logind: introduce libsystemd-login.so as fast path to access logind data

3 files changed, 439 insertions, 0 deletions

diff --git a/src/sd-login.c b/src/sd-login.c
new file mode 100644
index 0000000000..3ae850d801
--- /dev/null
+++ b/src/sd-login.c
@@ -0,0 +1,323 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "util.h"
+#include "cgroup-util.h"
+#include "macro.h"
+#include "sd-login.h"
+
+_public_ int sd_pid_get_session(pid_t pid, char **session) {
+        int r;
+        char *cg_process, *cg_init, *p;
+
+        if (pid == 0)
+                pid = getpid();
+
+        if (pid <= 0)
+                return -EINVAL;
+
+        if (!session)
+                return -EINVAL;
+
+        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
+        if (r < 0)
+                return r;
+
+        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &cg_init);
+        if (r < 0) {
+                free(cg_process);
+                return r;
+        }
+
+        if (endswith(cg_init, "/system"))
+                cg_init[strlen(cg_init)-7] = 0;
+        else if (streq(cg_init, "/"))
+                cg_init[0] = 0;
+
+        if (startswith(cg_process, cg_init))
+                p = cg_process + strlen(cg_init);
+        else
+                p = cg_process;
+
+        free(cg_init);
+
+        if (!startswith(p, "/user/")) {
+                free(cg_process);
+                return -ENOENT;
+        }
+
+        p += 6;
+        if (startswith(p, "shared/") || streq(p, "shared")) {
+                free(cg_process);
+                return -ENOENT;
+        }
+
+        p = strchr(p, '/');
+        if (!p) {
+                free(cg_process);
+                return -ENOENT;
+        }
+
+        p++;
+        p = strndup(p, strcspn(p, "/"));
+        free(cg_process);
+
+        if (!p)
+                return -ENOMEM;
+
+        *session = p;
+        return 0;
+}
+
+_public_ int sd_uid_get_state(uid_t uid, char**state) {
+        char *p, *s = NULL;
+        int r;
+
+        if (!state)
+                return -EINVAL;
+
+        if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
+        free(p);
+
+        if (r == -ENOENT) {
+                free(s);
+                s = strdup("offline");
+                if (!s)
+                        return -ENOMEM;
+
+                *state = s;
+                return 0;
+        } else if (r < 0) {
+                free(s);
+                return r;
+        } else if (!s)
+                return -EIO;
+
+        *state = s;
+        return 0;
+}
+
+static int uid_is_on_seat_internal(uid_t uid, const char *seat, const char *variable) {
+        char *p, *w, *t, *state, *s = NULL;
+        size_t l;
+        int r;
+
+        if (!seat)
+                return -EINVAL;
+
+        p = strappend("/run/systemd/seats/", seat);
+        if (!p)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "UIDS", &s, NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                return r;
+        }
+
+        if (!s)
+                return -EIO;
+
+        if (asprintf(&t, "%lu", (unsigned long) uid) < 0) {
+                free(s);
+                return -ENOMEM;
+        }
+
+        FOREACH_WORD(w, l, s, state) {
+                if (strncmp(t, w, l) == 0) {
+                        free(s);
+                        free(t);
+
+                        return 1;
+                }
+        }
+
+        free(s);
+        free(t);
+
+        return 0;
+}
+
+_public_ int sd_uid_is_on_seat(uid_t uid, const char *seat) {
+        return uid_is_on_seat_internal(uid, seat, "UIDS");
+}
+
+_public_ int sd_uid_is_active_on_seat(uid_t uid, const char *seat) {
+        return uid_is_on_seat_internal(uid, seat, "ACTIVE_UID");
+}
+
+_public_ int sd_session_is_active(const char *session) {
+        int r;
+        char *p, *s = NULL;
+
+        if (!session)
+                return -EINVAL;
+
+        p = strappend("/run/systemd/sessions/", session);
+        if (!p)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                return r;
+        }
+
+        if (!s)
+                return -EIO;
+
+        r = parse_boolean(s);
+        free(s);
+
+        return r;
+}
+
+_public_ int sd_session_get_uid(const char *session, uid_t *uid) {
+        int r;
+        char *p, *s = NULL;
+        unsigned long ul;
+
+        if (!session)
+                return -EINVAL;
+        if (!uid)
+                return -EINVAL;
+
+        p = strappend("/run/systemd/sessions/", session);
+        if (!p)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                return r;
