Makefile.flags: restrict Wno-constant-logical-operand and Wno-string-plus-int options...

[oweals/busybox.git] / networking / ftpd.c

diff --git a/networking/ftpd.c b/networking/ftpd.c
index e289a60517156d52c59f8f4bcf946719760b937d..6ca231c90b203d4ee54a6fb7fe46c5188b61441b 100644 (file)
--- 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 +66,15 @@
 //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"
+//
+// 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"
@@ -1155,11 +1161,12 @@ enum {
 #if !BB_MMU
        OPT_l = (1 << 0),
        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_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;
@@ -1179,24 +1186,25 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
        verbose_S = 0;
        G.timeout = 2 * 60;
 #if BB_MMU
-       opts = getopt32(argv, "^"    "vS"
-               IF_FEATURE_FTPD_WRITE("w") "t:+T:+" IF_FEATURE_FTPD_AUTHENTICATION("a:")
+       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:")
+       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 */
+               /* 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);
        }
 #endif
@@ -1254,30 +1262,32 @@ 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 +1319,9 @@ 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