From 67a06755f37fae5446940e2d78fe67de948a36c3 Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Thu, 12 Jul 2018 19:52:44 +0200 Subject: erl_interface: Make ei_connect_init more thread safe by not using unsafe ei_gethostbyname. --- lib/erl_interface/src/connect/ei_connect.c | 33 +++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) (limited to 'lib/erl_interface/src') diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c index be228ab853..4cfd68d954 100644 --- a/lib/erl_interface/src/connect/ei_connect.c +++ b/lib/erl_interface/src/connect/ei_connect.c @@ -138,6 +138,11 @@ static int recv_name(int fd, unsigned *version, unsigned *flags, ErlConnect *namebuf, unsigned ms); +static struct hostent* +dyn_gethostbyname_r(const char *name, struct hostent *hostp, char **buffer_p, + int buflen, int *h_errnop); + + /*************************************************************************** * @@ -480,10 +485,14 @@ int ei_connect_xinit(ei_cnode* ec, const char *thishostname, int ei_connect_init(ei_cnode* ec, const char* this_node_name, const char *cookie, short creation) { - struct hostent *hp; char thishostname[EI_MAXHOSTNAMELEN+1]; char thisnodename[MAXNODELEN+1]; char thisalivename[EI_MAXALIVELEN+1]; + struct hostent host, *hp; + char buffer[1024]; + char *buf = buffer; + int ei_h_errno; + int res; #ifdef __WIN32__ if (!initWinSock()) { @@ -517,10 +526,13 @@ int ei_connect_init(ei_cnode* ec, const char* this_node_name, strcpy(thisalivename, this_node_name); } - if ((hp = ei_gethostbyname(thishostname)) == 0) { + hp = dyn_gethostbyname_r(thishostname,&host,&buf,sizeof(buffer),&ei_h_errno); + if (hp == NULL) { /* Looking up IP given hostname fails. We must be on a standalone host so let's use loopback for communication instead. */ - if ((hp = ei_gethostbyname("localhost")) == 0) { + hp = dyn_gethostbyname_r("localhost", &host, &buf, sizeof(buffer), + &ei_h_errno); + if (hp == NULL) { #ifdef __WIN32__ char reason[1024]; @@ -549,8 +561,11 @@ int ei_connect_init(ei_cnode* ec, const char* this_node_name, sprintf(thisnodename, "%s@%s", this_node_name, hp->h_name); } } - return ei_connect_xinit(ec, thishostname, thisalivename, thisnodename, - (struct in_addr *)*hp->h_addr_list, cookie, creation); + res = ei_connect_xinit(ec, thishostname, thisalivename, thisnodename, + (struct in_addr *)*hp->h_addr_list, cookie, creation); + if (buf != buffer) + free(buf); + return res; } @@ -595,6 +610,13 @@ struct hostent *dyn_gethostbyname_r(const char *name, int buflen, int *h_errnop) { +#ifdef __WIN32__ + /* + * Apparently ei_gethostbyname_r not implemented for Windows (?) + * Fall back on ei_gethostbyname like before. + */ + return ei_gethostbyname(name); +#else char* buf = *buffer_p; struct hostent *hp; @@ -629,6 +651,7 @@ struct hostent *dyn_gethostbyname_r(const char *name, } } return hp; +#endif } /* -- cgit v1.2.3