codegen: Handle zero_terminated attribute in demashaller

Make sure the output array is zero terminated to simplify
code using the output structures.

Changed in generated code:

    diff -ru gen/generated_client_demarshallers.c common/generated_client_demarshallers.c
    --- gen/generated_client_demarshallers.c	2021-02-21 15:13:42.004307087 +0000
    +++ common/generated_client_demarshallers.c	2021-02-21 15:13:58.916513426 +0000
    @@ -565,15 +565,24 @@
         return NULL;
     }

    -static uint8_t * parse_array_uint8(uint8_t *message_start, SPICE_GNUC_UNUSED uint8_t *message_end, uint8_t *struct_data, PointerInfo *this_ptr_info)
    +static uint8_t * parse_array_uint8_terminated(uint8_t *message_start, SPICE_GNUC_UNUSED uint8_t *message_end, uint8_t *struct_data, PointerInfo *this_ptr_info)
     {
         uint8_t *in = message_start + this_ptr_info->offset;
         uint8_t *end;

         end = struct_data;
         memcpy(end, in, this_ptr_info->nelements);
    +#if defined(__GNUC__)
    +#pragma GCC diagnostic push
    +#pragma GCC diagnostic ignored "-Wstringop-overflow"
    +#endif
    +    ((char *) (end))[this_ptr_info->nelements] = 0;
    +#if defined(__GNUC__)
    +#pragma GCC diagnostic pop
    +#endif
         in += this_ptr_info->nelements;
         end += this_ptr_info->nelements;
    +    end += 1;
         return end;
     }

    @@ -622,7 +631,8 @@
                 dst_info_host_data__array__nelements = host_size__value;

                 dst_info_host_data__array__nw_size = dst_info_host_data__array__nelements;
    -            dst_info_host_data__array__mem_size = sizeof(uint8_t) * dst_info_host_data__array__nelements;
    +            dst_info_host_data__array__mem_size = sizeof(uint8_t) * dst_info_host_data__array__nelements + sizeof(uint8_t);
    +            dst_info_host_data__array__mem_size = SPICE_ALIGN(dst_info_host_data__array__mem_size, 4);
                 if (SPICE_UNLIKELY(dst_info_host_data__array__nw_size > (uintptr_t) (message_end - message_start - host_data__value))) {
                     goto error;
                 }
    @@ -650,7 +660,8 @@
                 dst_info_cert_subject_data__array__nelements = cert_subject_size__value;

                 dst_info_cert_subject_data__array__nw_size = dst_info_cert_subject_data__array__nelements;
    -            dst_info_cert_subject_data__array__mem_size = sizeof(uint8_t) * dst_info_cert_subject_data__array__nelements;
    +            dst_info_cert_subject_data__array__mem_size = sizeof(uint8_t) * dst_info_cert_subject_data__array__nelements + sizeof(uint8_t);
    +            dst_info_cert_subject_data__array__mem_size = SPICE_ALIGN(dst_info_cert_subject_data__array__mem_size, 4);
                 if (SPICE_UNLIKELY(dst_info_cert_subject_data__array__nw_size > (uintptr_t) (message_end - message_start - cert_subject_data__value))) {
                     goto error;
                 }
    @@ -685,14 +696,14 @@
             out->dst_info.sport = consume_uint16(&in);
             out->dst_info.host_size = consume_uint32(&in);
             ptr_info[n_ptr].offset = consume_uint32(&in);
    -        ptr_info[n_ptr].parse = parse_array_uint8;
    +        ptr_info[n_ptr].parse = parse_array_uint8_terminated;
             ptr_info[n_ptr].dest = (void **)&out->dst_info.host_data;
             host_data__array__nelements = out->dst_info.host_size;
             ptr_info[n_ptr].nelements = host_data__array__nelements;
             n_ptr++;
             out->dst_info.cert_subject_size = consume_uint32(&in);
             ptr_info[n_ptr].offset = consume_uint32(&in);
    -        ptr_info[n_ptr].parse = parse_array_uint8;
    +        ptr_info[n_ptr].parse = parse_array_uint8_terminated;
             ptr_info[n_ptr].dest = (void **)&out->dst_info.cert_subject_data;
             cert_subject_data__array__nelements = out->dst_info.cert_subject_size;
             ptr_info[n_ptr].nelements = cert_subject_data__array__nelements;
    @@ -1050,7 +1061,8 @@
             host_data__array__nelements = host_size__value;

             host_data__array__nw_size = host_data__array__nelements;
    -        host_data__array__mem_size = sizeof(uint8_t) * host_data__array__nelements;
    +        host_data__array__mem_size = sizeof(uint8_t) * host_data__array__nelements + sizeof(uint8_t);
    +        host_data__array__mem_size = SPICE_ALIGN(host_data__array__mem_size, 4);
             if (SPICE_UNLIKELY(host_data__array__nw_size > (uintptr_t) (message_end - message_start - host_data__value))) {
                 goto error;
             }
    @@ -1078,7 +1090,8 @@
             cert_subject_data__array__nelements = cert_subject_size__value;

