- djm@cvs.openbsd.org 2010/09/22 22:58:51

     [atomicio.c atomicio.h misc.c misc.h scp.c sftp-client.c]
     [sftp-client.h sftp.1 sftp.c]
     add an option per-read/write callback to atomicio

     factor out bandwidth limiting code from scp(1) into a generic bandwidth
     limiter that can be attached using the atomicio callback mechanism

     add a bandwidth limit option to sftp(1) using the above
     "very nice" markus@

10 files changed, 282 insertions, 213 deletions

diff --git a/ChangeLog b/ChangeLog
index 5f3914007..b3338dcb7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -44,6 +44,16 @@
      ssh_config.5: format the kexalgorithms in a more consistent
      (prettier!) way
      ok djm
+   - djm@cvs.openbsd.org 2010/09/22 22:58:51
+     [atomicio.c atomicio.h misc.c misc.h scp.c sftp-client.c]
+     [sftp-client.h sftp.1 sftp.c]
+     add an option per-read/write callback to atomicio
+
+     factor out bandwidth limiting code from scp(1) into a generic bandwidth
+     limiter that can be attached using the atomicio callback mechanism
+
+     add a bandwidth limit option to sftp(1) using the above
+     "very nice" markus@
 
 20100910
  - (dtucker) [openbsd-compat/port-linux.c] Check is_selinux_enabled for exact
diff --git a/atomicio.c b/atomicio.c
index a6b2d127a..601b3c371 100644
--- a/atomicio.c
+++ b/atomicio.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: atomicio.c,v 1.25 2007/06/25 12:02:27 dtucker Exp $ */
+/* $OpenBSD: atomicio.c,v 1.26 2010/09/22 22:58:51 djm Exp $ */
 /*
  * Copyright (c) 2006 Damien Miller. All rights reserved.
  * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
@@ -48,7 +48,8 @@
  * ensure all of data on socket comes through. f==read || f==vwrite
  */
 size_t
-atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
+atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
+    int (*cb)(void *, size_t), void *cb_arg)
 {
         char *s = _s;
         size_t pos = 0;
@@ -73,17 +74,28 @@ atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
                         return pos;
                 default:
                         pos += (size_t)res;
+                        if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
+                                errno = EINTR;
+                                return pos;
+                        }
                 }
         }
-        return (pos);
+        return pos;
+}
+
+size_t
+atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
+{
+        return atomicio6(f, fd, _s, n, NULL, NULL);
 }
 
 /*
  * ensure all of data on socket comes through. f==readv || f==writev
  */
 size_t
-atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
-    const struct iovec *_iov, int iovcnt)
+atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
+    const struct iovec *_iov, int iovcnt,
+    int (*cb)(void *, size_t), void *cb_arg)
 {
         size_t pos = 0, rem;
         ssize_t res;
@@ -137,6 +149,17 @@ atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
                         iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
                         iov[0].iov_len -= rem;
                 }
+                if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
+                        errno = EINTR;
+                        return pos;
+                }
         }
         return pos;
 }
+
+size_t
+atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
+    const struct iovec *_iov, int iovcnt)
+{
+        return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
+}
diff --git a/atomicio.h b/atomicio.h
index 2fcd25d43..0d728ac86 100644
--- a/atomicio.h
+++ b/atomicio.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: atomicio.h,v 1.10 2006/08/03 03:34:41 deraadt Exp $ */
+/* $OpenBSD: atomicio.h,v 1.11 2010/09/22 22:58:51 djm Exp $ */
 
 /*
  * Copyright (c) 2006 Damien Miller.  All rights reserved.
@@ -32,6 +32,9 @@
 /*
  * Ensure all of data on socket comes through. f==read || f==vwrite
  */
+size_t
+atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
+    int (*cb)(void *, size_t), void *);
 size_t  atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t);
 
 #define vwrite (ssize_t (*)(int, void *, size_t))write
@@ -39,6 +42,9 @@ size_t	atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t);
 /*
  * ensure all of data on socket comes through. f==readv || f==writev
  */
+size_t
+atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
+    const struct iovec *_iov, int iovcnt, int (*cb)(void *, size_t), void *);
 size_t  atomiciov(ssize_t (*)(int, const struct iovec *, int),
     int, const struct iovec *, int);
 
