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c41cba5a5

Denis Vlasenko

2009-03-09

FAILED Duration: 33s

Subject

ftpd: reuse ls applet for LIST/NLST/STAT generation

Binary

No binary (build failed)

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 →

coreutils/Kbuild +1 -0 coreutils/ls.c +0 -1 include/libbb.h +2 -0 networking/ftpd.c +154 -246

coreutils/Kbuild+1 -0

@@ -44,6 +44,7 @@ lib-$(CONFIG_LENGTH) += length.o
	lib-$(CONFIG_LN) += ln.o
	lib-$(CONFIG_LOGNAME) += logname.o
	lib-$(CONFIG_LS) += ls.o
+	lib-$(CONFIG_FTPD) += ls.o
	lib-$(CONFIG_MD5SUM) += md5_sha1_sum.o
	lib-$(CONFIG_MKDIR) += mkdir.o
	lib-$(CONFIG_MKFIFO) += mkfifo.o

coreutils/ls.c+0 -1

@@ -864,7 +864,6 @@ static const char ls_color_opt[] ALIGN1 =
	#endif


-	int ls_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int ls_main(int argc UNUSED_PARAM, char **argv)
	{
	struct dnode **dnd;

include/libbb.h+2 -0

@@ -917,6 +917,8 @@ int test_main(int argc, char **argv) USE_TEST(MAIN_EXTERNALLY_VISIBLE);
	int kill_main(int argc, char **argv) USE_KILL(MAIN_EXTERNALLY_VISIBLE);
	/* Similar, but used by chgrp, not shell */
	int chown_main(int argc, char **argv) USE_CHOWN(MAIN_EXTERNALLY_VISIBLE);
+	/* Used by ftpd */
+	int ls_main(int argc, char **argv) USE_LS(MAIN_EXTERNALLY_VISIBLE);
	/* Don't need USE_xxx() guard for these */
	int gunzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int bunzip2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;

networking/ftpd.c+154 -246

@@ -63,9 +63,24 @@
	#define STR1(s) #s
	#define STR(s) STR1(s)

+	/* Convert a constant to 3-digit string, packed into uint32_t */
	enum {
-	OPT_v = (1 << 0),
-	OPT_w = (1 << 1),
+	/* Shift for Nth decimal digit */
+	SHIFT0 = 16 * BB_LITTLE_ENDIAN + 8 * BB_BIG_ENDIAN,
+	SHIFT1 = 8 * BB_LITTLE_ENDIAN + 16 * BB_BIG_ENDIAN,
+	SHIFT2 = 0 * BB_LITTLE_ENDIAN + 24 * BB_BIG_ENDIAN,
+	};
+	#define STRNUM32(s) (uint32_t)(0 \
+	\| (('0' + ((s) / 1 % 10)) << SHIFT0) \
+	\| (('0' + ((s) / 10 % 10)) << SHIFT1) \
+	\| (('0' + ((s) / 100 % 10)) << SHIFT2) \
+	)
+
+	enum {
+	OPT_l = (1 << 0),
+	OPT_1 = (1 << 1),
+	OPT_v = (1 << 2),
+	OPT_w = (1 << 3),

	#define mk_const4(a,b,c,d) (((a * 0x100 + b) * 0x100 + c) * 0x100 + d)
	#define mk_const3(a,b,c) ((a * 0x100 + b) * 0x100 + c)
@@ -106,78 +121,84 @@ struct globals {
	len_and_sockaddr *local_addr;
	len_and_sockaddr *port_addr;
	int pasv_listen_fd;
-	int data_fd;
+	int proc_self_fd;
	off_t restart_pos;
	char *ftp_cmd;
	char *ftp_arg;
	#if ENABLE_FEATURE_FTP_WRITE
	char *rnfr_filename;
	#endif
-	smallint opts;
	};
	#define G ((struct globals)&bb_common_bufsiz1)
	#define INIT_G() do { } while (0)


	static char *
-	escape_text(const char prepend, const char str, char from, const char *to, char append)
+	escape_text(const char prepend, const char str, unsigned escapee)
	{
-	size_t retlen, remainlen, chunklen, tolen;
-	const char *remain;
+	unsigned retlen, remainlen, chunklen;
	char ret, found;
+	char append;

-	remain = str;
-	remainlen = strlen(str);
-	tolen = strlen(to);
+	append = (char)escapee;
+	escapee >>= 8;

