mirror of
https://github.com/systemd/systemd.git
synced 2025-02-03 17:47:28 +03:00
user-util: modernize get_user_creds() + get_group_creds()
Let's rename return parameters to ret_xyz, and let's guarantee the usual rule to initialize all return parameters on success, and not touch any on failure.
This commit is contained in:
Lennart Poettering
parent
c5ff54c40f
commit
83e9b584db
@ -184,27 +184,28 @@ const char* default_root_shell(const char *root) {
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static int synthesize_user_creds(
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const char **username,
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uid_t *uid, gid_t *gid,
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const char **home,
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const char **shell,
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uid_t *ret_uid, gid_t *ret_gid,
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const char **ret_home,
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const char **ret_shell,
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UserCredsFlags flags) {
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assert(username);
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assert(*username);
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/* We enforce some special rules for uid=0 and uid=65534: in order to avoid NSS lookups for root we hardcode
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* their user record data. */
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if (STR_IN_SET(*username, "root", "0")) {
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*username = "root";
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if (uid)
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*uid = 0;
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if (gid)
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*gid = 0;
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if (home)
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*home = "/root";
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if (shell)
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*shell = default_root_shell(NULL);
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if (ret_uid)
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*ret_uid = 0;
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if (ret_gid)
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*ret_gid = 0;
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if (ret_home)
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*ret_home = "/root";
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if (ret_shell)
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*ret_shell = default_root_shell(NULL);
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return 0;
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}
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@ -213,16 +214,14 @@ static int synthesize_user_creds(
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synthesize_nobody()) {
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*username = NOBODY_USER_NAME;
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if (uid)
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*uid = UID_NOBODY;
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if (gid)
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*gid = GID_NOBODY;
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if (home)
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*home = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : "/";
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if (shell)
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*shell = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : NOLOGIN;
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if (ret_uid)
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*ret_uid = UID_NOBODY;
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if (ret_gid)
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*ret_gid = GID_NOBODY;
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if (ret_home)
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*ret_home = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : "/";
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if (ret_shell)
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*ret_shell = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : NOLOGIN;
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return 0;
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}
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@ -232,11 +231,12 @@ static int synthesize_user_creds(
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int get_user_creds(
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const char **username,
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uid_t *uid, gid_t *gid,
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const char **home,
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const char **shell,
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uid_t *ret_uid, gid_t *ret_gid,
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const char **ret_home,
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const char **ret_shell,
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UserCredsFlags flags) {
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bool patch_username = false;
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uid_t u = UID_INVALID;
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struct passwd *p;
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int r;
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@ -245,7 +245,7 @@ int get_user_creds(
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assert(*username);
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if (!FLAGS_SET(flags, USER_CREDS_PREFER_NSS) ||
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(!home && !shell)) {
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(!ret_home && !ret_shell)) {
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/* So here's the deal: normally, we'll try to synthesize all records we can synthesize, and override
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* the user database with that. However, if the user specifies USER_CREDS_PREFER_NSS then the
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@ -256,7 +256,7 @@ int get_user_creds(
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* of the relevant users, but changing the UID/GID mappings for them is something we explicitly don't
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* support. */
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r = synthesize_user_creds(username, uid, gid, home, shell, flags);
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r = synthesize_user_creds(username, ret_uid, ret_gid, ret_home, ret_shell, flags);
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if (r >= 0)
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return 0;
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if (r != -ENOMEDIUM) /* not a username we can synthesize */
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@ -271,15 +271,21 @@ int get_user_creds(
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* instead of the first occurrence in the database. However if the uid was configured by a numeric uid,
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* then let's pick the real username from /etc/passwd. */
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if (p)
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*username = p->pw_name;
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else if (FLAGS_SET(flags, USER_CREDS_ALLOW_MISSING) && !gid && !home && !shell) {
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patch_username = true;
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else if (FLAGS_SET(flags, USER_CREDS_ALLOW_MISSING) && !ret_gid && !ret_home && !ret_shell) {
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/* If the specified user is a numeric UID and it isn't in the user database, and the caller
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* passed USER_CREDS_ALLOW_MISSING and was only interested in the UID, then just return that
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* and don't complain. */
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if (uid)
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*uid = u;
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if (ret_uid)
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*ret_uid = u;
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if (ret_gid)
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*ret_gid = GID_INVALID;
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if (ret_home)
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*ret_home = NULL;
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if (ret_shell)
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*ret_shell = NULL;
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return 0;
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}
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@ -293,65 +299,59 @@ int get_user_creds(
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r = IN_SET(errno, 0, ENOENT) ? -ESRCH : -errno;
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/* If the user requested that we only synthesize as fallback, do so now */
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if (FLAGS_SET(flags, USER_CREDS_PREFER_NSS)) {
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if (synthesize_user_creds(username, uid, gid, home, shell, flags) >= 0)
