Merge branch 'mdns-big-txt' into mdns-big-txt_bdk

This can be used to fix device adoption in ESPHome, which uses a long
"package_import_url" string to advertise the location of the sourcecode
for the device's configuration.

test/unit/mdns/test_mdns.c

@@ -35,6 +35,7 @@
 #include "lwip/pbuf.h"
 #include "lwip/apps/mdns.h"
 #include "lwip/apps/mdns_domain.h"
+#include "lwip/apps/mdns_out.h"
 #include "lwip/apps/mdns_priv.h"
 
 START_TEST(readname_basic)
@@ -876,6 +877,155 @@ START_TEST(compress_long_match)
 }
 END_TEST
 
+#define TXT_STRING_1 "path=/"
+#define TXT_LENGTH_1 6
+#define TXT_LENSTR_1 "\006"
+
+#define TXT_STRING_2 ""
+#define TXT_LENGTH_2 0
+#define TXT_LENSTR_2 "\000"
+
+#define TXT_STRING_3 "This sentence is sixty-three bytes long, including punctuation."
+#define TXT_LENGTH_3 63
+#define TXT_LENSTR_3 "\077"
+
+#define TXT_STRING_4 "This tests whether mdns_resp_add_service_txtitem can properly handle strings longer than 63 characters."
+#define TXT_LENGTH_4 103
+#define TXT_LENSTR_4 "\147"
+
+START_TEST(txt_short_item)
+{
+  const char *expected_txtdata = TXT_LENSTR_1 TXT_STRING_1;
+  const size_t expected_txtdata_length = 1 + TXT_LENGTH_1;
+
+  struct mdns_service service;
+  err_t res;
+  memset(&service, 0, sizeof(struct mdns_service));
+
+  mdns_prepare_txtdata(&service);
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_1, TXT_LENGTH_1);
+  fail_unless(res == ERR_OK);
+
+  fail_unless(service.txtdata.length == expected_txtdata_length);
+  fail_if(memcmp(service.txtdata.rdata, expected_txtdata, expected_txtdata_length));
+}
+END_TEST
+
+START_TEST(txt_empty_item)
+{
+  const char *expected_txtdata = TXT_LENSTR_2 TXT_STRING_2;
+  const size_t expected_txtdata_length = 1 + TXT_LENGTH_2;
+
+  struct mdns_service service;
+  err_t res;
+  memset(&service, 0, sizeof(struct mdns_service));
+
+  mdns_prepare_txtdata(&service);
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_2, TXT_LENGTH_2);
+  fail_unless(res == ERR_OK);
+
+  fail_unless(service.txtdata.length == expected_txtdata_length);
+  fail_if(memcmp(service.txtdata.rdata, expected_txtdata, expected_txtdata_length));
+}
+END_TEST
+
+START_TEST(txt_long_item)
+{
+  const char *expected_txtdata = TXT_LENSTR_4 TXT_STRING_4;
+  const size_t expected_txtdata_length = 1 + TXT_LENGTH_4;
+
+  struct mdns_service service;
+  err_t res;
+  memset(&service, 0, sizeof(struct mdns_service));
+
+  mdns_prepare_txtdata(&service);
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_4, TXT_LENGTH_4);
+  fail_unless(res == ERR_OK);
+
+  fail_unless(service.txtdata.length == expected_txtdata_length);
+  fail_if(memcmp(service.txtdata.rdata, expected_txtdata, expected_txtdata_length));
+}
+END_TEST
+
+START_TEST(txt_multiple_items)
+{
+  const char *expected_txtdata = (
+    TXT_LENSTR_1
+    TXT_STRING_1
+    TXT_LENSTR_2
+    TXT_STRING_2
+    TXT_LENSTR_3
+    TXT_STRING_3
+    TXT_LENSTR_4
+    TXT_STRING_4
+  );
+  const size_t expected_txtdata_length = (
+    1 + TXT_LENGTH_1
+    + 1 + TXT_LENGTH_2
+    + 1 + TXT_LENGTH_3
+    + 1 + TXT_LENGTH_4
+  );
+
+  struct mdns_service service;
+  err_t res;
+  memset(&service, 0, sizeof(struct mdns_service));
+
+  mdns_prepare_txtdata(&service);
+
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_1, TXT_LENGTH_1);
+  fail_unless(res == ERR_OK); /* TXT_STRING_1 */
+
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_2, TXT_LENGTH_2);
+  fail_unless(res == ERR_OK); /* TXT_STRING_1 */
+
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_3, TXT_LENGTH_3);
+  fail_unless(res == ERR_OK); /* TXT_STRING_3 */
+
+  res = mdns_resp_add_service_txtitem(&service, TXT_STRING_4, TXT_LENGTH_4);
+  fail_unless(res == ERR_OK); /* TXT_STRING_4 */
+
+  fail_unless(service.txtdata.length == expected_txtdata_length);
+  fail_if(memcmp(service.txtdata.rdata, expected_txtdata, expected_txtdata_length));
+}
+END_TEST
+
+START_TEST(txt_buffer_full)
+{
+  const char *expected_txtdata = (
+    TXT_LENSTR_3 TXT_STRING_3
+    TXT_LENSTR_3 TXT_STRING_3
+    TXT_LENSTR_3 TXT_STRING_3
+    TXT_LENSTR_3 TXT_STRING_3
+  );
+  const size_t expected_txtdata_length = 256;
+
+  struct mdns_service service;
+  err_t res;
+  int i;
+  memset(&service, 0, sizeof(struct mdns_service));
+
+  mdns_prepare_txtdata(&service);
+
+  /* add a 64-byte string 4 times = 256 bytes */
+  for (i = 0; i < 4; i++) {
+    res = mdns_resp_add_service_txtitem(&service, TXT_STRING_3, TXT_LENGTH_3);
+    ck_assert_msg(res == ERR_OK,
+      "adding text item failed with error %d (i=%d, txtdata.length=%d)",
+      res, i, service.txtdata.length);
+  }
+
+  /* Try to add a few more strings while the buffer is full. This should fail. */
+  res = mdns_resp_add_service_txtitem(&service, "", 0);
+  fail_unless(res != ERR_OK); /* empty string */
+
+  res = mdns_resp_add_service_txtitem(&service, "path=/", 6);
+  fail_unless(res != ERR_OK); /* short string */
+
+  fail_unless(service.txtdata.length == expected_txtdata_length);
+  fail_if(memcmp(service.txtdata.rdata, expected_txtdata, expected_txtdata_length));
+}
+END_TEST
+
 Suite* mdns_suite(void)
 {
   testfunc tests[] = {
@@ -911,6 +1061,12 @@ Suite* mdns_suite(void)
     TESTFUNC(compress_2nd_label_short),
     TESTFUNC(compress_jump_to_jump),
     TESTFUNC(compress_long_match),
+
+    TESTFUNC(txt_short_item),
+    TESTFUNC(txt_empty_item),
+    TESTFUNC(txt_long_item),
+    TESTFUNC(txt_multiple_items),
+    TESTFUNC(txt_buffer_full),
   };
   return create_suite("MDNS", tests, sizeof(tests)/sizeof(testfunc), NULL, NULL);
 }