libiproute: audit callgraph, shortcut error paths into die() functions.
Kill a few statics, made other globals smaller:
oneline is smallint, _SL_ is char

function                                             old     new   delta
print_tunnel                                         693     731     +38
print_route                                         1775    1777      +2
print_addrinfo                                      1495    1497      +2
ipaddr_list_or_flush                                2826    2828      +2
oneline                                                4       1      -3
_SL_                                                   4       1      -3
ipaddr_modify                                       1476    1472      -4
parse_address                                        124     119      -5
ip_parse_common_args                                 429     423      -6
on_off                                                53      46      -7
do_del_ioctl                                         113     106      -7
do_add_ioctl                                         120     113      -7
do_show                                              864     856      -8
iprule_list                                          157     148      -9
do_iptunnel                                          310     299     -11
do_add                                               143     126     -17
get_ctl_fd                                            95      76     -19
set_address                                          108      84     -24
ip_main                                              351     323     -28
static.ifr                                            32       -     -32
parse_args                                          1992    1949     -43
iproute_list_or_flush                               1673    1582     -91
do_iplink                                           1583    1485     -98
filter                                               280       -    -280
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 4/18 up/down: 44/-702)         Total: -658 bytes

diff --git a/networking/libiproute/iprule.c b/networking/libiproute/iprule.c
index 4b31303..d4cf282 100644
--- a/networking/libiproute/iprule.c
+++ b/networking/libiproute/iprule.c
@@ -155,11 +155,12 @@
 	} else if (r->rtm_type != RTN_UNICAST)
 		fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
 
-	fprintf(fp, "\n");
+	fputc('\n', fp);
 	fflush(fp);
 	return 0;
 }
 
+/* Return value becomes exitcode. It's okay to not return at all */
 static int iprule_list(int argc, char **argv)
 {
 	struct rtnl_handle rth;
@@ -178,19 +179,18 @@
 		return 1;
 
 	if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
-		bb_perror_msg("Cannot send dump request");
-		return 1;
+		bb_perror_msg_and_die("cannot send dump request");
 	}
 
 	if (rtnl_dump_filter(&rth, print_rule, stdout, NULL, NULL) < 0) {
-		bb_error_msg("Dump terminated");
-		return 1;
+		bb_error_msg_and_die("dump terminated");
 	}
 
 	return 0;
 }
 
 
+/* Return value becomes exitcode. It's okay to not return at all */
 static int iprule_modify(int cmd, int argc, char **argv)
 {
 	int table_ok = 0;
@@ -282,7 +282,8 @@
 			if (matches(*argv, "help") == 0)
 				bb_show_usage();
 			if (rtnl_rtntype_a2n(&type, *argv))
-				invarg("Failed to parse rule type", *argv);
+// bogus-looking error message "invalid argument 'cannot parse rule type' to '<*argv>'"
+				invarg("cannot parse rule type", *argv);
 			req.r.rtm_type = type;
 		}
 		argc--;
@@ -304,6 +305,7 @@
 	return 0;
 }
 
+/* Return value becomes exitcode. It's okay to not return at all */
 int do_iprule(int argc, char **argv)
 {
 	static const char * const ip_rule_commands[] =
@@ -331,4 +333,3 @@
 	}
 	return iprule_modify(cmd, argc-1, argv+1);
 }
-