diff options
Diffstat (limited to 'src/nspawn/nspawn-network.c')
| -rw-r--r-- | src/nspawn/nspawn-network.c | 661 |
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; +} |