diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/id.c | 31 |
1 files changed, 19 insertions, 12 deletions
@@ -38,13 +38,6 @@ proper_name ("Arnold Robbins"), \ proper_name ("David MacKenzie") -/* Whether the functions getuid, geteuid, getgid and getegid may fail. */ -#ifdef __GNU__ -# define GETID_MAY_FAIL 1 -#else -# define GETID_MAY_FAIL 0 -#endif - /* If nonzero, output only the SELinux context. -Z */ static int just_context = 0; @@ -208,22 +201,36 @@ main (int argc, char **argv) } else { + /* On GNU/Hurd hosts, getuid etc. can fail and return -1. + However, on GNU/Linux hosts, uid_t is an unsigned value and + getuid etc. can return the positive value (uid_t) -1. To + handle both cases correctly, consider getuid etc. to fail if + it returns a negative value (a value that is impossible on + GNU/Linux hosts). + + GNU/Linux sysadmins should not give users the UID (uid_t) -1 + even though uid_t is unsigned, as system calls like chown would + not have the desired behavior with such a UID, and other + coreutils applications therefore do not support such a UID. + However, 'id' makes a special attempt to handle this UID, to + help people diagnose the problem. */ + euid = geteuid (); - if (GETID_MAY_FAIL && euid == -1 && !use_real + if (euid < 0 && !use_real && !just_group && !just_group_list && !just_context) error (EXIT_FAILURE, errno, _("cannot get effective UID")); ruid = getuid (); - if (GETID_MAY_FAIL && ruid == -1 && use_real + if (ruid < 0 && use_real && !just_group && !just_group_list && !just_context) error (EXIT_FAILURE, errno, _("cannot get real UID")); egid = getegid (); - if (GETID_MAY_FAIL && egid == -1 && !use_real && !just_user) + if (egid < 0 && !use_real && !just_user) error (EXIT_FAILURE, errno, _("cannot get effective GID")); rgid = getgid (); - if (GETID_MAY_FAIL && rgid == -1 && use_real && !just_user) + if (rgid < 0 && use_real && !just_user) error (EXIT_FAILURE, errno, _("cannot get real GID")); } @@ -316,7 +323,7 @@ print_full_info (const char *username) gid_t *groups; int i; - int n_groups = xgetgroups (username, (pwd ? pwd->pw_gid : (gid_t) -1), + int n_groups = xgetgroups (username, (pwd ? pwd->pw_gid : -1), &groups); if (n_groups < 0) { |