path: root/daemon/smbval/rfcnb-io.inc.c

/* mod_ntlm file: $Id: rfcnb-io.inc.c,v 1.2 2003/02/21 01:55:14 casz Exp $ */


/* UNIX RFCNB (RFC1001/RFC1002) NEtBIOS implementation
 *
 * Version 1.0 RFCNB IO Routines ...
 *
 * Copyright (C) Richard Sharpe 1996
 *
 */

/*
 * 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 "std-includes.h"
#include "rfcnb-priv.h"
#include "rfcnb-util.h"
#include "rfcnb-io.h"
#include <sys/uio.h>
#include <sys/signal.h>
#include <string.h>

static int RFCNB_Timeout = 0;   /* Timeout in seconds ... */

/* Discard the rest of an incoming packet as we do not have space for
 * it in the buffer we allocated or were passed ... */
static int
RFCNB_Discard_Rest(struct RFCNB_Con *con, int len)
{
    char temp[100];             /* Read into here */
    int rest, this_read, bytes_read;

    /* len is the amount we should read */
#ifdef RFCNB_DEBUG
    fprintf(stderr, "Discard_Rest called to discard: %i\n", len);
#endif

    rest = len;
    while (rest > 0) {
        this_read = (rest > sizeof(temp) ? sizeof(temp) : rest);
        bytes_read = read(con->fd, temp, this_read);
        if (bytes_read <= 0) {  /* Error so return */
            if (bytes_read < 0)
                RFCNB_errno = RFCNBE_BadRead;
            else
                RFCNB_errno = RFCNBE_ConGone;

            RFCNB_saved_errno = errno;
            return (RFCNBE_Bad);
        }
        rest = rest - bytes_read;
    }
    return 0;
}

/* Send an RFCNB packet to the connection.  We just send each of the
 * blocks linked together ...  If we can, try to send it as one iovec
 * ...  */
static int
RFCNB_Put_Pkt(struct RFCNB_Con *con, struct RFCNB_Pkt *pkt, int len)
{
    int len_sent, tot_sent, this_len;
    struct RFCNB_Pkt *pkt_ptr;
    char *this_data;
    int i;
    struct iovec io_list[10];   /* We should never have more */
    /* If we do, this will blow up ... */

    /* Try to send the data ... We only send as many bytes as len
     * claims */
    /* We should try to stuff it into an IOVEC and send as one write */

    pkt_ptr = pkt;
    len_sent = tot_sent = 0;    /* Nothing sent so far */
    i = 0;

    while ((pkt_ptr != NULL) & (i < 10)) { /* Watch that magic number! */
        this_len = pkt_ptr->len;
        this_data = pkt_ptr->data;
        if ((tot_sent + this_len) > len)
            this_len = len - tot_sent;  /* Adjust so we don't send too
                                         * much */

        /* Now plug into the iovec ... */
        io_list[i].iov_len = this_len;
        io_list[i].iov_base = this_data;
        i++;

        tot_sent += this_len;

        if (tot_sent == len)
            break;              /* Let's not send too much */

        pkt_ptr = pkt_ptr->next;
    }

#ifdef RFCNB_DEBUG
    fprintf(stderr, "Frags = %i, tot_sent = %i\n", i, tot_sent);
#endif

    /* Set up an alarm if timeouts are set ... */

    if (RFCNB_Timeout > 0)
        alarm(RFCNB_Timeout);

    if ((len_sent = writev(con->fd, io_list, i)) < 0) { /* An error */
        con->rfc_errno = errno;
        if (errno == EINTR)     /* We were interrupted ... */
            RFCNB_errno = RFCNBE_Timeout;
        else
            RFCNB_errno = RFCNBE_BadWrite;
        RFCNB_saved_errno = errno;
        return (RFCNBE_Bad);
    }
    if (len_sent < tot_sent) {  /* Less than we wanted */
        if (errno == EINTR)     /* We were interrupted */
            RFCNB_errno = RFCNBE_Timeout;
        else
            RFCNB_errno = RFCNBE_BadWrite;
        RFCNB_saved_errno = errno;
        return (RFCNBE_Bad);
    }
    if (RFCNB_Timeout > 0)
        alarm(0);               /* Reset that sucker */

#ifdef RFCNB_DEBUG
    fprintf(stderr, "Len sent = %i ...\n", len_sent);
    RFCNB_Print_Pkt(stderr, "sent", pkt, len_sent); /* Print what send... */
#endif
    return len_sent;
}

/* Read an RFCNB packet off the connection.  We read the first 4
 * bytes, that tells us the length, then read the rest. We should
 * implement a timeout, but we don't just yet */
static int
RFCNB_Get_Pkt(struct RFCNB_Con *con, struct RFCNB_Pkt *pkt, int len)
{
    int read_len, pkt_len;
    char hdr[RFCNB_Pkt_Hdr_Len];        /* Local space for the header */
    struct RFCNB_Pkt *pkt_frag;
    int more, this_time, offset, frag_len, this_len;
    BOOL seen_keep_alive = TRUE;

