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authorSverker Eriksson <[email protected]>2018-04-18 11:31:53 +0200
committerSverker Eriksson <[email protected]>2018-04-18 11:31:53 +0200
commit3c8c8158de1b0f1880d588c1169be6a2f727c379 (patch)
treed6cc92e9e62760032ae595dbfa8d41b1bf0fbc1c /lib/erl_interface/src/connect/ei_connect.c
parent44b09e036b31b29dddc3b178e8f6b9fc96a9a874 (diff)
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erl_interface: Fix ei_connect
when ei_gethostbyname_r returns ERANGE.
Diffstat (limited to 'lib/erl_interface/src/connect/ei_connect.c')
-rw-r--r--lib/erl_interface/src/connect/ei_connect.c63
1 files changed, 60 insertions, 3 deletions
diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c
index ea9ecb31d5..5c01223e3d 100644
--- a/lib/erl_interface/src/connect/ei_connect.c
+++ b/lib/erl_interface/src/connect/ei_connect.c
@@ -583,6 +583,54 @@ static int cnct(uint16 port, struct in_addr *ip_addr, int addr_len, unsigned ms)
return s;
} /* cnct */
+
+/*
+ * Same as ei_gethostbyname_r, but also handles ERANGE error
+ * and may allocate larger buffer with malloc.
+ */
+static
+struct hostent *dyn_gethostbyname_r(const char *name,
+ struct hostent *hostp,
+ char **buffer_p,
+ int buflen,
+ int *h_errnop)
+{
+ char* buf = *buffer_p;
+ struct hostent *hp;
+
+ while (1) {
+ hp = ei_gethostbyname_r(name, hostp, buf, buflen, h_errnop);
+ if (hp) {
+ *buffer_p = buf;
+ break;
+ }
+
+ if (*h_errnop != ERANGE) {
+ if (buf != *buffer_p)
+ free(buf);
+ break;
+ }
+
+ buflen *= 2;
+ if (buf == *buffer_p)
+ buf = malloc(buflen);
+ else {
+ char* buf2 = realloc(buf, buflen);
+ if (buf2)
+ buf = buf2;
+ else {
+ free(buf);
+ buf = NULL;
+ }
+ }
+ if (!buf) {
+ *h_errnop = ENOMEM;
+ break;
+ }
+ }
+ return hp;
+}
+
/*
* Set up a connection to a given Node, and
* interchange hand shake messages with it.
@@ -597,8 +645,10 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
/* these are needed for the call to gethostbyname_r */
struct hostent host;
char buffer[1024];
+ char *buf = buffer;
int ei_h_errno;
#endif /* !win32 */
+ int res;
/* extract the host and alive parts from nodename */
if (!(hostname = strchr(nodename,'@'))) {
@@ -611,7 +661,7 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
}
#ifndef __WIN32__
- hp = ei_gethostbyname_r(hostname,&host,buffer,1024,&ei_h_errno);
+ hp = dyn_gethostbyname_r(hostname,&host,&buf,sizeof(buffer),&ei_h_errno);
if (hp == NULL) {
char thishostname[EI_MAXHOSTNAMELEN+1];
/* gethostname requies len to be max(hostname) + 1*/
@@ -627,7 +677,7 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
}
if (strcmp(hostname,thishostname) == 0)
/* Both nodes on same standalone host, use loopback */
- hp = ei_gethostbyname_r("localhost",&host,buffer,1024,&ei_h_errno);
+ hp = dyn_gethostbyname_r("localhost",&host,&buf,sizeof(buffer),&ei_h_errno);
if (hp == NULL) {
EI_TRACE_ERR2("ei_connect",
"Can't find host for %s: %d\n",nodename,ei_h_errno);
@@ -663,7 +713,14 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
}
}
#endif /* win32 */
- return ei_xconnect_tmo(ec, (Erl_IpAddr) *hp->h_addr_list, alivename, ms);
+
+ res = ei_xconnect_tmo(ec, (Erl_IpAddr) *hp->h_addr_list, alivename, ms);
+
+#ifndef __WIN32__
+ if (buf != buffer)
+ free(buf);
+#endif
+ return res;
} /* ei_connect */
int ei_connect(ei_cnode* ec, char *nodename)