X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=pb_decode.c;h=a8cd61a77bbddd72f3e2c5ac1c1a699a87aa0a70;hb=07375a126337916f3a34ea94f8085b8f89d789a1;hp=f0fa1cceddff63c64119eb55c07afa5d697552e4;hpb=500883048860cc98745d69ae1d16d85523cd5291;p=apps%2Fagl-service-can-low-level.git

diff --git a/pb_decode.c b/pb_decode.c
index f0fa1cce..a8cd61a7 100644
--- a/pb_decode.c
+++ b/pb_decode.c
@@ -23,9 +23,8 @@
 
 typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest) checkreturn;
 
-static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count);
-static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest);
-static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, uint8_t *buf, size_t *size);
+static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count);
+static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, pb_byte_t *buf, size_t *size);
 static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
 static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
 static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
@@ -43,11 +42,13 @@ static bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *f
 static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
 static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest);
 static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest);
+static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
 static bool checkreturn pb_skip_varint(pb_istream_t *stream);
 static bool checkreturn pb_skip_string(pb_istream_t *stream);
 
 #ifdef PB_ENABLE_MALLOC
 static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size);
+static bool checkreturn pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *iter);
 static void pb_release_single_field(const pb_field_iter_t *iter);
 #endif
 
@@ -64,34 +65,36 @@ static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = {
     &pb_dec_bytes,
     &pb_dec_string,
     &pb_dec_submessage,
-    NULL /* extensions */
+    NULL, /* extensions */
+    &pb_dec_fixed_length_bytes
 };
 
 /*******************************
  * pb_istream_t implementation *
  *******************************/
 
-static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count)
+static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count)
 {
-    uint8_t *source = (uint8_t*)stream->state;
-    stream->state = source + count;
+    size_t i;
+    const pb_byte_t *source = (const pb_byte_t*)stream->state;
+    stream->state = (pb_byte_t*)stream->state + count;
     
     if (buf != NULL)
     {
-        while (count--)
-            *buf++ = *source++;
+        for (i = 0; i < count; i++)
+            buf[i] = source[i];
     }
     
     return true;
 }
 
-bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t count)
+bool checkreturn pb_read(pb_istream_t *stream, pb_byte_t *buf, size_t count)
 {
 #ifndef PB_BUFFER_ONLY
 	if (buf == NULL && stream->callback != buf_read)
 	{
 		/* Skip input bytes */
-		uint8_t tmp[16];
+		pb_byte_t tmp[16];
 		while (count > 16)
 		{
 			if (!pb_read(stream, tmp, 16))
@@ -121,7 +124,7 @@ bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t count)
 
 /* Read a single byte from input stream. buf may not be NULL.
  * This is an optimization for the varint decoding. */
-static bool checkreturn pb_readbyte(pb_istream_t *stream, uint8_t *buf)
+static bool checkreturn pb_readbyte(pb_istream_t *stream, pb_byte_t *buf)
 {
     if (stream->bytes_left == 0)
         PB_RETURN_ERROR(stream, "end-of-stream");
@@ -130,8 +133,8 @@ static bool checkreturn pb_readbyte(pb_istream_t *stream, uint8_t *buf)
     if (!stream->callback(stream, buf, 1))
         PB_RETURN_ERROR(stream, "io error");
 #else
-    *buf = *(uint8_t*)stream->state;
-    stream->state = (uint8_t*)stream->state + 1;
+    *buf = *(const pb_byte_t*)stream->state;
+    stream->state = (pb_byte_t*)stream->state + 1;
 #endif
 
     stream->bytes_left--;
@@ -139,15 +142,23 @@ static bool checkreturn pb_readbyte(pb_istream_t *stream, uint8_t *buf)
     return true;    
 }
 
-pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
+pb_istream_t pb_istream_from_buffer(const pb_byte_t *buf, size_t bufsize)
 {
     pb_istream_t stream;
+    /* Cast away the const from buf without a compiler error.  We are
+     * careful to use it only in a const manner in the callbacks.
+     */
+    union {
+        void *state;
+        const void *c_state;
+    } state;
 #ifdef PB_BUFFER_ONLY
     stream.callback = NULL;
 #else
     stream.callback = &buf_read;
 #endif
-    stream.state = buf;
+    state.c_state = buf;
+    stream.state = state.state;
     stream.bytes_left = bufsize;
 #ifndef PB_NO_ERRMSG
     stream.errmsg = NULL;
@@ -159,9 +170,9 @@ pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
  * Helper functions *
  ********************/
 
