From bc18131d277d9b4b32eed8a49bedba0bb39be3b2 Mon Sep 17 00:00:00 2001
From: Richard Cochran <richardcochran@gmail.com>
Date: Mon, 2 Apr 2018 00:07:48 -0700
Subject: [PATCH] util: Add a method to compare binary addresses.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
---
 util.c | 28 ++++++++++++++++++++++++++++
 util.h |  9 +++++++++
 2 files changed, 37 insertions(+)

diff --git a/util.c b/util.c
index 799147a..73fb37e 100644
--- a/util.c
+++ b/util.c
@@ -69,6 +69,34 @@ const char *ev_str[] = {
 	"RS_PASSIVE",
 };
 
+int addreq(enum transport_type type, struct address *a, struct address *b)
+{
+	void *bufa, *bufb;
+	int len;
+
+	switch (type) {
+	case TRANS_UDP_IPV4:
+		bufa = &a->sin.sin_addr;
+		bufb = &b->sin.sin_addr;
+		len = sizeof(a->sin);
+		break;
+	case TRANS_IEEE_802_3:
+		bufa = &a->sll.sll_addr;
+		bufb = &b->sll.sll_addr;
+		len = MAC_LEN;
+		break;
+	case TRANS_UDS:
+	case TRANS_UDP_IPV6:
+	case TRANS_DEVICENET:
+	case TRANS_CONTROLNET:
+	case TRANS_PROFINET:
+	default:
+		pr_err("sorry, cannot compare addresses for this transport");
+		return 0;
+	}
+	return memcmp(bufa, bufb, len) == 0 ? 1 : 0;
+}
+
 char *bin2str_impl(Octet *data, int len, char *buf, int buf_len)
 {
 	int i, offset = 0;
diff --git a/util.h b/util.h
index 29ba5ca..1ab1b3f 100644
--- a/util.h
+++ b/util.h
@@ -41,6 +41,15 @@ extern const char *ps_str[];
  */
 extern const char *ev_str[];
 
+/**
+ * Compares two binary addresses for equality.
+ * @param type  One of the enumerated transport types.
+ * @param a     One address to compare.
+ * @param b     The second address to compare.
+ * @return      One if the addresses are identical, zero otherwise.
+ */
+int addreq(enum transport_type type, struct address *a, struct address *b);
+
 static inline uint16_t align16(uint16_t *p)
 {
 	uint16_t v;