discover: Change parsers to emit resources rather than filenames
[petitboot] / discover / device-handler.c
index 29c237131a4a267c25c11ce28e3f55d1b7c3ec95..950e730b995b89af52073b0ba8eaf0906d4147a9 100644 (file)
@@ -1,4 +1,5 @@
 
+#include <assert.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <talloc/talloc.h>
 #include <list/list.h>
 #include <log/log.h>
-#include <pb-protocol/pb-protocol.h>
+#include <types/types.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"
+#include "boot.h"
 
 struct device_handler {
-       struct discover_server *server;
-
-       struct device *devices;
-       int n_devices;
+       struct discover_server  *server;
+       int                     dry_run;
 
-       struct list contexts;
+       struct discover_device  **devices;
+       unsigned int            n_devices;
 };
 
-struct mount_map {
-       char *device_path;
-       char *mount_point;
-};
-
-int device_handler_get_current_devices(struct device_handler *handler,
-       const struct device **devices)
+/**
+ * context_commit - Commit a temporary discovery context to the handler,
+ * and notify the clients about any new options / devices
+ */
+static void context_commit(struct device_handler *handler,
+               struct discover_context *ctx)
 {
-       *devices = handler->devices;
-       return handler->n_devices;
-}
-
-static int mkdir_recursive(const char *dir)
-{
-       struct stat statbuf;
-       char *str, *sep;
-       int mode = 0755;
-
-       if (!*dir)
-               return 0;
-
-       if (!stat(dir, &statbuf)) {
-               if (!S_ISDIR(statbuf.st_mode)) {
-                       pb_log("%s: %s exists, but isn't a directory\n",
-                                       __func__, dir);
-                       return -1;
+       struct discover_device *dev = ctx->device;
+       struct discover_boot_option *opt, *tmp;
+       unsigned int i, existing_device;
+
+       /* do we already have this device? */
+       for (i = 0; i < handler->n_devices; i++) {
+               if (ctx->device == handler->devices[i]) {
+                       existing_device = 1;
+                       break;
                }
-               return 0;
        }
 
-       str = talloc_strdup(NULL, dir);
-       sep = strchr(*str == '/' ? str + 1 : str, '/');
-
-       while (1) {
-
-               /* terminate the path at sep */
-               if (sep)
-                       *sep = '\0';
+       /* if not already present, add the device to the handler's array */
+       if (!existing_device) {
+               handler->n_devices++;
+               handler->devices = talloc_realloc(handler, handler->devices,
+                       struct discover_device *, handler->n_devices);
+               handler->devices[handler->n_devices - 1] = dev;
+               talloc_steal(handler, dev);
 
-               if (mkdir(str, mode) && errno != EEXIST) {
-                       pb_log("mkdir(%s): %s\n", str, strerror(errno));
-                       return -1;
-               }
-
-               if (!sep)
-                       break;
-
-               /* reset dir to the full path */
-               strcpy(str, dir);
-               sep = strchr(sep + 1, '/');
+               discover_server_notify_device_add(handler->server, dev->device);
        }
 
-       talloc_free(str);
 
-       return 0;
+       /* move boot options from the context to the device */
+       list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
+               list_remove(&opt->list);
+               list_add(&dev->boot_options, &opt->list);
+               talloc_steal(dev, opt);
+               discover_server_notify_boot_option_add(handler->server,
+                                                       opt->option);
+       }
 }
 
-static int rmdir_recursive(const char *base, const char *dir)
+void discover_context_add_boot_option(struct discover_context *ctx,
+               struct discover_boot_option *boot_option)
 {
-       char *cur, *pos;
-
-       /* sanity check: make sure that dir is within base */
-       if (strncmp(base, dir, strlen(base)))
-               return -1;
-
-       cur = talloc_strdup(NULL, dir);
+       list_add(&ctx->boot_options, &boot_option->list);
+       talloc_steal(ctx, boot_option);
+}
 
-       while (strcmp(base, dir)) {
+/**
+ * device_handler_remove - Remove a device from the handler device array.
+ */
 
-               rmdir(dir);
+static void device_handler_remove(struct device_handler *handler,
+       struct discover_device *device)
+{
+       unsigned int i;
 
-               /* null-terminate at the last slash */
-               pos = strrchr(dir, '/');
-               if (!pos)
+       for (i = 0; i < handler->n_devices; i++)
+               if (handler->devices[i] == device)
                        break;
 
-               *pos = '\0';
+       if (i == handler->n_devices) {
+               assert(0 && "unknown device");
+               return;
        }
 
-       talloc_free(cur);
+       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 discover_device *, handler->n_devices);
 
-       return 0;
-}
+       discover_server_notify_device_remove(handler->server, device->device);
 
-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
-               }
-       };
-
-       for (link = links; link->env; link++) {
-               char *enc, *dir, *path;
-               const char *value;
-
-               value = udev_event_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 (!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(device);
+}
 
