X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=pb_decode.c;h=7eda89a44217bf7dc5d3f8715780e53b45c14365;hb=6a022985845a0a50b32b7c1fb22f9aee1f675825;hp=48068325a77ed3804387bfac58ee7c3f2d1e8dfd;hpb=07f24f9b7022086187f60f52e786d0dbdbd3b7f1;p=apps%2Fagl-service-can-low-level.git

diff --git a/pb_decode.c b/pb_decode.c
index 48068325..7eda89a4 100644
--- a/pb_decode.c
+++ b/pb_decode.c
@@ -11,9 +11,9 @@
     #define checkreturn __attribute__((warn_unused_result))
 #endif
 
+#define NANOPB_INTERNALS
 #include "pb.h"
 #include "pb_decode.h"
-#include <string.h>
 
 typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest) checkreturn;
 
@@ -35,35 +35,67 @@ static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = {
  * pb_istream *
  **************/
 
-bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t count)
+static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count)
 {
-    if (stream->bytes_left < count)
-        return false;
+    uint8_t *source = (uint8_t*)stream->state;
+    stream->state = source + count;
     
-    if (!stream->callback(stream, buf, count))
-        return false;
+    if (buf != NULL)
+    {
+        while (count--)
+            *buf++ = *source++;
+    }
     
-    stream->bytes_left -= count;
     return true;
 }
 
-static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count)
+bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t count)
 {
-    uint8_t *source = (uint8_t*)stream->state;
+#ifndef PB_BUFFER_ONLY
+	if (buf == NULL && stream->callback != buf_read)
+	{
+		/* Skip input bytes */
+		uint8_t tmp[16];
+		while (count > 16)
+		{
+			if (!pb_read(stream, tmp, 16))
+				return false;
+			
+			count -= 16;
+		}
+		
+		return pb_read(stream, tmp, count);
+	}
+#endif
+
+    if (stream->bytes_left < count)
+        PB_RETURN_ERROR(stream, "end-of-stream");
     
-    if (buf != NULL)
-        memcpy(buf, source, count);
+#ifndef PB_BUFFER_ONLY
+    if (!stream->callback(stream, buf, count))
+        PB_RETURN_ERROR(stream, "io error");
+#else
+    if (!buf_read(stream, buf, count))
+        return false;
+#endif
     
-    stream->state = source + count;
+    stream->bytes_left -= count;
     return true;
 }
 
 pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
 {
     pb_istream_t stream;
+#ifdef PB_BUFFER_ONLY
+    stream.callback = NULL;
+#else
     stream.callback = &buf_read;
+#endif
     stream.state = buf;
     stream.bytes_left = bufsize;
+#ifndef PB_NO_ERRMSG
+    stream.errmsg = NULL;
+#endif
     return stream;
 }
 
@@ -73,28 +105,60 @@ pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
 
 static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
 {
-    uint64_t temp;
-    bool status = pb_decode_varint(stream, &temp);
-    *dest = (uint32_t)temp;
-    return status;
+    uint8_t byte;
+    uint32_t result;
+    
+    if (!pb_read(stream, &byte, 1))
+        return false;
+    
+    if (!(byte & 0x80))
+    {
+        /* Quick case, 1 byte value */
+        result = byte;
+    }
+    else
+    {
+        /* Multibyte case */
+        uint8_t bitpos = 7;
+        result = byte & 0x7F;
+        
+        do
+        {
+            if (bitpos >= 32)
+                PB_RETURN_ERROR(stream, "varint overflow");
+            
+            if (!pb_read(stream, &byte, 1))
+                return false;
+            
+            result |= (uint32_t)(byte & 0x7F) << bitpos;
+            bitpos = (uint8_t)(bitpos + 7);
+        } while (byte & 0x80);
+   }
+   
+   *dest = result;
+   return true;
 }
 
 bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
 {
     uint8_t byte;
     uint8_t bitpos = 0;
-    *dest = 0;
+    uint64_t result = 0;
     
-    while (bitpos < 64 && pb_read(stream, &byte, 1))
+    do
     {
-        *dest |= (uint64_t)(byte & 0x7F) << bitpos;
-        bitpos += 7;
+        if (bitpos >= 64)
+            PB_RETURN_ERROR(stream, "varint overflow");
         
