util: make use of get_user_creds() and get_group_creds() wherever applicable

6 files changed, 105 insertions, 117 deletions

diff --git a/src/execute.c b/src/execute.c
index 40af7d65f1..7b2567976d 100644
--- a/src/execute.c
+++ b/src/execute.c
@@ -549,36 +549,6 @@ static int restore_confirm_stdio(const ExecContext *context,
         return 0;
 }
 
-static int get_group_creds(const char *groupname, gid_t *gid) {
-        struct group *g;
-        gid_t id;
-
-        assert(groupname);
-        assert(gid);
-
-        /* We enforce some special rules for gid=0: in order to avoid
-         * NSS lookups for root we hardcode its data. */
-
-        if (streq(groupname, "root") || streq(groupname, "0")) {
-                *gid = 0;
-                return 0;
-        }
-
-        if (parse_gid(groupname, &id) >= 0) {
-                errno = 0;
-                g = getgrgid(id);
-        } else {
-                errno = 0;
-                g = getgrnam(groupname);
-        }
-
-        if (!g)
-                return errno != 0 ? -errno : -ESRCH;
-
-        *gid = g->gr_gid;
-        return 0;
-}
-
 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
         bool keep_groups = false;
         int r;
@@ -590,9 +560,12 @@ static int enforce_groups(const ExecContext *context, const char *username, gid_
 
         if (context->group || username) {
 
-                if (context->group)
-                        if ((r = get_group_creds(context->group, &gid)) < 0)
+                if (context->group) {
+                        const char *g = context->group;
+
+                        if ((r = get_group_creds(&g, &gid)) < 0)
                                 return r;
+                }
 
                 /* First step, initialize groups from /etc/groups */
                 if (username && gid != 0) {
@@ -627,13 +600,16 @@ static int enforce_groups(const ExecContext *context, const char *username, gid_
                         k = 0;
 
                 STRV_FOREACH(i, context->supplementary_groups) {
+                        const char *g;
 
                         if (k >= ngroups_max) {
                                 free(gids);
                                 return -E2BIG;
                         }
 
-                        if ((r = get_group_creds(*i, gids+k)) < 0) {
+                        g = *i;
+                        r = get_group_creds(&g, gids+k);
+                        if (r < 0) {
                                 free(gids);
                                 return r;
                         }
diff --git a/src/loginctl.c b/src/loginctl.c
index 08ee804f43..53058d07a7 100644
--- a/src/loginctl.c
+++ b/src/loginctl.c
@@ -1061,17 +1061,11 @@ static int show(DBusConnection *bus, char **args, unsigned n) {
                         uid_t uid;
                         uint32_t u;
 
-                        if (parse_uid(args[i], &uid) < 0) {
-                                struct passwd *pw;
-
-                                pw = getpwnam(args[i]);
-                                if (!pw) {
-                                        log_error("User %s unknown.", args[i]);
-                                        ret = -ENOENT;
-                                        goto finish;
-                                }
-
-                                uid = pw->pw_uid;
+                        r = get_user_creds((const char**) (args+i), &uid, NULL, NULL);
+                        if (r < 0) {
+                                log_error("User %s unknown.", args[i]);
+                                r = -ENOENT;
+                                goto finish;
                         }
 
                         m = dbus_message_new_method_call(
@@ -1298,18 +1292,10 @@ static int enable_linger(DBusConnection *bus, char **args, unsigned n) {
                         goto finish;
                 }
 
-                if (parse_uid(args[i], &uid) < 0) {
-                        struct passwd *pw;
-
-                        errno = 0;
-                        pw = getpwnam(args[i]);
-                        if (!pw) {
-                                ret = errno ? -errno : -ENOENT;
-                                log_error("Failed to resolve user %s: %s", args[i], strerror(-ret));
-                                goto finish;
-                        }
-
-                        uid = pw->pw_uid;
+                ret = get_user_creds((const char**) (args+i), &uid, NULL, NULL);
+                if (ret < 0) {
+                        log_error("Failed to resolve user %s: %s", args[i], strerror(-ret));
+                        goto finish;
                 }
 
                 u = (uint32_t) uid;
@@ -1335,6 +1321,8 @@ static int enable_linger(DBusConnection *bus, char **args, unsigned n) {
                 m = reply = NULL;
         }
 
