Sprinkle some header comments in various files in an attempt to explain what

[u/mdw/putty] / telnet.c

diff --git a/telnet.c b/telnet.c
index 6f4f54c..5038833 100644 (file)
--- 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 =
@@ -244,6 +246,8 @@ typedef struct telnet_tag {
     } state;
 
     Config cfg;
+
+    Pinger pinger;
 } *Telnet;
 
 #define TELNET_MAX_BACKLOG 4096
@@ -394,9 +398,12 @@ 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)
@@ -518,8 +525,13 @@ static void process_subneg(Telnet telnet)
            b[n++] = IAC;
            b[n++] = SE;
            telnet->bufsize = sk_write(telnet->s, (char *)b, n);
-           logbuf = dupprintf("client:\tSB %s IS %s", telopt(telnet->sb_opt),
-                              n == 6 ? "<nothing>" : "<stuff>");
+           logbuf = dupprintf("client:\tSB %s IS %s%s%s%s",
+                              telopt(telnet->sb_opt),
+                              *telnet->cfg.username ? "USER=" : "",
+                              telnet->cfg.username,
+                              *telnet->cfg.username ? " " : "",
+                              n == 6 ? "<nothing>" :
+                              (*telnet->cfg.environmt ? "<stuff>" : ""));
            logevent(telnet->frontend, logbuf);
            sfree(logbuf);
        }
@@ -631,6 +643,22 @@ static void do_telnet_read(Telnet telnet, char *buf, int len)
     }
 }
 
+static void telnet_log(Plug plug, int type, SockAddr addr, int port,
+                      const char *error_msg, int error_code)
+{
+    Telnet telnet = (Telnet) plug;
+    char addrbuf[256], *msg;
+
+    sk_getaddr(addr, addrbuf, lenof(addrbuf));
+
+    if (type == 0)
+       msg = dupprintf("Connecting to %s port %d", addrbuf, port);
+    else
+       msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
+
+    logevent(telnet->frontend, msg);
+}
+
 static int telnet_closing(Plug plug, const char *error_msg, int error_code,
                          int calling_back)
 {
@@ -639,12 +667,13 @@ static int telnet_closing(Plug plug, const char *error_msg, int error_code,
     if (telnet->s) {
         sk_close(telnet->s);
         telnet->s = NULL;
+       notify_remote_exit(telnet->frontend);
     }
     if (error_msg) {
-       /* A socket error has occurred. */
        logevent(telnet->frontend, error_msg);
        connection_fatal(telnet->frontend, "%s", error_msg);
-    }                                 /* Otherwise, the remote side closed the connection normally. */
+    }
+    /* Otherwise, the remote side closed the connection normally. */
     return 0;
 }
 
@@ -677,6 +706,7 @@ static const char *telnet_init(void *frontend_handle, void **backend_handle,
                               int nodelay, int keepalive)
 {
     static const struct plug_function_table fn_table = {
+       telnet_log,
        telnet_closing,
        telnet_receive,
        telnet_sent
@@ -698,6 +728,8 @@ static const char *telnet_init(void *frontend_handle, void **backend_handle,
     telnet->term_width = telnet->cfg.width;
     telnet->term_height = telnet->cfg.height;
     telnet->state = TOP_LEVEL;
+    telnet->ldisc = NULL;
+    telnet->pinger = NULL;
     *backend_handle = telnet;
 
     /*
@@ -705,11 +737,14 @@ static const char *telnet_init(void *frontend_handle, void **backend_handle,
      */
     {
        char *buf;
-       buf = dupprintf("Looking up host \"%s\"", host);
+       buf = dupprintf("Looking up host \"%s\"%s", host,
+                       (cfg->addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
+                        (cfg->addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
+                         "")));
        logevent(telnet->frontend, buf);
        sfree(buf);
     }
-    addr = name_lookup(host, port, realhost, &telnet->cfg);
+    addr = name_lookup(host, port, realhost, &telnet->cfg, cfg->addressfamily);
     if ((err = sk_addr_error(addr)) != NULL) {
        sk_addr_free(addr);
        return err;
@@ -721,18 +756,13 @@ static const char *telnet_init(void *frontend_handle, void **backend_handle,
     /*
      * Open socket.
      */
-    {
-       char *buf, addrbuf[100];
-       sk_getaddr(addr, addrbuf, 100);
-       buf = dupprintf("Connecting to %s port %d", addrbuf, port);
-       logevent(telnet->frontend, buf);
-       sfree(buf);
-    }
     telnet->s = new_connection(addr, *realhost, port, 0, 1,
                               nodelay, keepalive, (Plug) telnet, &telnet->cfg);
     if ((err = sk_socket_error(telnet->s)) != NULL)
        return err;
 
+    telnet->pinger = pinger_new(&telnet->cfg, &telnet_backend, telnet);
+
     /*
      * Initialise option states.
      */
@@ -757,6 +787,11 @@ static const char *telnet_init(void *frontend_handle, void **backend_handle,
      */
     telnet->in_synch = FALSE;
 
+    /*
+     * We can send special commands from the start.
+     */
+    update_specials_menu(telnet->frontend);
+
     return NULL;
 }
 
@@ -767,6 +802,8 @@ static void telnet_free(void *handle)
     sfree(telnet->sb_buf);
     if (telnet->s)
        sk_close(telnet->s);
+    if (telnet->pinger)
+       pinger_free(telnet->pinger);
     sfree(telnet);
 }
 /*
@@ -777,6 +814,7 @@ static void telnet_free(void *handle)
 static void telnet_reconfig(void *handle, Config *cfg)
 {
     Telnet telnet = (Telnet) handle;
+    pinger_reconfig(telnet->pinger, &telnet->cfg, cfg);
     telnet->cfg = *cfg;                       /* STRUCTURE COPY */
 }
 
@@ -953,6 +991,8 @@ static void telnet_special(void *handle, Telnet_Special code)
            telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
        }
        break;
+      default:
+       break;  /* never heard of it */
     }
 }
 
@@ -966,15 +1006,15 @@ static const struct telnet_special *telnet_get_specials(void *handle)
        {"Erase Line", TS_EL},
        {"Go Ahead", TS_GA},
        {"No Operation", TS_NOP},
-       {"", 0},
+       {NULL, TS_SEP},
        {"Abort Process", TS_ABORT},
        {"Abort Output", TS_AO},
        {"Interrupt Process", TS_IP},
        {"Suspend Process", TS_SUSP},
-       {"", 0},
+       {NULL, TS_SEP},
        {"End Of Record", TS_EOR},
        {"End Of File", TS_EOF},
-       {NULL, 0}
+       {NULL, TS_EXITMENU}
     };
     return specials;
 }
@@ -1028,6 +1068,14 @@ static int telnet_exitcode(void *handle)
         return 0;
 }
 
+/*
+ * cfg_info for Telnet does nothing at all.
+ */
+static int telnet_cfg_info(void *handle)
+{
+    return 0;
+}
+
 Backend telnet_backend = {
     telnet_init,
     telnet_free,
@@ -1044,5 +1092,6 @@ Backend telnet_backend = {
     telnet_provide_ldisc,
     telnet_provide_logctx,
     telnet_unthrottle,
+    telnet_cfg_info,
     23
 };