-        if (!(byte & 0x80))
-            return true;
-    }
+        if (!pb_read(stream, &byte, 1))
+            return false;
+
+        result |= (uint64_t)(byte & 0x7F) << bitpos;
+        bitpos = (uint8_t)(bitpos + 7);
+    } while (byte & 0x80);
     
-    return false;
+    *dest = result;
+    return true;
 }
 
 bool checkreturn pb_skip_varint(pb_istream_t *stream)
@@ -151,7 +215,7 @@ bool checkreturn pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type)
         case PB_WT_64BIT: return pb_read(stream, NULL, 8);
         case PB_WT_STRING: return pb_skip_string(stream);
         case PB_WT_32BIT: return pb_read(stream, NULL, 4);
-        default: return false;
+        default: PB_RETURN_ERROR(stream, "invalid wire_type");
     }
 }
 
@@ -181,15 +245,14 @@ static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire
             *size = 4;
             return pb_read(stream, buf, 4);
         
-        default: return false;
+        default: PB_RETURN_ERROR(stream, "invalid wire_type");
     }
 }
 
 /* Decode string length from stream and return a substream with limited length.
- * Before disposing the substream, remember to copy the substream->state back
- * to stream->state.
+ * Remember to close the substream using pb_close_string_substream().
  */
-static bool checkreturn make_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+bool checkreturn pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream)
 {
     uint32_t size;
     if (!pb_decode_varint32(stream, &size))
@@ -197,19 +260,28 @@ static bool checkreturn make_string_substream(pb_istream_t *stream, pb_istream_t
     
     *substream = *stream;
     if (substream->bytes_left < size)
-        return false;
+        PB_RETURN_ERROR(stream, "parent stream too short");
     
     substream->bytes_left = size;
     stream->bytes_left -= size;
     return true;
 }
 
+void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+{
+    stream->state = substream->state;
+
+#ifndef PB_NO_ERRMSG
+    stream->errmsg = substream->errmsg;
+#endif
+}
+
 /* Iterator for pb_field_t list */
 typedef struct {
     const pb_field_t *start; /* Start of the pb_field_t array */
-    const pb_field_t *current; /* Current position of the iterator */
-    int field_index; /* Zero-based index of the field. */
-    int required_field_index; /* Zero-based index that counts only the required fields */
+    const pb_field_t *pos; /* Current position of the iterator */
+    unsigned field_index; /* Zero-based index of the field. */
+    unsigned required_field_index; /* Zero-based index that counts only the required fields */
     void *dest_struct; /* Pointer to the destination structure to decode to */
     void *pData; /* Pointer where to store current field value */
     void *pSize; /* Pointer where to store the size of current array field */
@@ -217,30 +289,36 @@ typedef struct {
 
 static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct)
 {
-    iter->start = iter->current = fields;
+    iter->start = iter->pos = fields;
     iter->field_index = 0;
     iter->required_field_index = 0;
-    iter->pData = (char*)dest_struct + iter->current->data_offset;
-    iter->pSize = (char*)iter->pData + iter->current->size_offset;
+    iter->pData = (char*)dest_struct + iter->pos->data_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
     iter->dest_struct = dest_struct;
 }
 
 static bool pb_field_next(pb_field_iterator_t *iter)
 {
     bool notwrapped = true;
-    size_t prev_size = iter->current->data_size;
+    size_t prev_size = iter->pos->data_size;
     
-    if (PB_HTYPE(iter->current->type) == PB_HTYPE_ARRAY)
-        prev_size *= iter->current->array_size;
+    if (PB_ATYPE(iter->pos->type) == PB_ATYPE_STATIC &&
+        PB_HTYPE(iter->pos->type) == PB_HTYPE_REPEATED)
+    {
+        prev_size *= iter->pos->array_size;
+    }
     
-    if (PB_HTYPE(iter->current->type) == PB_HTYPE_REQUIRED)
+    if (PB_HTYPE(iter->pos->type) == PB_HTYPE_REQUIRED)
         iter->required_field_index++;
     
