X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fftp.c;h=8a9b4ab2cd1653c6c2ad9f4eaf6b9a4ce325e96d;hb=8b4d2adf48213f2bf74ca1a423b1ac3dc8066f95;hp=46fad28d1230d3c88b8e4a3fd84b96306ef999d7;hpb=2f4fb7c15c5017546238241ea318b16b9a032c52;p=oftp

diff --git a/src/ftp.c b/src/ftp.c
index 46fad28..8a9b4ab 100644
--- a/src/ftp.c
+++ b/src/ftp.c
@@ -1,6 +1,13 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <ctype.h>
+#include <time.h>
 #include <sys/socket.h>
+#include <sys/select.h>
+#include <sys/swap.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netdb.h>
@@ -8,23 +15,77 @@
 #include "ftp.h"
 #include "util.h"
 
+#ifdef __unix__
+#include <unistd.h>
+#include <fcntl.h>
+#define closesocket		close
+#define fcntlsocket		fcntl
+#else
+#define select	select_s
+
+#ifndef O_NONBLOCK
+#define O_NONBLOCK	0x2000
+#endif
+#ifndef F_SETFL
+#define F_GETFL	101
+#define F_SETFL	102
+#endif
+#endif
+
+#define TIMEOUT	15
+
+static void free_dir(struct ftp_dirent *dir);
+
+static int newconn(struct ftp *ftp);
+static int sendcmd(struct ftp *ftp, const char *fmt, ...);
+static int handle_control(struct ftp *ftp);
+static int handle_data(struct ftp *ftp, int s);
+static void proc_control(struct ftp *ftp, const char *buf);
+
+static int cproc_active(struct ftp *ftp, int code, const char *buf, void *cls);
+static int cproc_pasv(struct ftp *ftp, int code, const char *buf, void *cls);
+static int cproc_pwd(struct ftp *ftp, int code, const char *buf, void *cls);
+static int cproc_cwd(struct ftp *ftp, int code, const char *buf, void *cls);
+
+static int cproc_list(struct ftp *ftp, int code, const char *buf, void *cls);
+static void dproc_list(struct ftp *ftp, const char *buf, int sz, void *cls);
+
+static int cproc_xfer(struct ftp *ftp, int code, const char *buf, void *cls);
+static void dproc_xfer(struct ftp *ftp, const char *buf, int sz, void *cls);
+
+
 struct ftp *ftp_alloc(void)
 {
 	struct ftp *ftp;
 
-	if(!(ftp = malloc(sizeof *ftp))) {
+	if(!(ftp = calloc(1, sizeof *ftp))) {
 		return 0;
 	}
-	ftp->ctl = ftp->data = -1;
+	ftp->ctl = ftp->data = ftp->lis = -1;
+	ftp->passive = 1;
+
+	ftp->dirent = darr_alloc(0, sizeof *ftp->dirent);
 	return ftp;
 }
 
 void ftp_free(struct ftp *ftp)
 {
 	if(!ftp) return;
+
 	if(ftp->ctl >= 0) {
 		ftp_close(ftp);
 	}
+
+	free_dir(ftp->dirent);
+}
+
+static void free_dir(struct ftp_dirent *dir)
+{
+	int i;
+	for(i=0; i<darr_size(dir); i++) {
+		free(dir[i].name);
+	}
+	darr_free(dir);
 }
 
 int ftp_connect(struct ftp *ftp, const char *hostname, int port)
@@ -44,8 +105,9 @@ int ftp_connect(struct ftp *ftp, const char *hostname, int port)
 		return -1;
 	}
 
+	memset(&addr, 0, sizeof addr);
 	addr.sin_family = AF_INET;
-	addr.sin_addr.s_addr = inet_addr(host->h_addr);
+	addr.sin_addr = *((struct in_addr*)host->h_addr);
 	addr.sin_port = htons(port);
 
