X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=pb_decode.c;h=b21bfe37f37c854cf7898f95f5f4e1ab9e246ebc;hb=1f86b707e3a845f2c403e77173d0859dbf6aa4b0;hp=fba8f64ca745c99e3816f2a68aea52bebc9f0963;hpb=e1b8a555f30d77a3c0094cf3678666b38f4b4bd3;p=apps%2Fagl-service-can-low-level.git

diff --git a/pb_decode.c b/pb_decode.c
index fba8f64c..b21bfe37 100644
--- a/pb_decode.c
+++ b/pb_decode.c
@@ -3,38 +3,74 @@
  * 2011 Petteri Aimonen <jpa@kapsi.fi>
  */
 
-/* The warn_unused_result attribute appeared first in gcc-3.4.0 */
+/* 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
-    /* Verify that we remember to check all return values for proper error propagation */
     #define checkreturn __attribute__((warn_unused_result))
 #endif
 
-#define NANOPB_INTERNALS
 #include "pb.h"
 #include "pb_decode.h"
-#include <string.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, uint8_t *buf, size_t count);
+static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest);
+static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, uint8_t *buf, size_t *size);
+static bool checkreturn 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_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_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
+
 /* --- 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
+    &pb_dec_submessage,
+    NULL /* extensions */
 };
 
-/**************
- * pb_istream *
- **************/
+/*******************************
+ * pb_istream_t implementation *
+ *******************************/
 
 static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count)
 {
@@ -84,6 +120,26 @@ bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t 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, uint8_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 = *(uint8_t*)stream->state;
+    stream->state = (uint8_t*)stream->state + 1;
+#endif
+
+    stream->bytes_left--;
+    
+    return true;    
+}
+
 pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
 {
     pb_istream_t stream;
@@ -109,10 +165,10 @@ static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
     uint8_t byte;
     uint32_t result;
     
-    if (!pb_read(stream, &byte, 1))
+    if (!pb_readbyte(stream, &byte))
         return false;
     
-    if (!(byte & 0x80))
+    if ((byte & 0x80) == 0)
     {
         /* Quick case, 1 byte value */
         result = byte;
@@ -128,7 +184,7 @@ static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
             if (bitpos >= 32)
                 PB_RETURN_ERROR(stream, "varint overflow");
             
-            if (!pb_read(stream, &byte, 1))
+            if (!pb_readbyte(stream, &byte))
                 return false;
             
             result |= (uint32_t)(byte & 0x7F) << bitpos;
@@ -151,7 +207,7 @@ bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
         if (bitpos >= 64)
             PB_RETURN_ERROR(stream, "varint overflow");
         
-        if (!pb_read(stream, &byte, 1))
+        if (!pb_readbyte(stream, &byte))
             return false;
 
         result |= (uint64_t)(byte & 0x7F) << bitpos;
@@ -277,144 +333,270 @@ void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
 #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 */
-    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 */
-} pb_field_iterator_t;
-
-static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct)
-{
-    iter->start = iter->current = 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->dest_struct = dest_struct;
-}
+/*************************
+ * Decode a single field *
+ *************************/
 
-static bool pb_field_next(pb_field_iterator_t *iter)
+static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
 {
-    bool notwrapped = true;
-    size_t prev_size = iter->current->data_size;
+    pb_type_t type;
+    pb_decoder_t func;
     
-    if (PB_ATYPE(iter->current->type) == PB_ATYPE_STATIC &&
-        PB_HTYPE(iter->current->type) == PB_HTYPE_REPEATED)
+    type = iter->pos->type;
+    func = PB_DECODERS[PB_LTYPE(type)];
+
+    switch (PB_HTYPE(type))
     {
-        prev_size *= iter->current->array_size;
-    }
+        case PB_HTYPE_REQUIRED:
+            return func(stream, iter->pos, iter->pData);
+            
+        case PB_HTYPE_OPTIONAL:
+            *(bool*)iter->pSize = true;
+            return func(stream, iter->pos, iter->pData);
     
