ifplugd: code shrink

function                                             old     new   delta
ifplugd_main                                        1089    1161     +72
method_table                                           -      40     +40
detect_link                                          221     207     -14
static.method                                         40       -     -40
netlink_open                                          79       -     -79
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 1/1 up/down: 112/-133)          Total: -21 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 164 insertions, 169 deletions

diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index eb7442881..2f8c90ffc 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -71,16 +71,6 @@ enum {
 # define OPTION_STR "+ansfFi:r:It:u:d:m:pqlx:M"
 #endif
 
-enum { // api mode
-        API_AUTO        = 'a',
-        API_ETHTOOL     = 'e',
-        API_MII         = 'm',
-        API_PRIVATE     = 'p',
-        API_WLAN        = 'w',
-        API_IFF         = 'i',
-};
-static const char api_modes[] ALIGN1 = "aempwi";
-
 enum { // interface status
         IFSTATUS_ERR = -1,
         IFSTATUS_DOWN = 0,
@@ -107,8 +97,6 @@ struct globals {
         const char *api_mode;
         const char *script_name;
         const char *extra_arg;
-
-        smallint (*detect_link_func)(void);
 };
 #define G (*ptr_to_globals)
 #define INIT_G() do { \
@@ -123,42 +111,12 @@ struct globals {
 } while (0)
 
 
-static const char *strstatus(int status)
-{
-        if (status == IFSTATUS_ERR)
-                return "error";
-        return "down\0up" + (status * 5);
-}
+/* Utility routines */
 
-static int run_script(const char *action)
+static void set_ifreq_to_ifname(struct ifreq *ifreq)
 {
-        char *env_PREVIOUS, *env_CURRENT;
-        char *argv[5];
-        int r;
-
-        bb_error_msg("executing '%s %s %s'", G.script_name, G.iface, action);
-
-        argv[0] = (char*) G.script_name;
-        argv[1] = (char*) G.iface;
-        argv[2] = (char*) action;
-        argv[3] = (char*) G.extra_arg;
-        argv[4] = NULL;
-
-        env_PREVIOUS = xasprintf("%s=%s", IFPLUGD_ENV_PREVIOUS, strstatus(G.iface_prev_status));
-        putenv(env_PREVIOUS);
-        env_CURRENT = xasprintf("%s=%s", IFPLUGD_ENV_CURRENT, strstatus(G.iface_last_status));
-        putenv(env_CURRENT);
-
-        /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
-        r = spawn_and_wait(argv);
-
-        unsetenv(IFPLUGD_ENV_PREVIOUS);
-        unsetenv(IFPLUGD_ENV_CURRENT);
-        free(env_PREVIOUS);
-        free(env_CURRENT);
-
-        bb_error_msg("exit code: %d", r & 0xff);
-        return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
+        memset(ifreq, 0, sizeof(struct ifreq));
+        strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
 }
 
 static int network_ioctl(int request, void* data, const char *errmsg)
@@ -169,80 +127,7 @@ static int network_ioctl(int request, void* data, const char *errmsg)
         return r;
 }
 
-static void set_ifreq_to_ifname(struct ifreq *ifreq)
-{
-        memset(ifreq, 0, sizeof(struct ifreq));
-        strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
-}
-
-static void up_iface(void)
-{
-        struct ifreq ifrequest;
-
-        if (!G.iface_exists)
-                return;
-
-        set_ifreq_to_ifname(&ifrequest);
-        if (network_ioctl(SIOCGIFFLAGS, &ifrequest, "getting interface flags") < 0) {
-                G.iface_exists = 0;
-                return;
-        }
-
-        if (!(ifrequest.ifr_flags & IFF_UP)) {
-                ifrequest.ifr_flags |= IFF_UP;
-                /* Let user know we mess up with interface */
-                bb_error_msg("upping interface");
-                if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0)
-                        xfunc_die();
-        }
-
-#if 0 /* why do we mess with IP addr? It's not our business */
-        if (network_ioctl(SIOCGIFADDR, &ifrequest, "can't get interface address") < 0) {
-        } else if (ifrequest.ifr_addr.sa_family != AF_INET) {
-                bb_perror_msg("the interface is not IP-based");
-        } else {
-                ((struct sockaddr_in*)(&ifrequest.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
-                network_ioctl(SIOCSIFADDR, &ifrequest, "can't set interface address");
-        }
-        network_ioctl(SIOCGIFFLAGS, &ifrequest, "can't get interface flags");
-#endif
-}
-
-static void maybe_up_new_iface(void)
-{
-        if (!(option_mask32 & FLAG_NO_AUTO))
-                up_iface();
-
-#if 0 /* bloat */
-        struct ifreq ifrequest;
-        struct ethtool_drvinfo driver_info;
-
-        set_ifreq_to_ifname(&ifrequest);
-        driver_info.cmd = ETHTOOL_GDRVINFO;
-        ifrequest.ifr_data = &driver_info;
-        if (network_ioctl(SIOCETHTOOL, &ifrequest, NULL) == 0) {
-                char buf[sizeof("/xx:xx:xx:xx:xx:xx")];
-
-                /* Get MAC */
-                buf[0] = '\0';
-                set_ifreq_to_ifname(&ifrequest);
-                if (network_ioctl(SIOCGIFHWADDR, &ifrequest, NULL) == 0) {
-                        sprintf(buf, "/%02X:%02X:%02X:%02X:%02X:%02X",
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[0]),
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[1]),
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[2]),
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[3]),
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[4]),
-                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[5]));
-                }
-
-                bb_error_msg("using interface %s%s with driver<%s> (version: %s)",
-                        G.iface, buf, driver_info.driver, driver_info.version);
-        }
-#endif
-        if (G.api_method_num == 0)
-                G.detect_link_func = NULL;
-}
+/* Link detection routines and table */
 
