1 files changed, 131 insertions, 0 deletions
diff --git a/libdwfl/debuginfod-client.c b/libdwfl/debuginfod-client.c
new file mode 100644
index 00000000..ee604ad9
--- /dev/null
+++ b/libdwfl/debuginfod-client.c
@@ -0,0 +1,131 @@
+/* Try to get an ELF or debug file through the debuginfod.
+   Copyright (C) 2019 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwflP.h"
+#include <dlfcn.h>
+
+static __typeof__ (debuginfod_begin) *fp_debuginfod_begin;
+static __typeof__ (debuginfod_find_executable) *fp_debuginfod_find_executable;
+static __typeof__ (debuginfod_find_debuginfo) *fp_debuginfod_find_debuginfo;
+static __typeof__ (debuginfod_end) *fp_debuginfod_end;
+
+/* NB: this is slightly thread-unsafe */
+
+static debuginfod_client *
+get_client (Dwfl *dwfl)
+{
+  if (dwfl->debuginfod != NULL)
+    return dwfl->debuginfod;
+
+  if (fp_debuginfod_begin != NULL)
+    {
+      dwfl->debuginfod = (*fp_debuginfod_begin) ();
+      return dwfl->debuginfod;
+    }
+
+  return NULL;
+}
+
+int
+__libdwfl_debuginfod_find_executable (Dwfl *dwfl,
+				      const unsigned char *build_id_bits,
+				      size_t build_id_len)
+{
+  int fd = -1;
+  if (build_id_len > 0)
+    {
+      debuginfod_client *c = get_client (dwfl);
+      if (c != NULL)
+	fd = (*fp_debuginfod_find_executable) (c, build_id_bits,
+					       build_id_len, NULL);
+    }
+
+  return fd;
+}
+
+int
+__libdwfl_debuginfod_find_debuginfo (Dwfl *dwfl,
+				     const unsigned char *build_id_bits,
+				     size_t build_id_len)
+{
+  int fd = -1;
+  if (build_id_len > 0)
+    {
+      debuginfod_client *c = get_client (dwfl);
+      if (c != NULL)
+	fd = (*fp_debuginfod_find_debuginfo) (c, build_id_bits,
+					      build_id_len, NULL);
+    }
+
+  return fd;
+}
+
+void
+__libdwfl_debuginfod_end (debuginfod_client *c)
+{
+  if (c != NULL)
+    (*fp_debuginfod_end) (c);
+}
+
+/* Try to get the libdebuginfod library functions to make sure
+   everything is initialized early.  */
+void __attribute__ ((constructor))
+__libdwfl_debuginfod_init (void)
+{
+  void *debuginfod_so = dlopen("libdebuginfod-" VERSION ".so", RTLD_LAZY);
+
+  if (debuginfod_so == NULL)
+    debuginfod_so = dlopen("libdebuginfod.so", RTLD_LAZY);
+
+  if (debuginfod_so != NULL)
+    {
+      fp_debuginfod_begin = dlsym (debuginfod_so, "debuginfod_begin");
+      fp_debuginfod_find_executable = dlsym (debuginfod_so,
+					     "debuginfod_find_executable");
+      fp_debuginfod_find_debuginfo = dlsym (debuginfod_so,
+					    "debuginfod_find_debuginfo");
+      fp_debuginfod_end = dlsym (debuginfod_so, "debuginfod_end");
+
+      /* We either get them all, or we get none.  */
+      if (fp_debuginfod_begin == NULL
+	  || fp_debuginfod_find_executable == NULL
+	  || fp_debuginfod_find_debuginfo == NULL
+	  || fp_debuginfod_end == NULL)
+	{
+	  fp_debuginfod_begin = NULL;
+	  fp_debuginfod_find_executable = NULL;
+	  fp_debuginfod_find_debuginfo = NULL;
+	  fp_debuginfod_end = NULL;
+	  dlclose (debuginfod_so);
+	}
+    }
+}