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-rw-r--r--src/chfn.c735
1 files changed, 735 insertions, 0 deletions
diff --git a/src/chfn.c b/src/chfn.c
new file mode 100644
index 0000000..1c2f1cc
--- /dev/null
+++ b/src/chfn.c
@@ -0,0 +1,735 @@
+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2001 - 2006, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <fcntl.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <getopt.h>
+#include "defines.h"
+#include "getdef.h"
+#include "nscd.h"
+#include "sssd.h"
+#ifdef USE_PAM
+#include "pam_defs.h"
+#endif
+#include "prototypes.h"
+#include "pwauth.h"
+#include "pwio.h"
+/*@-exitarg@*/
+#include "exitcodes.h"
+#include "shadowlog.h"
+
+/*
+ * Global variables.
+ */
+const char *Prog;
+static char fullnm[BUFSIZ];
+static char roomno[BUFSIZ];
+static char workph[BUFSIZ];
+static char homeph[BUFSIZ];
+static char slop[BUFSIZ + 1 + 80];
+static bool amroot;
+/* Flags */
+static bool fflg = false; /* -f - set full name */
+static bool rflg = false; /* -r - set room number */
+static bool wflg = false; /* -w - set work phone number */
+static bool hflg = false; /* -h - set home phone number */
+static bool oflg = false; /* -o - set other information */
+static bool pw_locked = false;
+
+/*
+ * External identifiers
+ */
+
+/* local function prototypes */
+static void fail_exit (int code);
+static /*@noreturn@*/void usage (int status);
+static bool may_change_field (int);
+static void new_fields (void);
+static char *copy_field (char *, char *, char *);
+static void process_flags (int argc, char **argv);
+static void check_perms (const struct passwd *pw);
+static void update_gecos (const char *user, char *gecos);
+static void get_old_fields (const char *gecos);
+
+/*
+ * fail_exit - exit with an error and do some cleanup
+ */
+static void fail_exit (int code)
+{
+ if (pw_locked) {
+ if (pw_unlock () == 0) {
+ fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
+ SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
+ /* continue */
+ }
+ }
+ pw_locked = false;
+
+ closelog ();
+
+ exit (code);
+}
+
+/*
+ * usage - print command line syntax and exit
+ */
+static /*@noreturn@*/void usage (int status)
+{
+ FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
+ (void) fprintf (usageout,
+ _("Usage: %s [options] [LOGIN]\n"
+ "\n"
+ "Options:\n"),
+ Prog);
+ (void) fputs (_(" -f, --full-name FULL_NAME change user's full name\n"), usageout);
+ (void) fputs (_(" -h, --home-phone HOME_PHONE change user's home phone number\n"), usageout);
+ (void) fputs (_(" -o, --other OTHER_INFO change user's other GECOS information\n"), usageout);
+ (void) fputs (_(" -r, --room ROOM_NUMBER change user's room number\n"), usageout);
+ (void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
+ (void) fputs (_(" -u, --help display this help message and exit\n"), usageout);
+ (void) fputs (_(" -w, --work-phone WORK_PHONE change user's office phone number\n"), usageout);
+ (void) fputs ("\n", usageout);
+ exit (status);
+}
+
+/*
+ * may_change_field - indicate if the user is allowed to change a given field
+ * of her gecos information
+ *
+ * root can change any field.
+ *
+ * field should be one of 'f', 'r', 'w', 'h'
+ *
+ * Return true if the user can change the field and false otherwise.
+ */
+static bool may_change_field (int field)
+{
+ const char *cp;
+
+ /*
+ * CHFN_RESTRICT can now specify exactly which fields may be changed
+ * by regular users, by using any combination of the following
+ * letters:
+ * f - full name
+ * r - room number
+ * w - work phone
+ * h - home phone
+ *
+ * This makes it possible to disallow changing the room number
+ * information, for example - this feature was suggested by Maciej
+ * 'Tycoon' Majchrowski.
+ *
+ * For backward compatibility, "yes" is equivalent to "rwh",
+ * "no" is equivalent to "frwh". Only root can change anything
+ * if the string is empty or not defined at all.
+ */
+ if (amroot) {
+ return true;
+ }
+
+ cp = getdef_str ("CHFN_RESTRICT");
+ if (NULL == cp) {
+ cp = "";
+ } else if (strcmp (cp, "yes") == 0) {
+ cp = "rwh";
+ } else if (strcmp (cp, "no") == 0) {
+ cp = "frwh";
+ }
+
+ if (strchr (cp, field) != NULL) {
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * new_fields - change the user's GECOS information interactively
+ *
+ * prompt the user for each of the four fields and fill in the fields from
+ * the user's response, or leave alone if nothing was entered.
