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telnet: convert CR NUL -> CR on input. Closes bug 2569

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function                                             old     new   delta
telnet_main                                         1558    1594     +36

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2010-10-29 02:12:22 +02:00
parent 6b3f0b0dab
commit 036dbb9d9a
1 changed files with 63 additions and 69 deletions
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132
networking/telnet.c
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@ -42,11 +42,13 @@ enum {
UF_ECHO = 0x01, UF_ECHO = 0x01,
UF_SGA = 0x02, UF_SGA = 0x02,
TS_0 = 1, TS_NORMAL = 0,
TS_COPY = 1,
TS_IAC = 2, TS_IAC = 2,
TS_OPT = 3, TS_OPT = 3,
TS_SUB1 = 4, TS_SUB1 = 4,
TS_SUB2 = 5, TS_SUB2 = 5,
TS_CR = 6,
}; };
typedef unsigned char byte; typedef unsigned char byte;
@ -83,13 +85,13 @@ struct globals {
}; \ }; \
} while (0) } while (0)
/* Function prototypes */
static void rawmode(void); static void rawmode(void);
static void cookmode(void); static void cookmode(void);
static void do_linemode(void); static void do_linemode(void);
static void will_charmode(void); static void will_charmode(void);
static void telopt(byte c); static void telopt(byte c);
static int subneg(byte c); static void subneg(byte c);
static void iac_flush(void) static void iac_flush(void)
{ {
@ -170,24 +172,24 @@ static void handle_net_output(int len)
* So I implemented it. It's really useful for me. I hope that * So I implemented it. It's really useful for me. I hope that
* other people will find it interesting too. * other people will find it interesting too.
*/ */
byte outbuf[2 * DATABUFSIZE];
int i, j;
byte *p = (byte*)G.buf; byte *p = (byte*)G.buf;
byte outbuf[4*DATABUFSIZE]; int j = 0;
for (i = len, j = 0; i > 0; i--, p++) { for (; len > 0; len--, p++) {
if (*p == 0x1d) { byte c = *p;
if (c == 0x1d) {
con_escape(); con_escape();
return; return;
} }
outbuf[j++] = *p; outbuf[j++] = c;
if (*p == 0xff) if (c == IAC)
outbuf[j++] = 0xff; outbuf[j++] = c; /* IAC -> IAC IAC */
else if (*p == 0x0d) else if (c == '\r')
outbuf[j++] = 0x00; outbuf[j++] = '\0'; /* CR -> CR NUL */
} }
if (j > 0) if (j > 0)
write(netfd, outbuf, j); full_write(netfd, outbuf, j);
} }
static void handle_net_input(int len) static void handle_net_input(int len)
@ -198,25 +200,44 @@ static void handle_net_input(int len)
for (i = 0; i < len; i++) { for (i = 0; i < len; i++) {
byte c = G.buf[i]; byte c = G.buf[i];
if (G.telstate == 0) { /* most of the time state == 0 */ if (G.telstate == TS_NORMAL) { /* most typical state */
if (c == IAC) { if (c == IAC) {
cstart = i; cstart = i;
G.telstate = TS_IAC; G.telstate = TS_IAC;
} }
else if (c == '\r') {
cstart = i + 1;
G.telstate = TS_CR;
}
/* No IACs were seen so far, no need to copy
* bytes within G.buf: */
continue; continue;
} }
switch (G.telstate) { switch (G.telstate) {
case TS_0: case TS_CR:
/* Prev char was CR. If cur one is NUL, ignore it.
* See RFC 1123 section 3.3.1 for discussion of telnet EOL handling.
