Cleanup --dry-run option code
[petitboot] / discover / device-handler.c
index 0e902df6b86ed4c1805868617cf7db85abb08bf7..6e03ef3fa159136b6015983a0054411cb7f126c8 100644 (file)
 
+#include <assert.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
 #include <talloc/talloc.h>
+#include <list/list.h>
+#include <log/log.h>
 #include <pb-protocol/pb-protocol.h>
+#include <system/system.h>
 
 #include "device-handler.h"
+#include "discover-server.h"
+#include "event.h"
+#include "parser.h"
+#include "udev.h"
+#include "paths.h"
+
+#define MOUNT_BIN "/bin/mount"
+
+#define UMOUNT_BIN "/bin/umount"
 
 struct device_handler {
        struct discover_server *server;
 
-       struct device *devices;
-       int n_devices;
+       struct device **devices;
+       unsigned int n_devices;
+
+       struct list contexts;
 };
 
-struct device_handler *device_handler_init(struct discover_server *server)
+struct mount_map {
+       char *device_path;
+       char *mount_point;
+};
+
+/**
+ * device_handler_add - Add a device to the handler device array.
+ */
+
+static void device_handler_add(struct device_handler *handler,
+       struct device *device)
 {
-       struct device_handler *handler;
+       handler->n_devices++;
+       handler->devices = talloc_realloc(handler, handler->devices,
+               struct device *, handler->n_devices);
+       handler->devices[handler->n_devices - 1] = device;
+}
 
-       handler = talloc(NULL, struct device_handler);
-       handler->devices = NULL;
-       handler->n_devices = 0;
+/**
+ * device_handler_remove - Remove a device from the handler device array.
+ */
 
-       return handler;
+static void device_handler_remove(struct device_handler *handler,
+       struct device *device)
+{
+       unsigned int i;
+
+       for (i = 0; i < handler->n_devices; i++)
+               if (handler->devices[i] == device)
+                       break;
+
+       if (i == handler->n_devices) {
+               assert(0 && "unknown device");
+               return;
+       }
+
+       handler->n_devices--;
+       memmove(&handler->devices[i], &handler->devices[i + 1],
+               (handler->n_devices - i) * sizeof(handler->devices[0]));
+       handler->devices = talloc_realloc(handler, handler->devices,
+               struct device *, handler->n_devices);
 }
 
-void device_handler_destroy(struct device_handler *devices)
+/**
+ * device_handler_find - Find a handler device by id.
+ */
+
+static struct device *device_handler_find(struct device_handler *handler,
+       const char *id)
 {
-       talloc_free(devices);
+       unsigned int i;
+
+       assert(id);
+
+       for (i = 0; i < handler->n_devices; i++)
+               if (handler->devices[i]->id
+                       && streq(handler->devices[i]->id, id))
+                       return handler->devices[i];
+
+       pb_log("%s: unknown device: %s\n", __func__, id);
+       return NULL;
 }
 
-static struct boot_option options[] = {
-       {
-               .id = "1.1",
-               .name = "meep one",
-               .description = "meep description one",
-               .icon_file = "meep.one.png",
-               .boot_args = "root=/dev/sda1",
-       },
-};
+/**
+ * device_handler_get_device_count - Get the count of current handler devices.
+ */
 
-static struct device device = {
-       .id = "1",
-       .name = "meep",
-       .description = "meep description",
-       .icon_file = "meep.png",
-       .n_options = 1,
-       .options = options,
-};
+int device_handler_get_device_count(const struct device_handler *handler)
+{
+       return handler->n_devices;
+}
 
-int device_handler_get_current_devices(struct device_handler *handler,
-               struct device **devices)
+/**
+ * device_handler_get_device - Get a handler device by index.
+ */
 
+const struct device *device_handler_get_device(
+       const struct device_handler *handler, unsigned int index)
 {
-       *devices = &device;
-       return 1;
+       if (index >= handler->n_devices) {
+               assert(0 && "bad index");
+               return NULL;
+       }
+
+       return handler->devices[index];
 }
 
