This commit is number 3 of 4.

In particular this commit focuses on:

Changing the Get_Pwnam code so that it can work in a const-enforced
environment.

While these changes have been mildly tested, and are pretty small, any
assistance in this is appreciated.

----

These changes allow for 'const' in the Samba tree.

There are a number of good reasons to do this:

	- I want to allow the SAM_ACCOUNT structure to move from wasteful
	pstrings and fstrings to  allocated strings.  We can't do that if
	people are modifying these outputs, as they may well make
	assumptions about getting pstrings and fstrings

	- I want --with-pam_smbpass to compile with a slightly sane
	volume of warnings, currently its  pretty bad, even in 2.2
	where is compiles at all.

	- Tridge assures me that he no longer opposes 'const religion'
	based on the ability to  #define const the problem away.

	- Changed Get_Pwnam(x,y) into two variants (so that the const
	parameter can work correctly): - Get_Pwnam(const x) and
	Get_Pwnam_Modify(x).

	- Reworked smbd/chgpasswd.c to work with these mods, passing
	around a 'struct passwd' rather  than the modified username

source/auth/auth_rhosts.c

@@ -86,7 +86,7 @@ static BOOL check_user_equiv(const char *user, const char *remote, const char *e
 	      static char *mydomain = NULL;
 	      if (!mydomain)
 		yp_get_default_domain(&mydomain);
-	      if (mydomain && innetgr(file_host,(char *)remote,(char *)user,mydomain))
+	      if (mydomain && innetgr(file_host,remote,user,mydomain))
 		host_ok = True;
 	    }
 #else
@@ -135,7 +135,7 @@ static BOOL check_hosts_equiv(char *user) /* should be const... */
 {
   char *fname = NULL;
   pstring rhostsfile;
-  struct passwd *pass = Get_Pwnam(user,False);
+  struct passwd *pass = Get_Pwnam(user);
 
   if (!pass) 
     return(False);

source/auth/auth_unix.c

@@ -89,7 +89,7 @@ NTSTATUS check_unix_security(const auth_usersupplied_info *user_info, auth_serve
 
 	become_root();
 	
-	pass = Get_Pwnam(user_info->unix_username.str, False);
+	pass = Get_Pwnam(user_info->unix_username.str);
 
 	nt_status = pass_check(pass,
 				pass ? pass->pw_name : user_info->unix_username.str, 

source/lib/substitute.c

@@ -186,7 +186,7 @@ void standard_sub_basic(char *str)
 			string_sub(p,"%U",tmp_str,l);
 			break;
 		case 'G' :
-			if ((pass = Get_Pwnam(current_user_info.smb_name, False))!=NULL) {
+			if ((pass = Get_Pwnam(current_user_info.smb_name))!=NULL) {
 				string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 			} else {
 				p += 2;

source/lib/username.c

@@ -22,18 +22,18 @@
 #include "includes.h"
 
 /* internal functions */
-static struct passwd *uname_string_combinations(char *s, struct passwd * (*fn) (char *), int N);
+static struct passwd *uname_string_combinations(char *s, struct passwd * (*fn) (const char *), int N);
-static struct passwd *uname_string_combinations2(char *s, int offset, struct passwd * (*fn) (char *), int N);
+static struct passwd *uname_string_combinations2(char *s, int offset, struct passwd * (*fn) (const char *), int N);
 
 /****************************************************************************
  Get a users home directory.
 ****************************************************************************/
 
-char *get_user_home_dir(char *user)
+char *get_user_home_dir(const char *user)
 {
   static struct passwd *pass;
 
-  pass = Get_Pwnam(user, False);
+  pass = Get_Pwnam(user);
 
   if (!pass) return(NULL);
   return(pass->pw_dir);      
@@ -158,7 +158,7 @@ BOOL map_username(char *user)
  Get_Pwnam wrapper
 ****************************************************************************/
 
-static struct passwd *_Get_Pwnam(char *s)
+static struct passwd *_Get_Pwnam(const char *s)
 {
   struct passwd *ret;
 
@@ -183,19 +183,17 @@ static struct passwd *_Get_Pwnam(char *s)
  *   - in all lower case if this differs from transmitted
  *   - in all upper case if this differs from transmitted
  *   - using lp_usernamelevel() for permutations.
- * NOTE: This can potentially modify 'user' depending on value of
- *       allow_change!
  */
-struct passwd *Get_Pwnam(char *user,BOOL allow_change)
+struct passwd *Get_Pwnam_internals(const char *user, char *user2)
 {
-	fstring user2;
 	struct passwd *ret = NULL;
 
+	if (!user2 || !(*user2))
+		return(NULL);
+
 	if (!user || !(*user))
 		return(NULL);
 
