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-rw-r--r--crypto/openssh/nchan.c369
1 files changed, 177 insertions, 192 deletions
diff --git a/crypto/openssh/nchan.c b/crypto/openssh/nchan.c
index eb9650136111..8153abbca099 100644
--- a/crypto/openssh/nchan.c
+++ b/crypto/openssh/nchan.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1999 Markus Friedl. All rights reserved.
+ * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -23,40 +23,79 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: nchan.c,v 1.23 2001/02/28 08:54:55 markus Exp $");
+RCSID("$OpenBSD: nchan.c,v 1.44 2002/01/21 23:27:10 markus Exp $");
#include "ssh1.h"
#include "ssh2.h"
#include "buffer.h"
#include "packet.h"
#include "channels.h"
-#include "nchan.h"
#include "compat.h"
#include "log.h"
+/*
+ * SSH Protocol 1.5 aka New Channel Protocol
+ * Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
+ * Written by Markus Friedl in October 1999
+ *
+ * Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
+ * tear down of channels:
+ *
+ * 1.3: strict request-ack-protocol:
+ * CLOSE ->
+ * <- CLOSE_CONFIRM
+ *
+ * 1.5: uses variations of:
+ * IEOF ->
+ * <- OCLOSE
+ * <- IEOF
+ * OCLOSE ->
+ * i.e. both sides have to close the channel
+ *
+ * 2.0: the EOF messages are optional
+ *
+ * See the debugging output from 'ssh -v' and 'sshd -d' of
+ * ssh-1.2.27 as an example.
+ *
+ */
+
/* functions manipulating channel states */
/*
* EVENTS update channel input/output states execute ACTIONS
*/
-/* events concerning the INPUT from socket for channel (istate) */
-chan_event_fn *chan_rcvd_oclose = NULL;
-chan_event_fn *chan_read_failed = NULL;
-chan_event_fn *chan_ibuf_empty = NULL;
-/* events concerning the OUTPUT from channel for socket (ostate) */
-chan_event_fn *chan_rcvd_ieof = NULL;
-chan_event_fn *chan_write_failed = NULL;
-chan_event_fn *chan_obuf_empty = NULL;
/*
* ACTIONS: should never update the channel states
*/
-static void chan_send_ieof1(Channel *c);
-static void chan_send_oclose1(Channel *c);
-static void chan_send_close2(Channel *c);
-static void chan_send_eof2(Channel *c);
+static void chan_send_ieof1(Channel *);
+static void chan_send_oclose1(Channel *);
+static void chan_send_close2(Channel *);
+static void chan_send_eof2(Channel *);
/* helper */
-static void chan_shutdown_write(Channel *c);
-static void chan_shutdown_read(Channel *c);
+static void chan_shutdown_write(Channel *);
+static void chan_shutdown_read(Channel *);
+
+static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
+static char *istates[] = { "open", "drain", "wait_oclose", "closed" };
+
+static void
+chan_set_istate(Channel *c, u_int next)
+{
+ if (c->istate > CHAN_INPUT_CLOSED || next > CHAN_INPUT_CLOSED)
+ fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
+ debug("channel %d: input %s -> %s", c->self, istates[c->istate],
+ istates[next]);
+ c->istate = next;
+}
+static void
+chan_set_ostate(Channel *c, u_int next)
+{
+ if (c->ostate > CHAN_OUTPUT_CLOSED || next > CHAN_OUTPUT_CLOSED)
+ fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
+ debug("channel %d: output %s -> %s", c->self, ostates[c->ostate],
+ ostates[next]);
+ c->ostate = next;
+}
/*
* SSH1 specific implementation of event functions
@@ -68,64 +107,61 @@ chan_rcvd_oclose1(Channel *c)
debug("channel %d: rcvd oclose", c->self);
switch (c->istate) {
case CHAN_INPUT_WAIT_OCLOSE:
- debug("channel %d: input wait_oclose -> closed", c->self);
- c->istate = CHAN_INPUT_CLOSED;
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
case CHAN_INPUT_OPEN:
- debug("channel %d: input open -> closed", c->self);
