X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/7555d6a50b05d96de39b5e95cf11a8f05f0c4fd9..acab36bc0e2b03bc71745a2e1e6cc64bebdf3c86:/telnet.c

diff --git a/telnet.c b/telnet.c
index 36c0f723..eeaa76f3 100644
--- a/telnet.c
+++ b/telnet.c
@@ -1,3 +1,7 @@
+/*
+ * Telnet backend.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -196,12 +200,10 @@ static const struct Opt o_tspeed =
     { WILL, WONT, DO, DONT, TELOPT_TSPEED, OPTINDEX_TSPEED, REQUESTED };
 static const struct Opt o_ttype =
     { WILL, WONT, DO, DONT, TELOPT_TTYPE, OPTINDEX_TTYPE, REQUESTED };
-static const struct Opt o_oenv = { WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON,
-    OPTINDEX_OENV, INACTIVE
-};
-static const struct Opt o_nenv = { WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON,
-    OPTINDEX_NENV, REQUESTED
-};
+static const struct Opt o_oenv =
+    { WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON, OPTINDEX_OENV, INACTIVE };
+static const struct Opt o_nenv =
+    { WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON, OPTINDEX_NENV, REQUESTED };
 static const struct Opt o_echo =
     { DO, DONT, WILL, WONT, TELOPT_ECHO, OPTINDEX_ECHO, REQUESTED };
 static const struct Opt o_we_sga =
@@ -252,11 +254,10 @@ typedef struct telnet_tag {
 
 #define SB_DELTA 1024
 
-static void c_write1(Telnet telnet, int c)
+static void c_write(Telnet telnet, char *buf, int len)
 {
     int backlog;
-    char cc = (char) c;
-    backlog = from_backend(telnet->frontend, 0, &cc, 1);
+    backlog = from_backend(telnet->frontend, 0, buf, len);
     sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
 }
 
@@ -396,9 +397,12 @@ static void proc_rec_opt(Telnet telnet, int cmd, int option)
     }
     /*
      * If we reach here, the option was one we weren't prepared to
-     * cope with. So send a negative ack.
+     * cope with. If the request was positive (WILL or DO), we send
+     * a negative ack to indicate refusal. If the request was
+     * negative (WONT / DONT), we must do nothing.
      */
-    send_opt(telnet, (cmd == WILL ? DONT : WONT), option);
+    if (cmd == WILL || cmd == DO)
+        send_opt(telnet, (cmd == WILL ? DONT : WONT), option);
 }
 
 static void process_subneg(Telnet telnet)
@@ -536,6 +540,16 @@ static void process_subneg(Telnet telnet)
 
 static void do_telnet_read(Telnet telnet, char *buf, int len)
 {
+    char *outbuf = NULL;
+    int outbuflen = 0, outbufsize = 0;
+
+#define ADDTOBUF(c) do { \
+    if (outbuflen >= outbufsize) { \
+	outbufsize = outbuflen + 256; \
+        outbuf = sresize(outbuf, outbufsize, char); \
+    } \
+    outbuf[outbuflen++] = (c); \
+} while (0)
 
     while (len--) {
 	int c = (unsigned char) *buf++;
@@ -549,7 +563,7 @@ static void do_telnet_read(Telnet telnet, char *buf, int len)
 		telnet->state = SEENIAC;
 	    else {
 		if (!telnet->in_synch)
-		    c_write1(telnet, c);
+		    ADDTOBUF(c);
 
 #if 1
 		/* I can't get the F***ing winsock to insert the urgent IAC
@@ -586,7 +600,7 @@ static void do_telnet_read(Telnet telnet, char *buf, int len)
 	    } else {
 		/* ignore everything else; print it if it's IAC */
 		if (c == IAC) {
-		    c_write1(telnet, c);
+		    ADDTOBUF(c);
 		}
 		telnet->state = TOP_LEVEL;
 	    }
@@ -636,6 +650,10 @@ static void do_telnet_read(Telnet telnet, char *buf, int len)
 	    break;
 	}
     }
+
+    if (outbuflen)
+	c_write(telnet, outbuf, outbuflen);
+    sfree(outbuf);
 }
 
 static void telnet_log(Plug plug, int type, SockAddr addr, int port,
@@ -1014,10 +1032,10 @@ static const struct telnet_special *telnet_get_specials(void *handle)
     return specials;
 }
 
-static Socket telnet_socket(void *handle)
+static int telnet_connected(void *handle)
 {
     Telnet telnet = (Telnet) handle;
-    return telnet->s;
+    return telnet->s != NULL;
 }
 
 static int telnet_sendok(void *handle)
@@ -1080,7 +1098,7 @@ Backend telnet_backend = {
     telnet_size,
     telnet_special,
     telnet_get_specials,
-    telnet_socket,
+    telnet_connected,
     telnet_exitcode,
     telnet_sendok,
     telnet_ldisc,
@@ -1088,5 +1106,7 @@ Backend telnet_backend = {
     telnet_provide_logctx,
     telnet_unthrottle,
     telnet_cfg_info,
+    "telnet",
+    PROT_TELNET,
     23
 };