minix3/lib/libc/gen/sethostname.c

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2020-02-21 00:59:27 +05:30
/* gethostname(2) system call emulation */
#include <sys/cdefs.h>
#include "namespace.h"
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <minix/paths.h>
#ifdef __weak_alias
__weak_alias(sethostname, _sethostname)
#endif
int sethostname(const char *buf, size_t len)
{
int fd;
int r;
int tmperr;
char name[20];
strlcpy(name, "/tmp/hostname.XXXXX",sizeof(name));
fd = mkstemp(name);
if (fd == -1)
return -1;
r = fchmod(fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (r == -1) {
tmperr = errno;
close(fd);
unlink(name);
errno = tmperr;
return -1;
}
r = write(fd, buf, len);
tmperr = errno;
close(fd);
if (r == -1) {
unlink(name);
errno = tmperr;
return -1;
}
if (r < len) {
unlink(name);
errno = ENOSPC;
return -1;
}
r = rename(name, _PATH_HOSTNAME_FILE);
if (r == -1) {
tmperr = errno;
unlink(name);
errno = tmperr;
}
return 0;
}