From ab046dde6f355f4a8b07ff6120a7ef51f5d49fc9 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Sun, 16 Feb 2014 21:12:47 +0100 Subject: [PATCH] nspawn: add new --network-bridge= switch This adds the host side of the veth link to the given bridge. Also refactor the creation of the veth interfaces a bit to set it up from the host rather than the container. This simplifies the addition to the bridge, but otherwise the behavior is unchanged. --- TODO | 1 - man/systemd-nspawn.xml | 14 +++++- src/nspawn/nspawn.c | 111 +++++++++++++++++++++++++++++++---------- 3 files changed, 98 insertions(+), 28 deletions(-) diff --git a/TODO b/TODO index 299f450d7..a77a99351 100644 --- a/TODO +++ b/TODO @@ -432,7 +432,6 @@ Features: - refuses to boot containers without /etc/machine-id (OK?), and with empty /etc/machine-id (not OK). - support taking a btrfs snapshot at startup and dropping it afterwards - maybe: hookup nspawn and PrivateNetwork=yes with "ip netns" - - introduce --network-bridge= which works like --network-veth but also adds the host side to an existing bridge - allow booting disk images with a GPT signature using the bootloaderspec partition uuids * cryptsetup: diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index d6f2d11dc..665518dd1 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -270,7 +270,7 @@ exception of the loopback device and those specified with - and configured ith + and configured with . If this option is specified the CAP_NET_ADMIN capability will be added @@ -318,6 +318,18 @@ . + + + + Adds the host side of the + ethernet link created with + + to the specified bridge. Note that + + implies + . + + diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index a81bb8ea4..34e72db06 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -133,6 +133,7 @@ static bool arg_register = true; static bool arg_keep_unit = false; static char **arg_network_interfaces = NULL; static bool arg_network_veth = false; +static char *arg_network_bridge = NULL; static int help(void) { @@ -153,6 +154,10 @@ static int help(void) { " container\n" " --network-veth Add a a virtual ethernet connection between host\n" " and container\n" + " --network-bridge=INTERFACE\n" + " Add a a virtual ethernet connection between host\n" + " and container and add it to an existing bridge on\n" + " the host\n" " -Z --selinux-context=SECLABEL\n" " Set the SELinux security context to be used by\n" " processes in the container\n" @@ -196,6 +201,7 @@ static int parse_argv(int argc, char *argv[]) { ARG_KEEP_UNIT, ARG_NETWORK_INTERFACE, ARG_NETWORK_VETH, + ARG_NETWORK_BRIDGE, }; static const struct option options[] = { @@ -222,7 +228,8 @@ static int parse_argv(int argc, char *argv[]) { { "register", required_argument, NULL, ARG_REGISTER }, { "keep-unit", no_argument, NULL, ARG_KEEP_UNIT }, { "network-interface", required_argument, NULL, ARG_NETWORK_INTERFACE }, - { "network-veth", no_argument, NULL, ARG_NETWORK_VETH }, + { "network-veth", no_argument, NULL, ARG_NETWORK_VETH }, + { "network-bridge", required_argument, NULL, ARG_NETWORK_BRIDGE }, {} }; @@ -262,6 +269,13 @@ static int parse_argv(int argc, char *argv[]) { break; + case ARG_NETWORK_BRIDGE: + arg_network_bridge = strdup(optarg); + if (!arg_network_bridge) + return log_oom(); + + /* fall through */ + case ARG_NETWORK_VETH: arg_network_veth = true; arg_private_network = true; @@ -1270,10 +1284,9 @@ static int reset_audit_loginuid(void) { return 0; } -static int setup_veth(int netns_fd) { +static int setup_veth(pid_t pid, char iface_name[]) { _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL; _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; - char iface_name[IFNAMSIZ] = "ve-"; int r; if (!arg_private_network) @@ -1282,7 +1295,7 @@ static int setup_veth(int netns_fd) { if (!arg_network_veth) return 