             cert_subject_data__array__nw_size = cert_subject_data__array__nelements;
    -        cert_subject_data__array__mem_size = sizeof(uint8_t) * cert_subject_data__array__nelements;
    +        cert_subject_data__array__mem_size = sizeof(uint8_t) * cert_subject_data__array__nelements + sizeof(uint8_t);
    +        cert_subject_data__array__mem_size = SPICE_ALIGN(cert_subject_data__array__mem_size, 4);
             if (SPICE_UNLIKELY(cert_subject_data__array__nw_size > (uintptr_t) (message_end - message_start - cert_subject_data__value))) {
                 goto error;
             }
    @@ -1107,13 +1120,13 @@
         out->sport = consume_uint16(&in);
         out->host_size = consume_uint32(&in);
         ptr_info[n_ptr].offset = consume_uint32(&in);
    -    ptr_info[n_ptr].parse = parse_array_uint8;
    +    ptr_info[n_ptr].parse = parse_array_uint8_terminated;
         ptr_info[n_ptr].dest = (void **)&out->host_data;
         ptr_info[n_ptr].nelements = host_data__array__nelements;
         n_ptr++;
         out->cert_subject_size = consume_uint32(&in);
         ptr_info[n_ptr].offset = consume_uint32(&in);
    -    ptr_info[n_ptr].parse = parse_array_uint8;
    +    ptr_info[n_ptr].parse = parse_array_uint8_terminated;
         ptr_info[n_ptr].dest = (void **)&out->cert_subject_data;
         ptr_info[n_ptr].nelements = cert_subject_data__array__nelements;
         n_ptr++;
    @@ -1338,7 +1351,8 @@
                 dst_info_host_data__array__nelements = host_size__value;

                 dst_info_host_data__array__nw_size = dst_info_host_data__array__nelements;
    -            dst_info_host_data__array__mem_size = sizeof(uint8_t) * dst_info_host_data__array__nelements;
    +            dst_info_host_data__array__mem_size = sizeof(uint8_t) * dst_info_host_data__array__nelements + sizeof(uint8_t);
    +            dst_info_host_data__array__mem_size = SPICE_ALIGN(dst_info_host_data__array__mem_size, 4);
                 if (SPICE_UNLIKELY(dst_info_host_data__array__nw_size > (uintptr_t) (message_end - message_start - host_data__value))) {
                     goto error;
                 }
    @@ -1366,7 +1380,8 @@
                 dst_info_cert_subject_data__array__nelements = cert_subject_size__value;

                 dst_info_cert_subject_data__array__nw_size = dst_info_cert_subject_data__array__nelements;
    -            dst_info_cert_subject_data__array__mem_size = sizeof(uint8_t) * dst_info_cert_subject_data__array__nelements;
    +            dst_info_cert_subject_data__array__mem_size = sizeof(uint8_t) * dst_info_cert_subject_data__array__nelements + sizeof(uint8_t);
    +            dst_info_cert_subject_data__array__mem_size = SPICE_ALIGN(dst_info_cert_subject_data__array__mem_size, 4);
                 if (SPICE_UNLIKELY(dst_info_cert_subject_data__array__nw_size > (uintptr_t) (message_end - message_start - cert_subject_data__value))) {
                     goto error;
                 }
    @@ -1401,14 +1416,14 @@
             out->dst_info.sport = consume_uint16(&in);
             out->dst_info.host_size = consume_uint32(&in);
             ptr_info[n_ptr].offset = consume_uint32(&in);
    -        ptr_info[n_ptr].parse = parse_array_uint8;
    +        ptr_info[n_ptr].parse = parse_array_uint8_terminated;
             ptr_info[n_ptr].dest = (void **)&out->dst_info.host_data;
             host_data__array__nelements = out->dst_info.host_size;
             ptr_info[n_ptr].nelements = host_data__array__nelements;
             n_ptr++;
             out->dst_info.cert_subject_size = consume_uint32(&in);
             ptr_info[n_ptr].offset = consume_uint32(&in);
    -        ptr_info[n_ptr].parse = parse_array_uint8;
    +        ptr_info[n_ptr].parse = parse_array_uint8_terminated;
             ptr_info[n_ptr].dest = (void **)&out->dst_info.cert_subject_data;
             cert_subject_data__array__nelements = out->dst_info.cert_subject_size;
             ptr_info[n_ptr].nelements = cert_subject_data__array__nelements;
    @@ -7582,7 +7597,8 @@
             name__array__nelements = name_size__value;

