discover: move device sources to the device handler
[petitboot] / discover / udev.c
index bc0282749fe282521c15017dbff539a69527866c..320dffd03c1676d5f401153bb24ed80bb3c21e55 100644 (file)
 
-#define _GNU_SOURCE
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
 
-#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <libudev.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
-#include <errno.h>
-#include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <sys/un.h>
 
+#include <log/log.h>
+#include <types/types.h>
 #include <talloc/talloc.h>
 #include <waiter/waiter.h>
-#include <log/log.h>
+#include <system/system.h>
 
 #include "event.h"
 #include "udev.h"
 #include "pb-discover.h"
 #include "device-handler.h"
+#include "cdrom.h"
 
-#define PBOOT_DEVICE_SOCKET "/tmp/petitboot.udev"
-
-#define max(a, b) ((a) > (b) ? (a) : (b))
+/* We set a default monitor buffer size, as we may not process monitor
+ * events while performing device discvoery. systemd uses a 128M buffer, so
+ * we'll do the same here */
+static const int monitor_bufsize = 128 * 1024 * 1024;
 
-struct udev {
+struct pb_udev {
+       struct udev *udev;
+       struct udev_monitor *monitor;
        struct device_handler *handler;
-       int socket;
 };
 
-static void udev_print_event(struct event *event)
+static int udev_destructor(void *p)
 {
-       const char *action, *params[] = {
-               "DEVNAME", "ID_TYPE", "ID_BUS", "ID_FS_UUID", "ID_FS_LABEL",
-               NULL,
-       };
-       int i;
+       struct pb_udev *udev = p;
 
-       action = event->action == EVENT_ACTION_ADD ? "add" : "remove";
+       udev_monitor_unref(udev->monitor);
+       udev->monitor = NULL;
 
-       pb_log("udev %s event:\n", action);
-       pb_log("\tdevice: %s\n", event->device);
+       udev_unref(udev->udev);
+       udev->udev = NULL;
 
-       for (i = 0; params[i]; i++)
-               pb_log("\t%-12s => %s\n",
-                               params[i], event_get_param(event, params[i]));
+       return 0;
+}
 
+static void udev_setup_device_params(struct udev_device *udev,
+               struct discover_device *dev)
+{
+       struct udev_list_entry *list, *entry;
+
+       list = udev_device_get_properties_list_entry(udev);
+       if (!list)
+               return;
+
+       udev_list_entry_foreach(entry, list)
+               discover_device_set_param(dev,
+                               udev_list_entry_get_name(entry),
+                               udev_list_entry_get_value(entry));
 }
 
-static void udev_handle_message(struct udev *udev, char *buf, int len)
+static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
+               const char *name)
 {
-       int result;
-       struct event *event;
+       struct discover_device *ddev;
+       const char *typestr;
+       const char *uuid;
+       const char *path;
+       const char *node;
+       const char *prop;
+       const char *type;
+       bool cdrom;
+
+       typestr = udev_device_get_devtype(dev);
+       if (!typestr) {
+               pb_debug("udev_device_get_devtype failed\n");
+               return -1;
+       }
 
-       event = talloc(udev, struct event);
-       event->type = EVENT_TYPE_UDEV;
+       if (!(!strcmp(typestr, "disk") || !strcmp(typestr, "partition"))) {
+               pb_log("SKIP %s: invalid type %s\n", name, typestr);
+               return 0;
+       }
 
-       pb_log("%s\n", buf);
+       node = udev_device_get_devnode(dev);
+       path = udev_device_get_devpath(dev);
+       if (path && (strstr(path, "virtual/block/loop")
+                       || strstr(path, "virtual/block/ram"))) {
+               pb_log("SKIP: %s: ignored (path=%s)\n", name, path);
+               return 0;
+       }
 
-       result = event_parse_ad_message(event, buf, len);
+       cdrom = node && !!udev_device_get_property_value(dev, "ID_CDROM");
+       if (cdrom) {
+               /* CDROMs require a little initialisation, to get
+                * petitboot-compatible tray behaviour */
+               cdrom_init(node);
+               if (!cdrom_media_present(node)) {
+                       pb_log("SKIP: %s: no media present\n", name);
+                       return 0;
+               }
+       }
 