+ */
+static void new_fields (void)
+{
+ puts (_("Enter the new value, or press ENTER for the default"));
+
+ if (may_change_field ('f')) {
+ change_field (fullnm, sizeof fullnm, _("Full Name"));
+ } else {
+ printf (_("\t%s: %s\n"), _("Full Name"), fullnm);
+ }
+
+ if (may_change_field ('r')) {
+ change_field (roomno, sizeof roomno, _("Room Number"));
+ } else {
+ printf (_("\t%s: %s\n"), _("Room Number"), fullnm);
+ }
+
+ if (may_change_field ('w')) {
+ change_field (workph, sizeof workph, _("Work Phone"));
+ } else {
+ printf (_("\t%s: %s\n"), _("Work Phone"), fullnm);
+ }
+
+ if (may_change_field ('h')) {
+ change_field (homeph, sizeof homeph, _("Home Phone"));
+ } else {
+ printf (_("\t%s: %s\n"), _("Home Phone"), fullnm);
+ }
+
+ if (amroot) {
+ change_field (slop, sizeof slop, _("Other"));
+ }
+}
+
+/*
+ * copy_field - get the next field from the gecos field
+ *
+ * copy_field copies the next field from the gecos field, returning a
+ * pointer to the field which follows, or NULL if there are no more fields.
+ *
+ * in - the current GECOS field
+ * out - where to copy the field to
+ * extra - fields with '=' get copied here
+ */
+static char *copy_field (char *in, char *out, char *extra)
+{
+ char *cp = NULL;
+
+ while (NULL != in) {
+ cp = strchr (in, ',');
+ if (NULL != cp) {
+ *cp++ = '\0';
+ }
+
+ if (strchr (in, '=') == NULL) {
+ break;
+ }
+
+ if (NULL != extra) {
+ if ('\0' != extra[0]) {
+ strcat (extra, ",");
+ }
+
+ strcat (extra, in);
+ }
+ in = cp;
+ }
+ if ((NULL != in) && (NULL != out)) {
+ strcpy (out, in);
+ }
+
+ return cp;
+}
+
+/*
+ * process_flags - parse the command line options
+ *
+ * It will not return if an error is encountered.
+ */
+static void process_flags (int argc, char **argv)
+{
+ int c; /* flag currently being processed */
+ static struct option long_options[] = {
+ {"full-name", required_argument, NULL, 'f'},
+ {"home-phone", required_argument, NULL, 'h'},
+ {"other", required_argument, NULL, 'o'},
+ {"room", required_argument, NULL, 'r'},
+ {"root", required_argument, NULL, 'R'},
+ {"help", no_argument, NULL, 'u'},
+ {"work-phone", required_argument, NULL, 'w'},
+ {NULL, 0, NULL, '\0'}
+ };
+
+ /*
+ * The remaining arguments will be processed one by one and executed
+ * by this command. The name is the last argument if it does not
+ * begin with a "-", otherwise the name is determined from the
+ * environment and must agree with the real UID. Also, the UID will
+ * be checked for any commands which are restricted to root only.
+ */
+ while ((c = getopt_long (argc, argv, "f:h:o:r:R:uw:",
+ long_options, NULL)) != -1) {
+ switch (c) {
+ case 'f':
+ if (!may_change_field ('f')) {
+ fprintf (stderr,
+ _("%s: Permission denied.\n"), Prog);
+ exit (E_NOPERM);
+ }
+ fflg = true;
+ STRFCPY (fullnm, optarg);
+ break;
+ case 'h':
+ if (!may_change_field ('h')) {
+ fprintf (stderr,
+ _("%s: Permission denied.\n"), Prog);
+ exit (E_NOPERM);
+ }
+ hflg = true;
+ STRFCPY (homeph, optarg);
+ break;
+ case 'o':
+ if (!amroot) {
+ fprintf (stderr,
+ _("%s: Permission denied.\n"), Prog);
+ exit (E_NOPERM);
+ }
+ oflg = true;
+ if (strlen (optarg) > (unsigned int) 80) {
+ fprintf (stderr,
+ _("%s: fields too long\n"), Prog);
+ exit (E_NOPERM);
+ }
+ STRFCPY (slop, optarg);
+ break;
+ case 'r':
+ if (!may_change_field ('r')) {
+ fprintf (stderr,
+ _("%s: Permission denied.\n"), Prog);
+ exit (E_NOPERM);
+ }
+ rflg = true;
+ STRFCPY (roomno, optarg);
+ break;
+ case 'R': /* no-op, handled in process_root_flag () */
+ break;
+ case 'u':
+ usage (E_SUCCESS);
+ /*@notreached@*/break;
+ case 'w':
+ if (!may_change_field ('w')) {
+ fprintf (stderr,
+ _("%s: Permission denied.\n"), Prog);
+ exit (E_NOPERM);
+ }
+ wflg = true;
+ STRFCPY (workph, optarg);
+ break;
+ default:
+ usage (E_USAGE);
+ }
+ }
+}
+
+/*
+ * check_perms - check if the caller is allowed to add a group
+ *
+ * Non-root users are only allowed to change their gecos field.