 	if(connect(ftp->ctl, (struct sockaddr*)&addr, sizeof addr) == -1) {
@@ -54,7 +116,9 @@ int ftp_connect(struct ftp *ftp, const char *hostname, int port)
 		ftp->ctl = -1;
 		return -1;
 	}
-		
+
+	fcntlsocket(ftp->ctl, F_SETFL, fcntlsocket(ftp->ctl, F_GETFL) | O_NONBLOCK);
+	ftp->num_crecv = 0;
 	return 0;
 }
 
@@ -62,10 +126,479 @@ void ftp_close(struct ftp *ftp)
 {
 	if(ftp->ctl >= 0) {
 		closesocket(ftp->ctl);
+		ftp->ctl = -1;
+		ftp->num_crecv = 0;
+	}
+	if(ftp->lis >= 0) {
+		closesocket(ftp->lis);
+		ftp->lis = -1;
 	}
 	if(ftp->data >= 0) {
 		closesocket(ftp->data);
+		ftp->data = -1;
+	}
+}
+
+int ftp_sockets(struct ftp *ftp, int *sockv, int maxsize)
+{
+	int *sptr = sockv;
+	if(ftp->ctl >= 0 && maxsize-- > 0) {
+		*sptr++ = ftp->ctl;
+	}
+	if(ftp->lis >= 0 && maxsize-- > 0) {
+		*sptr++ = ftp->lis;
+	}
+	if(ftp->data >= 0 && maxsize-- > 0) {
+		*sptr++ = ftp->data;
+	}
+	return sptr - sockv;
+}
+
+static void exec_op(struct ftp *ftp, struct ftp_op *fop)
+{
+	switch(fop->op) {
+	case FTP_TYPE:
+		ftp_type(ftp, fop->arg);
+		break;
+
+	case FTP_PWD:
+		ftp_pwd(ftp);
+		break;
+
+	case FTP_CHDIR:
+		ftp_chdir(ftp, fop->arg);
+		break;
+
+	case FTP_CDUP:
+		ftp_chdir(ftp, "..");
+		break;
+
+	case FTP_MKDIR:
+		ftp_mkdir(ftp, fop->arg);
+		break;
+
+	case FTP_RMDIR:
+		ftp_rmdir(ftp, fop->arg);
+		break;
+
+	case FTP_DEL:
+		ftp_delete(ftp, fop->arg);
+		break;
+
+	case FTP_LIST:
+		ftp_list(ftp);
+		break;
+
+	case FTP_RETR:
+		ftp_retrieve(ftp, fop->arg);
+		break;
+
+	case FTP_STORE:
+		ftp_store(ftp, fop->arg);
+		break;
+
+	case FTP_XFER:
+		ftp_transfer(ftp, fop->data);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void exec_queued(struct ftp *ftp)
+{
+	struct ftp_op *fop;
+
+	if(!(fop = ftp->qhead)) {
+		return;
+	}
+
+	if(ftp->qtail == fop) {
+		ftp->qhead = ftp->qtail = 0;
+	} else {
+		ftp->qhead = ftp->qhead->next;
+	}
+
+	exec_op(ftp, fop);
+
+	free(fop->arg);
+	free(fop);
+}
+
+
+int ftp_queue(struct ftp *ftp, int op, const char *arg)
+{
+	struct ftp_op *fop;
+
+	if(!ftp->busy && !ftp->qhead) {
+		struct ftp_op tmp = {0};
+		tmp.op = op;
+		tmp.arg = (char*)arg;
+		exec_op(ftp, &tmp);
+		return 0;
+	}
+
+	if(!(fop = malloc(sizeof *fop))) {
+		return -1;
+	}
+	if(arg) {
+		if(!(fop->arg = strdup(arg))) {
+			free(fop);
+			return -1;
+		}
+	} else {
+		fop->arg = 0;
+	}
+	fop->op = op;
+	fop->next = 0;
+
+	if(ftp->qhead) {
+		ftp->qtail->next = fop;
+		ftp->qtail = fop;
+	} else {
+		ftp->qhead = ftp->qtail = fop;
+	}
+	return 0;
+}
+
+int ftp_queue_transfer(struct ftp *ftp, struct ftp_transfer *xfer)
+{
+	struct ftp_op *fop;
+
+	if(!ftp->busy && !ftp->qhead) {
+		struct ftp_op tmp = {0};
+		tmp.op = FTP_XFER;
+		tmp.data = xfer;
+		exec_op(ftp, &tmp);
+		return 0;
 	}
+
+	if(!(fop = malloc(sizeof *fop))) {
+		return -1;
+	}
