file.c

操作系统源代码

{
char cmd[128];
char *argv[5];
int fds[2];
char *smallenv[] = { "PATH=/bin:/usr/bin:/usr/local/bin", NULL, NULL };

   if ((smallenv[1] = getenv("TZ")) != NULL) smallenv[1] -= 3;	/* ouch... */

   sprintf(cmd, "%s %s", xcmd, args);

   argv[0] = CMD_SH;
   argv[1] = "-c";
   argv[2] = cmd;
   argv[3] = (char *)NULL;

   if(pipe(fds) < 0)
	return(-1);

   if((cmdpid = fork()) < 0) {
	close(fds[0]);
	close(fds[1]);
	return(-1);
   }

   if(cmdpid == 0) { /* Child */
	close(fds[0]);
	close(0);
	open("/dev/null", O_RDONLY);
	dup2(fds[1], 1);
	dup2(fds[1], 2);
	close(fds[1]);
	execve(argv[0], argv, smallenv);
	exit(0);
   }

   close(fds[1]);

   return(fds[0]);
}

/* Same as close if not cmd child started */
static int endfdxcmd(fd)
int fd;
{
int s;
int cs;

   close(fd);

   if(cmdpid == -1)
	return(0);

   s = waitpid(cmdpid, &cs, 0);

   cmdpid = -1;

   return(0);
}

/* returns 1 = size could not be determined, */
/*         0 = size determined and in filesize */
static int asciisize(filename, filesize)
char *filename;
unsigned long *filesize;
{
unsigned long count;
int fd;
char *p, *pp;
int cnt;

   if((fd = open(filename, O_RDONLY)) < 0) {
	printf(msg550, filename, strerror(errno));
	return(1);
   }

   count = 0;

   while((cnt = read(fd, buffer, sizeof(buffer))) > 0) {
	count += cnt;
	p = buffer;
	while(cnt > 0)
		if((pp = memchr(p, '\n', cnt)) != (char *)NULL) {
			count++;
			cnt = cnt - 1 - (pp - p);
			p = pp + 1;
		} else
			break;
   }

   if(cnt == 0) {
	*filesize = count;
	close(fd);
	return(0);
   }

   printf(msg550, filename, strerror(errno));

   close(fd);

   return(1);
}

/* see if we need to run a command to convert the file */
static int cnvtfile(name, name2)
char *name;
char **name2;
{
struct stat st;
static char fname[256];
char *p;
int mode;

   if(!stat(name, &st))			/* file exists can't be a conversion */
   	if((st.st_mode & S_IFMT) != S_IFREG) {	/* must be regular file */
		printf("550 Not a regular file.\r\n");
		return(CNVT_ERROR);
	} else
		return(CNVT_NONE);

   if(errno != ENOENT) {	/* doesn't exist is okay, others are not */
	printf(msg550, name, strerror(errno));
	return(CNVT_ERROR);
   }

   /* find out what kind of conversion */
   strncpy(fname, name, sizeof(fname));
   fname[sizeof(fname)-1] = '\0';

   p = fname + strlen(fname);
   mode = CNVT_ERROR;
   while(p > fname && mode == CNVT_ERROR) {
	if(*p == '.') {
		if(!strcmp(p, ".tar"))
			mode = CNVT_TAR;
		else
		if(!strcmp(p, ".tar.Z"))
			mode = CNVT_TAR_Z;
		else
		if(!strcmp(p, ".Z"))
			mode = CNVT_COMP;
		else
		if(!strcmp(p, ".tar.gz"))
			mode = CNVT_TAR_GZ;
		else
		if(!strcmp(p, ".gz"))
			mode = CNVT_GZIP;

		if (mode != CNVT_ERROR) {
			/* is there a file to convert? */
			*p = '\0';
			if (!stat(fname, &st)) break;
			*p = '.';
			mode = CNVT_ERROR;
		}
	}
	p--;
   }

   if(mode == CNVT_ERROR) {
	printf(msg550, fname, strerror(errno));
	return(mode);
   }

   if(mode == CNVT_COMP || mode == CNVT_GZIP || mode == CNVT_UNCOMP)
	if((st.st_mode & S_IFMT) != S_IFREG) {
		printf("550 Not a regular file.\r\n");
		return(CNVT_ERROR);
	}

