/* Internet FTP Server server machine - see RFC 959
 * Copyright 1991 Phil Karn, KA9Q
 */
#include <ctype.h>
#include <time.h>
#ifdef  __TURBOC__
#include <io.h>
#include <dir.h>
#endif
#ifdef UNIX
#include <sys/types.h>
#include <sys/stat.h>
#endif
#include "global.h"
#include "mbuf.h"
#include "socket.h"
#include "ftp.h"
#include "ftpserv.h"
#include "proc.h"
#include "dirutil.h"
#include "files.h"
#include "commands.h"
#include "config.h"
#include "cmdparse.h"
#include "mailutil.h"
#ifdef  LZW
#include "lzw.h"
#endif
  
static void ftpserv __ARGS((int s,void *unused,void *p));
static int pport __ARGS((struct sockaddr_in *sock,char *arg));
static int ftplogin __ARGS((struct ftpserv *ftp,char *pass));
static int sendit __ARGS((struct ftpserv *ftp,char *command,char *file));
static int recvit __ARGS((struct ftpserv *ftp,char *command,char *file));
static void sendmsgfile __ARGS((int s,int num,char *buf,int size,FILE *fp));
int doftptdisc __ARGS((int argc, char *argv[], void *p));
static void SendPasv(int s, struct sockaddr_in *sock);
  
#ifdef FTPSERVER
  
extern char System[];
int FtpUsers=0;
  
/* Command table: ordering MUST match xxxx_CMD defines in ftpserv.h */
static char *commands[] = {
    "user",
    "acct",
    "pass",
    "type",
    "list",
    "cwd",
    "dele",
    "help",
    "quit",
    "retr",
    "stor",
    "port",
    "nlst",
    "pwd",
    "xpwd",                 /* For compatibility with 4.2BSD */
    "mkd ",
    "xmkd",                 /* For compatibility with 4.2BSD */
    "xrmd",                 /* For compatibility with 4.2BSD */
    "rmd ",
    "stru",
    "mode",
    "rsme",                 /* Added by IW0CNB, for resuming interrupted trasnfers */
    "rput",
    "noop",                 /* For OS/2 compatibility   kf5mg*/
    "syst",
    "pasv",                 /* PASV by g4ide, for proxy-ftp, Mosaic... */
#ifdef LZW
    "xlzw",                 /* LZW FTP Compression      kf5mg*/
#endif
    NULLCHAR
};
  
/* Response messages */
static char banner[] = "220- %s, JNOS FTP version %s\n";
static char banner1[] = "220  Ready on %s";
static char badcmd[] = "500 Unknown command\n";
static char binwarn[] = "150-Warning: type is ASCII and %s appears to be binary\n";
static char unsupp[] = "500 Unsupported command or option\n";
static char AnonymousLogin[] = "331- Anonymous login OK. Please give e-mail address as password!\n";
static char givepass[] = "331 Enter PASS command\n";
/* static char challenge[] = "399 PASS challenge : %016lx\r\n"; */
static char logged[] = "230 %s logged in\n";
static char loggeda[] = "230 Logged in as anonymous, restrictions apply\n";
static char typeok[] = "200 Type %s OK\n";
static char only8[] = "501 Only logical bytesize 8 supported\n";
static char deleok[] = "250 File deleted\n";
static char mkdok[] = "200 MKD ok\n";
static char delefail[] = "550 Delete failed: %s\n";
static char pwdmsg[] = "257 \"%s\" is current directory\n";
static char badtype[] = "501 Unknown type \"%s\"\n";
static char badport[] = "501 Bad port syntax\n";
static char unimp[] = "502 Command not yet implemented\n";
static char bye[] = "221 Goodbye!\n";
static char nodir[] = "553 Can't read directory \"%s\": %s\n";
static char notadir[] = "550 Not a directory: %s\n";
static char cantopen[] = "550 Can't read file \"%s\": %s\n";
static char sending[] = "150 Opening data connection for %s %s %s\n"; /*N1BEE*/
static char cantmake[] = "553 Can't create \"%s\": %s\n";
static char writerr[] = "552 Write error: %s\n";
static char portok[] = "200 Port command okay\n";
static char rxok[] = "226 File received OK\n";
static char txok[] = "226 File sent OK\n";
static char noperm[] = "550 Permission denied\n";
static char noconn[] = "425 Data connection reset\n";
static char badcheck[] = "425 Bad checksum\n";
static char lowmem[] = "421 System overloaded, try again later\n";
static char notlog[] = "530 Please log in with USER and PASS\n";
static char userfirst[] = "503 Login with USER first.\n";
static char okay[] = "200 Ok\n";
static char help[] = "214-The following commands are recognized.\n";
static char syst[] = "215 %s Type: L8 Version: %s\n";
  
