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/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */
#include "or.h"
extern int global_role; /* from main.c */
int connection_ap_process_inbuf(connection_t *conn) {
assert(conn && conn->type == CONN_TYPE_AP);
if(conn->inbuf_reached_eof) {
/* eof reached, kill it. */
log(LOG_DEBUG,"connection_ap_process_inbuf(): conn reached eof. Closing.");
return -1;
}
// log(LOG_DEBUG,"connection_ap_process_inbuf(): state %d.",conn->state);
switch(conn->state) {
case AP_CONN_STATE_SOCKS_WAIT:
return ap_handshake_process_socks(conn);
case AP_CONN_STATE_OPEN:
if(connection_package_raw_inbuf(conn) < 0)
return -1;
circuit_consider_stop_edge_reading(circuit_get_by_conn(conn), EDGE_AP);
return 0;
default:
log(LOG_DEBUG,"connection_ap_process_inbuf() called in state where I'm waiting. Ignoring buf for now.");
}
return 0;
}
int ap_handshake_process_socks(connection_t *conn) {
char c;
socks4_t socks4_info;
circuit_t *circ;
assert(conn);
log(LOG_DEBUG,"ap_handshake_process_socks() entered.");
if(!conn->socks_version) { /* try to pull it in */
if(conn->inbuf_datalen < sizeof(socks4_t)) /* basic info available? */
return 0; /* not yet */
if(connection_fetch_from_buf((char *)&socks4_info,sizeof(socks4_t),conn) < 0)
return -1;
log(LOG_DEBUG,"ap_handshake_process_socks(): Successfully read socks info.");
if(socks4_info.version != 4) {
log(LOG_NOTICE,"ap_handshake_process_socks(): Unrecognized version %d.",socks4_info.version);
ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
return -1;
}
conn->socks_version = socks4_info.version;
if(socks4_info.command != 1) { /* not a connect? we don't support it. */
log(LOG_NOTICE,"ap_handshake_process_socks(): command %d not '1'.",socks4_info.command);
ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
return -1;
}
conn->dest_port = ntohs(*(uint16_t*)&socks4_info.destport);
if(!conn->dest_port) {
log(LOG_NOTICE,"ap_handshake_process_socks(): Port is zero.");
ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
return -1;
}
log(LOG_NOTICE,"ap_handshake_process_socks(): Dest port is %d.",conn->dest_port);
if(socks4_info.destip[0] ||
socks4_info.destip[1] ||
socks4_info.destip[2] ||
!socks4_info.destip[3]) { /* not 0.0.0.x */
log(LOG_NOTICE,"ap_handshake_process_socks(): destip not in form 0.0.0.x.");
sprintf(conn->dest_tmp, "%d.%d.%d.%d", socks4_info.destip[0],
socks4_info.destip[1], socks4_info.destip[2], socks4_info.destip[3]);
conn->dest_addr = strdup(conn->dest_tmp);
log(LOG_DEBUG,"ap_handshake_process_socks(): Successfully read destip (%s)", conn->dest_addr);
}
}
if(!conn->read_username) { /* the socks spec says we've got to read stuff until we get a null */
for(;;) {
if(!conn->inbuf_datalen)
return 0; /* maybe next time */
if(connection_fetch_from_buf((char *)&c,1,conn) < 0)
return -1;
if(!c) {
conn->read_username = 1;
log(LOG_DEBUG,"ap_handshake_process_socks(): Successfully read username.");
break;
}
}
}
if(!conn->dest_addr) { /* no dest_addr found yet */
for(;;) {
if(!conn->inbuf_datalen)
return 0; /* maybe next time */
if(connection_fetch_from_buf((char *)&c,1,conn) < 0)
return -1;
conn->dest_tmp[conn->dest_tmplen++] = c;
if(conn->dest_tmplen > 500) {
log(LOG_NOTICE,"ap_handshake_process_socks(): dest_addr too long!");
ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
return -1;
}
if(!c) { /* we found the null; we're done */
conn->dest_addr = strdup(conn->dest_tmp);
log(LOG_NOTICE,"ap_handshake_process_socks(): successfully read dest addr '%s'",
conn->dest_addr);
break;
}
}
}
/* find the circuit that we should use, if there is one. */
circ = circuit_get_by_edge_type(EDGE_AP);
/* now we're all ready to make an onion or send a begin */
if(circ && circ->state == CIRCUIT_STATE_OPEN) {
/* FIXME if circ not yet open, figure out how to queue this begin? */
/* add it into the linked list of topics on this circuit */
