ctdb/common/pkt_write.c

   1 /*
   2    Write a packet
   3
   4    Copyright (C) Amitay Isaacs 2015
   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/network.h"
  22
  23 #include <talloc.h>
  24 #include <tevent.h>
  25
  26 #include "lib/util/tevent_unix.h"
  27
  28 #include "pkt_write.h"
  29
  30 /*
  31  * Write a packet
  32  */
  33
  34 struct pkt_write_state {
  35         int fd;
  36         uint8_t *buf;
  37         size_t buflen, offset;
  38 };
  39
  40 struct tevent_req *pkt_write_send(TALLOC_CTX *mem_ctx,
  41                                   struct tevent_context *ev,
  42                                   int fd, uint8_t *buf, size_t buflen)
  43 {
  44         struct tevent_req *req;
  45         struct pkt_write_state *state;
  46
  47         req = tevent_req_create(mem_ctx, &state, struct pkt_write_state);
  48         if (req == NULL) {
  49                 return NULL;
  50         }
  51
  52         state->fd = fd;
  53         state->buf = buf;
  54         state->buflen = buflen;
  55         state->offset = 0;
  56
  57         return req;
  58 }
  59
  60 void pkt_write_handler(struct tevent_context *ev, struct tevent_fd *fde,
  61                        uint16_t flags, struct tevent_req *req)
  62 {
  63         struct pkt_write_state *state = tevent_req_data(
  64                 req, struct pkt_write_state);
  65         ssize_t nwritten;
  66
  67         nwritten = write(state->fd, state->buf + state->offset,
  68                          state->buflen - state->offset);
  69         if ((nwritten == -1) && (errno == EINTR)) {
  70                 /* retry */
  71                 return;
  72         }
  73         if (nwritten == -1) {
  74                 tevent_req_error(req, errno);
  75                 return;
  76         }
  77         if (nwritten == 0) {
  78                 /* retry */
  79                 return;
  80         }
  81
  82         state->offset += nwritten;
  83         if (state->offset < state->buflen) {
  84                 /* come back later */
  85                 return;
  86         }
  87
  88         tevent_req_done(req);
  89 }
  90
  91 ssize_t pkt_write_recv(struct tevent_req *req, int *perrno)
  92 {
  93         struct pkt_write_state *state = tevent_req_data(
  94                 req, struct pkt_write_state);
  95
  96         if (tevent_req_is_unix_error(req, perrno)) {
  97                 return -1;
  98         }
  99
 100         return state->offset;
 101 }