#ifdef  LZW
static char LZWOk[] = "299 %d %d LZW OK\n";
extern int Ftpslzw;
extern int Ftpclzw;
#endif
  
int32 Ftptdiscinit;
  
/* Set ftp redundancy timer */
int
doftptdisc(argc,argv,p)
int argc;
char *argv[];
void *p;
{
    return setlong(&Ftptdiscinit,"Ftp redundancy timer (sec)",argc,argv);
}
  
/* Start up FTP service */
int
ftpstart(argc,argv,p)
int argc;
char *argv[];
void *p;
{
    int16 port;
  
    if(argc < 2)
        port = IPPORT_FTP;
    else
        port = atoi(argv[1]);
#ifdef LZW
    /* Both the Server and Client will default to trying to  */
    /* use lzw compressiom.                                  */
    Ftpslzw = 1;
    Ftpclzw = 1;
#endif
  
    return start_tcp(port,"FTP Server",ftpserv,2048);
}
  
static void sendmsgfile(int s,int num,char *buf,int size,FILE *fp) {
  
    while(fgets(buf,size,fp)) {
        rip(buf);
        usprintf(s,"%d- %s\n",num,buf);
    }
}
  
static void
ftpserv(s,unused,p)
int s;  /* Socket with user connection */
void *unused;
void *p;
{
    struct ftpserv ftp;
    char **cmdp,buf[512],*arg,*cp,*file,*mode;
    long t;
    int cnt,i,r=0;
    int using_pasv = FALSE;
    struct sockaddr_in sock, lsocket, lcsocket;
    FILE *fp,*fpm;
  
    sockmode(s,SOCK_ASCII);
    memset((char *)&ftp,0,sizeof(ftp));     /* Start with clear slate */
    ftp.data = -1;
  
    sockowner(s,Curproc);           /* We own it now */
    ftp.control = s;
    /* Set default data port */
    i = SOCKSIZE;
    getpeername(s,(char *)&sock,&i);
    sock.sin_port = IPPORT_FTPD;
    ASSIGN(ftp.port,sock);
#ifdef LZW
    /* Socket assumes that lzw is off for socket. */
    ftp.uselzw = 0;
#endif
  
    log(s,"open FTP");
    FtpUsers++;
  
    /* now go say 'hello' */
    usprintf(s,banner,Hostname,Version);
    if((fp = fopen(Ftpmotd,"r")) != NULL) {
        while(fgets(buf,128,fp)) {
            rip(buf);
            usprintf(s,"220- %s\n",buf);
        }
        fclose(fp);
    }
    time(&t);
    cp = ctime(&t);
    usprintf(s,banner1,cp);
  
    loop:
    /* Time-out after some inactivity time - WG7J */
    alarm((long)(Ftptdiscinit*1000L));
    if((cnt = recvline(s,buf,sizeof(buf))) == -1){
        /* He closed on us */
        goto finish;
    }
    alarm(0L);
  
    if(cnt == 0){
        /* Can't be a legal FTP command */
        usputs(ftp.control,badcmd);
        goto loop;
    }
    rip(buf);
    /* Translate first word to lower case */
    for(cp = buf;*cp != ' ' && *cp != '\0';cp++)
        *cp = tolower(*cp);
    /* Find command in table; if not present, return syntax error */
    for(cmdp = commands;*cmdp != NULLCHAR;cmdp++)
        if(strncmp(*cmdp,buf,strlen(*cmdp)) == 0)
            break;
    if(*cmdp == NULLCHAR){
        usputs(ftp.control,badcmd);
        goto loop;
    }
    /* Allow only USER, PASS, HELP and QUIT before logging in */
    if(ftp.cd == NULLCHAR || ftp.path == NULLCHAR){
        switch(cmdp-commands){
            case USER_CMD:
            case PASS_CMD:
            case HELP_CMD:
            case QUIT_CMD:
                break;
            default:
                usputs(ftp.control,notlog);
                goto loop;
        }
    }
    arg = &buf[strlen(*cmdp)];
    while(*arg == ' ')
        arg++;
  
