/* This file is part of GNUnet (C) 2010, 2013 Christian Grothoff (and other contributing authors) GNUnet 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. GNUnet 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 GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file transport/plugin_transport_unix.c * @brief Transport plugin using unix domain sockets (!) * Clearly, can only be used locally on Unix/Linux hosts... * ONLY INTENDED FOR TESTING!!! * @author Christian Grothoff * @author Nathan Evans */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_statistics_service.h" #include "gnunet_transport_service.h" #include "gnunet_transport_plugin.h" #include "transport.h" /** * Return code we give on 'send' if we failed to send right now * but it makes sense to retry later. (Note: we might want to * move this to the plugin API!?). */ #define RETRY 0 #define PLUGIN_NAME "unix" enum UNIX_ADDRESS_OPTIONS { UNIX_OPTIONS_NONE = 0, UNIX_OPTIONS_USE_ABSTRACT_SOCKETS = 1 }; /** * How long until we give up on transmitting the welcome message? */ #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5) #define LOG(kind,...) GNUNET_log_from (kind, "transport-unix",__VA_ARGS__) GNUNET_NETWORK_STRUCT_BEGIN struct UnixAddress { uint32_t options GNUNET_PACKED; uint32_t addrlen GNUNET_PACKED; }; /** * UNIX Message-Packet header. */ struct UNIXMessage { /** * Message header. */ struct GNUNET_MessageHeader header; /** * What is the identity of the sender (GNUNET_hash of public key) */ struct GNUNET_PeerIdentity sender; }; GNUNET_NETWORK_STRUCT_END /** * Handle for a session. */ struct Session { struct GNUNET_PeerIdentity target; struct Plugin * plugin; struct GNUNET_HELLO_Address *address; /** * Session timeout task */ GNUNET_SCHEDULER_TaskIdentifier timeout_task; }; struct UNIXMessageWrapper { /** * We keep messages in a doubly linked list. */ struct UNIXMessageWrapper *next; /** * We keep messages in a doubly linked list. */ struct UNIXMessageWrapper *prev; /** * The actual payload (allocated separately right now). */ struct UNIXMessage * msg; /** * Session this message belongs to. */ struct Session *session; /** * Function to call upon transmission. */ GNUNET_TRANSPORT_TransmitContinuation cont; /** * Closure for 'cont'. */ void *cont_cls; /** * Timeout for this message. */ struct GNUNET_TIME_Absolute timeout; /** * Number of bytes in 'msg'. */ size_t msgsize; /** * Number of bytes of payload encapsulated in 'msg'. */ size_t payload; /** * Priority of the message (ignored, just dragged along in UNIX). */ unsigned int priority; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin; /** * UNIX "Session" */ struct PeerSession { /** * Stored in a linked list. */ struct PeerSession *next; /** * Pointer to the global plugin struct. */ struct Plugin *plugin; /** * To whom are we talking to (set to our identity * if we are still waiting for the welcome message) */ struct GNUNET_PeerIdentity target; /** * Address of the other peer (either based on our 'connect' * call or on our 'accept' call). */ void *connect_addr; /** * Length of connect_addr. */ size_t connect_alen; /** * Are we still expecting the welcome message? (GNUNET_YES/GNUNET_NO) */ int expecting_welcome; /** * From which socket do we need to send to this peer? */ struct GNUNET_NETWORK_Handle *sock; /* * Queue of messages for this peer, in the case that * we have to await a connection... */ struct MessageQueue *messages; }; /** * Information we keep for each of our listen sockets. */ struct UNIX_Sock_Info { /** * The network handle */ struct GNUNET_NETWORK_Handle *desc; /** * The port we bound to (not an actual PORT, as UNIX domain sockets * don't have ports, but rather a number in the path name to make this * one unique). */ uint16_t port; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin { /** * ID of task used to update our addresses when one expires. */ GNUNET_SCHEDULER_TaskIdentifier address_update_task; /** * ID of select task */ GNUNET_SCHEDULER_TaskIdentifier select_task; /** * Number of bytes we currently have in our write queue. */ unsigned long long bytes_in_queue; /** * Our environment. */ struct GNUNET_TRANSPORT_PluginEnvironment *env; /** * Sessions */ struct GNUNET_CONTAINER_MultiPeerMap *session_map; /** * FD Read set */ struct GNUNET_NETWORK_FDSet *rs; /** * FD Write set */ struct GNUNET_NETWORK_FDSet *ws; /** * Path of our unix domain socket (/tmp/unix-plugin-PORT) */ char *unix_socket_path; /** * Head of queue of messages to transmit. */ struct UNIXMessageWrapper *msg_head; /** * Tail of queue of messages to transmit. */ struct UNIXMessageWrapper *msg_tail; /** * socket that we transmit all data with */ struct UNIX_Sock_Info unix_sock; /** * Address options in HBO */ uint32_t myoptions; /** * ATS network */ struct GNUNET_ATS_Information ats_network; /** * Is the write set in the current 'select' task? GNUNET_NO if the * write queue was empty when the main task was scheduled, * GNUNET_YES if we're already waiting for being allowed to write. */ int with_ws; int abstract; }; /** * Increment session timeout due to activity * * @param s session for which the timeout should be moved */ static void reschedule_session_timeout (struct Session *s); /** * We have been notified that our