chan_shutdown_read(c);
chan_send_ieof1(c);
- c->istate = CHAN_INPUT_CLOSED;
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
case CHAN_INPUT_WAIT_DRAIN:
/* both local read_failed and remote write_failed */
- log("channel %d: input drain -> closed", c->self);
chan_send_ieof1(c);
- c->istate = CHAN_INPUT_CLOSED;
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
default:
- error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
+ error("channel %d: protocol error: rcvd_oclose for istate %d",
c->self, c->istate);
return;
}
}
-static void
-chan_read_failed_12(Channel *c)
+void
+chan_read_failed(Channel *c)
{
debug("channel %d: read failed", c->self);
switch (c->istate) {
case CHAN_INPUT_OPEN:
- debug("channel %d: input open -> drain", c->self);
chan_shutdown_read(c);
- c->istate = CHAN_INPUT_WAIT_DRAIN;
- if (buffer_len(&c->input) == 0) {
- debug("channel %d: input: no drain shortcut", c->self);
- chan_ibuf_empty(c);
- }
+ chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
break;
default:
- error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
+ error("channel %d: chan_read_failed for istate %d",
c->self, c->istate);
break;
}
}
-static void
-chan_ibuf_empty1(Channel *c)
+void
+chan_ibuf_empty(Channel *c)
{
debug("channel %d: ibuf empty", c->self);
if (buffer_len(&c->input)) {
- error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
+ error("channel %d: chan_ibuf_empty for non empty buffer",
c->self);
return;
}
switch (c->istate) {
case CHAN_INPUT_WAIT_DRAIN:
- debug("channel %d: input drain -> wait_oclose", c->self);
- chan_send_ieof1(c);
- c->istate = CHAN_INPUT_WAIT_OCLOSE;
+ if (compat20) {
+ if (!(c->flags & CHAN_CLOSE_SENT))
+ chan_send_eof2(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ } else {
+ chan_send_ieof1(c);
+ chan_set_istate(c, CHAN_INPUT_WAIT_OCLOSE);
+ }
break;
default:
- error("channel %d: internal error: chan_ibuf_empty for istate %d",
+ error("channel %d: chan_ibuf_empty for istate %d",
c->self, c->istate);
break;
}
@@ -134,36 +170,15 @@ static void
chan_rcvd_ieof1(Channel *c)
{
debug("channel %d: rcvd ieof", c->self);
- if (c->type != SSH_CHANNEL_OPEN) {
- debug("channel %d: non-open", c->self);
- if (c->istate == CHAN_INPUT_OPEN) {
- debug("channel %d: non-open: input open -> wait_oclose", c->self);
- chan_shutdown_read(c);
- chan_send_ieof1(c);
- c->istate = CHAN_INPUT_WAIT_OCLOSE;
- } else {
- error("channel %d: istate %d != open", c->self, c->istate);
- }
- if (c->ostate == CHAN_OUTPUT_OPEN) {
- debug("channel %d: non-open: output open -> closed", c->self);
- chan_send_oclose1(c);
- c->ostate = CHAN_OUTPUT_CLOSED;
- } else {
- error("channel %d: ostate %d != open", c->self, c->ostate);
- }
- return;
- }
switch (c->ostate) {
case CHAN_OUTPUT_OPEN:
- debug("channel %d: output open -> drain", c->self);
- c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
break;
case CHAN_OUTPUT_WAIT_IEOF:
- debug("channel %d: output wait_ieof -> closed", c->self);
- c->ostate = CHAN_OUTPUT_CLOSED;
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
break;
default:
- error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
+ error("channel %d: protocol error: rcvd_ieof for ostate %d",
c->self, c->ostate);
break;
}
@@ -174,38 +189,39 @@ chan_write_failed1(Channel *c)
debug("channel %d: write failed", c->self);
switch (c->ostate) {
case CHAN_OUTPUT_OPEN:
- debug("channel %d: output open -> wait_ieof", c->self);
+ chan_shutdown_write(c);
chan_send_oclose1(c);
- c->ostate = CHAN_OUTPUT_WAIT_IEOF;
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
