libosmo-gtlv: add TLIV capability

During code review, it was indicated that some TLV protocols that we
will likely deal with in the near future also employ an I, and instance
value of a tag. Add TLIV support.

A usage example for a manually implemented TLIV structure is found in
tests/libosmo-gtlv/gtlv_test.c.

A usage example for a generated TLIV protocol is found in
tests/libosmo-gtlv/test_tliv/.

Related: SYS#5599
Change-Id: I0a076e54dfba6038cc779cb7c8f3967d212226aa

1 files changed, 41 insertions, 28 deletions

diff --git a/src/libosmo-gtlv/gtlv_dec_enc.c b/src/libosmo-gtlv/gtlv_dec_enc.c
index 28ee493..2e5509a 100644
--- a/src/libosmo-gtlv/gtlv_dec_enc.c
+++ b/src/libosmo-gtlv/gtlv_dec_enc.c
@@ -31,12 +31,21 @@
 /* Reverse offsetof(): return the address of the struct member for a given osmo_gtlv_msg and member ofs_foo value. */
 #define MEMB(M, MEMB_OFS) ((void *)((char *)(M) + (MEMB_OFS)))
 
-#define RETURN_ERROR(RC, IEI, FMT, ARGS...) \
+#define RETURN_ERROR(RC, TAG_INST, FMT, ARGS...) \
 	do {\
-		if (err_cb) \
-			err_cb(err_cb_data, (void *)decoded_struct, __FILE__, __LINE__, \
-			       "IE '%s' (0x%x): " FMT " (%d: %s)\n", \
-			       get_value_string(iei_strs, IEI), IEI, ##ARGS, RC, strerror((RC) > 0 ? (RC) : -(RC))); \
+		if (err_cb) { \
+			if ((TAG_INST).instance_present) \
+				err_cb(err_cb_data, (void *)decoded_struct, __FILE__, __LINE__, \
+				       "tag 0x%x = %s instance %u: " FMT " (%d: %s)\n", \
+				       (TAG_INST).tag, get_value_string(iei_strs, (TAG_INST).tag), \
+				       (TAG_INST).instance, ##ARGS, \
+				       RC, strerror((RC) > 0 ? (RC) : -(RC))); \
+			else \
+				err_cb(err_cb_data, (void *)decoded_struct, __FILE__, __LINE__, \
+				       "tag 0x%x = %s: " FMT " (%d: %s)\n", \
+				       (TAG_INST).tag, get_value_string(iei_strs, (TAG_INST).tag), ##ARGS, \
+				       RC, strerror((RC) > 0 ? (RC) : -(RC))); \
+		} \
 		return RC; \
 	} while (0)
 
@@ -72,7 +81,7 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 #define CHECK_SEEN(IEC) do { \
 			unsigned int ie_coding_idx = (IEC) - ie_coding; \
 			if (ie_coding_idx >= ARRAY_SIZE(seen_ie_coding_entries)) \
-				RETURN_ERROR(-ENOTSUP, gtlv->tag, \
+				RETURN_ERROR(-ENOTSUP, gtlv->ti, \
 					     "Too many IE definitions for decoding an unordered TLV structure"); \
 			seen_p = &seen_ie_coding_entries[ie_coding_idx]; \
 		} while (0)
@@ -91,7 +100,7 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 
 		rc = osmo_gtlv_load_next(gtlv);
 		if (rc)
-			RETURN_ERROR(rc, gtlv->tag, "Decoding IEs failed on or after this tag");
+			RETURN_ERROR(rc, gtlv->ti, "Decoding IEs failed on or after this tag");
 		if (!gtlv->val) {
 			/* End of the TLV structure */
 			break;
@@ -103,7 +112,9 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 
 		do {
 			/* Find the IE coding for this tag */
-			for (iec = ie_coding; !osmo_gtlv_coding_end(iec) && iec->tag != gtlv->tag; iec++);
+			for (iec = ie_coding;
+			     !osmo_gtlv_coding_end(iec) && osmo_gtlv_tag_inst_cmp(&iec->ti, &gtlv->ti);
+			     iec++);
 			/* No such IE coding found. */
 			if (osmo_gtlv_coding_end(iec))
 				break;
@@ -128,7 +139,7 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 			if (ie_max_allowed_count) {
 				/* There have been IE definitions for this IEI, but all slots to decode it are already
 				 * filled. */
-				RETURN_ERROR(-ENOTSUP, gtlv->tag, "Only %u instances of this IE are supported per message",
+				RETURN_ERROR(-ENOTSUP, gtlv->ti, "Only %u instances of this IE are supported per message",
 					     ie_max_allowed_count);
 			}
 			/* No such IE defined in ie_coding, just skip the TLV. */
@@ -166,14 +177,14 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 			rc = osmo_gtlvs_decode(decoded_struct, obj_ofs + memb_ofs, &inner_tlv, ordered, iec->nested_ies,
 					      err_cb, err_cb_data, iei_strs);
 			if (rc)
-				RETURN_ERROR(rc, gtlv->tag, "Error while decoding TLV structure nested inside this IE");
+				RETURN_ERROR(rc, gtlv->ti, "Error while decoding TLV structure nested inside this IE");
 		} else {
 			/* Normal IE, decode the specific IE data. */
 			if (!iec->dec_func)
-				RETURN_ERROR(-EIO, gtlv->tag, "IE definition lacks a dec_func()");
+				RETURN_ERROR(-EIO, gtlv->ti, "IE definition lacks a dec_func()");
 			rc = iec->dec_func(decoded_struct, MEMB(obj, memb_ofs), gtlv);
 			if (rc)
-				RETURN_ERROR(rc, gtlv->tag, "Error while decoding this IE");
+				RETURN_ERROR(rc, gtlv->ti, "Error while decoding this IE");
 		}
 