log(LOG_DEBUG,"ap_handshake_process_socks(): attaching new conn to circ. n_aci %d.", circ->n_aci);
conn->next_topic = circ->p_conn;
circ->p_conn = conn;
if(ap_handshake_send_begin(conn, circ) < 0) {
circuit_close(circ);
return -1;
}
} else {
if(ap_handshake_create_onion(conn) < 0) {
if(circ)
circuit_close(circ);
return -1;
}
}
return 0;
}
int ap_handshake_create_onion(connection_t *conn) {
int i;
int routelen = 0; /* length of the route */
unsigned int *route = NULL; /* hops in the route as an array of indexes into rarray */
unsigned char *onion = NULL; /* holds the onion */
int onionlen = 0; /* onion length in host order */
crypt_path_t **cpath = NULL; /* defines the crypt operations that need to be performed on incoming/outgoing data */
assert(conn);
/* choose a route */
route = (unsigned int *)router_new_route(&routelen);
if (!route) {
log(LOG_ERR,"ap_handshake_create_onion(): Error choosing a route through the OR network.");
return -1;
}
log(LOG_DEBUG,"ap_handshake_create_onion(): Chosen a route of length %u : ",routelen);
#if 0
for (i=routelen-1;i>=0;i--)
{
log(LOG_DEBUG,"ap_handshake_process_ss() : %u : %s:%u, %u",routelen-i,(routerarray[route[i]])->address,ntohs((routerarray[route[i]])->port),RSA_size((routerarray[route[i]])->pkey));
}
#endif
/* allocate memory for the crypt path */
cpath = malloc(routelen * sizeof(crypt_path_t *));
if (!cpath) {
log(LOG_ERR,"ap_handshake_create_onion(): Error allocating memory for cpath.");
free(route);
return -1;
}
/* create an onion and calculate crypto keys */
onion = router_create_onion(route,routelen,&onionlen,cpath);
if (!onion) {
log(LOG_ERR,"ap_handshake_create_onion(): Error creating an onion.");
free(route);
free(cpath); /* it's got nothing in it, since !onion */
return -1;
}
log(LOG_DEBUG,"ap_handshake_create_onion(): Created an onion of size %u bytes.",onionlen);
log(LOG_DEBUG,"ap_handshake_create_onion(): Crypt path :");
for (i=0;i<routelen;i++) {
log(LOG_DEBUG,"ap_handshake_create_onion() : %u/%u",(cpath[i])->forwf, (cpath[i])->backf);
}
return ap_handshake_establish_circuit(conn, route, routelen, onion, onionlen, cpath);
}
int ap_handshake_establish_circuit(connection_t *conn, unsigned int *route, int routelen, char *onion,
int onionlen, crypt_path_t **cpath) {
routerinfo_t *firsthop;
connection_t *n_conn;
circuit_t *circ;
/* now see if we're already connected to the first OR in 'route' */
firsthop = router_get_first_in_route(route, routelen);
assert(firsthop); /* should always be defined */
free(route); /* we don't need it anymore */
circ = circuit_new(0, conn); /* sets circ->p_aci and circ->p_conn */
circ->state = CIRCUIT_STATE_OR_WAIT;
circ->onion = onion;
circ->onionlen = onionlen;
circ->cpath = cpath;
circ->cpathlen = routelen;
log(LOG_DEBUG,"ap_handshake_establish_circuit(): Looking for firsthop '%s:%u'",
firsthop->address,firsthop->or_port);
n_conn = connection_twin_get_by_addr_port(firsthop->addr,firsthop->or_port);
if(!n_conn || n_conn->state != OR_CONN_STATE_OPEN) { /* not currently connected */
circ->n_addr = firsthop->addr;
circ->n_port = firsthop->or_port;
if(global_role & ROLE_OR_CONNECT_ALL) { /* we would be connected if he were up. but he's not. */
log(LOG_DEBUG,"ap_handshake_establish_circuit(): Route's firsthop isn't connected.");
circuit_close(circ);
return -1;
}
conn->state = AP_CONN_STATE_OR_WAIT;
connection_stop_reading(conn); /* Stop listening for input from the AP! */
if(!n_conn) { /* launch the connection */
n_conn = connection_or_connect_as_op(firsthop);
if(!n_conn) { /* connect failed, forget the whole thing */
log(LOG_DEBUG,"ap_handshake_establish_circuit(): connect to firsthop failed. Closing.");
circuit_close(circ);
return -1;
}
}
return 0; /* return success. The onion/circuit/etc will be taken care of automatically
* (may already have been) whenever n_conn reaches OR_CONN_STATE_OPEN.