0; - strncpy(iface_name+3, arg_machine, sizeof(iface_name) - 3); + strncpy(iface_name+3, arg_machine, IFNAMSIZ - 3); r = sd_rtnl_open(0, &rtnl); if (r < 0) { @@ -1296,9 +1309,9 @@ static int setup_veth(int netns_fd) { return r; } - r = sd_rtnl_message_append_string(m, IFLA_IFNAME, "host0"); + r = sd_rtnl_message_append_string(m, IFLA_IFNAME, iface_name); if (r < 0) { - log_error("Failed to append netlink kind: %s", strerror(-r)); + log_error("Failed to add netlink interface name: %s", strerror(-r)); return r; } @@ -1322,17 +1335,17 @@ static int setup_veth(int netns_fd) { r = sd_rtnl_message_open_container(m, VETH_INFO_PEER); if (r < 0) { - log_error("z Failed to open netlink container: %s", strerror(-r)); + log_error("Failed to open netlink container: %s", strerror(-r)); return r; } - r = sd_rtnl_message_append_string(m, IFLA_IFNAME, iface_name); + r = sd_rtnl_message_append_string(m, IFLA_IFNAME, "host0"); if (r < 0) { - log_error("Failed to append netlink kind: %s", strerror(-r)); + log_error("Failed to add netlink interface name: %s", strerror(-r)); return r; } - r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_FD, netns_fd); + r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid); if (r < 0) { log_error("Failed to add netlink namespace field: %s", strerror(-r)); return r; @@ -1365,6 +1378,59 @@ static int setup_veth(int netns_fd) { return 0; } +static int setup_bridge(const char veth_name[]) { + _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL; + _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; + int r, bridge; + + if (!arg_private_network) + return 0; + + if (!arg_network_veth) + return 0; + + if (!arg_network_bridge) + return 0; + + bridge = (int) if_nametoindex(arg_network_bridge); + if (bridge <= 0) { + log_error("Failed to resolve interface %s: %m", arg_network_bridge); + return -errno; + } + + r = sd_rtnl_open(0, &rtnl); + if (r < 0) { + log_error("Failed to connect to netlink: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_new_link(RTM_SETLINK, 0, &m); + if (r < 0) { + log_error("Failed to allocate netlink message: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_string(m, IFLA_IFNAME, veth_name); + if (r < 0) { + log_error("Failed to add netlink interface name field: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_u32(m, IFLA_MASTER, bridge); + if (r < 0) { + log_error("Failed to add netlink master field: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_call(rtnl, m, 0, NULL); + if (r < 0) { + log_error("Failed to add veth interface to bridge: %s", strerror(-r)); + return r; + } + + return 0; +} + static int move_network_interfaces(pid_t pid) { _cleanup_udev_unref_ struct udev *udev = NULL; _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; @@ -1497,6 +1563,7 @@ int main(int argc, char *argv[]) { int n_fd_passed; pid_t pid = 0; sigset_t mask; + char veth_name[IFNAMSIZ] = "ve-"; log_parse_environment(); log_open(); @@ -1603,14 +1670,6 @@ int main(int argc, char *argv[]) { goto finish; } - if (arg_network_veth) { - netns_fd = open("/proc/self/ns/net", O_RDWR|O_CLOEXEC); - if (netns_fd < 0) { - log_error("Failed to open network namespace fd: %m"); - goto finish; - } - } - if (access("/dev/kdbus/control", F_OK) >= 0) { if (arg_share_system) { @@ -1765,14 +1824,6 @@ int main(int argc, char *argv[]) { dev_setup(arg_directory); - if (setup_veth(netns_fd) < 0) - goto child_fail; - - if (netns_fd >= 0) { - close_nointr_nofail(netns_fd); - netns_fd = -1; - } - if (audit_still_doesnt_work_in_containers() < 0) goto child_fail; @@ -1987,6 +2038,14 @@ int main(int argc, char *argv[]) { if (r < 0) goto finish; + r = setup_veth(pid, veth_name); + if (r < 0) + goto finish; + + r = setup_bridge(veth_name); + if (r < 0) + goto finish; + eventfd_write(sync_fd, 1); close_nointr_nofail(sync_fd); sync_fd = -1; -- 2.30.2