libiproute: make rt_addr_n2a() and format_host() return auto strings

function                                             old     new   delta
rt_addr_n2a                                           56      53      -3
print_addrinfo                                      1227    1178     -49
print_neigh                                          933     881     -52
print_rule                                           689     617     -72
print_tunnel                                         640     560     -80
print_route                                         1727    1588    -139
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/6 up/down: 0/-395)           Total: -395 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

7 files changed, 57 insertions, 75 deletions

diff --git a/networking/libiproute/ipaddress.c b/networking/libiproute/ipaddress.c
index c0f27c7..5c975d8 100644
--- a/networking/libiproute/ipaddress.c
+++ b/networking/libiproute/ipaddress.c
@@ -214,8 +214,7 @@ static int FAST_FUNC print_addrinfo(const struct sockaddr_nl *who UNUSED_PARAM,
 {
 	struct ifaddrmsg *ifa = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
-	struct rtattr * rta_tb[IFA_MAX+1];
-	char abuf[256];
+	struct rtattr *rta_tb[IFA_MAX+1];
 
 	if (n->nlmsg_type != RTM_NEWADDR && n->nlmsg_type != RTM_DELADDR)
 		return 0;
@@ -291,9 +290,9 @@ static int FAST_FUNC print_addrinfo(const struct sockaddr_nl *who UNUSED_PARAM,
 		printf("    family %d ", ifa->ifa_family);
 
 	if (rta_tb[IFA_LOCAL]) {
-		fputs(rt_addr_n2a(ifa->ifa_family,
-					      RTA_DATA(rta_tb[IFA_LOCAL]),
-					      abuf, sizeof(abuf)), stdout);
+		fputs(rt_addr_n2a(ifa->ifa_family, RTA_DATA(rta_tb[IFA_LOCAL])),
+			stdout
+		);
 
 		if (rta_tb[IFA_ADDRESS] == NULL
 		 || memcmp(RTA_DATA(rta_tb[IFA_ADDRESS]), RTA_DATA(rta_tb[IFA_LOCAL]), 4) == 0
@@ -301,25 +300,22 @@ static int FAST_FUNC print_addrinfo(const struct sockaddr_nl *who UNUSED_PARAM,
 			printf("/%d ", ifa->ifa_prefixlen);
 		} else {
 			printf(" peer %s/%d ",
-				rt_addr_n2a(ifa->ifa_family,
-					    RTA_DATA(rta_tb[IFA_ADDRESS]),
-					    abuf, sizeof(abuf)),
-				ifa->ifa_prefixlen);
+				rt_addr_n2a(ifa->ifa_family, RTA_DATA(rta_tb[IFA_ADDRESS])),
+				ifa->ifa_prefixlen
+			);
 		}
 	}
 
 	if (rta_tb[IFA_BROADCAST]) {
 		printf("brd %s ",
 			rt_addr_n2a(ifa->ifa_family,
-					RTA_DATA(rta_tb[IFA_BROADCAST]),
-					abuf, sizeof(abuf))
+				RTA_DATA(rta_tb[IFA_BROADCAST]))
 		);
 	}
 	if (rta_tb[IFA_ANYCAST]) {
 		printf("any %s ",
 			rt_addr_n2a(ifa->ifa_family,
-					RTA_DATA(rta_tb[IFA_ANYCAST]),
-					abuf, sizeof(abuf))
+				RTA_DATA(rta_tb[IFA_ANYCAST]))
 		);
 	}
 	printf("scope %s ", rtnl_rtscope_n2a(ifa->ifa_scope));
diff --git a/networking/libiproute/ipneigh.c b/networking/libiproute/ipneigh.c
index 6588c12..179505c 100644
--- a/networking/libiproute/ipneigh.c
+++ b/networking/libiproute/ipneigh.c
@@ -91,7 +91,6 @@ static int FAST_FUNC print_neigh(const struct sockaddr_nl *who UNUSED_PARAM,
 	struct ndmsg *r = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
 	struct rtattr *tb[NDA_MAX+1];
-	char abuf[256];
 
