Line data    Source code

       1             : /*
       2             :  * Unix SMB/CIFS implementation.
       3             :  *
       4             :  * Copyright (C) Volker Lendecke 2019
       5             :  *
       6             :  * This program is free software; you can redistribute it and/or modify
       7             :  * it under the terms of the GNU General Public License as published by
       8             :  * the Free Software Foundation; either version 3 of the License, or
       9             :  * (at your option) any later version.
      10             :  *
      11             :  * This program is distributed in the hope that it will be useful,
      12             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :  * GNU General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU General Public License
      17             :  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
      18             :  */
      19             : 
      20             : #include "replace.h"
      21             : #include "system/filesys.h"
      22             : #include "tstream_u32_read.h"
      23             : #include "lib/util/byteorder.h"
      24             : #include "lib/util/tevent_unix.h"
      25             : 
      26             : struct tstream_u32_read_state {
      27             :         size_t max_msglen;
      28             :         size_t buflen;
      29             :         uint8_t *buf;
      30             : };
      31             : 
      32             : static int tstream_u32_read_next_vector(struct tstream_context *stream,
      33             :                                         void *private_data,
      34             :                                         TALLOC_CTX *mem_ctx,
      35             :                                         struct iovec **_vector,
      36             :                                         size_t *_count);
      37             : static void tstream_u32_read_done(struct tevent_req *subreq);
      38             : 
      39       98737 : struct tevent_req *tstream_u32_read_send(
      40             :         TALLOC_CTX *mem_ctx,
      41             :         struct tevent_context *ev,
      42             :         uint32_t max_msglen,
      43             :         struct tstream_context *stream)
      44             : {
      45       98737 :         struct tevent_req *req = NULL, *subreq = NULL;
      46       98737 :         struct tstream_u32_read_state *state = NULL;
      47             : 
      48       98737 :         req = tevent_req_create(
      49             :                 mem_ctx, &state, struct tstream_u32_read_state);
      50       98737 :         if (req == NULL) {
      51           0 :                 return NULL;
      52             :         }
      53       98737 :         state->max_msglen = max_msglen;
      54             : 
      55       98737 :         subreq = tstream_readv_pdu_send(
      56             :                 state,
      57             :                 ev,
      58             :                 stream,
      59             :                 tstream_u32_read_next_vector,
      60             :                 state);
      61       98737 :         if (tevent_req_nomem(subreq, req)) {
      62           0 :                 return tevent_req_post(req, ev);
      63             :         }
      64       98737 :         tevent_req_set_callback(subreq, tstream_u32_read_done, req);
      65       98737 :         return req;
      66             : }
      67             : 
      68      296211 : static int tstream_u32_read_next_vector(struct tstream_context *stream,
      69             :                                         void *private_data,
      70             :                                         TALLOC_CTX *mem_ctx,
      71             :                                         struct iovec **_vector,
      72             :                                         size_t *_count)
      73             : {
      74      296211 :         struct tstream_u32_read_state *state = talloc_get_type_abort(
      75             :                 private_data, struct tstream_u32_read_state);
      76      296211 :         size_t buflen = talloc_get_size(state->buf);
      77        3744 :         struct iovec *vector;
      78        3744 :         uint32_t msg_len;
      79      296211 :         size_t ofs = 0;
      80        3744 :         size_t count;
      81             : 
      82      296211 :         if (buflen == 0) {
      83       98737 :                 msg_len = 4;
      84       98737 :                 state->buf = talloc_array(state, uint8_t, msg_len);
      85       98737 :                 if (state->buf == NULL) {
      86           0 :                         return -1;
      87             :                 }
      88      197474 :         } else if (buflen == 4) {
      89             : 
      90       98737 :                 ofs = 4;
      91             : 
      92       98737 :                 msg_len = RIVAL(state->buf, 0);
      93       98737 :                 if ((msg_len == 0) || (msg_len > state->max_msglen)) {
      94           0 :                         errno = EMSGSIZE;
      95           0 :                         return -1;
      96             :                 }
      97       98737 :                 msg_len += ofs;
      98       98737 :                 if (msg_len < ofs) {
      99           0 :                         errno = EMSGSIZE;
     100           0 :                         return -1;
     101             :                 }
     102             : 
     103       98737 :                 state->buf = talloc_realloc(
     104             :                         state, state->buf, uint8_t, msg_len);
     105       98737 :                 if (state->buf == NULL) {
     106           0 :                         return -1;
     107             :                 }
     108             :         } else {
     109       98737 :                 *_vector = NULL;
     110       98737 :                 *_count = 0;
     111       98737 :                 return 0;
     112             :         }
     113             : 
     114      197474 :         vector = talloc(mem_ctx, struct iovec);
     115      197474 :         if (vector == NULL) {
     116           0 :                 return -1;
     117             :         }
     118      197474 :         *vector = (struct iovec) {
     119      197474 :                 .iov_base = state->buf + ofs, .iov_len = msg_len - ofs,
     120             :         };
     121      197474 :         count = 1;
     122             : 
     123      197474 :         *_vector = vector;
     124      197474 :         *_count = count;
     125      197474 :         return 0;
     126             : }
     127             : 
     128       98737 : static void tstream_u32_read_done(struct tevent_req *subreq)
     129             : {
     130       98737 :         struct tevent_req *req = tevent_req_callback_data(
     131             :                 subreq, struct tevent_req);
     132        1248 :         int ret, err;
     133             : 
     134       98737 :         ret = tstream_readv_pdu_recv(subreq, &err);
     135       98737 :         TALLOC_FREE(subreq);
     136       98737 :         if (ret == -1) {
     137           0 :                 tevent_req_error(req, err);
     138           0 :                 return;
     139             :         }
     140       98737 :         tevent_req_done(req);
     141             : }
     142             : 
     143       98737 : int tstream_u32_read_recv(
     144             :         struct tevent_req *req,
     145             :         TALLOC_CTX *mem_ctx,
     146             :         uint8_t **buf,
     147             :         size_t *buflen)
     148             : {
     149       98737 :         struct tstream_u32_read_state *state = tevent_req_data(
     150             :                 req, struct tstream_u32_read_state);
     151        1248 :         int err;
     152             : 
     153       98737 :         if (tevent_req_is_unix_error(req, &err)) {
     154           0 :                 return err;
     155             :         }
     156       98737 :         *buflen = talloc_get_size(state->buf);
     157       98737 :         *buf = talloc_move(mem_ctx, &state->buf);
     158       98737 :         return 0;
     159             : }