-	/* Simply alloc strlen(str)strlen(to). "to" is max 2 so it's ok /
+	remainlen = strlen(str);
	retlen = strlen(prepend);
-	ret = xmalloc(retlen + remainlen * tolen + 1 + 1);
+	ret = xmalloc(retlen + remainlen * 2 + 1 + 1);
	strcpy(ret, prepend);

	for (;;) {
-	found = strchrnul(remain, from);
-	chunklen = found - remain;
+	found = strchrnul(str, escapee);
+	chunklen = found - str + 1;

-	/* Copy chunk which doesn't contain 'from' to ret */
-	memcpy(&ret[retlen], remain, chunklen);
+	/* Copy chunk up to and including escapee (or NUL) to ret */
+	memcpy(ret + retlen, str, chunklen);
	retlen += chunklen;

-	if (*found != '\0') {
-	/* Now copy 'to' instead of 'from' */
-	memcpy(&ret[retlen], to, tolen);
-	retlen += tolen;
-
-	remain = found + 1;
-	} else {
-	ret[retlen] = append;
-	ret[retlen+1] = '\0';
+	if (*found == '\0') {
+	/* It wasn't escapee, it was NUL! */
+	ret[retlen - 1] = append; /* replace NUL */
+	ret[retlen] = '\0'; /* add NUL */
	break;
	}
+	ret[retlen++] = escapee; /* duplicate escapee */
+	str = found + 1;
	}
	return ret;
	}

-	static void
+	/* Returns strlen as a bonus */
+	static unsigned
	replace_char(char *str, char from, char to)
	{
-	while ((str = strchr(str, from)) != NULL)
-	*str++ = to;
+	char *p = str;
+	while (*p) {
+	if (*p == from)
+	*p = to;
+	p++;
+	}
+	return p - str;
	}

	static void
-	cmdio_write(unsigned status, const char *str)
+	cmdio_write(uint32_t status_str, const char *str)
	{
+	union {
+	char buf[4];
+	uint32_t v32;
+	} u;
	char *response;
	int len;

+	u.v32 = status_str;
+
	/* FTP allegedly uses telnet protocol for command link.
	* In telnet, 0xff is an escape char, and needs to be escaped: */
-	response = escape_text(utoa(status), str, '\xff', "\xff\xff", '\r');
+	response = escape_text(u.buf, str, (0xff << 8) + '\r');

	/* ?! does FTP send embedded LFs as NULs? wow */
-	len = strlen(response);
-	replace_char(response, '\n', '\0');
+	len = replace_char(response, '\n', '\0');

	response[len++] = '\n'; /* tack on trailing '\n' */
	xwrite(STDOUT_FILENO, response, len);
@@ -215,9 +236,9 @@ handle_pwd(void)
	cwd = xstrdup("");

	/* We have to promote each " to "" */
-	response = escape_text(" \"", cwd, '\"', "\"\"", '\"');
+	response = escape_text(" \"", cwd, ('"' << 8) + '"');
	free(cwd);
-	cmdio_write(FTP_PWDOK, response);
+	cmdio_write(STRNUM32(FTP_PWDOK), response);
	free(response);
	}

@@ -261,21 +282,6 @@ handle_help(void)

	/* Download commands */

-	static void
-	init_data_sock_params(int sock_fd)
-	{
-	struct linger linger;
-
-	G.data_fd = sock_fd;
-
-	memset(&linger, 0, sizeof(linger));
-	linger.l_onoff = 1;
-	linger.l_linger = 32767;
-
-	setsockopt(sock_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
-	setsockopt(sock_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
-	}
-
	static int
	ftpdataio_get_pasv_fd(void)
	{
@@ -288,39 +294,10 @@ ftpdataio_get_pasv_fd(void)
	return remote_fd;
	}

-	init_data_sock_params(remote_fd);
-	return remote_fd;
-	}
-
-	static int
-	ftpdataio_get_port_fd(void)
-	{
-	int remote_fd;
-
-	/* Do we want to die or print error to client? */
-	remote_fd = xconnect_stream(G.port_addr);
-
-	init_data_sock_params(remote_fd);
+	setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
	return remote_fd;
	}

