libbb: add setsockopt_foo helpers

function                                             old     new   delta
setsockopt_int                                         -      23     +23
do_load                                              918     934     +16
setsockopt_SOL_SOCKET_int                              -      14     +14
setsockopt_keepalive                                   -      10     +10
setsockopt_SOL_SOCKET_1                                -      10     +10
buffer_fill_and_print                                169     178      +9
setsockopt_1                                           -       8      +8
nfsmount                                            3560    3566      +6
redirect                                            1277    1282      +5
tcpudpsvd_main                                      1782    1786      +4
d6_send_kernel_packet                                272     275      +3
i2cget_main                                          380     382      +2
ed_main                                             2544    2545      +1
scan_recursive                                       380     378      -2
nbdclient_main                                       492     490      -2
hash_find                                            235     233      -2
cmdputs                                              334     332      -2
parse_command                                       1443    1440      -3
static.two                                             4       -      -4
ntpd_main                                           1039    1035      -4
const_int_1                                            4       -      -4
const_IPTOS_LOWDELAY                                   4       -      -4
RCVBUF                                                 4       -      -4
ntp_init                                             474     469      -5
change_listen_mode                                   316     310      -6
uevent_main                                          416     409      -7
arping_main                                         1697    1690      -7
telnet_main                                         1612    1603      -9
socket_want_pktinfo                                   42      33      -9
setsockopt_reuseaddr                                  21      10     -11
setsockopt_broadcast                                  21      10     -11
httpd_main                                           772     757     -15
get_remote_transfer_fd                               109      94     -15
make_new_session                                     503     487     -16
ftpd_main                                           2177    2160     -17
read_bunzip                                         1896    1866     -30
common_traceroute_main                              4099    4058     -41
common_ping_main                                    1836    1783     -53
------------------------------------------------------------------------------
(add/remove: 5/4 grow/shrink: 8/21 up/down: 111/-283)        Total: -172 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/traceroute.c b/networking/traceroute.c
index e41d89e..642110c 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -473,8 +473,8 @@
 
 #if ENABLE_TRACEROUTE6
 	if (dest_lsa->u.sa.sa_family == AF_INET6) {
-		res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
-		if (res < 0)
+		res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl);
+		if (res != 0)
 			bb_perror_msg_and_die("setsockopt(%s) %d", "UNICAST_HOPS", ttl);
 		out = outip;
 		len = packlen;
@@ -482,8 +482,8 @@
 #endif
 	{
 #if defined IP_TTL
-		res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
-		if (res < 0)
+		res = setsockopt_int(sndsock, IPPROTO_IP, IP_TTL, ttl);
+		if (res != 0)
 			bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl);
 #endif
 		out = outicmp;
@@ -902,13 +902,10 @@
 	if (af == AF_INET6) {
 		xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
 # ifdef IPV6_RECVPKTINFO
-		setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
-				&const_int_1, sizeof(const_int_1));
-		setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO);
+		setsockopt_1(rcvsock, SOL_IPV6, IPV6_2292PKTINFO);
 # else
-		setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_1(rcvsock, SOL_IPV6, IPV6_PKTINFO);
 # endif
 	} else
 #endif
@@ -918,17 +915,14 @@
 
 #if TRACEROUTE_SO_DEBUG
 	if (op & OPT_DEBUG)
-		setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_SOL_SOCKET_1(rcvsock, SO_DEBUG);
 #endif
 	if (op & OPT_BYPASS_ROUTE)
-		setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_SOL_SOCKET_1(rcvsock, SO_DONTROUTE);
 
 #if ENABLE_TRACEROUTE6
 	if (af == AF_INET6) {
-		static const int two = 2;
-		if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
+		if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0)
 			bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM");
 		xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
 	} else
@@ -966,28 +960,25 @@
 	}
 
 #ifdef SO_SNDBUF
-	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
-		bb_perror_msg_and_die("SO_SNDBUF");
+	if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) {
+		bb_perror_msg_and_die("setsockopt(%s)", "SO_SNDBUF");
 	}
 #endif
 #ifdef IP_TOS
-	if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
+	if ((op & OPT_TOS) && setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0) {
 		bb_perror_msg_and_die("setsockopt(%s) %d", "TOS", tos);
 	}
 #endif
 #ifdef IP_DONTFRAG
 	if (op & OPT_DONT_FRAGMNT)
-		setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_1(sndsock, IPPROTO_IP, IP_DONTFRAG);
 #endif
 #if TRACEROUTE_SO_DEBUG
 	if (op & OPT_DEBUG)
-		setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_SOL_SOCKET_1(sndsock, SO_DEBUG);
 #endif
 	if (op & OPT_BYPASS_ROUTE)
-		setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
-				&const_int_1, sizeof(const_int_1));
+		setsockopt_SOL_SOCKET_1(sndsock, SO_DONTROUTE);
 
 	outip = xzalloc(packlen);