/*-------------------------------------------------------*/
/* bbsd.c   ( NTHU CS MapleBBS Ver 3.00 )        */
/*-------------------------------------------------------*/
/* author : opus.bbs@bbs.cs.nthu.edu.tw          */
/* target : BBS daemon/main/login/top-menu routines      */
/* create : 95/03/29                     */
/* update : 96/10/10                     */
/*-------------------------------------------------------*/


#define _MAIN_C_


#include "bbs.h"
#include "dns.h"


#include <sys/wait.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/telnet.h>
#include <sys/resource.h>


#define QLEN        3
#define PID_FILE    "run/bbs.pid"
#define LOG_FILE    "run/bbs.log"
#undef  SERVER_USAGE

static int myports[MAX_BBSDPORT] = BBSD_PORT;

static pid_t currpid;

extern BCACHE *bshm;
extern UCACHE *ushm;

/* static int mport; */ /* Thor.990325: 不需要了:P */
static u_long tn_addr;


#ifdef CHAT_SECURE
char passbuf[PSWDLEN + 1];
#endif


#ifdef MODE_STAT
extern UMODELOG modelog;
extern time_t mode_lastchange;
#endif


/* ----------------------------------------------------- */
/* 離開 BBS 程式                     */
/* ----------------------------------------------------- */


    void
alog(mode, msg)     /* Admin 行為記錄 */
    char *mode, *msg;
{
    char buf[512];

    sprintf(buf, "%s %s %-13s%s\n", Now(), mode, cuser.userid, msg);
    f_cat(FN_RUN_ADMIN, buf);
}


    void
blog(mode, msg)     /* BBS 一般記錄 */
    char *mode, *msg;
{
    char buf[512];

    sprintf(buf, "%s %s %-13s%s\n", Now(), mode, cuser.userid, msg);
    f_cat(FN_RUN_USIES, buf);
}

    void
cclog(mode, msg)        /* 權限購買記錄 */
    char *mode, *msg;
{
    char buf[512];

    sprintf(buf, "%s %s %-13s%s\n", Now(), mode, cuser.userid, msg);
    f_cat("run/buyperm.log", buf);
}


#ifdef MODE_STAT
    void
log_modes()
{
    time(&modelog.logtime);
    rec_add(FN_RUN_MODE_CUR, &modelog, sizeof(UMODELOG));
}
#endif


    void
u_exit(mode)
    char *mode;
{
    int fd, diff;
    char fpath[80];
    ACCT tuser;

    if (currbno >= 0 && bshm->mantime[currbno] > 0)
        bshm->mantime[currbno]--;   /* 退出最後看的那個板 */

    utmp_free(cutmp);       /* 釋放 UTMP shm */

    diff = (time(&cuser.lastlogin) - ap_start) / 60;
    sprintf(fpath, "Stay: %d (%d)", diff, currpid);
    blog(mode, fpath);

    if (cuser.userlevel)
    {
        ve_backup();        /* 編輯器自動備份 */
        brh_save();         /* 儲存閱讀記錄檔 */
    }

#ifndef LOG_BMW /* 離站刪除水球 */
    usr_fpath(fpath, cuser.userid, fn_amw);
    unlink(fpath);
    usr_fpath(fpath, cuser.userid, fn_bmw);
    unlink(fpath);
#endif

#ifdef MODE_STAT
    log_modes();
#endif


    /* 寫回 .ACCT */

    if (!HAS_STATUS(STATUS_DATALOCK))   /* itoc.010811: 沒有被站長鎖定，才可以回存 .ACCT */
    {
        usr_fpath(fpath, cuser.userid, fn_acct);
        fd = open(fpath, O_RDWR);
        if (fd >= 0)
        {  
            if (read(fd, &tuser, sizeof(ACCT)) == sizeof(ACCT))
            {
                if (diff >= 1)
                {
                    cuser.numlogins++;  /* Thor.980727.註解: 在站上未超過一分鐘不予計算次數 */
                    addmoney(diff); /* itoc.010805: 上站一分鐘加一元 */
                }

                if (HAS_STATUS(STATUS_COINLOCK))    /* itoc.010831: 若是 multi-login 的第二隻以後，不儲存錢幣 */
                {
                    cuser.money = tuser.money;
                    cuser.gold = tuser.gold;
                }

                /* itoc.010811.註解: 如果使用者在線上沒有認證的話，
                     那麼 cuser 及 tuser 的 userlevel/tvalid 是同步的；
                     但若使用者在線上回認證信/填認證碼/被站長審核註冊單..等認證通過的話，
                     那麼 tuser 的 userlevel/tvalid 才是比較新的 */
                cuser.userlevel = tuser.userlevel;
                cuser.tvalid = tuser.tvalid;

                lseek(fd, (off_t) 0, SEEK_SET);
                write(fd, &cuser, sizeof(ACCT));
            }
            close(fd);
        }
    }
}


    void
abort_bbs()
{
    if (bbstate)
        u_exit("AXXED");
    exit(0);
}


    static void
login_abort(msg)
    char *msg;
{
    outs(msg);
    refresh();
    exit(0);
}


/* Thor.980903: lkchu patch: 不使用上站申請帳號時, 則下列 function均不用 */

#ifdef LOGINASNEW

/* ----------------------------------------------------- */
/* 檢查 user 註冊情況                  */
/* ----------------------------------------------------- */


    static int
belong(flist, key)
    char *flist;
    char *key;
{
    int fd, rc;

    rc = 0;
    if ((fd = open(flist, O_RDONLY)) >= 0)
    {
        mgets(-1);

        while (flist = mgets(fd))
        {
            str_lower(flist, flist);
            if (str_str(key, flist))
            {
                rc = 1;
                break;
            }
        }

        close(fd);
    }
    return rc;
}


    static int
is_badid(userid)
    char *userid;
{
    int ch;
    char *str;

    if (strlen(userid) < 2)
        return 1;

    if (!is_alpha(*userid))
        return 1;

    if (!str_cmp(userid, STR_NEW))
        return 1;

    str = userid;
    while (ch = *(++str))
    {
        if (!is_alnum(ch))
            return 1;
    }
    return (belong(FN_ETC_BADID, userid));
}


    static int
uniq_userno(fd)
    int fd;
{
    char buf[4096];
    int userno, size;
    SCHEMA *sp;         /* record length 16 可整除 4096 */