 		if (multi_count_p) {
@@ -197,14 +208,14 @@ static int osmo_gtlvs_decode_unordered(void *decoded_struct, unsigned int obj_of
 		multi_count_p = iec->has_count ? MEMB(obj, iec->count_ofs) : NULL;
 		if (multi_count_p) {
 			if (*multi_count_p < iec->count_mandatory)
-				RETURN_ERROR(-EINVAL, iec->tag, "Error while decoding: %u instances of this IE are mandatory, got %u",
+				RETURN_ERROR(-EINVAL, iec->ti, "%u instances of this IE are mandatory, got %u",
 					     iec->count_mandatory, *multi_count_p);
 			continue;
 		}
 		/* Neither an optional nor a multi member, hence it must be mandatory. */
 		CHECK_SEEN(iec);
 		if (!*seen_p)
-			RETURN_ERROR(-EINVAL, iec->tag, "Missing mandatory IE");
+			RETURN_ERROR(-EINVAL, iec->ti, "Missing mandatory IE");
 	}
 	return 0;
 }
@@ -235,19 +246,20 @@ static int osmo_gtlvs_decode_ordered(void *decoded_struct, unsigned int obj_ofs,
 		int rc;
 		bool *presence_flag = ie_coding->has_presence_flag ? MEMB(obj, ie_coding->presence_flag_ofs) : NULL;
 		unsigned int *multi_count = ie_coding->has_count ? MEMB(obj, ie_coding->count_ofs) : NULL;
+		struct osmo_gtlv_tag_inst peek_ti;
 
-		rc = osmo_gtlv_load_next_by_tag(gtlv, ie_coding->tag);
+		rc = osmo_gtlv_load_next_by_tag_inst(gtlv, &ie_coding->ti);
 		switch (rc) {
 		case 0:
 			break;
 		case -ENOENT:
 			if (!presence_flag && (!multi_count || *multi_count < ie_coding->count_mandatory))
-				RETURN_ERROR(rc, ie_coding->tag, "Missing mandatory IE");
+				RETURN_ERROR(rc, ie_coding->ti, "Missing mandatory IE");
 			if (presence_flag)
 				*presence_flag = false;
 			continue;
 		default:
-			RETURN_ERROR(rc, ie_coding->tag, "Error in TLV structure");
+			RETURN_ERROR(rc, ie_coding->ti, "Error in TLV structure");
 		}
 
 		for (;;) {
@@ -257,7 +269,7 @@ static int osmo_gtlvs_decode_ordered(void *decoded_struct, unsigned int obj_ofs,
 			unsigned int memb_ofs = ie_coding->memb_ofs + memb_next_array_idx * ie_coding->memb_array_pitch;
 
 			if (multi_count && memb_next_array_idx >= ie_coding->count_max)
-				RETURN_ERROR(-ENOTSUP, ie_coding->tag, "Only %u instances of this IE are supported per message",
+				RETURN_ERROR(-ENOTSUP, ie_coding->ti, "Only %u instances of this IE are supported per message",
 					     ie_coding->count_max);
 
