ash: fix for read $IFS splitting. Closes bug 235

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

diff --git a/networking/telnetd.c b/networking/telnetd.c
index 540387f1a985a4ad3b4fd5656174ac54b2c986c4..b0a1cc4d8632a71d6713aa967f98b411827b4c9c 100644 (file)
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -211,8 +211,10 @@ static size_t iac_safe_write(int fd, const char *buf, size_t count)
 enum {
        OPT_WATCHCHILD = (1 << 2), /* -K */
        OPT_INETD      = (1 << 3) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -i */
-       OPT_PORT       = (1 << 4) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -p */
+       OPT_PORT       = (1 << 4) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -p PORT */
        OPT_FOREGROUND = (1 << 6) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -F */
+       OPT_SYSLOG     = (1 << 7) * ENABLE_FEATURE_TELNETD_INETD_WAIT, /* -S */
+       OPT_WAIT       = (1 << 8) * ENABLE_FEATURE_TELNETD_INETD_WAIT, /* -w SEC */
 };
 
 static struct tsession *
@@ -286,7 +288,7 @@ make_new_session(
                /*ts->size2 = 0;*/
        }
 
-       fflush(NULL); /* flush all streams */
+       fflush_all();
        pid = vfork(); /* NOMMU-friendly */
        if (pid < 0) {
                free(ts);
@@ -329,7 +331,7 @@ make_new_session(
        /*termbuf.c_lflag &= ~ICANON;*/
        tcsetattr_stdin_TCSANOW(&termbuf);
 
-       /* Uses FILE-based I/O to stdout, but does fflush(stdout),
+       /* Uses FILE-based I/O to stdout, but does fflush_all(),
         * so should be safe with vfork.
         * I fear, though, that some users will have ridiculously big
         * issue files, and they may block writing to fd 1,
@@ -438,24 +440,29 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
        struct tsession *ts;
 #if ENABLE_FEATURE_TELNETD_STANDALONE
 #define IS_INETD (opt & OPT_INETD)
-       int master_fd = master_fd; /* be happy, gcc */
-       unsigned portnbr = 23;
+       int master_fd = master_fd; /* for compiler */
+       int sec_linger = sec_linger;
        char *opt_bindaddr = NULL;
        char *opt_portnbr;
 #else
        enum {
                IS_INETD = 1,
                master_fd = -1,
-               portnbr = 23,
        };
 #endif
        INIT_G();
 
+       /* -w NUM, and implies -F. -w and -i don't mix */
+       IF_FEATURE_TELNETD_INETD_WAIT(opt_complementary = "wF:w+:i--w:w--i";)
        /* Even if !STANDALONE, we accept (and ignore) -i, thus people
         * don't need to guess whether it's ok to pass -i to us */
-       opt = getopt32(argv, "f:l:Ki" IF_FEATURE_TELNETD_STANDALONE("p:b:F"),
+       opt = getopt32(argv, "f:l:Ki"
+                       IF_FEATURE_TELNETD_STANDALONE("p:b:F")
+                       IF_FEATURE_TELNETD_INETD_WAIT("Sw:"),
                        &G.issuefile, &G.loginpath
-                       IF_FEATURE_TELNETD_STANDALONE(, &opt_portnbr, &opt_bindaddr));
+                       IF_FEATURE_TELNETD_STANDALONE(, &opt_portnbr, &opt_bindaddr)
+                       IF_FEATURE_TELNETD_INETD_WAIT(, &sec_linger)
+       );
        if (!IS_INETD /*&& !re_execed*/) {
                /* inform that we start in standalone mode?
                 * May be useful when people forget to give -i */
@@ -467,32 +474,30 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
                }
        }
        /* Redirect log to syslog early, if needed */
-       if (IS_INETD || !(opt & OPT_FOREGROUND)) {
+       if (IS_INETD || (opt & OPT_SYSLOG) || !(opt & OPT_FOREGROUND)) {
                openlog(applet_name, LOG_PID, LOG_DAEMON);
                logmode = LOGMODE_SYSLOG;
        }
-       IF_FEATURE_TELNETD_STANDALONE(
-               if (opt & OPT_PORT)
-                       portnbr = xatou16(opt_portnbr);
-       );
-
-       /* Used to check access(G.loginpath, X_OK) here. Pointless.
-        * exec will do this for us for free later. */
-
 #if ENABLE_FEATURE_TELNETD_STANDALONE
        if (IS_INETD) {
                G.sessions = make_new_session(0);
                if (!G.sessions) /* pty opening or vfork problem, exit */
-                       return 1; /* make_new_session prints error message */
+                       return 1; /* make_new_session printed error message */
        } else {
-               master_fd = create_and_bind_stream_or_die(opt_bindaddr, portnbr);
-               xlisten(master_fd, 1);
+               master_fd = 0;
+               if (!(opt & OPT_WAIT)) {
+                       unsigned portnbr = 23;
+                       if (opt & OPT_PORT)
+                               portnbr = xatou16(opt_portnbr);
+                       master_fd = create_and_bind_stream_or_die(opt_bindaddr, portnbr);
+                       xlisten(master_fd, 1);
+               }
                close_on_exec_on(master_fd);
        }
 #else
        G.sessions = make_new_session();
        if (!G.sessions) /* pty opening or vfork problem, exit */
-               return 1; /* make_new_session prints error message */
+               return 1; /* make_new_session printed error message */
 #endif
 
        /* We don't want to die if just one session is broken */
@@ -556,7 +561,20 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
                        G.maxfd = master_fd;
        }
 
-       count = select(G.maxfd + 1, &rdfdset, &wrfdset, NULL, NULL);
+       {
+               struct timeval *tv_ptr = NULL;
+#if ENABLE_FEATURE_TELNETD_INETD_WAIT
+               struct timeval tv;
+               if ((opt & OPT_WAIT) && !G.sessions) {
+                       tv.tv_sec = sec_linger;
+                       tv.tv_usec = 0;
+                       tv_ptr = &tv;
+               }
+#endif
+               count = select(G.maxfd + 1, &rdfdset, &wrfdset, NULL, tv_ptr);
+       }
+       if (count == 0) /* "telnetd -w SEC" timed out */
+               return 0;
        if (count < 0)
                goto again; /* EINTR or ENOMEM */