libiproute: code and data shrink

function                                             old     new   delta
rtnl_a2n                                               -     126    +126
ll_remember_index                                    233     263     +30
find_by_index                                         26      36     +10
rtnl_rtprot_initialize                                66      70      +4
static.unit_chars                                      7       9      +2
rtnl_rttable_initialize                               73      75      +2
rtnl_rtscope_initialize                               83      85      +2
rtnl_rtrealm_initialize                               43      45      +2
rtnl_rtdsfield_initialize                             43      45      +2
rtnl_rttable_n2a                                      62      63      +1
rtnl_rtscope_n2a                                      62      63      +1
rtnl_rtrealm_n2a                                      62      63      +1
rtnl_dsfield_n2a                                      70      71      +1
ll_init_map                                           36      33      -3
make_human_readable_str                              262     258      -4
static.fmt                                            97      92      -5
static.fmt_tenths                                     10       -     -10
static.str                                            21       4     -17
static.res                                            20       -     -20
static.cache                                          24       4     -20
idxmap                                                64       4     -60
rtnl_rttable_a2n                                     154      39    -115
rtnl_rtscope_a2n                                     159      39    -120
rtnl_rtrealm_a2n                                     159      39    -120
rtnl_rtprot_a2n                                      159      39    -120
rtnl_dsfield_a2n                                     162      39    -123
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 12/11 up/down: 184/-737)       Total: -553 bytes
   text           data            bss            dec            hex        filename
 820376            445           7668         828489          ca449        busybox_old
 819950            445           7548         827943          ca227        busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/libiproute/rt_names.c b/networking/libiproute/rt_names.c
index e4d1061..2699dba 100644
--- a/networking/libiproute/rt_names.c
+++ b/networking/libiproute/rt_names.c
@@ -9,20 +9,23 @@
  *
  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  */
-
 #include "libbb.h"
 #include "rt_names.h"
 
-/* so far all callers have size == 256 */
-#define rtnl_tab_initialize(file, tab, size) rtnl_tab_initialize(file, tab)
-#define size 256
-static void rtnl_tab_initialize(const char *file, const char **tab, int size)
+typedef struct rtnl_tab_t {
+	const char *cached_str;
+	unsigned cached_result;
+	const char *tab[256];
+} rtnl_tab_t;
+
+static void rtnl_tab_initialize(const char *file, const char **tab)
 {
 	char *token[2];
 	parser_t *parser = config_open2(file, fopen_for_read);
+
 	while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
-		int id = bb_strtou(token[0], NULL, 0);
-		if (id < 0 || id > size) {
+		unsigned id = bb_strtou(token[0], NULL, 0);
+		if (id > 256) {
 			bb_error_msg("database %s is corrupted at line %d",
 				file, parser->lineno);
 			break;
@@ -31,9 +34,36 @@
 	}
 	config_close(parser);
 }
-#undef size
 
-static const char **rtnl_rtprot_tab; /* [256] */
+static int rtnl_a2n(rtnl_tab_t *tab, uint32_t *id, const char *arg, int base)
+{
+	unsigned i;
+
+	if (tab->cached_str && strcmp(tab->cached_str, arg) == 0) {
+		*id = tab->cached_result;
+		return 0;
+	}
+
+	for (i = 0; i < 256; i++) {
+		if (tab->tab[i]
+		 && strcmp(tab->tab[i], arg) == 0
+		) {
+			tab->cached_str = tab->tab[i];
+			tab->cached_result = i;
+			*id = i;
+			return 0;
+		}
+	}
+
+	i = bb_strtou(arg, NULL, base);
+	if (i > 255)
+		return -1;
+	*id = i;
+	return 0;
+}
+
+
+static rtnl_tab_t *rtnl_rtprot_tab;
 
 static void rtnl_rtprot_initialize(void)
 {
@@ -52,13 +82,13 @@
 		"zebra",
 		"bird",
 	};
-	if (rtnl_rtprot_tab) return;
-	rtnl_rtprot_tab = xzalloc(256 * sizeof(rtnl_rtprot_tab[0]));
-	memcpy(rtnl_rtprot_tab, init_tab, sizeof(init_tab));
-	rtnl_tab_initialize("/etc/iproute2/rt_protos",
-			    rtnl_rtprot_tab, 256);
-}
 
