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
gethostbyname2_r(const char * name,int af,struct hostent * h,char * buf,size_t buflen,struct hostent ** res,int * err)11 int 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 }
83