-static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
+bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
 {
-    uint8_t byte;
+    pb_byte_t byte;
     uint32_t result;
     
     if (!pb_readbyte(stream, &byte))
@@ -175,7 +186,7 @@ static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
     else
     {
         /* Multibyte case */
-        uint8_t bitpos = 7;
+        uint_fast8_t bitpos = 7;
         result = byte & 0x7F;
         
         do
@@ -187,7 +198,7 @@ static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
                 return false;
             
             result |= (uint32_t)(byte & 0x7F) << bitpos;
-            bitpos = (uint8_t)(bitpos + 7);
+            bitpos = (uint_fast8_t)(bitpos + 7);
         } while (byte & 0x80);
    }
    
@@ -197,8 +208,8 @@ static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
 
 bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
 {
-    uint8_t byte;
-    uint8_t bitpos = 0;
+    pb_byte_t byte;
+    uint_fast8_t bitpos = 0;
     uint64_t result = 0;
     
     do
@@ -210,7 +221,7 @@ bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
             return false;
 
         result |= (uint64_t)(byte & 0x7F) << bitpos;
-        bitpos = (uint8_t)(bitpos + 7);
+        bitpos = (uint_fast8_t)(bitpos + 7);
     } while (byte & 0x80);
     
     *dest = result;
@@ -219,7 +230,7 @@ bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
 
 bool checkreturn pb_skip_varint(pb_istream_t *stream)
 {
-    uint8_t byte;
+    pb_byte_t byte;
     do
     {
         if (!pb_read(stream, &byte, 1))
@@ -278,7 +289,7 @@ bool checkreturn pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type)
 /* Read a raw value to buffer, for the purpose of passing it to callback as
  * a substream. Size is maximum size on call, and actual size on return.
  */
-static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, uint8_t *buf, size_t *size)
+static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, pb_byte_t *buf, size_t *size)
 {
     size_t max_size = *size;
     switch (wire_type)
@@ -323,13 +334,19 @@ bool checkreturn pb_make_string_substream(pb_istream_t *stream, pb_istream_t *su
     return true;
 }
 
-void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+bool checkreturn pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
 {
+    if (substream->bytes_left) {
+        if (!pb_read(substream, NULL, substream->bytes_left))
+            return false;
+    }
+
     stream->state = substream->state;
 
 #ifndef PB_NO_ERRMSG
     stream->errmsg = substream->errmsg;
 #endif
+    return true;
 }
 
 /*************************
@@ -350,7 +367,8 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
             return func(stream, iter->pos, iter->pData);
             
         case PB_HTYPE_OPTIONAL:
-            *(bool*)iter->pSize = true;
+            if (iter->pSize != iter->pData)
+                *(bool*)iter->pSize = true;
             return func(stream, iter->pos, iter->pData);
     
         case PB_HTYPE_REPEATED:
@@ -366,7 +384,7 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                 
                 while (substream.bytes_left > 0 && *size < iter->pos->array_size)
                 {
-                    void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                    void *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
                     if (!func(&substream, iter->pos, pItem))
                     {
                         status = false;
@@ -374,18 +392,19 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                     }
                     (*size)++;
                 }
-                pb_close_string_substream(stream, &substream);
-                
+
                 if (substream.bytes_left != 0)
                     PB_RETURN_ERROR(stream, "array overflow");
-                
+                if (!pb_close_string_substream(stream, &substream))
+                    return false;
+
                 return status;
             }
             else
             {
                 /* Repeated field */
                 pb_size_t *size = (pb_size_t*)iter->pSize;
-                void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                void *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
                 if (*size >= iter->pos->array_size)
                     PB_RETURN_ERROR(stream, "array overflow");
                 
@@ -393,6 +412,17 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                 return func(stream, iter->pos, pItem);
             }
 
+        case PB_HTYPE_ONEOF:
+            *(pb_size_t*)iter->pSize = iter->pos->tag;
+            if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+            {
+                /* We memset to zero so that any callbacks are set to NULL.
+                 * Then set any default values. */
+                memset(iter->pData, 0, iter->pos->data_size);
+                pb_message_set_to_defaults((const pb_field_t*)iter->pos->ptr, iter->pData);
+            }
+            return func(stream, iter->pos, iter->pData);
+
         default:
             PB_RETURN_ERROR(stream, "invalid field type");
     }
@@ -470,6 +500,7 @@ static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_
     {
         case PB_HTYPE_REQUIRED:
         case PB_HTYPE_OPTIONAL:
+        case PB_HTYPE_ONEOF:
             if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE &&
                 *(void**)iter->pData != NULL)
             {
@@ -477,6 +508,11 @@ static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_
                 pb_release_single_field(iter);
             }
         
