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-rw-r--r--mbbsd/telnet.c338
1 files changed, 0 insertions, 338 deletions
diff --git a/mbbsd/telnet.c b/mbbsd/telnet.c
deleted file mode 100644
index 332b3f3a..00000000
--- a/mbbsd/telnet.c
+++ /dev/null
@@ -1,338 +0,0 @@
-/*
- * piaip's simplified implementation of TELNET protocol
- */
-#ifdef DEBUG
-#define TELOPTS
-#define TELCMDS
-#endif
-
-#include "bbs.h"
-
-#ifdef DETECT_CLIENT
-void UpdateClientCode(unsigned char c); // see mbbsd.c
-#endif
-
-unsigned int telnet_handler(unsigned char c) ;
-void telnet_init(void);
-ssize_t tty_read(unsigned char *buf, size_t max);
-
-enum TELNET_IAC_STATES {
- IAC_NONE,
- IAC_COMMAND,
- IAC_WAIT_OPT,
- IAC_WAIT_SE,
- IAC_PROCESS_OPT,
- IAC_ERROR
-};
-
-static unsigned char iac_state = 0; /* as byte to reduce memory */
-
-#define TELNET_IAC_MAXLEN (16)
-/* We don't reply to most commands, so this maxlen can be minimal.
- * Warning: if you want to support ENV passing or other long commands,
- * remember to increase this value. Howver, some poorly implemented
- * terminals like xxMan may not follow the protocols and user will hang
- * on those terminals when IACs were sent.
- */
-
-void
-telnet_init(void)
-{
- /* We are the boss. We don't respect to client.
- * It's client's responsibility to follow us.
- * Please write these codes in i-dont-care opt handlers.
- */
- const char telnet_init_cmds[] = {
- /* retrieve terminal type and throw away.
- * why? because without this, clients enter line mode.
- */
- IAC, DO, TELOPT_TTYPE,
- IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE,
-
- /* i'm a smart term with resize ability. */
- IAC, DO, TELOPT_NAWS,
-
- /* i will echo. */
- IAC, WILL, TELOPT_ECHO,
- /* supress ga. */
- IAC, WILL, TELOPT_SGA,
- /* 8 bit binary. */
- IAC, WILL, TELOPT_BINARY,
- IAC, DO, TELOPT_BINARY,
- };
-
- raw_connection = 1;
- write(0, telnet_init_cmds, sizeof(telnet_init_cmds));
-}
-
-/* tty_read
- * read from tty, process telnet commands if raw connection.
- * return: >0 = length, <=0 means read more, abort/eof is automatically processed.
- */
-ssize_t
-tty_read(unsigned char *buf, size_t max)
-{
- ssize_t l = read(0, buf, max);
-
- if(l == 0 || (l < 0 && !(errno == EINTR || errno == EAGAIN)))
- abort_bbs(0);
-
- if(!raw_connection)
- return l;
-
- /* process buffer */
- if (l > 0) {
- unsigned char *buf2 = buf;
- size_t i = 0, i2 = 0;
-
- /* prescan. because IAC is rare,
- * this cost is worthy. */
- if (iac_state == IAC_NONE && memchr(buf, IAC, l) == NULL)
- return l;
-
- /* we have to look into the buffer. */
- for (i = 0; i < l; i++, buf++)
- if(telnet_handler(*buf) == 0)
- *(buf2++) = *buf;
- else
- i2 ++;
- l = (i2 == l) ? -1L : l - i2;
- }
- return l;
-}
-
-#ifdef DBG_OUTRPT
-extern unsigned char fakeEscape;
-#endif // DBG_OUTRPT
-
-/* input: raw character
- * output: telnet command if c was handled, otherwise zero.
- */
-unsigned int
-telnet_handler(unsigned char c)
-{
- static unsigned char iac_quote = 0; /* as byte to reduce memory */
- static unsigned char iac_opt_req = 0;
-
- static unsigned char iac_buf[TELNET_IAC_MAXLEN];
- static unsigned int iac_buflen = 0;
-
- /* we have to quote all IACs. */
- if(c == IAC && !iac_quote) {
- iac_quote = 1;
- return NOP;
- }
-
-#ifdef DETECT_CLIENT
- /* hash client telnet sequences */
- if(cuser.userid[0]==0) {
- if(iac_state == IAC_WAIT_SE) {
- // skip suboption
- } else {
- if(iac_quote)
- UpdateClientCode(IAC);
- UpdateClientCode(c);
- }
- }
-#endif
-
- /* a special case is the top level iac. otherwise, iac is just a quote. */
- if (iac_quote) {
- if(iac_state == IAC_NONE)
- iac_state = IAC_COMMAND;
- if(iac_state == IAC_WAIT_SE && c == SE)
- iac_state = IAC_PROCESS_OPT;
- iac_quote = 0;
- }
-
- /* now, let's process commands by state */
- switch(iac_state) {
-
- case IAC_NONE:
- return 0;
-
- case IAC_COMMAND:
-#if 0 // def DEBUG
- {
- int cx = c; /* to make compiler happy */
- write(0, "-", 1);
- if(TELCMD_OK(cx))
- write(0, TELCMD(c), strlen(TELCMD(c)));
- write(0, " ", 1);
- }
-#endif
- iac_state = IAC_NONE; /* by default we restore state. */
- switch(c) {
- case IAC:
- // return 0;
- // we don't want to allow IACs as input.
