2/2: wrap ipa_name in osmo_cni_peer_id with type enum and union

To be prepared for the future in public API, wrap the new osmo_ipa_name struct
in an enum-type and union called osmo_cni_peer.

During code review it was requested to insert an ability to handle different
kinds of peer id, in order to be able to add a Global Title in the future.

Use the generic osmo_cni_peer only in the publicly visible API. For osmo-hlr
internal code, I intend to postpone implementing this into the future, when a
different peer identification actually gets introduced.

This way we don't need to implement it now in all osmo-hlr code paths (save
time now), but still make all external API users aware that this type may be
extended in the future.

Change-Id: Ide9dcdca283ab989240cfc6e53e9211862a199c5

3 files changed, 104 insertions, 13 deletions

diff --git a/src/gsupclient/Makefile.am b/src/gsupclient/Makefile.am
index 38b1582..3412c40 100644
--- a/src/gsupclient/Makefile.am
+++ b/src/gsupclient/Makefile.am
@@ -9,7 +9,7 @@ AM_CFLAGS = -Wall $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)/incl
 lib_LTLIBRARIES = libosmo-gsup-client.la
 
 libosmo_gsup_client_la_SOURCES = \
-	ipa_name.c \
+	cni_peer_id.c \
 	gsup_client.c \
 	gsup_req.c \
 	$(NULL)
diff --git a/src/gsupclient/ipa_name.c b/src/gsupclient/cni_peer_id.c
index 2db069f..de7b4bc 100644
--- a/src/gsupclient/ipa_name.c
+++ b/src/gsupclient/cni_peer_id.c
@@ -19,7 +19,12 @@
 #include <errno.h>
 #include <string.h>
 #include <osmocom/core/utils.h>
-#include <osmocom/gsupclient/ipa_name.h>
+#include <osmocom/gsupclient/cni_peer_id.h>
+
+bool osmo_ipa_name_is_empty(const struct osmo_ipa_name *ipa_name)
+{
+	return (!ipa_name) || (!ipa_name->len);
+}
 
 int osmo_ipa_name_set(struct osmo_ipa_name *ipa_name, const uint8_t *val, size_t len)
 {
@@ -34,19 +39,25 @@ int osmo_ipa_name_set(struct osmo_ipa_name *ipa_name, const uint8_t *val, size_t
 	return 0;
 }
 
-int osmo_ipa_name_set_str(struct osmo_ipa_name *ipa_name, const char *str_fmt, ...)
+static int osmo_ipa_name_set_str_va(struct osmo_ipa_name *ipa_name, const char *str_fmt, va_list ap)
 {
-	va_list ap;
 	if (!str_fmt)
 		return osmo_ipa_name_set(ipa_name, NULL, 0);
-
-	va_start(ap, str_fmt);
 	vsnprintf((char*)(ipa_name->val), sizeof(ipa_name->val), str_fmt, ap);
-	va_end(ap);
 	ipa_name->len = strlen((char*)(ipa_name->val))+1;
 	return 0;
 }
 
