commit 544ab27a949406628809869111b7288017a5bcb1 Author: Nick Mathewson nickm@torproject.org Date: Thu Jun 28 08:49:07 2018 -0400

Extract the alert-socket code into lib/net.

This code was in compat_threads, since it was _used_ for efficiently notifying the main libevent thread from another thread. But in spite of its usage, it's fundamentally a part of the network code. --- src/common/compat_threads.c | 269 ----------------------------------------- src/common/compat_threads.h | 26 ---- src/common/workqueue.c | 2 +- src/lib/net/alertsock.c | 284 ++++++++++++++++++++++++++++++++++++++++++++ src/lib/net/alertsock.h | 39 ++++++ src/lib/net/include.am | 2 + src/test/test_workqueue.c | 2 +- 7 files changed, 327 insertions(+), 297 deletions(-)

diff --git a/src/common/compat_threads.c b/src/common/compat_threads.c index e66143b35..87833c6cf 100644 --- a/src/common/compat_threads.c +++ b/src/common/compat_threads.c @@ -19,16 +19,6 @@ #include "common/util.h" #include "lib/log/torlog.h"

-#ifdef HAVE_SYS_EVENTFD_H -#include <sys/eventfd.h> -#endif -#ifdef HAVE_FCNTL_H -#include <fcntl.h> -#endif -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif - /** Allocate and return a new condition variable. */ tor_cond_t * tor_cond_new(void) @@ -66,265 +56,6 @@ in_main_thread(void) return main_thread_id == tor_get_thread_id(); }

