refactor channels.c

Move static state to a "struct ssh_channels" that is allocated at
runtime and tracked as a member of struct ssh.

Explicitly pass "struct ssh" to all channels functions.

Replace use of the legacy packet APIs in channels.c.

Rework sshd_config PermitOpen handling: previously the configuration
parser would call directly into the channels layer. After the refactor
this is not possible, as the channels structures are allocated at
connection time and aren't available when the configuration is parsed.
The server config parser now tracks PermitOpen itself and explicitly
configures the channels code later.

ok markus@

1 files changed, 38 insertions, 30 deletions

diff --git a/usr.bin/ssh/packet.c b/usr.bin/ssh/packet.c
index a63939b05f1..54c927dc006 100644
--- a/usr.bin/ssh/packet.c
+++ b/usr.bin/ssh/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.263 2017/07/23 23:37:02 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.264 2017/09/12 06:32:07 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2070,35 +2070,6 @@ ssh_packet_get_maxsize(struct ssh *ssh)
 	return ssh->state->max_packet_size;
 }
 
-/*
- * 9.2.  Ignored Data Message
- *
- *   byte      SSH_MSG_IGNORE
- *   string    data
- *
- * All implementations MUST understand (and ignore) this message at any
- * time (after receiving the protocol version). No implementation is
- * required to send them. This message can be used as an additional
- * protection measure against advanced traffic analysis techniques.
- */
-void
-ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
-{
-	u_int32_t rnd = 0;
-	int r, i;
-
-	if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
-	    (r = sshpkt_put_u32(ssh, nbytes)) != 0)
-		fatal("%s: %s", __func__, ssh_err(r));
-	for (i = 0; i < nbytes; i++) {
-		if (i % 4 == 0)
-			rnd = arc4random();
-		if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
-			fatal("%s: %s", __func__, ssh_err(r));
-		rnd >>= 8;
-	}
-}
-
 void
 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
 {
@@ -2517,6 +2488,12 @@ sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
 }
 
 int
+sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
+{
+	return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
+}
+
+int
 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
 {
 	return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
@@ -2597,6 +2574,37 @@ ssh_packet_send_mux(struct ssh *ssh)
 	return 0;
 }
 
+/*
+ * 9.2.  Ignored Data Message
+ *
+ *   byte      SSH_MSG_IGNORE
+ *   string    data
+ *
+ * All implementations MUST understand (and ignore) this message at any
+ * time (after receiving the protocol version). No implementation is
+ * required to send them. This message can be used as an additional
+ * protection measure against advanced traffic analysis techniques.
+ */
+int
+sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
+{
+	u_int32_t rnd = 0;
+	int r;
+	u_int i;
+
+	if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
+	    (r = sshpkt_put_u32(ssh, nbytes)) != 0)
+		return r;
+	for (i = 0; i < nbytes; i++) {
+		if (i % 4 == 0)
+			rnd = arc4random();
+		if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
+			return r;
+		rnd >>= 8;
+	}
+	return 0;
+}
+
 /* send it */
 
 int