+ * (see also may_change_field())
+ *
+ * Non-root users must be authenticated.
+ *
+ * It will not return if the user is not allowed.
+ */
+static void check_perms (const struct passwd *pw)
+{
+#ifdef USE_PAM
+ pam_handle_t *pamh = NULL;
+ int retval;
+ struct passwd *pampw;
+#endif
+
+ /*
+ * Non-privileged users are only allowed to change the gecos field
+ * if the UID of the user matches the current real UID.
+ */
+ if (!amroot && pw->pw_uid != getuid ()) {
+ fprintf (stderr, _("%s: Permission denied.\n"), Prog);
+ closelog ();
+ exit (E_NOPERM);
+ }
+#ifdef WITH_SELINUX
+ /*
+ * If the UID of the user does not match the current real UID,
+ * check if the change is allowed by SELinux policy.
+ */
+ if ((pw->pw_uid != getuid ())
+ && (check_selinux_permit ("chfn") != 0)) {
+ fprintf (stderr, _("%s: Permission denied.\n"), Prog);
+ closelog ();
+ exit (E_NOPERM);
+ }
+#endif
+
+#ifndef USE_PAM
+ /*
+ * Non-privileged users are optionally authenticated (must enter the
+ * password of the user whose information is being changed) before
+ * any changes can be made. Idea from util-linux chfn/chsh.
+ * --marekm
+ */
+ if (!amroot && getdef_bool ("CHFN_AUTH")) {
+ passwd_check (pw->pw_name, pw->pw_passwd, "chfn");
+ }
+
+#else /* !USE_PAM */
+ pampw = getpwuid (getuid ()); /* local, no need for xgetpwuid */
+ if (NULL == pampw) {
+ fprintf (stderr,
+ _("%s: Cannot determine your user name.\n"),
+ Prog);
+ exit (E_NOPERM);
+ }
+
+ retval = pam_start ("chfn", pampw->pw_name, &conv, &pamh);
+
+ if (PAM_SUCCESS == retval) {
+ retval = pam_authenticate (pamh, 0);
+ }
+
+ if (PAM_SUCCESS == retval) {
+ retval = pam_acct_mgmt (pamh, 0);
+ }
+
+ if (PAM_SUCCESS != retval) {
+ fprintf (stderr, _("%s: PAM: %s\n"),
+ Prog, pam_strerror (pamh, retval));
+ SYSLOG((LOG_ERR, "%s", pam_strerror (pamh, retval)));
+ if (NULL != pamh) {
+ (void) pam_end (pamh, retval);
+ }
+ exit (E_NOPERM);
+ }
+ (void) pam_end (pamh, retval);
+#endif /* USE_PAM */
+}
+
+/*
+ * update_gecos - update the gecos fields in the password database
+ *
+ * Commit the user's entry after changing her gecos field.
+ */
+static void update_gecos (const char *user, char *gecos)
+{
+ const struct passwd *pw; /* The user's password file entry */
+ struct passwd pwent; /* modified password file entry */
+
+ /*
+ * Before going any further, raise the ulimit to prevent colliding
+ * into a lowered ulimit, and set the real UID to root to protect
+ * against unexpected signals. Any keyboard signals are set to be
+ * ignored.
+ */
+ if (setuid (0) != 0) {
+ fputs (_("Cannot change ID to root.\n"), stderr);
+ SYSLOG ((LOG_ERR, "can't setuid(0)"));
+ fail_exit (E_NOPERM);
+ }
+ pwd_init ();
+
+ /*
+ * The passwd entry is now ready to be committed back to the
+ * password file. Get a lock on the file and open it.
