ftpd: added -A option to disable all authentication, closes 10921

function                                             old     new   delta
packed_usage                                       32745   32777     +32
ftpd_main                                           2162    2156      -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 32/-6)              Total: 26 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 40 insertions, 29 deletions

diff --git a/networking/ftpd.c b/networking/ftpd.c
index e289a6051..4ecdb4121 100644
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -57,7 +57,7 @@
 //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. Accesses by clients occur under ftpd's UID.\n"
+//usage:       "Anonymous FTP server. Client access occurs under ftpd's UID.\n"
 //usage:        )
 //usage:        IF_FEATURE_FTPD_AUTHENTICATION(
 //usage:       "FTP server. "
@@ -66,9 +66,11 @@
 //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\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"
 //usage:     "\n        -a USER Enable 'anonymous' login and map it to USER"
 //usage:        )
 //usage:     "\n        -v      Log errors to stderr. -vv: verbose log"
@@ -1157,9 +1159,12 @@ enum {
         OPT_1 = (1 << 1),
         OPT_A = (1 << 2),
 #endif
-        OPT_v = (1 << ((!BB_MMU) * 3 + 0)),
-        OPT_S = (1 << ((!BB_MMU) * 3 + 1)),
-        OPT_w = (1 << ((!BB_MMU) * 3 + 2)) * ENABLE_FEATURE_FTPD_WRITE,
+        BIT_v =        (!BB_MMU) * 3,
+        OPT_v = (1 << (BIT_v + 0)),
+        OPT_S = (1 << (BIT_v + 1)),
+        OPT_w = (1 << (BIT_v + 2)) * ENABLE_FEATURE_FTPD_WRITE,
+        BIT_A =        BIT_v + 2 + ENABLE_FEATURE_FTPD_WRITE,
+        OPT_A = (1 << (BIT_A + 0)) * ENABLE_FEATURE_FTPD_AUTHENTICATION,
 };
 
 int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -1180,14 +1185,16 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
         G.timeout = 2 * 60;
 #if BB_MMU
         opts = getopt32(argv, "^"    "vS"
-                IF_FEATURE_FTPD_WRITE("w") "t:+T:+" IF_FEATURE_FTPD_AUTHENTICATION("a:")
+                IF_FEATURE_FTPD_WRITE("w") IF_FEATURE_FTPD_AUTHENTICATION("A")
+                "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:")
+                IF_FEATURE_FTPD_WRITE("w") IF_FEATURE_FTPD_AUTHENTICATION("A")
+                "t:+T:+" IF_FEATURE_FTPD_AUTHENTICATION("a:")
                 "\0" "vv:SS",
                 &G.timeout, &abs_timeout, IF_FEATURE_FTPD_AUTHENTICATION(&anon_opt,)
                 &G.verbose, &verbose_S
@@ -1254,30 +1261,32 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
         signal(SIGALRM, timeout_handler);
 
 #if ENABLE_FEATURE_FTPD_AUTHENTICATION
-        while (1) {
-                uint32_t cmdval = cmdio_get_cmd_and_arg();
-                if (cmdval == const_USER) {
-                        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 (check_password(pw, G.ftp_arg) > 0) {
-                                break;  /* login success */
+        if (!(opts & OPT_A)) {
+                while (1) {
+                        uint32_t cmdval = cmdio_get_cmd_and_arg();
+                        if (cmdval == const_USER) {
+                                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 (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) {
+                                WRITE_OK(FTP_GOODBYE);
+                                return 0;
+                        } else {
+                                cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER+PASS\r\n");
                         }
-                        cmdio_write_raw(STR(FTP_LOGINERR)" Login failed\r\n");
-                        pw = NULL;
-                } else if (cmdval == const_QUIT) {
-                        WRITE_OK(FTP_GOODBYE);
-                        return 0;
-                } else {
-                        cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER+PASS\r\n");
                 }
+                WRITE_OK(FTP_LOGINOK);
         }
-        WRITE_OK(FTP_LOGINOK);
 #endif
 
         /* Do this after auth, else /etc/passwd is not accessible */
@@ -1309,7 +1318,9 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
         }
 
 #if ENABLE_FEATURE_FTPD_AUTHENTICATION
-        change_identity(pw);
+        if (pw)
+                change_identity(pw);
+        /* else: -A is in effect */
 #endif
 
         /* RFC-959 Section 5.1