/* Replay a remote debug session logfile for GDB.
Copyright (C) 1996-2024 Free Software Foundation, Inc.
Written by Fred Fish (
[email protected]) from pieces of gdbserver.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <
http://www.gnu.org/licenses/>. */
#undef PACKAGE
#undef PACKAGE_NAME
#undef PACKAGE_VERSION
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#include <config.h>
#include "gdbsupport/version.h"
#if HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#if HAVE_SIGNAL_H
#include <signal.h>
#endif
#include <ctype.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <unistd.h>
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif
#if HAVE_NETINET_TCP_H
#include <netinet/tcp.h>
#endif
#if USE_WIN32API
#include <ws2tcpip.h>
#endif
#include "gdbsupport/netstuff.h"
#include "gdbsupport/rsp-low.h"
#include "getopt.h"
#ifndef HAVE_SOCKLEN_T
typedef int socklen_t;
#endif
/* Sort of a hack... */
#define EOL (EOF - 1)
static int remote_desc_in;
static int remote_desc_out;
/* When true all packets are printed to stderr as they are handled by
gdbreplay. */
bool debug_logging = false;
static void
sync_error (FILE *fp, const char *desc, int expect, int got)
{
fprintf (stderr, "\n%s\n", desc);
fprintf (stderr, "At logfile offset %ld, expected '0x%x' got '0x%x'\n",
ftell (fp), expect, got);
fflush (stderr);
exit (1);
}
static void
remote_error (const char *desc)
{
fprintf (stderr, "\n%s\n", desc);
fflush (stderr);
exit (1);
}
static void
remote_close (void)
{
#ifdef USE_WIN32API
gdb_assert (remote_desc_in == remote_desc_out);
closesocket (remote_desc_in);
#else
close (remote_desc_in);
if (remote_desc_in != remote_desc_out)
close (remote_desc_out);
#endif
}
/* Open a connection to a remote debugger.
NAME is the filename used for communication. */
static void
remote_open (const char *name)
{
#ifndef USE_WIN32API
if (strcmp (name, "-") == 0)
{
remote_desc_in = 0;
remote_desc_out = 1;
return;
}
#endif
const char *last_colon = strrchr (name, ':');
if (last_colon == NULL)
{
fprintf (stderr, "%s: Must specify tcp connection as host:addr\n", name);
fflush (stderr);
exit (1);
}
#ifdef USE_WIN32API
static int winsock_initialized;
#endif
int tmp;
int tmp_desc;
struct addrinfo hint;
struct addrinfo *ainfo;
memset (&hint, 0, sizeof (hint));
/* Assume no prefix will be passed, therefore we should use
AF_UNSPEC. */
hint.ai_family = AF_UNSPEC;
hint.ai_socktype = SOCK_STREAM;
hint.ai_protocol = IPPROTO_TCP;
parsed_connection_spec parsed = parse_connection_spec (name, &hint);
if (parsed.port_str.empty ())
error (_("Missing port on hostname '%s'"), name);
#ifdef USE_WIN32API
if (!winsock_initialized)
{
WSADATA wsad;
WSAStartup (MAKEWORD (1, 0), &wsad);
winsock_initialized = 1;
}
#endif
int r = getaddrinfo (parsed.host_str.c_str (), parsed.port_str.c_str (),
&hint, &ainfo);
if (r != 0)
{
fprintf (stderr, "%s:%s: cannot resolve name: %s\n",
parsed.host_str.c_str (), parsed.port_str.c_str (),
gai_strerror (r));
fflush (stderr);
exit (1);
}
scoped_free_addrinfo free_ainfo (ainfo);
struct addrinfo *p;
for (p = ainfo; p != NULL; p = p->ai_next)
{
tmp_desc = socket (p->ai_family, p->ai_socktype, p->ai_protocol);
if (tmp_desc >= 0)
break;
}
if (p == NULL)
perror_with_name ("Cannot open socket");
/* Allow rapid reuse of this port. */
tmp = 1;
setsockopt (tmp_desc, SOL_SOCKET, SO_REUSEADDR, (char *) &tmp,
sizeof (tmp));
switch (p->ai_family)
{
case AF_INET:
((struct sockaddr_in *) p->ai_addr)->sin_addr.s_addr = INADDR_ANY;
break;
case AF_INET6:
((struct sockaddr_in6 *) p->ai_addr)->sin6_addr = in6addr_any;
break;
default:
fprintf (stderr, "Invalid 'ai_family' %d\n", p->ai_family);
exit (1);
}
if (bind (tmp_desc, p->ai_addr, p->ai_addrlen) != 0)
perror_with_name ("Can't bind address");
if (p->ai_socktype == SOCK_DGRAM)
remote_desc_in = tmp_desc;
else
{
struct sockaddr_storage sockaddr;
socklen_t sockaddrsize = sizeof (sockaddr);
char orig_host[GDB_NI_MAX_ADDR], orig_port[GDB_NI_MAX_PORT];
if (listen (tmp_desc, 1) != 0)
perror_with_name ("Can't listen on socket");
remote_desc_in = accept (tmp_desc, (struct sockaddr *) &sockaddr,
