/* watchgnupg.c - Socket server for GnuPG logs
* Copyright (C) 2003, 2004, 2010 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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.
*
* GnuPG 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 <https://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <assert.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <time.h>
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif
#define PGM "watchgnupg"
/* Allow for a standalone build on most systems. */
#ifdef VERSION
#define MYVERSION_LINE PGM " ("GNUPG_NAME") " VERSION
#define BUGREPORT_LINE "\nReport bugs to <bug-gnupg@gnu.org>.\n"
#else
#define MYVERSION_LINE PGM " (standalone build) " __DATE__
#define BUGREPORT_LINE ""
#endif
#if !defined(SUN_LEN) || !defined(PF_LOCAL) || !defined(AF_LOCAL)
#define GNUPG_COMMON_NEED_AFLOCAL
#include "../common/mischelp.h"
#endif
static int verbose;
static int time_only;
static void
die (const char *format, ...)
{
va_list arg_ptr;
fflush (stdout);
fprintf (stderr, "%s: ", PGM);
va_start (arg_ptr, format);
vfprintf (stderr, format, arg_ptr);
va_end (arg_ptr);
putc ('\n', stderr);
exit (1);
}
static void
err (const char *format, ...)
{
va_list arg_ptr;
fflush (stdout);
fprintf (stderr, "%s: ", PGM);
va_start (arg_ptr, format);
vfprintf (stderr, format, arg_ptr);
va_end (arg_ptr);
putc ('\n', stderr);
}
static void *
xmalloc (size_t n)
{
void *p = malloc (n);
if (!p)
die ("out of core");
return p;
}
static void *
xcalloc (size_t n, size_t m)
{
void *p = calloc (n, m);
if (!p)
die ("out of core");
return p;
}
static void *
xrealloc (void *old, size_t n)
{
void *p = realloc (old, n);
if (!p)
die ("out of core");
return p;
}
struct client_s {
struct client_s *next;
int fd;
size_t size; /* Allocated size of buffer. */
size_t len; /* Current length of buffer. */
unsigned char *buffer; /* Buffer to with data already read. */
};
typedef struct client_s *client_t;
/* The list of all connected peers. */
static client_t client_list;
static void
print_fd_and_time (int fd)
{
struct tm *tp;
time_t atime = time (NULL);
tp = localtime (&atime);
if (time_only)
printf ("%3d - %02d:%02d:%02d ",
fd,
tp->tm_hour, tp->tm_min, tp->tm_sec );
else
printf ("%3d - %04d-%02d-%02d %02d:%02d:%02d ",
fd,
1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday,
tp->tm_hour, tp->tm_min, tp->tm_sec );
}
/* Print LINE for the client identified by C. Calling this function
with LINE set to NULL, will flush the internal buffer. */
static void
print_line (client_t c, const char *line)
{
const char *s;
size_t n;
if (!line)
{
if (c->buffer && c->len)
{
print_fd_and_time (c->fd);
fwrite (c->buffer, c->len, 1, stdout);
putc ('\n', stdout);
c->len = 0;
}
return;
}
while ((s = strchr (line, '\n')))
{
print_fd_and_time (c->fd);
if (c->buffer && c->len)
{
fwrite (c->buffer, c->len, 1, stdout);
c->len = 0;
}
fwrite (line, s - line + 1, 1, stdout);
line = s + 1;
}
n = strlen (line);
if (n)
{
if (c->len + n >= c->size)
{
c->size += ((n + 255) & ~255);
c->buffer = (c->buffer
? xrealloc (c->buffer, c->size)
: xmalloc (c->size));
}
memcpy (c->buffer + c->len, line, n);
c->len += n;
}
}
static void
setup_client (int server_fd, int is_un)
{
struct sockaddr_un addr_un;
struct sockaddr_in addr_in;
struct sockaddr *addr;
socklen_t addrlen;
int fd;
client_t client;
if (is_un)
{
