su: cleanup usernames usage

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/login-utils/su-common.c b/login-utils/su-common.c
index adfc199e2377301f152af26b84932e4748f01970..c818b9eb82b89674e567568e5031de1493430cfe 100644 (file)
--- a/login-utils/su-common.c
+++ b/login-utils/su-common.c
@@ -94,7 +94,11 @@ struct su_context {
        const char      *tty_name;              /* tty_path without /dev prefix */
        const char      *tty_number;            /* end of the tty_path */
 
+       char            *new_user;              /* wanted user */
+       char            *old_user;              /* orginal user */
+
        unsigned int runuser :1,                /* flase=su, true=runuser */
+                    runuser_uopt :1,           /* runuser -u specified */
                     isterm :1,                 /* is stdin terminal? */
                     fast_startup :1,           /* pass the `-f' option to the subshell. */
                     simulate_login :1,         /* simulate a login instead of just starting a shell. */
@@ -118,27 +122,6 @@ su_catch_sig(int sig)
        caught_signal = sig;
 }
 
-
-static const struct passwd *
-current_getpwuid(void)
-{
-       uid_t ruid;
-
-       /* GNU Hurd implementation has an extension where a process can exist in a
-        * non-conforming environment, and thus be outside the realms of POSIX
-        * process identifiers; on this platform, getuid() fails with a status of
-        * (uid_t)(-1) and sets errno if a program is run from a non-conforming
-        * environment.
-        *
-        * http://austingroupbugs.net/view.php?id=511
-        */
-       errno = 0;
-       ruid = getuid();
-
-       return errno == 0 ? getpwuid(ruid) : NULL;
-}
-
-
 static void init_tty(struct su_context *su)
 {
        su->isterm = isatty(STDIN_FILENO) ? 1 : 0;
@@ -151,24 +134,11 @@ static void init_tty(struct su_context *su)
 
 static void log_syslog(struct su_context *su, bool successful)
 {
-       const char *new_user = su->pwd->pw_name,
-                  *old_user;
-
-       /* The utmp entry (via getlogin) is probably the best way to identify
-        * the user, especially if someone su's from a su-shell.
-        */
-       old_user = getlogin();
-       if (!old_user) {
-               /* probably lack of utmp entry; resort to getpwuid. */
-               const struct passwd *pwd = current_getpwuid();
-               old_user = pwd ? pwd->pw_name : "";
-       }
-
        openlog(program_invocation_short_name, 0, LOG_AUTH);
        syslog(LOG_NOTICE, "%s(to %s) %s on %s",
               successful ? "" :
               su->runuser ? "FAILED RUNUSER " : "FAILED SU ",
-              new_user, old_user,
+              su->new_user, su->old_user ? : "",
               su->tty_name ? : "none");
        closelog();
 }
@@ -246,7 +216,6 @@ static void supam_export_environment(struct su_context *su)
 
 static void supam_authenticate(struct su_context *su)
 {
-       const struct passwd *lpw = NULL;
        const char *srvname = NULL;
        int retval;
 
@@ -263,14 +232,11 @@ static void supam_authenticate(struct su_context *su)
                if (is_pam_failure(retval))
                        goto done;
        }
-
-       lpw = current_getpwuid();
-       if (lpw && lpw->pw_name) {
-               retval = pam_set_item(su->pamh, PAM_RUSER, (const void *)lpw->pw_name);
+       if (su->old_user) {
+               retval = pam_set_item(su->pamh, PAM_RUSER, (const void *) su->old_user);
                if (is_pam_failure(retval))
                        goto done;
        }
-
        if (su->runuser) {
                /*
                 * This is the only difference between runuser(1) and su(1). The command
@@ -722,11 +688,11 @@ su_main(int argc, char **argv, int mode)
        struct su_context _su = {
                .conv                   = { supam_conv, NULL },
                .runuser                = (mode == RUNUSER_MODE ? 1 : 0),
-               .change_environment     = 1
+               .change_environment     = 1,
+               .new_user               = DEFAULT_USER
        }, *su = &_su;
 
        int optc;
-       const char *new_user = DEFAULT_USER, *runuser_user = NULL;
        char *command = NULL;
        int request_same_session = 0;
        char *shell = NULL;
@@ -802,7 +768,8 @@ su_main(int argc, char **argv, int mode)
                case 'u':
                        if (!su->runuser)
                                errtryhelp(EXIT_FAILURE);
-                       runuser_user = optarg;
+                       su->runuser_uopt = 1;
+                       su->new_user = optarg;
                        break;
 
                case 'h':
@@ -832,19 +799,14 @@ su_main(int argc, char **argv, int mode)
 
        switch (mode) {
        case RUNUSER_MODE:
-               if (runuser_user) {
-                       /* runuser -u <user> <command> */
-                       new_user = runuser_user;
-                       if (shell || su->fast_startup || command || su->simulate_login) {
+               /* runuser -u <user> <command> */
+               if (su->runuser_uopt) {
+                       if (shell || su->fast_startup || command || su->simulate_login)
                                errx(EXIT_FAILURE,
-                                    _
-                                    ("options --{shell,fast,command,session-command,login} and "
+                                    _("options --{shell,fast,command,session-command,login} and "
                                      "--user are mutually exclusive"));
-                       }
                        if (optind == argc)
-                               errx(EXIT_FAILURE,
-                                    _("no command was specified"));
-
+                               errx(EXIT_FAILURE, _("no command was specified"));
                        break;
                }
                /* fallthrough if -u <user> is not specified, then follow
@@ -852,7 +814,7 @@ su_main(int argc, char **argv, int mode)
                 */
        case SU_MODE:
                if (optind < argc)
-                       new_user = argv[optind++];
+                       su->new_user = argv[optind++];
                break;
        }
 
@@ -863,12 +825,15 @@ su_main(int argc, char **argv, int mode)
        logindefs_set_loader(load_config, (void *) su);
        init_tty(su);
 
-       su->pwd = xgetpwnam(new_user, &su->pwdbuf);
+       su->pwd = xgetpwnam(su->new_user, &su->pwdbuf);
        if (!su->pwd
            || !su->pwd->pw_passwd
            || !su->pwd->pw_name || !*su->pwd->pw_name
            || !su->pwd->pw_dir  || !*su->pwd->pw_dir)
-               errx(EXIT_FAILURE, _("user %s does not exist"), new_user);
+               errx(EXIT_FAILURE, _("user %s does not exist"), su->new_user);
+
+       su->new_user = su->pwd->pw_name;
+       su->old_user = xgetlogin();
 
        if (!su->pwd->pw_shell || !*su->pwd->pw_shell)
                su->pwd->pw_shell = DEFAULT_SHELL;
@@ -884,7 +849,7 @@ su_main(int argc, char **argv, int mode)
                su->same_session = 1;
 
        /* initialize shell variable only if "-u <user>" not specified */
-       if (runuser_user) {
+       if (su->runuser_uopt) {
                shell = NULL;
        } else {
                if (!shell && !su->change_environment)