nanopb: fix import, update to 0.3.9.2

5 files changed, 2520 insertions, 0 deletions

diff --git a/include/lib/nanopb/pb.h b/include/lib/nanopb/pb.h
index a0dd323..3a5c760 100644
--- a/include/lib/nanopb/pb.h
+++ b/include/lib/nanopb/pb.h
@@ -66,6 +66,7 @@
 #include <stddef.h>
 #include <stdbool.h>
 #include <string.h>
+#include <limits.h>
 
 #ifdef PB_ENABLE_MALLOC
 #include <stdlib.h>
diff --git a/src/app/prototest/Makefile.inc b/src/app/prototest/Makefile.inc
index 0940fd2..3a9b4c3 100644
--- a/src/app/prototest/Makefile.inc
+++ b/src/app/prototest/Makefile.inc
@@ -23,3 +23,4 @@ endif
 %.pb.cc: %.proto
 	protoc --plugin=protoc-gen-nanopb=${HOME}/var/ess/protocol-modeling/nanopb/generator/protoc-gen-nanopb --nanopb_out=. src/app/prototest/nanopb.proto
 	mv src/app/prototest/nanopb.pb.c src/app/prototest/nanopb.pb.cc
+	sed -i 's!src/app/prototest/!!' src/app/prototest/nanopb.pb.cc
diff --git a/src/lib/nanopb/pb_common.cc b/src/lib/nanopb/pb_common.cc
new file mode 100644
index 0000000..4fb7186
--- /dev/null
+++ b/src/lib/nanopb/pb_common.cc
@@ -0,0 +1,97 @@
+/* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
+ *
+ * 2014 Petteri Aimonen <jpa@kapsi.fi>
+ */
+
+#include "pb_common.h"
+
+bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
+{
+    iter->start = fields;
+    iter->pos = fields;
+    iter->required_field_index = 0;
+    iter->dest_struct = dest_struct;
+    iter->pData = (char*)dest_struct + iter->pos->data_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
+    
+    return (iter->pos->tag != 0);
+}
+
+bool pb_field_iter_next(pb_field_iter_t *iter)
+{
+    const pb_field_t *prev_field = iter->pos;
+
+    if (prev_field->tag == 0)
+    {
+        /* Handle empty message types, where the first field is already the terminator.
+         * In other cases, the iter->pos never points to the terminator. */
+        return false;
+    }
+    
+    iter->pos++;
+    
+    if (iter->pos->tag == 0)
+    {
+        /* Wrapped back to beginning, reinitialize */
+        (void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
+        return false;
+    }
+    else
+    {
+        /* Increment the pointers based on previous field size */
+        size_t prev_size = prev_field->data_size;
+    
+        if (PB_HTYPE(prev_field->type) == PB_HTYPE_ONEOF &&
+            PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF &&
+            iter->pos->data_offset == PB_SIZE_MAX)
+        {
+            /* Don't advance pointers inside unions */
+            return true;
+        }
+        else if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
+                 PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
+        {
+            /* In static arrays, the data_size tells the size of a single entry and
+             * array_size is the number of entries */
+            prev_size *= prev_field->array_size;
+        }
+        else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
+        {
+            /* Pointer fields always have a constant size in the main structure.
+             * The data_size only applies to the dynamically allocated area. */
+            prev_size = sizeof(void*);
+        }
+
+        if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
+        {
+            /* Count the required fields, in order to check their presence in the
+             * decoder. */
+            iter->required_field_index++;
+        }
+    
+        iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
+        iter->pSize = (char*)iter->pData + iter->pos->size_offset;
+        return true;
+    }
+}
+
+bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
+{
+    const pb_field_t *start = iter->pos;
+    
+    do {
+        if (iter->pos->tag == tag &&
+            PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
+        {
+            /* Found the wanted field */
+            return true;
+        }
+        
+        (void)pb_field_iter_next(iter);
+    } while (iter->pos != start);
+    
+    /* Searched all the way back to start, and found nothing. */
+    return false;
+}
+
+
diff --git a/src/lib/nanopb/pb_decode.cc b/src/lib/nanopb/pb_decode.cc
new file mode 100644
index 0000000..d08259c
--- /dev/null
+++ b/src/lib/nanopb/pb_decode.cc
@@ -0,0 +1,1528 @@
+/* pb_decode.c -- decode a protobuf using minimal resources
+ *
+ * 2011 Petteri Aimonen <jpa@kapsi.fi>
+ */
+
+/* Use the GCC warn_unused_result attribute to check that all return values
+ * are propagated correctly. On other compilers and gcc before 3.4.0 just
+ * ignore the annotation.
+ */
+#if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
+    #define checkreturn
+#else
+    #define checkreturn __attribute__((warn_unused_result))
+#endif
+
+#include "pb.h"
+#include "pb_decode.h"
+#include "pb_common.h"
+
+/**************************************
+ * Declarations internal to this file *
+ **************************************/
+
+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, 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);
+static void iter_from_extension(pb_field_iter_t *iter, pb_extension_t *extension);
+static bool checkreturn default_extension_decoder(pb_istream_t *stream, pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type);
+static bool checkreturn decode_extension(pb_istream_t *stream, uint32_t tag, pb_wire_type_t wire_type, pb_field_iter_t *iter);
+static bool checkreturn find_extension_field(pb_field_iter_t *iter);
+static void pb_field_set_to_default(pb_field_iter_t *iter);
+static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct);
+static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest);
+static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof);
+static bool checkreturn pb_dec_uvarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
+static bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
+static bool checkreturn pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest);
+static bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest);
+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
+
+#ifdef PB_WITHOUT_64BIT
+#define pb_int64_t int32_t
+#define pb_uint64_t uint32_t
+#else
+#define pb_int64_t int64_t
+#define pb_uint64_t uint64_t
+#endif
+
+/* --- Function pointers to field decoders ---
+ * Order in the array must match pb_action_t LTYPE numbering.