+static void setup_device_links(struct discover_context *ctx)
+{
+       struct link {
+               char *env, *dir;
+       } *link, links[] = {
+               {
+                       .env = "ID_FS_UUID",
+                       .dir = "disk/by-uuid"
+               },
+               {
+                       .env = "ID_FS_LABEL",
+                       .dir = "disk/by-label"
+               },
+               {
+                       .env = NULL
+               }
+       };
 
-int device_handler_event(struct device_handler *handler,
-               struct udev_event *event)
+       for (link = links; link->env; link++) {
+               char *enc, *dir, *path;
+               const char *value;
+
+               value = event_get_param(ctx->event, link->env);
+               if (!value || !*value)
+                       continue;
+
+               enc = encode_label(ctx, value);
+               dir = join_paths(ctx, mount_base(), link->dir);
+               path = join_paths(ctx, dir, value);
+
+               if (!pb_mkdir_recursive(dir)) {
+                       unlink(path);
+                       if (symlink(ctx->mount_path, path)) {
+                               pb_log("symlink(%s,%s): %s\n",
+                                               ctx->mount_path, path,
+                                               strerror(errno));
+                               talloc_free(path);
+                       } else {
+                               int i = ctx->n_links++;
+                               ctx->links = talloc_realloc(ctx,
+                                               ctx->links, char *,
+                                               ctx->n_links);
+                               ctx->links[i] = path;
+                       }
+
+               }
+
+               talloc_free(dir);
+               talloc_free(enc);
+       }
+}
+
+static void remove_device_links(struct discover_context *ctx)
+{
+       int i;
+
+       for (i = 0; i < ctx->n_links; i++)
+               unlink(ctx->links[i]);
+}
+
+static int mount_device(struct discover_context *ctx)
 {
+       const char *mountpoint;
+       const char *argv[6];
+
+       if (!ctx->mount_path) {
+               mountpoint = mountpoint_for_device(ctx->device_path);
+               ctx->mount_path = talloc_strdup(ctx, mountpoint);
+       }
+
+       if (pb_mkdir_recursive(ctx->mount_path))
+               pb_log("couldn't create mount directory %s: %s\n",
+                               ctx->mount_path, strerror(errno));
+
+       argv[0] = MOUNT_BIN;
+       argv[1] = ctx->device_path;
+       argv[2] = ctx->mount_path;
+       argv[3] = "-o";
+       argv[4] = "ro";
+       argv[5] = NULL;
+
+       if (pb_run_cmd(argv, 1, 0)) {
+
+               /* Retry mount without ro option. */
+
+               argv[0] = MOUNT_BIN;
+               argv[1] = ctx->device_path;
+               argv[2] = ctx->mount_path;
+               argv[3] = NULL;
+
+               if (pb_run_cmd(argv, 1, 0))
+                       goto out_rmdir;
+       }
+
+       setup_device_links(ctx);
        return 0;
+
+out_rmdir:
+       pb_rmdir_recursive(mount_base(), ctx->mount_path);
+       return -1;
+}
+
+static int umount_device(struct discover_context *ctx)
+{
+       int status;
+       pid_t pid;
+
+       remove_device_links(ctx);
+
+       pid = fork();
+       if (pid == -1) {
+               pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
+               return -1;
+       }
+
+       if (pid == 0) {
+               execl(UMOUNT_BIN, UMOUNT_BIN, ctx->mount_path, NULL);
+               exit(EXIT_FAILURE);
+       }
+
+       if (waitpid(pid, &status, 0) == -1) {
+               pb_log("%s: waitpid failed: %s\n", __func__,
+                               strerror(errno));
+               return -1;
+       }
+
+       if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+               return -1;
+
+       pb_rmdir_recursive(mount_base(), ctx->mount_path);
+
+       return 0;
+}
+
+static struct discover_context *find_context(struct device_handler *handler,
+               const char *id)
+{
+       struct discover_context *ctx;
+
+       list_for_each_entry(&handler->contexts, ctx, list) {
+               if (!strcmp(ctx->id, id))
+                       return ctx;
+       }
+
+       return NULL;
+}
+
+static int destroy_context(void *arg)
+{
+       struct discover_context *ctx = arg;
+
+       list_remove(&ctx->list);
+       umount_device(ctx);
+
+       return 0;
+}
+
+static int handle_add_udev_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct discover_context *ctx;
