diff options
| -rw-r--r-- | networking/ftpd.c | 51 |
1 files changed, 30 insertions, 21 deletions
diff --git a/networking/ftpd.c b/networking/ftpd.c index df8188c..4e9f65c 100644 --- 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]) { |