1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2019 Isilon Systems, LLC.
5 * Copyright (c) 2005-2014 Sandvine Incorporated
6 * Copyright (c) 2000 Darrell Anderson <anderson@cs.duke.edu>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33/*
34 * Debugnet provides a reliable, bidirectional, UDP-encapsulated datagram
35 * transport while a machine is in a debug state.  (N-1 CPUs stopped,
36 * interrupts disabled, may or may not be in a panic(9) state.)  Only one
37 * stream may be active at a time.  A dedicated server must be running to
38 * accept connections.
39 */
40
41#pragma once
42
43#include <sys/types.h>
44#include <netinet/in.h>
45
46/*
47 * Debugnet protocol details.
48 */
49#define	DEBUGNET_HERALD		1	/* Connection handshake. */
50#define	DEBUGNET_FINISHED	2	/* Close the connection. */
51#define	DEBUGNET_DATA		3	/* Contains data. */
52
53struct debugnet_msg_hdr {
54	uint32_t	mh_type;	/* Debugnet message type. */
55	uint32_t	mh_seqno;	/* Match acks with msgs. */
56	uint64_t	mh_offset;	/* Offset in fragment. */
57	uint32_t	mh_len;		/* Attached data (bytes). */
58	uint32_t	mh_aux2;	/* Consumer-specific. */
59} __packed;
60
61struct debugnet_ack {
62	uint32_t	da_seqno;	/* Match acks with msgs. */
63} __packed;
64
65#define	DEBUGNET_MAX_IN_FLIGHT	64
66
67#ifdef _KERNEL
68/*
69 * Hook API for network drivers.
70 */
71enum debugnet_ev {
72	DEBUGNET_START,
73	DEBUGNET_END,
74};
75
76struct ifnet;
77struct mbuf;
78typedef void debugnet_init_t(struct ifnet *, int *nrxr, int *ncl, int *clsize);
79typedef void debugnet_event_t(struct ifnet *, enum debugnet_ev);
80typedef int debugnet_transmit_t(struct ifnet *, struct mbuf *);
81typedef int debugnet_poll_t(struct ifnet *, int);
82
83struct debugnet_methods {
84	debugnet_init_t		*dn_init;
85	debugnet_event_t	*dn_event;
86	debugnet_transmit_t	*dn_transmit;
87	debugnet_poll_t		*dn_poll;
88};
89
90#define	DEBUGNET_SUPPORTED_NIC(ifp)				\
91	((ifp)->if_debugnet_methods != NULL && (ifp)->if_type == IFT_ETHER)
92
93struct debugnet_pcb; /* opaque */
94
95/*
96 * Debugnet consumer API.
97 */
98struct debugnet_conn_params {
99	struct ifnet	*dc_ifp;
100	in_addr_t	dc_client;
101	in_addr_t	dc_server;
102	in_addr_t	dc_gateway;
103
104	uint16_t	dc_herald_port;
105	uint16_t	dc_client_port;
106
107	const void	*dc_herald_data;
108	uint32_t	dc_herald_datalen;
109
110	/*
111	 * Consistent with debugnet_send(), aux paramaters to debugnet
112	 * functions are provided host-endian (but converted to
113	 * network endian on the wire).
114	 */
115	uint32_t	dc_herald_aux2;
116	uint64_t	dc_herald_offset;
117
118	/*
119	 * If NULL, debugnet is a unidirectional channel from panic machine to
120	 * remote server (like netdump).
121	 *
122	 * If handler is non-NULL, packets received on the client port that are
123	 * not just tx acks are forwarded to the provided handler.
124	 *
125	 * The mbuf chain will have all non-debugnet framing headers removed
126	 * (ethernet, inet, udp).  It will start with a debugnet_msg_hdr, of
127	 * which the header is guaranteed to be contiguous.  If m_pullup is
128	 * used, the supplied in-out mbuf pointer should be updated
129	 * appropriately.
130	 *
131	 * If the handler frees the mbuf chain, it should set the mbuf pointer
132	 * to NULL.  Otherwise, the debugnet input framework will free the
133	 * chain.
134	 *
135	 * The handler should ACK receieved packets with debugnet_ack_output.
136	 */
137	void		(*dc_rx_handler)(struct debugnet_pcb *, struct mbuf **);
138};
139
140/*
141 * Open a stream to the specified server's herald port.
142 *
143 * If all goes well, the server will send ACK from a different port to our ack
144 * port.  This allows servers to somewhat gracefully handle multiple debugnet
145 * clients.  (Clients are limited to single connections.)
146 *
147 * Returns zero on success, or errno.
148 */
149int debugnet_connect(const struct debugnet_conn_params *,
150    struct debugnet_pcb **pcb_out);
151
152/*
153 * Free a debugnet stream that was previously successfully opened.