-	fstrcpy(user2, user);
-
 	/* Try in all lower case first as this is the most 
 	   common case on UNIX systems */
 	strlower(user2);
@@ -228,10 +226,44 @@ struct passwd *Get_Pwnam(char *user,BOOL allow_change)
 
 done:
 	DEBUG(5,("Get_Pwnam %s find a valid username!\n",ret ? "did":"didn't"));
-	/* If caller wants the modified username, ensure they get it  */
+	return ret;
-	if(allow_change)
+}
-		fstrcpy(user,user2);
 
+/****************************************************************************
+ Get_Pwnam wrapper for modification.
+  NOTE: This can potentially modify 'user'! 
+****************************************************************************/
+
+struct passwd *Get_Pwnam_Modify(char *user)
+{
+	fstring user2;
+	struct passwd *ret;
+
+	fstrcpy(user2, user);
+
+	ret = Get_Pwnam_internals(user, user2);
+	
+	/* If caller wants the modified username, ensure they get it  */
+	fstrcpy(user,user2);
+
+	/* We can safely assume ret is NULL if none of the above succeed */
+	return(ret);  
+}
+
+/****************************************************************************
+ Get_Pwnam wrapper without modification.
+  NOTE: This with NOT modify 'user'! 
+****************************************************************************/
+
+struct passwd *Get_Pwnam(const char *user)
+{
+	fstring user2;
+	struct passwd *ret;
+
+	fstrcpy(user2, user);
+
+	ret = Get_Pwnam_internals(user, user2);
+	
 	/* We can safely assume ret is NULL if none of the above succeed */
 	return(ret);  
 }
@@ -240,7 +272,7 @@ done:
  Check if a user is in a netgroup user list.
 ****************************************************************************/
 
-static BOOL user_in_netgroup_list(char *user,char *ngname)
+static BOOL user_in_netgroup_list(const char *user, const char *ngname)
 {
 #ifdef HAVE_NETGROUP
   static char *mydomain = NULL;
@@ -333,11 +365,11 @@ failed with error %s\n", strerror(errno) ));
  Check if a user is in a UNIX group.
 ****************************************************************************/
 
-static BOOL user_in_unix_group_list(char *user,char *gname)
+static BOOL user_in_unix_group_list(const char *user,const char *gname)
 {
 	struct group *gptr;
 	char **member;  
-	struct passwd *pass = Get_Pwnam(user,False);
+	struct passwd *pass = Get_Pwnam(user);
 
 	DEBUG(10,("user_in_unix_group_list: checking user %s in group %s\n", user, gname));
 
@@ -532,7 +564,11 @@ struct passwd *smb_getpwnam(char *user, BOOL allow_change)
 	char *sep;
 	extern pstring global_myname;
 
-	pw = Get_Pwnam(user, allow_change);
+	if (allow_change) {
+		pw = Get_Pwnam_Modify(user);
+	} else {
+		pw = Get_Pwnam(user);
+	}
 	if (pw) return pw;
 
 	/* if it is a domain qualified name and it isn't in our password
@@ -543,8 +579,11 @@ struct passwd *smb_getpwnam(char *user, BOOL allow_change)
 	p = strchr_m(user,*sep);
 	if (p && 
 	    strncasecmp(global_myname, user, strlen(global_myname))==0) {
-		return Get_Pwnam(p+1, allow_change);
+		if (allow_change) {
+			pw = Get_Pwnam_Modify(p+1);
+		} else {
+			pw = Get_Pwnam(p+1);
+		}
 	}
-
 	return NULL;
 }

source/passdb/smbpassgroup.c

@@ -157,7 +157,7 @@ static struct smb_passwd *getsmbfilegrpent(void *vp,
 			}
 		}
 
-		pwfile = Get_Pwnam(pw_buf.smb_name, False);
+		pwfile = Get_Pwnam(pw_buf.smb_name);
 		if (pwfile == NULL)
 		{
 			DEBUG(0,("getsmbfilegrpent: smbpasswd database is corrupt!\n"));

source/rpc_server/srv_samr_nt.c

@@ -864,7 +864,7 @@ static NTSTATUS get_group_alias_entries(TALLOC_CTX *ctx, DOMAIN_GRP **d_grp, DOM
 			}
 
