1e5d735a0a
- Use callout_pending() instead of our own flags. - Remove home-grown protection of node, which has a scheduled callout(). - Remove spl(9) calls. Tested by: bz
1560 lines
39 KiB
C
1560 lines
39 KiB
C
/*-
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* Copyright (c) 2001-2002 Packet Design, LLC.
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* All rights reserved.
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*
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* Subject to the following obligations and disclaimer of warranty,
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* use and redistribution of this software, in source or object code
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* forms, with or without modifications are expressly permitted by
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* Packet Design; provided, however, that:
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*
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* (i) Any and all reproductions of the source or object code
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* must include the copyright notice above and the following
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* disclaimer of warranties; and
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* (ii) No rights are granted, in any manner or form, to use
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* Packet Design trademarks, including the mark "PACKET DESIGN"
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* on advertising, endorsements, or otherwise except as such
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* appears in the above copyright notice or in the software.
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*
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* THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
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* TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
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* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
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* THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
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* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
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* OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
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* OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
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* OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
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* RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE
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* LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
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* OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
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* DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
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* USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
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* THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
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* THE POSSIBILITY OF SUCH DAMAGE.
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*
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* Author: Archie Cobbs <archie@freebsd.org>
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*
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* $FreeBSD$
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*/
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/*
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* L2TP netgraph node type.
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*
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* This node type implements the lower layer of the
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* L2TP protocol as specified in RFC 2661.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/time.h>
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#include <sys/conf.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/errno.h>
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#include <sys/libkern.h>
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#include <netgraph/ng_message.h>
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#include <netgraph/netgraph.h>
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#include <netgraph/ng_parse.h>
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#include <netgraph/ng_l2tp.h>
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#ifdef NG_SEPARATE_MALLOC
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MALLOC_DEFINE(M_NETGRAPH_L2TP, "netgraph_l2tp", "netgraph l2tp node");
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#else
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#define M_NETGRAPH_L2TP M_NETGRAPH
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#endif
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/* L2TP header format (first 2 bytes only) */
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#define L2TP_HDR_CTRL 0x8000 /* control packet */
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#define L2TP_HDR_LEN 0x4000 /* has length field */
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#define L2TP_HDR_SEQ 0x0800 /* has ns, nr fields */
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#define L2TP_HDR_OFF 0x0200 /* has offset field */
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#define L2TP_HDR_PRIO 0x0100 /* give priority */
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#define L2TP_HDR_VERS_MASK 0x000f /* version field mask */
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#define L2TP_HDR_VERSION 0x0002 /* version field */
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/* Bits that must be zero or one in first two bytes of header */
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#define L2TP_CTRL_0BITS 0x030d /* ctrl: must be 0 */
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#define L2TP_CTRL_1BITS 0xc802 /* ctrl: must be 1 */
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#define L2TP_DATA_0BITS 0x800d /* data: must be 0 */
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#define L2TP_DATA_1BITS 0x0002 /* data: must be 1 */
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/* Standard xmit ctrl and data header bits */
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#define L2TP_CTRL_HDR (L2TP_HDR_CTRL | L2TP_HDR_LEN \
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| L2TP_HDR_SEQ | L2TP_HDR_VERSION)
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#define L2TP_DATA_HDR (L2TP_HDR_VERSION) /* optional: len, seq */
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/* Some hard coded values */
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#define L2TP_MAX_XWIN 16 /* my max xmit window */
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#define L2TP_MAX_REXMIT 5 /* default max rexmit */
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#define L2TP_MAX_REXMIT_TO 30 /* default rexmit to */
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#define L2TP_DELAYED_ACK ((hz + 19) / 20) /* delayed ack: 50 ms */
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/* Default data sequence number configuration for new sessions */
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#define L2TP_CONTROL_DSEQ 1 /* we are the lns */
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#define L2TP_ENABLE_DSEQ 1 /* enable data seq # */
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/* Compare sequence numbers using circular math */
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#define L2TP_SEQ_DIFF(x, y) ((int)((int16_t)(x) - (int16_t)(y)))
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/*
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* Sequence number state
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*
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* Invariants:
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* - If cwnd < ssth, we're doing slow start, otherwise congestion avoidance
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* - The number of unacknowledged xmit packets is (ns - rack) <= seq->wmax
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* - The first (ns - rack) mbuf's in xwin[] array are copies of these
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* unacknowledged packets; the remainder of xwin[] consists first of
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* zero or more further untransmitted packets in the transmit queue
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* - We try to keep the peer's receive window as full as possible.
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* Therefore, (i < cwnd && xwin[i] != NULL) implies (ns - rack) > i.
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* - rack_timer is running iff (ns - rack) > 0 (unack'd xmit'd pkts)
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* - If xack != nr, there are unacknowledged recv packet(s) (delayed ack)
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* - xack_timer is running iff xack != nr (unack'd rec'd pkts)
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*/
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struct l2tp_seq {
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u_int16_t ns; /* next xmit seq we send */
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u_int16_t nr; /* next recv seq we expect */
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u_int16_t rack; /* last 'nr' we rec'd */
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u_int16_t xack; /* last 'nr' we sent */
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u_int16_t wmax; /* peer's max recv window */
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u_int16_t cwnd; /* current congestion window */
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u_int16_t ssth; /* slow start threshold */
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u_int16_t acks; /* # consecutive acks rec'd */
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u_int16_t rexmits; /* # retransmits sent */
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u_int16_t max_rexmits; /* max # retransmits sent */
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u_int16_t max_rexmit_to; /* max retransmit timeout */
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struct callout rack_timer; /* retransmit timer */
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struct callout xack_timer; /* delayed ack timer */
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struct mbuf *xwin[L2TP_MAX_XWIN]; /* transmit window */
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};
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/* Node private data */
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struct ng_l2tp_private {
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node_p node; /* back pointer to node */
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hook_p ctrl; /* hook to upper layers */
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hook_p lower; /* hook to lower layers */
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struct ng_l2tp_config conf; /* node configuration */
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struct ng_l2tp_stats stats; /* node statistics */
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struct l2tp_seq seq; /* ctrl sequence number state */
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ng_ID_t ftarget; /* failure message target */
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};
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typedef struct ng_l2tp_private *priv_p;
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/* Hook private data (data session hooks only) */
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struct ng_l2tp_hook_private {
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struct ng_l2tp_sess_config conf; /* hook/session config */
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struct ng_l2tp_session_stats stats; /* per sessions statistics */
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u_int16_t ns; /* data ns sequence number */
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u_int16_t nr; /* data nr sequence number */
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};
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typedef struct ng_l2tp_hook_private *hookpriv_p;
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/* Netgraph node methods */
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static ng_constructor_t ng_l2tp_constructor;
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static ng_rcvmsg_t ng_l2tp_rcvmsg;
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static ng_shutdown_t ng_l2tp_shutdown;
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static ng_newhook_t ng_l2tp_newhook;
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static ng_rcvdata_t ng_l2tp_rcvdata;