154 *
155 * No attempt is made to cleanly terminate communication with the remote
156 * server.  Consumers should first send an empty DEBUGNET_FINISHED message, or
157 * otherwise let the remote know they are signing off.
158 */
159void debugnet_free(struct debugnet_pcb *);
160
161/*
162 * Send a message, with common debugnet_msg_hdr header, to the connected remote
163 * server.
164 *
165 * - mhtype translates directly to mh_type (e.g., DEBUGNET_DATA, or some other
166 *   protocol-specific type).
167 * - Data and datalen describe the attached data; datalen may be zero.
168 * - If auxdata is NULL, mh_offset's initial value and mh_aux2 will be zero.
169 *   Otherwise, mh_offset's initial value will be auxdata->dp_offset_start and
170 *   mh_aux2 will have the value of auxdata->dp_aux2.
171 *
172 * Returns zero on success, or an errno on failure.
173 */
174struct debugnet_proto_aux {
175	uint64_t dp_offset_start;
176	uint32_t dp_aux2;
177};
178int debugnet_send(struct debugnet_pcb *, uint32_t mhtype, const void *data,
179    uint32_t datalen, const struct debugnet_proto_aux *auxdata);
180
181/*
182 * A simple wrapper around the above when no data or auxdata is needed.
183 */
184static inline int
185debugnet_sendempty(struct debugnet_pcb *pcb, uint32_t mhtype)
186{
187	return (debugnet_send(pcb, mhtype, NULL, 0, NULL));
188}
189
190/*
191 * Full-duplex RX should ACK received messages.
192 */
193int debugnet_ack_output(struct debugnet_pcb *, uint32_t seqno /*net endian*/);
194
195/*
196 * Check and/or wait for further packets.
197 */
198void debugnet_network_poll(struct debugnet_pcb *);
199
200/*
201 * PCB accessors.
202 */
203
204/*
205 * Get the 48-bit MAC address of the discovered next hop (gateway, or
206 * destination server if it is on the same segment.
207 */
208const unsigned char *debugnet_get_gw_mac(const struct debugnet_pcb *);
209
210/*
211 * Callbacks from core mbuf code.
212 */
213void debugnet_any_ifnet_update(struct ifnet *);
214
215/*
216 * DDB parsing helper for common debugnet options.
217 *
218 * -s <server> [-g <gateway -c <localip> -i <interface>]
219 *
220 * Order is not significant.  Interface is an online interface that supports
221 * debugnet and can route to the debugnet server.  The other parameters are all
222 * IP addresses.  Only the server parameter is required.  The others are
223 * inferred automatically from the routing table, if not explicitly provided.
224 *
225 * Provides basic '-h' using provided 'cmd' string.
226 *
227 * Returns zero on success, or errno.
228 */
229struct debugnet_ddb_config {
230	struct ifnet	*dd_ifp;	/* not ref'd */
231	in_addr_t	dd_client;
232	in_addr_t	dd_server;
233	in_addr_t	dd_gateway;
234	bool		dd_has_client : 1;
235	bool		dd_has_gateway : 1;
236};
237int debugnet_parse_ddb_cmd(const char *cmd,
238    struct debugnet_ddb_config *result);
239
240/* Expose sysctl variables for netdump(4) to alias. */
241extern int debugnet_npolls;
242extern int debugnet_nretries;
243extern int debugnet_arp_nretries;
244
245/*
246 * Conditionally-defined macros for device drivers so we can avoid ifdef
247 * wrappers in every single implementation.
248 */
249#ifdef DEBUGNET
250#define	DEBUGNET_DEFINE(driver)					\
251	static debugnet_init_t driver##_debugnet_init;		\
252	static debugnet_event_t driver##_debugnet_event;	\
253	static debugnet_transmit_t driver##_debugnet_transmit;	\
254	static debugnet_poll_t driver##_debugnet_poll;		\
255								\
256	static struct debugnet_methods driver##_debugnet_methods = { \
257		.dn_init = driver##_debugnet_init,		\
258		.dn_event = driver##_debugnet_event,		\
259		.dn_transmit = driver##_debugnet_transmit,	\
260		.dn_poll = driver##_debugnet_poll,		\
261	}
262
263#define	DEBUGNET_NOTIFY_MTU(ifp)	debugnet_any_ifnet_update(ifp)
264
265#define	DEBUGNET_SET(ifp, driver)				\
266	(ifp)->if_debugnet_methods = &driver##_debugnet_methods
267
268#else /* !DEBUGNET || !INET */
269
270#define	DEBUGNET_DEFINE(driver)
271#define	DEBUGNET_NOTIFY_MTU(ifp)
272#define	DEBUGNET_SET(ifp, driver)
273
274#endif /* DEBUGNET && INET */
275#endif /* _KERNEL */
276