send and receive packets

src/main.c

@@ -5,6 +5,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <stdint.h>
 
 const char *LOCALHOST = "127.0.0.1";
 
@@ -22,12 +23,10 @@ typedef struct {
 
 int read_env_int(const char *var) {
     const char* port_str = getenv(var);
-
     if (port_str == NULL) {
         fprintf(stderr, "error: %s environment variable not set.\n", var);
         exit(EXIT_FAILURE);
     }
-
     char* endptr;
     long val = strtol(port_str, &endptr, 10);
     if (endptr == port_str || *endptr != '\0') {
@@ -52,13 +51,14 @@ int rcon_connect(int port) {
 
     if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
         perror("connection failed");
+        close(sockfd);
         exit(EXIT_FAILURE);
     }
+
     printf("connected to rcon server\n");
     return sockfd;
 }
 
-
 void send_packet(int sockfd, int32_t id, int32_t type, const char *body) {
     int body_len = strlen(body);
     int32_t size = 10 + body_len; // 4 (id) + 4 (type) + body + 2 (null terminators)
@@ -76,7 +76,6 @@ int recv_packet(int sockfd, rcon_packet_t *packet) {
     if (recv(sockfd, &packet->id, sizeof(int32_t), 0) <= 0) { return -1; }
     if (recv(sockfd, &packet->type, sizeof(int32_t), 0) <= 0) { return -1; }
 
-    // read body (size - 10 bytes for id, type, and two null terminators)
     int body_size = packet->size - 10;
     if (body_size > 0 && body_size < sizeof(packet->body)) {
         if (recv(sockfd, packet->body, body_size + 2, 0) <= 0) {
@@ -108,27 +107,28 @@ int rcon_authenticate(int sockfd, const char *password) {
     return 0;
 }
 
-char* rcon_command(int sockfd, const char *command) {
-    static char result[8192];
+char* rcon_command_multipacket(int sockfd, const char *command) {
+    static char result[65536];
     result[0] = '\0';
 
-    send_packet(sockfd, 2, SERVERDATA_EXECCOMMAND, command);
+    int cmd_id = 100;
+    int dummy_id = 101;
 
-    // Handle multi-packet responses
+    send_packet(sockfd, cmd_id, SERVERDATA_EXECCOMMAND, command);
+    send_packet(sockfd, dummy_id, SERVERDATA_EXECCOMMAND, "");
+
+    // read packets until we get the dummy response
     while (1) {
         rcon_packet_t response;
         if (recv_packet(sockfd, &response) < 0) {
             perror("failed to receive command response\n");
             return NULL;
         }
-
-        if (response.type == SERVERDATA_RESPONSE_VALUE) {
+        if (response.id == dummy_id) {
+            break;
+        }
+        if (response.type == SERVERDATA_RESPONSE_VALUE && response.id == cmd_id) {
             strncat(result, response.body, sizeof(result) - strlen(result) - 1);
-
-            // Check if response is complete (body length < 4096)
-            if (strlen(response.body) < 4096) {
-                break;
-            }
         }
     }
 
@@ -153,10 +153,14 @@ int main(int argc, char **argv) {
         exit(EXIT_FAILURE);
     }
 
-    // example
-    char *response = rcon_command(sockfd, "help");
+    const char *get_player_positions_cmd = "execute as @a run data get entity @s Pos";
+    char *response = rcon_command_multipacket(sockfd, get_player_positions_cmd);
+
     if (response) {
-        printf("Response:\n%s\n", response);
+        printf("\n=== player positions ===\n");
+        printf("%s\n", response);
+    } else {
+        perror("failed to get player positions\n");
     }
 
     close(sockfd);