+	if (rtnl_rtprot_tab)
+		return;
+	rtnl_rtprot_tab = xzalloc(sizeof(*rtnl_rtprot_tab));
+	memcpy(rtnl_rtprot_tab->tab, init_tab, sizeof(init_tab));
+	rtnl_tab_initialize("/etc/iproute2/rt_protos", rtnl_rtprot_tab->tab);
+}
 
 const char* rtnl_rtprot_n2a(int id, char *buf, int len)
 {
@@ -69,59 +99,34 @@
 
 	rtnl_rtprot_initialize();
 
-	if (rtnl_rtprot_tab[id])
-		return rtnl_rtprot_tab[id];
+	if (rtnl_rtprot_tab->tab[id])
+		return rtnl_rtprot_tab->tab[id];
 	snprintf(buf, len, "%d", id);
 	return buf;
 }
 
 int rtnl_rtprot_a2n(uint32_t *id, char *arg)
 {
-	static const char *cache = NULL;
-	static unsigned long res;
-	int i;
-
-	if (cache && strcmp(cache, arg) == 0) {
-		*id = res;
-		return 0;
-	}
-
 	rtnl_rtprot_initialize();
-
-	for (i = 0; i < 256; i++) {
-		if (rtnl_rtprot_tab[i] &&
-		    strcmp(rtnl_rtprot_tab[i], arg) == 0) {
-			cache = rtnl_rtprot_tab[i];
-			res = i;
-			*id = res;
-			return 0;
-		}
-	}
-
-	res = bb_strtoul(arg, NULL, 0);
-	if (errno || res > 255)
-		return -1;
-	*id = res;
-	return 0;
+	return rtnl_a2n(rtnl_rtprot_tab, id, arg, 0);
 }
 
 
-static const char **rtnl_rtscope_tab; /* [256] */
+static rtnl_tab_t *rtnl_rtscope_tab;
 
 static void rtnl_rtscope_initialize(void)
 {
-	if (rtnl_rtscope_tab) return;
-	rtnl_rtscope_tab = xzalloc(256 * sizeof(rtnl_rtscope_tab[0]));
-	rtnl_rtscope_tab[0] = "global";
-	rtnl_rtscope_tab[255] = "nowhere";
-	rtnl_rtscope_tab[254] = "host";
-	rtnl_rtscope_tab[253] = "link";
-	rtnl_rtscope_tab[200] = "site";
-	rtnl_tab_initialize("/etc/iproute2/rt_scopes",
-			    rtnl_rtscope_tab, 256);
+	if (rtnl_rtscope_tab)
+		return;
+	rtnl_rtscope_tab = xzalloc(sizeof(*rtnl_rtscope_tab));
+	rtnl_rtscope_tab->tab[0] = "global";
+	rtnl_rtscope_tab->tab[255] = "nowhere";
+	rtnl_rtscope_tab->tab[254] = "host";
+	rtnl_rtscope_tab->tab[253] = "link";
+	rtnl_rtscope_tab->tab[200] = "site";
+	rtnl_tab_initialize("/etc/iproute2/rt_scopes", rtnl_rtscope_tab->tab);
 }
 
-
 const char* rtnl_rtscope_n2a(int id, char *buf, int len)
 {
 	if (id < 0 || id >= 256) {
@@ -131,83 +136,33 @@
 
 	rtnl_rtscope_initialize();
 
