1#include <sys/mman.h>
2#include <errno.h>
3#include <fcntl.h>
4#include <unistd.h>
5#include <string.h>
6#include <limits.h>
7#include <pthread.h>
8
9char *__shm_mapname(const char *name, char *buf)
10{
11 char *p;
12 while (*name == '/') name++;
13 if (*(p = __strchrnul(name, '/')) || p==name ||
14 (p-name <= 2 && name[0]=='.' && p[-1]=='.')) {
15 errno = EINVAL;
16 return 0;
17 }
18 if (p-name > NAME_MAX) {
19 errno = ENAMETOOLONG;
20 return 0;
21 }
22 memcpy(buf, "/dev/shm/", 9);
23 memcpy(buf+9, name, p-name+1);
24 return buf;
25}
26
27int shm_open(const char *name, int flag, mode_t mode)
28{
29 int cs;
30 char buf[NAME_MAX+10];
31 if (!(name = __shm_mapname(name, buf))) return -1;
32 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
33 int fd = open(name, flag|O_NOFOLLOW|O_CLOEXEC|O_NONBLOCK, mode);
34 pthread_setcancelstate(cs, 0);
35 return fd;
36}
37
38int shm_unlink(const char *name)
39{
40 char buf[NAME_MAX+10];
41 if (!(name = __shm_mapname(name, buf))) return -1;
42 return unlink(name);
43}