Added fake resolving of TXT records

Signed-off-by: Carson Reinke <carson@reinke.co>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

4 files changed, 86 insertions, 0 deletions

diff --git a/doc/resolv_wrapper.1.txt b/doc/resolv_wrapper.1.txt
index cf6c62b..dcd161d 100644
--- a/doc/resolv_wrapper.1.txt
+++ b/doc/resolv_wrapper.1.txt
@@ -48,6 +48,7 @@ For example:
     CNAME   kerberos.cwrap.org dc.cwrap.org
     SRV     _kerberos._tcp.cwrap.org kerberos.cwrap.org 88
     URI     _vpn.cwrap.org https://vpn.cwrap.org/VPN
+    TXT     cwrap.org v=spf1 mx
 
 *RESOLV_WRAPPER_DEBUGLEVEL*::
 
diff --git a/src/resolv_wrapper.c b/src/resolv_wrapper.c
index 5e9abc2..08e3020 100644
--- a/src/resolv_wrapper.c
+++ b/src/resolv_wrapper.c
@@ -194,6 +194,7 @@ struct rwrap_fake_rr {
 		struct rwrap_soa_rrdata soa_rec;
 		char cname_rec[MAXDNAME];
 		char ptr_rec[MAXDNAME];
+		char txt_rec[MAXDNAME];
 	} rrdata;
 
 	char key[MAXDNAME];
@@ -329,6 +330,17 @@ static int rwrap_create_fake_uri_rr(const char *key,
 	return 0;
 }
 
+static int rwrap_create_fake_txt_rr(const char *key,
+				    const char *value,
+				    struct rwrap_fake_rr *rr)
+{
+	memcpy(rr->rrdata.txt_rec, value, strlen(value) + 1);
+
+	memcpy(rr->key, key, strlen(key) + 1);
+	rr->type = ns_t_txt;
+	return 0;
+}
+
 static int rwrap_create_fake_soa_rr(const char *key,
 				    const char *value,
 				    struct rwrap_fake_rr *rr)
@@ -651,6 +663,34 @@ static ssize_t rwrap_fake_uri(struct rwrap_fake_rr *rr,
 	return resp_size;
 }
 
+static ssize_t rwrap_fake_txt(struct rwrap_fake_rr *rr,
+			      uint8_t *answer,
+			      size_t anslen)
+{
+	uint8_t *a = answer;
+	ssize_t resp_size;
+	size_t rdata_size;
+	size_t txt_len;
+
+	if (rr->type != ns_t_txt) {
+		RWRAP_LOG(RWRAP_LOG_ERROR, "Wrong type!\n");
+		return -1;
+	}
+	RWRAP_LOG(RWRAP_LOG_TRACE, "Adding TXT RR");
+	txt_len = strlen(rr->rrdata.txt_rec) + 1;
+	rdata_size = txt_len;
+
+	resp_size = rwrap_fake_rdata_common(ns_t_txt, rdata_size,
+					    rr->key, anslen, &a);
+	if (resp_size < 0) {
+		return -1;
+	}
+
+	memcpy(a, rr->rrdata.txt_rec, txt_len);
+
+	return resp_size;
+}
+
 static ssize_t rwrap_fake_soa(struct rwrap_fake_rr *rr,
 			      uint8_t *answer,
 			      size_t anslen)
@@ -947,6 +987,11 @@ static int rwrap_get_record(const char *hostfile, unsigned recursion,
 			rc = rwrap_create_fake_ptr_rr(key, value, rr);
 			break;
 		}
+		else if (TYPE_MATCH(type, ns_t_txt,
+				      rec_type, "TXT", key, query)) {
+			rc = rwrap_create_fake_txt_rr(key, value, rr);
+			break;
+		}
 	}
 
 	if (rc == ENOENT && recursion == 0 && key != NULL) {
@@ -998,6 +1043,7 @@ static inline bool rwrap_known_type(int type)
 	case ns_t_soa:
 	case ns_t_cname:
 	case ns_t_ptr:
+	case ns_t_txt:
 		return true;
 	}
 
@@ -1088,6 +1134,9 @@ static ssize_t rwrap_add_rr(struct rwrap_fake_rr *rr,
 	case ns_t_ptr:
 		resp_data = rwrap_fake_ptr(rr, answer, anslen);
 		break;
+	case ns_t_txt:
+		resp_data = rwrap_fake_txt(rr, answer, anslen);
+		break;
 	default:
 		return -1;
 	}
diff --git a/tests/fake_hosts.in b/tests/fake_hosts.in
index 824af57..931f004 100644
--- a/tests/fake_hosts.in
+++ b/tests/fake_hosts.in
@@ -17,3 +17,4 @@ URI _vpn.cwrap.org https://vpn2.cwrap.org/VPN 2 10
 URI _vpn.cwrap.org https://vpn3.cwrap.org/VPN 2 20
 URI _ftp.cwrap.org ftp://ftp.cwrap.org/public
 PTR 22.0.0.127.in-addr.arpa www.cwrap.org
+TXT cwrap.org v=spf1 mx
diff --git a/tests/test_dns_fake.c b/tests/test_dns_fake.c
index 28ee57a..420d32b 100644
--- a/tests/test_dns_fake.c
+++ b/tests/test_dns_fake.c
@@ -714,6 +714,40 @@ static void test_res_fake_ptr_query(void **state)
 	assert_string_equal(ptrname, "www.cwrap.org");
 }
 
+static void test_res_fake_txt_query(void **state)
+{
+	int rv;
+	struct __res_state dnsstate;
+	unsigned char answer[ANSIZE];
+	ns_msg handle;
+	ns_rr rr;   /* expanded resource record */
+	const uint8_t *rrdata;
+
+	(void) state; /* unused */
+
+	memset(&dnsstate, 0, sizeof(struct __res_state));
+	rv = res_ninit(&dnsstate);
+	assert_int_equal(rv, 0);
+
+	rv = res_nquery(&dnsstate, "cwrap.org", ns_c_in, ns_t_txt,
+			answer, sizeof(answer));
+	assert_in_range(rv, 1, 256);
+
+	ns_initparse(answer, sizeof(answer), &handle);
+
+	/*
+	 * The query must finish w/o an error, have one answer and the answer
+	 * must be a parseable RR of type TXT
+	 */
+	assert_int_equal(ns_msg_getflag(handle, ns_f_rcode), ns_r_noerror);
+	assert_int_equal(ns_msg_count(handle, ns_s_an), 1);
+	assert_int_equal(ns_parserr(&handle, ns_s_an, 0, &rr), 0);
+	assert_int_equal(ns_rr_type(rr), ns_t_txt);
+
+	rrdata = ns_rr_rdata(rr);
+	assert_string_equal(rrdata, "v=spf1 mx");
+}
+
 int main(void)
 {
 	int rc;
@@ -733,6 +767,7 @@ int main(void)
 		cmocka_unit_test(test_res_fake_cname_query),
 		cmocka_unit_test(test_res_fake_a_via_cname),
 		cmocka_unit_test(test_res_fake_ptr_query),
+		cmocka_unit_test(test_res_fake_txt_query),
 	};
 
 	rc = cmocka_run_group_tests(fake_tests, NULL, NULL);