+            if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
+            {
+                *(pb_size_t*)iter->pSize = iter->pos->tag;
+            }
+
             if (PB_LTYPE(type) == PB_LTYPE_STRING ||
                 PB_LTYPE(type) == PB_LTYPE_BYTES)
             {
@@ -522,7 +558,7 @@ static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_
                     }
 
                     /* Decode the array entry */
-                    pItem = *(uint8_t**)iter->pData + iter->pos->data_size * (*size);
+                    pItem = *(char**)iter->pData + iter->pos->data_size * (*size);
                     initialize_pointer_field(pItem, iter);
                     if (!func(&substream, iter->pos, pItem))
                     {
@@ -541,7 +577,8 @@ static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_
                     
                     (*size)++;
                 }
-                pb_close_string_substream(stream, &substream);
+                if (!pb_close_string_substream(stream, &substream))
+                    return false;
                 
                 return status;
             }
@@ -558,11 +595,11 @@ static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_
                 if (!allocate_field(stream, iter->pData, iter->pos->data_size, *size))
                     return false;
             
-                pItem = *(uint8_t**)iter->pData + iter->pos->data_size * (*size - 1);
+                pItem = *(char**)iter->pData + iter->pos->data_size * (*size - 1);
                 initialize_pointer_field(pItem, iter);
                 return func(stream, iter->pos, pItem);
             }
-            
+
         default:
             PB_RETURN_ERROR(stream, "invalid field type");
     }
@@ -595,7 +632,9 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
                 PB_RETURN_ERROR(stream, "callback failed");
         } while (substream.bytes_left);
         
-        pb_close_string_substream(stream, &substream);
+        if (!pb_close_string_substream(stream, &substream))
+            return false;
+
         return true;
     }
     else
@@ -605,7 +644,7 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
          * which in turn allows to use same callback for packed and
          * not-packed fields. */
         pb_istream_t substream;
-        uint8_t buffer[10];
+        pb_byte_t buffer[10];
         size_t size = sizeof(buffer);
         
         if (!read_raw_value(stream, wire_type, buffer, &size))
@@ -618,6 +657,16 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
 
 static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
 {
+#ifdef PB_ENABLE_MALLOC
+    /* When decoding an oneof field, check if there is old data that must be
+     * released first. */
+    if (PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF)
+    {
+        if (!pb_release_union_field(stream, iter))
+            return false;
+    }
+#endif
+
     switch (PB_ATYPE(iter->pos->type))
     {
         case PB_ATYPE_STATIC:
@@ -737,13 +786,15 @@ static void pb_field_set_to_default(pb_field_iter_t *iter)
              * itself also. */
             *(bool*)iter->pSize = false;
         }
-        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
+                 PB_HTYPE(type) == PB_HTYPE_ONEOF)
         {
-            /* Set array count to 0, no need to initialize contents. */
+            /* REPEATED: Set array count to 0, no need to initialize contents.
+               ONEOF: Set which_field to 0. */
             *(pb_size_t*)iter->pSize = 0;
             init_data = false;
         }
-        
+
         if (init_data)
         {
             if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
@@ -769,7 +820,8 @@ static void pb_field_set_to_default(pb_field_iter_t *iter)
         *(void**)iter->pData = NULL;
         
         /* Initialize array count to 0. */
-        if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
+            PB_HTYPE(type) == PB_HTYPE_ONEOF)
         {
             *(pb_size_t*)iter->pSize = 0;
         }
@@ -799,7 +851,8 @@ static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_str
 
 bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
 {
-    uint8_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 7) / 8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    uint32_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 31) / 32] = {0, 0};
+    const uint32_t allbits = ~(uint32_t)0;
     uint32_t extension_range_start = 0;
     pb_field_iter_t iter;
     
