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-rw-r--r--services/telnetd/telnetd.c510
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diff --git a/services/telnetd/telnetd.c b/services/telnetd/telnetd.c
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+/***********************************************************/
+/*
+ *
+ * The telnet DAEMON
+ *
+ * Author: 17,may 2001
+ *
+ * WORK: fernando.ruiz@ctv.es
+ * HOME: correo@fernando-ruiz.com
+ *
+ * After start the net you can start this daemon.
+ * It uses the previously inited pseudo-terminales (pty.c)
+ * getting a new terminal with getpty(). This function
+ * gives a terminal name passing a opened socket like parameter.
+ *
+ * With register_telnetd() you add a new command in the shell to start
+ * this daemon interactively. (Login in /dev/console of course)
+ *
+ * Sorry but OOB is not still implemented. (This is the first version)
+ *
+ * Till Straumann <strauman@slac.stanford.edu>
+ * - made the 'shell' interface more generic, i.e. it is now
+ * possible to have 'telnetd' run an arbitrary 'shell'
+ * program.
+ *
+ * Copyright (c) 2009 embedded brains GmbH and others.
+ *
+ * embedded brains GmbH
+ * Obere Lagerstr. 30
+ * D-82178 Puchheim
+ * Germany
+ * <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems.h>
+#include <rtems/error.h>
+#include <rtems/pty.h>
+#include <rtems/shell.h>
+#include <rtems/telnetd.h>
+#include <rtems/bspIo.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+
+#include <rtems/userenv.h>
+#include <rtems/error.h>
+#include <rtems/rtems_bsdnet.h>
+
+#define PARANOIA
+
+extern char *telnet_get_pty(int socket);
+extern int telnet_pty_initialize(void);
+
+struct shell_args {
+ char *devname;
+ void *arg;
+ char peername[16];
+ char delete_myself;
+};
+
+typedef union uni_sa {
+ struct sockaddr_in sin;
+ struct sockaddr sa;
+} uni_sa;
+
+static int sockpeername(int sock, char *buf, int bufsz);
+
+rtems_id telnetd_dflt_spawn(
+ const char *name,
+ unsigned priority,
+ unsigned stackSize,
+ void (*fn)(void*),
+ void *fnarg
+);
+
+/***********************************************************/
+static rtems_id telnetd_task_id = RTEMS_ID_NONE;
+
+rtems_id (*telnetd_spawn_task)(
+ const char *,
+ unsigned,
+ unsigned,
+ void (*)(void*),
+ void *
+) = telnetd_dflt_spawn;
+
+static char *grab_a_Connection(
+ int des_socket,
+ uni_sa *srv,
+ char *peername,
+ int sz
+)
+{
+ char *rval = 0;
+#if 0
+ socklen_t size_adr = sizeof(srv->sin);
+#else
+ /* 4.6 doesn't have socklen_t */
+ uint32_t size_adr = sizeof(srv->sin);
+#endif
+ int acp_sock;
+
+ acp_sock = accept(des_socket,&srv->sa,&size_adr);
+
+ if (acp_sock<0) {
+ perror("telnetd:accept");
+ goto bailout;
+ };
+
+ if ( !(rval=telnet_get_pty(acp_sock)) ) {
+ syslog( LOG_DAEMON | LOG_ERR, "telnetd: unable to obtain PTY");
+ /* NOTE: failing 'do_get_pty()' closed the socket */
+ goto bailout;
+ }
+
+ if (sockpeername(acp_sock, peername, sz))
+ strncpy(peername, "<UNKNOWN>", sz);
+
+#ifdef PARANOIA
+ syslog(LOG_DAEMON | LOG_INFO,
+ "telnetd: accepted connection from %s on %s",
+ peername,
+ rval);
+#endif
+
+bailout:
