remote: Add "ostree remote summary" command

Downloads and prints a remote summary file and any signatures in an
easy-to-read format, or alternatively with the --raw option, prints
the summary GVariant data directly.

https://bugzilla.gnome.org/show_bug.cgi?id=759250

src/ostree/ot-builtin-remote.c

@@ -38,6 +38,7 @@ static OstreeRemoteCommand remote_subcommands[] = {
   { "list", ot_remote_builtin_list },
   { "gpg-import", ot_remote_builtin_gpg_import },
   { "refs", ot_remote_builtin_refs },
+  { "summary", ot_remote_builtin_summary },
   { NULL, NULL }
 };
 

src/ostree/ot-dump.c

@@ -153,3 +153,102 @@ ot_dump_object (OstreeObjectType   objtype,
       break;
   }
 }
+
+static void
+dump_summary_ref (const char   *ref_name,
+                  guint64       commit_size,
+                  GVariant     *csum_v,
+                  GVariantIter *metadata)
+{
+  const guchar *csum_bytes;
+  GError *csum_error = NULL;
+  g_autofree char *size = NULL;
+  GVariant *value;
+  char *key;
+
+  g_print ("* %s\n", ref_name);
+
+  size = g_format_size (commit_size);
+  g_print ("    Latest Commit (%s):\n", size);
+
+  csum_bytes = ostree_checksum_bytes_peek_validate (csum_v, &csum_error);
+  if (csum_error == NULL)
+    {
+      char csum[65];
+
+      ostree_checksum_inplace_from_bytes (csum_bytes, csum);
+      g_print ("      %s\n", csum);
+    }
+  else
+    {
+      g_print ("      %s\n", csum_error->message);
+      g_clear_error (&csum_error);
+    }
+
+  while (g_variant_iter_loop (metadata, "{sv}", &key, &value))
+    {
+      g_autofree char *string = g_variant_print (value, FALSE);
+      g_print ("    %s: %s\n", key, string);
+    }
+}
+
+void
+ot_dump_summary_bytes (GBytes          *summary_bytes,
+                       OstreeDumpFlags  flags)
+{
+  g_autoptr(GVariant) summary = NULL;
+  g_autoptr(GVariant) refs = NULL;
+  g_autoptr(GVariant) exts = NULL;
+  GVariantIter iter;
+  GVariant *value;
+  char *key;
+
+  g_return_if_fail (summary_bytes != NULL);
+
+  summary = g_variant_new_from_bytes (OSTREE_SUMMARY_GVARIANT_FORMAT,
+                                      summary_bytes, FALSE);
+
+  if (flags & OSTREE_DUMP_RAW)
+    {
+      ot_dump_variant (summary);
+      return;
+    }
+
+  refs = g_variant_get_child_value (summary, 0);
+  exts = g_variant_get_child_value (summary, 1);
+
+  g_variant_iter_init (&iter, refs);
+
+  while ((value = g_variant_iter_next_value (&iter)) != NULL)
+    {
+      const char *ref_name = NULL;
+
+      g_variant_get_child (value, 0, "&s", &ref_name);
+
+      if (ref_name != NULL)
+        {
+          g_autoptr(GVariant) csum_v = NULL;
+          g_autoptr(GVariantIter) metadata = NULL;
+          guint64 commit_size;
+
+          g_variant_get_child (value, 1, "(t@aya{sv})",
+                               &commit_size, &csum_v, &metadata);
+
+          dump_summary_ref (ref_name, commit_size, csum_v, metadata);
+
+          g_print ("\n");
+        }
+
+      g_variant_unref (value);
+    }
+
+  g_variant_iter_init (&iter, exts);
+
+  /* XXX Should we print something more human-friendly for
+   *     known extension names like 'ostree.static-deltas'? */
+  while (g_variant_iter_loop (&iter, "{sv}", &key, &value))
+    {
+      g_autofree char *string = g_variant_print (value, FALSE);
+      g_print ("%s: %s\n", key, string);
+    }
+}