@@ -855,7 +908,8 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
         if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REQUIRED
             && iter.required_field_index < PB_MAX_REQUIRED_FIELDS)
         {
-            fields_seen[iter.required_field_index >> 3] |= (uint8_t)(1 << (iter.required_field_index & 7));
+            uint32_t tmp = ((uint32_t)1 << (iter.required_field_index & 31));
+            fields_seen[iter.required_field_index >> 5] |= tmp;
         }
             
         if (!decode_field(stream, wire_type, &iter))
@@ -880,16 +934,19 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
         if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag != 0)
             req_field_count++;
         
-        /* Check the whole bytes */
-        for (i = 0; i < (req_field_count >> 3); i++)
+        if (req_field_count > 0)
         {
-            if (fields_seen[i] != 0xFF)
+            /* Check the whole words */
+            for (i = 0; i < (req_field_count >> 5); i++)
+            {
+                if (fields_seen[i] != allbits)
+                    PB_RETURN_ERROR(stream, "missing required field");
+            }
+            
+            /* Check the remaining bits */
+            if (fields_seen[req_field_count >> 5] != (allbits >> (32 - (req_field_count & 31))))
                 PB_RETURN_ERROR(stream, "missing required field");
         }
-        
-        /* Check the remaining bits */
-        if (fields_seen[req_field_count >> 3] != (0xFF >> (8 - (req_field_count & 7))))
-            PB_RETURN_ERROR(stream, "missing required field");
     }
     
     return true;
@@ -918,16 +975,99 @@ bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *
         return false;
     
     status = pb_decode(&substream, fields, dest_struct);
-    pb_close_string_substream(stream, &substream);
+
+    if (!pb_close_string_substream(stream, &substream))
+        return false;
     return status;
 }
 
 #ifdef PB_ENABLE_MALLOC
+/* Given an oneof field, if there has already been a field inside this oneof,
+ * release it before overwriting with a different one. */
+static bool pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *iter)
+{
+    pb_size_t old_tag = *(pb_size_t*)iter->pSize; /* Previous which_ value */
+    pb_size_t new_tag = iter->pos->tag; /* New which_ value */
+
+    if (old_tag == 0)
+        return true; /* Ok, no old data in union */
+
+    if (old_tag == new_tag)
+        return true; /* Ok, old data is of same type => merge */
+
+    /* Release old data. The find can fail if the message struct contains
+     * invalid data. */
+    if (!pb_field_iter_find(iter, old_tag))
+        PB_RETURN_ERROR(stream, "invalid union tag");
+
+    pb_release_single_field(iter);
+
+    /* Restore iterator to where it should be.
+     * This shouldn't fail unless the pb_field_t structure is corrupted. */
+    if (!pb_field_iter_find(iter, new_tag))
+        PB_RETURN_ERROR(stream, "iterator error");
+    
+    return true;
+}
+
 static void pb_release_single_field(const pb_field_iter_t *iter)
 {
     pb_type_t type;
     type = iter->pos->type;
 
+    if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
+    {
+        if (*(pb_size_t*)iter->pSize != iter->pos->tag)
+            return; /* This is not the current field in the union */
+    }
+
+    /* Release anything contained inside an extension or submsg.
+     * This has to be done even if the submsg itself is statically
+     * allocated. */
+    if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
+    {
+        /* Release fields from all extensions in the linked list */
+        pb_extension_t *ext = *(pb_extension_t**)iter->pData;
+        while (ext != NULL)
+        {
+            pb_field_iter_t ext_iter;
+            iter_from_extension(&ext_iter, ext);
+            pb_release_single_field(&ext_iter);
+            ext = ext->next;
+        }
+    }
+    else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+    {
+        /* Release fields in submessage or submsg array */
+        void *pItem = iter->pData;
+        pb_size_t count = 1;
+        
+        if (PB_ATYPE(type) == PB_ATYPE_POINTER)
+        {
+            pItem = *(void**)iter->pData;
+        }
+        
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+        {
+            count = *(pb_size_t*)iter->pSize;
+
+            if (PB_ATYPE(type) == PB_ATYPE_STATIC && count > iter->pos->array_size)
+            {
+                /* Protect against corrupted _count fields */
+                count = iter->pos->array_size;
+            }
+        }
+        
+        if (pItem)
+        {
+            while (count--)
+            {
+                pb_release((const pb_field_t*)iter->pos->ptr, pItem);
+                pItem = (char*)pItem + iter->pos->data_size;
+            }
+        }
+    }
+    
     if (PB_ATYPE(type) == PB_ATYPE_POINTER)
     {
         if (PB_HTYPE(type) == PB_HTYPE_REPEATED &&
@@ -942,28 +1082,12 @@ static void pb_release_single_field(const pb_field_iter_t *iter)
                 pb_free(*pItem);
                 *pItem++ = NULL;
             }
-            *(pb_size_t*)iter->pSize = 0;
         }
-        else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+        
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
         {
-            /* Release fields in submessages */
-            void *pItem = *(void**)iter->pData;
-            if (pItem)
-            {
-                pb_size_t count = 1;
-                
-                if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
-                {
-                    count = *(pb_size_t*)iter->pSize;
-                    *(pb_size_t*)iter->pSize = 0;
-                }
-                
-                while (count--)
-                {
-                    pb_release((const pb_field_t*)iter->pos->ptr, pItem);
-                    pItem = (uint8_t*)pItem + iter->pos->data_size;
-                }
-            }
+            /* We are going to release the array, so set the size to 0 */
+            *(pb_size_t*)iter->pSize = 0;
         }
         