 			/* Decode IE value part */
@@ -286,15 +298,15 @@ static int osmo_gtlvs_decode_ordered(void *decoded_struct, unsigned int obj_ofs,
 				rc = osmo_gtlvs_decode(decoded_struct, obj_ofs + memb_ofs, &inner_tlv, ordered,
 						      ie_coding->nested_ies, err_cb, err_cb_data, iei_strs);
 				if (rc)
-					RETURN_ERROR(rc, ie_coding->tag,
+					RETURN_ERROR(rc, ie_coding->ti,
 						     "Error while decoding TLV structure nested inside this IE");
 			} else {
 				/* Normal IE, decode the specific IE data. */
 				if (!ie_coding->dec_func)
-					RETURN_ERROR(-EIO, ie_coding->tag, "IE definition lacks a dec_func()");
+					RETURN_ERROR(-EIO, ie_coding->ti, "IE definition lacks a dec_func()");
 				rc = ie_coding->dec_func(decoded_struct, MEMB(obj, memb_ofs), gtlv);
 				if (rc)
-					RETURN_ERROR(rc, ie_coding->tag, "Error while decoding this IE");
+					RETURN_ERROR(rc, ie_coding->ti, "Error while decoding this IE");
 			}
 
 			if (presence_flag)
@@ -312,7 +324,8 @@ static int osmo_gtlvs_decode_ordered(void *decoded_struct, unsigned int obj_ofs,
 			(*multi_count)++;
 
 			/* Does another one of these IEs follow? */
-			if (osmo_gtlv_load_peek_tag(gtlv) != gtlv->tag) {
+			if (osmo_gtlv_load_peek_tag(gtlv, &peek_ti)
+			    || osmo_gtlv_tag_inst_cmp(&peek_ti, &gtlv->ti)) {
 				/* Next tag is a different IE, end the repetition. */
 				break;
 			}
@@ -387,7 +400,7 @@ int osmo_gtlvs_encode(struct osmo_gtlv_put *gtlv, const void *decoded_struct, un
 		if (multi_count_p) {
 			n = *multi_count_p;
 			if (!ie_coding->memb_array_pitch)
-				RETURN_ERROR(-EFAULT, ie_coding->tag,
+				RETURN_ERROR(-EFAULT, ie_coding->ti,
 					     "Error in protocol definition: The ie_coding lacks a memb_array_pitch"
 					     " value, cannot be used as multi-IE\n");
 		} else {
@@ -397,11 +410,11 @@ int osmo_gtlvs_encode(struct osmo_gtlv_put *gtlv, const void *decoded_struct, un
 		for (i = 0; i < n; i++) {
 			unsigned int memb_ofs;
 
-			osmo_gtlv_put_tl(gtlv, ie_coding->tag, 0);
+			osmo_gtlv_put_tli(gtlv, &ie_coding->ti, 0);
 
 			/* If this is a repeated IE, encode from the correct array index */
 			if (multi_count_p && i >= ie_coding->count_max)
-				RETURN_ERROR(-ENOTSUP, ie_coding->tag,
+				RETURN_ERROR(-ENOTSUP, ie_coding->ti,
 					     "Only %u instances of this IE are supported per message", ie_coding->count_max);
 			memb_ofs = ie_coding->memb_ofs + i * ie_coding->memb_array_pitch;
 
@@ -413,12 +426,12 @@ int osmo_gtlvs_encode(struct osmo_gtlv_put *gtlv, const void *decoded_struct, un
 				rc = osmo_gtlvs_encode(&nested_tlv, decoded_struct, obj_ofs + memb_ofs,
 						      ie_coding->nested_ies, err_cb, err_cb_data, iei_strs);
 				if (rc)
-					RETURN_ERROR(rc, ie_coding->tag,
+					RETURN_ERROR(rc, ie_coding->ti,
 						     "Error while encoding TLV structure nested inside this IE");
 			} else {
 				rc = ie_coding->enc_func(gtlv, decoded_struct, MEMB(obj, memb_ofs));
 				if (rc)
-					RETURN_ERROR(rc, ie_coding->tag, "Error while encoding this IE");
+					RETURN_ERROR(rc, ie_coding->ti, "Error while encoding this IE");
 			}
 
 			osmo_gtlv_put_update_tl(gtlv);
@@ -467,7 +480,7 @@ int osmo_gtlvs_encode_to_str_buf(char *buf, size_t buflen, const void *decoded_s
 		if (!n)
 			continue;
 
-		OSMO_STRBUF_PRINTF(sb, " '%s'=", get_value_string(iei_strs, ie_coding->tag));
+		OSMO_STRBUF_PRINTF(sb, " '%s'=", get_value_string(iei_strs, ie_coding->ti.tag));
 		if (multi_count_p)
 			OSMO_STRBUF_PRINTF(sb, "{ ");