mirror of
https://github.com/checkpoint-restore/criu
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54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#ifndef __COMMON_SCM_H__
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#define __COMMON_SCM_H__
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#include <stdint.h>
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#include <stdbool.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <sys/uio.h>
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/*
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* Because of kernel doing kmalloc for user data passed
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* in SCM messages, and there is kernel's SCM_MAX_FD as a limit
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* for descriptors passed at once we're trying to reduce
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* the pressure on kernel memory manager and use predefined
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* known to work well size of the message buffer.
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*/
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#define CR_SCM_MSG_SIZE (1024)
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#define CR_SCM_MAX_FD (252)
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struct scm_fdset {
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struct msghdr hdr;
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struct iovec iov;
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char msg_buf[CR_SCM_MSG_SIZE];
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};
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#ifndef F_GETOWNER_UIDS
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#define F_GETOWNER_UIDS 17
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#endif
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extern int send_fds(int sock, struct sockaddr_un *saddr, int len, int *fds, int nr_fds, void *data, unsigned ch_size);
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extern int __recv_fds(int sock, int *fds, int nr_fds, void *data, unsigned ch_size, int flags);
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static inline int recv_fds(int sock, int *fds, int nr_fds, void *data, unsigned ch_size)
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{
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return __recv_fds(sock, fds, nr_fds, data, ch_size, 0);
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}
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static inline int send_fd(int sock, struct sockaddr_un *saddr, int saddr_len, int fd)
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{
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return send_fds(sock, saddr, saddr_len, &fd, 1, NULL, 0);
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}
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static inline int recv_fd(int sock)
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{
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int fd, ret;
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ret = recv_fds(sock, &fd, 1, NULL, 0);
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if (ret)
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return -1;
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return fd;
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}
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#endif
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