exchange/src/util/secmod_common.c
2022-01-18 09:15:54 -05:00

587 lines
14 KiB
C

/*
This file is part of TALER
Copyright (C) 2020 Taler Systems SA
TALER 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, or (at your option) any later version.
TALER 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
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file util/secmod_common.c
* @brief Common functions for the exchange security modules
* @author Florian Dold <dold@taler.net>
*/
#include "platform.h"
#include "taler_util.h"
#include "taler_signatures.h"
#include "secmod_common.h"
#include <poll.h>
#ifdef __linux__
#include <sys/eventfd.h>
#endif
/**
* Head of DLL of clients connected to us.
*/
struct TES_Client *TES_clients_head;
/**
* Tail of DLL of clients connected to us.
*/
struct TES_Client *TES_clients_tail;
/**
* Lock for the client queue.
*/
pthread_mutex_t TES_clients_lock;
/**
* Private key of this security module. Used to sign denomination key
* announcements.
*/
struct TALER_SecurityModulePrivateKeyP TES_smpriv;
/**
* Public key of this security module.
*/
struct TALER_SecurityModulePublicKeyP TES_smpub;
/**
* Our listen socket.
*/
static struct GNUNET_NETWORK_Handle *unix_sock;
/**
* Path where we are listening.
*/
static char *unixpath;
/**
* Task run to accept new inbound connections.
*/
static struct GNUNET_SCHEDULER_Task *listen_task;
/**
* Set once we are in shutdown and workers should terminate.
*/
static volatile bool in_shutdown;
enum GNUNET_GenericReturnValue
TES_transmit_raw (int sock,
size_t end,
const void *pos)
{
size_t off = 0;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Sending message of length %u\n",
(unsigned int) end);
while (off < end)
{
ssize_t ret = send (sock,
pos,
end - off,
0 /* no flags => blocking! */);
if ( (-1 == ret) &&
( (EAGAIN == errno) ||
(EINTR == errno) ) )
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG,
"send");
continue;
}
if (-1 == ret)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"send");
return GNUNET_SYSERR;
}
if (0 == ret)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
off += ret;
pos += ret;
}
return GNUNET_OK;
}
enum GNUNET_GenericReturnValue
TES_transmit (int sock,
const struct GNUNET_MessageHeader *hdr)
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Sending message of type %u and length %u\n",
(unsigned int) ntohs (hdr->type),
(unsigned int) ntohs (hdr->size));
return TES_transmit_raw (sock,
ntohs (hdr->size),
hdr);
}
struct GNUNET_NETWORK_Handle *
TES_open_socket (const char *unixpath)
{
int sock;
mode_t old_umask;
struct GNUNET_NETWORK_Handle *ret = NULL;
/* Change permissions so that group read/writes are allowed.
* We need this for multi-user exchange deployment with privilege
* separation, where taler-exchange-httpd is part of a group
* that allows it to talk to secmod.
