acooks/jittertrap

#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <signal.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <assert.h>

#include <syslog.h>
#include <unistd.h>

#include <libwebsockets.h>

#include "proto.h"
#include "proto-jittertrap.h"

#define xstr(s) str(s)
#define str(s) #s

char *resource_path = xstr(WEB_SERVER_DOCUMENT_ROOT);

static volatile int force_exit = 0;
static struct lws_context *context;


/* list of supported protocols and callbacks */
static struct lws_protocols protocols[] = {
        /* first protocol must always be HTTP handler */

        [PROTOCOL_HTTP] =
            {
                .name = "http-only",
                .callback = lws_callback_http_dummy
            },
        [PROTOCOL_JITTERTRAP] =
            {
                .name = "jittertrap",
                .callback = callback_jittertrap,
                .per_session_data_size =
                    sizeof(struct per_session_data__jittertrap),
                .rx_buffer_size = 0,
                .tx_packet_size = 4000,
            },

        /* terminator */
        [PROTOCOL_TERMINATOR] = {.name = NULL,
                                 .callback = NULL,
                                 .per_session_data_size = 0,
                                 .rx_buffer_size = 0 }
};

void sighandler(int sig __attribute__((unused)))
{
    force_exit = 1;
    lws_cancel_service(context);
}

static struct option options[] = {
    { "help", no_argument, NULL, 'h' },
    { "debug", required_argument, NULL, '1' },
    { "port", required_argument, NULL, 'p' },
    { "interface", required_argument, NULL, 'i' },
#ifndef LWS_NO_DAEMONIZE
    { "daemonize", no_argument, NULL, 'D' },
#endif
    { "resource_path", required_argument, NULL, 'r' },
    { NULL, 0, 0, 0 }
};


static struct lws_http_mount mount = {
        .mount_next             = NULL,             /* linked-list "next" */
        .mountpoint             = "/",              /* mountpoint URL */
        .origin                 = "./mount-origin", /* serve from dir */
        .def                    = "index.html",     /* default filename */
        .protocol               = NULL,
        .cgienv                 = NULL,
        .extra_mimetypes        = NULL,
        .interpret              = NULL,
        .cgi_timeout            = 0,
        .cache_max_age          = 0,
        .auth_mask              = 0,
        .cache_reusable         = 0,
        .cache_revalidate       = 0,
        .cache_intermediaries   = 0,
        .origin_protocol        = LWSMPRO_FILE,     /* files in a dir */
        .mountpoint_len         = 1,                /* char count */
        .basic_auth_login_file  = NULL
};

int main(int argc, char **argv)
{
    int n = 0;
    int opts = 0;
    char interface_name[128] = "";
    const char *iface = NULL;
    int syslog_options = LOG_PID | LOG_PERROR;
    struct lws_context_creation_info info;

    int debug_level = LOG_WARNING;
#ifndef LWS_NO_DAEMONIZE
    int daemonize = 0;
#endif

    memset(&info, 0, sizeof info);
    info.port = WEB_SERVER_PORT;

    while (n >= 0) {
        n = getopt_long(argc, argv, "ci:hsp:dDr:", options, NULL);
        if (n < 0)
            continue;
        switch (n) {
#ifndef LWS_NO_DAEMONIZE
        case 'D':
            daemonize = 1;
            syslog_options &= ~LOG_PERROR;
            break;
#endif
        /* opt that wont be a short opt either - for long --debug */
        case '1':
            debug_level = atoi(optarg);
            debug_level =
                (debug_level > LOG_DEBUG) ? LOG_DEBUG : debug_level;
            debug_level =
                (debug_level < LOG_EMERG) ? LOG_DEBUG : debug_level;
            break;
        case 'd':
            debug_level = LOG_DEBUG;
            break;
        case 'p':
            info.port = atoi(optarg);
            break;
        case 'i':
            strncpy(interface_name, optarg, sizeof interface_name);
            interface_name[(sizeof interface_name) - 1] = '\0';
            iface = interface_name;
            break;
        case 'r':
            resource_path = optarg;
            mount.origin = resource_path;
            break;
        case 'h':
            fprintf(stderr,
                    "Usage: " PROGNAME "[--port=<p>] "
                    "[-d <log level>]"
                    "[--resource_path <path>]\n");
            exit(1);
        }
    }

#if !defined(LWS_NO_DAEMONIZE)
    /*
     * normally lock path would be /var/lock/lwsts or similar, to
     * simplify getting started without having to take care about
     * permissions or running as root, set to /tmp/.lwsts-lock
     */
    if (daemonize && lws_daemonize("/tmp/.lwsts-lock")) {
        fprintf(stderr, "Failed to daemonize\n");
        return 1;
    }
#endif

    signal(SIGINT, sighandler);

    /* we will only try to log things according to our debug_level */
    setlogmask(LOG_UPTO(debug_level));
    openlog("jt-server", syslog_options, LOG_DAEMON);

    /* tell the library what debug level to emit and to send it to syslog */
    lws_set_log_level(LOG_UPTO(debug_level), lwsl_emit_syslog);

    syslog(LOG_NOTICE, "jittertrap server\n");
    syslog(LOG_INFO, "Using resource path \"%s\"\n", resource_path);

    info.iface = iface;
    info.protocols = protocols;
    info.mounts = &mount;
    info.gid = -1;
    info.uid = -1;
    info.options = opts;

    context = lws_create_context(&info);
    if (context == NULL) {
        syslog(LOG_ERR, "libwebsocket init failed\n");
        return -1;
    }

    n = 0;
    while (n >= 0 && !force_exit) {
        lws_callback_on_writable_all_protocol(
            context, &protocols[PROTOCOL_JITTERTRAP]);

               /*
        *  FIXME:
        *  The lws_service() timeout doesn't seem to work as expected.
        *  This helps slow things down, but it's not a proper solution.
                */
        const struct timespec rqtp = {.tv_sec = 0, .tv_nsec = 5E5 };
        nanosleep(&rqtp, NULL);

        n = lws_service(context, 1);
    }

    lws_context_destroy(context);

    syslog(LOG_INFO, "jittertrap server exited cleanly\n");

    closelog();

    return 0;
}