*
* Author: Adam Tkac <vonsch@gmail.com>
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*
* Only subset of FTP protocol is implemented but vast majority of clients
- * should not have any problem. You have to run this daemon via inetd.
+ * should not have any problem.
*
- * Options:
- * -w - enable FTP write commands
- *
- * TODO: implement "421 Timeout" thingy (alarm(60) while waiting for a cmd).
+ * You have to run this daemon via inetd.
*/
+//config:config FTPD
+//config: bool "ftpd (30 kb)"
+//config: default y
+//config: help
+//config: Simple FTP daemon. You have to run it via inetd.
+//config:
+//config:config FEATURE_FTPD_WRITE
+//config: bool "Enable -w (upload commands)"
+//config: default y
+//config: depends on FTPD
+//config: help
+//config: Enable -w option. "ftpd -w" will accept upload commands
+//config: such as STOR, STOU, APPE, DELE, MKD, RMD, rename commands.
+//config:
+//config:config FEATURE_FTPD_ACCEPT_BROKEN_LIST
+//config: bool "Enable workaround for RFC-violating clients"
+//config: default y
+//config: depends on FTPD
+//config: help
+//config: Some ftp clients (among them KDE's Konqueror) issue illegal
+//config: "LIST -l" requests. This option works around such problems.
+//config: It might prevent you from listing files starting with "-" and
+//config: it increases the code size by ~40 bytes.
+//config: Most other ftp servers seem to behave similar to this.
+//config:
+//config:config FEATURE_FTPD_AUTHENTICATION
+//config: bool "Enable authentication"
+//config: default y
+//config: depends on FTPD
+//config: help
+//config: Require login, and change to logged in user's UID:GID before
+//config: accessing any files. Option "-a USER" allows "anonymous"
+//config: logins (treats them as if USER logged in).
+//config:
+//config: If this option is not selected, ftpd runs with the rights
+//config: of the user it was started under, and does not require login.
+//config: Take care to not launch it under root.
+
+//applet:IF_FTPD(APPLET(ftpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_FTPD) += ftpd.o
+
+//usage:#define ftpd_trivial_usage
+//usage: "[-wvS]"IF_FEATURE_FTPD_AUTHENTICATION(" [-a USER]")" [-t N] [-T N] [DIR]"
+//usage:#define ftpd_full_usage "\n\n"
+//usage: IF_NOT_FEATURE_FTPD_AUTHENTICATION(
+//usage: "Anonymous FTP server. Client access occurs under ftpd's UID.\n"
+//usage: )
+//usage: IF_FEATURE_FTPD_AUTHENTICATION(
+//usage: "FTP server. "
+//usage: )
+//usage: "Chroots to DIR, if this fails (run by non-root), cds to it.\n"
+//usage: "Should be used as inetd service, inetd.conf line:\n"
+//usage: " 21 stream tcp nowait root ftpd ftpd /files/to/serve\n"
+//usage: "Can be run from tcpsvd:\n"
+//usage: " tcpsvd -vE 0.0.0.0 21 ftpd /files/to/serve"
+//usage: "\n"
+//usage: "\n -w Allow upload"
+//usage: IF_FEATURE_FTPD_AUTHENTICATION(
+//usage: "\n -A No login required, client access occurs under ftpd's UID"
+//
+// if !FTPD_AUTHENTICATION, -A is accepted too, but not shown in --help
+// since it's the only supported mode in that configuration
+//
+//usage: "\n -a USER Enable 'anonymous' login and map it to USER"
+//usage: )
+//usage: "\n -v Log errors to stderr. -vv: verbose log"
+//usage: "\n -S Log errors to syslog. -SS: verbose log"
+//usage: "\n -t,-T N Idle and absolute timeout"
#include "libbb.h"
+#include "common_bufsiz.h"
#include <syslog.h>
#include <netinet/tcp.h>
#define FTP_GIVEPWORD 331
#define FTP_RESTOK 350
#define FTP_RNFROK 350
+#define FTP_TIMEOUT 421
#define FTP_BADSENDCONN 425
#define FTP_BADSENDNET 426
#define FTP_BADSENDFILE 451
/* Convert a constant to 3-digit string, packed into uint32_t */
enum {
/* 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,
+ SHIFT2 = 0 * BB_LITTLE_ENDIAN + 24 * BB_BIG_ENDIAN,
+ SHIFT1 = 8 * BB_LITTLE_ENDIAN + 16 * BB_BIG_ENDIAN,
+ SHIFT0 = 16 * BB_LITTLE_ENDIAN + 8 * BB_BIG_ENDIAN,
+ /* And for 4th position (space) */
+ SHIFTsp = 24 * BB_LITTLE_ENDIAN + 0 * BB_BIG_ENDIAN,
};
#define STRNUM32(s) (uint32_t)(0 \
| (('0' + ((s) / 1 % 10)) << SHIFT0) \
| (('0' + ((s) / 10 % 10)) << SHIFT1) \
| (('0' + ((s) / 100 % 10)) << SHIFT2) \
)
+#define STRNUM32sp(s) (uint32_t)(0 \
+ | (' ' << SHIFTsp) \
+ | (('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)
- const_ALLO = mk_const4('A', 'L', 'L', 'O'),
- const_APPE = mk_const4('A', 'P', 'P', 'E'),
- const_CDUP = mk_const4('C', 'D', 'U', 'P'),
- const_CWD = mk_const3('C', 'W', 'D'),
- const_DELE = mk_const4('D', 'E', 'L', 'E'),
- const_EPSV = mk_const4('E', 'P', 'S', 'V'),
- const_HELP = mk_const4('H', 'E', 'L', 'P'),
- const_LIST = mk_const4('L', 'I', 'S', 'T'),
- const_MKD = mk_const3('M', 'K', 'D'),
- const_MODE = mk_const4('M', 'O', 'D', 'E'),
- const_NLST = mk_const4('N', 'L', 'S', 'T'),
- const_NOOP = mk_const4('N', 'O', 'O', 'P'),
- const_PASS = mk_const4('P', 'A', 'S', 'S'),
