process.c

来自「samba-3.0.22.tar.gz 编译smb服务器的源码」· C语言 代码 · 共 984 行 · 第 1/2 页

/* 
   Unix SMB/CIFS implementation.
   process incoming packets - main loop
   Copyright (C) Jean Fran鏾is Micouleau      1998-2002.
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "wins_repl.h"

extern fd_set *listen_set;
extern int listen_number;
extern int *sock_array;

WINS_OWNER global_wins_table[64][64];
int partner_count;

TALLOC_CTX *mem_ctx;

#define WINS_LIST "wins.tdb"
#define INFO_VERSION	"INFO/version"
#define INFO_COUNT	"INFO/num_entries"
#define INFO_ID_HIGH	"INFO/id_high"
#define INFO_ID_LOW	"INFO/id_low"
#define ENTRY_PREFIX 	"ENTRY/"


/*******************************************************************
fill the header of a reply.
********************************************************************/
static void fill_header(GENERIC_PACKET *g, int opcode, int ctx, int mess)
{
	if (g==NULL)
		return;

	g->header.opcode=opcode;
	g->header.assoc_ctx=ctx;
	g->header.mess_type=mess;
}

/*******************************************************************
dump the global table, that's a debug code.
********************************************************************/
static void dump_global_table(void)
{
	int i,j;
	
	for (i=0;i<partner_count;i++) {
		DEBUG(10,("\n%d ", i));
		for (j=0; global_wins_table[i][j].address.s_addr!=0; j++)
			DEBUG(10,("%s:%d \t", inet_ntoa(global_wins_table[i][j].address),
				(int)global_wins_table[i][j].max_version));
	}
	DEBUG(10,("\n"));
}

/*******************************************************************
start association
********************************************************************/
static void start_assoc_process(GENERIC_PACKET *q, GENERIC_PACKET *r)
{
	/*
	 * add this request to our current wins partners list
	 * this list is used to know with who we are in contact
	 *
	 */
	r->sa_rp.assoc_ctx=time(NULL);
	fill_header(r, OPCODE_NON_NBT, q->sa_rq.assoc_ctx, MESSAGE_TYPE_START_ASSOC_REPLY);

	/* reply we are a NT4 server */
	
	/* w2K is min=2, maj=5 */
	
	r->sa_rp.min_ver=1;
	r->sa_rp.maj_ver=1;

	add_partner(r->sa_rp.assoc_ctx, q->sa_rq.assoc_ctx, False, False);
}

/*******************************************************************
start association reply
********************************************************************/
static void start_assoc_reply(GENERIC_PACKET *q, GENERIC_PACKET *r)
{
	int i;

	/* check if we have already registered this client */
	if (!check_partner(q->header.assoc_ctx)) {
		DEBUG(0,("start_assoc_reply: unknown client\n"));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}

	if (!update_server_partner(q->header.assoc_ctx, q->sa_rp.assoc_ctx)) {
		DEBUG(0,("start_assoc_reply: can't update server ctx\n"));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}

	/* if pull, request map table */	
	if (check_pull_partner(q->header.assoc_ctx)) {
		fill_header(r, OPCODE_NON_NBT, get_server_assoc(q->header.assoc_ctx), MESSAGE_TYPE_REPLICATE);

		r->rep.msg_type=MESSAGE_REP_ADD_VERSION_REQUEST;
		DEBUG(5,("start_assoc_reply: requesting map table\n"));

		return;
	}

	/* if push, send our table */
	if (check_push_partner(q->header.assoc_ctx)) {
		fill_header(r, OPCODE_NON_NBT, get_server_assoc(q->header.assoc_ctx), MESSAGE_TYPE_REPLICATE);
		r->rep.msg_type=MESSAGE_REP_UPDATE_NOTIFY_REQUEST;
		r->rep.un_rq.partner_count=partner_count;
		
		r->rep.un_rq.wins_owner=talloc_array(mem_ctx, WINS_OWNER, partner_count);
		if (r->rep.un_rq.wins_owner==NULL) {
			DEBUG(0,("start_assoc_reply: can't alloc memory\n"));
			stop_packet(q, r, STOP_REASON_USER_REASON);
			return;
		}

		for (i=0; i<partner_count; i++)
			r->rep.un_rq.wins_owner[i]=global_wins_table[0][i];
		