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static ng_disconnect_t ng_l2tp_disconnect;
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/* Internal functions */
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static int ng_l2tp_recv_lower(node_p node, item_p item);
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static int ng_l2tp_recv_ctrl(node_p node, item_p item);
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static int ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv);
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static int ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns);
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static void ng_l2tp_seq_init(priv_p priv);
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static int ng_l2tp_seq_set(priv_p priv,
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const struct ng_l2tp_seq_config *conf);
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static int ng_l2tp_seq_adjust(priv_p priv,
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const struct ng_l2tp_config *conf);
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static void ng_l2tp_seq_reset(priv_p priv);
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static void ng_l2tp_seq_failure(priv_p priv);
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static void ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr);
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static int ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns);
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static void ng_l2tp_seq_xack_timeout(node_p node, hook_p hook,
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void *arg1, int arg2);
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static void ng_l2tp_seq_rack_timeout(node_p node, hook_p hook,
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void *arg1, int arg2);
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static ng_fn_eachhook ng_l2tp_find_session;
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static ng_fn_eachhook ng_l2tp_reset_session;
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#ifdef INVARIANTS
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static void ng_l2tp_seq_check(struct l2tp_seq *seq);
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#endif
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/* Parse type for struct ng_l2tp_seq_config. */
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static const struct ng_parse_struct_field
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ng_l2tp_seq_config_fields[] = NG_L2TP_SEQ_CONFIG_TYPE_INFO;
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static const struct ng_parse_type ng_l2tp_seq_config_type = {
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&ng_parse_struct_type,
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&ng_l2tp_seq_config_fields
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};
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/* Parse type for struct ng_l2tp_config */
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static const struct ng_parse_struct_field
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ng_l2tp_config_type_fields[] = NG_L2TP_CONFIG_TYPE_INFO;
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static const struct ng_parse_type ng_l2tp_config_type = {
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&ng_parse_struct_type,
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&ng_l2tp_config_type_fields,
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};
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/* Parse type for struct ng_l2tp_sess_config */
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static const struct ng_parse_struct_field
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ng_l2tp_sess_config_type_fields[] = NG_L2TP_SESS_CONFIG_TYPE_INFO;
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static const struct ng_parse_type ng_l2tp_sess_config_type = {
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&ng_parse_struct_type,
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&ng_l2tp_sess_config_type_fields,
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};
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/* Parse type for struct ng_l2tp_stats */
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static const struct ng_parse_struct_field
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ng_l2tp_stats_type_fields[] = NG_L2TP_STATS_TYPE_INFO;
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static const struct ng_parse_type ng_l2tp_stats_type = {
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&ng_parse_struct_type,
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&ng_l2tp_stats_type_fields
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};
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/* Parse type for struct ng_l2tp_session_stats. */
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static const struct ng_parse_struct_field
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ng_l2tp_session_stats_type_fields[] = NG_L2TP_SESSION_STATS_TYPE_INFO;
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static const struct ng_parse_type ng_l2tp_session_stats_type = {
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&ng_parse_struct_type,
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&ng_l2tp_session_stats_type_fields
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};
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/* List of commands and how to convert arguments to/from ASCII */
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static const struct ng_cmdlist ng_l2tp_cmdlist[] = {
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_SET_CONFIG,
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"setconfig",
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&ng_l2tp_config_type,
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NULL
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GET_CONFIG,
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"getconfig",
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NULL,
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&ng_l2tp_config_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_SET_SESS_CONFIG,
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"setsessconfig",
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&ng_l2tp_sess_config_type,
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NULL
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GET_SESS_CONFIG,
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"getsessconfig",
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&ng_parse_hint16_type,
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&ng_l2tp_sess_config_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GET_STATS,
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"getstats",
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NULL,
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&ng_l2tp_stats_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_CLR_STATS,
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"clrstats",
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NULL,
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NULL
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GETCLR_STATS,
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"getclrstats",
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NULL,
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&ng_l2tp_stats_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GET_SESSION_STATS,
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"getsessstats",
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&ng_parse_int16_type,
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&ng_l2tp_session_stats_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_CLR_SESSION_STATS,
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"clrsessstats",
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&ng_parse_int16_type,
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NULL
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_GETCLR_SESSION_STATS,
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"getclrsessstats",
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&ng_parse_int16_type,
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&ng_l2tp_session_stats_type
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_ACK_FAILURE,
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"ackfailure",
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NULL,
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NULL
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},
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{
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NGM_L2TP_COOKIE,
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NGM_L2TP_SET_SEQ,
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"setsequence",
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&ng_l2tp_seq_config_type,
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NULL
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},
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{ 0 }
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};
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/* Node type descriptor */
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static struct ng_type ng_l2tp_typestruct = {
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.version = NG_ABI_VERSION,
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.name = NG_L2TP_NODE_TYPE,
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.constructor = ng_l2tp_constructor,
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.rcvmsg = ng_l2tp_rcvmsg,
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.shutdown = ng_l2tp_shutdown,
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.newhook = ng_l2tp_newhook,
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.rcvdata = ng_l2tp_rcvdata,
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.disconnect = ng_l2tp_disconnect,
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.cmdlist = ng_l2tp_cmdlist,
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};
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NETGRAPH_INIT(l2tp, &ng_l2tp_typestruct);
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/* Sequence number state sanity checking */
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#ifdef INVARIANTS
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#define L2TP_SEQ_CHECK(seq) ng_l2tp_seq_check(seq)
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#else
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#define L2TP_SEQ_CHECK(x) do { } while (0)
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#endif
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/* memmove macro */
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#define memmove(d, s, l) bcopy(s, d, l)
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/* Whether to use m_copypacket() or m_dup() */
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#define L2TP_COPY_MBUF m_copypacket
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/************************************************************************
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NETGRAPH NODE STUFF
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************************************************************************/
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/*
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* Node type constructor
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*/
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static int
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ng_l2tp_constructor(node_p node)
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{
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priv_p priv;
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/* Allocate private structure */
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MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
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if (priv == NULL)
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return (ENOMEM);
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NG_NODE_SET_PRIVATE(node, priv);
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priv->node = node;
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/* Apply a semi-reasonable default configuration */
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priv->conf.peer_win = 1;
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priv->conf.rexmit_max = L2TP_MAX_REXMIT;
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priv->conf.rexmit_max_to = L2TP_MAX_REXMIT_TO;
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/* Initialize sequence number state */
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ng_l2tp_seq_init(priv);
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/* Done */
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return (0);
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}
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/*
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* Give our OK for a hook to be added.
