chfn: allow --help and --version without login.defs restrictions

Parse command line arguments twice: first pass handles --help and
--version before restrictions are applied, second pass enforces
login.defs CHFN_RESTRICT settings for field options.

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

diff --git a/login-utils/chfn.c b/login-utils/chfn.c
index bcd8599bc3913db99b4dcd1b89de9514b28fa65b..2a0f599d1437cc3efa1b3875b46bd3e6d3905c78 100644 (file)
--- a/login-utils/chfn.c
+++ b/login-utils/chfn.c
@@ -86,6 +86,18 @@ struct chfn_control {
 /* we do not accept gecos field sizes longer than MAX_FIELD_SIZE */
 #define MAX_FIELD_SIZE         256
 
+/* Global options - reused in both early check and main parsing */
+static const char *short_options = "f:r:p:h:o:uvV";
+static const struct option long_options[] = {
+       { "full-name",    required_argument, NULL, 'f' },
+       { "office",       required_argument, NULL, 'o' },
+       { "office-phone", required_argument, NULL, 'p' },
+       { "home-phone",   required_argument, NULL, 'h' },
+       { "help",         no_argument,       NULL, 'u' },
+       { "version",      no_argument,       NULL, 'V' },
+       { NULL, 0, NULL, 0 },
+};
+
 static void __attribute__((__noreturn__)) usage(void)
 {
        FILE *fp = stdout;
@@ -128,24 +140,40 @@ static int check_gecos_string(const char *msg, char *gecos)
 }
 
 /*
- *  parse_argv () --
- *     parse the command line arguments.
- *     returns true if no information beyond the username was given.
+ *  parse_argv_basic () --
+ *     early parse for --help and --version without login.defs restrictions
  */
-static void parse_argv(struct chfn_control *ctl, int argc, char **argv)
+static void parse_argv_basic(int argc, char **argv)
+{
+       int c, index;
+
+       opterr = 0;  /* suppress getopt error messages */
+       while ((c = getopt_long(argc, argv, short_options, long_options,
+                               &index)) != -1) {
+               switch (c) {
+               case 'v': /* deprecated */
+               case 'V':
+                       print_version(EXIT_SUCCESS);
+               case 'u':
+                       usage();
+               default:
+                       break;  /* ignore other options in early pass */
+               }
+       }
+       /* Reset getopt state for the main parse */
+       optind = 1;
+       opterr = 1;
+}
+
+/*
+ *  parse_argv_restricted () --
+ *     parse the command line arguments with login.defs restrictions applied
+ */
+static void parse_argv_restricted(struct chfn_control *ctl, int argc, char **argv)
 {
        int index, c, status = 0;
-       static const struct option long_options[] = {
-               { "full-name",    required_argument, NULL, 'f' },
-               { "office",       required_argument, NULL, 'o' },
-               { "office-phone", required_argument, NULL, 'p' },
-               { "home-phone",   required_argument, NULL, 'h' },
-               { "help",         no_argument,       NULL, 'u' },
-               { "version",      no_argument,       NULL, 'V' },
-               { NULL, 0, NULL, 0 },
-       };
 
-       while ((c = getopt_long(argc, argv, "f:r:p:h:o:uvV", long_options,
+       while ((c = getopt_long(argc, argv, short_options, long_options,
                                &index)) != -1) {
                switch (c) {
                case 'f':
@@ -172,11 +200,6 @@ static void parse_argv(struct chfn_control *ctl, int argc, char **argv)
                        ctl->newf.home_phone = optarg;
                        status += check_gecos_string(_("Home Phone"), optarg);
                        break;
-               case 'v': /* deprecated */
-               case 'V':
-                       print_version(EXIT_SUCCESS);
-               case 'u':
-                       usage();
                default:
                        errtryhelp(EXIT_FAILURE);
                }
@@ -411,10 +434,14 @@ int main(int argc, char **argv)
 
        uid = getuid();
 
+       /* early check for --help and --version before restrictions */
+       parse_argv_basic(argc, argv);
+
        /* check /etc/login.defs CHFN_RESTRICT */
        get_login_defs(&ctl);
 
-       parse_argv(&ctl, argc, argv);
+       /* parse command line with restrictions applied */
+       parse_argv_restricted(&ctl, argc, argv);
        if (!ctl.username) {
                ctl.pw = getpwuid(uid);
                if (!ctl.pw)