    userno = 1;

    while ((size = read(fd, buf, sizeof(buf))) > 0)
    {
        sp = (SCHEMA *) buf;
        do
        {
            if (sp->userid[0] == '\0')
            {
                lseek(fd, -size, SEEK_CUR);
                return userno;
            }
            userno++;
            size -= sizeof(SCHEMA);
            sp++;
        } while (size);
    }

    return userno;
}


    static void
acct_apply()
{
    SCHEMA slot;
    char buf[80];
    char *userid;
    int try, fd;

    film_out(FILM_APPLY, 0);

    memset(&cuser, 0, sizeof(ACCT));
    userid = cuser.userid;
    try = 0;
    for (;;)
    {
        if (!vget(18, 0, msg_uid, userid, IDLEN + 1, DOECHO))
            login_abort("\n再見 ...");

        if (is_badid(userid))
        {
            vmsg("無法接受這個代號，請使用英文字母，並且不要包含空格");
        }
        else
        {
            usr_fpath(buf, userid, NULL);
            if (dashd(buf))
                vmsg("此代號已經有人使用");
            else
                break;
        }

        if (++try >= 10)
            login_abort("\n您嘗試錯誤的輸入太多，請下次再來吧");
    }

    for (;;)
    {
        vget(19, 0, "請設定密碼：", buf, PSWDLEN + 1, NOECHO);
        if ((strlen(buf) < 4) || !strcmp(buf, userid))
        {
            vmsg("密碼太簡單，易遭入侵，至少要 4 個字，請重新輸入");
            continue;
        }

        vget(20, 0, "請檢查密碼：", buf + PSWDLEN + 2, PSWDLEN + 1, NOECHO);
        if (!strcmp(buf, buf + PSWDLEN + 2))
            break;

        vmsg("密碼輸入錯誤, 請重新輸入密碼");
    }

    str_ncpy(cuser.passwd, genpasswd(buf), sizeof(cuser.passwd));

    do
    {
        vget(20, 0, "暱    稱：", cuser.username, UNLEN + 1, DOECHO);
    } while (strlen(cuser.username) < 2);

    //  /* itoc.010317: 提示 user 以後將不能改姓名 */
    //  vmsg("注意：請輸入真實姓名，本站不提供修改姓名的功\能");

    do
    {
        vget(21, 0, "真實姓名：", cuser.realname, RNLEN + 1, DOECHO);
    } while (strlen(cuser.realname) < 4);

#if 0
    char year;      /* 生日(民國年) */
    char month;     /* 生日(月) */
    char day;     /* 生日(日) */

#endif

  int year;
    do
    {
        vget(22, 0, "出生年(民國)：", buf, 4, DOECHO);
        year = atoi(buf);
    } while (year < 1 || year > 255);

  cuser.year = year;

    do
    {
        vget (22, 18, "出生月：", buf, 3, DOECHO);
        cuser.month = atoi(buf);
    } while (cuser.month < 1 || cuser.month > 12);

    do
    {
        vget (22, 30, "出生日：", buf, 3, DOECHO);
        cuser.day = atoi(buf);
    } while (cuser.day < 1 || cuser.day > 31);

    do
    {
        vget (23, 0, "性別 (0)中性 (1)男性 (2)女性：", buf, 2, DOECHO);
        cuser.sex = atoi(buf);
    } while (cuser.sex < 0 || cuser.sex > 2);

    cuser.userlevel = PERM_DEFAULT;
    cuser.ufo = UFO_DEFAULT_NEW;
    cuser.numlogins = 1;
    cuser.tvalid = ap_start;        /* itoc.030724: 拿上站時間當第一次認證碼的 seed */
    sprintf(cuser.email, "%s.bbs@%s", cuser.userid, str_host);  /* itoc.010902: 預設 email */

    /* Ragnarok.050528: 可能二人同時申請同一個 ID，在此必須再檢查一次 */
    usr_fpath(buf, userid, NULL);
    if (dashd(buf))
    {
        vmsg("此代號剛被註冊走，請重新申請");
        abort_bbs();
    }

    /* dispatch unique userno */

    cuser.firstlogin = cuser.lastlogin = cuser.tcheck = slot.uptime = ap_start;
    memcpy(slot.userid, userid, IDLEN);

    fd = open(FN_SCHEMA, O_RDWR | O_CREAT, 0600);
    {
        /* flock(fd, LOCK_EX); */
        /* Thor.981205: 用 fcntl 取代flock, POSIX標準用法 */
        f_exlock(fd);

        cuser.userno = try = uniq_userno(fd);
        write(fd, &slot, sizeof(slot));
        /* flock(fd, LOCK_UN); */
        /* Thor.981205: 用 fcntl 取代flock, POSIX標準用法 */
        f_unlock(fd);
    }
    close(fd);

    /* create directory */

    /* usr_fpath(buf, userid, NULL); */ /* 剛做過 */
    mkdir(buf, 0700);
    strcat(buf, "/@");
    mkdir(buf, 0700);
    usr_fpath(buf, userid, "gem");  /* itoc.010727: 個人精華區 */
    /* mak_dirs(buf); */
    mak_links(buf);         /* itoc.010924: 減少個人精華區目錄 */
#ifdef MY_FAVORITE
    usr_fpath(buf, userid, "MF");
    mkdir(buf, 0700);
#endif

    usr_fpath(buf, userid, fn_acct);
    fd = open(buf, O_WRONLY | O_CREAT, 0600);
    write(fd, &cuser, sizeof(ACCT));
    close(fd);
    /* Thor.990416: 注意: 怎麼會有 .ACCT長度是0的, 而且只有 @目錄, 持續觀察中 */

    sprintf(buf, "%d", try);
    blog("APPLY", buf);
}

#endif /* LOGINASNEW */


/* ----------------------------------------------------- */
/* bad login                         */
/* ----------------------------------------------------- */


#define FN_BADLOGIN "logins.bad"

    static void
logattempt(type, content)
    int type;           /* '-' login failure   ' ' success */
    char *content;
{
    char buf[128], fpath[64];

    sprintf(buf, "%s %c %s\n", Btime(&ap_start), type, content);

    usr_fpath(fpath, cuser.userid, FN_LOG);
    f_cat(fpath, buf);

    if (type != ' ')
    {
        usr_fpath(fpath, cuser.userid, FN_BADLOGIN);
        sprintf(buf, "[%s] %s\n", Btime(&ap_start), fromhost);
        f_cat(fpath, buf);
    }
}


