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/* Copyright 2020-2021 IGEL Co., Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dlm-protocol.h"
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
bool receive_dlm_client_request(int socket, struct dlm_client_request *request)
{
ssize_t len;
struct iovec iov = {
.iov_base = request,
.iov_len = sizeof(*request),
};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
};
while ((len = recvmsg(socket, &msg, 0)) < 0) {
if (errno != EINTR)
return false;
}
if (len != sizeof(*request)) {
errno = EPROTO;
return false;
}
return true;
}
bool send_dlm_client_request(int socket, struct dlm_client_request *request)
{
struct iovec iov = {
.iov_base = request,
.iov_len = sizeof(*request),
};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
};
while (sendmsg(socket, &msg, 0) < 1) {
if (errno != EINTR)
return false;
}
return true;
}
int receive_lease_fd(int socket)
{
int lease_fd = -1;
char ctrl_buf[CMSG_SPACE(sizeof(lease_fd))];
char data;
struct iovec iov = {.iov_base = &data, .iov_len = sizeof(data)};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = ctrl_buf,
.msg_controllen = sizeof(ctrl_buf),
};
ssize_t len;
while ((len = recvmsg(socket, &msg, 0)) <= 0) {
if (len == 0) {
errno = EACCES;
goto err;
}
if (errno != EINTR)
goto err;
}
struct cmsghdr *cmsg;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int nfds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
int *fds = (int *)CMSG_DATA(cmsg);
if (nfds == 1) {
lease_fd = fds[0];
break;
}
/* Close any unexpected fds so we don't leak them. */
for (int i = 0; i < nfds; i++)
close(fds[i]);
break;
}
}
if (lease_fd < 0) {
errno = EPROTO;
goto err;
}
err:
return lease_fd;
}
bool send_lease_fd(int socket, int lease)
{
char data;
struct iovec iov = {
.iov_base = &data,
.iov_len = sizeof(data),
};
char ctrl_buf[CMSG_SPACE(sizeof(lease))] = {0};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_controllen = sizeof(ctrl_buf),
.msg_control = ctrl_buf,
};
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(lease));
*((int *)CMSG_DATA(cmsg)) = lease;
if (sendmsg(socket, &msg, 0) < 0)
return false;
return true;
}
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