Add an rcon shutdown method

1 files changed, 425 insertions, 0 deletions

diff --git a/rcon.c b/rcon.c
new file mode 100644
index 0000000..756d480
--- /dev/null
+++ b/rcon.c
@@ -0,0 +1,425 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+#include "main.h"
+#include "uring.h"
+#include "config.h"
+#include "server.h"
+#include "rcon.h"
+
+struct rcon {
+	struct server *server;
+	struct uring_task task;
+	unsigned next_rcon;
+	struct sockaddr_in46 rcon;
+	char rconstr[ADDRSTRLEN];
+	char rconbuf[4096];
+	size_t rconbuflen;
+	size_t rconbufdone;
+};
+
+static void
+rcon_free(struct uring_task *task)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+
+	fprintf(stderr, "%s: called with task 0x%p and idle 0x%p\n", __func__, task, rcon);
+	rcon->server->rcon = NULL;
+	free(rcon);
+}
+
+void
+rcon_refdump(struct rcon *rcon)
+{
+	if (!rcon)
+		return;
+
+	uring_task_refdump(&rcon->task);
+}
+
+void
+rcon_delete(struct cfg *cfg, struct server *server)
+{
+	struct rcon *rcon = server->rcon;
+
+	if (!rcon)
+		return;
+
+	fprintf(stderr, "%s called, closing fd %i\n", __func__, rcon->task.fd);
+	uring_cancel(cfg, &rcon->task);
+	uring_task_put(cfg, &rcon->task);
+	server->rcon = NULL;
+}
+
+static int32_t
+read_int(char **pos, size_t *len)
+{
+	uint32_t val;
+	char *p = *pos;
+
+	if (len && *len < 4)
+		return 0;
+
+	val  = ((uint8_t)p[0] <<  0);
+	val += ((uint8_t)p[1] <<  8);
+	val += ((uint8_t)p[2] << 16);
+	val += ((uint8_t)p[3] << 24);
+
+	*pos += 4;
+	if (len)
+		*len -= 4;
+
+	return (int32_t)val;
+}
+
+static void
+write_int(char **pos, size_t *len, int32_t orig)
+{
+	uint32_t val = (uint32_t)orig;
+	char *p = *pos;
+
+	p[0] = (val >>  0) & 0xff;
+	p[1] = (val >>  8) & 0xff;
+	p[2] = (val >> 16) & 0xff;
+	p[3] = (val >> 24) & 0xff;
+	*pos += 4;
+	if (len)
+		*len += 4;
+}
+
+static void
+write_str(char **pos, size_t *len, const char *str)
+{
+	size_t towrite = strlen(str);
+
+	memcpy(*pos, str, towrite);
+	*pos += towrite;
+	if (len)
+		*len += towrite;
+}
+
+static void
+write_end(char **pos, size_t *len)
+{
+	char *p = *pos;
+
+	p[0] = 0x00;
+	p[1] = 0x00;
+	*pos += 2;
+	if (len)
+		*len += 2;
+}
+
+enum rcon_packet_type {
+	RCON_PACKET_LOGIN	= 3,
+	RCON_PACKET_LOGIN_OK	= 2,
+	RCON_PACKET_LOGIN_FAIL	= -1,
+	RCON_PACKET_COMMAND	= 2,
+	RCON_PACKET_RESPONSE	= 0,
+};
+
+static void
+create_packet(struct cfg *cfg, struct rcon *rcon, int32_t reqid, enum rcon_packet_type type, const char *msg)
+{
+	char *pos = &rcon->rconbuf[4];
+
+	rcon->rconbufdone = 0;
+	rcon->rconbuflen = 4;
+	write_int(&pos, &rcon->rconbuflen, reqid);
+	write_int(&pos, &rcon->rconbuflen, type);
+	write_str(&pos, &rcon->rconbuflen, msg);
+	write_end(&pos, &rcon->rconbuflen);
+	pos = &rcon->rconbuf[0];
+	write_int(&pos, NULL, rcon->rconbuflen - 4);
+
+	fprintf(stderr, "Created packet (reqid: %" PRIi32 ", type %" PRIi32 ", len %zu, payload: %s)\n",
+		reqid, type, rcon->rconbuflen, msg);
+}
+
+static bool
+packet_complete(struct cfg *cfg, struct rcon *rcon)
+{
+	char *pos = rcon->rconbuf;
+	size_t len = rcon->rconbufdone;
+	int32_t plen;
+
+	if (rcon->rconbufdone < 14)
+		return false;
+
+	plen = read_int(&pos, &len);
+	fprintf(stderr, "Reply is %zu bytes, packet size %" PRIi32 "\n", rcon->rconbufdone, plen + 4);
+	if (rcon->rconbufdone < plen + 4)
+		return false;
+	else
+		return true;
+}
+
+static bool
+read_packet(struct cfg *cfg, struct rcon *rcon, int32_t *id, int32_t *type, char **rmsg)
