source: trunk/minix/commands/ftpd200/net.c@ 10

/* net.c Copyright 1992-2000 by Michael Temari All Rights Reserved
 *
 * This file is part of ftpd.
 *
 * This file handles:
 *
 *      PASV PORT
 *
 *
 * 01/25/1995 Initial Release   Michael Temari, <Michael@TemWare.Com>
 * 02/09/2005 Initial Release   Michael Temari, <Michael@TemWare.Com>
 */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <time.h>
#include <net/netlib.h>
#include <net/hton.h>
#include <net/gen/in.h>
#include <net/gen/inet.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>
#include <net/gen/socket.h>
#include <net/gen/netdb.h>

#include "ftpd.h"
#include "access.h"
#include "net.h"

_PROTOTYPE(static void timeout, (int sig));

static char *msg425 = "425-Could not open data connection.\r\n";
static char *msg501 = "501 Syntax error in parameters.\r\n";

static int gottimeout = 0;
static int lpid = -1;
static int didpassive = 0;

/* they must be behind a firewall or using a web browser */
int doPASV(buff)
char *buff;
{
nwio_tcpconf_t tcpconf;
nwio_tcpcl_t tcplopt;
char *tcp_device;
ipaddr_t ipaddr;
tcpport_t lport;
int s;
time_t starttime;
int retry;

   if(ChkLoggedIn())
        return(GOOD);

   CleanUpPasv();

   /* here we set up a connection to listen on */
   if((tcp_device = getenv("TCP_DEVICE")) == NULL)
        tcp_device = TCP_DEVICE;

   if(ftpdata_fd >= 0) {
        close(ftpdata_fd);
        ftpdata_fd = -1;
   }

   if((ftpdata_fd = open(tcp_device, O_RDWR)) < 0) {
        printf(msg425); 
        printf("425 Could not open tcp_device.  Error %s\r\n", strerror(errno));
        return(GOOD);
   }

   tcpconf.nwtc_flags = NWTC_LP_SEL | NWTC_SET_RA | NWTC_UNSET_RP;

   tcpconf.nwtc_remaddr = rmtipaddr;
   tcpconf.nwtc_remport = htons(0);
   tcpconf.nwtc_locport = htons(0);

   s = ioctl(ftpdata_fd, NWIOSTCPCONF, &tcpconf);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not ioctl NWIOSTCPCONF. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(GOOD);
   }

   s = ioctl(ftpdata_fd, NWIOGTCPCONF, &tcpconf);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not NWIOGTCPCONF. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(GOOD);
   }
   ipaddr = tcpconf.nwtc_locaddr;
   lport = tcpconf.nwtc_locport;

   /* Now lets fork a child to do the listening :-( */

   tcplopt.nwtcl_flags = 0;

   lpid = fork();
   if(lpid < 0) {
        printf(msg425);
        printf("425 Could not fork listener.  Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(GOOD);
   } else if(lpid == 0) {
        retry = 0;
        while(1) {
#ifdef DEBUG
                fprintf(logfile, "ftpd: child %d  parent %d  listen try %d\n", getpid(), getppid(), retry);
                fflush(logfile);
#endif
                s = ioctl(ftpdata_fd, NWIOTCPLISTEN, &tcplopt);
                if(!(s == -1 && errno == EAGAIN)) break;
                if(retry++ > 10) break;
                sleep(1);
        }
#ifdef DEBUG
        fprintf(logfile, "ftpd: child %d  s %d  errno %d\n", getpid(), s, errno);
        fflush(logfile);
#endif
        if(s < 0) 
                exit(errno);    /* tells parent listen failed */
        else
                exit(0);        /* tells parent listen okay */
   }

#ifdef DEBUG
   fprintf(logfile, "ftpd: parent %d  wait for %d\n", getpid(), lpid);
   fflush(logfile);
#endif

   /* wait for child to be listening, no more than serveral seconds */
   (void) time(&starttime);
   while(1) {
        if(time((time_t *)NULL) > (starttime + 15)) break;
        signal(SIGALRM, timeout);
        alarm(1);
        s = ioctl(ftpdata_fd, NWIOGTCPCONF, &tcpconf);
#ifdef DEBUG
        fprintf(logfile, "ftpd: parent %d  child %d  s %d  errno %d start %ld  now %ld\n",
                getpid(), lpid, s, errno, starttime, time((time_t *)NULL));
        fflush(logfile);
#endif
        alarm(0);
        if(s == -1) break;
        sleep(1);
   }