    /* Execute specific command */
    switch(cmdp-commands){
#ifdef LZW
        case LZW_CMD:
            if(!Ftpslzw) {
            /* if the server doens't want to use LZW compression, issue
             * the bad command message.
             */
                usputs(ftp.control,badcmd);
                ftp.uselzw  = 0;
            } else {
            /* Get bits and mode from clients XLZW request. */
                ftp.lzwmode = ftp.lzwbits = 0;
                sscanf(arg,"%d %d",&ftp.lzwbits,&ftp.lzwmode);
                if(!((ftp.lzwmode == 0 || ftp.lzwmode == 1)
                && (ftp.lzwbits > 8 && ftp.lzwbits < 17))) {
                /* bad args... DON'T use LZW and tell the client. */
                    ftp.lzwmode = LZWCOMPACT;
                    ftp.lzwbits = LZWBITS;
                    usputs(ftp.control,badcmd);
                    ftp.uselzw  = 0;
                } else {
                /* Tell the client that the command was accepted.    */
                    usprintf(ftp.control,LZWOk,ftp.lzwbits,ftp.lzwmode);
                /* And set the uselzw flag on the FTP socket struct. */
                    ftp.uselzw  = 1;
                }
            }
            break;
#endif /* LZW */
        case USER_CMD:
            free(ftp.username);
            ftp.username = strdup(arg);
            free(ftp.cd);   /* In case another 'user' command is issued - WG7J */
            free(ftp.path);
            ftp.cd = NULL;
            ftp.path = NULL;
        /* See if this would be an anonymous login */
        {
            int anony = 0;
            char *path;
  