+{
+	char *pos = rcon->rconbuf;
+	size_t len = rcon->rconbufdone;
+	int32_t plen;
+
+	plen = read_int(&pos, &len);
+	*id = read_int(&pos, &len);
+	*type = read_int(&pos, &len);
+	*rmsg = NULL;
+
+	if (plen < 10) {
+		fprintf(stderr, "Invalid packet length: %" PRIi32 "\n", plen);
+		return false;
+	}
+
+	fprintf(stderr, "Remaining = %zu\n", len);
+	if (len > 2) {
+		char *msg;
+
+		msg = malloc(len - 1);
+		if (!msg) {
+			perror("malloc");
+			return false;
+		}
+
+		memcpy(msg, pos, len - 2);
+		msg[len - 2] = '\0';
+
+		*rmsg = msg;
+		pos += len - 2;
+		len = 2;
+	}
+
+	if (len < 2) {
+		fprintf(stderr, "Short message\n");
+		return false;
+	}
+
+	if (pos[0] != '\0' || pos[1] != '\0') {
+		fprintf(stderr, "Invalid trailer\n");
+		return false;
+	}
+
+	fprintf(stderr, "Response - len: %" PRIi32 ", id: %" PRIi32
+		", type: %" PRIi32 ", msg: %s\n",
+		plen, *id, *type, *rmsg);
+
+	return true;
+}
+
+static void
+rcon_stop_reply(struct cfg *cfg, struct uring_task *task, int res)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+	int32_t id;
+	int32_t type;
+	char *msg;
+
+	fprintf(stderr, "%s: result %i\n", __func__, res);
+	if (res < 0)
+		goto out;
+
+	rcon->rconbufdone += res;
+
+	/* FIXME: could be multiple packets */
+	if (packet_complete(cfg, rcon)) {
+		fprintf(stderr, "Packet complete\n");
+		read_packet(cfg, rcon, &id, &type, &msg);
+		if (id != 2) {
+			fprintf(stderr, "RCon stop cmd failed - unexpected reply id (%" PRIi32 ")\n", id);
+			goto out;
+		} else if (type != RCON_PACKET_RESPONSE) {
+			fprintf(stderr, "RCon stop cmd failed - unexpected reply type (%" PRIi32 ")\n", type);
+			goto out;
+		}
+		fprintf(stderr, "RCon stop successful (%s)\n", msg);
+		free(msg);
+
+	} else {
+		fprintf(stderr, "Packet not complete\n");
+		uring_read(cfg, &rcon->task, &rcon->rconbuf + rcon->rconbufdone,
+			   sizeof(rcon->rconbuf) - rcon->rconbufdone, 0, rcon_stop_reply);
+	}
+
+out:
+	uring_task_put(cfg, &rcon->task);
+}
+
+static void
+rcon_stop_sent(struct cfg *cfg, struct uring_task *task, int res)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+
+	fprintf(stderr, "%s: result %i\n", __func__, res);
+	if (res < 0) {
+		uring_task_put(cfg, &rcon->task);
+		return;
+	}
+
+	rcon->rconbufdone += res;
+	if (rcon->rconbufdone < rcon->rconbuflen) {
+		uring_write(cfg, &rcon->task, rcon->rconbuf + rcon->rconbufdone,
+			    rcon->rconbuflen - rcon->rconbufdone, rcon_stop_sent);
+		return;
+	}
+
+	fprintf(stderr, "%s: stop cmd sent\n", __func__);
+	rcon->rconbufdone = 0;
+	rcon->rconbuflen = 0;
+	uring_read(cfg, &rcon->task, &rcon->rconbuf, sizeof(rcon->rconbuf), 0, rcon_stop_reply);
+}
+
+static void
+rcon_login_reply(struct cfg *cfg, struct uring_task *task, int res)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+	int32_t id;
+	int32_t type;
+	char *msg;
+
+	fprintf(stderr, "%s: result %i\n", __func__, res);
+	if (res < 0)
+		goto out;
+
+	rcon->rconbufdone += res;
+
+	if (packet_complete(cfg, rcon)) {
+		fprintf(stderr, "Packet complete\n");
+		read_packet(cfg, rcon, &id, &type, &msg);
+		if (id != 1) {
+			fprintf(stderr, "RCon login failed - unexpected reply id (%" PRIi32 ")\n", id);
+			goto out;
+		} else if (type == RCON_PACKET_LOGIN_FAIL) {
+			fprintf(stderr, "RCon login failed - incorrect password\n");
+			goto out;
+		} else if (type != RCON_PACKET_LOGIN_OK) {
+			fprintf(stderr, "RCon login failed - unexpected reply type (%" PRIi32 ")\n", type);