- return 1;
-
- /* we don't want to process these. or maybe in future. */
- case BREAK: /* break */
-#ifdef DBG_OUTRPT
- fakeEscape = !fakeEscape;
- return NOP;
-#endif
-
- case ABORT: /* Abort process */
- case SUSP: /* Suspend process */
- case AO: /* abort output--but let prog finish */
- case IP: /* interrupt process--permanently */
- case EOR: /* end of record (transparent mode) */
- case DM: /* data mark--for connect. cleaning */
- case xEOF: /* End of file: EOF is already used... */
- return NOP;
-
- case NOP: /* nop */
- return NOP;
-
- /* we should process these, but maybe in future. */
- case GA: /* you may reverse the line */
- case EL: /* erase the current line */
- case EC: /* erase the current character */
- return NOP;
-
- /* good */
- case AYT: /* are you there */
- {
- const char *alive = "I'm still alive, loading: ";
- char buf[STRLEN];
-
- /* respond as fast as we can */
- write(0, alive, strlen(alive));
- cpuload(buf);
- write(0, buf, strlen(buf));
- write(0, "\r\n", 2);
- }
- return NOP;
-
- case DONT: /* you are not to use option */
- case DO: /* please, you use option */
- case WONT: /* I won't use option */
- case WILL: /* I will use option */
- iac_opt_req = c;
- iac_state = IAC_WAIT_OPT;
- return NOP;
-
- case SB: /* interpret as subnegotiation */
- iac_state = IAC_WAIT_SE;
- iac_buflen = 0;
- return NOP;
-
- case SE: /* end sub negotiation */
- default:
- return NOP;
- }
- return 1;
-
- case IAC_WAIT_OPT:
-#if 0 // def DEBUG
- write(0, "-", 1);
- if(TELOPT_OK(c))
- write(0, TELOPT(c), strlen(TELOPT(c)));
- write(0, " ", 1);
-#endif
- iac_state = IAC_NONE;
- /*
- * According to RFC, there're some tricky steps to prevent loop.
- * However because we have a poor term which does not allow
- * most abilities, let's be a strong boss here.
- *
- * Although my old imeplementation worked, it's even better to follow this:
- * http://www.tcpipguide.com/free/t_TelnetOptionsandOptionNegotiation-3.htm
- */
- switch(c) {
- /* i-dont-care: i don't care about what client is.
- * these should be clamed in init and
- * client must follow me. */
- case TELOPT_TTYPE: /* termtype or line. */
- case TELOPT_NAWS: /* resize terminal */
- case TELOPT_SGA: /* supress GA */
- case TELOPT_ECHO: /* echo */
- case TELOPT_BINARY: /* we are CJK. */
- break;
-
- /* i-dont-agree: i don't understand/agree these.
- * according to RFC, saying NO stopped further
- * requests so there'll not be endless loop. */
- case TELOPT_RCP: /* prepare to reconnect */
- default:
- if (iac_opt_req == WILL || iac_opt_req == DO)
- {
- /* unknown option, reply with won't */
- unsigned char cmd[3] = { IAC, DONT, 0 };
- if(iac_opt_req == DO) cmd[1] = WONT;
- cmd[2] = c;
- write(0, cmd, sizeof(cmd));
- }
- break;
- }
- return 1;
-
- case IAC_WAIT_SE:
- iac_buf[iac_buflen++] = c;
- /* no need to convert state because previous quoting will do. */
-
- if(iac_buflen == TELNET_IAC_MAXLEN) {
- /* may be broken protocol?
- * whether finished or not, break for safety
- * or user may be frozen.
- */
- iac_state = IAC_NONE;
- return 0;
- }
- return 1;
-
- case IAC_PROCESS_OPT:
- iac_state = IAC_NONE;
-#if 0 // def DEBUG
- write(0, "-", 1);
- if(TELOPT_OK(iac_buf[0]))
- write(0, TELOPT(iac_buf[0]), strlen(TELOPT(iac_buf[0])));
- write(0, " ", 1);
-#endif
- switch(iac_buf[0]) {
-
- /* resize terminal */
- case TELOPT_NAWS:
- {
- int w = (iac_buf[1] << 8) + (iac_buf[2]);
- int h = (iac_buf[3] << 8) + (iac_buf[4]);
- term_resize(w, h);
-#ifdef DETECT_CLIENT
- if(cuser.userid[0]==0) {
- UpdateClientCode(iac_buf[0]);
- if(w==80 && h==24)
- UpdateClientCode(1);
- else if(w==80)
- UpdateClientCode(2);
- else if(h==24)
- UpdateClientCode(3);
- else
- UpdateClientCode(4);
- UpdateClientCode(IAC);
- UpdateClientCode(SE);
- }
-#endif
- }
- break;
-
- default:
-#ifdef DETECT_CLIENT
- if(cuser.userid[0]==0) {
- int i;
- for(i=0;i<iac_buflen;i++)
- UpdateClientCode(iac_buf[i]);
- UpdateClientCode(IAC);
- UpdateClientCode(SE);
- }
-#endif
- break;
- }
- return 1;
- }
- return 1; /* never reached */
-}
-
-// vim: sw=4
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