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/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <nft.h>
#include "nftutils.h"
#include <netdb.h>
/* Buffer size used for getprotobynumber_r() and similar. The manual comments
* that a buffer of 1024 should be sufficient "for most applications"(??), so
* let's double it. It still fits reasonably on the stack, so no need to
* choose a smaller one. */
#define NETDB_BUFSIZE 2048
bool nft_getprotobynumber(int proto, char *out_name, size_t name_len)
{
const struct protoent *result;
#if HAVE_DECL_GETPROTOBYNUMBER_R
struct protoent result_buf;
char buf[NETDB_BUFSIZE];
int r;
r = getprotobynumber_r(proto,
&result_buf,
buf,
sizeof(buf),
(struct protoent **) &result);
if (r != 0 || result != &result_buf)
result = NULL;
#else
result = getprotobynumber(proto);
#endif
if (!result)
return false;
if (strlen(result->p_name) >= name_len)
return false;
strcpy(out_name, result->p_name);
return true;
}
int nft_getprotobyname(const char *name)
{
const struct protoent *result;
#if HAVE_DECL_GETPROTOBYNAME_R
struct protoent result_buf;
char buf[NETDB_BUFSIZE];
int r;
r = getprotobyname_r(name,
&result_buf,
buf,
sizeof(buf),
(struct protoent **) &result);
if (r != 0 || result != &result_buf)
result = NULL;
#else
result = getprotobyname(name);
#endif
if (!result)
return -1;
if (result->p_proto < 0 || result->p_proto > UINT8_MAX)
return -1;
return (uint8_t) result->p_proto;
}
bool nft_getservbyport(int port, const char *proto, char *out_name, size_t name_len)
{
const struct servent *result;
#if HAVE_DECL_GETSERVBYPORT_R
struct servent result_buf;
char buf[NETDB_BUFSIZE];
int r;
r = getservbyport_r(port,
proto,
&result_buf,
buf,
sizeof(buf),
(struct servent**) &result);
if (r != 0 || result != &result_buf)
result = NULL;
#else
result = getservbyport(port, proto);
#endif
if (!result)
return false;
if (strlen(result->s_name) >= name_len)
return false;
strcpy(out_name, result->s_name);
return true;
}
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