telnetd: correctly output 0xff char. ~100 bytes.
authorDenis Vlasenko <vda.linux@googlemail.com>
Tue, 11 Nov 2008 02:56:39 +0000 (02:56 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Tue, 11 Nov 2008 02:56:39 +0000 (02:56 -0000)
telnet: fix some atrocious names and style. no code changes

networking/telnet.c
networking/telnetd.c

index 5d7ecef3bf40f3b563caccf32bc2367d64e16ba9..ba6f2fb8326cef6bf1efc949413f2dc85a37172d 100644 (file)
@@ -93,7 +93,7 @@ static void will_charmode(void);
 static void telopt(byte c);
 static int subneg(byte c);
 
-static void iacflush(void)
+static void iac_flush(void)
 {
        write(netfd, G.iacbuf, G.iaclen);
        G.iaclen = 0;
@@ -108,11 +108,11 @@ static void doexit(int ev)
        exit(ev);
 }
 
-static void conescape(void)
+static void con_escape(void)
 {
        char b;
 
-       if (bb_got_signal)      /* came from line  mode... go raw */
+       if (bb_got_signal) /* came from line mode... go raw */
                rawmode();
 
        write_str(1, "\r\nConsole escape. Commands are:\r\n\n"
@@ -128,13 +128,13 @@ static void conescape(void)
        case 'l':
                if (!bb_got_signal) {
                        do_linemode();
-                       goto rrturn;
+                       goto ret;
                }
                break;
        case 'c':
                if (bb_got_signal) {
                        will_charmode();
-                       goto rrturn;
+                       goto ret;
                }
                break;
        case 'z':
@@ -150,13 +150,12 @@ static void conescape(void)
 
        if (bb_got_signal)
                cookmode();
-
- rrturn:
+ ret:
        bb_got_signal = 0;
 
 }
 
-static void handlenetoutput(int len)
+static void handle_net_output(int len)
 {
        /* here we could do smart tricks how to handle 0xFF:s in output
         * stream like writing twice every sequence of FF:s (thus doing
@@ -169,19 +168,19 @@ static void handlenetoutput(int len)
         * first - I cannot use programs like sz/rz
         * second - the 0x0D is sent as one character and if the next
         *      char is 0x0A then it's eaten by a server side.
-        * third - whay doy you have to make 'many write()s'?
+        * third - why do you have to make 'many write()s'?
         *      I don't understand.
-        * So I implemented it. It's realy useful for me. I hope that
-        * others people will find it interesting too.
+        * So I implemented it. It's really useful for me. I hope that
+        * other people will find it interesting too.
         */
 
        int i, j;
-       byte * p = (byte*)G.buf;
+       byte *p = (byte*)G.buf;
        byte outbuf[4*DATABUFSIZE];
 
        for (i = len, j = 0; i > 0; i--, p++) {
                if (*p == 0x1d) {
-                       conescape();
+                       con_escape();
                        return;
                }
                outbuf[j++] = *p;
@@ -194,7 +193,7 @@ static void handlenetoutput(int len)
                write(netfd, outbuf, j);
 }
 
-static void handlenetinput(int len)
+static void handle_net_input(int len)
 {
        int i;
        int cstart = 0;
@@ -207,51 +206,54 @@ static void handlenetinput(int len)
                                cstart = i;
                                G.telstate = TS_IAC;
                        }
-               } else
-                       switch (G.telstate) {
-                       case TS_0:
-                               if (c == IAC)
-                                       G.telstate = TS_IAC;
-                               else
-                                       G.buf[cstart++] = c;
-                               break;
+                       continue;
+               }
+               switch (G.telstate) {
+               case TS_0:
+                       if (c == IAC)
+                               G.telstate = TS_IAC;
+                       else
+                               G.buf[cstart++] = c;
+                       break;
 
