libc/private/resolv_static.h

#ifndef _RESOLV_STATIC_H
#define _RESOLV_STATIC_H

#include <netdb.h>

/* this structure contains all the variables that were declared
 * 'static' in the original NetBSD resolver code.
 *
 * this caused vast amounts of crashes and memory corruptions
 * when the resolver was being used by multiple threads.
 *
 * (note: the OpenBSD/FreeBSD resolver has similar 'issues')
 */

#define	MAXALIASES	35
#define	MAXADDRS	35

typedef struct res_static {
    char*           h_addr_ptrs[MAXADDRS + 1];
    char*           host_aliases[MAXALIASES];
    char            hostbuf[8*1024];
    u_int32_t       host_addr[16 / sizeof(u_int32_t)];  /* IPv4 or IPv6 */
    FILE*           hostf;
    int             stayopen;
    const char*     servent_ptr;
    struct servent  servent;
    struct hostent  host;
} *res_static;

extern res_static __res_get_static(void);

#endif /* _RESOLV_STATIC_H */