*/
} else { /* it (or a twin) is already open. use it. */
circ->n_addr = n_conn->addr;
circ->n_port = n_conn->port;
return ap_handshake_send_onion(conn, n_conn, circ);
}
}
/* find circuits that are waiting on me, if any, and get them to send the onion */
void ap_handshake_n_conn_open(connection_t *or_conn) {
circuit_t *circ;
connection_t *p_conn;
log(LOG_DEBUG,"ap_handshake_n_conn_open(): Starting.");
circ = circuit_enumerate_by_naddr_nport(NULL, or_conn->addr, or_conn->port);
for(;;) {
if(!circ)
return;
p_conn = circ->p_conn;
if(p_conn->state != AP_CONN_STATE_OR_WAIT) {
log(LOG_WARNING,"Bug: ap_handshake_n_conn_open() got an ap_conn not in OR_WAIT state.");
}
connection_start_reading(p_conn); /* resume listening for reads */
log(LOG_DEBUG,"ap_handshake_n_conn_open(): Found circ, sending onion.");
if(ap_handshake_send_onion(p_conn, or_conn, circ) < 0) {
log(LOG_DEBUG,"ap_handshake_n_conn_open(): circuit marked for closing.");
circuit_close(circ);
return; /* FIXME will want to try the other circuits too? */
}
for(p_conn = p_conn->next_topic; p_conn; p_conn = p_conn->next_topic) { /* start up any other pending topics */
if(ap_handshake_send_begin(p_conn, circ) < 0) {
circuit_close(circ);
return;
}
}
circ = circuit_enumerate_by_naddr_nport(circ, or_conn->addr, or_conn->port);
}
}
int ap_handshake_send_onion(connection_t *ap_conn, connection_t *n_conn, circuit_t *circ) {
cell_t cell;
int tmpbuflen, dataleft;
char *tmpbuf;
circ->n_aci = get_unique_aci_by_addr_port(circ->n_addr, circ->n_port, ACI_TYPE_BOTH);
circ->n_conn = n_conn;
log(LOG_DEBUG,"ap_handshake_send_onion(): n_conn is %s:%u",n_conn->address,n_conn->port);
/* deliver the onion as one or more create cells */
cell.command = CELL_CREATE;
cell.aci = circ->n_aci;
tmpbuflen = circ->onionlen+4;
tmpbuf = malloc(tmpbuflen);
if(!tmpbuf)
return -1;
*(uint32_t*)tmpbuf = htonl(circ->onionlen);
memcpy(tmpbuf+4, circ->onion, circ->onionlen);
dataleft = tmpbuflen;
while(dataleft) {
cell.command = CELL_CREATE;
cell.aci = circ->n_aci;
log(LOG_DEBUG,"ap_handshake_send_onion(): Sending a create cell for the onion...");
if(dataleft >= CELL_PAYLOAD_SIZE) {
cell.length = CELL_PAYLOAD_SIZE;
memcpy(cell.payload, tmpbuf + tmpbuflen - dataleft, CELL_PAYLOAD_SIZE);
connection_write_cell_to_buf(&cell, n_conn);
dataleft -= CELL_PAYLOAD_SIZE;
} else { /* last cell */
cell.length = dataleft;
memcpy(cell.payload, tmpbuf + tmpbuflen - dataleft, dataleft);
/* fill extra space with 0 bytes */
memset(cell.payload + dataleft, 0, CELL_PAYLOAD_SIZE - dataleft);
connection_write_cell_to_buf(&cell, n_conn);
