Reverse the polarity of flowspec_cmp() so it works better with our

RB trees. Mainly RB_FOREACH() walks form RB_MIN to RB_MAX so the most
preferred entry should be at RB_MIN.
OK tb@

diff --git a/usr.sbin/bgpd/flowspec.c b/usr.sbin/bgpd/flowspec.c
index 0a2d6a1..7ce063f 100644 (file)
--- a/usr.sbin/bgpd/flowspec.c
+++ b/usr.sbin/bgpd/flowspec.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: flowspec.c,v 1.1 2023/04/17 08:02:21 claudio Exp $ */
+/*     $OpenBSD: flowspec.c,v 1.2 2023/04/17 20:54:57 claudio Exp $ */
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -91,7 +91,7 @@ flowspec_next_component(const uint8_t *buf, int len, int is_v6, int *type)
 
 /*
  * Compare two IPv4 flowspec prefix components.
- * Returns 1 if first prefix is preferred, -1 if second, 0 if equal.
+ * Returns -1 if first prefix is preferred, 1 if second, 0 if equal.
  */
 static int
 flowspec_cmp_prefix4(const uint8_t *abuf, int ablen, const uint8_t *bbuf,
@@ -113,15 +113,15 @@ flowspec_cmp_prefix4(const uint8_t *abuf, int ablen, const uint8_t *bbuf,
        /* lowest IP value has precedence */
        cmp = memcmp(a, b, sizeof(a));
        if (cmp < 0)
-               return 1;
-       if (cmp > 0)
                return -1;
+       if (cmp > 0)
+               return 1;
 
        /* if common prefix, more specific route has precedence */
        if (alen > blen)
-               return 1;
-       if (alen < blen)
                return -1;
+       if (alen < blen)
+               return 1;
        return 0;
 }
 
@@ -139,9 +139,9 @@ flowspec_cmp_prefix6(const uint8_t *abuf, int ablen, const uint8_t *bbuf,
 
        /* lowest offset has precedence */
        if (abuf[2] < bbuf[2])
-               return 1;
-       if (abuf[2] > bbuf[2])
                return -1;
+       if (abuf[2] > bbuf[2])
+               return 1;
 
        /* calculate actual pattern size (len - offset) */
        alen = abuf[1] - abuf[2];
@@ -157,15 +157,15 @@ flowspec_cmp_prefix6(const uint8_t *abuf, int ablen, const uint8_t *bbuf,
        /* lowest IP value has precedence */
        cmp = memcmp(a, b, sizeof(a));
        if (cmp < 0)
-               return 1;
-       if (cmp > 0)
                return -1;
+       if (cmp > 0)
+               return 1;
 
        /* if common prefix, more specific route has precedence */
        if (alen > blen)
-               return 1;
-       if (alen < blen)
                return -1;
+       if (alen < blen)
+               return 1;
        return 0;
 }
 
@@ -199,7 +199,7 @@ flowspec_valid(const uint8_t *buf, int len, int is_v6)
 
 /*
  * Compare two valid flowspec NLRI objects according to RFC 8955 & 8956.
- * Returns 1 if the first object has preference, -1 if not, and 0 if the
+ * Returns -1 if the first object has preference, 1 if not, and 0 if the
  * two objects are equal.
  */
 int
@@ -219,9 +219,9 @@ flowspec_cmp(const uint8_t *a, int alen, const uint8_t *b, int blen, int is_v6)
 
                /* If types differ, lowest type wins. */
                if (atype < btype)
-                       return 1;
-               if (atype > btype)
                        return -1;
+               if (atype > btype)
+                       return 1;
 
                switch (atype) {
                case FLOWSPEC_TYPE_DEST:
@@ -244,9 +244,9 @@ flowspec_cmp(const uint8_t *a, int alen, const uint8_t *b, int blen, int is_v6)
                         * string has precedence.
                         */
                        if (cmp < 0)
-                               return 1;
-                       if (cmp > 0)
                                return -1;
+                       if (cmp > 0)
+                               return 1;
                        /*
                         * Longest component wins when common prefix is equal.
                         * This is not really possible because EOL encoding will
@@ -254,9 +254,9 @@ flowspec_cmp(const uint8_t *a, int alen, const uint8_t *b, int blen, int is_v6)
                         * it (and it is cheap).
                         */
                        if (acomplen > bcomplen)
-                               return 1;
-                       if (acomplen < bcomplen)
                                return -1;
+                       if (acomplen < bcomplen)
+                               return 1;
                        break;
                }
                a += acomplen;
@@ -266,9 +266,9 @@ flowspec_cmp(const uint8_t *a, int alen, const uint8_t *b, int blen, int is_v6)
 
                /* Rule with more components wins */
                if (alen > 0 && blen <= 0)
-                       return 1;
-               if (alen <= 0 && blen > 0)
                        return -1;
+               if (alen <= 0 && blen > 0)
+                       return 1;
        }
        return 0;
 }