&sockaddrsize);
if (remote_desc_in == -1)
perror_with_name ("Accept failed");
/* Enable TCP keep alive process. */
tmp = 1;
setsockopt (tmp_desc, SOL_SOCKET, SO_KEEPALIVE,
(char *) &tmp, sizeof (tmp));
/* Tell TCP not to delay small packets. This greatly speeds up
interactive response. */
tmp = 1;
setsockopt (remote_desc_in, IPPROTO_TCP, TCP_NODELAY,
(char *) &tmp, sizeof (tmp));
if (getnameinfo ((struct sockaddr *) &sockaddr, sockaddrsize,
orig_host, sizeof (orig_host),
orig_port, sizeof (orig_port),
NI_NUMERICHOST | NI_NUMERICSERV) == 0)
{
fprintf (stderr, "Remote debugging from host %s, port %s\n",
orig_host, orig_port);
fflush (stderr);
}
#ifndef USE_WIN32API
close (tmp_desc); /* No longer need this */
signal (SIGPIPE, SIG_IGN); /* If we don't do this, then
gdbreplay simply exits when
the remote side dies. */
#else
closesocket (tmp_desc); /* No longer need this */
#endif
}
#if defined(F_SETFL) && defined (FASYNC)
fcntl (remote_desc_in, F_SETFL, FASYNC);
#endif
remote_desc_out = remote_desc_in;
fprintf (stderr, "Replay logfile using %s\n", name);
fflush (stderr);
}
static int
logchar (FILE *fp, bool print)
{
int ch;
int ch2;
ch = fgetc (fp);
if (ch != '\r' && (print || debug_logging))
{
fputc (ch, stderr);
fflush (stderr);
}
switch (ch)
{
/* Treat \r\n as a newline. */
case '\r':
ch = fgetc (fp);
if (ch == '\n')
ch = EOL;
else
{
ungetc (ch, fp);
ch = '\r';
}
if (print || debug_logging)
{
fputc (ch == EOL ? '\n' : '\r', stderr);
fflush (stderr);
}
break;
case '\n':
ch = EOL;
break;
case '\\':
ch = fgetc (fp);
if (print || debug_logging)
{
fputc (ch, stderr);
fflush (stderr);
}
switch (ch)
{
case '\\':
break;
case 'b':
ch = '\b';
break;
case 'f':
ch = '\f';
break;
case 'n':
ch = '\n';
break;
case 'r':
ch = '\r';
break;
case 't':
ch = '\t';
break;
case 'v':
ch = '\v';
break;
case 'x':
ch2 = fgetc (fp);
if (print || debug_logging)
{
fputc (ch2, stderr);
fflush (stderr);
}
ch = fromhex (ch2) << 4;
ch2 = fgetc (fp);
if (print || debug_logging)
{
fputc (ch2, stderr);
fflush (stderr);
}
ch |= fromhex (ch2);
break;
case 'c':
fputc (ch, stderr);
fflush (stderr);
break;
case 'E':
fputc (ch, stderr);
fflush (stderr);
break;
default:
/* Treat any other char as just itself */
break;
}
default:
break;
}
return (ch);
}
static int
gdbchar (int desc)
{
unsigned char fromgdb;
if (read (desc, &fromgdb, 1) != 1)
return -1;
else
return fromgdb;
}
/* Accept input from gdb and match with chars from fp (after skipping one
blank) up until a \n is read from fp (which is not matched) */
static void
expect (FILE *fp)
{
int fromlog;
int fromgdb;
if ((fromlog = logchar (fp, false)) != ' ')
{
sync_error (fp, "Sync error during gdb read of leading blank", ' ',
fromlog);
}
do
{
fromlog = logchar (fp, false);
if (fromlog == EOL)
break;
fromgdb = gdbchar (remote_desc_in);
if (fromgdb < 0)
remote_error ("Error during read from gdb");
}
while (fromlog == fromgdb);
if (fromlog != EOL)
{
sync_error (fp, "Sync error during read of gdb packet from log", fromlog,
fromgdb);
}
}
/* Calculate checksum for the packet stored in buffer buf. Store
the checksum in a hexadecimal format in a checksum_hex variable. */
static void
recalculate_csum (const std::string &buf, int off, unsigned char *checksum_hex)
{
unsigned char csum = 0;
int len = buf.length ();
for (int i = off; i < len; ++i)
csum += buf[i];
checksum_hex[0] = tohex ((csum >> 4) & 0xf);
checksum_hex[1] = tohex (csum & 0xf);
}
/* Play data back to gdb from fp (after skipping leading blank) up until a
\n is read from fp (which is discarded and not sent to gdb). */
static void
play (FILE *fp)
{
int fromlog;
int where_csum = 0, offset = 1;
unsigned char checksum[2] = {0, 0};
std::string line;
if ((fromlog = logchar (fp, false)) != ' ')
{
sync_error (fp, "Sync error skipping blank during write to gdb", ' ',
fromlog);
}
while ((fromlog = logchar (fp, false)) != EOL)
{
if (fromlog == '#')
where_csum = line.length ();
line.push_back (fromlog);
}
/* Packet starts with '+$' or '$', we don't want to calculate those
to the checksum, substract the offset to adjust the line length.