-                       case TS_IAC:
-                               if (c == IAC) { /* IAC IAC -> 0xFF */
-                                       G.buf[cstart++] = c;
-                                       G.telstate = TS_0;
-                                       break;
-                               }
-                               /* else */
-                               switch (c) {
-                               case SB:
-                                       G.telstate = TS_SUB1;
-                                       break;
-                               case DO:
-                               case DONT:
-                               case WILL:
-                               case WONT:
-                                       G.telwish =  c;
-                                       G.telstate = TS_OPT;
-                                       break;
-                               default:
-                                       G.telstate = TS_0;      /* DATA MARK must be added later */
-                               }
-                               break;
-                       case TS_OPT: /* WILL, WONT, DO, DONT */
-                               telopt(c);
+               case TS_IAC:
+                       if (c == IAC) { /* IAC IAC -> 0xFF */
+                               G.buf[cstart++] = c;
                                G.telstate = TS_0;
                                break;
-                       case TS_SUB1: /* Subnegotiation */
-                       case TS_SUB2: /* Subnegotiation */
-                               if (subneg(c))
-                                       G.telstate = TS_0;
+                       }
+                       /* else */
+                       switch (c) {
+                       case SB:
+                               G.telstate = TS_SUB1;
+                               break;
+                       case DO:
+                       case DONT:
+                       case WILL:
+                       case WONT:
+                               G.telwish =  c;
+                               G.telstate = TS_OPT;
                                break;
+                       default:
+                               G.telstate = TS_0;      /* DATA MARK must be added later */
                        }
+                       break;
+               case TS_OPT: /* WILL, WONT, DO, DONT */
+                       telopt(c);
+                       G.telstate = TS_0;
+                       break;
+               case TS_SUB1: /* Subnegotiation */
+               case TS_SUB2: /* Subnegotiation */
+                       if (subneg(c))
+                               G.telstate = TS_0;
+                       break;
+               }
        }
        if (G.telstate) {
-               if (G.iaclen) iacflush();
-               if (G.telstate == TS_0) G.telstate = 0;
+               if (G.iaclen)
+                       iac_flush();
+               if (G.telstate == TS_0)
+                       G.telstate = 0;
                len = cstart;
        }
 
@@ -259,87 +261,87 @@ static void handlenetinput(int len)
                write(STDOUT_FILENO, G.buf, len);
 }
 
-static void putiac(int c)
+static void put_iac(int c)
 {
        G.iacbuf[G.iaclen++] = c;
 }
 
-static void putiac2(byte wwdd, byte c)
+static void put_iac2(byte wwdd, byte c)
 {
        if (G.iaclen + 3 > IACBUFSIZE)
-               iacflush();
+               iac_flush();
 
-       putiac(IAC);
-       putiac(wwdd);
-       putiac(c);
+       put_iac(IAC);
+       put_iac(wwdd);
+       put_iac(c);
 }
 
 #if ENABLE_FEATURE_TELNET_TTYPE
-static void putiac_subopt(byte c, char *str)
+static void put_iac_subopt(byte c, char *str)
 {
-       int     len = strlen(str) + 6;   // ( 2 + 1 + 1 + strlen + 2 )
+       int len = strlen(str) + 6;   // ( 2 + 1 + 1 + strlen + 2 )
 
        if (G.iaclen + len > IACBUFSIZE)
-               iacflush();
+               iac_flush();
 
-       putiac(IAC);
-       putiac(SB);
-       putiac(c);
-       putiac(0);
+       put_iac(IAC);
+       put_iac(SB);
+       put_iac(c);
+       put_iac(0);
 
        while (*str)
-               putiac(*str++);
+               put_iac(*str++);
 
-       putiac(IAC);
-       putiac(SE);
+       put_iac(IAC);
+       put_iac(SE);
 }
 #endif
 
 #if ENABLE_FEATURE_TELNET_AUTOLOGIN
-static void putiac_subopt_autologin(void)
+static void put_iac_subopt_autologin(void)
 {
        int len = strlen(G.autologin) + 6;      // (2 + 1 + 1 + strlen + 2)
        const char *user = "USER";
 
        if (G.iaclen + len > IACBUFSIZE)
-               iacflush();
+               iac_flush();
 
-       putiac(IAC);
-       putiac(SB);
-       putiac(TELOPT_NEW_ENVIRON);
-       putiac(TELQUAL_IS);
-       putiac(NEW_ENV_VAR);
+       put_iac(IAC);
+       put_iac(SB);
+       put_iac(TELOPT_NEW_ENVIRON);
+       put_iac(TELQUAL_IS);
+       put_iac(NEW_ENV_VAR);
 
        while (*user)
-               putiac(*user++);
+               put_iac(*user++);
 
-       putiac(NEW_ENV_VALUE);
+       put_iac(NEW_ENV_VALUE);
 
        while (*G.autologin)
-               putiac(*G.autologin++);
+               put_iac(*G.autologin++);
 
-       putiac(IAC);
-       putiac(SE);
+       put_iac(IAC);
+       put_iac(SE);
 }
 #endif
 
 #if ENABLE_FEATURE_AUTOWIDTH
-static void putiac_naws(byte c, int x, int y)
+static void put_iac_naws(byte c, int x, int y)
 {
        if (G.iaclen + 9 > IACBUFSIZE)
-               iacflush();
+               iac_flush();
 
