ftp.c

tftp的示例代码,写得不错,值得一看

	}
	if (proxy) {
		proxtrans(cmd, local, remote);
		return;
	}
	if (curtype != type)
		changetype(type, 0);
	closefunc = NULL;
	oldintr = NULL;
	oldintp = NULL;
	lmode = "w";
	if (setjmp(sendabort)) {
		while (cpend) {
			getreply(0);
		}
		if (data >= 0) {
			close(data);
			data = -1;
		}
		if (oldintr)
			signal(SIGINT,oldintr);
		if (oldintp)
			signal(SIGPIPE,oldintp);
		code = -1;
		return;
	}
	oldintr = signal(SIGINT, abortsend);
	if (strcmp(local, "-") == 0)
		fin = stdin;
	else if (*local == '|') {
		oldintp = signal(SIGPIPE,SIG_IGN);
		fin = popen(local + 1, "r");
		if (fin == NULL) {
			error (0, errno, "%s", local + 1);
			signal(SIGINT, oldintr);
			signal(SIGPIPE, oldintp);
			code = -1;
			return;
		}
		closefunc = pclose;
	} else {
		fin = fopen(local, "r");
		if (fin == NULL) {
			error (0, errno, "local: %s", local);
			signal(SIGINT, oldintr);
			code = -1;
			return;
		}
		closefunc = fclose;
		if (fstat(fileno(fin), &st) < 0 ||
		    (st.st_mode&S_IFMT) != S_IFREG) {
			fprintf(stdout, "%s: not a plain file.\n", local);
			signal(SIGINT, oldintr);
			fclose(fin);
			code = -1;
			return;
		}
	}
	if (initconn()) {
		signal(SIGINT, oldintr);
		if (oldintp)
			signal(SIGPIPE, oldintp);
		code = -1;
		if (closefunc != NULL)
			(*closefunc)(fin);
		return;
	}
	if (setjmp(sendabort))
		goto abort;

	if (restart_point &&
	    (strcmp(cmd, "STOR") == 0 || strcmp(cmd, "APPE") == 0)) {
		int rc;

		switch (curtype) {
		case TYPE_A:
			rc = fseek(fin, (long) restart_point, SEEK_SET);
			break;
		case TYPE_I:
		case TYPE_L:
			rc = lseek(fileno(fin), restart_point, SEEK_SET);
			break;
		}
		if (rc < 0) {
			error (0, errno, "local: %s", local);
			restart_point = 0;
			if (closefunc != NULL)
				(*closefunc)(fin);
			return;
		}
		if (command("REST %ld", (long) restart_point)
			!= CONTINUE) {
			restart_point = 0;
			if (closefunc != NULL)
				(*closefunc)(fin);
			return;
		}
		restart_point = 0;
		lmode = "r+w";
	}
	if (remote) {
		if (command("%s %s", cmd, remote) != PRELIM) {
			signal(SIGINT, oldintr);
			if (oldintp)
				signal(SIGPIPE, oldintp);
			if (closefunc != NULL)
				(*closefunc)(fin);
			return;
		}
	} else
		if (command("%s", cmd) != PRELIM) {
			signal(SIGINT, oldintr);
			if (oldintp)
				signal(SIGPIPE, oldintp);
			if (closefunc != NULL)
				(*closefunc)(fin);
			return;
		}
	dout = dataconn(lmode);
	if (dout == NULL)
		goto abort;
	gettimeofday(&start, (struct timezone *)0);
	oldintp = signal(SIGPIPE, SIG_IGN);
	switch (curtype) {

	case TYPE_I:
	case TYPE_L:
		errno = d = 0;
		while ((c = read(fileno(fin), buf, sizeof (buf))) > 0) {
			bytes += c;
			for (bufp = buf; c > 0; c -= d, bufp += d)
				if ((d = write(fileno(dout), bufp, c)) <= 0)
					break;
			if (hash) {
				while (bytes >= local_hashbytes) {
					putchar('#');
					local_hashbytes += hashbytes;
				}
				fflush(stdout);
			}
		}
		if (hash && bytes > 0) {
			if (bytes < local_hashbytes)
				putchar('#');
			putchar('\n');
			fflush(stdout);
		}
		if (c < 0)
			error (0, errno, "local: %s", local);
		if (d < 0) {
			if (errno != EPIPE)
				error (0, errno, "netout");
			bytes = -1;
		}
		break;