If the line starts with '$', the offset remains set to 1. */
if (line[0] == '+')
offset = 2;
if (where_csum > 0)
line.resize (where_csum);
recalculate_csum (line, offset, checksum);
line.push_back ('#');
line.push_back (checksum[0]);
line.push_back (checksum[1]);
if (write (remote_desc_out, line.data (), line.size ()) != line.size ())
remote_error ("Error during write to gdb");
}
static void
gdbreplay_version (void)
{
printf ("GNU gdbreplay %s%s\n"
"Copyright (C) 2024 Free Software Foundation, Inc.\n"
"gdbreplay is free software, covered by "
"the GNU General Public License.\n"
"This gdbreplay was configured as \"%s\"\n",
PKGVERSION, version, host_name);
}
static void
gdbreplay_usage (FILE *stream)
{
fprintf (stream, "Usage:\tgdbreplay LOGFILE HOST:PORT\n");
}
static void
gdbreplay_help ()
{
gdbreplay_usage (stdout);
printf ("\n");
printf ("LOGFILE is a file generated by 'set remotelogfile' in gdb.\n");
printf ("COMM may either be a tty device (for serial debugging),\n");
printf ("HOST:PORT to listen for a TCP connection, or '-' or 'stdio' to use\n");
printf ("stdin/stdout of gdbserver.\n");
printf ("\n");
printf ("Options:\n\n");
printf (" --debug-logging Show packets as they are processed.\n");
printf (" --help Print this message and then exit.\n");
printf (" --version Display version information and then exit.\n");
if (REPORT_BUGS_TO[0])
{
printf ("\n");
printf ("Report bugs to \"%s\".\n", REPORT_BUGS_TO);
}
}
/* Main function. This is called by the real "main" function,
wrapped in a TRY_CATCH that handles any uncaught exceptions. */
[[noreturn]] static void
captured_main (int argc, char *argv[])
{
FILE *fp;
int ch, optc;
enum opts { OPT_VERSION = 1, OPT_HELP, OPT_LOGGING };
static struct option longopts[] =
{
{"version", no_argument, nullptr, OPT_VERSION},
{"help", no_argument, nullptr, OPT_HELP},
{"debug-logging", no_argument, nullptr, OPT_LOGGING},
{nullptr, no_argument, nullptr, 0}
};
while ((optc = getopt_long (argc, argv, "", longopts, nullptr)) != -1)
{
switch (optc)
{
case OPT_VERSION:
gdbreplay_version ();
exit (0);
case OPT_HELP:
gdbreplay_help ();
exit (0);
case OPT_LOGGING:
debug_logging = true;
break;
case '?':
fprintf (stderr,
"Use 'gdbreplay --help' for a complete list of options.\n");
exit (1);
}
}
if (optind + 2 != argc)
{
gdbreplay_usage (stderr);
exit (1);
}
fp = fopen (argv[optind], "r");
if (fp == NULL)
{
perror_with_name (argv[optind]);
}
remote_open (argv[optind + 1]);
while ((ch = logchar (fp, false)) != EOF)
{
switch (ch)
{
case 'w':
/* data sent from gdb to gdbreplay, accept and match it */
expect (fp);
break;
case 'r':
/* data sent from gdbreplay to gdb, play it */
play (fp);
break;
case 'c':
/* We want to always print the command executed by GDB. */
if (!debug_logging)
{
fprintf (stderr, "\n");
fprintf (stderr, "Command expected from GDB:\n");
}
while ((ch = logchar (fp, true)) != EOL);
break;
case 'E':
if (!debug_logging)
fprintf (stderr, "E");
while ((ch = logchar (fp, true)) != EOL);
break;
}
}
remote_close ();
exit (0);
}
int
main (int argc, char *argv[])
{
try
{
captured_main (argc, argv);
}
catch (const gdb_exception &exception)
{
if (exception.reason == RETURN_ERROR)
{
fflush (stdout);
fprintf (stderr, "%s\n", exception.what ());
}
exit (1);
}
gdb_assert_not_reached ("captured_main should never return");
}
