basic/user-util: split out placeholder suppression from USER_CREDS_CLEAN into its own flag

No functional change, preparation for later commits.
This commit is contained in:
Mike Yuan 2024-11-18 19:30:02 +01:00
parent 579ce77ead
commit eea9d3eb10
No known key found for this signature in database
GPG Key ID: 417471C0A40F58B3
4 changed files with 16 additions and 15 deletions

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@ -220,9 +220,9 @@ static int synthesize_user_creds(
if (ret_gid) if (ret_gid)
*ret_gid = GID_NOBODY; *ret_gid = GID_NOBODY;
if (ret_home) if (ret_home)
*ret_home = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : "/"; *ret_home = FLAGS_SET(flags, USER_CREDS_SUPPRESS_PLACEHOLDER) ? NULL : "/";
if (ret_shell) if (ret_shell)
*ret_shell = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : NOLOGIN; *ret_shell = FLAGS_SET(flags, USER_CREDS_SUPPRESS_PLACEHOLDER) ? NULL : NOLOGIN;
return 0; return 0;
} }
@ -244,6 +244,7 @@ int get_user_creds(
assert(username); assert(username);
assert(*username); assert(*username);
assert((ret_home || ret_shell) || !(flags & (USER_CREDS_SUPPRESS_PLACEHOLDER|USER_CREDS_CLEAN)));
if (!FLAGS_SET(flags, USER_CREDS_PREFER_NSS) || if (!FLAGS_SET(flags, USER_CREDS_PREFER_NSS) ||
(!ret_home && !ret_shell)) { (!ret_home && !ret_shell)) {
@ -315,16 +316,14 @@ int get_user_creds(
if (ret_home) if (ret_home)
/* Note: we don't insist on normalized paths, since there are setups that have /./ in the path */ /* Note: we don't insist on normalized paths, since there are setups that have /./ in the path */
*ret_home = (FLAGS_SET(flags, USER_CREDS_CLEAN) && *ret_home = (FLAGS_SET(flags, USER_CREDS_SUPPRESS_PLACEHOLDER) && empty_or_root(p->pw_dir)) ||
(empty_or_root(p->pw_dir) || (FLAGS_SET(flags, USER_CREDS_CLEAN) && (!path_is_valid(p->pw_dir) || !path_is_absolute(p->pw_dir)))
!path_is_valid(p->pw_dir) || ? NULL : p->pw_dir;
!path_is_absolute(p->pw_dir))) ? NULL : p->pw_dir;
if (ret_shell) if (ret_shell)
*ret_shell = (FLAGS_SET(flags, USER_CREDS_CLEAN) && *ret_shell = (FLAGS_SET(flags, USER_CREDS_SUPPRESS_PLACEHOLDER) && shell_is_placeholder(p->pw_shell)) ||
(shell_is_placeholder(p->pw_shell) || (FLAGS_SET(flags, USER_CREDS_CLEAN) && (!path_is_valid(p->pw_shell) || !path_is_absolute(p->pw_shell)))
!path_is_valid(p->pw_shell) || ? NULL : p->pw_shell;
!path_is_absolute(p->pw_shell))) ? NULL : p->pw_shell;
if (patch_username) if (patch_username)
*username = p->pw_name; *username = p->pw_name;

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@ -48,9 +48,10 @@ static inline bool shell_is_placeholder(const char *shell) {
} }
typedef enum UserCredsFlags { typedef enum UserCredsFlags {
USER_CREDS_PREFER_NSS = 1 << 0, /* if set, only synthesize user records if database lacks them. Normally we bypass the userdb entirely for the records we can synthesize */ USER_CREDS_PREFER_NSS = 1 << 0, /* if set, only synthesize user records if database lacks them. Normally we bypass the userdb entirely for the records we can synthesize */
USER_CREDS_ALLOW_MISSING = 1 << 1, /* if a numeric UID string is resolved, be OK if there's no record for it */ USER_CREDS_ALLOW_MISSING = 1 << 1, /* if a numeric UID string is resolved, be OK if there's no record for it */
USER_CREDS_CLEAN = 1 << 2, /* try to clean up shell and home fields with invalid data */ USER_CREDS_CLEAN = 1 << 2, /* try to clean up shell and home fields with invalid data */
USER_CREDS_SUPPRESS_PLACEHOLDER = 1 << 3, /* suppress home and/or shell fields if value is placeholder (root/empty/nologin) */
} UserCredsFlags; } UserCredsFlags;
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); 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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@ -858,7 +858,7 @@ static int get_fixed_user(
/* Note that we don't set $HOME or $SHELL if they are not particularly enlightening anyway /* Note that we don't set $HOME or $SHELL if they are not particularly enlightening anyway
* (i.e. are "/" or "/bin/nologin"). */ * (i.e. are "/" or "/bin/nologin"). */
r = get_user_creds(&user_or_uid, ret_uid, ret_gid, ret_home, ret_shell, USER_CREDS_CLEAN); r = get_user_creds(&user_or_uid, ret_uid, ret_gid, ret_home, ret_shell, USER_CREDS_CLEAN|USER_CREDS_SUPPRESS_PLACEHOLDER);
if (r < 0) if (r < 0)
return r; return r;

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@ -2297,7 +2297,8 @@ static int start_transient_scope(sd_bus *bus) {
uid_t uid; uid_t uid;
gid_t gid; gid_t gid;
r = get_user_creds(&arg_exec_user, &uid, &gid, &home, &shell, USER_CREDS_CLEAN|USER_CREDS_PREFER_NSS); r = get_user_creds(&arg_exec_user, &uid, &gid, &home, &shell,
USER_CREDS_CLEAN|USER_CREDS_SUPPRESS_PLACEHOLDER|USER_CREDS_PREFER_NSS);
if (r < 0) if (r < 0)
return log_error_errno(r, "Failed to resolve user %s: %m", arg_exec_user); return log_error_errno(r, "Failed to resolve user %s: %m", arg_exec_user);