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#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/select.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <talloc.h>
#include <unistd.h>
#include "osmo_mcast_sock.h"
struct mcast_server_sock *mcast_server_sock_setup(void *ctx,
char* tx_mcast_group,
int tx_mcast_port,
int loopback)
{
struct mcast_server_sock *serv_sock = talloc_zero(ctx,
struct mcast_server_sock);
serv_sock->osmo_fd = talloc_zero(ctx, struct osmo_fd);
serv_sock->sock_conf = talloc_zero(ctx, struct sockaddr_in);
// setup mcast server socket
serv_sock->osmo_fd->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (serv_sock->osmo_fd->fd == -1) {
perror("Failed to create Multicast Server Socket");
return NULL;
}
serv_sock->sock_conf->sin_family = AF_INET;
serv_sock->sock_conf->sin_addr.s_addr = inet_addr(tx_mcast_group);
serv_sock->sock_conf->sin_port = htons(tx_mcast_port);
// determines whether sent mcast packets should be looped back to the local sockets.
// loopback must be enabled if the mcast client is on the same machine
if (setsockopt(serv_sock->osmo_fd->fd, IPPROTO_IP,
IP_MULTICAST_LOOP, &loopback, sizeof(loopback)) < 0) {
perror("Failed to disable loopback.\n");
return NULL;
}
return serv_sock;
}
struct mcast_client_sock *mcast_client_sock_setup(
void *ctx, char* mcast_group, int mcast_port,
int (*fd_rx_cb)(struct osmo_fd *ofd, unsigned int what),
void *osmo_fd_data)
{
struct mcast_client_sock *client_sock = talloc_zero(ctx,
struct mcast_client_sock);
struct sockaddr_in *rx_sock_conf = talloc_zero(NULL,
struct sockaddr_in);
int rc, reuseaddr = 1, loopback = 1;
client_sock->osmo_fd = talloc_zero(ctx, struct osmo_fd);
client_sock->mcast_group = talloc_zero(ctx, struct ip_mreq);
// Create mcast client socket
client_sock->osmo_fd->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (client_sock->osmo_fd->fd == -1) {
perror("Could not create mcast client socket");
return NULL;
}
// Enable SO_REUSEADDR to allow multiple instances of this application to receive copies of the multicast datagrams.
rc = setsockopt(client_sock->osmo_fd->fd,
SOL_SOCKET,
SO_REUSEADDR, &reuseaddr, sizeof(reuseaddr));
if (rc < 0) {
perror("Failed to configure REUSEADDR option");
return NULL;
}
// Bind to the proper port number with the IP address specified as INADDR_ANY.
rx_sock_conf->sin_family = AF_INET;
rx_sock_conf->sin_addr.s_addr = htonl(INADDR_ANY);
rx_sock_conf->sin_port = htons(mcast_port);
rc = bind(client_sock->osmo_fd->fd, (struct sockaddr *)rx_sock_conf,
sizeof(*rx_sock_conf));
talloc_free(rx_sock_conf);
if (rc < 0) {
perror("Could not bind mcast client socket");
return NULL;
}
// Enable loopback of msgs to the host.
// Loopback must be enabled for the client, so multiple processes are able to recevie a mcast package.
rc = setsockopt(client_sock->osmo_fd->fd,
IPPROTO_IP,
IP_MULTICAST_LOOP, &loopback, sizeof(loopback));
if (rc < 0) {
perror("Failed to enable IP_MULTICAST_LOOP");
return NULL;
}
// Configure and join the multicast group
client_sock->mcast_group->imr_multiaddr.s_addr = inet_addr(mcast_group);
client_sock->mcast_group->imr_interface.s_addr = htonl(INADDR_ANY);
rc = setsockopt(client_sock->osmo_fd->fd,
IPPROTO_IP,
IP_ADD_MEMBERSHIP, client_sock->mcast_group,
sizeof(*client_sock->mcast_group));
if (rc < 0) {
perror("Failed to join to mcast goup");
return NULL;
}
// configure and register the osmocom filedescriptor
client_sock->osmo_fd->cb = fd_rx_cb;
client_sock->osmo_fd->when = BSC_FD_READ;
client_sock->osmo_fd->data = osmo_fd_data;
osmo_fd_register(client_sock->osmo_fd);
return client_sock;
}
struct mcast_bidir_sock *mcast_bidir_sock_setup(
void *ctx, char* tx_mcast_group, int tx_mcast_port,
char* rx_mcast_group, int rx_mcast_port, int loopback,
int (*fd_rx_cb)(struct osmo_fd *ofd, unsigned int what),
void *osmo_fd_data)
{
struct mcast_bidir_sock *bidir_sock = talloc(ctx,
struct mcast_bidir_sock);
bidir_sock->rx_sock = mcast_client_sock_setup(ctx, rx_mcast_group,
rx_mcast_port, fd_rx_cb, osmo_fd_data);
bidir_sock->tx_sock = mcast_server_sock_setup(ctx, tx_mcast_group,
tx_mcast_port, loopback);
if (!bidir_sock->rx_sock || !bidir_sock->tx_sock) {
return NULL;
}
return bidir_sock;
}
int mcast_client_sock_rx(struct mcast_client_sock *client_sock, void* buf,
int buf_len)
{
return recv(client_sock->osmo_fd->fd, buf, buf_len, 0);
}
int mcast_server_sock_tx(struct mcast_server_sock *serv_sock, void* data,
int data_len)
{
return sendto(serv_sock->osmo_fd->fd, data, data_len, 0,
(struct sockaddr *)serv_sock->sock_conf,
sizeof(*serv_sock->sock_conf));
}
int mcast_bidir_sock_tx(struct mcast_bidir_sock *bidir_sock, void* data,
int data_len)
{
return mcast_server_sock_tx(bidir_sock->tx_sock, data, data_len);
}
int mcast_bidir_sock_rx(struct mcast_bidir_sock *bidir_sock, void* buf,
int buf_len)
{
return mcast_client_sock_rx(bidir_sock->rx_sock, buf, buf_len);
}
void mcast_client_sock_close(struct mcast_client_sock *client_sock)
{
setsockopt(client_sock->osmo_fd->fd,
IPPROTO_IP,
IP_DROP_MEMBERSHIP, client_sock->mcast_group,
sizeof(*client_sock->mcast_group));
osmo_fd_unregister(client_sock->osmo_fd);
client_sock->osmo_fd->fd = -1;
client_sock->osmo_fd->when = 0;
close(client_sock->osmo_fd->fd);
talloc_free(client_sock->mcast_group);
talloc_free(client_sock->osmo_fd);
talloc_free(client_sock);
}
void mcast_server_sock_close(struct mcast_server_sock *serv_sock)
{
close(serv_sock->osmo_fd->fd);
talloc_free(serv_sock->sock_conf);
talloc_free(serv_sock);
}
void mcast_bidir_sock_close(struct mcast_bidir_sock *bidir_sock)
{
mcast_client_sock_close(bidir_sock->rx_sock);
mcast_server_sock_close(bidir_sock->tx_sock);
talloc_free(bidir_sock);
}
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