commit ba7816db5f55d76e925c2edcbbbe689490d85650 Author: Nick Mathewson nickm@torproject.org Date: Mon Jul 13 14:35:51 2020 -0400

New functions to describe connections and peers.

These will let us refactor away a lot of code that currently uses "addr" and "address" for logging purposes. --- src/core/mainloop/connection.c | 150 +++++++++++++++++++++++++++++++++++++++++ src/core/mainloop/connection.h | 3 + 2 files changed, 153 insertions(+)

diff --git a/src/core/mainloop/connection.c b/src/core/mainloop/connection.c index 1d53e077d1..a91bc6408f 100644 --- a/src/core/mainloop/connection.c +++ b/src/core/mainloop/connection.c @@ -352,13 +352,163 @@ conn_state_to_string(int type, int state) break; }

+ if (state == 0) { + return "uninitialized"; + } + log_warn(LD_BUG, "unknown connection state %d (type %d)", state, type); tor_snprintf(buf, sizeof(buf), "unknown state [%d] on unknown [%s] connection", state, conn_type_to_string(type)); + tor_assert_nonfatal_unreached_once(); return buf; }

+/** + * Helper: describe the peer or address of connection @a conn in a + * human-readable manner. + * + * Returns a pointer to a static buffer; future calls to + * connection_describe_peer_internal() will invalidate this buffer. + * + * If <b>include_preposition</b> is true, include a preposition before the + * peer address. + * + * Nobody should parse the output of this function; it can and will change in + * future versions of tor. + **/ +static const char * +connection_describe_peer_internal(const connection_t *conn, + bool include_preposition) +{ + IF_BUG_ONCE(!conn) { + return "null peer"; + } + + static char peer_buf[256]; + const tor_addr_t *addr = &conn->addr; + const char *address = NULL; + const char *prep; + char extra_buf[128]; + extra_buf[0] = 0; + + /* First, figure out the preposition to use */ + switch (conn->type) { + CASE_ANY_LISTENER_TYPE: + prep = "on"; + break; + case CONN_TYPE_EXIT: + prep = "to"; + break; + case CONN_TYPE_CONTROL: + case CONN_TYPE_AP: + case CONN_TYPE_EXT_OR: + prep = "from"; + break; + default: + prep = "with"; + break; + } + + /* Now figure out the address. */ + if (conn->socket_family == AF_UNIX) { + /* For unix sockets, we always use the `address` string. */ + address = conn->address ? conn->address : "unix socket"; + } else if (conn->type == CONN_TYPE_OR) { + /* For OR connections, we have a lot to do. */ + const or_connection_t *or_conn = TO_OR_CONN((connection_t *)conn); + char id_buf[HEX_DIGEST_LEN+1]; + /* we report 'real_addr' as the address we're talking with */ + addr = &or_conn->real_addr; + /* We report the IDs we're talking to... */ + if (fast_digest_is_zero(or_conn->identity_digest)) { + strlcpy(id_buf, "unknown", sizeof(id_buf)); + } else { + base16_encode(id_buf, sizeof(id_buf), + or_conn->identity_digest, DIGEST_LEN); + } + tor_snprintf(extra_buf, sizeof(extra_buf), + " ID=%s", id_buf); + if (! tor_addr_eq(addr, &conn->addr)) { + /* We report canonical address, if it's different */ + char canonical_addr_buf[TOR_ADDR_BUF_LEN]; + if (tor_addr_to_str(canonical_addr_buf, &conn->addr, + sizeof(canonical_addr_buf), 1)) { + strlcat(extra_buf, " canonical_addr=", sizeof(extra_buf)); + strlcat(extra_buf, canonical_addr_buf, sizeof(extra_buf)); + } + } + } else if (conn->type == CONN_TYPE_EXIT) { + if (tor_addr_is_null(addr)) { + address = conn->address; + strlcpy(extra_buf, " (DNS lookup pending)", sizeof(extra_buf)); + } + } + + char addr_buf[TOR_ADDR_BUF_LEN]; + if (address == NULL) { + if (tor_addr_family(addr) == 0) { + address = "<unset>"; + } else { + address = tor_addr_to_str(addr_buf, addr, sizeof(addr_buf), 1); + if (!address) { + address = "<can't format!>"; + tor_assert_nonfatal_unreached_once(); + } + } + } + + const char *sp = include_preposition ? " " : ""; + if (! include_preposition) + prep = ""; + + tor_snprintf(peer_buf, sizeof(peer_buf), + "%s%s%s%s", prep, sp, address, extra_buf); + return peer_buf; +} + +/** + * Describe the peer or address of connection @a conn in a + * human-readable manner. + * + * Returns a pointer to a static buffer; future calls to + * connection_describe_peer() or connection_describe() will invalidate this + * buffer. + * + * Nobody should parse the output of this function; it can and will change in + * future versions of tor. + **/ +const char * +connection_describe_peer(const connection_t *conn) +{ + return connection_describe_peer_internal(conn, false); +} + +/** + * Describe a connection for logging purposes. + * + * Returns a pointer to a static buffer; future calls to connection_describe() + * will invalidate this buffer. + * + * Nobody should parse the output of this function; it can and will change in + * future versions of tor. + **/ +const char * +connection_describe(const connection_t *conn) +{ + IF_BUG_ONCE(!conn) { + return "null connection"; + } + static char desc_buf[256]; + const char *peer = connection_describe_peer_internal(conn, true); + tor_snprintf(desc_buf, sizeof(desc_buf), + "%s connection (%s) %s", + conn_type_to_string(conn->type), + conn_state_to_string(conn->type, conn->state), + peer); + return desc_buf; +} + /** Allocate and return a new dir_connection_t, initialized as by * connection_init(). */ dir_connection_t * diff --git a/src/core/mainloop/connection.h b/src/core/mainloop/connection.h index bcd3d590a5..af45007676 100644 --- a/src/core/mainloop/connection.h +++ b/src/core/mainloop/connection.h @@ -116,6 +116,9 @@ const char *conn_type_to_string(int type); const char *conn_state_to_string(int type, int state); int conn_listener_type_supports_af_unix(int type);

+const char *connection_describe(const connection_t *conn); +const char *connection_describe_peer(const connection_t *conn); + struct dir_connection_t *dir_connection_new(int socket_family); struct or_connection_t *or_connection_new(int type, int socket_family); struct edge_connection_t *edge_connection_new(int type, int socket_family);