-    iter->current++;
+    if (iter->pos->tag == 0)
+        return false; /* Only happens with empty message types */
+    
+    iter->pos++;
     iter->field_index++;
-    if (iter->current->tag == 0)
+    if (iter->pos->tag == 0)
     {
-        iter->current = iter->start;
+        iter->pos = iter->start;
         iter->field_index = 0;
         iter->required_field_index = 0;
         iter->pData = iter->dest_struct;
@@ -248,17 +326,17 @@ static bool pb_field_next(pb_field_iterator_t *iter)
         notwrapped = false;
     }
     
-    iter->pData = (char*)iter->pData + prev_size + iter->current->data_offset;
-    iter->pSize = (char*)iter->pData + iter->current->size_offset;
+    iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
     return notwrapped;
 }
 
 static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag)
 {
-    int start = iter->field_index;
+    unsigned start = iter->field_index;
     
     do {
-        if (iter->current->tag == tag)
+        if (iter->pos->tag == tag)
             return true;
         pb_field_next(iter);
     } while (iter->field_index != start);
@@ -270,96 +348,127 @@ static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag)
  * Decode a single field *
  *************************/
 
-static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
+static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
 {
-    pb_decoder_t func = PB_DECODERS[PB_LTYPE(iter->current->type)];
+    pb_type_t type;
+    pb_decoder_t func;
     
-    switch (PB_HTYPE(iter->current->type))
+    type = iter->pos->type;
+    func = PB_DECODERS[PB_LTYPE(type)];
+
+    switch (PB_HTYPE(type))
     {
         case PB_HTYPE_REQUIRED:
-            return func(stream, iter->current, iter->pData);
+            return func(stream, iter->pos, iter->pData);
             
         case PB_HTYPE_OPTIONAL:
             *(bool*)iter->pSize = true;
-            return func(stream, iter->current, iter->pData);
+            return func(stream, iter->pos, iter->pData);
     
-        case PB_HTYPE_ARRAY:
+        case PB_HTYPE_REPEATED:
             if (wire_type == PB_WT_STRING
-                && PB_LTYPE(iter->current->type) <= PB_LTYPE_LAST_PACKABLE)
+                && PB_LTYPE(type) <= PB_LTYPE_LAST_PACKABLE)
             {
                 /* Packed array */
-                bool status;
+                bool status = true;
                 size_t *size = (size_t*)iter->pSize;
                 pb_istream_t substream;
-                if (!make_string_substream(stream, &substream))
+                if (!pb_make_string_substream(stream, &substream))
                     return false;
                 
-                while (substream.bytes_left && *size < iter->current->array_size)
+                while (substream.bytes_left && *size < iter->pos->array_size)
                 {
-                    void *pItem = (uint8_t*)iter->pData + iter->current->data_size * (*size);
-                    if (!func(&substream, iter->current, pItem))
-                        return false;
+                    void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                    if (!func(&substream, iter->pos, pItem))
+                    {
+                        status = false;
+                        break;
+                    }
                     (*size)++;
                 }
-                status = (substream.bytes_left == 0);
-                stream->state = substream.state;
+                pb_close_string_substream(stream, &substream);
+                
+                if (substream.bytes_left != 0)
+                    PB_RETURN_ERROR(stream, "array overflow");
+                
                 return status;
             }
             else
             {
                 /* Repeated field */
                 size_t *size = (size_t*)iter->pSize;
-                void *pItem = (uint8_t*)iter->pData + iter->current->data_size * (*size);
-                if (*size >= iter->current->array_size)
-                    return false;
+                void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                if (*size >= iter->pos->array_size)
+                    PB_RETURN_ERROR(stream, "array overflow");
                 
                 (*size)++;
-                return func(stream, iter->current, pItem);
+                return func(stream, iter->pos, pItem);
             }
+
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
+    }
+}
+
+static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
+{
+    pb_callback_t *pCallback = (pb_callback_t*)iter->pData;
+    
+#ifdef PB_OLD_CALLBACK_STYLE
+    void *arg = pCallback->arg;
+#else
+    void **arg = &(pCallback->arg);
+#endif
+    
+    if (pCallback->funcs.decode == NULL)
+        return pb_skip_field(stream, wire_type);
+    
+    if (wire_type == PB_WT_STRING)
+    {
+        pb_istream_t substream;
+        
+        if (!pb_make_string_substream(stream, &substream))
+            return false;
         
