_name
, &mac_host
, "host0", &mac_container
);
205 i
= (int) if_nametoindex(iface_name
);
207 return log_error_errno(errno
, "Failed to resolve interface %s: %m", iface_name
);
212 int setup_veth_extra(
213 const char *machine_name
,
217 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
222 assert(machine_name
);
225 if (strv_isempty(pairs
))
228 r
= sd_netlink_open(&rtnl
);
230 return log_error_errno(r
, "Failed to connect to netlink: %m");
232 STRV_FOREACH_PAIR(a
, b
, pairs
) {
233 struct ether_addr mac_host
, mac_container
;
235 r
= generate_mac(machine_name
, &mac_container
, VETH_EXTRA_CONTAINER_HASH_KEY
, idx
);
237 return log_error_errno(r
, "Failed to generate predictable MAC address for container side of extra veth link: %m");
239 r
= generate_mac(machine_name
, &mac_host
, VETH_EXTRA_HOST_HASH_KEY
, idx
);
241 return log_error_errno(r
, "Failed to generate predictable MAC address for container side of extra veth link: %m");
243 r
= add_veth(rtnl
, pid
, *a
, &mac_host
, *b
, &mac_container
);
253 static int join_bridge(sd_netlink
*rtnl
, const char *veth_name
, const char *bridge_name
) {
254 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
261 bridge_ifi
= (int) if_nametoindex(bridge_name
);
265 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_SETLINK
, 0);
269 r
= sd_rtnl_message_link_set_flags(m
, IFF_UP
, IFF_UP
);
273 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, veth_name
);
277 r
= sd_netlink_message_append_u32(m
, IFLA_MASTER
, bridge_ifi
);
281 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
288 static int create_bridge(sd_netlink
*rtnl
, const char *bridge_name
) {
289 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
292 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_NEWLINK
, 0);
296 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, bridge_name
);
300 r
= sd_netlink_message_open_container(m
, IFLA_LINKINFO
);
304 r
= sd_netlink_message_open_container_union(m
, IFLA_INFO_DATA
, "bridge");
308 r
= sd_netlink_message_close_container(m
);
312 r
= sd_netlink_message_close_container(m
);
316 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
323 int setup_bridge(const char *veth_name
, const char *bridge_name
, bool create
) {
324 _cleanup_(release_lock_file
) LockFile bridge_lock
= LOCK_FILE_INIT
;
325 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
332 r
= sd_netlink_open(&rtnl
);
334 return log_error_errno(r
, "Failed to connect to netlink: %m");
337 /* We take a system-wide lock here, so that we can safely check whether there's still a member in the
338 * bridge before removing it, without risking interference from other nspawn instances. */
340 r
= make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX
, &bridge_lock
);
342 return log_error_errno(r
, "Failed to take network zone lock: %m");
346 bridge_ifi
= join_bridge(rtnl
, veth_name
, bridge_name
);
349 if (bridge_ifi
!= -ENODEV
|| !create
|| n
> 10)
350 return log_error_errno(bridge_ifi
, "Failed to add interface %s to bridge %s: %m", veth_name
, bridge_name
);
352 /* Count attempts, so that we don't enter an endless loop here. */
355 /* The bridge doesn't exist yet. Let's create it */
356 r
= create_bridge(rtnl
, bridge_name
);
358 return log_error_errno(r
, "Failed to create bridge interface %s: %m", bridge_name
);
360 /* Try again, now that the bridge exists */
364 int remove_bridge(const char *bridge_name
) {
365 _cleanup_(release_lock_file
) LockFile bridge_lock
= LOCK_FILE_INIT
;
366 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
