Hello, I sent a mail about this program with a source a couple of days ago, not really pretty code, cleaned it up and gotten some help from #bsdcode@EFnet with some fixes. So I send the source again so you could take another look at it and tell me if I am missing something.
-- Eirik Nygaard <[EMAIL PROTECTED]> Http://kverka.org/~eirik/ PGP Key: 83C55EDE
/*
* Copyright 2002 Eirik Nygaard.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer as
* the first lines of this file unmodified.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY EIRIK NYGAARD ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL GUY HELMER BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* rmuser - C programme to remove users
*
* Eirik Nygaard <[EMAIL PROTECTED]>, 08/08/02
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <sys/resource.h>
#include <err.h>
#include <fcntl.h>
#include <dirent.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
char passwd_file[] = "/etc/master.passwd";
char passwd_tmp[PATH_MAX] = "/etc/ptmp.XXXXX";
char *passwd_tmp2;
char group_file[] = "/etc/group";
char new_group_file[] = "/etc/group.new";
char mail_dir[] = "/var/mail";
char crontab_dir[] = "/var/cron/tabs";
char path[] = "/bin:/sbin:/usr/bin:/usr/sbin";
int yes; /* Always yes? */
int removehomedir = 1;
char *user = NULL; /* User to delete */
char user2[BUFSIZ];
char answer[BUFSIZ];
int fp;
FILE *fp2;
char line[PATH_MAX + 50];
char homedir[PATH_MAX];
struct passwd *password;
struct stat sb;
void usage();
void getuser();
void remove_files_from_dir(int uid, char *path);
int recvnl( char *buf, int fd);
void update_passwd();
void update_group();
void killuser(int uid, int gid);
void del_mail();
void sighandle(int sig);
int main(int argc, char **argv)
{
int ch, numbuf = 0;
/* Check for root */
if (getuid() != 0) {
errx(EX_NOPERM, "You must be root to run this program.");
}
signal(SIGINT, sighandle);
signal(SIGTERM, sighandle);
signal(SIGHUP, sighandle);
signal(SIGQUIT, sighandle);
/* Set the path we need */
setenv("PATH", path, 1);
/* Set umode */
umask(022);
/* Get command line arguments */
while ((ch = getopt(argc, argv, "yu:")) != -1) {
switch (ch) {
case 'y':
yes = 1;
break;
case 'u':
user = optarg;
break;
case '?':
default:
usage();
}
}
if (user == NULL) {
getuser();
}
if ((password = getpwnam(user)) == NULL) {
errx(EX_NOUSER, "No user found by that name: %s.\n", user);
}
printf("\nMatching password entry: \n");
printf("\t%s:%s:%d:%d:%s:%s\n", password->pw_name, password->pw_passwd,
password->pw_uid, password->pw_gid, password->pw_dir, password->pw_shell);
if (yes == 0) {
printf("Is this the entry you wish to remove?(y/n) ");
fgets(answer, sizeof(answer), stdin);
if (strncmp(answer, "y", 1) != 0 && strncmp(answer, "Y", 1) != 0) {
printf("User %s not removed.\n", user);
exit(1);
}
}
if ((password = getpwnam(user)) == NULL) {
errx(EX_NOUSER, "No user found by that name: %s.\n", user);
}
if (yes == 0) {
printf("Remove homedir(%s)?(y/n) ", password->pw_dir);
fgets(answer, sizeof(answer), stdin);
if (strncmp(answer, "y", 1) == 0 || strncmp(answer, "Y", 1) == 0)
removehomedir = 1;
else
removehomedir = 0;
}
else {
removehomedir = 1;
}
strncpy(homedir, password->pw_dir, sizeof(homedir));
next:
lstat(homedir, &sb);
if (removehomedir == 1) {
if (!S_ISLNK(sb.st_mode) && !S_ISDIR(sb.st_mode)) {
warnx("Home %s is not a directory, so it won't be removed\n",
homedir);
removehomedir = 0;
}
if (S_ISLNK(sb.st_mode)) {
numbuf = readlink(password->pw_dir, homedir, sizeof(homedir));
printf("%s\n", homedir);
homedir[numbuf] = '\0';
goto next;
}
if (sb.st_uid != password->pw_uid) {
if (removehomedir == 1)
warnx("Home %s is not owned by %s, so it will not be
removed.\n", homedir, user);
removehomedir = 0;