diff --git a/misc.c b/misc.c
index a82e7936e..41c92a82b 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.80 2010/07/21 02:10:58 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.81 2010/09/22 22:58:51 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -860,6 +860,70 @@ timingsafe_bcmp(const void *b1, const void *b2, size_t n)
                 ret |= *p1++ ^ *p2++;
         return (ret != 0);
 }
+
+void
+bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
+{
+        bw->buflen = buflen;
+        bw->rate = kbps;
+        bw->thresh = bw->rate;
+        bw->lamt = 0;
+        timerclear(&bw->bwstart);
+        timerclear(&bw->bwend);
+}       
+
+/* Callback from read/write loop to insert bandwidth-limiting delays */
+void
+bandwidth_limit(struct bwlimit *bw, size_t read_len)
+{
+        u_int64_t waitlen;
+        struct timespec ts, rm;
+
+        if (!timerisset(&bw->bwstart)) {
+                gettimeofday(&bw->bwstart, NULL);
+                return;
+        }
+
+        bw->lamt += read_len;
+        if (bw->lamt < bw->thresh)
+                return;
+
+        gettimeofday(&bw->bwend, NULL);
+        timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
+        if (!timerisset(&bw->bwend))
+                return;
+
+        bw->lamt *= 8;
+        waitlen = (double)1000000L * bw->lamt / bw->rate;
+
+        bw->bwstart.tv_sec = waitlen / 1000000L;
+        bw->bwstart.tv_usec = waitlen % 1000000L;
+
+        if (timercmp(&bw->bwstart, &bw->bwend, >)) {
+                timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
+
+                /* Adjust the wait time */
+                if (bw->bwend.tv_sec) {
+                        bw->thresh /= 2;
+                        if (bw->thresh < bw->buflen / 4)
+                                bw->thresh = bw->buflen / 4;
+                } else if (bw->bwend.tv_usec < 10000) {
+                        bw->thresh *= 2;
+                        if (bw->thresh > bw->buflen * 8)
+                                bw->thresh = bw->buflen * 8;
+                }
+
+                TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
+                while (nanosleep(&ts, &rm) == -1) {
+                        if (errno != EINTR)
+                                break;
+                        ts = rm;
+                }
+        }
+
+        bw->lamt = 0;
+        gettimeofday(&bw->bwstart, NULL);
+}
 void
 sock_set_v6only(int s)
 {
diff --git a/misc.h b/misc.h
index bb799f616..f5aab029b 100644
--- a/misc.h
+++ b/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.43 2010/07/13 23:13:16 djm Exp $ */
+/* $OpenBSD: misc.h,v 1.44 2010/09/22 22:58:51 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -80,6 +80,15 @@ void		put_u32(void *, u_int32_t)
 void            put_u16(void *, u_int16_t)
     __attribute__((__bounded__( __minbytes__, 1, 2)));
 
+struct bwlimit {
+        size_t buflen;
+        u_int64_t rate, thresh, lamt;
+        struct timeval bwstart, bwend;
+};
+
+void bandwidth_limit_init(struct bwlimit *, u_int64_t, size_t);
+void bandwidth_limit(struct bwlimit *, size_t);
+
 
 /* readpass.c */
 
diff --git a/scp.c b/scp.c
index e07de42f7..a4066c668 100644
--- a/scp.c
+++ b/scp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.166 2010/07/01 13:06:59 millert Exp $ */
+/* $OpenBSD: scp.c,v 1.167 2010/09/22 22:58:51 djm Exp $ */
 /*
  * scp - secure remote copy.  This is basically patched BSD rcp which
  * uses ssh to do the data transfer (instead of using rcmd).
@@ -120,13 +120,12 @@ extern char *__progname;
 
 int do_cmd(char *host, char *remuser, char *cmd, int *fdin, int *fdout);
 
-void bwlimit(int);
-
 /* Struct for addargs */
 arglist args;
 
 /* Bandwidth limit */
-off_t limit_rate = 0;
+long long limit_kbps = 0;
+struct bwlimit bwlimit;
 
 /* Name of current file being transferred. */
 char *curfile;
@@ -312,15 +311,14 @@ void sink(int, char *[]);
 void source(int, char *[]);
 void tolocal(int, char *[]);
 void toremote(char *, int, char *[]);
-size_t scpio(ssize_t (*)(int, void *, size_t), int, void *, size_t, off_t *);
 void usage(void);
 
 int
 main(int argc, char **argv)
 {
         int ch, fflag, tflag, status, n;
-        double speed;
-        char *targ, *endp, **newargv;
+        char *targ, **newargv;
+        const char *errstr;
         extern char *optarg;
         extern int optind;
 
@@ -369,10 +367,12 @@ main(int argc, char **argv)
                         addargs(&args, "-oBatchmode yes");
                         break;
                 case 'l':
-                        speed = strtod(optarg, &endp);
-                        if (speed <= 0 || *endp != '\0')
+                        limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
+                            &errstr);
+                        if (errstr != NULL)
                                 usage();
-                        limit_rate = speed * 1024;
+                        limit_kbps *= 1024; /* kbps */
+                        bandwidth_limit_init(&bwlimit, limit_kbps, COPY_BUFLEN);
                         break;
                 case 'p':
                         pflag = 1;
@@ -474,41 +474,16 @@ main(int argc, char **argv)
         exit(errs != 0);
 }
 
