Merge branch 'goeldeepak/erts/fix_inet_gethost_long/ERL-61/PR-1345/OTP-14310'

* goeldeepak/erts/fix_inet_gethost_long/ERL-61/PR-1345/OTP-14310:
  This patch fixes the issue in which erlang fails to start if the hostname is 64 characters on a linux system.

9 files changed, 29 insertions, 23 deletions

diff --git a/erts/emulator/beam/erl_mtrace.c b/erts/emulator/beam/erl_mtrace.c
index e275867928..bb6f8660f1 100644
--- a/erts/emulator/beam/erl_mtrace.c
+++ b/erts/emulator/beam/erl_mtrace.c
@@ -572,7 +572,7 @@ void erts_mtrace_pre_init(void)
 
 void erts_mtrace_init(char *receiver, char *nodename)
 {
-    char hostname[MAXHOSTNAMELEN];
+    char hostname[MAXHOSTNAMELEN + 1];
     char pid[21]; /* enough for a 64 bit number */
 
     socket_desc = ERTS_SOCK_INVALID_SOCKET;
@@ -613,9 +613,10 @@ void erts_mtrace_init(char *receiver, char *nodename)
 	}
 	tracep = trace_buffer;
 	endp = trace_buffer + TRACE_BUF_SZ;
-	if (erts_sock_gethostname(hostname, MAXHOSTNAMELEN) != 0)
+        /* gethostname requires that the len is max(hostname) + 1 */
+	if (erts_sock_gethostname(hostname, MAXHOSTNAMELEN + 1) != 0)
 	    hostname[0] = '\0';
-	hostname[MAXHOSTNAMELEN-1] = '\0';
+	hostname[MAXHOSTNAMELEN] = '\0';
 	sys_get_pid(pid, sizeof(pid));
 	write_trace_header(nodename ? nodename : "", pid, hostname);
 	erts_mtrace_update_heap_size();
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 278abe4e00..0fe5183b42 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -8345,10 +8345,10 @@ static ErlDrvData inet_start(ErlDrvPort port, int size, int protocol)
     return (ErlDrvData)desc;
 }
 
-
-#ifndef MAXHOSTNAMELEN
-#define MAXHOSTNAMELEN 256
-#endif
+/* MAXHOSTNAMELEN could be 64 or 255 depending
+on the platform. Instead, use INET_MAXHOSTNAMELEN
+which is always 255 across all platforms */
+#define INET_MAXHOSTNAMELEN 255
 
 /*
 ** common TCP/UDP/SCTP control command
@@ -8525,13 +8525,14 @@ static ErlDrvSSizeT inet_ctl(inet_descriptor* desc, int cmd, char* buf,
     }
 	
     case INET_REQ_GETHOSTNAME: { /* get host name */
-	char tbuf[MAXHOSTNAMELEN];
+	char tbuf[INET_MAXHOSTNAMELEN + 1];
 
 	DEBUGF(("inet_ctl(%ld): GETHOSTNAME\r\n", (long)desc->port)); 
 	if (len != 0)
 	    return ctl_error(EINVAL, rbuf, rsize);
 
-	if (IS_SOCKET_ERROR(sock_hostname(tbuf, MAXHOSTNAMELEN)))
+        /* gethostname requires len to be max(hostname) + 1 */
+	if (IS_SOCKET_ERROR(sock_hostname(tbuf, INET_MAXHOSTNAMELEN + 1)))
 	    return ctl_error(sock_errno(), rbuf, rsize);
 	return ctl_reply(INET_REP_OK, tbuf, strlen(tbuf), rbuf, rsize);
     }
diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c
index c193fd804a..27b919c093 100644
--- a/lib/erl_interface/src/connect/ei_connect.c
+++ b/lib/erl_interface/src/connect/ei_connect.c
@@ -497,7 +497,8 @@ int ei_connect_init(ei_cnode* ec, const char* this_node_name,
     }
 #endif /* _REENTRANT */
     