+
+ return rval;
+}
+
+
+static void release_a_Connection(char *devname, char *peername, FILE **pstd, int n)
+{
+
+#ifdef PARANOIA
+ syslog( LOG_DAEMON | LOG_INFO,
+ "telnetd: releasing connection from %s on %s",
+ peername,
+ devname );
+#endif
+
+ while (--n>=0)
+ if (pstd[n]) fclose(pstd[n]);
+
+}
+
+static int sockpeername(int sock, char *buf, int bufsz)
+{
+ uni_sa peer;
+ int rval = sock < 0;
+#if 0
+ socklen_t len = sizeof(peer.sin);
+#else
+ /* 4.6 doesn't have socklen_t */
+ uint32_t len = sizeof(peer.sin);
+#endif
+
+ if ( !rval )
+ rval = getpeername(sock, &peer.sa, &len);
+
+ if ( !rval )
+ rval = !inet_ntop( AF_INET, &peer.sin.sin_addr, buf, bufsz );
+
+ return rval;
+}
+
+static void
+spawned_shell(void *arg);
+
+/***********************************************************/
+static void
+rtems_task_telnetd(void *task_argument)
+{
+ int des_socket;
+ uni_sa srv;
+ char *devname;
+ char peername[16];
+ int i=1;
+ int size_adr;
+ struct shell_args *arg = NULL;
+
+ if ((des_socket=socket(PF_INET,SOCK_STREAM,0))<0) {
+ perror("telnetd:socket");
+ telnetd_task_id = RTEMS_ID_NONE;
+ rtems_task_delete(RTEMS_SELF);
+ };
+ setsockopt(des_socket,SOL_SOCKET,SO_KEEPALIVE,&i,sizeof(i));
+
+ memset(&srv,0,sizeof(srv));
+ srv.sin.sin_family=AF_INET;
+ srv.sin.sin_port=htons(23);
+ size_adr=sizeof(srv.sin);
+ if ((bind(des_socket,&srv.sa,size_adr))<0) {
+ perror("telnetd:bind");
+ close(des_socket);
+ telnetd_task_id = RTEMS_ID_NONE;
+ rtems_task_delete(RTEMS_SELF);
+ };
+ if ((listen(des_socket,5))<0) {
+ perror("telnetd:listen");
+ close(des_socket);
+ telnetd_task_id = RTEMS_ID_NONE;
+ rtems_task_delete(RTEMS_SELF);
+ };
+
+ /* we don't redirect stdio as this probably
+ * was started from the console anyways..
+ */
+ do {
+ if (rtems_telnetd_config.keep_stdio) {
+ bool start = true;
+ char device_name [32];
+
+ ttyname_r( 1, device_name, sizeof( device_name));
+ if (rtems_telnetd_config.login_check != NULL) {
+ start = rtems_shell_login_prompt(
+ stdin,
+ stderr,
+ device_name,
+ rtems_telnetd_config.login_check
+ );
+ }
+ if (start) {
+ rtems_telnetd_config.command( device_name, arg->arg);
+ } else {
+ syslog(
+ LOG_AUTHPRIV | LOG_WARNING,
+ "telnetd: to many wrong passwords entered from %s",
+ device_name
+ );
+ }
+ } else {
+ devname = grab_a_Connection(des_socket, &srv, peername, sizeof(peername));
+
+ if ( !devname ) {
+ /* if something went wrong, sleep for some time */
+ sleep(10);
+ continue;
+ }
+
+ arg = malloc( sizeof(*arg) );
+
+ arg->devname = devname;
+ arg->arg = rtems_telnetd_config.arg;
+ strncpy(arg->peername, peername, sizeof(arg->peername));
+
+ telnetd_task_id = telnetd_spawn_task(
+ devname,
+ rtems_telnetd_config.priority,
+ rtems_telnetd_config.stack_size,
+ spawned_shell,
+ arg
+ );
+ if (telnetd_task_id == RTEMS_ID_NONE) {
+ FILE *dummy;
+
+ if ( telnetd_spawn_task != telnetd_dflt_spawn ) {
+ fprintf(stderr,"Telnetd: Unable to spawn child task\n");
+ }
+
+ /* hmm - the pty driver slot can only be
+ * released by opening and subsequently
+ * closing the PTY - this also closes
+ * the underlying socket. So we mock up
+ * a stream...
