// systemtap compile-server web api server
// Copyright (C) 2017-2018 Red Hat Inc.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.

#include "api.h"
#include "server.h"
#include <iostream>
#include <fstream>
#include <sstream>
#include "../staputil.h"
#include "backends.h"
#include "../cmdline.h"
#include "utils.h"
#include "../nsscommon.h"
#include "../privilege.h"

extern "C" {
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <glob.h>
#include <sched.h>
#include <limits.h>
}

using namespace std;

static server *httpd = NULL;

struct result_file_info
{
    string path;
    mode_t mode;
};

class resource
{
public:
    resource(string resource_base) {
	uuid_str = get_uuid();
	uri = resource_base + uuid_str;
    }

    virtual ~resource() { }

    string get_uuid_str() {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);
	return uuid_str;
    }

    string get_uri() {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);
	return uri;
    }

    virtual void generate_response(response &r) = 0;
    virtual void generate_file_response(response &r, string &) { 
	r = get_404_response();
    }

protected:
    mutex res_mutex;
    string uuid_str;
    string uri;
};

class result_info : public resource
{
public:
    result_info(int rc, string &out_path, string &err_path)
	: resource("/results/"), rc(rc), stdout_path(out_path),
	  stderr_path(err_path), status_code(0)
    {
	size_t found = stdout_path.find_last_of("/");
	if (found != string::npos) {
	    stdout_file = stdout_path.substr(found + 1);
	}
	found = stderr_path.find_last_of("/");
	if (found != string::npos) {
	    stderr_file = stderr_path.substr(found + 1);
	}
    }
    result_info(unsigned int status_code, string content)
	: resource("/results/"), rc(0), status_code(status_code),
	  content(content)
    {
    }

    ~result_info()
    {
	if (!files.empty()) {
	    for (auto it = files.begin(); it != files.end(); it++) {
		delete it->second;
	    }
	    files.clear();
	}
    }

    void generate_response(response &r);
    void generate_file_response(response &r, string &f);

    void add_file(string &path, mode_t mode)
    {
	size_t found = path.find_last_of("/");
	string file_name;

	if (found != string::npos) {
	    file_name = path.substr(found + 1);
	}
	else {
	    file_name = path;
	}
	struct result_file_info *rfi = new struct result_file_info;
	rfi->path = path;
	rfi->mode = mode;
	files[file_name] = rfi;
    }

protected:
    int rc;
    string stdout_path;
    string stdout_file;
    string stderr_path;
    string stderr_file;
    map<string, struct result_file_info *> files;

    unsigned int status_code;
    string content;
};

static void result_infos_erase(result_info *r);

class build_info : public resource
{
public:
    build_info(client_request_data *crd)
	: resource("/builds/"), crd(crd), builder_thread_running(false),
	  result(NULL) { }

    ~build_info()
    {
	if (builder_thread_running) {
	    pthread_join(builder_tid, NULL);
	    builder_thread_running = false;
	}
	if (result) {
	    // If this build has an associated result, be sure to delete it
	    // from the results list.
	    result_infos_erase(result);
	    delete result;
	    result = NULL;
	}
	if (crd) {
	    delete crd;
	    crd = NULL;
	}
    }

    void generate_response(response &r);
    void start_module_build();

    bool is_build_finished()
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);
	return (result != NULL);
    }

private:
    client_request_data *crd;

    bool builder_thread_running;
    pthread_t builder_tid;

    void parse_cmd_args(void);
    static void *module_build_shim(void *arg);
    void *module_build();
    result_info *result;

    void set_result(result_info *ri);
};

void result_info::generate_response(response &r)
{
    ostringstream os;

    if (status_code != 0) {
	r.status_code = status_code;
	r.content = content;
	return;
    }

    r.status_code = 200;
    r.content_type = "application/json";
    os << "{" << endl;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);

	os << "  \"version\": \"" VERSION "\"";
	os << "," << endl << "  \"uuid\": \"" << uuid_str << "\"";
	os << "," << endl << "  \"rc\": " << rc;

	// Always output stdout and stderr.
	if (!stdout_path.empty()) {
	    os << "," << endl << "  \"stdout_location\": \""
	       << uri + '/' + stdout_file << "\"";
	}
	if (!stderr_path.empty()) {
	    os << "," << endl << "  \"stderr_location\": \""
	       << uri + '/' + stderr_file << "\"";
	}