break;
case CHAN_OUTPUT_WAIT_DRAIN:
- debug("channel %d: output wait_drain -> closed", c->self);
+ chan_shutdown_write(c);
chan_send_oclose1(c);
- c->ostate = CHAN_OUTPUT_CLOSED;
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
break;
default:
- error("channel %d: internal error: chan_write_failed for ostate %d",
+ error("channel %d: chan_write_failed for ostate %d",
c->self, c->ostate);
break;
}
}
-static void
-chan_obuf_empty1(Channel *c)
+void
+chan_obuf_empty(Channel *c)
{
debug("channel %d: obuf empty", c->self);
if (buffer_len(&c->output)) {
- error("channel %d: internal error: chan_obuf_empty for non empty buffer",
+ error("channel %d: chan_obuf_empty for non empty buffer",
c->self);
return;
}
switch (c->ostate) {
case CHAN_OUTPUT_WAIT_DRAIN:
- debug("channel %d: output drain -> closed", c->self);
- chan_send_oclose1(c);
- c->ostate = CHAN_OUTPUT_CLOSED;
+ chan_shutdown_write(c);
+ if (!compat20)
+ chan_send_oclose1(c);
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
break;
default:
- error("channel %d: internal error: chan_obuf_empty for ostate %d",
+ error("channel %d: internal error: obuf_empty for ostate %d",
c->self, c->ostate);
break;
}
@@ -222,7 +238,7 @@ chan_send_ieof1(Channel *c)
packet_send();
break;
default:
- error("channel %d: internal error: cannot send ieof for istate %d",
+ error("channel %d: cannot send ieof for istate %d",
c->self, c->istate);
break;
}
@@ -234,15 +250,14 @@ chan_send_oclose1(Channel *c)
switch (c->ostate) {
case CHAN_OUTPUT_OPEN:
case CHAN_OUTPUT_WAIT_DRAIN:
- chan_shutdown_write(c);
- buffer_consume(&c->output, buffer_len(&c->output));
+ buffer_clear(&c->output);
packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
packet_put_int(c->remote_id);
packet_send();
break;
default:
- error("channel %d: internal error: cannot send oclose for ostate %d",
- c->self, c->ostate);
+ error("channel %d: cannot send oclose for ostate %d",
+ c->self, c->ostate);
break;
}
}
@@ -251,7 +266,7 @@ chan_send_oclose1(Channel *c)
* the same for SSH2
*/
static void
-chan_rcvd_oclose2(Channel *c)
+chan_rcvd_close2(Channel *c)
{
debug("channel %d: rcvd close", c->self);
if (c->flags & CHAN_CLOSE_RCVD)
@@ -259,59 +274,36 @@ chan_rcvd_oclose2(Channel *c)
c->flags |= CHAN_CLOSE_RCVD;
if (c->type == SSH_CHANNEL_LARVAL) {
/* tear down larval channels immediately */
- c->ostate = CHAN_OUTPUT_CLOSED;
- c->istate = CHAN_INPUT_CLOSED;
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
return;
}
switch (c->ostate) {
case CHAN_OUTPUT_OPEN:
- /* wait until a data from the channel is consumed if a CLOSE is received */
- debug("channel %d: output open -> drain", c->self);
- c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+ /*
+ * wait until a data from the channel is consumed if a CLOSE
+ * is received
+ */
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
break;
}
switch (c->istate) {
case CHAN_INPUT_OPEN:
- debug("channel %d: input open -> closed", c->self);
chan_shutdown_read(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
case CHAN_INPUT_WAIT_DRAIN:
- debug("channel %d: input drain -> closed", c->self);
chan_send_eof2(c);
- break;
- }
- c->istate = CHAN_INPUT_CLOSED;
-}
-static void
-chan_ibuf_empty2(Channel *c)
-{
- debug("channel %d: ibuf empty", c->self);
- if (buffer_len(&c->input)) {
- error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
- c->self);
- return;
- }
- switch (c->istate) {
- case CHAN_INPUT_WAIT_DRAIN:
- debug("channel %d: input drain -> closed", c->self);
- if (!(c->flags & CHAN_CLOSE_SENT))
- chan_send_eof2(c);
