Use a list for device->boot_options
[petitboot] / discover / device-handler.c
index 0e902df6b86ed4c1805868617cf7db85abb08bf7..1f8938f295b322e68b2df19fb7eeadd8146b1ca1 100644 (file)
@@ -1,31 +1,50 @@
 
+#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 <pb-protocol/pb-protocol.h>
 
 #include "device-handler.h"
+#include "udev.h"
+#include "log.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 list contexts;
 };
 
-struct device_handler *device_handler_init(struct discover_server *server)
-{
-       struct device_handler *handler;
+struct discover_context {
+       char *id;
+       char *device_path;
+       char *mount_path;
+       struct udev_event *event;
+       struct device *device;
+       char **links;
+       int n_links;
 
-       handler = talloc(NULL, struct device_handler);
-       handler->devices = NULL;
-       handler->n_devices = 0;
+       struct list_item list;
+};
 
-       return handler;
-}
+struct mount_map {
+       char *device_path;
+       char *mount_point;
+};
 
-void device_handler_destroy(struct device_handler *devices)
-{
-       talloc_free(devices);
-}
 
 static struct boot_option options[] = {
        {
@@ -42,8 +61,6 @@ static struct device device = {
        .name = "meep",
        .description = "meep description",
        .icon_file = "meep.png",
-       .n_options = 1,
-       .options = options,
 };
 
 int device_handler_get_current_devices(struct device_handler *handler,
@@ -54,9 +71,333 @@ int device_handler_get_current_devices(struct device_handler *handler,
        return 1;
 }
 
+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;
+               }
+               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 (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, '/');
+       }
+
+       talloc_free(str);
+
+       return 0;
+}
+
+static int rmdir_recursive(const char *base, const char *dir)
+{
+       char *cur, *pos;
 
-int device_handler_event(struct device_handler *handler,
+       /* sanity check: make sure that dir is within base */
+       if (strncmp(base, dir, strlen(base)))
+               return -1;
+
+       cur = talloc_strdup(NULL, dir);
+
+       while (strcmp(base, dir)) {
+
+               rmdir(dir);
+
+               /* null-terminate at the last slash */
+               pos = strrchr(dir, '/');
+               if (!pos)
+                       break;
+
+               *pos = '\0';
+       }
+
+       talloc_free(cur);
+
+       return 0;
+}
+
+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(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;
+       int status;
+       pid_t pid;
+
+       if (!ctx->mount_path) {
+               mountpoint = mountpoint_for_device(ctx->device_path);
+               ctx->mount_path = talloc_strdup(ctx, mountpoint);
+       }
+
+       if (mkdir_recursive(ctx->mount_path))
+               pb_log("couldn't create mount directory %s: %s\n",
+                               ctx->mount_path, strerror(errno));
+
+       pid = fork();
+       if (pid == -1) {
+               pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
+               goto out_rmdir;
+       }
+
+       if (pid == 0) {
+               execl(MOUNT_BIN, MOUNT_BIN, ctx->device_path, ctx->mount_path,
+                               "-o", "ro", NULL);
+               exit(EXIT_FAILURE);
+       }
+
+       if (waitpid(pid, &status, 0) == -1) {
+               pb_log("%s: waitpid failed: %s\n", __func__,
+                               strerror(errno));
+               goto out_rmdir;
+       }
+
+       if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+               goto out_rmdir;
+
+       setup_device_links(ctx);
+       return 0;
+
+out_rmdir:
+       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;
+
+       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_event(struct device_handler *handler,
+               struct udev_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 = udev_event_param(ctx->event, "DEVNAME");
+       if (!devname) {
+               pb_log("no devname for %s?\n", event->device);
+               return 0;
+       }
+
+       ctx->device_path = talloc_strdup(ctx, devname);
+
+       rc = mount_device(ctx);
+       if (rc) {
+               pb_log("mount_device failed for %s\n", event->device);
+               talloc_free(ctx);
+               return 0;
+       }
+
+       list_add(&handler->contexts, &ctx->list);
+
+       talloc_set_destructor(ctx, destroy_context);
+
+       return 0;
+}
+
+static int handle_remove_event(struct device_handler *handler,
                struct udev_event *event)
 {
+       struct discover_context *ctx;
+
+       ctx = find_context(handler, event->device);
+       if (!ctx)
+               return 0;
+
+       talloc_free(ctx);
+
        return 0;
 }
+
+int device_handler_event(struct device_handler *handler,
+               struct udev_event *event)
+{
+       int rc;
+
+       switch (event->action) {
+       case UDEV_ACTION_ADD:
+               rc = handle_add_event(handler, event);
+               break;
+
+       case UDEV_ACTION_REMOVE:
+               rc = handle_remove_event(handler, event);
+               break;
+       }
+
+       return rc;
+}
+
+struct device_handler *device_handler_init(struct discover_server *server)
+{
+       struct device_handler *handler;
+       int i;
+
+       handler = talloc(NULL, struct device_handler);
+       handler->devices = NULL;
+       handler->n_devices = 0;
+
+       list_init(&handler->contexts);
+
+       /* set up our mount point base */
+       mkdir_recursive(mount_base());
+
+       /* setup out test objects */
+       list_init(&device.boot_options);
+
+       for (i = 0; i < sizeof(options) / sizeof(options[0]); i++)
+               list_add(&device.boot_options, &options[i].list);
+
+       return handler;
+}
+
+void device_handler_destroy(struct device_handler *handler)
+{
+       talloc_free(handler);
+}
+