/* ----------------------------------------------------- */
/* 登錄 BBS 程式                     */
/* ----------------------------------------------------- */


extern void talk_rqst();
extern void bmw_rqst();


#ifdef HAVE_WHERE
//static
    int     /* 1:在list中 0:不在list中 */
belong_list(filelist, key, desc)
    char *filelist, *key, *desc;
{
    FILE *fp;
    char buf[80], *str;
    int rc;

    rc = 0;
    if (fp = fopen(filelist, "r"))
    {
        while (fgets(buf, sizeof(buf), fp))
        {
            if (buf[0] == '#')
                continue;

            if (str = (char *) strchr(buf, ' '))
            {
                *str = '\0';
                if (strstr(key, buf))
                {
                    /* 跳過空白分隔 */
                    for (str++; *str && isspace(*str); str++)
                        ;

                    strcpy(desc, str);
                    if (str = (char *) strchr(desc, '\n'))  /* 最後的 '\n' 不要 */
                        *str = '\0';
                    rc = 1;
                    break;
                }
            }
        }
        fclose(fp);
    }
    return rc;
}
#endif


    static void
utmp_setup(mode)
    int mode;
{
    UTMP utmp;
    uschar *addr;

    memset(&utmp, 0, sizeof(utmp));

    utmp.pid = currpid;
    utmp.userno = cuser.userno;
    utmp.mode = bbsmode = mode;
    /* utmp.in_addr = tn_addr; */ /* itoc.010112: 改變umtp.in_addr以使ulist_cmp_host正常 */
    addr = (uschar *) &tn_addr;
    utmp.in_addr = (addr[0] << 24) + (addr[1] << 16) + (addr[2] << 8) + addr[3];
    utmp.userlevel = cuser.userlevel;   /* itoc.010309: 把 userlevel 也放入 cache */
    utmp.ufo = cuser.ufo;
    utmp.status = 0;

    strcpy(utmp.userid, cuser.userid);
    strcpy(utmp.realid, cuser.userid);
#ifdef DETAIL_IDLETIME
    utmp.idle_time = ap_start;
#endif

#ifdef GUEST_NICK
    if (!cuser.userlevel)       /* guest */
    {
        char nick[9][5] = {"遊子", "水滴", "訪客", "補帖", "豬頭", "影子", "病毒", "童年", "石像"};
        sprintf(cuser.username, "太陽下的%s", nick[ap_start % 9]);
    }
#endif  /* GUEST_NICK */

    strcpy(utmp.username, cuser.username);

#ifdef HAVE_WHERE

#  ifdef GUEST_WHERE
    if (!cuser.userlevel)       /* guest */
    {
        /* itoc.010910: GUEST_NICK 和 GUEST_WHERE 的亂數模數避免一樣 */
        char from[16][9] = {"風亭九思", "青埔朝陽", "率意通衢", "南台遠眺", "康莊迎曦", "碧草如茵", "緣慧潤生", "西庭笑語",
            "玉樹向榮", "綠掩重樓", "松林立翠", "竹湖晨風", "竹園映亭", "曲道夾蔭", "荷塘月色", "思園春曉"};
        strcpy(utmp.from, from[ap_start % 16]);
    }
    else
#  endif    /* GUEST_WHERE */
    {

        /* 像 hinet 這種 ip 很多， DN 很少的，就寫入 etc/fqdn    *
         * 像 140.112. 這種就寫在 etc/host                       *
         * 即使 DNS 爛掉，在 etc/host 裡面的還是可以照樣判斷成功 *
         * 如果把 140.112. 寫入 etc/host 中，就不用把 ntu.edu.tw *
         * 重覆寫入 etc/fqdn 裡了                                */

        char name[256];

        /* 先比對 ID */
        str_lower(name, cuser.userid);
        if (!belong_list(FN_ETC_IDHOME, name, utmp.from))
        {
            /* 再比對 FQDN */
            str_lower(name, fromhost);  /* itoc.011011: 大小寫均可，etc/fqdn 裡面都要寫小寫 */
            if (!belong_list(FN_ETC_FQDN, name, utmp.from))
            {
                /* 再比對 ip */
                sprintf(name, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
                if (!belong_list(FN_ETC_HOST, name, utmp.from))
                    str_ncpy(utmp.from, fromhost, sizeof(utmp.from)); /* 如果都沒找到對應故鄉，就是用 fromhost */
            }
        }
    }

#else
    str_ncpy(utmp.from, fromhost, sizeof(utmp.from));
#endif  /* HAVE_WHERE */      

    /* Thor: 告訴User已經滿了放不下... */
    if (!utmp_new(&utmp))
        login_abort("\n您剛剛選的位子已經被人捷足先登了，請下次再來吧");

    /* itoc.001223: utmp_new 完再 pal_cache，如果 login_abort 就不做了 */
    pal_cache();
}


/* ----------------------------------------------------- */
/* user login                        */
/* ----------------------------------------------------- */


    static int      /* 回傳 multi */
login_user(content)
    char *content;
{
    int attempts;       /* 嘗試幾次錯誤 */
    int multi;
    char fpath[64], uid[IDLEN + 1];
#ifndef CHAT_SECURE
    char passbuf[PSWDLEN + 1];
#endif

    move(b_lines, 0);
    time_t now = time(NULL);
    if (now >= 1301587200 && now <= 1301673600) /* 愚人節計畫 */
    {
        outs("\033[1;44m   ※ 本站不開放 \033[1;32m" STR_GUEST "\033[1;37m 參觀"
                "  申請新帳號：\033[1;31m" STR_NEW "\033[1;44m                                   \033[m");
    }
    else
    {
        outs("   ※ 本站不開放 \033[1;32m" STR_GUEST "\033[m 參觀"
                "  申請新帳號：\033[1;31m" STR_NEW "\033[m");
    }
    attempts = 0;
    multi = 0;
    for (;;)
    {
        if (++attempts > LOGINATTEMPTS)
        {
            film_out(FILM_TRYOUT, 0);
            login_abort("\n再見 ...");
        }
        
