antd-tunnel-publishers/broadcast/broadcast.c
2021-11-28 18:04:37 +01:00

510 lines
19 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <antd/bst.h>
#include <antd/utils.h>
#include <antd/list.h>
#include "../tunnel.h"
#define BC_ERROR(r, fd, c, ...) \
do \
{ \
r.header.client_id = c; \
r.header.type = CHANNEL_ERROR; \
(void)snprintf(r.data, BUFFLEN, ##__VA_ARGS__); \
r.header.size = strlen(r.data); \
M_ERROR(MODULE_NAME, "%s", r.data); \
(void)msg_write(fd, &r); \
} while (0)
#define MODULE_NAME "broadcast"
#define BC_SUBSCRIPTION 0x0A
#define BC_UNSUBSCRIPTION 0x0B
#define BC_QUERY_USER 0x0C
#define BC_QUERY_GROUP 0x0D
#define MAX_STR_LEN 255
typedef struct
{
int ref;
char name[MAX_STR_LEN];
bst_node_t *groups;
} bc_client_t;
/**
* @brief Send notified to client.
*
* @param type
* @param bc_client broadcast client handle
* @param groupname group name
*/
static void bc_notify(bst_node_t *node, void **argv, int argc);
static void int_handler(int dummy);
static void bc_get_handle(bst_node_t *node, void **argv, int argc);
static void bc_unsubscription(bst_node_t *node, void **args, int argc);
static void unsubscribe(bst_node_t *node, void **args, int argc);
static void bc_send_query_user(bst_node_t *node, void **argv, int argc);
static void bc_send_query_group(bst_node_t *node, void **argv, int argc);
static bst_node_t *clients = NULL;
static uint8_t msg_buffer[BUFFLEN];
static volatile int running = 1;
static void int_handler(int dummy)
{
(void)dummy;
running = 0;
}
static void bc_get_handle(bst_node_t *node, void **argv, int argc)
{
(void)argc;
bc_client_t **bc_client = (bc_client_t **)argv[1];
char *name = (char *)argv[2];
bc_client_t *node_client = (bc_client_t *)node->data;
if (bc_client == NULL || name == NULL || node->data == NULL)
{
return;
}
M_DEBUG(MODULE_NAME, "comparing %s vs %s", name, node_client->name);
if (strcmp(name, node_client->name) == 0)
{
M_LOG(MODULE_NAME, "Handle for user %s exits (ref %d)", name, node_client->ref);
*bc_client = node_client;
}
}
static void bc_unsubscription(bst_node_t *node, void **args, int argc)
{
(void)argc;
tunnel_msg_t *msg = (tunnel_msg_t *)args[1];
int len = *((int *)args[3]) + 2;
if (!node)
return;
// write hash value to data
int hash = node->key;
uint32_t net32 = htonl(hash);
(void)memcpy(&msg->data[len], &net32, sizeof(net32));
msg->header.size = len + sizeof(net32);
args[2] = &hash;
M_DEBUG(MODULE_NAME, "All clients subscribed to the groupe %d is notified that user is leaving", hash);
bst_for_each(clients, bc_notify, args, 3);
if(node->data)
{
free(node->data);
node->data = NULL;
}
}
static void bc_free_groupname(void* data)
{
if(data)
{
free(data);
}
}
static void unsubscribe(bst_node_t *node, void **args, int argc)
{
(void)argc;
tunnel_msg_t msg;
int *ufd = (int *)args[0];
int len;
bc_client_t *bc_client = (bc_client_t *)node->data;
void *bc_argv[] = {ufd, &msg, 0, &len};
if (!node || !node->data)
{
return;
}
bc_client->ref--;
// notify all clients in our groups that we're done
msg.header.type = CHANNEL_CTRL;
msg.data = msg_buffer;
msg.data[0] = BC_UNSUBSCRIPTION;
len = strlen(bc_client->name);
msg.data[1] = (uint8_t)len;
(void)memcpy(&msg.data[2], bc_client->name, len);
// group name
// unsubscribe
if (bc_client->ref <= 0)
{
