loader.cc

/*
 * Copyright (C) 2013 Cloudius Systems, Ltd.
 *
 * This work is open source software, licensed under the terms of the
 * BSD license as described in the LICENSE file in the top-level directory.
 */

#include "fs/fs.hh"
#include <bsd/init.hh>
#include <bsd/net.hh>
#include <boost/format.hpp>
#include <boost/program_options.hpp>
#include <boost/algorithm/string.hpp>
#include <cctype>
#include <osv/elf.hh>
#include "arch-tls.hh"
#include <osv/debug.hh>
#include <osv/clock.hh>

#include "smp.hh"

#ifndef AARCH64_PORT_STUB
#include "drivers/acpi.hh"
#endif /* !AARCH64_PORT_STUB */

#include <osv/sched.hh>
#include <osv/barrier.hh>
#include "arch.hh"
#include "arch-setup.hh"
#include "osv/trace.hh"
#include <osv/power.hh>
#include <osv/rcu.hh>
#include <osv/mempool.hh>
#include <bsd/porting/networking.hh>
#include <bsd/porting/shrinker.h>
#include <bsd/porting/route.h>
#include <osv/dhcp.hh>
#include <osv/version.h>
#include <osv/run.hh>
#include <osv/shutdown.hh>
#include <osv/commands.hh>
#include <osv/boot.hh>
#include <osv/sampler.hh>
#include <osv/app.hh>
#include <osv/firmware.hh>
#include <dirent.h>
#include <iostream>
#include <fstream>

#include "drivers/zfs.hh"
#include "drivers/random.hh"
#include "drivers/console.hh"
#include "drivers/null.hh"

#include "libc/network/__dns.hh"

using namespace osv;
using namespace osv::clock::literals;

asm(".pushsection \".debug_gdb_scripts\", \"MS\",@progbits,1 \n"
    ".byte 1 \n"
    ".asciz \"scripts/loader.py\" \n"
    ".popsection \n");

elf::Elf64_Ehdr* elf_header __attribute__ ((aligned(8)));

size_t elf_size;
void* elf_start;
elf::tls_data tls_data;

boot_time_chart boot_time;

void setup_tls(elf::init_table inittab)
{
    tls_data = inittab.tls;
    sched::init_tls(tls_data);

    extern char tcb0[]; // defined by linker script
    arch_setup_tls(tcb0, tls_data);
}

extern "C" {
    void premain();
    void vfs_init(void);
    void mount_zfs_rootfs(void);
    void ramdisk_init(void);
}

void premain()
{
    arch_init_early_console();

    /* besides reporting the OSV version, this string has the function
       to check if the early console really works early enough,
       without depending on prior initialization. */
    debug_early("OSv " OSV_VERSION "\n");

    arch_init_premain();

    auto inittab = elf::get_init(elf_header);

    if (inittab.tls.start == nullptr) {
        debug_early("premain: failed to get TLS data from ELF\n");
        arch::halt_no_interrupts();
    }

    setup_tls(inittab);
    boot_time.event("TLS initialization");
    for (auto init = inittab.start; init < inittab.start + inittab.count; ++init) {
        (*init)();
    }
    boot_time.event(".init functions");
}

int main(int ac, char **av)
{
    smp_initial_find_current_cpu()->init_on_cpu();
    void main_cont(int ac, char** av);
    sched::init([=] { main_cont(ac, av); });
}

static bool opt_leak = false;
static bool opt_noshutdown = false;
bool opt_power_off_on_abort = false;
static bool opt_log_backtrace = false;
static bool opt_mount = true;
static bool opt_random = true;
static bool opt_init = true;
static std::string opt_console = "all";
static bool opt_verbose = false;
static std::string opt_chdir;
static bool opt_bootchart = false;
static std::vector<std::string> opt_ip;
static std::string opt_defaultgw;
static std::string opt_nameserver;
static std::chrono::nanoseconds boot_delay;
bool opt_assign_net = false;

static int sampler_frequency;
static bool opt_enable_sampler = false;

std::tuple<int, char**> parse_options(int ac, char** av)
{
    namespace bpo = boost::program_options;
    namespace bpos = boost::program_options::command_line_style;

    std::vector<const char*> args = { "osv" };

