source: branches/samba-3.3.x/source/printing/notify.c

/* 
   Unix SMB/Netbios implementation.
   Version 3.0
   printing backend routines
   Copyright (C) Tim Potter, 2002
   Copyright (C) Gerald Carter,         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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "printing.h"

static TALLOC_CTX *send_ctx;

static unsigned int num_messages;

static struct notify_queue {
        struct notify_queue *next, *prev;
        struct spoolss_notify_msg *msg;
        struct timeval tv;
        uint8 *buf;
        size_t buflen;
} *notify_queue_head = NULL;

static struct timed_event *notify_event;

static bool create_send_ctx(void)
{
        if (!send_ctx)
                send_ctx = talloc_init("print notify queue");

        if (!send_ctx)
                return False;

        return True;
}

/****************************************************************************
 Turn a queue name into a snum.
****************************************************************************/

int print_queue_snum(const char *qname)
{
        int snum = lp_servicenumber(qname);
        if (snum == -1 || !lp_print_ok(snum))
                return -1;
        return snum;
}

/*******************************************************************
 Used to decide if we need a short select timeout.
*******************************************************************/

bool print_notify_messages_pending(void)
{
        return (notify_queue_head != NULL);
}

/*******************************************************************
 Flatten data into a message.
*******************************************************************/

static bool flatten_message(struct notify_queue *q)
{
        struct spoolss_notify_msg *msg = q->msg;
        uint8 *buf = NULL;
        size_t buflen = 0, len;

again:
        len = 0;

        /* Pack header */

        len += tdb_pack(buf + len, buflen - len, "f", msg->printer);

        len += tdb_pack(buf + len, buflen - len, "ddddddd",
                        (uint32)q->tv.tv_sec, (uint32)q->tv.tv_usec,
                        msg->type, msg->field, msg->id, msg->len, msg->flags);

        /* Pack data */

        if (msg->len == 0)
                len += tdb_pack(buf + len, buflen - len, "dd",
                                msg->notify.value[0], msg->notify.value[1]);
        else
                len += tdb_pack(buf + len, buflen - len, "B",
                                msg->len, msg->notify.data);

        if (buflen != len) {
                buf = (uint8 *)TALLOC_REALLOC(send_ctx, buf, len);
                if (!buf)
                        return False;
                buflen = len;
                goto again;
        }

        q->buf = buf;
        q->buflen = buflen;

        return True;
}

/*******************************************************************
 Send the batched messages - on a per-printer basis.
*******************************************************************/

static void print_notify_send_messages_to_printer(struct messaging_context *msg_ctx,
                                                  const char *printer,
                                                  unsigned int timeout)
{
        char *buf;
        struct notify_queue *pq, *pq_next;
        size_t msg_count = 0, offset = 0;
        size_t num_pids = 0;
        size_t i;
        pid_t *pid_list = NULL;
        struct timeval end_time = timeval_zero();

        /* Count the space needed to send the messages. */
        for (pq = notify_queue_head; pq; pq = pq->next) {
                if (strequal(printer, pq->msg->printer)) {
                        if (!flatten_message(pq)) {
                                DEBUG(0,("print_notify_send_messages: Out of memory\n"));
                                talloc_free_children(send_ctx);
                                num_messages = 0;
                                return;
                        }
                        offset += (pq->buflen + 4);
                        msg_count++;
                }       
        }
        offset += 4; /* For count. */

        buf = (char *)TALLOC(send_ctx, offset);
        if (!buf) {
                DEBUG(0,("print_notify_send_messages: Out of memory\n"));
                talloc_free_children(send_ctx);
                num_messages = 0;
                return;
        }

        offset = 0;
        SIVAL(buf,offset,msg_count);
        offset += 4;
        for (pq = notify_queue_head; pq; pq = pq_next) {
                pq_next = pq->next;

                if (strequal(printer, pq->msg->printer)) {
                        SIVAL(buf,offset,pq->buflen);
                        offset += 4;
                        memcpy(buf + offset, pq->buf, pq->buflen);
                        offset += pq->buflen;

                        /* Remove from list. */
                        DLIST_REMOVE(notify_queue_head, pq);
                }
        }

