Merge pull request #30 from nattgris/od_load

Fix multiple data corruption in OD load

Author: hefloryd

src/co_od.c

@@ -374,7 +374,7 @@ uint32_t co_od_load (co_net_t * net, co_store_t store)
       uint16_t index;
       uint8_t subindex;
       size_t size;
-      uint64_t value;
+      uint64_t value = 0;
       uint8_t * ptr;
       uint32_t abort;
 
@@ -398,7 +398,14 @@ uint32_t co_od_load (co_net_t * net, co_store_t store)
       if (entry == NULL || !(entry->flags & OD_WRITE))
          continue;
 
-      if (size > sizeof (value))
+      if (size <= sizeof (value))
+      {
+         if (net->read (arg, &value, size) < 0)
+            goto error;
+
+         co_od_set_value (net, obj, entry, subindex, value);
+      }
+      else if (size == CO_BYTELENGTH (entry->bitlength))
       {
          /* Get pointer to storage */
          abort = co_od_get_ptr (net, obj, entry, subindex, &ptr);
@@ -410,10 +417,16 @@ uint32_t co_od_load (co_net_t * net, co_store_t store)
       }
       else
       {
+         /* Stored size does not match object size. Discard data. */
+         while (size > sizeof(value))
+         {
+            if (net->read (arg, &value, sizeof (value)) < 0)
+               goto error;
+            size -= sizeof(value);
+         }
+
          if (net->read (arg, &value, size) < 0)
             goto error;
-
-         co_od_set_value (net, obj, entry, subindex, value);
       }
    }
 

test/test_od.cpp

@@ -239,6 +239,57 @@ TEST_F (OdTest, StoreThenLoadOD)
    EXPECT_EQ (0x12345678u, value);
 }
 
+TEST_F (OdTest, StoreThenLoadNewOD)
+{
+   uint32_t value2000_01;
+   uint32_t value2000_02;
+   char str2001[16];
+   char expect_str2001[sizeof(str2001)] = {0};
+   const co_entry_t OD2000_1[] = {
+      {0x00, OD_RO, DTYPE_UNSIGNED8, 8, 0x02, NULL},
+      {0x01, OD_RW, DTYPE_UNSIGNED32, 32, 0, &value2000_01},
+      {0x02, OD_RW, DTYPE_UNSIGNED16, 16, 0, &value2000_02},
+   };
+   co_entry_t OD2001_1[] = {
+      {0, OD_RW, DTYPE_VISIBLE_STRING, 8 * sizeof (str2001), 0, str2001},
+   };
+   const co_obj_t OD1[] = {
+      {0x2000, OTYPE_RECORD, 2, OD2000_1, NULL},
+      {0x2001, OTYPE_VAR, 0, OD2001_1, NULL},
+      {0, OTYPE_NULL, 0, NULL, NULL},
+   };
+   const co_entry_t OD2000_2[12] = {
+      {0x00, OD_RO, DTYPE_UNSIGNED8, 8, 0x02, NULL},
+      {0x01, OD_RW, DTYPE_UNSIGNED16, 16, 0, &value2000_01}, // Grows
+      {0x02, OD_RW, DTYPE_UNSIGNED32, 32, 0, &value2000_02}, // Shrinks
+   };
+   co_entry_t OD2001_2[] = {
+      // Shrinks, should discard data
+      {0, OD_RW, DTYPE_VISIBLE_STRING, 8 * (sizeof (str2001) - 1), 0, str2001},
+   };
+   const co_obj_t OD2[] = {
+      {0x2000, OTYPE_RECORD, 2, OD2000_2, NULL},
+      {0x2001, OTYPE_VAR, 0, OD2001_2, NULL},
+      {0, OTYPE_NULL, 0, NULL, NULL},
+   };
+
+   net.od = OD1;
+   value2000_01 = 0xFFFFFFFF;
+   value2000_02 = 0xFFFF;
+   memset (str2001, 0xFF, sizeof(str2001));
+   co_od_store (&net, CO_STORE_APP, 0x2000, 0x2FFF);
+
+   value2000_01 = 0xAAAAAAAA;
+   value2000_02 = 0x55555555;
+   memset (str2001, 0xAA, sizeof(str2001));
+
+   net.od = OD2;
+   co_od_reset (&net, CO_STORE_APP, 0x2000, 0x2FFF);
+   EXPECT_EQ (0xAAAAFFFFu, value2000_01);
+   EXPECT_EQ (0x0000FFFFu, value2000_02);
+   EXPECT_EQ (0, memcmp (expect_str2001, str2001, sizeof(str2001) - 1));
+}
+
 TEST_F (OdTest, OD1010)
 {
    const co_obj_t * obj1010 = find_obj (0x1010);