-        case PB_HTYPE_CALLBACK:
+        while (substream.bytes_left)
         {
-            pb_callback_t *pCallback = (pb_callback_t*)iter->pData;
-            
-            if (pCallback->funcs.decode == NULL)
-                return pb_skip_field(stream, wire_type);
-            
-            if (wire_type == PB_WT_STRING)
-            {
-                pb_istream_t substream;
-                
-                if (!make_string_substream(stream, &substream))
-                    return false;
-                
-                while (substream.bytes_left)
-                {
-                    if (!pCallback->funcs.decode(&substream, iter->current, pCallback->arg))
-                        return false;
-                }
-                
-                stream->state = substream.state;
-                return true;
-            }
-            else
-            {
-                /* Copy the single scalar value to stack.
-                 * This is required so that we can limit the stream length,
-                 * which in turn allows to use same callback for packed and
-                 * not-packed fields. */
-                pb_istream_t substream;
-                uint8_t buffer[10];
-                size_t size = sizeof(buffer);
-                
-                if (!read_raw_value(stream, wire_type, buffer, &size))
-                    return false;
-                substream = pb_istream_from_buffer(buffer, size);
-                
-                return pCallback->funcs.decode(&substream, iter->current, pCallback->arg);
-            }
+            if (!pCallback->funcs.decode(&substream, iter->pos, arg))
+                PB_RETURN_ERROR(stream, "callback failed");
         }
         
-        default:
+        pb_close_string_substream(stream, &substream);
+        return true;
+    }
+    else
+    {
+        /* Copy the single scalar value to stack.
+         * This is required so that we can limit the stream length,
+         * which in turn allows to use same callback for packed and
+         * not-packed fields. */
+        pb_istream_t substream;
+        uint8_t buffer[10];
+        size_t size = sizeof(buffer);
+        
+        if (!read_raw_value(stream, wire_type, buffer, &size))
             return false;
+        substream = pb_istream_from_buffer(buffer, size);
+        
+        return pCallback->funcs.decode(&substream, iter->pos, arg);
+    }
+}
+
+static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
+{
+    switch (PB_ATYPE(iter->pos->type))
+    {
+        case PB_ATYPE_STATIC:
+            return decode_static_field(stream, wire_type, iter);
+        
+        case PB_ATYPE_CALLBACK:
+            return decode_callback_field(stream, wire_type, iter);
+        
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
     }
 }
 
@@ -372,37 +481,43 @@ static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_str
     /* Initialize size/has fields and apply default values */
     do
     {
-        if (iter.current->tag == 0)
+        pb_type_t type;
+        type = iter.pos->type;
+    
+        if (iter.pos->tag == 0)
             continue;
         
-        /* Initialize the size field for optional/repeated fields to 0. */
-        if (PB_HTYPE(iter.current->type) == PB_HTYPE_OPTIONAL)
-        {
-            *(bool*)iter.pSize = false;
-        }
-        else if (PB_HTYPE(iter.current->type) == PB_HTYPE_ARRAY)
+        if (PB_ATYPE(type) == PB_ATYPE_STATIC)
         {
-            *(size_t*)iter.pSize = 0;
-            continue; /* Array is empty, no need to initialize contents */
+            /* Initialize the size field for optional/repeated fields to 0. */
+            if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL)
+            {
+                *(bool*)iter.pSize = false;
+            }
+            else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+            {
+                *(size_t*)iter.pSize = 0;
+                continue; /* Array is empty, no need to initialize contents */
+            }
+            
+            /* Initialize field contents to default value */
+            if (PB_LTYPE(iter.pos->type) == PB_LTYPE_SUBMESSAGE)
+            {
+                pb_message_set_to_defaults((const pb_field_t *) iter.pos->ptr, iter.pData);
+            }
+            else if (iter.pos->ptr != NULL)
+            {
+                memcpy(iter.pData, iter.pos->ptr, iter.pos->data_size);
+            }
+            else
+            {
+                memset(iter.pData, 0, iter.pos->data_size);
+            }
         }
-        
-        /* Initialize field contents to default value */
-        if (PB_HTYPE(iter.current->type) == PB_HTYPE_CALLBACK)
+        else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
         {
             continue; /* Don't overwrite callback */
         }
-        else if (PB_LTYPE(iter.current->type) == PB_LTYPE_SUBMESSAGE)
-        {
-            pb_message_set_to_defaults((const pb_field_t *) iter.current->ptr, iter.pData);
-        }
-        else if (iter.current->ptr != NULL)
-        {
-            memcpy(iter.pData, iter.current->ptr, iter.current->data_size);
-        }
-        else
-        {
-            memset(iter.pData, 0, iter.current->data_size);
-        }
     } while (pb_field_next(&iter));
 }
 
