tor/src/or/connection_exit.c
2003-03-19 21:59:07 +00:00

390 lines
13 KiB
C

/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */
#include "or.h"
int connection_exit_process_inbuf(connection_t *conn) {
circuit_t *circ;
cell_t cell;
assert(conn && conn->type == CONN_TYPE_EXIT);
if(conn->inbuf_reached_eof) {
#ifdef HALF_OPEN
/* XXX!!! If this is right, duplicate it in connection_ap.c */
/* eof reached; we're done reading, but we might want to write more. */
conn->done_receiving = 1;
shutdown(conn->s, 0); /* XXX check return, refactor NM */
if (conn->done_sending)
conn->marked_for_close = 1;
/* XXX Factor out common logic here and in circuit_about_to_close NM */
circ = circuit_get_by_conn(conn);
if (!circ)
return -1;
memset(&cell, 0, sizeof(cell_t));
cell.command = CELL_DATA;
cell.length = TOPIC_HEADER_SIZE;
*(uint16_t *)(cell.payload+2) = htons(conn->topic_id);
*cell.payload = TOPIC_COMMAND_END;
cell.aci = circ->p_aci;
if (circuit_deliver_data_cell_from_edge(&cell, circ, EDGE_EXIT) < 0) {
log(LOG_DEBUG,"connection_exit_process_inbuf: circuit_deliver_data_cell_from_edge failed. Closing");
circuit_close(circ);
}
return 0;
#else
/* eof reached, kill it. */
log(LOG_DEBUG,"connection_exit_process_inbuf(): conn reached eof. Closing.");
return -1;
#endif
}
log(LOG_DEBUG,"connection_exit_process_inbuf(): state %d.",conn->state);
switch(conn->state) {
case EXIT_CONN_STATE_CONNECTING:
log(LOG_DEBUG,"connection_exit_process_inbuf(): text from server while in 'connecting' state. Leaving it on buffer.");
return 0;
case EXIT_CONN_STATE_OPEN:
if(connection_package_raw_inbuf(conn) < 0)
return -1;
circuit_consider_stop_edge_reading(circuit_get_by_conn(conn), EDGE_EXIT);
return 0;
}
return 0;
}
int connection_exit_finished_flushing(connection_t *conn) {
int e, len=sizeof(e);
assert(conn && conn->type == CONN_TYPE_EXIT);
switch(conn->state) {
case EXIT_CONN_STATE_CONNECTING:
if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, &e, &len) < 0) { /* not yet */
if(errno != EINPROGRESS){
/* yuck. kill it. */
log(LOG_DEBUG,"connection_exit_finished_flushing(): in-progress connect failed. Removing.");
return -1;
} else {
log(LOG_DEBUG,"connection_exit_finished_flushing(): in-progress connect still waiting.");
return 0; /* no change, see if next time is better */
}
}
/* the connect has finished. */
log(LOG_DEBUG,"connection_exit_finished_flushing(): Connection to %s:%u established.",
conn->address,conn->port);
conn->state = EXIT_CONN_STATE_OPEN;
connection_watch_events(conn, POLLIN); /* stop writing, continue reading */
if(connection_wants_to_flush(conn)) /* in case there are any queued data cells */
connection_start_writing(conn);
return
connection_exit_send_connected(conn) || /* deliver a 'connected' data cell back through the circuit. */
connection_process_inbuf(conn); /* in case the server has written anything */
case EXIT_CONN_STATE_OPEN:
/* FIXME down the road, we'll clear out circuits that are pending to close */
log(LOG_DEBUG,"connection_exit_finished_flushing(): finished flushing.");
connection_stop_writing(conn);
#ifdef USE_ZLIB
if (connection_decompress_to_buf(NULL, 0, conn, Z_SYNC_FLUSH) < 0)
return -1;
#endif
connection_consider_sending_sendme(conn, EDGE_EXIT);
return 0;
default:
log(LOG_DEBUG,"Bug: connection_exit_finished_flushing() called in unexpected state.");
return 0;
}
return 0;
}
int connection_exit_send_connected(connection_t *conn) {
circuit_t *circ;
cell_t cell;
assert(conn);
circ = circuit_get_by_conn(conn);
if(!circ) {
log(LOG_DEBUG,"connection_exit_send_connected(): client-side sent destroy just as we completed server connection. Closing.");
return -1;
}
memset(&cell, 0, sizeof(cell_t));
cell.aci = circ->p_aci;
cell.command = CELL_DATA;
*(uint16_t *)(cell.payload+2) = htons(conn->topic_id);
*cell.payload = TOPIC_COMMAND_CONNECTED;
cell.length = TOPIC_HEADER_SIZE;
