From 3a41611bc5ddeda6044e1f1e2956174b25389ce0 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 5 Apr 2010 22:10:38 +0200 Subject: 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 --- libbb/utmp.c | 123 +++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 86 insertions(+), 37 deletions(-) (limited to 'libbb/utmp.c') diff --git a/libbb/utmp.c b/libbb/utmp.c index 06b939b9d..d6ba336e3 100644 --- a/libbb/utmp.c +++ b/libbb/utmp.c @@ -15,37 +15,87 @@ static void touch(const char *filename) close(open(filename, O_WRONLY | O_CREAT, 0664)); } +// TODO: move to libbb +static const char* skip_dev_pfx(const char *tty_name) +{ + if (strncmp(tty_name, "/dev/", 5) == 0) + tty_name += 5; + return tty_name; +} + +void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname) +{ + struct utmp utent; + char *id; + unsigned width; + + memset(&utent, 0, sizeof(utent)); + utent.ut_pid = pid; + utent.ut_type = new_type; + tty_name = skip_dev_pfx(tty_name); + safe_strncpy(utent.ut_line, tty_name, sizeof(utent.ut_line)); + if (username) + safe_strncpy(utent.ut_user, username, sizeof(utent.ut_user)); + if (hostname) + safe_strncpy(utent.ut_host, hostname, sizeof(utent.ut_host)); + utent.ut_tv.tv_sec = time(NULL); + + /* Invent our own ut_id. ut_id is only 4 chars wide. + * Try to fit something remotely meaningful... */ + id = utent.ut_id; + width = sizeof(utent.ut_id); + if (tty_name[0] == 'p') { + /* if "ptyXXX", map to "pXXX" */ + /* if "pts/XX", map to "p/XX" */ + *id++ = 'p'; + width--; + } /* else: usually it's "ttyXXXX", map to "XXXX" */ + if (strlen(tty_name) > 3) + tty_name += 3; + strncpy(id, tty_name, width); + + touch(_PATH_UTMP); + //utmpname(_PATH_UTMP); + setutent(); + /* Append new one (hopefully, unless we collide on ut_id) */ + pututline(&utent); + endutent(); + +#if ENABLE_FEATURE_WTMP + /* "man utmp" says wtmp file should *not* be created automagically */ + /*touch(bb_path_wtmp_file);*/ + updwtmp(bb_path_wtmp_file, &utent); +#endif +} + /* * Read "man utmp" to make sense out of it. */ -void FAST_FUNC update_utmp(int new_type, const char *short_tty, const char *username, const char *opt_host) +void FAST_FUNC update_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname) { struct utmp utent; - struct utmp *ut; - pid_t pid; + struct utmp *utp; touch(_PATH_UTMP); - utmpname(_PATH_UTMP); + //utmpname(_PATH_UTMP); setutent(); - pid = getpid(); /* Did init/getty/telnetd/sshd/... create an entry for us? * It should be (new_type-1), but we'd also reuse * any other potentially stale xxx_PROCESS entry */ - while ((ut = getutent()) != NULL) { - if (ut->ut_pid == pid + while ((utp = getutent()) != NULL) { + if (utp->ut_pid == pid // && ut->ut_line[0] - && ut->ut_id[0] /* must have nonzero id */ - && ( ut->ut_type == INIT_PROCESS - || ut->ut_type == LOGIN_PROCESS - || ut->ut_type == USER_PROCESS - || ut->ut_type == DEAD_PROCESS + && utp->ut_id[0] /* must have nonzero id */ + && ( utp->ut_type == INIT_PROCESS + || utp->ut_type == LOGIN_PROCESS + || utp->ut_type == USER_PROCESS + || utp->ut_type == DEAD_PROCESS ) ) { - utent = *ut; /* struct copy */ - if (ut->ut_type >= new_type) { + if (utp->ut_type >= new_type) { /* Stale record. Nuke hostname */ - memset(utent.ut_host, 0, sizeof(utent.ut_host)); + memset(utp->ut_host, 0, sizeof(utp->ut_host)); } /* NB: pututline (see later) searches for matching utent * using getutid(utent) - we must not change ut_id @@ -54,39 +104,38 @@ void FAST_FUNC update_utmp(int new_type, const char *short_tty, const char *user break; } } - endutent(); + //endutent(); - no need, pututline can deal with (and actually likes) + //the situation when utmp file is positioned on found record - if (!ut) { - /* Didn't find anything, create new one */ - memset(&utent, 0, sizeof(utent)); - utent.ut_pid = pid; - /* Invent our own ut_id. ut_id is only 4 chars wide. - * Try to fit something remotely meaningful... */ - if (short_tty[0] == 'p') { - /* if "ptyXXX", map to "pXXX" */ - /* if "pts/XX", map to "p/XX" */ - utent.ut_id[0] = 'p'; - strncpy(utent.ut_id + 1, short_tty + 3, sizeof(utent.ut_id)-1); - } else { - /* assuming it's "ttyXXXX", map to "XXXX" */ - strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id)); - } + if (!utp) { + if (new_type != DEAD_PROCESS) + write_new_utmp(pid, new_type, tty_name, username, hostname); + else + endutent(); + return; } + /* Make a copy. We can't use *utp, pututline's internal getutid + * will overwrite it before it is used! */ + utent = *utp; + utent.ut_type = new_type; - safe_strncpy(utent.ut_line, short_tty, sizeof(utent.ut_line)); - safe_strncpy(utent.ut_user, username, sizeof(utent.ut_user)); - if (opt_host) - safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host)); + if (tty_name) + safe_strncpy(utent.ut_line, skip_dev_pfx(tty_name), sizeof(utent.ut_line)); + if (username) + safe_strncpy(utent.ut_user, username, sizeof(utent.ut_user)); + if (hostname) + safe_strncpy(utent.ut_host, hostname, sizeof(utent.ut_host)); utent.ut_tv.tv_sec = time(NULL); /* Update, or append new one */ - setutent(); + //setutent(); pututline(&utent); endutent(); #if ENABLE_FEATURE_WTMP - touch(bb_path_wtmp_file); + /* "man utmp" says wtmp file should *not* be created automagically */ + /*touch(bb_path_wtmp_file);*/ updwtmp(bb_path_wtmp_file, &utent); #endif } -- cgit v1.2.3