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*/
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static int
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ng_l2tp_newhook(node_p node, hook_p hook, const char *name)
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{
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const priv_p priv = NG_NODE_PRIVATE(node);
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/* Check hook name */
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if (strcmp(name, NG_L2TP_HOOK_CTRL) == 0) {
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if (priv->ctrl != NULL)
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return (EISCONN);
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priv->ctrl = hook;
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} else if (strcmp(name, NG_L2TP_HOOK_LOWER) == 0) {
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if (priv->lower != NULL)
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return (EISCONN);
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priv->lower = hook;
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} else {
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static const char hexdig[16] = "0123456789abcdef";
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u_int16_t session_id;
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hookpriv_p hpriv;
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const char *hex;
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int i;
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int j;
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/* Parse hook name to get session ID */
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if (strncmp(name, NG_L2TP_HOOK_SESSION_P,
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sizeof(NG_L2TP_HOOK_SESSION_P) - 1) != 0)
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return (EINVAL);
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hex = name + sizeof(NG_L2TP_HOOK_SESSION_P) - 1;
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for (session_id = i = 0; i < 4; i++) {
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for (j = 0; j < 16 && hex[i] != hexdig[j]; j++);
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if (j == 16)
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return (EINVAL);
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session_id = (session_id << 4) | j;
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}
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if (hex[i] != '\0')
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return (EINVAL);
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/* Create hook private structure */
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MALLOC(hpriv, hookpriv_p,
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sizeof(*hpriv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
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if (hpriv == NULL)
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return (ENOMEM);
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hpriv->conf.session_id = htons(session_id);
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hpriv->conf.control_dseq = L2TP_CONTROL_DSEQ;
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hpriv->conf.enable_dseq = L2TP_ENABLE_DSEQ;
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NG_HOOK_SET_PRIVATE(hook, hpriv);
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}
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/* Done */
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return (0);
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}
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|
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/*
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* Receive a control message.
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*/
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static int
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ng_l2tp_rcvmsg(node_p node, item_p item, hook_p lasthook)
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{
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const priv_p priv = NG_NODE_PRIVATE(node);
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struct ng_mesg *resp = NULL;
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struct ng_mesg *msg;
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int error = 0;
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NGI_GET_MSG(item, msg);
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switch (msg->header.typecookie) {
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case NGM_L2TP_COOKIE:
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switch (msg->header.cmd) {
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case NGM_L2TP_SET_CONFIG:
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{
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struct ng_l2tp_config *const conf =
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(struct ng_l2tp_config *)msg->data;
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/* Check for invalid or illegal config */
|
|
if (msg->header.arglen != sizeof(*conf)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
conf->enabled = !!conf->enabled;
|
|
conf->match_id = !!conf->match_id;
|
|
conf->tunnel_id = htons(conf->tunnel_id);
|
|
conf->peer_id = htons(conf->peer_id);
|
|
if (priv->conf.enabled
|
|
&& ((priv->conf.tunnel_id != 0
|
|
&& conf->tunnel_id != priv->conf.tunnel_id)
|
|
|| ((priv->conf.peer_id != 0
|
|
&& conf->peer_id != priv->conf.peer_id)))) {
|
|
error = EBUSY;
|
|
break;
|
|
}
|
|
|
|
/* Save calling node as failure target */
|
|
priv->ftarget = NGI_RETADDR(item);
|
|
|
|
/* Adjust sequence number state */
|
|
if ((error = ng_l2tp_seq_adjust(priv, conf)) != 0)
|
|
break;
|
|
|
|
/* Update node's config */
|
|
priv->conf = *conf;
|
|
break;
|
|
}
|
|
case NGM_L2TP_GET_CONFIG:
|
|
{
|
|
struct ng_l2tp_config *conf;
|
|
|
|
NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
|
|
if (resp == NULL) {
|
|
error = ENOMEM;
|
|
break;
|
|
}
|
|
conf = (struct ng_l2tp_config *)resp->data;
|
|
*conf = priv->conf;
|
|
|
|
/* Put ID's in host order */
|
|
conf->tunnel_id = ntohs(conf->tunnel_id);
|
|
conf->peer_id = ntohs(conf->peer_id);
|
|
break;
|
|
}
|
|
case NGM_L2TP_SET_SESS_CONFIG:
|
|
{
|
|
struct ng_l2tp_sess_config *const conf =
|
|
(struct ng_l2tp_sess_config *)msg->data;
|
|
hookpriv_p hpriv;
|
|
hook_p hook;
|
|
|
|
/* Check for invalid or illegal config. */
|
|
