source: branches/samba-3.2.x/source/lib/packet.c@ 201

/* 
   Unix SMB/CIFS implementation.
   Packet handling
   Copyright (C) Volker Lendecke 2007
   
   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"

struct packet_context {
        int fd;
        struct data_blob in, out;
};

/*
 * Close the underlying fd
 */
static int packet_context_destructor(struct packet_context *ctx)
{
        return close(ctx->fd);
}

/*
 * Initialize a packet context. The fd is given to the packet context, meaning
 * that it is automatically closed when the packet context is freed.
 */
struct packet_context *packet_init(TALLOC_CTX *mem_ctx, int fd)
{
        struct packet_context *result;

        if (!(result = TALLOC_ZERO_P(mem_ctx, struct packet_context))) {
                return NULL;
        }

        result->fd = fd;
        talloc_set_destructor(result, packet_context_destructor);
        return result;
}

/*
 * Pull data from the fd
 */
NTSTATUS packet_fd_read(struct packet_context *ctx)
{
        int res, available;
        size_t new_size;
        uint8 *in;

        res = ioctl(ctx->fd, FIONREAD, &available);

        if (res == -1) {
                DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", strerror(errno)));
                return map_nt_error_from_unix(errno);
        }

        SMB_ASSERT(available >= 0);

        if (available == 0) {
                return NT_STATUS_END_OF_FILE;
        }

        new_size = ctx->in.length + available;

        if (new_size < ctx->in.length) {
                DEBUG(0, ("integer wrap\n"));
                return NT_STATUS_NO_MEMORY;
        }