src/ostree/ot-dump.h

@@ -37,3 +37,6 @@ void   ot_dump_object     (OstreeObjectType   objtype,
                            const char        *checksum,
                            GVariant          *variant,
                            OstreeDumpFlags    flags);
+
+void   ot_dump_summary_bytes  (GBytes          *summary_bytes,
+                               OstreeDumpFlags  flags);

src/ostree/ot-remote-builtin-summary.c

@@ -0,0 +1,119 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "otutil.h"
+
+#include "ot-main.h"
+#include "ot-dump.h"
+#include "ot-remote-builtins.h"
+
+static gboolean opt_raw;
+
+static GOptionEntry option_entries[] = {
+  { "raw", 0, 0, G_OPTION_ARG_NONE, &opt_raw, "Show raw variant data", NULL },
+  { NULL }
+};
+
+gboolean
+ot_remote_builtin_summary (int argc, char **argv, GCancellable *cancellable, GError **error)
+{
+  GOptionContext *context;
+  glnx_unref_object OstreeRepo *repo = NULL;
+  const char *remote_name;
+  g_autoptr(GBytes) summary_bytes = NULL;
+  g_autoptr(GBytes) signature_bytes = NULL;
+  OstreeDumpFlags flags = OSTREE_DUMP_NONE;
+  gboolean gpg_verify_summary;
+  gboolean ret = FALSE;
+
+  context = g_option_context_new ("NAME - Show remote summary");
+
+  if (!ostree_option_context_parse (context, option_entries, &argc, &argv,
+                                    OSTREE_BUILTIN_FLAG_NONE, &repo, cancellable, error))
+    goto out;
+
+  if (argc < 2)
+    {
+      ot_util_usage_error (context, "NAME must be specified", error);
+      goto out;
+    }
+
+  remote_name = argv[1];
+
+  if (opt_raw)
+    flags |= OSTREE_DUMP_RAW;
+
+  if (!ostree_repo_remote_fetch_summary (repo, remote_name,
+                                         &summary_bytes,
+                                         &signature_bytes,
+                                         cancellable, error))
+    goto out;
+
+  if (summary_bytes == NULL)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Remote server has no summary file");
+      goto out;
+    }
+
+  ot_dump_summary_bytes (summary_bytes, flags);
+
+  if (!ostree_repo_remote_get_gpg_verify_summary (repo, remote_name,
+                                                  &gpg_verify_summary,
+                                                  error))
+    goto out;
+
+  if (!gpg_verify_summary)
+    g_clear_pointer (&signature_bytes, g_bytes_unref);
+
+  /* XXX Note we don't show signatures for "--raw".  My intuition is
+   *     if someone needs to see or parse raw summary data, including
+   *     signatures in the output would probably just interfere.
+   *     If there's demand for it I suppose we could introduce a new
+   *     option for raw signature data like "--raw-signatures". */
+  if (signature_bytes != NULL && !opt_raw)
+    {
+      glnx_unref_object OstreeGpgVerifyResult *result = NULL;
+
+      /* The actual signed summary verification happens above in
+       * ostree_repo_remote_fetch_summary().  Here we just parse
+       * the signatures again for the purpose of printing. */
+      result = ostree_repo_verify_summary (repo,
+                                           remote_name,
+                                           summary_bytes,
+                                           signature_bytes,
+                                           cancellable,
+                                           error);
+      if (result == NULL)
+        goto out;
+
+      g_print ("\n");
+      ostree_print_gpg_verify_result (result);
+    }
+
+  ret = TRUE;
+
+out:
+  g_option_context_free (context);
+
+  return ret;
+}

src/ostree/ot-remote-builtins.h

@@ -30,5 +30,6 @@ gboolean ot_remote_builtin_gpg_import (int argc, char **argv, GCancellable *canc
 gboolean ot_remote_builtin_list (int argc, char **argv, GCancellable *cancellable, GError **error);
 gboolean ot_remote_builtin_show_url (int argc, char **argv, GCancellable *cancellable, GError **error);
 gboolean ot_remote_builtin_refs (int argc, char **argv, GCancellable *cancellable, GError **error);
+gboolean ot_remote_builtin_summary (int argc, char **argv, GCancellable *cancellable, GError **error);
 
 G_END_DECLS