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
(This used to be commit e7634f81c5116ff4addfb7e495f54b6bb78e8f77)

1 files changed, 58 insertions, 19 deletions

diff --git a/source3/lib/username.c b/source3/lib/username.c
index 24195b196b..074e6c8992 100644
--- a/source3/lib/username.c
+++ b/source3/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_combinations2(char *s, int offset, 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) (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;
 
@@ -183,18 +183,16 @@ 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 (!user || !(*user))
+	if (!user2 || !(*user2))
 		return(NULL);
 
-	fstrcpy(user2, user);
+	if (!user || !(*user))
+		return(NULL);
 
 	/* Try in all lower case first as this is the most 
 	   common case on UNIX systems */
@@ -228,19 +226,53 @@ struct passwd *Get_Pwnam(char *user,BOOL allow_change)
 
 done:
 	DEBUG(5,("Get_Pwnam %s find a valid username!\n",ret ? "did":"didn't"));
+	return ret;
+}
+
+/****************************************************************************
+ 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  */
-	if(allow_change)
-		fstrcpy(user,user2);
+	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);  
+}
+
+/****************************************************************************
  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;
 }