		DEBUG(5,("start_assoc_reply: sending update table\n"));
		return;
	}
	
	/* neither push/pull, stop */
	/* we should not come here */
	DEBUG(0,("we have a partner which is neither push nor pull !\n"));
	stop_packet(q, r, STOP_REASON_USER_REASON);
}

/****************************************************************************
initialise and fill the in-memory partner table.
****************************************************************************/
int init_wins_partner_table(void)
{
	int i=1,j=0,k;
	char **partner = str_list_make(lp_wins_partners(), NULL);

	if (partner==NULL) {
		DEBUG(0,("wrepld: no partner list in smb.conf, exiting\n"));
		exit_server("normal exit");
		return(0);
	}

	DEBUG(4, ("init_wins_partner_table: partners: %s\n", lp_wins_partners()));

	global_wins_table[0][0].address=*iface_n_ip(0);
	global_wins_table[0][0].max_version=0;
	global_wins_table[0][0].min_version=0;
	global_wins_table[0][0].type=0;

	while (partner[j]!=NULL) {
		DEBUG(3,("init_wins_partner_table, adding partner: %s\n", partner[j]));
		
		global_wins_table[0][i].address=*interpret_addr2(partner[j]);
		global_wins_table[0][i].max_version=0;
		global_wins_table[0][i].min_version=0;
		global_wins_table[0][i].type=0;
		global_wins_table[0][i].last_pull=0;
		global_wins_table[0][i].last_push=0;

		i++;
		j++;
	}
	
	for (k=1; k<i;k++)
		for (j=0; j<i; j++)
			global_wins_table[k][j]=global_wins_table[0][j];
	
	str_list_free (&partner);
	
	return i;
}

/****************************************************************************
read the last ID from the wins tdb file.
****************************************************************************/
static void get_our_last_id(WINS_OWNER *wins_owner)
{
	TDB_CONTEXT *tdb;

	tdb = tdb_open_log(lock_path(WINS_LIST), 0, TDB_DEFAULT, O_RDONLY, 0600);
	if (!tdb) {
		DEBUG(2,("get_our_last_id: Can't open wins database file %s. Error was %s\n", WINS_LIST, strerror(errno) ));
		return;
	}
	
	wins_owner->max_version=((SMB_BIG_UINT)tdb_fetch_int32(tdb, INFO_ID_HIGH))<<32 | 
				 (SMB_BIG_UINT)tdb_fetch_int32(tdb, INFO_ID_LOW);

	tdb_close(tdb);
}

/****************************************************************************
send the list of wins server we know.
****************************************************************************/
static void send_version_number_map_table(GENERIC_PACKET *q, GENERIC_PACKET *r)
{
	int i;
	int s_ctx=get_server_assoc(q->header.assoc_ctx);

	if (s_ctx==0) {
		DEBUG(5, ("send_version_number_map_table: request for a partner not in our table\n"));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}

	/*
	 * return an array of wins servers, we are partner with.
	 * each entry contains the IP address and the version info
	 * version: ID of the last entry we've got
	 */

	/* the first wins server must be self */

	/*
	 * get our last ID from the wins database
	 * it can have been updated since last read
	 * as nmbd got registration/release.
	 */ 
	get_our_last_id(&global_wins_table[0][0]);

	r->rep.avmt_rep.wins_owner=talloc_array(mem_ctx, WINS_OWNER, partner_count);
	if (r->rep.avmt_rep.wins_owner==NULL) {
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}
	
	DEBUG(5,("send_version_number_map_table: partner_count: %d\n", partner_count));

	for (i=0; i<partner_count; i++) {
		DEBUG(5,("send_version_number_map_table, partner: %d -> %s, \n", i, inet_ntoa(global_wins_table[0][i].address)));
		r->rep.avmt_rep.wins_owner[i]=global_wins_table[0][i];
	}
	
	r->rep.msg_type=1;
	r->rep.avmt_rep.partner_count=partner_count;
	r->rep.avmt_rep.initiating_wins_server.s_addr=0; /* blatant lie, NT4/w2K do the same ! */
	fill_header(r, OPCODE_NON_NBT, s_ctx, MESSAGE_TYPE_REPLICATE);
}