-       if (result)
-               return;
+       type = udev_device_get_property_value(dev, "ID_FS_TYPE");
+       if (!type) {
+               pb_log("SKIP: %s: no ID_FS_TYPE property\n", name);
+               return 0;
+       }
+
+       /* We may see multipath devices; they'll have the same uuid as an
+        * existing device, so only parse the first. */
+       uuid = udev_device_get_property_value(dev, "ID_FS_UUID");
+       if (uuid) {
+               ddev = device_lookup_by_uuid(udev->handler, uuid);
+               if (ddev) {
+                       pb_log("SKIP: %s UUID [%s] already present (as %s)\n",
+                                       name, uuid, ddev->device->id);
+                       return 0;
+               }
+       }
+
+       ddev = discover_device_create(udev->handler, name);
 
-       udev_print_event(event);
-       device_handler_event(udev->handler, event);
-       talloc_free(event);
+       ddev->device_path = talloc_strdup(ddev, node);
 
-       return;
+       if (uuid)
+               ddev->uuid = talloc_strdup(ddev, uuid);
+       prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
+       if (prop)
+               ddev->label = talloc_strdup(ddev, prop);
+       ddev->device->type = cdrom ? DEVICE_TYPE_OPTICAL : DEVICE_TYPE_DISK;
+
+       udev_setup_device_params(dev, ddev);
+
+       device_handler_discover(udev->handler, ddev);
+
+       return 0;
 }
 
-static int udev_process(void *arg)
+static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
 {
-       struct udev *udev = arg;
-       char buf[4096];
-       int len;
+       const char *subsys;
+       const char *name;
+
+       name = udev_device_get_sysname(dev);
+       if (!name) {
+               pb_debug("udev_device_get_sysname failed\n");
+               return -1;
+       }
+
+       subsys = udev_device_get_subsystem(dev);
+       if (!subsys) {
+               pb_debug("udev_device_get_subsystem failed\n");
+               return -1;
+       }
+
+       if (device_lookup_by_id(udev->handler, name)) {
+               pb_debug("device %s is already present?\n", name);
+               return -1;
+       }
+
+       if (!strcmp(subsys, "block")) {
+               return udev_handle_block_add(udev, dev, name);
+       }
+
+       pb_log("SKIP %s: unknown subsystem %s\n", name, subsys);
+       return -1;
+}
 
-       len = recvfrom(udev->socket, buf, sizeof(buf), 0, NULL, NULL);
 
-       if (len < 0) {
-               pb_log("udev socket read failed: %s", strerror(errno));
+static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
+{
+       struct discover_device *ddev;
+       const char *name;
+
+       name = udev_device_get_sysname(dev);
+       if (!name) {
+               pb_debug("udev_device_get_sysname failed\n");
                return -1;
        }
 
-       if (len == 0)
+       ddev = device_lookup_by_id(udev->handler, name);
+       if (!ddev)
                return 0;
 
-       udev_handle_message(udev, buf, len);
+       device_handler_remove(udev->handler, ddev);
 