-/*
- * atomicio-like wrapper that also applies bandwidth limits and updates
- * the progressmeter counter.
- */
-size_t
-scpio(ssize_t (*f)(int, void *, size_t), int fd, void *_p, size_t l, off_t *c)
+/* Callback from atomicio6 to update progress meter and limit bandwidth */
+static int
+scpio(void *_cnt, size_t s)
 {
-        u_char *p = (u_char *)_p;
-        size_t offset;
-        ssize_t r;
-        struct pollfd pfd;
-
-        pfd.fd = fd;
-        pfd.events = f == read ? POLLIN : POLLOUT;
-        for (offset = 0; offset < l;) {
-                r = f(fd, p + offset, l - offset);
-                if (r == 0) {
-                        errno = EPIPE;
-                        return offset;
-                }
-                if (r < 0) {
-                        if (errno == EINTR)
-                                continue;
-                        if (errno == EAGAIN || errno == EWOULDBLOCK) {
-                                (void)poll(&pfd, 1, -1); /* Ignore errors */
-                                continue;
-                        }
-                        return offset;
-                }
-                offset += (size_t)r;
-                *c += (off_t)r;
-                if (limit_rate)
-                        bwlimit(r);
-        }
-        return offset;
+        off_t *cnt = (off_t *)_cnt;
+
+        *cnt += s;
+        if (limit_kbps > 0)
+                bandwidth_limit(&bwlimit, s);
+        return 0;
 }
 
 void
@@ -750,7 +725,7 @@ next:			if (fd != -1) {
                                 (void)atomicio(vwrite, remout, bp->buf, amt);
                                 continue;
                         }
-                        if (scpio(vwrite, remout, bp->buf, amt,
+                        if (atomicio6(vwrite, remout, bp->buf, amt, scpio,
                             &statbytes) != amt)
                                 haderr = errno;
                 }
@@ -825,60 +800,6 @@ rsource(char *name, struct stat *statp)
 }
 
 void
-bwlimit(int amount)
-{
-        static struct timeval bwstart, bwend;
-        static int lamt, thresh = 16384;
-        u_int64_t waitlen;
-        struct timespec ts, rm;
-
-        if (!timerisset(&bwstart)) {
-                gettimeofday(&bwstart, NULL);
-                return;
-        }
-
-        lamt += amount;
-        if (lamt < thresh)
-                return;
-
-        gettimeofday(&bwend, NULL);
-        timersub(&bwend, &bwstart, &bwend);
-        if (!timerisset(&bwend))
-                return;
-
-        lamt *= 8;
-        waitlen = (double)1000000L * lamt / limit_rate;
-
-        bwstart.tv_sec = waitlen / 1000000L;
-        bwstart.tv_usec = waitlen % 1000000L;
-
-        if (timercmp(&bwstart, &bwend, >)) {
-                timersub(&bwstart, &bwend, &bwend);
-
-                /* Adjust the wait time */
-                if (bwend.tv_sec) {
-                        thresh /= 2;
-                        if (thresh < 2048)
-                                thresh = 2048;
-                } else if (bwend.tv_usec < 10000) {
-                        thresh *= 2;
-                        if (thresh > COPY_BUFLEN * 4)
-                                thresh = COPY_BUFLEN * 4;
-                }
-
-                TIMEVAL_TO_TIMESPEC(&bwend, &ts);
-                while (nanosleep(&ts, &rm) == -1) {
-                        if (errno != EINTR)
-                                break;
-                        ts = rm;
-                }
-        }
-
-        lamt = 0;
-        gettimeofday(&bwstart, NULL);
-}
-
-void
 sink(int argc, char **argv)
 {
         static BUF buffer;
@@ -1071,7 +992,8 @@ bad:			run_err("%s: %s", np, strerror(errno));
                                 amt = size - i;
                         count += amt;
                         do {
-                                j = scpio(read, remin, cp, amt, &statbytes);
+                                j = atomicio6(read, remin, cp, amt,
+                                    scpio, &statbytes);
                                 if (j == 0) {
                                         run_err("%s", j != EPIPE ?
                                             strerror(errno) :
diff --git a/sftp-client.c b/sftp-client.c
index 9dab47780..4e009ef25 100644
--- a/sftp-client.c
+++ b/sftp-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-client.c,v 1.92 2010/07/19 03:16:33 djm Exp $ */
+/* $OpenBSD: sftp-client.c,v 1.93 2010/09/22 22:58:51 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -76,14 +76,26 @@ struct sftp_conn {
 #define SFTP_EXT_STATVFS        0x00000002
 #define SFTP_EXT_FSTATVFS       0x00000004
         u_int exts;
+        u_int64_t limit_kbps;
+        struct bwlimit bwlimit_in, bwlimit_out;
 };
 
 static char *
-get_handle(int fd, u_int expected_id, u_int *len, const char *errfmt, ...)
-    __attribute__((format(printf, 4, 5)));
+get_handle(struct sftp_conn *conn, u_int expected_id, u_int *len,
+    const char *errfmt, ...) __attribute__((format(printf, 4, 5)));
+
+/* ARGSUSED */
+static int
+sftpio(void *_bwlimit, size_t amount)
+{
+        struct bwlimit *bwlimit = (struct bwlimit *)_bwlimit;
+
+        bandwidth_limit(bwlimit, amount);
+        return 0;
+}
 
 static void
-send_msg(int fd, Buffer *m)
+send_msg(struct sftp_conn *conn, Buffer *m)
 {
         u_char mlen[4];
         struct iovec iov[2];
@@ -98,19 +110,22 @@ send_msg(int fd, Buffer *m)
         iov[1].iov_base = buffer_ptr(m);
         iov[1].iov_len = buffer_len(m);
 