if (msg->header.arglen != sizeof(*conf)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* Put ID's in network order */
|
|
conf->session_id = htons(conf->session_id);
|
|
conf->peer_id = htons(conf->peer_id);
|
|
|
|
/* Find matching hook */
|
|
NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
|
|
(void *)(uintptr_t)conf->session_id, hook);
|
|
if (hook == NULL) {
|
|
error = ENOENT;
|
|
break;
|
|
}
|
|
hpriv = NG_HOOK_PRIVATE(hook);
|
|
|
|
/* Update hook's config */
|
|
hpriv->conf = *conf;
|
|
break;
|
|
}
|
|
case NGM_L2TP_GET_SESS_CONFIG:
|
|
{
|
|
struct ng_l2tp_sess_config *conf;
|
|
u_int16_t session_id;
|
|
hookpriv_p hpriv;
|
|
hook_p hook;
|
|
|
|
/* Get session ID */
|
|
if (msg->header.arglen != sizeof(session_id)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
memcpy(&session_id, msg->data, 2);
|
|
session_id = htons(session_id);
|
|
|
|
/* Find matching hook */
|
|
NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
|
|
(void *)(uintptr_t)session_id, hook);
|
|
if (hook == NULL) {
|
|
error = ENOENT;
|
|
break;
|
|
}
|
|
hpriv = NG_HOOK_PRIVATE(hook);
|
|
|
|
/* Send response */
|
|
NG_MKRESPONSE(resp, msg, sizeof(hpriv->conf), M_NOWAIT);
|
|
if (resp == NULL) {
|
|
error = ENOMEM;
|
|
break;
|
|
}
|
|
conf = (struct ng_l2tp_sess_config *)resp->data;
|
|
*conf = hpriv->conf;
|
|
|
|
/* Put ID's in host order */
|
|
conf->session_id = ntohs(conf->session_id);
|
|
conf->peer_id = ntohs(conf->peer_id);
|
|
break;
|
|
}
|
|
case NGM_L2TP_GET_STATS:
|
|
case NGM_L2TP_CLR_STATS:
|
|
case NGM_L2TP_GETCLR_STATS:
|
|
{
|
|
if (msg->header.cmd != NGM_L2TP_CLR_STATS) {
|
|
NG_MKRESPONSE(resp, msg,
|
|
sizeof(priv->stats), M_NOWAIT);
|
|
if (resp == NULL) {
|
|
error = ENOMEM;
|
|
break;
|
|
}
|
|
memcpy(resp->data,
|
|
&priv->stats, sizeof(priv->stats));
|
|
}
|
|
if (msg->header.cmd != NGM_L2TP_GET_STATS)
|
|
memset(&priv->stats, 0, sizeof(priv->stats));
|
|
break;
|
|
}
|
|
case NGM_L2TP_GET_SESSION_STATS:
|
|
case NGM_L2TP_CLR_SESSION_STATS:
|
|
case NGM_L2TP_GETCLR_SESSION_STATS:
|
|
{
|
|
uint16_t session_id;
|
|
hookpriv_p hpriv;
|
|
hook_p hook;
|
|
|
|
/* Get session ID. */
|
|
if (msg->header.arglen != sizeof(session_id)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
bcopy(msg->data, &session_id, sizeof(uint16_t));
|
|
session_id = htons(session_id);
|
|
|
|
/* Find matching hook. */
|
|
NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
|
|
(void *)(uintptr_t)session_id, hook);
|
|
if (hook == NULL) {
|
|
error = ENOENT;
|
|
break;
|
|
}
|
|
hpriv = NG_HOOK_PRIVATE(hook);
|
|
|
|
if (msg->header.cmd != NGM_L2TP_CLR_SESSION_STATS) {
|
|
NG_MKRESPONSE(resp, msg,
|
|
sizeof(hpriv->stats), M_NOWAIT);
|
|
if (resp == NULL) {
|
|
error = ENOMEM;
|
|
break;
|
|
}
|
|
bcopy(&hpriv->stats, resp->data,
|
|
sizeof(hpriv->stats));
|
|
}
|
|
if (msg->header.cmd != NGM_L2TP_GET_SESSION_STATS)
|
|
bzero(&hpriv->stats, sizeof(hpriv->stats));
|
|
break;
|
|
}
|
|
case NGM_L2TP_SET_SEQ:
|
|
{
|
|
struct ng_l2tp_seq_config *const conf =
|
|
(struct ng_l2tp_seq_config *)msg->data;
|
|
|
|
/* Check for invalid or illegal seq config. */
|
|
if (msg->header.arglen != sizeof(*conf)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
conf->ns = htons(conf->ns);
|
|
conf->nr = htons(conf->nr);
|
|
conf->rack = htons(conf->rack);
|
|
conf->xack = htons(conf->xack);
|
|
|
|
/* Set sequence numbers. */
|
|
error = ng_l2tp_seq_set(priv, conf);
|
|
break;
|
|
}
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* Done */
|
|
NG_RESPOND_MSG(error, node, item, resp);
|
|
NG_FREE_MSG(msg);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Receive incoming data on a hook.
|
|
*/
|
|
static int
|
|
ng_l2tp_rcvdata(hook_p hook, item_p item)
|
|
{
|
|
const node_p node = NG_HOOK_NODE(hook);
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
int error;
|
|
|
|
/* Sanity check */
|
|
L2TP_SEQ_CHECK(&priv->seq);
|
|
|
|
/* If not configured, reject */
|
|
if (!priv->conf.enabled) {
|
|
NG_FREE_ITEM(item);
|
|
return (ENXIO);
|
|
}
|
|
|
|
/* Handle incoming frame from below */
|
|
if (hook == priv->lower) {
|
|
error = ng_l2tp_recv_lower(node, item);
|
|
goto done;
|
|
}
|
|
|
|
/* Handle outgoing control frame */
|
|
if (hook == priv->ctrl) {
|
|
error = ng_l2tp_recv_ctrl(node, item);
|
|
goto done;
|
|
}
|
|
|
|
/* Handle outgoing data frame */
|
|
error = ng_l2tp_recv_data(node, item, NG_HOOK_PRIVATE(hook));
|
|
|
|
done:
|
|
/* Done */
|
|
L2TP_SEQ_CHECK(&priv->seq);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Destroy node
|
|
*/
|
|
static int
|
|
ng_l2tp_shutdown(node_p node)
|
|
{
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
|
|
/* Sanity check */
|
|
L2TP_SEQ_CHECK(seq);
|
|
|
|
/* Reset sequence number state */
|
|
ng_l2tp_seq_reset(priv);
|
|
|
|
/* Free private data if neither timer is running */
|
|
ng_uncallout(&seq->rack_timer, node);
|
|
ng_uncallout(&seq->xack_timer, node);
|
|
|
|
FREE(priv, M_NETGRAPH_L2TP);
|
|
|
|
/* Unref node */
|
|
NG_NODE_UNREF(node);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Hook disconnection
|
|
*/
|
|
static int
|
|
ng_l2tp_disconnect(hook_p hook)
|
|
{
|
|
const node_p node = NG_HOOK_NODE(hook);
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
|
|
/* Zero out hook pointer */
|
|
if (hook == priv->ctrl)
|
|
priv->ctrl = NULL;
|
|
else if (hook == priv->lower)
|
|
priv->lower = NULL;
|
|
else {
|
|
FREE(NG_HOOK_PRIVATE(hook), M_NETGRAPH_L2TP);
|
|
NG_HOOK_SET_PRIVATE(hook, NULL);
|
|
}
|
|
|
|
/* Go away if no longer connected to anything */
|
|
if (NG_NODE_NUMHOOKS(node) == 0 && NG_NODE_IS_VALID(node))
|
|
ng_rmnode_self(node);
|
|
return (0);
|
|
}
|
|
|
|
/*************************************************************************
|
|
INTERNAL FUNCTIONS
|
|
*************************************************************************/
|
|
|
|
/*
|
|
* Find the hook with a given session ID.
|
|
*/
|
|
static int
|
|
ng_l2tp_find_session(hook_p hook, void *arg)
|
|
{
|
|
const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
|
|
const u_int16_t sid = (u_int16_t)(uintptr_t)arg;
|
|
|
|
if (hpriv == NULL || hpriv->conf.session_id != sid)
|
|
return (-1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Reset a hook's session state.
|
|
*/
|
|
static int
|
|
ng_l2tp_reset_session(hook_p hook, void *arg)
|
|
{
|
|
const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
|
|
|
|
if (hpriv != NULL) {
|
|
hpriv->conf.control_dseq = 0;
|
|
hpriv->conf.enable_dseq = 0;
|
|
bzero(&hpriv->conf, sizeof(struct ng_l2tp_session_stats));
|
|
hpriv->nr = 0;
|
|
hpriv->ns = 0;
|
|
}
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Handle an incoming frame from below.
