source: branches/samba-3.5.x/source4/libcli/raw/raweas.c

/* 
   Unix SMB/CIFS implementation.
   parsing of EA (extended attribute) lists
   Copyright (C) Andrew Tridgell 2003
   
   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 "libcli/raw/libcliraw.h"
#include "libcli/raw/raw_proto.h"

/*
  work out how many bytes on the wire a ea list will consume. 
  This assumes the names are strict ascii, which should be a
  reasonable assumption
*/
size_t ea_list_size(uint_t num_eas, struct ea_struct *eas)
{
        uint_t total = 4;
        int i;
        for (i=0;i<num_eas;i++) {
                total += 4 + strlen(eas[i].name.s)+1 + eas[i].value.length;
        }
        return total;
}

/*
  work out how many bytes on the wire a ea name list will consume. 
*/
static uint_t ea_name_list_size(uint_t num_names, struct ea_name *eas)
{
        uint_t total = 4;
        int i;
        for (i=0;i<num_names;i++) {
                total += 1 + strlen(eas[i].name.s) + 1;
        }
        return total;
}

/*
  work out how many bytes on the wire a chained ea list will consume.
  This assumes the names are strict ascii, which should be a
  reasonable assumption
*/
size_t ea_list_size_chained(uint_t num_eas, struct ea_struct *eas, unsigned alignment)
{
        uint_t total = 0;
        int i;
        for (i=0;i<num_eas;i++) {
                uint_t len = 8 + strlen(eas[i].name.s)+1 + eas[i].value.length;
                len = (len + (alignment-1)) & ~(alignment-1);
                total += len;
        }
        return total;
}

/*
  put a ea_list into a pre-allocated buffer - buffer must be at least
  of size ea_list_size()
*/
void ea_put_list(uint8_t *data, uint_t num_eas, struct ea_struct *eas)
{
        int i;
        uint32_t ea_size;

        ea_size = ea_list_size(num_eas, eas);

        SIVAL(data, 0, ea_size);
        data += 4;

        for (i=0;i<num_eas;i++) {
                uint_t nlen = strlen(eas[i].name.s);
                SCVAL(data, 0, eas[i].flags);
                SCVAL(data, 1, nlen);
                SSVAL(data, 2, eas[i].value.length);
                memcpy(data+4, eas[i].name.s, nlen+1);
                memcpy(data+4+nlen+1, eas[i].value.data, eas[i].value.length);
                data += 4+nlen+1+eas[i].value.length;
        }
}


/*
  put a chained ea_list into a pre-allocated buffer - buffer must be
  at least of size ea_list_size()
*/
void ea_put_list_chained(uint8_t *data, uint_t num_eas, struct ea_struct *eas,
                         unsigned alignment)
{
        int i;

        for (i=0;i<num_eas;i++) {
                uint_t nlen = strlen(eas[i].name.s);
                uint32_t len = 8+nlen+1+eas[i].value.length;
                uint_t pad = ((len + (alignment-1)) & ~(alignment-1)) - len;
                if (i == num_eas-1) {
                        SIVAL(data, 0, 0);
                } else {
                        SIVAL(data, 0, len+pad);
                }
                SCVAL(data, 4, eas[i].flags);
                SCVAL(data, 5, nlen);
                SSVAL(data, 6, eas[i].value.length);
                memcpy(data+8, eas[i].name.s, nlen+1);
                memcpy(data+8+nlen+1, eas[i].value.data, eas[i].value.length);
                memset(data+len, 0, pad);
                data += len + pad;
        }
}


/*
  pull a ea_struct from a buffer. Return the number of bytes consumed
*/
uint_t ea_pull_struct(const DATA_BLOB *blob, 
                      TALLOC_CTX *mem_ctx,
                      struct ea_struct *ea)
{
        uint8_t nlen;
        uint16_t vlen;

        ZERO_STRUCTP(ea);

        if (blob->length < 6) {
                return 0;
        }

        ea->flags = CVAL(blob->data, 0);
        nlen = CVAL(blob->data, 1);
        vlen = SVAL(blob->data, 2);

        if (nlen+1+vlen > blob->length-4) {
                return 0;
        }

        ea->name.s = talloc_strndup(mem_ctx, (const char *)(blob->data+4), nlen);
        ea->name.private_length = nlen;
        ea->value = data_blob_talloc(mem_ctx, NULL, vlen+1);
        if (!ea->value.data) return 0;
        if (vlen) {
                memcpy(ea->value.data, blob->data+4+nlen+1, vlen);
        }
        ea->value.data[vlen] = 0;
        ea->value.length--;

        return 4 + nlen+1 + vlen;
}


/*
  pull a ea_list from a buffer
*/
NTSTATUS ea_pull_list(const DATA_BLOB *blob, 
                      TALLOC_CTX *mem_ctx,
                      uint_t *num_eas, struct ea_struct **eas)
{
        int n;
        uint32_t ea_size, ofs;

        if (blob->length < 4) {
                return NT_STATUS_INFO_LENGTH_MISMATCH;
        }

        ea_size = IVAL(blob->data, 0);
        if (ea_size > blob->length) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        ofs = 4;
        n = 0;
        *num_eas = 0;
        *eas = NULL;

        while (ofs < ea_size) {
                uint_t len;
                DATA_BLOB blob2;

                blob2.data = blob->data + ofs;
                blob2.length = ea_size - ofs;

