source3/lib/util_tsock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Utilities around tsocket
   4    Copyright (C) Volker Lendecke 2009
   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 "includes.h"
  21 #include "../lib/tsocket/tsocket.h"
  22 #include "../lib/util/tevent_unix.h"
  23
  24 struct tstream_read_packet_state {
  25         struct tevent_context *ev;
  26         struct tstream_context *stream;
  27         ssize_t (*more)(uint8_t *buf, size_t buflen, void *private_data);
  28         void *private_data;
  29         uint8_t *buf;
  30         struct iovec iov;
  31 };
  32
  33 static void tstream_read_packet_done(struct tevent_req *subreq);
  34
  35 struct tevent_req *tstream_read_packet_send(TALLOC_CTX *mem_ctx,
  36                                             struct tevent_context *ev,
  37                                             struct tstream_context *stream,
  38                                             size_t initial,
  39                                             ssize_t (*more)(uint8_t *buf,
  40                                                             size_t buflen,
  41                                                             void *private_data),
  42                                             void *private_data)
  43 {
  44         struct tevent_req *req, *subreq;
  45         struct tstream_read_packet_state *state;
  46
  47         req = tevent_req_create(mem_ctx, &state,
  48                                 struct tstream_read_packet_state);
  49         if (req == NULL) {
  50                 return NULL;
  51         }
  52         state->buf = talloc_array(state, uint8_t, initial);
  53         if (tevent_req_nomem(state->buf, req)) {
  54                 return tevent_req_post(req, ev);
  55         }
  56         state->iov.iov_base = (void *)state->buf;
  57         state->iov.iov_len = initial;
  58
  59         state->ev = ev;
  60         state->stream = stream;
  61         state->more = more;
  62         state->private_data = private_data;
  63
  64         subreq = tstream_readv_send(state, ev, stream, &state->iov, 1);
  65         if (tevent_req_nomem(subreq, req)) {
  66                 return tevent_req_post(req, ev);
  67         }
  68         tevent_req_set_callback(subreq, tstream_read_packet_done, req);
  69
  70         return req;
  71 }
  72
  73 static void tstream_read_packet_done(struct tevent_req *subreq)
  74 {
  75         struct tevent_req *req = tevent_req_callback_data(
  76                 subreq, struct tevent_req);
  77         struct tstream_read_packet_state *state = tevent_req_data(
  78                 req, struct tstream_read_packet_state);
  79         int ret, err;
  80         size_t total;
  81         ssize_t more;
  82         uint8_t *tmp;
  83
  84         ret = tstream_readv_recv(subreq, &err);
  85         TALLOC_FREE(subreq);
  86         if (ret == 0) {
  87                 err = EPIPE;
  88         }
  89         if (ret <= 0) {
  90                 tevent_req_error(req, err);
  91                 return;
  92         }
  93
  94         if (state->more == NULL) {
  95                 /* Nobody to ask, this is a async read_data */
  96                 tevent_req_done(req);
  97                 return;
  98         }
  99         total = talloc_array_length(state->buf);
 100
 101         more = state->more(state->buf, total, state->private_data);
 102         if (more == -1) {
 103                 /* We got an invalid packet, tell the caller */
 104                 tevent_req_error(req, EIO);
 105                 return;
 106         }
 107         if (more == 0) {
 108                 /* We're done, full packet received */
 109                 tevent_req_done(req);
 110                 return;
 111         }
 112
 113         if (total + more < total) {
 114                 tevent_req_error(req, EMSGSIZE);
 115                 return;
 116         }
 117
 118         tmp = talloc_realloc(state, state->buf, uint8_t, total+more);
 119         if (tevent_req_nomem(tmp, req)) {
 120                 return;
 121         }
 122         state->buf = tmp;
 123
 124         state->iov.iov_base = (void *)(state->buf + total);
 125         state->iov.iov_len = more;
 126
 127         subreq = tstream_readv_send(state, state->ev, state->stream,
 128                                     &state->iov, 1);
 129         if (tevent_req_nomem(subreq, req)) {
 130                 return;
 131         }
 132         tevent_req_set_callback(subreq, tstream_read_packet_done, req);
 133 }
 134
 135 ssize_t tstream_read_packet_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 136                                  uint8_t **pbuf, int *perrno)
 137 {
 138         struct tstream_read_packet_state *state =
 139                 tevent_req_data(req, struct tstream_read_packet_state);
 140
 141         if (tevent_req_is_unix_error(req, perrno)) {
 142                 return -1;
 143         }
 144         *pbuf = talloc_move(mem_ctx, &state->buf);
 145         return talloc_array_length(*pbuf);
 146 }