/*
 * Copyright (C) 2012 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 */
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <net/if.h>

#include <arpa/inet.h>

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <signal.h>

#include "netinet/ip_compat.h"
#include "netinet/ip_fil.h"
#include "netinet/ip_nat.h"
#include "netinet/ip_state.h"
#include "netinet/ip_sync.h"


int     main(int, char *[]);
void    usage(const char *);

int     terminate = 0;

void usage(const char *progname) {
        fprintf(stderr, "Usage: %s <destination IP> <destination port>\n", progname);
}

#if 0
static void handleterm(int sig)
{
        terminate = sig;
}
#endif


/* should be large enough to hold header + any datatype */
#define BUFFERLEN 1400

int main(argc, argv)
        int argc;
        char *argv[];
{
        struct sockaddr_in sin;
        char buff[BUFFERLEN];
        synclogent_t *sl;
        syncupdent_t *su;
        int nfd = -1, lfd = -1, n1, n2, n3, len;
        int inbuf;
        u_32_t magic;
        synchdr_t *sh;
        char *progname;

        progname = strrchr(argv[0], '/');
        if (progname) {
                progname++;
        } else {
                progname = argv[0];
        }


        if (argc < 2) {
                usage(progname);
                exit(1);
        }

#if 0
        signal(SIGHUP, handleterm);
        signal(SIGINT, handleterm);
        signal(SIGTERM, handleterm);
#endif

        openlog(progname, LOG_PID, LOG_SECURITY);

        bzero((char *)&sin, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = inet_addr(argv[1]);
        if (argc > 2)
                sin.sin_port = htons(atoi(argv[2]));
        else
                sin.sin_port = htons(43434);

        while (1) {

                if (lfd != -1)
                        close(lfd);
                if (nfd != -1)
                        close(nfd);

                lfd = open(IPSYNC_NAME, O_RDONLY);
                if (lfd == -1) {
                        syslog(LOG_ERR, "Opening %s :%m", IPSYNC_NAME);
                        goto tryagain;
                }

                nfd = socket(AF_INET, SOCK_DGRAM, 0);
                if (nfd == -1) {
                        syslog(LOG_ERR, "Socket :%m");
                        goto tryagain;
                }

                if (connect(nfd, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
                        syslog(LOG_ERR, "Connect: %m");
                        goto tryagain;
                }

                syslog(LOG_INFO, "Sending data to %s",
                       inet_ntoa(sin.sin_addr));

                inbuf = 0;
                while (1) {

                        n1 = read(lfd, buff+inbuf, BUFFERLEN-inbuf);

                        printf("header : %d bytes read (header = %d bytes)\n",
                               n1, (int) sizeof(*sh));

                        if (n1 < 0) {
                                syslog(LOG_ERR, "Read error (header): %m");
                                goto tryagain;
                        }

                        if (n1 == 0) {
                                /* XXX can this happen??? */
                                syslog(LOG_ERR,
                                       "Read error (header) : No data");
                                sleep(1);
                                continue;
                        }

                        inbuf += n1;

moreinbuf:
                        if (inbuf < sizeof(*sh)) {
                                continue; /* need more data */
                        }

                        sh = (synchdr_t *)buff;
                        len = ntohl(sh->sm_len);
                        magic = ntohl(sh->sm_magic);

                        if (magic != SYNHDRMAGIC) {
                                syslog(LOG_ERR,
                                       "Invalid header magic %x", magic);
                                goto tryagain;
                        }

#define IPSYNC_DEBUG
#ifdef IPSYNC_DEBUG
                        printf("v:%d p:%d len:%d magic:%x", sh->sm_v,
                               sh->sm_p, len, magic);

                        if (sh->sm_cmd == SMC_CREATE)
                                printf(" cmd:CREATE");
                        else if (sh->sm_cmd == SMC_UPDATE)
                                printf(" cmd:UPDATE");
                        else
                                printf(" cmd:Unknown(%d)", sh->sm_cmd);

                        if (sh->sm_table == SMC_NAT)
                                printf(" table:NAT");
                        else if (sh->sm_table == SMC_STATE)
                                printf(" table:STATE");
                        else
                                printf(" table:Unknown(%d)", sh->sm_table);

                        printf(" num:%d\n", (u_32_t)ntohl(sh->sm_num));
#endif

                        if (inbuf < sizeof(*sh) + len) {
                                continue; /* need more data */
                                goto tryagain;
                        }

#ifdef IPSYNC_DEBUG
                        if (sh->sm_cmd == SMC_CREATE) {
                                sl = (synclogent_t *)buff;

                        } else if (sh->sm_cmd == SMC_UPDATE) {
                                su = (syncupdent_t *)buff;
                                if (sh->sm_p == IPPROTO_TCP) {
                                        printf(" TCP Update: age %lu state %d/%d\n",
                                                su->sup_tcp.stu_age,
                                                su->sup_tcp.stu_state[0],
                                                su->sup_tcp.stu_state[1]);
                                }
                        } else {
                                printf("Unknown command\n");
                        }
#endif

                        n2 = sizeof(*sh) + len;
                        n3 = write(nfd, buff, n2);
                        if (n3 <= 0) {
                                syslog(LOG_ERR, "Write error: %m");
                                goto tryagain;
                        }


                        if (n3 != n2) {
                                syslog(LOG_ERR, "Incomplete write (%d/%d)",
                                       n3, n2);
                                goto tryagain;
                        }

                        /* signal received? */
                        if (terminate)
                                break;

                        /* move buffer to the front,we might need to make
                         * this more efficient, by using a rolling pointer
                         * over the buffer and only copying it, when
                         * we are reaching the end
                         */
                        inbuf -= n2;
                        if (inbuf) {
                                bcopy(buff+n2, buff, inbuf);
                                printf("More data in buffer\n");
                                goto moreinbuf;
                        }
                }

                if (terminate)
                        break;
tryagain:
                sleep(1);
        }


        /* terminate */
        if (lfd != -1)
                close(lfd);
        if (nfd != -1)
                close(nfd);

        syslog(LOG_ERR, "signal %d received, exiting...", terminate);

        exit(1);
}