}
}
killuser(password->pw_uid, password->pw_gid);
update_passwd();
update_group();
if (removehomedir == 1) {
printf("Removeing home %s.\n", homedir);
remove_files_from_dir(password->pw_uid, homedir);
if (rmdir(homedir) == -1)
warn("Warning: Unable to remove home %s - continuing.\n",
homedir);
}
snprintf(line, sizeof(line), "%s/%s", crontab_dir, user);
if ((fp2 = fopen(line, "r")) != NULL) {
fclose(fp2);
if (unlink(line) == -1)
warn("Warning: Unable to remove crontab file %s -
continuing.\n", line);
printf("Removeing users' crontab: ");
snprintf(line, sizeof(line), "/usr/bin/crontab -u %s -r", user);
system(line);
printf("done.\n");
}
del_mail();
printf("Removing files belonging to %s from /tmp.\n", user);
remove_files_from_dir(password->pw_uid, "/tmp");
printf("Removing files belonging to %s from /var/tmp.\n", user);
remove_files_from_dir(password->pw_uid, "/var/tmp");
return 0;
}
void usage()
{
printf("Usage: %s [-y] [-u username]\n", getprogname());
exit(1);
}
void getuser()
{
printf("Enter login name for user to remove: ");
fgets(user2, sizeof(user2), stdin);
user2[strlen(user2) - 1] = '\0';
user = user2;
}
/* Remove all files and folders belonging to uid in path */
void remove_files_from_dir(int uid, char *path)
{
int Tmp;
struct dirent *DirEntryPtr;
DIR *DirPtr;
struct stat Stat;
char Path[PATH_MAX];
DirPtr = opendir(path);
while (1) {
DirEntryPtr = readdir(DirPtr);
if (DirEntryPtr == 0) break;
if (strcmp(DirEntryPtr->d_name,".") != 0 &&
strcmp(DirEntryPtr->d_name,"..") != 0) {
Path[0] = 0;
strlcat(Path,homedir, sizeof(Path));
strlcat(Path,"/", sizeof(Path));
strlcat(Path,DirEntryPtr->d_name, sizeof(Path));
Tmp = lstat(Path,&Stat);
if (S_ISDIR(Stat.st_mode)) {
remove_files_from_dir(uid, Path);
if (Stat.st_uid == uid)
if (rmdir(Path) == -1)
warn("Warning: Unable to remove dir %s
- continuing.\n", Path);
}
if (Stat.st_uid == uid) {
/* printf("Removeing file %s\n", Path); */
if (unlink(Path) == -1)
warn("Warning: unlink on %s failed -
continuing.\n", Path);
}
}
}
closedir(DirPtr);
}
/* Remove the user from the passwd file */
void update_passwd()
{
int fp_pw, fp2_pw;
char string[BUFSIZ], string2[BUFSIZ];
int skipped = 0;
if ((fp_pw = open(passwd_file, O_RDONLY|O_EXLOCK)) == -1) {
warn("Warning: Unable to open %s, so can not remove the user -
continuing.\n", passwd_file);
return;
}
if ((fp2_pw = open(passwd_tmp, O_WRONLY|O_EXLOCK|O_CREAT, 0600)) == -1) {
printf("Warning: Unable to open %s, so can not remove the user -
continuing.\n", passwd_tmp);
return;
}
snprintf(string2, sizeof(string2), "%s:", user);
while (recvnl(string, fp) != -1) {
if (strncmp(string, "#", 1) == 0) {
write(fp2_pw, string, strlen(string));
continue;
}
if (strncasecmp(string, string2, strlen(user) + 1) != 0) {
write(fp2_pw, string, strlen(string));
write(fp2_pw, "\n", 1);
}
else {
if (skipped == 1) {
write(fp2_pw, string, strlen(string));
write(fp2_pw, "\n", 1);
}
/* printf("Droped entry for %s\n", string); */
skipped = 1;
}
}
if (skipped == 0) {
printf("Whoops! Didn't find %s's entry second time around!\n", user);
close(fp_pw); close(fp2_pw);
exit(1);
}
close(fp_pw); close(fp2_pw);
/* Rebuild db */
snprintf(line, sizeof(line), "/usr/sbin/pwd_mkdb -p %s", passwd_tmp);
system(line);
}
/* Remove user from the group file and the users group */
void update_group()
{
char string[BUFSIZ], string2[BUFSIZ], string3[BUFSIZ];
int fp_g, fp2_g, users;
char *p, *p2;
int a = 0;
char group[BUFSIZ], gid[BUFSIZ], pass[BUFSIZ], users2[BUFSIZ],
users3[BUFSIZ];
if ((fp_g = open(group_file, O_RDONLY|O_EXLOCK)) == -1) {
printf("Warning: Unable to open %s, so can not remove the user's group
- continuing.\n", passwd_file);
return;
}
if ((fp2_g = open(new_group_file, O_WRONLY|O_EXLOCK|O_CREAT, 0644)) == -1) {