            path = mallocw(FILE_PATH_SIZE);
            userlogin(ftp.username,NULL,&path,FILE_PATH_SIZE,&anony,"ftpperm");
            if(anony)
                usputs(ftp.control,AnonymousLogin);
            free(path);
        }
            usputs(ftp.control,givepass);
            break;
        case TYPE_CMD:
        switch(arg[0]){
            case 'A':
            case 'a':       /* Ascii */
                ftp.type = ASCII_TYPE;
                usprintf(ftp.control,typeok,arg);
                break;
            case 'l':
            case 'L':
                while(*arg != ' ' && *arg != '\0')
                    arg++;
                if(*arg == '\0' || *++arg != '8'){
                    usputs(ftp.control,only8);
                    break;
                }
                ftp.type = LOGICAL_TYPE;
                ftp.logbsize = 8;
                usprintf(ftp.control,typeok,arg);
                break;
            case 'B':
            case 'b':       /* Binary */
            case 'I':
            case 'i':       /* Image */
                ftp.type = IMAGE_TYPE;
                usprintf(ftp.control,typeok,arg);
                break;
            default:        /* Invalid */
                usprintf(ftp.control,badtype,arg);
                break;
        }
            break;
        case QUIT_CMD:
            usputs(ftp.control,bye);
            goto finish;
        case RETR_CMD:
        case RSME_CMD:
            file = pathname(ftp.cd,arg);
        switch(ftp.type){
            case IMAGE_TYPE:
            case LOGICAL_TYPE:
                mode = READ_BINARY;
                break;
            case ASCII_TYPE:
                mode = READ_TEXT;
                break;
        }
            if(!permcheck(ftp.path,RETR_CMD,file)){
                usputs(ftp.control,noperm);
            } else if((ftp.fp = fopen(file,mode)) == NULLFILE){
                usprintf(ftp.control,cantopen,file,sys_errlist[errno]);
            } else {
                if((cmdp-commands) == RSME_CMD) {
                    log(ftp.control,"RSME %s",file);
                    if(ftp.type == ASCII_TYPE && isbinary(ftp.fp)){
                        usprintf(ftp.control,binwarn,file);
                    }
                    sendit(&ftp,"RSME",file);
                } else {
                    log(ftp.control,"RETR %s",file);
                    if(ftp.type == ASCII_TYPE && isbinary(ftp.fp)){
                        usprintf(ftp.control,binwarn,file);
                    }
                    sendit(&ftp,"RETR",file);
                }
            }
            free(file);
            break;
        case STOR_CMD:
        case RPUT_CMD:
            file = pathname(ftp.cd,arg);
        switch(ftp.type){
            case IMAGE_TYPE:
            case LOGICAL_TYPE:
                if(cmdp-commands == RPUT_CMD)
                    mode = APPEND_BINARY;
                else
                    mode = WRITE_BINARY;
                break;
            case ASCII_TYPE:
                if(cmdp-commands == RPUT_CMD)
                    mode = APPEND_TEXT;
                else
                    mode = WRITE_TEXT;
                break;
        }
            if(cmdp-commands == RPUT_CMD){
                if(!permcheck(ftp.path,RPUT_CMD,file)){
                    usputs(ftp.control,noperm);
                } else if((ftp.fp = fopen(file,mode)) == NULLFILE){
                    usprintf(ftp.control,cantmake,file,sys_errlist[errno]);
                } else {
                    log(ftp.control,"RPUT %s",file);
                    recvit(&ftp,"RPUT",file);
                }
            } else {
                if(!permcheck(ftp.path,STOR_CMD,file)){
                    usputs(ftp.control,noperm);
                } else if((ftp.fp = fopen(file,mode)) == NULLFILE){
                    usprintf(ftp.control,cantmake,file,sys_errlist[errno]);
                } else {
                    log(ftp.control,"STOR %s",file);
                    recvit(&ftp,"STOR",file);
                }
            }
            free(file);
            break;
        case PORT_CMD:
            if(pport(&ftp.port,arg) == -1){
                usputs(ftp.control,badport);
            } else {
                usputs(ftp.control,portok);
            }
            break;
#ifndef CPM
        case LIST_CMD:
            file = pathname(ftp.cd,arg);
            if(!permcheck(ftp.path,RETR_CMD,file)){
                usputs(ftp.control,noperm);
            } else if((ftp.fp = dir(file,1)) == NULLFILE){
                usprintf(ftp.control,nodir,file,sys_errlist[errno]);
            } else {
                sendit(&ftp,"LIST",file);
            }
            free(file);
            break;
        case NLST_CMD:
            file = pathname(ftp.cd,arg);
            if(!permcheck(ftp.path,RETR_CMD,file)){
                usputs(ftp.control,noperm);
            } else if((ftp.fp = dir(file,0)) == NULLFILE){
                usprintf(ftp.control,nodir,file,sys_errlist[errno]);
            } else {
                sendit(&ftp,"NLST",file);
            }
            free(file);
            break;
        case CWD_CMD:
            file = pathname(ftp.cd,arg);

            /* Selcuk: Let's interpret '/' to mean the starting dir (Lynx, Mosaic compat). */
            if(!strcmp(file,"/")) {
                free(file);
                file = firstpath(ftp.path);
            }
            if(!permcheck(ftp.path,RETR_CMD,file)){
                usputs(ftp.control,noperm);
                free(file);
#ifdef  MSDOS
        /* Don'tcha just LOVE %%$#@!! MS-DOS? access() fails on some root dirs */
            } else if(strcmp(file,"/") == 0 || strcmp(file+1,":/") == 0 || access(file,0) == 0){
#else
            } else if(access(file,0) == 0){ /* See if it exists */
#endif

#ifdef MSDOS
                if((fpm = fopen(file,"r")) == NULLFILE) {  /* is it a dir? */
#else
                struct stat st;

                if((stat(file,&st)==0 && st.st_mode&S_IFDIR) {/* is it a dir? */
                    
#endif
                    /* Succeeded, record in control block */
                    free(ftp.cd);
                    ftp.cd = file;
  
