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#define _GNU_SOURCE
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <inttypes.h>
#include <errno.h>
#include <string.h>
int getservbyname_r(const char *name, const char *prots,
struct servent *se, char *buf, size_t buflen, struct servent **res)
{
struct addrinfo *ai, hint = { .ai_family = AF_INET };
int i;
if (!prots) {
int r = getservbyname_r(name, "tcp", se, buf, buflen, res);
if (r) r = getservbyname_r(name, "udp", se, buf, buflen, res);
return r;
}
/* Align buffer */
i = (uintptr_t)buf & sizeof(char *)-1;
if (!i) i = sizeof(char *);
if (buflen < 3*sizeof(char *)-i)
return ERANGE;
buf += sizeof(char *)-i;
buflen -= sizeof(char *)-i;
if (!strcmp(prots, "tcp")) hint.ai_protocol = IPPROTO_TCP;
else if (!strcmp(prots, "udp")) hint.ai_protocol = IPPROTO_UDP;
else return EINVAL;
switch (getaddrinfo(0, name, &hint, &ai)) {
case EAI_MEMORY:
case EAI_SYSTEM:
return ENOMEM;
default:
return ENOENT;
case 0:
break;
}
se->s_name = (char *)name;
se->s_aliases = (void *)buf;
se->s_aliases[0] = se->s_name;
se->s_aliases[1] = 0;
se->s_port = ((struct sockaddr_in *)ai->ai_addr)->sin_port;
se->s_proto = (char *)prots;
freeaddrinfo(ai);
*res = se;
return 0;
}
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