/*
* chfn.c -- change your finger information
* (c) 1994 by salvatore valente <svalente@athena.mit.edu>
*
* this program is free software. you can redistribute it and
* modify it under the terms of the gnu general public license.
* there is no warranty.
*
* $Author: faith $
* $Revision: 1.8 $
* $Date: 1995/10/12 14:46:35 $
*
* Updated Thu Oct 12 09:19:26 1995 by faith@cs.unc.edu with security
* patches from Zefram <A.Main@dcs.warwick.ac.uk>
*
*/
static char rcsId[] = "$Version: $Id: chfn.c,v 1.8 1995/10/12 14:46:35 faith Exp $ $";
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <errno.h>
#include <ctype.h>
#include <getopt.h>
#undef P
#if __STDC__
#define P(foo) foo
#else
#define P(foo) ()
#endif
typedef unsigned char boolean;
#define false 0
#define true 1
static char *version_string = "chfn 0.9a beta";
static char *whoami;
static char buf[1024];
struct finfo {
struct passwd *pw;
char *username;
char *full_name;
char *office;
char *office_phone;
char *home_phone;
char *other;
};
static boolean parse_argv P((int argc, char *argv[], struct finfo *pinfo));
static void usage P((FILE *fp));
static void parse_passwd P((struct passwd *pw, struct finfo *pinfo));
static void ask_info P((struct finfo *oldfp, struct finfo *newfp));
static char *prompt P((char *question, char *def_val));
static int check_gecos_string P((char *msg, char *gecos));
static boolean set_changed_data P((struct finfo *oldfp, struct finfo *newfp));
static int save_new_data P((struct finfo *pinfo));
static void *xmalloc P((int bytes));
#if 0
extern int strcasecmp P((char *, char *));
extern int setpwnam P((struct passwd *pwd));
#endif
#define memzero(ptr, size) memset((char *) ptr, 0, size)
int main (argc, argv)
int argc;
char *argv[];
{
char *cp, *pwdstr;
uid_t uid;
struct finfo oldf, newf;
boolean interactive;
int status;
extern int errno;
/* whoami is the program name for error messages */
whoami = argv[0];
if (! whoami) whoami = "chfn";
for (cp = whoami; *cp; cp++)
if (*cp == '/') whoami = cp + 1;
/*
* "oldf" contains the users original finger information.
* "newf" contains the changed finger information, and contains NULL
* in fields that haven't been changed.
* in the end, "newf" is folded into "oldf".
* the reason the new finger information is not put _immediately_ into
* "oldf" is that on the command line, new finger information can
* be specified before we know what user the information is being
* specified for.
*/
uid = getuid ();
memzero (&oldf, sizeof (oldf));
memzero (&newf, sizeof (newf));
interactive = parse_argv (argc, argv, &newf);
if (! newf.username) {
parse_passwd (getpwuid (uid), &oldf);
if (! oldf.username) {
fprintf (stderr, "%s: you (user %d) don't exist.\n", whoami, uid);
return (-1); }
}
else {
parse_passwd (getpwnam (newf.username), &oldf);
if (! oldf.username) {
cp = newf.username;
fprintf (stderr, "%s: user \"%s\" does not exist.\n", whoami, cp);
return (-1); }
}
/* reality check */
if (uid != 0 && uid != oldf.pw->pw_uid) {
errno = EACCES;
perror (whoami);
return (-1);
}
printf ("Changing finger information for %s.\n", oldf.username);
#if REQUIRE_PASSWORD
/* require password, unless root */
if(uid != 0 && oldf.pw->pw_passwd && oldf.pw->pw_passwd[0]) {
pwdstr = getpass("Password: ");
if(strncmp(oldf.pw->pw_passwd,
crypt(pwdstr, oldf.pw->pw_passwd), 13)) {
puts("Incorrect password.");
exit(1);
}
}
#endif
if (interactive) ask_info (&oldf, &newf);
if (! set_changed_data (&oldf, &newf)) {
printf ("Finger information not changed.\n");
return 0;
}
status = save_new_data (&oldf);
return status;
}
/*
* parse_argv () --
* parse the command line arguments.
