add osmo_sockaddr_str_cmp()

Currently planned user: for Distributed GSM in osmo-hlr: setting per-MSC
service addresses in VTY: replace/remove existing entries.

osmo_sockaddr_str_cmp() is useful to catch identical resulting IP addresses,
regardless of differing strings (e.g. '0::' and '::' are equal but differ in
strings).

Change-Id: I0dbc1cf707098dcda75f8e07c1b936951f9f9501

2 files changed, 3 insertions, 0 deletions

diff --git a/include/osmocom/core/sockaddr_str.h b/include/osmocom/core/sockaddr_str.h
index 6dd428c7..d7a8cdf6 100644
--- a/include/osmocom/core/sockaddr_str.h
+++ b/include/osmocom/core/sockaddr_str.h
@@ -70,6 +70,7 @@ struct osmo_sockaddr_str {
 
 bool osmo_sockaddr_str_is_set(const struct osmo_sockaddr_str *sockaddr_str);
 bool osmo_sockaddr_str_is_nonzero(const struct osmo_sockaddr_str *sockaddr_str);
+int osmo_sockaddr_str_cmp(const struct osmo_sockaddr_str *a, const struct osmo_sockaddr_str *b);
 
 int osmo_sockaddr_str_from_str(struct osmo_sockaddr_str *sockaddr_str, const char *ip, uint16_t port);
 
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index 601bb565..c4e6f5fc 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -21,6 +21,8 @@
 #define OSMO_MAX(a, b) ((a) >= (b) ? (a) : (b))
 /*! Return the minimum of two specified values */
 #define OSMO_MIN(a, b) ((a) >= (b) ? (b) : (a))
+/*! Return a typical cmp result for comparable entities a and b. */
+#define OSMO_CMP(a, b) ((a) < (b)? -1 : ((a) > (b)? 1 : 0))
 /*! Stringify the name of a macro x, e.g. an FSM event name.
  * Note: if nested within another preprocessor macro, this will
  * stringify the value of x instead of its name. */