-	if (rtnl_rtscope_tab[id])
-		return rtnl_rtscope_tab[id];
+	if (rtnl_rtscope_tab->tab[id])
+		return rtnl_rtscope_tab->tab[id];
 	snprintf(buf, len, "%d", id);
 	return buf;
 }
 
 int rtnl_rtscope_a2n(uint32_t *id, char *arg)
 {
-	static const char *cache = NULL;
-	static unsigned long res;
-	int i;
-
-	if (cache && strcmp(cache, arg) == 0) {
-		*id = res;
-		return 0;
-	}
-
 	rtnl_rtscope_initialize();
-
-	for (i = 0; i < 256; i++) {
-		if (rtnl_rtscope_tab[i] &&
-		    strcmp(rtnl_rtscope_tab[i], arg) == 0) {
-			cache = rtnl_rtscope_tab[i];
-			res = i;
-			*id = res;
-			return 0;
-		}
-	}
-
-	res = bb_strtoul(arg, NULL, 0);
-	if (errno || res > 255)
-		return -1;
-	*id = res;
-	return 0;
+	return rtnl_a2n(rtnl_rtscope_tab, id, arg, 0);
 }
 
 
-static const char **rtnl_rtrealm_tab; /* [256] */
+static rtnl_tab_t *rtnl_rtrealm_tab;
 
 static void rtnl_rtrealm_initialize(void)
 {
 	if (rtnl_rtrealm_tab) return;
-	rtnl_rtrealm_tab = xzalloc(256 * sizeof(rtnl_rtrealm_tab[0]));
-	rtnl_rtrealm_tab[0] = "unknown";
-	rtnl_tab_initialize("/etc/iproute2/rt_realms",
-			    rtnl_rtrealm_tab, 256);
+	rtnl_rtrealm_tab = xzalloc(sizeof(*rtnl_rtrealm_tab));
+	rtnl_rtrealm_tab->tab[0] = "unknown";
+	rtnl_tab_initialize("/etc/iproute2/rt_realms", rtnl_rtrealm_tab->tab);
 }
 
-
 int rtnl_rtrealm_a2n(uint32_t *id, char *arg)
 {
-	static const char *cache = NULL;
-	static unsigned long res;
-	int i;
-
-	if (cache && strcmp(cache, arg) == 0) {
-		*id = res;
-		return 0;
-	}
-
 	rtnl_rtrealm_initialize();
-
-	for (i = 0; i < 256; i++) {
-		if (rtnl_rtrealm_tab[i] &&
-		    strcmp(rtnl_rtrealm_tab[i], arg) == 0) {
-			cache = rtnl_rtrealm_tab[i];
-			res = i;
-			*id = res;
-			return 0;
-		}
-	}
-
-	res = bb_strtoul(arg, NULL, 0);
-	if (errno || res > 255)
-		return -1;
-	*id = res;
-	return 0;
+	return rtnl_a2n(rtnl_rtrealm_tab, id, arg, 0);
 }
 
 #if ENABLE_FEATURE_IP_RULE
@@ -220,26 +175,24 @@
 
 	rtnl_rtrealm_initialize();
 
-	if (rtnl_rtrealm_tab[id])
-		return rtnl_rtrealm_tab[id];
+	if (rtnl_rtrealm_tab->tab[id])
+		return rtnl_rtrealm_tab->tab[id];
 	snprintf(buf, len, "%d", id);
 	return buf;
 }
 #endif
 
 
-static const char **rtnl_rtdsfield_tab; /* [256] */
+static rtnl_tab_t *rtnl_rtdsfield_tab;
 
 static void rtnl_rtdsfield_initialize(void)
 {
 	if (rtnl_rtdsfield_tab) return;
-	rtnl_rtdsfield_tab = xzalloc(256 * sizeof(rtnl_rtdsfield_tab[0]));
-	rtnl_rtdsfield_tab[0] = "0";
-	rtnl_tab_initialize("/etc/iproute2/rt_dsfield",
-			    rtnl_rtdsfield_tab, 256);
+	rtnl_rtdsfield_tab = xzalloc(sizeof(*rtnl_rtdsfield_tab));
+	rtnl_rtdsfield_tab->tab[0] = "0";
+	rtnl_tab_initialize("/etc/iproute2/rt_dsfield", rtnl_rtdsfield_tab->tab);
 }
 