-	static void
-	ftpdataio_dispose_transfer_fd(void)
-	{
-	/* This close() blocks because we set SO_LINGER */
-	if (G.data_fd > STDOUT_FILENO) {
-	if (close(G.data_fd) < 0) {
-	/* Do it again without blocking. */
-	struct linger linger;
-
-	memset(&linger, 0, sizeof(linger));
-	setsockopt(G.data_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
-	close(G.data_fd);
-	}
-	}
-	G.data_fd = -1;
-	}
-
	static inline int
	port_active(void)
	{
@@ -341,12 +318,12 @@ get_remote_transfer_fd(const char *p_status_msg)
	if (pasv_active())
	remote_fd = ftpdataio_get_pasv_fd();
	else
-	remote_fd = ftpdataio_get_port_fd();
+	remote_fd = xconnect_stream(G.port_addr);

	if (remote_fd < 0)
	return remote_fd;

-	cmdio_write(FTP_DATACONN, p_status_msg);
+	cmdio_write(STRNUM32(FTP_DATACONN), p_status_msg);
	return remote_fd;
	}

@@ -374,21 +351,21 @@ port_pasv_cleanup(void)
	static unsigned
	bind_for_passive_mode(void)
	{
+	int fd;
	unsigned port;

	port_pasv_cleanup();

-	G.pasv_listen_fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0);
-	setsockopt_reuseaddr(G.pasv_listen_fd);
+	G.pasv_listen_fd = fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0);
+	setsockopt_reuseaddr(fd);

	set_nport(G.local_addr, 0);
-	xbind(G.pasv_listen_fd, &G.local_addr->u.sa, G.local_addr->len);
-	xlisten(G.pasv_listen_fd, 1);
-	getsockname(G.pasv_listen_fd, &G.local_addr->u.sa, &G.local_addr->len);
+	xbind(fd, &G.local_addr->u.sa, G.local_addr->len);
+	xlisten(fd, 1);
+	getsockname(fd, &G.local_addr->u.sa, &G.local_addr->len);

	port = get_nport(&G.local_addr->u.sa);
	port = ntohs(port);
-
	return port;
	}

@@ -487,7 +464,7 @@ handle_retr(void)
	G.restart_pos = 0;

	if (!data_transfer_checks_ok())
-	return;
+	return; /* data_transfer_checks_ok emitted error response */

	/* O_NONBLOCK is useful if file happens to be a device node */
	opened_file = G.ftp_arg ? open(G.ftp_arg, O_RDONLY \| O_NONBLOCK) : -1;
@@ -520,7 +497,7 @@ handle_retr(void)
	goto port_pasv_cleanup_out;

	trans_ret = bb_copyfd_eof(opened_file, remote_fd);
-	ftpdataio_dispose_transfer_fd();
+	close(remote_fd);
	if (trans_ret < 0)
	cmdio_write_error(FTP_BADSENDFILE);
	else
@@ -535,185 +512,105 @@ handle_retr(void)