M_DEBUG(MODULE_NAME, "User %s is leaving all its subscribed groups (%d)", bc_client->name, bc_client->groups == NULL);
bst_for_each(bc_client->groups, bc_unsubscription, bc_argv, 3);
M_DEBUG(MODULE_NAME, "Handle for user %s ref is %d, free handle data", bc_client->name, bc_client->ref);
bst_free(bc_client->groups);
free(node->data);
}
msg.header.type = CHANNEL_UNSUBSCRIBE;
msg.header.client_id = node->key;
msg.header.size = 0;
msg.data = NULL;
if (msg_write(*ufd, &msg) == -1)
{
M_ERROR(MODULE_NAME, "Unable to request unsubscribe to client %d", node->key);
}
}
static void bc_send_query_group(bst_node_t *node, void **argv, int argc)
{
(void)argc;
int *fd = (int *)argv[0];
tunnel_msg_t *msg = (tunnel_msg_t *)argv[1];
char *gname = NULL;
if (!node->data)
{
return;
}
int net32 = htonl(node->key);
(void)memcpy(&msg->data[1], &net32, sizeof(net32));
gname = (char*)node->data;
(void)memcpy(&msg->data[sizeof(net32) + 1u], gname, strlen(gname));
msg->header.size = sizeof(net32) + 1u + strlen(gname);
M_DEBUG(MODULE_NAME, "Sent group query to client %d: group %s (%d)", msg->header.client_id, gname, node->key);
if (msg_write(*fd, msg) == -1)
{
M_ERROR(MODULE_NAME, "Unable to write query message to client %d", node->key);
}
}
static void bc_send_query_user(bst_node_t *node, void **argv, int argc)
{
(void)argc;
int *fd = (int *)argv[0];
tunnel_msg_t *msg = (tunnel_msg_t *)argv[1];
bc_client_t *bc_client = NULL;
int *group = (int *)argv[2];
int len = *(int *)argv[3];
if (!node->data)
{
return;
}
bc_client = (bc_client_t *)node->data;
if (bst_find(bc_client->groups, *group) == NULL)
{
return;
}
(void)memcpy(&msg->data[len], bc_client->name, strlen(bc_client->name));
msg->header.size = len + strlen(bc_client->name);
M_DEBUG(MODULE_NAME, "Sent user query to client %d: User %s is in group %d", msg->header.client_id, bc_client->name, *group);
if (msg_write(*fd, msg) == -1)
{
M_ERROR(MODULE_NAME, "Unable to write query message to client %d", node->key);
}
}
static void bc_notify(bst_node_t *node, void **argv, int argc)
{
(void)argc;
int *fd = (int *)argv[0];
tunnel_msg_t *msg = (tunnel_msg_t *)argv[1];
bc_client_t *bc_client = NULL;
int *group = (int *)argv[2];
if (!node->data)
{
return;
}
bc_client = (bc_client_t *)node->data;
if (bst_find(bc_client->groups, *group) == NULL)
{
return;
}
msg->header.client_id = node->key;
if (msg_write(*fd, msg) == -1)
{
M_ERROR(MODULE_NAME, "Unable to write notify message to client %d", node->key);
}
M_DEBUG(MODULE_NAME, "Notify message sent to client %d", node->key);
}
int main(int argc, char **argv)
{
int fd, hash;
size_t len;
tunnel_msg_t request, response;
fd_set fd_in;
int status, length;
char name[MAX_STR_LEN + 1];
void *fargv[4];
bst_node_t *node_p;
uint32_t net32;
bc_client_t *bc_client;
LOG_INIT(MODULE_NAME);
if (argc != 3)
{
printf("Usage: %s path/to/hotline/socket channel_name\n", argv[0]);
return -1;
}
signal(SIGPIPE, SIG_IGN);
signal(SIGABRT, SIG_IGN);
signal(SIGINT, int_handler);
// now try to request new channel from hotline
fd = open_unix_socket(argv[1]);
if (fd == -1)
{
M_ERROR(MODULE_NAME, "Unable to open the hotline: %s", argv[1]);
return -1;
}
request.header.type = CHANNEL_OPEN;
request.header.channel_id = 0;
request.header.client_id = 0;
M_LOG(MODULE_NAME, "Request to open the channel %s", argv[2]);
(void)strncpy(name, argv[2], sizeof(name));