370 /* Removes the specified bridge, but only if it is currently empty */
372 if (isempty(bridge_name
))
375 r
= make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX
, &bridge_lock
);
377 return log_error_errno(r
, "Failed to take network zone lock: %m");
379 path
= strjoina("/sys/class/net/", bridge_name
, "/brif");
381 r
= dir_is_empty(path
);
382 if (r
== -ENOENT
) /* Already gone? */
385 return log_error_errno(r
, "Can't detect if bridge %s is empty: %m", bridge_name
);
386 if (r
== 0) /* Still populated, leave it around */
389 r
= sd_netlink_open(&rtnl
);
391 return log_error_errno(r
, "Failed to connect to netlink: %m");
393 return remove_one_link(rtnl
, bridge_name
);
396 static int parse_interface(const char *name
) {
397 _cleanup_(sd_device_unrefp
) sd_device
*d
= NULL
;
398 char ifi_str
[2 + DECIMAL_STR_MAX(int)];
401 ifi
= (int) if_nametoindex(name
);
403 return log_error_errno(errno
, "Failed to resolve interface %s: %m", name
);
405 sprintf(ifi_str
, "n%i", ifi
);
406 r
= sd_device_new_from_device_id(&d
, ifi_str
);
408 return log_error_errno(r
, "Failed to get device for interface %s: %m", name
);
410 r
= sd_device_get_is_initialized(d
);
412 return log_error_errno(r
, "Failed to determine whether interface %s is initialized or not: %m", name
);
414 log_error("Network interface %s is not initialized yet.", name
);
421 int move_network_interfaces(pid_t pid
, char **ifaces
) {
422 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
426 if (strv_isempty(ifaces
))
429 r
= sd_netlink_open(&rtnl
);
431 return log_error_errno(r
, "Failed to connect to netlink: %m");
433 STRV_FOREACH(i
, ifaces
) {
434 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
437 ifi
= parse_interface(*i
);
441 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_SETLINK
, ifi
);
443 return log_error_errno(r
, "Failed to allocate netlink message: %m");
445 r
= sd_netlink_message_append_u32(m
, IFLA_NET_NS_PID
, pid
);
447 return log_error_errno(r
, "Failed to append namespace PID to netlink message: %m");
449 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
451 return log_error_errno(r
, "Failed to move interface %s to namespace: %m", *i
);
457 int setup_macvlan(const char *machine_name
, pid_t pid
, char **ifaces
) {
458 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
463 if (strv_isempty(ifaces
))
466 r
= sd_netlink_open(&rtnl
);
468 return log_error_errno(r
, "Failed to connect to netlink: %m");
470 STRV_FOREACH(i
, ifaces
) {
471 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
472 _cleanup_free_
char *n
= NULL
;
473 struct ether_addr mac
;
476 ifi
= parse_interface(*i
);
480 r
= generate_mac(machine_name
, &mac
, MACVLAN_HASH_KEY
, idx
++);
482 return log_error_errno(r
, "Failed to create MACVLAN MAC address: %m");
484 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_NEWLINK
, 0);
486 return log_error_errno(r
, "Failed to allocate netlink message: %m");
488 r
= sd_netlink_message_append_u32(m
, IFLA_LINK
, ifi
);
490 return log_error_errno(r
, "Failed to add netlink interface index: %m");
492 n
= strappend("mv-", *i
);
496 strshorten(n
, IFNAMSIZ
-1);
498 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, n
);
500 return log_error_errno(r
, "Failed to add netlink interface name: %m");
502 r
= sd_netlink_message_append_ether_addr(m
, IFLA_ADDRESS
, &mac
);
504 return log_error_errno(r
, "Failed to add netlink MAC address: %m");
506 r
= sd_netlink_message_append_u32(m
, IFLA_NET_NS_PID
, pid
);
508 return log_error_errno(r
, "Failed to add netlink namespace field: %m");
510 r
= sd_netlink_message_open_container(m
