Fix interrupted scans

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Deprecated
 ### Removed
 ### Fixed
+Fix interrupted scan, when the process table is full. [#832](https://github.com/greenbone/openvas-scanner/pull/832)
 
 [21.4.3]: https://github.com/greenbone/openvas-scanner/compare/v21.4.2...gvmd-21.04
 

src/attack.c

@@ -432,7 +432,10 @@ launch_plugin (struct scan_globals *globals, struct scheduler_plugin *plugin,
   if (pid < 0)
     {
       plugin->running_state = PLUGIN_STATUS_UNRUN;
-      ret = ERR_CANT_FORK;
+      if (pid == ERR_NO_FREE_SLOT)
+        ret = ERR_NO_FREE_SLOT;
+      else
+        ret = ERR_CANT_FORK;
       goto finish_launch_plugin;
     }
 
@@ -519,13 +522,21 @@ attack_host (struct scan_globals *globals, struct in6_addr *ip, GSList *vhosts,
                   kb_item_push_str (main_kb, "internal/results", buffer);
                   goto host_died;
                 }
+              else if (e == ERR_NO_FREE_SLOT)
+                {
+                  g_debug (
+                    "fork() failed for %s. Not free slot to run a plugin.",
+                    plugin->oid);
+                  goto again;
+                }
               else if (e == ERR_CANT_FORK)
                 {
                   if (forks_retry < MAX_FORK_RETRIES)
                     {
                       forks_retry++;
-                      g_debug ("fork() failed - sleeping %d seconds (%s)",
-                               forks_retry, strerror (errno));
+                      g_debug (
+                        "fork() failed for %s - sleeping %d seconds (%s)",
+                        plugin->oid, forks_retry, strerror (errno));
                       fork_sleep (forks_retry);
                       goto again;
                     }

src/pluginlaunch.c

@@ -239,8 +239,8 @@ simult_ports (const char *oid, const char *next_oid)
 /**
  * If another NVT with same port requirements is running, wait.
  *
- * @return -1 if MAX_PROCESSES are running, the index of the first free "slot"
- *          in the processes array otherwise.
+ * @return ERR_NO_FREE_SLOT if MAX_PROCESSES are running, the index of the first
+ * free "slot" in the processes array otherwise.
  */
 static int
 next_free_process (kb_t kb, struct scheduler_plugin *upcoming)
@@ -262,7 +262,7 @@ next_free_process (kb_t kb, struct scheduler_plugin *upcoming)
   for (r = 0; r < MAX_PROCESSES; r++)
     if (processes[r].pid <= 0)
       return r;
-  return -1;
+  return ERR_NO_FREE_SLOT;
 }
 
 void
@@ -402,7 +402,15 @@ plugin_launch (struct scan_globals *globals, struct scheduler_plugin *plugin,
   pluginlaunch_wait_for_free_process (main_kb);
   p = next_free_process (main_kb, plugin);
   if (p < 0)
-    return -1;
+    {
+      g_debug ("There are currently no free slot for running a new plugins, "
+               "probably because the parallel check is temporally disabled. "
+               "Current parallel checks: %d. Old parallel checks: %d",
+               max_running_processes, old_max_running_processes);
+      usleep (250000);
+      return ERR_NO_FREE_SLOT;
+    }
+
   processes[p].plugin = plugin;
   processes[p].timeout = plugin_timeout (nvti);
   gettimeofday (&(processes[p].start), NULL);
@@ -461,8 +469,15 @@ pluginlaunch_wait_for_free_process (kb_t kb)
   update_running_processes (kb);
   /* Max number of processes are still running, wait for a child to exit or
    * to timeout. */
+
+  if (num_running_processes >= max_running_processes)
+    g_debug ("%s. Number of running processes >= maximum running processes (%d "
+             ">= %d). "
+             "Waitting for free slot for processes.",
+             __func__, num_running_processes, max_running_processes);
+
   while (
-    (num_running_processes == max_running_processes)
+    (num_running_processes >= max_running_processes)
     || (num_running_processes > 0 && (check_memory () || check_sysload ())))
     {
       sigset_t mask;

src/pluginlaunch.h

@@ -29,6 +29,11 @@
 #include "pluginload.h"      /* for struct pl_class_t */
 #include "pluginscheduler.h" /* for struct plugins_scheduler_t */
 
+/**
+ * @brief Error for max. number of concurrent plugins per host reached.
+ */
+#define ERR_NO_FREE_SLOT -99
+
 void
 pluginlaunch_init (const char *);
 void pluginlaunch_wait (kb_t);