machined: introduce pseudo-machine ".host" refererring to the host system

Some of the operations machined/machinectl implement are also very
useful when applied to the host system (such as machinectl login,
machinectl shell or machinectl status), hence introduce a pseudo-machine
by the name of ".host" in machined that refers to the host system, and
may be used top execute operations on the host system with.

This copies the pseudo-image ".host" machined already implements for
image related commands.

(This commit also adds a PK privilege for opening a PTY in a container,
which was previously not accessible for non-root.)

1 files changed, 44 insertions, 3 deletions

diff --git a/src/machine/machined.c b/src/machine/machined.c
index 9b9a334838..df3cc9972a 100644
--- a/src/machine/machined.c
+++ b/src/machine/machined.c
@@ -90,6 +90,45 @@ void manager_free(Manager *m) {
         free(m);
 }
 
+static int manager_add_host_machine(Manager *m) {
+        _cleanup_free_ char *rd = NULL, *unit = NULL;
+        sd_id128_t mid;
+        Machine *t;
+        int r;
+
+        if (m->host_machine)
+                return 0;
+
+        r = sd_id128_get_machine(&mid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get machine ID: %m");
+
+        rd = strdup("/");
+        if (!rd)
+                return log_oom();
+
+        unit = strdup("-.slice");
+        if (!unit)
+                return log_oom();
+
+        t = machine_new(m, MACHINE_HOST, ".host");
+        if (!t)
+                return log_oom();
+
+        t->leader = 1;
+        t->id = mid;
+
+        t->root_directory = rd;
+        t->unit = unit;
+        rd = unit = NULL;
+
+        dual_timestamp_from_boottime_or_monotonic(&t->timestamp, 0);
+
+        m->host_machine = t;
+
+        return 0;
+}
+
 int manager_enumerate_machines(Manager *m) {
         _cleanup_closedir_ DIR *d = NULL;
         struct dirent *de;
@@ -97,6 +136,10 @@ int manager_enumerate_machines(Manager *m) {
 
         assert(m);
 
+        r = manager_add_host_machine(m);
+        if (r < 0)
+                return r;
+
         /* Read in machine data stored on disk */
         d = opendir("/run/systemd/machines");
         if (!d) {
@@ -123,9 +166,7 @@ int manager_enumerate_machines(Manager *m) {
 
                 k = manager_add_machine(m, de->d_name, &machine);
                 if (k < 0) {
-                        log_error_errno(k, "Failed to add machine by file name %s: %m", de->d_name);
-
-                        r = k;
+                        r = log_error_errno(k, "Failed to add machine by file name %s: %m", de->d_name);
                         continue;
                 }