- const_PASV = mk_const4('P', 'A', 'S', 'V'),
- const_PORT = mk_const4('P', 'O', 'R', 'T'),
- const_PWD = mk_const3('P', 'W', 'D'),
- const_QUIT = mk_const4('Q', 'U', 'I', 'T'),
- const_REST = mk_const4('R', 'E', 'S', 'T'),
- const_RETR = mk_const4('R', 'E', 'T', 'R'),
- const_RMD = mk_const3('R', 'M', 'D'),
- const_RNFR = mk_const4('R', 'N', 'F', 'R'),
- const_RNTO = mk_const4('R', 'N', 'T', 'O'),
- const_SIZE = mk_const4('S', 'I', 'Z', 'E'),
- const_STAT = mk_const4('S', 'T', 'A', 'T'),
- const_STOR = mk_const4('S', 'T', 'O', 'R'),
- const_STOU = mk_const4('S', 'T', 'O', 'U'),
- const_STRU = mk_const4('S', 'T', 'R', 'U'),
- const_SYST = mk_const4('S', 'Y', 'S', 'T'),
- const_TYPE = mk_const4('T', 'Y', 'P', 'E'),
- const_USER = mk_const4('U', 'S', 'E', 'R'),
-};
+#define MSG_OK "Operation successful\r\n"
+#define MSG_ERR "Error\r\n"
struct globals {
- char *p_control_line_buf;
- len_and_sockaddr *local_addr;
- len_and_sockaddr *port_addr;
int pasv_listen_fd;
- int proc_self_fd;
+#if !BB_MMU
+ int root_fd;
+#endif
+ int local_file_fd;
+ unsigned end_time;
+ unsigned timeout;
+ unsigned verbose;
+ off_t local_file_pos;
off_t restart_pos;
+ len_and_sockaddr *local_addr;
+ len_and_sockaddr *port_addr;
char *ftp_cmd;
char *ftp_arg;
-#if ENABLE_FEATURE_FTP_WRITE
+#if ENABLE_FEATURE_FTPD_WRITE
char *rnfr_filename;
#endif
-};
-#define G (*(struct globals*)&bb_common_bufsiz1)
-#define INIT_G() do { } while (0)
+ /* We need these aligned to uint32_t */
+ char msg_ok [(sizeof("NNN " MSG_OK ) + 3) & 0xfffc];
+ char msg_err[(sizeof("NNN " MSG_ERR) + 3) & 0xfffc];
+} FIX_ALIASING;
+#define G (*ptr_to_globals)
+/* ^^^ about 75 bytes smaller code than this: */
+//#define G (*(struct globals*)bb_common_bufsiz1)
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+ /*setup_common_bufsiz();*/ \
+ \
+ /* Moved to main */ \
+ /*strcpy(G.msg_ok + 4, MSG_OK );*/ \
+ /*strcpy(G.msg_err + 4, MSG_ERR);*/ \
+} while (0)
static char *
return p - str;
}
+static void
+verbose_log(const char *str)
+{
+ bb_error_msg("%.*s", (int)strcspn(str, "\r\n"), str);
+}
+
+/* NB: status_str is char[4] packed into uint32_t */
static void
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.
+ /* FTP uses telnet protocol for command link.
* In telnet, 0xff is an escape char, and needs to be escaped: */
- response = escape_text(u.buf, str, (0xff << 8) + '\r');
+ response = escape_text((char *) &status_str, str, (0xff << 8) + '\r');
- /* ?! does FTP send embedded LFs as NULs? wow */
+ /* FTP sends embedded LFs as NULs */
len = replace_char(response, '\n', '\0');
response[len++] = '\n'; /* tack on trailing '\n' */
xwrite(STDOUT_FILENO, response, len);
+ if (G.verbose > 1)
+ verbose_log(response);
free(response);
}
static void
-cmdio_write_ok(int status)
+cmdio_write_ok(unsigned status)
{
- fdprintf(STDOUT_FILENO, "%u Operation successful\r\n", status);
+ *(bb__aliased_uint32_t *) G.msg_ok = status;
+ xwrite(STDOUT_FILENO, G.msg_ok, sizeof("NNN " MSG_OK) - 1);
+ if (G.verbose > 1)
+ verbose_log(G.msg_ok);
}
+#define WRITE_OK(a) cmdio_write_ok(STRNUM32sp(a))
/* TODO: output strerr(errno) if errno != 0? */
static void
-cmdio_write_error(int status)
+cmdio_write_error(unsigned status)
{
- fdprintf(STDOUT_FILENO, "%u Error\r\n", status);
+ *(bb__aliased_uint32_t *) G.msg_err = status;
+ xwrite(STDOUT_FILENO, G.msg_err, sizeof("NNN " MSG_ERR) - 1);
+ if (G.verbose > 0)
+ verbose_log(G.msg_err);
}
+#define WRITE_ERR(a) cmdio_write_error(STRNUM32sp(a))
static void
cmdio_write_raw(const char *p_text)
{
xwrite_str(STDOUT_FILENO, p_text);
+ if (G.verbose > 1)
+ verbose_log(p_text);
+}
+
+static void
+timeout_handler(int sig UNUSED_PARAM)
+{
+ off_t pos;
+ int sv_errno = errno;
+
+ if ((int)(monotonic_sec() - G.end_time) >= 0)
+ goto timed_out;
+
+ if (!G.local_file_fd)
+ goto timed_out;
+
+ pos = xlseek(G.local_file_fd, 0, SEEK_CUR);
+ if (pos == G.local_file_pos)
+ goto timed_out;
+ G.local_file_pos = pos;
+
+ alarm(G.timeout);
+ errno = sv_errno;
+ return;
+
+ timed_out:
+ cmdio_write_raw(STR(FTP_TIMEOUT)" Timeout\r\n");
+/* TODO: do we need to abort (as opposed to usual shutdown) data transfer? */
+ exit(1);
}
/* Simple commands */
handle_cwd(void)
{
if (!G.ftp_arg || chdir(G.ftp_arg) != 0) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- cmdio_write_ok(FTP_CWDOK);
+ WRITE_OK(FTP_CWDOK);
}
static void
static void
handle_stat(void)
{
- cmdio_write_raw(STR(FTP_STATOK)"-FTP server status:\r\n"
+ cmdio_write_raw(STR(FTP_STATOK)"-Server status:\r\n"
" TYPE: BINARY\r\n"
STR(FTP_STATOK)" Ok\r\n");
}
+/* Examples of HELP and FEAT:
+# nc -vvv ftp.kernel.org 21
+ftp.kernel.org (130.239.17.4:21) open
+220 Welcome to ftp.kernel.org.
+FEAT
+211-Features:
+ EPRT
+ EPSV
+ MDTM
+ PASV
+ REST STREAM
+ SIZE
+ TVFS
+ UTF8
+211 End
+HELP
+214-The following commands are recognized.
