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run telnet from inetd, present login prompt if login is configured,

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patch from Bastian Blank
This commit is contained in:
Glenn L McGrath
2003-01-21 20:55:56 +00:00
parent 4c51202b9d
commit 9e5d6c002c
6 changed files with 121 additions and 157 deletions
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107
networking/telnetd.c
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@@ -1,4 +1,4 @@
/* $Id: telnetd.c,v 1.2 2002/11/10 22:26:19 bug1 Exp $
/* $Id: telnetd.c,v 1.3 2003/01/21 20:55:56 bug1 Exp $
*
* Simple telnet server
* Bjorn Wesen, Axis Communications AB (bjornw@axis.com)
@@ -48,7 +48,13 @@
#define BUFSIZE 4000
static const char *loginpath = "/bin/sh";
static const char *loginpath =
#ifdef CONFIG_LOGIN
"/bin/login";
#else
"/bin/sh";
#endif
static const char *issuefile = "/etc/issue.net";
/* shell name and arguments */
@@ -57,8 +63,12 @@ static const char *argv_init[] = {NULL, NULL};
/* 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;
@@ -204,7 +214,11 @@ send_iac(struct tsession *ts, unsigned char command, int option)
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;
@@ -214,7 +228,12 @@ make_new_session(int sockfd)
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;
@@ -278,6 +297,8 @@ make_new_session(int sockfd)
/*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);
@@ -291,6 +312,7 @@ make_new_session(int sockfd)
return ts;
}
#ifndef CONFIG_FEATURE_TELNETD_INETD
static void
free_session(struct tsession *ts)
{
@@ -319,30 +341,44 @@ free_session(struct tsession *ts)
free(ts);
}
#endif /* CONFIG_FEATURE_TELNETD_INETD */
int
telnetd_main(int argc, char **argv)
{
#ifndef CONFIG_FEATURE_TELNETD_INETD
struct sockaddr_in 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;
#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:";
#endif /* CONFIG_FEATURE_TELNETD_INETD */
for (;;) {
c = getopt( argc, argv, "p:l:");
c = getopt( argc, argv, options);
if (c == EOF) break;
switch (c) {
case 'p':
portnbr = atoi(optarg);
case 'f':
issuefile = strdup (optarg);
break;
case 'l':
loginpath = strdup (optarg);
break;
#ifndef CONFIG_FEATURE_TELNETD_INETD
case 'p':
portnbr = atoi(optarg);
break;
#endif /* CONFIG_FEATURE_TELNETD_INETD */
default:
show_usage();
}
@@ -353,6 +389,12 @@ telnetd_main(int argc, char **argv)
}
argv_init[0] = loginpath;
#ifdef CONFIG_FEATURE_TELNETD_INETD
sessions = make_new_session();
maxfd = 1;
#else /* CONFIG_EATURE_TELNETD_INETD */
sessions = 0;
/* Grab a TCP socket. */
@@ -382,6 +424,7 @@ telnetd_main(int argc, char **argv)
maxfd = master_fd;
#endif /* CONFIG_FEATURE_TELNETD_INETD */
do {
struct tsession *ts;
@@ -393,10 +436,14 @@ telnetd_main(int argc, char **argv)
* 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
*/
@@ -404,22 +451,33 @@ telnetd_main(int argc, char **argv)
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;
@@ -447,9 +505,12 @@ telnetd_main(int argc, char **argv)
ts = sessions;
while (ts) { /* For all sessions... */
#endif /* CONFIG_FEATURE_TELNETD_INETD */
int maxlen, w, r;
#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;
char *ptr;
@@ -459,9 +520,13 @@ telnetd_main(int argc, char **argv)
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;
@@ -469,31 +534,51 @@ telnetd_main(int argc, char **argv)
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)
@@ -511,9 +596,13 @@ telnetd_main(int argc, char **argv)
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;
@@ -529,8 +618,10 @@ telnetd_main(int argc, char **argv)
ts->rdidx2 = 0;
ts->wridx2 = 0;
}
#ifndef CONFIG_FEATURE_TELNETD_INETD
ts = next;
}
#endif /* CONFIG_FEATURE_TELNETD_INETD */
} while (1);