/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1998-2016. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
#include <stdlib.h>
#include <string.h>
#include "eidef.h"
#include "eiext.h"
#include "eisend.h"
#include "eirecv.h"
#include "ei_connect_int.h"
#include "erl_interface.h"
#include "erl_connect.h"
#define GLOBALNAMEBUF (16*1024) /* not very small actually */
/* return a list of all registered names. Function allocates and
* returns a NULL-terminated array of pointers to strings. The caller
* is responsible for freeing the array. Space for the array and
* all strings is allocated with a single call to malloc, so the
* caller can make one call to free().
*/
/* global:registered_names() -> [name1,name2,...] */
char **erl_global_names(int fd, int *count)
{
char buf[GLOBALNAMEBUF];
char *bufp=buf;
char tmpbuf[64];
int size = 0;
int index = 0;
erlang_pid *self = erl_self();
erlang_msg msg;
int i;
int version;
int arity;
int msglen;
char **names;
char *s;
self->num = fd;
ei_encode_version(buf,&index);
ei_encode_tuple_header(buf,&index,2);
ei_encode_pid(buf,&index,self); /* PidFrom */
ei_encode_tuple_header(buf,&index,5);
ei_encode_atom(buf,&index,"call"); /* call */
ei_encode_atom(buf,&index,"global"); /* Mod */
ei_encode_atom(buf,&index,"registered_names"); /* Fun */
ei_encode_list_header(buf,&index,0); /* Args: [ ] */
ei_encode_atom(buf,&index,"user"); /* user */
/* make the rpc call */
if (ei_send_reg_encoded(fd,self,"rex",buf,index)) return NULL;
while (1) {
index = GLOBALNAMEBUF;
if (!(i = ei_recv_internal(fd,&bufp,&index,&msg,&msglen,1,0))) continue;
else break;
}
if (i != ERL_SEND) return NULL;
/* expecting { rex, [name1, name2, ...] } */
size = msglen;
index = 0;
if (ei_decode_version(buf,&index,&version)
|| ei_decode_tuple_header(buf,&index,&arity)
|| (arity != 2)
|| ei_decode_atom(buf,&index,tmpbuf)
|| strcmp(tmpbuf,"rex")
|| ei_decode_list_header(buf,&index,&arity)) return NULL;
/* we use the size of the rest of the received message to estimate
* the buffer space required for all the strings. we know how many
* they are (arity) so we need space for that many pointers, plus
* a little less than the atoms themselves needed in the reply.
*/
arity++; /* we will need a terminating NULL as well */
if (!(names = malloc((arity * sizeof(char**)) + (size-index)))) return NULL;
/* arity pointers first, followed by s */
s = (char *)(names+arity);
if (count) *count = 0;
for (i=0; i<arity; i++) {
names[i] = s; /* insert the pointer */
if (ei_decode_atom(buf,&index,s)) break; /* copy the data */
if (count) (*count)++;
s += strlen(names[i]) + 1; /* advance pointer */
}
names[i]=NULL;
return names;
}
