libdlmclient/dlmclient.c

   1 /* Copyright 2020-2021 IGEL Co., Ltd.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include "dlmclient.h"
  17
  18 #include "dlm-protocol.h"
  19 #include "log.h"
  20 #include "socket-path.h"
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <stdarg.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <unistd.h>
  31
  32 void dlm_enable_debug_log(bool enable)
  33 {
  34         dlm_log_enable_debug(enable);
  35 }
  36
  37 struct dlm_lease {
  38         int dlm_server_sock;
  39         int lease_fd;
  40 };
  41
  42 static bool lease_connect(struct dlm_lease *lease, const char *name)
  43 {
  44         struct sockaddr_un sa = {
  45             .sun_family = AF_UNIX,
  46         };
  47
  48         if (!sockaddr_set_lease_server_path(&sa, name))
  49                 return false;
  50
  51         int dlm_server_sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
  52         if (dlm_server_sock < 0) {
  53                 DEBUG_LOG("Socket creation failed: %s\n", strerror(errno));
  54                 return false;
  55         }
  56
  57         while (connect(dlm_server_sock, (struct sockaddr *)&sa,
  58                        sizeof(struct sockaddr_un)) == -1) {
  59                 if (errno == EINTR)
  60                         continue;
  61                 DEBUG_LOG("Cannot connect to %s: %s\n", sa.sun_path,
  62                           strerror(errno));
  63                 close(dlm_server_sock);
  64                 return false;
  65         }
  66         lease->dlm_server_sock = dlm_server_sock;
  67         return true;
  68 }
  69
  70 static bool lease_send_request(struct dlm_lease *lease, enum dlm_opcode opcode)
  71 {
  72         struct dlm_client_request request = {
  73             .opcode = opcode,
  74         };
  75
  76         if (!send_dlm_client_request(lease->dlm_server_sock, &request)) {
  77                 DEBUG_LOG("Socket data send error: %s\n", strerror(errno));
  78                 return false;
  79         }
  80         return true;
  81 }
  82
  83 static bool lease_recv_fd(struct dlm_lease *lease)
  84 {
  85         lease->lease_fd = receive_lease_fd(lease->dlm_server_sock);
  86
  87         if (lease->lease_fd < 0)
  88                 goto err;
  89
  90         return true;
  91
  92 err:
  93         switch (errno) {
  94         case EACCES:
  95                 DEBUG_LOG("Lease request rejected by DRM lease manager\n");
  96                 break;
  97         case EPROTO:
  98                 DEBUG_LOG("Unexpected data received from lease manager\n");
  99                 break;
 100         default:
 101                 DEBUG_LOG("Lease manager receive data error: %s\n",
 102                           strerror(errno));
 103                 break;
 104         }
 105         return false;
 106 }
 107
 108 struct dlm_lease *dlm_get_lease(const char *name)
 109 {
 110         int saved_errno;
 111         struct dlm_lease *lease = calloc(1, sizeof(struct dlm_lease));
 112         if (!lease) {
 113                 DEBUG_LOG("can't allocate memory : %s\n", strerror(errno));
 114                 return NULL;
 115         }
 116
 117         if (!lease_connect(lease, name)) {
 118                 free(lease);
 119                 return NULL;
 120         }
 121
 122         if (!lease_send_request(lease, DLM_GET_LEASE))
 123                 goto err;
 124
 125         if (!lease_recv_fd(lease))
 126                 goto err;
 127
 128         return lease;
 129
 130 err:
 131         saved_errno = errno;
 132         dlm_release_lease(lease);
 133         errno = saved_errno;
 134         return NULL;
 135 }
 136
 137 void dlm_release_lease(struct dlm_lease *lease)
 138 {
 139         if (!lease)
 140                 return;
 141
 142         lease_send_request(lease, DLM_RELEASE_LEASE);
 143         close(lease->lease_fd);
 144         close(lease->dlm_server_sock);
 145         free(lease);
 146 }
 147
 148 int dlm_lease_fd(struct dlm_lease *lease)
 149 {
 150         if (!lease)
 151                 return -1;
 152
 153         return lease->lease_fd;
 154 }