        time_t now = time(NULL);
        if (now >= 1301587200 && now <= 1301673600) /* 愚人節 */
        {
            vget(b_lines - 2, 0, "   [Login ID] ", uid, IDLEN + 1, DOECHO);
        }
        else
        {
            vget(b_lines - 2, 0, "   [您的帳號] ", uid, IDLEN + 1, DOECHO);
        }

        if (!str_cmp(uid, STR_NEW))
        {
#ifdef LOGINASNEW
#  ifdef HAVE_GUARANTOR     /* itoc.000319: 保證人制度 */
            vget(b_lines - 2, 0, "   [您的保人] ", uid, IDLEN + 1, DOECHO);
            if (!*uid || (acct_load(&cuser, uid) < 0))
            {
                vmsg("抱歉，沒有介紹人不得加入本站");
            }
            else if (!HAS_PERM(PERM_GUARANTOR))
            {
                vmsg("抱歉，您不夠資格擔任別人的介紹人");
            }
            else if (!vget(b_lines - 2, 40, "[保人密碼] ", passbuf, PSWDLEN + 1, NOECHO))
            {       
                continue;
            }
            else
            {
                if (chkpasswd(cuser.passwd, passbuf))
                {
                    logattempt('-', content);
                    vmsg(ERR_PASSWD);
                }
                else
                {
                    FILE *fp;
                    char parentid[IDLEN + 1], buf[80];
                    time_t now;

                    /* itoc.010820: 記錄保人於保證人及被保人 */
                    strcpy(parentid, cuser.userid);
                    acct_apply();
                    time(&now);

                    /* itoc.010820.註解: 把對方 log 在行首，在 reaper 時可以方便砍 tree */
                    sprintf(buf, "%s 於 %s 介紹此人(%s)加入本站\n", parentid, Btime(&now), cuser.userid);
                    usr_fpath(fpath, cuser.userid, "guarantor");
                    if (fp = fopen(fpath, "a"))
                    {
                        fputs(buf, fp);
                        fclose(fp);
                    }
                    sprintf(buf, "%s 於 %s 被此人(%s)介紹加入本站\n", cuser.userid, Btime(&now), parentid);
                    usr_fpath(fpath, parentid, "guarantor");
                    if (fp = fopen(fpath, "a"))
                    {
                        fputs(buf, fp);
                        fclose(fp);
                    }

                    break;
                }
            }
#  else
            acct_apply(); /* Thor.980917: 註解: setup cuser ok */
            break;
#  endif
#else
            outs("\n本系統目前暫停線上註冊, 請用 " STR_GUEST " 進入");
            continue;
#endif
        }
        else if (!*uid)
        {
            /* 若沒輸入 ID，那麼 continue */
        }
        else if (str_cmp(uid, STR_GUEST))   /* 一般使用者 */
        {
            if (now >= 1301587200 && now <= 1301673600) /* 愚人節 */
            {
                if (!vget(b_lines - 2, 40, "[驗證金鑰] ", passbuf, PSWDLEN + 1, NOECHO))
                    continue;   /* 不打密碼則取消登入 */
            }
            else
            {
                if (!vget(b_lines - 2, 40, "[您的密碼] ", passbuf, PSWDLEN + 1, NOECHO))
                    continue; /* 不打密碼則取消登入 */
            }
            /* itoc.040110: 在輸入完 ID 及密碼，才載入 .ACCT */
            if (acct_load(&cuser, uid) < 0)
            {
                vmsg(err_uid);
                continue;
            }

            if (chkpasswd(cuser.passwd, passbuf))
            {
                logattempt('-', content);
                vmsg(ERR_PASSWD);
            }
            else
            {

                if (!str_cmp(cuser.userid, str_sysop))
                {
#ifdef SYSOP_SU
                    /* 簡單的 SU 功能 */
                    if (vans("變更使用者身分(Y/N)？[N] ") == 'y')
                    {
                        for (;;)
                        {
                            if (vget(b_lines - 2, 0, "   [變更帳號] ", uid, IDLEN + 1, DOECHO) && 
                                    acct_load(&cuser, uid) >= 0)
                                break;
                            vmsg(err_uid);
                        }
                    }
                    else
#endif
                    {
                        /* SYSOP gets all permission bits */
                        /* itoc.010902: DENY perm 排外 */
                        //      cuser.userlevel = ~0 ^ (PERM_DENYMAIL | PERM_DENYTALK | PERM_DENYCHAT | PERM_DENYPOST | PERM_DENYLOGIN | PERM_PURGE);
                    }   
                }

                if (cuser.ufo & UFO_ACL)
                {
                    usr_fpath(fpath, cuser.userid, FN_ACL);
                    str_lower(fromhost, fromhost);  /* lkchu.981201: 換小寫 */
                    if (!acl_has(fpath, "", fromhost))
                    {   /* Thor.980728: 注意 acl 檔中要全部小寫 */
                        logattempt('-', content);
                        login_abort("\n您的上站地點不太對勁，請核對 [上站地點設定檔]");
                    }
                }

                logattempt(' ', content);

                /* check for multi-session */

                if (!HAS_PERM(PERM_ALLADMIN))
                {
                    UTMP *ui;
                    pid_t pid;

                    if (HAS_PERM(PERM_DENYLOGIN | PERM_PURGE))
                        login_abort("\n這個帳號暫停服務，詳情請向站長洽詢。");


                    if (!(ui = (UTMP *) utmp_find(cuser.userno)))
                        break;      /* user isn't logged in */

                    pid = ui->pid;
                    if (pid && vans("您想踢掉其他重複的 login (Y/N)嗎？[Y] ") != 'n' && pid == ui->pid)
                    {
                        if ((kill(pid, SIGTERM) == -1) && (errno == ESRCH))
                            utmp_free(ui);
                        else
                            sleep(3);           /* 被踢的人這時候正在自我了斷 */ 
                        blog("MULTI", cuser.userid);
                    }

                    if ((multi = utmp_count(cuser.userno, 0)) >= MULTI_MAX ||   /* 線上已有 MULTI_MAX 隻自己，禁止登入 */
                            (!multi && acct_load(&cuser, uid) < 0))         /* yiting.050101: 若剛已踢掉所有 multi-login，那麼重新讀取以套用變更 */
                        login_abort("\n再見 ...");
                }
                break;
            }
        }
        else
        {               /* guest */
            vmsg("抱歉，本站不開放 " STR_GUEST " 參觀");
            continue;
        }
    }

    return multi;
}


    static void
login_level()
{
    int fd;
    usint level;
    ACCT tuser;
    char fpath[64];