- c->istate = CHAN_INPUT_CLOSED;
- break;
- default:
- error("channel %d: internal error: chan_ibuf_empty for istate %d",
- c->self, c->istate);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
}
}
static void
-chan_rcvd_ieof2(Channel *c)
+chan_rcvd_eof2(Channel *c)
{
debug("channel %d: rcvd eof", c->self);
- if (c->ostate == CHAN_OUTPUT_OPEN) {
- debug("channel %d: output open -> drain", c->self);
- c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
- }
+ if (c->ostate == CHAN_OUTPUT_OPEN)
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
}
static void
chan_write_failed2(Channel *c)
@@ -319,38 +311,12 @@ chan_write_failed2(Channel *c)
debug("channel %d: write failed", c->self);
switch (c->ostate) {
case CHAN_OUTPUT_OPEN:
- debug("channel %d: output open -> closed", c->self);
- chan_shutdown_write(c); /* ?? */
- c->ostate = CHAN_OUTPUT_CLOSED;
- break;
- case CHAN_OUTPUT_WAIT_DRAIN:
- debug("channel %d: output drain -> closed", c->self);
- chan_shutdown_write(c);
- c->ostate = CHAN_OUTPUT_CLOSED;
- break;
- default:
- error("channel %d: internal error: chan_write_failed for ostate %d",
- c->self, c->ostate);
- break;
- }
-}
-static void
-chan_obuf_empty2(Channel *c)
-{
- debug("channel %d: obuf empty", c->self);
- if (buffer_len(&c->output)) {
- error("internal error: chan_obuf_empty %d for non empty buffer",
- c->self);
- return;
- }
- switch (c->ostate) {
case CHAN_OUTPUT_WAIT_DRAIN:
- debug("channel %d: output drain -> closed", c->self);
chan_shutdown_write(c);
- c->ostate = CHAN_OUTPUT_CLOSED;
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
break;
default:
- error("channel %d: internal error: chan_obuf_empty for ostate %d",
+ error("channel %d: chan_write_failed for ostate %d",
c->self, c->ostate);
break;
}
@@ -366,7 +332,7 @@ chan_send_eof2(Channel *c)
packet_send();
break;
default:
- error("channel %d: internal error: cannot send eof for istate %d",
+ error("channel %d: cannot send eof for istate %d",
c->self, c->istate);
break;
}
@@ -377,10 +343,10 @@ chan_send_close2(Channel *c)
debug("channel %d: send close", c->self);
if (c->ostate != CHAN_OUTPUT_CLOSED ||
c->istate != CHAN_INPUT_CLOSED) {
- error("channel %d: internal error: cannot send close for istate/ostate %d/%d",
+ error("channel %d: cannot send close for istate/ostate %d/%d",
c->self, c->istate, c->ostate);
} else if (c->flags & CHAN_CLOSE_SENT) {
- error("channel %d: internal error: already sent close", c->self);
+ error("channel %d: already sent close", c->self);
} else {
packet_start(SSH2_MSG_CHANNEL_CLOSE);
packet_put_int(c->remote_id);
@@ -391,9 +357,47 @@ chan_send_close2(Channel *c)
/* shared */
+void
+chan_rcvd_ieof(Channel *c)
+{
+ if (compat20)
+ chan_rcvd_eof2(c);
+ else
+ chan_rcvd_ieof1(c);
+ if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
+ buffer_len(&c->output) == 0)
+ chan_obuf_empty(c);
+}
+void
+chan_rcvd_oclose(Channel *c)
+{
+ if (compat20)
+ chan_rcvd_close2(c);
+ else
+ chan_rcvd_oclose1(c);
+}
+void
+chan_write_failed(Channel *c)
+{
+ if (compat20)
+ chan_write_failed2(c);
+ else
+ chan_write_failed1(c);
+}
+
+void
+chan_mark_dead(Channel *c)
+{
+ c->type = SSH_CHANNEL_ZOMBIE;
+}
+
int
-chan_is_dead(Channel *c)
+chan_is_dead(Channel *c, int send)
{
+ if (c->type == SSH_CHANNEL_ZOMBIE) {
+ debug("channel %d: zombie", c->self);
+ return 1;
+ }
if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
return 0;
if (!compat20) {
@@ -414,10 +418,19 @@ chan_is_dead(Channel *c)
debug2("channel %d: active efd: %d len %d type %s",
c->self, c->efd, buffer_len(&c->extended),
c->extended_usage==CHAN_EXTENDED_READ ?