	/* List commands */

-	static char *
-	statbuf_getperms(const struct stat *statbuf)
-	{
-	char *perms;
-	enum { r = 'r', w = 'w', x = 'x', s = 's', S = 'S' };
-
-	perms = xmalloc(11);
-	memset(perms, '-', 10);
-
-	perms[0] = '?';
-	switch (statbuf->st_mode & S_IFMT) {
-	case S_IFREG: perms[0] = '-'; break;
-	case S_IFDIR: perms[0] = 'd'; break;
-	case S_IFLNK: perms[0] = 'l'; break;
-	case S_IFIFO: perms[0] = 'p'; break;
-	case S_IFSOCK: perms[0] = s; break;
-	case S_IFCHR: perms[0] = 'c'; break;
-	case S_IFBLK: perms[0] = 'b'; break;
-	}
-
-	if (statbuf->st_mode & S_IRUSR) perms[1] = r;
-	if (statbuf->st_mode & S_IWUSR) perms[2] = w;
-	if (statbuf->st_mode & S_IXUSR) perms[3] = x;
-	if (statbuf->st_mode & S_IRGRP) perms[4] = r;
-	if (statbuf->st_mode & S_IWGRP) perms[5] = w;
-	if (statbuf->st_mode & S_IXGRP) perms[6] = x;
-	if (statbuf->st_mode & S_IROTH) perms[7] = r;
-	if (statbuf->st_mode & S_IWOTH) perms[8] = w;
-	if (statbuf->st_mode & S_IXOTH) perms[9] = x;
-	if (statbuf->st_mode & S_ISUID) perms[3] = (perms[3] == x) ? s : S;
-	if (statbuf->st_mode & S_ISGID) perms[6] = (perms[6] == x) ? s : S;
-	if (statbuf->st_mode & S_ISVTX) perms[9] = (perms[9] == x) ? 't' : 'T';
-
-	perms[10] = '\0';
-
-	return perms;
-	}
-
-	static void
-	write_filestats(int fd, const char *filename,
-	const struct stat *statbuf)
-	{
-	off_t size;
-	char stats, lnkname = NULL, *perms;
-	const char *name;
-	char timestr[32];
-	struct tm *tm;
-
-	name = bb_get_last_path_component_nostrip(filename);
-
-	if (statbuf != NULL) {
-	size = statbuf->st_size;
-
-	if (S_ISLNK(statbuf->st_mode))
-	/* Damn symlink... */
-	lnkname = xmalloc_readlink(filename);
-
-	tm = gmtime(&statbuf->st_mtime);
-	if (strftime(timestr, sizeof(timestr), "%b %d %H:%M", tm) == 0)
-	bb_error_msg_and_die("strftime");
-
-	timestr[sizeof(timestr) - 1] = '\0';
-
-	perms = statbuf_getperms(statbuf);
-
-	stats = xasprintf("%s %u\tftp ftp %"OFF_FMT"u\t%s %s",
-	perms, (int) statbuf->st_nlink,
-	size, timestr, name);
-
-	free(perms);
-	} else
-	stats = xstrdup(name);
-
-	xwrite_str(fd, stats);
-	free(stats);
-	if (lnkname != NULL) {
-	xwrite_str(fd, " -> ");
-	xwrite_str(fd, lnkname);
-	free(lnkname);
-	}
-	xwrite_str(fd, "\r\n");
-	}
-
-	static void
-	write_dirstats(int fd, const char *dname, int details)
+	static int
+	popen_ls(const char *opt)
	{
-	DIR *dir;
-	struct dirent *dirent;
-	struct stat statbuf;
-	char *filename;
-
-	dir = xopendir(dname);
+	char *cwd;
+	const char *argv[5] = { "ftpd", opt, NULL, G.ftp_arg, NULL };
+	struct fd_pair outfd;
+	pid_t pid;

-	for (;;) {
-	dirent = readdir(dir);
-	if (dirent == NULL)
-	break;
+	cwd = xrealloc_getcwd_or_warn(NULL);

-	/* Ignore . and .. */
-	if (dirent->d_name[0] == '.') {
-	if (dirent->d_name[1] == '\0'
-	\|\| (dirent->d_name[1] == '.' && dirent->d_name[2] == '\0')
-	) {
-	continue;
-	}
+	xpiped_pair(outfd);
+
+	fflush(NULL);
+	pid = vfork();
+
+	switch (pid) {
+	case -1: /* failure */
+	bb_perror_msg_and_die("vfork");
+	case 0: /* child */
+	/* NB: close _first_, then move fds! */
+	close(outfd.rd);
+	xmove_fd(outfd.wr, STDOUT_FILENO);
+	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);
	}
-
-	if (details) {
-	filename = xasprintf("%s/%s", dname, dirent->d_name);
-	if (lstat(filename, &statbuf) != 0) {
-	free(filename);
-	break;
-	}
-	} else
-	filename = xstrdup(dirent->d_name);
-
-	write_filestats(fd, filename, details ? &statbuf : NULL);
-	free(filename);
+	_exit(127);
	}
-
-	closedir(dir);
+	/* parent */
+	close(outfd.wr);
+	free(cwd);
+	return outfd.rd;
	}

	static void
-	handle_dir_common(int full_details, int stat_cmd)
+	handle_dir_common(int opts)
	{
-	int fd;
-	struct stat statbuf;
+	FILE *ls_fp;
+	char *line;
+	int ls_fd;

-	if (!stat_cmd && !data_transfer_checks_ok())
-	return;
+	if (!(opts & 1) && !data_transfer_checks_ok())
+	return; /* data_transfer_checks_ok emitted error response */
+
+	ls_fd = popen_ls((opts & 2) ? "-l" : "-1");
+	ls_fp = fdopen(ls_fd, "r");
+	if (!ls_fp) /* never happens. paranoia */
+	bb_perror_msg_and_die("fdopen");

