Add process_reset_environment() to the Process subsystem.

This patch adds a new function that allows us to reset the environment
of a given process_t with a list of key/value pairs.

See: https://bugs.torproject.org/28179

2 files changed, 18 insertions, 0 deletions

diff --git a/src/lib/process/process.c b/src/lib/process/process.c
index 657b319f54..915217e132 100644
--- a/src/lib/process/process.c
+++ b/src/lib/process/process.c
@@ -441,6 +441,23 @@ process_get_argv(const process_t *process)
   return argv;
 }
 
+/** This function clears the internal environment and copies over every string
+ * from <b>env</b> as the new environment. */
+void
+process_reset_environment(process_t *process, const smartlist_t *env)
+{
+  tor_assert(process);
+  tor_assert(env);
+
+  /* Cleanup old environment. */
+  SMARTLIST_FOREACH(process->environment, char *, x, tor_free(x));
+  smartlist_free(process->environment);
+  process->environment = smartlist_new();
+
+  SMARTLIST_FOREACH(env, char *, x,
+                    smartlist_add(process->environment, tor_strdup(x)));
+}
+
 /** Set the given <b>key</b>/<b>value</b> pair as environment variable in the
  * given process. */
 void
diff --git a/src/lib/process/process.h b/src/lib/process/process.h
index c6b733a065..6092c2da7d 100644
--- a/src/lib/process/process.h
+++ b/src/lib/process/process.h
@@ -83,6 +83,7 @@ void process_append_argument(process_t *process, const char *argument);
 const smartlist_t *process_get_arguments(const process_t *process);
 char **process_get_argv(const process_t *process);
 
+void process_reset_environment(process_t *process, const smartlist_t *env);
 void process_set_environment(process_t *process,
                              const char *key,
                              const char *value);