 	if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
 		bb_error_msg_and_die("not RTM_NEWNEIGH: %08x %08x %08x",
@@ -155,8 +154,8 @@ static int FAST_FUNC print_neigh(const struct sockaddr_nl *who UNUSED_PARAM,
 		printf("%s ",
 		       format_host(r->ndm_family,
 				   RTA_PAYLOAD(tb[NDA_DST]),
-				   RTA_DATA(tb[NDA_DST]),
-				   abuf, sizeof(abuf)));
+				   RTA_DATA(tb[NDA_DST]))
+		);
 	}
 	if (!G_filter.index && r->ndm_ifindex)
 		printf("dev %s ", ll_index_to_name(r->ndm_ifindex));
diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index 0d29144..d232ee6 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -61,7 +61,6 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	struct rtmsg *r = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
 	struct rtattr *tb[RTA_MAX+1];
-	char abuf[256];
 	inet_prefix dst;
 	inet_prefix src;
 	int host_len = -1;
@@ -218,17 +217,15 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 
 	if (tb[RTA_DST]) {
 		if (r->rtm_dst_len != host_len) {
-			printf("%s/%u ", rt_addr_n2a(r->rtm_family,
-						RTA_DATA(tb[RTA_DST]),
-						abuf, sizeof(abuf)),
-					r->rtm_dst_len
-					);
+			printf("%s/%u ",
+				rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_DST])),
+				r->rtm_dst_len
+			);
 		} else {
 			printf("%s ", format_host(r->rtm_family,
 						RTA_PAYLOAD(tb[RTA_DST]),
-						RTA_DATA(tb[RTA_DST]),
-						abuf, sizeof(abuf))
-					);
+						RTA_DATA(tb[RTA_DST]))
+			);
 		}
 	} else if (r->rtm_dst_len) {
 		printf("0/%d ", r->rtm_dst_len);
@@ -237,17 +234,15 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	}
 	if (tb[RTA_SRC]) {
 		if (r->rtm_src_len != host_len) {
-			printf("from %s/%u ", rt_addr_n2a(r->rtm_family,
-						RTA_DATA(tb[RTA_SRC]),
-						abuf, sizeof(abuf)),
-					r->rtm_src_len
-					);
+			printf("from %s/%u ",
+				rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
+				r->rtm_src_len
+			);
 		} else {
 			printf("from %s ", format_host(r->rtm_family,
 						RTA_PAYLOAD(tb[RTA_SRC]),
-						RTA_DATA(tb[RTA_SRC]),
-						abuf, sizeof(abuf))
-					);
+						RTA_DATA(tb[RTA_SRC]))
+			);
 		}
 	} else if (r->rtm_src_len) {
 		printf("from 0/%u ", r->rtm_src_len);
@@ -255,8 +250,8 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	if (tb[RTA_GATEWAY] && G_filter.rvia.bitlen != host_len) {
 		printf("via %s ", format_host(r->rtm_family,
 					RTA_PAYLOAD(tb[RTA_GATEWAY]),
-					RTA_DATA(tb[RTA_GATEWAY]),
-					abuf, sizeof(abuf)));
+					RTA_DATA(tb[RTA_GATEWAY]))
+		);
 	}
 	if (tb[RTA_OIF]) {
 		printf("dev %s ", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_OIF])));
@@ -269,8 +264,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 		   and symbolic name will not be useful.
 		 */
 		printf(" src %s ", rt_addr_n2a(r->rtm_family,
-					RTA_DATA(tb[RTA_PREFSRC]),
-					abuf, sizeof(abuf)));
+					RTA_DATA(tb[RTA_PREFSRC])));
 	}
 	if (tb[RTA_PRIORITY]) {
 		printf(" metric %d ", *(uint32_t*)RTA_DATA(tb[RTA_PRIORITY]));
diff --git a/networking/libiproute/iprule.c b/networking/libiproute/iprule.c
index c3b2109..dba6434 100644
--- a/networking/libiproute/iprule.c
+++ b/networking/libiproute/iprule.c
@@ -44,7 +44,6 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 	int len = n->nlmsg_len;
 	int host_len = -1;
 	struct rtattr * tb[RTA_MAX+1];
-	char abuf[256];
 
 	if (n->nlmsg_type != RTM_NEWRULE)
 		return 0;
@@ -71,16 +70,14 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 	printf("from ");
 	if (tb[RTA_SRC]) {
 		if (r->rtm_src_len != host_len) {
-			printf("%s/%u", rt_addr_n2a(r->rtm_family,
-							RTA_DATA(tb[RTA_SRC]),
-							abuf, sizeof(abuf)),
+			printf("%s/%u",
+				rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
 				r->rtm_src_len
 			);
 		} else {
 			fputs(format_host(r->rtm_family,
 						RTA_PAYLOAD(tb[RTA_SRC]),
-						RTA_DATA(tb[RTA_SRC]),
-						abuf, sizeof(abuf)),
+						RTA_DATA(tb[RTA_SRC])),
 				stdout
 			);
 		}
@@ -94,15 +91,13 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 	if (tb[RTA_DST]) {
 		if (r->rtm_dst_len != host_len) {
 			printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
-							 RTA_DATA(tb[RTA_DST]),
-							 abuf, sizeof(abuf)),
+							 RTA_DATA(tb[RTA_DST])),
 				r->rtm_dst_len
 				);
 		} else {
 			printf("to %s ", format_host(r->rtm_family,
 						       RTA_PAYLOAD(tb[RTA_DST]),
-						       RTA_DATA(tb[RTA_DST]),
-						       abuf, sizeof(abuf)));
+						       RTA_DATA(tb[RTA_DST])));
 		}
 	} else if (r->rtm_dst_len) {
 		printf("to 0/%d ", r->rtm_dst_len);
@@ -139,8 +134,8 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 			printf("map-to %s ",
 				format_host(r->rtm_family,
 					    RTA_PAYLOAD(tb[RTA_GATEWAY]),
-					    RTA_DATA(tb[RTA_GATEWAY]),
-					    abuf, sizeof(abuf)));
+					    RTA_DATA(tb[RTA_GATEWAY]))
+			);
 		} else
 			printf("masquerade");
 	} else if (r->rtm_type != RTN_UNICAST)
diff --git a/networking/libiproute/iptunnel.c b/networking/libiproute/iptunnel.c
index b88c3a4..eb136e4 100644
--- a/networking/libiproute/iptunnel.c
+++ b/networking/libiproute/iptunnel.c
@@ -404,22 +404,18 @@ static int do_del(char **argv)
 
