ifupdown: if $PATH is not set, do not set it to "" in children

Also random code shrink:

function                                             old     new   delta
set_environ                                          328     330      +2
static.label_buf                                       4       -      -4
startup_PATH                                           4       -      -4
my_environ                                             4       -      -4
ifupdown_main                                       2148    2134     -14
setlocalenv                                          117      90     -27
get_var                                              139     112     -27
------------------------------------------------------------------------------
(add/remove: 0/3 grow/shrink: 1/3 up/down: 2/-80)             Total: -78 bytes

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

1 files changed, 65 insertions, 59 deletions

diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index 6d608105e..7a9709e40 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -87,23 +87,29 @@ struct interfaces_file_t {
         struct mapping_defn_t *mappings;
 };
 
+
 #define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
 enum {
-        OPT_do_all = 0x1,
-        OPT_no_act = 0x2,
-        OPT_verbose = 0x4,
-        OPT_force = 0x8,
+        OPT_do_all      = 0x1,
+        OPT_no_act      = 0x2,
+        OPT_verbose     = 0x4,
+        OPT_force       = 0x8,
         OPT_no_mappings = 0x10,
 };
-#define DO_ALL (option_mask32 & OPT_do_all)
-#define NO_ACT (option_mask32 & OPT_no_act)
-#define VERBOSE (option_mask32 & OPT_verbose)
-#define FORCE (option_mask32 & OPT_force)
+#define DO_ALL      (option_mask32 & OPT_do_all)
+#define NO_ACT      (option_mask32 & OPT_no_act)
+#define VERBOSE     (option_mask32 & OPT_verbose)
+#define FORCE       (option_mask32 & OPT_force)
 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 
-static char **my_environ;
 
-static const char *startup_PATH;
+struct globals {
+        char **my_environ;
+        const char *startup_PATH;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
+
 
 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 
@@ -126,7 +132,7 @@ static int strncmpz(const char *l, const char *r, size_t llen)
         int i = strncmp(l, r, llen);
 
         if (i == 0)
-                return -r[llen];
+                return - (unsigned char)r[llen];
         return i;
 }
 
@@ -135,16 +141,17 @@ static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
         int i;
 
         if (strncmpz(id, "iface", idlen) == 0) {
-                static char *label_buf;
+                // ubuntu's ifup doesn't do this:
+                //static char *label_buf;
                 //char *result;
-
-                free(label_buf);
-                label_buf = xstrdup(ifd->iface);
-                // Remove virtual iface suffix - why?
-                // ubuntu's ifup doesn't do this
+                //free(label_buf);
+                //label_buf = xstrdup(ifd->iface);
+                // Remove virtual iface suffix
                 //result = strchrnul(label_buf, ':');
                 //*result = '\0';
-                return label_buf;
+                //return label_buf;
+
+                return ifd->iface;
         }
         if (strncmpz(id, "label", idlen) == 0) {
                 return ifd->iface;
@@ -547,7 +554,7 @@ static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 
         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
                 if (exists_execable(ext_dhcp_clients[i].name)) {
-                        result += execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
+                        result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
                         if (result)
                                 break;
                 }
@@ -620,13 +627,13 @@ static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 }
 
 static const struct method_t methods[] = {
-        { "manual", manual_up_down, manual_up_down, },
-        { "wvdial", wvdial_up, wvdial_down, },
-        { "ppp", ppp_up, ppp_down, },
-        { "static", static_up, static_down, },
-        { "bootp", bootp_up, static_down, },
-        { "dhcp", dhcp_up, dhcp_down, },
-        { "loopback", loopback_up, loopback_down, },
+        { "manual"  , manual_up_down, manual_up_down, },
+        { "wvdial"  , wvdial_up     , wvdial_down   , },
+        { "ppp"     , ppp_up        , ppp_down      , },
+        { "static"  , static_up     , static_down   , },
+        { "bootp"   , bootp_up      , static_down   , },
+        { "dhcp"    , dhcp_up       , dhcp_down     , },
+        { "loopback", loopback_up   , loopback_down , },
 };
 
 static const struct address_family_t addr_inet = {
@@ -896,43 +903,40 @@ static struct interfaces_file_t *read_interfaces(const char *filename)
 static char *setlocalenv(const char *format, const char *name, const char *value)
 {
         char *result;
-        char *here;
-        char *there;
+        char *dst;
+        char *src;
+        char c;
 
         result = xasprintf(format, name, value);
 