        return 0;
 }
 
-static int udev_destructor(void *p)
+/* returns true if further event processing should stop (eg., we've
+ * ejected the cdrom)
+ */
+static bool udev_handle_cdrom_events(struct pb_udev *udev,
+               struct udev_device *dev, struct discover_device *ddev)
+{
+       const char *node;
+
+       node = udev_device_get_devnode(dev);
+
+       /* handle CDROM eject requests */
+       if (udev_device_get_property_value(dev, "DISK_EJECT_REQUEST")) {
+               bool eject = false;
+
+               pb_debug("udev: eject request\n");
+
+               /* If the device is mounted, cdrom_id's own eject request may
+                * have failed. So, we'll need to do our own here.
+                */
+               if (ddev) {
+                       eject = ddev->mounted;
+                       udev_handle_dev_remove(udev, dev);
+                       return false;
+               }
+
+               if (eject)
+                       cdrom_eject(node);
+
+               return true;
+       }
+
+       if (udev_device_get_property_value(dev, "DISK_MEDIA_CHANGE")) {
+               if (cdrom_media_present(node))
+                       udev_handle_dev_add(udev, dev);
+               else
+                       udev_handle_dev_remove(udev, dev);
+               return true;
+       }
+
+       return false;
+}
+
+static int udev_handle_dev_change(struct pb_udev *udev, struct udev_device *dev)
+{
+       struct discover_device *ddev;
+       const char *name;
+       int rc = 0;
+
+       name = udev_device_get_sysname(dev);
+
+       ddev = device_lookup_by_id(udev->handler, name);
+
+       /* if this is a CDROM device, process eject & media change requests;
+        * these may stop further processing */
+       if (!udev_device_get_property_value(dev, "ID_CDROM")) {
+               if (udev_handle_cdrom_events(udev, dev, ddev))
+                       return 0;
+       }
+
+       /* if this is a new device, treat it as an add */
+       if (!ddev)
+               rc = udev_handle_dev_add(udev, dev);
+
+       return rc;
+}
+
+static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 {
-       struct udev *udev = p;
+       struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
+
+#ifdef DEBUG
+       {
+               struct udev_list_entry *list;
+               const char *name;
+
+               list = udev_device_get_properties_list_entry(dev);
+               name = udev_device_get_sysname(dev);
+
+               pb_debug("%s: action %s, device %s\n", __func__, action, name);
+               pb_debug("%s properties:\n", __func__);
+
+               for (; list; list = udev_list_entry_get_next(list))
+                       pb_log("\t%-20s: %s\n", udev_list_entry_get_name(list),
+                                       udev_list_entry_get_value(list));
+       } while (0);
+#endif
+
+       if (!strcmp(action, "add"))
+               return udev_handle_dev_add(udev, dev);
+
+       else if (!strcmp(action, "remove"))
+               return udev_handle_dev_remove(udev, dev);
 
-       if (udev->socket >= 0)
-               close(udev->socket);
+       else if (!strcmp(action, "change"))
+               return udev_handle_dev_change(udev, dev);
 
        return 0;
 }
 
-struct udev *udev_init(struct device_handler *handler)
+static int udev_enumerate(struct udev *udev)
 {
-       struct sockaddr_un addr;
-       struct udev *udev;
+       int result;
+       struct udev_list_entry *list, *entry;
+       struct udev_enumerate *enumerate;
 
-       unlink(PBOOT_DEVICE_SOCKET);
+       enumerate = udev_enumerate_new(udev);
 
-       udev = talloc(NULL, struct udev);
+       if (!enumerate) {
+               pb_log("udev_enumerate_new failed\n");
+               return -1;
+       }
 
-       udev->handler = handler;
+       result = udev_enumerate_add_match_subsystem(enumerate, "block");
+       if (result) {
+               pb_log("udev_enumerate_add_match_subsystem failed\n");
+               goto fail;
+       }
+
+       result = udev_enumerate_add_match_is_initialized(enumerate);
+       if (result) {
+               pb_log("udev_enumerate_add_match_is_initialised failed\n");
+               goto fail;
+       }
+
+       udev_enumerate_scan_devices(enumerate);
 
-       udev->socket = socket(PF_UNIX, SOCK_DGRAM, 0);
-       if (udev->socket < 0) {
-               pb_log("Error creating udev socket: %s\n", strerror(errno));
+       list = udev_enumerate_get_list_entry(enumerate);
+
+       if (!list) {
+               pb_log("udev_enumerate_get_list_entry failed\n");
+               goto fail;
+       }
+
+       udev_list_entry_foreach(entry, list) {
+               const char *syspath;
+               struct udev_device *dev;
+
+               syspath = udev_list_entry_get_name(entry);
+               dev = udev_device_new_from_syspath(udev, syspath);
+
+               udev_handle_dev_action(dev, "add");
+
+               udev_device_unref(dev);
+       }
+
+       udev_enumerate_unref(enumerate);
+       return 0;
+
+fail:
+       udev_enumerate_unref(enumerate);
+       return -1;
+}
+
+static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
+{
+       int result;
+       struct udev_monitor *m;
+
+       *monitor = NULL;
+       m = udev_monitor_new_from_netlink(udev, "udev");
+
+       if (!m) {
+               pb_log("udev_monitor_new_from_netlink failed\n");
                goto out_err;
        }
 
