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Diffstat (limited to 'src/or/connection_st.h')
| -rw-r--r-- | src/or/connection_st.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/or/connection_st.h b/src/or/connection_st.h new file mode 100644 index 0000000000..b65238693f --- /dev/null +++ b/src/or/connection_st.h @@ -0,0 +1,132 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2017, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#ifndef CONNECTION_ST_H +#define CONNECTION_ST_H + +struct buf_t; + +/** Description of a connection to another host or process, and associated + * data. + * + * A connection is named based on what it's connected to -- an "OR + * connection" has a Tor node on the other end, an "exit + * connection" has a website or other server on the other end, and an + * "AP connection" has an application proxy (and thus a user) on the + * other end. + * + * Every connection has a type and a state. Connections never change + * their type, but can go through many state changes in their lifetime. + * + * Every connection has two associated input and output buffers. + * Listeners don't use them. For non-listener connections, incoming + * data is appended to conn->inbuf, and outgoing data is taken from + * conn->outbuf. Connections differ primarily in the functions called + * to fill and drain these buffers. + */ +typedef struct connection_t { + uint32_t magic; /**< For memory debugging: must equal one of + * *_CONNECTION_MAGIC. */ + + uint8_t state; /**< Current state of this connection. */ + unsigned int type:5; /**< What kind of connection is this? */ + unsigned int purpose:5; /**< Only used for DIR and EXIT types currently. */ + + /* The next fields are all one-bit booleans. Some are only applicable to + * connection subtypes, but we hold them here anyway, to save space. + */ + unsigned int read_blocked_on_bw:1; /**< Boolean: should we start reading + * again once the bandwidth throttler allows it? */ + unsigned int write_blocked_on_bw:1; /**< Boolean: should we start writing + * again once the bandwidth throttler allows + * writes? */ + unsigned int hold_open_until_flushed:1; /**< Despite this connection's being + * marked for close, do we flush it + * before closing it? */ + unsigned int inbuf_reached_eof:1; /**< Boolean: did read() return 0 on this + * conn? */ + /** Set to 1 when we're inside connection_flushed_some to keep us from + * calling connection_handle_write() recursively. */ + unsigned int in_flushed_some:1; + /** True if connection_handle_write is currently running on this connection. + */ + unsigned int in_connection_handle_write:1; + + /* For linked connections: + */ + unsigned int linked:1; /**< True if there is, or has been, a linked_conn. */ + /** True iff we'd like to be notified about read events from the + * linked conn. */ + unsigned int reading_from_linked_conn:1; + /** True iff we're willing to write to the linked conn. */ + unsigned int writing_to_linked_conn:1; + /** True iff we're currently able to read on the linked conn, and our + * read_event should be made active with libevent. */ + unsigned int active_on_link:1; + /** True iff we've called connection_close_immediate() on this linked + * connection. */ + unsigned int linked_conn_is_closed:1; + + /** CONNECT/SOCKS proxy client handshake state (for outgoing connections). */ + unsigned int proxy_state:4; + + /** Our socket; set to TOR_INVALID_SOCKET if this connection is closed, + * or has no socket. */ + tor_socket_t s; + int conn_array_index; /**< Index into the global connection array. */ + + struct event *read_event; /**< Libevent event structure. */ + struct event *write_event; /**< Libevent event structure. */ + struct buf_t *inbuf; /**< Buffer holding data read over this connection. */ + struct buf_t *outbuf; /**< Buffer holding data to write over this + * connection. */ + size_t outbuf_flushlen; /**< How much data should we try to flush from the + * outbuf? */ + time_t timestamp_last_read_allowed; /**< When was the last time libevent said + * we could read? */ + time_t timestamp_last_write_allowed; /**< When was the last time libevent + * said we could write? */ + + time_t timestamp_created; /**< When was this connection_t created? */ + + int socket_family; /**< Address family of this connection's socket. Usually + * AF_INET, but it can also be AF_UNIX, or AF_INET6 */ + tor_addr_t addr; /**< IP that socket "s" is directly connected to; + * may be the IP address for a proxy or pluggable transport, + * see "address" for the address of the final destination. + */ + uint16_t port; /**< If non-zero, port that socket "s" is directly connected + * to; may be the port for a proxy or pluggable transport, + * see "address" for the port at the final destination. */ + uint16_t marked_for_close; /**< Should we close this conn on the next + * iteration of the main loop? (If true, holds + * the line number where this connection was + * marked.) */ + const char *marked_for_close_file; /**< For debugging: in which file were + * we marked for close? */ + char *address; /**< FQDN (or IP) and port of the final destination for this + * connection; this is always the remote address, it is + * passed to a proxy or pluggable transport if one in use. + * See "addr" and "port" for the address that socket "s" is + * directly connected to. + * strdup into this, because free_connection() frees it. */ + /** Another connection that's connected to this one in lieu of a socket. */ + struct connection_t *linked_conn; + + /** Unique identifier for this connection on this Tor instance. */ + uint64_t global_identifier; + + /** Bytes read since last call to control_event_conn_bandwidth_used(). + * Only used if we're configured to emit CONN_BW events. */ + uint32_t n_read_conn_bw; + + /** Bytes written since last call to control_event_conn_bandwidth_used(). + * Only used if we're configured to emit CONN_BW events. */ + uint32_t n_written_conn_bw; +} connection_t; + +#endif + |