lslogins: use lastlog as wtmp fallback

The wtmp file tends to rotate higher rate than lastlog, so use the later as
fallback in when wtmp tells nothing in LAST-LOGIN column.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/bash-completion/lslogins b/bash-completion/lslogins
index 8651fe9df265c1c0402097531c68dc1e4d8cb1b4..93c9773b299d8f0e0fb672d45f0dbde8c96bb408 100755 (executable)
--- a/bash-completion/lslogins
+++ b/bash-completion/lslogins
@@ -23,7 +23,7 @@ _lslogins_module()
                        COMPREPLY=( $(compgen -W "short full iso" -- $cur) )
                        return 0
                        ;;
-               '--wtmp-file'|'--btmp-file')
+               '--wtmp-file'|'--btmp-file'|'--lastlog')
                        local IFS=$'\n'
                        compopt -o filenames
                        COMPREPLY=( $(compgen -f -- $cur) )
@@ -69,6 +69,7 @@ _lslogins_module()
                        --print0
                        --wtmp-file
                        --btmp-file
+                       --lastlog
                        --help
                        --version
                " -- $cur) )

diff --git a/login-utils/lslogins.1 b/login-utils/lslogins.1
index 06bad42ab4e032ee0a5e978d4bce776da7afb0df..fbeaacedf649d7d66198ff2111c00480372a76a3 100644 (file)
--- a/login-utils/lslogins.1
+++ b/login-utils/lslogins.1
@@ -113,6 +113,9 @@ Display version information and exit.
 \fB\-\-wtmp\-file \fIpath\fP
 Alternate path for wtmp.
 .TP
+\fB\-\-lastlog \fIpath\fP
+Alternate path for lastlog.
+.TP
 \fB\-Z\fR, \fB\-\-context\fR
 Display the users' security context.
 .TP

diff --git a/login-utils/lslogins.c b/login-utils/lslogins.c
index 6e2d0ff25f18af4d770208c3e3f98f073980792a..c687e58e8955fc1e4a6f0c49fc4fba1510428413 100644 (file)
--- a/login-utils/lslogins.c
+++ b/login-utils/lslogins.c
@@ -36,6 +36,7 @@
 #include <err.h>
 #include <limits.h>
 #include <search.h>
+#include <lastlog.h>
 
 #include <libsmartcols.h>
 #ifdef HAVE_LIBSELINUX
@@ -95,6 +96,12 @@ enum {
        OUT_PRETTY
 };
 
+enum {
+       LASTLOG_TIME,
+       LASTLOG_LINE,
+       LASTLOG_HOST
+};
+
 struct lslogins_user {
        char *login;
        uid_t uid;
@@ -252,6 +259,8 @@ struct lslogins_control {
        struct utmpx *btmp;
        size_t btmp_size;
 
+       int lastlogin_fd;
+
        void *usertree;
 
        uid_t uid;
@@ -516,6 +525,31 @@ static int parse_btmp(struct lslogins_control *ctl, char *path)
        return rc;
 }
 
