ftpd: code shrink

function                                             old     new   delta
MMU:
handle_dir_common                                    354     338     -16
NOMMU:
ftpd_main                                           2437    2442      +5
popen_ls                                             201     174     -27

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

diff --git a/networking/ftpd.c b/networking/ftpd.c
index df8188cbafbc60510f3865286a511dfa5b81f356..4e9f65ca3d5de8549edf4f0e182b7f0c55d1625e 100644 (file)
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -616,18 +616,22 @@ handle_retr(void)
 static int
 popen_ls(const char *opt)
 {
-       char *cwd;
-       const char *argv[] = {
-                       "ftpd",
-                       opt,
-                       BB_MMU ? "--" : NULL,
-                       G.ftp_arg,
-                       NULL
-       };
+       const char *argv[5];
        struct fd_pair outfd;
        pid_t pid;
 
-       cwd = xrealloc_getcwd_or_warn(NULL);
+       argv[0] = "ftpd";
+       argv[1] = opt; /* "-l" or "-1" */
+#if BB_MMU
+       argv[2] = "--";
+#else
+       /* NOMMU ftpd ls helper chdirs to argv[2],
+        * preventing peer from seeing real root. */
+       argv[2] = xrealloc_getcwd_or_warn(NULL);
+#endif
+       argv[3] = G.ftp_arg;
+       argv[4] = NULL;
+
        xpiped_pair(outfd);
 
        /*fflush_all(); - so far we dont use stdio on output */
@@ -638,9 +642,14 @@ popen_ls(const char *opt)
        if (pid == 0) {
                /* child */
 #if !BB_MMU
+               /* On NOMMU, we want to execute a child - copy of ourself.
+                * In chroot we usually can't do it. Thus we chdir
+                * out of the chroot back to original root,
+                * and (see later below) execute bb_busybox_exec_path
+                * relative to current directory */
                if (fchdir(G.root_fd) != 0)
                        _exit(127);
-               close(G.root_fd);
+               /*close(G.root_fd); - close_on_exec_on() took care of this */
 #endif
                /* NB: close _first_, then move fd! */
                close(outfd.rd);
@@ -651,25 +660,23 @@ popen_ls(const char *opt)
                 * ls won't read it anyway */
                close(STDIN_FILENO);
                dup(STDOUT_FILENO); /* copy will become STDIN_FILENO */
-#if !BB_MMU
-               /* ftpd ls helper chdirs to argv[2],
-                * preventing peer from seeing real root we are in now
-                */
-               argv[2] = cwd;
+#if BB_MMU
+               /* memset(&G, 0, sizeof(G)); - ls_main does it */
+               exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv));
+#else
                /* + 1: we must use relative path here if in chroot.
                 * For example, execv("/proc/self/exe") will fail, since
                 * it looks for "/proc/self/exe" _relative to chroot!_ */
                execv(bb_busybox_exec_path + 1, (char**) argv);
                _exit(127);
-#else
-               /* memset(&G, 0, sizeof(G)); - ls_main does it */
-               exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv));
 #endif
        }
 
        /* parent */
        close(outfd.wr);
-       free(cwd);
+#if !BB_MMU
+       free((char*)argv[2]);
+#endif
        return outfd.rd;
 }
 
@@ -1108,8 +1115,9 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
        opts = getopt32(argv, "l1vS" IF_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose, &verbose_S);
        if (opts & (OPT_l|OPT_1)) {
                /* Our secret backdoor to ls */
-/* TODO: pass -n too? */
-/* --group-directories-first would be nice, but ls don't do that yet */
+/* TODO: pass -n? It prevents user/group resolution, whicj may not work in chroot anyway */
+/* TODO: pass -A? It shows dot files */
+/* TODO: pass --group-directories-first? would be nice, but ls don't do that yet */
                xchdir(argv[2]);
                argv[2] = (char*)"--";
                /* memset(&G, 0, sizeof(G)); - ls_main does it */
@@ -1151,6 +1159,7 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
 
 #if !BB_MMU
        G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY);
+       close_on_exec_on(G.root_fd);
 #endif
 
        if (argv[optind]) {