Roll back to using static MACHINE.SID after consultation with Andrew. This

code will be removed soon and a SID auto-generated from (probably) primary
hostname and never stored in a file will replace it.
Jeremy.
(This used to be commit fbfe94a799cda7f728bc920d4f0655d4f537e3b6)

1 files changed, 201 insertions, 57 deletions

diff --git a/source3/passdb/passdb.c b/source3/passdb/passdb.c
index 272182a714..f520a11157 100644
--- a/source3/passdb/passdb.c
+++ b/source3/passdb/passdb.c
@@ -797,34 +797,54 @@ BOOL pdb_name_to_rid(char *user_name, uint32 *u_rid, uint32 *g_rid)
 }
 
 /****************************************************************************
- Generate the global machine sid. Look for the DOMAINNAME.SID file first, if
- not found then look in smb.conf and use it to create the DOMAINNAME.SID file.
+ Read the machine SID from a file.
 ****************************************************************************/
-BOOL pdb_generate_sam_sid(char *domain_name, DOM_SID *sid)
+
+static BOOL read_sid_from_file(int fd, char *sid_file)
 {
+  fstring fline;
+
+  memset(fline, '\0', sizeof(fline));
+
+  if(read(fd, fline, sizeof(fline) -1 ) < 0) {
+    DEBUG(0,("unable to read file %s. Error was %s\n",
+           sid_file, strerror(errno) ));
+    return False;
+  }
+
+  /*
+   * Convert to the machine SID.
+   */
+
+  fline[sizeof(fline)-1] = '\0';
+  if(!string_to_sid( &global_sam_sid, fline)) {
+    DEBUG(0,("unable to generate machine SID.\n"));
+    return False;
+  }
+
+  return True;
+}
+
+/****************************************************************************
+ Generate the global machine sid. Look for the MACHINE.SID file first, if
+ not found then look in smb.conf and use it to create the MACHINE.SID file.
+ Note this function will be replaced soon. JRA.
+****************************************************************************/
+
+BOOL pdb_generate_sam_sid(void)
+{
+	int fd;
 	char *p;
 	pstring sid_file;
-	pstring machine_sid_file;
-	fstring file_name;
+	fstring sid_string;
+	SMB_STRUCT_STAT st;
+	BOOL overwrite_bad_sid = False;
 
 	generate_wellknown_sids();
 
-	if (sid == NULL)
-	{
-		sid = &global_sam_sid;
-	}
-
 	pstrcpy(sid_file, lp_smb_passwd_file());
-
-	if (sid_file[0] == 0)
-	{
-		DEBUG(0,("cannot find smb passwd file\n"));
-		return False;
-	}
-
 	p = strrchr(sid_file, '/');
-	if (p != NULL)
-	{
+	if(p != NULL) {
 		*++p = '\0';
 	}
 
@@ -836,53 +856,177 @@ BOOL pdb_generate_sam_sid(char *domain_name, DOM_SID *sid)
 		}
 	}
 
-	pstrcpy(machine_sid_file, sid_file);
-	pstrcat(machine_sid_file, "MACHINE.SID");
-
-	slprintf(file_name, sizeof(file_name)-1, "%s.SID", domain_name);
-	strupper(file_name);
-	pstrcat(sid_file, file_name);
+	pstrcat(sid_file, "MACHINE.SID");
     
-	if (file_exist(machine_sid_file, NULL))
-	{
-		if (file_exist(sid_file, NULL))
-		{
-			DEBUG(0,("both %s and %s exist when only one should, unable to continue\n",
-			          machine_sid_file, sid_file));
+	if((fd = sys_open(sid_file, O_RDWR | O_CREAT, 0644)) == -1) {
+		DEBUG(0,("unable to open or create file %s. Error was %s\n",
+			 sid_file, strerror(errno) ));
+		return False;
+	} 
+  
+	/*
+	 * Check if the file contains data.
+	 */
+	
+	if(sys_fstat( fd, &st) < 0) {
+		DEBUG(0,("unable to stat file %s. Error was %s\n",
+			 sid_file, strerror(errno) ));
+		close(fd);
+		return False;
+	} 
+  
+	if(st.st_size > 0) {
+		/*
+		 * We have a valid SID - read it.
+		 */
+		if(!read_sid_from_file( fd, sid_file)) {
+			DEBUG(0,("unable to read file %s. Error was %s\n",
+				 sid_file, strerror(errno) ));
+			close(fd);
 			return False;
 		}
-		if (file_rename(machine_sid_file, sid_file))
-		{
-			DEBUG(0,("could not rename %s to %s.  Error was %s\n",
-			          machine_sid_file, sid_file, strerror(errno)));
-			return False;
+
+		/*
+		 * JRA. Reversed the sense of this test now that I have
+		 * actually done this test *personally*. One more reason
+		 * to never trust third party information you have not
+		 * independently verified.... sigh. JRA.
+		 */
+
+		if(global_sam_sid.num_auths > 0 && global_sam_sid.sub_auths[0] == 0x21) {
+			/*
+			 * Fix and re-write...
+			 */
+			overwrite_bad_sid = True;
+			global_sam_sid.sub_auths[0] = 21;
+			DEBUG(5,("pdb_generate_sam_sid: Old (incorrect) sid id_auth of hex 21 \
+detected - re-writing to be decimal 21 instead.\n" ));
+			sid_to_string(sid_string, &global_sam_sid);
+			if(sys_lseek(fd, (SMB_OFF_T)0, SEEK_SET) != 0) {
+				DEBUG(0,("unable to seek file file %s. Error was %s\n",
+					 sid_file, strerror(errno) ));
+				close(fd);
+				return False;
+			}
+		} else {
+			close(fd);
+			return True;
 		}
-	}
+	} else {
+		/*
+		 * The file contains no data - we need to generate our
+		 * own sid.
+		 * Generate the new sid data & turn it into a string.
+		 */
+		int i;
+		uchar raw_sid_data[12];
+		DOM_SID mysid;
+
+		memset((char *)&mysid, '\0', sizeof(DOM_SID));
+		mysid.sid_rev_num = 1;
+		mysid.id_auth[5] = 5;
+		mysid.num_auths = 0;
+		mysid.sub_auths[mysid.num_auths++] = 21;
+
+		generate_random_buffer( raw_sid_data, 12, True);
+		for( i = 0; i < 3; i++)
+			mysid.sub_auths[mysid.num_auths++] = IVAL(raw_sid_data, i*4);
+
+		sid_to_string(sid_string, &mysid);
+	} 
 	
