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 c0f27c70d..5c975d8c5 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 6588c12f1..179505c2d 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 0d2914405..d232ee6fd 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 c3b210982..dba64346f 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 b88c3a401..eb136e435 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 7f7cb4203..42025bc66 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 9bbed6481..408d5f65f 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;