+ */
+static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = {
+    &pb_dec_varint,
+    &pb_dec_uvarint,
+    &pb_dec_svarint,
+    &pb_dec_fixed32,
+    &pb_dec_fixed64,
+    
+    &pb_dec_bytes,
+    &pb_dec_string,
+    &pb_dec_submessage,
+    NULL, /* extensions */
+    &pb_dec_fixed_length_bytes
+};
+
+/*******************************
+ * pb_istream_t implementation *
+ *******************************/
+
+static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t 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)
+    {
+        for (i = 0; i < count; i++)
+            buf[i] = source[i];
+    }
+    
+    return true;
+}
+
+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 */
+		pb_byte_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");
+    
+#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->bytes_left -= count;
+    return true;
+}
+
+/* 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, pb_byte_t *buf)
+{
+    if (stream->bytes_left == 0)
+        PB_RETURN_ERROR(stream, "end-of-stream");
+
+#ifndef PB_BUFFER_ONLY
+    if (!stream->callback(stream, buf, 1))
+        PB_RETURN_ERROR(stream, "io error");
+#else
+    *buf = *(const pb_byte_t*)stream->state;
+    stream->state = (pb_byte_t*)stream->state + 1;
+#endif
+
+    stream->bytes_left--;
+    
+    return true;    
+}
+
+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
+    state.c_state = buf;
+    stream.state = state.state;
+    stream.bytes_left = bufsize;
+#ifndef PB_NO_ERRMSG
+    stream.errmsg = NULL;
+#endif
+    return stream;
+}
+
+/********************
+ * Helper functions *
+ ********************/
+
+static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof)
+{
+    pb_byte_t byte;
+    uint32_t result;
+    
+    if (!pb_readbyte(stream, &byte))
+    {
+        if (stream->bytes_left == 0)
+        {
+            if (eof)
+            {
+                *eof = true;
+            }
+        }
+
+        return false;
+    }
+    
+    if ((byte & 0x80) == 0)
+    {
+        /* Quick case, 1 byte value */
+        result = byte;
+    }
+    else
+    {
+        /* Multibyte case */
+        uint_fast8_t bitpos = 7;
+        result = byte & 0x7F;
+        
+        do
+        {
+            if (!pb_readbyte(stream, &byte))
+                return false;
+            
+            if (bitpos >= 32)
+            {
+                /* Note: The varint could have trailing 0x80 bytes, or 0xFF for negative. */
+                uint8_t sign_extension = (bitpos < 63) ? 0xFF : 0x01;
+                
+                if ((byte & 0x7F) != 0x00 && ((result >> 31) == 0 || byte != sign_extension))
+                {
+                    PB_RETURN_ERROR(stream, "varint overflow");
+                }
+            }
+            else
+            {
+                result |= (uint32_t)(byte & 0x7F) << bitpos;
+            }
+            bitpos = (uint_fast8_t)(bitpos + 7);
+        } while (byte & 0x80);
+        
+        if (bitpos == 35 && (byte & 0x70) != 0)
+        {
+            /* The last byte was at bitpos=28, so only bottom 4 bits fit. */
+            PB_RETURN_ERROR(stream, "varint overflow");
+        }
+   }
+   
+   *dest = result;
+   return true;
+}
+
+bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
+{
+    return pb_decode_varint32_eof(stream, dest, NULL);
+}
+
+#ifndef PB_WITHOUT_64BIT
+bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
+{
+    pb_byte_t byte;
+    uint_fast8_t bitpos = 0;
+    uint64_t result = 0;
+    
+    do
+    {
+        if (bitpos >= 64)
+            PB_RETURN_ERROR(stream, "varint overflow");
+        
+        if (!pb_readbyte(stream, &byte))
+            return false;
+
+        result |= (uint64_t)(byte & 0x7F) << bitpos;
+        bitpos = (uint_fast8_t)(bitpos + 7);
+    } while (byte & 0x80);
+    
+    *dest = result;
+    return true;
+}
+#endif
+
+bool checkreturn pb_skip_varint(pb_istream_t *stream)
+{
+    pb_byte_t byte;
+    do
+    {
+        if (!pb_read(stream, &byte, 1))
+            return false;
+    } while (byte & 0x80);
+    return true;
+}
+
+bool checkreturn pb_skip_string(pb_istream_t *stream)
+{
+    uint32_t length;
+    if (!pb_decode_varint32(stream, &length))
+        return false;
+    
+    return pb_read(stream, NULL, length);
+}
+
+bool checkreturn pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof)
+{
+    uint32_t temp;
+    *eof = false;
+    *wire_type = (pb_wire_type_t) 0;
+    *tag = 0;
+    
+    if (!pb_decode_varint32_eof(stream, &temp, eof))
+    {
+        return false;
+    }
+    
+    if (temp == 0)
+    {
+        *eof = true; /* Special feature: allow 0-terminated messages. */
+        return false;
+    }
+    
+    *tag = temp >> 3;
+    *wire_type = (pb_wire_type_t)(temp & 7);
+    return true;
+}
+
+bool checkreturn pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type)
+{
+    switch (wire_type)
+    {
+        case PB_WT_VARINT: return pb_skip_varint(stream);
+        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: PB_RETURN_ERROR(stream, "invalid 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, pb_byte_t *buf, size_t *size)
+{
+    size_t max_size = *size;
+    switch (wire_type)
+    {
+        case PB_WT_VARINT:
+            *size = 0;
+            do
+            {
+                (*size)++;
+                if (*size > max_size) return false;
+                if (!pb_read(stream, buf, 1)) return false;
+            } while (*buf++ & 0x80);
+            return true;
+            
+        case PB_WT_64BIT:
+            *size = 8;
+            return pb_read(stream, buf, 8);
+        
+        case PB_WT_32BIT:
+            *size = 4;
+            return pb_read(stream, buf, 4);
+        
+        case PB_WT_STRING:
+            /* Calling read_raw_value with a PB_WT_STRING is an error.
+             * Explicitly handle this case and fallthrough to default to avoid
+             * compiler warnings.
+             */
+
+        default: PB_RETURN_ERROR(stream, "invalid wire_type");
+    }
+}
+
+/* Decode string length from stream and return a substream with limited length.
+ * Remember to close the substream using pb_close_string_substream().
+ */
+bool checkreturn pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream)
+{
+    uint32_t size;
+    if (!pb_decode_varint32(stream, &size))
+        return false;
+    
+    *substream = *stream;
+    if (substream->bytes_left < size)
+        PB_RETURN_ERROR(stream, "parent stream too short");
+    
+    substream->bytes_left = size;
+    stream->bytes_left -= size;
+    return true;
+}
+
+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;
+}
+
+/*************************
+ * Decode a single field *
+ *************************/
+
+static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
+{
+    pb_type_t type;
+    pb_decoder_t func;
+    
+    type = iter->pos->type;
+    func = PB_DECODERS[PB_LTYPE(type)];
+
+    switch (PB_HTYPE(type))
+    {
+        case PB_HTYPE_REQUIRED:
+            return func(stream, iter->pos, iter->pData);
+            
+        case PB_HTYPE_OPTIONAL:
+            if (iter->pSize != iter->pData)
+                *(bool*)iter->pSize = true;
+            return func(stream, iter->pos, iter->pData);
+    
+        case PB_HTYPE_REPEATED:
+            if (wire_type == PB_WT_STRING
+                && PB_LTYPE(type) <= PB_LTYPE_LAST_PACKABLE)
+            {
+                /* Packed array */
+                bool status = true;
+                pb_size_t *size = (pb_size_t*)iter->pSize;
+
+                pb_istream_t substream;
+                if (!pb_make_string_substream(stream, &substream))
+                    return false;
+
+                while (substream.bytes_left > 0 && *size < iter->pos->array_size)
+                {
+                    void *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
+                    if (!func(&substream, iter->pos, pItem))
+                    {
+                        status = false;
+                        break;
+                    }
+                    (*size)++;
+                }
+
+                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;
+                char *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
+
+                if ((*size)++ >= iter->pos->array_size)
+                    PB_RETURN_ERROR(stream, "array overflow");
+
+                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");
+    }
+}
+
+#ifdef PB_ENABLE_MALLOC
+/* Allocate storage for the field and store the pointer at iter->pData.
+ * array_size is the number of entries to reserve in an array.
+ * Zero size is not allowed, use pb_free() for releasing.
+ */
+static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size)
+{    
+    void *ptr = *(void**)pData;
+    
+    if (data_size == 0 || array_size == 0)
+        PB_RETURN_ERROR(stream, "invalid size");
+    
+    /* Check for multiplication overflows.
+     * This code avoids the costly division if the sizes are small enough.
+     * Multiplication is safe as long as only half of bits are set
+     * in either multiplicand.
+     */
+    {
+        const size_t check_limit = (size_t)1 << (sizeof(size_t) * 4);
+        if (data_size >= check_limit || array_size >= check_limit)
+        {
+            const size_t size_max = (size_t)-1;
+            if (size_max / array_size < data_size)
+            {
+                PB_RETURN_ERROR(stream, "size too large");
+            }
+        }
+    }
+    
+    /* Allocate new or expand previous allocation */
+    /* Note: on failure the old pointer will remain in the structure,
+     * the message must be freed by caller also on error return. */
+    ptr = pb_realloc(ptr, array_size * data_size);
+    if (ptr == NULL)
+        PB_RETURN_ERROR(stream, "realloc failed");
+    
+    *(void**)pData = ptr;
+    return true;
+}
+
+/* Clear a newly allocated item in case it contains a pointer, or is a submessage. */
+static void initialize_pointer_field(void *pItem, pb_field_iter_t *iter)
+{
+    if (PB_LTYPE(iter->pos->type) == PB_LTYPE_STRING ||
+        PB_LTYPE(iter->pos->type) == PB_LTYPE_BYTES)
+    {
+        *(void**)pItem = NULL;
+    }
+    else if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
+    {
+        /* We memset to zero so that any callbacks are set to NULL.