log(LOG_INFO,"connection_exit_send_connected(): passing back cell (aci %d).",circ->p_aci);
if(circuit_deliver_data_cell_from_edge(&cell, circ, EDGE_EXIT) < 0) {
log(LOG_DEBUG,"connection_exit_send_connected(): circuit_deliver_data_cell (backward) failed. Closing.");
circuit_close(circ);
return 0;
}
return 0;
}
int connection_exit_begin_conn(cell_t *cell, circuit_t *circ) {
connection_t *n_conn;
char *comma;
if(!memchr(cell->payload + TOPIC_HEADER_SIZE,0,cell->length - TOPIC_HEADER_SIZE)) {
log(LOG_WARNING,"connection_exit_begin_conn(): topic begin cell has no \\0. Dropping.");
return 0;
}
comma = strchr(cell->payload + TOPIC_HEADER_SIZE, ',');
if(!comma) {
log(LOG_WARNING,"connection_exit_begin_conn(): topic begin cell has no comma. Dropping.");
return 0;
}
*comma = 0;
if(!atoi(comma+1)) { /* bad port */
log(LOG_DEBUG,"connection_exit_begin_conn(): topic begin cell has invalid port. Dropping.");
return 0;
}
log(LOG_DEBUG,"connection_exit_begin_conn(): Creating new exit connection.");
n_conn = connection_new(CONN_TYPE_EXIT);
if(!n_conn) {
log(LOG_DEBUG,"connection_exit_begin_conn(): connection_new failed. Dropping.");
return 0;
}
cell->payload[0] = 0;
n_conn->topic_id = ntohs(*(uint16_t *)(cell->payload+2));
n_conn->address = strdup(cell->payload + TOPIC_HEADER_SIZE);
n_conn->port = atoi(comma+1);
n_conn->state = EXIT_CONN_STATE_RESOLVING;
n_conn->receiver_bucket = -1; /* edge connections don't do receiver buckets */
n_conn->bandwidth = -1;
n_conn->s = -1; /* not yet valid */
n_conn->n_receive_topicwindow = TOPICWINDOW_START;
n_conn->p_receive_topicwindow = TOPICWINDOW_START;
if(connection_add(n_conn) < 0) { /* no space, forget it */
log(LOG_DEBUG,"connection_exit_begin_conn(): connection_add failed. Dropping.");
connection_free(n_conn);
return 0;
}
/* add it into the linked list of topics on this circuit */
n_conn->next_topic = circ->n_conn;
circ->n_conn = n_conn;
/* send it off to the gethostbyname farm */
if(dns_resolve(n_conn) < 0) {
log(LOG_DEBUG,"connection_exit_begin_conn(): Couldn't queue resolve request.");
connection_remove(n_conn);
connection_free(n_conn);
return 0;
}
return 0;
}
int connection_exit_process_data_cell(cell_t *cell, circuit_t *circ) {
connection_t *conn;
int topic_command;
int topic_id;
static int num_seen=0;
/* an outgoing data cell has arrived */
assert(cell && circ);
topic_command = *cell->payload;
topic_id = ntohs(*(uint16_t *)(cell->payload+2));
log(LOG_DEBUG,"connection_exit_process_data_cell(): command %d topic %d", topic_command, topic_id);
num_seen++;
log(LOG_DEBUG,"connection_exit_process_data_cell(): Now seen %d data cells here.", num_seen);
circuit_consider_sending_sendme(circ, EDGE_EXIT);
for(conn = circ->n_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 != EXIT_CONN_STATE_OPEN) {
if(topic_command == TOPIC_COMMAND_END) {
log(LOG_ERR,"connection_exit_process_data_cell(): Got an end before we're connected. Marking for close.");
conn->marked_for_close = 1;
return 0;
} else {
log(LOG_INFO,"connection_exit_process_data_cell(): Got a non-end data cell when not in 'open' state. Dropping.");
return 0;
}
}
switch(topic_command) {
case TOPIC_COMMAND_BEGIN:
if(conn) {
log(LOG_INFO,"connection_exit_process_data_cell(): begin cell for known topic. Dropping.");
return 0;
}
return connection_exit_begin_conn(cell, circ);
case TOPIC_COMMAND_DATA:
if(!conn) {
log(LOG_INFO,"connection_exit_process_data_cell(): data cell for unknown topic. Dropping.");
return 0;
}
if(--conn->p_receive_topicwindow < 0) { /* is it below 0 after decrement? */
log(LOG_DEBUG,"connection_exit_process_data_cell(): receive_topicwindow at exit below 0. Killing.");
return -1; /* AP breaking protocol. kill the whole circuit. */
}
log(LOG_DEBUG,"connection_exit_process_data_cell(): willing to receive %d more cells from circ",conn->p_receive_topicwindow);
if(conn->state != EXIT_CONN_STATE_OPEN) {