    /* Read that header straight into the buffer */
    if (len < RFCNB_Pkt_Hdr_Len) {      /* What a bozo */
#ifdef RFCNB_DEBUG
        fprintf(stderr, "Trying to read less than a packet:");
        perror("");
#endif
        RFCNB_errno = RFCNBE_BadParam;
        return (RFCNBE_Bad);
    }
    /* We discard keep alives here ... */
    if (RFCNB_Timeout > 0)
        alarm(RFCNB_Timeout);

    while (seen_keep_alive) {
        if ((read_len = read(con->fd, hdr, sizeof(hdr))) < 0) { /* Problems */
#ifdef RFCNB_DEBUG
            fprintf(stderr, "Reading the packet, we got:");
            perror("");
#endif
            if (errno == EINTR)
                RFCNB_errno = RFCNBE_Timeout;
            else
                RFCNB_errno = RFCNBE_BadRead;
            RFCNB_saved_errno = errno;
            return (RFCNBE_Bad);
        }
        /* Now we check out what we got */
        if (read_len == 0) {    /* Connection closed, send back eof?  */
#ifdef RFCNB_DEBUG
            fprintf(stderr, "Connection closed reading\n");
#endif
            if (errno == EINTR)
                RFCNB_errno = RFCNBE_Timeout;
            else
                RFCNB_errno = RFCNBE_ConGone;
            RFCNB_saved_errno = errno;
            return (RFCNBE_Bad);
        }
        if (RFCNB_Pkt_Type(hdr) == RFCNB_SESSION_KEEP_ALIVE) {
#ifdef RFCNB_DEBUG
            fprintf(stderr, "RFCNB KEEP ALIVE received\n");
#endif
        } else {
            seen_keep_alive = FALSE;
        }
    }

    /* What if we got less than or equal to a hdr size in bytes? */
    if (read_len < sizeof(hdr)) {       /* We got a small packet */
        /* Now we need to copy the hdr portion we got into the
         * supplied packet */
        memcpy(pkt->data, hdr, read_len);       /* Copy data */
#ifdef RFCNB_DEBUG
        RFCNB_Print_Pkt(stderr, "rcvd", pkt, read_len);
#endif
        return read_len;
    }
    /* Now, if we got at least a hdr size, alloc space for rest, if we
     * need it */
    pkt_len = RFCNB_Pkt_Len(hdr);

#ifdef RFCNB_DEBUG
    fprintf(stderr, "Reading Pkt: Length = %i\n", pkt_len);
#endif

    /* Now copy in the hdr */
    memcpy(pkt->data, hdr, sizeof(hdr));

    /* Get the rest of the packet ... first figure out how big our buf
     * is? And make sure that we handle the fragments properly
     * ... Sure should use an iovec ... */
    if (len < pkt_len)          /* Only get as much as we have space for */
        more = len - RFCNB_Pkt_Hdr_Len;
    else
        more = pkt_len;

    this_time = 0;

    /* We read for each fragment ... */
    if (pkt->len == read_len) { /* If this frag was exact size */
        pkt_frag = pkt->next;   /* Stick next lot in next frag */
        offset = 0;             /* then we start at 0 in next  */
    } else {
        pkt_frag = pkt;         /* Otherwise use rest of this frag */
        offset = RFCNB_Pkt_Hdr_Len;     /* Otherwise skip the header */
    }

    frag_len = pkt_frag->len;
    if (more <= frag_len)       /* If len left to get less than frag space */
        this_len = more;        /* Get the rest ... */
    else
        this_len = frag_len - offset;

    while (more > 0) {
        if ((this_time = read(con->fd, (pkt_frag->data) + offset,
                              this_len)) <= 0) { /* Problems */
            if (errno == EINTR) {
                RFCNB_errno = RFCNB_Timeout;
            } else {
                if (this_time < 0)
                    RFCNB_errno = RFCNBE_BadRead;
                else
                    RFCNB_errno = RFCNBE_ConGone;
            }
            RFCNB_saved_errno = errno;
            return (RFCNBE_Bad);

        }
#ifdef RFCNB_DEBUG
        fprintf(stderr, "Frag_Len = %i, this_time = %i, this_len = %i, more = %i\n", frag_len,
                this_time, this_len, more);
#endif

        read_len = read_len + this_time; /* How much have we read... */
        /* Now set up the next part */
        if (pkt_frag->next == NULL)
            break;              /* That's it here */

        pkt_frag = pkt_frag->next;
        this_len = pkt_frag->len;
        offset = 0;

        more = more - this_time;
    }

#ifdef RFCNB_DEBUG
    fprintf(stderr, "Pkt Len = %i, read_len = %i\n", pkt_len, read_len);
    RFCNB_Print_Pkt(stderr, "rcvd", pkt, read_len + sizeof(hdr));
#endif

    if (read_len < (pkt_len + sizeof(hdr))) {   /* Discard the rest */
        return (RFCNB_Discard_Rest(con, (pkt_len + sizeof(hdr)) - read_len));
    }
    if (RFCNB_Timeout > 0)
        alarm(0);               /* Reset that sucker */

    return (read_len + sizeof(RFCNB_Hdr));
}