|
|
*/
|
|
static int
|
|
ng_l2tp_recv_lower(node_p node, item_p item)
|
|
{
|
|
static const u_int16_t req_bits[2][2] = {
|
|
{ L2TP_DATA_0BITS, L2TP_DATA_1BITS },
|
|
{ L2TP_CTRL_0BITS, L2TP_CTRL_1BITS },
|
|
};
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
hookpriv_p hpriv = NULL;
|
|
hook_p hook = NULL;
|
|
u_int16_t ids[2];
|
|
struct mbuf *m;
|
|
u_int16_t hdr;
|
|
u_int16_t ns;
|
|
u_int16_t nr;
|
|
int is_ctrl;
|
|
int error;
|
|
int len, plen;
|
|
|
|
/* Grab mbuf */
|
|
NGI_GET_M(item, m);
|
|
|
|
/* Remember full packet length; needed for per session accounting. */
|
|
plen = m->m_pkthdr.len;
|
|
|
|
/* Update stats */
|
|
priv->stats.recvPackets++;
|
|
priv->stats.recvOctets += plen;
|
|
|
|
/* Get initial header */
|
|
if (m->m_pkthdr.len < 6) {
|
|
priv->stats.recvRunts++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EINVAL);
|
|
}
|
|
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (EINVAL);
|
|
}
|
|
hdr = ntohs(*mtod(m, u_int16_t *));
|
|
m_adj(m, 2);
|
|
|
|
/* Check required header bits and minimum length */
|
|
is_ctrl = (hdr & L2TP_HDR_CTRL) != 0;
|
|
if ((hdr & req_bits[is_ctrl][0]) != 0
|
|
|| (~hdr & req_bits[is_ctrl][1]) != 0) {
|
|
priv->stats.recvInvalid++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EINVAL);
|
|
}
|
|
if (m->m_pkthdr.len < 4 /* tunnel, session id */
|
|
+ (2 * ((hdr & L2TP_HDR_LEN) != 0)) /* length field */
|
|
+ (4 * ((hdr & L2TP_HDR_SEQ) != 0)) /* seq # fields */
|
|
+ (2 * ((hdr & L2TP_HDR_OFF) != 0))) { /* offset field */
|
|
priv->stats.recvRunts++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
/* Get and validate length field if present */
|
|
if ((hdr & L2TP_HDR_LEN) != 0) {
|
|
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (EINVAL);
|
|
}
|
|
len = (u_int16_t)ntohs(*mtod(m, u_int16_t *)) - 4;
|
|
m_adj(m, 2);
|
|
if (len < 0 || len > m->m_pkthdr.len) {
|
|
priv->stats.recvInvalid++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EINVAL);
|
|
}
|
|
if (len < m->m_pkthdr.len) /* trim extra bytes */
|
|
m_adj(m, -(m->m_pkthdr.len - len));
|
|
}
|
|
|
|
/* Get tunnel ID and session ID */
|
|
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (EINVAL);
|
|
}
|
|
memcpy(ids, mtod(m, u_int16_t *), 4);
|
|
m_adj(m, 4);
|
|
|
|
/* Check tunnel ID */
|
|
if (ids[0] != priv->conf.tunnel_id
|
|
&& (priv->conf.match_id || ids[0] != 0)) {
|
|
priv->stats.recvWrongTunnel++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EADDRNOTAVAIL);
|
|
}
|
|
|
|
/* Check session ID (for data packets only) */
|
|
if ((hdr & L2TP_HDR_CTRL) == 0) {
|
|
NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
|
|
(void *)(uintptr_t)ids[1], hook);
|
|
if (hook == NULL) {
|
|
priv->stats.recvUnknownSID++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (ENOTCONN);
|
|
}
|
|
hpriv = NG_HOOK_PRIVATE(hook);
|
|
}
|
|
|
|
/* Get Ns, Nr fields if present */
|
|
if ((hdr & L2TP_HDR_SEQ) != 0) {
|
|
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (EINVAL);
|
|
}
|
|
memcpy(&ns, &mtod(m, u_int16_t *)[0], 2);
|
|
ns = ntohs(ns);
|
|
memcpy(&nr, &mtod(m, u_int16_t *)[1], 2);
|
|
nr = ntohs(nr);
|
|
m_adj(m, 4);
|
|
}
|
|
|
|
/* Strip offset padding if present */
|
|
if ((hdr & L2TP_HDR_OFF) != 0) {
|
|
u_int16_t offset;
|
|
|
|
/* Get length of offset padding */
|
|
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (EINVAL);
|
|
}
|
|
memcpy(&offset, mtod(m, u_int16_t *), 2);
|
|
offset = ntohs(offset);
|
|
|
|
/* Trim offset padding */
|
|
if ((2+offset) > m->m_pkthdr.len) {
|
|
priv->stats.recvInvalid++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EINVAL);
|
|
}
|
|
m_adj(m, 2+offset);
|
|
}
|
|
|
|
/* Handle control packets */
|
|
if ((hdr & L2TP_HDR_CTRL) != 0) {
|
|
|
|
/* Handle receive ack sequence number Nr */
|
|
ng_l2tp_seq_recv_nr(priv, nr);
|
|
|
|
/* Discard ZLB packets */
|
|
if (m->m_pkthdr.len == 0) {
|
|
priv->stats.recvZLBs++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Prepend session ID to packet here: we don't want to accept
|
|
* the send sequence number Ns if we have to drop the packet
|
|
* later because of a memory error, because then the upper
|
|
* layer would never get the packet.
|
|
*/
|
|
M_PREPEND(m, 2, M_DONTWAIT);
|
|
if (m == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (ENOBUFS);
|
|
}
|
|
memcpy(mtod(m, u_int16_t *), &ids[1], 2);
|
|
|
|
/* Now handle send sequence number */
|
|
if (ng_l2tp_seq_recv_ns(priv, ns) == -1) {
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (0);
|
|
}
|
|
|
|
/* Deliver packet to upper layers */
|
|
NG_FWD_NEW_DATA(error, item, priv->ctrl, m);
|
|
return (error);
|
|
}
|
|
|
|
/* Per session packet, account it. */
|
|
hpriv->stats.recvPackets++;
|
|
hpriv->stats.recvOctets += plen;
|
|
|
|
/* Follow peer's lead in data sequencing, if configured to do so */
|
|
if (!hpriv->conf.control_dseq)
|
|
hpriv->conf.enable_dseq = ((hdr & L2TP_HDR_SEQ) != 0);
|
|
|
|
/* Handle data sequence numbers if present and enabled */
|
|
if ((hdr & L2TP_HDR_SEQ) != 0) {
|
|
if (hpriv->conf.enable_dseq
|
|
&& L2TP_SEQ_DIFF(ns, hpriv->nr) < 0) {
|
|
NG_FREE_ITEM(item); /* duplicate or out of order */
|
|
NG_FREE_M(m);
|
|
priv->stats.recvDataDrops++;
|
|
return (0);
|
|
}
|
|
hpriv->nr = ns + 1;
|
|
}
|
|
|
|
/* Drop empty data packets */
|
|
if (m->m_pkthdr.len == 0) {
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (0);
|
|
}
|
|
|
|
/* Deliver data */
|
|
NG_FWD_NEW_DATA(error, item, hook, m);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Handle an outgoing control frame.