-       putiac(IAC);
-       putiac(SB);
-       putiac(c);
+       put_iac(IAC);
+       put_iac(SB);
+       put_iac(c);
 
-       putiac((x >> 8) & 0xff);
-       putiac(x & 0xff);
-       putiac((y >> 8) & 0xff);
-       putiac(y & 0xff);
+       put_iac((x >> 8) & 0xff);
+       put_iac(x & 0xff);
+       put_iac((y >> 8) & 0xff);
+       put_iac(y & 0xff);
 
-       putiac(IAC);
-       putiac(SE);
+       put_iac(IAC);
+       put_iac(SE);
 }
 #endif
 
@@ -368,9 +370,9 @@ static void will_charmode(void)
        G.telflags |= (UF_ECHO | UF_SGA);
        setConMode();
 
-       putiac2(DO, TELOPT_ECHO);
-       putiac2(DO, TELOPT_SGA);
-       iacflush();
+       put_iac2(DO, TELOPT_ECHO);
+       put_iac2(DO, TELOPT_SGA);
+       iac_flush();
 }
 
 static void do_linemode(void)
@@ -379,24 +381,24 @@ static void do_linemode(void)
        G.telflags &= ~(UF_ECHO | UF_SGA);
        setConMode();
 
-       putiac2(DONT, TELOPT_ECHO);
-       putiac2(DONT, TELOPT_SGA);
-       iacflush();
+       put_iac2(DONT, TELOPT_ECHO);
+       put_iac2(DONT, TELOPT_SGA);
+       iac_flush();
 }
 
 static void to_notsup(char c)
 {
        if (G.telwish == WILL)
-               putiac2(DONT, c);
+               put_iac2(DONT, c);
        else if (G.telwish == DO)
-               putiac2(WONT, c);
+               put_iac2(WONT, c);
 }
 
 static void to_echo(void)
 {
        /* if server requests ECHO, don't agree */
        if (G.telwish == DO) {
-               putiac2(WONT, TELOPT_ECHO);
+               put_iac2(WONT, TELOPT_ECHO);
                return;
        }
        if (G.telwish == DONT)
@@ -412,9 +414,9 @@ static void to_echo(void)
                G.telflags ^= UF_ECHO;
 
        if (G.telflags & UF_ECHO)
-               putiac2(DO, TELOPT_ECHO);
+               put_iac2(DO, TELOPT_ECHO);
        else
-               putiac2(DONT, TELOPT_ECHO);
+               put_iac2(DONT, TELOPT_ECHO);
 
        setConMode();
        write_str(1, "\r\n");  /* sudden modec */
@@ -432,9 +434,9 @@ static void to_sga(void)
 
        G.telflags ^= UF_SGA; /* toggle */
        if (G.telflags & UF_SGA)
-               putiac2(DO, TELOPT_SGA);
+               put_iac2(DO, TELOPT_SGA);
        else
-               putiac2(DONT, TELOPT_SGA);
+               put_iac2(DONT, TELOPT_SGA);
 }
 
 #if ENABLE_FEATURE_TELNET_TTYPE
@@ -443,9 +445,9 @@ static void to_ttype(void)
        /* Tell server we will (or won't) do TTYPE */
 
        if (G.ttype)
-               putiac2(WILL, TELOPT_TTYPE);
+               put_iac2(WILL, TELOPT_TTYPE);
        else
-               putiac2(WONT, TELOPT_TTYPE);
+               put_iac2(WONT, TELOPT_TTYPE);
 }
 #endif
 
@@ -455,9 +457,9 @@ static void to_new_environ(void)
        /* Tell server we will (or will not) do AUTOLOGIN */
 
        if (G.autologin)
-               putiac2(WILL, TELOPT_NEW_ENVIRON);
+               put_iac2(WILL, TELOPT_NEW_ENVIRON);
        else
-               putiac2(WONT, TELOPT_NEW_ENVIRON);
+               put_iac2(WONT, TELOPT_NEW_ENVIRON);
 }
 #endif
 
@@ -465,7 +467,7 @@ static void to_new_environ(void)
 static void to_naws(void)
 {
        /* Tell server we will do NAWS */
-       putiac2(WILL, TELOPT_NAWS);
+       put_iac2(WILL, TELOPT_NAWS);
 }
 #endif
 
