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src/nspawn/nspawn-network.c
1 056 строк
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Daan De Meyer
tree-wide: Migrate to pidref_safe_fork()
02 янв 2026, 22:08
02 янв 2026, 22:08
52ecf37
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/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include <linux/if.h> #include <linux/nl80211.h> #include <linux/veth.h> #include <net/if.h> #include <sys/file.h> #include <sys/mount.h> #include <unistd.h> #include "sd-device.h" #include "sd-id128.h" #include "sd-netlink.h" #include "alloc-util.h" #include "device-private.h" #include "device-util.h" #include "ether-addr-util.h" #include "extract-word.h" #include "fd-util.h" #include "lock-util.h" #include "mkdir.h" #include "mount-util.h" #include "namespace-util.h" #include "netif-util.h" #include "netlink-util.h" #include "nspawn-network.h" #include "pidref.h" #include "process-util.h" #include "socket-util.h" #include "stat-util.h" #include "string-util.h" #include "strv.h" #include "udev-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 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, const PidRef *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(pidref_is_set(pid)); 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->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; } int setup_veth(const char *machine_name, const PidRef *pid, char iface_name[IFNAMSIZ], bool bridge, const struct ether_addr *provided_mac) { _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(pidref_is_set(pid)); 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 = net_shorten_ifname(n, /* check_naming_scheme= */ true); if (r > 0) a = strjoina(bridge ? "vb-" : "ve-", machine_name); if (ether_addr_is_null(provided_mac)){ r = net_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"); } else mac_container = *provided_mac; r = net_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, const PidRef *pid, char **pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; uint64_t idx = 0; int r; assert(machine_name); assert(pidref_is_set(pid)); 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 = net_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 = net_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, /* ignore_hidden_or_backup= */ false); 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 test_network_interface_initialized(const char *name) { _cleanup_(sd_device_unrefp) sd_device *d = NULL; int r; if (!udev_available()) 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 = device_is_processed(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 test_network_interfaces_initialized(char **iface_pairs) { int r; STRV_FOREACH_PAIR(a, b, iface_pairs) { r = test_network_interface_initialized(*a); if (r < 0) return r; } return 0; } int resolve_network_interface_names(char **iface_pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; int r; /* Due to a bug in kernel fixed by 8e15aee621618a3ee3abecaf1fd8c1428098b7ef (v6.6, backported to * 6.1.60 and 6.5.9), an interface with alternative names cannot be resolved by the alternative name * if the interface is moved to another network namespace. Hence, we need to adjust the provided * names before moving interfaces to container namespace. */ STRV_FOREACH_PAIR(from, to, iface_pairs) { _cleanup_free_ char *name = NULL; _cleanup_strv_free_ char **altnames = NULL; r = rtnl_resolve_ifname_full(&rtnl, _RESOLVE_IFNAME_ALL, *from, &name, &altnames); if (r < 0) return r; /* Always use the resolved name for 'from'. */ free_and_replace(*from, name); /* If the name 'to' is assigned as an alternative name, we cannot rename the interface. * Hence, use the assigned interface name (including the alternative names) as is, and * use the resolved name for 'to'. */ if (strv_contains(altnames, *to)) { r = free_and_strdup_warn(to, *from); if (r < 0) return r; } } return 0; } static int netns_child_begin(int netns_fd, int *ret_original_netns_fd) { _cleanup_close_ int original_netns_fd = -EBADF; int r; assert(netns_fd >= 0); if (ret_original_netns_fd) { original_netns_fd = namespace_open_by_type(NAMESPACE_NET); if (original_netns_fd < 0) return log_error_errno(original_netns_fd, "Failed to open original network namespace: %m"); } r = namespace_enter(/* pidns_fd= */ -EBADF, /* mntns_fd= */ -EBADF, netns_fd, /* userns_fd= */ -EBADF, /* root_fd= */ -EBADF); if (r < 0) return log_error_errno(r, "Failed to enter child network namespace: %m"); r = umount_recursive("/sys/", /* flags= */ 0); if (r < 0) log_debug_errno(r, "Failed to unmount directories below /sys/, ignoring: %m"); (void) mkdir_p("/sys/", 0755); /* Populate new sysfs instance associated with the client netns, to make sd_device usable. */ r = mount_nofollow_verbose(LOG_ERR, "sysfs", "/sys/", "sysfs", MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, /* options= */ NULL); if (r < 0) return log_error_errno(r, "Failed to mount sysfs on /sys/: %m"); /* udev_avaliable() might be called previously and the result may be cached. * Now, we (re-)mount sysfs. Hence, we need to reset the cache. */ reset_cached_udev_availability(); if (ret_original_netns_fd) *ret_original_netns_fd = TAKE_FD(original_netns_fd); return 