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5b492ee87

Denis Vlasenko

2009-03-18

FAILED Duration: 39s

Subject

ftpd: do not use nasty tricks for re-execing if we are on MMU machine. On NOMMU, code is alomost the same, on MMU:

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

networking/ftpd.c +57 -22

networking/ftpd.c+57 -22

@@ -87,7 +87,9 @@ enum {

	struct globals {
	int pasv_listen_fd;
-	int proc_self_fd;
+	#if !BB_MMU
+	int root_fd;
+	#endif
	int local_file_fd;
	unsigned end_time;
	unsigned timeout;
@@ -615,7 +617,13 @@ static int
	popen_ls(const char *opt)
	{
	char *cwd;
-	const char *argv[5] = { "ftpd", opt, NULL, G.ftp_arg, NULL };
+	const char *argv[] = {
+	"ftpd",
+	opt,
+	BB_MMU ? "--" : NULL,
+	G.ftp_arg,
+	NULL
+	};
	struct fd_pair outfd;
	pid_t pid;

@@ -623,25 +631,40 @@ popen_ls(const char *opt)
	xpiped_pair(outfd);

	/fflush(NULL); - so far we dont use stdio on output /
-	pid = vfork();
-	switch (pid) {
-	case -1: /* failure */
-	bb_perror_msg_and_die("vfork");
-	case 0: /* child */
-	/* NB: close _first_, then move fds! */
+	pid = BB_MMU ? fork() : vfork();
+	if (pid < 0)
+	bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
+
+	if (pid == 0) {
+	/* child */
+	#if !BB_MMU
+	if (fchdir(G.root_fd) != 0)
+	_exit(127);
+	close(G.root_fd);
+	#endif
+	/* NB: close _first_, then move fd! */
	close(outfd.rd);
	xmove_fd(outfd.wr, STDOUT_FILENO);
+	/* Opening /dev/null in chroot is hard.
+	* Just making sure STDIN_FILENO is opened
+	* to something harmless. Paranoia,
+	* ls won't read it anyway */
	close(STDIN_FILENO);
-	/* xopen("/dev/null", O_RDONLY); - chroot may lack it! */
-	if (fchdir(G.proc_self_fd) == 0) {
-	close(G.proc_self_fd);
-	argv[2] = cwd;
-	/* ftpd ls helper chdirs to argv[2],
-	* preventing peer from seeing /proc/self
-	*/
-	execv("exe", (char**) argv);
-	}
+	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;
+	/* + 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(CONFIG_BUSYBOX_EXEC_PATH + 1, (char**) argv);
	_exit(127);
+	#else
+	memset(&G, 0, sizeof(G));
+	exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv));
+	#endif
	}

	/* parent */
@@ -1006,15 +1029,21 @@ enum {
	const_TYPE = mk_const4('T', 'Y', 'P', 'E'),
	const_USER = mk_const4('U', 'S', 'E', 'R'),

+	#if !BB_MMU
	OPT_l = (1 << 0),
	OPT_1 = (1 << 1),
-	OPT_v = (1 << 2),
-	OPT_S = (1 << 3),
-	OPT_w = (1 << 4),
+	#endif
+	OPT_v = (1 << ((!BB_MMU) * 2 + 0)),
+	OPT_S = (1 << ((!BB_MMU) * 2 + 1)),
+	OPT_w = (1 << ((!BB_MMU) * 2 + 2)) * ENABLE_FEATURE_FTP_WRITE,
	};

	int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+	#if !BB_MMU
	int ftpd_main(int argc, char **argv)
+	#else
+	int ftpd_main(int argc UNUSED_PARAM, char **argv)
+	#endif
	{
	unsigned abs_timeout;
	smallint opts;
@@ -1024,16 +1053,20 @@ int ftpd_main(int argc, char **argv)
	abs_timeout = 1 * 60 * 60;
	G.timeout = 2 * 60;
	opt_complementary = "t+:T+:vv";
+	#if BB_MMU
+	opts = getopt32(argv, "vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose);
+	#else
	opts = getopt32(argv, "l1vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose);
	if (opts & (OPT_l\|OPT_1)) {
	/* Our secret backdoor to ls */
-	memset(&G, 0, sizeof(G));
	/* TODO: pass -n too? */
	/* --group-directories-first would be nice, but ls don't do that yet */
	xchdir(argv[2]);
	argv[2] = (char*)"--";
+	memset(&G, 0, sizeof(G));
	return ls_main(argc, argv);
	}
+	#endif
	if (abs_timeout \| G.timeout) {
	if (abs_timeout == 0)
	abs_timeout = INT_MAX;
@@ -1065,7 +1098,9 @@ int ftpd_main(int argc, char **argv)
	if (logmode)
	applet_name = xasprintf("%s[%u]", applet_name, (int)getpid());

-	G.proc_self_fd = xopen("/proc/self", O_RDONLY \| O_DIRECTORY);
+	#if !BB_MMU
+	G.root_fd = xopen("/", O_RDONLY \| O_DIRECTORY);
+	#endif

	if (argv[optind]) {
	xchdir(argv[optind]);