adig and ahost should return failure exit codes on resolution failures

docs/adig.1

@@ -170,6 +170,21 @@ Alias for +[no]tcp
 
 ${XDG_CONFIG_HOME}/adigrc
 
+.SH RETURN VALUES
+.TP
+\fB0\fR
+Success
+.TP
+\fB1\fR
+Internal System Error
+.TP
+\fB2\fR
+Command line misuse
+.TP
+\fB3\fR
+At least one DNS query failed
+.TP
+
 .SH "REPORTING BUGS"
 Report bugs to the c-ares github issues tracker
 .br

docs/ahost.1

@@ -41,6 +41,22 @@ Specify the \fIdomain\fP to search instead of using the default values from
 /etc/resolv.conf
 for DNS configuration; it has no effect on other platforms (such as Win32
 or Android).
+
+.SH RETURN VALUES
+.TP
+\fB0\fR
+Success
+.TP
+\fB1\fR
+Internal System Error
+.TP
+\fB2\fR
+Command line misuse
+.TP
+\fB3\fR
+At least one DNS query failed
+.TP
+
 .SH "REPORTING BUGS"
 Report bugs to the c-ares mailing list:
 .br

src/tools/adig.c

@@ -56,6 +56,12 @@
 #  define PATH_MAX 1024
 #endif
 
+#define RV_OK     0 /* Success */
+#define RV_SYSERR 1 /* Internal system failure */
+#define RV_MISUSE 2 /* Misuse (command line) */
+#define RV_FAIL   3 /* Resolution failure */
+static int final_rv = RV_OK;
+
 typedef struct {
   unsigned short port;
   size_t         tries;
@@ -773,6 +779,10 @@ static void callback(void *arg, ares_status_t status, size_t timeouts,
   (void)arg;
   (void)timeouts;
 
+  if (status != ARES_SUCCESS) {
+    final_rv = RV_FAIL;
+  }
+
   if (global_config.opts.display_comments) {
     /* We got a "Server status" */
     if (status >= ARES_SUCCESS && status <= ARES_EREFUSED) {
@@ -1484,7 +1494,6 @@ int main(int argc, char **argv)
 {
   ares_channel_t *channel = NULL;
   ares_status_t   status;
-  int             rv = 0;
 
 #ifdef USE_WINSOCK
   WORD    wVersionRequested = MAKEWORD(USE_WINSOCK, USE_WINSOCK);
@@ -1495,15 +1504,15 @@ int main(int argc, char **argv)
   status = (ares_status_t)ares_library_init(ARES_LIB_INIT_ALL);
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "ares_library_init: %s\n", ares_strerror((int)status));
-    return 1;
+    return RV_SYSERR;
   }
 
   config_defaults();
 
   if (!read_cmdline(argc, (const char * const *)argv, 1)) {
     printf("\n** ERROR: %s\n\n", global_config.error);
     print_help();
-    rv = 1;
+    final_rv = RV_MISUSE;
     goto done;
   }
 
@@ -1519,7 +1528,7 @@ int main(int argc, char **argv)
   if (global_config.name == NULL) {
     printf("missing query name\n");
     print_help();
-    rv = 1;
+    final_rv = RV_MISUSE;
     goto done;
   }
 
@@ -1529,7 +1538,7 @@ int main(int argc, char **argv)
                                             global_config.optmask);
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "ares_init_options: %s\n", ares_strerror((int)status));
-    rv = 1;
+    final_rv = RV_SYSERR;
     goto done;
   }
 
@@ -1539,7 +1548,7 @@ int main(int argc, char **argv)
     if (status != ARES_SUCCESS) {
       fprintf(stderr, "ares_set_servers_ports_csv: %s: %s\n",
               ares_strerror((int)status), global_config.servers);
-      rv = 1;
+      final_rv = RV_MISUSE;
       goto done;
     }
   }
@@ -1556,12 +1565,14 @@ int main(int argc, char **argv)
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "Failed to create query for %s: %s\n", global_config.name,
             ares_strerror((int)status));
-    rv = 1;
+    final_rv = RV_MISUSE;
     goto done;
   }
 
   /* Process events */
-  rv = event_loop(channel);
+  if (event_loop(channel) != 0) {
+    final_rv = RV_SYSERR;
+  }
 
 done:
   free_config();
@@ -1571,5 +1582,5 @@ int main(int argc, char **argv)
 #ifdef USE_WINSOCK
   WSACleanup();
 #endif
-  return rv;
+  return final_rv;
 }

src/tools/ahost.c

@@ -44,12 +44,21 @@
 
 #include "ares_str.h"
 
+#define RV_OK     0 /* Success */
+#define RV_SYSERR 1 /* Internal system failure */
+#define RV_MISUSE 2 /* Misuse (command line) */
+#define RV_FAIL   3 /* Resolution failure */
+static int final_rv = RV_OK;
+
+
 static void callback(void *arg, int status, int timeouts, struct hostent *host);
 static void ai_callback(void *arg, int status, int timeouts,
                         struct ares_addrinfo *result);
 static void usage(void);
 static void print_help_info_ahost(void);
 
+
+
 int         main(int argc, char **argv)
 {
   struct ares_options  options;
@@ -79,7 +88,7 @@ int         main(int argc, char **argv)
   status = ares_library_init(ARES_LIB_INIT_ALL);
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "ares_library_init: %s\n", ares_strerror(status));
-    return 1;
+    return RV_SYSERR;
   }
 
   ares_getopt_init(&state, argc, (const char * const *)argv);
@@ -139,7 +148,7 @@ int         main(int argc, char **argv)
   if (status != ARES_SUCCESS) {
     free(servers);
     fprintf(stderr, "ares_init: %s\n", ares_strerror(status));
-    return 1;
+    return RV_SYSERR;
   }
 
   if (servers) {
@@ -148,7 +157,7 @@ int         main(int argc, char **argv)
       fprintf(stderr, "ares_set_serveres_csv: %s\n", ares_strerror(status));
       free(servers);
       usage();
-      return 1;
+      return RV_MISUSE;
     }
     free(servers);
   }
@@ -197,7 +206,7 @@ int         main(int argc, char **argv)
   WSACleanup();
 #endif
 
-  return 0;
+  return final_rv;
 }
 
 static void callback(void *arg, int status, int timeouts, struct hostent *host)
@@ -208,6 +217,7 @@ static void callback(void *arg, int status, int timeouts, struct hostent *host)
 
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "%s: %s\n", (char *)arg, ares_strerror(status));
+    final_rv = RV_FAIL;
     return;
   }
 
@@ -229,6 +239,7 @@ static void ai_callback(void *arg, int status, int timeouts,
 
   if (status != ARES_SUCCESS) {
     fprintf(stderr, "%s: %s\n", (char *)arg, ares_strerror(status));
+    final_rv = RV_FAIL;
     return;
   }
 
@@ -257,7 +268,7 @@ static void usage(void)
 {
   fprintf(stderr, "usage: ahost [-h] [-d] [[-D {domain}] ...] [-s {server}] "
                   "[-t {a|aaaa|u}] {host|addr} ...\n");
-  exit(1);
+  exit(RV_MISUSE);
 }
 
 /* Information from the man page. Formatting taken from man -h */
@@ -282,5 +293,5 @@ static void print_help_info_ahost(void)
     "              If type is \"aaaa\", print the AAAA record.\n"
     "              If type is \"u\" (default), print both A and AAAA records.\n"
     "\n");
-  exit(0);
+  exit(RV_OK);
 }