+	fop->op = FTP_XFER;
+	fop->arg = 0;
+	fop->data = xfer;
+	fop->next = 0;
+
+	if(ftp->qhead) {
+		ftp->qtail->next = fop;
+		ftp->qtail = fop;
+	} else {
+		ftp->qhead = ftp->qtail = fop;
+	}
+	return 0;
+}
+
+int ftp_waitresp(struct ftp *ftp, long timeout)
+{
+	fd_set rdset;
+	struct timeval tv;
+	time_t start;
+
+	ftp->last_resp = -1;
+	start = time(0);
+
+	for(;;) {
+		FD_ZERO(&rdset);
+		FD_SET(ftp->ctl, &rdset);
+
+		if(timeout >= 0) {
+			tv.tv_sec = timeout;
+			tv.tv_usec = 0;
+		}
+
+		if(select(ftp->ctl + 1, &rdset, 0, 0, timeout >= 0 ? &tv : 0) == -1 && errno == EINTR) {
+			continue;
+		}
+
+		if(FD_ISSET(ftp->ctl, &rdset)) {
+			ftp->last_resp = -1;
+			ftp_handle(ftp, ftp->ctl);
+			if(ftp->last_resp) {
+				break;
+			}
+		}
+
+		if(timeout > 0) {
+			timeout -= time(0) - start;
+			if(timeout <= 0) {
+				return -1;
+			}
+		}
+
+	}
+	return ftp->last_resp;
+}
+
+static int ftp_active(struct ftp *ftp)
+{
+	struct sockaddr_in sa = {0};
+	int len;
+	unsigned long addr;
+	unsigned short port;
+
+	if(ftp->lis >= 0) {
+		closesocket(ftp->lis);
+	}
+	if(ftp->data >= 0) {
+		closesocket(ftp->data);
+		ftp->data = -1;
+	}
+
+	if((ftp->lis = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
+		errmsg("ftp_active: failed to create listening socket\n");
+		return -1;
+	}
+
+	len = sizeof sa;
+	getsockname(ftp->ctl, (struct sockaddr*)&sa, &len);
+
+	sa.sin_family = AF_INET;
+	sa.sin_port = 0;
+
+	if(bind(ftp->lis, (struct sockaddr*)&sa, sizeof sa) == -1) {
+		errmsg("ftp_active: failed to bind listening socket\n");
+		closesocket(ftp->lis);
+		ftp->lis = -1;
+		return -1;
+	}
+	listen(ftp->lis, 1);
+
+	len = sizeof sa;
+	if(getsockname(ftp->lis, (struct sockaddr*)&sa, &len) == -1) {
+		errmsg("ftp_active: failed to retrieve listening socket address\n");
+		closesocket(ftp->lis);
+		ftp->lis = -1;
+		return -1;
+	}
+
+	addr = ntohl(sa.sin_addr.s_addr);
+	port = ntohs(sa.sin_port);
+	infomsg("listening on %s port %d\n", inet_ntoa(sa.sin_addr), port);
+
+	sendcmd(ftp, "PORT %d,%d,%d,%d,%d,%d", addr >> 24, (addr >> 16) & 0xff,
+			(addr >> 8) & 0xff, addr & 0xff, port >> 8, port & 0xff);
+
+	ftp->cproc = cproc_active;
+	return 0;
+}
+
+static int ftp_passive(struct ftp *ftp)
+{
+	if(ftp->lis >= 0) {
+		closesocket(ftp->lis);
+		ftp->lis = -1;
+	}
+	if(ftp->data >= 0) {
+		closesocket(ftp->data);
+		ftp->data = -1;
+	}
+
+	sendcmd(ftp, "PASV");
+	ftp->cproc = cproc_pasv;
+	return 0;
+}
+
+int ftp_handle(struct ftp *ftp, int s)
+{
+	if(s == ftp->ctl) {
+		return handle_control(ftp);
+	}
+	if(s == ftp->data) {
+		return handle_data(ftp, s);
+	}
+	if(s == ftp->lis) {
+		int ns = accept(s, 0, 0);
+		if(ftp->data >= 0) {
+			closesocket(ns);
+		} else {
+			ftp->data = ns;
+		}
+		return 0;
+	}
+	return -1;
+}
+
+static int sendcmd(struct ftp *ftp, const char *fmt, ...)