#define hiword(x)       ((u16_t)((x) >> 16))
#define loword(x)       ((u16_t)(x & 0xffff)) 
#define hibyte(x)       (((x) >> 8) & 0xff)
#define lobyte(x)       ((x) & 0xff)

   printf("227 Entering Passive Mode (%u,%u,%u,%u,%u,%u).\r\n",
                hibyte(hiword(htonl(ipaddr))), lobyte(hiword(htonl(ipaddr))),
                hibyte(loword(htonl(ipaddr))), lobyte(loword(htonl(ipaddr))),
                hibyte(htons(lport)), lobyte(htons(lport)));

#ifdef DEBUG
   fprintf(logfile, "ftpd: parent %d  child %d  send 227\n", getpid(), lpid);
   fflush(logfile);
#endif

   didpassive = -1;

   return(GOOD);
}

/* they want us to connect here */
int doPORT(buff)
char *buff;
{
u32_t ipaddr;
u16_t port;
int i;

   if(ftpdata_fd >= 0) {
        close(ftpdata_fd);
        ftpdata_fd = -1;
   }

   ipaddr = (u32_t)0;
   for(i = 0; i < 4; i++) {
        ipaddr = (ipaddr << 8) + (u32_t)atoi(buff);
        if((buff = strchr(buff, ',')) == (char *)0) {
                printf(msg501);
                return(GOOD);
        }
        buff++;
   }
   port = (u16_t)atoi(buff);
   if((buff = strchr(buff, ',')) == (char *)0) {
        printf(msg501);
        return(0);
   }
   buff++;
   port = (port << 8) + (u16_t)atoi(buff);

   dataaddr = htonl(ipaddr);
   dataport = htons(port);
   if(dataaddr != rmtipaddr) {
        printf(msg501);
        return(GOOD);
   }

   printf("200 Port command okay.\r\n");

   return(GOOD);
}

/* connect, huh? */
int DataConnect()
{
nwio_tcpconf_t tcpconf;
nwio_tcpcl_t tcpcopt;
nwio_tcpcl_t tcplopt;
char *tcp_device;
int s, cs;
int retry;

   if(didpassive && ftpdata_fd >= 0) {
        didpassive = 0;
        gottimeout = 0;
        signal(SIGALRM, timeout);
        alarm(10);
        while(!gottimeout) {
                s = waitpid(lpid, &cs, 0);
                if((s == lpid) || (s < 0 && errno == ECHILD)) break;
#ifdef DEBUG
                fprintf(logfile, "ftpd: parent %d  child %d waitpid s %d  cs %04x  errno %d\n", getpid(), lpid, s, cs, errno);
                fflush(logfile);
#endif
        }
        alarm(0);
#ifdef DEBUG
        fprintf(logfile, "ftpd: parent %d  child %d waitpid s %d  cs %04x  errno %d\n", getpid(), lpid, s, cs, errno);
                fflush(logfile);
#endif
        if(gottimeout) {
#ifdef DEBUG
                fprintf(logfile, "ftpd: parent %d  child %d  got timeout\n", getpid(), lpid);
                fflush(logfile);
#endif
                kill(lpid, SIGKILL);
                s = waitpid(lpid, &cs, 0);
        }
#ifdef DEBUG
        fprintf(logfile, "ftpd: parent %d  child %d continuing\n", getpid(), lpid);
        fflush(logfile);
#endif
        lpid = -1;
        if(gottimeout) {
                printf(msg425);
                printf("425 Child listener timeout.\r\n");
                close(ftpdata_fd);
                ftpdata_fd = -1;
                return(BAD);
        }
        if(s < 0) {
                printf(msg425);
                printf("425 Child listener vanished.\r\n");
                close(ftpdata_fd);
                ftpdata_fd = -1;
                return(BAD);
        }
        if((cs & 0x00ff)) {
                printf(msg425);
                printf("425 Child listener failed %04x\r\n", cs);
                close(ftpdata_fd);
                ftpdata_fd = -1;
                return(BAD);
        }
        cs = (cs >> 8) & 0x00ff;
        if(cs) {
                printf(msg425);
                printf("425 Child listener error %s\r\n", strerror(cs));
                close(ftpdata_fd);
                ftpdata_fd = -1;
                return(BAD);
        }
#ifdef DEBUG
        fprintf(logfile, "ftpd: parent %d  child %d pasv done\n", getpid(), lpid);
        fflush(logfile);
#endif
        return(GOOD);
   }