    /* itoc.010804.註解: 有 PERM_VALID 者自動發給 PERM_POST PERM_PAGE PERM_CHAT */
    level = cuser.userlevel | (PERM_ALLVALID ^ PERM_VALID);

    if (!(level & PERM_ALLADMIN))
    {
#ifdef JUSTIFY_PERIODICAL
        if ((level & PERM_VALID) && (cuser.tvalid + VALID_PERIOD < ap_start))
        {
            level ^= PERM_VALID;
            /* itoc.011116: 主動發信通知使用者，一直送信不知道會不會太耗空間 !? */
            mail_self(FN_ETC_REREG, str_sysop, "您的認證已經過期，請重新認證", 0);
        }
#endif

#ifdef NEWUSER_LIMIT
        /* 即使已經通過認證，還是要見習三天 */
        if (ap_start - cuser.firstlogin < 3 * 86400)
            level &= ~PERM_POST;
#endif

        /* itoc.000520: 未經身分認證, 禁止 post/chat/talk/write */
        if (!(level & PERM_VALID))
            level &= ~(PERM_POST | PERM_CHAT | PERM_PAGE);

        if (level & PERM_DENYPOST)
            level &= ~PERM_POST;

        if (level & PERM_DENYTALK)
            level &= ~PERM_PAGE;

        if (level & PERM_DENYCHAT)
            level &= ~PERM_CHAT;

        if ((cuser.numemails >> 4) > (cuser.numlogins + cuser.numposts))
            level |= PERM_DENYMAIL;
    }

    cuser.userlevel = level;

    usr_fpath(fpath, cuser.userid, fn_acct);
    if ((fd = open(fpath, O_RDWR)) >= 0)
    {
        if (read(fd, &tuser, sizeof(ACCT)) == sizeof(ACCT))
        {
            /* itoc.010805.註解: 這次的寫回 .ACCT 是為了讓別人 Query 線上使用者時
                 出現的上站時間/來源正確，以及回存正確的 userlvel */
tuser.userlevel = level;
            tuser.lastlogin = ap_start;
            strcpy(tuser.lasthost, cuser.lasthost);

            lseek(fd, (off_t) 0, SEEK_SET);
            write(fd, &tuser, sizeof(ACCT));
        }
        close(fd);
    }
}


    static void
login_status(multi)
    int multi;
{
    usint status;
    char fpath[64];
    struct tm *ptime;

    status = 0;

    /* itoc.010831: multi-login 的第二隻加上不可變動錢幣的旗標 */
    if (multi)
        status |= STATUS_COINLOCK;

    /* itoc.011022: 加入生日旗標 */
    ptime = localtime(&ap_start);
    if (cuser.day == ptime->tm_mday && cuser.month == ptime->tm_mon + 1)
        status |= STATUS_BIRTHDAY;

    /* 朋友名單同步、清理過期信件 */
    if (ap_start > cuser.tcheck + CHECK_PERIOD)
    {
        outz(MSG_CHKDATA);
        refresh();

        cuser.tcheck = ap_start;
        usr_fpath(fpath, cuser.userid, fn_pal);
        pal_sync(fpath);
#ifdef HAVE_ALOHA
        usr_fpath(fpath, cuser.userid, FN_FRIENZ);
        frienz_sync(fpath);
#endif
#ifdef OVERDUE_MAILDEL
        status |= m_quota();        /* Thor.註解: 資料整理稽核有包含 BIFF check */
#endif
    }
#ifdef OVERDUE_MAILDEL
    else
#endif
        status |= m_query(cuser.userid);

    /* itoc.010924: 檢查個人精華區是否過多 */
#ifndef LINUX   /* 在 Linux 下這檢查怪怪的 */
    {
        struct stat st;
        usr_fpath(fpath, cuser.userid, "gem");
        if (!stat(fpath, &st) && (st.st_size >= 512 * 7))
            status |= STATUS_MGEMOVER;
    }
#endif

    cutmp->status |= status;
}


    static void
login_other()
{
    usint status;
    char fpath[64];

    /* 刪除錯誤登入記錄 */
    usr_fpath(fpath, cuser.userid, FN_BADLOGIN);
    if (more(fpath, (char *) -1) >= 0 && vans("以上為輸入密碼錯誤時的上站地點記錄，要刪除嗎(Y/N)？[Y] ") != 'n')
        unlink(fpath);

    if (!HAS_PERM(PERM_VALID))
        film_out(FILM_NOTIFY, -1);      /* 尚未認證通知 */
#ifdef JUSTIFY_PERIODICAL
    else if (!HAS_PERM(PERM_ALLADMIN) && (cuser.tvalid + VALID_PERIOD - INVALID_NOTICE_PERIOD < ap_start))
        film_out(FILM_REREG, -1);       /* 有效時間逾期 10 天前提出警告 */
#endif

#ifdef NEWUSER_LIMIT
    if (ap_start - cuser.firstlogin < 3 * 86400)
        film_out(FILM_NEWUSER, -1);     /* 即使已經通過認證，還是要見習三天 */
#endif

    status = cutmp->status;

#ifdef OVERDUE_MAILDEL
    if (status & STATUS_MQUOTA)
        film_out(FILM_MQUOTA, -1);      /* 過期信件即將清除警告 */
#endif

    if (status & STATUS_MAILOVER)
        film_out(FILM_MAILOVER, -1);    /* 信件過多或寄信過多 */

    //if (status & STATUS_MGEMOVER)
        //film_out(FILM_MGEMOVER, -1);  /* itoc.010924: 個人精華區過多警告 */

    if (status & STATUS_BIRTHDAY)
        film_out(FILM_BIRTHDAY, -1);    /* itoc.010415: 生日當天上站有 special 歡迎畫面 */

    ve_recover();               /* 上次斷線，編輯器回存 */
}


    static void
tn_login()
{
    int multi;
    char buf[128];

    bbsmode = M_LOGIN;  /* itoc.020828: 以免過久未輸入時 igetch 會出現 movie */

    /* --------------------------------------------------- */
    /* 登錄系統                      */
    /* --------------------------------------------------- */