|
|
*/
|
|
static int
|
|
ng_l2tp_recv_ctrl(node_p node, item_p item)
|
|
{
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
struct mbuf *m;
|
|
int i;
|
|
|
|
/* Grab mbuf and discard other stuff XXX */
|
|
NGI_GET_M(item, m);
|
|
NG_FREE_ITEM(item);
|
|
|
|
/* Packet should have session ID prepended */
|
|
if (m->m_pkthdr.len < 2) {
|
|
priv->stats.xmitInvalid++;
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
/* Check max length */
|
|
if (m->m_pkthdr.len >= 0x10000 - 14) {
|
|
priv->stats.xmitTooBig++;
|
|
m_freem(m);
|
|
return (EOVERFLOW);
|
|
}
|
|
|
|
/* Find next empty slot in transmit queue */
|
|
for (i = 0; i < L2TP_MAX_XWIN && seq->xwin[i] != NULL; i++);
|
|
if (i == L2TP_MAX_XWIN) {
|
|
priv->stats.xmitDrops++;
|
|
m_freem(m);
|
|
return (ENOBUFS);
|
|
}
|
|
seq->xwin[i] = m;
|
|
|
|
/* Sanity check receive ack timer state */
|
|
KASSERT((i == 0) ^ callout_pending(&seq->rack_timer),
|
|
("%s: xwin %d full but rack timer %s running",
|
|
__FUNCTION__, i, callout_pending(&seq->rack_timer) ? "" : "not "));
|
|
|
|
/* If peer's receive window is already full, nothing else to do */
|
|
if (i >= seq->cwnd)
|
|
return (0);
|
|
|
|
/* Start retransmit timer if not already running */
|
|
if (!callout_pending(&seq->rack_timer))
|
|
ng_callout(&seq->rack_timer, node, NULL,
|
|
hz, ng_l2tp_seq_rack_timeout, NULL, 0);
|
|
|
|
/* Copy packet */
|
|
if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_DONTWAIT)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
return (ENOBUFS);
|
|
}
|
|
|
|
/* Send packet and increment xmit sequence number */
|
|
return (ng_l2tp_xmit_ctrl(priv, m, seq->ns++));
|
|
}
|
|
|
|
/*
|
|
* Handle an outgoing data frame.
|
|
*/
|
|
static int
|
|
ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv)
|
|
{
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
struct mbuf *m;
|
|
u_int16_t hdr;
|
|
int error;
|
|
int i = 1;
|
|
|
|
/* Get mbuf */
|
|
NGI_GET_M(item, m);
|
|
|
|
/* Check max length */
|
|
if (m->m_pkthdr.len >= 0x10000 - 12) {
|
|
priv->stats.xmitDataTooBig++;
|
|
NG_FREE_ITEM(item);
|
|
NG_FREE_M(m);
|
|
return (EOVERFLOW);
|
|
}
|
|
|
|
/* Prepend L2TP header */
|
|
M_PREPEND(m, 6
|
|
+ (2 * (hpriv->conf.include_length != 0))
|
|
+ (4 * (hpriv->conf.enable_dseq != 0)),
|
|
M_DONTWAIT);
|
|
if (m == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
NG_FREE_ITEM(item);
|
|
return (ENOBUFS);
|
|
}
|
|
hdr = L2TP_DATA_HDR;
|
|
if (hpriv->conf.include_length) {
|
|
hdr |= L2TP_HDR_LEN;
|
|
mtod(m, u_int16_t *)[i++] = htons(m->m_pkthdr.len);
|
|
}
|
|
mtod(m, u_int16_t *)[i++] = priv->conf.peer_id;
|
|
mtod(m, u_int16_t *)[i++] = hpriv->conf.peer_id;
|
|
if (hpriv->conf.enable_dseq) {
|
|
hdr |= L2TP_HDR_SEQ;
|
|
mtod(m, u_int16_t *)[i++] = htons(hpriv->ns);
|
|
mtod(m, u_int16_t *)[i++] = htons(hpriv->nr);
|
|
hpriv->ns++;
|
|
}
|
|
mtod(m, u_int16_t *)[0] = htons(hdr);
|
|
|
|
/* Update per session stats. */
|
|
hpriv->stats.xmitPackets++;
|
|
hpriv->stats.xmitOctets += m->m_pkthdr.len;
|
|
|
|
/* Send packet */
|
|
NG_FWD_NEW_DATA(error, item, priv->lower, m);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Send a message to our controlling node that we've failed.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_failure(priv_p priv)
|
|
{
|
|
struct ng_mesg *msg;
|
|
int error;
|
|
|
|
NG_MKMESSAGE(msg, NGM_L2TP_COOKIE, NGM_L2TP_ACK_FAILURE, 0, M_NOWAIT);
|
|
if (msg == NULL)
|
|
return;
|
|
NG_SEND_MSG_ID(error, priv->node, msg, priv->ftarget, 0);
|
|
}
|
|
|
|
/************************************************************************
|
|
SEQUENCE NUMBER HANDLING
|
|
************************************************************************/
|
|
|
|
/*
|
|
* Initialize sequence number state.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_init(priv_p priv)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
|
|
KASSERT(priv->conf.peer_win >= 1,
|
|
("%s: peer_win is zero", __FUNCTION__));
|
|
memset(seq, 0, sizeof(*seq));
|
|
seq->cwnd = 1;
|
|
seq->wmax = priv->conf.peer_win;
|
|
if (seq->wmax > L2TP_MAX_XWIN)
|
|
seq->wmax = L2TP_MAX_XWIN;
|
|
seq->ssth = seq->wmax;
|
|
seq->max_rexmits = priv->conf.rexmit_max;
|
|
seq->max_rexmit_to = priv->conf.rexmit_max_to;
|
|
ng_callout_init(&seq->rack_timer);
|
|
ng_callout_init(&seq->xack_timer);
|
|
L2TP_SEQ_CHECK(seq);
|
|
}
|
|
|
|
/*
|
|
* Set sequence number state as given from user.
|
|
*/
|
|
static int
|
|
ng_l2tp_seq_set(priv_p priv, const struct ng_l2tp_seq_config *conf)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
|
|
/* If node is enabled, deny update to sequence numbers. */
|
|
if (priv->conf.enabled)
|
|
return (EBUSY);
|
|
|
|
/* We only can handle the simple cases. */
|
|
if (conf->xack != conf->nr || conf->ns != conf->rack)
|
|
return (EINVAL);
|
|
|
|
/* Set ns,nr,rack,xack parameters. */
|
|
seq->ns = conf->ns;
|
|
seq->nr = conf->nr;
|
|
seq->rack = conf->rack;
|
|
seq->xack = conf->xack;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Adjust sequence number state accordingly after reconfiguration.