        DEBUG(5, ("print_notify_send_messages_to_printer: sending %lu print notify message%s to printer %s\n", 
                  (unsigned long)msg_count, msg_count != 1 ? "s" : "", printer));

        /*
         * Get the list of PID's to send to.
         */

        if (!print_notify_pid_list(printer, send_ctx, &num_pids, &pid_list))
                return;

        if (timeout != 0) {
                end_time = timeval_current_ofs(timeout, 0);
        }

        for (i = 0; i < num_pids; i++) {
                messaging_send_buf(msg_ctx,
                                   pid_to_procid(pid_list[i]),
                                   MSG_PRINTER_NOTIFY2 | MSG_FLAG_LOWPRIORITY,
                                   (uint8 *)buf, offset);

                if ((timeout != 0) && timeval_expired(&end_time)) {
                        break;
                }
        }
}

/*******************************************************************
 Actually send the batched messages.
*******************************************************************/

void print_notify_send_messages(struct messaging_context *msg_ctx,
                                unsigned int timeout)
{
        if (!print_notify_messages_pending())
                return;

        if (!create_send_ctx())
                return;

        while (print_notify_messages_pending())
                print_notify_send_messages_to_printer(
                        msg_ctx, notify_queue_head->msg->printer, timeout);

        talloc_free_children(send_ctx);
        num_messages = 0;
}

/*******************************************************************
 Event handler to send the messages.
*******************************************************************/

static void print_notify_event_send_messages(struct event_context *event_ctx,
                                        struct timed_event *te,
                                        struct timeval now,
                                        void *private_data)
{
        /* Remove this timed event handler. */
        TALLOC_FREE(notify_event);

        change_to_root_user();
        print_notify_send_messages(smbd_messaging_context(), 0);
}

/**********************************************************************
 deep copy a SPOOLSS_NOTIFY_MSG structure using a TALLOC_CTX
 *********************************************************************/
 
static bool copy_notify2_msg( SPOOLSS_NOTIFY_MSG *to, SPOOLSS_NOTIFY_MSG *from )
{

        if ( !to || !from )
                return False;
        
        memcpy( to, from, sizeof(SPOOLSS_NOTIFY_MSG) );
        
        if ( from->len ) {
                to->notify.data = (char *)TALLOC_MEMDUP(send_ctx, from->notify.data, from->len );
                if ( !to->notify.data ) {
                        DEBUG(0,("copy_notify2_msg: TALLOC_MEMDUP() of size [%d] failed!\n", from->len ));
                        return False;
                }
        }
        

        return True;
}

/*******************************************************************
 Batch up print notify messages.
*******************************************************************/

static void send_spoolss_notify2_msg(SPOOLSS_NOTIFY_MSG *msg)
{
        struct notify_queue *pnqueue, *tmp_ptr;

        /*
         * Ensure we only have one job total_bytes and job total_pages for
         * each job. There is no point in sending multiple messages that match
         * as they will just cause flickering updates in the client.
         */

        if ((num_messages < 100) && (msg->type == JOB_NOTIFY_TYPE) 
                && (msg->field == JOB_NOTIFY_TOTAL_BYTES 
                    || msg->field == JOB_NOTIFY_TOTAL_PAGES )) 
        {

                for (tmp_ptr = notify_queue_head; tmp_ptr; tmp_ptr = tmp_ptr->next) 
                {
                        if (tmp_ptr->msg->type == msg->type &&
                                        tmp_ptr->msg->field == msg->field &&
                                        tmp_ptr->msg->id == msg->id &&
                                        tmp_ptr->msg->flags == msg->flags &&
                                        strequal(tmp_ptr->msg->printer, msg->printer)) {

                                DEBUG(5,("send_spoolss_notify2_msg: replacing message 0x%02x/0x%02x for "
                                         "printer %s in notify_queue\n", msg->type, msg->field, msg->printer));

                                tmp_ptr->msg = msg;
                                return;
                        }
                }
        }

        /* Store the message on the pending queue. */

        pnqueue = TALLOC_P(send_ctx, struct notify_queue);
        if (!pnqueue) {
                DEBUG(0,("send_spoolss_notify2_msg: Out of memory.\n"));
                return;
        }