 static smallint detect_link_mii(void)
 {
@@ -349,18 +234,139 @@ static smallint detect_link_wlan(void)
         return IFSTATUS_UP;
 }
 
+enum { // api mode
+        API_ETHTOOL, // 'e'
+        API_MII,     // 'm'
+        API_PRIVATE, // 'p'
+        API_WLAN,    // 'w'
+        API_IFF,     // 'i'
+        API_AUTO,    // 'a'
+};
+
+static const char api_modes[] ALIGN1 = "empwia";
+
+static const struct {
+        const char *name;
+        smallint (*func)(void);
+} method_table[] = {
+        { "SIOCETHTOOL"       , &detect_link_ethtool },
+        { "SIOCGMIIPHY"       , &detect_link_mii     },
+        { "SIOCDEVPRIVATE"    , &detect_link_priv    },
+        { "wireless extension", &detect_link_wlan    },
+        { "IFF_RUNNING"       , &detect_link_iff     },
+};
+
+
+
+static const char *strstatus(int status)
+{
+        if (status == IFSTATUS_ERR)
+                return "error";
+        return "down\0up" + (status * 5);
+}
+
+static int run_script(const char *action)
+{
+        char *env_PREVIOUS, *env_CURRENT;
+        char *argv[5];
+        int r;
+
+        bb_error_msg("executing '%s %s %s'", G.script_name, G.iface, action);
+
+        argv[0] = (char*) G.script_name;
+        argv[1] = (char*) G.iface;
+        argv[2] = (char*) action;
+        argv[3] = (char*) G.extra_arg;
+        argv[4] = NULL;
+
+        env_PREVIOUS = xasprintf("%s=%s", IFPLUGD_ENV_PREVIOUS, strstatus(G.iface_prev_status));
+        putenv(env_PREVIOUS);
+        env_CURRENT = xasprintf("%s=%s", IFPLUGD_ENV_CURRENT, strstatus(G.iface_last_status));
+        putenv(env_CURRENT);
+
+        /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
+        r = spawn_and_wait(argv);
+
+        unsetenv(IFPLUGD_ENV_PREVIOUS);
+        unsetenv(IFPLUGD_ENV_CURRENT);
+        free(env_PREVIOUS);
+        free(env_CURRENT);
+
+        bb_error_msg("exit code: %d", r & 0xff);
+        return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
+}
+
+static void up_iface(void)
+{
+        struct ifreq ifrequest;
+
+        if (!G.iface_exists)
+                return;
+
+        set_ifreq_to_ifname(&ifrequest);
+        if (network_ioctl(SIOCGIFFLAGS, &ifrequest, "getting interface flags") < 0) {
+                G.iface_exists = 0;
+                return;
+        }
+
+        if (!(ifrequest.ifr_flags & IFF_UP)) {
+                ifrequest.ifr_flags |= IFF_UP;
+                /* Let user know we mess up with interface */
+                bb_error_msg("upping interface");
+                if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0)
+                        xfunc_die();
+        }
+
+#if 0 /* why do we mess with IP addr? It's not our business */
+        if (network_ioctl(SIOCGIFADDR, &ifrequest, "can't get interface address") < 0) {
+        } else if (ifrequest.ifr_addr.sa_family != AF_INET) {
+                bb_perror_msg("the interface is not IP-based");
+        } else {
+                ((struct sockaddr_in*)(&ifrequest.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
+                network_ioctl(SIOCSIFADDR, &ifrequest, "can't set interface address");
+        }
+        network_ioctl(SIOCGIFFLAGS, &ifrequest, "can't get interface flags");
+#endif
+}
+
+static void maybe_up_new_iface(void)
+{
+        if (!(option_mask32 & FLAG_NO_AUTO))
+                up_iface();
+
+#if 0 /* bloat */
+        struct ifreq ifrequest;
+        struct ethtool_drvinfo driver_info;
+
+        set_ifreq_to_ifname(&ifrequest);
+        driver_info.cmd = ETHTOOL_GDRVINFO;
+        ifrequest.ifr_data = &driver_info;
+        if (network_ioctl(SIOCETHTOOL, &ifrequest, NULL) == 0) {
+                char buf[sizeof("/xx:xx:xx:xx:xx:xx")];
+
+                /* Get MAC */
+                buf[0] = '\0';
+                set_ifreq_to_ifname(&ifrequest);
+                if (network_ioctl(SIOCGIFHWADDR, &ifrequest, NULL) == 0) {
+                        sprintf(buf, "/%02X:%02X:%02X:%02X:%02X:%02X",
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[0]),
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[1]),
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[2]),
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[3]),
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[4]),
+                                (uint8_t)(ifrequest.ifr_hwaddr.sa_data[5]));
+                }
+
+                bb_error_msg("using interface %s%s with driver<%s> (version: %s)",
+                        G.iface, buf, driver_info.driver, driver_info.version);
+        }
+#endif
+        if (G.api_mode[0] == 'a')
+                G.api_method_num = API_AUTO;
+}
+
 static smallint detect_link(void)
 {
-        static const struct {
-                const char *name;
-                smallint (*func)(void);
-        } method[] = {
-                { "SIOCETHTOOL"       , &detect_link_ethtool },
-                { "SIOCGMIIPHY"       , &detect_link_mii     },
-                { "SIOCDEVPRIVATE"    , &detect_link_priv    },
-                { "wireless extension", &detect_link_wlan    },
-                { "IFF_RUNNING"       , &detect_link_iff     },
-        };
         smallint status;
 