    // due to https://svn.boost.org/trac/boost/ticket/6991, we can't terminate
    // command line parsing on the executable name, so we need to look for it
    // ourselves

    auto nr_options = std::find_if(av, av + ac,
                                   [](const char* arg) { return arg[0] != '-'; }) - av;
    std::copy(av, av + nr_options, std::back_inserter(args));

    bpo::options_description desc("OSv options");
    desc.add_options()
        ("help", "show help text")
        ("sampler", bpo::value<int>(), "start stack sampling profiler")
        ("trace", bpo::value<std::vector<std::string>>(), "tracepoints to enable")
        ("trace-backtrace", "log backtraces in the tracepoint log")
        ("leak", "start leak detector after boot")
        ("nomount", "don't mount the file system")
        ("assign-net", "assign virtio network to the application")
        ("norandom", "don't initialize any random device")
        ("noshutdown", "continue running after main() returns")
	("power-off-on-abort", "use poweroff instead of halt if it's aborted")
        ("noinit", "don't run commands from /init")
        ("verbose", "be verbose, print debug messages")
        ("console", bpo::value<std::vector<std::string>>(), "select console driver")
        ("env", bpo::value<std::vector<std::string>>(), "set Unix-like environment variable (putenv())")
        ("cwd", bpo::value<std::vector<std::string>>(), "set current working directory")
        ("bootchart", "perform a test boot measuring a time distribution of the various operations\n")
        ("ip", bpo::value<std::vector<std::string>>(), "set static IP on NIC")
        ("defaultgw", bpo::value<std::string>(), "set default gateway address")
        ("nameserver", bpo::value<std::string>(), "set nameserver address")
        ("delay", bpo::value<float>()->default_value(0), "delay in seconds before boot")
    ;
    bpo::variables_map vars;
    // don't allow --foo bar (require --foo=bar) so we can find the first non-option
    // argument
    int style = bpos::unix_style & ~(bpos::long_allow_next | bpos::short_allow_next);
    try {
        bpo::store(bpo::parse_command_line(args.size(), args.data(), desc, style), vars);
    } catch(std::exception &e) {
        std::cout << e.what() << '\n';
        std::cout << desc << '\n';
        osv::poweroff();
    }
    bpo::notify(vars);

    if (vars.count("help")) {
        std::cout << desc << "\n";
    }

    if (vars.count("leak")) {
        opt_leak = true;
    }

    if (vars.count("noshutdown")) {
        opt_noshutdown = true;
    }

    if (vars.count("power-off-on-abort")) {
        opt_power_off_on_abort = true;
    }

    if (vars.count("assign-net")) {
        opt_assign_net = true;
    }

    if (vars.count("trace-backtrace")) {
        opt_log_backtrace = true;
    }

    if (vars.count("verbose")) {
        opt_verbose = true;
        enable_verbose();
    }

    if (vars.count("sampler")) {
        sampler_frequency = vars["sampler"].as<int>();
        opt_enable_sampler = true;
    }

    if (vars.count("bootchart")) {
        opt_bootchart = true;
    }

    if (vars.count("trace")) {
        auto tv = vars["trace"].as<std::vector<std::string>>();
        for (auto t : tv) {
            std::vector<std::string> tmp;
            boost::split(tmp, t, boost::is_any_of(" ,"), boost::token_compress_on);
            for (auto t : tmp) {
                enable_tracepoint(t);
            }
        }
    }
    opt_mount = !vars.count("nomount");
    opt_random = !vars.count("norandom");
    opt_init = !vars.count("noinit");

    if (vars.count("console")) {
        auto v = vars["console"].as<std::vector<std::string>>();
        if (v.size() > 1) {
            printf("Ignoring '--console' options after the first.");
        }
        opt_console = v.front();
        debug("console=%s\n", opt_console);
    }

    if (vars.count("env")) {
        for (auto t : vars["env"].as<std::vector<std::string>>()) {
            debug("Setting in environment: %s\n", t);
            putenv(strdup(t.c_str()));
        }
    }

    if (vars.count("cwd")) {
        auto v = vars["cwd"].as<std::vector<std::string>>();
        if (v.size() > 1) {
            printf("Ignoring '--cwd' options after the first.");
        }
        opt_chdir = v.front();
    }

    if (vars.count("ip")) {
        opt_ip = vars["ip"].as<std::vector<std::string>>();
    }

    if (vars.count("defaultgw")) {
        opt_defaultgw = vars["defaultgw"].as<std::string>();
    }

    if (vars.count("nameserver")) {
        opt_nameserver = vars["nameserver"].as<std::string>();
    }