 static void print_tunnel(struct ip_tunnel_parm *p)
 {
-	char s1[256];
-	char s2[256];
-	char s3[64];
-	char s4[64];
-
-	format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
-	format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
-	inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
-	inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
+	char s3[INET_ADDRSTRLEN];
+	char s4[INET_ADDRSTRLEN];
 
 	printf("%s: %s/ip  remote %s  local %s ",
-	       p->name,
-	       p->iph.protocol == IPPROTO_IPIP ? "ip" :
-	       (p->iph.protocol == IPPROTO_GRE ? "gre" :
-		(p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
-	       p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
+		p->name,
+		p->iph.protocol == IPPROTO_IPIP ? "ip" :
+			p->iph.protocol == IPPROTO_GRE ? "gre" :
+			p->iph.protocol == IPPROTO_IPV6 ? "ipv6" :
+			"unknown",
+		p->iph.daddr ? format_host(AF_INET, 4, &p->iph.daddr) : "any",
+		p->iph.saddr ? format_host(AF_INET, 4, &p->iph.saddr) : "any"
+	);
 	if (p->link) {
 		char *n = do_ioctl_get_ifname(p->link);
 		if (n) {
@@ -442,9 +438,11 @@ static void print_tunnel(struct ip_tunnel_parm *p)
 	if (!(p->iph.frag_off & htons(IP_DF)))
 		printf(" nopmtudisc");
 
+	inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
+	inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
 	if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
 		printf(" key %s", s3);
-	else if ((p->i_flags | p->o_flags) & GRE_KEY) {
+	else {
 		if (p->i_flags & GRE_KEY)
 			printf(" ikey %s ", s3);
 		if (p->o_flags & GRE_KEY)
diff --git a/networking/libiproute/utils.c b/networking/libiproute/utils.c
index 7f7cb42..42025bc 100644
--- a/networking/libiproute/utils.c
+++ b/networking/libiproute/utils.c
@@ -276,20 +276,21 @@ int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits)
 	return 0;
 }
 
-const char *rt_addr_n2a(int af,
-		void *addr, char *buf, int buflen)
+const char *rt_addr_n2a(int af, void *addr)
 {
 	switch (af) {
 	case AF_INET:
 	case AF_INET6:
-		return inet_ntop(af, addr, buf, buflen);
+		return inet_ntop(af, addr,
+			auto_string(xzalloc(INET6_ADDRSTRLEN)), INET6_ADDRSTRLEN
+		);
 	default:
 		return "???";
 	}
 }
 
 #ifdef RESOLVE_HOSTNAMES
-const char *format_host(int af, int len, void *addr, char *buf, int buflen)
+const char *format_host(int af, int len, void *addr)
 {
 	if (resolve_hosts) {
 		struct hostent *h_ent;
@@ -308,11 +309,10 @@ const char *format_host(int af, int len, void *addr, char *buf, int buflen)
 		if (len > 0) {
 			h_ent = gethostbyaddr(addr, len, af);
 			if (h_ent != NULL) {
-				safe_strncpy(buf, h_ent->h_name, buflen);
-				return buf;
+				return auto_string(xstrdup(h_ent->h_name));
 			}
 		}
 	}
-	return rt_addr_n2a(af, addr, buf, buflen);
+	return rt_addr_n2a(af, addr);
 }
 #endif
diff --git a/networking/libiproute/utils.h b/networking/libiproute/utils.h
index 9bbed64..408d5f6 100644
--- a/networking/libiproute/utils.h
+++ b/networking/libiproute/utils.h
@@ -66,12 +66,12 @@ extern unsigned get_unsigned(char *arg, const char *errmsg);
 extern uint32_t get_u32(char *arg, const char *errmsg);
 extern uint16_t get_u16(char *arg, const char *errmsg);
 
-extern const char *rt_addr_n2a(int af, void *addr, char *buf, int buflen);
+extern const char *rt_addr_n2a(int af, void *addr);
 #ifdef RESOLVE_HOSTNAMES
-extern const char *format_host(int af, int len, void *addr, char *buf, int buflen);
+extern const char *format_host(int af, int len, void *addr);
 #else
-#define format_host(af, len, addr, buf, buflen) \
-	rt_addr_n2a(af, addr, buf, buflen)
+#define format_host(af, len, addr) \
+	rt_addr_n2a(af, addr)
 #endif
 
 void invarg_1_to_2(const char *, const char *) NORETURN;