| // Copyright 2019 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/developer/sshd-host/service.h" |
| |
| #include <arpa/inet.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <fuchsia/boot/cpp/fidl.h> |
| #include <lib/async-loop/cpp/loop.h> |
| #include <lib/async-loop/default.h> |
| #include <lib/async/cpp/wait.h> |
| #include <lib/async/default.h> |
| #include <lib/fdio/directory.h> |
| #include <lib/fdio/fd.h> |
| #include <lib/fdio/fdio.h> |
| #include <lib/fdio/io.h> |
| #include <lib/fdio/spawn.h> |
| #include <lib/sys/cpp/component_context.h> |
| #include <lib/sys/cpp/service_directory.h> |
| #include <lib/syslog/cpp/macros.h> |
| #include <lib/zx/job.h> |
| #include <lib/zx/process.h> |
| #include <netdb.h> |
| #include <netinet/in.h> |
| #include <sys/socket.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #include <memory> |
| #include <vector> |
| |
| #include <fbl/string_printf.h> |
| #include <fbl/unique_fd.h> |
| |
| #include "src/lib/files/glob.h" |
| #include "src/lib/fsl/tasks/fd_waiter.h" |
| #include "src/lib/fxl/macros.h" |
| #include "src/lib/fxl/strings/string_printf.h" |
| #include "src/sys/lib/chrealm/chrealm.h" |
| |
| const auto kSshdPath = "/pkg/bin/sshd"; |
| const char* kSshdArgv[] = {kSshdPath, "-ie", "-f", "/config/data/sshd_config", nullptr}; |
| |
| namespace sshd_host { |
| zx_status_t provision_authorized_keys_from_bootloader_file( |
| std::shared_ptr<sys::ServiceDirectory> service_directory) { |
| zx_status_t status; |
| fuchsia::boot::ItemsSyncPtr boot_items; |
| status = service_directory->Connect(boot_items.NewRequest()); |
| if (status != ZX_OK) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: failed to connect to boot items service: " |
| << zx_status_get_string(status); |
| return status; |
| } |
| |
| zx::vmo vmo; |
| status = boot_items->GetBootloaderFile(std::string(kAuthorizedKeysBootloaderFileName.data(), |
| kAuthorizedKeysBootloaderFileName.size()), |
| &vmo); |
| if (status != ZX_OK) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: GetBootloaderFile failed with: " |
| << zx_status_get_string(status); |
| return status; |
| } |
| |
| if (!vmo.is_valid()) { |
| FX_LOGS(INFO) << "Provisioning keys from boot item: bootloader file not found: " |
| << kAuthorizedKeysBootloaderFileName; |
| return ZX_ERR_NOT_FOUND; |
| } |
| |
| uint64_t size; |
| status = vmo.get_property(ZX_PROP_VMO_CONTENT_SIZE, &size, sizeof(size)); |
| if (status != ZX_OK) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: unable to get file size: " |
| << zx_status_get_string(status); |
| return status; |
| } |
| |
| auto buffer = std::make_unique<uint8_t[]>(size); |
| |
| status = vmo.read(buffer.get(), 0, size); |
| if (status != ZX_OK) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: failed to read file: " |
| << zx_status_get_string(status); |
| return status; |
| } |
| |
| if (mkdir(kSshDirectory, 0700) && errno != EEXIST) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: failed to create directory: " |
| << kSshDirectory << " Error: " << strerror(errno); |
| return ZX_ERR_IO; |
| } |
| |
| fbl::unique_fd kfd(open(kAuthorizedKeysPath, O_CREAT | O_EXCL | O_WRONLY)); |
| if (!kfd) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: open failed: " << kAuthorizedKeysPath |
| << " error: " << strerror(errno); |
| return errno == EEXIST ? ZX_ERR_ALREADY_EXISTS : ZX_ERR_IO; |
| } |
| |
| if (write(kfd.get(), buffer.get(), size) != static_cast<ssize_t>(size)) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: write failed: " << strerror(errno); |