	// Here we output any extra files, like a module. For each
	// file print the location and mode (in decimal, since JSON
	// doesn't do octal).
	if (!files.empty()) {
	    os << "," << endl << "  \"files\": [" << endl;
	    bool first = true;
	    for (auto it = files.begin(); it != files.end(); it++) {
		if (!first)
		    os << "," << endl;
		else
		    first = false;
		os << "    { \"location\": \""
		   << uri + '/' + it->first
		   << "\", \"mode\": " << it->second->mode << " }";
	    }
	    os << endl << "  ]";
	}
    }
    os << endl << "}" << endl;
    r.content = os.str();
}

void result_info::generate_file_response(response &r, string &file)
{
    // We don't want to serve any old file (which would be a security
    // hole), only the files we told the user about.
    server_error(_F("Trying to retrieve file '%s'", file.c_str()));
    string path;
    r.status_code = 200;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);

	if (!stdout_path.empty() && file == stdout_file) {
	    path = stdout_path;
	}
	else if (!stderr_path.empty() && file == stderr_file) {
	    path = stderr_path;
	}
	else if (!files.empty()) {
	    auto it = files.find(file);
	    if (it != files.end()) {
		path = it->second->path;
	    }
	}
    }

    if (!path.empty()) {
	server_error(_F("File requested:  %s", file.c_str()));
	server_error(_F("Served from   :  %s", path.c_str()));
	r.file = path;
    }
    else {
	server_error("Couldn't find file");
	r = get_404_response();
    }
}

void build_info::generate_response(response &r)
{
    ostringstream os;

    r.content_type = "application/json";
    os << "{" << endl;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);

	if (result == NULL) {
	    r.status_code = 200;
	}
	else {
	    r.status_code = 303;
	    r.headers["Location"] = result->get_uri();
	}

	os << "  \"version\": \"" VERSION "\"," << endl;
	os << "  \"uuid\": \"" << uuid_str << "\"," << endl;
	os << "  \"kver\": \"" << crd->kver << "\"," << endl;
	os << "  \"arch\": \"" << crd->arch << "\"," << endl;

	os << "  \"cmd_args\": [" << endl;
	bool first = true;
	for (auto it = crd->cmd_args.begin(); it != crd->cmd_args.end();
	     it++) {
	    struct json_object *j = json_object_new_string((*it).c_str());
	    if (j) {
		if (!first)
		    os << "," << endl;
		else
		    first = false;
		os << "    "
		   << json_object_to_json_string_ext(j, JSON_C_TO_STRING_PLAIN);
		json_object_put(j);
	    }
	}
	os << endl << "  ]" << endl;
    }
    os << "}" << endl;
    r.content = os.str();
}

void build_info::start_module_build()
{
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(res_mutex);
	if (builder_thread_running) {
	    // This really shouldn't happen. Error out.
	    server_error("Multiple attempts to build module.");
	    return;
	}
	builder_thread_running = true;
    }

    /* Create a thread to handle the module build. */
    if (pthread_create(&builder_tid, NULL, module_build_shim, this) < 0) {
	server_error(_F("Failed to create thread: %s", strerror(errno)));
	exit(1);
    }
}


mutex builds_mutex;
vector<build_info *> build_infos;

mutex results_mutex;
vector<result_info *> result_infos;

static void
result_infos_erase(result_info *r)
{
    // Use a lock_guard to ensure the mutex gets released
    // even if an exception is thrown.
    lock_guard<mutex> lock(results_mutex);
    for (auto it = result_infos.begin(); it != result_infos.end(); it++) {
	if (r->get_uuid_str() == (*it)->get_uuid_str()) {
	    result_infos.erase(it);
	    break;
	}
    }
}


class build_collection_rh : public request_handler
{
public:
    response POST(const request &req);

    build_collection_rh(string n) : request_handler(n) {}
};

response build_collection_rh::POST(const request &req)
{
    client_request_data *crd = new client_request_data;
    if (crd == NULL) {
	// Return an error.
	server_error("500 - internal server error");
	response error500(500);
	error500.content = "<h1>Internal server error, memory allocation failed.</h1>";
	return error500;
    }