+        ret = 0;
+
 finish:
         if (m)
                 dbus_message_unref(m);
@@ -1373,18 +1361,10 @@ static int terminate_user(DBusConnection *bus, char **args, unsigned n) {
                         goto finish;
                 }
 
-                if (parse_uid(args[i], &uid) < 0) {
-                        struct passwd *pw;
-
-                        errno = 0;
-                        pw = getpwnam(args[i]);
-                        if (!pw) {
-                                ret = errno ? -errno : -ENOENT;
-                                log_error("Failed to look up user %s: %s", args[i], strerror(-ret));
-                                goto finish;
-                        }
-
-                        uid = pw->pw_uid;
+                ret = get_user_creds((const char**) (args+i), &uid, NULL, NULL);
+                if (ret < 0) {
+                        log_error("Failed to look up user %s: %s", args[i], strerror(-ret));
+                        goto finish;
                 }
 
                 u = (uint32_t) uid;
@@ -1408,6 +1388,8 @@ static int terminate_user(DBusConnection *bus, char **args, unsigned n) {
                 m = reply = NULL;
         }
 
+        ret = 0;
+
 finish:
         if (m)
                 dbus_message_unref(m);
@@ -1449,18 +1431,10 @@ static int kill_user(DBusConnection *bus, char **args, unsigned n) {
                         goto finish;
                 }
 
-                if (parse_uid(args[i], &uid) < 0) {
-                        struct passwd *pw;
-
-                        errno = 0;
-                        pw = getpwnam(args[i]);
-                        if (!pw) {
-                                ret = errno ? -errno : -ENOENT;
-                                log_error("Failed to look up user %s: %s", args[i], strerror(-ret));
-                                goto finish;
-                        }
-
-                        uid = pw->pw_uid;
+                ret = get_user_creds((const char**) (args+i), &uid, NULL, NULL);
+                if (ret < 0) {
+                        log_error("Failed to look up user %s: %s", args[i], strerror(-ret));
+                        goto finish;
                 }
 
                 u = (uint32_t) uid;
@@ -1485,6 +1459,8 @@ static int kill_user(DBusConnection *bus, char **args, unsigned n) {
                 m = reply = NULL;
         }
 
+        ret = 0;
+
 finish:
         if (m)
                 dbus_message_unref(m);
diff --git a/src/logind.c b/src/logind.c
index a081501a8c..8b99065b23 100644
--- a/src/logind.c
+++ b/src/logind.c
@@ -239,17 +239,18 @@ int manager_add_user(Manager *m, uid_t uid, gid_t gid, const char *name, User **
 }
 
 int manager_add_user_by_name(Manager *m, const char *name, User **_user) {
-        struct passwd *p;
+        uid_t uid;
+        gid_t gid;
+        int r;
 
         assert(m);
         assert(name);
 
-        errno = 0;
-        p = getpwnam(name);
-        if (!p)
-                return errno ? -errno : -ENOENT;
+        r = get_user_creds(&name, &uid, &gid, NULL);
+        if (r < 0)
+                return r;
 
-        return manager_add_user(m, p->pw_uid, p->pw_gid, name, _user);
+        return manager_add_user(m, uid, gid, name, _user);
 }
 
 int manager_add_user_by_uid(Manager *m, uid_t uid, User **_user) {
diff --git a/src/tmpfiles.c b/src/tmpfiles.c
index a1b2f8b1d2..3a1985a363 100644
--- a/src/tmpfiles.c
+++ b/src/tmpfiles.c
@@ -757,18 +757,11 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         }
 
         if (user && !streq(user, "-")) {
-                uid_t uid;
-                struct passwd *p;
-
-                if (streq(user, "root") || streq(user, "0"))
-                        i->uid = 0;
-                else if (parse_uid(user, &uid) >= 0)
-                        i->uid = uid;
-                else if ((p = getpwnam(user)))
-                        i->uid = p->pw_uid;
-                else {
+                const char *u = user;
+
+                r = get_user_creds(&u, &i->uid, NULL, NULL);
+                if (r < 0) {
                         log_error("[%s:%u] Unknown user '%s'.", fname, line, user);
-                        r = -ENOENT;
                         goto finish;
                 }
 