                    /* If exists, send the contents of 'desc.ftp' in the new
                     * directory (unless the login passwd began with a '-').
                     */
                    strcpy(buf,file);
                    if(r!=2 && (fpm = fopen(strcat(buf,"/desc.ftp"),"r")) != NULL) {
                        sendmsgfile(ftp.control,257,buf,sizeof(buf),fpm);
                        fclose(fpm);
                    }
  
                    usprintf(ftp.control,pwdmsg,file);
                }
                else {
                    /* Failed because file is not a directory */
                    usprintf(ftp.control,notadir,file);
                    free(file);
#ifdef MSDOS
                    fclose(fpm);
#endif
                }
            } else {
            /* Failed, don't change anything */
                usprintf(ftp.control,nodir,file,sys_errlist[errno]);
                free(file);
            }
            break;
        case XPWD_CMD:
        case PWD_CMD:
            usprintf(ftp.control,pwdmsg,ftp.cd);
            break;
#else
        case LIST_CMD:
        case NLST_CMD:
        case CWD_CMD:
        case XPWD_CMD:
        case PWD_CMD:
#endif
        case ACCT_CMD:
            usputs(ftp.control,unimp);
            break;
        case HELP_CMD:
            usputs(ftp.control,help);
            for(cmdp = commands,i=buf[0]=0;*cmdp != NULLCHAR;cmdp++) {
                    strcat(buf,"   ");
                    strcat(buf,*cmdp);
                    if (i++ == 7) {
                        strupr(buf);
                        usprintf(ftp.control,"%s\n", buf);
                        i=buf[0]=0;
                    }
            }
            if (i) {
                strupr(buf);
                usprintf(ftp.control,"%s\n", buf);
            }
            usprintf(ftp.control,"214 Report problems to sysop@%s\n",Hostname);
            break;
        case NOOP_CMD:
            usputs(ftp.control,okay);
            break;
        case DELE_CMD:
            file = pathname(ftp.cd,arg);
            if(!permcheck(ftp.path,DELE_CMD,file)){
                usputs(ftp.control,noperm);
            } else if(unlink(file) == 0){
                log(ftp.control,"DELE %s",file);
                usputs(ftp.control,deleok);
            } else {
                usprintf(ftp.control,delefail,sys_errlist[errno]);
            }
            free(file);
            break;
        case PASS_CMD:
            if(ftp.username == NULLCHAR)
                usputs(ftp.control,userfirst);
            else
                r=ftplogin(&ftp,arg);
            break;
#ifndef CPM
        case XMKD_CMD:
        case MKD_CMD:
            file = pathname(ftp.cd,arg);
            if(!permcheck(ftp.path,MKD_CMD,file)){
                usputs(ftp.control,noperm);
#ifdef  UNIX
            } else if(mkdir(file,0777) == 0){
#else
            } else if(mkdir(file) == 0){
#endif
                log(ftp.control,"MKD %s",file);
                usputs(ftp.control,mkdok);
            } else {
                usprintf(ftp.control,cantmake,file,sys_errlist[errno]);
            }
            free(file);
            break;
        case XRMD_CMD:
        case RMD_CMD:
            file = pathname(ftp.cd,arg);
            if(!permcheck(ftp.path,RMD_CMD,file)){
                usputs(ftp.control,noperm);
            } else if(rmdir(file) == 0){
                log(ftp.control,"RMD %s",file);
                usputs(ftp.control,deleok);
            } else {
                usprintf(ftp.control,delefail,sys_errlist[errno]);
            }
            free(file);
            break;
        case STRU_CMD:
            if(tolower(arg[0]) != 'f')
                usputs(ftp.control,unsupp);
            else
                usputs(ftp.control,okay);
            break;
        case MODE_CMD:
            if(tolower(arg[0]) != 's')
                usputs(ftp.control,unsupp);
            else
                usputs(ftp.control,okay);
            break;
        case SYST_CMD:
            usprintf(ftp.control,syst,System,shortversion);
            break;
        case PASV_CMD:
            using_pasv = TRUE;
            /*
             * Send the PASV message. Use the IP address
             * on the local end of our control connection.
             */
            if (ftp.data != -1) /* left over error - kill the socket first */
               close_s(ftp.data);

            ftp.data = socket(AF_INET,SOCK_STREAM,0);
            listen(ftp.data,0);
            i = SOCKSIZE;
            getsockname(ftp.data,(char *)&lsocket,&i);
            i = SOCKSIZE;
            getsockname(ftp.control,(char *)&lcsocket,&i);
            lsocket.sin_addr.s_addr = lcsocket.sin_addr.s_addr;
            /*
             * send the address to the client.
             */
            SendPasv(ftp.control, &lsocket);
            break;
    }
#endif
    goto loop;
    finish:
  
