emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

telnetd: correctly output 0xff char. ~100 bytes.

Browse Source 
telnet: fix some atrocious names and style. no code changes
This commit is contained in:
Denis Vlasenko 2008-11-11 02:56:39 +00:00
parent e9b9a19ad3
commit 9f2f808b0d
2 changed files with 169 additions and 123 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

234
networking/telnet.c
View 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;
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);
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) */

58
networking/telnetd.c
View 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;