@@ -410,13 +525,11 @@ static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_str
  * Decode all fields *
  *********************/
 
-bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+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}; /* Used to check for required fields */
     pb_field_iterator_t iter;
     
-    pb_message_set_to_defaults(fields, dest_struct);
-    
     pb_field_init(&iter, fields, dest_struct);
     
     while (stream->bytes_left)
@@ -441,10 +554,10 @@ bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void
             continue;
         }
         
-        if (PB_HTYPE(iter.current->type) == PB_HTYPE_REQUIRED
+        if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REQUIRED
             && iter.required_field_index < PB_MAX_REQUIRED_FIELDS)
         {
-            fields_seen[iter.required_field_index >> 3] |= 1 << (iter.required_field_index & 7);
+            fields_seen[iter.required_field_index >> 3] |= (uint8_t)(1 << (iter.required_field_index & 7));
         }
             
         if (!decode_field(stream, wire_type, &iter))
@@ -452,93 +565,146 @@ bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void
     }
     
     /* Check that all required fields were present. */
-    pb_field_init(&iter, fields, dest_struct);
-    do {
-        if (PB_HTYPE(iter.current->type) == PB_HTYPE_REQUIRED &&
-            iter.required_field_index < PB_MAX_REQUIRED_FIELDS &&
-            !(fields_seen[iter.required_field_index >> 3] & (1 << (iter.required_field_index & 7))))
+    {
+        /* First figure out the number of required fields by
+         * seeking to the end of the field array. Usually we
+         * are already close to end after decoding.
+         */
+        unsigned req_field_count;
+        pb_type_t last_type;
+        unsigned i;
+        do {
+            req_field_count = iter.required_field_index;
+            last_type = iter.pos->type;
+        } while (pb_field_next(&iter));
+        
+        /* Fixup if last field was also required. */
+        if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag)
+            req_field_count++;
+        
+        /* Check the whole bytes */
+        for (i = 0; i < (req_field_count >> 3); i++)
         {
-            return false;
+            if (fields_seen[i] != 0xFF)
+                PB_RETURN_ERROR(stream, "missing required field");
         }
-    } while (pb_field_next(&iter));
+        
+        /* 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;
 }
 
+bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    pb_message_set_to_defaults(fields, dest_struct);
+    return pb_decode_noinit(stream, fields, dest_struct);
+}
+
 /* Field decoders */
 
-/* Copy destsize bytes from src so that values are casted properly.
- * On little endian machine, copy first n bytes of src
- * On big endian machine, copy last n bytes of src
- * srcsize must always be larger than destsize
- */
-static void endian_copy(void *dest, void *src, size_t destsize, size_t srcsize)
+bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest)
 {
-#ifdef __BIG_ENDIAN__
-    memcpy(dest, (char*)src + (srcsize - destsize), destsize);
-#else
-    UNUSED(srcsize);
-    memcpy(dest, src, destsize);
-#endif
+    uint64_t value;
+    if (!pb_decode_varint(stream, &value))
+        return false;
+    
+    if (value & 1)
+        *dest = (int64_t)(~(value >> 1));
+    else
+        *dest = (int64_t)(value >> 1);
+    
+    return true;
+}
+
+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))
+        return false;
+    
+    bytes[0] = lebytes[3];
+    bytes[1] = lebytes[2];
+    bytes[2] = lebytes[1];
+    bytes[3] = lebytes[0];
+    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))
+        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];
+    return true;
+    #else
+    return pb_read(stream, (uint8_t*)dest, 8);
+    #endif   
 }
 
 bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-    uint64_t temp;
-    bool status = pb_decode_varint(stream, &temp);
-    endian_copy(dest, &temp, field->data_size, sizeof(temp));
-    return status;
+    uint64_t value;
+    if (!pb_decode_varint(stream, &value))
+        return false;
+    
+    switch (field->data_size)
+    {
+        case 1: *(uint8_t*)dest = (uint8_t)value; break;
+        case 2: *(uint16_t*)dest = (uint16_t)value; break;
+        case 4: *(uint32_t*)dest = (uint32_t)value; break;
+        case 8: *(uint64_t*)dest = value; break;
+        default: PB_RETURN_ERROR(stream, "invalid data_size");
+    }
+    
+    return true;
 }
 
 bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-    uint64_t temp;
-    bool status = pb_decode_varint(stream, &temp);
-    temp = (temp >> 1) ^ -(int64_t)(temp & 1);
-    endian_copy(dest, &temp, field->data_size, sizeof(temp));
-    return status;
+    int64_t value;
+    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");
+    }
+    
+    return true;
 }
 
 bool checkreturn pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-#ifdef __BIG_ENDIAN__
-    uint8_t bytes[4] = {0};
-    bool status = pb_read(stream, bytes, 4);
-    if (status) {
-        uint8_t *d = (uint8_t*)dest;
-        d[0] = bytes[3];
-        d[1] = bytes[2];
-        d[2] = bytes[1];
-        d[3] = bytes[0];
-    }
-    return status;
-#else
     UNUSED(field);
-    return pb_read(stream, (uint8_t*)dest, 4);
-#endif
+    return pb_decode_fixed32(stream, dest);
 }
 
 bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-#ifdef __BIG_ENDIAN__
-    uint8_t bytes[8] = {0};
-    bool status = pb_read(stream, bytes, 8);
-    if (status) {
-        uint8_t *d = (uint8_t*)dest;
-        d[0] = bytes[7];
-        d[1] = bytes[6];
-        d[2] = bytes[5]; 
-        d[3] = bytes[4];
-        d[4] = bytes[3];
-        d[5] = bytes[2];
-        d[6] = bytes[1];
-        d[7] = bytes[0];
-    }
-    return status;
-#else
     UNUSED(field);
-    return pb_read(stream, (uint8_t*)dest, 8);
-#endif
+    return pb_decode_fixed64(stream, dest);
 }
 
 bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest)
@@ -552,7 +718,7 @@ bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, voi
     
     /* Check length, noting the space taken by the size_t header. */
     if (x->size > field->data_size - offsetof(pb_bytes_array_t, bytes))
-        return false;
+        PB_RETURN_ERROR(stream, "bytes overflow");
     
     return pb_read(stream, x->bytes, x->size);
 }
@@ -566,7 +732,7 @@ bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, vo
     
     /* Check length, noting the null terminator */
     if (size + 1 > field->data_size)
-        return false;
+        PB_RETURN_ERROR(stream, "string overflow");
     
     status = pb_read(stream, (uint8_t*)dest, size);
     *((uint8_t*)dest + size) = 0;
@@ -577,14 +743,21 @@ bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field
 {
     bool status;
     pb_istream_t substream;
+    const pb_field_t* submsg_fields = (const pb_field_t*)field->ptr;
     
-    if (!make_string_substream(stream, &substream))
+    if (!pb_make_string_substream(stream, &substream))
         return false;
     
     if (field->ptr == NULL)
-        return false;
+        PB_RETURN_ERROR(stream, "invalid field descriptor");
+    
+    /* New array entries need to be initialized, while required and optional
+     * submessages have already been initialized in the top-level pb_decode. */
+    if (PB_HTYPE(field->type) == PB_HTYPE_REPEATED)
+        status = pb_decode(&substream, submsg_fields, dest);
+    else
+        status = pb_decode_noinit(&substream, submsg_fields, dest);
     
-    status = pb_decode(&substream, (pb_field_t*)field->ptr, dest);
-    stream->state = substream.state;
+    pb_close_string_substream(stream, &substream);
     return status;
 }