chiark / gitweb /
device: only expose devices with SYSTEMD_EXPOSE=1, ignore all others
[elogind.git] / device.c
index 34d760a48a55930982958aa3a129cf8c3de86e31..f906fd50021dedc822b224bc88a7784167046de5 100644 (file)
--- a/device.c
+++ b/device.c
@@ -1,12 +1,33 @@
 /*-*- Mode: C; c-basic-offset: 8 -*-*/
 
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
 #include <errno.h>
+#include <sys/epoll.h>
 #include <libudev.h>
 
 #include "unit.h"
 #include "device.h"
 #include "strv.h"
 #include "log.h"
+#include "unit-name.h"
 
 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
         [DEVICE_DEAD] = UNIT_INACTIVE,
@@ -22,7 +43,18 @@ static void device_done(Unit *u) {
         Device *d = DEVICE(u);
 
         assert(d);
+
         free(d->sysfs);
+        d->sysfs = NULL;
+}
+
+static void device_init(Unit *u) {
+        Device *d = DEVICE(u);
+
+        assert(d);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        d->state = 0;
 }
 
 static void device_set_state(Device *d, DeviceState state) {
@@ -32,7 +64,8 @@ static void device_set_state(Device *d, DeviceState state) {
         old_state = d->state;
         d->state = state;
 
-        log_debug("%s changed %s → %s", unit_id(UNIT(d)), state_string_table[old_state], state_string_table[state]);
+        if (state != old_state)
+                log_debug("%s changed %s → %s", UNIT(d)->meta.id, state_string_table[old_state], state_string_table[state]);
 
         unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state]);
 }
@@ -67,7 +100,13 @@ static UnitActiveState device_active_state(Unit *u) {
         return state_translation_table[DEVICE(u)->state];
 }
 
-static int device_add_escaped_name(Unit *u, const char *prefix, const char *dn, bool make_id) {
+static const char *device_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return state_string_table[DEVICE(u)->state];
+}
+
+static int device_add_escaped_name(Unit *u, const char *dn, bool make_id) {
         char *e;
         int r;
 
@@ -75,7 +114,7 @@ static int device_add_escaped_name(Unit *u, const char *prefix, const char *dn,
         assert(dn);
         assert(dn[0] == '/');
 
-        if (!(e = unit_name_escape_path(prefix, dn+1, ".device")))
+        if (!(e = unit_name_build_escape(dn+1, NULL, ".device")))
                 return -ENOMEM;
 
         r = unit_add_name(u, e);
@@ -91,79 +130,134 @@ static int device_add_escaped_name(Unit *u, const char *prefix, const char *dn,
         return 0;
 }
 
-static int device_process_device(Manager *m, struct udev_device *dev) {
-        const char *dn, *names, *wants, *sysfs;
+static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
+        char *e;
+        Unit *u;
+
+        assert(m);
+        assert(dn);
+        assert(dn[0] == '/');
+        assert(_u);
+
+        if (!(e = unit_name_build_escape(dn+1, NULL, ".device")))
+                return -ENOMEM;
+
+        u = manager_get_unit(m, e);
+        free(e);
+
+        if (u) {
+                *_u = u;
+                return 1;
+        }
+
+        return 0;
+}
+
+static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
+        const char *dn, *names, *wants, *sysfs, *expose, *model;
         Unit *u = NULL;
         int r;
-        char *e, *w, *state;
+        char *w, *state;
         size_t l;
         bool delete;
         struct udev_list_entry *item = NULL, *first = NULL;
+        int b;
 
         assert(m);
 
+        if (!(sysfs = udev_device_get_syspath(dev)))
+                return -ENOMEM;
+
+        if (!(expose = udev_device_get_property_value(dev, "SYSTEMD_EXPOSE")))
+                return 0;
+
+        if ((b = parse_boolean(expose)) < 0) {
+                log_error("Failed to parse SYSTEMD_EXPOSE udev property for device %s: %s", sysfs, expose);
+                return 0;
+        }
+
+        if (!b)
+                return 0;
+
         /* Check whether this entry is even relevant for us. */
         dn = udev_device_get_devnode(dev);
         names = udev_device_get_property_value(dev, "SYSTEMD_NAMES");
         wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
 
-        if (!dn && !names && !wants)
-                return 0;
+        if ((r = device_find_escape_name(m, sysfs, &u)) < 0)
+                return r;
 