+         * Then set any default values. */
+        memset(pItem, 0, iter->pos->data_size);
+        pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, pItem);
+    }
+}
+#endif
+
+static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
+{
+#ifndef PB_ENABLE_MALLOC
+    PB_UNUSED(wire_type);
+    PB_UNUSED(iter);
+    PB_RETURN_ERROR(stream, "no malloc support");
+#else
+    pb_type_t type;
+    pb_decoder_t func;
+    
+    type = iter->pos->type;
+    func = PB_DECODERS[PB_LTYPE(type)];
+    
+    switch (PB_HTYPE(type))
+    {
+        case PB_HTYPE_REQUIRED:
+        case PB_HTYPE_OPTIONAL:
+        case PB_HTYPE_ONEOF:
+            if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE &&
+                *(void**)iter->pData != NULL)
+            {
+                /* Duplicate field, have to release the old allocation first. */
+                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)
+            {
+                return func(stream, iter->pos, iter->pData);
+            }
+            else
+            {
+                if (!allocate_field(stream, iter->pData, iter->pos->data_size, 1))
+                    return false;
+                
+                initialize_pointer_field(*(void**)iter->pData, iter);
+                return func(stream, iter->pos, *(void**)iter->pData);
+            }
+    
+        case PB_HTYPE_REPEATED:
+            if (wire_type == PB_WT_STRING
+                && PB_LTYPE(type) <= PB_LTYPE_LAST_PACKABLE)
+            {
+                /* Packed array, multiple items come in at once. */
+                bool status = true;
+                pb_size_t *size = (pb_size_t*)iter->pSize;
+                size_t allocated_size = *size;
+                void *pItem;
+                pb_istream_t substream;
+                
+                if (!pb_make_string_substream(stream, &substream))
+                    return false;
+                
+                while (substream.bytes_left)
+                {
+                    if ((size_t)*size + 1 > allocated_size)
+                    {
+                        /* Allocate more storage. This tries to guess the
+                         * number of remaining entries. Round the division
+                         * upwards. */
+                        allocated_size += (substream.bytes_left - 1) / iter->pos->data_size + 1;
+                        
+                        if (!allocate_field(&substream, iter->pData, iter->pos->data_size, allocated_size))
+                        {
+                            status = false;
+                            break;
+                        }
+                    }
+
+                    /* Decode the array entry */
+                    pItem = *(char**)iter->pData + iter->pos->data_size * (*size);
+                    initialize_pointer_field(pItem, iter);
+                    if (!func(&substream, iter->pos, pItem))
+                    {
+                        status = false;
+                        break;
+                    }
+                    
+                    if (*size == PB_SIZE_MAX)
+                    {
+#ifndef PB_NO_ERRMSG
+                        stream->errmsg = "too many array entries";
+#endif
+                        status = false;
+                        break;
+                    }
+                    
+                    (*size)++;
+                }
+                if (!pb_close_string_substream(stream, &substream))
+                    return false;
+                
+                return status;
+            }
+            else
+            {
+                /* Normal repeated field, i.e. only one item at a time. */
+                pb_size_t *size = (pb_size_t*)iter->pSize;
+                void *pItem;
+                
+                if (*size == PB_SIZE_MAX)
+                    PB_RETURN_ERROR(stream, "too many array entries");
+                
+                (*size)++;
+                if (!allocate_field(stream, iter->pData, iter->pos->data_size, *size))
+                    return false;
+            
+                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");
+    }
+#endif
+}
+
+static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
+{
+    pb_callback_t *pCallback = (pb_callback_t*)iter->pData;
+#ifdef PB_OLD_CALLBACK_STYLE
+    void *arg;
+#else
+    void **arg;
+#endif
+    
+    if (pCallback == NULL || pCallback->funcs.decode == NULL)
+        return pb_skip_field(stream, wire_type);
+
+#ifdef PB_OLD_CALLBACK_STYLE
+    arg = pCallback->arg;
+#else
+    arg = &(pCallback->arg);
+#endif
+    
+    if (wire_type == PB_WT_STRING)
+    {
+        pb_istream_t substream;
+        
+        if (!pb_make_string_substream(stream, &substream))
+            return false;
+        
+        do
+        {
+            if (!pCallback->funcs.decode(&substream, iter->pos, arg))
+                PB_RETURN_ERROR(stream, "callback failed");
+        } while (substream.bytes_left);
+        
+        if (!pb_close_string_substream(stream, &substream))
+            return false;
+
+        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;
+        pb_byte_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_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:
+            return decode_static_field(stream, wire_type, iter);
+        
+        case PB_ATYPE_POINTER:
+            return decode_pointer_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");
+    }
+}
+
+static void iter_from_extension(pb_field_iter_t *iter, pb_extension_t *extension)
+{
+    /* Fake a field iterator for the extension field.
+     * It is not actually safe to advance this iterator, but decode_field
+     * will not even try to. */
+    const pb_field_t *field = (const pb_field_t*)extension->type->arg;
+    (void)pb_field_iter_begin(iter, field, extension->dest);
+    iter->pData = extension->dest;
+    iter->pSize = &extension->found;
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        /* For pointer extensions, the pointer is stored directly
+         * in the extension structure. This avoids having an extra
+         * indirection. */
+        iter->pData = &extension->dest;
+    }
+}
+
+/* Default handler for extension fields. Expects a pb_field_t structure
+ * in extension->type->arg. */
+static bool checkreturn default_extension_decoder(pb_istream_t *stream,
+    pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type)
+{
+    const pb_field_t *field = (const pb_field_t*)extension->type->arg;
+    pb_field_iter_t iter;
+    
+    if (field->tag != tag)
+        return true;
+    
+    iter_from_extension(&iter, extension);
+    extension->found = true;
+    return decode_field(stream, wire_type, &iter);
+}
+
+/* Try to decode an unknown field as an extension field. Tries each extension
+ * decoder in turn, until one of them handles the field or loop ends. */
+static bool checkreturn decode_extension(pb_istream_t *stream,
+    uint32_t tag, pb_wire_type_t wire_type, pb_field_iter_t *iter)
+{
+    pb_extension_t *extension = *(pb_extension_t* const *)iter->pData;
+    size_t pos = stream->bytes_left;
+    
+    while (extension != NULL && pos == stream->bytes_left)
+    {
+        bool status;
+        if (extension->type->decode)
+            status = extension->type->decode(stream, extension, tag, wire_type);
+        else
+            status = default_extension_decoder(stream, extension, tag, wire_type);
+
+        if (!status)
+            return false;
+        
+        extension = extension->next;
+    }
+    
+    return true;
+}
+
+/* Step through the iterator until an extension field is found or until all
+ * entries have been checked. There can be only one extension field per
+ * message. Returns false if no extension field is found. */
+static bool checkreturn find_extension_field(pb_field_iter_t *iter)
+{
+    const pb_field_t *start = iter->pos;
+    
+    do {
+        if (PB_LTYPE(iter->pos->type) == PB_LTYPE_EXTENSION)
+            return true;
+        (void)pb_field_iter_next(iter);
+    } while (iter->pos != start);
+    
+    return false;
+}
+
+/* Initialize message fields to default values, recursively */
+static void pb_field_set_to_default(pb_field_iter_t *iter)
+{
+    pb_type_t type;
+    type = iter->pos->type;
+    
+    if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
+    {
+        pb_extension_t *ext = *(pb_extension_t* const *)iter->pData;
+        while (ext != NULL)
+        {
+            pb_field_iter_t ext_iter;
+            ext->found = false;
+            iter_from_extension(&ext_iter, ext);
+            pb_field_set_to_default(&ext_iter);
+            ext = ext->next;
+        }
+    }
+    else if (PB_ATYPE(type) == PB_ATYPE_STATIC)
+    {
+        bool init_data = true;
+        if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && iter->pSize != iter->pData)
+        {
+            /* Set has_field to false. Still initialize the optional field
+             * itself also. */
+            *(bool*)iter->pSize = false;
+        }
+        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
+                 PB_HTYPE(type) == PB_HTYPE_ONEOF)
+        {
+            /* 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)
+            {
+                /* Initialize submessage to defaults */
+                pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, iter->pData);
+            }
+            else if (iter->pos->ptr != NULL)
+            {
+                /* Initialize to default value */
+                memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
+            }
+            else
+            {
+                /* Initialize to zeros */
+                memset(iter->pData, 0, iter->pos->data_size);
+            }
+        }
+    }
+    else if (PB_ATYPE(type) == PB_ATYPE_POINTER)
+    {
+        /* Initialize the pointer to NULL. */
+        *(void**)iter->pData = NULL;
+        
+        /* Initialize array count to 0. */
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
+            PB_HTYPE(type) == PB_HTYPE_ONEOF)
+        {
+            *(pb_size_t*)iter->pSize = 0;
+        }
+    }
+    else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
+    {
+        /* Don't overwrite callback */
+    }
+}
+
+static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct)
+{
+    pb_field_iter_t iter;
+
+    if (!pb_field_iter_begin(&iter, fields, dest_struct))
+        return; /* Empty message type */
+    
+    do
+    {
+        pb_field_set_to_default(&iter);
+    } while (pb_field_iter_next(&iter));
+}
+
+/*********************
+ * Decode all fields *
+ *********************/
+
+bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    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;
+
+    /* 'fixed_count_field' and 'fixed_count_size' track position of a repeated fixed
+     * count field. This can only handle _one_ repeated fixed count field that
+     * is unpacked and unordered among other (non repeated fixed count) fields.
