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authorSverker Eriksson <[email protected]>2018-07-12 19:52:44 +0200
committerSverker Eriksson <[email protected]>2018-07-12 19:52:44 +0200
commit67a06755f37fae5446940e2d78fe67de948a36c3 (patch)
tree5ec5c07be5b081a2dd36c7d2cdbbaf200c1a6dba
parent857156bcadae45fe112911bd7ca735ac6f3ca9d2 (diff)
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erl_interface: Make ei_connect_init more thread safe
by not using unsafe ei_gethostbyname.
-rw-r--r--lib/erl_interface/src/connect/ei_connect.c33
1 files changed, 28 insertions, 5 deletions
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
}
/*