   if(ftpdata_fd >= 0)
        return(GOOD);

   if((tcp_device = getenv("TCP_DEVICE")) == NULL)
        tcp_device = TCP_DEVICE;

   if((ftpdata_fd = open(tcp_device, O_RDWR)) < 0) {
        printf(msg425);
        printf("425 Could not open tcp_device. Error %s\r\n", strerror(errno));
        return(BAD);
   }

   tcpconf.nwtc_flags = NWTC_LP_SET | NWTC_SET_RA | NWTC_SET_RP;
   tcpconf.nwtc_remaddr = dataaddr;
   tcpconf.nwtc_remport = dataport;
   tcpconf.nwtc_locport = htons(20);

   s = ioctl(ftpdata_fd, NWIOSTCPCONF, &tcpconf);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not ioctl NWIOSTCPCONF. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(BAD);
   }

   s = ioctl(ftpdata_fd, NWIOGTCPCONF, &tcpconf);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not ioctl NWIOGTCPCONF. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(BAD);
   }

   tcpcopt.nwtcl_flags = 0;

   retry = 0;
   do  {
#ifdef DEBUG
        fprintf(logfile, "try connect\n"); fflush(logfile);
        fflush(logfile);
#endif
        sleep(2);
        s = ioctl(ftpdata_fd, NWIOTCPCONN, &tcpcopt);
#ifdef DEBUG
        fprintf(logfile, "after connect %d %d\n", s, errno);
        fflush(logfile);
#endif
        if(!(s == -1 && errno == EAGAIN)) break;
        if(retry++ > 10) break;
        sleep(1);
   } while(1);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not ioctl NWIOTCPCONN. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(BAD);
   }

   s = ioctl(ftpdata_fd, NWIOGTCPCONF, &tcpconf);
   if(s < 0) {
        printf(msg425);
        printf("425 Could not ioctl NWIOGTCPCONF. Error %s\r\n", strerror(errno));
        close(ftpdata_fd);
        ftpdata_fd = -1;
        return(BAD);
   }

   return(GOOD);
}

/* Clean up stuff we did to get a Pasv connection going */
int CleanUpPasv()
{
int s, cs;

   if(lpid >= 0) {
        kill(lpid, SIGKILL);
        while(1) {
                s = waitpid(lpid, &cs, 0);
                if(s == lpid || (s == -1 && errno == ECHILD))
                        break;
        }
   }

   lpid = -1;

   didpassive = 0;

   return(GOOD);
}

void GetNetInfo()
{
nwio_tcpconf_t tcpconf;
int s;
struct hostent *hostent;

   /* Ask the system what our hostname is. */
   if(gethostname(myhostname, sizeof(myhostname)) < 0)
        strcpy(myhostname, "unknown");

   /* lets get our ip address and the clients ip address */
   s = ioctl(0, NWIOGTCPCONF, &tcpconf);
   if(s < 0) {
        printf("421 FTP service unable to get remote ip address. Closing.\r\n");
        fflush(stdout);
        exit(1);
   }

   myipaddr = tcpconf.nwtc_locaddr;
   myport = tcpconf.nwtc_locport;
   rmtipaddr = tcpconf.nwtc_remaddr;
   rmtport = tcpconf.nwtc_remport;

   /* Look up the host name of the remote host. */
   hostent = gethostbyaddr((char *) &rmtipaddr, sizeof(rmtipaddr), AF_INET);
   if(!hostent)
        strcpy(rmthostname, inet_ntoa(rmtipaddr));
   else {
        strncpy(rmthostname, hostent->h_name, sizeof(rmthostname)-1);
        rmthostname[sizeof(rmthostname)-1] = '\0';
   }
}

static void timeout(sig)
int sig;
{
   gottimeout = 1;
}