+     */
+    const pb_field_t *fixed_count_field = NULL;
+    pb_size_t fixed_count_size = 0;
+
+    /* Return value ignored, as empty message types will be correctly handled by
+     * pb_field_iter_find() anyway. */
+    (void)pb_field_iter_begin(&iter, fields, dest_struct);
+
+    while (stream->bytes_left)
+    {
+        uint32_t tag;
+        pb_wire_type_t wire_type;
+        bool eof;
+
+        if (!pb_decode_tag(stream, &wire_type, &tag, &eof))
+        {
+            if (eof)
+                break;
+            else
+                return false;
+        }
+
+        if (!pb_field_iter_find(&iter, tag))
+        {
+            /* No match found, check if it matches an extension. */
+            if (tag >= extension_range_start)
+            {
+                if (!find_extension_field(&iter))
+                    extension_range_start = (uint32_t)-1;
+                else
+                    extension_range_start = iter.pos->tag;
+
+                if (tag >= extension_range_start)
+                {
+                    size_t pos = stream->bytes_left;
+
+                    if (!decode_extension(stream, tag, wire_type, &iter))
+                        return false;
+
+                    if (pos != stream->bytes_left)
+                    {
+                        /* The field was handled */
+                        continue;
+                    }
+                }
+            }
+
+            /* No match found, skip data */
+            if (!pb_skip_field(stream, wire_type))
+                return false;
+            continue;
+        }
+
+        /* If a repeated fixed count field was found, get size from
+         * 'fixed_count_field' as there is no counter contained in the struct.
+         */
+        if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REPEATED
+            && iter.pSize == iter.pData)
+        {
+            if (fixed_count_field != iter.pos) {
+                /* If the new fixed count field does not match the previous one,
+                 * check that the previous one is NULL or that it finished
+                 * receiving all the expected data.
+                 */
+                if (fixed_count_field != NULL &&
+                    fixed_count_size != fixed_count_field->array_size)
+                {
+                    PB_RETURN_ERROR(stream, "wrong size for fixed count field");
+                }
+
+                fixed_count_field = iter.pos;
+                fixed_count_size = 0;
+            }
+
+            iter.pSize = &fixed_count_size;
+        }
+
+        if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REQUIRED
+            && iter.required_field_index < PB_MAX_REQUIRED_FIELDS)
+        {
+            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))
+            return false;
+    }
+
+    /* Check that all elements of the last decoded fixed count field were present. */
+    if (fixed_count_field != NULL &&
+        fixed_count_size != fixed_count_field->array_size)
+    {
+        PB_RETURN_ERROR(stream, "wrong size for fixed count field");
+    }
+
+    /* Check that all required fields were present. */
+    {
+        /* 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_iter_next(&iter));
+        
+        /* Fixup if last field was also required. */
+        if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag != 0)
+            req_field_count++;
+        
+        if (req_field_count > PB_MAX_REQUIRED_FIELDS)
+            req_field_count = PB_MAX_REQUIRED_FIELDS;
+
+        if (req_field_count > 0)
+        {
+            /* 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 any) */
+            if ((req_field_count & 31) != 0)
+            {
+                if (fields_seen[req_field_count >> 5] !=
+                    (allbits >> (32 - (req_field_count & 31))))
+                {
+                    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)
+{
+    bool status;
+    pb_message_set_to_defaults(fields, dest_struct);
+    status = pb_decode_noinit(stream, fields, dest_struct);
+    
+#ifdef PB_ENABLE_MALLOC
+    if (!status)
+        pb_release(fields, dest_struct);
+#endif
+    
+    return status;
+}
+
+bool pb_decode_delimited_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    pb_istream_t substream;
+    bool status;
+
+    if (!pb_make_string_substream(stream, &substream))
+        return false;
+
+    status = pb_decode_noinit(&substream, fields, dest_struct);
+
+    if (!pb_close_string_substream(stream, &substream))
+        return false;
+    return status;
+}
+
+bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    pb_istream_t substream;
+    bool status;
+    
+    if (!pb_make_string_substream(stream, &substream))
+        return false;
+    
+    status = pb_decode(&substream, fields, dest_struct);
+
+    if (!pb_close_string_substream(stream, &substream))
+        return false;
+    return status;
+}
+
+bool pb_decode_nullterminated(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    /* This behaviour will be separated in nanopb-0.4.0, see issue #278. */
+    return pb_decode(stream, fields, dest_struct);
+}
+
+#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 && PB_ATYPE(type) != PB_ATYPE_CALLBACK)
+    {
+        /* 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)
+        {
+            if (PB_ATYPE(type) == PB_ATYPE_STATIC && iter->pSize == iter->pData) {
+                /* No _count field so use size of the array */
+                count = iter->pos->array_size;
+            } else {
+                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 &&
+            (PB_LTYPE(type) == PB_LTYPE_STRING ||
+             PB_LTYPE(type) == PB_LTYPE_BYTES))
+        {
+            /* Release entries in repeated string or bytes array */
+            void **pItem = *(void***)iter->pData;
+            pb_size_t count = *(pb_size_t*)iter->pSize;
+            while (count--)
+            {
+                pb_free(*pItem);
+                *pItem++ = NULL;
+            }
+        }
+        
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+        {
+            /* We are going to release the array, so set the size to 0 */
+            *(pb_size_t*)iter->pSize = 0;
+        }
+        
+        /* Release main item */
+        pb_free(*(void**)iter->pData);
+        *(void**)iter->pData = NULL;
+    }
+}
+
+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 */
+    
+    do
+    {
+        pb_release_single_field(&iter);
+    } while (pb_field_iter_next(&iter));
+}
+#endif
+
+/* Field decoders */
+
+bool pb_decode_svarint(pb_istream_t *stream, pb_int64_t *dest)
+{
+    pb_uint64_t value;
+    if (!pb_decode_varint(stream, &value))
+        return false;
+    
+    if (value & 1)
+        *dest = (pb_int64_t)(~(value >> 1));
+    else
+        *dest = (pb_int64_t)(value >> 1);
+    
+    return true;
+}
+
+bool pb_decode_fixed32(pb_istream_t *stream, void *dest)
+{
+    union {
+        uint32_t fixed32;
+        pb_byte_t bytes[4];
+    } u;
+