0; } static int netns_fork_and_wait(int netns_fd, int *ret_original_netns_fd) { int r; assert(netns_fd >= 0); r = pidref_safe_fork( "(sd-netns)", FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGTERM|FORK_WAIT|FORK_LOG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, /* ret= */ NULL); if (r < 0) return log_error_errno(r, "Failed to fork process (sd-netns): %m"); if (r == 0) { if (netns_child_begin(netns_fd, ret_original_netns_fd) < 0) _exit(EXIT_FAILURE); return 0; } if (ret_original_netns_fd) *ret_original_netns_fd = -EBADF; return 1; } static int move_wlan_interface_impl(sd_netlink **genl, int netns_fd, sd_device *dev) { _cleanup_(sd_netlink_unrefp) sd_netlink *our_genl = NULL; _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; int r; assert(netns_fd >= 0); assert(dev); if (!genl) genl = &our_genl; if (!*genl) { r = sd_genl_socket_open(genl); if (r < 0) return log_error_errno(r, "Failed to connect to generic netlink: %m"); } r = sd_genl_message_new(*genl, NL80211_GENL_NAME, NL80211_CMD_SET_WIPHY_NETNS, &m); if (r < 0) return log_device_error_errno(dev, r, "Failed to allocate netlink message: %m"); uint32_t phy_index; r = device_get_sysattr_u32(dev, "phy80211/index", &phy_index); if (r < 0) return log_device_error_errno(dev, r, "Failed to get phy index: %m"); r = sd_netlink_message_append_u32(m, NL80211_ATTR_WIPHY, phy_index); if (r < 0) return log_device_error_errno(dev, r, "Failed to append phy index to netlink message: %m"); r = sd_netlink_message_append_u32(m, NL80211_ATTR_NETNS_FD, netns_fd); if (r < 0) return log_device_error_errno(dev, r, "Failed to append namespace fd to netlink message: %m"); r = sd_netlink_call(*genl, m, 0, NULL); if (r < 0) return log_device_error_errno(dev, r, "Failed to move interface to namespace: %m"); return 0; } static int move_wlan_interface_one( sd_netlink **rtnl, sd_netlink **genl, int *temp_netns_fd, int netns_fd, sd_device *dev, const char *name) { int r; assert(rtnl); assert(genl); assert(temp_netns_fd); assert(netns_fd >= 0); assert(dev); if (!name) return move_wlan_interface_impl(genl, netns_fd, dev); /* The command NL80211_CMD_SET_WIPHY_NETNS takes phy instead of network interface, and does not take * an interface name in the passed network namespace. Hence, we need to move the phy and interface to * a temporary network namespace, rename the interface in it, and move them to the requested netns. */ if (*temp_netns_fd < 0) { r = netns_acquire(); if (r < 0) return log_error_errno(r, "Failed to acquire new network namespace: %m"); *temp_netns_fd = r; } r = move_wlan_interface_impl(genl, *temp_netns_fd, dev); if (r < 0) return r; const char *sysname; r = sd_device_get_sysname(dev, &sysname); if (r < 0) return log_device_error_errno(dev, r, "Failed to get interface name: %m"); r = netns_fork_and_wait(*temp_netns_fd, NULL); if (r < 0) return log_error_errno(r, "Failed to fork process (nspawn-rename-wlan): %m"); if (r == 0) { _cleanup_(sd_device_unrefp) sd_device *temp_dev = NULL; r = rtnl_rename_link(NULL, sysname, name); if (r < 0) { log_error_errno(r, "Failed to rename network interface '%s' to '%s': %m", sysname, name); goto finalize; } r = sd_device_new_from_ifname(&temp_dev, name); if (r < 0) { log_error_errno(r, "Failed to acquire device '%s': %m", name); goto finalize; } r = move_wlan_interface_impl(NULL, netns_fd, temp_dev); finalize: _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); } return 0; } static int move_network_interface_one(sd_netlink **rtnl, int netns_fd, sd_device *dev, const char *name) { _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; int r; assert(rtnl); assert(netns_fd >= 0); assert(dev); if (!*rtnl) { r = sd_netlink_open(rtnl); if (r < 0) return log_error_errno(r, "Failed to connect to rtnetlink: %m"); } int ifindex; r = sd_device_get_ifindex(dev, &ifindex); if (r < 0) return log_device_error_errno(dev, r, "Failed to get ifindex: %m"); r = sd_rtnl_message_new_link(*rtnl, &m, RTM_SETLINK, ifindex); if (r < 0) return log_device_error_errno(dev, 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_device_error_errno(dev, r, "Failed to append namespace fd to netlink message: %m"); if (name) { r = sd_netlink_message_append_string(m, IFLA_IFNAME, name); if (r < 0) return log_device_error_errno(dev, r, "Failed to add netlink interface name: %m"); } r = sd_netlink_call(*rtnl, m, 0, NULL); if (r < 0) return log_device_error_errno(dev, r, "Failed to move interface to namespace: %m"); return 0; } int move_network_interfaces(int netns_fd, char **iface_pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL, *genl = NULL; _cleanup_close_ int temp_netns_fd = -EBADF; int r; assert(netns_fd >= 0); if (strv_isempty(iface_pairs)) return 0; STRV_FOREACH_PAIR(from, to, iface_pairs) { _cleanup_(sd_device_unrefp) sd_device *dev = NULL; const char *name; name = streq(*from, *to) ? NULL : *to; r = sd_device_new_from_ifname(&dev, *from); if (r < 0) return log_error_errno(r, "Unknown interface name %s: %m", *from); if (device_is_devtype(dev, "wlan")) r = move_wlan_interface_one(&rtnl, &genl, &temp_netns_fd, netns_fd, dev, name); else r = move_network_interface_one(&rtnl, netns_fd, dev, name); if (r < 0) return r; } return 0; } int move_back_network_interfaces(int