-    if (PB_HTYPE(iter->current->type) == PB_HTYPE_REQUIRED)
-        iter->required_field_index++;
+        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 = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                    if (!func(&substream, iter->pos, pItem))
+                    {
+                        status = false;
+                        break;
+                    }
+                    (*size)++;
+                }
+                pb_close_string_substream(stream, &substream);
+                
+                if (substream.bytes_left != 0)
+                    PB_RETURN_ERROR(stream, "array overflow");
+                
+                return status;
+            }
+            else
+            {
+                /* Repeated field */
+                pb_size_t *size = (pb_size_t*)iter->pSize;
+                void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
+                if (*size >= iter->pos->array_size)
+                    PB_RETURN_ERROR(stream, "array overflow");
+                
+                (*size)++;
+                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 (iter->current->tag == 0)
-        return false; /* Only happens with empty message types */
+    if (data_size == 0 || array_size == 0)
+        PB_RETURN_ERROR(stream, "invalid size");
     
-    iter->current++;
-    iter->field_index++;
-    if (iter->current->tag == 0)
+    /* 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.
+     */
     {
-        iter->current = iter->start;
-        iter->field_index = 0;
-        iter->required_field_index = 0;
-        iter->pData = iter->dest_struct;
-        prev_size = 0;
-        notwrapped = false;
+        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");
+            }
+        }
     }
     
-    iter->pData = (char*)iter->pData + prev_size + iter->current->data_offset;
-    iter->pSize = (char*)iter->pData + iter->current->size_offset;
-    return notwrapped;
+    /* 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;
 }
 
-static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag)
+/* 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)
 {
-    unsigned start = iter->field_index;
-    
-    do {
-        if (iter->current->tag == tag)
-            return true;
-        pb_field_next(iter);
-    } while (iter->field_index != start);
-    
-    return false;
+    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)
+    {
+        pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, pItem);
+    }
 }
+#endif
 
-/*************************
- * Decode a single field *
- *************************/
-
-static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
+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->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);
-            
         case PB_HTYPE_OPTIONAL:
-            *(bool*)iter->pSize = true;
-            return func(stream, iter->current, iter->pData);
+        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 */
+                /* Packed array, multiple items come in at once. */
                 bool status = true;
-                size_t *size = (size_t*)iter->pSize;
+                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 && *size < iter->current->array_size)
+                while (substream.bytes_left)
                 {
-                    void *pItem = (uint8_t*)iter->pData + iter->current->data_size * (*size);
-                    if (!func(&substream, iter->current, pItem))
+                    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 = *(uint8_t**)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)++;
                 }
                 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)
-                    PB_RETURN_ERROR(stream, "array overflow");
+                /* 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)++;
-                return func(stream, iter->current, pItem);
+                if (!allocate_field(stream, iter->pData, iter->pos->data_size, *size))
+                    return false;
+            
+                pItem = *(uint8_t**)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_iterator_t *iter)
+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 = pCallback->arg;
+#else
+    void **arg = &(pCallback->arg);
+#endif
+    
     if (pCallback->funcs.decode == NULL)
         return pb_skip_field(stream, wire_type);
     
@@ -425,11 +607,11 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
         if (!pb_make_string_substream(stream, &substream))
             return false;
         
-        while (substream.bytes_left)
+        do
         {
-            if (!pCallback->funcs.decode(&substream, iter->current, pCallback->arg))
+            if (!pCallback->funcs.decode(&substream, iter->pos, arg))
                 PB_RETURN_ERROR(stream, "callback failed");
-        }
+        } while (substream.bytes_left);
         
         pb_close_string_substream(stream, &substream);
         return true;
@@ -448,17 +630,30 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
             return false;
         substream = pb_istream_from_buffer(buffer, size);
         
-        return pCallback->funcs.decode(&substream, iter->current, pCallback->arg);
+        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)
+static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
 {
-    switch (PB_ATYPE(iter->current->type))
+#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);
         
@@ -467,53 +662,166 @@ static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_t
     }
 }
 
-/* Initialize message fields to default values, recursively */
-static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct)
+static void iter_from_extension(pb_field_iter_t *iter, pb_extension_t *extension)
 {
-    pb_field_iterator_t iter;
-    pb_field_init(&iter, fields, dest_struct);
+    /* 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;
     
-    /* Initialize size/has fields and apply default values */
-    do
+    if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
     {
-        pb_type_t type;
-        type = iter.current->type;
+        /* 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 (iter.current->tag == 0)
-            continue;
+    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;
         
