recv() not triggering with libevent - c

Question

I am trying to connect to the local openvpn client over its managment socket and query its state/status.
I have implemented the follow program with libevent support.
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <event2/event.h>
#include <fcntl.h>
#include <string.h>
char message[1000], server_reply[2000];
struct event *ev, *ev1, *ev2;
int fd_set_blocking(int fd, int blocking)
{
int flags = fcntl(fd, F_GETFL, 0);
if (flags == -1) {
return 0;
}
if (blocking) {
flags &= ~O_NONBLOCK;
} else {
flags |= O_NONBLOCK;
}
return fcntl(fd, F_SETFL, flags) != -1;
}
void cb_func_hold_release(evutil_socket_t fd, short what, void *arg)
{
int sock = *(int *)arg;
struct timeval one_seconds = {1,0};
printf("IN CB CONNECT\n");
sprintf (message, "hold release\n");
if (send (sock, message, strlen (message), 0) < 0) {
printf("send failed\n");
}
event_add(ev1, NULL);
}
void cb_func_write(evutil_socket_t fd, short what, void *arg)
{
int sock = *(int *)arg;
printf("IN CB CHECKSTATUS\n");
sprintf (message, "status\n");
if (send (sock, message, strlen (message), 0) < 0) {
printf("send failed\n");
}
/*
int reclen = recv (sock, server_reply, 2000, 0);
if (reclen < 0) {
printf("recving failed");
} else {
if (reclen > 1) {
server_reply[reclen-1] = '\0';
}
printf("SERVER REPLT< %s\n", server_reply);
}
if (strstr(message, "CONNECTED")) {
printf("VPN CONNECTED");
}
*/
event_add(ev2, NULL);
if (event_pending(ev2,EV_READ|EV_PERSIST, NULL)) {
printf("ADDED READ EVENT\n");
}
}
void cb_func_read(evutil_socket_t fd, short what, void *arg)
{
int sock = *(int *)arg;
printf("IN CB READ\n");
int reclen = recv (sock, server_reply, 2000, 0);
if (reclen < 0) {
printf("recving failed");
} else {
if (reclen > 1) {
server_reply[reclen-1] = '\0';
}
printf("SERVER REPLY %s\n", server_reply);
}
if (strstr(message, "CONNECTED")) {
printf("VPN CONNECTED");
}
}
int main(void)
{
int flags;
int mgmretry = 0;
int sock = 0;
struct sockaddr_in server;
struct timeval five_seconds = {1,0};
struct event_base *base = event_base_new();
ev = event_new(base, sock, EV_TIMEOUT, cb_func_hold_release, &sock);
ev1 = event_new(base, sock, EV_WRITE, cb_func_write, &sock);
ev2 = event_new(base, sock, EV_READ, cb_func_read, &sock);
sock = socket (AF_INET, SOCK_STREAM, 0);
if (sock == -1) {
printf("COUILD NOT CREATE SOCKET\n");
exit(0);
}
fd_set_blocking(sock, 1);
server.sin_addr.s_addr = inet_addr("127.0.0.1");
server.sin_family = AF_INET;
server.sin_port = htons (12345);
if (connect (sock, (struct sockaddr *)&server, sizeof (server)) < 0) {
printf("connecting failed\n");
exit(0);
}
event_add(ev, &five_seconds);
printf("DISPATCHING\n");
event_base_dispatch(base);
}
The issue is the the read callback "cb_func_read" is not being triggered. My expectation is that after I send the "status" message to the vpn from cb_func_write(), there is some data sent back which should trigger the read callback but that's not happening.
If I recv() directly after send() in the write callback(the commented portion) I can print the response sent from openvpn so the communication between these two are working.

Answer 1

The event will not trigger unless you armed it using event_add().
You have only done this for the ev event, but not for ev1 and ev2.

Answer 2

silly ,mistake...events ev,ev1,ev2 with event_new() come AFTER creating a socket+making it nonblock... not before