+    if (!pb_read(stream, u.bytes, 4))
+        return false;
+
+#if defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN && CHAR_BIT == 8
+    /* fast path - if we know that we're on little endian, assign directly */
+    *(uint32_t*)dest = u.fixed32;
+#else
+    *(uint32_t*)dest = ((uint32_t)u.bytes[0] << 0) |
+                       ((uint32_t)u.bytes[1] << 8) |
+                       ((uint32_t)u.bytes[2] << 16) |
+                       ((uint32_t)u.bytes[3] << 24);
+#endif
+    return true;
+}
+
+#ifndef PB_WITHOUT_64BIT
+bool pb_decode_fixed64(pb_istream_t *stream, void *dest)
+{
+    union {
+        uint64_t fixed64;
+        pb_byte_t bytes[8];
+    } u;
+
+    if (!pb_read(stream, u.bytes, 8))
+        return false;
+
+#if defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN && CHAR_BIT == 8
+    /* fast path - if we know that we're on little endian, assign directly */
+    *(uint64_t*)dest = u.fixed64;
+#else
+    *(uint64_t*)dest = ((uint64_t)u.bytes[0] << 0) |
+                       ((uint64_t)u.bytes[1] << 8) |
+                       ((uint64_t)u.bytes[2] << 16) |
+                       ((uint64_t)u.bytes[3] << 24) |
+                       ((uint64_t)u.bytes[4] << 32) |
+                       ((uint64_t)u.bytes[5] << 40) |
+                       ((uint64_t)u.bytes[6] << 48) |
+                       ((uint64_t)u.bytes[7] << 56);
+#endif
+    return true;
+}
+#endif
+
+static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    pb_uint64_t value;
+    pb_int64_t svalue;
+    pb_int64_t clamped;
+    if (!pb_decode_varint(stream, &value))
+        return false;
+    
+    /* 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(pb_int64_t))
+        svalue = (pb_int64_t)value;
+    else
+        svalue = (int32_t)value;
+
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(pb_int64_t))
+        clamped = *(pb_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)
+{
+    pb_uint64_t value, clamped;
+    if (!pb_decode_varint(stream, &value))
+        return false;
+    
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(pb_uint64_t))
+        clamped = *(pb_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)
+{
+    pb_int64_t value, clamped;
+    if (!pb_decode_svarint(stream, &value))
+        return false;
+    
+    /* Cast to the proper field size, while checking for overflows */
+    if (field->data_size == sizeof(pb_int64_t))
+        clamped = *(pb_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;
+}
+
+static bool checkreturn pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    PB_UNUSED(field);
+    return pb_decode_fixed32(stream, dest);
+}
+
+static bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    PB_UNUSED(field);
+#ifndef PB_WITHOUT_64BIT
+    return pb_decode_fixed64(stream, dest);
+#else
+    PB_UNUSED(dest);
+    PB_RETURN_ERROR(stream, "no 64bit support");
+#endif
+}
+
+static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    uint32_t size;
+    size_t alloc_size;
+    pb_bytes_array_t *bdest;
+    
+    if (!pb_decode_varint32(stream, &size))
+        return false;
+    
+    if (size > PB_SIZE_MAX)
+        PB_RETURN_ERROR(stream, "bytes overflow");
+    
+    alloc_size = PB_BYTES_ARRAY_T_ALLOCSIZE(size);
+    if (size > alloc_size)
+        PB_RETURN_ERROR(stream, "size too large");
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+#ifndef PB_ENABLE_MALLOC
+        PB_RETURN_ERROR(stream, "no malloc support");
+#else
+        if (!allocate_field(stream, dest, alloc_size, 1))
+            return false;
+        bdest = *(pb_bytes_array_t**)dest;
+#endif
+    }
+    else
+    {
+        if (alloc_size > field->data_size)
+            PB_RETURN_ERROR(stream, "bytes overflow");
+        bdest = (pb_bytes_array_t*)dest;
+    }
+
+    bdest->size = (pb_size_t)size;
+    return pb_read(stream, bdest->bytes, size);
+}
+
+static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    uint32_t size;
+    size_t alloc_size;
+    bool status;
+    if (!pb_decode_varint32(stream, &size))
+        return false;
+    
+    /* Space for null terminator */
+    alloc_size = size + 1;
+    
+    if (alloc_size < size)
+        PB_RETURN_ERROR(stream, "size too large");
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+#ifndef PB_ENABLE_MALLOC
+        PB_RETURN_ERROR(stream, "no malloc support");
+#else
+        if (!allocate_field(stream, dest, alloc_size, 1))
+            return false;
+        dest = *(void**)dest;
+#endif
+    }
+    else
+    {
+        if (alloc_size > field->data_size)
+            PB_RETURN_ERROR(stream, "string overflow");
+    }
+    
+    status = pb_read(stream, (pb_byte_t*)dest, size);
+    *((pb_byte_t*)dest + size) = 0;
+    return status;
+}
+
+static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest)
+{
+    bool status;
+    pb_istream_t substream;
+    const pb_field_t* submsg_fields = (const pb_field_t*)field->ptr;
+    
+    if (!pb_make_string_substream(stream, &substream))
+        return false;
+    
+    if (field->ptr == NULL)
+        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);
+    
+    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);
+}
diff --git a/src/lib/nanopb/pb_encode.cc b/src/lib/nanopb/pb_encode.cc
new file mode 100644
index 0000000..f37ceec
--- /dev/null
+++ b/src/lib/nanopb/pb_encode.cc
@@ -0,0 +1,893 @@
+/* pb_encode.c -- encode a protobuf using minimal resources
+ *
+ * 2011 Petteri Aimonen <jpa@kapsi.fi>
+ */
+
+#include "pb.h"
+#include "pb_encode.h"
+#include "pb_common.h"
+
+/* Use the GCC warn_unused_result attribute to check that all return values
+ * are propagated correctly. On other compilers and gcc before 3.4.0 just
+ * ignore the annotation.
+ */
+#if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
+    #define checkreturn
+#else
+    #define checkreturn __attribute__((warn_unused_result))
+#endif
+
+/**************************************
+ * Declarations internal to this file *
+ **************************************/
+typedef bool (*pb_encoder_t)(pb_ostream_t *stream, const pb_field_t *field, const void *src) checkreturn;
+
+static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count);
+static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, const void *pData, size_t count, pb_encoder_t func);
+static bool checkreturn encode_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
+static bool checkreturn default_extension_encoder(pb_ostream_t *stream, const pb_extension_t *extension);
+static bool checkreturn encode_extension_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
+static void *pb_const_cast(const void *p);
+static bool checkreturn pb_encode_varint_32(pb_ostream_t *stream, uint32_t low, uint32_t high);
+static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
+
+#ifdef PB_WITHOUT_64BIT
+#define pb_int64_t int32_t
+#define pb_uint64_t uint32_t
+#else
+#define pb_int64_t int64_t
+#define pb_uint64_t uint64_t
+#endif
+
+/* --- Function pointers to field encoders ---
+ * Order in the array must match pb_action_t LTYPE numbering.