*/
old_umask = umask (S_IROTH | S_IWOTH | S_IXOTH);
sock = socket (PF_UNIX,
SOCK_STREAM,
0);
if (-1 == sock)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
"socket");
goto cleanup;
}
{
struct sockaddr_un un;
if (GNUNET_OK !=
GNUNET_DISK_directory_create_for_file (unixpath))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"mkdir(dirname)",
unixpath);
}
if (0 != unlink (unixpath))
{
if (ENOENT != errno)
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"unlink",
unixpath);
}
memset (&un,
0,
sizeof (un));
un.sun_family = AF_UNIX;
strncpy (un.sun_path,
unixpath,
sizeof (un.sun_path) - 1);
if (0 != bind (sock,
(const struct sockaddr *) &un,
sizeof (un)))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
"bind",
unixpath);
GNUNET_break (0 == close (sock));
goto cleanup;
}
ret = GNUNET_NETWORK_socket_box_native (sock);
if (GNUNET_OK !=
GNUNET_NETWORK_socket_listen (ret,
512))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
"listen",
unixpath);
GNUNET_break (GNUNET_OK ==
GNUNET_NETWORK_socket_close (ret));
ret = NULL;
}
}
cleanup:
(void) umask (old_umask);
return ret;
}
void
TES_wake_clients (void)
{
uint64_t num = 1;
GNUNET_assert (0 == pthread_mutex_lock (&TES_clients_lock));
for (struct TES_Client *client = TES_clients_head;
NULL != client;
client = client->next)
{
GNUNET_assert (sizeof (num) ==
#ifdef __linux__
write (client->esock,
#else
write (client->esock_in,
#endif
&num,
sizeof (num)));
}
GNUNET_assert (0 == pthread_mutex_unlock (&TES_clients_lock));
}
enum GNUNET_GenericReturnValue
TES_read_work (void *cls,
TES_MessageDispatch dispatch)
{
struct TES_Client *client = cls;
char *buf = client->iobuf;
size_t off = 0;
uint16_t msize = 0;
const struct GNUNET_MessageHeader *hdr = NULL;
enum GNUNET_GenericReturnValue ret;
do
{
ssize_t recv_size;
recv_size = recv (client->csock,
&buf[off],
sizeof (client->iobuf) - off,
0);
if (-1 == recv_size)
{
if ( (0 == off) &&
(EAGAIN == errno) )
return GNUNET_NO;
if ( (EINTR == errno) ||
(EAGAIN == errno) )
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG,
"recv");
continue;
}
if (ECONNRESET != errno)
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"recv");
return GNUNET_SYSERR;
}
if (0 == recv_size)
{
/* regular disconnect? */
GNUNET_break_op (0 == off);
return GNUNET_SYSERR;
}
off += recv_size;
more:
if (off < sizeof (struct GNUNET_MessageHeader))
continue;
hdr = (const struct GNUNET_MessageHeader *) buf;
msize = ntohs (hdr->size);
#if 0
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Received message of type %u with %u bytes\n",
(unsigned int) ntohs (hdr->type),
(unsigned int) msize);
#endif
if (msize < sizeof (struct GNUNET_MessageHeader))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
} while (off < msize);
ret = dispatch (client,
hdr);
if ( (GNUNET_OK != ret) ||
(off == msize) )
return ret;
memmove (buf,
&buf[msize],
off - msize);
off -= msize;
goto more;
}
bool
TES_await_ready (struct TES_Client *client)
{
/* wait for reply with 1s timeout */
struct pollfd pfds[] = {
{
.fd = client->csock,
.events = POLLIN
},
{
#ifdef __linux__
.fd = client->esock,
#else
.fd = client->esock_out,
#endif
.events = POLLIN
},
};
int ret;
ret = poll (pfds,
2,
-1);
if ( (-1 == ret) &&
(EINTR != errno) )
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
"poll");
for (int i = 0; i<2; i++)
{
#ifdef __linux__
if ( (pfds[i].fd == client->esock) &&
#else
if ( (pfds[i].fd == client->esock_out) &&
#endif
(POLLIN == pfds[i].revents) )
{
uint64_t num;
GNUNET_assert (sizeof (num) ==
#ifdef __linux__
read (client->esock,
#else
read (client->esock_out,
#endif
&num,
sizeof (num)));
return true;
}
}
return false;
}
void
TES_free_client (struct TES_Client *client)
{
GNUNET_assert (0 == pthread_mutex_lock (&TES_clients_lock));
GNUNET_CONTAINER_DLL_remove (TES_clients_head,
TES_clients_tail,
client);
GNUNET_assert (0 == pthread_mutex_unlock (&TES_clients_lock));
GNUNET_break (0 == close (client->csock));
#ifdef __linux__
GNUNET_break (0 == close (client->esock));
#else
GNUNET_break (0 == close (client->esock_in));
GNUNET_break (0 == close (client->esock_out));
#endif
pthread_detach (client->worker);
GNUNET_free (client);
}
/**
* Main function of a worker thread that signs.