-        if (atomiciov(writev, fd, iov, 2) != buffer_len(m) + sizeof(mlen))
+        if (atomiciov6(writev, conn->fd_out, iov, 2,
+            conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_out) != 
+            buffer_len(m) + sizeof(mlen))
                 fatal("Couldn't send packet: %s", strerror(errno));
 
         buffer_clear(m);
 }
 
 static void
-get_msg(int fd, Buffer *m)
+get_msg(struct sftp_conn *conn, Buffer *m)
 {
         u_int msg_len;
 
         buffer_append_space(m, 4);
-        if (atomicio(read, fd, buffer_ptr(m), 4) != 4) {
+        if (atomicio6(read, conn->fd_in, buffer_ptr(m), 4,
+            conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in) != 4) {
                 if (errno == EPIPE)
                         fatal("Connection closed");
                 else
@@ -122,7 +137,9 @@ get_msg(int fd, Buffer *m)
                 fatal("Received message too long %u", msg_len);
 
         buffer_append_space(m, msg_len);
-        if (atomicio(read, fd, buffer_ptr(m), msg_len) != msg_len) {
+        if (atomicio6(read, conn->fd_in, buffer_ptr(m), msg_len,
+            conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in)
+            != msg_len) {
                 if (errno == EPIPE)
                         fatal("Connection closed");
                 else
@@ -131,7 +148,7 @@ get_msg(int fd, Buffer *m)
 }
 
 static void
-send_string_request(int fd, u_int id, u_int code, char *s,
+send_string_request(struct sftp_conn *conn, u_int id, u_int code, char *s,
     u_int len)
 {
         Buffer msg;
@@ -140,14 +157,14 @@ send_string_request(int fd, u_int id, u_int code, char *s,
         buffer_put_char(&msg, code);
         buffer_put_int(&msg, id);
         buffer_put_string(&msg, s, len);
-        send_msg(fd, &msg);
-        debug3("Sent message fd %d T:%u I:%u", fd, code, id);
+        send_msg(conn, &msg);
+        debug3("Sent message fd %d T:%u I:%u", conn->fd_out, code, id);
         buffer_free(&msg);
 }
 
 static void
-send_string_attrs_request(int fd, u_int id, u_int code, char *s,
-    u_int len, Attrib *a)
+send_string_attrs_request(struct sftp_conn *conn, u_int id, u_int code,
+    char *s, u_int len, Attrib *a)
 {
         Buffer msg;
 
@@ -156,19 +173,19 @@ send_string_attrs_request(int fd, u_int id, u_int code, char *s,
         buffer_put_int(&msg, id);
         buffer_put_string(&msg, s, len);
         encode_attrib(&msg, a);
-        send_msg(fd, &msg);
-        debug3("Sent message fd %d T:%u I:%u", fd, code, id);
+        send_msg(conn, &msg);
+        debug3("Sent message fd %d T:%u I:%u", conn->fd_out, code, id);
         buffer_free(&msg);
 }
 
 static u_int
-get_status(int fd, u_int expected_id)
+get_status(struct sftp_conn *conn, u_int expected_id)
 {
         Buffer msg;
         u_int type, id, status;
 
         buffer_init(&msg);
-        get_msg(fd, &msg);
+        get_msg(conn, &msg);
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
 
@@ -183,11 +200,12 @@ get_status(int fd, u_int expected_id)
 
         debug3("SSH2_FXP_STATUS %u", status);
 
-        return(status);
+        return status;
 }
 
 static char *
-get_handle(int fd, u_int expected_id, u_int *len, const char *errfmt, ...)
+get_handle(struct sftp_conn *conn, u_int expected_id, u_int *len,
+    const char *errfmt, ...)
 {
         Buffer msg;
         u_int type, id;
@@ -201,7 +219,7 @@ get_handle(int fd, u_int expected_id, u_int *len, const char *errfmt, ...)
         va_end(args);
 
         buffer_init(&msg);
-        get_msg(fd, &msg);
+        get_msg(conn, &msg);
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
 
@@ -225,14 +243,14 @@ get_handle(int fd, u_int expected_id, u_int *len, const char *errfmt, ...)
 }
 
 static Attrib *
-get_decode_stat(int fd, u_int expected_id, int quiet)
+get_decode_stat(struct sftp_conn *conn, u_int expected_id, int quiet)
 {
         Buffer msg;
         u_int type, id;
         Attrib *a;
 
         buffer_init(&msg);
-        get_msg(fd, &msg);
+        get_msg(conn, &msg);
 
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
@@ -260,14 +278,14 @@ get_decode_stat(int fd, u_int expected_id, int quiet)
 }
 
 static int
-get_decode_statvfs(int fd, struct sftp_statvfs *st, u_int expected_id,
-    int quiet)
+get_decode_statvfs(struct sftp_conn *conn, struct sftp_statvfs *st,
+    u_int expected_id, int quiet)
 {
         Buffer msg;
         u_int type, id, flag;
 
         buffer_init(&msg);
-        get_msg(fd, &msg);
+        get_msg(conn, &msg);
 
