Add thread-safe wrapper for ctime.

nbase/nbase.h

@@ -458,6 +458,7 @@ void usleep(unsigned long usec);
 /* localtime is not thread safe. This will use a thread safe alternative on
  * supported platforms. */
 int n_localtime(const time_t *timer, struct tm *result);
+int n_ctime(char *buffer, size_t bufsz, const time_t *timer);
 
 /***************** String functions -- See nbase_str.c ******************/
 /* I modified this conditional because !@# Redhat does not easily provide

nbase/nbase_time.c

@@ -165,33 +165,71 @@ int n_localtime(const time_t *timer, struct tm *result) {
   return localtime_s(result, timer);
 }
 
-#else
+int n_ctime(char *buffer, size_t bufsz, const time_t *timer) {
+  return ctime_s(buffer, bufsz, timer);
+}
+
+#else //WIN32
+
 #include <errno.h>
-int n_localtime(const time_t *timer, struct tm *result) {
 #ifdef HAVE_LOCALTIME_S
 /* C11 localtime_s similar to Posix localtime_r, but with validity checking:
  * struct tm *localtime_s(const time_t *restrict time, struct tm *restrict result);
  */
+int n_localtime(const time_t *timer, struct tm *result) {
   struct tm *tmp = localtime_s(timer, result);
-#else
-#ifdef HAVE_LOCALTIME_R
-/* POSIX localtime_r thread-safe localtime function:
- * struct tm *localtime_r(const time_t *timep, struct tm *result);
- */
-  struct tm *tmp = localtime_r(timer, result);
-#else
-/* No thread-safe alternative; use localtime. */
-  struct tm *tmp = localtime(timer);
-  if (tmp)
-    *result = *tmp;
-#endif
-#endif
   if (!tmp) {
     return errno;
   }
   return 0;
 }
-#endif
+
+int n_ctime(char *buffer, size_t bufsz, const time_t *timer) {
+  return ctime_s(buffer, bufsz, timer);
+}
+#else
+#ifdef HAVE_LOCALTIME_R
+/* POSIX localtime_r thread-safe localtime function:
+ * struct tm *localtime_r(const time_t *timep, struct tm *result);
+ */
+int n_localtime(const time_t *timer, struct tm *result) {
+  struct tm *tmp = localtime_r(timer, result);
+  if (!tmp) {
+    return errno;
+  }
+  return 0;
+}
+
+int n_ctime(char *buffer, size_t bufsz, const time_t *timer) {
+  char *tmp = ctime_r(timer, buffer);
+  if (!tmp) {
+    return errno;
+  }
+  return 0;
+}
+
+#else
+/* No thread-safe alternatives. */
+int n_localtime(const time_t *timer, struct tm *result) {
+  struct tm *tmp = localtime(timer); /* lgtm [cpp/potentially-dangerous-function] */
+  if (tmp)
+    *result = *tmp;
+  else
+    return errno;
+  return 0;
+}
+
+int n_ctime(char *buffer, size_t bufsz, const time_t *timer) {
+  char *tmp = ctime(timer); /* lgtm [cpp/potentially-dangerous-function] */
+  if (tmp)
+    Strncpy(buffer, tmp, bufsz);
+  else
+    return errno;
+  return 0;
+}
+#endif //HAVE_LOCALTIME_R
+#endif //HAVE_LOCALTIME_S
+#endif //WIN32
 
 #ifdef WIN32
 int gettimeofday(struct timeval *tv, struct timeval *tz)

nmap.cc

@@ -1919,7 +1919,10 @@ int nmap_main(int argc, char *argv[]) {
   fflush(stderr);
 
   timep = time(NULL);
-  Strncpy(mytime, ctime(&timep), sizeof(mytime));
+  err = n_ctime(mytime, sizeof(mytime), &timep);
+  if (err) {
+    fatal("n_ctime failed: %s", strerror(err));
+  }
   chomp(mytime);
 