+ ABOR ACCT ALLO APPE CDUP CWD DELE EPRT EPSV FEAT HELP LIST MDTM MKD
+ MODE NLST NOOP OPTS PASS PASV PORT PWD QUIT REIN REST RETR RMD RNFR
+ RNTO SITE SIZE SMNT STAT STOR STOU STRU SYST TYPE USER XCUP XCWD XMKD
+ XPWD XRMD
+214 Help OK.
+*/
static void
-handle_help(void)
-{
- cmdio_write_raw(STR(FTP_HELP)"-Commands:\r\n"
- " ALLO CDUP CWD EPSV HELP LIST\r\n"
- " MODE NLST NOOP PASS PASV PORT PWD QUIT\r\n"
- " REST RETR SIZE STAT STRU SYST TYPE USER\r\n"
-#if ENABLE_FEATURE_FTP_WRITE
- " APPE DELE MKD RMD RNFR RNTO STOR STOU\r\n"
-#endif
- STR(FTP_HELP)" Ok\r\n");
+handle_feat(unsigned status)
+{
+ cmdio_write(status, "-Features:");
+ cmdio_write_raw(" EPSV\r\n"
+ " PASV\r\n"
+ " REST STREAM\r\n"
+ " MDTM\r\n"
+ " SIZE\r\n");
+ cmdio_write(status, " Ok");
}
/* Download commands */
+static inline int
+port_active(void)
+{
+ return (G.port_addr != NULL);
+}
+
+static inline int
+pasv_active(void)
+{
+ return (G.pasv_listen_fd > STDOUT_FILENO);
+}
+
+static void
+port_pasv_cleanup(void)
+{
+ free(G.port_addr);
+ G.port_addr = NULL;
+ if (G.pasv_listen_fd > STDOUT_FILENO)
+ close(G.pasv_listen_fd);
+ G.pasv_listen_fd = -1;
+}
+
+/* On error, emits error code to the peer */
static int
ftpdataio_get_pasv_fd(void)
{
remote_fd = accept(G.pasv_listen_fd, NULL, 0);
if (remote_fd < 0) {
- cmdio_write_error(FTP_BADSENDCONN);
+ WRITE_ERR(FTP_BADSENDCONN);
return remote_fd;
}
- setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
+ setsockopt_keepalive(remote_fd);
return remote_fd;
}
-static inline int
-port_active(void)
-{
- return (G.port_addr != NULL);
-}
-
-static inline int
-pasv_active(void)
-{
- return (G.pasv_listen_fd > STDOUT_FILENO);
-}
-
+/* Clears port/pasv data.
+ * This means we dont waste resources, for example, keeping
+ * PASV listening socket open when it is no longer needed.
+ * On error, emits error code to the peer (or exits).
+ * On success, emits p_status_msg to the peer.
+ */
static int
get_remote_transfer_fd(const char *p_status_msg)
{
int remote_fd;
if (pasv_active())
+ /* On error, emits error code to the peer */
remote_fd = ftpdataio_get_pasv_fd();
else
+ /* Exits on error */
remote_fd = xconnect_stream(G.port_addr);
+ port_pasv_cleanup();
+
if (remote_fd < 0)
return remote_fd;
return remote_fd;
}
+/* If there were neither PASV nor PORT, emits error code to the peer */
static int
-data_transfer_checks_ok(void)
+port_or_pasv_was_seen(void)
{
if (!pasv_active() && !port_active()) {
- cmdio_write_raw(STR(FTP_BADSENDCONN)" Use PORT or PASV first\r\n");
+ cmdio_write_raw(STR(FTP_BADSENDCONN)" Use PORT/PASV first\r\n");
return 0;
}
return 1;
}
-static void
-port_pasv_cleanup(void)
-{
- free(G.port_addr);
- G.port_addr = NULL;
- if (G.pasv_listen_fd > STDOUT_FILENO)
- close(G.pasv_listen_fd);
- G.pasv_listen_fd = -1;
-}
-
+/* Exits on error */
static unsigned
bind_for_passive_mode(void)
{
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);
+ set_nport(&G.local_addr->u.sa, 0);
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);
return port;
}
+/* Exits on error */
static void
handle_pasv(void)
{
addr = xstrdup("0.0.0.0");
replace_char(addr, '.', ',');
- response = xasprintf(STR(FTP_PASVOK)" Entering Passive Mode (%s,%u,%u)\r\n",
+ response = xasprintf(STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n",
addr, (int)(port >> 8), (int)(port & 255));
free(addr);
cmdio_write_raw(response);
free(response);
}
+/* Exits on error */
static void
handle_epsv(void)
{
char *response;
port = bind_for_passive_mode();
- response = xasprintf(STR(FTP_EPSVOK)" EPSV Ok (|||%u|)\r\n", port);
+ response = xasprintf(STR(FTP_EPSVOK)" EPSV ok (|||%u|)\r\n", port);
cmdio_write_raw(response);
free(response);
}
static void
handle_port(void)
{
- unsigned short port;
- char *raw, *port_part;
- len_and_sockaddr *lsa = NULL;
+ unsigned port, port_hi;
+ char *raw, *comma;
+#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
+ socklen_t peer_ipv4_len;
+ struct sockaddr_in peer_ipv4;
+ struct in_addr port_ipv4_sin_addr;
+#endif
port_pasv_cleanup();
raw = G.ftp_arg;
- /* buglets:
- * xatou16 will accept wrong input,
- * xatou16 will exit instead of generating error to peer
- */
+ /* PORT command format makes sense only over IPv4 */
+ if (!raw
+#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
+ || G.local_addr->u.sa.sa_family != AF_INET
+#endif
+ ) {
+ bail:
+ WRITE_ERR(FTP_BADCMD);
+ return;
+ }
- port_part = strrchr(raw, ',');
- if (port_part == NULL)
+ comma = strrchr(raw, ',');
+ if (comma == NULL)
+ goto bail;
+ *comma = '\0';
+ port = bb_strtou(&comma[1], NULL, 10);
+ if (errno || port > 0xff)
goto bail;
- port = xatou16(&port_part[1]);
- *port_part = '\0';
- port_part = strrchr(raw, ',');
- if (port_part == NULL)
+ comma = strrchr(raw, ',');
+ if (comma == NULL)
+ goto bail;
+ *comma = '\0';
+ port_hi = bb_strtou(&comma[1], NULL, 10);
+ if (errno || port_hi > 0xff)
goto bail;
- port |= xatou16(&port_part[1]) << 8;
- *port_part = '\0';
+ port |= port_hi << 8;
+#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
replace_char(raw, ',', '.');
- lsa = xdotted2sockaddr(raw, port);
- if (lsa == NULL) {
- bail:
- cmdio_write_error(FTP_BADCMD);
- return;
- }
+ /* We are verifying that PORT's IP matches getpeername().
