From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: bgpd: use unsigned int instead of uint8_t as loop iterator var
To: tech@openbsd.org
Date: Thu, 7 May 2026 21:11:28 +0200

I like to move away from using size restricted variables for loop indexes
and length variables.

Too often the limited range cause overflows in unexpeced ways. It is
better to use a default int type instead.

This converts the uint8_t length vars for iterating over the others
attribute array to unsigned int. I also added early breaks in the loop in
two places since after the first NULL all values will be NULL as well.

-- 
:wq Claudio

Index: mrt.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/mrt.c,v
diff -u -p -r1.134 mrt.c
--- mrt.c	17 Feb 2026 14:06:44 -0000	1.134
+++ mrt.c	7 May 2026 18:48:22 -0000
@@ -222,9 +222,10 @@ mrt_attr_dump(struct ibuf *buf, struct r
 	struct attr	*oa;
 	u_char		*pdata;
 	uint32_t	 tmp;
+	unsigned int	 l;
 	int		 neednewpath = 0;
 	uint16_t	 plen, afi;
-	uint8_t		 l, safi;
+	uint8_t		 safi;
 
 	/* origin */
 	if (attr_writebuf(buf, ATTR_WELL_KNOWN, ATTR_ORIGIN,
Index: rde.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde.c,v
diff -u -p -r1.696 rde.c
--- rde.c	7 May 2026 09:42:26 -0000	1.696
+++ rde.c	7 May 2026 18:47:04 -0000
@@ -2923,7 +2923,7 @@ rde_dump_rib_as(struct prefix *p, struct
 	struct rde_peer		*peer;
 	monotime_t		 staletime;
 	size_t			 aslen;
-	uint8_t			 l;
+	unsigned int		 l;
 
 	nexthop = prefix_nexthop(p);
 	peer = prefix_peer(p);
@@ -3041,7 +3041,7 @@ rde_dump_adjout_as(struct rde_peer *peer
 	struct rde_aspath	*asp;
 	struct nexthop		*nexthop;
 	size_t			 aslen;
-	uint8_t			 l;
+	unsigned int		 l;
 
 	nexthop = attrs->nexthop;
 	asp = attrs->aspath;
Index: rde_attr.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde_attr.c,v
diff -u -p -r1.143 rde_attr.c
--- rde_attr.c	5 May 2026 08:37:45 -0000	1.143
+++ rde_attr.c	7 May 2026 18:52:37 -0000
@@ -152,7 +152,7 @@ attr_optadd(struct rde_aspath *asp, uint
 struct attr *
 attr_optget(const struct rde_aspath *asp, uint8_t type)
 {
-	uint8_t l;
+	unsigned int l;
 
 	for (l = 0; l < asp->others_len; l++) {
 		if (asp->others[l] == NULL)
@@ -168,7 +168,7 @@ attr_optget(const struct rde_aspath *asp
 void
 attr_copy(struct rde_aspath *t, const struct rde_aspath *s)
 {
-	uint8_t l;
+	unsigned int l;
 
 	if (t->others != NULL)
 		attr_freeall(t);
@@ -208,22 +208,25 @@ attr_eq(const struct attr *oa, const str
 int
 attr_equal(const struct rde_aspath *a, const struct rde_aspath *b)
 {
-	uint8_t l;
+	unsigned int l;
 
 	if (a->others_len != b->others_len)
 		return (0);
-	for (l = 0; l < a->others_len; l++)
+	for (l = 0; l < a->others_len; l++) {
 		if (a->others[l] != b->others[l])
 			return (0);
+		if (a->others[l] == NULL)
+			break;
+	}
 	return (1);
 }
 
 void
 attr_free(struct rde_aspath *asp, struct attr *attr)
 {
-	uint8_t l;
+	unsigned int l;
 
-	for (l = 0; l < asp->others_len; l++)
+	for (l = 0; l < asp->others_len; l++) {
 		if (asp->others[l] == attr) {
 			attr_put(asp->others[l]);
 			for (++l; l < asp->others_len; l++)
@@ -231,6 +234,9 @@ attr_free(struct rde_aspath *asp, struct
 			asp->others[asp->others_len - 1] = NULL;
 			return;
 		}
+		if (asp->others[l] == NULL)
+			break;
+	}
 
 	/* no realloc() because the slot may be reused soon */
 }
@@ -238,7 +244,7 @@ attr_free(struct rde_aspath *asp, struct
 void
 attr_freeall(struct rde_aspath *asp)
 {
-	uint8_t l;
+	unsigned int l;
 
 	for (l = 0; l < asp->others_len; l++)
 		attr_put(asp->others[l]);
Index: rde_update.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde_update.c,v
diff -u -p -r1.193 rde_update.c
--- rde_update.c	11 Feb 2026 10:24:57 -0000	1.193
+++ rde_update.c	7 May 2026 18:49:19 -0000
@@ -591,9 +591,10 @@ up_generate_attr(struct ibuf *buf, struc
 	struct attr	*oa = NULL, *newaggr = NULL;
 	u_char		*pdata;
 	uint32_t	 tmp32;
+	unsigned int	 oalen = 0;
 	int		 flags, neednewpath = 0, rv;
 	uint16_t	 plen;
-	uint8_t		 oalen = 0, type;
+	uint8_t		 type;
 
 	if (asp->others_len > 0)
 		oa = asp->others[oalen++];