dataleft = 0;
}
}
free(tmpbuf);
if(ap_handshake_send_begin(ap_conn, circ) < 0) {
return -1;
}
circ->state = CIRCUIT_STATE_OPEN;
/* FIXME should set circ->expire to something here */
return 0;
}
int ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ) {
cell_t cell;
memset(&cell, 0, sizeof(cell_t));
/* deliver the dest_addr in a data cell */
cell.command = CELL_DATA;
cell.aci = circ->n_aci;
crypto_pseudo_rand(2, cell.payload+2); /* bytes 0-1 is blank, bytes 2-3 are random */
/* FIXME check for collisions */
ap_conn->topic_id = ntohs(*(uint16_t *)(cell.payload+2));
cell.payload[0] = TOPIC_COMMAND_BEGIN;
snprintf(cell.payload+4, CELL_PAYLOAD_SIZE-4, "%s,%d", ap_conn->dest_addr, ap_conn->dest_port);
cell.length = strlen(cell.payload+TOPIC_HEADER_SIZE)+1+TOPIC_HEADER_SIZE;
log(LOG_DEBUG,"ap_handshake_send_begin(): Sending data cell to begin topic %d.", ap_conn->topic_id);
if(circuit_deliver_data_cell_from_edge(&cell, circ, EDGE_AP) < 0) {
log(LOG_DEBUG,"ap_handshake_send_begin(): failed to deliver begin cell. Closing.");
return -1;
}
ap_conn->n_receive_topicwindow = TOPICWINDOW_START;
ap_conn->p_receive_topicwindow = TOPICWINDOW_START;
ap_conn->state = AP_CONN_STATE_OPEN;
log(LOG_INFO,"ap_handshake_send_begin(): Address/port sent, ap socket %d, n_aci %d",ap_conn->s,circ->n_aci);
return 0;
}
int ap_handshake_socks_reply(connection_t *conn, char result) {
socks4_t socks4_info;
assert(conn);
socks4_info.version = 0;
socks4_info.command = result;
socks4_info.destport[0] = socks4_info.destport[1] = 0;
socks4_info.destip[0] = socks4_info.destip[1] = socks4_info.destip[2] = socks4_info.destip[3] = 0;
if(connection_write_to_buf((char *)&socks4_info, sizeof(socks4_t), conn) < 0)
return -1;
return connection_flush_buf(conn); /* try to flush it, in case we're about to close the conn */
}
int connection_ap_process_data_cell(cell_t *cell, circuit_t *circ) {
connection_t *conn;
int topic_command;
int topic_id;
static int num_seen=0;
/* an incoming data cell has arrived */
assert(cell && circ);
topic_command = *cell->payload;
topic_id = ntohs(*(uint16_t *)(cell->payload+2));
log(LOG_DEBUG,"connection_ap_process_data_cell(): command %d topic %d", topic_command, topic_id);
num_seen++;
log(LOG_DEBUG,"connection_ap_process_data_cell(): Now seen %d data cells here.", num_seen);
circuit_consider_sending_sendme(circ, EDGE_AP);
for(conn = circ->p_conn; conn && conn->topic_id != topic_id; conn = conn->next_topic) ;
/* now conn is either NULL, in which case we don't recognize the topic_id, or
* it is set, in which case cell is talking about this conn.