+ * Otherwise peer can make us open data connections
+ * to other hosts (security problem!)
+ * This code would be too simplistic:
+ * lsa = xdotted2sockaddr(raw, port);
+ * if (lsa == NULL) goto bail;
+ */
+ if (!inet_aton(raw, &port_ipv4_sin_addr))
+ goto bail;
+ peer_ipv4_len = sizeof(peer_ipv4);
+ if (getpeername(STDIN_FILENO, &peer_ipv4, &peer_ipv4_len) != 0)
+ goto bail;
+ if (memcmp(&port_ipv4_sin_addr, &peer_ipv4.sin_addr, sizeof(struct in_addr)) != 0)
+ goto bail;
- G.port_addr = lsa;
- cmdio_write_ok(FTP_PORTOK);
+ G.port_addr = xdotted2sockaddr(raw, port);
+#else
+ G.port_addr = get_peer_lsa(STDIN_FILENO);
+ set_nport(&G.port_addr->u.sa, htons(port));
+#endif
+ WRITE_OK(FTP_PORTOK);
}
static void
handle_rest(void)
{
/* When ftp_arg == NULL simply restart from beginning */
- G.restart_pos = G.ftp_arg ? xatoi_u(G.ftp_arg) : 0;
- cmdio_write_ok(FTP_RESTOK);
+ G.restart_pos = G.ftp_arg ? XATOOFF(G.ftp_arg) : 0;
+ WRITE_OK(FTP_RESTOK);
}
static void
handle_retr(void)
{
struct stat statbuf;
- int trans_ret;
+ off_t bytes_transferred;
int remote_fd;
- int opened_file;
+ int local_file_fd;
off_t offset = G.restart_pos;
char *response;
G.restart_pos = 0;
- if (!data_transfer_checks_ok())
- return; /* data_transfer_checks_ok emitted error response */
+ if (!port_or_pasv_was_seen())
+ return; /* port_or_pasv_was_seen 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;
- if (opened_file < 0) {
- cmdio_write_error(FTP_FILEFAIL);
+ local_file_fd = G.ftp_arg ? open(G.ftp_arg, O_RDONLY | O_NONBLOCK) : -1;
+ if (local_file_fd < 0) {
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- if (fstat(opened_file, &statbuf) != 0 || !S_ISREG(statbuf.st_mode)) {
+ if (fstat(local_file_fd, &statbuf) != 0 || !S_ISREG(statbuf.st_mode)) {
/* Note - pretend open failed */
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
goto file_close_out;
}
+ G.local_file_fd = local_file_fd;
- /* Now deactive O_NONBLOCK, otherwise we have a problem on DMAPI filesystems
- * such as XFS DMAPI.
+ /* Now deactive O_NONBLOCK, otherwise we have a problem
+ * on DMAPI filesystems such as XFS DMAPI.
*/
- ndelay_off(opened_file);
+ ndelay_off(local_file_fd);
/* Set the download offset (from REST) if any */
if (offset != 0)
- xlseek(opened_file, offset, SEEK_SET);
+ xlseek(local_file_fd, offset, SEEK_SET);
response = xasprintf(
- " Opening BINARY mode data connection for %s (%"OFF_FMT"u bytes)",
+ " Opening BINARY connection for %s (%"OFF_FMT"u bytes)",
G.ftp_arg, statbuf.st_size);
remote_fd = get_remote_transfer_fd(response);
free(response);
if (remote_fd < 0)
- goto port_pasv_cleanup_out;
+ goto file_close_out;
- trans_ret = bb_copyfd_eof(opened_file, remote_fd);
+ bytes_transferred = bb_copyfd_eof(local_file_fd, remote_fd);
close(remote_fd);
- if (trans_ret < 0)
- cmdio_write_error(FTP_BADSENDFILE);
+ if (bytes_transferred < 0)
+ WRITE_ERR(FTP_BADSENDFILE);
else
- cmdio_write_ok(FTP_TRANSFEROK);
-
- port_pasv_cleanup_out:
- port_pasv_cleanup();
+ WRITE_OK(FTP_TRANSFEROK);
file_close_out:
- close(opened_file);
+ close(local_file_fd);
+ G.local_file_fd = 0;
}
/* List commands */
static int
popen_ls(const char *opt)
{
- char *cwd;
- const char *argv[5] = { "ftpd", opt, 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; /* "-lA" or "-1A" */
+ argv[2] = "--";
+ argv[3] = G.ftp_arg;
+ argv[4] = NULL;
+
+ /* Improve compatibility with non-RFC conforming FTP clients
+ * which send e.g. "LIST -l", "LIST -la", "LIST -aL".
+ * See https://bugs.kde.org/show_bug.cgi?id=195578 */
+ if (ENABLE_FEATURE_FTPD_ACCEPT_BROKEN_LIST
+ && G.ftp_arg && G.ftp_arg[0] == '-'
+ ) {
+ const char *tmp = strchr(G.ftp_arg, ' ');
+ if (tmp) /* skip the space */
+ tmp++;
+ argv[3] = tmp;
+ }
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! */
+ /*fflush_all(); - so far we dont use stdio on output */
+ pid = BB_MMU ? xfork() : xvfork();
+ if (pid == 0) {
+#if !BB_MMU
+ int cur_fd;
+#endif
+ /* child */
+ /* 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
+ /* memset(&G, 0, sizeof(G)); - ls_main does it */
+ exit(ls_main(/*argc_unused*/ 0, (char**) argv));
+#else
+ cur_fd = xopen(".", O_RDONLY | O_DIRECTORY);
+ /* 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);
- free(cwd);
return outfd.rd;
}
+enum {
+ USE_CTRL_CONN = 1,
+ LONG_LISTING = 2,
+};
+
static void
handle_dir_common(int opts)
{
char *line;
int ls_fd;
- if (!(opts & 1) && !data_transfer_checks_ok())
- return; /* data_transfer_checks_ok emitted error response */
+ if (!(opts & USE_CTRL_CONN) && !port_or_pasv_was_seen())
+ return; /* port_or_pasv_was_seen 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");
+ ls_fd = popen_ls((opts & LONG_LISTING) ? "-lA" : "-1A");
+ ls_fp = xfdopen_for_read(ls_fd);
+/* FIXME: filenames with embedded newlines are mishandled */
- if (opts & 1) {
+ if (opts & USE_CTRL_CONN) {
/* STAT <filename> */
- cmdio_write_raw(STR(FTP_STATFILE_OK)"-Status follows:\r\n");
+ cmdio_write_raw(STR(FTP_STATFILE_OK)"-File status:\r\n");
while (1) {
- line = xmalloc_fgetline(ls_fp);
+ line = xmalloc_fgetline(ls_fp);
if (!line)
break;
- cmdio_write(0, line); /* hack: 0 results in no status at all */
+ /* Hack: 0 results in no status at all */
+ /* Note: it's ok that we don't prepend space,
+ * ftp.kernel.org doesn't do that too */
+ cmdio_write(0, line);
free(line);
}
- cmdio_write_ok(FTP_STATFILE_OK);
+ WRITE_OK(FTP_STATFILE_OK);
} else {
/* LIST/NLST [<filename>] */
- int remote_fd = get_remote_transfer_fd(" Here comes the directory listing");
+ int remote_fd = get_remote_transfer_fd(" Directory listing");
if (remote_fd >= 0) {
while (1) {
- line = xmalloc_fgetline(ls_fp);
+ unsigned len;
+
+ line = xmalloc_fgets(ls_fp);
if (!line)
break;
- xwrite_str(remote_fd, line);
- xwrite(remote_fd, "\r\n", 2);
+ /* I've seen clients complaining when they
+ * are fed with ls output with bare '\n'.