+int osmo_ipa_name_set_str(struct osmo_ipa_name *ipa_name, const char *str_fmt, ...)
+{
+	va_list ap;
+	int rc;
+	va_start(ap, str_fmt);
+	rc = osmo_ipa_name_set_str_va(ipa_name, str_fmt, ap);
+	va_end(ap);
+	return rc;
+}
+
 int osmo_ipa_name_cmp(const struct osmo_ipa_name *a, const struct osmo_ipa_name *b)
 {
 	int cmp;
@@ -95,3 +106,82 @@ const char *osmo_ipa_name_to_str_c(void *ctx, const struct osmo_ipa_name *ipa_na
 		len--;
 	return osmo_escape_str_c(ctx, (char*)ipa_name->val, len);
 }
+
+bool osmo_cni_peer_id_is_empty(const struct osmo_cni_peer_id *cni_peer_id)
+{
+	if (!cni_peer_id)
+		return true;
+	switch (cni_peer_id->type) {
+	case OSMO_CNI_PEER_ID_EMPTY:
+		return true;
+	case OSMO_CNI_PEER_ID_IPA_NAME:
+		return osmo_ipa_name_is_empty(&cni_peer_id->ipa_name);
+	default:
+		return false;
+	}
+}
+int osmo_cni_peer_id_set(struct osmo_cni_peer_id *cni_peer_id, enum osmo_cni_peer_id_type type,
+			  const uint8_t *val, size_t len)
+{
+	cni_peer_id->type = type;
+	switch (type) {
+	case OSMO_CNI_PEER_ID_IPA_NAME:
+		return osmo_ipa_name_set(&cni_peer_id->ipa_name, val, len);
+	default:
+		return -EINVAL;
+	}
+}
+
+int osmo_cni_peer_id_set_str(struct osmo_cni_peer_id *cni_peer_id, enum osmo_cni_peer_id_type type,
+			      const char *str_fmt, ...)
+{
+	va_list ap;
+	int rc;
+
+	*cni_peer_id = (struct osmo_cni_peer_id){};
+
+	switch (type) {
+	case OSMO_CNI_PEER_ID_IPA_NAME:
+		cni_peer_id->type = OSMO_CNI_PEER_ID_IPA_NAME;
+		va_start(ap, str_fmt);
+		rc = osmo_ipa_name_set_str_va(&cni_peer_id->ipa_name, str_fmt, ap);
+		va_end(ap);
+		return rc;
+	default:
+		return -EINVAL;
+	}
+}
+
+int osmo_cni_peer_id_cmp(const struct osmo_cni_peer_id *a, const struct osmo_cni_peer_id *b)
+{
+	if (a->type != b->type)
+		return OSMO_CMP(a->type, b->type);
+	switch (a->type) {
+	case OSMO_CNI_PEER_ID_IPA_NAME:
+		return osmo_ipa_name_cmp(&a->ipa_name, &b->ipa_name);
+	default:
+		return -EINVAL;
+	}
+}
+
+const struct value_string osmo_cni_peer_id_type_names[] = {
+	{ OSMO_CNI_PEER_ID_IPA_NAME, "IPA-name" },
+	{}
+};
+
+/* Call osmo_cni_peer_id_to_str_c with OTC_SELECT */
+const char *osmo_cni_peer_id_to_str(const struct osmo_cni_peer_id *cpi)
+{
+	return osmo_cni_peer_id_to_str_c(OTC_SELECT, cpi);
+}
+
+/* Return an unquoted string, not including the terminating zero. Used for writing VTY config. */
+const char *osmo_cni_peer_id_to_str_c(void *ctx, const struct osmo_cni_peer_id *cpi)
+{
+	switch (cpi->type) {
+	case OSMO_CNI_PEER_ID_IPA_NAME:
+		return osmo_ipa_name_to_str_c(ctx, &cpi->ipa_name);
+	default:
+		return talloc_strdup(ctx, osmo_cni_peer_id_type_name(cpi->type));
+	}
+}
diff --git a/src/gsupclient/gsup_req.c b/src/gsupclient/gsup_req.c
index 4a2ff23..a8a66d5 100644
--- a/src/gsupclient/gsup_req.c
+++ b/src/gsupclient/gsup_req.c
@@ -99,7 +99,7 @@
  * \return a newly allocated osmo_gsup_req, or NULL on error. If NULL is returned, an error response has already been
  *         dispatched to the send_response_cb.
  */
-struct osmo_gsup_req *osmo_gsup_req_new(void *ctx, const struct osmo_ipa_name *from_peer, struct msgb *msg,
+struct osmo_gsup_req *osmo_gsup_req_new(void *ctx, const struct osmo_cni_peer_id *from_peer, struct msgb *msg,
 					osmo_gsup_req_send_response_t send_response_cb, void *cb_data,
 					struct llist_head *add_to_list)
 {
@@ -109,7 +109,7 @@ struct osmo_gsup_req *osmo_gsup_req_new(void *ctx, const struct osmo_ipa_name *f
 
 	if (!msgb_l2(msg) || !msgb_l2len(msg)) {
 		LOGP(DLGSUP, LOGL_ERROR, "Rx GSUP from %s: missing or empty L2 data\n",
-		     osmo_ipa_name_to_str(from_peer));
+		     osmo_cni_peer_id_to_str(from_peer));
 		msgb_free(msg);
 		return NULL;
 	}
@@ -125,7 +125,7 @@ struct osmo_gsup_req *osmo_gsup_req_new(void *ctx, const struct osmo_ipa_name *f
 		req->source_name = *from_peer;
 	rc = osmo_gsup_decode(msgb_l2(req->msg), msgb_l2len(req->msg), (struct osmo_gsup_message*)&req->gsup);
 	if (rc < 0) {
-		LOGP(DLGSUP, LOGL_ERROR, "Rx GSUP from %s: cannot decode (rc=%d)\n", osmo_ipa_name_to_str(from_peer), rc);
+		LOGP(DLGSUP, LOGL_ERROR, "Rx GSUP from %s: cannot decode (rc=%d)\n", osmo_cni_peer_id_to_str(from_peer), rc);
 		osmo_gsup_req_free(req);
 		return NULL;
 	}
@@ -133,17 +133,18 @@ struct osmo_gsup_req *osmo_gsup_req_new(void *ctx, const struct osmo_ipa_name *f
 	LOG_GSUP_REQ(req, LOGL_DEBUG, "new request: {%s}\n", osmo_gsup_message_to_str_c(OTC_SELECT, &req->gsup));
 
 	if (req->gsup.source_name_len) {
-		if (osmo_ipa_name_set(&req->source_name, req->gsup.source_name, req->gsup.source_name_len)) {
+		if (osmo_cni_peer_id_set(&req->source_name, OSMO_CNI_PEER_ID_IPA_NAME,
+					  req->gsup.source_name, req->gsup.source_name_len)) {
 			LOGP(DLGSUP, LOGL_ERROR,
 			     "Rx GSUP from %s: failed to decode source_name, message is not routable\n",
-			     osmo_ipa_name_to_str(from_peer));
+			     osmo_cni_peer_id_to_str(from_peer));
 			osmo_gsup_req_respond_msgt(req, OSMO_GSUP_MSGT_ROUTING_ERROR, true);
 			return NULL;
 		}
 
 		/* The source of the GSUP message is not the immediate GSUP peer; the peer is our proxy for that source.
 		 */
-		if (osmo_ipa_name_cmp(&req->source_name, from_peer))
+		if (osmo_cni_peer_id_cmp(&req->source_name, from_peer))
 			req->via_proxy = *from_peer;
 	}