request.header.size = strlen(name);
request.data = (uint8_t *)name;
if (msg_write(fd, &request) == -1)
{
M_ERROR(MODULE_NAME, "Unable to write message to hotline");
(void)close(fd);
return -1;
}
M_DEBUG(MODULE_NAME, "Wait for comfirm creation of %s", argv[2]);
// now wait for message
if (msg_read(fd, &response) == -1)
{
M_ERROR(MODULE_NAME, "Unable to read message from hotline");
(void)close(fd);
return -1;
}
if (response.header.type == CHANNEL_OK)
{
M_LOG(MODULE_NAME, "Channel created: %s", argv[2]);
}
else
{
M_ERROR(MODULE_NAME, "Channel is not created: %s. Tunnel service responds with msg of type %d", argv[2], response.header.type);
running = 0;
}
if (response.data)
free(response.data);
// now read data
fargv[0] = (void *)&fd;
while (running)
{
FD_ZERO(&fd_in);
FD_SET(fd, &fd_in);
status = select(fd + 1, &fd_in, NULL, NULL, NULL);
switch (status)
{
case -1:
M_ERROR(MODULE_NAME, "Error %d on select()\n", errno);
running = 0;
break;
case 0:
break;
// we have data
default:
if (msg_read(fd, &request) == -1)
{
M_ERROR(MODULE_NAME, "Unable to read message from channel. quit");
running = 0;
}
else
{
switch (request.header.type)
{
case CHANNEL_SUBSCRIBE:
if (request.header.size > MAX_STR_LEN - 1)
{
M_ERROR(MODULE_NAME, "User name string overflow");
}
else
{
node_p = bst_find(clients, request.header.client_id);
if (node_p)
{
M_LOG(MODULE_NAME, "Client %d is already subscript to this channel", request.header.client_id);
}
{
// store user name
bc_client = NULL;
(void)memcpy(name, request.data, request.header.size);
name[request.header.size] = '\0';
fargv[1] = &bc_client;
fargv[2] = name;
bst_for_each(clients, bc_get_handle, fargv, 3);
if (bc_client)
{
bc_client->ref++;
}
else
{
bc_client = (bc_client_t *)malloc(sizeof(bc_client_t));
(void)strncpy(bc_client->name, name, MAX_STR_LEN);
bc_client->groups = NULL;
bc_client->ref = 1;
}
clients = bst_insert(clients, request.header.client_id, bc_client);
M_LOG(MODULE_NAME, "Client %s (%d) subscribes to the chanel (ref %d)", bc_client->name, request.header.client_id, bc_client->ref);
}
}
break;
case CHANNEL_CTRL:
/**
* @brief message in format [code][group name]
*
*/
if (request.header.size > 0u && request.header.size <= MAX_STR_LEN)
{
node_p = bst_find(clients, request.header.client_id);
if (node_p && node_p->data)
{
bc_client = (bc_client_t *)node_p->data;
fargv[1] = &response;
fargv[2] = &hash;
response.header.channel_id = request.header.channel_id;
response.header.type = CHANNEL_CTRL;
response.data = msg_buffer;
response.data[0] = request.data[0];
switch (request.data[0])
{
case BC_SUBSCRIPTION:
case BC_UNSUBSCRIPTION:
/**
* @brief * The notify message is in the following format
* [1 byte type][1 byte user name size][user name][4byte gid][groupname (optional)]
*
*/
if (request.data[0] == BC_SUBSCRIPTION)
{
memcpy(name, &request.data[1], request.header.size - 1u);
name[request.header.size - 1u] = '\0';
hash = simple_hash(name);
if(bst_find(bc_client->groups, hash) == NULL)
{
bc_client->groups = (void *)bst_insert(bc_client->groups, hash, strdup(name));
M_LOG(MODULE_NAME, "Client %d subscription to broadcast group: %s (%d)", request.header.client_id, name, hash);
}
else
{
M_LOG(MODULE_NAME, "Client %d is already subscribed to the group %s", request.header.client_id, name);