addr = (struct sockaddr *)&addr_un;
addrlen = sizeof addr_un;
}
else
{
addr = (struct sockaddr *)&addr_in;
addrlen = sizeof addr_in;
}
fd = accept (server_fd, addr, &addrlen);
if (fd == -1)
{
printf ("[accepting %s connection failed: %s]\n",
is_un? "local":"tcp", strerror (errno));
}
else if (fd >= FD_SETSIZE)
{
close (fd);
printf ("[connection request denied: too many connections]\n");
}
else
{
for (client = client_list; client && client->fd != -1;
client = client->next)
;
if (!client)
{
client = xcalloc (1, sizeof *client);
client->next = client_list;
client_list = client;
}
client->fd = fd;
printf ("[client at fd %d connected (%s)]\n",
client->fd, is_un? "local":"tcp");
}
}
static void
print_version (int with_help)
{
fputs (MYVERSION_LINE "\n"
"Copyright (C) 2017 Free Software Foundation, Inc.\n"
"License GPLv3+: "
"GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>\n"
"This is free software: you are free to change and redistribute it.\n"
"There is NO WARRANTY, to the extent permitted by law.\n",
stdout);
if (with_help)
fputs
("\n"
"Usage: " PGM " [OPTIONS] SOCKETNAME\n"
" " PGM " [OPTIONS] PORT [SOCKETNAME]\n"
"Open the local socket SOCKETNAME (or the TCP port PORT)\n"
"and display log messages\n"
"\n"
" --tcp listen on a TCP port and optionally on a local socket\n"
" --force delete an already existing socket file\n"
" --verbose enable extra informational output\n"
" --time-only print only the time; not a full timestamp\n"
" --version print version of the program and exit\n"
" --help display this help and exit\n"
BUGREPORT_LINE, stdout );
exit (0);
}
int
main (int argc, char **argv)
{
int last_argc = -1;
int force = 0;
int tcp = 0;
struct sockaddr_un srvr_addr_un;
struct sockaddr_in srvr_addr_in;
struct sockaddr *addr_in = NULL;
struct sockaddr *addr_un = NULL;
socklen_t addrlen_in, addrlen_un;
unsigned short port;
int server_un, server_in;
int flags;
if (argc)
{
argc--; argv++;
}
while (argc && last_argc != argc )
{
last_argc = argc;
if (!strcmp (*argv, "--"))
{
argc--; argv++;
break;
}
else if (!strcmp (*argv, "--version"))
print_version (0);
else if (!strcmp (*argv, "--help"))
print_version (1);
else if (!strcmp (*argv, "--verbose"))
{
verbose = 1;
argc--; argv++;
}
else if (!strcmp (*argv, "--time-only"))
{
time_only = 1;
argc--; argv++;
}
else if (!strcmp (*argv, "--force"))
{
force = 1;
argc--; argv++;
}
else if (!strcmp (*argv, "--tcp"))
{
tcp = 1;
argc--; argv++;
}
}
if (!((!tcp && argc == 1) || (tcp && (argc == 1 || argc == 2))))
{
fprintf (stderr, "usage: " PGM " socketname\n"
" " PGM " --tcp port [socketname]\n");
exit (1);
}
if (tcp)
{
port = atoi (*argv);
argc--; argv++;
}
else
{
port = 0;
}
setvbuf (stdout, NULL, _IOLBF, 0);
if (tcp)
{
int i = 1;
server_in = socket (PF_INET, SOCK_STREAM, 0);
if (server_in == -1)
die ("socket(PF_INET) failed: %s\n", strerror (errno));
if (setsockopt (server_in, SOL_SOCKET, SO_REUSEADDR,
(unsigned char *)&i, sizeof (i)))
err ("setsockopt(SO_REUSEADDR) failed: %s\n", strerror (errno));
if (verbose)
fprintf (stderr, "listening on port %hu\n", port);
}
else
server_in = -1;
if (argc)
{
server_un = socket (PF_LOCAL, SOCK_STREAM, 0);
if (server_un == -1)
die ("socket(PF_LOCAL) failed: %s\n", strerror (errno));
if (verbose)
fprintf (stderr, "listening on socket '%s'\n", *argv);
}
else
server_un = -1;