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
@@ -311,21 +329,29 @@ get_decode_statvfs(int fd, struct sftp_statvfs *st, u_int expected_id,
 }
 
 struct sftp_conn *
-do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
+do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests,
+    u_int64_t limit_kbps)
 {
-        u_int type, exts = 0;
-        int version;
+        u_int type;
         Buffer msg;
         struct sftp_conn *ret;
 
+        ret = xmalloc(sizeof(*ret));
+        ret->fd_in = fd_in;
+        ret->fd_out = fd_out;
+        ret->transfer_buflen = transfer_buflen;
+        ret->num_requests = num_requests;
+        ret->exts = 0;
+        ret->limit_kbps = 0;
+
         buffer_init(&msg);
         buffer_put_char(&msg, SSH2_FXP_INIT);
         buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
-        send_msg(fd_out, &msg);
+        send_msg(ret, &msg);
 
         buffer_clear(&msg);
 
-        get_msg(fd_in, &msg);
+        get_msg(ret, &msg);
 
         /* Expecting a VERSION reply */
         if ((type = buffer_get_char(&msg)) != SSH2_FXP_VERSION) {
@@ -334,9 +360,9 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
                 buffer_free(&msg);
                 return(NULL);
         }
-        version = buffer_get_int(&msg);
+        ret->version = buffer_get_int(&msg);
 
-        debug2("Remote version: %d", version);
+        debug2("Remote version: %u", ret->version);
 
         /* Check for extensions */
         while (buffer_len(&msg) > 0) {
@@ -346,15 +372,15 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
 
                 if (strcmp(name, "posix-rename@openssh.com") == 0 &&
                     strcmp(value, "1") == 0) {
-                        exts |= SFTP_EXT_POSIX_RENAME;
+                        ret->exts |= SFTP_EXT_POSIX_RENAME;
                         known = 1;
                 } else if (strcmp(name, "statvfs@openssh.com") == 0 &&
                     strcmp(value, "2") == 0) {
-                        exts |= SFTP_EXT_STATVFS;
+                        ret->exts |= SFTP_EXT_STATVFS;
                         known = 1;
                 } if (strcmp(name, "fstatvfs@openssh.com") == 0 &&
                     strcmp(value, "2") == 0) {
-                        exts |= SFTP_EXT_FSTATVFS;
+                        ret->exts |= SFTP_EXT_FSTATVFS;
                         known = 1;
                 }
                 if (known) {
@@ -369,26 +395,25 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
 
         buffer_free(&msg);
 
-        ret = xmalloc(sizeof(*ret));
-        ret->fd_in = fd_in;
-        ret->fd_out = fd_out;
-        ret->transfer_buflen = transfer_buflen;
-        ret->num_requests = num_requests;
-        ret->version = version;
-        ret->msg_id = 1;
-        ret->exts = exts;
-
         /* Some filexfer v.0 servers don't support large packets */
-        if (version == 0)
+        if (ret->version == 0)
                 ret->transfer_buflen = MIN(ret->transfer_buflen, 20480);
 
-        return(ret);
+        ret->limit_kbps = limit_kbps;
+        if (ret->limit_kbps > 0) {
+                bandwidth_limit_init(&ret->bwlimit_in, ret->limit_kbps,
+                    ret->transfer_buflen);
+                bandwidth_limit_init(&ret->bwlimit_out, ret->limit_kbps,
+                    ret->transfer_buflen);
+        }
+
+        return ret;
 }
 
 u_int
 sftp_proto_version(struct sftp_conn *conn)
 {
-        return(conn->version);
+        return conn->version;
 }
 
 int
@@ -403,16 +428,16 @@ do_close(struct sftp_conn *conn, char *handle, u_int handle_len)
         buffer_put_char(&msg, SSH2_FXP_CLOSE);
         buffer_put_int(&msg, id);
         buffer_put_string(&msg, handle, handle_len);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         debug3("Sent message SSH2_FXP_CLOSE I:%u", id);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't close file: %s", fx2txt(status));
 
         buffer_free(&msg);
 
-        return(status);
+        return status;
 }
 
 
@@ -430,14 +455,14 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int printflag,
         buffer_put_char(&msg, SSH2_FXP_OPENDIR);
         buffer_put_int(&msg, id);
         buffer_put_cstring(&msg, path);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
 
         buffer_clear(&msg);
 
-        handle = get_handle(conn->fd_in, id, &handle_len,
+        handle = get_handle(conn, id, &handle_len,
             "remote readdir(\"%s\")", path);
         if (handle == NULL)
-                return(-1);
+                return -1;
 
         if (dir) {
                 ents = 0;
@@ -454,11 +479,11 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int printflag,
                 buffer_put_char(&msg, SSH2_FXP_READDIR);
                 buffer_put_int(&msg, id);
                 buffer_put_string(&msg, handle, handle_len);
-                send_msg(conn->fd_out, &msg);
+                send_msg(conn, &msg);
 
                 buffer_clear(&msg);
 