    // Gather up the info we need.
    vector<string> file_name;
    vector<string> build_id;
    vector<string> file_pkg;
    for (auto it = req.params.begin(); it != req.params.end(); it++) {
	if (it->first == "kver") {
	    crd->kver = it->second[0];
	}
	else if (it->first == "arch") {
	    crd->arch = it->second[0];
	}
	else if (it->first == "cmd_args") {
	    crd->cmd_args = it->second;
	}
	else if (it->first == "distro_name") {
	    // Notice we're lowercasing the distro name to make things
	    // simpler.
	    crd->distro_name = it->second[0];
	    transform(crd->distro_name.begin(), crd->distro_name.end(),
		      crd->distro_name.begin(), ::tolower);

	}
	else if (it->first == "distro_version") {
	    crd->distro_version = it->second[0];
	}
	else if (it->first == "build_id") {
	    build_id = it->second;
	}
	else if (it->first == "file_name") {
	    file_name = it->second;
	}
	else if (it->first == "file_pkg") {
	    file_pkg = it->second;
	}
	else if (it->first == "env_vars") {
	    // Get rid of a few standard environment variables (which
	    // might cause us to do unintended things) from the list
	    // the client sent us.
	    for (auto it2 = it->second.begin(); it2 != it->second.end();
		 it2++) {
		if (*it2 == "IFS" || *it2 == "CDPATH" || *it2 == "ENV"
		    || *it2 == "BASH_ENV") {
		    server_error(_F("ignoring client environment variable: %s",
				    (*it2).c_str()));
		}
		else {
		    crd->env_vars.push_back(*it2);
		}
	    }
	}
	// Notice we silently ignore any "extra" parameters.
    }

    // Combine the file info fields.
    if (! file_name.empty() || ! build_id.empty() || ! file_pkg.empty()) {
	if (file_name.size() != build_id.size()
	    || file_name.size() != file_pkg.size()) {
	    // Return an error.
	    server_error("400 - bad request (1)");
	    response error400(400);
	    error400.content = "<h1>Bad request</h1>";
	    return error400;
	}
	for (unsigned i = 0; i < file_name.size(); ++i) {
	    auto finfo = make_shared<struct file_info>();
	    finfo->name = file_name[i];
	    finfo->pkg = file_pkg[i];
	    finfo->build_id = build_id[i];
	    crd->file_info.push_back(finfo);
	}
    }

    // We've got 2 directories that we use:
    //   server_dir: the directory for "server" files - stuff received
    //               from the client, files generated on the server
    //               (like stdout/stderr files)
    //   client_dir: directory for "client" files, file to be operated
    //               on (or generated by) by systemtap itself
    // We need to create the client_dir.
    crd->server_dir = req.base_dir;
    if (crd->server_dir.empty() && !make_temp_dir(crd->server_dir)) {
	response error500(500);
	error500.content = "<h1>Internal server error, mkdtemp failed.</h1>";
	return error500;
    }
    if (!make_temp_dir(crd->client_dir)) {
	response error500(500);
	error500.content = "<h1>Internal server error, mkdtemp failed.</h1>";
	return error500;
    }

    if (! req.files.empty()) {
	server_error("Files received:");
	for (auto i = req.files.begin(); i != req.files.end(); i++) {
	    for (auto j = i->second.begin(); j != i->second.end();
		 j++) {
		server_error(*j);
		crd->files.push_back(*j);
	    }
	}
    }

    // Make sure we've got everything we need.
    if (crd->kver.empty() || crd->arch.empty() || crd->cmd_args.empty()
	|| crd->distro_name.empty() || crd->distro_version.empty()) {
	// Return an error.
	server_error("400 - bad request (2)");
	response error400(400);
	error400.content = "<h1>Bad request</h1>";
	return error400;
    }

    // Create a build with the information we've gathered.
    build_info *b = new build_info(crd);
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(builds_mutex);
	build_infos.push_back(b);
    }

    // Kick off the module build.
    b->start_module_build();

