emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

telnetd: write LOGIN/DEAD_PROCESS utmp records. Closes bug 1363

Browse Source 
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>
This commit is contained in:
Denys Vlasenko
2010-04-05 22:10:38 +02:00
parent 37f5bef63c
commit 3a41611bc5
7 changed files with 134 additions and 56 deletions
Download Patch File Download Diff File Expand all files Collapse all files

123
libbb/utmp.c
View File

@ -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
}