-               }
+/**
+ * device_handler_get_device_count - Get the count of current handler devices.
+ */
 
-               talloc_free(dir);
-               talloc_free(enc);
-       }
+int device_handler_get_device_count(const struct device_handler *handler)
+{
+       return handler->n_devices;
 }
 
-static void remove_device_links(struct discover_context *ctx)
+/**
+ * device_handler_get_device - Get a handler device by index.
+ */
+
+const struct discover_device *device_handler_get_device(
+       const struct device_handler *handler, unsigned int index)
 {
-       int i;
+       if (index >= handler->n_devices) {
+               assert(0 && "bad index");
+               return NULL;
+       }
 
-       for (i = 0; i < ctx->n_links; i++)
-               unlink(ctx->links[i]);
+       return handler->devices[index];
 }
 
-static int mount_device(struct discover_context *ctx)
+static int mount_device(struct discover_device *dev)
 {
-       const char *mountpoint;
-       int status;
-       pid_t pid;
+       const char *argv[6];
 
-       if (!ctx->mount_path) {
-               mountpoint = mountpoint_for_device(ctx->device_path);
-               ctx->mount_path = talloc_strdup(ctx, mountpoint);
-       }
+       if (!dev->mount_path)
+               dev->mount_path = join_paths(dev, mount_base(),
+                                               dev->device_path);
 
-       if (mkdir_recursive(ctx->mount_path))
+       if (pb_mkdir_recursive(dev->mount_path))
                pb_log("couldn't create mount directory %s: %s\n",
-                               ctx->mount_path, strerror(errno));
+                               dev->mount_path, strerror(errno));
 
-       pid = fork();
-       if (pid == -1) {
-               pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
-               goto out_rmdir;
-       }
+       argv[0] = pb_system_apps.mount;
+       argv[1] = dev->device_path;
+       argv[2] = dev->mount_path;
+       argv[3] = "-o";
+       argv[4] = "ro";
+       argv[5] = NULL;
 
-       if (pid == 0) {
-               execl(MOUNT_BIN, MOUNT_BIN, ctx->device_path, ctx->mount_path,
-                               "-o", "ro", NULL);
-               exit(EXIT_FAILURE);
-       }
+       if (pb_run_cmd(argv, 1, 0)) {
 
-       if (waitpid(pid, &status, 0) == -1) {
-               pb_log("%s: waitpid failed: %s\n", __func__,
-                               strerror(errno));
-               goto out_rmdir;
-       }
+               /* Retry mount without ro option. */
 
-       if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-               pb_log("%s: mount failed (%d): %s\n", __func__,
-                       WEXITSTATUS(status), ctx->event->device);
-               goto out_rmdir;
+               argv[0] = pb_system_apps.mount;
+               argv[1] = dev->device_path;
+               argv[2] = dev->mount_path;
+               argv[3] = NULL;
+
+               if (pb_run_cmd(argv, 1, 0))
+                       goto out_rmdir;
        }
 
-       setup_device_links(ctx);
        return 0;
 
 out_rmdir:
-       rmdir_recursive(mount_base(), ctx->mount_path);
+       pb_rmdir_recursive(mount_base(), dev->mount_path);
        return -1;
 }
 
-static int umount_device(struct discover_context *ctx)
+static int umount_device(struct discover_device *dev)
 {
        int status;
        pid_t pid;
 
-       remove_device_links(ctx);
+       if (!dev->mount_path)
+               return 0;
 
        pid = fork();
        if (pid == -1) {
@@ -235,7 +184,8 @@ static int umount_device(struct discover_context *ctx)
        }
 
        if (pid == 0) {
-               execl(UMOUNT_BIN, UMOUNT_BIN, ctx->mount_path, NULL);
+               execl(pb_system_apps.umount, pb_system_apps.umount,
+                                               dev->mount_path, NULL);
                exit(EXIT_FAILURE);
        }
 
@@ -248,115 +198,202 @@ static int umount_device(struct discover_context *ctx)
        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
                return -1;
 
-       rmdir_recursive(mount_base(), ctx->mount_path);
+       pb_rmdir_recursive(mount_base(), dev->mount_path);
 
        return 0;
 }
 
-static struct discover_context *find_context(struct device_handler *handler,
+static struct discover_device *find_device(struct device_handler *handler,
                const char *id)
 {
-       struct discover_context *ctx;
+       struct discover_device *dev;
+       unsigned int i;
 
-       list_for_each_entry(&handler->contexts, ctx, list) {
-               if (!strcmp(ctx->id, id))
-                       return ctx;
+       for (i = 0; i < handler->n_devices; i++) {
+               dev = handler->devices[i];
+               if (!strcmp(dev->device->id, id))
+                       return dev;
        }
 
        return NULL;
 }
 
-static int destroy_context(void *arg)
+static int destroy_device(void *arg)
 {
-       struct discover_context *ctx = arg;
+       struct discover_device *dev = arg;
 