	case TYPE_A:
		while ((c = getc(fin)) != EOF) {
			if (c == '\n') {
				while (hash && (bytes >= local_hashbytes)) {
					putchar('#');
					fflush(stdout);
					local_hashbytes += hashbytes;
				}
				if (ferror(dout))
					break;
				putc('\r', dout);
				bytes++;
			}
			putc(c, dout);
			bytes++;
	/*		if (c == '\r') {			  	*/
	/*		(void)	putc('\0', dout);  // this violates rfc */
	/*			bytes++;				*/
	/*		}                          			*/
		}
		if (hash) {
			if (bytes < local_hashbytes)
				putchar('#');
			putchar('\n');
			fflush(stdout);
		}
		if (ferror(fin))
			error (0, errno, "local: %s", local);
		if (ferror(dout)) {
			if (errno != EPIPE)
				error (0, errno, "netout");
			bytes = -1;
		}
		break;
	}
	if (closefunc != NULL)
		(*closefunc)(fin);
	fclose(dout);
	gettimeofday(&stop, (struct timezone *)0);
	getreply(0);
	signal(SIGINT, oldintr);
	if (oldintp)
		signal(SIGPIPE, oldintp);
	if (bytes > 0)
		ptransfer("sent", bytes, &start, &stop);
	return;
abort:
	signal(SIGINT, oldintr);
	if (oldintp)
		signal(SIGPIPE, oldintp);
	if (!cpend) {
		code = -1;
		return;
	}
	if (data >= 0) {
		close(data);
		data = -1;
	}
	if (dout)
		fclose(dout);
	getreply(0);
	code = -1;
	if (closefunc != NULL && fin != NULL)
		(*closefunc)(fin);
	gettimeofday(&stop, (struct timezone *)0);
	if (bytes > 0)
		ptransfer("sent", bytes, &start, &stop);
}

jmp_buf	recvabort;

void
abortrecv(sig)
  int sig;
{

	mflag = 0;
	abrtflag = 0;
	printf("\nreceive aborted\nwaiting for remote to finish abort\n");
	fflush(stdout);
	longjmp(recvabort, 1);
}

void
recvrequest(cmd, local, remote, lmode, printnames)
	char *cmd, *local, *remote, *lmode;
	int printnames;
{
	FILE *fout, *din = 0;
	int (*closefunc) (FILE *);
	sig_t oldintr, oldintp;
	int c, d, is_retr, tcrflag, bare_lfs = 0, blksize;
	static int bufsize=0;
	static char *buf;
	long bytes = 0, local_hashbytes = hashbytes;
	struct timeval start, stop;

	is_retr = strcmp(cmd, "RETR") == 0;
	if (is_retr && verbose && printnames) {
		if (local && *local != '-')
			printf("local: %s ", local);
		if (remote)
			printf("remote: %s\n", remote);
	}
	if (proxy && is_retr) {
		proxtrans(cmd, local, remote);
		return;
	}
	closefunc = NULL;
	oldintr = NULL;
	oldintp = NULL;
	tcrflag = !crflag && is_retr;
	if (setjmp(recvabort)) {
		while (cpend) {
			getreply(0);
		}
		if (data >= 0) {
			close(data);
			data = -1;
		}
		if (oldintr)
			signal(SIGINT, oldintr);
		code = -1;
		return;
	}
	oldintr = signal(SIGINT, abortrecv);
	if (strcmp(local, "-") && *local != '|') {
		if (runique && (local = gunique(local)) == NULL) {
			signal(SIGINT, oldintr);
			code = -1;
			return;
		}
	}
	if (!is_retr) {
		if (curtype != TYPE_A)
			changetype(TYPE_A, 0);
	} else if (curtype != type)
		changetype(type, 0);
	if (initconn()) {
		signal(SIGINT, oldintr);
		code = -1;
		return;
	}
	if (setjmp(recvabort))
		goto abort;
	if (is_retr && restart_point &&
	    command("REST %ld", (long) restart_point) != CONTINUE)
		return;
	if (remote) {
		if (command("%s %s", cmd, remote) != PRELIM) {
			signal(SIGINT, oldintr);
			return;
		}
	} else {
		if (command("%s", cmd) != PRELIM) {
			signal(SIGINT, oldintr);
			return;
		}
	}
	din = dataconn("r");
	if (din == NULL)
		goto abort;
	if (strcmp(local, "-") == 0)
		fout = stdout;
	else if (*local == '|') {
		oldintp = signal(SIGPIPE, SIG_IGN);
		fout = popen(local + 1, "w");
		if (fout == NULL) {
			error (0, errno, "%s", local+1);
			goto abort;
		}
		closefunc = pclose;
	} else {
		fout = fopen(local, lmode);
		if (fout == NULL) {
			error (0, errno, "local: %s", local);
			goto abort;
		}
		closefunc = fclose;
	}
	blksize = BUFSIZ;
	if (blksize > bufsize) {
		if (buf)
			free(buf);
		buf = malloc((unsigned)blksize);
		if (buf == NULL) {
			error (0, errno, "malloc");
			bufsize = 0;
			goto abort;
		}
		bufsize = blksize;
	}
	gettimeofday(&start, (struct timezone *)0);
	switch (curtype) {