 			/* Don't return user private groups... */
-			if (Get_Pwnam(smap.nt_name, False) != 0) {
+			if (Get_Pwnam(smap.nt_name) != 0) {
 				DEBUG(10,("get_group_alias_entries: not returing %s, clashes with user.\n", smap.nt_name ));
 				continue;			
 			}
@@ -1362,7 +1362,7 @@ NTSTATUS _samr_chgpasswd_user(pipes_struct *p, SAMR_Q_CHGPASSWD_USER *q_u, SAMR_
 	/*
 	 * Do any UNIX username case mangling.
 	 */
-	(void)Get_Pwnam( user_name, True);
+	(void)Get_Pwnam_Modify( user_name);
 
     if (!pass_oem_change(user_name, q_u->lm_newpass.pass, q_u->lm_oldhash.hash,
                          q_u->nt_newpass.pass, q_u->nt_oldhash.hash))

source/smbd/auth_rhosts.c

@@ -86,7 +86,7 @@ static BOOL check_user_equiv(const char *user, const char *remote, const char *e
 	      static char *mydomain = NULL;
 	      if (!mydomain)
 		yp_get_default_domain(&mydomain);
-	      if (mydomain && innetgr(file_host,(char *)remote,(char *)user,mydomain))
+	      if (mydomain && innetgr(file_host,remote,user,mydomain))
 		host_ok = True;
 	    }
 #else
@@ -135,7 +135,7 @@ static BOOL check_hosts_equiv(char *user) /* should be const... */
 {
   char *fname = NULL;
   pstring rhostsfile;
-  struct passwd *pass = Get_Pwnam(user,False);
+  struct passwd *pass = Get_Pwnam(user);
 
   if (!pass) 
     return(False);

source/smbd/auth_unix.c

@@ -89,7 +89,7 @@ NTSTATUS check_unix_security(const auth_usersupplied_info *user_info, auth_serve
 
 	become_root();
 	
-	pass = Get_Pwnam(user_info->unix_username.str, False);
+	pass = Get_Pwnam(user_info->unix_username.str);
 
 	nt_status = pass_check(pass,
 				pass ? pass->pw_name : user_info->unix_username.str, 

source/smbd/chgpasswd.c

@@ -118,20 +118,18 @@ static int findpty(char **slave)
 	return (-1);
 }
 
-static int dochild(int master, char *slavedev, char *name,
+static int dochild(int master, const char *slavedev, const struct passwd *pass,
-		   char *passwordprogram, BOOL as_root)
+		   const char *passwordprogram, BOOL as_root)
 {
 	int slave;
 	struct termios stermios;
-	struct passwd *pass = Get_Pwnam(name, True);
 	gid_t gid;
 	uid_t uid;
 
 	if (pass == NULL)
 	{
 		DEBUG(0,
-		      ("dochild: user name %s doesn't exist in the UNIX password database.\n",
+		      ("dochild: user doesn't exist in the UNIX password database.\n"));
-		       name));
 		return False;
 	}
 
@@ -318,7 +316,7 @@ static int talktochild(int master, char *seq)
 	return (count > 0);
 }
 
-static BOOL chat_with_program(char *passwordprogram, char *name,
+static BOOL chat_with_program(char *passwordprogram, struct passwd *pass,
 			      char *chatsequence, BOOL as_root)
 {
 	char *slavedev;
@@ -327,12 +325,19 @@ static BOOL chat_with_program(char *passwordprogram, char *name,
 	int wstat;
 	BOOL chstat = False;
 
+	if (pass == NULL)
+	{
+		DEBUG(0,
+		      ("chat_with_program: user doesn't exist in the UNIX password database.\n"));
+		return False;
+	}
+
 	/* allocate a pseudo-terminal device */
 	if ((master = findpty(&slavedev)) < 0)
 	{
 		DEBUG(3,
 		      ("Cannot Allocate pty for password change: %s\n",
-		       name));
+		       pass->pw_name));
 		return (False);
 	}
 
@@ -347,7 +352,7 @@ static BOOL chat_with_program(char *passwordprogram, char *name,
 	{
 		DEBUG(3,
 		      ("Cannot fork() child for password change: %s\n",
-		       name));
+		       pass->pw_name));
 		close(master);
 		CatchChild();
 		return (False);
@@ -360,7 +365,7 @@ static BOOL chat_with_program(char *passwordprogram, char *name,
 		{
 			DEBUG(3,
 			      ("Child failed to change password: %s\n",
-			       name));
+			       pass->pw_name));
 			kill(pid, SIGKILL);	/* be sure to end this process */
 		}
 
@@ -426,10 +431,10 @@ static BOOL chat_with_program(char *passwordprogram, char *name,
 			become_root();
 
 		DEBUG(3,
-		      ("Dochild for user %s (uid=%d,gid=%d)\n", name,
+		      ("Dochild for user %s (uid=%d,gid=%d)\n", pass->pw_name,
 		       (int)getuid(), (int)getgid()));
 		chstat =
-			dochild(master, slavedev, name, passwordprogram,
+			dochild(master, slavedev, pass, passwordprogram,
 				as_root);
 
 		if (as_root)
@@ -448,19 +453,20 @@ static BOOL chat_with_program(char *passwordprogram, char *name,
 	if (chstat)
 		DEBUG(3,
 		      ("Password change %ssuccessful for user %s\n",
-		       (chstat ? "" : "un"), name));
+		       (chstat ? "" : "un"), pass->pw_name));
 	return (chstat);
 }
 
