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-rw-r--r--include/usage.h15
-rw-r--r--networking/Config.in10
-rw-r--r--networking/telnet.c85
3 files changed, 110 insertions, 0 deletions
diff --git a/include/usage.h b/include/usage.h
index 59e81c2d3..56650d565 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2415,11 +2415,26 @@
"$ cat /tmp/foo\n" \
"Hello\n"
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+#define telnet_trivial_usage \
+ "[-a] [-l USER] HOST [PORT]"
+#define telnet_full_usage \
+ "Telnet is used to establish interactive communication with another\n" \
+ "computer over a network using the TELNET protocol.\n\n" \
+ "Options:\n" \
+ "\t-a\t\tAttempt an automatic login with the USER variable.\n" \
+ "\t-l USER\t\tAttempt an automatic login with the USER argument.\n" \
+ "\tHOST\t\tThe official name, alias or the IP address of the\n" \
+ "\t\t\tremote host.\n" \
+ "\tPORT\t\tThe remote port number to connect to. If it is not\n" \
+ "\t\t\tspecified, the default telnet (23) port is used.\n"
+#else
#define telnet_trivial_usage \
"HOST [PORT]"
#define telnet_full_usage \
"Telnet is used to establish interactive communication with another\n"\
"computer over a network using the TELNET protocol."
+#endif
#ifdef CONFIG_FEATURE_TELNETD_INETD
#define telnetd_trivial_usage \
diff --git a/networking/Config.in b/networking/Config.in
index f250e78cc..d2916e7cd 100644
--- a/networking/Config.in
+++ b/networking/Config.in
@@ -479,6 +479,16 @@ config CONFIG_FEATURE_TELNET_TTYPE
remote host you are connecting to. This is useful to make sure that
things like ANSI colors and other control sequences behave.
+config CONFIG_FEATURE_TELNET_AUTOLOGIN
+ bool " Pass USER type to remote host"
+ default y
+ depends on CONFIG_TELNET
+ help
+ Setting this option will forward the USER environment variable to the
+ remote host you are connecting to. This is useful when you need to
+ log into a machine without telling the username (autologin). This
+ option enables `-a' and `-l USER' arguments.
+
config CONFIG_TELNETD
bool "telnetd"
default n
diff --git a/networking/telnet.c b/networking/telnet.c
index 1b71bf26a..574fe8dab 100644
--- a/networking/telnet.c
+++ b/networking/telnet.c
@@ -28,6 +28,8 @@
* Modified 2000/06/13 for inclusion into BusyBox by Erik Andersen <andersen@codepoet.org>
* Modified 2001/05/07 to add ability to pass TTYPE to remote host by Jim McQuillan
* <jam@ltsp.org>
+ * Modified 2004/02/11 to add ability to pass the USER variable to remote host
+ * by Fernando Silveira <swrh@gmx.net>
*
*/
@@ -129,6 +131,10 @@ static int one = 1;
static char *ttype;
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static char *autologin;
+#endif
+
#ifdef CONFIG_FEATURE_AUTOWIDTH
static int win_width, win_height;
#endif
@@ -355,6 +361,34 @@ static void putiac_subopt(byte c, char *str)
}
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static void putiac_subopt_autologin(void)
+{
+ int len = strlen(autologin) + 6; // (2 + 1 + 1 + strlen + 2)
+ char *user = "USER";
+
+ if (G.iaclen + len > IACBUFSIZE)
+ iacflush();
+
+ putiac(IAC);
+ putiac(SB);
+ putiac(TELOPT_NEW_ENVIRON);
+ putiac(TELQUAL_IS);
+ putiac(NEW_ENV_VAR);
+
+ while(*user)
+ putiac(*user++);
+
+ putiac(NEW_ENV_VALUE);
+
+ while(*autologin)
+ putiac(*autologin++);
+
+ putiac(IAC);
+ putiac(SE);
+}
+#endif
+
#ifdef CONFIG_FEATURE_AUTOWIDTH
static void putiac_naws(byte c, int x, int y)
{
@@ -495,6 +529,20 @@ static inline void to_ttype(void)
}
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static inline void to_new_environ(void)
+{
+ /* Tell server we will (or will not) do AUTOLOGIN */
+
+ if (autologin)
+ putiac2(WILL, TELOPT_NEW_ENVIRON);
+ else
+ putiac2(WONT, TELOPT_NEW_ENVIRON);
+
+ return;
+}
+#endif
+
#ifdef CONFIG_FEATURE_AUTOWIDTH
static inline void to_naws(void)
{
@@ -513,6 +561,9 @@ static void telopt(byte c)
#ifdef CONFIG_FEATURE_TELNET_TTYPE
case TELOPT_TTYPE: to_ttype();break;
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+ case TELOPT_NEW_ENVIRON: to_new_environ(); break;
+#endif
#ifdef CONFIG_FEATURE_AUTOWIDTH
case TELOPT_NAWS: to_naws();
putiac_naws(c, win_width, win_height);
@@ -540,6 +591,11 @@ static int subneg(byte c)
if (c == TELOPT_TTYPE)
putiac_subopt(TELOPT_TTYPE,ttype);
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+ else
+ if (c == TELOPT_NEW_ENVIRON)
+ putiac_subopt_autologin();
+#endif
break;
case TS_SUB2:
if (c == SE)
@@ -579,6 +635,10 @@ extern int telnet_main(int argc, char** argv)
int maxfd;
#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+ int opt;
+#endif
+
#ifdef CONFIG_FEATURE_AUTOWIDTH
get_terminal_width_height(0, &win_width, &win_height);
#endif
@@ -598,8 +658,33 @@ extern int telnet_main(int argc, char** argv)
if (argc < 2)
bb_show_usage();
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+ autologin = NULL;
+ while ((opt = getopt(argc, argv, "al:")) != EOF) {
+ switch (opt) {
+ case 'l':
+ autologin = bb_xstrdup(optarg);
+ break;
+ case 'a':
+ autologin = getenv("USER");
+ break;
+ case '?':
+ bb_show_usage();
+ break;
+ }
+ }
+ if (optind < argc) {
+ bb_lookup_host(&s_in, argv[optind++]);
+ s_in.sin_port = bb_lookup_port((optind < argc) ? argv[optind++] :
+ "telnet", "tcp", 23);
+ if (optind < argc)
+ bb_show_usage();
+ } else
+ bb_show_usage();
+#else
bb_lookup_host(&s_in, argv[1]);
s_in.sin_port = bb_lookup_port((argc == 3) ? argv[2] : "telnet", "tcp", 23);
+#endif
G.netfd = xconnect(&s_in);