         /* Release main item */
@@ -976,6 +1100,9 @@ void pb_release(const pb_field_t fields[], void *dest_struct)
 {
     pb_field_iter_t iter;
     
+    if (!dest_struct)
+        return; /* Ignore NULL pointers, similar to free() */
+
     if (!pb_field_iter_begin(&iter, fields, dest_struct))
         return; /* Empty message type */
     
@@ -1004,92 +1131,118 @@ bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest)
 
 bool pb_decode_fixed32(pb_istream_t *stream, void *dest)
 {
-    #ifdef __BIG_ENDIAN__
-    uint8_t *bytes = (uint8_t*)dest;
-    uint8_t lebytes[4];
-    
-    if (!pb_read(stream, lebytes, 4))
+    pb_byte_t bytes[4];
+
+    if (!pb_read(stream, bytes, 4))
         return false;
     
-    bytes[0] = lebytes[3];
-    bytes[1] = lebytes[2];
-    bytes[2] = lebytes[1];
-    bytes[3] = lebytes[0];
+    *(uint32_t*)dest = ((uint32_t)bytes[0] << 0) |
+                       ((uint32_t)bytes[1] << 8) |
+                       ((uint32_t)bytes[2] << 16) |
+                       ((uint32_t)bytes[3] << 24);
     return true;
-    #else
-    return pb_read(stream, (uint8_t*)dest, 4);
-    #endif   
 }
 
 bool pb_decode_fixed64(pb_istream_t *stream, void *dest)
 {
-    #ifdef __BIG_ENDIAN__
-    uint8_t *bytes = (uint8_t*)dest;
-    uint8_t lebytes[8];
-    
-    if (!pb_read(stream, lebytes, 8))
+    pb_byte_t bytes[8];
+
+    if (!pb_read(stream, bytes, 8))
         return false;
     
-    bytes[0] = lebytes[7];
-    bytes[1] = lebytes[6];
-    bytes[2] = lebytes[5];
-    bytes[3] = lebytes[4];
-    bytes[4] = lebytes[3];
-    bytes[5] = lebytes[2];
-    bytes[6] = lebytes[1];
-    bytes[7] = lebytes[0];
+    *(uint64_t*)dest = ((uint64_t)bytes[0] << 0) |
+                       ((uint64_t)bytes[1] << 8) |
+                       ((uint64_t)bytes[2] << 16) |
+                       ((uint64_t)bytes[3] << 24) |
+                       ((uint64_t)bytes[4] << 32) |
+                       ((uint64_t)bytes[5] << 40) |
+                       ((uint64_t)bytes[6] << 48) |
+                       ((uint64_t)bytes[7] << 56);
+    
     return true;
-    #else
-    return pb_read(stream, (uint8_t*)dest, 8);
-    #endif   
 }
 
 static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
     uint64_t value;
+    int64_t svalue;
+    int64_t clamped;
     if (!pb_decode_varint(stream, &value))
         return false;
     
