subsystem myipc 500; // Arbitrary name and iduserprefix USERPREF; // Prefix for created functions in the clientserverprefix SERVERPREF; // Prefix for created functions in the server#include<mach/mach_types.defs>#include<mach/std_types.defs>simpleroutineSubtract(server_port : mach_port_t;n1 : uint32_t;n2 : uint32_t);
/* Description of this subsystem, for use in direct RPC */conststruct SERVERPREFmyipc_subsystem SERVERPREFmyipc_subsystem = {myipc_server_routine,500, // start ID501, // end ID(mach_msg_size_t)sizeof(union __ReplyUnion__SERVERPREFmyipc_subsystem),(vm_address_t)0,{{ (mig_impl_routine_t) 0,// Function to call(mig_stub_routine_t) _XSubtract,3,0, (routine_arg_descriptor_t)0, (mach_msg_size_t)sizeof(__Reply__Subtract_t)},}};
/* Description of this subsystem, for use in direct RPC */externconststruct SERVERPREFmyipc_subsystem {mig_server_routine_t server; /* Server routine */mach_msg_id_t start; /* Min routine number */mach_msg_id_t end; /* Max routine number + 1 */unsignedint maxsize; /* Max msg size */vm_address_t reserved; /* Reserved */struct routine_descriptor /* Array of routine descriptors */routine[1];} SERVERPREFmyipc_subsystem;
// gcc myipc_server.c myipcServer.c -o myipc_server#include<stdio.h>#include<mach/mach.h>#include<servers/bootstrap.h>#include"myipcServer.h"kern_return_tSERVERPREFSubtract(mach_port_t server_port,uint32_t n1,uint32_t n2){printf("Received: %d - %d = %d\n", n1, n2, n1 - n2);return KERN_SUCCESS;}intmain() {mach_port_t port;kern_return_t kr;// Register the mach servicekr =bootstrap_check_in(bootstrap_port,"xyz.hacktricks.mig",&port);if (kr != KERN_SUCCESS) {printf("bootstrap_check_in() failed with code 0x%x\n", kr);return1;}// myipc_server is the function that handles incoming messages (check previous exlpanation)mach_msg_server(myipc_server,sizeof(union __RequestUnion__SERVERPREFmyipc_subsystem), port, MACH_MSG_TIMEOUT_NONE);}
macOS IPC: Inter-Process Communication
macOS MIG: Mach Interface Generator
Mach Interface Generator (MIG) is a tool used to define inter-process communication (IPC) for macOS. It generates client-side and server-side code for message-based IPC. MIG is commonly used in macOS kernel programming for defining system calls and handling IPC between user-space and kernel-space.
To use MIG, you need to define an interface definition file (.defs) that specifies the messages and data structures exchanged between processes. This file is then processed by MIG to generate the necessary C code for IPC.
Here is a basic example of using MIG for IPC in macOS:
Define the interface in a .defs file.
Run MIG on the .defs file to generate C code.
Include the generated C code in your client and server applications.
Use the generated functions to send and receive messages between processes.
By leveraging MIG, developers can easily implement secure and efficient IPC mechanisms in macOS applications.
For more information on MIG and IPC in macOS, refer to the official Apple documentation.
#include<stdio.h>#include<mach/mach.h>#include"myipc.h"intmain() {mach_port_t server_port;kern_return_t kr; kr =bootstrap_look_up(bootstrap_port,"com.example.myipcserver",&server_port);if (kr != KERN_SUCCESS) {printf("Failed to look up server port\n");return1; }myipc_server_routine(server_port);return0;}
// gcc myipc_client.c myipcUser.c -o myipc_client#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<mach/mach.h>#include<servers/bootstrap.h>#include"myipcUser.h"intmain() {// Lookup the receiver port using the bootstrap server.mach_port_t port;kern_return_t kr =bootstrap_look_up(bootstrap_port,"xyz.hacktricks.mig",&port);if (kr != KERN_SUCCESS) {printf("bootstrap_look_up() failed with code 0x%x\n", kr);return1;}printf("Port right name %d\n", port);USERPREFSubtract(port,40,2);}