    // Return a 202 response.
    server_error("Returning a 202");
    response resp(202);
    resp.headers["Location"] = b->get_uri();
    resp.headers["Retry-After"] = "10";
    return resp;
}

class individual_build_rh : public request_handler
{
public:
    individual_build_rh(string n) : request_handler(n) {}

    response GET(const request &req);
    response DELETE(const request &req);
};

response individual_build_rh::GET(const request &req)
{
    // matches[0] is the entire string '/builds/XXXX'. matches[1] is
    // just the buildid 'XXXX'.
    string buildid = req.matches[1];
    build_info *b = NULL;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(builds_mutex);
	for (auto it = build_infos.begin(); it != build_infos.end(); it++) {
	    if (buildid == (*it)->get_uuid_str()) {
		b = *it;
		break;
	    }
	}
    }

    if (b == NULL) {
	server_error(_F("Couldn't find build '%s'", buildid.c_str()));
	return get_404_response();
    }

    response rsp(0);
    b->generate_response(rsp);
    return rsp;
}

response individual_build_rh::DELETE(const request &req)
{
    // matches[0] is the entire string '/builds/XXXX'. matches[1] is
    // just the buildid 'XXXX'.
    string buildid = req.matches[1];
    build_info *b = NULL;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(builds_mutex);
	for (auto it = build_infos.begin(); it != build_infos.end(); it++) {
	    if (buildid == (*it)->get_uuid_str()) {
		b = *it;
		build_infos.erase(it);
		break;
	    }
	}
    }

    if (b == NULL) {
	server_error(_F("Couldn't find build '%s'", buildid.c_str()));
	return get_404_response();
    }

    // At this point we've found a matching build. Delete it.
    delete b;
    response rsp(300);
    rsp.content = "";
    return rsp;
}

class individual_result_rh : public request_handler
{
public:
    response GET(const request &req);

    individual_result_rh(string n) : request_handler(n) {}
};

response individual_result_rh::GET(const request &req)
{
    // matches[0] is the entire string '/results/XXXX'. matches[1] is
    // just the id_str 'XXXX'.
    string id_str = req.matches[1];
    result_info *ri = NULL;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(results_mutex);
	for (auto it = result_infos.begin(); it != result_infos.end(); it++) {
	    if (id_str == (*it)->get_uuid_str()) {
		ri = *it;
		break;
	    }
	}
    }

    if (ri == NULL) {
	server_error(_F("Couldn't find result id '%s'", id_str.c_str()));
	return get_404_response();
    }

    response rsp(0);
    ri->generate_response(rsp);
    return rsp;
}

class result_file_rh : public request_handler
{
public:
    response GET(const request &req);

    result_file_rh(string n) : request_handler(n) {}
};

response result_file_rh::GET(const request &req)
{
    // matches[0] is the entire string
    // '/results/XXXX/FILE'. matches[1] is the result uuid string
    // 'XXXX'. matches[2] is the filename 'FILE'.
    string id_str = req.matches[1];
    string file_str = req.matches[2];
    result_info *ri = NULL;
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(results_mutex);
	for (auto it = result_infos.begin(); it != result_infos.end(); it++) {
	    if (id_str == (*it)->get_uuid_str()) {
		ri = *it;
		break;
	    }
	}
    }

    if (ri == NULL) {
	server_error(_F("Couldn't find result id '%s'", id_str.c_str()));
	return get_404_response();
    }

    response rsp(0);
    ri->generate_file_response(rsp, file_str);
    return rsp;
}

build_collection_rh builds_rh("build collection");
individual_build_rh build_rh("individual build");
individual_result_rh result_rh("individual result");
result_file_rh result_file_rh("result file");

void
build_info::set_result(result_info *ri)
{
    {
	// Use a lock_guard to ensure the mutex gets released
	// even if an exception is thrown.
	lock_guard<mutex> lock(res_mutex);
	result = ri;
    }
    {
	// Use a lock_guard to ensure the mutex gets released
	// even if an exception is thrown.
	lock_guard<mutex> lock(results_mutex);
	result_infos.push_back(ri);
    }
}

void *
build_info::module_build_shim(void *arg)
{
    build_info *bi = static_cast<build_info *>(arg);

    return bi->module_build();
}

void
build_info::parse_cmd_args(void)
{
    // Here we parse the stap command line for anything
    // interesting. Note that we're not parsing the httpd command
    // line, but the stap command line the user entered on the client
    // side.
    //
    // Also note that we need not do any options consistency checking
    // since our spawned stap instance will do that.