* returns true if no information beyond the username was given.
*/
static boolean parse_argv (argc, argv, pinfo)
int argc;
char *argv[];
struct finfo *pinfo;
{
int index, c, status;
boolean info_given;
static struct option long_options[] = {
{ "full-name", required_argument, 0, 'f' },
{ "office", required_argument, 0, 'o' },
{ "office-phone", required_argument, 0, 'p' },
{ "home-phone", required_argument, 0, 'h' },
{ "help", no_argument, 0, 'u' },
{ "version", no_argument, 0, 'v' },
{ NULL, no_argument, 0, '0' },
};
optind = 0;
info_given = false;
while (true) {
c = getopt_long (argc, argv, "f:r:p:h:o:uv", long_options, &index);
if (c == EOF) break;
/* version? output version and exit. */
if (c == 'v') {
printf ("%s\n", version_string);
exit (0);
}
if (c == 'u') {
usage (stdout);
exit (0);
}
/* all other options must have an argument. */
if (! optarg) {
usage (stderr);
exit (-1);
}
/* ok, we were given an argument */
info_given = true;
status = 0;
strcpy (buf, whoami); strcat (buf, ": ");
/* now store the argument */
switch (c) {
case 'f':
pinfo->full_name = optarg;
strcat (buf, "full name");
status = check_gecos_string (buf, optarg);
break;
case 'o':
pinfo->office = optarg;
strcat (buf, "office");
status = check_gecos_string (buf, optarg);
break;
case 'p':
pinfo->office_phone = optarg;
strcat (buf, "office phone");
status = check_gecos_string (buf, optarg);
break;
case 'h':
pinfo->home_phone = optarg;
strcat (buf, "home phone");
status = check_gecos_string (buf, optarg);
break;
default:
usage (stderr);
status = (-1);
}
if (status < 0) exit (status);
}
/* done parsing arguments. check for a username. */
if (optind < argc) {
if (optind + 1 < argc) {
usage (stderr);
exit (-1);
}
pinfo->username = argv[optind];
}
return (! info_given);
}
/*
* usage () --
* print out a usage message.
*/
static void usage (fp)
FILE *fp;
{
fprintf (fp, "Usage: %s [ -f full-name ] [ -o office ] ", whoami);
fprintf (fp, "[ -p office-phone ]\n [ -h home-phone ] ");
fprintf (fp, "[ --help ] [ --version ]\n");
}
/*
* parse_passwd () --
* take a struct password and fill in the fields of the
* struct finfo.
*/
static void parse_passwd (pw, pinfo)
struct passwd *pw;
struct finfo *pinfo;
{
char *cp;
if (pw) {
pinfo->pw = pw;
pinfo->username = pw->pw_name;
/* use pw_gecos */
cp = pw->pw_gecos;
pinfo->full_name = cp;
cp = strchr (cp, ',');
if (cp) { *cp = 0, cp++; } else return;
pinfo->office = cp;
cp = strchr (cp, ',');
if (cp) { *cp = 0, cp++; } else return;
pinfo->office_phone = cp;
cp = strchr (cp, ',');
if (cp) { *cp = 0, cp++; } else return;
pinfo->home_phone = cp;
/* extra fields contain site-specific information, and
* can not be changed by this version of chfn. */
cp = strchr (cp, ',');
if (cp) { *cp = 0, cp++; } else return;
pinfo->other = cp;
}
}
/*
* ask_info () --
* prompt the user for the finger information and store it.
*/
static void ask_info (oldfp, newfp)
struct finfo *oldfp;
struct finfo *newfp;
{
newfp->full_name = prompt ("Name", oldfp->full_name);
newfp->office = prompt ("Office", oldfp->office);
newfp->office_phone = prompt ("Office Phone", oldfp->office_phone);
newfp->home_phone = prompt ("Home Phone", oldfp->home_phone);
printf ("\n");
}
/*
* prompt () --
* ask the user for a given field and check that the string is legal.