-    switch (field->data_size)
-    {
-        case 1: *(int8_t*)dest = (int8_t)value; break;
-        case 2: *(int16_t*)dest = (int16_t)value; break;
-        case 4: *(int32_t*)dest = (int32_t)value; break;
-        case 8: *(int64_t*)dest = (int64_t)value; break;
-        default: PB_RETURN_ERROR(stream, "invalid data_size");
-    }
+    /* See issue 97: Google's C++ protobuf allows negative varint values to
+     * be cast as int32_t, instead of the int64_t that should be used when
+     * encoding. Previous nanopb versions had a bug in encoding. In order to
+     * not break decoding of such messages, we cast <=32 bit fields to
+     * int32_t first to get the sign correct.
+     */
+    if (field->data_size == sizeof(int64_t))
+        svalue = (int64_t)value;
+    else
+        svalue = (int32_t)value;
+
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(int64_t))
+        clamped = *(int64_t*)dest = svalue;
+    else if (field->data_size == sizeof(int32_t))
+        clamped = *(int32_t*)dest = (int32_t)svalue;
+    else if (field->data_size == sizeof(int_least16_t))
+        clamped = *(int_least16_t*)dest = (int_least16_t)svalue;
+    else if (field->data_size == sizeof(int_least8_t))
+        clamped = *(int_least8_t*)dest = (int_least8_t)svalue;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
+
+    if (clamped != svalue)
+        PB_RETURN_ERROR(stream, "integer too large");
     
     return true;
 }
 
 static bool checkreturn pb_dec_uvarint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-    uint64_t value;
+    uint64_t value, clamped;
     if (!pb_decode_varint(stream, &value))
         return false;
     
-    switch (field->data_size)
-    {
-        case 4: *(uint32_t*)dest = (uint32_t)value; break;
-        case 8: *(uint64_t*)dest = value; break;
-        default: PB_RETURN_ERROR(stream, "invalid data_size");
-    }
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(uint64_t))
+        clamped = *(uint64_t*)dest = value;
+    else if (field->data_size == sizeof(uint32_t))
+        clamped = *(uint32_t*)dest = (uint32_t)value;
+    else if (field->data_size == sizeof(uint_least16_t))
+        clamped = *(uint_least16_t*)dest = (uint_least16_t)value;
+    else if (field->data_size == sizeof(uint_least8_t))
+        clamped = *(uint_least8_t*)dest = (uint_least8_t)value;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
     
+    if (clamped != value)
+        PB_RETURN_ERROR(stream, "integer too large");
+
     return true;
 }
 
 static bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-    int64_t value;
+    int64_t value, clamped;
     if (!pb_decode_svarint(stream, &value))
         return false;
     
-    switch (field->data_size)
-    {
-        case 4: *(int32_t*)dest = (int32_t)value; break;
-        case 8: *(int64_t*)dest = value; break;
-        default: PB_RETURN_ERROR(stream, "invalid data_size");
-    }
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(int64_t))
+        clamped = *(int64_t*)dest = value;
+    else if (field->data_size == sizeof(int32_t))
+        clamped = *(int32_t*)dest = (int32_t)value;
+    else if (field->data_size == sizeof(int_least16_t))
+        clamped = *(int_least16_t*)dest = (int_least16_t)value;
+    else if (field->data_size == sizeof(int_least8_t))
+        clamped = *(int_least8_t*)dest = (int_least8_t)value;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
+
+    if (clamped != value)
+        PB_RETURN_ERROR(stream, "integer too large");
     
     return true;
 }
@@ -1173,8 +1326,8 @@ static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *fi
             PB_RETURN_ERROR(stream, "string overflow");
     }
     
-    status = pb_read(stream, (uint8_t*)dest, size);
-    *((uint8_t*)dest + size) = 0;
+    status = pb_read(stream, (pb_byte_t*)dest, size);
+    *((pb_byte_t*)dest + size) = 0;
     return status;
 }
 
@@ -1197,6 +1350,30 @@ static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t
     else
         status = pb_decode_noinit(&substream, submsg_fields, dest);
     
-    pb_close_string_substream(stream, &substream);
+    if (!pb_close_string_substream(stream, &substream))
+        return false;
     return status;
 }
+
+static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    uint32_t size;
+
+    if (!pb_decode_varint32(stream, &size))
+        return false;
+
+    if (size > PB_SIZE_MAX)
+        PB_RETURN_ERROR(stream, "bytes overflow");
+
+    if (size == 0)
+    {
+        /* As a special case, treat empty bytes string as all zeros for fixed_length_bytes. */
+        memset(dest, 0, field->data_size);
+        return true;
+    }
+
+    if (size != field->data_size)
+        PB_RETURN_ERROR(stream, "incorrect fixed length bytes size");
+
+    return pb_read(stream, (pb_byte_t*)dest, field->data_size);
+}