    FtpUsers--;
    log(ftp.control,"close FTP");
    /* Clean up */
    close_s(ftp.control);
    if(ftp.data != -1)
        close_s(ftp.data);
    if(ftp.fp != NULLFILE)
        fclose(ftp.fp);
    free(ftp.username);
    free(ftp.path);
    free(ftp.cd);
}
  
/* Shut down FTP server */
int
ftp0(argc,argv,p)
int argc;
char *argv[];
void *p;
{
    int16 port;
  
    if(argc < 2)
        port = IPPORT_FTP;
    else
        port = atoi(argv[1]);
    return stop_tcp(port);
}
  
static
int
pport(sock,arg)
struct sockaddr_in *sock;
char *arg;
{
    int32 n;
    int i;
  
    n = 0;
    for(i=0;i<4;i++){
        n = atoi(arg) + (n << 8);
        if((arg = strchr(arg,',')) == NULLCHAR)
            return -1;
        arg++;
    }
    sock->sin_addr.s_addr = n;
    n = atoi(arg);
    if((arg = strchr(arg,',')) == NULLCHAR)
        return -1;
    arg++;
    n = atoi(arg) + (n << 8);
    sock->sin_port = n;
    return 0;
}
  
/* Attempt to log in the user whose name is in ftp->username and password
 * in pass.  Return 0 if unsuccessful, 1 or 2 otherwise. Return 2 if passwd
 * began with a '-' (implying we should minimize extraneous reports). (Selcuk)
 */
static int
ftplogin(ftp,pass)
struct ftpserv *ftp;
char *pass;
{
    char *path;
    char *p;
    int len,anony = 0, r=1;
    FILE *fp;
    char buf[128];
  
    if(*pass == '-') {    /* no message.ftp, desc.ftp, reports */
      pass++;
      r = 2;
    }
    path = mallocw(FILE_PATH_SIZE);
    if(userlogin(ftp->username,pass,&path,FILE_PATH_SIZE,&anony,"ftpperm") == -1) {
        usputs(ftp->control,noperm);
        free(path);
        return 0;
    }
    /* Set up current directory and path prefix */
    ftp->path = strdup(path);
    ftp->cd = firstpath(path);
    free(path);
  
    strcpy(buf,ftp->cd);
    /* If path ends on /, cut if off; this allows the message to be
     * send when login is to the root dir - WG7J
     */
    len = strlen(buf);
    if(buf[len-1] == '/')
        buf[len-1] = '\0';
  
    if(r!=2 && (fp = fopen(strcat(buf,"/message.ftp"),"r")) != NULL) {
        sendmsgfile(ftp->control,230,buf,sizeof(buf),fp);
        fclose(fp);
    }
  
    if(!anony){
        usprintf(ftp->control,logged,ftp->username);
        log(ftp->control,"%s logged in",ftp->username);
    } else {
        usputs(ftp->control,loggeda);
        log(ftp->control,"%s logged in, ID %s",ftp->username,pass);
    }
    return r;
}
  
static int
sendit(ftp,command,file)
struct ftpserv *ftp;
char *command;
char *file;
{
    long total, starting;
    unsigned long check;
    struct sockaddr_in dport;
    char *cp;
    char fsizetext[20] = "";                /* N1BEE */
  
   if(ftp->data == -1) {  /* not PASV */
    ftp->data = socket(AF_INET,SOCK_STREAM,0);
    dport.sin_family = AF_INET;
    dport.sin_addr.s_addr = INADDR_ANY;
    dport.sin_port = IPPORT_FTPD;
    bind(ftp->data,(char *)&dport,SOCKSIZE);
    sprintf(fsizetext, "(%lu bytes)", filelength(fileno(ftp->fp)));
    usprintf(ftp->control,sending,command,file,fsizetext);  /* N1BEE */
    if(connect(ftp->data,(char *)&ftp->port,SOCKSIZE) == -1){
        fclose(ftp->fp);
        ftp->fp = NULLFILE;
        close_s(ftp->data);
        ftp->data = -1;
        usputs(ftp->control,noconn);
        return -1;
    }
   } else { /* PASV mode */
      /* wait for the client to open the connection */
      /* ftp->data has been setup already */
      accept(ftp->data,NULLCHAR,(int *)NULL);
      sprintf(fsizetext, "(%lu bytes)", filelength(fileno(ftp->fp)));
      usprintf(ftp->control,sending,command,file,fsizetext);  /* N1BEE */
   }