+ */
+static const pb_encoder_t PB_ENCODERS[PB_LTYPES_COUNT] = {
+    &pb_enc_varint,
+    &pb_enc_uvarint,
+    &pb_enc_svarint,
+    &pb_enc_fixed32,
+    &pb_enc_fixed64,
+    
+    &pb_enc_bytes,
+    &pb_enc_string,
+    &pb_enc_submessage,
+    NULL, /* extensions */
+    &pb_enc_fixed_length_bytes
+};
+
+/*******************************
+ * pb_ostream_t implementation *
+ *******************************/
+
+static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
+{
+    size_t i;
+    pb_byte_t *dest = (pb_byte_t*)stream->state;
+    stream->state = dest + count;
+    
+    for (i = 0; i < count; i++)
+        dest[i] = buf[i];
+    
+    return true;
+}
+
+pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize)
+{
+    pb_ostream_t stream;
+#ifdef PB_BUFFER_ONLY
+    stream.callback = (void*)1; /* Just a marker value */
+#else
+    stream.callback = &buf_write;
+#endif
+    stream.state = buf;
+    stream.max_size = bufsize;
+    stream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    stream.errmsg = NULL;
+#endif
+    return stream;
+}
+
+bool checkreturn pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
+{
+    if (stream->callback != NULL)
+    {
+        if (stream->bytes_written + count > stream->max_size)
+            PB_RETURN_ERROR(stream, "stream full");
+
+#ifdef PB_BUFFER_ONLY
+        if (!buf_write(stream, buf, count))
+            PB_RETURN_ERROR(stream, "io error");
+#else        
+        if (!stream->callback(stream, buf, count))
+            PB_RETURN_ERROR(stream, "io error");
+#endif
+    }
+    
+    stream->bytes_written += count;
+    return true;
+}
+
+/*************************
+ * Encode a single field *
+ *************************/
+
+/* Encode a static array. Handles the size calculations and possible packing. */
+static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field,
+                         const void *pData, size_t count, pb_encoder_t func)
+{
+    size_t i;
+    const void *p;
+    size_t size;
+    
+    if (count == 0)
+        return true;
+
+    if (PB_ATYPE(field->type) != PB_ATYPE_POINTER && count > field->array_size)
+        PB_RETURN_ERROR(stream, "array max size exceeded");
+    
+    /* We always pack arrays if the datatype allows it. */
+    if (PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE)
+    {
+        if (!pb_encode_tag(stream, PB_WT_STRING, field->tag))
+            return false;
+        
+        /* Determine the total size of packed array. */
+        if (PB_LTYPE(field->type) == PB_LTYPE_FIXED32)
+        {
+            size = 4 * count;
+        }
+        else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED64)
+        {
+            size = 8 * count;
+        }
+        else
+        { 
+            pb_ostream_t sizestream = PB_OSTREAM_SIZING;
+            p = pData;
+            for (i = 0; i < count; i++)
+            {
+                if (!func(&sizestream, field, p))
+                    return false;
+                p = (const char*)p + field->data_size;
+            }
+            size = sizestream.bytes_written;
+        }
+        
+        if (!pb_encode_varint(stream, (pb_uint64_t)size))
+            return false;
+        
+        if (stream->callback == NULL)
+            return pb_write(stream, NULL, size); /* Just sizing.. */
+        
+        /* Write the data */
+        p = pData;
+        for (i = 0; i < count; i++)
+        {
+            if (!func(stream, field, p))
+                return false;
+            p = (const char*)p + field->data_size;
+        }
+    }
+    else
+    {
+        p = pData;
+        for (i = 0; i < count; i++)
+        {
+            if (!pb_encode_tag_for_field(stream, field))
+                return false;
+
+            /* Normally the data is stored directly in the array entries, but
+             * for pointer-type string and bytes fields, the array entries are
+             * actually pointers themselves also. So we have to dereference once
+             * more to get to the actual data. */
+            if (PB_ATYPE(field->type) == PB_ATYPE_POINTER &&
+                (PB_LTYPE(field->type) == PB_LTYPE_STRING ||
+                 PB_LTYPE(field->type) == PB_LTYPE_BYTES))
+            {
+                if (!func(stream, field, *(const void* const*)p))
+                    return false;
+            }
+            else
+            {
+                if (!func(stream, field, p))
+                    return false;
+            }
+            p = (const char*)p + field->data_size;
+        }
+    }
+    
+    return true;
+}
+
+/* In proto3, all fields are optional and are only encoded if their value is "non-zero".
+ * This function implements the check for the zero value. */
+static bool pb_check_proto3_default_value(const pb_field_t *field, const void *pData)
+{
+    pb_type_t type = field->type;
+    const void *pSize = (const char*)pData + field->size_offset;
+
+    if (PB_HTYPE(type) == PB_HTYPE_REQUIRED)
+    {
+        /* Required proto2 fields inside proto3 submessage, pretty rare case */
+        return false;
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+    {
+        /* Repeated fields inside proto3 submessage: present if count != 0 */
+        return *(const pb_size_t*)pSize == 0;
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
+    {
+        /* Oneof fields */
+        return *(const pb_size_t*)pSize == 0;
+    }
+    else if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && field->size_offset != 0)
+    {
+        /* Proto2 optional fields inside proto3 submessage */
+        return *(const bool*)pSize == false;
+    }
+
+    /* Rest is proto3 singular fields */
+
+    if (PB_ATYPE(type) == PB_ATYPE_STATIC)
+    {
+        if (PB_LTYPE(type) == PB_LTYPE_BYTES)
+        {
+            const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData;
+            return bytes->size == 0;
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_STRING)
+        {
+            return *(const char*)pData == '\0';
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_FIXED_LENGTH_BYTES)
+        {
+            /* Fixed length bytes is only empty if its length is fixed
+             * as 0. Which would be pretty strange, but we can check
+             * it anyway. */
+            return field->data_size == 0;
+        }
+        else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+        {
+            /* Check all fields in the submessage to find if any of them
+             * are non-zero. The comparison cannot be done byte-per-byte
+             * because the C struct may contain padding bytes that must
+             * be skipped.
+             */
+            pb_field_iter_t iter;
+            if (pb_field_iter_begin(&iter, (const pb_field_t*)field->ptr, pb_const_cast(pData)))
+            {
+                do
+                {
+                    if (!pb_check_proto3_default_value(iter.pos, iter.pData))
+                    {
+                        return false;
+                    }
+                } while (pb_field_iter_next(&iter));
+            }
+            return true;
+        }
+    }
+    
+	{
+	    /* Catch-all branch that does byte-per-byte comparison for zero value.
+	     *
+	     * This is for all pointer fields, and for static PB_LTYPE_VARINT,
+	     * UVARINT, SVARINT, FIXED32, FIXED64, EXTENSION fields, and also
+	     * callback fields. These all have integer or pointer value which
+	     * can be compared with 0.
+	     */
+	    pb_size_t i;
+	    const char *p = (const char*)pData;
+	    for (i = 0; i < field->data_size; i++)
+	    {
+	        if (p[i] != 0)
+	        {
+	            return false;
+	        }
+	    }
+
+	    return true;
+	}
+}
+
+/* Encode a field with static or pointer allocation, i.e. one whose data
+ * is available to the encoder directly. */
+static bool checkreturn encode_basic_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    pb_encoder_t func;
+    bool implicit_has;
+    const void *pSize = &implicit_has;
+    
+    func = PB_ENCODERS[PB_LTYPE(field->type)];
+    
+    if (field->size_offset)
+    {
+        /* Static optional, repeated or oneof field */
+        pSize = (const char*)pData + field->size_offset;
+    }
+    else if (PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL)
+    {
+        /* Proto3 style field, optional but without explicit has_ field. */
+        implicit_has = !pb_check_proto3_default_value(field, pData);
+    }
+    else
+    {
+        /* Required field, always present */
+        implicit_has = true;
+    }
+
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        /* pData is a pointer to the field, which contains pointer to
+         * the data. If the 2nd pointer is NULL, it is interpreted as if
+         * the has_field was false.
