diff options
| -rw-r--r-- | networking/ftpd.c | 53 |
1 files changed, 21 insertions, 32 deletions
diff --git a/networking/ftpd.c b/networking/ftpd.c index e724734df..839a85d73 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -620,16 +620,12 @@ popen_ls(const char *opt) const char *argv[5]; struct fd_pair outfd; pid_t pid; - +#if !BB_MMU + int cur_fd = xopen(".", O_RDONLY | O_DIRECTORY); +#endif 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; @@ -651,16 +647,6 @@ popen_ls(const char *opt) pid = BB_MMU ? xfork() : xvfork(); 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_on_exec_on() took care of this */ -#endif /* NB: close _first_, then move fd! */ close(outfd.rd); xmove_fd(outfd.wr, STDOUT_FILENO); @@ -674,19 +660,25 @@ popen_ls(const char *opt) /* 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); + /* On NOMMU, we want to execute a child - copy of ourself + * in order to unblock parent after vfork. + * In chroot we usually can't re-exec. Thus we escape + * out of the chroot back to original root. + */ + if (G.root_fd >= 0) { + if (fchdir(G.root_fd) != 0 || chroot(".") != 0) + _exit(127); + /*close(G.root_fd); - close_on_exec_on() took care of this */ + } + /* Child expects directory to list on fd #3 */ + xmove_fd(cur_fd, 3); + execv(bb_busybox_exec_path, (char**) argv); _exit(127); #endif } /* parent */ close(outfd.wr); -#if !BB_MMU - free((char*)argv[2]); -#endif return outfd.rd; } @@ -705,8 +697,6 @@ handle_dir_common(int opts) if (!(opts & USE_CTRL_CONN) && !port_or_pasv_was_seen()) return; /* port_or_pasv_was_seen emitted error response */ - /* -n prevents user/groupname display, - * which can be problematic in chroot */ ls_fd = popen_ls((opts & LONG_LISTING) ? "-l" : "-1"); ls_fp = xfdopen_for_read(ls_fd); /* FIXME: filenames with embedded newlines are mishandled */ @@ -1139,11 +1129,10 @@ 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? It prevents user/group resolution, which may not work in chroot anyway */ /* TODO: pass -A? It shows dot files */ /* TODO: pass --group-directories-first? would be nice, but ls doesn't do that yet */ - xchdir(argv[2]); - argv[2] = (char*)"--"; + if (fchdir(3) != 0) + _exit(127); /* memset(&G, 0, sizeof(G)); - ls_main does it */ return ls_main(argc, argv); } @@ -1185,9 +1174,9 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); close_on_exec_on(G.root_fd); #endif - - if (argv[optind]) { - xchroot(argv[optind]); + argv += optind; + if (argv[0]) { + xchroot(argv[0]); } //umask(077); - admin can set umask before starting us |