+ * Replace trailing "\n\0" with "\r\n".
+ */
+ len = strlen(line);
+ if (len != 0) /* paranoia check */
+ line[len - 1] = '\r';
+ line[len] = '\n';
+ xwrite(remote_fd, line, len + 1);
free(line);
}
}
close(remote_fd);
- port_pasv_cleanup();
- cmdio_write_ok(FTP_TRANSFEROK);
+ WRITE_OK(FTP_TRANSFEROK);
}
fclose(ls_fp); /* closes ls_fd too */
}
static void
handle_list(void)
{
- handle_dir_common(2);
+ handle_dir_common(LONG_LISTING);
}
static void
handle_nlst(void)
{
+ /* NLST returns list of names, "\r\n" terminated without regard
+ * to the current binary flag. Names may start with "/",
+ * then they represent full names (we don't produce such names),
+ * otherwise names are relative to current directory.
+ * Embedded "\n" are replaced by NULs. This is safe since names
+ * can never contain NUL.
+ */
handle_dir_common(0);
}
static void
handle_stat_file(void)
{
- handle_dir_common(3);
+ handle_dir_common(LONG_LISTING + USE_CTRL_CONN);
}
+/* This can be extended to handle MLST, as all info is available
+ * in struct stat for that:
+ * MLST file_name
+ * 250-Listing file_name
+ * type=file;size=4161;modify=19970214165800; /dir/dir/file_name
+ * 250 End
+ * Nano-doc:
+ * MLST [<file or dir name, "." assumed if not given>]
+ * Returned name should be either the same as requested, or fully qualified.
+ * If there was no parameter, return "" or (preferred) fully-qualified name.
+ * Returned "facts" (case is not important):
+ * size - size in octets
+ * modify - last modification time
+ * type - entry type (file,dir,OS.unix=block)
+ * (+ cdir and pdir types for MLSD)
+ * unique - unique id of file/directory (inode#)
+ * perm -
+ * a: can be appended to (APPE)
+ * d: can be deleted (RMD/DELE)
+ * f: can be renamed (RNFR)
+ * r: can be read (RETR)
+ * w: can be written (STOR)
+ * e: can CWD into this dir
+ * l: this dir can be listed (dir only!)
+ * c: can create files in this dir
+ * m: can create dirs in this dir (MKD)
+ * p: can delete files in this dir
+ * UNIX.mode - unix file mode
+ */
static void
-handle_size(void)
+handle_size_or_mdtm(int need_size)
{
struct stat statbuf;
- char buf[sizeof(STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n") + sizeof(off_t)*3];
+ struct tm broken_out;
+ char buf[(sizeof("NNN %"OFF_FMT"u\r\n") + sizeof(off_t) * 3)
+ | sizeof("NNN YYYYMMDDhhmmss\r\n")
+ ];
if (!G.ftp_arg
|| stat(G.ftp_arg, &statbuf) != 0
|| !S_ISREG(statbuf.st_mode)
) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- sprintf(buf, STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n", statbuf.st_size);
+ if (need_size) {
+ sprintf(buf, STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n", statbuf.st_size);
+ } else {
+ gmtime_r(&statbuf.st_mtime, &broken_out);
+ sprintf(buf, STR(FTP_STATFILE_OK)" %04u%02u%02u%02u%02u%02u\r\n",
+ broken_out.tm_year + 1900,
+ broken_out.tm_mon + 1,
+ broken_out.tm_mday,
+ broken_out.tm_hour,
+ broken_out.tm_min,
+ broken_out.tm_sec);
+ }
cmdio_write_raw(buf);
}
/* Upload commands */
-#if ENABLE_FEATURE_FTP_WRITE
+#if ENABLE_FEATURE_FTPD_WRITE
static void
handle_mkd(void)
{
if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- cmdio_write_ok(FTP_MKDIROK);
+ WRITE_OK(FTP_MKDIROK);
}
static void
handle_rmd(void)
{
if (!G.ftp_arg || rmdir(G.ftp_arg) != 0) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- cmdio_write_ok(FTP_RMDIROK);
+ WRITE_OK(FTP_RMDIROK);
}
static void
handle_dele(void)
{
if (!G.ftp_arg || unlink(G.ftp_arg) != 0) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- cmdio_write_ok(FTP_DELEOK);
+ WRITE_OK(FTP_DELEOK);
}
static void
{
free(G.rnfr_filename);
G.rnfr_filename = xstrdup(G.ftp_arg);
- cmdio_write_ok(FTP_RNFROK);
+ WRITE_OK(FTP_RNFROK);
}
static void
/* If we didn't get a RNFR, throw a wobbly */
if (G.rnfr_filename == NULL || G.ftp_arg == NULL) {
- cmdio_write_raw(STR(FTP_NEEDRNFR)" RNFR required first\r\n");
+ cmdio_write_raw(STR(FTP_NEEDRNFR)" Use RNFR first\r\n");
return;
}
G.rnfr_filename = NULL;
if (retval) {
- cmdio_write_error(FTP_FILEFAIL);
+ WRITE_ERR(FTP_FILEFAIL);
return;
}
- cmdio_write_ok(FTP_RENAMEOK);
+ WRITE_OK(FTP_RENAMEOK);
}
static void
handle_upload_common(int is_append, int is_unique)
{
- char *tempname = NULL;
- int trans_ret;
+ struct stat statbuf;
+ char *tempname;
+ off_t bytes_transferred;
+ off_t offset;
int local_file_fd;
int remote_fd;
- off_t offset;
offset = G.restart_pos;
G.restart_pos = 0;
- if (!data_transfer_checks_ok())
- return;
+ if (!port_or_pasv_was_seen())
+ return; /* port_or_pasv_was_seen emitted error response */
