-/* $Id: telnetd.c,v 1.2 2002/11/10 22:26:19 bug1 Exp $
- *
+/* vi: set sw=4 ts=4: */
+/*
* Simple telnet server
* Bjorn Wesen, Axis Communications AB (bjornw@axis.com)
*
- * This file is distributed under the Gnu Public License (GPL),
- * please see the file LICENSE for further information.
+ * Licensed under GPL, see file LICENSE in this tarball for details.
*
* ---------------------------------------------------------------------------
* (C) Copyright 2000, Axis Communications AB, LUND, SWEDEN
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/wait.h>
+#include <sys/ioctl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <netinet/in.h>
+#include <arpa/inet.h>
#include <fcntl.h>
#include <stdio.h>
#include <signal.h>
#define BUFSIZE 4000
-static const char *loginpath = "/bin/sh";
+#ifdef CONFIG_FEATURE_IPV6
+#define SOCKET_TYPE AF_INET6
+typedef struct sockaddr_in6 sockaddr_type;
+#else
+#define SOCKET_TYPE AF_INET
+typedef struct sockaddr_in sockaddr_type;
+#endif
+
+
+#ifdef CONFIG_LOGIN
+static const char *loginpath = "/bin/login";
+#else
+static const char *loginpath;
+#endif
+static const char *issuefile = "/etc/issue.net";
/* shell name and arguments */
/* structure that describes a session */
struct tsession {
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ int sockfd_read, sockfd_write, ptyfd;
+#else /* CONFIG_FEATURE_TELNETD_INETD */
struct tsession *next;
int sockfd, ptyfd;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
int shell_pid;
/* two circular buffers */
char *buf1, *buf2;
+-------+ wridx1++ +------+ rdidx1++ +----------+
| | <-------------- | buf1 | <-------------- | |
| | size1-- +------+ size1++ | |
- | pty | | socket |
+ | pty | | socket |
| | rdidx2++ +------+ wridx2++ | |
| | --------------> | buf2 | --------------> | |
+-------+ size2++ +------+ size2-- +----------+
FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
what is the escape character? We aren't handling that situation here.
+ CR-LF ->'s CR mapping is also done here, for convenience
+
*/
static char *
remove_iacs(struct tsession *ts, int *pnum_totty) {
- unsigned char *ptr0 = ts->buf1 + ts->wridx1;
+ unsigned char *ptr0 = (unsigned char *)ts->buf1 + ts->wridx1;
unsigned char *ptr = ptr0;
unsigned char *totty = ptr;
unsigned char *end = ptr + MIN(BUFSIZE - ts->wridx1, ts->size1);
while (ptr < end) {
if (*ptr != IAC) {
+ int c = *ptr;
*totty++ = *ptr++;
+ /* We now map \r\n ==> \r for pragmatic reasons.
+ * Many client implementations send \r\n when
+ * the user hits the CarriageReturn key.
+ */
+ if (c == '\r' && (*ptr == '\n' || *ptr == 0) && ptr < end)
+ ptr++;
}
else {
- if ((ptr+2) < end) {
- /* the entire IAC is contained in the buffer
- we were asked to process. */
-#ifdef DEBUG
- fprintf(stderr, "Ignoring IAC %s,%s\n",
- *ptr, TELCMD(*(ptr+1)), TELOPT(*(ptr+2)));
-#endif
- ptr += 3;
- } else {
+ /*
+ * TELOPT_NAWS support!
+ */
+ if ((ptr+2) >= end) {
/* only the beginning of the IAC is in the
buffer we were asked to process, we can't
process this char. */
break;
}
+
+ /*
+ * IAC -> SB -> TELOPT_NAWS -> 4-byte -> IAC -> SE
+ */
+ else if (ptr[1] == SB && ptr[2] == TELOPT_NAWS) {
+ struct winsize ws;
+ if ((ptr+8) >= end)
+ break; /* incomplete, can't process */
+ ws.ws_col = (ptr[3] << 8) | ptr[4];
+ ws.ws_row = (ptr[5] << 8) | ptr[6];
+ (void) ioctl(ts->ptyfd, TIOCSWINSZ, (char *)&ws);
+ ptr += 9;
+ }
+ else {
+ /* skip 3-byte IAC non-SB cmd */
+#ifdef DEBUG
+ fprintf(stderr, "Ignoring IAC %s,%s\n",
+ TELCMD(*(ptr+1)), TELOPT(*(ptr+2)));
+#endif
+ ptr += 3;
+ }
}
}
static struct tsession *
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+make_new_session(void)
+#else /* CONFIG_FEATURE_TELNETD_INETD */
make_new_session(int sockfd)
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
{
struct termios termbuf;
int pty, pid;
ts->buf1 = (char *)(&ts[1]);
ts->buf2 = ts->buf1 + BUFSIZE;
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ ts->sockfd_read = 0;
+ ts->sockfd_write = 1;
+#else /* CONFIG_FEATURE_TELNETD_INETD */