@@ -487,7 +489,7 @@ static void telopt(byte c)
 #if ENABLE_FEATURE_AUTOWIDTH
        case TELOPT_NAWS:
                to_naws();
-               putiac_naws(c, G.win_width, G.win_height);
+               put_iac_naws(c, G.win_width, G.win_height);
                break;
 #endif
        default:
@@ -506,12 +508,12 @@ static int subneg(byte c)
 #if ENABLE_FEATURE_TELNET_TTYPE
                else
                if (c == TELOPT_TTYPE)
-                       putiac_subopt(TELOPT_TTYPE, G.ttype);
+                       put_iac_subopt(TELOPT_TTYPE, G.ttype);
 #endif
 #if ENABLE_FEATURE_TELNET_AUTOLOGIN
                else
                if (c == TELOPT_NEW_ENVIRON)
-                       putiac_subopt_autologin();
+                       put_iac_subopt_autologin();
 #endif
                break;
        case TS_SUB2:
@@ -611,7 +613,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
                case -1:
                        /* error, ignore and/or log something, bay go to loop */
                        if (bb_got_signal)
-                               conescape();
+                               con_escape();
                        else
                                sleep(1);
                        break;
@@ -627,7 +629,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
                                if (len <= 0)
                                        doexit(EXIT_SUCCESS);
                                TRACE(0, ("Read con: %d\n", len));
-                               handlenetoutput(len);
+                               handle_net_output(len);
                        }
 
 #ifdef USE_POLL
@@ -642,7 +644,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
                                        doexit(EXIT_FAILURE);
                                }
                                TRACE(0, ("Read netfd (%d): %d\n", netfd, len));
-                               handlenetinput(len);
+                               handle_net_input(len);
                        }
                }
        } /* while (1) */
index 46dfb318f11dc2b051545f041a43e97c8be857c3..f04b32f9e85dfc659689a49ecf5a759441502c21 100644 (file)
@@ -74,9 +74,6 @@ static const char *issuefile = "/etc/issue.net";
    past (bf + len) then that IAC will be left unprocessed and *processed
    will be less than len.
 
-   FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
-   what is the escape character?  We aren't handling that situation here.
-
    CR-LF ->'s CR mapping is also done here, for convenience.
 
    NB: may fail to remove iacs which wrap around buffer!
@@ -159,6 +156,47 @@ remove_iacs(struct tsession *ts, int *pnum_totty)
        return memmove(ptr - num_totty, ptr0, num_totty);
 }
 
+/*
+ * Converting single 0xff into double on output
+ */
+static size_t iac_safe_write(int fd, const char *buf, size_t count)
+{
+       const char *oxff;
+       size_t wr, rc, total;
+
+       total = 0;
+       while (1) {
+               if (count == 0)
+                       return total;
+               if (*buf == (char)0xff) {
+                       rc = safe_write(fd, "\xff\xff", 2);
+                       if (rc != 2)
+                               break;
+                       buf++;
+                       total++;
+                       count--;
+                       continue;
+               }
+               /* count != 0, *buf != 0xff */
+               oxff = memchr(buf, 0xff, count);
+               wr = count;
+               if (oxff)
+                       wr = oxff - buf;
+               rc = safe_write(fd, buf, wr);
+               if (rc != wr)
+                       break;
+               buf += rc;
+               total += rc;
+               count -= rc;
+       }
+       /* here: rc - result of last short write */
+       if ((ssize_t)rc < 0) { /* error? */
+               if (total == 0)
+                       return rc;
+               rc = 0;
+       }
+       return total + rc;
+}
 
 static struct tsession *
 make_new_session(
@@ -212,9 +250,15 @@ make_new_session(
                        IAC, WILL, TELOPT_ECHO,
                        IAC, WILL, TELOPT_SGA
                };
-               memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
-               ts->rdidx2 = sizeof(iacs_to_send);
-               ts->size2 = sizeof(iacs_to_send);
+               /* This confuses iac_safe_write(), it will try to duplicate
+                * each IAC... */
+               //memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
+               //ts->rdidx2 = sizeof(iacs_to_send);
+               //ts->size2 = sizeof(iacs_to_send);
+               /* So just stuff it into TCP buffer! */
+               safe_write(sock, iacs_to_send, sizeof(iacs_to_send));
+               /*ts->rdidx2 = 0; - xzalloc did it! */
+               /*ts->size2 = 0;*/
        }
 
        fflush(NULL); /* flush all streams */
@@ -538,7 +582,7 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
                if (/*ts->size2 &&*/ FD_ISSET(ts->sockfd_write, &wrfdset)) {
                        /* Write to socket from buffer 2. */
                        count = MIN(BUFSIZE - ts->wridx2, ts->size2);
-                       count = safe_write(ts->sockfd_write, TS_BUF2 + ts->wridx2, count);
+                       count = iac_safe_write(ts->sockfd_write, (void*)(TS_BUF2 + ts->wridx2), count);
                        if (count < 0) {
                                if (errno == EAGAIN)
                                        goto skip2;