/****************************************************************************
for a given partner, ask it to send entries we don't have.
****************************************************************************/
static BOOL check_partners_and_send_entries(GENERIC_PACKET *q, GENERIC_PACKET *r, int partner)
{
	int server;
	int other;
	SMB_BIG_UINT temp;
	SMB_BIG_UINT current;


	/*
	 * we check if our partner has more records than us.
	 * we need to check more than our direct partners as
	 * we can have this case:
	 * us: A, partners: B,C, indirect partner: D
	 * A<->B, A<->C, B<->D, C<->D
	 *
	 * So if we're talking to B, we need to check if between
	 * B and C, which one have more records about D.
	 * and also check if we don't already have the records.
	 */


	 /* check all servers even indirect */
	 for (server=1; global_wins_table[0][server].address.s_addr!=0; server++) {
		current = global_wins_table[partner][server].max_version;
		
		temp=0;
		
		for (other=1; other<partner_count; other++) {
			/* skip the partner itself */
			if (other==partner)
				continue;

			if (global_wins_table[other][server].max_version > temp)
				temp=global_wins_table[other][server].max_version;
		}
		
		if (current >= temp && current > global_wins_table[0][server].max_version) {
			/* 
			 * it has more records than every body else and more than us,
			 * ask it the difference between what we have and what it has
			 */
			fill_header(r, OPCODE_NON_NBT, get_server_assoc(q->header.assoc_ctx), MESSAGE_TYPE_REPLICATE);

			r->rep.msg_type=MESSAGE_REP_SEND_ENTRIES_REQUEST;
			r->rep.se_rq.wins_owner.address=global_wins_table[partner][server].address;
			
			r->rep.se_rq.wins_owner.max_version=global_wins_table[partner][server].max_version;
			r->rep.se_rq.wins_owner.min_version=global_wins_table[0][server].max_version;
			r->rep.se_rq.wins_owner.type=0;
			
			write_server_assoc_table(q->header.assoc_ctx, global_wins_table[0][partner].address, global_wins_table[partner][server].address);
			
			/*
			 * and we update our version for this server
			 * as we can't use the IDs returned in the send_entries function
			 * the max ID can be larger than the largest ID returned
			 */
			
			global_wins_table[0][server].max_version=global_wins_table[partner][server].max_version;

			return True;
		}
	}
	return False;
}
	
/****************************************************************************
receive the list of wins server we know.
****************************************************************************/
static void receive_version_number_map_table(GENERIC_PACKET *q, GENERIC_PACKET *r)
{
	fstring peer;
	struct in_addr addr;
	int i,j,k,l;
	int s_ctx=get_server_assoc(q->header.assoc_ctx);

	if (s_ctx==0) {
		DEBUG(5, ("receive_version_number_map_table: request for a partner not in our table\n"));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}

	fstrcpy(peer,get_peer_addr(q->fd));
	addr=*interpret_addr2(peer);

	get_our_last_id(&global_wins_table[0][0]);
	
	DEBUG(5,("receive_version_number_map_table: received a map of %d server from: %s\n", 
	          q->rep.avmt_rep.partner_count ,inet_ntoa(q->rep.avmt_rep.initiating_wins_server)));
	DEBUG(5,("real peer is: %s\n", peer));

	for (i=0; global_wins_table[0][i].address.s_addr!=addr.s_addr && i<partner_count;i++)
		;

	if (i==partner_count) {
		DEBUG(5,("receive_version_number_map_table: unknown partner: %s\n", peer));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}

	for (j=0; j<q->rep.avmt_rep.partner_count;j++) {
		/*
		 * search if we already have this entry or if it's a new one
		 * it can be a new one in case of propagation
		 */
		for (k=0; global_wins_table[0][k].address.s_addr!=0 && 
			  global_wins_table[0][k].address.s_addr!=q->rep.avmt_rep.wins_owner[j].address.s_addr; k++);

		global_wins_table[i][k].address.s_addr=q->rep.avmt_rep.wins_owner[j].address.s_addr;
		global_wins_table[i][k].max_version=q->rep.avmt_rep.wins_owner[j].max_version;
		global_wins_table[i][k].min_version=q->rep.avmt_rep.wins_owner[j].min_version;
		global_wins_table[i][k].type=q->rep.avmt_rep.wins_owner[j].type;
		