        /* allocate a new msg structure and copy the fields */
        
        if ( !(pnqueue->msg = TALLOC_P(send_ctx, SPOOLSS_NOTIFY_MSG)) ) {
                DEBUG(0,("send_spoolss_notify2_msg: talloc() of size [%lu] failed!\n", 
                        (unsigned long)sizeof(SPOOLSS_NOTIFY_MSG)));
                return;
        }
        copy_notify2_msg(pnqueue->msg, msg);
        GetTimeOfDay(&pnqueue->tv);
        pnqueue->buf = NULL;
        pnqueue->buflen = 0;

        DEBUG(5, ("send_spoolss_notify2_msg: appending message 0x%02x/0x%02x for printer %s \
to notify_queue_head\n", msg->type, msg->field, msg->printer));

        /*
         * Note we add to the end of the list to ensure
         * the messages are sent in the order they were received. JRA.
         */

        DLIST_ADD_END(notify_queue_head, pnqueue, struct notify_queue *);
        num_messages++;

        if ((notify_event == NULL) && (smbd_event_context() != NULL)) {
                /* Add an event for 1 second's time to send this queue. */
                notify_event = event_add_timed(smbd_event_context(), NULL,
                                        timeval_current_ofs(1,0),
                                        print_notify_event_send_messages, NULL);
        }

}

static void send_notify_field_values(const char *sharename, uint32 type,
                                     uint32 field, uint32 id, uint32 value1, 
                                     uint32 value2, uint32 flags)
{
        struct spoolss_notify_msg *msg;

        if (lp_disable_spoolss())
                return;

        if (!create_send_ctx())
                return;

        msg = TALLOC_P(send_ctx, struct spoolss_notify_msg);
        if (!msg)
                return;

        ZERO_STRUCTP(msg);

        fstrcpy(msg->printer, sharename);
        msg->type = type;
        msg->field = field;
        msg->id = id;
        msg->notify.value[0] = value1;
        msg->notify.value[1] = value2;
        msg->flags = flags;

        send_spoolss_notify2_msg(msg);
}

static void send_notify_field_buffer(const char *sharename, uint32 type,
                                     uint32 field, uint32 id, uint32 len,
                                     const char *buffer)
{
        struct spoolss_notify_msg *msg;

        if (lp_disable_spoolss())
                return;

        if (!create_send_ctx())
                return;

        msg = TALLOC_P(send_ctx, struct spoolss_notify_msg);
        if (!msg)
                return;

        ZERO_STRUCTP(msg);

        fstrcpy(msg->printer, sharename);
        msg->type = type;
        msg->field = field;
        msg->id = id;
        msg->len = len;
        msg->notify.data = CONST_DISCARD(char *,buffer);

        send_spoolss_notify2_msg(msg);
}

/* Send a message that the printer status has changed */

void notify_printer_status_byname(const char *sharename, uint32 status)
{
        /* Printer status stored in value1 */

        int snum = print_queue_snum(sharename);

        send_notify_field_values(sharename, PRINTER_NOTIFY_TYPE, 
                                 PRINTER_NOTIFY_STATUS, snum,
                                 status, 0, 0);
}

void notify_printer_status(int snum, uint32 status)
{
        const char *sharename = SERVICE(snum); 

        if (sharename)
                notify_printer_status_byname(sharename, status);
}

void notify_job_status_byname(const char *sharename, uint32 jobid, uint32 status,
                              uint32 flags)
{
        /* Job id stored in id field, status in value1 */

        send_notify_field_values(sharename, JOB_NOTIFY_TYPE,
                                 JOB_NOTIFY_STATUS, jobid,
                                 status, 0, flags);
}

void notify_job_status(const char *sharename, uint32 jobid, uint32 status)
{
        notify_job_status_byname(sharename, jobid, status, 0);
}

void notify_job_total_bytes(const char *sharename, uint32 jobid,
                            uint32 size)
{
        /* Job id stored in id field, status in value1 */

        send_notify_field_values(sharename, JOB_NOTIFY_TYPE,
                                 JOB_NOTIFY_TOTAL_BYTES, jobid,
                                 size, 0, 0);
}

void notify_job_total_pages(const char *sharename, uint32 jobid,
                            uint32 pages)
{
        /* Job id stored in id field, status in value1 */