*
* @param cls the client we are working on
* @return NULL
*/
static void *
sign_worker (void *cls)
{
struct TES_Client *client = cls;
if (GNUNET_OK !=
client->cb.init (client))
{
GNUNET_break (0);
TES_free_client (client);
return NULL;
}
while (! in_shutdown)
{
if (TES_await_ready (client))
{
if (GNUNET_OK !=
client->cb.updater (client))
break;
}
if (GNUNET_SYSERR ==
TES_read_work (client,
client->cb.dispatch))
break;
}
TES_free_client (client);
return NULL;
}
/**
* Task that listens for incoming clients.
*
* @param cls a `struct TES_Callbacks`
*/
static void
listen_job (void *cls)
{
const struct TES_Callbacks *cb = cls;
int s;
#ifdef __linux__
int e;
#else
int e[2];
#endif
struct sockaddr_storage sa;
socklen_t sa_len = sizeof (sa);
listen_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
unix_sock,
&listen_job,
cls);
s = accept (GNUNET_NETWORK_get_fd (unix_sock),
(struct sockaddr *) &sa,
&sa_len);
if (-1 == s)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"accept");
return;
}
#ifdef __linux__
e = eventfd (0,
EFD_CLOEXEC);
if (-1 == e)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"eventfd");
GNUNET_break (0 == close (s));
return;
}
#else
if (0 != pipe (e))
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"pipe");
GNUNET_break (0 == close (s));
return;
}
#endif
{
struct TES_Client *client;
client = GNUNET_new (struct TES_Client);
client->cb = *cb;
client->csock = s;
#ifdef __linux__
client->esock = e;
#else
client->esock_in = e[1];
client->esock_out = e[0];
#endif
GNUNET_assert (0 == pthread_mutex_lock (&TES_clients_lock));
GNUNET_CONTAINER_DLL_insert (TES_clients_head,
TES_clients_tail,
client);
GNUNET_assert (0 == pthread_mutex_unlock (&TES_clients_lock));
if (0 !=
pthread_create (&client->worker,
NULL,
&sign_worker,
client))
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"pthread_create");
TES_free_client (client);
}
}
}
int
TES_listen_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
const char *section,
const struct TES_Callbacks *cb)
{
{
char *pfn;
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_filename (cfg,
section,
"SM_PRIV_KEY",
&pfn))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
section,
"SM_PRIV_KEY");
return EXIT_NOTCONFIGURED;
}
if (GNUNET_SYSERR ==
GNUNET_CRYPTO_eddsa_key_from_file (pfn,
GNUNET_YES,
&TES_smpriv.eddsa_priv))
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
section,
"SM_PRIV_KEY",
"Could not use file to persist private key");
GNUNET_free (pfn);
return EXIT_NOPERMISSION;
}
GNUNET_free (pfn);
GNUNET_CRYPTO_eddsa_key_get_public (&TES_smpriv.eddsa_priv,
&TES_smpub.eddsa_pub);
}
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_filename (cfg,
section,
"UNIXPATH",
&unixpath))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
section,
"UNIXPATH");
return EXIT_NOTCONFIGURED;
}
GNUNET_assert (NULL != unixpath);
unix_sock = TES_open_socket (unixpath);
if (NULL == unix_sock)
{
GNUNET_free (unixpath);
GNUNET_break (0);
return EXIT_NOPERMISSION;
}
/* start job to accept incoming requests on 'sock' */
listen_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
unix_sock,
&listen_job,
(void *) cb);
return 0;
}
void
TES_listen_stop (void)
{
if (NULL != listen_task)
{
GNUNET_SCHEDULER_cancel (listen_task);
listen_task = NULL;
}
if (NULL != unix_sock)
{
GNUNET_break (GNUNET_OK ==
GNUNET_NETWORK_socket_close (unix_sock));
unix_sock = NULL;
}
if (0 != unlink (unixpath))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"unlink",
unixpath);
}
GNUNET_free (unixpath);
in_shutdown = true;
TES_wake_clients ();
}