From af5ef029fe96a8703a1de7a60063c473d17d37a4 Mon Sep 17 00:00:00 2001
From: Martin Kutlak <mkutlak@redhat.com>
Date: Tue, 21 May 2019 10:45:55 +0200
Subject: [PATCH] dd: introduce dd_get_env_variable

I was thinking about adding 'dd_open_element' function returning file
descriptor but I thrown this idea because we should try to hide
implementation details and do not let users to parse elements on their
own.

Cherry-picked from https://github.com/abrt/libreport/commit/a1d7a0397b8251be58783dd5e8665099bf8ce868
---
 src/include/dump_dir.h | 11 +++++++++++
 src/lib/dump_dir.c     | 11 +++++++++++
 tests/dump_dir.at      | 31 +++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/src/include/dump_dir.h b/src/include/dump_dir.h
index b617c6c..a7ed431 100644
--- a/src/include/dump_dir.h
+++ b/src/include/dump_dir.h
@@ -118,6 +118,17 @@ int dd_get_next_file(struct dump_dir *dd, char **short_name, char **full_name);
 
 char* dd_load_text_ext(const struct dump_dir *dd, const char *name, unsigned flags);
 char* dd_load_text(const struct dump_dir *dd, const char *name);
+
+/* Returns value of environment variable with given name.
+ *
+ * @param dd Dump directory
+ * @param name Variables's name
+ * @param value Return value.
+ * @return 0 no success, or negative value if an error occurred (-ENOENT if the
+ * given dd does not support environment variables).
+ */
+int dd_get_env_variable(struct dump_dir *dd, const char *name, char **value);
+
 void dd_save_text(struct dump_dir *dd, const char *name, const char *data);
 void dd_save_binary(struct dump_dir *dd, const char *name, const char *data, unsigned size);
 int dd_copy_file(struct dump_dir *dd, const char *name, const char *source_path);
diff --git a/src/lib/dump_dir.c b/src/lib/dump_dir.c
index 5e32c08..0da96cd 100644
--- a/src/lib/dump_dir.c
+++ b/src/lib/dump_dir.c
@@ -1242,6 +1242,17 @@ char* dd_load_text(const struct dump_dir *dd, const char *name)
     return dd_load_text_ext(dd, name, /*flags:*/ 0);
 }
 
+int dd_get_env_variable(struct dump_dir *dd, const char *name, char **value)
+{
+    const int fd = openat(dd->dd_fd, FILENAME_ENVIRON, O_RDONLY | O_NOFOLLOW);
+    if (fd < 0)
+        return -errno;
+
+    const int r  = get_env_variable_ext(fd, '\n', name, value);
+    close(fd);
+    return r;
+}
+
 void dd_save_text(struct dump_dir *dd, const char *name, const char *data)
 {
     if (!dd->locked)
diff --git a/tests/dump_dir.at b/tests/dump_dir.at
index 98d564c..12a0c5c 100644
--- a/tests/dump_dir.at
+++ b/tests/dump_dir.at
@@ -615,3 +615,34 @@ int main(int argc, char **argv)
     return 0;
 }
 ]])
+## ------------------- ##
+## dd_get_env_variable ##
+## ------------------- ##
+
+AT_TESTFUN([dd_get_env_variable],
+[[
+#include "testsuite.h"
+#include "testsuite_tools.h"
+
+TS_MAIN
+{
+    struct dump_dir *dd = testsuite_dump_dir_create(-1, -1, 0);
+
+    dd_create_basic_files(dd, geteuid(), NULL);
+
+    char *value = NULL;
+    TS_ASSERT_SIGNED_EQ(dd_get_env_variable(dd, "FROG", &value), -ENOENT);
+    TS_ASSERT_PTR_IS_NULL_MESSAGE(value, "Untouched return value on -ENOENT");
+
+    dd_save_text(dd, FILENAME_ENVIRON, "FROG=ribbit\nROOSTER=cockle-doodle-doo");
+
+    TS_ASSERT_FUNCTION(dd_get_env_variable(dd, "HORSE", &value));
+    TS_ASSERT_PTR_IS_NULL_MESSAGE(value, "Untouched return value on missing variable");
+
+    TS_ASSERT_FUNCTION(dd_get_env_variable(dd, "ROOSTER", &value));
+    TS_ASSERT_STRING_EQ(value, "cockle-doodle-doo", "Variable ROOSTER loaded from the dump dir");
+
+    testsuite_dump_dir_delete(dd);
+}
+TS_RETURN_MAIN
+]])
-- 
2.21.0