-    if (gethostname(thishostname, EI_MAXHOSTNAMELEN) == -1) {
+    /* gethostname requires len to be max(hostname) + 1 */
+    if (gethostname(thishostname, EI_MAXHOSTNAMELEN+1) == -1) {
 #ifdef __WIN32__
 	EI_TRACE_ERR1("ei_connect_init","Failed to get host name: %d",
 		      WSAGetLastError());
@@ -613,7 +614,8 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
     hp = ei_gethostbyname_r(hostname,&host,buffer,1024,&ei_h_errno);
     if (hp == NULL) {
 	char thishostname[EI_MAXHOSTNAMELEN+1];
-	if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) {
+        /* gethostname requies len to be max(hostname) + 1*/
+	if (gethostname(thishostname,EI_MAXHOSTNAMELEN+1) < 0) {
 	    EI_TRACE_ERR0("ei_connect_tmo",
 			  "Failed to get name of this host");
 	    erl_errno = EHOSTUNREACH;
@@ -636,7 +638,8 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms)
 #else /* __WIN32__ */
     if ((hp = ei_gethostbyname(hostname)) == NULL) {
 	char thishostname[EI_MAXHOSTNAMELEN+1];
-	if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) {
+        /* gethostname requires len to be max(hostname) + 1 */
+	if (gethostname(thishostname,EI_MAXHOSTNAMELEN+1) < 0) {
 	    EI_TRACE_ERR1("ei_connect_tmo",
 			  "Failed to get name of this host: %d", 
 			  WSAGetLastError());
diff --git a/lib/erl_interface/src/prog/erl_call.c b/lib/erl_interface/src/prog/erl_call.c
index d233ed26a2..0b09d412db 100644
--- a/lib/erl_interface/src/prog/erl_call.c
+++ b/lib/erl_interface/src/prog/erl_call.c
@@ -325,7 +325,8 @@ int erl_call(int argc, char **argv)
       initWinSock();
 #endif
 
-      if (gethostname(h_hostname, EI_MAXHOSTNAMELEN) < 0) {
+      /* gethostname requires len to be max(hostname) + 1 */
+      if (gethostname(h_hostname, EI_MAXHOSTNAMELEN+1) < 0) {
 	  fprintf(stderr,"erl_call: failed to get host name: %d\n", errno);
 	  exit(1);
       }
diff --git a/lib/ic/test/c_client_erl_server_SUITE_data/c_client.c b/lib/ic/test/c_client_erl_server_SUITE_data/c_client.c
index af189a74f7..b3a18e03d4 100644
--- a/lib/ic/test/c_client_erl_server_SUITE_data/c_client.c
+++ b/lib/ic/test/c_client_erl_server_SUITE_data/c_client.c
@@ -58,7 +58,7 @@
 #include "erl_interface.h"
 #include "m_i.h"
 
-#define HOSTNAMESZ 256
+#define HOSTNAMESZ 255
 #define NODENAMESZ 512
 
 #define INBUFSZ 10
@@ -295,7 +295,7 @@ int main(int argc, char **argv)
     
     progname = argv[0];
     host[HOSTNAMESZ] = '\0';
-    if (gethostname(host, HOSTNAMESZ) < 0) {
+    if (gethostname(host, HOSTNAMESZ + 1) < 0) {
 	fprintf(stderr, "Can't find own hostname\n");
 	done(1);
     } 
diff --git a/lib/ic/test/c_client_erl_server_proto_SUITE_data/c_client.c b/lib/ic/test/c_client_erl_server_proto_SUITE_data/c_client.c
index b7609d63e5..40c7328f03 100644
--- a/lib/ic/test/c_client_erl_server_proto_SUITE_data/c_client.c
+++ b/lib/ic/test/c_client_erl_server_proto_SUITE_data/c_client.c
@@ -61,7 +61,7 @@
 #include "erl_interface.h"
 #include "m_i.h"
 
