Merge "adb: don\'t use setenv after forking."

#include <termios.h>

#include <memory>

#include <string>

#include <unordered_map>

#include <vector>

#include <android-base/logging.h>

#include <android-base/stringprintf.h>

    ScopedFd parent_error_sfd, child_error_sfd;

    char pts_name[PATH_MAX];

    // Create a socketpair for the fork() child to report any errors back to

    // the parent. Since we use threads, logging directly from the child could

    // create a race condition.

    // Create a socketpair for the fork() child to report any errors back to the parent. Since we

    // use threads, logging directly from the child might deadlock due to locks held in another

    // thread during the fork.

    if (!CreateSocketpair(&parent_error_sfd, &child_error_sfd)) {

        LOG(ERROR) << "failed to create pipe for subprocess error reporting";

    }

    // Construct the environment for the child before we fork.

    passwd* pw = getpwuid(getuid());

    std::unordered_map<std::string, std::string> env;

    char** current = environ;

    while (char* env_cstr = *current++) {

        std::string env_string = env_cstr;

        char* delimiter = strchr(env_string.c_str(), '=');

        *delimiter++ = '\0';

        env[env_string.c_str()] = delimiter;

    }

    if (pw != nullptr) {

        // TODO: $HOSTNAME? Normally bash automatically sets that, but mksh doesn't.

        env["HOME"] = pw->pw_dir;

        env["LOGNAME"] = pw->pw_name;

        env["USER"] = pw->pw_name;

        env["SHELL"] = pw->pw_shell;

    }

    if (!terminal_type_.empty()) {

        env["TERM"] = terminal_type_;

    }

    std::vector<std::string> joined_env;

    for (auto it : env) {

        const char* key = it.first.c_str();

        const char* value = it.second.c_str();

        joined_env.push_back(android::base::StringPrintf("%s=%s", key, value));

    }

    std::vector<const char*> cenv;

    for (const std::string& str : joined_env) {

        cenv.push_back(str.c_str());

    }

    cenv.push_back(nullptr);

    if (type_ == SubprocessType::kPty) {

        int fd;

        pid_ = forkpty(&fd, pts_name, nullptr, nullptr);

        parent_error_sfd.Reset();

        close_on_exec(child_error_sfd.fd());

        // TODO: $HOSTNAME? Normally bash automatically sets that, but mksh doesn't.

        passwd* pw = getpwuid(getuid());

        if (pw != nullptr) {

            setenv("HOME", pw->pw_dir, 1);

            setenv("LOGNAME", pw->pw_name, 1);

            setenv("SHELL", pw->pw_shell, 1);

            setenv("USER", pw->pw_name, 1);

        }

        if (!terminal_type_.empty()) {

            setenv("TERM", terminal_type_.c_str(), 1);

        }

        if (is_interactive()) {

            execl(_PATH_BSHELL, _PATH_BSHELL, "-", nullptr);

            execle(_PATH_BSHELL, _PATH_BSHELL, "-", nullptr, cenv.data());

        } else {

            execl(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr);

            execle(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr, cenv.data());

        }

        WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed");

        child_error_sfd.Reset();

        exit(-1);

        _Exit(1);

    }

    // Subprocess parent.

        return false;

    }

    D("subprocess parent: exec completed");

    if (protocol_ == SubprocessProtocol::kNone) {

        // No protocol: all streams pass through the stdinout FD and hook

        // directly into the local socket for raw data transfer.

        return false;

    }

    D("subprocess parent: completed");

    return true;

}