ts->sockfd = sockfd;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
ts->rdidx1 = ts->wridx1 = ts->size1 = 0;
ts->rdidx2 = ts->wridx2 = ts->size2 = 0;
pty = getpty(tty_name);
if (pty < 0) {
- syslog_msg(LOG_USER, LOG_ERR, "All network ports in use!");
+ syslog(LOG_ERR, "All network ports in use!");
return 0;
}
*/
send_iac(ts, DO, TELOPT_ECHO);
+ send_iac(ts, DO, TELOPT_NAWS);
send_iac(ts, DO, TELOPT_LFLOW);
send_iac(ts, WILL, TELOPT_ECHO);
send_iac(ts, WILL, TELOPT_SGA);
if ((pid = fork()) < 0) {
- syslog_msg(LOG_USER, LOG_ERR, "Can`t forking");
+ syslog(LOG_ERR, "Can`t forking");
}
if (pid == 0) {
/* In child, open the child's side of the tty. */
setsid();
if (open(tty_name, O_RDWR /*| O_NOCTTY*/) < 0) {
- syslog_msg(LOG_USER, LOG_ERR, "Could not open tty");
+ syslog(LOG_ERR, "Could not open tty");
exit(1);
}
dup(0);
/*termbuf.c_lflag &= ~ICANON;*/
tcsetattr(0, TCSANOW, &termbuf);
+ print_login_issue(issuefile, NULL);
+
/* exec shell, with correct argv and env */
execv(loginpath, (char *const *)argv_init);
/* NOT REACHED */
- syslog_msg(LOG_USER, LOG_ERR, "execv error");
+ syslog(LOG_ERR, "execv error");
exit(1);
}
return ts;
}
+#ifndef CONFIG_FEATURE_TELNETD_INETD
static void
free_session(struct tsession *ts)
{
free(ts);
}
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
int
telnetd_main(int argc, char **argv)
{
- struct sockaddr_in sa;
+#ifndef CONFIG_FEATURE_TELNETD_INETD
+ sockaddr_type sa;
int master_fd;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
fd_set rdfdset, wrfdset;
int selret;
+#ifndef CONFIG_FEATURE_TELNETD_INETD
int on = 1;
int portnbr = 23;
+ struct in_addr bind_addr = { .s_addr = 0x0 };
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
int c;
-
- /* check if user supplied a port number */
+ static const char options[] =
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ "f:l:";
+#else /* CONFIG_EATURE_TELNETD_INETD */
+ "f:l:p:b:";
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
+ int maxlen, w, r;
+
+#ifndef CONFIG_LOGIN
+ loginpath = DEFAULT_SHELL;
+#endif
for (;;) {
- c = getopt( argc, argv, "p:l:");
+ c = getopt( argc, argv, options);
if (c == EOF) break;
switch (c) {
+ case 'f':
+ issuefile = optarg;
+ break;
+ case 'l':
+ loginpath = optarg;
+ break;
+#ifndef CONFIG_FEATURE_TELNETD_INETD
case 'p':
portnbr = atoi(optarg);
break;
- case 'l':
- loginpath = strdup (optarg);
+ case 'b':
+ if (inet_aton(optarg, &bind_addr) == 0)
+ bb_show_usage();
break;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
default:
- show_usage();
+ bb_show_usage();
}
}
if (access(loginpath, X_OK) < 0) {
- error_msg_and_die ("'%s' unavailable.", loginpath);
+ bb_error_msg_and_die ("'%s' unavailable.", loginpath);
}
argv_init[0] = loginpath;
+
+ openlog(bb_applet_name, 0, LOG_USER);
+
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ maxfd = 1;
+ sessions = make_new_session();
+#else /* CONFIG_EATURE_TELNETD_INETD */
sessions = 0;
/* Grab a TCP socket. */
- master_fd = socket(AF_INET, SOCK_STREAM, 0);
- if (master_fd < 0) {
- perror_msg_and_die("socket");
- }
+ master_fd = bb_xsocket(SOCKET_TYPE, SOCK_STREAM, 0);
(void)setsockopt(master_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
/* Set it to listen to specified port. */
memset((void *)&sa, 0, sizeof(sa));
+#ifdef CONFIG_FEATURE_IPV6
+ sa.sin6_family = AF_INET6;
+ sa.sin6_port = htons(portnbr);
+ /* sa.sin6_addr = bind_addr6; */
+#else
sa.sin_family = AF_INET;
sa.sin_port = htons(portnbr);
+ sa.sin_addr = bind_addr;
+#endif
- if (bind(master_fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
- perror_msg_and_die("bind");
- }
-
- if (listen(master_fd, 1) < 0) {
- perror_msg_and_die("listen");
- }
-
- if (daemon(0, 0) < 0)
- perror_msg_and_die("daemon");
-
+ bb_xbind(master_fd, (struct sockaddr *) &sa, sizeof(sa));
+ bb_xlisten(master_fd, 1);
+ bb_xdaemon(0, 0);
maxfd = master_fd;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
do {
struct tsession *ts;
* ptys if there is room in their respective session buffers.