+ tempname = NULL;
local_file_fd = -1;
if (is_unique) {
tempname = xstrdup(" FILE: uniq.XXXXXX");
flags = O_WRONLY | O_CREAT;
local_file_fd = open(G.ftp_arg, flags, 0666);
}
- if (local_file_fd < 0) {
- cmdio_write_error(FTP_UPLOADFAIL);
+
+ if (local_file_fd < 0
+ || fstat(local_file_fd, &statbuf) != 0
+ || !S_ISREG(statbuf.st_mode)
+ ) {
+ free(tempname);
+ WRITE_ERR(FTP_UPLOADFAIL);
+ if (local_file_fd >= 0)
+ goto close_local_and_bail;
return;
}
-
- /* TODO: paranoia: fstat it, refuse to do anything if it's not a regular file */
+ G.local_file_fd = local_file_fd;
if (offset)
xlseek(local_file_fd, offset, SEEK_SET);
free(tempname);
if (remote_fd < 0)
- goto bail;
+ goto close_local_and_bail;
- trans_ret = bb_copyfd_eof(remote_fd, local_file_fd);
+ bytes_transferred = bb_copyfd_eof(remote_fd, local_file_fd);
close(remote_fd);
-
- if (trans_ret < 0)
- cmdio_write_error(FTP_BADSENDFILE);
+ if (bytes_transferred < 0)
+ WRITE_ERR(FTP_BADSENDFILE);
else
- cmdio_write_ok(FTP_TRANSFEROK);
+ WRITE_OK(FTP_TRANSFEROK);
- bail:
- port_pasv_cleanup();
+ close_local_and_bail:
close(local_file_fd);
+ G.local_file_fd = 0;
}
static void
G.restart_pos = 0;
handle_upload_common(0, 1);
}
-#endif /* ENABLE_FEATURE_FTP_WRITE */
+#endif /* ENABLE_FEATURE_FTPD_WRITE */
static uint32_t
cmdio_get_cmd_and_arg(void)
{
- size_t len;
+ int len;
uint32_t cmdval;
char *cmd;
+ alarm(G.timeout);
+
free(G.ftp_cmd);
- len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
- G.ftp_cmd = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
- if (!cmd)
- exit(0);
-
- len = strlen(cmd) - 1;
- while (len >= 0 && cmd[len] == '\r') {
- cmd[len] = '\0';
- len--;
+ {
+ /* Paranoia. Peer may send 1 gigabyte long cmd... */
+ /* Using separate len_on_stk instead of len optimizes
+ * code size (allows len to be in CPU register) */
+ size_t len_on_stk = 8 * 1024;
+ G.ftp_cmd = cmd = xmalloc_fgets_str_len(stdin, "\r\n", &len_on_stk);
+ if (!cmd)
+ exit(0);
+ len = len_on_stk;
}
- G.ftp_arg = strchr(cmd, ' ');
- if (G.ftp_arg != NULL) {
- *G.ftp_arg = '\0';
- G.ftp_arg++;
+ /* De-escape telnet: 0xff,0xff => 0xff */
+ /* RFC959 says that ABOR, STAT, QUIT may be sent even during
+ * data transfer, and may be preceded by telnet's "Interrupt Process"
+ * code (two-byte sequence 255,244) and then by telnet "Synch" code
+ * 255,242 (byte 242 is sent with TCP URG bit using send(MSG_OOB)
+ * and may generate SIGURG on our side. See RFC854).
+ * So far we don't support that (may install SIGURG handler if we'd want to),
+ * but we need to at least remove 255,xxx pairs. lftp sends those. */
+ /* Then de-escape FTP: NUL => '\n' */
+ /* Testing for \xff:
+ * Create file named '\xff': echo Hello >`echo -ne "\xff"`
+ * Try to get it: ftpget -v 127.0.0.1 Eff `echo -ne "\xff\xff"`
+ * (need "\xff\xff" until ftpget applet is fixed to do escaping :)
+ * Testing for embedded LF:
+ * LF_HERE=`echo -ne "LF\nHERE"`
+ * echo Hello >"$LF_HERE"
+ * ftpget -v 127.0.0.1 LF_HERE "$LF_HERE"
+ */
+ {
+ int dst, src;
+
+ /* Strip "\r\n" if it is there */
+ if (len != 0 && cmd[len - 1] == '\n') {
+ len--;
+ if (len != 0 && cmd[len - 1] == '\r')
+ len--;
+ cmd[len] = '\0';
+ }
+ src = strchrnul(cmd, 0xff) - cmd;
+ /* 99,99% there are neither NULs nor 255s and src == len */
+ if (src < len) {
+ dst = src;
+ do {
+ if ((unsigned char)(cmd[src]) == 255) {
+ src++;
+ /* 255,xxx - skip 255 */
+ if ((unsigned char)(cmd[src]) != 255) {
+ /* 255,!255 - skip both */
+ src++;
+ continue;
+ }
+ /* 255,255 - retain one 255 */
+ }
+ /* NUL => '\n' */
+ cmd[dst++] = cmd[src] ? cmd[src] : '\n';
+ src++;
+ } while (src < len);
+ cmd[dst] = '\0';
+ }
}
+
+ if (G.verbose > 1)
+ verbose_log(cmd);
+
+ G.ftp_arg = strchr(cmd, ' ');
+ if (G.ftp_arg != NULL)
+ *G.ftp_arg++ = '\0';
+
+ /* Uppercase and pack into uint32_t first word of the command */
cmdval = 0;
while (*cmd)
cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20);
return cmdval;
}
+#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)
+enum {
+ const_ALLO = mk_const4('A', 'L', 'L', 'O'),
+ const_APPE = mk_const4('A', 'P', 'P', 'E'),
+ const_CDUP = mk_const4('C', 'D', 'U', 'P'),
+ const_CWD = mk_const3('C', 'W', 'D'),
+ const_DELE = mk_const4('D', 'E', 'L', 'E'),
+ const_EPSV = mk_const4('E', 'P', 'S', 'V'),
+ const_FEAT = mk_const4('F', 'E', 'A', 'T'),
+ const_HELP = mk_const4('H', 'E', 'L', 'P'),
+ const_LIST = mk_const4('L', 'I', 'S', 'T'),
+ const_MDTM = mk_const4('M', 'D', 'T', 'M'),
+ const_MKD = mk_const3('M', 'K', 'D'),
+ const_MODE = mk_const4('M', 'O', 'D', 'E'),