+ */
+
+ if ( !(dummy=fopen(devname,"r+")) )
+ perror("Unable to dummy open the pty, losing a slot :-(");
+ release_a_Connection(devname, peername, &dummy, 1);
+ free(arg);
+ sleep(2); /* don't accept connections too fast */
+ }
+ }
+ } while(1);
+
+ /* TODO: how to free the connection semaphore? But then -
+ * stopping the daemon is probably only needed during
+ * development/debugging.
+ * Finalizer code should collect all the connection semaphore
+ * counts and eventually clean up...
+ */
+ close(des_socket);
+ telnetd_task_id = RTEMS_ID_NONE;
+}
+
+rtems_status_code rtems_telnetd_initialize( void)
+{
+ if (telnetd_task_id != RTEMS_ID_NONE) {
+ fprintf(stderr, "telnetd already started\n");
+ return RTEMS_RESOURCE_IN_USE;
+ }
+
+ if (rtems_telnetd_config.command == NULL) {
+ fprintf(stderr, "telnetd setup with invalid command\n");
+ return RTEMS_IO_ERROR;
+ }
+
+ if ( !telnet_pty_initialize() ) {
+ fprintf(stderr, "telnetd cannot initialize PTY driver\n");
+ return RTEMS_IO_ERROR;
+ }
+
+ /* Check priority */
+ if (rtems_telnetd_config.priority <= 0) {
+ rtems_telnetd_config.priority = rtems_bsdnet_config.network_task_priority;
+ }
+ if (rtems_telnetd_config.priority < 2) {
+ rtems_telnetd_config.priority = 100;
+ }
+
+ /* Check stack size */
+ if (rtems_telnetd_config.stack_size <= 0) {
+ rtems_telnetd_config.stack_size = (size_t)32 * 1024;
+ }
+
+ /* Spawn task */
+ telnetd_task_id = telnetd_spawn_task(
+ "TNTD",
+ rtems_telnetd_config.priority,
+ rtems_telnetd_config.stack_size,
+ rtems_task_telnetd,
+ 0
+ );
+ if (telnetd_task_id == RTEMS_ID_NONE) {
+ return RTEMS_IO_ERROR;
+ }
+
+ /* Print status */
+ if (!rtems_telnetd_config.keep_stdio) {
+ fprintf(
+ stderr,
+ "telnetd started with stacksize = %u and priority = %d\n",
+ (unsigned) rtems_telnetd_config.stack_size,
+ (unsigned) rtems_telnetd_config.priority
+ );
+ }
+
+ return RTEMS_SUCCESSFUL;
+}
+
+/* utility wrapper */
+static void
+spawned_shell(void *targ)
+{
+ rtems_status_code sc;
+ FILE *nstd[3]={0};
+ FILE *ostd[3]={ stdin, stdout, stderr };
+ int i=0;
+ struct shell_args *arg = targ;
+ bool login_failed = false;
+ bool start = true;
+
+ sc=rtems_libio_set_private_env();
+
+ /* newlib hack/workaround. Before we change stdin/out/err we must make
+ * sure the internal data are initialized (fileno(stdout) has this sideeffect).
+ * This should probably be done from RTEMS' libc support layer...
