type-agnostic extraction of content into string buffers

include/libtcap.h

@@ -7,10 +7,24 @@
 #include "constr_TYPE.h"
 
 
+struct output_buffer {
+	char *buf;
+	size_t buf_size;
+	size_t used;
+};
+#define OUTPUT_BUFFER_INIT(o, i) output_buffer_init(o, i, sizeof(i))
+static inline void output_buffer_init(struct output_buffer *o, char *i, size_t s) {
+	o->buf = i;
+	o->buf_size = s;
+	o->used = 0;
+}
+
+
+
 TCMessage_t *tcap_decode(const char *buf, size_t len);
 void *inap_decode(Invoke_t *invoke, asn_TYPE_descriptor_t **);
-int tcap_extract(const char *buf, size_t len, const char *spec, void *out);
-int inap_extract(const char *buf, size_t len, const char *spec, void *out);
+int tcap_extract(const char *buf, size_t len, const char *spec, struct output_buffer *out);
+int inap_extract(const char *buf, size_t len, const char *spec, struct output_buffer *out);
 
 
 #endif

src/tcap.c

@@ -102,7 +102,19 @@ static inline int next_token_2(const char **token, const char **c) {
 	return 0;
 }
 
-static int asn1_extract(const char *spec, void *out, asn_TYPE_descriptor_t *type, void *element) {
+int cb(const void *buf, size_t s, void *app_key) {
+	struct output_buffer *out = app_key;
+
+	if (out->buf_size - out->used < s)
+		return -1;
+	memcpy(out->buf + out->used, buf, s);
+	out->used += s;
+	return 0;
+}
+
+static int asn1_extract(const char *spec, struct output_buffer *out, asn_TYPE_descriptor_t *type,
+		void *element)
+{
 	const char *token, *c;
 	int token_len, i, num;
 	asn_TYPE_member_t *member;
@@ -181,14 +193,7 @@ found_element:
 	if (type->elements_count)
 		goto out;
 
-	if (type == &asn_DEF_INTEGER) {
-		if (asn_INTEGER2long(element, out))
-			goto error;
-	}
-	else if (!type->specifics) {
-		/* primitive integer */
-		*((long *) out) = *((long *) element);
-	}
+	type->print_struct(type, element, 0, cb, out);
 
 out:
 	return 0;
@@ -199,13 +204,13 @@ error:
 
 
 
-int tcap_extract(const char *buf, size_t len, const char *spec, void *out) {
+int tcap_extract(const char *buf, size_t len, const char *spec, struct output_buffer *out) {
 	return asn1_extract(spec, out, &asn_DEF_TCMessage, tcap_decode(buf, len));
 }
 
 
 
-int inap_extract(const char *buf, size_t len, const char *spec, void *out) {
+int inap_extract(const char *buf, size_t len, const char *spec, struct output_buffer *out) {
 	TCMessage_t *tcm;
 	ComponentPortion_t *cp;
 	Component_t *cmp;

tests/basic.c

@@ -10,93 +10,27 @@ const int tcap_len = sizeof(tcap) - 1;
 
 
 int main() {
-	TCMessage_t *tcm;
-	ComponentPortion_t *components = 0;
-	Component_t *component;
 	int i;
-	void *arg;
-	asn_TYPE_descriptor_t *type;
-	long l;
+	struct output_buffer out;
+	char buf[256];
 
-	tcm = tcap_decode(tcap, tcap_len);
+	OUTPUT_BUFFER_INIT(&out, buf);
+	i = tcap_extract(tcap, tcap_len, "end.components.1.invoke.opCode.localValue", &out);
+	printf("tcap_extract opcode: returned %i, value %.*s\n", i, (int) out.used, out.buf);
 
-	printf("TCMessage: %p\n", tcm);
-
-	switch (tcm->present) {
-		case TCMessage_PR_NOTHING:
-			printf("nothing\n");
-			break;
-
-		case TCMessage_PR_unidirectional:
-			printf("unidirectional\n");
-			components = &tcm->choice.unidirectional.components;
-			break;
-
-		case TCMessage_PR_begin:
-			printf("begin\n");
-			components = tcm->choice.begin.components;
-			break;
-
-		case TCMessage_PR_end:
-			printf("end\n");
-			components = tcm->choice.end.components;
-			break;
-
-		case TCMessage_PR_continue:
-			printf("continue\n");
-			components = tcm->choice.Continue.components;
-			break;
-
-		case TCMessage_PR_abort:
-			printf("abort\n");
-			break;
-	}
-
-	if (components) {
-		printf("%i components\n", components->list.count);
-
-		for (i = 0; i < components->list.count; i++) {
-			printf("Component #%i\n", i);
-
-			component = components->list.array[i];
-
-			switch (component->present) {
-				case Component_PR_NOTHING:
-					printf("nothing\n");
-					break;
-
-				case Component_PR_invoke:
-					printf("invoke\n");
-					arg = inap_decode(&component->choice.invoke, &type);
-					printf("arg: type %s -> %p\n", type ? type->name : "n/a", arg);
-					break;
-
-				case Component_PR_returnResultLast:
-					printf("returnResultLast\n");
-					break;
-
-				case Component_PR_returnError:
-					printf("returnError\n");
-					break;
-
-				case Component_PR_reject:
-					printf("reject\n");
-					break;
+	i = inap_extract(tcap, tcap_len, "ConnectArg", NULL);
+	printf("inap_extract ConnectArg: returned %i\n", i);
 
-				case Component_PR_returnResultNotLast:
-					printf("returnResultNotLast\n");
-					break;
-			}
-		}
-	}
+	OUTPUT_BUFFER_INIT(&out, buf);
+	i = inap_extract(tcap, tcap_len, "ConnectArg.cutAndPaste", &out);
+	printf("inap_extract ConnectArg: returned %i, value %.*s\n", i, (int) out.used, out.buf);
 
-	i = tcap_extract(tcap, tcap_len, "end.components.1.invoke.opCode.localValue", &l);
-	printf("tcap_extract opcode: returned %i, value %li\n", i, l);
+	i = inap_extract(tcap, tcap_len, "ConnectArg.destinationRoutingAddress", NULL);
+	printf("inap_extract ConnectArg.destinationRoutingAddress: returned %i\n", i);
 
-	i = inap_extract(tcap, tcap_len, "ConnectArg", NULL);
-	printf("inap_extract ConnectArg: returned %i\n", i);
-	i = inap_extract(tcap, tcap_len, "ConnectArg.cutAndPaste", &l);
-	printf("inap_extract ConnectArg: returned %i, value %li\n", i, l);
+	OUTPUT_BUFFER_INIT(&out, buf);
+	i = inap_extract(tcap, tcap_len, "ConnectArg.destinationRoutingAddress.0", &out);
+	printf("inap_extract ConnectArg: returned %i, value %.*s\n", i, (int) out.used, out.buf);
 
 	return 0;
 }