*/
+#ifndef CONFIG_FEATURE_TELNETD_INETD
FD_SET(master_fd, &rdfdset);
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
ts = sessions;
+#ifndef CONFIG_FEATURE_TELNETD_INETD
while (ts) {
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
/* buf1 is used from socket to pty
* buf2 is used from pty to socket
*/
FD_SET(ts->ptyfd, &wrfdset); /* can write to pty */
}
if (ts->size1 < BUFSIZE) {
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ FD_SET(ts->sockfd_read, &rdfdset); /* can read from socket */
+#else /* CONFIG_FEATURE_TELNETD_INETD */
FD_SET(ts->sockfd, &rdfdset); /* can read from socket */
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
}
if (ts->size2 > 0) {
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ FD_SET(ts->sockfd_write, &wrfdset); /* can write to socket */
+#else /* CONFIG_FEATURE_TELNETD_INETD */
FD_SET(ts->sockfd, &wrfdset); /* can write to socket */
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
}
if (ts->size2 < BUFSIZE) {
FD_SET(ts->ptyfd, &rdfdset); /* can read from pty */
}
+#ifndef CONFIG_FEATURE_TELNETD_INETD
ts = ts->next;
}
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
selret = select(maxfd + 1, &rdfdset, &wrfdset, 0, 0);
if (!selret)
break;
+#ifndef CONFIG_FEATURE_TELNETD_INETD
/* First check for and accept new sessions. */
if (FD_ISSET(master_fd, &rdfdset)) {
int fd, salen;
ts = sessions;
while (ts) { /* For all sessions... */
- int maxlen, w, r;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
+#ifndef CONFIG_FEATURE_TELNETD_INETD
struct tsession *next = ts->next; /* in case we free ts. */
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
if (ts->size1 && FD_ISSET(ts->ptyfd, &wrfdset)) {
int num_totty;
w = write(ts->ptyfd, ptr, num_totty);
if (w < 0) {
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ exit(0);
+#else /* CONFIG_FEATURE_TELNETD_INETD */
free_session(ts);
ts = next;
continue;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
}
ts->wridx1 += w;
ts->size1 -= w;
ts->wridx1 = 0;
}
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ if (ts->size2 && FD_ISSET(ts->sockfd_write, &wrfdset)) {
+#else /* CONFIG_FEATURE_TELNETD_INETD */
if (ts->size2 && FD_ISSET(ts->sockfd, &wrfdset)) {
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
/* Write to socket from buffer 2. */
maxlen = MIN(BUFSIZE - ts->wridx2, ts->size2);
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ w = write(ts->sockfd_write, ts->buf2 + ts->wridx2, maxlen);
+ if (w < 0)
+ exit(0);
+#else /* CONFIG_FEATURE_TELNETD_INETD */
w = write(ts->sockfd, ts->buf2 + ts->wridx2, maxlen);
if (w < 0) {
free_session(ts);
ts = next;
continue;
}
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
ts->wridx2 += w;
ts->size2 -= w;
if (ts->wridx2 == BUFSIZE)
ts->wridx2 = 0;
}
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd_read, &rdfdset)) {
+#else /* CONFIG_FEATURE_TELNETD_INETD */
if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd, &rdfdset)) {
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
/* Read from socket to buffer 1. */
maxlen = MIN(BUFSIZE - ts->rdidx1,
BUFSIZE - ts->size1);
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ r = read(ts->sockfd_read, ts->buf1 + ts->rdidx1, maxlen);
+ if (!r || (r < 0 && errno != EINTR))
+ exit(0);
+#else /* CONFIG_FEATURE_TELNETD_INETD */
r = read(ts->sockfd, ts->buf1 + ts->rdidx1, maxlen);
if (!r || (r < 0 && errno != EINTR)) {
free_session(ts);
ts = next;
continue;
}
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
if(!*(ts->buf1 + ts->rdidx1 + r - 1)) {
r--;
if(!r)
BUFSIZE - ts->size2);
r = read(ts->ptyfd, ts->buf2 + ts->rdidx2, maxlen);
if (!r || (r < 0 && errno != EINTR)) {
+#ifdef CONFIG_FEATURE_TELNETD_INETD
+ exit(0);
+#else /* CONFIG_FEATURE_TELNETD_INETD */
free_session(ts);
ts = next;
continue;
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
}
ts->rdidx2 += r;
ts->size2 += r;
ts->rdidx2 = 0;
ts->wridx2 = 0;
}
+#ifndef CONFIG_FEATURE_TELNETD_INETD
ts = next;
}
+#endif /* CONFIG_FEATURE_TELNETD_INETD */
} while (1);
projects / oweals / busybox.git / blobdiff