diff options
Diffstat (limited to 'src/nspawn')
-rw-r--r-- | src/nspawn/nspawn.c | 408 |
1 files changed, 357 insertions, 51 deletions
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index 59f6f38a49..2b1feb6aa3 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -93,11 +93,22 @@ #include "cap-list.h" #include "btrfs-util.h" #include "machine-image.h" +#include "list.h" +#include "in-addr-util.h" +#include "fw-util.h" +#include "local-addresses.h" #ifdef HAVE_SECCOMP #include "seccomp-util.h" #endif +typedef struct ExposePort { + int protocol; + uint16_t host_port; + uint16_t container_port; + LIST_FIELDS(struct ExposePort, ports); +} ExposePort; + typedef enum ContainerStatus { CONTAINER_TERMINATED, CONTAINER_REBOOTED @@ -172,6 +183,7 @@ static const char *arg_network_bridge = NULL; static unsigned long arg_personality = 0xffffffffLU; static char *arg_image = NULL; static Volatile arg_volatile = VOLATILE_NO; +static ExposePort *arg_expose_ports = NULL; static void help(void) { printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n" @@ -203,6 +215,8 @@ static void help(void) { " Add a virtual ethernet connection between host\n" " and container and add it to an existing bridge on\n" " the host\n" + " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n" + " Expose a container IP port ont the host\n" " -Z --selinux-context=SECLABEL\n" " Set the SELinux security context to be used by\n" " processes in the container\n" @@ -225,8 +239,8 @@ static void help(void) { " --register=BOOLEAN Register container as machine\n" " --keep-unit Do not register a scope for the machine, reuse\n" " the service unit nspawn is running in\n" - " --volatile[=MODE] Run the system in volatile mode\n", - program_invocation_short_name); + " --volatile[=MODE] Run the system in volatile mode\n" + , program_invocation_short_name); } static int set_sanitized_path(char **b, const char *path) { @@ -309,6 +323,7 @@ static int parse_argv(int argc, char *argv[]) { { "personality", required_argument, NULL, ARG_PERSONALITY }, { "image", required_argument, NULL, 'i' }, { "volatile", optional_argument, NULL, ARG_VOLATILE }, + { "port", required_argument, NULL, 'p' }, {} }; @@ -318,7 +333,7 @@ static int parse_argv(int argc, char *argv[]) { assert(argc >= 0); assert(argv); - while ((c = getopt_long(argc, argv, "+hD:u:bL:M:jS:Z:qi:x", options, NULL)) >= 0) + while ((c = getopt_long(argc, argv, "+hD:u:bL:M:jS:Z:qi:xp:", options, NULL)) >= 0) switch (c) { @@ -643,6 +658,65 @@ static int parse_argv(int argc, char *argv[]) { break; + case 'p': { + const char *split, *e; + uint16_t container_port, host_port; + int protocol; + ExposePort *p; + + if ((e = startswith(optarg, "tcp:"))) + protocol = IPPROTO_TCP; + else if ((e = startswith(optarg, "udp:"))) + protocol = IPPROTO_UDP; + else { + e = optarg; + protocol = IPPROTO_TCP; + } + + split = strchr(e, ':'); + if (split) { + char v[split - e + 1]; + + memcpy(v, e, split - e); + v[split - e] = 0; + + r = safe_atou16(v, &host_port); + if (r < 0 || host_port <= 0) { + log_error("Failed to parse host port: %s", optarg); + return -EINVAL; + } + + r = safe_atou16(split + 1, &container_port); + } else { + r = safe_atou16(e, &container_port); + host_port = container_port; + } + + if (r < 0 || container_port <= 0) { + log_error("Failed to parse host port: %s", optarg); + return -EINVAL; + } + + LIST_FOREACH(ports, p, arg_expose_ports) { + if (p->protocol == protocol && p->host_port == host_port) { + log_error("Duplicate port specification: %s", optarg); + return -EINVAL; + } + } + + p = new(ExposePort, 1); + if (!p) + return log_oom(); + + p->protocol = protocol; + p->host_port = host_port; + p->container_port = container_port; + + LIST_PREPEND(ports, arg_expose_ports, p); + + break; + } + case '?': return -EINVAL; @@ -698,6 +772,11 @@ static int parse_argv(int argc, char *argv[]) { return -EINVAL; } + if (arg_expose_ports && !arg_private_network) { + log_error("Cannot use --port= without private networking."); + return -EINVAL; + } + arg_retain = (arg_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus; return 1; @@ -1349,8 +1428,8 @@ static int setup_dev_console(const char *dest, const char *console) { static int setup_kmsg(const char *dest, int kmsg_socket) { _cleanup_free_ char *from = NULL, *to = NULL; - int r, fd, k; _cleanup_umask_ mode_t u; + int r, fd, k; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(int))]; @@ -1401,7 +1480,7 @@ static int setup_kmsg(const char *dest, int kmsg_socket) { /* Store away the fd in the socket, so that it stays open as * long as we run the child */ - k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); + k = sendmsg(kmsg_socket, &mh, MSG_NOSIGNAL); safe_close(fd); if (k < 0) @@ -1412,6 +1491,198 @@ static int setup_kmsg(const char *dest, int kmsg_socket) { return 0; } +static int send_rtnl(int send_fd) { + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + _cleanup_close_ int fd = -1; + ssize_t k; + + assert(send_fd >= 0); + + if (!arg_expose_ports) + return 0; + + fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE); + if (fd < 0) + return log_error_errno(errno, "failed to allocate container netlink: %m"); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); + + mh.msg_controllen = cmsg->cmsg_len; + + /* Store away the fd in the socket, so that it stays open as + * long as we run the child */ + k = sendmsg(send_fd, &mh, MSG_NOSIGNAL); + if (k < 0) + return log_error_errno(errno, "Failed to send netlink fd: %m"); + + return 0; +} + +static int flush_ports(union in_addr_union *exposed) { + ExposePort *p; + int r, af = AF_INET; + + assert(exposed); + + if (!arg_expose_ports) + return 0; + + if (in_addr_is_null(af, exposed)) + return 0; + + log_debug("Lost IP address."); + + LIST_FOREACH(ports, p, arg_expose_ports) { + r = fw_add_local_dnat(false, + af, + p->protocol, + NULL, + NULL, 0, + NULL, 0, + p->host_port, + exposed, + p->container_port, + NULL); + if (r < 0) + log_warning_errno(r, "Failed to modify firewall: %m"); + } + + *exposed = IN_ADDR_NULL; + return 0; +} + +static int expose_ports(sd_rtnl *rtnl, union in_addr_union *exposed) { + _cleanup_free_ struct local_address *addresses = NULL; + _cleanup_free_ char *pretty = NULL; + union in_addr_union new_exposed; + ExposePort *p; + bool add; + int af = AF_INET, r; + + assert(exposed); + + /* Invoked each time an address is added or removed inside the + * container */ + + if (!arg_expose_ports) + return 0; + + r = local_addresses(rtnl, 0, af, &addresses); + if (r < 0) + return log_error_errno(r, "Failed to enumerate local addresses: %m"); + + add = r > 0 && + addresses[0].family == af && + addresses[0].scope < RT_SCOPE_LINK; + + if (!add) + return flush_ports(exposed); + + new_exposed = addresses[0].address; + if (in_addr_equal(af, exposed, &new_exposed)) + return 0; + + in_addr_to_string(af, &new_exposed, &pretty); + log_debug("New container IP is %s.", strna(pretty)); + + LIST_FOREACH(ports, p, arg_expose_ports) { + + r = fw_add_local_dnat(true, + af, + p->protocol, + NULL, + NULL, 0, + NULL, 0, + p->host_port, + &new_exposed, + p->container_port, + in_addr_is_null(af, exposed) ? NULL : exposed); + if (r < 0) + log_warning_errno(r, "Failed to modify firewall: %m"); + } + + *exposed = new_exposed; + return 0; +} + +static int on_address_change(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) { + union in_addr_union *exposed = userdata; + + assert(rtnl); + assert(m); + assert(exposed); + + expose_ports(rtnl, exposed); + return 0; +} + +static int watch_rtnl(sd_event *event, int recv_fd, union in_addr_union *exposed, sd_rtnl **ret) { + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; + int fd, r; + ssize_t k; + + assert(event); + assert(recv_fd >= 0); + assert(ret); + + if (!arg_expose_ports) + return 0; + + k = recvmsg(recv_fd, &mh, MSG_NOSIGNAL); + if (k < 0) + return log_error_errno(errno, "Failed to recv netlink fd: %m"); + + cmsg = CMSG_FIRSTHDR(&mh); + assert(cmsg->cmsg_level == SOL_SOCKET); + assert(cmsg->cmsg_type == SCM_RIGHTS); + assert(cmsg->cmsg_len = CMSG_LEN(sizeof(int))); + memcpy(&fd, CMSG_DATA(cmsg), sizeof(int)); + + r = sd_rtnl_open_fd(&rtnl, fd, 1, RTNLGRP_IPV4_IFADDR); + if (r < 0) { + safe_close(fd); + return log_error_errno(r, "Failed to create rtnl object: %m"); + } + + r = sd_rtnl_add_match(rtnl, RTM_NEWADDR, on_address_change, exposed); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m"); + + r = sd_rtnl_add_match(rtnl, RTM_DELADDR, on_address_change, exposed); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m"); + + r = sd_rtnl_attach_event(rtnl, event, 0); + if (r < 0) + return log_error_errno(r, "Failed to add to even loop: %m"); + + *ret = rtnl; + rtnl = NULL; + + return 0; +} + static int setup_hostname(void) { if (arg_share_system) @@ -3059,7 +3330,6 @@ int main(int argc, char *argv[]) { _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL, *console = NULL; bool root_device_rw = true, home_device_rw = true, srv_device_rw = true; _cleanup_close_ int master = -1, image_fd = -1; - _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }; _cleanup_fdset_free_ FDSet *fds = NULL; int r, n_fd_passed, loop_nr = -1; char veth_name[IFNAMSIZ]; @@ -3067,6 +3337,7 @@ int main(int argc, char *argv[]) { sigset_t mask, mask_chld; pid_t pid = 0; int ret = EXIT_SUCCESS; + union in_addr_union exposed = {}; log_parse_environment(); log_open(); @@ -3233,11 +3504,6 @@ int main(int argc, char *argv[]) { goto finish; } - if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) { - r = log_error_errno(errno, "Failed to create kmsg socket pair: %m"); - goto finish; - } - assert_se(sigemptyset(&mask) == 0); sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1); assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0); @@ -3246,6 +3512,7 @@ int main(int argc, char *argv[]) { assert_se(sigaddset(&mask_chld, SIGCHLD) == 0); for (;;) { + _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }, rtnl_socket_pair[2] = { -1, -1 }; ContainerStatus container_status; _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL; struct sigaction sa = { @@ -3259,6 +3526,16 @@ int main(int argc, char *argv[]) { goto finish; } + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) { + r = log_error_errno(errno, "Failed to create kmsg socket pair: %m"); + goto finish; + } + + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0) { + r = log_error_errno(errno, "Failed to create rtnl socket pair: %m"); + goto finish; + } + /* Child can be killed before execv(), so handle SIGCHLD * in order to interrupt parent's blocking calls and * give it a chance to call wait() and terminate. */ @@ -3317,6 +3594,7 @@ int main(int argc, char *argv[]) { close_nointr(STDERR_FILENO); kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]); + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); reset_all_signal_handlers(); reset_signal_mask(); @@ -3412,9 +3690,12 @@ int main(int argc, char *argv[]) { if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0) _exit(EXIT_FAILURE); - kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]); + if (send_rtnl(rtnl_socket_pair[1]) < 0) + _exit(EXIT_FAILURE); + rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]); + /* Tell the parent that we are ready, and that * it can cgroupify us to that we lack access * to certain devices and resources. */ @@ -3585,13 +3866,13 @@ int main(int argc, char *argv[]) { fdset_free(fds); fds = NULL; + kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]); + rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]); + /* Wait for the most basic Child-setup to be done, * before we add hardware to it, and place it in a * cgroup. */ if (barrier_sync_next(&barrier)) { - _cleanup_event_unref_ sd_event *event = NULL; - _cleanup_(pty_forward_freep) PTYForward *forward = NULL; - char last_char = 0; int ifi = 0; r = move_network_interfaces(pid); @@ -3631,52 +3912,67 @@ int main(int argc, char *argv[]) { (void) barrier_place(&barrier); /* And wait that the child is completely ready now. */ - (void) barrier_place_and_sync(&barrier); + if (barrier_place_and_sync(&barrier)) { + _cleanup_event_unref_ sd_event *event = NULL; + _cleanup_(pty_forward_freep) PTYForward *forward = NULL; + _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; + char last_char = 0; - sd_notify(false, - "READY=1\n" - "STATUS=Container running."); + sd_notify(false, + "READY=1\n" + "STATUS=Container running."); - r = sd_event_new(&event); - if (r < 0) { - log_error_errno(r, "Failed to get default event source: %m"); - goto finish; - } + r = sd_event_new(&event); + if (r < 0) { + log_error_errno(r, "Failed to get default event source: %m"); + goto finish; + } - if (arg_boot) { - /* Try to kill the init system on SIGINT or SIGTERM */ - sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, UINT32_TO_PTR(pid)); - sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, UINT32_TO_PTR(pid)); - } else { - /* Immediately exit */ - sd_event_add_signal(event, NULL, SIGINT, NULL, NULL); - sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL); - } + if (arg_boot) { + /* Try to kill the init system on SIGINT or SIGTERM */ + sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, UINT32_TO_PTR(pid)); + sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, UINT32_TO_PTR(pid)); + } else { + /* Immediately exit */ + sd_event_add_signal(event, NULL, SIGINT, NULL, NULL); + sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL); + } - /* simply exit on sigchld */ - sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL); + /* simply exit on sigchld */ + sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL); - r = pty_forward_new(event, master, true, &forward); - if (r < 0) { - log_error_errno(r, "Failed to create PTY forwarder: %m"); - goto finish; - } + if (arg_expose_ports) { + r = watch_rtnl(event, rtnl_socket_pair[0], &exposed, &rtnl); + if (r < 0) + goto finish; - r = sd_event_loop(event); - if (r < 0) { - log_error_errno(r, "Failed to run event loop: %m"); - goto finish; - } + (void) expose_ports(rtnl, &exposed); + } - pty_forward_get_last_char(forward, &last_char); + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); - forward = pty_forward_free(forward); + r = pty_forward_new(event, master, true, &forward); + if (r < 0) { + log_error_errno(r, "Failed to create PTY forwarder: %m"); + goto finish; + } - if (!arg_quiet && last_char != '\n') - putc('\n', stdout); + r = sd_event_loop(event); + if (r < 0) { + log_error_errno(r, "Failed to run event loop: %m"); + goto finish; + } + + pty_forward_get_last_char(forward, &last_char); + + forward = pty_forward_free(forward); + + if (!arg_quiet && last_char != '\n') + putc('\n', stdout); - /* Kill if it is not dead yet anyway */ - terminate_machine(pid); + /* Kill if it is not dead yet anyway */ + terminate_machine(pid); + } } /* Normally redundant, but better safe than sorry */ @@ -3714,6 +4010,8 @@ int main(int argc, char *argv[]) { r = 0; break; } + + flush_ports(&exposed); } finish: @@ -3753,5 +4051,13 @@ finish: strv_free(arg_bind_ro); strv_free(arg_tmpfs); + flush_ports(&exposed); + + while (arg_expose_ports) { + ExposePort *p = arg_expose_ports; + LIST_REMOVE(ports, arg_expose_ports, p); + free(p); + } + return r < 0 ? EXIT_FAILURE : ret; } |