diff --git a/networking/libiproute/ipaddress.c b/networking/libiproute/ipaddress.c
index 39af88324..86d27548b 100644
--- a/networking/libiproute/ipaddress.c
+++ b/networking/libiproute/ipaddress.c
@@ -162,7 +162,7 @@ static NOINLINE int print_linkinfo(const struct nlmsghdr *n)
 
 	if (!filter.family || filter.family == AF_PACKET) {
 		SPRINT_BUF(b1);
-		printf("%c    link/%s ", _SL_, ll_type_n2a(ifi->ifi_type, b1, sizeof(b1)));
+		printf("%c    link/%s ", _SL_, ll_type_n2a(ifi->ifi_type, b1));
 
 		if (tb[IFLA_ADDRESS]) {
 			fputs(ll_addr_n2a(RTA_DATA(tb[IFLA_ADDRESS]),
@@ -308,7 +308,7 @@ static int FAST_FUNC print_addrinfo(const struct sockaddr_nl *who UNUSED_PARAM,
 				    RTA_DATA(rta_tb[IFA_ANYCAST]),
 				    abuf, sizeof(abuf)));
 	}
-	printf("scope %s ", rtnl_rtscope_n2a(ifa->ifa_scope, b1, sizeof(b1)));
+	printf("scope %s ", rtnl_rtscope_n2a(ifa->ifa_scope, b1));
 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 		ifa->ifa_flags &= ~IFA_F_SECONDARY;
 		printf("secondary ");
diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index ac7eec598..7031bed34 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -196,7 +196,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 		printf("Deleted ");
 	}
 	if (r->rtm_type != RTN_UNICAST && !filter.type) {
-		printf("%s ", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
+		printf("%s ", rtnl_rtntype_n2a(r->rtm_type, b1));
 	}
 
 	if (tb[RTA_DST]) {
diff --git a/networking/libiproute/iprule.c b/networking/libiproute/iprule.c
index bec530dcb..e52473117 100644
--- a/networking/libiproute/iprule.c
+++ b/networking/libiproute/iprule.c
@@ -113,7 +113,7 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 	}
 
 	if (r->rtm_tos) {
-		printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
+		printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1));
 	}
 	if (tb[RTA_PROTOINFO]) {
 		printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
@@ -124,7 +124,7 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 	}
 
 	if (r->rtm_table)
-		printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
+		printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1));
 
 	if (tb[RTA_FLOW]) {
 		uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
@@ -132,10 +132,10 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 		to &= 0xFFFF;
 		if (from) {
 			printf("realms %s/",
-				rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
+				rtnl_rtrealm_n2a(from, b1));
 		}
 		printf("%s ",
-			rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
+			rtnl_rtrealm_n2a(to, b1));
 	}
 
 	if (r->rtm_type == RTN_NAT) {
@@ -148,7 +148,7 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 		} else
 			printf("masquerade");
 	} else if (r->rtm_type != RTN_UNICAST)
-		fputs(rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)), stdout);
+		fputs(rtnl_rtntype_n2a(r->rtm_type, b1), stdout);
 
 	bb_putchar('\n');
 	/*fflush(stdout);*/
diff --git a/networking/libiproute/iptunnel.c b/networking/libiproute/iptunnel.c
index 6a841aadb..836709c7e 100644
--- a/networking/libiproute/iptunnel.c
+++ b/networking/libiproute/iptunnel.c
@@ -436,7 +436,7 @@ static void print_tunnel(struct ip_tunnel_parm *p)
 			printf(" inherit");
 		if (p->iph.tos & ~1)
 			printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
-			       rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
+			       rtnl_dsfield_n2a(p->iph.tos & ~1, b1));
 	}
 	if (!(p->iph.frag_off & htons(IP_DF)))
 		printf(" nopmtudisc");
diff --git a/networking/libiproute/ll_addr.c b/networking/libiproute/ll_addr.c
index f50e37193..f59831cc1 100644
--- a/networking/libiproute/ll_addr.c
+++ b/networking/libiproute/ll_addr.c
@@ -17,7 +17,7 @@
 #include "utils.h"
 
 
-const char *ll_addr_n2a(unsigned char *addr, int alen, int type, char *buf, int blen)
+const char* FAST_FUNC ll_addr_n2a(unsigned char *addr, int alen, int type, char *buf, int blen)
 {
 	int i;
 	int l;
@@ -27,13 +27,13 @@ const char *ll_addr_n2a(unsigned char *addr, int alen, int type, char *buf, int
 		return inet_ntop(AF_INET, addr, buf, blen);
 	}
 	l = 0;
-	for (i=0; i<alen; i++) {
-		if (i==0) {
-			snprintf(buf+l, blen, ":%02x"+1, addr[i]);
+	for (i = 0; i < alen; i++) {
+		if (i == 0) {
+			snprintf(buf + l, blen, ":%02x"+1, addr[i]);
 			blen -= 2;
 			l += 2;
 		} else {
-			snprintf(buf+l, blen, ":%02x", addr[i]);
+			snprintf(buf + l, blen, ":%02x", addr[i]);
 			blen -= 3;
 			l += 3;
 		}
@@ -41,7 +41,7 @@ const char *ll_addr_n2a(unsigned char *addr, int alen, int type, char *buf, int
 	return buf;
 }
 