|
|
*/
|
|
static int
|
|
ng_l2tp_seq_adjust(priv_p priv, const struct ng_l2tp_config *conf)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
u_int16_t new_wmax;
|
|
|
|
/* If disabling node, reset state sequence number */
|
|
if (!conf->enabled) {
|
|
ng_l2tp_seq_reset(priv);
|
|
return (0);
|
|
}
|
|
|
|
/* Adjust peer's max recv window; it can only increase */
|
|
new_wmax = conf->peer_win;
|
|
if (new_wmax > L2TP_MAX_XWIN)
|
|
new_wmax = L2TP_MAX_XWIN;
|
|
if (new_wmax == 0)
|
|
return (EINVAL);
|
|
if (new_wmax < seq->wmax)
|
|
return (EBUSY);
|
|
seq->wmax = new_wmax;
|
|
|
|
/* Update retransmit parameters */
|
|
seq->max_rexmits = conf->rexmit_max;
|
|
seq->max_rexmit_to = conf->rexmit_max_to;
|
|
|
|
/* Done */
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Reset sequence number state.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_reset(priv_p priv)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
hook_p hook;
|
|
int i;
|
|
|
|
/* Sanity check */
|
|
L2TP_SEQ_CHECK(seq);
|
|
|
|
/* Stop timers */
|
|
ng_uncallout(&seq->rack_timer, priv->node);
|
|
ng_uncallout(&seq->xack_timer, priv->node);
|
|
|
|
/* Free retransmit queue */
|
|
for (i = 0; i < L2TP_MAX_XWIN; i++) {
|
|
if (seq->xwin[i] == NULL)
|
|
break;
|
|
m_freem(seq->xwin[i]);
|
|
}
|
|
|
|
/* Reset session hooks' sequence number states */
|
|
NG_NODE_FOREACH_HOOK(priv->node, ng_l2tp_reset_session, NULL, hook);
|
|
|
|
/* Reset node's sequence number state */
|
|
memset(seq, 0, sizeof(*seq));
|
|
seq->cwnd = 1;
|
|
seq->wmax = L2TP_MAX_XWIN;
|
|
seq->ssth = seq->wmax;
|
|
|
|
/* Done */
|
|
L2TP_SEQ_CHECK(seq);
|
|
}
|
|
|
|
/*
|
|
* Handle receipt of an acknowledgement value (Nr) from peer.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
struct mbuf *m;
|
|
int nack;
|
|
int i;
|
|
|
|
/* Verify peer's ACK is in range */
|
|
if ((nack = L2TP_SEQ_DIFF(nr, seq->rack)) <= 0)
|
|
return; /* duplicate ack */
|
|
if (L2TP_SEQ_DIFF(nr, seq->ns) > 0) {
|
|
priv->stats.recvBadAcks++; /* ack for packet not sent */
|
|
return;
|
|
}
|
|
KASSERT(nack <= L2TP_MAX_XWIN,
|
|
("%s: nack=%d > %d", __FUNCTION__, nack, L2TP_MAX_XWIN));
|
|
|
|
/* Update receive ack stats */
|
|
seq->rack = nr;
|
|
seq->rexmits = 0;
|
|
|
|
/* Free acknowledged packets and shift up packets in the xmit queue */
|
|
for (i = 0; i < nack; i++)
|
|
m_freem(seq->xwin[i]);
|
|
memmove(seq->xwin, seq->xwin + nack,
|
|
(L2TP_MAX_XWIN - nack) * sizeof(*seq->xwin));
|
|
memset(seq->xwin + (L2TP_MAX_XWIN - nack), 0,
|
|
nack * sizeof(*seq->xwin));
|
|
|
|
/*
|
|
* Do slow-start/congestion avoidance windowing algorithm described
|
|
* in RFC 2661, Appendix A. Here we handle a multiple ACK as if each
|
|
* ACK had arrived separately.
|
|
*/
|
|
if (seq->cwnd < seq->wmax) {
|
|
|
|
/* Handle slow start phase */
|
|
if (seq->cwnd < seq->ssth) {
|
|
seq->cwnd += nack;
|
|
nack = 0;
|
|
if (seq->cwnd > seq->ssth) { /* into cg.av. phase */
|
|
nack = seq->cwnd - seq->ssth;
|
|
seq->cwnd = seq->ssth;
|
|
}
|
|
}
|
|
|
|
/* Handle congestion avoidance phase */
|
|
if (seq->cwnd >= seq->ssth) {
|
|
seq->acks += nack;
|
|
while (seq->acks >= seq->cwnd) {
|
|
seq->acks -= seq->cwnd;
|
|
if (seq->cwnd < seq->wmax)
|
|
seq->cwnd++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Stop xmit timer */
|
|
if (callout_pending(&seq->rack_timer))
|
|
ng_uncallout(&seq->rack_timer, priv->node);
|
|
|
|
/* If transmit queue is empty, we're done for now */
|
|
if (seq->xwin[0] == NULL)
|
|
return;
|
|
|
|
/* Start restransmit timer again */
|
|
ng_callout(&seq->rack_timer, priv->node, NULL,
|
|
hz, ng_l2tp_seq_rack_timeout, NULL, 0);
|
|
|
|
/*
|
|
* Send more packets, trying to keep peer's receive window full.
|
|
* If there is a memory error, pretend packet was sent, as it
|
|
* will get retransmitted later anyway.
|
|
*/
|
|
while ((i = L2TP_SEQ_DIFF(seq->ns, seq->rack)) < seq->cwnd
|
|
&& seq->xwin[i] != NULL) {
|
|
if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_DONTWAIT)) == NULL)
|
|
priv->stats.memoryFailures++;
|
|
else
|
|
ng_l2tp_xmit_ctrl(priv, m, seq->ns);
|
|
seq->ns++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle receipt of a sequence number value (Ns) from peer.
|
|
* We make no attempt to re-order out of order packets.
|
|
*
|
|
* This function should only be called for non-ZLB packets.
