diff options
Diffstat (limited to 'networking/telnetd.c')
| -rw-r--r-- | networking/telnetd.c | 33 |
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; } |