-int ll_addr_a2n(unsigned char *lladdr, int len, char *arg)
+int FAST_FUNC ll_addr_a2n(unsigned char *lladdr, int len, char *arg)
 {
 	int i;
 
diff --git a/networking/libiproute/ll_proto.c b/networking/libiproute/ll_proto.c
index a93493538..145902b2e 100644
--- a/networking/libiproute/ll_proto.c
+++ b/networking/libiproute/ll_proto.c
@@ -98,7 +98,7 @@ __PF(ECONET,econet)
 #undef __PF
 
 
-const char *ll_proto_n2a(unsigned short id, char *buf, int len)
+const char* FAST_FUNC ll_proto_n2a(unsigned short id, char *buf, int len)
 {
 	unsigned i;
 	id = ntohs(id);
@@ -110,7 +110,7 @@ const char *ll_proto_n2a(unsigned short id, char *buf, int len)
 	return buf;
 }
 
-int ll_proto_a2n(unsigned short *id, char *buf)
+int FAST_FUNC ll_proto_a2n(unsigned short *id, char *buf)
 {
 	unsigned i;
 	for (i = 0; i < ARRAY_SIZE(llproto_names); i++) {
diff --git a/networking/libiproute/ll_types.c b/networking/libiproute/ll_types.c
index d5d2a1f39..3861c2870 100644
--- a/networking/libiproute/ll_types.c
+++ b/networking/libiproute/ll_types.c
@@ -15,7 +15,7 @@
 #include "libbb.h"
 #include "rt_names.h"
 
-const char *ll_type_n2a(int type, char *buf, int len)
+const char* FAST_FUNC ll_type_n2a(int type, char *buf)
 {
 	static const char arphrd_name[] =
 	/* 0,                  */ "generic" "\0"
@@ -200,6 +200,6 @@ const char *ll_type_n2a(int type, char *buf, int len)
 			return aname;
 		aname += strlen(aname) + 1;
 	}
-	snprintf(buf, len, "[%d]", type);
+	sprintf(buf, "[%d]", type);
 	return buf;
 }
diff --git a/networking/libiproute/rt_names.c b/networking/libiproute/rt_names.c
index 2699dba3d..8dd16e3d3 100644
--- a/networking/libiproute/rt_names.c
+++ b/networking/libiproute/rt_names.c
@@ -90,10 +90,10 @@ static void rtnl_rtprot_initialize(void)
 	rtnl_tab_initialize("/etc/iproute2/rt_protos", rtnl_rtprot_tab->tab);
 }
 
-const char* rtnl_rtprot_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_rtprot_n2a(int id, char *buf)
 {
 	if (id < 0 || id >= 256) {
-		snprintf(buf, len, "%d", id);
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 
@@ -101,11 +101,12 @@ const char* rtnl_rtprot_n2a(int id, char *buf, int len)
 
 	if (rtnl_rtprot_tab->tab[id])
 		return rtnl_rtprot_tab->tab[id];
-	snprintf(buf, len, "%d", id);
+	/* buf is SPRINT_BSIZE big */
+	sprintf(buf, "%d", id);
 	return buf;
 }
 
-int rtnl_rtprot_a2n(uint32_t *id, char *arg)
+int FAST_FUNC rtnl_rtprot_a2n(uint32_t *id, char *arg)
 {
 	rtnl_rtprot_initialize();
 	return rtnl_a2n(rtnl_rtprot_tab, id, arg, 0);
@@ -127,10 +128,10 @@ static void rtnl_rtscope_initialize(void)
 	rtnl_tab_initialize("/etc/iproute2/rt_scopes", rtnl_rtscope_tab->tab);
 }
 
-const char* rtnl_rtscope_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_rtscope_n2a(int id, char *buf)
 {
 	if (id < 0 || id >= 256) {
-		snprintf(buf, len, "%d", id);
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 
@@ -138,11 +139,12 @@ const char* rtnl_rtscope_n2a(int id, char *buf, int len)
 
 	if (rtnl_rtscope_tab->tab[id])
 		return rtnl_rtscope_tab->tab[id];
-	snprintf(buf, len, "%d", id);
+	/* buf is SPRINT_BSIZE big */
+	sprintf(buf, "%d", id);
 	return buf;
 }
 