    // Create an argv/argc for use by getopt_long. Note that we have
    // to add an argument 0 (for the 'stap' command itself) to make
    // getopt_long() happy.
    unsigned argc = crd->cmd_args.size() + 1;
    char **argv = new char *[argc + 1];
    char arg0[] = "stap";
    argv[0] = arg0;
    for (unsigned i = 0; i < crd->cmd_args.size(); ++i) {
	argv[i + 1] = (char *)crd->cmd_args[i].c_str();
    }
    argv[argc] = NULL;

    optind = 1;
    unsigned perpass_verbose[5] = { 0 };
    unsigned verbose = 0;
    privilege_t privilege = pr_highest; // Until specified otherwise.
    while (true) {
	int grc = getopt_long(argc, argv, STAP_SHORT_OPTIONS,
			      stap_long_options, NULL);
	if (grc < 0)
	    break;
	switch (grc) {
        case 'v':
	    for (unsigned i = 0; i < 5; i++)
		perpass_verbose[i]++;
	    verbose++;
	    break;
	case LONG_OPT_VERBOSE_PASS:
            assert(optarg);
	    if (strlen(optarg) > 0 && strlen(optarg) <= 5) {
		for (unsigned i = 0; i < strlen(optarg); i++) {
		    if (isdigit(optarg[i]))
			perpass_verbose[i] += (optarg[i] - '0');
		}
	    }
	    break;
	case LONG_OPT_PRIVILEGE:
	    if (strcmp(optarg, "stapdev") == 0)
		privilege = pr_stapdev;
	    else if (strcmp(optarg, "stapsys") == 0)
		privilege = pr_stapsys;
	    else if (strcmp(optarg, "stapusr") == 0)
		privilege = pr_stapusr;
	    else {
		// FIXME: what to do here?
		server_error(_F("Invalid argument '%s' for --privilege",
				optarg));
		privilege = pr_highest;
	    }
	    break;
	case LONG_OPT_UNPRIVILEGED:
	    privilege = pr_unprivileged;
	    break;
	default:
	    // We silently ignore all options we aren't interested in.
	    break;
	}
    }
    delete[] argv;

    // Now that we've finished parsing the arguments, we'll take the
    // pass 2 verbose level as the level of verbosity to report things
    // back to the client.
    crd->verbose = perpass_verbose[1];
    server_error(_F("Verbose level: %d", crd->verbose));
    crd->privilege = privilege;
    server_error(_F("Privilege: %d", crd->privilege));
}

void *
build_info::module_build()
{
    vector<string> argv;
    bool client_zip_exists = false;

    // The client can optionally send over a "client.zip" file, which
    // we automatically unzip here.
    for (auto i = crd->files.begin(); i != crd->files.end(); i++) {
	if (*i == "client.zip") {
	    string zip_path = crd->server_dir + "/client.zip";
	    vector<string> zip_argv = { "unzip", "-q", "-d", crd->client_dir,
					zip_path };
	    int rc = stap_system (2, zip_argv);
	    if (rc != 0) {
		// Return an error.
		server_error(_F("unzip failed: %d", rc));
		result_info *ri = new result_info(400,
						  "<h1>Bad request</h1>");
		set_result(ri);
		return NULL;
	    }
	    client_zip_exists = true;
	}
    }

    // Process the command arguments.
    argv.push_back("stap");

    // Specify the right kernel version.  Since we might be using a
    // '--sysroot' option, we need to specify the full path to the
    // kernel build directory (or stap will look for it in the
    // sysroot).
    argv.push_back("-r");
    string kernel_build_tree = "/lib/modules/" + crd->kver + "/build";
    argv.push_back(kernel_build_tree);

    if (client_zip_exists) {
	// If a directory called "files" exists in the stuff we
	// unzipped from client.zip, then we need a sysroot option (so
	// that stap can find the target user executables).
	struct stat stbuf;
	string files_path = crd->client_dir + "/files";
	if (stat(files_path.c_str(), &stbuf) == 0) {
	    argv.push_back("--sysroot=" + files_path);
	}
    }