-       talloc_set_destructor(udev, udev_destructor);
+       result = udev_monitor_set_receive_buffer_size(m, monitor_bufsize);
+       if (result) {
+               pb_log("udev_monitor_set_rx_bufsize(%d) failed\n",
+                       monitor_bufsize);
+       }
 
-       addr.sun_family = AF_UNIX;
-       strcpy(addr.sun_path, PBOOT_DEVICE_SOCKET);
+       result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
+               NULL);
 
-       if (bind(udev->socket, (struct sockaddr *)&addr, sizeof(addr))) {
-               pb_log("Error binding udev socket: %s\n", strerror(errno));
+       if (result) {
+               pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
                goto out_err;
        }
 
-       waiter_register(udev->socket, WAIT_IN, udev_process, udev);
+       result = udev_monitor_enable_receiving(m);
 
-       pb_log("%s: waiting on %s\n", __func__, PBOOT_DEVICE_SOCKET);
+       if (result) {
+               pb_log("udev_monitor_enable_receiving failed\n");
+               goto out_err;
+       }
 
-       return udev;
+       *monitor = m;
+       return 0;
 
 out_err:
-       talloc_free(udev);
-       return NULL;
+       udev_monitor_unref(m);
+       return -1;
 }
 
-int udev_trigger(struct udev __attribute__((unused)) *udev)
+/*
+ * udev_process - waiter callback for monitor netlink.
+ */
+
+static int udev_process(void *arg)
 {
-       int rc = system("/sbin/udevadm trigger --subsystem-match=block --action=add");
+       struct udev_monitor *monitor = arg;
+       struct udev_device *dev;
+       const char *action;
+
+       dev = udev_monitor_receive_device(monitor);
+       if (!dev) {
+               pb_log("udev_monitor_receive_device failed\n");
+               return -1;
+       }
 
-       if (rc)
-               pb_log("udev trigger failed: %d (%d)\n", rc, WEXITSTATUS(rc));
+       action = udev_device_get_action(dev);
 
-       return WEXITSTATUS(rc);
+       if (!action) {
+               pb_log("udev_device_get_action failed\n");
+       } else {
+               udev_handle_dev_action(dev, action);
+       }
+
+       udev_device_unref(dev);
+       return 0;
 }
 
-void udev_destroy(struct udev *udev)
+static void udev_log_fn(struct udev __attribute__((unused)) *udev,
+       int __attribute__((unused)) priority, const char *file, int line,
+       const char *fn, const char *format, va_list args)
 {
+      pb_log("libudev: %s %s:%d: ", fn, file, line);
+      vfprintf(pb_log_get_stream(), format, args);
+}
+
+struct pb_udev *udev_init(struct device_handler *handler,
+               struct waitset *waitset)
+{
+       struct pb_udev *udev;
+       int result;
+
+       udev = talloc(handler, struct pb_udev);
+       talloc_set_destructor(udev, udev_destructor);
+       udev->handler = handler;
+
+       udev->udev = udev_new();
+
+       if (!udev->udev) {
+               pb_log("udev_new failed\n");
+               goto fail_new;
+       }
+
+       udev_set_userdata(udev->udev, udev);
+
+       udev_set_log_fn(udev->udev, udev_log_fn);
+
+       result = udev_setup_monitor(udev->udev, &udev->monitor);
+       if (result)
+               goto fail_monitor;
+
+       result = udev_enumerate(udev->udev);
+       if (result)
+               goto fail_enumerate;
+
+       waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
+               udev_process, udev->monitor);
+
+       pb_debug("%s: waiting on udev\n", __func__);
+
+       return udev;
+
+fail_monitor:
+       udev_monitor_unref(udev->monitor);
+fail_enumerate:
+       udev_unref(udev->udev);
+fail_new:
        talloc_free(udev);
+       return NULL;
 }