-        if (PB_ATYPE(type) == PB_ATYPE_STATIC)
+        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)
         {
-            /* 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.current->type) == PB_LTYPE_SUBMESSAGE)
+            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)
+        {
+            /* 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)
             {
-                pb_message_set_to_defaults((const pb_field_t *) iter.current->ptr, iter.pData);
+                /* Initialize submessage to defaults */
+                pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, iter->pData);
             }
-            else if (iter.current->ptr != NULL)
+            else if (iter->pos->ptr != NULL)
             {
-                memcpy(iter.pData, iter.current->ptr, iter.current->data_size);
+                /* Initialize to default value */
+                memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
             }
             else
             {
-                memset(iter.pData, 0, iter.current->data_size);
+                /* Initialize to zeros */
+                memset(iter->pData, 0, iter->pos->data_size);
             }
         }
-        else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
+    }
+    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)
         {
-            continue; /* Don't overwrite callback */
+            *(pb_size_t*)iter->pSize = 0;
         }
-    } while (pb_field_next(&iter));
+    }
+    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));
 }
 
 /*********************
@@ -522,10 +830,13 @@ static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_str
 
 bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
 {
-    uint8_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 7) / 8] = {0}; /* Used to check for required fields */
-    pb_field_iterator_t iter;
+    uint8_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 7) / 8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    uint32_t extension_range_start = 0;
+    pb_field_iter_t iter;
     
-    pb_field_init(&iter, fields, dest_struct);
+    /* 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)
     {
@@ -541,15 +852,38 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
                 return false;
         }
         
-        if (!pb_field_find(&iter, tag))
+        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 (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] |= (uint8_t)(1 << (iter.required_field_index & 7));
@@ -570,11 +904,11 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
         unsigned i;
         do {
             req_field_count = iter.required_field_index;
-            last_type = iter.current->type;
-        } while (pb_field_next(&iter));
+            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.current->tag)
+        if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag != 0)
             req_field_count++;
         
         /* Check the whole bytes */
@@ -594,10 +928,154 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
 
 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);
-    return pb_decode_noinit(stream, 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(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);
+    pb_close_string_substream(stream, &substream);
+    return status;
+}
+
+#ifdef PB_ENABLE_MALLOC
+/* Given an oneof field, if there has already been a field inside this oneof,
+ * release it before overwriting with a different one. */
+static bool pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *iter)
+{
+    pb_size_t old_tag = *(pb_size_t*)iter->pSize; /* Previous which_ value */
+    pb_size_t new_tag = iter->pos->tag; /* New which_ value */
+
+    if (old_tag == 0)
+        return true; /* Ok, no old data in union */
+
+    if (old_tag == new_tag)
+        return true; /* Ok, old data is of same type => merge */
+
+    /* Release old data. The find can fail if the message struct contains
+     * invalid data. */
+    if (!pb_field_iter_find(iter, old_tag))
+        PB_RETURN_ERROR(stream, "invalid union tag");
+
+    pb_release_single_field(iter);
+
+    /* Restore iterator to where it should be.
+     * This shouldn't fail unless the pb_field_t structure is corrupted. */
+    if (!pb_field_iter_find(iter, new_tag))
+        PB_RETURN_ERROR(stream, "iterator error");
+    
+    return true;
+}
+
+static void pb_release_single_field(const pb_field_iter_t *iter)
+{
+    pb_type_t type;
+    type = iter->pos->type;
+
+    if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
+    {
+        if (*(pb_size_t*)iter->pSize != iter->pos->tag)
+            return; /* This is not the current field in the union */
+    }
+
+    /* Release anything contained inside an extension or submsg.
+     * This has to be done even if the submsg itself is statically
+     * allocated. */
+    if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
+    {
+        /* Release fields from all extensions in the linked list */
+        pb_extension_t *ext = *(pb_extension_t**)iter->pData;
+        while (ext != NULL)
+        {
+            pb_field_iter_t ext_iter;
+            iter_from_extension(&ext_iter, ext);
+            pb_release_single_field(&ext_iter);
+            ext = ext->next;
+        }
+    }
+    else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
+    {
+        /* Release fields in submessage or submsg array */
+        void *pItem = iter->pData;
+        pb_size_t count = 1;
+        
+        if (PB_ATYPE(type) == PB_ATYPE_POINTER)
+        {
+            pItem = *(void**)iter->pData;
+        }
+        
+        if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
+        {
+            count = *(pb_size_t*)iter->pSize;
+        }
+        
+        if (pItem)
+        {
+            while (count--)
+            {
+                pb_release((const pb_field_t*)iter->pos->ptr, pItem);
+                pItem = (uint8_t*)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 (!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, int64_t *dest)
@@ -656,83 +1134,167 @@ bool pb_decode_fixed64(pb_istream_t *stream, void *dest)
     #endif   
 }
 
-bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest)
+static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
     uint64_t value;
-    bool status = pb_decode_varint(stream, &value);
+    int64_t svalue;
+    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 == 8)
+        svalue = (int64_t)value;
+    else
+        svalue = (int32_t)value;
+
     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;
+        case 1: clamped = *(int8_t*)dest = (int8_t)svalue; break;
+        case 2: clamped = *(int16_t*)dest = (int16_t)svalue; break;
+        case 4: clamped = *(int32_t*)dest = (int32_t)svalue; break;
+        case 8: clamped = *(int64_t*)dest = svalue; break;
         default: PB_RETURN_ERROR(stream, "invalid data_size");
     }
+
+    if (clamped != svalue)
+        PB_RETURN_ERROR(stream, "integer too large");
     
-    return status;
+    return true;
 }
 
-bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest)
+static bool checkreturn pb_dec_uvarint(pb_istream_t *stream, const pb_field_t *field, void *dest)
 {
-    int64_t value;
-    bool status = pb_decode_svarint(stream, &value);
+    uint64_t value, clamped;
+    if (!pb_decode_varint(stream, &value))
+        return false;
     
     switch (field->data_size)
     {
-        case 4: *(int32_t*)dest = (int32_t)value; break;
-        case 8: *(int64_t*)dest = value; break;
+        case 1: clamped = *(uint8_t*)dest = (uint8_t)value; break;
+        case 2: clamped = *(uint16_t*)dest = (uint16_t)value; break;
+        case 4: clamped = *(uint32_t*)dest = (uint32_t)value; break;
+        case 8: clamped = *(uint64_t*)dest = value; break;
         default: PB_RETURN_ERROR(stream, "invalid data_size");
     }
     
-    return status;
+    if (clamped != value)
+        PB_RETURN_ERROR(stream, "integer too large");
+
+    return true;
 }
 
-bool checkreturn pb_dec_fixed32(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)
 {
-    UNUSED(field);
+    int64_t value, clamped;
+    if (!pb_decode_svarint(stream, &value))
+        return false;
+    
+    switch (field->data_size)
+    {
+        case 1: clamped = *(int8_t*)dest = (int8_t)value; break;
+        case 2: clamped = *(int16_t*)dest = (int16_t)value; break;
+        case 4: clamped = *(int32_t*)dest = (int32_t)value; break;
+        case 8: clamped = *(int64_t*)dest = value; break;
+        default: 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);
 }
 
-bool checkreturn pb_dec_fixed64(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)
 {
-    UNUSED(field);
+    PB_UNUSED(field);
     return pb_decode_fixed64(stream, dest);
 }
 
-bool checkreturn pb_dec_bytes(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)
 {
-    pb_bytes_array_t *x = (pb_bytes_array_t*)dest;
+    uint32_t size;
+    size_t alloc_size;
+    pb_bytes_array_t *bdest;
     
-    uint32_t temp;
-    if (!pb_decode_varint32(stream, &temp))
+    if (!pb_decode_varint32(stream, &size))
         return false;
-    x->size = temp;
     
-    /* Check length, noting the space taken by the size_t header. */
-    if (x->size > field->data_size - offsetof(pb_bytes_array_t, bytes))
+    if (size > PB_SIZE_MAX)
         PB_RETURN_ERROR(stream, "bytes overflow");
     
-    return pb_read(stream, x->bytes, x->size);
+    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);
 }
 
-bool checkreturn pb_dec_string(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)
 {
     uint32_t size;
+    size_t alloc_size;
     bool status;
     if (!pb_decode_varint32(stream, &size))
         return false;
     
-    /* Check length, noting the null terminator */
-    if (size + 1 > field->data_size)
-        PB_RETURN_ERROR(stream, "string overflow");
+    /* 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, (uint8_t*)dest, size);
     *((uint8_t*)dest + size) = 0;
     return status;
 }
 
-bool checkreturn pb_dec_submessage(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)
 {
     bool status;
     pb_istream_t substream;