   if (!o.resuming) {

output.cc

@@ -2041,17 +2041,23 @@ void printosscanoutput(Target *currenths) {
     char tmbuf[128];
     struct timeval tv;
     double uptime;
-    strncpy(tmbuf, ctime(&currenths->seq.lastboot), sizeof(tmbuf));
+    int err = n_ctime(tmbuf, sizeof(tmbuf), &currenths->seq.lastboot);
     chomp(tmbuf);
     gettimeofday(&tv, NULL);
     uptime = difftime(tv.tv_sec, currenths->seq.lastboot);
-    if (o.verbose)
-      log_write(LOG_PLAIN, "Uptime guess: %.3f days (since %s)\n",
+    if (o.verbose) {
+      if (err)
+        log_write(LOG_PLAIN, "Uptime guess: %.3f days\n",
+                uptime / 86400);
+      else
+        log_write(LOG_PLAIN, "Uptime guess: %.3f days (since %s)\n",
                 uptime / 86400,
                 tmbuf);
+    }
     xml_open_start_tag("uptime");
     xml_attribute("seconds", "%.0f", uptime);
-    xml_attribute("lastboot", "%s", tmbuf);
+    if (!err)
+      xml_attribute("lastboot", "%s", tmbuf);
     xml_close_empty_tag();
     xml_newline();
   }
@@ -2526,20 +2532,30 @@ void printStatusMessage() {
    You have to close the tag with xml_close_empty_tag. */
 void print_xml_finished_open(time_t timep, const struct timeval *tv) {
   char mytime[128];
+  int err = n_ctime(mytime, sizeof(mytime), &timep);
 
-  Strncpy(mytime, ctime(&timep), sizeof(mytime));
   chomp(mytime);
 
   xml_open_start_tag("finished");
   xml_attribute("time", "%lu", (unsigned long) timep);
-  xml_attribute("timestr", "%s", mytime);
+  if (!err) {
+    xml_attribute("timestr", "%s", mytime);
+    xml_attribute("summary",
+        "Nmap done at %s; %u %s (%u %s up) scanned in %.2f seconds",
+        mytime, o.numhosts_scanned,
+        (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
+        o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
+        o.TimeSinceStart(tv));
+  }
+  else {
+    xml_attribute("summary",
+        "Nmap done; %u %s (%u %s up) scanned in %.2f seconds",
+        o.numhosts_scanned,
+        (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
+        o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
+        o.TimeSinceStart(tv));
+  }
   xml_attribute("elapsed", "%.2f", o.TimeSinceStart(tv));
-  xml_attribute("summary",
-    "Nmap done at %s; %u %s (%u %s up) scanned in %.2f seconds",
-    mytime, o.numhosts_scanned,
-    (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
-    o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
-    o.TimeSinceStart(tv));
 }
 
 void print_xml_hosts() {
@@ -2555,6 +2571,7 @@ void print_xml_hosts() {
 void printfinaloutput() {
   time_t timep;
   char mytime[128];
+  int err = 0;
   struct timeval tv;
   char statbuf[128];
 
@@ -2592,9 +2609,6 @@ void printfinaloutput() {
     log_write(LOG_STDOUT | LOG_SKID, "           %s\n",
               getFinalPacketStats(statbuf, sizeof(statbuf)));
 
-  Strncpy(mytime, ctime(&timep), sizeof(mytime));
-  chomp(mytime);
-
   xml_start_tag("runstats");
   print_xml_finished_open(timep, &tv);
   xml_attribute("exit", "success");
@@ -2604,12 +2618,24 @@ void printfinaloutput() {
   xml_end_tag();
   xml_newline();
 
-  log_write(LOG_NORMAL | LOG_MACHINE,
-            "# Nmap done at %s -- %u %s (%u %s up) scanned in %.2f seconds\n",
-            mytime, o.numhosts_scanned,
-            (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
-            o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
-            o.TimeSinceStart(&tv));
+  err = n_ctime(mytime, sizeof(mytime), &timep);
+  if (!err) {
+    chomp(mytime);
+    log_write(LOG_NORMAL | LOG_MACHINE,
+        "# Nmap done at %s -- %u %s (%u %s up) scanned in %.2f seconds\n",
+        mytime, o.numhosts_scanned,
+        (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
+        o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
+        o.TimeSinceStart(&tv));
+  }
+  else {
+    log_write(LOG_NORMAL | LOG_MACHINE,
+        "# Nmap done -- %u %s (%u %s up) scanned in %.2f seconds\n",
+        o.numhosts_scanned,
+        (o.numhosts_scanned == 1) ? "IP address" : "IP addresses",
+        o.numhosts_up, (o.numhosts_up == 1) ? "host" : "hosts",
+        o.TimeSinceStart(&tv));
+  }
 
   xml_end_tag(); /* nmaprun */
   xml_newline();