*/
G.telstate = TS_COPY;
if (c == '\0')
break;
/* else: fall through - need to handle CR IAC ... properly */
case TS_COPY: /* Prev char was ordinary */
/* Similar to NORMAL, but in TS_COPY we need to copy bytes */
if (c == IAC) if (c == IAC)
G.telstate = TS_IAC; G.telstate = TS_IAC;
else else
G.buf[cstart++] = c; G.buf[cstart++] = c;
if (c == '\r')
G.telstate = TS_CR;
break; break;
case TS_IAC: case TS_IAC: /* Prev char was IAC */
if (c == IAC) { /* IAC IAC -> 0xFF */ if (c == IAC) { /* IAC IAC -> one IAC */
G.buf[cstart++] = c; G.buf[cstart++] = c;
G.telstate = TS_0; G.telstate = TS_COPY;
break; break;
} }
/* else */ /* else */
@ -228,34 +249,38 @@ static void handle_net_input(int len)
case DONT: case DONT:
case WILL: case WILL:
case WONT: case WONT:
G.telwish = c; G.telwish = c;
G.telstate = TS_OPT; G.telstate = TS_OPT;
break; break;
/* DATA MARK must be added later */
default: default:
G.telstate = TS_0; /* DATA MARK must be added later */ G.telstate = TS_COPY;
} }
break; break;
case TS_OPT: /* WILL, WONT, DO, DONT */
case TS_OPT: /* Prev chars were IAC WILL/WONT/DO/DONT */
telopt(c); telopt(c);
G.telstate = TS_0; G.telstate = TS_COPY;
break; break;
case TS_SUB1: /* Subnegotiation */ case TS_SUB1: /* Subnegotiation */
case TS_SUB2: /* Subnegotiation */ case TS_SUB2: /* Subnegotiation */
if (subneg(c)) subneg(c); /* can change G.telstate */
G.telstate = TS_0;
break; break;
} }
} }
if (G.telstate) {
if (G.telstate != TS_NORMAL) {
/* We had some IACs, or CR */
if (G.iaclen) if (G.iaclen)
iac_flush(); iac_flush();
if (G.telstate == TS_0) if (G.telstate == TS_COPY) /* we aren't in the middle of IAC */
G.telstate = 0; G.telstate = TS_NORMAL;
len = cstart; len = cstart;
} }
if (len) if (len)
write(STDOUT_FILENO, G.buf, len); full_write(STDOUT_FILENO, G.buf, len);
} }
static void put_iac(int c) static void put_iac(int c)
@ -495,7 +520,7 @@ static void telopt(byte c)
} }
/* subnegotiation -- ignore all (except TTYPE,NAWS) */ /* subnegotiation -- ignore all (except TTYPE,NAWS) */
static int subneg(byte c) static void subneg(byte c)
{ {
switch (G.telstate) { switch (G.telstate) {
case TS_SUB1: case TS_SUB1:
@ -513,12 +538,13 @@ static int subneg(byte c)
#endif #endif
break; break;
case TS_SUB2: case TS_SUB2:
if (c == SE) if (c == SE) {
return TRUE; G.telstate = TS_COPY;
return;
}
G.telstate = TS_SUB1; G.telstate = TS_SUB1;
/* break; */ break;
} }
return FALSE;
} }
static void rawmode(void) static void rawmode(void)
@ -533,21 +559,13 @@ static void cookmode(void)
tcsetattr(0, TCSADRAIN, &G.termios_def); tcsetattr(0, TCSADRAIN, &G.termios_def);
} }
/* poll gives smaller (-70 bytes) code */
#define USE_POLL 1
int telnet_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int telnet_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int telnet_main(int argc UNUSED_PARAM, char **argv) int telnet_main(int argc UNUSED_PARAM, char **argv)
{ {
char *host; char *host;
int port; int port;
int len; int len;
#ifdef USE_POLL
struct pollfd ufds[2]; struct pollfd ufds[2];
#else
fd_set readfds;
int maxfd;
#endif
INIT_G(); INIT_G();
@ -585,25 +603,11 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
signal(SIGINT, record_signo); signal(SIGINT, record_signo);
#ifdef USE_POLL
ufds[0].fd = 0; ufds[1].fd = netfd; ufds[0].fd = 0; ufds[1].fd = netfd;
ufds[0].events = ufds[1].events = POLLIN; ufds[0].events = ufds[1].events = POLLIN;
#else
FD_ZERO(&readfds);
FD_SET(STDIN_FILENO, &readfds);
FD_SET(netfd, &readfds);
maxfd = netfd + 1;
#endif
while (1) { while (1) {
#ifndef USE_POLL switch (poll(ufds, 2, -1)) {
fd_set rfds = readfds;
switch (select(maxfd, &rfds, NULL, NULL, NULL))
#else
switch (poll(ufds, 2, -1))
#endif
{
case 0: case 0:
/* timeout */ /* timeout */
case -1: case -1:
@ -615,12 +619,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
break; break;
default: default:
#ifdef USE_POLL if (ufds[0].revents) {
if (ufds[0].revents)
#else
if (FD_ISSET(STDIN_FILENO, &rfds))
#endif
{
len = safe_read(STDIN_FILENO, G.buf, DATABUFSIZE); len = safe_read(STDIN_FILENO, G.buf, DATABUFSIZE);
if (len <= 0) if (len <= 0)
doexit(EXIT_SUCCESS); doexit(EXIT_SUCCESS);
@ -628,12 +627,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
handle_net_output(len); handle_net_output(len);
} }
#ifdef USE_POLL if (ufds[1].revents) {
if (ufds[1].revents)
#else
if (FD_ISSET(netfd, &rfds))
#endif
{
len = safe_read(netfd, G.buf, DATABUFSIZE); len = safe_read(netfd, G.buf, DATABUFSIZE);
if (len <= 0) { if (len <= 0) {
full_write1_str("Connection closed by foreign host\r\n"); full_write1_str("Connection closed by foreign host\r\n");