Add MCPI_API_PORT

docs/COMMAND_LINE.md

@@ -30,6 +30,9 @@ The world used will always be re-created on start and uses a hard-coded seed.
 ### ``MCPI_DEBUG``
 This enables debug logging if it is set.
 
+### ``MCPI_API_PORT``
+This configures the API to use a different port (the default is 4711).
+
 ### Client Mode Only
 If any of the following variables aren't set, one configuration dialog will open on startup for each unset variable.
 

mods/src/misc/misc.c

@@ -1,6 +1,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
 
 #include <GLES/gl.h>
 
@@ -309,6 +311,25 @@ static void HumanoidMobRenderer_render_injection(unsigned char *model_renderer,
     *(bool *) (model + HumanoidModel_is_sneaking_property_offset) = 0;
 }
 
+// Custom API Port
+HOOK(bind, int, (int sockfd, const struct sockaddr *addr, socklen_t addrlen)) {
+    const struct sockaddr *new_addr = addr;
+    struct sockaddr_in in_addr;
+    if (addr->sa_family == AF_INET) {
+        in_addr = *(const struct sockaddr_in *) new_addr;
+        if (in_addr.sin_port == ntohs(4711)) {
+            const char *new_port_str = getenv("MCPI_API_PORT");
+            long int new_port;
+            if (new_port_str != NULL && (new_port = strtol(new_port_str, NULL, 0)) != 0L) {
+                in_addr.sin_port = htons(new_port);
+            }
+        }
+        new_addr = (const struct sockaddr *) &in_addr;
+    }
+    ensure_bind();
+    return (*real_bind)(sockfd, new_addr, addrlen);
+}
+
 // Init
 static void nop() {
 }