summaryrefslogtreecommitdiff
path: root/networking/telnetd.c
diff options
context:
space:
mode:
authorDenys Vlasenko2010-04-05 22:10:38 +0200
committerDenys Vlasenko2010-04-05 22:10:38 +0200
commit3a41611bc5ddeda6044e1f1e2956174b25389ce0 (patch)
treeadfc8a982cf321cc859900a28e9e92c82d43caea /networking/telnetd.c
parent37f5bef63c0db4892d8ffa3c38a04c7998e10f83 (diff)
downloadbusybox-3a41611bc5ddeda6044e1f1e2956174b25389ce0.zip
busybox-3a41611bc5ddeda6044e1f1e2956174b25389ce0.tar.gz
telnetd: write LOGIN/DEAD_PROCESS utmp records. Closes bug 1363
function old new delta write_new_utmp - 253 +253 skip_dev_pfx - 30 +30 handle_sigchld 42 72 +30 telnetd_main 1650 1673 +23 make_new_session 415 438 +23 ... login_main 1140 1148 +8 update_utmp 337 313 -24 write_wtmp 220 154 -66 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 11/6 up/down: 406/-115) Total: ~291 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking/telnetd.c')
-rw-r--r--networking/telnetd.c33
1 files changed, 28 insertions, 5 deletions
diff --git a/networking/telnetd.c b/networking/telnetd.c
index cab94f0..b3e66eb 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -20,18 +20,22 @@
* Vladimir Oleynik <dzo@simtreas.ru> 2001
* Set process group corrections, initial busybox port
*/
-
#define DEBUG 0
#include "libbb.h"
#include <syslog.h>
#if DEBUG
-#define TELCMDS
-#define TELOPTS
+# define TELCMDS
+# define TELOPTS
#endif
#include <arpa/telnet.h>
+#if ENABLE_FEATURE_UTMP
+# include <utmp.h> /* LOGIN_PROCESS */
+#endif
+
+
struct tsession {
struct tsession *next;
pid_t shell_pid;
@@ -319,7 +323,11 @@ make_new_session(
xopen(tty_name, O_RDWR); /* becomes our ctty */
xdup2(0, 1);
xdup2(0, 2);
- tcsetpgrp(0, getpid()); /* switch this tty's process group to us */
+ pid = getpid();
+ tcsetpgrp(0, pid); /* switch this tty's process group to us */
+
+//TODO: fetch remote addr via getpeername (see ftpd.c)
+ write_new_utmp(pid, LOGIN_PROCESS, tty_name, /*username:*/ "LOGIN", /*hostname:*/ NULL);
/* The pseudo-terminal allocated to the client is configured to operate
* in cooked mode, and with XTABS CRMOD enabled (see tty(4)) */
@@ -358,12 +366,13 @@ make_new_session(
static void
free_session(struct tsession *ts)
{
- struct tsession *t = G.sessions;
+ struct tsession *t;
if (option_mask32 & OPT_INETD)
exit(EXIT_SUCCESS);
/* Unlink this telnet session from the session list */
+ t = G.sessions;
if (t == ts)
G.sessions = ts->next;
else {
@@ -414,6 +423,7 @@ static void handle_sigchld(int sig UNUSED_PARAM)
{
pid_t pid;
struct tsession *ts;
+ int save_errno = errno;
/* Looping: more than one child may have exited */
while (1) {
@@ -424,11 +434,22 @@ static void handle_sigchld(int sig UNUSED_PARAM)
while (ts) {
if (ts->shell_pid == pid) {
ts->shell_pid = -1;
+// man utmp:
+// When init(8) finds that a process has exited, it locates its utmp entry
+// by ut_pid, sets ut_type to DEAD_PROCESS, and clears ut_user, ut_host
+// and ut_time with null bytes.
+// [same applies to other processes which maintain utmp entries, like telnetd]
+//
+// We do not bother actually clearing fields:
+// it might be interesting to know who was logged in and from where
+ update_utmp(pid, DEAD_PROCESS, /*tty_name:*/ NULL, /*username:*/ NULL, /*hostname:*/ NULL);
break;
}
ts = ts->next;
}
}
+
+ errno = save_errno;
}
int telnetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -689,6 +710,8 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
ts = next;
continue;
kill_session:
+ if (ts->shell_pid > 0)
+ update_utmp(ts->shell_pid, DEAD_PROCESS, /*tty_name:*/ NULL, /*username:*/ NULL, /*hostname:*/ NULL);
free_session(ts);
ts = next;
}