ifplugd: code shrink

function                                             old     new   delta
detect_link                                          122     221     +99
api_modes                                              -       7      +7
maybe_up_new_iface                                    27      33      +6
ifplugd_main                                        1143    1089     -54
detect_link_auto                                     117       -    -117
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 2/1 up/down: 112/-171)          Total: -59 bytes

Signed-off-by: Maksym Kryzhanovskyy <xmaks@email.cz>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 35 insertions, 60 deletions

diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index 8cb07db5d..eb7442881 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -79,6 +79,7 @@ enum { // api mode
         API_WLAN        = 'w',
         API_IFF         = 'i',
 };
+static const char api_modes[] ALIGN1 = "aempwi";
 
 enum { // interface status
         IFSTATUS_ERR = -1,
@@ -95,6 +96,7 @@ struct globals {
         smallint iface_last_status;
         smallint iface_prev_status;
         smallint iface_exists;
+        smallint api_method_num;
 
         /* Used in getopt32, must have sizeof == sizeof(int) */
         unsigned poll_time;
@@ -107,7 +109,6 @@ struct globals {
         const char *extra_arg;
 
         smallint (*detect_link_func)(void);
-        smallint (*cached_detect_link_func)(void);
 };
 #define G (*ptr_to_globals)
 #define INIT_G() do { \
@@ -239,8 +240,8 @@ static void maybe_up_new_iface(void)
                         G.iface, buf, driver_info.driver, driver_info.version);
         }
 #endif
-
-        G.cached_detect_link_func = NULL;
+        if (G.api_method_num == 0)
+                G.detect_link_func = NULL;
 }
 
 static smallint detect_link_mii(void)
@@ -348,7 +349,7 @@ static smallint detect_link_wlan(void)
         return IFSTATUS_UP;
 }
 
-static smallint detect_link_auto(void)
+static smallint detect_link(void)
 {
         static const struct {
                 const char *name;
@@ -360,32 +361,6 @@ static smallint detect_link_auto(void)
                 { "wireless extension", &detect_link_wlan    },
                 { "IFF_RUNNING"       , &detect_link_iff     },
         };
-        int i;
-        smallint iface_status;
-        smallint sv_logmode;
-
-        if (G.cached_detect_link_func) {
-                iface_status = G.cached_detect_link_func();
-                if (iface_status != IFSTATUS_ERR)
-                        return iface_status;
-        }
-
-        sv_logmode = logmode;
-        for (i = 0; i < ARRAY_SIZE(method); i++) {
-                logmode = LOGMODE_NONE;
-                iface_status = method[i].func();
-                logmode = sv_logmode;
-                if (iface_status != IFSTATUS_ERR) {
-                        G.cached_detect_link_func = method[i].func;
-                        bb_error_msg("using %s detection mode", method[i].name);
-                        break;
-                }
-        }
-        return iface_status;
-}
-
-static smallint detect_link(void)
-{
         smallint status;
 
         if (!G.iface_exists)
@@ -398,20 +373,38 @@ static smallint detect_link(void)
         if (!(option_mask32 & FLAG_NO_AUTO))
                 up_iface();
 
+        if (!G.detect_link_func) {
+                if (G.api_method_num == 0) {
+                        int i;
+                        smallint sv_logmode;
+
+                        sv_logmode = logmode;
+                        for (i = 0; i < ARRAY_SIZE(method); i++) {
+                                logmode = LOGMODE_NONE;
+                                status = method[i].func();
+                                logmode = sv_logmode;
+                                if (status != IFSTATUS_ERR) {
+                                        G.detect_link_func = method[i].func;
+                                        bb_error_msg("using %s detection mode", method[i].name);
+                                        goto _2;
+                                }
+                        }
+                        goto _1;
+                }
+                G.detect_link_func = method[G.api_method_num - 1].func;
+        }
+
         status = G.detect_link_func();
+ _1:
         if (status == IFSTATUS_ERR) {
                 if (option_mask32 & FLAG_IGNORE_FAIL)
                         status = IFSTATUS_DOWN;
-                if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
+                else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
                         status = IFSTATUS_UP;
+                else if (G.api_method_num == 0)
+                        bb_error_msg("can't detect link status");
         }
-
-        if (status == IFSTATUS_ERR
-         && G.detect_link_func == detect_link_auto
-        ) {
-                bb_error_msg("can't detect link status");
-        }
-
+ _2:
         if (status != G.iface_last_status) {
                 G.iface_prev_status = G.iface_last_status;
                 G.iface_last_status = status;
@@ -523,6 +516,7 @@ int ifplugd_main(int argc UNUSED_PARAM, char **argv)
         const char *iface_status_str;
         struct pollfd netlink_pollfd[1];
         unsigned opts;
+        const char *api_mode_found;
 #if ENABLE_FEATURE_PIDFILE
         char *pidfile_name;
         pid_t pid_from_pidfile;
@@ -551,29 +545,10 @@ int ifplugd_main(int argc UNUSED_PARAM, char **argv)
         if (pid_from_pidfile > 0 && kill(pid_from_pidfile, 0) == 0)
                 bb_error_msg_and_die("daemon already running");
 #endif
-
-        switch (G.api_mode[0]) {
-        case API_AUTO:
-                G.detect_link_func = detect_link_auto;
-                break;
-        case API_ETHTOOL:
-                G.detect_link_func = detect_link_ethtool;
-                break;
-        case API_MII:
-                G.detect_link_func = detect_link_mii;
-                break;
-        case API_PRIVATE:
-                G.detect_link_func = detect_link_priv;
-                break;
-        case API_WLAN:
-                G.detect_link_func = detect_link_wlan;
-                break;
-        case API_IFF:
-                G.detect_link_func = detect_link_iff;
-                break;
-        default:
+        api_mode_found = strchr(api_modes, G.api_mode[0]);
+        if (!api_mode_found)
                 bb_error_msg_and_die("unknown API mode '%s'", G.api_mode);
-        }
+        G.api_method_num = api_mode_found - api_modes;
 
         if (!(opts & FLAG_NO_DAEMON))
                 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);