+       const char *devname;
+       int rc;
+
+       /* create our context */
+       ctx = talloc(handler, struct discover_context);
+       ctx->event = event;
+       ctx->mount_path = NULL;
+       ctx->links = NULL;
+       ctx->n_links = 0;
+
+       ctx->id = talloc_strdup(ctx, event->device);
+
+       devname = event_get_param(ctx->event, "DEVNAME");
+       assert(devname);
+       ctx->device_path = talloc_strdup(ctx, devname);
+
+       rc = mount_device(ctx);
+       if (rc) {
+               talloc_free(ctx);
+               return 0;
+       }
+
+       list_add(&handler->contexts, &ctx->list);
+       talloc_set_destructor(ctx, destroy_context);
+
+       /* set up the top-level device */
+       ctx->device = talloc_zero(ctx, struct device);
+       ctx->device->id = talloc_strdup(ctx->device, ctx->id);
+       list_init(&ctx->device->boot_options);
+
+       /* run the parsers */
+       iterate_parsers(ctx);
+
+       /* add device to handler device array */
+       device_handler_add(handler, ctx->device);
+
+       discover_server_notify_add(handler->server, ctx->device);
+
+       return 0;
+}
+
+static int handle_remove_udev_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct discover_context *ctx;
+
+       ctx = find_context(handler, event->device);
+       if (!ctx)
+               return 0;
+
+       discover_server_notify_remove(handler->server, ctx->device);
+
+       /* remove device from handler device array */
+       device_handler_remove(handler, ctx->device);
+
+       talloc_free(ctx);
+
+       return 0;
+}
+
+static int handle_add_user_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct device *device;
+
+       assert(event->device);
+
+       device = talloc_zero(handler, struct device);
+
+       if (!device)
+               goto fail;
+
+       device->id = talloc_strdup(device, event->device);
+       list_init(&device->boot_options);
+
+       parse_user_event(device, event);
+
+       discover_server_notify_add(handler->server, device);
+
+       /* add device to handler device array */
+       device_handler_add(handler, device);
+
+       return 0;
+
+fail:
+       talloc_free(device);
+       return 0;
+}
+
+static int handle_remove_user_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct device *device = device_handler_find(handler, event->device);
+
+       if (!device)
+               return 0;
+
+       discover_server_notify_remove(handler->server, device);
+
+       /* remove device from handler device array */
+       device_handler_remove(handler, device);
+
+       talloc_free(device);
+       return 0;
+}
+
+int device_handler_event(struct device_handler *handler,
+               struct event *event)
+{
+       int rc = 0;
+
+       switch (event->type) {
+       case EVENT_TYPE_UDEV:
+               switch (event->action) {
+               case EVENT_ACTION_ADD:
+                       rc = handle_add_udev_event(handler, event);
+                       break;
+               case EVENT_ACTION_REMOVE:
+                       rc = handle_remove_udev_event(handler, event);
+                       break;
+               default:
+                       pb_log("%s unknown action: %d\n", __func__,
+                               event->action);
+                       break;
+               }
+               break;
+       case EVENT_TYPE_USER:
+               switch (event->action) {
+               case EVENT_ACTION_ADD:
+                       rc = handle_add_user_event(handler, event);
+                       break;
+               case EVENT_ACTION_REMOVE:
+                       rc = handle_remove_user_event(handler, event);
+                       break;
+               default:
+                       pb_log("%s unknown action: %d\n", __func__,
+                               event->action);
+                       break;
+               }
+               break;
+       default:
+               pb_log("%s unknown type: %d\n", __func__, event->type);
+               break;
+       }
+
+       return rc;
+}
+
+struct device_handler *device_handler_init(struct discover_server *server)
+{
+       struct device_handler *handler;
+
+       handler = talloc(NULL, struct device_handler);
+       handler->devices = NULL;
+       handler->n_devices = 0;
+       handler->server = server;
+
+       list_init(&handler->contexts);
+
+       /* set up our mount point base */
+       pb_mkdir_recursive(mount_base());
+
+       parser_init();
+
+       return handler;
+}
+
+void device_handler_destroy(struct device_handler *handler)
+{
+       talloc_free(handler);
 }