log(LOG_DEBUG,"connection_exit_process_data_cell(): data received while resolving/connecting. Queueing.");
}
log(LOG_DEBUG,"connection_exit_process_data_cell(): put %d bytes on outbuf.",cell->length - TOPIC_HEADER_SIZE);
#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) {
log(LOG_INFO,"connection_exit_process_data_cell(): write to buf failed. Marking for close.");
conn->marked_for_close = 1;
return 0;
}
#endif
if(connection_consider_sending_sendme(conn, EDGE_EXIT) < 0)
conn->marked_for_close = 1;
return 0;
case TOPIC_COMMAND_END:
if(!conn) {
log(LOG_DEBUG,"connection_exit_process_data_cell(): end cell dropped, unknown topic %d.",topic_id);
return 0;
}
log(LOG_DEBUG,"connection_exit_process_data_cell(): end cell for topic %d. Removing topic.",topic_id);
#if 0
/* go through and identify who points to conn. remove conn from the list. */
if(conn == circ->n_conn) {
circ->n_conn = conn->next_topic;
}
for(prevconn = circ->n_conn; prevconn->next_topic != conn; prevconn = prevconn->next_topic) ;
prevconn->next_topic = conn->next_topic;
#endif
#ifdef HALF_OPEN
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:
log(LOG_INFO,"connection_exit_process_data_cell(): topic connected request unsupported. Dropping.");
break;
case TOPIC_COMMAND_SENDME:
if(!conn) {
log(LOG_DEBUG,"connection_exit_process_data_cell(): sendme cell dropped, unknown topic %d.",topic_id);
return 0;
}
conn->n_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_EXIT);
break;
default:
log(LOG_DEBUG,"connection_exit_process_data_cell(): unknown topic command %d.",topic_command);
}
return 0;
}
#if 0
static uint32_t address_to_addr(char *address) {
struct hostent *rent;
uint32_t addr;
char *caddr;
rent = gethostbyname(address);
if (!rent) {
log(LOG_ERR,"address_to_addr(): Could not resolve dest addr %s.",address);
return 0;
}
memcpy(&addr, rent->h_addr,rent->h_length);
addr = ntohl(addr); /* get it back to host order */
caddr = (char *)&addr;
log(LOG_DEBUG,"address_to_addr(): addr is %d %d %d %d",
caddr[0], caddr[1], caddr[2], caddr[3]);
return addr;
}
#endif
int connection_exit_connect(connection_t *conn) {
int s; /* for the new socket */
struct sockaddr_in dest_addr;
/* all the necessary info is here. Start the connect() */
s=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
if (s < 0) {
log(LOG_ERR,"connection_exit_connect(): Error creating network socket.");
return -1;
}
fcntl(s, F_SETFL, O_NONBLOCK); /* set s to non-blocking */
memset((void *)&dest_addr,0,sizeof(dest_addr));
dest_addr.sin_family = AF_INET;
dest_addr.sin_port = htons(conn->port);
dest_addr.sin_addr.s_addr = htonl(conn->addr);
log(LOG_DEBUG,"connection_exit_connect(): Connecting to %s:%u.",conn->address,conn->port);
if(connect(s,(struct sockaddr *)&dest_addr,sizeof(dest_addr)) < 0) {
if(errno != EINPROGRESS){
/* yuck. kill it. */
perror("connect");
log(LOG_DEBUG,"connection_exit_connect(): Connect failed.");
return -1;
} else {
/* it's in progress. set state appropriately and return. */
conn->s = s;
connection_set_poll_socket(conn);
conn->state = EXIT_CONN_STATE_CONNECTING;
log(LOG_DEBUG,"connection_exit_connect(): connect in progress, socket %d.",s);
connection_watch_events(conn, POLLOUT | POLLIN);
return 0;
}
}
/* it succeeded. we're connected. */
log(LOG_DEBUG,"connection_exit_connect(): Connection to %s:%u established.",conn->address,conn->port);
conn->s = s;
connection_set_poll_socket(conn);
conn->state = EXIT_CONN_STATE_OPEN;
if(connection_wants_to_flush(conn)) { /* in case there are any queued data cells */
log(LOG_ERR,"connection_exit_connect(): tell roger: newly connected conn had data waiting!");
// connection_start_writing(conn);
}
// connection_process_inbuf(conn);
connection_watch_events(conn, POLLIN);
/* also, deliver a 'connected' cell back through the circuit. */
return connection_exit_send_connected(conn);
}