-        /* Ok, seems kinda interesting. Now, let's see if this one
-         * already exists. */
+        if (r == 0 && dn)
+                if ((r = device_find_escape_name(m, dn, &u)) < 0)
+                        return r;
 
-        if (!(sysfs = udev_device_get_syspath(dev)))
-                return -ENOMEM;
+        if (r == 0) {
+                first = udev_device_get_devlinks_list_entry(dev);
+                udev_list_entry_foreach(item, first) {
+                        if ((r = device_find_escape_name(m, udev_list_entry_get_name(item), &u)) < 0)
+                                return r;
 
-        assert(sysfs[0] == '/');
-        if (!(e = unit_name_escape_path("sysfs-", sysfs+1, ".device")))
-                return -ENOMEM;
+                        if (r > 0)
+                                break;
+                }
+        }
 
-        if (!(u = manager_get_unit(m, e))) {
-                const char *model;
+        /* FIXME: this needs proper merging */
 
+        assert((r > 0) == !!u);
+
+        /* If this is a different unit, then let's not merge things */
+        if (u && DEVICE(u)->sysfs && !streq(DEVICE(u)->sysfs, sysfs))
+                u = NULL;
+
+        if (!u) {
                 delete = true;
 
-                if (!(u = unit_new(m))) {
-                        free(e);
+                if (!(u = unit_new(m)))
                         return -ENOMEM;
-                }
 
-                r = unit_add_name(u, e);
-                free(e);
-
-                if (r < 0)
+                if ((r = device_add_escaped_name(u, sysfs, true)) < 0)
                         goto fail;
 
+                unit_add_to_load_queue(u);
+        } else
+                delete = false;
+
+        if (!(DEVICE(u)->sysfs))
                 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
                         r = -ENOMEM;
                         goto fail;
                 }
 
-                if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
-                    (model = udev_device_get_property_value(dev, "ID_MODEL")))
-                        if ((r = unit_set_description(u, model)) < 0)
-                                goto fail;
-
-        } else {
-                delete = false;
-                free(e);
-        }
-
         if (dn)
-                if ((r = device_add_escaped_name(u, "node-", dn, true)) < 0)
+                if ((r = device_add_escaped_name(u, dn, true)) < 0)
                         goto fail;
 
         first = udev_device_get_devlinks_list_entry(dev);
         udev_list_entry_foreach(item, first)
-                if ((r = device_add_escaped_name(u, "node-", udev_list_entry_get_name(item), false)) < 0)
+                if ((r = device_add_escaped_name(u, udev_list_entry_get_name(item), false)) < 0)
+                        goto fail;
+
+        if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
+            (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
+                if ((r = unit_set_description(u, model)) < 0)
+                        goto fail;
+        } else if (dn)
+                if ((r = unit_set_description(u, dn)) < 0)
                         goto fail;
 
+        /* We don't remove names that are gone. But that should be
+         * fine and should probably be fixed only on a configuration
+         * refresh. */
+
         if (names) {
                 FOREACH_WORD(w, l, names, state) {
-                        if (!(e = strndup(w, l)))
+                        char *e;
+
+                        if (!(e = strndup(w, l))) {
+                                r = -ENOMEM;
                                 goto fail;
+                        }
 
                         r = unit_add_name(u, e);
                         free(e);
@@ -173,18 +267,16 @@ static int device_process_device(Manager *m, struct udev_device *dev) {
                 }
         }
 
-
-        if (set_isempty(u->meta.names)) {
-                r = -EEXIST;
-                goto fail;
-        }
-
         if (wants) {
                 FOREACH_WORD(w, l, wants, state) {
-                        if (!(e = strndup(w, l)))
+                        char *e;
+
+                        if (!(e = strndup(w, l))) {
+                                r = -ENOMEM;
                                 goto fail;
+                        }
 
-                        r = unit_add_dependency_by_name(u, UNIT_WANTS, e);
+                        r = unit_add_dependency_by_name(u, UNIT_WANTS, NULL, e);
                         free(e);
 
                         if (r < 0)
@@ -192,7 +284,13 @@ static int device_process_device(Manager *m, struct udev_device *dev) {
                 }
         }
 