, IFLA_LINKINFO
);
512 return log_error_errno(r
, "Failed to open netlink container: %m");
514 r
= sd_netlink_message_open_container_union(m
, IFLA_INFO_DATA
, "macvlan");
516 return log_error_errno(r
, "Failed to open netlink container: %m");
518 r
= sd_netlink_message_append_u32(m
, IFLA_MACVLAN_MODE
, MACVLAN_MODE_BRIDGE
);
520 return log_error_errno(r
, "Failed to append macvlan mode: %m");
522 r
= sd_netlink_message_close_container(m
);
524 return log_error_errno(r
, "Failed to close netlink container: %m");
526 r
= sd_netlink_message_close_container(m
);
528 return log_error_errno(r
, "Failed to close netlink container: %m");
530 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
532 return log_error_errno(r
, "Failed to add new macvlan interfaces: %m");
538 int setup_ipvlan(const char *machine_name
, pid_t pid
, char **ifaces
) {
539 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
543 if (strv_isempty(ifaces
))
546 r
= sd_netlink_open(&rtnl
);
548 return log_error_errno(r
, "Failed to connect to netlink: %m");
550 STRV_FOREACH(i
, ifaces
) {
551 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*m
= NULL
;
552 _cleanup_free_
char *n
= NULL
;
555 ifi
= parse_interface(*i
);
559 r
= sd_rtnl_message_new_link(rtnl
, &m
, RTM_NEWLINK
, 0);
561 return log_error_errno(r
, "Failed to allocate netlink message: %m");
563 r
= sd_netlink_message_append_u32(m
, IFLA_LINK
, ifi
);
565 return log_error_errno(r
, "Failed to add netlink interface index: %m");
567 n
= strappend("iv-", *i
);
571 strshorten(n
, IFNAMSIZ
-1);
573 r
= sd_netlink_message_append_string(m
, IFLA_IFNAME
, n
);
575 return log_error_errno(r
, "Failed to add netlink interface name: %m");
577 r
= sd_netlink_message_append_u32(m
, IFLA_NET_NS_PID
, pid
);
579 return log_error_errno(r
, "Failed to add netlink namespace field: %m");
581 r
= sd_netlink_message_open_container(m
, IFLA_LINKINFO
);
583 return log_error_errno(r
, "Failed to open netlink container: %m");
585 r
= sd_netlink_message_open_container_union(m
, IFLA_INFO_DATA
, "ipvlan");
587 return log_error_errno(r
, "Failed to open netlink container: %m");
589 r
= sd_netlink_message_append_u16(m
, IFLA_IPVLAN_MODE
, IPVLAN_MODE_L2
);
591 return log_error_errno(r
, "Failed to add ipvlan mode: %m");
593 r
= sd_netlink_message_close_container(m
);
595 return log_error_errno(r
, "Failed to close netlink container: %m");
597 r
= sd_netlink_message_close_container(m
);
599 return log_error_errno(r
, "Failed to close netlink container: %m");
601 r
= sd_netlink_call(rtnl
, m
, 0, NULL
);
603 return log_error_errno(r
, "Failed to add new ipvlan interfaces: %m");
609 int veth_extra_parse(char ***l
, const char *p
) {
610 _cleanup_free_
char *a
= NULL
, *b
= NULL
;
613 r
= extract_first_word(&p
, &a
, ":", EXTRACT_DONT_COALESCE_SEPARATORS
);
616 if (r
== 0 || !ifname_valid(a
))
619 r
= extract_first_word(&p
, &b
, ":", EXTRACT_DONT_COALESCE_SEPARATORS
);
622 if (r
== 0 || !ifname_valid(b
)) {
632 r
= strv_push_pair(l
, a
, b
);
640 int remove_veth_links(const char *primary
, char **pairs
) {
641 _cleanup_(sd_netlink_unrefp
) sd_netlink
*rtnl
= NULL
;
645 /* In some cases the kernel might pin the veth links between host and container even after the namespace
646 * died. Hence, let's better remove them explicitly too. */
648 if (isempty(primary
) && strv_isempty(pairs
))
651 r
= sd_netlink_open(&rtnl
);
653 return log_error_errno(r
, "Failed to connect to netlink: %m");
655 remove_one_link(rtnl
, primary
);
657 STRV_FOREACH_PAIR(a
, b
, pairs
)
658 remove_one_link(rtnl
, *a
);