-	if (stat_cmd) {
-	fd = STDIN_FILENO;
+	if (opts & 1) {
+	/* STAT <filename> */
	cmdio_write_raw(STR(FTP_STATFILE_OK)"-Status follows:\r\n");
+	while (1) {
+	line = xmalloc_fgetline(ls_fp);
+	if (!line)
+	break;
+	cmdio_write(0, line); /* hack: 0 results in no status at all */
+	free(line);
+	}
+	cmdio_write_ok(FTP_STATFILE_OK);
	} else {
-	fd = get_remote_transfer_fd(" Here comes the directory listing");
-	if (fd < 0)
-	goto bail;
-	}
-
-	if (G.ftp_arg) {
-	if (lstat(G.ftp_arg, &statbuf) != 0) {
-	/* Dir doesn't exist => return ok to client */
-	goto bail;
+	/* LIST/NLST [<filename>] */
+	int remote_fd = get_remote_transfer_fd(" Here comes the directory listing");
+	if (remote_fd >= 0) {
+	while (1) {
+	line = xmalloc_fgetline(ls_fp);
+	if (!line)
+	break;
+	xwrite_str(remote_fd, line);
+	xwrite(remote_fd, "\r\n", 2);
+	free(line);
+	}
	}
-	if (S_ISREG(statbuf.st_mode) \|\| S_ISLNK(statbuf.st_mode))
-	write_filestats(fd, G.ftp_arg, &statbuf);
-	else if (S_ISDIR(statbuf.st_mode))
-	write_dirstats(fd, G.ftp_arg, full_details);
-	} else
-	write_dirstats(fd, ".", full_details);
-
-	bail:
-	/* Well, if we can't open directory/file it doesn't matter */
-	if (!stat_cmd) {
-	ftpdataio_dispose_transfer_fd();
+	close(remote_fd);
	port_pasv_cleanup();
	cmdio_write_ok(FTP_TRANSFEROK);
-	} else
-	cmdio_write_ok(FTP_STATFILE_OK);
+	}
+	fclose(ls_fp); /* closes ls_fd too */
	}
-
	static void
	handle_list(void)
	{
-	handle_dir_common(1, 0);
+	handle_dir_common(2);
	}
-
	static void
	handle_nlst(void)
	{
-	handle_dir_common(0, 0);
+	handle_dir_common(0);
	}
-
	static void
	handle_stat_file(void)
	{
-	handle_dir_common(1, 1);
+	handle_dir_common(3);
	}

	static void
@@ -840,7 +737,7 @@ handle_upload_common(int is_append, int is_unique)
	goto bail;

	trans_ret = bb_copyfd_eof(remote_fd, local_file_fd);
-	ftpdataio_dispose_transfer_fd();
+	close(remote_fd);

	if (trans_ret < 0)
	cmdio_write_error(FTP_BADSENDFILE);
@@ -905,8 +802,19 @@ cmdio_get_cmd_and_arg(void)
	}

	int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-	int ftpd_main(int argc UNUSED_PARAM, char **argv)
+	int ftpd_main(int argc, char **argv)
	{
+	smallint opts;
+
+	opts = getopt32(argv, "l1v" USE_FEATURE_FTP_WRITE("w"));
+
+	if (opts & (OPT_l\|OPT_1)) {
+	/* Our secret backdoor to ls */
+	xchdir(argv[2]);
+	argv[2] = (char*)"--";
+	return ls_main(argc, argv);
+	}
+
	INIT_G();

	G.local_addr = get_sock_lsa(STDIN_FILENO);
@@ -920,13 +828,13 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
	* failure */
	}

-	G.opts = getopt32(argv, "v" USE_FEATURE_FTP_WRITE("w"));
-
	openlog(applet_name, LOG_PID, LOG_DAEMON);
	logmode \|= LOGMODE_SYSLOG;
-	if (!(G.opts & OPT_v))
+	if (!(opts & OPT_v))
	logmode = LOGMODE_SYSLOG;

+	G.proc_self_fd = xopen("/proc/self", O_RDONLY \| O_DIRECTORY);
+
	if (argv[optind]) {
	xchdir(argv[optind]);
	chroot(".");
@@ -1064,7 +972,7 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
	else if (cmdval == const_REST)
	handle_rest();
	#if ENABLE_FEATURE_FTP_WRITE
-	else if (G.opts & OPT_w) {
+	else if (opts & OPT_w) {
	if (cmdval == const_STOR)
	handle_stor();
	else if (cmdval == const_MKD)