		/*
		 * in case it's a new one, rewrite the address for all the partner
		 * to reserve the slot.
		 */

		for(l=0; l<partner_count; l++)
			global_wins_table[l][k].address.s_addr=q->rep.avmt_rep.wins_owner[j].address.s_addr;
	}

	dump_global_table();

	/*
	 * if this server have newer records than what we have
	 * for several wins servers, we need to ask it.
	 * Alas a send entry request is only on one server.
	 * So in the send entry reply, we'll ask for the next server if required.
	 */

	if (check_partners_and_send_entries(q, r, i))
		return;

	/* it doesn't have more entries than us */
	stop_packet(q, r, STOP_REASON_USER_REASON);
}

/****************************************************************************
add an entry to the wins list we'll send.
****************************************************************************/
static BOOL add_record_to_winsname(WINS_NAME **wins_name, int *max_names, char *name, int type, int wins_flags, int id, struct in_addr *ip_list, int num_ips)
{
	WINS_NAME *temp_list;
	int i;
	int current=*max_names;

	temp_list=talloc_realloc(mem_ctx, *wins_name, WINS_NAME, current + 1);
	if (temp_list==NULL)
		return False;

	temp_list[current].name_len=0x11;
	
	safe_strcpy(temp_list[current].name, name, 15);

	temp_list[current].type=type;
	temp_list[current].empty=0;

	temp_list[current].name_flag=wins_flags;

	if ( (wins_flags&0x03) == 1 || (wins_flags&0x03)==2)
		temp_list[current].group_flag=0x01000000;
	else
		temp_list[current].group_flag=0x00000000;
	
	temp_list[current].id=id;
	
	temp_list[current].owner.s_addr=ip_list[0].s_addr;

	if (temp_list[current].name_flag & 2) {
		temp_list[current].num_ip=num_ips;
		temp_list[current].others=talloc_array(mem_ctx, struct in_addr, num_ips);
		if (temp_list[current].others==NULL)
			return False;
	
		for (i=0; i<num_ips; i++)
			temp_list[current].others[i].s_addr=ip_list[i].s_addr;

	} else 
		temp_list[current].num_ip=1;

	temp_list[current].foo=0xffffffff;

	*wins_name=temp_list;
	
	return True;
}

/****************************************************************************
send the list of name we have.
****************************************************************************/
static void send_entry_request(GENERIC_PACKET *q, GENERIC_PACKET *r)
{
	int max_names=0;
	int i;
	time_t time_now = time(NULL);
	WINS_OWNER *wins_owner;
	TDB_CONTEXT *tdb;
	TDB_DATA kbuf, dbuf, newkey;
	int s_ctx=get_server_assoc(q->header.assoc_ctx);
	int num_interfaces = iface_count();

	if (s_ctx==0) {
		DEBUG(1, ("send_entry_request: request for a partner not in our table\n"));
		stop_packet(q, r, STOP_REASON_USER_REASON);
		return;
	}


	wins_owner=&q->rep.se_rq.wins_owner;
	r->rep.se_rp.wins_name=NULL;

	DEBUG(3,("send_entry_request: we have been asked to send the list of wins records\n"));
	DEBUGADD(3,("owned by: %s and between min: %d and max: %d\n", inet_ntoa(wins_owner->address),
		    (int)wins_owner->min_version, (int)wins_owner->max_version));

	/*
	 * if we are asked to send records owned by us
	 * we overwrite the wins ip with 0.0.0.0
	 * to make it easy in case of multihomed
	 */

	for (i=0; i<num_interfaces; i++)
		if (ip_equal(wins_owner->address, *iface_n_ip(i))) {
			wins_owner->address=*interpret_addr2("0.0.0.0");
			break;
		}


	tdb = tdb_open_log(lock_path(WINS_LIST), 0, TDB_DEFAULT, O_RDONLY, 0600);