Fix the concurrent access to batchname in dig.c

diff --git a/bin/dig/dig.c b/bin/dig/dig.c
index daaf486534aabaccb428752118338694d6756c79..4bc848a4c642217240952789329fd11d7483da0d 100644 (file)
--- a/bin/dig/dig.c
+++ b/bin/dig/dig.c
@@ -54,7 +54,7 @@
 
 dig_lookup_t *default_lookup = NULL;
 
-static char *batchname = NULL;
+static atomic_uintptr_t batchname = ATOMIC_VAR_INIT(0);
 static FILE *batchfp = NULL;
 static char *argv0;
 static int addresscount = 0;
@@ -1874,7 +1874,7 @@ dash_option(char *option, char *next, dig_lookup_t **lookup,
                                value);
                return (value_from_next);
        case 'f':
-               batchname = value;
+               atomic_store(&batchname, (uintptr_t)value);
                return (value_from_next);
        case 'k':
                strlcpy(keyfile, value, sizeof(keyfile));
@@ -2327,13 +2327,15 @@ parse_args(bool is_batchfile, bool config_only,
         * first entry, then trust the callback in dighost_shutdown
         * to get the rest
         */
-       if ((batchname != NULL) && !(is_batchfile)) {
-               if (strcmp(batchname, "-") == 0)
+       char *filename = (char *)atomic_load(&batchname);
+       if ((filename != NULL) && !(is_batchfile)) {
+               if (strcmp(filename, "-") == 0) {
                        batchfp = stdin;
-               else
-                       batchfp = fopen(batchname, "r");
+               } else {
+                       batchfp = fopen(filename, "r");
+               }
                if (batchfp == NULL) {
-                       perror(batchname);
+                       perror(filename);
                        if (exitcode < 8)
                                exitcode = 8;
                        fatal("couldn't open specified batch file");
@@ -2388,14 +2390,14 @@ query_finished(void) {
        int bargc;
        char *bargv[16];
 
-       if (batchname == NULL) {
+       if (atomic_load(&batchname) == 0) {
                isc_app_shutdown();
                return;
        }
 
        fflush(stdout);
        if (feof(batchfp)) {
-               batchname = NULL;
+               atomic_store(&batchname, 0);
                isc_app_shutdown();
                if (batchfp != stdin)
                        fclose(batchfp);
@@ -2409,7 +2411,7 @@ query_finished(void) {
                parse_args(true, false, bargc, (char **)bargv);
                start_lookup();
        } else {
-               batchname = NULL;
+               atomic_store(&batchname, 0);
                if (batchfp != stdin)
                        fclose(batchfp);
                isc_app_shutdown();
@@ -2539,10 +2541,11 @@ void dig_query_start()
 void
 dig_shutdown() {
        destroy_lookup(default_lookup);
-       if (batchname != NULL) {
-               if (batchfp != stdin)
+       if (atomic_load(&batchname) != 0) {
+               if (batchfp != stdin) {
                        fclose(batchfp);
-               batchname = NULL;
+               }
+               atomic_store(&batchname, 0);
        }
        cancel_all();
        destroy_libs();