+{
+	char buf[256];
+	va_list ap;
+
+	if(ftp->ctl < 0) {
+		return -1;
+	}
+
+	ftp->busy = 1;
+
+	va_start(ap, fmt);
+	vsprintf(buf, fmt, ap);
+	va_end(ap);
+	infomsg("send: %s\n", buf);
+	strcat(buf, "\r\n");
+	return send(ftp->ctl, buf, strlen(buf), 0);
+}
+
+static int handle_control(struct ftp *ftp)
+{
+	int i, sz, rd;
+	char *buf, *start, *end;
+
+	for(;;) {
+		if((sz = sizeof ftp->crecv - ftp->num_crecv) <= 0) {
+			/* discard buffer */
+			warnmsg("discard buffer\n");
+			sz = sizeof ftp->crecv;
+			ftp->num_crecv = 0;
+		}
+		start = ftp->crecv + ftp->num_crecv;
+		if((rd = recv(ftp->ctl, start, sz, 0)) == -1) {
+			if(errno == EINTR) continue;
+			/* assume EWOULDBLOCK, try again next time */
+			return 0;
+		}
+		if(rd == 0) {
+			ftp_close(ftp);
+			return -1;
+		}
+
+		end = start + rd;
+		buf = ftp->crecv;
+		for(i=0; i<rd; i++) {
+			if(start[i] == '\r') {
+				start[i] = 0;
+			} else if(start[i] == '\n') {
+				start[i] = 0;
+				proc_control(ftp, buf);
+				buf = start + i + 1;
+			}
+		}
+		if(buf != ftp->crecv && buf < end) {
+			ftp->num_crecv = end - buf;
+			memmove(ftp->crecv, buf, ftp->num_crecv);
+		} else {
+			ftp->num_crecv = 0;
+		}
+	}
+	return 0;
+}
+
+static int handle_data(struct ftp *ftp, int s)
+{
+	int i, rd;
+
+	if(ftp->data == -1) {
+		return -1;
+	}
+
+	/* get at most 4 packets at a time, to allow returning back to the main loop
+	 * to process input
+	 */
+	for(i=0; i<4; i++) {
+		if((rd = recv(ftp->data, ftp->drecv, sizeof ftp->drecv, 0)) == -1) {
+			if(errno == EINTR) continue;
+			/* assume EWOULDBLOCK, try again next time */
+			break;
+		}
+
+		/* call the callback first, so that we'll get a 0-count call to indicate
+		 * EOF when the server closes the data connection
+		 */
+		if(ftp->dproc) {
+			ftp->dproc(ftp, ftp->drecv, rd, ftp->dproc_cls);
+		}
+
+		if(rd == 0) {
+			closesocket(ftp->data);
+			ftp->data = -1;
+			return -1;
+		}
+	}
+	return 0;
+}
+
+static int respcode(const char *resp)
+{
+	if(!isdigit(resp[0]) || !isdigit(resp[1]) || !isdigit(resp[2])) {
+		return 0;
+	}
+
+	if(isspace(resp[3])) {
+		return atoi(resp);
+	}
+	if(resp[3] == '-') {
+		return -atoi(resp);
+	}
+	return 0;
+}
+
+static void proc_control(struct ftp *ftp, const char *buf)
+{
+	int code;
+	char *end;
+
+	while(*buf && isspace(*buf)) buf++;
+	if((end = strchr(buf, '\r'))) {
+		*end = 0;
+	}
+
+	infomsg("recv: %s\n", buf);
+
+	if((code = respcode(buf)) == 0) {
+		warnmsg("ignoring invalid response: %s\n", buf);
+		return;
+	}
+	if(code < 0) {
+		return;	/* ignore continuations for now */
+	}
+
+	ftp->last_resp = code;
+
+	if(ftp->cproc) {
+		if(ftp->cproc(ftp, code, buf, ftp->cproc_cls) <= 0) {
+			ftp->cproc = 0;
+			ftp->busy = 0;
+
+			/* execute next operation if there's one queued */
+			exec_queued(ftp);
+		}
+		return;
+	}
+	ftp->busy = 0;
+
+	switch(code) {
+	case 220:
+		sendcmd(ftp, "user %s", ftp->user ? ftp->user : "anonymous");
+		break;
+	case 331:
+		sendcmd(ftp, "pass %s", ftp->pass ? ftp->pass : "foobar");
+		break;
+	case 230:
+		infomsg("login successful\n");
+		if(newconn(ftp) == -1) {
+			ftp_close(ftp);
+		}
+		break;
+	case 530:
+		ftp->status = 0;
+		errmsg("login failed\n");
+		break;
+
+	default:
+		ftp->busy = 0;
+
+		/* execute next operation if there's one queued */
+		exec_queued(ftp);
+	}
+}
+
+static int newconn(struct ftp *ftp)
+{
+	ftp_queue(ftp, FTP_TYPE, "I");
+	ftp_queue(ftp, FTP_PWD, 0);
+	ftp_queue(ftp, FTP_LIST, 0);
+	return 0;
 }
 
 int ftp_update(struct ftp *ftp)
@@ -73,7 +606,434 @@ int ftp_update(struct ftp *ftp)
 	return -1;
 }
 
+int ftp_type(struct ftp *ftp, const char *type)
+{
+	int tc = toupper(type[0]);
+	if(tc != 'I' && tc != 'A') {
+		return -1;
+	}
+	sendcmd(ftp, "type %c", tc);
+	return 0;
+}
+
+int ftp_pwd(struct ftp *ftp)
+{
+	sendcmd(ftp, "pwd");
+	ftp->cproc = cproc_pwd;
+	return 0;
+}
+
 int ftp_chdir(struct ftp *ftp, const char *dirname)
 {
+	if(strcmp(dirname, "..") == 0) {
+		sendcmd(ftp, "cdup");
+	} else {
+		sendcmd(ftp, "cwd %s", dirname);
+	}
+	ftp->cproc = cproc_cwd;
+	return 0;
+}
+
+int ftp_mkdir(struct ftp *ftp, const char *dirname)
+{
+	return -1;
+}
+
+int ftp_rmdir(struct ftp *ftp, const char *dirname)
+{
+	return -1;
+}
+
+int ftp_delete(struct ftp *ftp, const char *fname)
+{
+	return -1;
+}
+
+static int prepare_data(struct ftp *ftp)
+{
+	if(ftp->data >= 0) {
+		return 0;
+	}
+
+	if(ftp->passive) {
+		ftp_passive(ftp);
+		ftp_waitresp(ftp, TIMEOUT);
+	} else {
+		if(ftp_active(ftp) == -1) {
+			return -1;
+		}
+	}
+	if(ftp->data == -1) {
+		return -1;
+	}
+	return 0;
+}
+
+struct recvbuf {
+	char *buf;
+	long size, bufsz;
+};
+
+int ftp_list(struct ftp *ftp)
+{
+	struct recvbuf *rbuf;
+
+	if(prepare_data(ftp) == -1) {
+		return -1;
+	}
+
+	if(!(rbuf = malloc(sizeof *rbuf))) {
+		errmsg("failed to allocate receive buffer\n");
+		return -1;
+	}
+	rbuf->size = 0;
+	rbuf->bufsz = 1024;
+	if(!(rbuf->buf = malloc(rbuf->bufsz))) {
+		free(rbuf);
+		errmsg("failed to allocate receive buffer\n");
+		return -1;
+	}
+
+	sendcmd(ftp, "list");
+	ftp->cproc = cproc_list;
+	ftp->dproc = dproc_list;
+	ftp->cproc_cls = ftp->dproc_cls = rbuf;
+	return 0;
+}
+
+int ftp_retrieve(struct ftp *ftp, const char *fname)
+{
+	return -1;
+}
+
+int ftp_store(struct ftp *ftp, const char *fname)
+{
 	return -1;
 }
+
+#define XFER_BUF_SIZE	1024
+
+int ftp_transfer(struct ftp *ftp, struct ftp_transfer *xfer)
+{
+	if(prepare_data(ftp) == -1) {
+		return -1;
+	}
+
+	if(xfer->op == FTP_RETR) {
+		sendcmd(ftp, "retr %s", xfer->rname);
+		ftp->cproc = cproc_xfer;
+		ftp->dproc = dproc_xfer;
+		ftp->cproc_cls = ftp->dproc_cls = xfer;
+	} else {
+		/* TODO */
+	}
+	return 0;
+}
+
+static int get_quoted_text(const char *str, char *buf)
+{
+	int len;
+	const char *src, *end;
+
+	if(!(src = strchr(str, '"'))) {
+		return -1;
+	}
+	src++;
+	end = src;
+	while(*end && *end != '"') end++;
+	if(!*end) return -1;
+
+	len = end - src;
+	memcpy(buf, src, len);
+	buf[len] = 0;
+	return 0;
+}
+
+static int cproc_active(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	if(code != 200) {