-	/* attempt to read the SID from the file */
-	if (read_sid(domain_name, sid))
-	{
-		return True;
-	}
+	fstrcat(sid_string, "\n");
+	
+	/*
+	 * Ensure our new SID is valid.
+	 */
+	
+	if(!string_to_sid( &global_sam_sid, sid_string)) {
+		DEBUG(0,("unable to generate machine SID.\n"));
+		return False;
+	} 
   
-	if (!create_new_sid(sid))
-	{
+	/*
+	 * Do an exclusive blocking lock on the file.
+	 */
+	
+	if(!do_file_lock( fd, 60, F_WRLCK)) {
+		DEBUG(0,("unable to lock file %s. Error was %s\n",
+			 sid_file, strerror(errno) ));
+		close(fd);
 		return False;
-	}
-	/* attempt to read the SID from the file */
-	if (!write_sid(domain_name, sid))
-	{
-		return True;
-	}
+	} 
+ 
+	if(!overwrite_bad_sid) {
+		/*
+		 * At this point we have a blocking lock on the SID
+		 * file - check if in the meantime someone else wrote
+		 * SID data into the file. If so - they were here first,
+		 * use their data.
+		 */
+	
+		if(sys_fstat( fd, &st) < 0) {
+			DEBUG(0,("unable to stat file %s. Error was %s\n",
+				 sid_file, strerror(errno) ));
+			close(fd);
+			return False;
+		} 
   
-	/* during the attempt to write, someone else wrote? */
-
-	/* attempt to read the SID from the file */
-	if (read_sid(domain_name, sid))
-	{
-		return True;
+		if(st.st_size > 0) {
+			/*
+			 * Unlock as soon as possible to reduce
+			 * contention on the exclusive lock.
+			 */ 
+			do_file_lock( fd, 60, F_UNLCK);
+		
+			/*
+			 * We have a valid SID - read it.
+			 */
+		
+			if(!read_sid_from_file( fd, sid_file)) {
+				DEBUG(0,("unable to read file %s. Error was %s\n",
+					 sid_file, strerror(errno) ));
+				close(fd);
+				return False;
+			}
+			close(fd);
+			return True;
+		} 
 	}
-  
+	
+	/*
+	 * The file is still empty and we have an exlusive lock on it,
+	 * or we're fixing an earlier mistake.
+	 * Write out out SID data into the file.
+	 */
+
+	/*
+	 * Use chmod here as some (strange) UNIX's don't
+	 * have fchmod. JRA.
+	 */	
+
+	if(chmod(sid_file, 0644) < 0) {
+		DEBUG(0,("unable to set correct permissions on file %s. \
+Error was %s\n", sid_file, strerror(errno) ));
+		do_file_lock( fd, 60, F_UNLCK);
+		close(fd);
+		return False;
+	} 
+	
+	if(write( fd, sid_string, strlen(sid_string)) != strlen(sid_string)) {
+		DEBUG(0,("unable to write file %s. Error was %s\n",
+			 sid_file, strerror(errno) ));
+		do_file_lock( fd, 60, F_UNLCK);
+		close(fd);
+		return False;
+	} 
+	
+	/*
+	 * Unlock & exit.
+	 */
+	
+	do_file_lock( fd, 60, F_UNLCK);
+	close(fd);
 	return True;
 }   
 /*******************************************************************