-        for (here = there = result; *there != '=' && *there; there++) {
-                if (*there == '-')
-                        *there = '_';
-                if (isalpha(*there))
-                        *there = toupper(*there);
-
-                if (isalnum(*there) || *there == '_') {
-                        *here = *there;
-                        here++;
-                }
+        for (dst = src = result; (c = *src) != '=' && c; src++) {
+                if (c == '-')
+                        c = '_';
+                if (c >= 'a' && c <= 'z')
+                        c -= ('a' - 'A');
+                if (isalnum(c) || c == '_')
+                        *dst++ = c;
         }
-        memmove(here, there, strlen(there) + 1);
+        overlapping_strcpy(dst, src);
 
         return result;
 }
 
 static void set_environ(struct interface_defn_t *iface, const char *mode)
 {
-        char **environend;
         int i;
-        const int n_env_entries = iface->n_options + 5;
-        char **ppch;
+        char **pp;
 
-        if (my_environ != NULL) {
-                for (ppch = my_environ; *ppch; ppch++) {
-                        free(*ppch);
-                        *ppch = NULL;
+        if (G.my_environ != NULL) {
+                for (pp = G.my_environ; *pp; pp++) {
+                        free(*pp);
                 }
-                free(my_environ);
+                free(G.my_environ);
         }
-        my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
-        environend = my_environ;
+
+        /* note: last element will stay NULL: */
+        G.my_environ = xzalloc(sizeof(char *) * (iface->n_options + 6));
+        pp = G.my_environ;
 
         for (i = 0; i < iface->n_options; i++) {
                 if (strcmp(iface->option[i].name, "up") == 0
@@ -942,14 +946,15 @@ static void set_environ(struct interface_defn_t *iface, const char *mode)
                 ) {
                         continue;
                 }
-                *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
+                *pp++ = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
         }
 
-        *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
-        *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
-        *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
-        *(environend++) = setlocalenv("%s=%s", "MODE", mode);
-        *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
+        *pp++ = setlocalenv("%s=%s", "IFACE", iface->iface);
+        *pp++ = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
+        *pp++ = setlocalenv("%s=%s", "METHOD", iface->method->name);
+        *pp++ = setlocalenv("%s=%s", "MODE", mode);
+        if (G.startup_PATH)
+                *pp++ = setlocalenv("%s=%s", "PATH", G.startup_PATH);
 }
 
 static int doit(char *str)
@@ -967,7 +972,7 @@ static int doit(char *str)
                 case -1: /* failure */
                         return 0;
                 case 0: /* child */
-                        execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, (char *) NULL, my_environ);
+                        execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, (char *) NULL, G.my_environ);
                         _exit(127);
                 }
                 safe_waitpid(child, &status, 0);
@@ -1142,6 +1147,10 @@ int ifupdown_main(int argc, char **argv)
         const char *interfaces = "/etc/network/interfaces";
         bool any_failures = 0;
 
+        INIT_G();
+
+        G.startup_PATH = getenv("PATH");
+
         cmds = iface_down;
         if (applet_name[2] == 'u') {
                 /* ifup command */
@@ -1159,9 +1168,6 @@ int ifupdown_main(int argc, char **argv)
         defn = read_interfaces(interfaces);
         debug_noise("\ndone reading %s\n\n", interfaces);
 
-        startup_PATH = getenv("PATH");
-        if (!startup_PATH) startup_PATH = "";
-
         /* Create a list of interfaces to work on */
         if (DO_ALL) {
                 target_list = defn->autointerfaces;