#include <sys/wait.h>
#include <android-base/cmsg.h>
#include <cmd.h>
#include "adb.h"
#include "adb_io.h"
#include "adb_utils.h"
#include "shell_service.h"
namespace {
class AdbFdTextOutput : public android::TextOutput {
  public:
    explicit AdbFdTextOutput(int fd) : mFD(fd) {}
  private:
    android::status_t print(const char* txt, size_t len) override {
        return WriteFdExactly(mFD, txt, len) ? android::OK : -errno;
    }
    void moveIndent(int delta) override { /*not implemented*/
    }
    void pushBundle() override { /*not implemented*/
    }
    void popBundle() override { /*not implemented*/
    }
  private:
    int mFD;
};
std::vector<std::string_view> parseCmdArgs(std::string_view args) {
    std::vector<std::string_view> argv;
    char delim = ABB_ARG_DELIMETER;
    size_t size = args.size();
    size_t base = 0;
    while (base < size) {
        size_t found;
        for (found = base; found < size && args[found] && args[found] != delim; ++found)
            ;
        if (found > base) {
            argv.emplace_back(args.substr(base, found - base));
        }
        base = found + 1;
    }
    return argv;
}
}  // namespace
static int execCmd(std::string_view args, int in, int out, int err) {
    AdbFdTextOutput oin(out);
    AdbFdTextOutput oerr(err);
    return cmdMain(parseCmdArgs(args), oin, oerr, in, out, err, RunMode::kLibrary);
}
int main(int argc, char* const argv[]) {
    signal(SIGPIPE, SIG_IGN);
    int fd = STDIN_FILENO;
    std::string data;
    while (true) {
        std::string error;
        if (!ReadProtocolString(fd, &data, &error)) {
            PLOG(ERROR) << "Failed to read message: " << error;
            break;
        }
        std::string_view name = data;
        auto protocol = SubprocessProtocol::kShell;
        if (ConsumePrefix(&name, "abb:")) {
            protocol = SubprocessProtocol::kShell;
        } else if (ConsumePrefix(&name, "abb_exec:")) {
            protocol = SubprocessProtocol::kNone;
        } else {
            LOG(FATAL) << "Unknown command prefix for abb: " << data;
        }
        unique_fd result = StartCommandInProcess(std::string(name), &execCmd, protocol);
        if (android::base::SendFileDescriptors(fd, "", 1, result.get()) != 1) {
            PLOG(ERROR) << "Failed to send an inprocess fd for command: " << data;
            break;
        }
    }
}


abb_service.cpp

#include "adb.h"
#include "adb_io.h"
#include "adb_unique_fd.h"
#include "adb_utils.h"
#include "shell_service.h"

#include <android-base/cmsg.h>

namespace {

struct AbbProcess;
static auto& abbp = *new std::unique_ptr<AbbProcess>(std::make_unique<AbbProcess>());

struct AbbProcess {
    unique_fd sendCommand(std::string_view command);

  private:
    static unique_fd startAbbProcess(unique_fd* error_fd);

    static constexpr auto kRetries = 2;
    static constexpr auto kErrorProtocol = SubprocessProtocol::kShell;

    std::mutex locker_;
    unique_fd socket_fd_;
};

unique_fd AbbProcess::sendCommand(std::string_view command) {
    std::unique_lock lock{locker_};

    for (int i = 0; i < kRetries; ++i) {
        unique_fd error_fd;
        if (socket_fd_ == -1) {
            socket_fd_ = startAbbProcess(&error_fd);
        }
        if (socket_fd_ == -1) {
            LOG(ERROR) << "failed to start abb process";
            return error_fd;
        }

        if (!SendProtocolString(socket_fd_, std::string(command))) {
            PLOG(ERROR) << "failed to send command to abb";
            socket_fd_.reset();
            continue;
        }

        unique_fd fd;
        std::string error;
        char buf;
        if (android::base::ReceiveFileDescriptors(socket_fd_, &buf, 1, &fd) != 1) {
            PLOG(ERROR) << "failed to receive FD from abb";
            socket_fd_.reset();
            continue;
        }

        return fd;
    }

    LOG(ERROR) << "abb is unavailable";
    socket_fd_.reset();
    return ReportError(kErrorProtocol, "abb is unavailable");
}

unique_fd AbbProcess::startAbbProcess(unique_fd* error_fd) {
    constexpr auto abb_process_type = SubprocessType::kRaw;
    constexpr auto abb_protocol = SubprocessProtocol::kNone;
    constexpr auto make_pty_raw = false;
    return StartSubprocess("abb", "dumb", abb_process_type, abb_protocol, make_pty_raw,
                           kErrorProtocol, error_fd);
}

}  // namespace

unique_fd execute_abb_command(std::string_view command) {
    return abbp->sendCommand(command);
}