-                get_msg(conn->fd_in, &msg);
+                get_msg(conn, &msg);
 
                 type = buffer_get_char(&msg);
                 id = buffer_get_int(&msg);
@@ -537,7 +562,7 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int printflag,
                 **dir = NULL;
         }
 
-        return(0);
+        return 0;
 }
 
 int
@@ -566,9 +591,8 @@ do_rm(struct sftp_conn *conn, char *path)
         debug2("Sending SSH2_FXP_REMOVE \"%s\"", path);
 
         id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_REMOVE, path,
-            strlen(path));
-        status = get_status(conn->fd_in, id);
+        send_string_request(conn, id, SSH2_FXP_REMOVE, path, strlen(path));
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't delete file: %s", fx2txt(status));
         return(status);
@@ -580,10 +604,10 @@ do_mkdir(struct sftp_conn *conn, char *path, Attrib *a, int printflag)
         u_int status, id;
 
         id = conn->msg_id++;
-        send_string_attrs_request(conn->fd_out, id, SSH2_FXP_MKDIR, path,
+        send_string_attrs_request(conn, id, SSH2_FXP_MKDIR, path,
             strlen(path), a);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK && printflag)
                 error("Couldn't create directory: %s", fx2txt(status));
 
@@ -596,10 +620,10 @@ do_rmdir(struct sftp_conn *conn, char *path)
         u_int status, id;
 
         id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_RMDIR, path,
+        send_string_request(conn, id, SSH2_FXP_RMDIR, path,
             strlen(path));
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't remove directory: %s", fx2txt(status));
 
@@ -613,11 +637,11 @@ do_stat(struct sftp_conn *conn, char *path, int quiet)
 
         id = conn->msg_id++;
 
-        send_string_request(conn->fd_out, id,
+        send_string_request(conn, id,
             conn->version == 0 ? SSH2_FXP_STAT_VERSION_0 : SSH2_FXP_STAT,
             path, strlen(path));
 
-        return(get_decode_stat(conn->fd_in, id, quiet));
+        return(get_decode_stat(conn, id, quiet));
 }
 
 Attrib *
@@ -634,10 +658,10 @@ do_lstat(struct sftp_conn *conn, char *path, int quiet)
         }
 
         id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_LSTAT, path,
+        send_string_request(conn, id, SSH2_FXP_LSTAT, path,
             strlen(path));
 
-        return(get_decode_stat(conn->fd_in, id, quiet));
+        return(get_decode_stat(conn, id, quiet));
 }
 
 #ifdef notyet
@@ -647,10 +671,10 @@ do_fstat(struct sftp_conn *conn, char *handle, u_int handle_len, int quiet)
         u_int id;
 
         id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_FSTAT, handle,
+        send_string_request(conn, id, SSH2_FXP_FSTAT, handle,
             handle_len);
 
-        return(get_decode_stat(conn->fd_in, id, quiet));
+        return(get_decode_stat(conn, id, quiet));
 }
 #endif
 
@@ -660,10 +684,10 @@ do_setstat(struct sftp_conn *conn, char *path, Attrib *a)
         u_int status, id;
 
         id = conn->msg_id++;
-        send_string_attrs_request(conn->fd_out, id, SSH2_FXP_SETSTAT, path,
+        send_string_attrs_request(conn, id, SSH2_FXP_SETSTAT, path,
             strlen(path), a);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't setstat on \"%s\": %s", path,
                     fx2txt(status));
@@ -678,10 +702,10 @@ do_fsetstat(struct sftp_conn *conn, char *handle, u_int handle_len,
         u_int status, id;
 
         id = conn->msg_id++;
-        send_string_attrs_request(conn->fd_out, id, SSH2_FXP_FSETSTAT, handle,
+        send_string_attrs_request(conn, id, SSH2_FXP_FSETSTAT, handle,
             handle_len, a);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't fsetstat: %s", fx2txt(status));
 
@@ -697,12 +721,12 @@ do_realpath(struct sftp_conn *conn, char *path)
         Attrib *a;
 
         expected_id = id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_REALPATH, path,
+        send_string_request(conn, id, SSH2_FXP_REALPATH, path,
             strlen(path));
 
         buffer_init(&msg);
 
-        get_msg(conn->fd_in, &msg);
+        get_msg(conn, &msg);
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
 
@@ -756,13 +780,13 @@ do_rename(struct sftp_conn *conn, char *oldpath, char *newpath)
         }
         buffer_put_cstring(&msg, oldpath);
         buffer_put_cstring(&msg, newpath);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         debug3("Sent message %s \"%s\" -> \"%s\"",
             (conn->exts & SFTP_EXT_POSIX_RENAME) ? "posix-rename@openssh.com" :
             "SSH2_FXP_RENAME", oldpath, newpath);
         buffer_free(&msg);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't rename file \"%s\" to \"%s\": %s", oldpath,
                     newpath, fx2txt(status));
@@ -789,12 +813,12 @@ do_symlink(struct sftp_conn *conn, char *oldpath, char *newpath)
         buffer_put_int(&msg, id);
         buffer_put_cstring(&msg, oldpath);
         buffer_put_cstring(&msg, newpath);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         debug3("Sent message SSH2_FXP_SYMLINK \"%s\" -> \"%s\"", oldpath,
             newpath);
         buffer_free(&msg);
 