#ifdef LZW
    if(ftp->uselzw == 1)
        /* do lzwinit() for socket. */
        lzwinit(ftp->data,ftp->lzwbits,ftp->lzwmode);
#endif
    if(strcmp(command,"RSME") == 0) {
        cp = mallocw(40);
        recvline(ftp->control,cp,40);
        starting = atol(cp);
        /* If checksum field is not present go on anyway, for compatibility
         * with previous scheme. If present check it and barf if wrong.
         */
        if(strchr(cp,' ') != NULL){
            check = (unsigned long)atol(strchr(cp,' '));
            check -= checksum(ftp->fp,starting);
            if(check != 0){
                free(cp);
                usputs(ftp->control,badcheck);
                shutdown(ftp->data,1);  /* Blow away data connection */
                goto send_err;
            }
        } else if(fseek(ftp->fp,starting,SEEK_SET) != 0) {
            free(cp);
            usputs(ftp->control,noconn);
            shutdown(ftp->data,2);  /* Blow away data connection */
            goto send_err;
        }
    }
  
    /* Do the actual transfer */
    total = sendfile(ftp->fp,ftp->data,ftp->type,0,NULL);
  
    if(total == -1){
        /* An error occurred on the data connection */
        usputs(ftp->control,noconn);
        shutdown(ftp->data,2);  /* Blow away data connection */
    } else {
        usputs(ftp->control,txok);
    }
    send_err:       fclose(ftp->fp);
    ftp->fp = NULLFILE;
    close_s(ftp->data);
    ftp->data = -1;
#ifdef LZW
    /* Done with data socket. Turn off lzw for now */
    ftp->uselzw = 0;
#endif
    if(total == -1)
        return -1;
    else
        return 0;
}
static int
recvit(ftp,command,file)
struct ftpserv *ftp;
char *command;
char *file;
{
    struct sockaddr_in dport;
    long total, starting;
  
   if(ftp->data == -1) {  /* not PASV */
    ftp->data = socket(AF_INET,SOCK_STREAM,0);
    dport.sin_family = AF_INET;
    dport.sin_addr.s_addr = INADDR_ANY;
    dport.sin_port = IPPORT_FTPD;
    bind(ftp->data,(char *)&dport,SOCKSIZE);
    usprintf(ftp->control,sending,command,file,"");
    if(connect(ftp->data,(char *)&ftp->port,SOCKSIZE) == -1){
        fclose(ftp->fp);
        ftp->fp = NULLFILE;
        close_s(ftp->data);
        ftp->data = -1;
        usputs(ftp->control,noconn);
        return -1;
    }
   } else {  /* PASV mode */
      /* wait for the client to open the connection */
      /* ftp->data has been setup already */
      accept(ftp->data,NULLCHAR,(int *)NULL);
      usprintf(ftp->control,sending,command,file,"");
   }

#ifdef LZW
    if(ftp->uselzw == 1)
        /* do lzwinit() for socket. */
        lzwinit(ftp->data,ftp->lzwbits,ftp->lzwmode);
#endif
    if(strcmp(command,"RPUT") == 0){
        if((starting = getsize(ftp->fp)) == -1)
            starting = 0L;
        usprintf(ftp->control,"%ld %lu\n",starting,checksum(ftp->fp,starting));
        fseek(ftp->fp,starting,SEEK_SET);
    }
  
    total = recvfile(ftp->fp,ftp->data,ftp->type,0);
  