printf("Warning: Unable to open %s, so can not remove the user's group
- continuing.\n", passwd_tmp);
return;
}
snprintf(string2, sizeof(string2), "%s:", user);
while (recvnl(string, fp_g) != -1) {
if (strncmp(string, "#", 1) == 0) {
write(fp2_g, string, strlen(string));
continue;
}
if (strncasecmp(string, string2, strlen(user) + 1) != 0) {
/* Check if user is in the group */
string3[0] = '\0';
strlcpy(string3, string, sizeof(string3));
for (p = strtok(string3, ":\n"); p != NULL; p = strtok(NULL,
":\n")) {
switch(a) {
case 0:
strlcpy(group, p, sizeof(group));
break;
case 1:
strlcpy(pass, p, sizeof(pass));
break;
case 2:
strlcpy(gid, p, sizeof(gid));
break;
case 3:
strlcpy(users2, p, sizeof(users2));
break;
}
a++;
}
a = 0;
users3[0] = '\0';
for (p = strtok(users2, ",\n"); p != NULL; p = strtok(NULL,
",\n")) {
if (strcasecmp(user, p) != 0) {
if (a == 0) {
strlcat(users3, p, sizeof(users3));
a = 1;
}
else {
strlcat(users3, ",", sizeof(users3));
strlcat(users3, p, sizeof(users3));
}
}
}
snprintf(string3, sizeof(string3), "%s:%s:%s:%s\n", group,
pass, gid, users3);
write(fp2_g, string3, strlen(string3));
a = 0;
}
else {
/* Check if there is other users added to the group */
p = string;
while (*p != ':') *p++; /* Skip groupname */
*p++;
while (*p != ':') *p++; /* Skip password section */
*p++;
while (*p != ':') *p++; /* Skip gid section */
*p++;
strlcpy(string3, p, sizeof(string3));
for (p2 = strtok(string3, ","); p2 != NULL; p2 = strtok(NULL,
",")) {
users = 1;
}
if (users == 1) {
warnx("Warning: Other users in group %s, not removing
- continuing.\n", user);
write(fp2_g, string, strlen(string));
}
else {
/* printf("Droped entry %s\n", string); */
}
}
}
close(fp_g); close(fp2_g);
rename(new_group_file, group_file);
}
/* Recieve a string from fd untill a \n */
int recvnl(char *buf, int fd)
{
int bytes = 0;
char buf2[2];
char buf3[BUFSIZ];
buf3[0] = '\0';
while ( read(fd, buf2, 1) != 0) {
buf2[1] = '\0';
if (strncmp(buf2, "\n", 1) == 0) {
strncpy(buf, buf3, BUFSIZ);
return bytes;
}
else {
strlcat(buf3, buf2, sizeof(buf3));
bytes++;
}
}
return -1;
}
/* Kill users processes */
void killuser(int uid, int gid)
{
int pid;
if (( pid = fork()) == 0) {
if (setgid(gid) == -1) {
warn("Warning: Unable to set gid - continuing.\n");
return;
}
if (setuid(uid) == -1) {
warn("Warning: Unable to set uid - continuing.\n");
return;
}
kill(0, SIGTERM);
sleep(1);
kill(0, SIGKILL);
exit(1);
}
if (pid == -1) {
warn("Error creating child processes - continuing.\n");
return;
}
else {
while (waitpid(-1,NULL,0) != pid)
; /* Do nothing */
}
}
void del_mail()
{
char string[BUFSIZ];
snprintf(string, sizeof(string), "%s/%s", mail_dir, user);
if (unlink(string) < 0 && errno != ENOENT)
warn("can't remove mailbox: %s", string);
}
/* Signal handeling */
void sighandle(int sig)
{
char unknown[] = "UNKNOWN", sint[] = "SIGINT", squit[] = "SIGQUIT", shup[]
= "SIGHUP", sterm[] = "SGITERM";
struct iovec vec[3];
char msg1[] = "\nCaught signal ", msg2[] = " -- cleaning up\n";
vec[0].iov_base = msg1; vec[0].iov_len = sizeof(msg1) - 1;
vec[2].iov_base = msg2; vec[2].iov_len = sizeof(msg2) - 1;
switch (sig) {
case SIGINT:
vec[1].iov_base = sint; vec[1].iov_len = sizeof(sint) - 1;
break;
case SIGQUIT:
vec[1].iov_base = squit; vec[1].iov_len = sizeof(squit) - 1;
break;
case SIGTERM:
vec[1].iov_base = sterm; vec[1].iov_len = sizeof(sterm) - 1;
break;
case SIGHUP:
vec[1].iov_base = shup; vec[1].iov_len = sizeof(shup) - 1;
break;
default:
vec[1].iov_base = unknown; vec[1].iov_len = sizeof(unknown) -
1;
break;
}
writev(STDOUT_FILENO, vec, sizeof(vec) / sizeof(*vec));
unlink(passwd_tmp);
unlink(new_group_file);
close(fp);
exit(1);
}
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