- "read": "write");
+ "read": "write");
} else {
if (!(c->flags & CHAN_CLOSE_SENT)) {
- chan_send_close2(c);
+ if (send) {
+ chan_send_close2(c);
+ } else {
+ /* channel would be dead if we sent a close */
+ if (c->flags & CHAN_CLOSE_RCVD) {
+ debug("channel %d: almost dead",
+ c->self);
+ return 1;
+ }
+ }
}
if ((c->flags & CHAN_CLOSE_SENT) &&
(c->flags & CHAN_CLOSE_RCVD)) {
@@ -428,55 +441,25 @@ chan_is_dead(Channel *c)
return 0;
}
-void
-chan_init_iostates(Channel *c)
-{
- c->ostate = CHAN_OUTPUT_OPEN;
- c->istate = CHAN_INPUT_OPEN;
- c->flags = 0;
-}
-
-/* init */
-void
-chan_init(void)
-{
- if (compat20) {
- chan_rcvd_oclose = chan_rcvd_oclose2;
- chan_read_failed = chan_read_failed_12;
- chan_ibuf_empty = chan_ibuf_empty2;
-
- chan_rcvd_ieof = chan_rcvd_ieof2;
- chan_write_failed = chan_write_failed2;
- chan_obuf_empty = chan_obuf_empty2;
- } else {
- chan_rcvd_oclose = chan_rcvd_oclose1;
- chan_read_failed = chan_read_failed_12;
- chan_ibuf_empty = chan_ibuf_empty1;
-
- chan_rcvd_ieof = chan_rcvd_ieof1;
- chan_write_failed = chan_write_failed1;
- chan_obuf_empty = chan_obuf_empty1;
- }
-}
-
/* helper */
static void
chan_shutdown_write(Channel *c)
{
- buffer_consume(&c->output, buffer_len(&c->output));
+ buffer_clear(&c->output);
if (compat20 && c->type == SSH_CHANNEL_LARVAL)
return;
/* shutdown failure is allowed if write failed already */
debug("channel %d: close_write", c->self);
if (c->sock != -1) {
if (shutdown(c->sock, SHUT_WR) < 0)
- debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s",
+ debug("channel %d: chan_shutdown_write: "
+ "shutdown() failed for fd%d: %.100s",
c->self, c->sock, strerror(errno));
} else {
- if (close(c->wfd) < 0)
- log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s",
+ if (channel_close_fd(&c->wfd) < 0)
+ log("channel %d: chan_shutdown_write: "
+ "close() failed for fd%d: %.100s",
c->self, c->wfd, strerror(errno));
- c->wfd = -1;
}
}
static void
@@ -487,12 +470,14 @@ chan_shutdown_read(Channel *c)
debug("channel %d: close_read", c->self);
if (c->sock != -1) {
if (shutdown(c->sock, SHUT_RD) < 0)
- error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
- c->self, c->sock, c->istate, c->ostate, strerror(errno));
+ error("channel %d: chan_shutdown_read: "
+ "shutdown() failed for fd%d [i%d o%d]: %.100s",
+ c->self, c->sock, c->istate, c->ostate,
+ strerror(errno));
} else {
- if (close(c->rfd) < 0)
- log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
+ if (channel_close_fd(&c->rfd) < 0)
+ log("channel %d: chan_shutdown_read: "
+ "close() failed for fd%d: %.100s",
c->self, c->rfd, strerror(errno));
- c->rfd = -1;
}
}
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