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ftpd: code shrink

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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>
This commit is contained in:
Denys Vlasenko 2010-01-17 22:32:22 +01:00
parent 96a6bdcb77
commit 33f9dc08e5
1 changed files with 30 additions and 21 deletions
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51
networking/ftpd.c
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@ -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]) {