-        status = get_status(conn->fd_in, id);
+        status = get_status(conn, id);
         if (status != SSH2_FX_OK)
                 error("Couldn't symlink file \"%s\" to \"%s\": %s", oldpath,
                     newpath, fx2txt(status));
@@ -812,12 +836,11 @@ do_readlink(struct sftp_conn *conn, char *path)
         Attrib *a;
 
         expected_id = id = conn->msg_id++;
-        send_string_request(conn->fd_out, id, SSH2_FXP_READLINK, path,
-            strlen(path));
+        send_string_request(conn, id, SSH2_FXP_READLINK, path, strlen(path));
 
         buffer_init(&msg);
 
-        get_msg(conn->fd_in, &msg);
+        get_msg(conn, &msg);
         type = buffer_get_char(&msg);
         id = buffer_get_int(&msg);
 
@@ -871,10 +894,10 @@ do_statvfs(struct sftp_conn *conn, const char *path, struct sftp_statvfs *st,
         buffer_put_int(&msg, id);
         buffer_put_cstring(&msg, "statvfs@openssh.com");
         buffer_put_cstring(&msg, path);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         buffer_free(&msg);
 
-        return get_decode_statvfs(conn->fd_in, st, id, quiet);
+        return get_decode_statvfs(conn, st, id, quiet);
 }
 
 #ifdef notyet
@@ -898,16 +921,16 @@ do_fstatvfs(struct sftp_conn *conn, const char *handle, u_int handle_len,
         buffer_put_int(&msg, id);
         buffer_put_cstring(&msg, "fstatvfs@openssh.com");
         buffer_put_string(&msg, handle, handle_len);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         buffer_free(&msg);
 
-        return get_decode_statvfs(conn->fd_in, st, id, quiet);
+        return get_decode_statvfs(conn, st, id, quiet);
 }
 #endif
 
 static void
-send_read_request(int fd_out, u_int id, u_int64_t offset, u_int len,
-    char *handle, u_int handle_len)
+send_read_request(struct sftp_conn *conn, u_int id, u_int64_t offset,
+    u_int len, char *handle, u_int handle_len)
 {
         Buffer msg;
 
@@ -918,7 +941,7 @@ send_read_request(int fd_out, u_int id, u_int64_t offset, u_int len,
         buffer_put_string(&msg, handle, handle_len);
         buffer_put_int64(&msg, offset);
         buffer_put_int(&msg, len);
-        send_msg(fd_out, &msg);
+        send_msg(conn, &msg);
         buffer_free(&msg);
 }
 
@@ -976,10 +999,10 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
         buffer_put_int(&msg, SSH2_FXF_READ);
         attrib_clear(&junk); /* Send empty attributes */
         encode_attrib(&msg, &junk);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         debug3("Sent message SSH2_FXP_OPEN I:%u P:%s", id, remote_path);
 
-        handle = get_handle(conn->fd_in, id, &handle_len,
+        handle = get_handle(conn, id, &handle_len,
             "remote open(\"%s\")", remote_path);
         if (handle == NULL) {
                 buffer_free(&msg);
@@ -1032,12 +1055,12 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
                         offset += buflen;
                         num_req++;
                         TAILQ_INSERT_TAIL(&requests, req, tq);
-                        send_read_request(conn->fd_out, req->id, req->offset,
+                        send_read_request(conn, req->id, req->offset,
                             req->len, handle, handle_len);
                 }
 
                 buffer_clear(&msg);
-                get_msg(conn->fd_in, &msg);
+                get_msg(conn, &msg);
                 type = buffer_get_char(&msg);
                 id = buffer_get_int(&msg);
                 debug3("Received reply T:%u I:%u R:%d", type, id, max_req);
@@ -1092,7 +1115,7 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
                                 req->id = conn->msg_id++;
                                 req->len -= len;
                                 req->offset += len;
-                                send_read_request(conn->fd_out, req->id,
+                                send_read_request(conn, req->id,
                                     req->offset, req->len, handle, handle_len);
                                 /* Reduce the request size */
                                 if (len < buflen)
@@ -1327,12 +1350,12 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
         buffer_put_cstring(&msg, remote_path);
         buffer_put_int(&msg, SSH2_FXF_WRITE|SSH2_FXF_CREAT|SSH2_FXF_TRUNC);
         encode_attrib(&msg, &a);
-        send_msg(conn->fd_out, &msg);
+        send_msg(conn, &msg);
         debug3("Sent message SSH2_FXP_OPEN I:%u P:%s", id, remote_path);
 
         buffer_clear(&msg);
 