             name__array__nw_size = name__array__nelements;
    -        name__array__mem_size = sizeof(uint8_t) * name__array__nelements;
    +        name__array__mem_size = sizeof(uint8_t) * name__array__nelements + sizeof(uint8_t);
    +        name__array__mem_size = SPICE_ALIGN(name__array__mem_size, 4);
             if (SPICE_UNLIKELY(name__array__nw_size > (uintptr_t) (message_end - message_start - name__value))) {
                 goto error;
             }
    @@ -7609,7 +7625,7 @@

         out->name_size = consume_uint32(&in);
         ptr_info[n_ptr].offset = consume_uint32(&in);
    -    ptr_info[n_ptr].parse = parse_array_uint8;
    +    ptr_info[n_ptr].parse = parse_array_uint8_terminated;
         ptr_info[n_ptr].dest = (void **)&out->name;
         ptr_info[n_ptr].nelements = name__array__nelements;
         n_ptr++;

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Acked-by: Victor Toso <victortoso@redhat.com>

2 files changed, 28 insertions, 1 deletions

diff --git a/python_modules/demarshal.py b/python_modules/demarshal.py
index efc4c99..2a111be 100644
--- a/python_modules/demarshal.py
+++ b/python_modules/demarshal.py
@@ -384,6 +384,10 @@ def write_validate_array_item(writer, container, item, scope, parent_scope, star
         # TODO: Overflow check the multiplication
         if array.has_attr("ptr_array"):
             writer.assign(mem_size, "sizeof(void *) + SPICE_ALIGN(%s * %s, 4)" % (element_type.sizeof(), nelements))
+        elif array.has_attr('zero_terminated'):
+            # don't use +1 here to avoid possible integer overflow or suboptimizations
+            writer.assign(mem_size, "%s * %s + %s" % (element_type.sizeof(), nelements, element_type.sizeof()))
+            writer.assign(mem_size, "SPICE_ALIGN(%s, 4)" % mem_size);
         else:
             writer.assign(mem_size, "%s * %s" % (element_type.sizeof(), nelements))
         want_mem_size = False
@@ -724,7 +728,10 @@ def write_switch_parser(writer, container, switch, dest, scope):
 
 def write_parse_ptr_function(writer, target_type):
     if target_type.is_array():
-        parse_function = "parse_array_%s" % target_type.element_type.primitive_type()
+        if target_type.has_attr("zero_terminated"):
+            parse_function = "parse_array_%s_terminated" % target_type.element_type.primitive_type()
+        else:
+            parse_function = "parse_array_%s" % target_type.element_type.primitive_type()
     else:
         parse_function = "parse_struct_%s" % target_type.c_type()
     if writer.is_generated("parser", parse_function):
@@ -787,10 +794,28 @@ def write_array_parser(writer, member, nelements, array, dest, scope):
         if array.has_attr("ptr_array"):
             raise Exception("Attribute ptr_array not supported for arrays of int8/uint8")
         writer.statement("memcpy(%s, in, %s)" % (array_start, nelements))
+        if array.has_attr("zero_terminated"):
+            indentation = writer.indentation
+            writer.indentation = 0;
+            writer.writeln("#if defined(__GNUC__)")
+            writer.writeln("#pragma GCC diagnostic push")
+            writer.writeln("#pragma GCC diagnostic ignored \"-Wstringop-overflow\"")
+            writer.writeln("#endif")
+            writer.indentation = indentation;
+            writer.assign("((char *) (%s))[%s]" % (array_start, nelements), 0)
+            writer.indentation = 0;
+            writer.writeln("#if defined(__GNUC__)")
+            writer.writeln("#pragma GCC diagnostic pop")
+            writer.writeln("#endif")
+            writer.indentation = indentation;
         writer.increment("in", nelements)
         if at_end:
             writer.increment("end", nelements)
+            if array.has_attr("zero_terminated"):
+                writer.increment("end", 1)
     else:
+        if array.has_attr("zero_terminated"):
+            raise Exception("Attribute zero_terminated specified for wrong array")
         with writer.index() as index:
             if member:
                 array_pos = "%s[%s]" % (array_start, index)
diff --git a/python_modules/ptypes.py b/python_modules/ptypes.py
index e3eb8fd..d68dc67 100644
--- a/python_modules/ptypes.py
+++ b/python_modules/ptypes.py
@@ -553,6 +553,8 @@ class ArrayType(Type):
             return writer.writeln('%s *%s[0];' % (self.c_type(), name))
         if member.has_end_attr():
             return writer.writeln('%s %s[0];' % (self.c_type(), name))
+        if self.is_constant_length() and self.has_attr("zero_terminated"):
+            return writer.writeln('%s %s[%s];' % (self.c_type(), name, self.size + 1))
         if self.is_constant_length():
             return writer.writeln('%s %s[%s];' % (self.c_type(), name, self.size))
         if self.is_identifier_length():