    /* Thor.990415: 記錄ip, 怕正查不到 */
    sprintf(buf, "%s ip:%08x (%d)", fromhost, tn_addr, currpid);

    multi = login_user(buf);

    blog("ENTER", buf);

    /* --------------------------------------------------- */
    /* 初始化 utmp、flag、mode、信箱             */
    /* --------------------------------------------------- */

    bbstate = STAT_STARTED; /* 進入系統以後才可以回水球 */
    utmp_setup(M_LOGIN);        /* Thor.980917: 註解: cutmp, cutmp-> setup ok */
    total_user = ushm->count;   /* itoc.011027: 未進使用者名單前，啟始化 total_user */

    mbox_main();

#ifdef MODE_STAT
    memset(&modelog, 0, sizeof(UMODELOG));
    mode_lastchange = ap_start;
#endif

    if (cuser.userlevel)        /* not guest */
    {
        /* ------------------------------------------------- */
        /* 核對 user level 並將 .ACCT 寫回             */
        /* ------------------------------------------------- */

        /* itoc.030929: 在 .ACCT 寫回以前，不可以有任何 vmsg(NULL) 或 more(xxxx, NULL)
             等的東西，這樣如果 user 在 vmsg(NULL) 時回認證信，才不會被寫回的 cuser 蓋過 */

        cuser.lastlogin = ap_start;
        str_ncpy(cuser.lasthost, fromhost, sizeof(cuser.lasthost));

        login_level();

        /* ------------------------------------------------- */
        /* 設定 status                     */
        /* ------------------------------------------------- */

        login_status(multi);

        /* ------------------------------------------------- */
        /* 秀些資訊                      */
        /* ------------------------------------------------- */

        login_other();
    }

    srand(ap_start * cuser.userno * currpid);
}


    static void
tn_motd()
{
    usint ufo;

    ufo = cuser.ufo;

    if (!(ufo & UFO_MOTD))
    {
        more("gem/@/@-day", NULL);  /* 今日熱門話題 */
        pad_view();
    }
    time_t now = time(NULL);
    if (now >= 1301587200 && now <= 1301673600)
        more("gem/@/@FOOLDAYPOST", NULL); /* 愚人節 */

#ifdef HAVE_NOALOHA
    if (!(ufo & UFO_NOALOHA))
#endif
    {
#ifdef LOGIN_NOTIFY
        loginNotify();
#endif
#ifdef HAVE_ALOHA
        aloha();
#endif
    }

#ifdef HAVE_FORCE_BOARD
    brd_force();    /* itoc.000319: 強制閱讀公告板 */
#endif
}


/* ----------------------------------------------------- */
/* trap signals                      */
/* ----------------------------------------------------- */


    static void
tn_signals()
{
    struct sigaction act;

    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;

    act.sa_handler = (void *) abort_bbs;
    sigaction(SIGBUS, &act, NULL);
    sigaction(SIGSEGV, &act, NULL);
    sigaction(SIGTERM, &act, NULL);
    sigaction(SIGXCPU, &act, NULL);
#ifdef SIGSYS
    /* Thor.981221: easy for porting */
    sigaction(SIGSYS, &act, NULL);/* bad argument to system call */
#endif

    act.sa_handler = (void *) talk_rqst;
    sigaction(SIGUSR1, &act, NULL);

    act.sa_handler = (void *) bmw_rqst;
    sigaction(SIGUSR2, &act, NULL);

    /* 在此借用 sigset_t act.sa_mask */
    sigaddset(&act.sa_mask, SIGPIPE);
    sigprocmask(SIG_BLOCK, &act.sa_mask, NULL);

}

    static int
show_file(fpath, ln, lines)
    char *fpath;
    int ln, lines;
{
    FILE *fp;
    char buf[ANSILINELEN];
    int i;

    if ((fp = fopen(fpath, "r")))
    {
        i = lines;
        while (fgets(buf, ANSILINELEN, fp) && i--)
            outs(buf);
        fclose(fp);
        return 1;
    }

    sprintf(buf, "%s 遺失，請告知站長", fpath);
    zmsg(buf);
    return 0;
}

    static inline void
tn_main()
{
    clear();

#ifdef HAVE_LOGIN_DENIED
    if (acl_has(BBS_ACLFILE, "", fromhost))
        login_abort("\n貴機器於不被敝站接受");
#endif

/*
    outs("系統維護中\n\n造成您的困擾深感抱歉<(_ _)>");
        if (vkey() != 'm' || vkey() != 'p' || vkey() != '6' || vkey() != '0' || vkey() != '7')
        login_abort("\n關站維修，再見");
*/
      move(0, 0);
    time(&ap_start);

    time_t now = time(NULL);
    if (now >= 1301587200 && now <= 1301673600)
    {
        prints("\033[1;36;44msony.tfcis.org\033[0;44m      \033[1;32m→→→\033[0;44m        \033[1;33m南一資訊\033[0;44m        \033[1;32m←←←\033[0;44          \033[1;36m210.70.137.212\033[m\n");
        prints("\033[1;44m                      歡迎光臨【\033[33;46m  索尼小站  \033[37;44m】目前線上人數 [\033[33m%d\033[37m] 人\033[0;44m              \033[m", ushm->count);
    }
    else
    {
        prints("%s ⊙ " SCHOOLNAME " ⊙ " MYIPADDR "\n"
                "歡迎光臨【\033[1;33;46m %s \033[m】目前線上人數 [%d] 人",
                str_host, str_site, ushm->count);
    }
    //film_out((ap_start % 3) + FILM_OPENING0, 3);  /* 亂數顯示開頭畫面 */
    char fpath[64];
    time(&ap_start);
    sprintf(fpath, "gem/@/@opening.%d", time(0) % 3);
    prints("\n\n"); /* Chensc.070322: 修正進站畫面垂直位置 */
    show_file(fpath, 3, 20);

    currpid = getpid();

    tn_signals();   /* Thor.980806: 放於 tn_login前, 以便 call in不會被踢 */
    tn_login();

    board_main();
    gem_main();
#ifdef MY_FAVORITE
    mf_main();
#endif
    talk_main();

    tn_motd();

    menu();
    abort_bbs();    /* to make sure it will terminate */
}


/* ----------------------------------------------------- */
/* FSA (finite state automata) for telnet protocol   */
/* ----------------------------------------------------- */


    static void
telnet_init()
{
    static char svr[] = 
    {
        IAC, DO, TELOPT_TTYPE,
        IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE,
        IAC, WILL, TELOPT_ECHO,
        IAC, WILL, TELOPT_SGA
    };

    int n, len;
    char *cmd;
    int rset;
    struct timeval to;
    char buf[64];