+		errmsg("ftp_active failed\n");
+		ftp_close(ftp);
+	} else {
+		ftp->status = FTP_CONN_ACT;
+	}
+	return 0;
+}
+
+static int cproc_pasv(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	const char *str;
+	unsigned int addr[6];
+	struct sockaddr_in sa;
+	unsigned int ipaddr;
+	int port;
+
+	if(code != 227) {
+		errmsg("ftp_passive failed\n");
+		goto nopasv;
+	}
+
+	str = buf;
+	while(*str) {
+		if(sscanf(str, "%u,%u,%u,%u,%u,%u", addr, addr + 1, addr + 2, addr + 3,
+					addr + 4, addr + 5) == 6) {
+			break;
+		}
+		str++;
+	}
+	if(!*str || (addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]) >= 256) {
+		errmsg("ftp_passive: failed to parse response: %s\n", buf);
+		goto nopasv;
+	}
+	port = (addr[4] << 8) | addr[5];
+	ipaddr = ((unsigned int)addr[0] << 24) | ((unsigned int)addr[1] << 16) |
+		((unsigned int)addr[2] << 8) | addr[3];
+
+	if((ftp->data = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
+		fprintf(stderr, "ftp_passive: failed to allocate socket\n");
+		goto nopasv;
+	}
+
+	infomsg("passive mode: %d.%d.%d.%d port %d\n", addr[0], addr[1], addr[2], addr[3],
+			port);
+
+	sa.sin_family = AF_INET;
+	sa.sin_addr.s_addr = htonl(ipaddr);
+	sa.sin_port = htons(port);
+
+	if(connect(ftp->data, (struct sockaddr*)&sa, sizeof sa) == -1) {
+		errmsg("ftp_passive: failed to connect to %s:%p\n", inet_ntoa(sa.sin_addr), port);
+		closesocket(ftp->data);
+		ftp->data = -1;
+		goto nopasv;
+	}
+
+	ftp->status = FTP_CONN_PASV;
+	return 0;
+
+nopasv:
+	ftp->passive = 0;
+	ftp_active(ftp);
+	return 0;
+}
+
+static int cproc_pwd(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	char *dirname;
+
+	if(code != 257) {
+		warnmsg("pwd failed\n");
+		return -1;
+	}
+
+	dirname = alloca(strlen(buf) + 1);
+	if(get_quoted_text(buf, dirname) == -1) {
+		warnmsg("pwd: invalid response: %s\n", buf);
+		return -1;
+	}
+
+	free(ftp->curdir);
+	ftp->curdir = strdup_nf(dirname);
+	ftp->modified = FTP_MOD_DIR;
+	return 0;
+}
+
+static int cproc_cwd(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	if(code != 250) {
+		warnmsg("cwd failed\n");
+		return -1;
+	}
+
+	ftp_queue(ftp, FTP_PWD, 0);
+	ftp_queue(ftp, FTP_LIST, 0);
+	return 0;
+}
+
+static int cproc_list(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	if(code < 200) {
+		/* expect more */
+		return 1;
+	}
+
+	if(code >= 400) {
+		errmsg("failed to retrieve directory listing\n");
+	}
+	return 0;
+}
+
+#define SKIP_FIELD(p) \
+	do { \
+		while(*(p) && *(p) != '\n' && !isspace(*(p))) (p)++; \
+		while(*(p) && *(p) != '\n' && isspace(*(p))) (p)++; \
+	} while(0)
+
+static int parse_dirent(struct ftp_dirent *ent, const char *line)
+{
+	int len;
+	const char *ptr = line;
+	const char *end;
+
+	if(!(end = strchr(line, '\r')) && !(end = strchr(line, '\n'))) {
+		return -1;
+	}
+
+	if(line[0] == 'd') {
+		ent->type = FTP_DIR;
+	} else {
+		ent->type = FTP_FILE;
+	}
+
+	SKIP_FIELD(ptr);		/* skip mode */
+	SKIP_FIELD(ptr);		/* skip links */
+	SKIP_FIELD(ptr);		/* skip owner */
+	SKIP_FIELD(ptr);		/* skip group */