        send_notify_field_values(sharename, JOB_NOTIFY_TYPE,
                                 JOB_NOTIFY_TOTAL_PAGES, jobid,
                                 pages, 0, 0);
}

void notify_job_username(const char *sharename, uint32 jobid, char *name)
{
        send_notify_field_buffer(
                sharename, JOB_NOTIFY_TYPE, JOB_NOTIFY_USER_NAME,
                jobid, strlen(name) + 1, name);
}

void notify_job_name(const char *sharename, uint32 jobid, char *name)
{
        send_notify_field_buffer(
                sharename, JOB_NOTIFY_TYPE, JOB_NOTIFY_DOCUMENT,
                jobid, strlen(name) + 1, name);
}

void notify_job_submitted(const char *sharename, uint32 jobid,
                          time_t submitted)
{
        send_notify_field_buffer(
                sharename, JOB_NOTIFY_TYPE, JOB_NOTIFY_SUBMITTED,
                jobid, sizeof(submitted), (char *)&submitted);
}

void notify_printer_driver(int snum, char *driver_name)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_DRIVER_NAME,
                snum, strlen(driver_name) + 1, driver_name);
}

void notify_printer_comment(int snum, char *comment)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_COMMENT,
                snum, strlen(comment) + 1, comment);
}

void notify_printer_sharename(int snum, char *share_name)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_SHARE_NAME,
                snum, strlen(share_name) + 1, share_name);
}

void notify_printer_printername(int snum, char *printername)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_PRINTER_NAME,
                snum, strlen(printername) + 1, printername);
}

void notify_printer_port(int snum, char *port_name)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_PORT_NAME,
                snum, strlen(port_name) + 1, port_name);
}

void notify_printer_location(int snum, char *location)
{
        const char *sharename = SERVICE(snum);

        send_notify_field_buffer(
                sharename, PRINTER_NOTIFY_TYPE, PRINTER_NOTIFY_LOCATION,
                snum, strlen(location) + 1, location);
}

void notify_printer_byname( const char *printername, uint32 change, const char *value )
{
        int snum = print_queue_snum(printername);
        int type = PRINTER_NOTIFY_TYPE;
        
        if ( snum == -1 )
                return;
                
        send_notify_field_buffer( printername, type, change, snum, strlen(value)+1, value );
} 


/****************************************************************************
 Return a malloced list of pid_t's that are interested in getting update
 messages on this print queue. Used in printing/notify to send the messages.
****************************************************************************/

bool print_notify_pid_list(const char *printername, TALLOC_CTX *mem_ctx, size_t *p_num_pids, pid_t **pp_pid_list)
{
        struct tdb_print_db *pdb = NULL;
        TDB_CONTEXT *tdb = NULL;
        TDB_DATA data;
        bool ret = True;
        size_t i, num_pids, offset;
        pid_t *pid_list;

        *p_num_pids = 0;
        *pp_pid_list = NULL;

        pdb = get_print_db_byname(printername);
        if (!pdb)
                return False;
        tdb = pdb->tdb;

        if (tdb_read_lock_bystring_with_timeout(tdb, NOTIFY_PID_LIST_KEY, 10) == -1) {
                DEBUG(0,("print_notify_pid_list: Failed to lock printer %s database\n",
                                        printername));
                if (pdb)
                        release_print_db(pdb);
                return False;
        }

        data = get_printer_notify_pid_list( tdb, printername, True );

        if (!data.dptr) {
                ret = True;
                goto done;
        }

        num_pids = data.dsize / 8;

        if (num_pids) {
                if ((pid_list = TALLOC_ARRAY(mem_ctx, pid_t, num_pids)) == NULL) {
                        ret = False;
                        goto done;
                }
        } else {
                pid_list = NULL;
        }

        for( i = 0, offset = 0; i < num_pids; offset += 8, i++)
                pid_list[i] = (pid_t)IVAL(data.dptr, offset);

        *pp_pid_list = pid_list;
        *p_num_pids = num_pids;

        ret = True;

  done:

        tdb_read_unlock_bystring(tdb, NOTIFY_PID_LIST_KEY);
        if (pdb)
                release_print_db(pdb);
        SAFE_FREE(data.dptr);
        return ret;
}