Files
adsb-tools/client.c
2016-02-17 16:40:09 -08:00

146 lines
3.3 KiB
C

#include <stdbool.h>
#include <stdlib.h>
#include <assert.h>
#include <strings.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include "common.h"
#include "json.h"
#include "stats.h"
#include "client.h"
struct client {
struct peer peer;
char id[UUID_LEN];
struct serializer *serializer;
struct client *prev;
struct client *next;
};
typedef void (*serializer)(struct packet *, struct buf *);
struct serializer {
char *name;
serializer serialize;
struct client *client_head;
} serializers[] = {
{
.name = "json",
.serialize = json_serialize,
},
{
.name = "stats",
.serialize = stats_serialize,
},
};
#define NUM_SERIALIZERS (sizeof(serializers) / sizeof(*serializers))
static void client_hangup(struct client *client) {
fprintf(stderr, "C %s (%s): Client disconnected\n", client->id, client->serializer->name);
if (client->prev) {
client->prev->next = client->next;
} else {
client->serializer->client_head = client->next;
}
if (client->next) {
client->next->prev = client->prev;
}
close(client->peer.fd);
free(client);
}
static void client_hangup_wrapper(struct peer *peer) {
client_hangup((struct client *) peer);
}
static bool client_hello(int fd, struct serializer *serializer) {
struct buf buf = BUF_INIT;
serializer->serialize(NULL, &buf);
if (buf.length == 0) {
return true;
}
if (write(fd, buf_at(&buf, 0), buf.length) != buf.length) {
return false;
}
return true;
}
void client_init() {
signal(SIGPIPE, SIG_IGN);
}
struct serializer *client_get_serializer(char *name) {
for (int i = 0; i < NUM_SERIALIZERS; i++) {
if (strcasecmp(serializers[i].name, name) == 0) {
return &serializers[i];
}
}
return NULL;
}
void client_add(int fd, struct serializer *serializer) {
int flags = fcntl(fd, F_GETFL, 0);
assert(flags >= 0);
flags |= O_NONBLOCK;
assert(fcntl(fd, F_SETFL, flags) == 0);
if (!client_hello(fd, serializer)) {
fprintf(stderr, "C xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx: Failed to write hello to client\n");
return;
}
struct client *client = malloc(sizeof(*client));
assert(client);
client->peer.fd = fd;
client->peer.event_handler = client_hangup_wrapper;
uuid_gen(client->id);
client->serializer = serializer;
client->prev = NULL;
client->next = serializer->client_head;
serializer->client_head = client;
// Only listen for hangup
peer_epoll_add((struct peer *) client, EPOLLIN);
fprintf(stderr, "C %s (%s): New client\n", client->id, serializer->name);
}
void client_add_wrapper(int fd, void *passthrough) {
client_add(fd, (struct serializer *) passthrough);
}
void client_write(struct packet *packet) {
for (int i = 0; i < NUM_SERIALIZERS; i++) {
struct serializer *serializer = &serializers[i];
if (serializer->client_head == NULL) {
continue;
}
struct buf buf = BUF_INIT;
serializer->serialize(packet, &buf);
if (buf.length == 0) {
continue;
}
struct client *client = serializer->client_head;
while (client) {
if (write(client->peer.fd, buf_at(&buf, 0), buf.length) == buf.length) {
client = client->next;
} else {
struct client *next = client->next;
client_hangup(client);
client = next;
}
}
}
}
void client_print_usage() {
fprintf(stderr, "\nSupported output formats:\n");
for (int i = 0; i < NUM_SERIALIZERS; i++) {
fprintf(stderr, "\t%s\n", serializers[i].name);
}
}