+ * (T.S., newlibc-1.13; 2005/10)
+ */
+
+ fileno(stdout);
+
+ if (RTEMS_SUCCESSFUL != sc) {
+ rtems_error(sc,"rtems_libio_set_private_env");
+ goto cleanup;
+ }
+
+ /* redirect stdio */
+ for (i=0; i<3; i++) {
+ if ( !(nstd[i]=fopen(arg->devname,"r+")) ) {
+ perror("unable to open stdio");
+ goto cleanup;
+ }
+ }
+
+ stdin = nstd[0];
+ stdout = nstd[1];
+ stderr = nstd[2];
+
+ #if 0
+ printk("STDOUT is now %x (%x) (FD %i/%i)\n",
+ stdout,nstd[1],fileno(stdout),fileno(nstd[1]));
+ printf("hello\n");
+ write(fileno(stdout),"hellofd\n",8);
+ #endif
+
+ /* call their routine */
+ if (rtems_telnetd_config.login_check != NULL) {
+ start = rtems_shell_login_prompt(
+ stdin,
+ stderr,
+ arg->devname,
+ rtems_telnetd_config.login_check
+ );
+ login_failed = !start;
+ }
+ if (start) {
+ rtems_telnetd_config.command( arg->devname, arg->arg);
+ }
+
+ stdin = ostd[0];
+ stdout = ostd[1];
+ stderr = ostd[2];
+
+ if (login_failed) {
+ syslog(
+ LOG_AUTHPRIV | LOG_WARNING,
+ "telnetd: to many wrong passwords entered from %s",
+ arg->peername
+ );
+ }
+
+cleanup:
+ release_a_Connection(arg->devname, arg->peername, nstd, i);
+ free(arg);
+}
+
+struct wrap_delete_args {
+ void (*t)(void *);
+ void *a;
+};
+
+static rtems_task
+wrap_delete(rtems_task_argument arg)
+{
+ struct wrap_delete_args *pwa = (struct wrap_delete_args *)arg;
+ register void (*t)(void *) = pwa->t;
+ register void *a = pwa->a;
+
+ /* free argument before calling function (which may never return if
+ * they choose to delete themselves)
+ */
+ free(pwa);
+ t(a);
+ rtems_task_delete(RTEMS_SELF);
+}
+
+rtems_id
+telnetd_dflt_spawn(const char *name, unsigned int priority, unsigned int stackSize, void (*fn)(void *), void* fnarg)
+{
+ rtems_status_code sc;
+ rtems_id task_id = RTEMS_ID_NONE;
+ char nm[4] = {'X','X','X','X' };
+ struct wrap_delete_args *pwa = malloc(sizeof(*pwa));
+
+ strncpy(nm, name, 4);
+
+ if ( !pwa ) {
+ perror("Telnetd: no memory\n");
+ return RTEMS_ID_NONE;
+ }
+
+ pwa->t = fn;
+ pwa->a = fnarg;
+
+ if ((sc=rtems_task_create(
+ rtems_build_name(nm[0], nm[1], nm[2], nm[3]),
+ (rtems_task_priority)priority,
+ stackSize,
+ RTEMS_DEFAULT_MODES,
+ RTEMS_DEFAULT_ATTRIBUTES | RTEMS_FLOATING_POINT,
+ &task_id)) ||
+ (sc=rtems_task_start(
+ task_id,
+ wrap_delete,
+ (rtems_task_argument)pwa))) {
+ free(pwa);
+ rtems_error(sc,"Telnetd: spawning task failed");
+ return RTEMS_ID_NONE;
+ }
+ return task_id;
+}
+
+/* convenience routines for CEXP (retrieve stdio descriptors
+ * from reent structure)
+ */
+#ifdef stdin
+static __inline__ FILE *
+_stdin(void) { return stdin; }
+#undef stdin
+FILE *stdin(void) { return _stdin(); }
+#endif
+#ifdef stdout
+static __inline__ FILE *
+_stdout(void) { return stdout; }
+#undef stdout
+FILE *stdout(void) { return _stdout(); }
+#endif
+#ifdef stderr
+static __inline__ FILE *
+_stderr(void) { return stderr; }
+#undef stderr
+FILE *stderr(void) { return _stderr(); }
+#endif
+
+/* MUST NOT USE stdin & friends below here !!!!!!!!!!!!! */
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