+        }
+
+        if (!s)
+                return -EIO;
+
+        r = safe_atolu(s, &ul);
+        free(s);
+
+        if (r < 0)
+                return r;
+
+        *uid = (uid_t) ul;
+        return 0;
+}
+
+_public_ int sd_session_get_seat(const char *session, char **seat) {
+        char *p, *s = NULL;
+        int r;
+
+        if (!session)
+                return -EINVAL;
+        if (!seat)
+                return -EINVAL;
+
+        p = strappend("/run/systemd/sessions/", session);
+        if (!p)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "SEAT", &s, NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                return r;
+        }
+
+        if (isempty(s))
+                return -ENOENT;
+
+        *seat = s;
+        return 0;
+}
+
+_public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
+        char *p, *s = NULL, *t = NULL;
+        int r;
+
+        if (!seat)
+                return -EINVAL;
+        if (!session && !uid)
+                return -EINVAL;
+
+        p = strappend("/run/systemd/seats/", seat);
+        if (!p)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE,
+                           "ACTIVE", &s,
+                           "ACTIVE_UID", &t,
+                           NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                free(t);
+                return r;
+        }
+
+        if (session && !s)  {
+                free(t);
+                return -EIO;
+        }
+
+        if (uid && !t) {
+                free(s);
+                return -EIO;
+        }
+
+        if (uid && t) {
+                unsigned long ul;
+
+                r = safe_atolu(t, &ul);
+                if (r < 0) {
+                        free(t);
+                        free(s);
+                        return r;
+                }
+
+                *uid = (uid_t) ul;
+        }
+
+        free(t);
+
+        if (session && s)
+                *session = s;
+        else
+                free(s);
+
+        return 0;
+}
diff --git a/src/sd-login.h b/src/sd-login.h
new file mode 100644
index 0000000000..f23ac80526
--- /dev/null
+++ b/src/sd-login.h
@@ -0,0 +1,51 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#ifndef foosdloginhfoo
+#define foosdloginhfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+
+/* Get session from PID */
+int sd_pid_get_session(pid_t pid, char **session);
+
+/* Get state from uid. Possible states: offline, lingering, online, active */
+int sd_uid_get_state(uid_t uid, char**state);
+
+/* Return 1 if uid has session on seat */
+int sd_uid_is_on_seat(uid_t uid, const char *seat);
+
+/* Return 1 if uid has active session on seat */
+int sd_uid_is_active_on_seat(uid_t uid, const char *seat);
+
+/* Return 1 if the session is a active */
+int sd_session_is_active(const char *session);
+
+/* Determine user id of session */
+int sd_session_get_uid(const char *session, uid_t *uid);
+
+/* Determine seat of session */
+int sd_session_get_seat(const char *session, char **seat);
+
+/* Return active session and user of seat */
+int sd_seat_get_active(const char *seat, char **session, uid_t *uid);
+
+#endif
diff --git a/src/test-login.c b/src/test-login.c
new file mode 100644
index 0000000000..97313fcbcb
--- /dev/null
+++ b/src/test-login.c
@@ -0,0 +1,65 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-login.h"
+#include "util.h"
+
+int main(int argc, char* argv[]) {
+    int r, k;
+    uid_t u, u2;
+        char *seat;
+        char *session;
+        char *state;
+        char *session2;
+
+        assert_se(sd_pid_get_session(0, &session) == 0);
+        printf("session = %s\n", session);
+
+        r = sd_session_is_active(session);
+        assert_se(r >= 0);
+        printf("active = %s\n", yes_no(r));
+
+        assert_se(sd_session_get_uid(session, &u) >= 0);
+        printf("uid = %lu\n", (unsigned long) u);
+
+        assert_se(sd_session_get_seat(session, &seat) >= 0);
+        printf("seat = %s\n", seat);
+
+        assert_se(sd_uid_get_state(u, &state) >= 0);
+        printf("state = %s\n", state);
+
+        assert_se(sd_uid_is_on_seat(u, seat) > 0);
+
+        k = sd_uid_is_active_on_seat(u, seat);
+        assert_se(k >= 0);
+        assert_se(!!r == !!r);
+
+        assert_se(sd_seat_get_active(seat, &session2, &u2) >= 0);
+        printf("session2 = %s\n", session2);
+        printf("uid2 = %lu\n", (unsigned long) u2);
+
+        free(session);
+        free(state);
+        free(session2);
+        free(seat);
+
+        return 0;
+}