    boot_delay = std::chrono::duration_cast<std::chrono::nanoseconds>(1_s * vars["delay"].as<float>());

    av += nr_options;
    ac -= nr_options;
    return std::make_tuple(ac, av);
}

// return the std::string and the commands_args poiting to them as a move
std::vector<std::vector<std::string> > prepare_commands(int ac, char** av)
{
    if (ac == 0) {
        puts("This image has an empty command line. Nothing to run.");
#ifdef AARCH64_PORT_STUB
        abort(); // a good test for the backtrace code
#endif
        osv::poweroff();
    }
    std::vector<std::vector<std::string> > commands;
    std::string line = std::string("");
    bool ok;

    // concatenate everything
    for (auto i = 0; i < ac; i++) {
        std::string arg("");
        char* env = strchr(av[i],'$');
        if (av[i] && env) {
            *env = '\0';
            env++;
            auto tmp = getenv(env);
            arg = av[i];
            if (tmp) {
                arg += tmp;
            }
        } else {
            arg = av[i];
        }
        line += arg + " ";
    }

    commands = osv::parse_command_line(line, ok);

    if (!ok) {
        puts("Failed to parse command line.");
        osv::poweroff();
    }

    return commands;
}

static std::string read_file(std::string fn)
{
  std::ifstream in(fn, std::ios::in | std::ios::binary);
  return std::string((std::istreambuf_iterator<char>(in)),
          std::istreambuf_iterator<char>());
}

void* do_main_thread(void *_main_args)
{
    auto main_args = static_cast<std::tuple<int,char**> *>(_main_args);

    if (!arch_setup_console(opt_console)) {
        abort("Unknown console:%s\n", opt_console.c_str());
    }
    arch_init_drivers();
    console::console_init();
    nulldev::nulldev_init();
    if (opt_random) {
        randomdev::randomdev_init();
    }
    boot_time.event("drivers loaded");

    if (opt_mount) {
        zfsdev::zfsdev_init();
        mount_zfs_rootfs();
        bsd_shrinker_init();
    }
    boot_time.event("ZFS mounted");

    bool has_if = false;
    osv::for_each_if([&has_if] (std::string if_name) {
        if (if_name == "lo0")
            return;

        has_if = true;
        // Start DHCP by default and wait for an IP
        if (osv::start_if(if_name, "0.0.0.0", "255.255.255.0") != 0 ||
            osv::ifup(if_name) != 0)
            debug("Could not initialize network interface.\n");
    });
    if (has_if) {
        if (opt_ip.size() == 0) {
            dhcp_start(true);
        } else {
            for (auto t : opt_ip) {
                std::vector<std::string> tmp;
                boost::split(tmp, t, boost::is_any_of(" ,"), boost::token_compress_on);
                if (tmp.size() != 3)
                    abort("incorrect parameter on --ip");

                printf("%s: %s\n",tmp[0].c_str(),tmp[1].c_str());

                if (osv::start_if(tmp[0], tmp[1], tmp[2]) != 0)
                    debug("Could not initialize network interface.\n");
            }
            if (opt_defaultgw.size() != 0) {
                osv_route_add_network("0.0.0.0",
                                      "0.0.0.0",
                                      opt_defaultgw.c_str());
            }
            if (opt_nameserver.size() != 0) {
                auto addr = boost::asio::ip::address_v4::from_string(opt_nameserver);
                osv::set_dns_config({addr}, std::vector<std::string>());
            }
        }
    }

    std::string if_ip;
    auto nr_ips = 0;

    osv::for_each_if([&](std::string if_name) {
        if (if_name == "lo0")
            return;
        if_ip = osv::if_ip(if_name);
        nr_ips++;
    });
    if (nr_ips == 1) {
       setenv("OSV_IP", if_ip.c_str(), 1);
    }

    if (!opt_chdir.empty()) {
        debug("Chdir to: '%s'\n", opt_chdir.c_str());

        if (chdir(opt_chdir.c_str()) != 0) {
            perror("chdir");
        }
        debug("chdir done\n");
    }

    if (opt_leak) {
        debug("Enabling leak detector.\n");
        memory::tracker_enabled = true;
    }

    boot_time.event("Total time");

    if (opt_bootchart) {
        boot_time.print_chart();
    }

    auto commands = prepare_commands(std::get<0>(*main_args), std::get<1>(*main_args));

