49 lines
998 B
C
49 lines
998 B
C
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/* shm_open - open a shared memory file */
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/* Copyright 2002, Red Hat Inc. */
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#include <sys/types.h>
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#include <sys/mman.h>
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#include <unistd.h>
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#include <string.h>
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#include <fcntl.h>
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#include <limits.h>
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int
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shm_open (const char *name, int oflag, mode_t mode)
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{
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int fd;
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char shm_name[PATH_MAX+20] = "/dev/shm/";
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/* skip opening slash */
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if (*name == '/')
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++name;
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/* create special shared memory file name and leave enough space to
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cause a path/name error if name is too long */
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strlcpy (shm_name + 9, name, PATH_MAX + 10);
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fd = open (shm_name, oflag, mode);
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if (fd != -1)
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{
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/* once open we must add FD_CLOEXEC flag to file descriptor */
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int flags = fcntl (fd, F_GETFD, 0);
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if (flags >= 0)
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{
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flags |= FD_CLOEXEC;
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flags = fcntl (fd, F_SETFD, flags);
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}
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/* on failure, just close file and give up */
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if (flags == -1)
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{
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close (fd);
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fd = -1;
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}
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}
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return fd;
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}
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