ray/src/plasma/fling.h
2016-10-25 14:27:45 -07:00

35 lines
1.4 KiB
C

/* FLING: Exchanging file descriptors over sockets
*
* This is a little library for sending file descriptors over a socket
* between processes. The reason for doing that (as opposed to using
* filenames to share the files) is so (a) no files remain in the
* filesystem after all the processes terminate, (b) to make sure that
* there are no name collisions and (c) to be able to control who has
* access to the data.
*
* Most of the code is from https://github.com/sharvil/flingfd */
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
/* This is neccessary for Mac OS X, see http://www.apuebook.com/faqs2e.html
* (10). */
#if !defined(CMSG_SPACE) && !defined(CMSG_LEN)
#define CMSG_SPACE(len) \
(__DARWIN_ALIGN32(sizeof(struct cmsghdr)) + __DARWIN_ALIGN32(len))
#define CMSG_LEN(len) (__DARWIN_ALIGN32(sizeof(struct cmsghdr)) + (len))
#endif
void init_msg(struct msghdr *msg, struct iovec *iov, char *buf, size_t buf_len);
/* Send a file descriptor "fd" and a payload "payload" of size "size"
* over the socket "conn". Return 0 on success. */
int send_fd(int conn, int fd, const char *payload, int size);
/* Receive a file descriptor and a payload of size up to "size" from a
* socket "conn". The payload will be written to "payload" and the file
* descriptor will be returned. Returns -1 on failure. */
int recv_fd(int conn, char *payload, int size);