-        handle = get_handle(conn->fd_in, id, &handle_len,
+        handle = get_handle(conn, id, &handle_len,
             "remote open(\"%s\")", remote_path);
         if (handle == NULL) {
                 close(local_fd);
@@ -1381,7 +1404,7 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
                         buffer_put_string(&msg, handle, handle_len);
                         buffer_put_int64(&msg, offset);
                         buffer_put_string(&msg, data, len);
-                        send_msg(conn->fd_out, &msg);
+                        send_msg(conn, &msg);
                         debug3("Sent message SSH2_FXP_WRITE I:%u O:%llu S:%u",
                             id, (unsigned long long)offset, len);
                 } else if (TAILQ_FIRST(&acks) == NULL)
@@ -1395,7 +1418,7 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
                         u_int r_id;
 
                         buffer_clear(&msg);
-                        get_msg(conn->fd_in, &msg);
+                        get_msg(conn, &msg);
                         type = buffer_get_char(&msg);
                         r_id = buffer_get_int(&msg);
 
diff --git a/sftp-client.h b/sftp-client.h
index 1d08c4049..145fc38ee 100644
--- a/sftp-client.h
+++ b/sftp-client.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-client.h,v 1.18 2009/08/18 18:36:20 djm Exp $ */
+/* $OpenBSD: sftp-client.h,v 1.19 2010/09/22 22:58:51 djm Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
@@ -51,7 +51,7 @@ struct sftp_statvfs {
  * Initialise a SSH filexfer connection. Returns NULL on error or
  * a pointer to a initialized sftp_conn struct on success.
  */
-struct sftp_conn *do_init(int, int, u_int, u_int);
+struct sftp_conn *do_init(int, int, u_int, u_int, u_int64_t);
 
 u_int sftp_proto_version(struct sftp_conn *);
 
diff --git a/sftp.1 b/sftp.1
index 49d88de03..b2a19b72d 100644
--- a/sftp.1
+++ b/sftp.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: sftp.1,v 1.84 2010/09/19 21:30:05 jmc Exp $
+.\" $OpenBSD: sftp.1,v 1.85 2010/09/22 22:58:51 djm Exp $
 .\"
 .\" Copyright (c) 2001 Damien Miller.  All rights reserved.
 .\"
@@ -22,7 +22,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: September 19 2010 $
+.Dd $Mdocdate: September 22 2010 $
 .Dt SFTP 1
 .Os
 .Sh NAME
@@ -38,6 +38,7 @@
 .Op Fl D Ar sftp_server_path
 .Op Fl F Ar ssh_config
 .Op Fl i Ar identity_file
+.Op Fl l Ar limit
 .Op Fl o Ar ssh_option
 .Op Fl P Ar port
 .Op Fl R Ar num_requests
@@ -159,6 +160,8 @@ Selects the file from which the identity (private key) for public key
 authentication is read.
 This option is directly passed to
 .Xr ssh 1 .
+.It Fl l Ar limit
+Limits the used bandwidth, specified in Kbit/s.
 .It Fl o Ar ssh_option
 Can be used to pass options to
 .Nm ssh
diff --git a/sftp.c b/sftp.c
index 229f12987..8ce7d91fb 100644
--- a/sftp.c
+++ b/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.125 2010/06/18 00:58:39 djm Exp $ */
+/* $OpenBSD: sftp.c,v 1.126 2010/09/22 22:58:51 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -2073,6 +2073,7 @@ main(int argc, char **argv)
         int debug_level = 0, sshver = 2;
         char *file1 = NULL, *sftp_server = NULL;
         char *ssh_program = _PATH_SSH_PROGRAM, *sftp_direct = NULL;
+        const char *errstr;
         LogLevel ll = SYSLOG_LEVEL_INFO;
         arglist args;
         extern int optind;
@@ -2080,6 +2081,7 @@ main(int argc, char **argv)
         struct sftp_conn *conn;
         size_t copy_buffer_len = DEFAULT_COPY_BUFLEN;
         size_t num_requests = DEFAULT_NUM_REQUESTS;
+        long long limit_kbps = 0;
 
         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
         sanitise_stdfd();
@@ -2097,7 +2099,7 @@ main(int argc, char **argv)
         infile = stdin;
 
         while ((ch = getopt(argc, argv,
-            "1246hpqrvCc:D:i:o:s:S:b:B:F:P:R:")) != -1) {
+            "1246hpqrvCc:D:i:l:o:s:S:b:B:F:P:R:")) != -1) {
                 switch (ch) {
                 /* Passed through to ssh(1) */
                 case '4':
@@ -2158,6 +2160,13 @@ main(int argc, char **argv)
                 case 'D':
                         sftp_direct = optarg;
                         break;
+                case 'l':
+                        limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
+                            &errstr);
+                        if (errstr != NULL)
+                                usage();
+                        limit_kbps *= 1024; /* kbps */
+                        break;
                 case 'r':
                         global_rflag = 1;
                         break;
@@ -2235,7 +2244,7 @@ main(int argc, char **argv)
         }
         freeargs(&args);
 
-        conn = do_init(in, out, copy_buffer_len, num_requests);
+        conn = do_init(in, out, copy_buffer_len, num_requests, limit_kbps);
         if (conn == NULL)
                 fatal("Couldn't initialise connection to server");