From a105da15cc7393d9b568e32590ab839ee06d2d9d Mon Sep 17 00:00:00 2001
From: Jennifer Richards <jennifer@painless-security.com>
Date: Wed, 18 Apr 2018 13:45:21 -0400
Subject: [PATCH] Track and clean up monitoring processes by pid, fix some
 debug msgs

---
 include/mon_internal.h |  1 +
 mon/mons.c             | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
 tid/tids.c             |  6 +++---
 3 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/include/mon_internal.h b/include/mon_internal.h
index 4dac054..45eb60b 100644
--- a/include/mon_internal.h
+++ b/include/mon_internal.h
@@ -134,6 +134,7 @@ struct mons_instance {
   MONS_AUTH_FUNC *auth_handler;
   void *cookie;
   GPtrArray *handlers;
+  GArray *pids; /* PIDs of active mons processes */
 };
 
 /* Client instance */
diff --git a/mon/mons.c b/mon/mons.c
index 82495ee..f2e69c5 100644
--- a/mon/mons.c
+++ b/mon/mons.c
@@ -46,12 +46,17 @@
 
 #include "mons_handlers.h"
 
+static void mons_sweep_procs(MONS_INSTANCE *mons);
+
 static int mons_destructor(void *object)
 {
   MONS_INSTANCE *mons = talloc_get_type_abort(object, MONS_INSTANCE);
-  if (mons->handlers) {
+  if (mons->handlers)
     g_ptr_array_unref(mons->handlers);
-  }
+
+  if (mons->pids)
+    g_array_unref(mons->pids);
+
   return 0;
 }
 
@@ -88,6 +93,12 @@ MONS_INSTANCE *mons_new(TALLOC_CTX *mem_ctx)
       talloc_free(mons);
       return NULL;
     }
+
+    mons->pids = g_array_new(FALSE, FALSE, sizeof(pid_t));
+    if (mons->pids == NULL) {
+      talloc_free(mons);
+      return NULL;
+    }
   }
   return mons;
 }
@@ -233,12 +244,41 @@ int mons_accept(MONS_INSTANCE *mons, int listen)
     );
     close(conn);
     exit(0); /* exit to kill forked child process */
-  } else {
-    close(conn);
   }
 
+  /* Only the parent process gets here */
+  close(conn);
+  g_array_append_val(mons->pids, pid);
+
   /* clean up any processes that have completed */
-  //while (waitpid(-1, 0, WNOHANG) > 0); TODO: only clean up our own pids
+  mons_sweep_procs(mons);
 
   return 0;
 }
+
+void mons_sweep_procs(MONS_INSTANCE *mons)
+{
+  guint ii;
+  pid_t pid;
+  int status;
+
+  /* loop backwards over the array so we can remove elements as we go */
+  for (ii=mons->pids->len; ii > 0; ii--) {
+    /* ii-1 is the current index */
+    pid = g_array_index(mons->pids, pid_t, ii-1);
+    if (waitpid(pid, &status, WNOHANG) > 0) {
+      /* the process exited */
+      tr_debug("mons_sweep_procs: monitoring process %d terminated.", pid);
+
+      g_array_remove_index_fast(mons->pids, ii-1); /* disturbs only indices >= ii-1 which we've already handled */
+      if (WIFEXITED(status)) {
+        if (WEXITSTATUS(status) == 0)
+          tr_debug("mons_sweep_procs: monitoring process %d succeeded.", pid);
+        else
+          tr_debug("mons_sweep_procs: monitoring process %d exited with status %d.", pid, WTERMSIG(status));
+      } else if (WIFSIGNALED(status)) {
+        tr_debug("mons_sweep_procs: monitoring process %d terminated by signal %d.", pid, WTERMSIG(status));
+      }
+    }
+  }
+}
diff --git a/tid/tids.c b/tid/tids.c
index bcbd820..f7c587a 100644
--- a/tid/tids.c
+++ b/tid/tids.c
@@ -444,15 +444,15 @@ void tids_sweep_procs(TIDS_INSTANCE *tids)
 
       g_array_remove_index_fast(tids->pids, ii-1); /* disturbs only indices >= ii-1 which we've already handled */
       if (WIFEXITED(status) && (WEXITSTATUS(status) == 0)) {
-        tr_debug("tids_sweep_procs: TID process succeeded");
+        tr_debug("tids_sweep_procs: TID process %d succeeded.", pid);
         tids->req_count++;
       } else {
         tids->error_count++;
 
         if (WIFEXITED(status)) {
-          tr_debug("tids_sweep_procs: TID process %d exited with status %d", pid, WTERMSIG(status));
+          tr_debug("tids_sweep_procs: TID process %d exited with status %d.", pid, WTERMSIG(status));
         } else if (WIFSIGNALED(status)) {
-          tr_debug("tids_sweep_procs: TID process %d terminated by signal %d", pid, WTERMSIG(status));
+          tr_debug("tids_sweep_procs: TID process %d terminated by signal %d.", pid, WTERMSIG(status));
         }
       }
     }
-- 
2.1.4