+static void get_lastlog(struct lslogins_control *ctl, uid_t uid, void *dst, int what)
+{
+       struct lastlog ll;
+
+       if (ctl->lastlogin_fd < 0 ||
+           pread(ctl->lastlogin_fd, (void *)&ll, sizeof(ll), uid * sizeof(ll)) != sizeof(ll))
+               return;
+
+       switch (what) {
+       case LASTLOG_TIME: {
+               time_t *t = (time_t *)dst;
+               *t = ll.ll_time;
+               break;
+               }
+       case LASTLOG_LINE:
+               mem2strcpy(dst, ll.ll_line, sizeof(ll.ll_line), sizeof(ll.ll_line) + 1);
+               break;
+       case LASTLOG_HOST:
+               mem2strcpy(dst, ll.ll_host, sizeof(ll.ll_host), sizeof(ll.ll_host) + 1);
+               break;
+       default:
+               abort();
+       }
+}
+
 static int get_sgroups(gid_t **list, size_t *len, struct passwd *pwd)
 {
        size_t n = 0;
@@ -737,23 +771,31 @@ static struct lslogins_user *get_user_info(struct lslogins_control *ctl, const c
                        if (user_wtmp) {
                                time = user_wtmp->ut_tv.tv_sec;
                                user->last_login = make_time(ctl->time_mode, time);
+                       } else {
+                               time = 0;
+                               get_lastlog(ctl, pwd->pw_uid, &time, LASTLOG_TIME);
+                               if (time)
+                                       user->last_login = make_time(ctl->time_mode, time);
                        }
                        break;
                case COL_LAST_TTY:
+                       user->last_tty = xcalloc(1, sizeof(user_wtmp->ut_line) + 1);
                        if (user_wtmp) {
-                               user->last_tty = xmalloc(sizeof(user_wtmp->ut_line) + 1);
                                mem2strcpy(user->last_tty, user_wtmp->ut_line,
                                                sizeof(user_wtmp->ut_line),
                                                sizeof(user_wtmp->ut_line) + 1);;
+                       }  else {
+                               get_lastlog(ctl, user->uid, user->last_tty, LASTLOG_LINE);
                        }
                        break;
                case COL_LAST_HOSTNAME:
+                       user->last_hostname = xcalloc(1, sizeof(user_wtmp->ut_host) + 1);
                        if (user_wtmp) {
-                               user->last_hostname = xmalloc(sizeof(user_wtmp->ut_host) + 1);
                                mem2strcpy(user->last_hostname, user_wtmp->ut_host,
                                                sizeof(user_wtmp->ut_host),
                                                sizeof(user_wtmp->ut_host) + 1);;
-                       }
+                       }  else
+                               get_lastlog(ctl, user->uid, user->last_hostname, LASTLOG_HOST);
                        break;
                case COL_FAILED_LOGIN:
                        if (user_btmp) {
@@ -1363,6 +1405,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -z, --print0             delimit user entries with a nul character\n"), out);
        fputs(_("     --wtmp-file <path>   set an alternate path for wtmp\n"), out);
        fputs(_("     --btmp-file <path>   set an alternate path for btmp\n"), out);
+       fputs(_("     --lastlog <path>     set an alternate path for lastlog\n"), out);
        fputs(USAGE_SEPARATOR, out);
        printf(USAGE_HELP_OPTIONS(26));
 
@@ -1379,7 +1422,7 @@ int main(int argc, char *argv[])
 {
        int c;
        char *logins = NULL, *groups = NULL, *outarg = NULL;
-       char *path_wtmp = _PATH_WTMP, *path_btmp = _PATH_BTMP;
+       char *path_lastlog = _PATH_LASTLOG, *path_wtmp = _PATH_WTMP, *path_btmp = _PATH_BTMP;
        struct lslogins_control *ctl = xcalloc(1, sizeof(struct lslogins_control));
        size_t i;
 
@@ -1387,6 +1430,7 @@ int main(int argc, char *argv[])
        enum {
                OPT_WTMP = CHAR_MAX + 1,
                OPT_BTMP,
+               OPT_LASTLOG,
                OPT_NOTRUNC,
                OPT_NOHEAD,
                OPT_TIME_FMT,
@@ -1417,6 +1461,7 @@ int main(int argc, char *argv[])
                { "print0",         no_argument,        0, 'z' },
                { "wtmp-file",      required_argument,  0, OPT_WTMP },
                { "btmp-file",      required_argument,  0, OPT_BTMP },
+               { "lastlog-file",   required_argument,  0, OPT_LASTLOG },
 #ifdef HAVE_LIBSELINUX
                { "context",        no_argument,        0, 'Z' },
 #endif
@@ -1524,6 +1569,9 @@ int main(int argc, char *argv[])
                case 'z':
                        outmode = OUT_NUL;
                        break;
+               case OPT_LASTLOG:
+                       path_lastlog = optarg;
+                       break;
                case OPT_WTMP:
                        path_wtmp = optarg;
                        break;
@@ -1591,8 +1639,10 @@ int main(int argc, char *argv[])
                                         &ncolumns, column_name_to_id) < 0)
                return EXIT_FAILURE;
 
-       if (require_wtmp())
+       if (require_wtmp()) {
                parse_wtmp(ctl, path_wtmp);
+               ctl->lastlogin_fd = open(path_lastlog, O_RDONLY, 0);
+       }
        if (require_btmp())
                parse_btmp(ctl, path_btmp);
 
@@ -1606,6 +1656,7 @@ int main(int argc, char *argv[])
 
        scols_unref_table(tb);
        tdestroy(ctl->usertree, free_user);
+       close(ctl->lastlogin_fd);
        free_ctl(ctl);
 
        return EXIT_SUCCESS;