/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include "sd-device.h" #include "sd-id128.h" #include "sd-netlink.h" #include "alloc-util.h" #include "ether-addr-util.h" #include "hexdecoct.h" #include "lockfile-util.h" #include "missing_network.h" #include "netif-naming-scheme.h" #include "netlink-util.h" #include "nspawn-network.h" #include "parse-util.h" #include "siphash24.h" #include "socket-netlink.h" #include "socket-util.h" #include "stat-util.h" #include "string-util.h" #include "strv.h" #include "udev-util.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) #define SHORTEN_IFNAME_HASH_KEY SD_ID128_MAKE(e1,90,a4,04,a8,ef,4b,51,8c,cc,c3,3a,9f,11,fc,a2) 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 set_alternative_ifname(sd_netlink *rtnl, const char *ifname, const char *altifname) { int r; assert(rtnl); assert(ifname); if (!altifname) return 0; if (strlen(altifname) >= ALTIFNAMSIZ) return log_warning_errno(SYNTHETIC_ERRNO(ERANGE), "Alternative interface name '%s' for '%s' is too long, ignoring", altifname, ifname); r = rtnl_set_link_alternative_names_by_ifname(&rtnl, ifname, STRV_MAKE(altifname)); if (r < 0) return log_warning_errno(r, "Failed to set alternative interface name '%s' to '%s', ignoring: %m", altifname, ifname); return 0; } static int add_veth( sd_netlink *rtnl, pid_t pid, const char *ifname_host, const char *altifname_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); (void) set_alternative_ifname(rtnl, ifname_host, altifname_host); return 0; } static int shorten_ifname(char *ifname) { char new_ifname[IFNAMSIZ]; assert(ifname); if (strlen(ifname) < IFNAMSIZ) /* Name is short enough */ return 0; if (naming_scheme_has(NAMING_NSPAWN_LONG_HASH)) { uint64_t h; /* Calculate 64bit hash value */ h = siphash24(ifname, strlen(ifname), SHORTEN_IFNAME_HASH_KEY.bytes); /* Set the final four bytes (i.e. 32bit) to the lower 24bit of the hash, encoded in url-safe base64 */ memcpy(new_ifname, ifname, IFNAMSIZ - 5); new_ifname[IFNAMSIZ - 5] = urlsafe_base64char(h >> 18); new_ifname[IFNAMSIZ - 4] = urlsafe_base64char(h >> 12); new_ifname[IFNAMSIZ - 3] = urlsafe_base64char(h >> 6); new_ifname[IFNAMSIZ - 2] = urlsafe_base64char(h); } else /* On old nspawn versions we just truncated the name, provide compatibility */ memcpy(new_ifname, ifname, IFNAMSIZ-1); new_ifname[IFNAMSIZ - 1] = 0; /* Log the incident to make it more discoverable */ log_warning("Network interface name '%s' has been changed to '%s' to fit length constraints.", ifname, new_ifname); strcpy(ifname, new_ifname); return 1; } 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; unsigned u; char *n, *a = NULL; int r; assert(machine_name); assert(pid > 0); assert(iface_name); /* Use two different interface name prefixes depending whether * we are in bridge mode or not. */ n = strjoina(bridge ? "vb-" : "ve-", machine_name); r = shorten_ifname(n); if (r > 0) a = strjoina(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, n, a, &mac_host, "host0", &mac_container); if (r < 0) return r; u = if_nametoindex(n); /* We don't need to use rtnl_resolve_ifname() here because the * name we assigned is always the main name. */ if (u == 0) return log_error_errno(errno, "Failed to resolve interface %s: %m", n); strcpy(iface_name, n); return (int) u; } 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; 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 host side of extra veth link: %m"); r = add_veth(rtnl, pid, *a, NULL, &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 = rtnl_resolve_interface(&rtnl, bridge_name); if (bridge_ifi < 0) return bridge_ifi; 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); } int test_network_interface_initialized(const char *name) { _cleanup_(sd_device_unrefp) sd_device *d = NULL; int r; if (path_is_read_only_fs("/sys") > 0) return 0; /* udev should be around. */ r = sd_device_new_from_ifname(&d, name); if (r < 0) return log_error_errno(r, "Failed to get device %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: %m", name); if (r == 0) return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Network interface %s is not initialized yet.", name); r = device_is_renaming(d); if (r < 0) return log_error_errno(r, "Failed to determine the interface %s is being renamed: %m", name); if (r > 0) return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Interface %s is being renamed.", name); return 0; } int move_network_interfaces(int netns_fd, char **ifaces) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; 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 = rtnl_resolve_interface_or_warn(&rtnl, *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_FD, netns_fd); if (r < 0) return log_error_errno(r, "Failed to append namespace fd 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; 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, *a = NULL; struct ether_addr mac; int ifi; ifi = rtnl_resolve_interface_or_warn(&rtnl, *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 = strjoin("mv-", *i); if (!n) return log_oom(); r = shorten_ifname(n); if (r > 0) { a = strjoin("mv-", *i); if (!a) return log_oom(); } 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"); (void) set_alternative_ifname(rtnl, n, a); } return 0; } int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; 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, *a = NULL; int ifi; ifi = rtnl_resolve_interface_or_warn(&rtnl, *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 = strjoin("iv-", *i); if (!n) return log_oom(); r = shorten_ifname(n); if (r > 0) { a = strjoin("iv-", *i); if (!a) return log_oom(); } 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"); (void) set_alternative_ifname(rtnl, n, a); } 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; 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; }