*/
if(conn && conn->state != AP_CONN_STATE_OPEN) {
/* we should not have gotten this cell */
log(LOG_DEBUG,"connection_ap_process_data_cell(): Got a data cell when not in 'open' state. Dropping.");
return 0;
}
switch(topic_command) {
case TOPIC_COMMAND_BEGIN:
log(LOG_INFO,"connection_ap_process_data_cell(): topic begin request unsupported. Dropping.");
break;
case TOPIC_COMMAND_DATA:
if(!conn) {
log(LOG_DEBUG,"connection_ap_process_data_cell(): data cell dropped, unknown topic %d.",topic_id);
return 0;
}
if(--conn->n_receive_topicwindow < 0) { /* is it below 0 after decrement? */
log(LOG_DEBUG,"connection_ap_process_data_cell(): receive_topicwindow at exit below 0. Killing.");
return -1; /* exit node breaking protocol. kill the whole circuit. */
}
log(LOG_DEBUG,"connection_ap_process_data_cell(): willing to receive %d more cells from circ",conn->n_receive_topicwindow);
#ifdef USE_ZLIB
if(connection_decompress_to_buf(cell->payload + TOPIC_HEADER_SIZE,
cell->length - TOPIC_HEADER_SIZE,
conn, Z_SYNC_FLUSH) < 0) {
log(LOG_INFO,"connection_exit_process_data_cell(): write to buf failed. Marking for close.");
conn->marked_for_close = 1;
return 0;
}
#else
if(connection_write_to_buf(cell->payload + TOPIC_HEADER_SIZE,
cell->length - TOPIC_HEADER_SIZE, conn) < 0) {
conn->marked_for_close = 1;
return 0;
}
#endif
if(connection_consider_sending_sendme(conn, EDGE_AP) < 0)
conn->marked_for_close = 1;
return 0;
case TOPIC_COMMAND_END:
if(!conn) {
log(LOG_DEBUG,"connection_ap_process_data_cell(): end cell dropped, unknown topic %d.",topic_id);
return 0;
}
log(LOG_DEBUG,"connection_ap_process_data_cell(): end cell for topic %d. Removing topic.",topic_id);
/* go through and identify who points to conn. remove conn from the list. */
#if 0
if(conn == circ->p_conn) {
circ->p_conn = conn->next_topic;
}
for(prevconn = circ->p_conn; prevconn->next_topic != conn; prevconn = prevconn->next_topic) ;
prevconn->next_topic = conn->next_topic;
#endif
#if 0
conn->done_sending = 1;
shutdown(conn->s, 1); /* XXX check return; refactor NM */
if (conn->done_receiving)
conn->marked_for_close = 1;
#endif
conn->marked_for_close = 1;
break;
case TOPIC_COMMAND_CONNECTED:
if(!conn) {
log(LOG_DEBUG,"connection_ap_process_data_cell(): connected cell dropped, unknown topic %d.",topic_id);
break;
}
log(LOG_DEBUG,"connection_ap_process_data_cell(): Connected! Notifying application.");
if(ap_handshake_socks_reply(conn, SOCKS4_REQUEST_GRANTED) < 0) {
conn->marked_for_close = 1;
}
break;
case TOPIC_COMMAND_SENDME:
if(!conn) {
log(LOG_DEBUG,"connection_ap_process_data_cell(): sendme cell dropped, unknown topic %d.",topic_id);
return 0;
}
conn->p_receive_topicwindow += TOPICWINDOW_INCREMENT;
connection_start_reading(conn);
connection_package_raw_inbuf(conn); /* handle whatever might still be on the inbuf */
circuit_consider_stop_edge_reading(circ, EDGE_AP);
break;
default:
log(LOG_DEBUG,"connection_ap_process_data_cell(): unknown topic command %d.",topic_command);
}
return 0;
}
int connection_ap_finished_flushing(connection_t *conn) {
assert(conn && conn->type == CONN_TYPE_AP);
switch(conn->state) {
case AP_CONN_STATE_OPEN:
/* FIXME down the road, we'll clear out circuits that are pending to close */
connection_stop_writing(conn);
return connection_consider_sending_sendme(conn, EDGE_AP);
default:
log(LOG_DEBUG,"Bug: connection_ap_finished_flushing() called in unexpected state.");
return 0;
}
return 0;
}
int connection_ap_create_listener(struct sockaddr_in *bindaddr) {
log(LOG_DEBUG,"connection_create_ap_listener starting");
return connection_create_listener(bindaddr, CONN_TYPE_AP_LISTENER);
}
int connection_ap_handle_listener_read(connection_t *conn) {
log(LOG_NOTICE,"AP: Received a connection request. Waiting for socksinfo.");
return connection_handle_listener_read(conn, CONN_TYPE_AP, AP_CONN_STATE_SOCKS_WAIT);
}
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