}
}
else
{
name[0] = '\0';
(void)memcpy(&hash, &request.data[1], sizeof(hash));
hash = ntohl(hash);
}
len = strlen(bc_client->name);
response.data[1] = (uint8_t)len;
(void)memcpy(&response.data[2], bc_client->name, len);
len += 2u;
// group name
net32 = htonl(hash);
(void)memcpy(&response.data[len], &net32, sizeof(net32));
len += sizeof(net32);
(void)memcpy(&response.data[len], name, strlen(name));
response.header.size = len + strlen(name);
bst_for_each(clients, bc_notify, fargv, 3);
if (request.data[0] == BC_UNSUBSCRIPTION)
{
bc_client->groups = (void *)bst_delete(bc_client->groups, hash);
M_LOG(MODULE_NAME, "Client %d leaves broadcast group: %d", request.header.client_id, hash);
}
break;
case BC_QUERY_USER:
(void)memcpy(&hash, &request.data[1], sizeof(hash));
hash = ntohl(hash);
net32 = htonl(hash);
(void)memcpy(&response.data[1], &net32, sizeof(net32));
len = len = sizeof(net32) + 1u;
fargv[3] = &len;
response.header.client_id = request.header.client_id;
if (bst_find(bc_client->groups, hash) == NULL)
{
BC_ERROR(response, fd, request.header.client_id, "Client %d query a group that it does not belong to", request.header.client_id);
}
else
{
// data format [type][4bytes group][user]
M_LOG(MODULE_NAME, "Client %d query user from group %d", request.header.client_id, hash);
bst_for_each(clients, bc_send_query_user, fargv, 4);
}
break;
case BC_QUERY_GROUP:
if(bc_client->groups)
{
/** send back group to client one by one inform of [type][gid 4][group name]*/
response.header.client_id = request.header.client_id;
M_LOG(MODULE_NAME, "Client %d query all user subscribed group", request.header.client_id);
bst_for_each(bc_client->groups, bc_send_query_group, fargv, 2);
}
break;
default:
BC_ERROR(response, fd, request.header.client_id, "Invalid client control message: 0x%.2X", request.data[0]);
break;
}
}
else
{
BC_ERROR(response, fd, request.header.client_id, "Client %d does not previously subscribe to the channel", request.header.client_id);
}
}
else
{
BC_ERROR(response, fd, request.header.client_id, "Invalid CTRL message size: %d", request.header.size);
}
break;
case CHANNEL_DATA:
/**
* @brief Send message to a group of client
* message is in the following format
* [4bytes group id][data]
*/
(void)memcpy(&hash, &request.data[0], sizeof(hash));
hash = ntohl(hash);
fargv[1] = &request;
fargv[2] = &hash;
bst_for_each(clients, bc_notify, fargv, 3);
break;
case CHANNEL_UNSUBSCRIBE:
M_LOG(MODULE_NAME, "Client %d unsubscribes to the chanel", request.header.client_id);
node_p = bst_find(clients, request.header.client_id);
unsubscribe(node_p, fargv, 1);
clients = bst_delete(clients, request.header.client_id);
break;
default:
M_LOG(MODULE_NAME, "Client %d send message of type %d",
request.header.client_id, request.header.type);
break;
}
if (request.data)
{
free(request.data);
}
}
}
}
// unsubscribe all client
bst_for_each(clients, unsubscribe, fargv, 1);
bst_free(clients);
// close the channel
M_LOG(MODULE_NAME, "Close the channel %s (%d)", argv[2], fd);
request.header.type = CHANNEL_CLOSE;
request.header.size = 0;
request.data = NULL;
if (msg_write(fd, &request) == -1)
{
M_ERROR(MODULE_NAME, "Unable to request channel close");
}
if (msg_read(fd, &response) == 0)
{
if (response.data)
{
free(response.data);
}
}
(void)close(fd);
return 0;
}