mifare: Correct processing MADs

NFC sectors have to be continuous, so only some sectors
at the beginning and at the end of tag can be non-NFC.
First non-NFC sector after NFC sectors should end
MAD processing and than resulting tag size and sector list
should be saved.

diff --git a/plugins/mifare.c b/plugins/mifare.c
index 03e5921..948e28b 100644 (file)
--- a/plugins/mifare.c
+++ b/plugins/mifare.c
@@ -500,9 +500,20 @@ static int mifare_process_MADs(void *data)
                goto out_err;
        }
 
-       for (i = 0; i < MAD_V1_AIDS_LEN; i++) {
+       /* Skip non-NFC sectors at the beginning of the tag, if any */
+       for (i = 0 ; i < MAD_V1_AIDS_LEN; i++) {
+               if (mf_ck->mad_1->aids[i] == NFC_AID_TAG)
+                       break;
+       }
+
+       /*
+        * NFC sectors have to be continuous,
+        * so only some sectors at the beginning and at the end of tag
+        * can be non-NFC.
+        */
+       for (; i < MAD_V1_AIDS_LEN; i++) {
                if (mf_ck->mad_1->aids[i] != NFC_AID_TAG)
-                       continue;
+                       goto done_mad;
 
                /* Save in the global list */
                mf_ck->g_sect_list = g_slist_append(mf_ck->g_sect_list,
@@ -515,9 +526,20 @@ static int mifare_process_MADs(void *data)
        if (mf_ck->mad_2 == NULL)
                goto done_mad;
 
-       for (i = 0; i < MAD_V2_AIDS_LEN; i++) {
+       /*
+        * If all sectors from MAD1 were non-NFC,
+        * skip initial non-NFC sectors from MAD2
+        */
+       i = 0;
+
+       if (global_tag_size == 0)
+               for (; i < MAD_V2_AIDS_LEN; i++)
+                       if (mf_ck->mad_2->aids[i] == NFC_AID_TAG)
+                               break;
+
+       for (; i < MAD_V2_AIDS_LEN; i++) {
                if (mf_ck->mad_2->aids[i] != NFC_AID_TAG)
-                       continue;
+                       goto done_mad;
 
                mf_ck->g_sect_list = g_slist_append( mf_ck->g_sect_list,
                                                GINT_TO_POINTER(ioffset + i));
@@ -528,6 +550,14 @@ static int mifare_process_MADs(void *data)
        }
 
 done_mad:
+       if (global_tag_size == 0) {
+
+               /* no NFC sectors - mark tag as blank */
+               near_error("TAG Global size: [%d], not valid NFC tag.",
+                               global_tag_size);
+               return -ENODEV;
+       }
+
        /* n sectors, each sector is 3 blocks, each block is 16 bytes */
        DBG("TAG Global size: [%d]", global_tag_size);