ctl_socket_client.c

   1 /*****************************************************************************
   2   Copyright (c) 2006 EMC Corporation.
   3
   4   This program is free software; you can redistribute it and/or modify it
   5   under the terms of the GNU General Public License as published by the Free
   6   Software Foundation; either version 2 of the License, or (at your option)
   7   any later version.
   8
   9   This program is distributed in the hope that it will be useful, but WITHOUT
  10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12   more details.
  13
  14   You should have received a copy of the GNU General Public License along with
  15   this program; if not, write to the Free Software Foundation, Inc., 59
  16   Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17
  18   The full GNU General Public License is included in this distribution in the
  19   file called LICENSE.
  20
  21   Authors: Srinivas Aji <Aji_Srinivas@emc.com>
  22
  23 ******************************************************************************/
  24
  25 #include "ctl_socket.h"
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <unistd.h>
  31 #include <sys/poll.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34
  35 #include "log.h"
  36
  37 static int fd = -1;
  38
  39 int ctl_client_init(void)
  40 {
  41   struct sockaddr_un sa_svr;
  42   int s;
  43   TST (strlen(RSTP_SERVER_SOCK_NAME) < sizeof(sa_svr.sun_path), -1);
  44
  45   s = socket(PF_UNIX, SOCK_DGRAM, 0);
  46   if (s < 0) {
  47     ERROR("Couldn't open unix socket: %m");
  48     return -1;
  49   }
  50
  51   set_socket_address(&sa_svr, RSTP_SERVER_SOCK_NAME);
  52
  53   struct sockaddr_un sa;
  54   char tmpname[64];
  55   sprintf(tmpname, "RSTPCTL_%d", getpid());
  56   set_socket_address(&sa, tmpname);
  57   /* We need this bind. The autobind on connect isn't working properly.
  58      The server doesn't get a proper sockaddr in recvmsg if we don't do this.
  59   */
  60   if (bind(s, (struct sockaddr *)&sa, sizeof(sa)) != 0) {
  61     ERROR("Couldn't bind socket: %m");
  62     close(s);
  63     return -1;
  64   }
  65
  66   if (connect(s, (struct sockaddr *)&sa_svr, sizeof(sa_svr)) != 0) {
  67     ERROR("Couldn't connect to server");
  68     close(s);
  69     return -1;
  70   }
  71   fd = s;
  72
  73   return 0;
  74 }
  75
  76 void ctl_client_cleanup(void)
  77 {
  78   if (fd >= 0) {
  79     close(fd);
  80     fd = -1;
  81   }
  82 }
  83
  84 int send_ctl_message(int cmd, void *inbuf, int lin, void *outbuf, int *lout,
  85                      int *res)
  86 {
  87   struct ctl_msg_hdr mhdr;
  88   struct msghdr msg;
  89   struct iovec iov[2];
  90   int l;
  91
  92   msg.msg_name = NULL; msg.msg_namelen = 0;
  93   msg.msg_iov = iov; msg.msg_iovlen = 2;
  94   msg.msg_control = NULL; msg.msg_controllen = 0;
  95
  96   mhdr.cmd = cmd;
  97   mhdr.lin = lin;
  98   mhdr.lout = lout != NULL ? *lout : 0;
  99   iov[0].iov_base = &mhdr; iov[0].iov_len = sizeof(mhdr);
 100   iov[1].iov_base = (void *)inbuf; iov[1].iov_len = lin;
 101
 102   l = sendmsg(fd, &msg, 0);
 103   if (l < 0) {
 104     ERROR("Error sending message to server: %m");
 105     return -1;
 106   }
 107   if (l != sizeof(mhdr) + lin) {
 108     ERROR("Error sending message to server: Partial write");
 109     return -1;
 110   }
 111
 112   iov[1].iov_base = outbuf;
 113   iov[1].iov_len = lout != NULL ? *lout : 0;
 114
 115   {
 116     struct pollfd pfd;
 117     int timeout = 5000; /* 5 s */
 118     int r;
 119
 120     pfd.fd = fd;
 121     pfd.events = POLLIN;
 122     do {
 123       r = poll(&pfd, 1, timeout);
 124       if (r == 0) {
 125         ERROR("Error getting message from server: Timeout");
 126         return -1;
 127       }
 128       if (r < 0) {
 129         ERROR("Error getting message from server: poll error: %m");
 130         return -1;
 131       }
 132     } while ((pfd.revents & (POLLERR | POLLHUP | POLLNVAL | POLLIN)) == 0);
 133
 134     l = recvmsg(fd, &msg, 0);
 135     if (l < 0) {
 136       ERROR("Error getting message from server: %m");
 137       return -1;
 138     }
 139     if (l < sizeof(mhdr) || l != sizeof(mhdr) + mhdr.lout || mhdr.cmd != cmd) {
 140       ERROR("Error getting message from server: Bad format");
 141       return -1;
 142     }
 143   }
 144   if (lout)
 145     *lout = mhdr.lout;
 146   if (res)
 147     *res = mhdr.res;
 148
 149   return 0;
 150 }