|
|
*
|
|
* Returns:
|
|
* 0 Accept packet
|
|
* -1 Drop packet
|
|
*/
|
|
static int
|
|
ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
|
|
/* If not what we expect, drop packet and send an immediate ZLB ack */
|
|
if (ns != seq->nr) {
|
|
if (L2TP_SEQ_DIFF(ns, seq->nr) < 0)
|
|
priv->stats.recvDuplicates++;
|
|
else
|
|
priv->stats.recvOutOfOrder++;
|
|
ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
|
|
return (-1);
|
|
}
|
|
|
|
/* Update recv sequence number */
|
|
seq->nr++;
|
|
|
|
/* Start receive ack timer, if not already running */
|
|
if (!callout_pending(&seq->xack_timer))
|
|
ng_callout(&seq->xack_timer, priv->node, NULL,
|
|
L2TP_DELAYED_ACK, ng_l2tp_seq_xack_timeout, NULL, 0);
|
|
|
|
/* Accept packet */
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Handle an ack timeout. We have an outstanding ack that we
|
|
* were hoping to piggy-back, but haven't, so send a ZLB.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_xack_timeout(node_p node, hook_p hook, void *arg1, int arg2)
|
|
{
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
|
|
/* Sanity check */
|
|
L2TP_SEQ_CHECK(seq);
|
|
|
|
/* If ack is still outstanding, send a ZLB */
|
|
if (seq->xack != seq->nr)
|
|
ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
|
|
|
|
/* Done */
|
|
L2TP_SEQ_CHECK(seq);
|
|
}
|
|
|
|
/*
|
|
* Handle a transmit timeout. The peer has failed to respond
|
|
* with an ack for our packet, so retransmit it.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_rack_timeout(node_p node, hook_p hook, void *arg1, int arg2)
|
|
{
|
|
const priv_p priv = NG_NODE_PRIVATE(node);
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
struct mbuf *m;
|
|
u_int delay;
|
|
|
|
/* Sanity check */
|
|
L2TP_SEQ_CHECK(seq);
|
|
|
|
/* Make sure peer's ack is still outstanding before doing anything */
|
|
if (seq->rack == seq->ns)
|
|
goto done;
|
|
|
|
priv->stats.xmitRetransmits++;
|
|
|
|
/* Have we reached the retransmit limit? If so, notify owner. */
|
|
if (seq->rexmits++ >= seq->max_rexmits)
|
|
ng_l2tp_seq_failure(priv);
|
|
|
|
/* Restart timer, this time with an increased delay */
|
|
delay = (seq->rexmits > 12) ? (1 << 12) : (1 << seq->rexmits);
|
|
if (delay > seq->max_rexmit_to)
|
|
delay = seq->max_rexmit_to;
|
|
ng_callout(&seq->rack_timer, node, NULL,
|
|
hz * delay, ng_l2tp_seq_rack_timeout, NULL, 0);
|
|
|
|
/* Do slow-start/congestion algorithm windowing algorithm */
|
|
seq->ssth = (seq->cwnd + 1) / 2;
|
|
seq->cwnd = 1;
|
|
seq->acks = 0;
|
|
|
|
/* Retransmit oldest unack'd packet */
|
|
if ((m = L2TP_COPY_MBUF(seq->xwin[0], M_DONTWAIT)) == NULL)
|
|
priv->stats.memoryFailures++;
|
|
else
|
|
ng_l2tp_xmit_ctrl(priv, m, seq->rack);
|
|
|
|
done:
|
|
/* Done */
|
|
L2TP_SEQ_CHECK(seq);
|
|
}
|
|
|
|
/*
|
|
* Transmit a control stream packet, payload optional.
|
|
* The transmit sequence number is not incremented.
|
|
*/
|
|
static int
|
|
ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns)
|
|
{
|
|
struct l2tp_seq *const seq = &priv->seq;
|
|
u_int16_t session_id = 0;
|
|
int error;
|
|
|
|
/* If no mbuf passed, send an empty packet (ZLB) */
|
|
if (m == NULL) {
|
|
|
|
/* Create a new mbuf for ZLB packet */
|
|
MGETHDR(m, M_DONTWAIT, MT_DATA);
|
|
if (m == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
return (ENOBUFS);
|
|
}
|
|
m->m_len = m->m_pkthdr.len = 12;
|
|
m->m_pkthdr.rcvif = NULL;
|
|
priv->stats.xmitZLBs++;
|
|
} else {
|
|
|
|
/* Strip off session ID */
|
|
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
return (ENOBUFS);
|
|
}
|
|
memcpy(&session_id, mtod(m, u_int16_t *), 2);
|
|
m_adj(m, 2);
|
|
|
|
/* Make room for L2TP header */
|
|
M_PREPEND(m, 12, M_DONTWAIT);
|
|
if (m == NULL) {
|
|
priv->stats.memoryFailures++;
|
|
return (ENOBUFS);
|
|
}
|
|
}
|
|
|
|
/* Fill in L2TP header */
|
|
mtod(m, u_int16_t *)[0] = htons(L2TP_CTRL_HDR);
|
|
mtod(m, u_int16_t *)[1] = htons(m->m_pkthdr.len);
|
|
mtod(m, u_int16_t *)[2] = priv->conf.peer_id;
|
|
mtod(m, u_int16_t *)[3] = session_id;
|
|
mtod(m, u_int16_t *)[4] = htons(ns);
|
|
mtod(m, u_int16_t *)[5] = htons(seq->nr);
|
|
|
|
/* Update sequence number info and stats */
|
|
priv->stats.xmitPackets++;
|
|
priv->stats.xmitOctets += m->m_pkthdr.len;
|
|
|
|
/* Stop ack timer: we're sending an ack with this packet */
|
|
if (callout_pending(&seq->xack_timer))
|
|
ng_uncallout(&seq->xack_timer, priv->node);
|
|
|
|
seq->xack = seq->nr;
|
|
|
|
/* Send packet */
|
|
NG_SEND_DATA_ONLY(error, priv->lower, m);
|
|
return (error);
|
|
}
|
|
|
|
#ifdef INVARIANTS
|
|
/*
|
|
* Sanity check sequence number state.
|
|
*/
|
|
static void
|
|
ng_l2tp_seq_check(struct l2tp_seq *seq)
|
|
{
|
|
const int self_unack = L2TP_SEQ_DIFF(seq->nr, seq->xack);
|
|
const int peer_unack = L2TP_SEQ_DIFF(seq->ns, seq->rack);
|
|
int i;
|
|
|
|
#define CHECK(p) KASSERT((p), ("%s: not: %s", __FUNCTION__, #p))
|
|
|
|
CHECK(seq->wmax <= L2TP_MAX_XWIN);
|
|
CHECK(seq->cwnd >= 1);
|
|
CHECK(seq->cwnd <= seq->wmax);
|
|
CHECK(seq->ssth >= 1);
|
|
CHECK(seq->ssth <= seq->wmax);
|
|
if (seq->cwnd < seq->ssth)
|
|
CHECK(seq->acks == 0);
|
|
else
|
|
CHECK(seq->acks <= seq->cwnd);
|
|
CHECK(self_unack >= 0);
|
|
CHECK(peer_unack >= 0);
|
|
CHECK(peer_unack <= seq->wmax);
|
|
CHECK((self_unack == 0) ^ callout_pending(&seq->xack_timer));
|
|
CHECK((peer_unack == 0) ^ callout_pending(&seq->rack_timer));
|
|
for (i = 0; i < peer_unack; i++)
|
|
CHECK(seq->xwin[i] != NULL);
|
|
for ( ; i < seq->cwnd; i++) /* verify peer's recv window full */
|
|
CHECK(seq->xwin[i] == NULL);
|
|
|
|
#undef CHECK
|
|
}
|
|
#endif /* INVARIANTS */
|