    // Run command lines in /init/* before the manual command line
    if (opt_init) {
        std::vector<std::vector<std::string>> init_commands;
        struct dirent **namelist;
        int count = scandir("/init", &namelist, NULL, alphasort);
        for (int i = 0; i < count; i++) {
            if (!strcmp(".", namelist[i]->d_name) ||
                    !strcmp("..", namelist[i]->d_name)) {
                continue;
            }
            std::string fn("/init/");
            fn += namelist[i]->d_name;
            auto cmdline = read_file(fn);
            debug("Running from %s: %s\n", fn.c_str(), cmdline.c_str());
            bool ok;
            auto new_commands = osv::parse_command_line(cmdline, ok);
            free(namelist[i]);
            if (ok) {
                init_commands.insert(init_commands.end(),
                        new_commands.begin(), new_commands.end());
            }
        }
        free(namelist);
        commands.insert(commands.begin(),
                 init_commands.begin(), init_commands.end());
    }

    // run each payload in order
    // Our parse_command_line() leaves at the end of each command a delimiter,
    // can be '&' if we need to run this command in a new thread, or ';' or
    // empty otherwise, to run in this thread. '&!' is the same as '&', but
    // doesn't wait for the thread to finish before exiting OSv.
    std::vector<shared_app_t> detached;
    for (auto &it : commands) {
        std::vector<std::string> newvec(it.begin(), std::prev(it.end()));
        auto suffix = it.back();
        try {
            bool background = (suffix == "&") || (suffix == "&!");
            auto app = application::run(newvec);
            if (suffix == "&!") {
                detached.push_back(app);
            } else if (!background) {
                app->join();
            }
        } catch (const launch_error& e) {
            std::cerr << e.what() << ". Powering off.\n";
            osv::poweroff();
        }
    }

    for (auto app : detached) {
        app->request_termination();
        debug("Requested termination of %s, waiting...\n", app->get_command());
    }

    application::join_all();
    return nullptr;
}

void main_cont(int ac, char** av)
{
    osv::firmware_probe();

    debug("Firmware vendor: %s\n", osv::firmware_vendor().c_str());

    new elf::program();
    elf::get_program()->set_search_path({"/", "/usr/lib"});
    std::vector<std::vector<std::string> > cmds;

    std::tie(ac, av) = parse_options(ac, av);

    smp_launch();
    setenv("OSV_CPUS", std::to_string(sched::cpus.size()).c_str(), 1);
    boot_time.event("SMP launched");

    auto end = osv::clock::uptime::now() + boot_delay;
    while (end > osv::clock::uptime::now()) {
        // spin
    }

    memory::enable_debug_allocator();

#ifndef AARCH64_PORT_STUB
    acpi::init();
#endif /* !AARCH64_PORT_STUB */

    if (sched::cpus.size() > sched::max_cpus) {
        printf("Too many cpus, can't boot with greater than %u cpus.\n", sched::max_cpus);
        poweroff();
    }

    enable_trace();
    if (opt_log_backtrace) {
        // can only do this after smp_launch, otherwise the IDT is not initialized,
        // and backtrace_safe() fails as soon as we get an exception
        enable_backtraces();
    }
    sched::init_detached_threads_reaper();

    bsd_init();

    vfs_init();
    boot_time.event("VFS initialized");
    ramdisk_init();

    net_init();
    boot_time.event("Network initialized");

    arch::irq_enable();

#ifndef AARCH64_PORT_STUB
    if (opt_enable_sampler) {
        prof::config config{std::chrono::nanoseconds(1000000000 / sampler_frequency)};
        prof::start_sampler(config);
    }
#endif /* !AARCH64_PORT_STUB */

    // multiple programs can be run -> separate their arguments

    pthread_t pthread;
    // run the payload in a pthread, so pthread_self() etc. work
    std::tuple<int,char**> main_args = std::make_tuple(ac,av);
    pthread_create(&pthread, nullptr, do_main_thread, (void *) &main_args);
    void* retval;
    pthread_join(pthread, &retval);

    if (opt_noshutdown) {
        // If the --noshutdown option is given, continue running the system,
        // and whatever threads might be running, even after main returns
        debug("main() returned.\n");
        sched::thread::wait_until([] { return false; });
    }

    if (memory::tracker_enabled) {
        debug("Leak testing done. Please use 'osv leak show' in gdb to analyze results.\n");
        osv::halt();
    } else {
        osv::shutdown();
    }
}

int __argc;
char** __argv;