@@ -776,18 +769,11 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         }
 
         if (group && !streq(group, "-")) {
-                gid_t gid;
-                struct group *g;
-
-                if (streq(group, "root") || streq(group, "0"))
-                        i->gid = 0;
-                else if (parse_gid(group, &gid) >= 0)
-                        i->gid = gid;
-                else if ((g = getgrnam(group)))
-                        i->gid = g->gr_gid;
-                else {
+                const char *g = group;
+
+                r = get_group_creds(&g, &i->gid);
+                if (r < 0) {
                         log_error("[%s:%u] Unknown group '%s'.", fname, line, group);
-                        r = -ENOENT;
                         goto finish;
                 }
 
diff --git a/src/util.c b/src/util.c
index 3a82ef7600..45b578bd03 100644
--- a/src/util.c
+++ b/src/util.c
@@ -54,6 +54,7 @@
 #include <sys/time.h>
 #include <linux/rtc.h>
 #include <glob.h>
+#include <grp.h>
 
 #include "macro.h"
 #include "util.h"
@@ -5266,18 +5267,21 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
 
         assert(username);
         assert(*username);
-        assert(uid);
-        assert(gid);
-        assert(home);
 
         /* We enforce some special rules for uid=0: in order to avoid
          * NSS lookups for root we hardcode its data. */
 
         if (streq(*username, "root") || streq(*username, "0")) {
                 *username = "root";
-                *uid = 0;
-                *gid = 0;
-                *home = "/root";
+
+                if (uid)
+                        *uid = 0;
+
+                if (gid)
+                        *gid = 0;
+
+                if (home)
+                        *home = "/root";
                 return 0;
         }
 
@@ -5300,9 +5304,53 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
         if (!p)
                 return errno != 0 ? -errno : -ESRCH;
 
-        *uid = p->pw_uid;
-        *gid = p->pw_gid;
-        *home = p->pw_dir;
+        if (uid)
+                *uid = p->pw_uid;
+
+        if (gid)
+                *gid = p->pw_gid;
+
+        if (home)
+                *home = p->pw_dir;
+
+        return 0;
+}
+
+int get_group_creds(const char **groupname, gid_t *gid) {
+        struct group *g;
+        gid_t id;
+
+        assert(groupname);
+
+        /* We enforce some special rules for gid=0: in order to avoid
+         * NSS lookups for root we hardcode its data. */
+
+        if (streq(*groupname, "root") || streq(*groupname, "0")) {
+                *groupname = "root";
+
+                if (gid)
+                        *gid = 0;
+
+                return 0;
+        }
+
+        if (parse_gid(*groupname, &id) >= 0) {
+                errno = 0;
+                g = getgrgid(id);
+
+                if (g)
+                        *groupname = g->gr_name;
+        } else {
+                errno = 0;
+                g = getgrnam(*groupname);
+        }
+
+        if (!g)
+                return errno != 0 ? -errno : -ESRCH;
+
+        if (gid)
+                *gid = g->gr_gid;
+
         return 0;
 }
 
diff --git a/src/util.h b/src/util.h
index 9537d130d3..bf5703c5aa 100644
--- a/src/util.h
+++ b/src/util.h
@@ -449,6 +449,7 @@ bool display_is_local(const char *display);
 int socket_from_display(const char *display, char **path);
 
 int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home);
+int get_group_creds(const char **groupname, gid_t *gid);
 
 int glob_exists(const char *path);