	case TYPE_I:
	case TYPE_L:
		if (restart_point &&
		    lseek(fileno(fout), restart_point, SEEK_SET) < 0) {
			error (0, errno, "local: %s", local);
			if (closefunc != NULL)
				(*closefunc)(fout);
			return;
		}
		errno = d = 0;
		while ((c = read(fileno(din), buf, bufsize)) > 0) {
			if ((d = write(fileno(fout), buf, c)) != c)
				break;
			bytes += c;
			if (hash) {
				while (bytes >= local_hashbytes) {
					putchar('#');
					local_hashbytes += hashbytes;
				}
				fflush(stdout);
			}
		}
		if (hash && bytes > 0) {
			if (bytes < local_hashbytes)
				putchar('#');
			putchar('\n');
			fflush(stdout);
		}
		if (c < 0) {
			if (errno != EPIPE)
				error (0, errno, "netin");
			bytes = -1;
		}
		if (d < c) {
			if (d < 0)
				error (0, errno, "local: %s", local);
			else
				error (0, 0, "%s: short write", local);
		}
		break;

	case TYPE_A:
		if (restart_point) {
			int i, n, ch;

			if (fseek(fout, 0L, SEEK_SET) < 0)
				goto done;
			n = restart_point;
			for (i = 0; i++ < n;) {
				if ((ch = getc(fout)) == EOF)
					goto done;
				if (ch == '\n')
					i++;
			}
			if (fseek(fout, 0L, SEEK_CUR) < 0) {
done:
				error (0, errno, "local: %s", local);
				if (closefunc != NULL)
					(*closefunc)(fout);
				return;
			}
		}
		while ((c = getc(din)) != EOF) {
			if (c == '\n')
				bare_lfs++;
			while (c == '\r') {
				while (hash && (bytes >= local_hashbytes)) {
					putchar('#');
					fflush(stdout);
					local_hashbytes += hashbytes;
				}
				bytes++;
				if ((c = getc(din)) != '\n' || tcrflag) {
					if (ferror(fout))
						goto break2;
					putc('\r', fout);
					if (c == '\0') {
						bytes++;
						goto contin2;
					}
					if (c == EOF)
						goto contin2;
				}
			}
			putc(c, fout);
			bytes++;
	contin2:	;
		}
break2:
		if (bare_lfs) {
			printf("WARNING! %d bare linefeeds received in ASCII mode\n", bare_lfs);
			printf("File may not have transferred correctly.\n");
		}
		if (hash) {
			if (bytes < local_hashbytes)
				putchar('#');
			putchar('\n');
			fflush(stdout);
		}
		if (ferror(din)) {
			if (errno != EPIPE)
				error (0, errno, "netin");
			bytes = -1;
		}
		if (ferror(fout))
			error (0, errno, "local: %s", local);
		break;
	}
	if (closefunc != NULL)
		(*closefunc)(fout);
	signal(SIGINT, oldintr);
	if (oldintp)
		signal(SIGPIPE, oldintp);
	fclose(din);
	gettimeofday(&stop, (struct timezone *)0);
	getreply(0);
	if (bytes > 0 && is_retr)
		ptransfer("received", bytes, &start, &stop);
	return;
abort:

/* abort using RFC959 recommended IP,SYNC sequence  */

	if (oldintp)
		signal(SIGPIPE, oldintr);
	signal(SIGINT, SIG_IGN);
	if (!cpend) {
		code = -1;
		signal(SIGINT, oldintr);
		return;
	}

	abort_remote(din);
	code = -1;
	if (data >= 0) {
		close(data);
		data = -1;
	}
	if (closefunc != NULL && fout != NULL)
		(*closefunc)(fout);
	if (din)
		fclose(din);
	gettimeofday(&stop, (struct timezone *)0);
	if (bytes > 0)
		ptransfer("received", bytes, &start, &stop);
	signal(SIGINT, oldintr);
}

/*
 * Need to start a listen on the data channel before we send the command,
 * otherwise the server's connect may fail.
 */
int
initconn()
{
	char *p, *a;
	int result, len, tmpno = 0;
	int on = 1;
	int a0, a1, a2, a3, p0, p1;

	if (passivemode) {
		data = socket(AF_INET, SOCK_STREAM, 0);
		if (data < 0) {
			perror("ftp: socket");
			return(1);
		}
		if ((options & SO_DEBUG) &&
		    setsockopt(data, SOL_SOCKET, SO_DEBUG, (char *)&on,
			       sizeof (on)) < 0)
			perror("ftp: setsockopt (ignored)");
		if (command("PASV") != COMPLETE) {
			printf("Passive mode refused.\n");
			goto bad;
		}