   *name2 = fname;

   return(mode);
}

static int procfile(name)
char *name;
{
int fd;
char *name2;
static char command[512];

   switch(cnvtfile(name, &name2)) {
	case CNVT_TAR:
		fd = fdxcmd("tar cf -", name2);
		break;
	case CNVT_TAR_Z:
		sprintf(command, "tar cf - %s | compress -q", name2);
		fd = fdxcmd(command, "");
		break;
	case CNVT_COMP:
		fd = fdxcmd("compress -cq", name2);
		break;
	case CNVT_TAR_GZ:
		sprintf(command, "tar cf - %s | gzip", name2);
		fd = fdxcmd(command, "");
		break;
	case CNVT_GZIP:
		fd = fdxcmd("gzip -c", name2);
		break;
	case CNVT_UNCOMP:
		fd = fdxcmd("compress -dcq", name2);
		break;
	case CNVT_NONE:
		fd = open(name, O_RDONLY);
		break;
	case CNVT_ERROR:
	default:
		return(-1);
   }

   if(fd < 0)
	printf(msg550, name, strerror(errno));

   return(fd);
}

/* oh no, they're taking a file */
static int sendfile(name, xmode)
char *name;
int xmode;
{
char *fname;
int fd, s;
time_t datastart, dataend;
unsigned long datacount;
long kbs;
char c;
char *p;
char *op, *ope;
off_t sp;
int doascii;

   if(ChkLoggedIn()) 
	return(CleanUpData());

   switch(xmode) {
	case SEND_NLST:
		fname = "NLST";
		fd = fdxcmd(CMD_NLST, name);
		if(fd < 0)
			printf(msg550, name, strerror(errno));
		break;
	case SEND_LIST:
		fname = "LIST";
		fd = fdxcmd(CMD_LIST, name);
		if(fd < 0)
			printf(msg550, name, strerror(errno));
		break;
	default:
		fname = name;
		fd = procfile(name);
		if(fd < 0)
			logit("FAIL", path(fname));
		else
			logit("SEND", path(fname));
   }

   if(fd < 0)
	return(CleanUpData());

   /* set file position at approriate spot */
   if(file_restart) {
	if(type == TYPE_A) {
		sp = 0;
		while(sp < file_restart) {
			sp++;
			s = read(fd, buffer, 1);
			if(s < 0) {
				printf(msg550, fname, strerror(errno));
				endfdxcmd(fd);
				file_restart = 0;
				return(CleanUpData());
			}
			if(s == 0) break;
			if(*buffer == '\n')
				sp++;
		}
	} else {
		sp = lseek(fd, file_restart, SEEK_SET);
		if(sp == -1) {
			printf(msg550, fname, strerror(errno));
			endfdxcmd(fd);
			file_restart = 0;
			return(CleanUpData());
		}
	}
	if(sp != file_restart) {
		printf("550 File restart point error. %lu not %lu\r\n", sp, file_restart);
		endfdxcmd(fd);
		file_restart = 0;
		return(CleanUpData());
	}
   }
   file_restart = 0;

   printf("150 File %s okay.  Opening data connection.\r\n", fname);
   fflush(stdout);

   if(DataConnect()) {
	endfdxcmd(fd);
	return(GOOD);
   }

#ifdef DEBUG
   fprintf(stderr, "ftpd: parent %d start sendfile \n", getpid());
#endif

   /* start transfer */
   doascii = (type == TYPE_A) ||
   	((xmode == SEND_LIST) || (xmode == SEND_NLST)); /* per RFC1123 4.1.2.7 */
   datacount = 0;
   time(&datastart);
   op = bufout; ope = bufout + sizeof(bufout) - 3;
   while((s = read(fd, buffer, sizeof(buffer))) > 0) {
	datacount += s;
	if(doascii) {
		p = buffer;
		while(s-- > 0) {
			c = *p++;
			if(c == '\n') {
				*op++ = '\r';
				datacount++;
			}
			*op++ = c;
			if(op >= ope) {
				write(ftpdata_fd, bufout, op - bufout);
				op = bufout;
			}
		}
	} else
		write(ftpdata_fd, buffer, s);
   }
   if(op > bufout)
	write(ftpdata_fd, bufout, op - bufout);
   time(&dataend);

