diff options
Diffstat (limited to 'src/systemd-nspawn/nspawn-network.c')
| -rw-r--r-- | src/systemd-nspawn/nspawn-network.c | 184 |
1 files changed, 169 insertions, 15 deletions
diff --git a/src/systemd-nspawn/nspawn-network.c b/src/systemd-nspawn/nspawn-network.c index 58d6035ddb..917827eac1 100644 --- a/src/systemd-nspawn/nspawn-network.c +++ b/src/systemd-nspawn/nspawn-network.c @@ -26,8 +26,11 @@ #include "alloc-util.h" #include "ether-addr-util.h" +#include "lockfile-util.h" #include "nspawn-network.h" #include "siphash24.h" +#include "socket-util.h" +#include "stat-util.h" #include "string-util.h" #include "udev-util.h" #include "util.h" @@ -38,6 +41,30 @@ #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, @@ -231,51 +258,155 @@ int setup_veth_extra( if (r < 0) return r; - idx ++; + idx++; } return 0; } -int setup_bridge(const char *veth_name, const char *bridge_name) { +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; - _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = 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 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"); + return -errno; 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"); + return r; 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"); + return r; 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"); + return r; 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"); + return r; 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 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 interferance 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(struct udev *udev, const char *name) { _cleanup_udev_device_unref_ struct udev_device *d = NULL; char ifi_str[2 + DECIMAL_STR_MAX(int)]; @@ -514,13 +645,13 @@ int veth_extra_parse(char ***l, const char *p) { r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS); if (r < 0) return r; - if (r == 0 || isempty(a)) + 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 || isempty(b)) { + if (r == 0 || !ifname_valid(b)) { free(b); b = strdup(a); if (!b) @@ -537,3 +668,26 @@ int veth_extra_parse(char ***l, const char *p) { 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; +} |