-       list_remove(&ctx->list);
-       umount_device(ctx);
+       umount_device(dev);
 
        return 0;
 }
 
-static int handle_add_event(struct device_handler *handler,
-               struct udev_event *event)
+static struct discover_device *discover_device_create(
+               struct device_handler *handler,
+               struct discover_context *ctx,
+               struct event *event)
 {
-       struct discover_context *ctx;
+       struct discover_device *dev;
        const char *devname;
+
+       dev = find_device(handler, event->device);
+       if (dev)
+               return dev;
+
+       dev = talloc_zero(ctx, struct discover_device);
+       dev->device = talloc_zero(dev, struct device);
+       list_init(&dev->boot_options);
+
+       devname = event_get_param(ctx->event, "DEVNAME");
+       if (devname)
+               dev->device_path = talloc_strdup(dev, devname);
+
+       dev->device->id = talloc_strdup(dev, event->device);
+
+       talloc_set_destructor(dev, destroy_device);
+
+       return dev;
+}
+
+struct discover_boot_option *discover_boot_option_create(
+               struct discover_context *ctx,
+               struct discover_device *device)
+{
+       struct discover_boot_option *opt;
+
+       opt = talloc_zero(ctx, struct discover_boot_option);
+       opt->option = talloc_zero(opt, struct boot_option);
+       opt->device = device;
+
+       return opt;
+}
+
+
+static int handle_add_udev_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct discover_context *ctx;
+       struct discover_device *dev;
+       const char *param;
        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;
+       list_init(&ctx->boot_options);
 
-       ctx->id = talloc_strdup(ctx, event->device);
+       /* create our top-level device */
+       dev = discover_device_create(handler, ctx, event);
 
-       devname = udev_event_param(ctx->event, "DEVNAME");
-       if (!devname) {
-               pb_log("no devname for %s?\n", event->device);
-               return 0;
-       }
+       ctx->device = dev;
+
+       /* try to parse UUID and labels */
+       param = event_get_param(ctx->event, "ID_FS_UUID");
+       if (param)
+               dev->uuid = talloc_strdup(dev, param);
 
-       ctx->device_path = talloc_strdup(ctx, devname);
+       param = event_get_param(ctx->event, "ID_FS_LABEL");
+       if (param)
+               dev->label = talloc_strdup(dev, param);
 
-       rc = mount_device(ctx);
+       rc = mount_device(dev);
        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 */
+       /* run the parsers. This will populate the ctx's boot_option list. */
        iterate_parsers(ctx);
 
-       discover_server_notify_add(handler->server, ctx->device);
+       /* add discovered stuff to the handler */
+       context_commit(handler, ctx);
+
+       talloc_free(ctx);
 
        return 0;
 }
 
-static int handle_remove_event(struct device_handler *handler,
-               struct udev_event *event)
+static int handle_remove_udev_event(struct device_handler *handler,
+               struct event *event)
 {
-       struct discover_context *ctx;
+       struct discover_device *dev;
 
-       ctx = find_context(handler, event->device);
-       if (!ctx)
+       dev = find_device(handler, event->device);
+       if (!dev)
                return 0;
 
-       discover_server_notify_remove(handler->server, ctx->device);
-
-       talloc_free(ctx);
+       /* remove device from handler device array */
+       device_handler_remove(handler, dev);
 
        return 0;
 }
 
-int device_handler_event(struct device_handler *handler,
-               struct udev_event *event)
+static int handle_add_user_event(struct device_handler *handler,
+               struct event *event)
 {
+       struct discover_context *ctx;
+       struct discover_device *dev;
        int rc;
 
-       switch (event->action) {
-       case UDEV_ACTION_ADD:
-               rc = handle_add_event(handler, event);
-               break;
+       assert(event->device);
 
-       case UDEV_ACTION_REMOVE:
-               rc = handle_remove_event(handler, event);
-               break;
-       }
+       ctx = talloc(handler, struct discover_context);
+       ctx->event = event;
+       list_init(&ctx->boot_options);
+
+       dev = discover_device_create(handler, ctx, event);
+       ctx->device = dev;
+
+       rc = parse_user_event(ctx, event);
+
+       if (!rc)
+               context_commit(handler, ctx);
 