-#define HOSTNAMESZ 256
+#define HOSTNAMESZ 255
 #define NODENAMESZ 512
 
 #define INBUFSZ 10
@@ -298,7 +298,7 @@ int main(int argc, char **argv)
     
     progname = argv[0];
     host[HOSTNAMESZ] = '\0';
-    if (gethostname(host, HOSTNAMESZ) < 0) {
+    if (gethostname(host, HOSTNAMESZ + 1) < 0) {
 	fprintf(stderr, "Can't find own hostname\n");
 	done(1);
     } 
diff --git a/lib/ic/test/c_client_erl_server_proto_tmo_SUITE_data/c_client.c b/lib/ic/test/c_client_erl_server_proto_tmo_SUITE_data/c_client.c
index 23dc089555..33cfe71322 100644
--- a/lib/ic/test/c_client_erl_server_proto_tmo_SUITE_data/c_client.c
+++ b/lib/ic/test/c_client_erl_server_proto_tmo_SUITE_data/c_client.c
@@ -61,7 +61,7 @@
 #include "erl_interface.h"
 #include "m_i.h"
 
-#define HOSTNAMESZ 256
+#define HOSTNAMESZ 255
 #define NODENAMESZ 512
 
 #define INBUFSZ 10
@@ -298,7 +298,7 @@ int main(int argc, char **argv)
     
     progname = argv[0];
     host[HOSTNAMESZ] = '\0';
-    if (gethostname(host, HOSTNAMESZ) < 0) {
+    if (gethostname(host, HOSTNAMESZ + 1) < 0) {
 	fprintf(stderr, "Can't find own hostname\n");
 	done(1);
     } 
diff --git a/lib/ic/test/erl_client_c_server_SUITE_data/c_server.c b/lib/ic/test/erl_client_c_server_SUITE_data/c_server.c
index 53345d561b..f48480e8dc 100644
--- a/lib/ic/test/erl_client_c_server_SUITE_data/c_server.c
+++ b/lib/ic/test/erl_client_c_server_SUITE_data/c_server.c
@@ -81,7 +81,7 @@ static void showtime(MyTimeval *start, MyTimeval *stop);
 static void usage(void);
 static void done(int r);
 
-#define HOSTNAMESZ 	256
+#define HOSTNAMESZ 	255
 #define NODENAMESZ 	512
 #define INBUFSZ 	 10
 #define OUTBUFSZ 	  0
@@ -122,7 +122,7 @@ int main(int argc, char **argv)
     
     progname = argv[0];
     host[HOSTNAMESZ] = '\0';
-    if (gethostname(host, HOSTNAMESZ) < 0) {
+    if (gethostname(host, HOSTNAMESZ + 1) < 0) {
 	fprintf(stderr, "Can't find own hostname\n");
 	done(1);
     } 
diff --git a/lib/ic/test/erl_client_c_server_proto_SUITE_data/c_server.c b/lib/ic/test/erl_client_c_server_proto_SUITE_data/c_server.c
index a18f0e7ba9..e2ba5bd5b6 100644
--- a/lib/ic/test/erl_client_c_server_proto_SUITE_data/c_server.c
+++ b/lib/ic/test/erl_client_c_server_proto_SUITE_data/c_server.c
@@ -81,7 +81,7 @@ static void showtime(MyTimeval *start, MyTimeval *stop);
 static void usage(void);
 static void done(int r);
 
-#define HOSTNAMESZ 	256
+#define HOSTNAMESZ 	255
 #define NODENAMESZ 	512
 #define INBUFSZ 	 10
 #define OUTBUFSZ 	  0
@@ -122,7 +122,7 @@ int main(int argc, char **argv)
     
     progname = argv[0];
     host[HOSTNAMESZ] = '\0';
-    if (gethostname(host, HOSTNAMESZ) < 0) {
+    if (gethostname(host, HOSTNAMESZ + 1) < 0) {
 	fprintf(stderr, "Can't find own hostname\n");
 	done(1);
     }