                *eas = talloc_realloc(mem_ctx, *eas, struct ea_struct, n+1);
                if (! *eas) return NT_STATUS_NO_MEMORY;

                len = ea_pull_struct(&blob2, mem_ctx, &(*eas)[n]);
                if (len == 0) {
                        return NT_STATUS_INVALID_PARAMETER;
                }

                ofs += len;
                n++;
        }

        *num_eas = n;

        return NT_STATUS_OK;
}


/*
  pull a chained ea_list from a buffer
*/
NTSTATUS ea_pull_list_chained(const DATA_BLOB *blob, 
                              TALLOC_CTX *mem_ctx,
                              uint_t *num_eas, struct ea_struct **eas)
{
        int n;
        uint32_t ofs;

        if (blob->length < 4) {
                return NT_STATUS_INFO_LENGTH_MISMATCH;
        }

        ofs = 0;
        n = 0;
        *num_eas = 0;
        *eas = NULL;

        while (ofs < blob->length) {
                uint_t len;
                DATA_BLOB blob2;
                uint32_t next_ofs = IVAL(blob->data, ofs);

                blob2.data = blob->data + ofs + 4;
                blob2.length = blob->length - (ofs + 4);

                *eas = talloc_realloc(mem_ctx, *eas, struct ea_struct, n+1);
                if (! *eas) return NT_STATUS_NO_MEMORY;

                len = ea_pull_struct(&blob2, mem_ctx, &(*eas)[n]);
                if (len == 0) {
                        return NT_STATUS_INVALID_PARAMETER;
                }

                ofs += next_ofs;

                if (ofs+4 > blob->length) {
                        return NT_STATUS_INVALID_PARAMETER;
                }
                n++;
                if (next_ofs == 0) break;
        }

        *num_eas = n;

        return NT_STATUS_OK;
}


/*
  pull a ea_name from a buffer. Return the number of bytes consumed
*/
static uint_t ea_pull_name(const DATA_BLOB *blob, 
                           TALLOC_CTX *mem_ctx,
                           struct ea_name *ea)
{
        uint8_t nlen;

        if (blob->length < 2) {
                return 0;
        }

        nlen = CVAL(blob->data, 0);

        if (nlen+2 > blob->length) {
                return 0;
        }

        ea->name.s = talloc_strndup(mem_ctx, (const char *)(blob->data+1), nlen);
        ea->name.private_length = nlen;

        return nlen+2;
}


/*
  pull a ea_name list from a buffer
*/
NTSTATUS ea_pull_name_list(const DATA_BLOB *blob, 
                           TALLOC_CTX *mem_ctx,
                           uint_t *num_names, struct ea_name **ea_names)
{
        int n;
        uint32_t ea_size, ofs;

        if (blob->length < 4) {
                return NT_STATUS_INFO_LENGTH_MISMATCH;
        }

        ea_size = IVAL(blob->data, 0);
        if (ea_size > blob->length) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        ofs = 4;
        n = 0;
        *num_names = 0;
        *ea_names = NULL;

        while (ofs < ea_size) {
                uint_t len;
                DATA_BLOB blob2;

                blob2.data = blob->data + ofs;
                blob2.length = ea_size - ofs;

                *ea_names = talloc_realloc(mem_ctx, *ea_names, struct ea_name, n+1);
                if (! *ea_names) return NT_STATUS_NO_MEMORY;

                len = ea_pull_name(&blob2, mem_ctx, &(*ea_names)[n]);
                if (len == 0) {
                        return NT_STATUS_INVALID_PARAMETER;
                }

                ofs += len;
                n++;
        }

        *num_names = n;

        return NT_STATUS_OK;
}


/*
  put a ea_name list into a data blob
*/
bool ea_push_name_list(TALLOC_CTX *mem_ctx,
                       DATA_BLOB *data, uint_t num_names, struct ea_name *eas)
{
        int i;
        uint32_t ea_size;
        uint32_t off;

        ea_size = ea_name_list_size(num_names, eas);

        *data = data_blob_talloc(mem_ctx, NULL, ea_size);
        if (data->data == NULL) {
                return false;
        }

        SIVAL(data->data, 0, ea_size);
        off = 4;

        for (i=0;i<num_names;i++) {
                uint_t nlen = strlen(eas[i].name.s);
                SCVAL(data->data, off, nlen);
                memcpy(data->data+off+1, eas[i].name.s, nlen+1);
                off += 1+nlen+1;
        }

        return true;
}