Skip NXDOMAIN test when using evil ISPs

Some ISPs like to inject their own "Suggestions" page whenever you hit
NXDOMAIN. This confuses Redis as well as addrinfo (black-holing the
route).

1 files changed, 35 insertions, 20 deletions

diff --git a/test.c b/test.c
index 0f5bfe5..a5eb9c7 100644
--- a/test.c
+++ b/test.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <strings.h>
 #include <sys/time.h>
+#include <netdb.h>
 #include <assert.h>
 #include <unistd.h>
 #include <signal.h>
@@ -91,7 +92,7 @@ static int disconnect(redisContext *c, int keep_fd) {
     return -1;
 }
 
-static redisContext *connect(struct config config) {
+static redisContext *do_connect(struct config config) {
     redisContext *c = NULL;
 
     if (config.type == CONN_TCP) {
@@ -248,7 +249,7 @@ static void test_append_formatted_commands(struct config config) {
     char *cmd;
     int len;
 
-    c = connect(config);
+    c = do_connect(config);
 
     test("Append format command: ");
 
@@ -434,18 +435,32 @@ static void test_free_null(void) {
 
 static void test_blocking_connection_errors(void) {
     redisContext *c;
-
-    test("Returns error when host cannot be resolved: ");
-    c = redisConnect((char*)"idontexist.test", 6379);
-    test_cond(c->err == REDIS_ERR_OTHER &&
-        (strcmp(c->errstr,"Name or service not known") == 0 ||
-         strcmp(c->errstr,"Can't resolve: idontexist.test") == 0 ||
-         strcmp(c->errstr,"nodename nor servname provided, or not known") == 0 ||
-         strcmp(c->errstr,"No address associated with hostname") == 0 ||
-         strcmp(c->errstr,"Temporary failure in name resolution") == 0 ||
-         strcmp(c->errstr,"hostname nor servname provided, or not known") == 0 ||
-         strcmp(c->errstr,"no address associated with name") == 0));
-    redisFree(c);
+    struct addrinfo hints = {.ai_family = AF_INET};
+    struct addrinfo *ai_tmp = NULL;
+    const char *bad_domain = "idontexist.com";
+
+    int rv = getaddrinfo(bad_domain, "6379", &hints, &ai_tmp);
+    if (rv != 0) {
+        // Address does *not* exist
+        test("Returns error when host cannot be resolved: ");
+        // First see if this domain name *actually* resolves to NXDOMAIN
+        c = redisConnect("dontexist.com", 6379);
+        test_cond(
+            c->err == REDIS_ERR_OTHER &&
+            (strcmp(c->errstr, "Name or service not known") == 0 ||
+             strcmp(c->errstr, "Can't resolve: sadkfjaskfjsa.com") == 0 ||
+             strcmp(c->errstr,
+                    "nodename nor servname provided, or not known") == 0 ||
+             strcmp(c->errstr, "No address associated with hostname") == 0 ||
+             strcmp(c->errstr, "Temporary failure in name resolution") == 0 ||
+             strcmp(c->errstr,
+                    "hostname nor servname provided, or not known") == 0 ||
+             strcmp(c->errstr, "no address associated with name") == 0));
+        redisFree(c);
+    } else {
+        printf("Skipping NXDOMAIN test. Found evil ISP!\n");
+        freeaddrinfo(ai_tmp);
+    }
 
     test("Returns error when the port is not open: ");
     c = redisConnect((char*)"localhost", 1);
@@ -463,7 +478,7 @@ static void test_blocking_connection(struct config config) {
     redisContext *c;
     redisReply *reply;
 
-    c = connect(config);
+    c = do_connect(config);
 
     test("Is able to deliver commands: ");
     reply = redisCommand(c,"PING");
@@ -544,7 +559,7 @@ static void test_blocking_connection_timeouts(struct config config) {
     const char *cmd = "DEBUG SLEEP 3\r\n";
     struct timeval tv;
 
-    c = connect(config);
+    c = do_connect(config);
     test("Successfully completes a command when the timeout is not exceeded: ");
     reply = redisCommand(c,"SET foo fast");
     freeReplyObject(reply);
@@ -556,7 +571,7 @@ static void test_blocking_connection_timeouts(struct config config) {
     freeReplyObject(reply);
     disconnect(c, 0);
 
-    c = connect(config);
+    c = do_connect(config);
     test("Does not return a reply when the command times out: ");
     s = write(c->fd, cmd, strlen(cmd));
     tv.tv_sec = 0;
@@ -590,7 +605,7 @@ static void test_blocking_io_errors(struct config config) {
     int major, minor;
 
     /* Connect to target given by config. */
-    c = connect(config);
+    c = do_connect(config);
     {
         /* Find out Redis version to determine the path for the next test */
         const char *field = "redis_version:";
@@ -625,7 +640,7 @@ static void test_blocking_io_errors(struct config config) {
         strcmp(c->errstr,"Server closed the connection") == 0);
     redisFree(c);
 
-    c = connect(config);
+    c = do_connect(config);
     test("Returns I/O error on socket timeout: ");
     struct timeval tv = { 0, 1000 };
     assert(redisSetTimeout(c,tv) == REDIS_OK);
@@ -659,7 +674,7 @@ static void test_invalid_timeout_errors(struct config config) {
 }
 
 static void test_throughput(struct config config) {
-    redisContext *c = connect(config);
+    redisContext *c = do_connect(config);
     redisReply **replies;
     int i, num;
     long long t1, t2;