ish/app/UpgradeRootViewController.m

//
//  UpgradeRootViewController.m
//  iSH
//
//  Created by Theodore Dubois on 11/27/21.
//

#import "UpgradeRootViewController.h"
#import "AppDelegate.h"
#import "TerminalView.h"
#import "CurrentRoot.h"
#include "kernel/calls.h"
#include "kernel/init.h"
#include "fs/devices.h"

@interface UpgradeRootViewController ()

@property (weak, nonatomic) IBOutlet TerminalView *terminalView;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *upgradeButton;
@property (nonatomic) Terminal *terminal;
@property (nonatomic) struct tty *tty;
@property (nonatomic) int upgradePid;

@end

@implementation UpgradeRootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
#if !ISH_LINUX
    [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(processExited:) name:ProcessExitedNotification object:nil];

    lock(&pids_lock);
    current = pid_get_task(1); // pray
    unlock(&pids_lock);
    self.terminal = [Terminal createPseudoTerminal:&self->_tty];
    current = NULL;
    
    self.terminalView.terminal = self.terminal;
#endif
    self.upgradeButton.enabled = NO;
    if (FsNeedsRepositoryUpdate()) {
        self.upgradeButton.enabled = YES;
        [self printToTerminal:@"# /sbin/apk upgrade"];
    } else {
        [self showAlertWithTitle:@"fuck" message:@"No update needed. If you're seeing this message, there's a bug."];
    }
}

- (void)printToTerminal:(NSString *)message, ... {
    va_list args;
    va_start(args, message);
    message = [[NSString alloc] initWithFormat:message arguments:args];
    message = [message stringByReplacingOccurrencesOfString:@"\n" withString:@"\r\n"];
    [self.terminal sendOutput:message.UTF8String length:(int)[message lengthOfBytesUsingEncoding:NSUTF8StringEncoding]];
}

- (void)showAlertWithTitle:(NSString *)title message:(NSString *)message, ... {
    va_list args;
    va_start(args, message);
    message = [[NSString alloc] initWithFormat:message arguments:args];
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    [alert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
    [self presentViewController:alert animated:YES completion:nil];
}

#if !ISH_LINUX
- (void)processExited:(NSNotification *)notif {
    int pid = [notif.userInfo[@"pid"] intValue];
    if (pid != self.upgradePid)
        return;
    self.upgradePid = 0;
    [self setDismissable:YES];
    int code = [notif.userInfo[@"code"] intValue];
    [self printToTerminal:@"\n"];
    if (code != 0) {
        [self printToTerminal:@"Upgrade failed with exit status %d.\nPlease send a bug report.\n", code];
    } else {
        lock(&pids_lock);
        current = pid_get_task(1); // pray
        unlock(&pids_lock);
        FsUpdateRepositories();
        current = NULL;
        [self printToTerminal:@"Upgrade complete!\nIf anything that was working before stops working, please send a bug report.\n"];
    }
    [self.terminal destroy];
    self.terminal = nil;
}
#endif

- (int)startUpgrade {
    if (self.upgradePid != 0)
        return _EEXIST;
#if !ISH_LINUX
    int err = become_new_init_child();
    if (err < 0)
        return err;
    FsUpdateOnlyRepositoriesFile();
    NSString *stdioFile = [NSString stringWithFormat:@"/dev/pts/%d", self.tty->num];
    err = create_stdio(stdioFile.fileSystemRepresentation, TTY_PSEUDO_SLAVE_MAJOR, self.tty->num);
    if (err < 0)
        return err;
    err = do_execve("/sbin/apk", 2, "/sbin/apk\0upgrade\0", "TERM=xterm-256color\0");
    if (err < 0)
        return err;
    self.upgradePid = current->pid;
    task_start(current);
    current = NULL;
    return 0;
#else
    return _ENOSYS;
#endif
}

- (IBAction)upgrade:(id)sender {
    self.upgradeButton.enabled = NO;
    [self setDismissable:NO];
    [self printToTerminal:@"\n"];
    int err = [self startUpgrade];
    if (err < 0) {
        [self showAlertWithTitle:@"Failed to start upgrade" message:@"error %d", err];
    }
}

- (void)setDismissable:(BOOL)dismissable {
    [self.navigationItem setHidesBackButton:!dismissable animated:YES];
    self.navigationController.interactivePopGestureRecognizer.enabled = dismissable;
    if (@available(iOS 13, *)) {
        self.modalInPresentation = !dismissable;
    }
}

- (void)dealloc {
    [self.terminal destroy];
    if (self.tty != NULL)
        tty_release(self.tty);
}

@end