child_netns_fd, char **interface_pairs) { _cleanup_close_ int parent_netns_fd = -EBADF; int r; assert(child_netns_fd >= 0); if (strv_isempty(interface_pairs)) return 0; r = netns_fork_and_wait(child_netns_fd, &parent_netns_fd); if (r < 0) return r; if (r == 0) { /* Reverse network interfaces pair list so that interfaces get their initial name back. * This is about ensuring interfaces get their old name back when being moved back. */ interface_pairs = strv_reverse(interface_pairs); r = move_network_interfaces(parent_netns_fd, interface_pairs); _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); } return 0; } int setup_macvlan(const char *machine_name, const PidRef *pid, char **iface_pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; unsigned idx = 0; int r; assert(pidref_is_set(pid)); if (strv_isempty(iface_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(i, b, iface_pairs) { _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; _cleanup_free_ char *n = NULL; int shortened, ifi; struct ether_addr mac; ifi = rtnl_resolve_interface_or_warn(&rtnl, *i); if (ifi < 0) return ifi; r = net_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 = strdup(*b); if (!n) return log_oom(); shortened = net_shorten_ifname(n, /* check_naming_scheme= */ true); 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->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"); if (shortened > 0) (void) set_alternative_ifname(rtnl, n, *b); } return 0; } static int remove_macvlan_impl(char **interface_pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; int r; assert(interface_pairs); r = sd_netlink_open(&rtnl); if (r < 0) return log_error_errno(r, "Failed to connect to netlink: %m"); STRV_FOREACH_PAIR(a, b, interface_pairs) { _cleanup_free_ char *n = NULL; n = strdup(*b); if (!n) return log_oom(); (void) net_shorten_ifname(n, /* check_naming_scheme= */ true); r = remove_one_link(rtnl, n); if (r < 0) log_warning_errno(r, "Failed to remove macvlan interface %s, ignoring: %m", n); } return 0; } int remove_macvlan(int child_netns_fd, char **interface_pairs) { _cleanup_close_ int parent_netns_fd = -EBADF; int r; /* In some cases the kernel might pin the macvlan links on the container even after the namespace * died. Hence, let's better remove them explicitly too. See issue #680. */ assert(child_netns_fd >= 0); if (strv_isempty(interface_pairs)) return 0; r = netns_fork_and_wait(child_netns_fd, &parent_netns_fd); if (r < 0) return r; if (r == 0) { r = remove_macvlan_impl(interface_pairs); _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); } return 0; } int setup_ipvlan(const char *machine_name, const PidRef *pid, char **iface_pairs) { _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; int r; assert(pidref_is_set(pid)); if (strv_isempty(iface_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(i, b, iface_pairs) { _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; _cleanup_free_ char *n = NULL; int shortened, 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 = strdup(*b); if (!n) return log_oom(); shortened = net_shorten_ifname(n, /* check_naming_scheme= */ true); 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->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"); if (shortened > 0) (void) set_alternative_ifname(rtnl, n, *b); } 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)) { r = free_and_strdup(&b, a); if (r < 0) return r; } 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; } static int network_iface_pair_parse(const char* iftype, char ***l, const char *p, const char* ifprefix) { int r; for (;;) { _cleanup_free_ char *word = NULL, *a = NULL, *b = NULL; const char *interface; r = extract_first_word(&p, &word, NULL, 0); if (r < 0) return log_error_errno(r, "Failed to parse interface name: %m"); if (r == 0) break; interface = word; r = extract_first_word(&interface, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS); if (r < 0) return log_error_errno(r, "Failed to extract first word in %s parameter: %m", iftype); if (r == 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Short read while reading %s parameter.", iftype); if (!ifname_valid(a)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "%s, interface name not valid: %s", iftype, a); /* Here, we only check the validity of the specified second name. If it is not specified, * the copied or prefixed name should be already valid, except for its length. If it is too * long, then it will be shortened later. */ if (!isempty(interface)) { if (!ifname_valid(interface)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "%s, interface name not valid: %s", iftype, interface); b = strdup(interface); } else if (ifprefix) b = strjoin(ifprefix, a); else b = strdup(a); if (!b) return log_oom(); r = strv_consume_pair(l, TAKE_PTR(a), TAKE_PTR(b)); if (r < 0) return log_oom(); } return 0; } int interface_pair_parse(char ***l, const char *p) { return network_iface_pair_parse("Network interface", l, p, NULL); } int macvlan_pair_parse(char ***l, const char *p) { return network_iface_pair_parse("MACVLAN network interface", l, p, "mv-"); } int ipvlan_pair_parse(char ***l, const char *p) { return network_iface_pair_parse("IPVLAN network interface", l, p, "iv-"); }