         if (!G.iface_exists)
@@ -373,38 +379,34 @@ 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;
-                                }
+        if (G.api_method_num == API_AUTO) {
+                int i;
+                smallint sv_logmode;
+
+                sv_logmode = logmode;
+                for (i = 0; i < ARRAY_SIZE(method_table); i++) {
+                        logmode = LOGMODE_NONE;
+                        status = method_table[i].func();
+                        logmode = sv_logmode;
+                        if (status != IFSTATUS_ERR) {
+                                G.api_method_num = i;
+                                bb_error_msg("using %s detection mode", method_table[i].name);
+                                break;
                         }
-                        goto _1;
                 }
-                G.detect_link_func = method[G.api_method_num - 1].func;
+        } else {
+                status = method_table[G.api_method_num].func();
         }
 
-        status = G.detect_link_func();
- _1:
         if (status == IFSTATUS_ERR) {
                 if (option_mask32 & FLAG_IGNORE_FAIL)
                         status = IFSTATUS_DOWN;
                 else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
                         status = IFSTATUS_UP;
-                else if (G.api_method_num == 0)
+                else if (G.api_mode[0] == 'a')
                         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;
@@ -475,23 +477,6 @@ static NOINLINE int check_existence_through_netlink(void)
         return G.iface_exists;
 }
 
-static NOINLINE int netlink_open(void)
-{
-        int fd;
-        struct sockaddr_nl addr;
-
-        fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
-
-        memset(&addr, 0, sizeof(addr));
-        addr.nl_family = AF_NETLINK;
-        addr.nl_groups = RTMGRP_LINK;
-        addr.nl_pid = getpid();
-
-        xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
-
-        return fd;
-}
-
 #if ENABLE_FEATURE_PIDFILE
 static NOINLINE pid_t read_pid(const char *filename)
 {
@@ -545,6 +530,7 @@ 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
+
         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);
@@ -555,7 +541,16 @@ int ifplugd_main(int argc UNUSED_PARAM, char **argv)
 
         xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
         if (opts & FLAG_MONITOR) {
-                xmove_fd(netlink_open(), netlink_fd);
+                struct sockaddr_nl addr;
+                int fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+
+                memset(&addr, 0, sizeof(addr));
+                addr.nl_family = AF_NETLINK;
+                addr.nl_groups = RTMGRP_LINK;
+                addr.nl_pid = getpid();
+
+                xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
+                xmove_fd(fd, netlink_fd);
         }
 
         write_pidfile(pidfile_name);