    // Make sure stap knows where to put the results.
    argv.push_back(string("--tmpdir=") + crd->client_dir);

    // Add the "client options" argument, which tells stap to do some
    // extra command line validation and to stop at pass 4.
    argv.push_back("--client-options");

    // Add the rest of the client's arguments.
    for (auto it = crd->cmd_args.begin(); it != crd->cmd_args.end(); it++) {
	argv.push_back(*it);
    }

    // We need to do a chdir() to the client directory. However, all
    // threads in a process share the same root directory and working
    // directory. If we just do a chdir() here and then call spawn, it
    // is possible that a different thread is also here and does a
    // chdir() right after ours but before the spawn. So, instead
    // we'll call unshare() first to "unshare" the thread's working
    // directory. Then when we do a chdir(), it won't affect the other
    // threads working directory.
    if (unshare(CLONE_FS) < 0) {
	// Return an error.
	server_error(_F("Error in unshare: %s", strerror(errno)));
	result_info *ri = new result_info(500,
					  "<h1>Internal server error, unshare failed.</h1>");
	set_result(ri);
	return NULL;
    }
    if (chdir(crd->client_dir.c_str()) < 0) {
	// Return an error.
	server_error(_F("Error in chdir: %s", strerror(errno)));
	result_info *ri = new result_info(500,
					  "<h1>Internal server error, chdir failed.</h1>");
	set_result(ri);
	return NULL;
    }

    // Parse the client's command args.
    parse_cmd_args();

    // Create empty stdout/stderr files, so they always exist.
    string stdout_path = crd->server_dir + "/stdout";
    ofstream file;
    file.open(stdout_path, ios::out);
    file.close();
    string stderr_path = crd->server_dir + "/stderr";
    file.open(stderr_path, ios::out);
    file.close();

    int staprc = -1;
    vector<backend_base *> backends;
    get_backends(backends);
    bool backend_found = false;
    for (auto it = backends.begin(); it != backends.end(); it++) {
	if ((*it)->can_generate_module(crd)) {
	    backend_found = true;
	    staprc = (*it)->generate_module(crd, argv, get_uuid_str(),
					    stdout_path, stderr_path);
	    break;
	}
    }

    // If none of the backends can handle the request, send an error.
    if (!backend_found) {
	// Return an error.
	server_error("Error: No backends can satisfy this request,"
		     " returning a 501.");
	result_info *ri = new result_info(501, "<h1>Not implemented.</h1>");
	set_result(ri);
	return NULL;
    }

    // See if we built a module.
    string module_path;
    mode_t module_mode = 0;
    string module_sign_path;
    if (staprc == 0) {
	glob_t globber;
	string pattern = crd->client_dir + "/*.ko";
	int rc = glob(pattern.c_str(), GLOB_ERR, NULL, &globber);
	if (rc) {
	    server_error(_F("Unable to find a module in %s",
			    crd->client_dir.c_str()));
	}
	else {
	    if (globber.gl_pathc != 1) {
		server_error(_F("Too many modules (%ld) in %s",
				(long)globber.gl_pathc,
				crd->client_dir.c_str()));
	    }
	    else {
		module_path = globber.gl_pathv[0];
		// We've got a path. Also figure out the file mode by
		// calling stat().
		struct stat stbuf;
		if (stat(module_path.c_str(), &stbuf) == 0) {
		    module_mode = stbuf.st_mode & 07777;
		}
		else {
		    module_path.clear();
		}
	    }
	    globfree(&globber);
	}

	// If we've got a module, it might need signing.
	if (! module_path.empty()
	    && (pr_contains(crd->privilege, pr_stapusr)
		|| pr_contains(crd->privilege, pr_stapsys))) {
	    server_error("Signing file...");
	    module_sign_path = module_path + ".sgn";
	    sign_file(httpd->get_cert_db_path(), server_cert_nickname(),
		      module_path, module_sign_path);
	}
    }

