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 ENOENT;
26	case EAI_AGAIN:
27		*err = TRY_AGAIN;
28		return EAGAIN;
29	default:
30	case EAI_FAIL:
31		*err = NO_RECOVERY;
32		return EBADMSG;
33	case EAI_MEMORY:
34	case EAI_SYSTEM:
35		*err = NO_RECOVERY;
36		return errno;
37	}
38
39	h->h_addrtype = af;
40	h->h_length = af==AF_INET6 ? 16 : 4;
41
42	/* Align buffer */
43	align = -(uintptr_t)buf & sizeof(char *)-1;
44
45	need = 4*sizeof(char *);
46	need += (cnt + 1) * (sizeof(char *) + h->h_length);
47	need += strlen(name)+1;
48	need += strlen(canon)+1;
49	need += align;
50
51	if (need > buflen) return ERANGE;
52
53	buf += align;
54	h->h_aliases = (void *)buf;
55	buf += 3*sizeof(char *);
56	h->h_addr_list = (void *)buf;
57	buf += (cnt+1)*sizeof(char *);
58
59	for (i=0; i<cnt; i++) {
60		h->h_addr_list[i] = (void *)buf;
61		buf += h->h_length;
62		memcpy(h->h_addr_list[i], addrs[i].addr, h->h_length);
63	}
64	h->h_addr_list[i] = 0;
65
66	h->h_name = h->h_aliases[0] = buf;
67	strcpy(h->h_name, canon);
68	buf += strlen(h->h_name)+1;
69
70	if (strcmp(h->h_name, name)) {
71		h->h_aliases[1] = buf;
72		strcpy(h->h_aliases[1], name);
73		buf += strlen(h->h_aliases[1])+1;
74	} else h->h_aliases[1] = 0;
75
76	h->h_aliases[2] = 0;
77
78	*res = h;
79	return 0;
80}
81