#ifdef  CPM
    if(ftp->type == ASCII_TYPE)
        putc(CTLZ,ftp->fp);
#endif
    if(total == -1) {
        /* An error occurred while writing the file */
        usprintf(ftp->control,writerr,sys_errlist[errno]);
        shutdown(ftp->data,2);  /* Blow it away */
    } else
        usputs(ftp->control,rxok);
  
    close_s(ftp->data);
    ftp->data = -1;
    fclose(ftp->fp);
    ftp->fp = NULLFILE;
#ifdef LZW
    /* Done with data socket. Turn off lzw for now */
    ftp->uselzw = 0;
#endif
    if(total == -1)
        return -1;
    else
        return 0;
}
  
#endif /* FTPSERVER */
  
#ifdef  MSDOS
/* Illegal characters in a DOS filename */
static char badchars[] = "\"[]|<>+=;,";
#endif
  
/* Return 1 if the file operation is allowed, 0 otherwise */
int
permcheck(path,op,file)
char *path;
int op;
char *file;
{
    char *cp,*privs;
    long perms;
  
    if(file == NULLCHAR || path == NULLCHAR)
        return 0;       /* Probably hasn't logged in yet */
  
#ifdef  MSDOS
    /* Check for characters illegal in MS-DOS file names */
  
#ifdef notdef
    for(cp = file;*cp != '\0';cp++){
        if(*cp != '\\' && *cp != '/' && *cp != '.' && *cp != ':'
            && *cp != '?' && *cp != '*' && dosfnchr(*cp) == 0)
            return 0;
    }
#endif
  
    if(strpbrk(file,badchars) != NULLCHAR)
        return 0;
  
#endif
  
#ifndef MAC
    /* The target file must be under the user's allowed search path */
    /* We let them specify multiple paths using path;path... -russ */
    /* Now full form: path[;path...] perm path[;path...] perm ... */
    {
        int pathlen;
  
        for(cp = path;;){
            /* Make sure format is valid, privs field should be present! */
            if((privs=strpbrk(cp," \t")) == NULLCHAR)
                return 0;
            /* Find length of path */
            pathlen = strcspn(cp,"; \t");
            while(pathlen) {
                /* Check filename with path */
                if(strncmp(file,cp,pathlen) == 0 && (
                    /* Some path validation */
                    file[pathlen] == '\0' ||
                    file[pathlen] == '/' ||
                    file[pathlen-1] == '/'))
                    break;
                /* Check next path */
                cp += pathlen;
                if(*cp == ';')  /* There is more in this compound path ! */
                    pathlen = strcspn(++cp,"; \t");
                else
                    pathlen = 0;
            }
            if(pathlen) /* we found a match, no check privs */
                break;
            /* now see if there is more after the privs... */
            privs = skipwhite(privs);
            if((cp = strpbrk(privs," \t")) == NULL)
                return 0;   /* Nothing there ! */
            /* skip spaces or tabs to get start of next 'path perm' entry */
            cp = skipwhite(cp);
        }
    }
#endif
  
    /* Now find start of privs */
    privs = skipwhite(privs);
    if(strnicmp(privs,"0x",2) == 0)
        perms = htol(privs);
    else
        perms = atol(privs);
  
    switch(op){
        case RETR_CMD:
        /* User must have permission to read files */
            if(perms & FTP_READ)
                return 1;
            return 0;
        case DELE_CMD:
        case RMD_CMD:
        case RPUT_CMD:
        /* User must have permission to (over)write files */
            if(perms & FTP_WRITE)
                return 1;
            return 0;
        case STOR_CMD:
        case MKD_CMD:
        /* User must have permission to (over)write files, or permission
         * to create them if the file doesn't already exist
         */
            if(perms & FTP_WRITE)
                return 1;
            if(access(file,2) == -1 && (perms & FTP_CREATE))
                return 1;
            return 0;
    }
    return 0;       /* "can't happen" -- keep lint happy */
}
  

static void
SendPasv(int s, struct sockaddr_in *socket)
{
    /* Send PORT a,a,a,a,p,p message */
    usprintf(s,"227 Entering Passive Mode. %u,%u,%u,%u,%u,%u\n",
    hibyte(hiword(socket->sin_addr.s_addr)),
    lobyte(hiword(socket->sin_addr.s_addr)),
    hibyte(loword(socket->sin_addr.s_addr)),
    lobyte(loword(socket->sin_addr.s_addr)),
    hibyte(socket->sin_port),
    lobyte(socket->sin_port));
}

