Mach ports client and server

client.c

// cc client.c -o client
#include <stdio.h>
#include <stdlib.h>
#include <mach/mach.h>
#include <bootstrap.h>
#include <string.h>
#include <unistd.h>

typedef struct {
	mach_msg_header_t header;
	char body_str[32];
} message;

int main(void) {
	int kr;
	mach_port_name_t task = mach_task_self();

	// Create bootstrap port
	mach_port_t bootstrap_port;
	kr = task_get_special_port(task, TASK_BOOTSTRAP_PORT, &bootstrap_port);

	if (kr != KERN_SUCCESS) {
		return -1;
	}

	printf("[*] Got special bootstrap port: 0x%x\n", bootstrap_port);

	// Get port to send to the com.echo.macherino.as-a-service and store it in port
	mach_port_t port;
	kr = bootstrap_look_up(bootstrap_port, "com.echo.macherino.as-a-service", &port);

	if (kr != KERN_SUCCESS) {
		return -2;
	}

	printf("[*] Port for com.echo.macherino.as-a-service: 0x%x\n", port);

	// Create the message for sending
	message msg = {0};
	msg.header.msgh_remote_port = port;

	msg.header.msgh_bits = MACH_MSGH_BITS_SET(
		MACH_MSG_TYPE_COPY_SEND,
		0,
		0,
		0);
	msg.header.msgh_id = 4;
	msg.header.msgh_size = sizeof(msg);

	strcpy(msg.body_str, "test message");

	mach_msg_return_t ret = mach_msg(
		(mach_msg_header_t *)&msg,
		MACH_SEND_MSG,
		sizeof(msg),
		0,
		MACH_PORT_NULL,
		MACH_MSG_TIMEOUT_NONE,
		MACH_PORT_NULL);
		
	return ret;
}

server.c

// cc server.c -o server
#include <bootstrap.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <mach/mach.h>

typedef struct {
	mach_msg_header_t header;
	char body_str[32];
	mach_msg_trailer_t trailer;
} message;

mach_msg_return_t receive_msg(mach_port_name_t);

int main(void) {
	int kr;
	mach_port_t task = mach_task_self();

	mach_port_name_t recv_port;
	kr = mach_port_allocate(task, MACH_PORT_RIGHT_RECEIVE, &recv_port);

	if (kr != KERN_SUCCESS)
		return EXIT_FAILURE;

	printf("[*] Created port with MACH_PORT_RIGHT_RECEIVE: 0x%x\n", recv_port);

	kr = mach_port_insert_right(task, recv_port, recv_port, MACH_MSG_TYPE_MAKE_SEND);

	if (kr != KERN_SUCCESS)
		return EXIT_FAILURE;

	printf("[*] Added send right to the port\n");

	mach_port_t bootstrap_port;
	kr = task_get_special_port(task, TASK_BOOTSTRAP_PORT, &bootstrap_port);

	printf("[*] Got bootstrap port: 0x%x\n", bootstrap_port);

	if (kr != KERN_SUCCESS)
		return EXIT_FAILURE;

	kr = bootstrap_check_in(bootstrap_port, "com.echo.macherino.as-a-service", &recv_port);

	if (kr != KERN_SUCCESS)
		return EXIT_FAILURE;

	printf("[*] Registered our service\n");
		

	while(true) {
		mach_msg_return_t ret = receive_msg(recv_port);
	}
}

mach_msg_return_t receive_msg(mach_port_name_t recv_port) {
	message msg = {0};

	mach_msg_return_t ret = mach_msg(
		(mach_msg_header_t *)&msg,
		MACH_RCV_MSG,
		0,
		sizeof(msg),
		recv_port,
		MACH_MSG_TIMEOUT_NONE,
		MACH_PORT_NULL);

	if (ret != MACH_MSG_SUCCESS)
		return ret;

	printf("got message\n");
	printf("\tid: %d\n", msg.header.msgh_id);
	printf("\tbodys: %s\n", msg.body_str);

	return MACH_MSG_SUCCESS;
}
	

Server:

$ ./server
[*] Created port with MACH_PORT_RIGHT_RECEIVE: 0xb03
[*] Added send right to the port
[*] Got bootstrap port: 0x707
[*] Registered our service
got message
	id: 4
	bodys: test message

Client:

$ ./client
[*] Got special bootstrap port: 0x707
[*] Port for com.echo.macherino.as-a-service: 0x1203