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/* Code based on Stevens' UNIX Network Programming, and simplified. */
/* Florian Weimer <fw@deneb.enyo.de>, April 2008 */
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include "pass_fd.h"
int
s_pipe(int fd[2])
{
return socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
}
int
send_fd(int clifd, int fd)
{
union {
struct cmsghdr cm;
char control[CMSG_SPACE(sizeof(int))];
} control_aligned;
struct msghdr msg = {0};
msg.msg_control = control_aligned.control;
msg.msg_controllen = sizeof(control_aligned.control);
struct cmsghdr *cmptr = CMSG_FIRSTHDR(&msg);
cmptr->cmsg_len = CMSG_LEN(sizeof(int));
cmptr->cmsg_level = SOL_SOCKET;
cmptr->cmsg_type = SCM_RIGHTS;
*((int *) CMSG_DATA(cmptr)) = fd;
char buf[1] = {0};
struct iovec iov = {.iov_base = buf, .iov_len = sizeof(buf)};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
if (sendmsg(clifd, &msg, 0) != 1)
return -1;
return 0;
}
int
recv_fd(int servfd)
{
union {
struct cmsghdr cm;
char control[CMSG_SPACE(sizeof(int))];
} control_aligned;
struct msghdr msg = {0};
msg.msg_control = control_aligned.control;
msg.msg_controllen = sizeof(control_aligned.control);
char buf[1] = {0};
struct iovec iov = {.iov_base = buf, .iov_len = sizeof(buf)};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
ssize_t result = recvmsg(servfd, &msg, 0);
if (result < 0)
return -1;
if (result != 1) {
errno = EINVAL;
return -1;
}
struct cmsghdr *cmptr = CMSG_FIRSTHDR(&msg);
if (cmptr && cmptr->cmsg_len == CMSG_LEN(sizeof(int))
&& cmptr->cmsg_level == SOL_SOCKET && cmptr->cmsg_type == SCM_RIGHTS)
return *((int *) CMSG_DATA(cmptr));
errno = ENXIO;
return -1;
}
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