1#define _GNU_SOURCE
 2#include <sys/socket.h>
 3#include <netinet/in.h>
 4#include <netdb.h>
 5#include <inttypes.h>
 6#include <errno.h>
 7#include <string.h>
 8#include <stdlib.h>
 9#include "lookup.h"
10
11#define ALIGN (sizeof(struct { char a; char *b; }) - sizeof(char *))
12
13int getservbyname_r(const char *name, const char *prots,
14	struct servent *se, char *buf, size_t buflen, struct servent **res)
15{
16	struct service servs[MAXSERVS];
17	int cnt, proto, align;
18
19	*res = 0;
20
21	/* Don't treat numeric port number strings as service records. */
22	char *end = "";
23	strtoul(name, &end, 10);
24	if (!*end) return ENOENT;
25
26	/* Align buffer */
27	align = -(uintptr_t)buf & ALIGN-1;
28	if (buflen < 2*sizeof(char *)+align)
29		return ERANGE;
30	buf += align;
31
32	if (!prots) proto = 0;
33	else if (!strcmp(prots, "tcp")) proto = IPPROTO_TCP;
34	else if (!strcmp(prots, "udp")) proto = IPPROTO_UDP;
35	else return EINVAL;
36
37	cnt = __lookup_serv(servs, name, proto, 0, 0);
38	if (cnt<0) switch (cnt) {
39	case EAI_MEMORY:
40	case EAI_SYSTEM:
41		return ENOMEM;
42	default:
43		return ENOENT;
44	}
45
46	se->s_name = (char *)name;
47	se->s_aliases = (void *)buf;
48	se->s_aliases[0] = se->s_name;
49	se->s_aliases[1] = 0;
50	se->s_port = htons(servs[0].port);
51	se->s_proto = servs[0].proto == IPPROTO_TCP ? "tcp" : "udp";
52
53	*res = se;
54	return 0;
55}