| return ZX_ERR_IO; |
| } |
| |
| fsync(kfd.get()); |
| |
| if (close(kfd.release())) { |
| FX_LOGS(ERROR) << "Provisioning keys from boot item: close failed: " << strerror(errno); |
| return ZX_ERR_IO; |
| } |
| |
| FX_LOGS(INFO) << "Provisioning keys from boot item: authorized_keys provisioned"; |
| return ZX_OK; |
| } |
| |
| zx_status_t make_child_job(const zx::job& parent, std::string name, zx::job* job) { |
| zx_status_t s; |
| if ((s = zx::job::create(parent, 0, job)) != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to create child job; parent = " << parent.get(); |
| return s; |
| } |
| |
| if ((s = job->set_property(ZX_PROP_NAME, name.data(), name.size())) != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to set name of child job; job = " << job->get(); |
| return s; |
| } |
| if ((s = job->replace(kChildJobRights, job)) != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to set rights on child job; job = " << job->get(); |
| return s; |
| } |
| |
| return ZX_OK; |
| } |
| |
| Service::Service(uint16_t port) : port_(port) { |
| sock_ = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP); |
| if (sock_ < 0) { |
| FX_LOGS(ERROR) << "Failed to create socket: " << strerror(errno); |
| exit(1); |
| } |
| |
| const struct sockaddr_in6 addr { |
| .sin6_family = AF_INET6, .sin6_port = htons(port_), .sin6_addr = in6addr_any, |
| }; |
| if (bind(sock_, reinterpret_cast<const sockaddr*>(&addr), sizeof addr) < 0) { |
| FX_LOGS(ERROR) << "Failed to bind to " << port_ << ": " << strerror(errno); |
| exit(1); |
| } |
| |
| FX_SLOG(INFO, "listen() for inbound SSH connections", "port", (int)port_); |
| if (listen(sock_, 10) < 0) { |
| FX_LOGS(ERROR) << "Failed to listen: " << strerror(errno); |
| exit(1); |
| } |
| |
| std::string job_name = fxl::StringPrintf("tcp:%d", port); |
| if (make_child_job(*zx::job::default_job(), job_name, &job_) != ZX_OK) { |
| exit(1); |
| } |
| |
| Wait(); |
| } |
| |
| Service::~Service() { |
| for (auto& waiter : process_waiters_) { |
| zx_status_t s; |
| if ((s = zx_task_kill(waiter->object())) != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed kill child task"; |
| } |
| if ((s = zx_handle_close(waiter->object())) != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed close child handle"; |
| } |
| } |
| } |
| |
| void Service::Wait() { |
| waiter_.Wait( |
| [this](zx_status_t /*success*/, uint32_t /*events*/) { |
| struct sockaddr_in6 peer_addr {}; |
| socklen_t peer_addr_len = sizeof(peer_addr); |
| FX_SLOG(INFO, "Waiting for next connection"); |
| int conn = accept(sock_, reinterpret_cast<struct sockaddr*>(&peer_addr), &peer_addr_len); |
| if (conn < 0) { |
| if (errno == EPIPE) { |
| FX_LOGS(ERROR) << "The netstack died. Terminating."; |
| exit(1); |
| } else { |
| FX_LOGS(ERROR) << "Failed to accept: " << strerror(errno); |
| // Wait for another connection. |
| Wait(); |
| } |
| return; |
| } |
| std::string peer_name = "unknown"; |
| char host[NI_MAXHOST]; |
| char port[NI_MAXSERV]; |
| if (int res = |
| getnameinfo(reinterpret_cast<struct sockaddr*>(&peer_addr), peer_addr_len, host, |
| sizeof(host), port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV); |
| res == 0) { |
| peer_name = fxl::StringPrintf("%s:%s", host, port); |
| } else { |
| FX_LOGS(WARNING) |
| << "Error from getnameinfo(.., NI_NUMERICHOST | NI_NUMERICSERV) for peer address: " |
| << gai_strerror(res); |
| } |
| Launch(conn, peer_name); |
| Wait(); |
| }, |
