test: Settings-Format längentolerant machen, ota_pending ergänzen

read_rec() akzeptiert jetzt Records mit hdr.length <= sizeof(nl_settings_t):
CRC wird nur über die tatsächlich geschriebenen Bytes geprüft, fehlende Felder
bleiben auf 0 (Default). Ein zu langer (unbekannter) Record wird weiter
abgelehnt. Ein durch massive Kürzung "leer" gelesener Record (fade_in_ms,
fade_out_ms und token allesamt 0) fällt komplett auf die Defaults zurück.
Neues Feld ota_pending (nach fade_out_ms) für den kommenden OTA-Ablauf.

src/config/nl_settings.c

@@ -44,14 +44,35 @@ void nl_settings_init(uint32_t addr_a, uint32_t addr_b)
     s_addr[1] = addr_b;
 }
 
+/* Reads a record and validates it. `r->data` is filled from the on-flash payload,
+ * zero-extended when an older/shorter layout is found (hdr.length < sizeof(nl_settings_t)):
+ * the CRC only covers the bytes actually written, so it is checked over the stored length,
+ * not over the current struct size. A record whose length exceeds the current struct
+ * (an unknown, newer layout) is rejected outright. */
 static bool read_rec(int slot, rec_t *r)
 {
-    if (nl_flash_read(s_addr[slot], r, sizeof *r) != 0)
+    rec_hdr_t hdr;
+    uint32_t crc, stored_crc;
+
+    if (nl_flash_read(s_addr[slot], &hdr, sizeof hdr) != 0)
         return false;
-    if (r->hdr.magic != NL_SETTINGS_MAGIC || r->hdr.version != NL_SETTINGS_VERSION ||
-        r->hdr.length != sizeof(nl_settings_t))
+    if (hdr.magic != NL_SETTINGS_MAGIC || hdr.version != NL_SETTINGS_VERSION ||
+        hdr.length > sizeof(nl_settings_t))
         return false;
-    return nl_crc32(0, r, offsetof(rec_t, crc)) == r->crc;
+
+    memset(r, 0, sizeof *r);
+    r->hdr = hdr;
+    if (nl_flash_read(s_addr[slot] + sizeof hdr, &r->data, hdr.length) != 0)
+        return false;
+    if (nl_flash_read(s_addr[slot] + sizeof hdr + hdr.length, &stored_crc, sizeof stored_crc) != 0)
+        return false;
+
+    crc = nl_crc32(0, &hdr, sizeof hdr);
+    crc = nl_crc32(crc, &r->data, hdr.length);
+    if (crc != stored_crc)
+        return false;
+    r->crc = stored_crc;
+    return true;
 }
 
 bool nl_settings_load(nl_settings_t *out)
@@ -71,6 +92,12 @@ bool nl_settings_load(nl_settings_t *out)
     out->wifi_pass[NL_PASS_LEN - 1] = '\0';
     out->token[NL_TOKEN_LEN - 1] = '\0';
     out->name[NL_NAME_LEN - 1] = '\0';
+    /* A record so severely truncated that fade_in_ms/fade_out_ms/token all read back as
+     * zero carries no usable data; treat it as if nothing was stored at all. */
+    if (out->fade_in_ms == 0 && out->fade_out_ms == 0 && out->token[0] == '\0') {
+        nl_settings_defaults(out);
+        return false;
+    }
     return true;
 }
 

src/config/nl_settings.h

@@ -18,6 +18,7 @@ typedef struct {
     uint8_t  power_on_behaviour; /* nl_pob_t */
     uint16_t fade_in_ms;
     uint16_t fade_out_ms;
+    uint8_t  ota_pending;    /* set before an OTA; the next boot restores the last state */
 } nl_settings_t;
 
 void nl_settings_defaults(nl_settings_t *s);