    /* --------------------------------------------------- */
    /* init telnet protocol              */
    /* --------------------------------------------------- */

    cmd = svr;

    for (n = 0; n < 4; n++)
    {
        len = (n == 1 ? 6 : 3);
        send(0, cmd, len, 0);
        cmd += len;

        rset = 1;
        /* Thor.981221: for future reservation bug */
        to.tv_sec = 1;
        to.tv_usec = 1;
        if (select(1, (fd_set *) & rset, NULL, NULL, &to) > 0)
            recv(0, buf, sizeof(buf), 0);
    }
}


/* ----------------------------------------------------- */
/* 支援超過 24 列的畫面                  */
/* ----------------------------------------------------- */


    static void
term_init()
{
#if 0   /* fuse.030518: 註解 */
    server問：你會改變行列數嗎？(TN_NAWS, Negotiate About Window Size)
        client答：Yes, I do. (TNCH_DO)

        那麼在連線時，當TERM變化行列數時就會發出：
        TNCH_IAC + TNCH_SB + TN_NAWS + 行數列數 + TNCH_IAC + TNCH_SE;
#endif

    /* ask client to report it's term size */
    static char svr[] =         /* server */
    {
        IAC, DO, TELOPT_NAWS
    };

    int rset;
    char buf[64], *rcv;
struct timeval to;

    /* 問對方 (telnet client) 有沒有支援不同的螢幕寬高 */
    send(0, svr, 3, 0);

    rset = 1;
    to.tv_sec = 1;
    to.tv_usec = 1;
    if (select(1, (fd_set *) & rset, NULL, NULL, &to) > 0)
        recv(0, buf, sizeof(buf), 0);

    rcv = NULL;
    if ((uschar) buf[0] == IAC && buf[2] == TELOPT_NAWS)
    {
        /* gslin: Unix 的 telnet 對有無加 port 參數的行為不太一樣 */
        if ((uschar) buf[1] == SB)
        {
            rcv = buf + 3;
        }
        else if ((uschar) buf[1] == WILL)
        {
            if ((uschar) buf[3] != IAC)
            {
                rset = 1;
                to.tv_sec = 1;
                to.tv_usec = 1;
                if (select(1, (fd_set *) & rset, NULL, NULL, &to) > 0)
                    recv(0, buf + 3, sizeof(buf) - 3, 0);
            }
            if ((uschar) buf[3] == IAC && (uschar) buf[4] == SB && buf[5] == TELOPT_NAWS)
                rcv = buf + 6;
        }
    }

    if (rcv)
    {
        b_lines = ntohs(* (short *) (rcv + 2)) - 1;
        b_cols = ntohs(* (short *) rcv) - 1;

        /* b_lines 至少要 23，最多不能超過 T_LINES - 1 */
        if (b_lines >= T_LINES)
            b_lines = T_LINES - 1;
        else if (b_lines < 23)
            b_lines = 23;
        /* b_cols 至少要 79，最多不能超過 T_COLS - 1 */
        if (b_cols >= T_COLS)
            b_cols = T_COLS - 1;
        else if (b_cols < 79)
            b_cols = 79;
    }
    else
    {
        b_lines = 23;
        b_cols = 79;
    }

    d_cols = b_cols - 79;
}


/* ----------------------------------------------------- */
/* stand-alone daemon                    */
/* ----------------------------------------------------- */


    static void
start_daemon(port)
    int port; /* Thor.981206: 取 0 代表 *沒有參數* , -1 代表 -i (inetd) */
{
    int n;
    struct linger ld;
    struct sockaddr_in sin;
#ifdef HAVE_RLIMIT
    struct rlimit limit;
#endif
    char buf[80], data[80];
    time_t val;

    /*
     * More idiot speed-hacking --- the first time conversion makes the C
     * library open the files containing the locale definition and time zone.
     * If this hasn't happened in the parent process, it happens in the
     * children, once per connection --- and it does add up.
     */

    time(&val);
    strftime(buf, 80, "%d/%b/%Y %H:%M:%S", localtime(&val));

#ifdef HAVE_RLIMIT
    /* --------------------------------------------------- */
    /* adjust resource : 16 mega is enough       */
    /* --------------------------------------------------- */

    limit.rlim_cur = limit.rlim_max = 16 * 1024 * 1024;
    /* setrlimit(RLIMIT_FSIZE, &limit); */
    setrlimit(RLIMIT_DATA, &limit);

#ifdef SOLARIS
#define RLIMIT_RSS RLIMIT_AS    /* Thor.981206: port for solaris 2.6 */
#endif

    setrlimit(RLIMIT_RSS, &limit);

    limit.rlim_cur = limit.rlim_max = RLIM_INFINITY;
    setrlimit(RLIMIT_CORE, &limit);

    limit.rlim_cur = limit.rlim_max = 60 * 20;
    setrlimit(RLIMIT_CPU, &limit);
#endif

    /* --------------------------------------------------- */
    /* speed-hacking DNS resolve                 */
    /* --------------------------------------------------- */

    dns_init();

    /* --------------------------------------------------- */
    /* change directory to bbshome                   */
    /* --------------------------------------------------- */

    chdir(BBSHOME);
    umask(077);

    /* --------------------------------------------------- */
    /* detach daemon process                 */
    /* --------------------------------------------------- */

    /* The integer file descriptors associated with the streams
         stdin, stdout, and stderr are 0,1, and 2, respectively. */

    close(1);
    close(2);

    if (port == -1) /* Thor.981206: inetd -i */
    {
        /* Give up root privileges: no way back from here    */
        setgid(BBSGID);
        setuid(BBSUID);
#if 1
        n = sizeof(sin);
        if (getsockname(0, (struct sockaddr *) &sin, &n) >= 0)
            port = ntohs(sin.sin_port);
#endif
        /* mport = port; */ /* Thor.990325: 不需要了:P */

        sprintf(data, "%d\t%s\t%d\tinetd -i\n", getpid(), buf, port);
        f_cat(PID_FILE, data);
        return;
    }

    close(0);

    if (fork())
        exit(0);

    setsid();

    if (fork())
        exit(0);