#ifdef DEBUG
   fprintf(stderr, "ftpd: parent %d end sendfile \n", getpid());
#endif

   endfdxcmd(fd);
   close(ftpdata_fd);
   ftpdata_fd = -1;

   if(dataend == datastart) dataend++;
   kbs = (datacount * 100 / (dataend - datastart)) / 1024;

   if(s < 0)
	printf("451 Transfer aborted.\r\n");
   else
	printf("226 Transfer finished successfully. %ld.%02d KB/s\r\n",
		(long)(kbs / 100), (int)(kbs % 100));

   return(GOOD);
}

static int recvfile(name, xmode)
char *name;
int xmode;
{
char *fname;
time_t datastart, dataend;
unsigned long datacount;
long kbs;
char c;
char *p;
char *op, *ope;
int fd, oflag;
int s;
int gotcr;
off_t sp;

   if(ChkLoggedIn())
	return(CleanUpData());

   fname = name;

   switch(xmode) {
	case RECV_APND:
		oflag = O_WRONLY | O_APPEND;
		break;
	case RECV_UNIQ:
		fname = uniqname();
		oflag = O_WRONLY | O_CREAT;
		break;
	default:
		oflag = O_WRONLY | O_CREAT | O_TRUNC;
   }

   if(file_restart)
	oflag = O_RDWR;

   fd = open(fname, oflag, 0666);

   if(fd < 0) {
	printf(msg550, fname, strerror(errno));
	return(CleanUpData());
   }

   /* log the received file */
   logit("RECV", path(fname));

   /* set file position at approriate spot */
   if(file_restart) {
	if(type == TYPE_A) {
		sp = 0;
		while(sp < file_restart) {
			sp++;
			s = read(fd, buffer, 1);
			if(s < 0) {
				printf(msg550, fname, strerror(errno));
				close(fd);
				file_restart = 0;
				return(CleanUpData());
			}
			if(s == 0) break;
			if(*buffer == '\n')
				sp++;
		}
	} else {
		sp = lseek(fd, file_restart, SEEK_SET);
		if(sp == -1) {
			printf(msg550, fname, strerror(errno));
			close(fd);
			file_restart = 0;
			return(CleanUpData());
		}
	}
	if(sp != file_restart) {
		printf("550 File restart point error. %lu not %lu\r\n", sp, file_restart);
		close(fd);
		file_restart = 0;
		return(CleanUpData());
	}
   }
   file_restart = 0;

   if(xmode == RECV_UNIQ)
   	printf("150 FILE: %s\r\n", fname);	/* per RFC1123 4.1.2.9 */
   else
	printf("150 File %s okay.  Opening data connection.\r\n", fname);
   fflush(stdout);

   if(DataConnect()) {
   	close(fd);
	return(GOOD);
   }

#ifdef DEBUG
   fprintf(stderr, "ftpd: parent %d start recvfile \n", getpid());
#endif

   /* start receiving file */
   datacount = 0;
   gotcr = 0;
   op = bufout; ope = bufout + sizeof(bufout) - 3;
   time(&datastart);
   while((s = read(ftpdata_fd, buffer, sizeof(buffer))) > 0) {
	datacount += s;
	if(type == TYPE_A) {
		p = buffer;
		while(s-- > 0) {
			c = *p++;
			if(gotcr) {
				gotcr = 0;
				if(c != '\n')
					*op++ = '\r';
			}
			if(c == '\r')
				gotcr = 1;
			else
				*op++ = c;
			if(op >= ope) {
				write(fd, bufout, op - bufout);
				op = bufout;
			}
		}
	} else
		write(fd, buffer, s);
   }
   if(gotcr)
	*op++ = '\r';
   if(op > bufout)
	write(fd, bufout, op - bufout);
   time(&dataend);

#ifdef DEBUG
   fprintf(stderr, "ftpd: parent %d end recvfile \n", getpid());
#endif

   close(fd);
   close(ftpdata_fd); 
   ftpdata_fd = -1;

   if(dataend == datastart) dataend++;
   kbs = (datacount * 100 / (dataend - datastart)) / 1024;

   if(s < 0)
	printf("451 Transfer aborted.\r\n");
   else {
	printf("226 Transfer finished successfully. ");
	if(xmode == RECV_UNIQ)
		printf("Unique file %s. ", fname);
	printf("%ld.%02d KB/s\r\n", (long)(kbs / 100), (int)(kbs % 100));
   }

   return(GOOD);
}

static char *uniqname()
{
static char uniq[14+1];
int i;
struct stat st;

   for(i = 0; i < 1000; i++) {
	sprintf(uniq, "ftpd%d%d", getpid(), i);
	if(stat(uniq, &st) == -1)
		return(uniq);
   }
   return(uniq);
}

static char *spath[256];
static char *path(fname)
char *fname;
{
char dir[128];

   if(getcwd(dir, sizeof(dir)) == (char *)NULL)
	sprintf(dir, "???");

   if(fname[0] == '/')
	sprintf((char *)spath, "%s%s", newroot, fname);
   else
	if(dir[1] == '\0')
		sprintf((char *)spath, "%s%s%s", newroot, dir, fname);
	else
		sprintf((char *)spath, "%s%s/%s", newroot, dir, fname);

   return((char *)spath);
}