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if (FLAGS_SET(flags, USER_CREDS_PREFER_NSS))
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if (synthesize_user_creds(username, ret_uid, ret_gid, ret_home, ret_shell, flags) >= 0)
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return 0;
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}
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return r;
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}
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if (uid) {
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if (!uid_is_valid(p->pw_uid))
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return -EBADMSG;
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if (ret_uid && !uid_is_valid(p->pw_uid))
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return -EBADMSG;
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*uid = p->pw_uid;
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}
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if (ret_gid && !gid_is_valid(p->pw_gid))
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return -EBADMSG;
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if (gid) {
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if (!gid_is_valid(p->pw_gid))
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return -EBADMSG;
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if (ret_uid)
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*ret_uid = p->pw_uid;
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*gid = p->pw_gid;
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}
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if (ret_gid)
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*ret_gid = p->pw_gid;
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if (home) {
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if (FLAGS_SET(flags, USER_CREDS_CLEAN) &&
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(empty_or_root(p->pw_dir) ||
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!path_is_valid(p->pw_dir) ||
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!path_is_absolute(p->pw_dir)))
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*home = NULL; /* Note: we don't insist on normalized paths, since there are setups that have /./ in the path */
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else
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*home = p->pw_dir;
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}
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if (ret_home)
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/* Note: we don't insist on normalized paths, since there are setups that have /./ in the path */
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*ret_home = (FLAGS_SET(flags, USER_CREDS_CLEAN) &&
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(empty_or_root(p->pw_dir) ||
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!path_is_valid(p->pw_dir) ||
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!path_is_absolute(p->pw_dir))) ? NULL : p->pw_dir;
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if (shell) {
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if (FLAGS_SET(flags, USER_CREDS_CLEAN) &&
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(isempty(p->pw_shell) ||
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!path_is_valid(p->pw_dir) ||
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!path_is_absolute(p->pw_shell) ||
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is_nologin_shell(p->pw_shell)))
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*shell = NULL;
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else
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*shell = p->pw_shell;
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}
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if (ret_shell)
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*ret_shell = (FLAGS_SET(flags, USER_CREDS_CLEAN) &&
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(isempty(p->pw_shell) ||
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!path_is_valid(p->pw_dir) ||
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!path_is_absolute(p->pw_shell) ||
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is_nologin_shell(p->pw_shell))) ? NULL : p->pw_shell;
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if (patch_username)
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*username = p->pw_name;
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return 0;
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}
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int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags) {
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int get_group_creds(const char **groupname, gid_t *ret_gid, UserCredsFlags flags) {
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bool patch_groupname = false;
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struct group *g;
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gid_t id;
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assert(groupname);
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assert(*groupname);
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/* We enforce some special rules for gid=0: in order to avoid NSS lookups for root we hardcode its data. */
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if (STR_IN_SET(*groupname, "root", "0")) {
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*groupname = "root";
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if (gid)
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*gid = 0;
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if (ret_gid)
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*ret_gid = 0;
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return 0;
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}
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@ -360,8 +360,8 @@ int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags) {
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synthesize_nobody()) {
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*groupname = NOBODY_GROUP_NAME;
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if (gid)
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*gid = GID_NOBODY;
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if (ret_gid)
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*ret_gid = GID_NOBODY;
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return 0;
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}
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@ -371,10 +371,10 @@ int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags) {
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g = getgrgid(id);
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if (g)
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*groupname = g->gr_name;
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patch_groupname = true;
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else if (FLAGS_SET(flags, USER_CREDS_ALLOW_MISSING)) {
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if (gid)
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*gid = id;
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if (ret_gid)
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*ret_gid = id;
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return 0;
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}
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@ -388,13 +388,16 @@ int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags) {
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* For us that is equivalent to the name not being defined. */
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return IN_SET(errno, 0, ENOENT) ? -ESRCH : -errno;
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if (gid) {
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if (ret_gid) {
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if (!gid_is_valid(g->gr_gid))
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return -EBADMSG;
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*gid = g->gr_gid;
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*ret_gid = g->gr_gid;
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}
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if (patch_groupname)
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*groupname = g->gr_name;
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return 0;
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}
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@ -42,8 +42,8 @@ typedef enum UserCredsFlags {
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USER_CREDS_CLEAN = 1 << 2, /* try to clean up shell and home fields with invalid data */
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} UserCredsFlags;
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int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell, UserCredsFlags flags);
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int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags);
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int get_user_creds(const char **username, uid_t *ret_uid, gid_t *ret_gid, const char **ret_home, const char **ret_shell, UserCredsFlags flags);
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int get_group_creds(const char **groupname, gid_t *ret_gid, UserCredsFlags flags);
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char* uid_to_name(uid_t uid);
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char* gid_to_name(gid_t gid);
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