*/
static char *prompt (question, def_val)
char *question;
char *def_val;
{
static char *blank = "none";
int len;
char *ans, *cp;
while (true) {
if (! def_val) def_val = "";
printf("%s [%s]: ", question, def_val);
*buf = 0;
if (fgets (buf, sizeof (buf), stdin) == NULL) {
printf ("\nAborted.\n");
exit (-1);
}
/* remove the newline at the end of buf. */
ans = buf;
while (isspace (*ans)) ans++;
len = strlen (ans);
while (len > 0 && isspace (ans[len-1])) len--;
if (len <= 0) return NULL;
ans[len] = 0;
if (! strcasecmp (ans, blank)) return "";
if (check_gecos_string (NULL, ans) >= 0) break;
}
cp = (char *) xmalloc (len + 1);
strcpy (cp, ans);
return cp;
}
/*
* check_gecos_string () --
* check that the given gecos string is legal. if it's not legal,
* output "msg" followed by a description of the problem, and
* return (-1).
*/
static int check_gecos_string (msg, gecos)
char *msg;
char *gecos;
{
int i, c;
for (i = 0; i < strlen (gecos); i++) {
c = gecos[i];
if (c == ',' || c == ':' || c == '=' || c == '"' || c == '\n') {
if (msg) printf ("%s: ", msg);
printf ("'%c' is not allowed.\n", c);
return (-1);
}
if (iscntrl (c)) {
if (msg) printf ("%s: ", msg);
printf ("Control characters are not allowed.\n");
return (-1);
}
}
return (0);
}
/*
* set_changed_data () --
* incorporate the new data into the old finger info.
*/
static boolean set_changed_data (oldfp, newfp)
struct finfo *oldfp;
struct finfo *newfp;
{
boolean changed = false;
if (newfp->full_name) {
oldfp->full_name = newfp->full_name; changed = true; }
if (newfp->office) {
oldfp->office = newfp->office; changed = true; }
if (newfp->office_phone) {
oldfp->office_phone = newfp->office_phone; changed = true; }
if (newfp->home_phone) {
oldfp->home_phone = newfp->home_phone; changed = true; }
return changed;
}
/*
* save_new_data () --
* save the given finger info in /etc/passwd.
* return zero on success.
*/
static int save_new_data (pinfo)
struct finfo *pinfo;
{
char *gecos;
int len;
/* null fields will confuse printf(). */
if (! pinfo->full_name) pinfo->full_name = "";
if (! pinfo->office) pinfo->office = "";
if (! pinfo->office_phone) pinfo->office_phone = "";
if (! pinfo->home_phone) pinfo->home_phone = "";
if (! pinfo->other) pinfo->other = "";
/* create the new gecos string */
len = (strlen (pinfo->full_name) + strlen (pinfo->office) +
strlen (pinfo->office_phone) + strlen (pinfo->home_phone) +
strlen (pinfo->other) + 4);
gecos = (char *) xmalloc (len + 1);
sprintf (gecos, "%s,%s,%s,%s,%s", pinfo->full_name, pinfo->office,
pinfo->office_phone, pinfo->home_phone, pinfo->other);
/* write the new struct passwd to the passwd file. */
pinfo->pw->pw_gecos = gecos;
if (setpwnam (pinfo->pw) < 0) {
perror ("setpwnam");
printf( "Finger information *NOT* changed. Try again later.\n" );
return (-1);
}
printf ("Finger information changed.\n");
return 0;
}
/*
* xmalloc () -- malloc that never fails.
*/
static void *xmalloc (bytes)
int bytes;
{
void *vp;
vp = malloc (bytes);
if (! vp && bytes > 0) {
perror ("malloc failed");
exit (-1);
}
return vp;
}