+ const_NLST = mk_const4('N', 'L', 'S', 'T'),
+ const_NOOP = mk_const4('N', 'O', 'O', 'P'),
+ const_PASS = mk_const4('P', 'A', 'S', 'S'),
+ const_PASV = mk_const4('P', 'A', 'S', 'V'),
+ const_PORT = mk_const4('P', 'O', 'R', 'T'),
+ const_PWD = mk_const3('P', 'W', 'D'),
+ /* Same as PWD. Reportedly used by windows ftp client */
+ const_XPWD = mk_const4('X', 'P', 'W', 'D'),
+ const_QUIT = mk_const4('Q', 'U', 'I', 'T'),
+ const_REST = mk_const4('R', 'E', 'S', 'T'),
+ const_RETR = mk_const4('R', 'E', 'T', 'R'),
+ const_RMD = mk_const3('R', 'M', 'D'),
+ const_RNFR = mk_const4('R', 'N', 'F', 'R'),
+ const_RNTO = mk_const4('R', 'N', 'T', 'O'),
+ const_SIZE = mk_const4('S', 'I', 'Z', 'E'),
+ const_STAT = mk_const4('S', 'T', 'A', 'T'),
+ const_STOR = mk_const4('S', 'T', 'O', 'R'),
+ const_STOU = mk_const4('S', 'T', 'O', 'U'),
+ const_STRU = mk_const4('S', 'T', 'R', 'U'),
+ const_SYST = mk_const4('S', 'Y', 'S', 'T'),
+ 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),
+#endif
+ BIT_A = (!BB_MMU) * 2,
+ OPT_A = (1 << (BIT_A + 0)),
+ OPT_v = (1 << (BIT_A + 1)),
+ OPT_S = (1 << (BIT_A + 2)),
+ OPT_w = (1 << (BIT_A + 3)) * ENABLE_FEATURE_FTPD_WRITE,
+};
+
int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int ftpd_main(int argc, char **argv)
+int ftpd_main(int argc UNUSED_PARAM, char **argv)
{
+#if ENABLE_FEATURE_FTPD_AUTHENTICATION
+ struct passwd *pw = NULL;
+ char *anon_opt = NULL;
+#endif
+ unsigned abs_timeout;
+ unsigned verbose_S;
smallint opts;
- opts = getopt32(argv, "l1v" USE_FEATURE_FTP_WRITE("w"));
+ INIT_G();
+ abs_timeout = 1 * 60 * 60;
+ verbose_S = 0;
+ G.timeout = 2 * 60;
+#if BB_MMU
+ opts = getopt32(argv, "^" "AvS" IF_FEATURE_FTPD_WRITE("w")
+ "t:+T:+" IF_FEATURE_FTPD_AUTHENTICATION("a:")
+ "\0" "vv:SS",
+ &G.timeout, &abs_timeout, IF_FEATURE_FTPD_AUTHENTICATION(&anon_opt,)
+ &G.verbose, &verbose_S
+ );
+#else
+ opts = getopt32(argv, "^" "l1AvS" IF_FEATURE_FTPD_WRITE("w")
+ "t:+T:+" IF_FEATURE_FTPD_AUTHENTICATION("a:")
+ "\0" "vv:SS",
+ &G.timeout, &abs_timeout, IF_FEATURE_FTPD_AUTHENTICATION(&anon_opt,)
+ &G.verbose, &verbose_S
+ );
if (opts & (OPT_l|OPT_1)) {
- /* Our secret backdoor to ls */
- xchdir(argv[2]);
- argv[2] = (char*)"--";
- return ls_main(argc, argv);
+ /* Our secret backdoor to ls: see popen_ls() */
+ if (fchdir(3) != 0)
+ _exit(127);
+ /* memset(&G, 0, sizeof(G)); - ls_main does it */
+ /* NB: in this case -A has a different meaning: like "ls -A" */
+ return ls_main(/*argc_unused*/ 0, argv);
}
-
- INIT_G();
+#endif
+ if (G.verbose < verbose_S)
+ G.verbose = verbose_S;
+ if (abs_timeout | G.timeout) {
+ if (abs_timeout == 0)
+ abs_timeout = INT_MAX;
+ G.end_time = monotonic_sec() + abs_timeout;
+ if (G.timeout > abs_timeout)
+ G.timeout = abs_timeout;
+ }
+ strcpy(G.msg_ok + 4, MSG_OK );
+ strcpy(G.msg_err + 4, MSG_ERR);
G.local_addr = get_sock_lsa(STDIN_FILENO);
if (!G.local_addr) {
* failure */
}
- openlog(applet_name, LOG_PID, LOG_DAEMON);
- logmode |= LOGMODE_SYSLOG;
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(".");
+ logmode = LOGMODE_NONE;
+ if (opts & OPT_S) {
+ /* LOG_NDELAY is needed since we may chroot later */
+ openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
+ logmode |= LOGMODE_SYSLOG;
}
+ if (logmode)
+ applet_name = xasprintf("%s[%u]", applet_name, (int)getpid());
//umask(077); - admin can set umask before starting us
- /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */
- signal(SIGPIPE, SIG_IGN);
+ /* Signals */
+ bb_signals(0
+ /* We'll always take EPIPE rather than a rude signal, thanks */
+ + (1 << SIGPIPE)
+ /* LIST command spawns chilren. Prevent zombies */
+ + (1 << SIGCHLD)
+ , SIG_IGN);
/* Set up options on the command socket (do we need these all? why?) */
- setsockopt(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY, &const_int_1, sizeof(const_int_1));
- setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
- setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &const_int_1, sizeof(const_int_1));
+ setsockopt_1(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY);
+ setsockopt_keepalive(STDIN_FILENO);
+ /* Telnet protocol over command link may send "urgent" data,
+ * we prefer it to be received in the "normal" data stream: */
+ setsockopt_1(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE);
- cmdio_write_ok(FTP_GREET);
+ WRITE_OK(FTP_GREET);
+ signal(SIGALRM, timeout_handler);
-#ifdef IF_WE_WANT_TO_REQUIRE_LOGIN
- {
- smallint user_was_specified = 0;
+#if ENABLE_FEATURE_FTPD_AUTHENTICATION
+ if (!(opts & OPT_A)) {
while (1) {
uint32_t cmdval = cmdio_get_cmd_and_arg();
