useradd, groupadd, and mkpasswd submitted by Ashwini Sharma.

1 files changed, 246 insertions, 0 deletions

diff --git a/toys/pending/useradd.c b/toys/pending/useradd.c
new file mode 100644
index 00000000..ecfd638f
--- /dev/null
+++ b/toys/pending/useradd.c
@@ -0,0 +1,246 @@
+/* useradd.c - add a new user
+ *
+ * Copyright 2013 Ashwini Kumar <ak.ashwini@gmail.com>
+ * Copyright 2013 Kyungwan Han <asura321@gmail.com>
+ *
+ * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/useradd.html
+
+USE_USERADD(NEWTOY(useradd, "<1>2u#<0G:s:g:h:SDH", TOYFLAG_NEEDROOT|TOYFLAG_SBIN))
+USE_USERADD(OLDTOY(adduser, useradd, OPTSTR_useradd, TOYFLAG_NEEDROOT|TOYFLAG_SBIN))
+
+config USERADD
+  bool "useradd"
+  default n
+  help
+    usage: useradd [-SDH] [-hDIR] [-sSHELL] [-G GRP] [-gGECOS] [-uUID] USER [GROUP]
+
+    Create new user, or add USER to GROUP
+    
+    -h DIR   Home directory
+    -g GECOS GECOS field
+    -s SHELL Login shell
+    -G GRP   Add user to existing group
+    -S       Create a system user
+    -D       Don't assign a password
+    -H       Don't create home directory
+    -u UID   User id
+*/
+
+#define FOR_useradd
+#include "toys.h"
+
+GLOBALS(
+  char *dir;
+  char *gecos;
+  char *shell;
+  char *u_grp;
+  long uid;
+  long gid;
+)
+
+static char* get_shell(void)    
+{                               
+  char *shell = getenv("SHELL");
+
+  if (!shell) {
+    struct passwd *pw;
+    pw = getpwuid(getuid());
+    if (pw && pw->pw_shell && pw->pw_shell[0])
+      shell = pw->pw_shell;                                                                                                           
+    else shell = "/bin/sh";     
+  }                             
+  return xstrdup(shell);        
+}
+
+/* exec_wait() function does a fork(), and exec the command,
+ * waits for the child to exit and return the status to parent
+ */
+static int exec_wait(char **args)
+{
+  int status = 0;
+  pid_t pid = fork();
+
+  if (!pid) xexec(args);
+  else if (pid > 0) waitpid(pid, &status, 0);
+  else perror_exit("fork failed");
+  return WEXITSTATUS(status);
+}
+
+/* create_copy_skel(), This function will create the home directory of the
+ * user, by copying /etc/skel/ contents to /home/<username>.
+ * Then change the ownership of home dir to the UID and GID of new user,
+ * and Mode to 0700, i.e. rwx------ for user.
+ */
+static void create_copy_skel(char *skel, char *hdir)
+{
+  char *args[5];
+  struct stat sb;
+
+  if (toys.optflags & FLAG_H) return;
+
+  umask(0);
+  args[4] = NULL;
+  if (stat(hdir, &sb)) {
+    args[0] = "cp";
+    args[1] = "-R";
+    args[2] = skel;
+    args[3] = hdir;
+    // Copy /etc/skel to home dir 
+    toys.exitval = exec_wait(args);
+
+    args[0] = "chown";
+    args[1] = "-R";
+    args[2] = xmsprintf("%u:%u", TT.uid, TT.gid);
+    args[3] = hdir;
+    //Change ownership to that of UID and GID of new user
+    toys.exitval = exec_wait(args);
+
+  } else xprintf("Warning: home directory for the user already exists\n"
+      "Not copying any file from skel directory into it.\n");
+
+  if (chown(hdir, TT.uid, TT.gid) || chmod(hdir, 0700))
+    perror_exit("chown/chmod failed for '%s'", hdir);
+}
+
+/* Add a new group to the system, if UID is given then that is validated
+ * to be free, else a free UID is choosen by self.
