Phase 1 working: captive portal, DNS hijack, NAT-based access control

- Fix WiFi init order: netif creation before esp_wifi_init, set mode before set_config
- Replace broken netif input filter with NAPT on/off per authentication state
- NAPT disabled by default, enabled when client granted, disabled on revoke
- Fix test helpers: use -I wlp59s0 for ping, handle nslookup exit code 1
- All 20 API tests pass, all 6 smoke tests pass

1 files changed, 1 insertions, 2 deletions

diff --git a/main/dns_server.c b/main/dns_server.c
index f7977c6..733e771 100644
--- a/main/dns_server.c
+++ b/main/dns_server.c
@@ -85,7 +85,6 @@ static void parse_dns_name(const uint8_t *buf, int buf_len, int offset, char *ou
 
 static int build_nxdomain(uint8_t *response, int req_len)
 {
-    memcpy(response, response, req_len);
     dns_header_t *hdr = (dns_header_t *)response;
     hdr->flags = htons(0x8403);
     hdr->ancount = 0;
@@ -96,7 +95,7 @@ static int build_nxdomain(uint8_t *response, int req_len)
 
 static int build_redirect_response(uint8_t *response, int req_len)
 {
-    memcpy(response, response, req_len);
+    memmove(response, response, req_len);
     dns_header_t *hdr = (dns_header_t *)response;
     hdr->flags = htons(0x8180);
     hdr->ancount = htons(1);