        return rc;
 }
 
-struct device_handler *device_handler_init(struct discover_server *server)
+static int handle_remove_user_event(struct device_handler *handler,
+               struct event *event)
+{
+       struct discover_device *dev = find_device(handler, event->device);
+
+       if (!dev)
+               return 0;
+
+       /* remove device from handler device array */
+       device_handler_remove(handler, dev);
+
+       return 0;
+}
+
+typedef int (*event_handler)(struct device_handler *, struct event *);
+
+static event_handler handlers[EVENT_TYPE_MAX][EVENT_ACTION_MAX] = {
+       [EVENT_TYPE_UDEV] = {
+               [EVENT_ACTION_ADD]      = handle_add_udev_event,
+               [EVENT_ACTION_REMOVE]   = handle_remove_udev_event,
+       },
+       [EVENT_TYPE_USER] = {
+               [EVENT_ACTION_ADD]      = handle_add_user_event,
+               [EVENT_ACTION_REMOVE]   = handle_remove_user_event,
+       }
+};
+
+int device_handler_event(struct device_handler *handler,
+               struct event *event)
+{
+       if (event->type >= EVENT_TYPE_MAX ||
+                       event->action >= EVENT_ACTION_MAX ||
+                       !handlers[event->type][event->action]) {
+               pb_log("%s unknown type/action: %d/%d\n", __func__,
+                               event->type, event->action);
+               return 0;
+       }
+
+       return handlers[event->type][event->action](handler, event);
+}
+
+struct device_handler *device_handler_init(struct discover_server *server,
+               int dry_run)
 {
        struct device_handler *handler;
 
@@ -364,11 +401,10 @@ struct device_handler *device_handler_init(struct discover_server *server)
        handler->devices = NULL;
        handler->n_devices = 0;
        handler->server = server;
-
-       list_init(&handler->contexts);
+       handler->dry_run = dry_run;
 
        /* set up our mount point base */
-       mkdir_recursive(mount_base());
+       pb_mkdir_recursive(mount_base());
 
        parser_init();
 
@@ -379,3 +415,117 @@ void device_handler_destroy(struct device_handler *handler)
 {
        talloc_free(handler);
 }
+
+static int device_match_path(struct discover_device *dev, const char *path)
+{
+       return !strcmp(dev->device_path, path);
+}
+
+static int device_match_uuid(struct discover_device *dev, const char *uuid)
+{
+       return dev->uuid && !strcmp(dev->uuid, uuid);
+}
+
+static int device_match_label(struct discover_device *dev, const char *label)
+{
+       return dev->label && !strcmp(dev->label, label);
+}
+
+static int device_match_id(struct discover_device *dev, const char *id)
+{
+       return !strcmp(dev->device->id, id);
+}
+
+static struct discover_device *device_lookup(
+               struct device_handler *device_handler,
+               int (match_fn)(struct discover_device *, const char *),
+               const char *str)
+{
+       struct discover_device *dev;
+       unsigned int i;
+
+       if (!str)
+               return NULL;
+
+       for (i = 0; i < device_handler->n_devices; i++) {
+               dev = device_handler->devices[i];
+
+               if (match_fn(dev, str))
+                       return dev;
+       }
+
+       return NULL;
+}
+
+struct discover_device *device_lookup_by_name(struct device_handler *handler,
+               const char *name)
+{
+       struct discover_device *dev;
+       char *path;
+
+       if (strncmp(name, "/dev/", strlen("/dev/")))
+               path = talloc_asprintf(NULL, "/dev/%s", name);
+       else
+               path = talloc_strdup(NULL, name);
+
+       dev = device_lookup_by_path(handler, path);
+
+       talloc_free(path);
+
+       return dev;
+}
+
+struct discover_device *device_lookup_by_path(
+               struct device_handler *device_handler,
+               const char *path)
+{
+       return device_lookup(device_handler, device_match_path, path);
+}
+
+struct discover_device *device_lookup_by_uuid(
+               struct device_handler *device_handler,
+               const char *uuid)
+{
+       return device_lookup(device_handler, device_match_uuid, uuid);
+}
+
+struct discover_device *device_lookup_by_label(
+               struct device_handler *device_handler,
+               const char *label)
+{
+       return device_lookup(device_handler, device_match_label, label);
+}
+
+struct discover_device *device_lookup_by_id(
+               struct device_handler *device_handler,
+               const char *id)
+{
+       return device_lookup(device_handler, device_match_id, id);
+}
+
+static struct discover_boot_option *find_boot_option_by_id(
+               struct device_handler *handler, const char *id)
+{
+       unsigned int i;
+
+       for (i = 0; i < handler->n_devices; i++) {
+               struct discover_device *dev = handler->devices[i];
+               struct discover_boot_option *opt;
+
+               list_for_each_entry(&dev->boot_options, opt, list)
+                       if (!strcmp(opt->option->id, id))
+                               return opt;
+       }
+
+       return NULL;
+}
+
+void device_handler_boot(struct device_handler *handler,
+               struct boot_command *cmd)
+{
+       struct discover_boot_option *opt;
+
+       opt = find_boot_option_by_id(handler, cmd->option_id);
+
+       boot(handler, opt, cmd, handler->dry_run);
+}