+         */
+        pData = *(const void* const*)pData;
+        implicit_has = (pData != NULL);
+    }
+
+    switch (PB_HTYPE(field->type))
+    {
+        case PB_HTYPE_REQUIRED:
+            if (!pData)
+                PB_RETURN_ERROR(stream, "missing required field");
+            if (!pb_encode_tag_for_field(stream, field))
+                return false;
+            if (!func(stream, field, pData))
+                return false;
+            break;
+        
+        case PB_HTYPE_OPTIONAL:
+            if (*(const bool*)pSize)
+            {
+                if (!pb_encode_tag_for_field(stream, field))
+                    return false;
+            
+                if (!func(stream, field, pData))
+                    return false;
+            }
+            break;
+        
+        case PB_HTYPE_REPEATED: {
+            pb_size_t count;
+            if (field->size_offset != 0) {
+                count = *(const pb_size_t*)pSize;
+            } else {
+                count = field->array_size;
+            }
+            if (!encode_array(stream, field, pData, count, func))
+                return false;
+            break;
+        }
+        
+        case PB_HTYPE_ONEOF:
+            if (*(const pb_size_t*)pSize == field->tag)
+            {
+                if (!pb_encode_tag_for_field(stream, field))
+                    return false;
+
+                if (!func(stream, field, pData))
+                    return false;
+            }
+            break;
+            
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
+    }
+    
+    return true;
+}
+
+/* Encode a field with callback semantics. This means that a user function is
+ * called to provide and encode the actual data. */
+static bool checkreturn encode_callback_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    const pb_callback_t *callback = (const pb_callback_t*)pData;
+    
+#ifdef PB_OLD_CALLBACK_STYLE
+    const void *arg = callback->arg;
+#else
+    void * const *arg = &(callback->arg);
+#endif    
+    
+    if (callback->funcs.encode != NULL)
+    {
+        if (!callback->funcs.encode(stream, field, arg))
+            PB_RETURN_ERROR(stream, "callback error");
+    }
+    return true;
+}
+
+/* Encode a single field of any callback or static type. */
+static bool checkreturn encode_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    switch (PB_ATYPE(field->type))
+    {
+        case PB_ATYPE_STATIC:
+        case PB_ATYPE_POINTER:
+            return encode_basic_field(stream, field, pData);
+        
+        case PB_ATYPE_CALLBACK:
+            return encode_callback_field(stream, field, pData);
+        
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
+    }
+}
+
+/* Default handler for extension fields. Expects to have a pb_field_t
+ * pointer in the extension->type->arg field. */
+static bool checkreturn default_extension_encoder(pb_ostream_t *stream,
+    const pb_extension_t *extension)
+{
+    const pb_field_t *field = (const pb_field_t*)extension->type->arg;
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        /* For pointer extensions, the pointer is stored directly
+         * in the extension structure. This avoids having an extra
+         * indirection. */
+        return encode_field(stream, field, &extension->dest);
+    }
+    else
+    {
+        return encode_field(stream, field, extension->dest);
+    }
+}
+
+/* Walk through all the registered extensions and give them a chance
+ * to encode themselves. */
+static bool checkreturn encode_extension_field(pb_ostream_t *stream,
+    const pb_field_t *field, const void *pData)
+{
+    const pb_extension_t *extension = *(const pb_extension_t* const *)pData;
+    PB_UNUSED(field);
+    
+    while (extension)
+    {
+        bool status;
+        if (extension->type->encode)
+            status = extension->type->encode(stream, extension);
+        else
+            status = default_extension_encoder(stream, extension);
+
+        if (!status)
+            return false;
+        
+        extension = extension->next;
+    }
+    
+    return true;
+}
+
+/*********************
+ * Encode all fields *
+ *********************/
+
+static void *pb_const_cast(const void *p)
+{
+    /* Note: this casts away const, in order to use the common field iterator
+     * logic for both encoding and decoding. */
+    union {
+        void *p1;
+        const void *p2;
+    } t;
+    t.p2 = p;
+    return t.p1;
+}
+
+bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    pb_field_iter_t iter;
+    if (!pb_field_iter_begin(&iter, fields, pb_const_cast(src_struct)))
+        return true; /* Empty message type */
+    
+    do {
+        if (PB_LTYPE(iter.pos->type) == PB_LTYPE_EXTENSION)
+        {
+            /* Special case for the extension field placeholder */
+            if (!encode_extension_field(stream, iter.pos, iter.pData))
+                return false;
+        }
+        else
+        {
+            /* Regular field */
+            if (!encode_field(stream, iter.pos, iter.pData))
+                return false;
+        }
+    } while (pb_field_iter_next(&iter));
+    
+    return true;
+}
+
+bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    return pb_encode_submessage(stream, fields, src_struct);
+}
+
+bool pb_encode_nullterminated(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    const pb_byte_t zero = 0;
+
+    if (!pb_encode(stream, fields, src_struct))
+        return false;
+
+    return pb_write(stream, &zero, 1);
+}
+
+bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct)
+{
+    pb_ostream_t stream = PB_OSTREAM_SIZING;
+    
+    if (!pb_encode(&stream, fields, src_struct))
+        return false;
+    
+    *size = stream.bytes_written;
+    return true;
+}
+
+/********************
+ * Helper functions *
+ ********************/
+
+/* This function avoids 64-bit shifts as they are quite slow on many platforms. */
+static bool checkreturn pb_encode_varint_32(pb_ostream_t *stream, uint32_t low, uint32_t high)
+{
+    size_t i = 0;
+    pb_byte_t buffer[10];
+    pb_byte_t byte = (pb_byte_t)(low & 0x7F);
+    low >>= 7;
+
+    while (i < 4 && (low != 0 || high != 0))
+    {
+        byte |= 0x80;
+        buffer[i++] = byte;
+        byte = (pb_byte_t)(low & 0x7F);
+        low >>= 7;
+    }
+
+    if (high)
+    {
+        byte = (pb_byte_t)(byte | ((high & 0x07) << 4));
+        high >>= 3;
+
+        while (high)
+        {
+            byte |= 0x80;
+            buffer[i++] = byte;
+            byte = (pb_byte_t)(high & 0x7F);
+            high >>= 7;
+        }
+    }
+
+    buffer[i++] = byte;
+
+    return pb_write(stream, buffer, i);
+}
+
+bool checkreturn pb_encode_varint(pb_ostream_t *stream, pb_uint64_t value)
+{
+    if (value <= 0x7F)
+    {
+        /* Fast path: single byte */
+        pb_byte_t byte = (pb_byte_t)value;
+        return pb_write(stream, &byte, 1);
+    }
+    else
+    {
+#ifdef PB_WITHOUT_64BIT
+        return pb_encode_varint_32(stream, value, 0);
+#else
+        return pb_encode_varint_32(stream, (uint32_t)value, (uint32_t)(value >> 32));
+#endif
+    }
+}
+
+bool checkreturn pb_encode_svarint(pb_ostream_t *stream, pb_int64_t value)
+{
+    pb_uint64_t zigzagged;
+    if (value < 0)
+        zigzagged = ~((pb_uint64_t)value << 1);
+    else
+        zigzagged = (pb_uint64_t)value << 1;
+    
+    return pb_encode_varint(stream, zigzagged);
+}
+
+bool checkreturn pb_encode_fixed32(pb_ostream_t *stream, const void *value)
+{
+    uint32_t val = *(const uint32_t*)value;
+    pb_byte_t bytes[4];
+    bytes[0] = (pb_byte_t)(val & 0xFF);
+    bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
+    bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
+    bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
+    return pb_write(stream, bytes, 4);