writeset has something to read. We don't * know which socket needs to be read, so we have to check each one * Then reschedule this function to be called again once more is available. * * @param cls the plugin handle * @param tc the scheduling context (for rescheduling this function again) */ static void unix_plugin_select (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); static struct sockaddr_un * unix_address_to_sockaddr (const char *unixpath, socklen_t *sock_len) { struct sockaddr_un *un; size_t slen; GNUNET_assert (0 < strlen (unixpath)); /* sanity check */ un = GNUNET_new (struct sockaddr_un); un->sun_family = AF_UNIX; slen = strlen (unixpath); if (slen >= sizeof (un->sun_path)) slen = sizeof (un->sun_path) - 1; memcpy (un->sun_path, unixpath, slen); un->sun_path[slen] = '\0'; slen = sizeof (struct sockaddr_un); #if HAVE_SOCKADDR_IN_SIN_LEN un->sun_len = (u_char) slen; #endif (*sock_len) = slen; return un; } /** * Function called for a quick conversion of the binary address to * a numeric address. Note that the caller must not free the * address and that the next call to this function is allowed * to override the address again. * * @param cls closure * @param addr binary address * @param addrlen length of the address * @return string representing the same address */ static const char * unix_address_to_string (void *cls, const void *addr, size_t addrlen) { static char rbuf[1024]; struct UnixAddress *ua = (struct UnixAddress *) addr; char *addrstr; size_t addr_str_len; unsigned int off; if ((NULL == addr) || (sizeof (struct UnixAddress) > addrlen)) { GNUNET_break(0); return NULL ; } addrstr = (char *) &ua[1]; addr_str_len = ntohl (ua->addrlen); if (addr_str_len != addrlen - sizeof(struct UnixAddress)) { GNUNET_break(0); return NULL ; } if ('\0' != addrstr[addr_str_len - 1]) { GNUNET_break(0); return NULL ; } if (strlen (addrstr) + 1 != addr_str_len) { GNUNET_break(0); return NULL ; } off = 0; if ('\0' == addrstr[0]) off++; memset (rbuf, 0, sizeof (rbuf)); GNUNET_snprintf (rbuf, sizeof (rbuf) - 1, "%s.%u.%s%.*s", PLUGIN_NAME, ntohl (ua->options), (off == 1) ? "@" : "", (int) (addr_str_len - off), &addrstr[off]); /* GNUNET_snprintf (rbuf, sizeof(rbuf), "%s.%u.%s", PLUGIN_NAME, ntohl (ua->options), addrstr);*/ return rbuf; } /** * Re-schedule the main 'select' callback (unix_plugin_select) * for this plugin. * * @param plugin the plugin context */ static void reschedule_select (struct Plugin * plugin) { if (plugin->select_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (plugin->select_task); plugin->select_task = GNUNET_SCHEDULER_NO_TASK; } if (NULL != plugin->msg_head) { plugin->select_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, plugin->ws, &unix_plugin_select, plugin); plugin->with_ws = GNUNET_YES; } else { plugin->select_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, NULL, &unix_plugin_select, plugin); plugin->with_ws = GNUNET_NO; } } /** * Closure to #lookup_session_it. */ struct LookupCtx { /** * Location to store the session, if found. */ struct Session *res; struct GNUNET_HELLO_Address *address; }; /** * Function called to find a session by address. * * @param cls the 'struct LookupCtx' * @param key peer we are looking for (unused) * @param value a session * @return #GNUNET_YES if not found (continue looking), #GNUNET_NO on success */ static int lookup_session_it (void *cls, const struct GNUNET_PeerIdentity * key, void *value) { struct LookupCtx *lctx = cls; struct Session *s = value; if (0 == GNUNET_HELLO_address_cmp (lctx->address, s->address)) { lctx->res = s; return GNUNET_NO; } return GNUNET_YES; } /** * Find an existing session by address. * * @param plugin the plugin * @param address the address to find * @return NULL if session was not found */ static struct Session * lookup_session (struct Plugin *plugin, struct GNUNET_HELLO_Address *address) { struct LookupCtx lctx; lctx.address = address; lctx.res = NULL; GNUNET_CONTAINER_multipeermap_get_multiple (plugin->session_map, &address->peer, &lookup_session_it, &lctx); return lctx.res; } /** * Functions with this signature are called whenever we need * to close a session due to a disconnect or failure to * establish a connection. * * @param cls closure with the `struct Plugin` * @param s session to close down * @return #GNUNET_OK on success */ static int unix_session_disconnect (void *cls, struct Session *s) { struct Plugin *plugin = cls; struct UNIXMessageWrapper *msgw; struct UNIXMessageWrapper *next; int removed; LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting session for peer `%s' `%s'\n", GNUNET_i2s (&s->target), unix_address_to_string (NULL, s->address->address, s->address->address_length) ); plugin->env->session_end (plugin->env->cls, s->address, s); removed = GNUNET_NO; next = plugin->msg_head; while (NULL != next) { msgw = next; next = msgw->next; if (msgw->session != s) continue; GNUNET_CONTAINER_DLL_remove (plugin->msg_head, plugin->msg_tail, msgw); if (NULL != msgw->cont) msgw->cont (msgw->cont_cls, &msgw->session->target, GNUNET_SYSERR, msgw->payload, 0); GNUNET_free (msgw->msg); GNUNET_free (msgw); removed = GNUNET_YES; } GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (plugin->session_map, &s->target, s)); GNUNET_STATISTICS_set (plugin->env->stats, "# UNIX sessions active", GNUNET_CONTAINER_multipeermap_size (plugin->session_map), GNUNET_NO); if ((GNUNET_YES == removed) && (NULL == plugin->msg_head)) reschedule_select (plugin); if (GNUNET_SCHEDULER_NO_TASK != s->timeout_task) { GNUNET_SCHEDULER_cancel (s->timeout_task); s->timeout_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_HELLO_address_free (s->address); GNUNET_free (s); return GNUNET_OK; } /** * Function that is called to get the keepalive factor. * GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to * calculate the interval between keepalive packets. * * @param cls closure with the `struct Plugin` * @return keepalive factor */ static unsigned int unix_query_keepalive_factor (void *cls) { return 3; } /** * Actually send out the message, assume we've got the address and * send_handle squared away! * * @param cls closure * @param send_handle which handle to send message on * @param target who should receive this message (ignored by UNIX) * @param msgbuf one or more GNUNET_MessageHeader(s) strung together * @param msgbuf_size the size of the msgbuf to send * @param priority how important is the message (ignored by UNIX) * @param timeout when should we time out (give up) if we can not transmit? * @param addr the addr to send the message to, needs to be a sockaddr for us * @param addrlen the len of @a addr * @param payload bytes payload to send * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...) * @param cont_cls closure for @a cont * @return on success the number of bytes written, RETRY for retry, -1 on errors */ static ssize_t unix_real_send (void *cls, struct GNUNET_NETWORK_Handle *send_handle, const struct GNUNET_PeerIdentity *target, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Absolute timeout, const struct UnixAddress *addr, size_t addrlen, size_t payload, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; ssize_t sent; struct sockaddr_un *un; socklen_t un_len; const char *unixpath; GNUNET_assert (NULL != plugin); if (NULL == send_handle) { GNUNET_break (0); /* We do not have a send handle */ return GNUNET_SYSERR; } if ((NULL == addr) || (0 == addrlen)) { GNUNET_break (0); /* Can never send if we don't have an address */ return GNUNET_SYSERR; } /* Prepare address */ unixpath = (const char *) &addr[1]; if (NULL == (un = unix_address_to_sockaddr (unixpath, &un_len))) { GNUNET_break (0); return -1; } if ((GNUNET_YES == plugin->abstract) && (0 != (UNIX_OPTIONS_USE_ABSTRACT_SOCKETS & ntohl(addr->options) )) ) { un->sun_path[0] = '\0'; } resend: /* Send the data */ sent = GNUNET_NETWORK_socket_sendto (send_handle, msgbuf, msgbuf_size, (const struct sockaddr *) un, un_len); if (GNUNET_SYSERR == sent) { if ( (EAGAIN == errno) || (ENOBUFS == errno) ) { GNUNET_free (un); return RETRY; /* We have to retry later */ } if (EMSGSIZE == errno) { socklen_t size = 0; socklen_t len = sizeof (size); GNUNET_NETWORK_socket_getsockopt ((struct GNUNET_NETWORK_Handle *) send_handle, SOL_SOCKET, SO_SNDBUF, &size, &len); if (size < msgbuf_size) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying to increase socket buffer size from %i to %i for message size %i\n", size, ((msgbuf_size / 1000) + 2) * 1000, msgbuf_size); size = ((msgbuf_size / 1000) + 2) * 1000; if (GNUNET_OK == GNUNET_NETWORK_socket_setsockopt ((struct GNUNET_NETWORK_Handle *) send_handle, SOL_SOCKET, SO_SNDBUF, &size, sizeof (size))) goto resend; /* Increased buffer size, retry sending */ else { /* Could not increase buffer size: error, no retry */ GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "setsockopt"); GNUNET_free (un); return GNUNET_SYSERR; } } else { /* Buffer is bigger than message: error, no retry * This should never happen!*/ GNUNET_break (0); GNUNET_free (un); return GNUNET_SYSERR; } } } LOG (GNUNET_ERROR_TYPE_DEBUG, "UNIX transmit %u-byte message to %s (%d: %s)\n", (unsigned int) msgbuf_size, GNUNET_a2s ((const struct sockaddr *)un, un_len), (int) sent, (sent < 0) ? STRERROR (errno) : "ok"); GNUNET_free (un); return sent; } /** * Closure for 'get_session_it'. */ struct GetSessionIteratorContext { /** * Location to store the session, if found. */ struct Session *res; /** * Address information. */ const struct GNUNET_HELLO_Address *address; }; /** * Function called to find a session by address. * * @param cls the 'struct LookupCtx' * @param key peer we are looking for (unused) * @param value a session * @return #GNUNET_YES if not found (continue looking), #GNUNET_NO on success */ static int get_session_it (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct GetSessionIteratorContext *gsi = cls; struct Session *s = value; if (0 == GNUNET_HELLO_address_cmp(s->address, gsi->address)) { gsi->res = s; return GNUNET_NO; } return GNUNET_YES; } /** * Session was idle for too long, so disconnect it * * @param cls the 'struct Session' to disconnect * @param tc scheduler context */ static void session_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Session *s = cls; s->timeout_task = GNUNET_SCHEDULER_NO_TASK; LOG (GNUNET_ERROR_TYPE_DEBUG, "Session %p was idle for %s, disconnecting\n", s, GNUNET_STRINGS_relative_time_to_string (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_YES)); unix_session_disconnect (s->plugin, s); } /** * Function obtain the network type for a session * * @param cls closure ('struct Plugin*') * @param session the session * @return the network type in HBO or #GNUNET_SYSERR */ static enum GNUNET_ATS_Network_Type unix_get_network (void *cls, struct Session *session) { GNUNET_assert (NULL != session); return GNUNET_ATS_NET_LOOPBACK; } /** * Creates a new outbound session the transport service will use to send data to the * peer * * @param cls the plugin * @param address the address * @return the session or NULL of max connections exceeded */ static struct Session * unix_plugin_get_session (void *cls, const struct GNUNET_HELLO_Address *address) { struct Plugin *plugin = cls; struct Session *s; struct GetSessionIteratorContext gsi; struct UnixAddress *ua; char * addrstr; uint32_t addr_str_len; uint32_t addr_option; GNUNET_assert (NULL != plugin); GNUNET_assert (NULL != address); ua = (struct UnixAddress *) address->address; if ((NULL == address->address) || (0 == address->address_length) || (sizeof (struct UnixAddress) > address->address_length)) { GNUNET_break (0); return NULL; } addrstr = (char *) &ua[1]; addr_str_len = ntohl (ua->addrlen); addr_option = ntohl (ua->options); if ( (0 != (UNIX_OPTIONS_USE_ABSTRACT_SOCKETS & addr_option)) && (GNUNET_NO == plugin->abstract)) { return NULL; } if (addr_str_len != address->address_length - sizeof (struct UnixAddress)) { return NULL; /* This can be a legacy address */ } if ('\0' != addrstr[addr_str_len - 1]) { GNUNET_break (0); return NULL; } if (strlen (addrstr) + 1 != addr_str_len) { GNUNET_break (0); return NULL; } /* Check if already existing */ gsi.address = address; gsi.res = NULL; GNUNET_CONTAINER_multipeermap_get_multiple (plugin->session_map, &address->peer, &get_session_it, &gsi); if (NULL != gsi.res) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Found existing session %p for address `%s'\n", gsi.res, unix_address_to_string (NULL, address->address, address->address_length)); return gsi.res; } /* create a new session */ s = GNUNET_new (struct Session); s->target = address->peer; s->address = GNUNET_HELLO_address_copy (address); s->plugin = plugin; GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == s->timeout_task); s->timeout_task = GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, &session_timeout, s); LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating a new session %p for address `%s'\n", s, unix_address_to_string (NULL, address->address, address->address_length)); (void) GNUNET_CONTAINER_multipeermap_put (plugin->session_map, &address->peer, s, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); GNUNET_STATISTICS_set (plugin->env->stats, "# UNIX sessions active", GNUNET_CONTAINER_multipeermap_size (plugin->session_map), GNUNET_NO); return s; } static void unix_plugin_update_session_timeout (void *cls, const struct GNUNET_PeerIdentity *peer, struct Session *session) { struct Plugin *plugin = cls; if (GNUNET_OK != GNUNET_CONTAINER_multipeermap_contains_value (plugin->session_map, &session->target, session)) return; reschedule_session_timeout (session); } /** * Function that can be used by the transport service to transmit * a message using the plugin. Note that in the case of a * peer disconnecting, the continuation MUST be called * prior to the disconnect notification itself. This function * will be called with this peer's HELLO message to initiate * a fresh connection to another peer. * * @param cls closure * @param session which session must be used * @param msgbuf the message to transmit * @param msgbuf_size number of bytes in @a msgbuf * @param priority how important is the message (most plugins will * ignore message priority and just FIFO) * @param to how long to wait at most for the transmission (does not * require plugins to discard the message after the timeout, * just advisory for the desired delay; most plugins will ignore * this as well) * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...); can be NULL * @param cont_cls closure for @a cont * @return number of bytes used (on the physical network, with overheads); * -1 on hard errors (i.e. address invalid); 0 is a legal value * and does NOT mean that the message was not transmitted (DV) */ static ssize_t unix_plugin_send (void *cls, struct Session *session, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative to, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; struct UNIXMessageWrapper *wrapper; struct UNIXMessage *message; int ssize; if (GNUNET_OK != GNUNET_CONTAINER_multipeermap_contains_value (plugin->session_map, &session->target, session)) { LOG (GNUNET_ERROR_TYPE_ERROR, "Invalid session for peer `%s' `%s'\n", GNUNET_i2s (&session->target), unix_address_to_string(NULL, session->address->address, session->address->address_length)); GNUNET_break (0); return GNUNET_SYSERR; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Sending %u bytes with session for peer `%s' `%s'\n", msgbuf_size, GNUNET_i2s (&session->target), unix_address_to_string(NULL, session->address->address, session->address->address_length)); ssize = sizeof (struct UNIXMessage) + msgbuf_size; message = GNUNET_malloc (sizeof (struct UNIXMessage) + msgbuf_size); message->header.size = htons (ssize); message->header.type = htons (0); memcpy (&message->sender, plugin->env->my_identity, sizeof (struct GNUNET_PeerIdentity)); memcpy (&message[1], msgbuf, msgbuf_size); wrapper = GNUNET_new (struct UNIXMessageWrapper); wrapper->msg = message; wrapper->msgsize = ssize; wrapper->payload = msgbuf_size; wrapper->priority = priority; wrapper->timeout = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), to); wrapper->cont = cont; wrapper->cont_cls = cont_cls; wrapper->session = session; GNUNET_CONTAINER_DLL_insert (plugin->msg_head, plugin->msg_tail, wrapper); plugin->bytes_in_queue += ssize; GNUNET_STATISTICS_set (plugin->env->stats, "# bytes currently in UNIX buffers", plugin->bytes_in_queue, GNUNET_NO); if (GNUNET_NO == plugin->with_ws) reschedule_select (plugin); return ssize; } /** * Demultiplexer for UNIX messages * * @param plugin the main plugin for this transport * @param sender from which peer the message was received * @param currhdr pointer to the header of the message * @param ua address to look for * @param ua_len length of the address @a ua */ static void unix_demultiplexer (struct Plugin *plugin, struct GNUNET_PeerIdentity *sender, const struct GNUNET_MessageHeader *currhdr, const struct UnixAddress *ua, size_t ua_len) { struct Session *s = NULL; struct GNUNET_HELLO_Address *address; GNUNET_break (ntohl(plugin->ats_network.value) != GNUNET_ATS_NET_UNSPECIFIED); GNUNET_assert (ua_len >= sizeof (struct UnixAddress)); LOG (GNUNET_ERROR_TYPE_DEBUG, "Received message from %s\n", unix_address_to_string(NULL, ua, ua_len)); GNUNET_STATISTICS_update (plugin->env->stats, "# bytes received via UNIX", ntohs (currhdr->size), GNUNET_NO); /* Look for existing session */ address = GNUNET_HELLO_address_allocate (sender, PLUGIN_NAME, ua, ua_len, GNUNET_HELLO_ADDRESS_INFO_NONE); /* UNIX does not have "inbound" sessions */ s = lookup_session (plugin, address); if (NULL == s) { s = unix_plugin_get_session (plugin, address); /* Notify transport and ATS about new inbound session */ plugin->env->session_start (NULL, s->address, s, &plugin->ats_network, 1); } GNUNET_HELLO_address_free (address); reschedule_session_timeout (s); plugin->env->receive (plugin->env->cls, s->address, s, currhdr); plugin->env->update_address_metrics (plugin->env->cls, s->address, s, &plugin->ats_network, 1); } /** * Read from UNIX domain socket (it is ready). * * @param plugin the plugin */ static void unix_plugin_select_read (struct Plugin *plugin) { char buf[65536] GNUNET_ALIGN; struct UnixAddress *ua; struct UNIXMessage *msg; struct GNUNET_PeerIdentity sender; struct sockaddr_un un; socklen_t addrlen; ssize_t ret; int offset; int tsize; int is_abstract; char *msgbuf; const struct GNUNET_MessageHeader *currhdr; uint16_t csize; size_t ua_len; addrlen = sizeof (un); memset (&un, 0, sizeof (un)); ret = GNUNET_NETWORK_socket_recvfrom (plugin->unix_sock.desc, buf, sizeof (buf), (struct sockaddr *) &un, &addrlen); if ((GNUNET_SYSERR == ret) && ((errno == EAGAIN) || (errno == ENOBUFS))) return; if (ret == GNUNET_SYSERR) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "recvfrom"); return; } else { LOG (GNUNET_ERROR_TYPE_DEBUG, "Read %d bytes from socket %s\n", (int) ret, un.sun_path); } GNUNET_assert (AF_UNIX == (un.sun_family)); is_abstract = GNUNET_NO; if ('\0' == un.sun_path[0]) { un.sun_path[0] = '@'; is_abstract = GNUNET_YES; } ua_len = sizeof (struct UnixAddress) + strlen (un.sun_path) + 1; ua = GNUNET_malloc (ua_len); ua->addrlen = htonl (strlen (&un.sun_path[0]) +1); memcpy (&ua[1], &un.sun_path[0], strlen (un.sun_path) + 1); if (is_abstract) ua->options = htonl(UNIX_OPTIONS_USE_ABSTRACT_SOCKETS); else ua->options = htonl(UNIX_OPTIONS_NONE); msg = (struct UNIXMessage *) buf; csize = ntohs (msg->header.size); if ((csize < sizeof (struct UNIXMessage)) || (csize > ret)) { GNUNET_break_op (0); GNUNET_free (ua); return; } msgbuf = (char *) &msg[1]; memcpy (&sender, &msg->sender, sizeof (struct GNUNET_PeerIdentity)); offset = 0; tsize = csize - sizeof (struct UNIXMessage); while (offset + sizeof (struct GNUNET_MessageHeader) <= tsize) { currhdr = (struct GNUNET_MessageHeader *) &msgbuf[offset]; csize = ntohs (currhdr->size); if ((csize < sizeof (struct GNUNET_MessageHeader)) || (csize > tsize - offset)) { GNUNET_break_op (0); break; } unix_demultiplexer (plugin, &sender, currhdr, ua, ua_len); offset += csize; } GNUNET_free (ua); } /** * Write to UNIX domain socket (it is ready). * * @param plugin the plugin */ static void unix_plugin_select_write (struct Plugin *plugin) { int sent = 0; struct UNIXMessageWrapper * msgw; while (NULL != (msgw = plugin->msg_tail)) { if (GNUNET_TIME_absolute_get_remaining (msgw->timeout).rel_value_us > 0) break; /* Message is ready for sending */ /* Message has a timeout */ LOG (GNUNET_ERROR_TYPE_DEBUG, "Timeout for message with %u bytes \n", (unsigned int) msgw->msgsize); GNUNET_CONTAINER_DLL_remove (plugin->msg_head, plugin->msg_tail, msgw); plugin->bytes_in_queue -= msgw->msgsize; GNUNET_STATISTICS_set (plugin->env->stats, "# bytes currently in UNIX buffers", plugin->bytes_in_queue, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, "# UNIX bytes discarded", msgw->msgsize, GNUNET_NO); if (NULL != msgw->cont) msgw->cont (msgw->cont_cls, &msgw->session->target, GNUNET_SYSERR, msgw->payload, 0); GNUNET_free (msgw->msg); GNUNET_free (msgw); } if (NULL == msgw) return; /* Nothing to send at the moment */ sent = unix_real_send (plugin, plugin->unix_sock.desc, &msgw->session->target, (const char *) msgw->msg, msgw->msgsize, msgw->priority, msgw->timeout, msgw->session->address->address, msgw->session->address->address_length, msgw->payload, msgw->cont, msgw->cont_cls); if (RETRY == sent) { GNUNET_STATISTICS_update (plugin->env->stats, "# UNIX retry attempts", 1, GNUNET_NO); return; } if (GNUNET_SYSERR == sent) { /* failed and no retry */ if (NULL != msgw->cont) msgw->cont (msgw->cont_cls, &msgw->session->target, GNUNET_SYSERR, msgw->payload, 0); GNUNET_CONTAINER_DLL_remove(plugin->msg_head, plugin->msg_tail, msgw); GNUNET_assert (plugin->bytes_in_queue >= msgw->msgsize); plugin->bytes_in_queue -= msgw->msgsize; GNUNET_STATISTICS_set (plugin->env->stats, "# bytes currently in UNIX buffers", plugin->bytes_in_queue, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, "# UNIX bytes discarded", msgw->msgsize, GNUNET_NO); GNUNET_free (msgw->msg); GNUNET_free (msgw); return; } /* successfully sent bytes */ GNUNET_break (sent > 0); GNUNET_CONTAINER_DLL_remove (plugin->msg_head, plugin->msg_tail, msgw); GNUNET_assert (plugin->bytes_in_queue >= msgw->msgsize); plugin->bytes_in_queue -= msgw->msgsize; GNUNET_STATISTICS_set (plugin->env->stats, "# bytes currently in UNIX buffers", plugin->bytes_in_queue, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, "# bytes transmitted via UNIX", msgw->msgsize, GNUNET_NO); if (NULL != msgw->cont) msgw->cont (msgw->cont_cls, &msgw->session->target, GNUNET_OK, msgw->payload, msgw->msgsize); GNUNET_free (msgw->msg); GNUNET_free (msgw); } /** * We have been notified that our writeset has something to read. We don't * know which socket needs to be read, so we have to check each one * Then reschedule this function to be called again once more is available. * * @param cls the plugin handle * @param tc the scheduling context (for rescheduling this function again) */ static void unix_plugin_select (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Plugin *plugin = cls; plugin->select_task = GNUNET_SCHEDULER_NO_TASK; if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; if ((tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY) != 0) { /* Ready to send data */ GNUNET_assert (GNUNET_NETWORK_fdset_isset (tc->write_ready, plugin->unix_sock.desc)); if (NULL != plugin->msg_head) unix_plugin_select_write (plugin); } if ((tc->reason & GNUNET_SCHEDULER_REASON_READ_READY) != 0) { /* Ready to receive data */ GNUNET_assert (GNUNET_NETWORK_fdset_isset (tc->read_ready, plugin->unix_sock.desc)); unix_plugin_select_read (plugin); } reschedule_select (plugin); } /** * Create a slew of UNIX sockets. If possible, use IPv6 and IPv4. * * @param cls closure for server start, should be a struct Plugin * * @return number of sockets created or #GNUNET_SYSERR on error */ static int unix_transport_server_start (void *cls) { struct Plugin *plugin = cls; struct sockaddr_un *un; socklen_t un_len; un = unix_address_to_sockaddr (plugin->unix_socket_path, &un_len); if (GNUNET_YES == plugin->abstract) { plugin->unix_socket_path[0] = '@'; un->sun_path[0] = '\0'; } plugin->ats_network = plugin->env->get_address_type (plugin->env->cls, (const struct sockaddr *) un, un_len); plugin->unix_sock.desc = GNUNET_NETWORK_socket_create (AF_UNIX, SOCK_DGRAM, 0); if (NULL == plugin->unix_sock.desc) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "socket"); return GNUNET_SYSERR; } if ('\0' != un->sun_path[0]) { if (GNUNET_OK != GNUNET_DISK_directory_create_for_file (un->sun_path)) { LOG (GNUNET_ERROR_TYPE_ERROR, _("Cannot create path to `%s'\n"), un->sun_path); GNUNET_NETWORK_socket_close (plugin->unix_sock.desc); plugin->unix_sock.desc = NULL; GNUNET_free (un); return GNUNET_SYSERR; } } if (GNUNET_OK != GNUNET_NETWORK_socket_bind (plugin->unix_sock.desc, (const struct sockaddr *) un, un_len)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind"); GNUNET_NETWORK_socket_close (plugin->unix_sock.desc); plugin->unix_sock.desc = NULL; GNUNET_free (un); return GNUNET_SYSERR; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Bound to `%s'\n", plugin->unix_socket_path); plugin->rs = GNUNET_NETWORK_fdset_create (); plugin->ws = GNUNET_NETWORK_fdset_create (); GNUNET_NETWORK_fdset_zero (plugin->rs); GNUNET_NETWORK_fdset_zero (plugin->ws); GNUNET_NETWORK_fdset_set (plugin->rs, plugin->unix_sock.desc); GNUNET_NETWORK_fdset_set (plugin->ws, plugin->unix_sock.desc); reschedule_select (plugin); GNUNET_free (un); return 1; } /** * Function that will be called to check if a binary address for this * plugin is well-formed and corresponds to an address for THIS peer * (as per our configuration). Naturally, if absolutely necessary, * plugins can be a bit conservative in their answer, but in general * plugins should make sure that the address does not redirect * traffic to a 3rd party that might try to man-in-the-middle our * traffic. * * @param cls closure, should be our handle to the Plugin * @param addr pointer to the address * @param addrlen length of addr * @return GNUNET_OK if this is a plausible address for this peer * and transport, GNUNET_SYSERR if not * */ static int unix_check_address (void *cls, const void *addr, size_t addrlen) { struct Plugin* plugin = cls; struct UnixAddress *ua = (struct UnixAddress *) addr; char *addrstr; size_t addr_str_len; if ((NULL == addr) || (0 == addrlen) || (sizeof (struct UnixAddress) > addrlen)) { GNUNET_break (0); return GNUNET_SYSERR; } addrstr = (char *) &ua[1]; addr_str_len = ntohl (ua->addrlen); if ('\0' != addrstr[addr_str_len - 1]) { GNUNET_break (0); return GNUNET_SYSERR; } if (strlen (addrstr) + 1 != addr_str_len) { GNUNET_break (0); return GNUNET_SYSERR; } if (0 == strcmp (plugin->unix_socket_path, addrstr)) return GNUNET_OK; return GNUNET_SYSERR; } /** * Convert the transports address to a nice, human-readable * format. * * @param cls closure * @param type name of the transport that generated the address * @param addr one of the addresses of the host, NULL for the last address * the specific address format depends on the transport * @param addrlen length of the @a addr * @param numeric should (IP) addresses be displayed in numeric form? * @param timeout after how long should we give up? * @param asc function to call on each string * @param asc_cls closure for @a asc */ static void unix_plugin_address_pretty_printer (void *cls, const char *type, const void *addr, size_t addrlen, int numeric, struct GNUNET_TIME_Relative timeout, GNUNET_TRANSPORT_AddressStringCallback asc, void *asc_cls) { if ((NULL != addr) && (addrlen > 0)) { asc (asc_cls, unix_address_to_string (NULL, addr, addrlen)); } else if (0 == addrlen) { asc (asc_cls, TRANSPORT_SESSION_INBOUND_STRING); } else { GNUNET_break (0); asc (asc_cls, ""); } asc (asc_cls, NULL); } /** * Function called to convert a string address to * a binary address. * * @param cls closure ('struct Plugin*') * @param addr string address * @param addrlen length of the @a addr (strlen(addr) + '\0') * @param buf location to store the buffer * If the function returns #GNUNET_SYSERR, its contents are undefined. * @param added length of created address * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure */ static int unix_string_to_address (void *cls, const char *addr, uint16_t addrlen, void **buf, size_t *added) { struct UnixAddress *ua; char *address; char *plugin; char *optionstr; uint32_t options; size_t ua_size; /* Format unix.options.address */ address = NULL; plugin = NULL; optionstr = NULL; if ((NULL == addr) || (addrlen == 0)) { GNUNET_break (0); return GNUNET_SYSERR; } if ('\0' != addr[addrlen - 1]) { GNUNET_break (0); return GNUNET_SYSERR; } if (strlen (addr) != addrlen - 1) { GNUNET_break (0); return GNUNET_SYSERR; } plugin = GNUNET_strdup (addr); optionstr = strchr (plugin, '.'); if (NULL == optionstr) { GNUNET_break (0); GNUNET_free (plugin); return GNUNET_SYSERR; } optionstr[0] = '\0'; optionstr++; options = atol (optionstr); address = strchr (optionstr, '.'); if (NULL == address) { GNUNET_break (0); GNUNET_free (plugin); return GNUNET_SYSERR; } address[0] = '\0'; address++; if (0 != strcmp(plugin, PLUGIN_NAME)) { GNUNET_break (0); GNUNET_free (plugin); return GNUNET_SYSERR; } ua_size = sizeof (struct UnixAddress) + strlen (address) + 1; ua = GNUNET_malloc (ua_size); ua->options = htonl (options); ua->addrlen = htonl (strlen (address) + 1); memcpy (&ua[1], address, strlen (address) + 1); GNUNET_free (plugin); (*buf) = ua; (*added) = ua_size; return GNUNET_OK; } /** * Notify transport service about address * * @param cls the plugin * @param tc unused */ static void address_notification (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Plugin *plugin = cls; struct GNUNET_HELLO_Address *address; size_t len; struct UnixAddress *ua; char *unix_path; len = sizeof (struct UnixAddress) + strlen (plugin->unix_socket_path) + 1; ua = GNUNET_malloc (len); ua->options = htonl (plugin->myoptions); ua->addrlen = htonl(strlen (plugin->unix_socket_path) + 1); unix_path = (char *) &ua[1]; memcpy (unix_path, plugin->unix_socket_path, strlen (plugin->unix_socket_path) + 1); plugin->address_update_task = GNUNET_SCHEDULER_NO_TASK; address = GNUNET_HELLO_address_allocate (plugin->env->my_identity, PLUGIN_NAME, ua, len, GNUNET_HELLO_ADDRESS_INFO_NONE); plugin->env->notify_address (plugin->env->cls, GNUNET_YES, address); GNUNET_free (ua); GNUNET_free (address); } /** * Increment session timeout due to activity * * @param s session for which the timeout should be rescheduled */ static void reschedule_session_timeout (struct Session *s) { GNUNET_assert (NULL != s); GNUNET_assert (GNUNET_SCHEDULER_NO_TASK != s->timeout_task); GNUNET_SCHEDULER_cancel (s->timeout_task); s->timeout_task = GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, &session_timeout, s); LOG (GNUNET_ERROR_TYPE_DEBUG, "Timeout rescheduled for session %p set to %s\n", s, GNUNET_STRINGS_relative_time_to_string (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_YES)); } /** * Function called on sessions to disconnect * * @param cls the plugin * @param key peer identity (unused) * @param value the 'struct Session' to disconnect * @return #GNUNET_YES (always, continue to iterate) */ static int get_session_delete_it (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct Plugin *plugin = cls; struct Session *s = value; unix_session_disconnect (plugin, s); return GNUNET_YES; } /** * Disconnect from a remote node. Clean up session if we have one for this peer * * @param cls closure for this call (should be handle to Plugin) * @param target the peeridentity of the peer to disconnect * @return #GNUNET_OK on success, #GNUNET_SYSERR if the operation failed */ static void unix_peer_disconnect (void *cls, const struct GNUNET_PeerIdentity *target) { struct Plugin *plugin = cls; GNUNET_assert (plugin != NULL); GNUNET_CONTAINER_multipeermap_get_multiple (plugin->session_map, target, &get_session_delete_it, plugin); } /** * The exported method. Initializes the plugin and returns a * struct with the callbacks. * * @param cls the plugin's execution environment * @return NULL on error, plugin functions otherwise */ void * libgnunet_plugin_transport_unix_init (void *cls) { struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; struct GNUNET_TRANSPORT_PluginFunctions *api; struct Plugin *plugin; int sockets_created; if (NULL == env->receive) { /* run in 'stub' mode (i.e. as part of gnunet-peerinfo), don't fully initialze the plugin or the API */ api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); api->cls = NULL; api->address_pretty_printer = &unix_plugin_address_pretty_printer; api->address_to_string = &unix_address_to_string; api->string_to_address = &unix_string_to_address; return api; } plugin = GNUNET_new (struct Plugin); if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename(env->cfg, "transport-unix", "UNIXPATH", &plugin->unix_socket_path)) { LOG (GNUNET_ERROR_TYPE_ERROR, _("No UNIXPATH given in configuration!\n")); GNUNET_free (plugin); return NULL; } plugin->env = env; /* Initialize my flags */ #ifdef LINUX plugin->abstract = GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg, "testing", "USE_ABSTRACT_SOCKETS"); #endif plugin->myoptions = UNIX_OPTIONS_NONE; if (GNUNET_YES == plugin->abstract) { plugin->myoptions = UNIX_OPTIONS_USE_ABSTRACT_SOCKETS; } api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); api->cls = plugin; api->get_session = &unix_plugin_get_session; api->send = &unix_plugin_send; api->disconnect_peer = &unix_peer_disconnect; api->disconnect_session = &unix_session_disconnect; api->query_keepalive_factor = &unix_query_keepalive_factor; api->address_pretty_printer = &unix_plugin_address_pretty_printer; api->address_to_string = &unix_address_to_string; api->check_address = &unix_check_address; api->string_to_address = &unix_string_to_address; api->get_network = &unix_get_network; api->update_session_timeout = &unix_plugin_update_session_timeout; sockets_created = unix_transport_server_start (plugin); if ((0 == sockets_created) || (GNUNET_SYSERR == sockets_created)) { LOG (GNUNET_ERROR_TYPE_WARNING, _("Failed to open UNIX listen socket\n")); GNUNET_free (api); GNUNET_free (plugin->unix_socket_path); GNUNET_free (plugin); return NULL; } plugin->session_map = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO); plugin->address_update_task = GNUNET_SCHEDULER_add_now (&address_notification, plugin); return api; } /** * Shutdown the plugin. * * @param cls the plugin API returned from the initialization function * @return NULL (always) */ void * libgnunet_plugin_transport_unix_done (void *cls) { struct GNUNET_TRANSPORT_PluginFunctions *api = cls; struct Plugin *plugin = api->cls; struct GNUNET_HELLO_Address *address; struct UNIXMessageWrapper * msgw; struct UnixAddress *ua; size_t len; if (NULL == plugin) { GNUNET_free (api); return NULL; } len = sizeof (struct UnixAddress) + strlen (plugin->unix_socket_path) + 1; ua = GNUNET_malloc (len); ua->options = htonl (plugin->myoptions); ua->addrlen = htonl(strlen (plugin->unix_socket_path) + 1); memcpy (&ua[1], plugin->unix_socket_path, strlen (plugin->unix_socket_path) + 1); address = GNUNET_HELLO_address_allocate (plugin->env->my_identity, PLUGIN_NAME, ua, len, GNUNET_HELLO_ADDRESS_INFO_NONE); plugin->env->notify_address (plugin->env->cls, GNUNET_NO, address); GNUNET_free (address); GNUNET_free (ua); while (NULL != (msgw = plugin->msg_head)) { GNUNET_CONTAINER_DLL_remove (plugin->msg_head, plugin->msg_tail, msgw); if (msgw->cont != NULL) msgw->cont (msgw->cont_cls, &msgw->session->target, GNUNET_SYSERR, msgw->payload, 0); GNUNET_free (msgw->msg); GNUNET_free (msgw); } if (GNUNET_SCHEDULER_NO_TASK != plugin->select_task) { GNUNET_SCHEDULER_cancel (plugin->select_task); plugin->select_task = GNUNET_SCHEDULER_NO_TASK; } if (GNUNET_SCHEDULER_NO_TASK != plugin->address_update_task) { GNUNET_SCHEDULER_cancel (plugin->address_update_task); plugin->address_update_task = GNUNET_SCHEDULER_NO_TASK; } if (NULL != plugin->unix_sock.desc) { GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (plugin->unix_sock.desc)); plugin->unix_sock.desc = NULL; plugin->with_ws = GNUNET_NO; } GNUNET_CONTAINER_multipeermap_iterate (plugin->session_map, &get_session_delete_it, plugin); GNUNET_CONTAINER_multipeermap_destroy (plugin->session_map); if (NULL != plugin->rs) GNUNET_NETWORK_fdset_destroy (plugin->rs); if (NULL != plugin->ws) GNUNET_NETWORK_fdset_destroy (plugin->ws); GNUNET_free (plugin->unix_socket_path); GNUNET_free (plugin); GNUNET_free (api); return NULL; } /* end of plugin_transport_unix.c */