add osmo_pfcp_ip_addrs_to_str_*()

Move static function ip_addrs_to_str_buf() to public API as
osmo_pfcp_ip_addrs_to_str_buf() and osmo_pfcp_ip_addrs_to_str_c().

So far the static function was only used in places where it follows
other strings, so that it made sense to always start with a comma. Move
this comma out of the function to the callers.

Sensibly handle a NULL pointer and an empty address set.

Rationale: osmo-upf would like to print an osmo_pfcp_ip_addrs struct in
logging.

Change-Id: I5f67db8d347690cbb1ce273a2d072636859f1bf6

1 files changed, 2 insertions, 0 deletions

diff --git a/include/osmocom/pfcp/pfcp_ies_custom.h b/include/osmocom/pfcp/pfcp_ies_custom.h
index f273a87..565fee2 100644
--- a/include/osmocom/pfcp/pfcp_ies_custom.h
+++ b/include/osmocom/pfcp/pfcp_ies_custom.h
@@ -37,6 +37,8 @@ struct osmo_pfcp_ip_addrs {
 };
 
 int osmo_pfcp_ip_addrs_set(struct osmo_pfcp_ip_addrs *dst, const struct osmo_sockaddr *addr);
+int osmo_pfcp_ip_addrs_to_str_buf(char *buf, size_t buflen, const struct osmo_pfcp_ip_addrs *addrs);
+char *osmo_pfcp_ip_addrs_to_str_c(void *ctx, const struct osmo_pfcp_ip_addrs *addrs);
 
 /* 3GPP TS 29.244 8.2.38, IETF RFC 1035 3.1 */
 struct osmo_pfcp_ie_node_id {