+ */
+ if (pw_lock () == 0) {
+ fprintf (stderr,
+ _("%s: cannot lock %s; try again later.\n"),
+ Prog, pw_dbname ());
+ fail_exit (E_NOPERM);
+ }
+ pw_locked = true;
+ if (pw_open (O_CREAT | O_RDWR) == 0) {
+ fprintf (stderr,
+ _("%s: cannot open %s\n"), Prog, pw_dbname ());
+ fail_exit (E_NOPERM);
+ }
+
+ /*
+ * Get the entry to update using pw_locate() - we want the real one
+ * from /etc/passwd, not the one from getpwnam() which could contain
+ * the shadow password if (despite the warnings) someone enables
+ * AUTOSHADOW (or SHADOW_COMPAT in libc). --marekm
+ */
+ pw = pw_locate (user);
+ if (NULL == pw) {
+ fprintf (stderr,
+ _("%s: user '%s' does not exist in %s\n"),
+ Prog, user, pw_dbname ());
+ fail_exit (E_NOPERM);
+ }
+
+ /*
+ * Make a copy of the entry, then change the gecos field. The other
+ * fields remain unchanged.
+ */
+ pwent = *pw;
+ pwent.pw_gecos = gecos;
+
+ /*
+ * Update the passwd file entry. If there is a DBM file, update that
+ * entry as well.
+ */
+ if (pw_update (&pwent) == 0) {
+ fprintf (stderr,
+ _("%s: failed to prepare the new %s entry '%s'\n"),
+ Prog, pw_dbname (), pwent.pw_name);
+ fail_exit (E_NOPERM);
+ }
+
+ /*
+ * Changes have all been made, so commit them and unlock the file.
+ */
+ if (pw_close () == 0) {
+ fprintf (stderr, _("%s: failure while writing changes to %s\n"), Prog, pw_dbname ());
+ SYSLOG ((LOG_ERR, "failure while writing changes to %s", pw_dbname ()));
+ fail_exit (E_NOPERM);
+ }
+ if (pw_unlock () == 0) {
+ fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
+ SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
+ /* continue */
+ }
+ pw_locked = false;
+}
+
+/*
+ * get_old_fields - parse the old gecos and use the old value for the fields
+ * which are not set on the command line
+ */
+static void get_old_fields (const char *gecos)
+{
+ char *cp; /* temporary character pointer */
+ char old_gecos[BUFSIZ]; /* buffer for old GECOS fields */
+ STRFCPY (old_gecos, gecos);
+
+ /*
+ * Now get the full name. It is the first comma separated field in
+ * the GECOS field.
+ */
+ cp = copy_field (old_gecos, fflg ? (char *) 0 : fullnm, slop);
+
+ /*
+ * Now get the room number. It is the next comma separated field,
+ * if there is indeed one.
+ */
+ if (NULL != cp) {
+ cp = copy_field (cp, rflg ? (char *) 0 : roomno, slop);
+ }
+
+ /*
+ * Now get the work phone number. It is the third field.
+ */
+ if (NULL != cp) {
+ cp = copy_field (cp, wflg ? (char *) 0 : workph, slop);
+ }
+
+ /*
+ * Now get the home phone number. It is the fourth field.
+ */
+ if (NULL != cp) {
+ cp = copy_field (cp, hflg ? (char *) 0 : homeph, slop);
+ }
+
+ /*
+ * Anything left over is "slop".
+ */
+ if ((NULL != cp) && !oflg) {
+ if ('\0' != slop[0]) {
+ strcat (slop, ",");
+ }
+
+ strcat (slop, cp);
+ }
+}
+
+/*
+ * check_fields - check all of the fields for valid information
+ *
+ * It will not return if a field is not valid.
+ */
+static void check_fields (void)
+{
+ int err;
+ err = valid_field (fullnm, ":,=\n");
+ if (err > 0) {
+ fprintf (stderr, _("%s: name with non-ASCII characters: '%s'\n"), Prog, fullnm);
+ } else if (err < 0) {
+ fprintf (stderr, _("%s: invalid name: '%s'\n"), Prog, fullnm);
+ fail_exit (E_NOPERM);
+ }
+ err = valid_field (roomno, ":,=\n");
+ if (err > 0) {
+ fprintf (stderr, _("%s: room number with non-ASCII characters: '%s'\n"), Prog, roomno);
+ } else if (err < 0) {
+ fprintf (stderr, _("%s: invalid room number: '%s'\n"),
+ Prog, roomno);
+ fail_exit (E_NOPERM);
+ }
+ if (valid_field (workph, ":,=\n") != 0) {
+ fprintf (stderr, _("%s: invalid work phone: '%s'\n"),
+ Prog, workph);
+ fail_exit (E_NOPERM);
+ }
+ if (valid_field (homeph, ":,=\n") != 0) {
+ fprintf (stderr, _("%s: invalid home phone: '%s'\n"),
+ Prog, homeph);
+ fail_exit (E_NOPERM);
+ }
+ err = valid_field (slop, ":\n");
+ if (err > 0) {
+ fprintf (stderr, _("%s: '%s' contains non-ASCII characters\n"), Prog, slop);
+ } else if (err < 0) {
+ fprintf (stderr,
+ _("%s: '%s' contains illegal characters\n"),
+ Prog, slop);
+ fail_exit (E_NOPERM);
+ }
+}
+
+/*
+ * chfn - change a user's password file information
+ *
+ * This command controls the GECOS field information in the password
+ * file entry.