+			goto out;
+		}
+		free(msg);
+		fprintf(stderr, "RCon login successful\n");
+		create_packet(cfg, rcon, 2, RCON_PACKET_COMMAND, "stop");
+		uring_write(cfg, &rcon->task, rcon->rconbuf, rcon->rconbuflen, rcon_stop_sent);
+
+	} else {
+		fprintf(stderr, "Packet not complete\n");
+		uring_read(cfg, &rcon->task, &rcon->rconbuf + rcon->rconbufdone,
+			   sizeof(rcon->rconbuf) - rcon->rconbufdone, 0, rcon_login_reply);
+	}
+
+	return;
+
+out:
+	uring_task_put(cfg, &rcon->task);
+}
+
+static void
+rcon_login_sent(struct cfg *cfg, struct uring_task *task, int res)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+
+	fprintf(stderr, "%s: result %i\n", __func__, res);
+	if (res < 0) {
+		uring_task_put(cfg, &rcon->task);
+		return;
+	}
+
+	rcon->rconbufdone += res;
+	if (rcon->rconbufdone < rcon->rconbuflen) {
+		uring_write(cfg, &rcon->task, rcon->rconbuf + rcon->rconbufdone,
+			    rcon->rconbuflen - rcon->rconbufdone, rcon_login_sent);
+		return;
+	}
+
+	fprintf(stderr, "%s: login sent\n", __func__);
+	rcon->rconbufdone = 0;
+	rcon->rconbuflen = 0;
+	uring_read(cfg, &rcon->task, &rcon->rconbuf, sizeof(rcon->rconbuf), 0, rcon_login_reply);
+}
+
+static void rcon_connect_next_rcon(struct cfg *cfg, struct rcon *rcon);
+
+static void
+rcon_connected(struct cfg *cfg, struct uring_task *task, int res)
+{
+	struct rcon *rcon = container_of(task, struct rcon, task);
+
+	fprintf(stderr, "%s: connected %i\n", __func__, res);
+	if (res < 0) {
+		rcon_connect_next_rcon(cfg, rcon);
+		return;
+	}
+
+	create_packet(cfg, rcon, 1, RCON_PACKET_LOGIN, rcon->server->rcon_password);
+	uring_write(cfg, &rcon->task, rcon->rconbuf, rcon->rconbuflen, rcon_login_sent);
+}
+
+/* FIXME: Parts of this could be shared with proxy.c, probably in server.c */
+static void
+rcon_connect_next_rcon(struct cfg *cfg, struct rcon *rcon)
+{
+        struct sockaddr_in46 *remote, *tmp;
+	struct server *scfg = rcon->server;
+        int sfd;
+        unsigned i = 0;
+
+again:
+        remote = NULL;
+        list_for_each_entry(tmp, &scfg->rcons, list) {
+                if (i == rcon->next_rcon) {
+                        remote = tmp;
+                        break;
+                }
+                i++;
+        }
+
+        if (!remote) {
+                fprintf(stderr, "No more rcon addresses to attempt\n");
+		uring_task_put(cfg, &rcon->task);
+                return;
+        }
+
+        rcon->next_rcon++;
+        rcon->rcon = *remote;
+	sockaddr_to_str(&rcon->rcon, rcon->rconstr, sizeof(rcon->rconstr));
+        fprintf(stderr, "%s: attempting rcon connection to %s (len %u)\n",
+                scfg->name, rcon->rconstr, rcon->rcon.addrlen);
+
+        sfd = socket(rcon->rcon.storage.ss_family, SOCK_STREAM, 0);
+        if (sfd < 0) {
+                perror("socket");
+                goto again;
+        }
+
+        uring_task_set_fd(&rcon->task, sfd);
+        uring_connect(cfg, &rcon->task, &rcon->rcon, rcon_connected);
+}
+
+void
+rcon_init(struct cfg *cfg, struct server *server)
+{
+	struct rcon *rcon;
+
+	if (!server)
+		return;
+
+	if (list_empty(&server->rcons) || !server->rcon_password)
+		return;
+
+	rcon = zmalloc(sizeof(*rcon));
+	if (!rcon)
+		perrordie("malloc");
+
+	uring_task_init(&rcon->task, "rcon", &server->task, rcon_free);
+	rcon->server = server;
+	server->rcon = rcon;
+
+	rcon_connect_next_rcon(cfg, rcon);
+}