/* We better set the listening socket to non-blocking so that we
don't get bitten by race conditions in accept. The should not
happen for Unix Domain sockets but well, shit happens. */
if (server_in != -1)
{
flags = fcntl (server_in, F_GETFL, 0);
if (flags == -1)
die ("fcntl (F_GETFL) failed: %s\n", strerror (errno));
if ( fcntl (server_in, F_SETFL, (flags | O_NONBLOCK)) == -1)
die ("fcntl (F_SETFL) failed: %s\n", strerror (errno));
}
if (server_un != -1)
{
flags = fcntl (server_un, F_GETFL, 0);
if (flags == -1)
die ("fcntl (F_GETFL) failed: %s\n", strerror (errno));
if ( fcntl (server_un, F_SETFL, (flags | O_NONBLOCK)) == -1)
die ("fcntl (F_SETFL) failed: %s\n", strerror (errno));
}
if (tcp)
{
memset (&srvr_addr_in, 0, sizeof srvr_addr_in);
srvr_addr_in.sin_family = AF_INET;
srvr_addr_in.sin_port = htons (port);
srvr_addr_in.sin_addr.s_addr = htonl (INADDR_ANY);
addr_in = (struct sockaddr *)&srvr_addr_in;
addrlen_in = sizeof srvr_addr_in;
}
if (argc)
{
memset (&srvr_addr_un, 0, sizeof srvr_addr_un);
srvr_addr_un.sun_family = AF_LOCAL;
strncpy (srvr_addr_un.sun_path, *argv, sizeof (srvr_addr_un.sun_path)-1);
srvr_addr_un.sun_path[sizeof (srvr_addr_un.sun_path) - 1] = 0;
addr_un = (struct sockaddr *)&srvr_addr_un;
addrlen_un = SUN_LEN (&srvr_addr_un);
}
else
addrlen_un = 0; /* Silent gcc. */
if (server_in != -1 && bind (server_in, addr_in, addrlen_in))
die ("bind to port %hu failed: %s\n", port, strerror (errno));
again:
if (server_un != -1 && bind (server_un, addr_un, addrlen_un))
{
if (errno == EADDRINUSE && force)
{
force = 0;
remove (srvr_addr_un.sun_path);
goto again;
}
else
die ("bind to '%s' failed: %s\n", *argv, strerror (errno));
}
if (server_in != -1 && listen (server_in, 5))
die ("listen on inet failed: %s\n", strerror (errno));
if (server_un != -1 && listen (server_un, 5))
die ("listen on local failed: %s\n", strerror (errno));
for (;;)
{
fd_set rfds;
int max_fd;
client_t client;
/* Usually we don't have that many connections, thus it is okay
to set them always from scratch and don't maintain an active
fd_set. */
FD_ZERO (&rfds);
max_fd = -1;
if (server_in != -1)
{
FD_SET (server_in, &rfds);
max_fd = server_in;
}
if (server_un != -1)
{
FD_SET (server_un, &rfds);
if (server_un > max_fd)
max_fd = server_un;
}
for (client = client_list; client; client = client->next)
if (client->fd != -1)
{
FD_SET (client->fd, &rfds);
if (client->fd > max_fd)
max_fd = client->fd;
}
if (select (max_fd + 1, &rfds, NULL, NULL, NULL) <= 0)
continue; /* Ignore any errors. */
if (server_in != -1 && FD_ISSET (server_in, &rfds))
setup_client (server_in, 0);
if (server_un != -1 && FD_ISSET (server_un, &rfds))
setup_client (server_un, 1);
for (client = client_list; client; client = client->next)
if (client->fd != -1 && FD_ISSET (client->fd, &rfds))
{
char line[256];
int n;
n = read (client->fd, line, sizeof line - 1);
if (n < 0)
{
int save_errno = errno;
print_line (client, NULL); /* flush */
printf ("[client at fd %d read error: %s]\n",
client->fd, strerror (save_errno));
close (client->fd);
client->fd = -1;
}
else if (!n)
{
print_line (client, NULL); /* flush */
close (client->fd);
printf ("[client at fd %d disconnected]\n", client->fd);
client->fd = -1;
}
else
{
line[n] = 0;
print_line (client, line);
}
}
}
return 0;
}
/*
Local Variables:
compile-command: "gcc -Wall -g -o watchgnupg watchgnupg.c"
End:
*/