libdaemon/client/daemon-client.c

   1 /*
   2  * Copyright (C) 2011-2012 Red Hat, Inc.
   3  *
   4  * This file is part of LVM2.
   5  *
   6  * This copyrighted material is made available to anyone wishing to use,
   7  * modify, copy, or redistribute it subject to the terms and conditions
   8  * of the GNU Lesser General Public License v.2.1.
   9  *
  10  * You should have received a copy of the GNU Lesser General Public License
  11  * along with this program; if not, write to the Free Software Foundation,
  12  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  13  */
  14
  15 #include "daemon-shared.h"
  16 #include "daemon-client.h"
  17
  18 #include <sys/un.h>
  19 #include <sys/socket.h>
  20 #include <string.h>
  21 #include <stdio.h>
  22 #include <unistd.h>
  23 #include <assert.h>
  24 #include <errno.h> // ENOMEM
  25
  26 daemon_handle daemon_open(daemon_info i) {
  27         daemon_handle h = { .protocol_version = 0, .error = 0 };
  28         daemon_reply r = { .cft = NULL };
  29         struct sockaddr_un sockaddr;
  30
  31         if ((h.socket_fd = socket(PF_UNIX, SOCK_STREAM /* | SOCK_NONBLOCK */, 0)) < 0)
  32                 goto error;
  33
  34         memset(&sockaddr, 0, sizeof(sockaddr));
  35         strcpy(sockaddr.sun_path, i.socket);
  36         sockaddr.sun_family = AF_UNIX;
  37         if (connect(h.socket_fd,(struct sockaddr *) &sockaddr, sizeof(sockaddr)))
  38                 goto error;
  39
  40         r = daemon_send_simple(h, "hello", NULL);
  41         if (r.error || strcmp(daemon_reply_str(r, "response", "unknown"), "OK"))
  42                 goto error;
  43
  44         h.protocol = daemon_reply_str(r, "protocol", NULL);
  45         if (h.protocol)
  46                 h.protocol = dm_strdup(h.protocol); /* keep around */
  47         h.protocol_version = daemon_reply_int(r, "version", 0);
  48
  49         if (i.protocol && (!h.protocol || strcmp(h.protocol, i.protocol)))
  50                 goto error;
  51         if (i.protocol_version && h.protocol_version != i.protocol_version)
  52                 goto error;
  53
  54         daemon_reply_destroy(r);
  55         return h;
  56
  57 error:
  58         h.error = errno;
  59         if (h.socket_fd >= 0)
  60                 close(h.socket_fd);
  61         if (r.cft)
  62                 daemon_reply_destroy(r);
  63         h.socket_fd = -1;
  64         return h;
  65 }
  66
  67 daemon_reply daemon_send(daemon_handle h, daemon_request rq)
  68 {
  69         daemon_reply reply = { .cft = NULL, .error = 0 };
  70         assert(h.socket_fd >= 0);
  71
  72         if (!rq.buffer) {
  73                 /* TODO: build the buffer from rq.cft */
  74         }
  75
  76         assert(rq.buffer);
  77         if (!write_buffer(h.socket_fd, rq.buffer, strlen(rq.buffer)))
  78                 reply.error = errno;
  79
  80         if (read_buffer(h.socket_fd, &reply.buffer)) {
  81                 reply.cft = dm_config_from_string(reply.buffer);
  82         } else
  83                 reply.error = errno;
  84
  85         return reply;
  86 }
  87
  88 void daemon_reply_destroy(daemon_reply r) {
  89         if (r.cft)
  90                 dm_config_destroy(r.cft);
  91         dm_free(r.buffer);
  92 }
  93
  94 daemon_reply daemon_send_simple(daemon_handle h, const char *id, ...)
  95 {
  96         static const daemon_reply err = { .error = ENOMEM, .buffer = NULL, .cft = NULL };
  97         daemon_request rq = { .cft = NULL };
  98         daemon_reply repl;
  99         va_list ap;
 100
 101         va_start(ap, id);
 102         rq.buffer = format_buffer("request", id, ap);
 103         va_end(ap);
 104
 105         if (!rq.buffer)
 106                 return err;
 107
 108         repl = daemon_send(h, rq);
 109         dm_free(rq.buffer);
 110
 111         return repl;
 112 }
 113
 114 void daemon_close(daemon_handle h)
 115 {
 116         dm_free((char *)h.protocol);
 117 }