Cleaner shutdown on mistimed version-select

TSAN thinks there's a thread leak. It's true, but not very
important. Nevertheless this commit eliminates it in the
interests of cleaner test runs.

Author: ewxrjk

globals.c

@@ -21,11 +21,32 @@
 #include "sftpcommon.h"
 #include "types.h"
 #include "globals.h"
+#include "thread.h"
+#include "utils.h"
+#include <stdlib.h>
+#include <string.h>
 
 #if NTHREADS > 1
 struct queue *workqueue = 0;
 #endif
 
+static pthread_mutex_t state_lock = PTHREAD_MUTEX_INITIALIZER;
+static enum sftp_state state;
+
+void sftp_state_set(enum sftp_state s) {
+  ferrcheck(pthread_mutex_lock(&state_lock));
+  state = s;
+  ferrcheck(pthread_mutex_unlock(&state_lock));
+}
+
+enum sftp_state sftp_state_get(void) {
+  enum sftp_state r;
+  ferrcheck(pthread_mutex_lock(&state_lock));
+  r = state;
+  ferrcheck(pthread_mutex_unlock(&state_lock));
+  return r;
+}
+
 /*
 Local Variables:
 c-basic-offset:2

sftpcommon.h

@@ -94,6 +94,22 @@ struct stat;
  */
 const char *status_to_string(uint32_t status);
 
+/** @brief Possible SFTP service states */
+enum sftp_state {
+  sftp_state_run = 0,
+  sftp_state_stop = 1,
+};
+
+/** @brief Get the current SFTP service state
+ * @return State value
+ */
+enum sftp_state sftp_state_get(void);
+
+/** @brief Set the SFTP service state
+ * @param s New state value
+ */
+void sftp_state_set(enum sftp_state s);
+
 #endif /* SFTPCOMMON_H */
 
 /*

sftpserver.c

@@ -658,7 +658,7 @@ static void sftp_service(void) {
   /* draft -13 s7.6 "The server SHOULD NOT apply a 'umask' to the mode
    * bits". */
   umask(0);
-  while(!do_read(0, &len, sizeof len)) {
+  while(sftp_state_get() != sftp_state_stop && !do_read(0, &len, sizeof len)) {
     job = xmalloc(sizeof *job);
     job->len = ntohl(len);
     if(!job->len || job->len > MAXREQUEST)

v6.c

@@ -28,6 +28,7 @@
 #include "debug.h"
 #include "utils.h"
 #include "globals.h"
+#include "queue.h"
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
@@ -178,7 +179,8 @@ uint32_t sftp_v6_version_select(struct sftpjob *job) {
     sftp_send_status(job, SSH_FX_INVALID_PARAMETER,
                      "badly timed version-select");
   /* We MUST close the channel.  (-13, s5.5). */
-  exit(-1);
+  sftp_state_set(sftp_state_stop);
+  return HANDLER_RESPONDED;             /* even though we sent nothing */
 }
 
 static const struct sftpcmd sftpv6tab[] = {