+}
+
+#ifndef PB_WITHOUT_64BIT
+bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value)
+{
+    uint64_t val = *(const uint64_t*)value;
+    pb_byte_t bytes[8];
+    bytes[0] = (pb_byte_t)(val & 0xFF);
+    bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
+    bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
+    bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
+    bytes[4] = (pb_byte_t)((val >> 32) & 0xFF);
+    bytes[5] = (pb_byte_t)((val >> 40) & 0xFF);
+    bytes[6] = (pb_byte_t)((val >> 48) & 0xFF);
+    bytes[7] = (pb_byte_t)((val >> 56) & 0xFF);
+    return pb_write(stream, bytes, 8);
+}
+#endif
+
+bool checkreturn pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number)
+{
+    pb_uint64_t tag = ((pb_uint64_t)field_number << 3) | wiretype;
+    return pb_encode_varint(stream, tag);
+}
+
+bool checkreturn pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field)
+{
+    pb_wire_type_t wiretype;
+    switch (PB_LTYPE(field->type))
+    {
+        case PB_LTYPE_VARINT:
+        case PB_LTYPE_UVARINT:
+        case PB_LTYPE_SVARINT:
+            wiretype = PB_WT_VARINT;
+            break;
+        
+        case PB_LTYPE_FIXED32:
+            wiretype = PB_WT_32BIT;
+            break;
+        
+        case PB_LTYPE_FIXED64:
+            wiretype = PB_WT_64BIT;
+            break;
+        
+        case PB_LTYPE_BYTES:
+        case PB_LTYPE_STRING:
+        case PB_LTYPE_SUBMESSAGE:
+        case PB_LTYPE_FIXED_LENGTH_BYTES:
+            wiretype = PB_WT_STRING;
+            break;
+        
+        default:
+            PB_RETURN_ERROR(stream, "invalid field type");
+    }
+    
+    return pb_encode_tag(stream, wiretype, field->tag);
+}
+
+bool checkreturn pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size)
+{
+    if (!pb_encode_varint(stream, (pb_uint64_t)size))
+        return false;
+    
+    return pb_write(stream, buffer, size);
+}
+
+bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
+{
+    /* First calculate the message size using a non-writing substream. */
+    pb_ostream_t substream = PB_OSTREAM_SIZING;
+    size_t size;
+    bool status;
+    
+    if (!pb_encode(&substream, fields, src_struct))
+    {
+#ifndef PB_NO_ERRMSG
+        stream->errmsg = substream.errmsg;
+#endif
+        return false;
+    }
+    
+    size = substream.bytes_written;
+    
+    if (!pb_encode_varint(stream, (pb_uint64_t)size))
+        return false;
+    
+    if (stream->callback == NULL)
+        return pb_write(stream, NULL, size); /* Just sizing */
+    
+    if (stream->bytes_written + size > stream->max_size)
+        PB_RETURN_ERROR(stream, "stream full");
+        
+    /* Use a substream to verify that a callback doesn't write more than
+     * what it did the first time. */
+    substream.callback = stream->callback;
+    substream.state = stream->state;
+    substream.max_size = size;
+    substream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    substream.errmsg = NULL;
+#endif
+    
+    status = pb_encode(&substream, fields, src_struct);
+    
+    stream->bytes_written += substream.bytes_written;
+    stream->state = substream.state;
+#ifndef PB_NO_ERRMSG
+    stream->errmsg = substream.errmsg;
+#endif
+    
+    if (substream.bytes_written != size)
+        PB_RETURN_ERROR(stream, "submsg size changed");
+    
+    return status;
+}
+
+/* Field encoders */
+
+static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    pb_int64_t value = 0;
+    
+    if (field->data_size == sizeof(int_least8_t))
+        value = *(const int_least8_t*)src;
+    else if (field->data_size == sizeof(int_least16_t))
+        value = *(const int_least16_t*)src;
+    else if (field->data_size == sizeof(int32_t))
+        value = *(const int32_t*)src;
+    else if (field->data_size == sizeof(pb_int64_t))
+        value = *(const pb_int64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
+    
+#ifdef PB_WITHOUT_64BIT
+    if (value < 0)
+        return pb_encode_varint_32(stream, (uint32_t)value, (uint32_t)-1);
+    else
+#endif
+        return pb_encode_varint(stream, (pb_uint64_t)value);
+}
+
+static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    pb_uint64_t value = 0;
+    
+    if (field->data_size == sizeof(uint_least8_t))
+        value = *(const uint_least8_t*)src;
+    else if (field->data_size == sizeof(uint_least16_t))
+        value = *(const uint_least16_t*)src;
+    else if (field->data_size == sizeof(uint32_t))
+        value = *(const uint32_t*)src;
+    else if (field->data_size == sizeof(pb_uint64_t))
+        value = *(const pb_uint64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
+    
+    return pb_encode_varint(stream, value);
+}
+
+static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    pb_int64_t value = 0;
+    
+    if (field->data_size == sizeof(int_least8_t))
+        value = *(const int_least8_t*)src;
+    else if (field->data_size == sizeof(int_least16_t))
+        value = *(const int_least16_t*)src;
+    else if (field->data_size == sizeof(int32_t))
+        value = *(const int32_t*)src;
+    else if (field->data_size == sizeof(pb_int64_t))
+        value = *(const pb_int64_t*)src;
+    else
+        PB_RETURN_ERROR(stream, "invalid data_size");
+    
+    return pb_encode_svarint(stream, value);
+}
+
+static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    PB_UNUSED(field);
+#ifndef PB_WITHOUT_64BIT
+    return pb_encode_fixed64(stream, src);
+#else
+    PB_UNUSED(src);
+    PB_RETURN_ERROR(stream, "no 64bit support");
+#endif
+}
+
+static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    PB_UNUSED(field);
+    return pb_encode_fixed32(stream, src);
+}
+
+static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    const pb_bytes_array_t *bytes = NULL;
+
+    bytes = (const pb_bytes_array_t*)src;
+    
+    if (src == NULL)
+    {
+        /* Treat null pointer as an empty bytes field */
+        return pb_encode_string(stream, NULL, 0);
+    }
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_STATIC &&
+        PB_BYTES_ARRAY_T_ALLOCSIZE(bytes->size) > field->data_size)
+    {
+        PB_RETURN_ERROR(stream, "bytes size exceeded");
+    }
+    
+    return pb_encode_string(stream, bytes->bytes, bytes->size);
+}
+
+static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    size_t size = 0;
+    size_t max_size = field->data_size;
+    const char *p = (const char*)src;
+    
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
+    {
+        max_size = (size_t)-1;
+    }
+    else
+    {
+        /* pb_dec_string() assumes string fields end with a null
+         * terminator when the type isn't PB_ATYPE_POINTER, so we
+         * shouldn't allow more than max-1 bytes to be written to
+         * allow space for the null terminator.
+         */
+        if (max_size == 0)
+            PB_RETURN_ERROR(stream, "zero-length string");
+
+        max_size -= 1;
+    }
+
+
+    if (src == NULL)
+    {
+        size = 0; /* Treat null pointer as an empty string */
+    }
+    else
+    {
+        /* strnlen() is not always available, so just use a loop */
+        while (size < max_size && *p != '\0')
+        {
+            size++;
+            p++;
+        }
+
+        if (*p != '\0')
+        {
+            PB_RETURN_ERROR(stream, "unterminated string");
+        }
+    }
+
+    return pb_encode_string(stream, (const pb_byte_t*)src, size);
+}
+
+static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    if (field->ptr == NULL)
+        PB_RETURN_ERROR(stream, "invalid field descriptor");
+    
+    return pb_encode_submessage(stream, (const pb_field_t*)field->ptr, src);
+}
+
+static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
+{
+    return pb_encode_string(stream, (const pb_byte_t*)src, field->data_size);
+}
+