1#define _GNU_SOURCE
 2
 3#include <sys/socket.h>
 4#include <netdb.h>
 5#include <string.h>
 6#include <netinet/in.h>
 7#include <errno.h>
 8#include <stdint.h>
 9#include "lookup.h"
10
11int gethostbyname2_r(const char *name, int af,
12	struct hostent *h, char *buf, size_t buflen,
13	struct hostent **res, int *err)
14{
15	struct address addrs[MAXADDRS];
16	char canon[256];
17	int i, cnt;
18	size_t align, need;
19
20	*res = 0;
21	cnt = __lookup_name(addrs, canon, name, af, AI_CANONNAME);
22	if (cnt<0) switch (cnt) {
23	case EAI_NONAME:
24		*err = HOST_NOT_FOUND;
25		return 0;
26	case EAI_NODATA:
27		*err = NO_DATA;
28		return 0;
29	case EAI_AGAIN:
30		*err = TRY_AGAIN;
31		return EAGAIN;
32	default:
33	case EAI_FAIL:
34		*err = NO_RECOVERY;
35		return EBADMSG;
36	case EAI_SYSTEM:
37		*err = NO_RECOVERY;
38		return errno;
39	}
40
41	h->h_addrtype = af;
42	h->h_length = af==AF_INET6 ? 16 : 4;
43
44	/* Align buffer */
45	align = -(uintptr_t)buf & sizeof(char *)-1;
46
47	need = 4*sizeof(char *);
48	need += (cnt + 1) * (sizeof(char *) + h->h_length);
49	need += strlen(name)+1;
50	need += strlen(canon)+1;
51	need += align;
52
53	if (need > buflen) return ERANGE;
54
55	buf += align;
56	h->h_aliases = (void *)buf;
57	buf += 3*sizeof(char *);
58	h->h_addr_list = (void *)buf;
59	buf += (cnt+1)*sizeof(char *);
60
61	for (i=0; i<cnt; i++) {
62		h->h_addr_list[i] = (void *)buf;
63		buf += h->h_length;
64		memcpy(h->h_addr_list[i], addrs[i].addr, h->h_length);
65	}
66	h->h_addr_list[i] = 0;
67
68	h->h_name = h->h_aliases[0] = buf;
69	strcpy(h->h_name, canon);
70	buf += strlen(h->h_name)+1;
71
72	if (strcmp(h->h_name, name)) {
73		h->h_aliases[1] = buf;
74		strcpy(h->h_aliases[1], name);
75		buf += strlen(h->h_aliases[1])+1;
76	} else h->h_aliases[1] = 0;
77
78	h->h_aliases[2] = 0;
79
80	*res = h;
81	return 0;
82}