+ *
+ * The valid options are
+ *
+ * -f full name
+ * -r room number
+ * -w work phone number
+ * -h home phone number
+ * -o other information (*)
+ *
+ * (*) requires root permission to execute.
+ */
+int main (int argc, char **argv)
+{
+ const struct passwd *pw; /* password file entry */
+ char new_gecos[BUFSIZ]; /* buffer for new GECOS fields */
+ char *user;
+
+ /*
+ * Get the program name. The program name is used as a
+ * prefix to most error messages.
+ */
+ Prog = Basename (argv[0]);
+ log_set_progname(Prog);
+ log_set_logfd(stderr);
+
+ sanitize_env ();
+ (void) setlocale (LC_ALL, "");
+ (void) bindtextdomain (PACKAGE, LOCALEDIR);
+ (void) textdomain (PACKAGE);
+
+ process_root_flag ("-R", argc, argv);
+
+ /*
+ * This command behaves different for root and non-root
+ * users.
+ */
+ amroot = (getuid () == 0);
+
+ OPENLOG ("chfn");
+
+ /* parse the command line options */
+ process_flags (argc, argv);
+
+ /*
+ * Get the name of the user to check. It is either the command line
+ * name, or the name getlogin() returns.
+ */
+ if (optind < argc) {
+ user = argv[optind];
+ pw = xgetpwnam (user);
+ if (NULL == pw) {
+ fprintf (stderr, _("%s: user '%s' does not exist\n"), Prog,
+ user);
+ fail_exit (E_NOPERM);
+ }
+ } else {
+ pw = get_my_pwent ();
+ if (NULL == pw) {
+ fprintf (stderr,
+ _("%s: Cannot determine your user name.\n"),
+ Prog);
+ SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
+ (unsigned long) getuid ()));
+ fail_exit (E_NOPERM);
+ }
+ user = xstrdup (pw->pw_name);
+ }
+
+#ifdef USE_NIS
+ /*
+ * Now we make sure this is a LOCAL password entry for this user ...
+ */
+ if (__ispwNIS ()) {
+ char *nis_domain;
+ char *nis_master;
+
+ fprintf (stderr,
+ _("%s: cannot change user '%s' on NIS client.\n"),
+ Prog, user);
+
+ if (!yp_get_default_domain (&nis_domain) &&
+ !yp_master (nis_domain, "passwd.byname", &nis_master)) {
+ fprintf (stderr,
+ _
+ ("%s: '%s' is the NIS master for this client.\n"),
+ Prog, nis_master);
+ }
+ fail_exit (E_NOPERM);
+ }
+#endif
+
+ /* Check that the caller is allowed to change the gecos of the
+ * specified user */
+ check_perms (pw);
+
+ /* If some fields were not set on the command line, load the value from
+ * the old gecos fields. */
+ get_old_fields (pw->pw_gecos);
+
+ /*
+ * If none of the fields were changed from the command line, let the
+ * user interactively change them.
+ */
+ if (!fflg && !rflg && !wflg && !hflg && !oflg) {
+ printf (_("Changing the user information for %s\n"), user);
+ new_fields ();
+ }
+
+ /*
+ * Check all of the fields for valid information
+ */
+ check_fields ();
+
+ /*
+ * Build the new GECOS field by plastering all the pieces together,
+ * if they will fit ...
+ */
+ if ((strlen (fullnm) + strlen (roomno) + strlen (workph) +
+ strlen (homeph) + strlen (slop)) > (unsigned int) 80) {
+ fprintf (stderr, _("%s: fields too long\n"), Prog);
+ fail_exit (E_NOPERM);
+ }
+ snprintf (new_gecos, sizeof new_gecos, "%s,%s,%s,%s%s%s",
+ fullnm, roomno, workph, homeph,
+ ('\0' != slop[0]) ? "," : "", slop);
+
+ /* Rewrite the user's gecos in the passwd file */
+ update_gecos (user, new_gecos);
+
+ SYSLOG ((LOG_INFO, "changed user '%s' information", user));
+
+ nscd_flush_cache ("passwd");
+ sssd_flush_cache (SSSD_DB_PASSWD);
+
+ closelog ();
+ exit (E_SUCCESS);
+}
+
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