-        unit_add_to_load_queue(u);
+        if (update_state) {
+                manager_dispatch_load_queue(u->meta.manager);
+                device_set_state(DEVICE(u), DEVICE_AVAILABLE);
+        }
+
+        unit_add_to_dbus_queue(u);
+
         return 0;
 
 fail:
@@ -201,7 +299,7 @@ fail:
         return r;
 }
 
-static int device_process_path(Manager *m, const char *path) {
+static int device_process_path(Manager *m, const char *path, bool update_state) {
         int r;
         struct udev_device *dev;
 
@@ -213,19 +311,53 @@ static int device_process_path(Manager *m, const char *path) {
                 return -ENOMEM;
         }
 
-        r = device_process_device(m, dev);
+        r = device_process_new_device(m, dev, update_state);
         udev_device_unref(dev);
         return r;
 }
 
+static int device_process_removed_device(Manager *m, struct udev_device *dev) {
+        const char *sysfs;
+        char *e;
+        Unit *u;
+        Device *d;
+
+        assert(m);
+        assert(dev);
+
+        if (!(sysfs = udev_device_get_syspath(dev)))
+                return -ENOMEM;
+
+        assert(sysfs[0] == '/');
+        if (!(e = unit_name_build_escape(sysfs+1, NULL, ".device")))
+                return -ENOMEM;
+
+        u = manager_get_unit(m, e);
+        free(e);
+
+        if (!u)
+                return 0;
+
+        d = DEVICE(u);
+        free(d->sysfs);
+        d->sysfs = NULL;
+
+        device_set_state(d, DEVICE_DEAD);
+        return 0;
+}
+
 static void device_shutdown(Manager *m) {
         assert(m);
 
+        if (m->udev_monitor)
+                udev_monitor_unref(m->udev_monitor);
+
         if (m->udev)
                 udev_unref(m->udev);
 }
 
 static int device_enumerate(Manager *m) {
+        struct epoll_event ev;
         int r;
         struct udev_enumerate *e = NULL;
         struct udev_list_entry *item = NULL, *first = NULL;
@@ -235,6 +367,26 @@ static int device_enumerate(Manager *m) {
         if (!(m->udev = udev_new()))
                 return -ENOMEM;
 
+        if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
+                r = -EIO;
+                goto fail;
+        }
+
+        m->udev_watch.type = WATCH_UDEV;
+        m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
+
+        zero(ev);
+        ev.events = EPOLLIN;
+        ev.data.ptr = &m->udev_watch;
+
+        if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
+                return -errno;
+
         if (!(e = udev_enumerate_new(m->udev))) {
                 r = -ENOMEM;
                 goto fail;
@@ -247,10 +399,9 @@ static int device_enumerate(Manager *m) {
 
         first = udev_enumerate_get_list_entry(e);
         udev_list_entry_foreach(item, first)
-                device_process_path(m, udev_list_entry_get_name(item));
+                device_process_path(m, udev_list_entry_get_name(item), false);
 
         udev_enumerate_unref(e);
-
         return 0;
 
 fail:
@@ -261,16 +412,55 @@ fail:
         return r;
 }
 
+void device_fd_event(Manager *m, int events) {
+        struct udev_device *dev;
+        int r;
+        const char *action;
+
+        assert(m);
+        assert(events == EPOLLIN);
+
+        if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
+                log_error("Failed to receive device.");
+                return;
+        }
+
+        if (!(action = udev_device_get_action(dev))) {
+                log_error("Failed to get udev action string.");
+                goto fail;
+        }
+
+        if (streq(action, "remove")) {
+                if ((r = device_process_removed_device(m, dev)) < 0) {
+                        log_error("Failed to process udev device event: %s", strerror(-r));
+                        goto fail;
+                }
+        } else {
+                if ((r = device_process_new_device(m, dev, true)) < 0) {
+                        log_error("Failed to process udev device event: %s", strerror(-r));
+                        goto fail;
+                }
+        }
+
+fail:
+        udev_device_unref(dev);
+}
+
 const UnitVTable device_vtable = {
         .suffix = ".device",
 
-        .init = unit_load_fragment_and_dropin,
+        .no_requires = true,
+        .no_instances = true,
+
+        .init = device_init,
+        .load = unit_load_fragment_and_dropin_optional,
         .done = device_done,
         .coldplug = device_coldplug,
 
         .dump = device_dump,
 
         .active_state = device_active_state,
+        .sub_state_to_string = device_sub_state_to_string,
 
         .enumerate = device_enumerate,
         .shutdown = device_shutdown