+
+	if(ent->type == FTP_FILE) {
+		ent->size = atoi(ptr);
+	}
+	SKIP_FIELD(ptr);		/* skip size */
+	SKIP_FIELD(ptr);		/* skip month */
+	SKIP_FIELD(ptr);		/* skip day */
+	SKIP_FIELD(ptr);		/* skip year */
+
+	if(ptr >= end) return -1;
+
+	len = end - ptr;
+	ent->name = malloc(len + 1);
+	memcpy(ent->name, ptr, len);
+	ent->name[len] = 0;
+
+	return 0;
+}
+
+int ftp_direntcmp(const void *a, const void *b)
+{
+	const struct ftp_dirent *da = a, *db = b;
+
+	if(da->type == db->type) {
+		return strcmp(da->name, db->name);
+	}
+	return da->type == FTP_DIR ? -1 : 1;
+}
+
+static void dproc_list(struct ftp *ftp, const char *buf, int sz, void *cls)
+{
+	int num;
+	struct recvbuf *rbuf = cls;
+
+	if(sz == 0) {
+		/* EOF condition, we got the whole list, update directory entries */
+		char *ptr = rbuf->buf;
+		char *end = rbuf->buf + rbuf->size;
+		struct ftp_dirent ent;
+
+		darr_clear(ftp->dirent);
+
+		while(ptr < end) {
+			if(parse_dirent(&ent, ptr) != -1) {
+				darr_push(ftp->dirent, &ent);
+			}
+			while(ptr < end && *ptr != '\n' && *ptr != '\r') ptr++;
+			while(ptr < end && (*ptr == '\r' || *ptr == '\n')) ptr++;
+		}
+		ftp->modified |= FTP_MOD_DIR;
+
+		free(rbuf->buf);
+		free(rbuf);
+		ftp->dproc = 0;
+
+		num = darr_size(ftp->dirent);
+		qsort(ftp->dirent, num, sizeof *ftp->dirent, ftp_direntcmp);
+		return;
+	}
+
+	if(rbuf->size + sz > rbuf->bufsz) {
+		char *tmp;
+		int newsz = rbuf->bufsz << 1;
+
+		if(!(tmp = realloc(rbuf->buf, newsz))) {
+			errmsg("failed to resize receive buffer\n");
+			return;
+		}
+		rbuf->buf = tmp;
+		rbuf->bufsz = newsz;
+	}
+
+	memcpy(rbuf->buf + rbuf->size, buf, sz);
+	rbuf->size += sz;
+}
+
+static int cproc_xfer(struct ftp *ftp, int code, const char *buf, void *cls)
+{
+	char *ptr;
+	struct ftp_transfer *xfer = cls;
+
+	if(code < 200) {
+		/* expect more */
+		if(code == 150 && (ptr = strchr(buf, '('))) {
+			/* update total size */
+			sscanf(ptr, "(%ld bytes)", &xfer->total);
+		}
+		return 1;
+	}
+
+	if(code >= 400) {
+		errmsg("failed to retrieve file\n");
+	}
+	return 0;
+}
+
+static void dproc_xfer(struct ftp *ftp, const char *buf, int sz, void *cls)
+{
+	struct ftp_transfer *xfer = cls;
+
+	if(xfer->op == FTP_RETR) {
+		if(sz == 0) {
+			/* EOF condition, got the whole file */
+			if(xfer->fp) {
+				fclose(xfer->fp);
+				xfer->fp = 0;
+			}
+
+			if(xfer->done) {
+				xfer->done(ftp, xfer);
+			}
+			return;
+		}
+
+		if(xfer->fp) {
+			((char*)buf)[sz] = 0;
+			fwrite(buf, 1, sz, xfer->fp);
+
+		} else if(xfer->mem) {
+			int prevsz = darr_size(xfer->mem);
+			darr_resize(xfer->mem, prevsz + sz);
+			memcpy(xfer->mem + prevsz, buf, sz);
+		}
+
+		xfer->count += sz;
+		if(xfer->count > xfer->total) {
+			xfer->count = xfer->total;
+		}
+
+	} else { /* FTP_STOR */
+		/* TODO */
+	}
+}
+
+const char *ftp_curdir(struct ftp *ftp)
+{
+	return ftp->curdir;
+}
+
+int ftp_num_dirent(struct ftp *ftp)
+{
+	return darr_size(ftp->dirent);
+}
+
+struct ftp_dirent *ftp_dirent(struct ftp *ftp, int idx)
+{
+	return ftp->dirent + idx;
+}