    /* --------------------------------------------------- */
    /* fork daemon process               */
    /* --------------------------------------------------- */

    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = INADDR_ANY;

    if (port == 0) /* Thor.981206: port 0 代表沒有參數 */
    {
        n = MAX_BBSDPORT - 1;
        while (n)
        {
            if (fork() == 0)
                break;

            sleep(1);
            n--;
        }
        port = myports[n];
    }

    n = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    val = 1;
    setsockopt(n, SOL_SOCKET, SO_REUSEADDR, (char *) &val, sizeof(val));

    ld.l_onoff = ld.l_linger = 0;
    setsockopt(n, SOL_SOCKET, SO_LINGER, (char *) &ld, sizeof(ld));

    /* mport = port; */ /* Thor.990325: 不需要了:P */
    sin.sin_port = htons(port);
    if ((bind(n, (struct sockaddr *) &sin, sizeof(sin)) < 0) || (listen(n, QLEN) < 0))
        exit(1);

    /* --------------------------------------------------- */
    /* Give up root privileges: no way back from here    */
    /* --------------------------------------------------- */

    setgid(BBSGID);
    setuid(BBSUID);

    /* standalone */
    sprintf(data, "%d\t%s\t%d\n", getpid(), buf, port);
    f_cat(PID_FILE, data);
}


/* ----------------------------------------------------- */
/* reaper - clean up zombie children             */
/* ----------------------------------------------------- */


    static inline void
reaper()
{
    while (waitpid(-1, NULL, WNOHANG | WUNTRACED) > 0);
}


#ifdef  SERVER_USAGE
    static void
servo_usage()
{
    struct rusage ru;
    FILE *fp;

    fp = fopen("run/bbs.usage", "a");

    if (!getrusage(RUSAGE_CHILDREN, &ru))
    {
        fprintf(fp, "\n[Server Usage] %d: %d\n\n"
                "user time: %.6f\n"
                "system time: %.6f\n"
                "maximum resident set size: %lu P\n"
                "integral resident set size: %lu\n"
                "page faults not requiring physical I/O: %d\n"
                "page faults requiring physical I/O: %d\n"
                "swaps: %d\n"
                "block input operations: %d\n"
                "block output operations: %d\n"
                "messages sent: %d\n"
                "messages received: %d\n"
                "signals received: %d\n"
                "voluntary context switches: %d\n"
                "involuntary context switches: %d\n\n",

                getpid(), ap_start,
                (double) ru.ru_utime.tv_sec + (double) ru.ru_utime.tv_usec / 1000000.0,
                (double) ru.ru_stime.tv_sec + (double) ru.ru_stime.tv_usec / 1000000.0,
                ru.ru_maxrss,
                ru.ru_idrss,
                ru.ru_minflt,
                ru.ru_majflt,
                ru.ru_nswap,
                ru.ru_inblock,
                ru.ru_oublock,
                ru.ru_msgsnd,
                ru.ru_msgrcv,
                ru.ru_nsignals,
                ru.ru_nvcsw,
                ru.ru_nivcsw);
    }

    fclose(fp);
}
#endif


    static void
main_term()
{
#ifdef  SERVER_USAGE
    servo_usage();
#endif
    exit(0);
}


    static inline void
main_signals()
{
    struct sigaction act;

    /* act.sa_mask = 0; */ /* Thor.981105: 標準用法 */
    sigemptyset(&act.sa_mask);      
    act.sa_flags = 0;

    act.sa_handler = reaper;
    sigaction(SIGCHLD, &act, NULL);

    act.sa_handler = main_term;
    sigaction(SIGTERM, &act, NULL);

#ifdef  SERVER_USAGE
    act.sa_handler = servo_usage;
    sigaction(SIGPROF, &act, NULL);
#endif

    /* sigblock(sigmask(SIGPIPE)); */
}


    int
main(argc, argv)
    int argc;
    char *argv[];
{
    int csock;          /* socket for Master and Child */
    int value;
    int *totaluser;
    struct sockaddr_in sin;

    /* --------------------------------------------------- */
    /* setup standalone daemon               */
    /* --------------------------------------------------- */

    /* Thor.990325: usage, bbsd, or bbsd -i, or bbsd 1234 */
    /* Thor.981206: 取 0 代表 *沒有參數*, -1 代表 -i */
    start_daemon(argc > 1 ? strcmp("-i", argv[1]) ? atoi(argv[1]) : -1 : 0);

    main_signals();

    /* --------------------------------------------------- */
    /* attach shared memory & semaphore          */
    /* --------------------------------------------------- */

#ifdef HAVE_SEM
    sem_init();
#endif
    ushm_init();
    bshm_init();
    fshm_init();

    /* --------------------------------------------------- */
    /* main loop                         */
    /* --------------------------------------------------- */

    totaluser = &ushm->count;
    /* avgload = &ushm->avgload; */

    for (;;)
    {
        value = 1;
        if (select(1, (fd_set *) & value, NULL, NULL, NULL) < 0)
            continue;

        value = sizeof(sin);
        csock = accept(0, (struct sockaddr *) &sin, &value);
        if (csock < 0)
        {
            reaper();
            continue;
        }

        ap_start++;
        argc = *totaluser;
        if (argc >= MAXACTIVE - 5 /* || *avgload > THRESHOLD */ )
        {
            /* 借用 currtitle */
            sprintf(currtitle, "目前線上人數 [%d] 人，系統飽和，請稍後再來\n", argc);
            send(csock, currtitle, strlen(currtitle), 0);
            close(csock);
            continue;
        }

        if (fork())
        {
            close(csock);
            continue;
        }

        dup2(csock, 0);
        close(csock);

        /* ------------------------------------------------- */
        /* ident remote host / user name via RFC931      */
        /* ------------------------------------------------- */

        tn_addr = sin.sin_addr.s_addr;
        dns_name((char *) &sin.sin_addr, fromhost);

        telnet_init();
        term_init();
        tn_main();
    }
}