Commit 2b872562 authored by Manikantan Subramanian's avatar Manikantan Subramanian Committed by Richard Levitte
Browse files

Use gethostbyname_r if available 



Fixes #7228

The function BIO_get_host_ip uses gethostbyname, which is not thread safe
and hence we grab a lock. In multi-threaded applications, this lock sometimes
causes performance bottlenecks.
This patch uses the function gethostbyname_r (thread safe version), when
available.

Reviewed-by: default avatarPaul Dale <paul.dale@oracle.com>
Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7250)
parent 7a6d121e

crypto/bio/b_sock.c

+22 −1
Original line number Diff line number Diff line
@@ -56,6 +56,9 @@ 
 * [including the GNU Public Licence.]

 */



#define _DEFAULT_SOURCE

#define _BSD_SOURCE



#include <stdio.h>

#include <stdlib.h>

#include <errno.h>
@@ -83,6 +86,11 @@ NETDB_DEFINE_CONTEXT 
static int wsa_init_done = 0;

# endif



# if defined(__GLIBC__)

#  define HAVE_GETHOSTBYNAME_R

#  define GETHOSTNAME_R_BUF     (2 * 1024)

# endif



/*

 * WSAAPI specifier is required to make indirect calls to run-time

 * linked WinSock 2 functions used in this module, to be specific
@@ -116,7 +124,12 @@ int BIO_get_host_ip(const char *str, unsigned char *ip) 
    int i;

    int err = 1;

    int locked = 0;

    struct hostent *he;

    struct hostent *he = NULL;

# ifdef HAVE_GETHOSTBYNAME_R

    char buf[GETHOSTNAME_R_BUF];

    struct hostent hostent;

    int h_errnop;

# endif



    i = get_ip(str, ip);

    if (i < 0) {
@@ -138,10 +151,18 @@ int BIO_get_host_ip(const char *str, unsigned char *ip) 
    if (i > 0)

        return (1);



    /* if gethostbyname_r is supported, use it. */

# ifdef HAVE_GETHOSTBYNAME_R

    memset(&hostent, 0x00, sizeof(hostent));

    /* gethostbyname_r() sets |he| to NULL on error, we check it further down */

    gethostbyname_r(str, &hostent, buf, sizeof(buf), &he, &h_errnop);

# else

    /* do a gethostbyname */

    CRYPTO_w_lock(CRYPTO_LOCK_GETHOSTBYNAME);

    locked = 1;

    he = BIO_gethostbyname(str);

# endif



    if (he == NULL) {

        BIOerr(BIO_F_BIO_GET_HOST_IP, BIO_R_BAD_HOSTNAME_LOOKUP);

        goto err;