-
 const char * rtnl_dsfield_n2a(int id, char *buf, int len)
 {
 	if (id < 0 || id >= 256) {
@@ -249,59 +202,33 @@
 
 	rtnl_rtdsfield_initialize();
 
-	if (rtnl_rtdsfield_tab[id])
-		return rtnl_rtdsfield_tab[id];
+	if (rtnl_rtdsfield_tab->tab[id])
+		return rtnl_rtdsfield_tab->tab[id];
 	snprintf(buf, len, "0x%02x", id);
 	return buf;
 }
 
-
 int rtnl_dsfield_a2n(uint32_t *id, char *arg)
 {
-	static const char *cache = NULL;
-	static unsigned long res;
-	int i;
-
-	if (cache && strcmp(cache, arg) == 0) {
-		*id = res;
-		return 0;
-	}
-
 	rtnl_rtdsfield_initialize();
-
-	for (i = 0; i < 256; i++) {
-		if (rtnl_rtdsfield_tab[i] &&
-		    strcmp(rtnl_rtdsfield_tab[i], arg) == 0) {
-			cache = rtnl_rtdsfield_tab[i];
-			res = i;
-			*id = res;
-			return 0;
-		}
-	}
-
-	res = bb_strtoul(arg, NULL, 16);
-	if (errno || res > 255)
-		return -1;
-	*id = res;
-	return 0;
+	return rtnl_a2n(rtnl_rtdsfield_tab, id, arg, 16);
 }
 
 
 #if ENABLE_FEATURE_IP_RULE
-static const char **rtnl_rttable_tab; /* [256] */
+static rtnl_tab_t *rtnl_rttable_tab;
 
 static void rtnl_rttable_initialize(void)
 {
 	if (rtnl_rtdsfield_tab) return;
-	rtnl_rttable_tab = xzalloc(256 * sizeof(rtnl_rttable_tab[0]));
-	rtnl_rttable_tab[0] = "unspec";
-	rtnl_rttable_tab[255] = "local";
-	rtnl_rttable_tab[254] = "main";
-	rtnl_rttable_tab[253] = "default";
-	rtnl_tab_initialize("/etc/iproute2/rt_tables", rtnl_rttable_tab, 256);
+	rtnl_rttable_tab = xzalloc(sizeof(*rtnl_rttable_tab));
+	rtnl_rttable_tab->tab[0] = "unspec";
+	rtnl_rttable_tab->tab[255] = "local";
+	rtnl_rttable_tab->tab[254] = "main";
+	rtnl_rttable_tab->tab[253] = "default";
+	rtnl_tab_initialize("/etc/iproute2/rt_tables", rtnl_rttable_tab->tab);
 }
 
-
 const char *rtnl_rttable_n2a(int id, char *buf, int len)
 {
 	if (id < 0 || id >= 256) {
@@ -311,39 +238,16 @@
 
 	rtnl_rttable_initialize();
 
-	if (rtnl_rttable_tab[id])
-		return rtnl_rttable_tab[id];
+	if (rtnl_rttable_tab->tab[id])
+		return rtnl_rttable_tab->tab[id];
 	snprintf(buf, len, "%d", id);
 	return buf;
 }
 
-int rtnl_rttable_a2n(uint32_t * id, char *arg)
+int rtnl_rttable_a2n(uint32_t *id, char *arg)
 {
-	static char *cache = NULL;
-	static unsigned long res;
-	int i;
-
-	if (cache && strcmp(cache, arg) == 0) {
-		*id = res;
-		return 0;
-	}
-
 	rtnl_rttable_initialize();
-
-	for (i = 0; i < 256; i++) {
-		if (rtnl_rttable_tab[i] && strcmp(rtnl_rttable_tab[i], arg) == 0) {
-			cache = (char*)rtnl_rttable_tab[i];
-			res = i;
-			*id = res;
-			return 0;
-		}
-	}
-
-	i = bb_strtoul(arg, NULL, 0);
-	if (errno || i > 255)
-		return -1;
-	*id = i;
-	return 0;
+	return rtnl_a2n(rtnl_rttable_tab, id, arg, 0);
 }
 
 #endif