45bf92cd20
NetGDB(4) is a component of a system using a panic-time network stack to remotely debug crashed FreeBSD kernels over the network, instead of traditional serial interfaces. There are three pieces in the complete NetGDB system. First, a dedicated proxy server must be running to accept connections from both NetGDB and gdb(1), and pass bidirectional traffic between the two protocols. Second, the NetGDB client is activated much like ordinary 'gdb' and similarly to 'netdump' in ddb(4) after a panic. Like other debugnet(4) clients (netdump(4)), the network interface on the route to the proxy server must be online and support debugnet(4). Finally, the remote (k)gdb(1) uses 'target remote <proxy>:<port>' (like any other TCP remote) to connect to the proxy server. The NetGDB v1 protocol speaks the literal GDB remote serial protocol, and uses a 1:1 relationship between GDB packets and sequences of debugnet packets (fragmented by MTU). There is no encryption utilized to keep debugging sessions private, so this is only appropriate for local segments or trusted networks. Submitted by: John Reimer <john.reimer AT emc.com> (earlier version) Discussed some with: emaste, markj Relnotes: sure Differential Revision: https://reviews.freebsd.org/D21568
97 lines
3.1 KiB
C
97 lines
3.1 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2019 Isilon Systems, LLC.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#pragma once
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#ifndef DEBUGNET_INTERNAL
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#error "Don't include this"
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#endif
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#define DNETDEBUG(f, ...) do { \
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if (debugnet_debug > 0) \
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printf(("%s: " f), __func__, ## __VA_ARGS__); \
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} while (0)
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#define DNETDEBUG_IF(i, f, ...) do { \
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if (debugnet_debug > 0) \
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if_printf((i), ("%s: " f), __func__, ## __VA_ARGS__); \
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} while (0)
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#define DNETDEBUGV(f, ...) do { \
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if (debugnet_debug > 1) \
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printf(("%s: " f), __func__, ## __VA_ARGS__); \
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} while (0)
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enum dnet_pcb_st {
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DN_STATE_INIT = 1,
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DN_STATE_HAVE_GW_MAC,
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DN_STATE_GOT_HERALD_PORT,
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DN_STATE_REMOTE_CLOSED,
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};
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struct debugnet_pcb {
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uint64_t dp_rcvd_acks;
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in_addr_t dp_client;
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in_addr_t dp_server;
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in_addr_t dp_gateway;
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uint32_t dp_seqno;
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struct ether_addr dp_gw_mac;
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uint16_t dp_server_port;
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struct ifnet *dp_ifp;
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/* Saved driver if_input to restore on close. */
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void (*dp_drv_input)(struct ifnet *, struct mbuf *);
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/* RX handler for bidirectional protocols. */
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void (*dp_rx_handler)(struct debugnet_pcb *,
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struct mbuf **);
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enum dnet_pcb_st dp_state;
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uint16_t dp_client_port;
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bool dp_event_started;
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};
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/* TODO(CEM): Obviate this assertion by using a BITSET(9) for acks. */
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CTASSERT(sizeof(((struct debugnet_pcb *)0)->dp_rcvd_acks) * NBBY >=
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DEBUGNET_MAX_IN_FLIGHT);
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extern unsigned debugnet_debug;
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SYSCTL_DECL(_net_debugnet);
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int debugnet_ether_output(struct mbuf *, struct ifnet *, struct ether_addr,
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u_short);
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void debugnet_handle_udp(struct debugnet_pcb *, struct mbuf **);
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#ifdef INET
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int debugnet_arp_gw(struct debugnet_pcb *);
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void debugnet_handle_arp(struct debugnet_pcb *, struct mbuf **);
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void debugnet_handle_ip(struct debugnet_pcb *, struct mbuf **);
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int debugnet_ip_output(struct debugnet_pcb *, struct mbuf *);
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#endif
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