    result_info *ri = new result_info(staprc, stdout_path, stderr_path);
    if (! module_path.empty()) {
	ri->add_file(module_path, module_mode);
	if (! module_sign_path.empty()) {
	    // We've got a module signature. Also figure out the file
	    // mode by calling stat().
	    struct stat stbuf;
	    mode_t mode = 0;
	    if (stat(module_sign_path.c_str(), &stbuf) == 0) {
		mode = stbuf.st_mode & 07777;
	    }
	    else {
		module_sign_path.clear();
	    }
	    if (! module_sign_path.empty()) {
		ri->add_file(module_sign_path, mode);
	    }
	}
    }
    set_result(ri);
    return NULL;
}

client_request_data::~client_request_data()
{
    if (!server_dir.empty()) {
	// Remove the temporary directory.
	vector<string> cleanupcmd { "rm", "-rf", server_dir };
	int rc = stap_system(0, cleanupcmd);
	if (rc != 0)
	    server_error (_("Error in tmpdir cleanup"));
	if (verbose > 1)
	    server_error(_F("Removed temporary directory \"%s\"",
			    server_dir.c_str()));
	server_dir.clear();
    }
    if (!client_dir.empty()) {
	// Remove the temporary directory.
	vector<string> cleanupcmd { "rm", "-rf", client_dir };
	int rc = stap_system(0, cleanupcmd);
	if (rc != 0)
	    server_error (_("Error in tmpdir cleanup"));
	if (verbose > 1)
	    server_error(_F("Removed temporary directory \"%s\"",
			    client_dir.c_str()));
	client_dir.clear();
    }
}

// Return a json representation of the client_request_data. The caller
// is responsible for calling json_object_put() on the returned object.
struct json_object *
client_request_data::get_json_object() const
{
    // To make sure we have all the latest changes, we always make a
    // "fresh" json object.
    struct json_object *root = json_object_new_object();

    struct json_object *item = json_object_new_string(kver.c_str());
    json_object_object_add(root, "kver", item);
    item = json_object_new_string(arch.c_str());
    json_object_object_add(root, "arch", item);
    item = json_object_new_string(server_dir.c_str());
    json_object_object_add(root, "server_dir", item);
    item = json_object_new_string(client_dir.c_str());
    json_object_object_add(root, "client_dir", item);
    item = json_object_new_string(distro_name.c_str());
    json_object_object_add(root, "distro_name", item);
    item = json_object_new_string(distro_version.c_str());
    json_object_object_add(root, "distro_version", item);

    struct json_object *array = json_object_new_array();
    for (auto it = cmd_args.begin(); it != cmd_args.end(); ++it) {
	item = json_object_new_string((*it).c_str());
	json_object_array_add(array, item);
    }
    json_object_object_add(root, "cmd_args", array);
    
    array = json_object_new_array();
    for (auto it = files.begin(); it != files.end(); ++it) {
	item = json_object_new_string((*it).c_str());
	json_object_array_add(array, item);
    }
    json_object_object_add(root, "files", array);

    array = json_object_new_array();
    for (auto it = file_info.begin(); it != file_info.end(); ++it) {
	struct json_object *name = json_object_new_string((*it)->name.c_str());
	struct json_object *pkg = json_object_new_string((*it)->pkg.c_str());
	struct json_object *build_id = json_object_new_string((*it)->build_id.c_str());
	item = json_object_new_object();
	json_object_object_add(item, "name", name);
	json_object_object_add(item, "pkg", pkg);
	json_object_object_add(item, "build_id", build_id);
	json_object_array_add(array, item);
    }
    json_object_object_add(root, "file_info", array);
    return root;
}

void api_cleanup()
{    
    kill_stap_spawn(SIGTERM);
    {
	// Use a lock_guard to ensure the mutex gets released even if an
	// exception is thrown.
	lock_guard<mutex> lock(builds_mutex);
	for (size_t idx = 0; idx < build_infos.size(); idx++) {
	    delete build_infos[idx];
	}
	build_infos.clear();
    }
}

void api_add_request_handlers(server &http)
{
    // Remember the server.
    httpd = &http;
    
    // Add the request handlers.
    http.add_request_handler("/builds$", builds_rh);
    http.add_request_handler("/builds/([0-9a-f]+)$", build_rh);
    http.add_request_handler("/results/([0-9a-f]+)$", result_rh);
    http.add_request_handler("/results/([^/]+)/([^/]+)$", result_file_rh);
}