-int rtnl_rtscope_a2n(uint32_t *id, char *arg)
+int FAST_FUNC rtnl_rtscope_a2n(uint32_t *id, char *arg)
 {
 	rtnl_rtscope_initialize();
 	return rtnl_a2n(rtnl_rtscope_tab, id, arg, 0);
@@ -159,17 +161,17 @@ static void rtnl_rtrealm_initialize(void)
 	rtnl_tab_initialize("/etc/iproute2/rt_realms", rtnl_rtrealm_tab->tab);
 }
 
-int rtnl_rtrealm_a2n(uint32_t *id, char *arg)
+int FAST_FUNC rtnl_rtrealm_a2n(uint32_t *id, char *arg)
 {
 	rtnl_rtrealm_initialize();
 	return rtnl_a2n(rtnl_rtrealm_tab, id, arg, 0);
 }
 
 #if ENABLE_FEATURE_IP_RULE
-const char* rtnl_rtrealm_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_rtrealm_n2a(int id, char *buf)
 {
 	if (id < 0 || id >= 256) {
-		snprintf(buf, len, "%d", id);
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 
@@ -177,7 +179,8 @@ const char* rtnl_rtrealm_n2a(int id, char *buf, int len)
 
 	if (rtnl_rtrealm_tab->tab[id])
 		return rtnl_rtrealm_tab->tab[id];
-	snprintf(buf, len, "%d", id);
+	/* buf is SPRINT_BSIZE big */
+	sprintf(buf, "%d", id);
 	return buf;
 }
 #endif
@@ -193,10 +196,10 @@ static void rtnl_rtdsfield_initialize(void)
 	rtnl_tab_initialize("/etc/iproute2/rt_dsfield", rtnl_rtdsfield_tab->tab);
 }
 
-const char * rtnl_dsfield_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_dsfield_n2a(int id, char *buf)
 {
 	if (id < 0 || id >= 256) {
-		snprintf(buf, len, "%d", id);
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 
@@ -204,11 +207,12 @@ const char * rtnl_dsfield_n2a(int id, char *buf, int len)
 
 	if (rtnl_rtdsfield_tab->tab[id])
 		return rtnl_rtdsfield_tab->tab[id];
-	snprintf(buf, len, "0x%02x", id);
+	/* buf is SPRINT_BSIZE big */
+	sprintf(buf, "0x%02x", id);
 	return buf;
 }
 
-int rtnl_dsfield_a2n(uint32_t *id, char *arg)
+int FAST_FUNC rtnl_dsfield_a2n(uint32_t *id, char *arg)
 {
 	rtnl_rtdsfield_initialize();
 	return rtnl_a2n(rtnl_rtdsfield_tab, id, arg, 16);
@@ -229,10 +233,10 @@ static void rtnl_rttable_initialize(void)
 	rtnl_tab_initialize("/etc/iproute2/rt_tables", rtnl_rttable_tab->tab);
 }
 
-const char *rtnl_rttable_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_rttable_n2a(int id, char *buf)
 {
 	if (id < 0 || id >= 256) {
-		snprintf(buf, len, "%d", id);
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 
@@ -240,11 +244,12 @@ const char *rtnl_rttable_n2a(int id, char *buf, int len)
 
 	if (rtnl_rttable_tab->tab[id])
 		return rtnl_rttable_tab->tab[id];
-	snprintf(buf, len, "%d", id);
+	/* buf is SPRINT_BSIZE big */
+	sprintf(buf, "%d", id);
 	return buf;
 }
 
-int rtnl_rttable_a2n(uint32_t *id, char *arg)
+int FAST_FUNC rtnl_rttable_a2n(uint32_t *id, char *arg)
 {
 	rtnl_rttable_initialize();
 	return rtnl_a2n(rtnl_rttable_tab, id, arg, 0);
diff --git a/networking/libiproute/rt_names.h b/networking/libiproute/rt_names.h
index a2d4fd142..e73aa851c 100644
--- a/networking/libiproute/rt_names.h
+++ b/networking/libiproute/rt_names.h
@@ -4,25 +4,26 @@
 
 PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
-extern const char* rtnl_rtprot_n2a(int id, char *buf, int len);
-extern const char* rtnl_rtscope_n2a(int id, char *buf, int len);
-extern const char* rtnl_rtrealm_n2a(int id, char *buf, int len);
-extern const char* rtnl_dsfield_n2a(int id, char *buf, int len);
-extern const char* rtnl_rttable_n2a(int id, char *buf, int len);
-extern int rtnl_rtprot_a2n(uint32_t *id, char *arg);
-extern int rtnl_rtscope_a2n(uint32_t *id, char *arg);
-extern int rtnl_rtrealm_a2n(uint32_t *id, char *arg);
-extern int rtnl_dsfield_a2n(uint32_t *id, char *arg);
-extern int rtnl_rttable_a2n(uint32_t *id, char *arg);
+/* buf is SPRINT_BSIZE big */
+extern const char* rtnl_rtprot_n2a(int id, char *buf) FAST_FUNC;
+extern const char* rtnl_rtscope_n2a(int id, char *buf) FAST_FUNC;
+extern const char* rtnl_rtrealm_n2a(int id, char *buf) FAST_FUNC;
+extern const char* rtnl_dsfield_n2a(int id, char *buf) FAST_FUNC;
+extern const char* rtnl_rttable_n2a(int id, char *buf) FAST_FUNC;
+extern int rtnl_rtprot_a2n(uint32_t *id, char *arg) FAST_FUNC;
+extern int rtnl_rtscope_a2n(uint32_t *id, char *arg) FAST_FUNC;
+extern int rtnl_rtrealm_a2n(uint32_t *id, char *arg) FAST_FUNC;
+extern int rtnl_dsfield_a2n(uint32_t *id, char *arg) FAST_FUNC;
+extern int rtnl_rttable_a2n(uint32_t *id, char *arg) FAST_FUNC;
 
-extern const char* ll_type_n2a(int type, char *buf, int len);
+extern const char* ll_type_n2a(int type, char *buf) FAST_FUNC;
 
 extern const char* ll_addr_n2a(unsigned char *addr, int alen, int type,
-				char *buf, int blen);
-extern int ll_addr_a2n(unsigned char *lladdr, int len, char *arg);
+				char *buf, int blen) FAST_FUNC;
+extern int ll_addr_a2n(unsigned char *lladdr, int len, char *arg) FAST_FUNC;
 
-extern const char* ll_proto_n2a(unsigned short id, char *buf, int len);
-extern int ll_proto_a2n(unsigned short *id, char *buf);
+extern const char* ll_proto_n2a(unsigned short id, char *buf, int len) FAST_FUNC;
+extern int ll_proto_a2n(unsigned short *id, char *buf) FAST_FUNC;
 
 POP_SAVED_FUNCTION_VISIBILITY
 
diff --git a/networking/libiproute/rtm_map.c b/networking/libiproute/rtm_map.c
index 6fe5c4b75..5e358e105 100644
--- a/networking/libiproute/rtm_map.c
+++ b/networking/libiproute/rtm_map.c
@@ -15,7 +15,7 @@
 #include "rt_names.h"
 #include "utils.h"
 
-const char *rtnl_rtntype_n2a(int id, char *buf, int len)
+const char* FAST_FUNC rtnl_rtntype_n2a(int id, char *buf)
 {
 	switch (id) {
 	case RTN_UNSPEC:
@@ -43,13 +43,14 @@ const char *rtnl_rtntype_n2a(int id, char *buf, int len)
 	case RTN_XRESOLVE:
 		return "xresolve";
 	default:
-		snprintf(buf, len, "%d", id);
+		/* buf is SPRINT_BSIZE big */
+		sprintf(buf, "%d", id);
 		return buf;
 	}
 }
 
 
-int rtnl_rtntype_a2n(int *id, char *arg)
+int FAST_FUNC rtnl_rtntype_a2n(int *id, char *arg)
 {
 	static const char keywords[] ALIGN1 =
 		"local\0""nat\0""broadcast\0""brd\0""anycast\0"
@@ -95,7 +96,7 @@ int rtnl_rtntype_a2n(int *id, char *arg)
 	return 0;
 }
 
-int get_rt_realms(uint32_t *realms, char *arg)
+int FAST_FUNC get_rt_realms(uint32_t *realms, char *arg)
 {
 	uint32_t realm = 0;
 	char *p = strchr(arg, '/');
diff --git a/networking/libiproute/rtm_map.h b/networking/libiproute/rtm_map.h
index ab1b70e45..4377bd590 100644
--- a/networking/libiproute/rtm_map.h
+++ b/networking/libiproute/rtm_map.h
@@ -4,10 +4,10 @@
 
 PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
-const char *rtnl_rtntype_n2a(int id, char *buf, int len);
-int rtnl_rtntype_a2n(int *id, char *arg);
+const char *rtnl_rtntype_n2a(int id, char *buf) FAST_FUNC;
+int rtnl_rtntype_a2n(int *id, char *arg) FAST_FUNC;
 
-int get_rt_realms(uint32_t *realms, char *arg);
+int get_rt_realms(uint32_t *realms, char *arg) FAST_FUNC;
 
 POP_SAVED_FUNCTION_VISIBILITY