+ * SYSTEM IDs are considered in the range 100 ... 999
+ * add_user(), add a new entry in /etc/passwd, /etc/shadow files
+ */
+static void new_user()
+{
+  struct passwd pwd;
+  char *entry, *args[4];
+  int max = INT_MAX;
+
+  pwd.pw_name = *toys.optargs;
+  pwd.pw_passwd = (char *)"x";
+  if (toys.optflags & FLAG_g) pwd.pw_gecos = TT.gecos;
+  else pwd.pw_gecos = "Linux User,";
+  if (toys.optflags & FLAG_h) pwd.pw_dir = TT.dir;
+  else pwd.pw_dir = xmsprintf("/home/%s", *toys.optargs);
+  if (toys.optflags & FLAG_s) pwd.pw_shell = TT.shell;
+  else pwd.pw_shell = get_shell();
+
+  if (toys.optflags & FLAG_u) {
+    if (TT.uid > INT_MAX) error_exit("uid should be less than  '%d' ", INT_MAX);
+    if (getpwuid(TT.uid)) error_exit("user '%ld' is in use", TT.uid);
+    pwd.pw_uid = TT.uid;
+  } else {
+    if (toys.optflags & FLAG_S) {
+      TT.uid = SYS_FIRST_ID;
+      max = SYS_LAST_ID;
+    } else {
+      TT.uid = SYS_LAST_ID + 1; //i.e. starting from 1000
+      max = 60000; // as per config file on Linux desktop
+    }
+    //find unused uid
+    while (TT.uid <= max) {
+      if (!getpwuid(TT.uid)) break;
+      if (TT.uid == max) error_exit("no more free uids left");
+      TT.uid++;
+    }
+    pwd.pw_uid = TT.uid;
+  }
+
+  if (toys.optflags & FLAG_G) {
+    struct group *gr = getgrnam(TT.u_grp);
+    if (!gr) error_exit("The group '%s' doesn't exist", TT.u_grp);
+    TT.gid = gr->gr_gid;
+  } else {
+    // Set the GID for the user, if not specified
+    if (toys.optflags & FLAG_S) {
+      TT.gid = SYS_FIRST_ID;
+      max = SYS_LAST_ID;
+    } else TT.gid = ((TT.uid > SYS_LAST_ID) ? TT.uid : SYS_LAST_ID + 1);
+    if (getgrnam(pwd.pw_name)) error_exit("group '%s' is in use", pwd.pw_name);
+    //find unused gid
+    while (TT.gid <= max) {
+      if (!getgrgid(TT.gid)) break;
+      if (TT.gid == max) error_exit("no more free gids left");
+      TT.gid++;   
+    }
+  }
+  pwd.pw_gid = TT.gid;
+
+  if (!(toys.optflags & FLAG_G)) {
+    // Create a new group for user 
+    //add group, invoke addgroup command
+    args[0] = "groupadd";
+    args[1] = toys.optargs[0];
+    args[2] = xmsprintf("-g%ld", pwd.pw_gid);
+    args[3] = NULL;
+    if (exec_wait(args)) error_msg("addgroup fail");
+  }
+
+  /*add user to system 
+   * 1. add an entry to /etc/passwd and /etcshadow file
+   * 2. Copy /etc/skel dir contents to use home dir
+   * 3. update the user passwd by running 'passwd' utility
+   */
+
+  // 1. add an entry to /etc/passwd and /etc/shadow file
+  entry = xmsprintf("%s:%s:%ld:%ld:%s:%s:%s", pwd.pw_name, pwd.pw_passwd,
+      pwd.pw_uid, pwd.pw_gid, pwd.pw_gecos, pwd.pw_dir, pwd.pw_shell);
+  if (update_password("/etc/passwd", pwd.pw_name, entry)) error_exit("updating passwd file failed");
+  free(entry);
+
+  if (toys.optflags & FLAG_S) 
+  entry = xmsprintf("%s:!!:%u::::::", pwd.pw_name, 
+      (unsigned)(time(NULL))/(24*60*60)); //passwd is not set initially
+  else entry = xmsprintf("%s:!!:%u:%ld:%ld:%ld:::", pwd.pw_name, 
+            (unsigned)(time(NULL))/(24*60*60), 0, 99999, 7); //passwd is not set initially
+  update_password("/etc/shadow", pwd.pw_name, entry);
+  free(entry);
+
+  //2. craete home dir & copy skel dir to home
+  if (!(toys.optflags & FLAG_S)) create_copy_skel("/etc/skel", pwd.pw_dir);
+
+  //3. update the user passwd by running 'passwd' utility
+  if (!(toys.optflags & FLAG_D)) {
+    args[0] = "passwd";
+    args[1] = pwd.pw_name;
+    args[2] = NULL;
+    if (exec_wait(args)) error_exit("changing user passwd failed");
+  }
+  if (toys.optflags & FLAG_G) {
+    /*add user to the existing group, invoke addgroup command */
+    args[0] = "groupadd";
+    args[1] = toys.optargs[0];
+    args[2] = TT.u_grp;
+    args[3] = NULL;
+    if (exec_wait(args)) error_exit("adding user to group Failed");
+  }
+}
+
+/* Entry point for useradd feature 
+ * Specifying options and User, Group at cmdline is treated as error.
+ * If only 2 parameters (Non-Option) are given, then User is added to the 
+ * Group
+ */
+void useradd_main(void)
+{
+  struct passwd *pwd = NULL;
+
+  if (toys.optflags && toys.optc == 2) {
+    toys.exithelp = 1;
+    error_exit("options, user and group can't be together");
+  }
+
+  if (toys.optc == 2) {
+    //add user to group
+    //toys.optargs[0]- user, toys.optargs[1] - group
+    char *args[4];
+    args[0] = "groupadd";
+    args[1] = toys.optargs[0];
+    args[2] = toys.optargs[1];
+    args[3] = NULL;
+    toys.exitval = exec_wait(args);
+  } else {    //new user to be created
+    // investigate the user to be created
+    if ((pwd = getpwnam(*toys.optargs))) 
+      error_exit("user '%s' is in use", *toys.optargs);
+    is_valid_username(*toys.optargs); //validate the user name
+    new_user();
+  }
+}