| sock_, POLLIN); |
| } |
| |
| void Service::Launch(int conn, const std::string& peer_name) { |
| FX_SLOG(INFO, "accepted connection", "remote", peer_name.c_str()); |
| // Create a new job to run the child in. |
| zx::job child_job; |
| |
| if (make_child_job(job_, peer_name, &child_job) != ZX_OK) { |
| shutdown(conn, SHUT_RDWR); |
| close(conn); |
| FX_LOGS(ERROR) << "Child job creation failed, connection closed"; |
| return; |
| } |
| |
| // Launch process with chrealm so that it gets /svc of sys realm |
| const std::vector<fdio_spawn_action_t> actions{ |
| // Transfer the socket as stdin and stdout |
| {.action = FDIO_SPAWN_ACTION_CLONE_FD, .fd = {.local_fd = conn, .target_fd = STDIN_FILENO}}, |
| {.action = FDIO_SPAWN_ACTION_TRANSFER_FD, |
| .fd = {.local_fd = conn, .target_fd = STDOUT_FILENO}}, |
| // Clone this process' stderr. |
| {.action = FDIO_SPAWN_ACTION_CLONE_FD, |
| .fd = {.local_fd = STDERR_FILENO, .target_fd = STDERR_FILENO}}, |
| }; |
| |
| // Find the sys realm |
| // TODO(fxbug.dev/97903): don't give sshd all of legacy sys. |
| std::string sys_path; |
| files::Glob glob("/hub/r/sys/*"); |
| if (glob.size() == 0) { |
| // sshd-host.cmx is launched in sys, so its /hub is sys. |
| // TODO(fxbug.dev/90440): delete this branch once sshd-host.cmx is gone. |
| sys_path = "/hub"; |
| } else if (glob.size() == 1) { |
| sys_path = *(glob.begin()); |
| } else { |
| FX_LOGS(ERROR) << "Could not find sys realm, found " << glob.size() << " matches"; |
| return; |
| } |
| |
| constexpr uint32_t kSpawnFlags = |
| FDIO_SPAWN_CLONE_JOB | FDIO_SPAWN_DEFAULT_LDSVC | FDIO_SPAWN_CLONE_UTC_CLOCK; |
| zx::process process; |
| std::string error; |
| zx_status_t status = |
| chrealm::SpawnBinaryInRealmAsync(sys_path, kSshdArgv, child_job.get(), kSpawnFlags, actions, |
| process.reset_and_get_address(), &error); |
| if (status < 0) { |
| shutdown(conn, SHUT_RDWR); |
| close(conn); |
| FX_LOGS(ERROR) << "Error from chrealm: " << error; |
| return; |
| } |
| |
| std::unique_ptr<async::Wait> waiter = |
| std::make_unique<async::Wait>(process.get(), ZX_PROCESS_TERMINATED); |
| waiter->set_handler([this, process = std::move(process), job = std::move(child_job)]( |
| async_dispatcher_t*, async::Wait*, zx_status_t /*status*/, |
| const zx_packet_signal_t* /*signal*/) mutable { |
| ProcessTerminated(std::move(process), std::move(job)); |
| }); |
| waiter->Begin(async_get_default_dispatcher()); |
| process_waiters_.push_back(std::move(waiter)); |
| } |
| |
| void Service::ProcessTerminated(zx::process process, zx::job job) { |
| { |
| zx_info_process_t info; |
| if (zx_status_t s = process.get_info(ZX_INFO_PROCESS, &info, sizeof(info), nullptr, nullptr); |
| s != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to get proces info"; |
| } |
| if (info.return_code != 0) { |
| FX_LOGS(WARNING) << "Process finished with nonzero status: " << info.return_code; |
| } |
| } |
| |
| // Kill the process and the job. |
| if (zx_status_t s = process.kill(); s != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to kill child process"; |
| } |
| if (zx_status_t s = job.kill(); s != ZX_OK) { |
| FX_PLOGS(ERROR, s) << "Failed to kill child job"; |
| } |
| |
| // Find the waiter. |
| auto i = std::find_if( |
| process_waiters_.begin(), process_waiters_.end(), |
| [&process](const std::unique_ptr<async::Wait>& w) { return w->object() == process.get(); }); |
| // And remove it. |
| if (i != process_waiters_.end()) { |
| process_waiters_.erase(i); |
| } |
| } |
| } // namespace sshd_host |