-
if (cmdval == const_USER) {
- if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0)
- cmdio_write_raw(STR(FTP_LOGINERR)" Server is anonymous only\r\n");
- else {
- user_was_specified = 1;
- cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify the password\r\n");
+ if (anon_opt && strcmp(G.ftp_arg, "anonymous") == 0) {
+ pw = getpwnam(anon_opt);
+ if (pw)
+ break; /* does not even ask for password */
}
+ pw = getpwnam(G.ftp_arg);
+ cmdio_write_raw(STR(FTP_GIVEPWORD)" Specify password\r\n");
} else if (cmdval == const_PASS) {
- if (user_was_specified)
- break;
- cmdio_write_raw(STR(FTP_NEEDUSER)" Login with USER\r\n");
+ if (check_password(pw, G.ftp_arg) > 0) {
+ break; /* login success */
+ }
+ cmdio_write_raw(STR(FTP_LOGINERR)" Login failed\r\n");
+ pw = NULL;
} else if (cmdval == const_QUIT) {
- cmdio_write_ok(FTP_GOODBYE);
+ WRITE_OK(FTP_GOODBYE);
return 0;
} else {
- cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER and PASS\r\n");
+ cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER+PASS\r\n");
}
}
+ WRITE_OK(FTP_LOGINOK);
}
- cmdio_write_ok(FTP_LOGINOK);
+#endif
+
+ /* Do this after auth, else /etc/passwd is not accessible */
+#if !BB_MMU
+ G.root_fd = -1;
+#endif
+ argv += optind;
+ if (argv[0]) {
+ const char *basedir = argv[0];
+#if !BB_MMU
+ G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY);
+ close_on_exec_on(G.root_fd);
+#endif
+ if (chroot(basedir) == 0)
+ basedir = "/";
+#if !BB_MMU
+ else {
+ close(G.root_fd);
+ G.root_fd = -1;
+ }
+#endif
+ /*
+ * If chroot failed, assume that we aren't root,
+ * and at least chdir to the specified DIR
+ * (older versions were dying with error message).
+ * If chroot worked, move current dir to new "/":
+ */
+ xchdir(basedir);
+ }
+
+#if ENABLE_FEATURE_FTPD_AUTHENTICATION
+ if (pw)
+ change_identity(pw);
+ /* else: -A is in effect */
#endif
/* RFC-959 Section 5.1
uint32_t cmdval = cmdio_get_cmd_and_arg();
if (cmdval == const_QUIT) {
- cmdio_write_ok(FTP_GOODBYE);
+ WRITE_OK(FTP_GOODBYE);
return 0;
}
else if (cmdval == const_USER)
- cmdio_write_ok(FTP_GIVEPWORD);
+ /* This would mean "ok, now give me PASS". */
+ /*WRITE_OK(FTP_GIVEPWORD);*/
+ /* vsftpd can be configured to not require that,
+ * and this also saves one roundtrip:
+ */
+ WRITE_OK(FTP_LOGINOK);
else if (cmdval == const_PASS)
- cmdio_write_ok(FTP_LOGINOK);
+ WRITE_OK(FTP_LOGINOK);
else if (cmdval == const_NOOP)
- cmdio_write_ok(FTP_NOOPOK);
+ WRITE_OK(FTP_NOOPOK);
else if (cmdval == const_TYPE)
- cmdio_write_ok(FTP_TYPEOK);
+ WRITE_OK(FTP_TYPEOK);
else if (cmdval == const_STRU)
- cmdio_write_ok(FTP_STRUOK);
+ WRITE_OK(FTP_STRUOK);
else if (cmdval == const_MODE)
- cmdio_write_ok(FTP_MODEOK);
+ WRITE_OK(FTP_MODEOK);
else if (cmdval == const_ALLO)
- cmdio_write_ok(FTP_ALLOOK);
+ WRITE_OK(FTP_ALLOOK);
else if (cmdval == const_SYST)
cmdio_write_raw(STR(FTP_SYSTOK)" UNIX Type: L8\r\n");
- else if (cmdval == const_PWD)
+ else if (cmdval == const_PWD || cmdval == const_XPWD)
handle_pwd();
else if (cmdval == const_CWD)
handle_cwd();
else if (cmdval == const_CDUP) /* cd .. */
handle_cdup();
- else if (cmdval == const_HELP)
- handle_help();
+ /* HELP is nearly useless, but we can reuse FEAT for it */
+ /* lftp uses FEAT */
+ else if (cmdval == const_HELP || cmdval == const_FEAT)
+ handle_feat(cmdval == const_HELP
+ ? STRNUM32(FTP_HELP)
+ : STRNUM32(FTP_STATOK)
+ );
else if (cmdval == const_LIST) /* ls -l */
handle_list();
else if (cmdval == const_NLST) /* "name list", bare ls */
handle_nlst();
- else if (cmdval == const_SIZE)
- handle_size();
+ /* SIZE is crucial for wget's download indicator etc */
+ /* Mozilla, lftp use MDTM (presumably for caching) */
+ else if (cmdval == const_SIZE || cmdval == const_MDTM)
+ handle_size_or_mdtm(cmdval == const_SIZE);
else if (cmdval == const_STAT) {
if (G.ftp_arg == NULL)
handle_stat();
handle_port();
else if (cmdval == const_REST)
handle_rest();
-#if ENABLE_FEATURE_FTP_WRITE
+#if ENABLE_FEATURE_FTPD_WRITE
else if (opts & OPT_w) {
if (cmdval == const_STOR)
handle_stor();
handle_appe();
else if (cmdval == const_STOU) /* "store unique" */
handle_stou();
+ else
+ goto bad_cmd;
}
#endif
#if 0
else {
/* Which unsupported commands were seen in the wild?
* (doesn't necessarily mean "we must support them")
- * lftp 3.6.3: FEAT - is it useful?
- * MDTM - works fine without it anyway
+ * foo 1.2.3: XXXX - comment
*/
+#if ENABLE_FEATURE_FTPD_WRITE
+ bad_cmd:
+#endif
cmdio_write_raw(STR(FTP_BADCMD)" Unknown command\r\n");
}
}
projects / oweals / busybox.git / blobdiff