 
-BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
+BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
 {
 	pstring passwordprogram;
 	pstring chatsequence;
 	size_t i;
 	size_t len;
 
-	strlower(name);
+	struct passwd *pass;
+
 	DEBUG(3, ("Password change for user: %s\n", name));
 
 #if DEBUG_PASSWORD
@@ -505,6 +511,8 @@ BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
 			return False;
 		}
 	}
+	
+	pass = Get_Pwnam(name);
 
 #ifdef WITH_PAM
 	if (lp_pam_password_change()) {
@@ -513,8 +521,12 @@ BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
 		if (as_root)
 			become_root();
 
-		ret = smb_pam_passchange(name, oldpass, newpass);
+		if (pass) {
-
+			ret = smb_pam_passchange(pass->pw_name, oldpass, newpass);
+		} else {
+			ret = smb_pam_passchange(name, oldpass, newpass);
+		}
+			
 		if (as_root)
 			unbecome_root();
 
@@ -522,6 +534,16 @@ BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
 	}
 #endif
 
+	/* A non-PAM password change just doen't make sense without a valid local user */
+
+	if (pass == NULL)
+	{
+		DEBUG(0,
+		      ("chgpasswd: user %s doesn't exist in the UNIX password database.\n",
+		       name));
+		return False;
+	}
+
 	pstrcpy(passwordprogram, lp_passwd_program());
 	pstrcpy(chatsequence, lp_passwd_chat());
 
@@ -553,12 +575,12 @@ the string %%u, and the given string %s does not.\n", passwordprogram ));
 	all_string_sub(chatsequence, "%o", oldpass, sizeof(pstring));
 	all_string_sub(chatsequence, "%n", newpass, sizeof(pstring));
 	return (chat_with_program
-		(passwordprogram, name, chatsequence, as_root));
+		(passwordprogram, pass, chatsequence, as_root));
 }
 
 #else /* ALLOW_CHANGE_PASSWORD */
 
-BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
+BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
 {
 	DEBUG(0, ("Password changing not compiled in (user=%s)\n", name));
 	return (False);

source/smbd/lanman.c

@@ -1954,7 +1954,7 @@ static BOOL api_SetUserPassword(connection_struct *conn,uint16 vuid, char *param
   /*
    * Do any UNIX username case mangling.
    */
-  passwd = Get_Pwnam( user, True);
+  passwd = Get_Pwnam_Modify( user );
 
   /*
    * Attempt to verify the old password against smbpasswd entries
@@ -2082,7 +2082,7 @@ static BOOL api_SamOEMChangePassword(connection_struct *conn,uint16 vuid, char *
   /*
    * Do any UNIX username case mangling.
    */
-  (void)Get_Pwnam( user, True);
+  (void)Get_Pwnam_Modify( user );
 
   if (pass_oem_change(user, (uchar*) data, (uchar *)&data[516], NULL, NULL))
   {

source/smbd/password.c

@@ -276,7 +276,7 @@ void add_session_user(char *user)
   fstring suser;
   StrnCpy(suser,user,sizeof(suser)-1);
 
-  if (!Get_Pwnam(suser,True)) return;
+  if (!Get_Pwnam_Modify(suser)) return;
 
   if (suser && *suser && !in_list(suser,session_users,False))
     {
@@ -551,7 +551,7 @@ and given password ok (%s)\n", user));
 	if (!ok && GUEST_OK(snum)) {
 		fstring guestname;
 		StrnCpy(guestname,lp_guestaccount(snum),sizeof(guestname)-1);
-		if (Get_Pwnam(guestname,True)) {
+		if (Get_Pwnam(guestname)) {
 			fstrcpy(user,guestname);
 			ok = True;
 			DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",

source/smbd/service.c

@@ -450,7 +450,7 @@ connection_struct *make_connection(char *service,char *password,
 		/* Allow %S to be used by force user. */
 		pstring_sub(fuser,"%S",service);
 
-		pass2 = (struct passwd *)Get_Pwnam(fuser,True);
+		pass2 = (struct passwd *)Get_Pwnam_Modify(fuser);
 		if (pass2) {
 			conn->uid = pass2->pw_uid;
 			conn->gid = pass2->pw_gid;

source/smbd/uid.c

@@ -36,7 +36,7 @@ BOOL change_to_guest(void)
 	static fstring guest_name;
 
 	if (!pass) {
-		pass = Get_Pwnam(lp_guestaccount(-1),True);
+		pass = Get_Pwnam(lp_guestaccount(-1));
 		if (!pass)
 			return(False);
 		guest_uid = pass->pw_uid;