-#if defined(HAVE_EVENTFD) || defined(HAVE_PIPE) -/* As write(), but retry on EINTR, and return the negative error code on - * error. */ -static int -write_ni(int fd, const void *buf, size_t n) -{ - int r; - again: - r = (int) write(fd, buf, n); - if (r < 0) { - if (errno == EINTR) - goto again; - else - return -errno; - } - return r; -} -/* As read(), but retry on EINTR, and return the negative error code on error. - */ -static int -read_ni(int fd, void *buf, size_t n) -{ - int r; - again: - r = (int) read(fd, buf, n); - if (r < 0) { - if (errno == EINTR) - goto again; - else - return -errno; - } - return r; -} -#endif /* defined(HAVE_EVENTFD) || defined(HAVE_PIPE) */ - -/** As send(), but retry on EINTR, and return the negative error code on - * error. */ -static int -send_ni(int fd, const void *buf, size_t n, int flags) -{ - int r; - again: - r = (int) send(fd, buf, n, flags); - if (r < 0) { - int error = tor_socket_errno(fd); - if (ERRNO_IS_EINTR(error)) - goto again; - else - return -error; - } - return r; -} - -/** As recv(), but retry on EINTR, and return the negative error code on - * error. */ -static int -recv_ni(int fd, void *buf, size_t n, int flags) -{ - int r; - again: - r = (int) recv(fd, buf, n, flags); - if (r < 0) { - int error = tor_socket_errno(fd); - if (ERRNO_IS_EINTR(error)) - goto again; - else - return -error; - } - return r; -} - -#ifdef HAVE_EVENTFD -/* Increment the event count on an eventfd <b>fd</b> */ -static int -eventfd_alert(int fd) -{ - uint64_t u = 1; - int r = write_ni(fd, (void*)&u, sizeof(u)); - if (r < 0 && -r != EAGAIN) - return -1; - return 0; -} - -/* Drain all events from an eventfd <b>fd</b>. */ -static int -eventfd_drain(int fd) -{ - uint64_t u = 0; - int r = read_ni(fd, (void*)&u, sizeof(u)); - if (r < 0 && -r != EAGAIN) - return r; - return 0; -} -#endif /* defined(HAVE_EVENTFD) */ - -#ifdef HAVE_PIPE -/** Send a byte over a pipe. Return 0 on success or EAGAIN; -1 on error */ -static int -pipe_alert(int fd) -{ - ssize_t r = write_ni(fd, "x", 1); - if (r < 0 && -r != EAGAIN) - return (int)r; - return 0; -} - -/** Drain all input from a pipe <b>fd</b> and ignore it. Return 0 on - * success, -1 on error. */ -static int -pipe_drain(int fd) -{ - char buf[32]; - ssize_t r; - do { - r = read_ni(fd, buf, sizeof(buf)); - } while (r > 0); - if (r < 0 && errno != EAGAIN) - return -errno; - /* A value of r = 0 means EOF on the fd so successfully drained. */ - return 0; -} -#endif /* defined(HAVE_PIPE) */ - -/** Send a byte on socket <b>fd</b>t. Return 0 on success or EAGAIN, - * -1 on error. */ -static int -sock_alert(tor_socket_t fd) -{ - ssize_t r = send_ni(fd, "x", 1, 0); - if (r < 0 && !ERRNO_IS_EAGAIN(-r)) - return (int)r; - return 0; -} - -/** Drain all the input from a socket <b>fd</b>, and ignore it. Return 0 on - * success, -errno on error. */ -static int -sock_drain(tor_socket_t fd) -{ - char buf[32]; - ssize_t r; - do { - r = recv_ni(fd, buf, sizeof(buf), 0); - } while (r > 0); - if (r < 0 && !ERRNO_IS_EAGAIN(-r)) - return (int)r; - /* A value of r = 0 means EOF on the fd so successfully drained. */ - return 0; -} - -/** Allocate a new set of alert sockets, and set the appropriate function - * pointers, in <b>socks_out</b>. */ -int -alert_sockets_create(alert_sockets_t *socks_out, uint32_t flags) -{ - tor_socket_t socks[2] = { TOR_INVALID_SOCKET, TOR_INVALID_SOCKET }; - -#ifdef HAVE_EVENTFD - /* First, we try the Linux eventfd() syscall. This gives a 64-bit counter - * associated with a single file descriptor. */ -#if defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK) - if (!(flags & ASOCKS_NOEVENTFD2)) - socks[0] = eventfd(0, EFD_CLOEXEC|EFD_NONBLOCK); -#endif - if (socks[0] < 0 && !(flags & ASOCKS_NOEVENTFD)) { - socks[0] = eventfd(0,0); - if (socks[0] >= 0) { - if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 || - set_socket_nonblocking(socks[0]) < 0) { - // LCOV_EXCL_START -- if eventfd succeeds, fcntl will. - tor_assert_nonfatal_unreached(); - close(socks[0]); - return -1; - // LCOV_EXCL_STOP - } - } - } - if (socks[0] >= 0) { - socks_out->read_fd = socks_out->write_fd = socks[0]; - socks_out->alert_fn = eventfd_alert; - socks_out->drain_fn = eventfd_drain; - return 0; - } -#endif /* defined(HAVE_EVENTFD) */ - -#ifdef HAVE_PIPE2 - /* Now we're going to try pipes. First type the pipe2() syscall, if we - * have it, so we can save some calls... */ - if (!(flags & ASOCKS_NOPIPE2) && - pipe2(socks, O_NONBLOCK|O_CLOEXEC) == 0) { - socks_out->read_fd = socks[0]; - socks_out->write_fd = socks[1]; - socks_out->alert_fn = pipe_alert; - socks_out->drain_fn = pipe_drain; - return 0; - } -#endif /* defined(HAVE_PIPE2) */ - -#ifdef HAVE_PIPE - /* Now try the regular pipe() syscall. Pipes have a bit lower overhead than - * socketpairs, fwict. */ - if (!(flags & ASOCKS_NOPIPE) && - pipe(socks) == 0) { - if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 || - fcntl(socks[1], F_SETFD, FD_CLOEXEC) < 0 || - set_socket_nonblocking(socks[0]) < 0 || - set_socket_nonblocking(socks[1]) < 0) { - // LCOV_EXCL_START -- if pipe succeeds, you can fcntl the output - tor_assert_nonfatal_unreached(); - close(socks[0]); - close(socks[1]); - return -1; - // LCOV_EXCL_STOP - } - socks_out->read_fd = socks[0]; - socks_out->write_fd = socks[1]; - socks_out->alert_fn = pipe_alert; - socks_out->drain_fn = pipe_drain; - return 0; - } -#endif /* defined(HAVE_PIPE) */ - - /* If nothing else worked, fall back on socketpair(). */ - if (!(flags & ASOCKS_NOSOCKETPAIR) && - tor_socketpair(AF_UNIX, SOCK_STREAM, 0, socks) == 0) { - if (set_socket_nonblocking(socks[0]) < 0 || - set_socket_nonblocking(socks[1])) { - // LCOV_EXCL_START -- if socketpair worked, you can make it nonblocking. - tor_assert_nonfatal_unreached(); - tor_close_socket(socks[0]); - tor_close_socket(socks[1]); - return -1; - // LCOV_EXCL_STOP - } - socks_out->read_fd = socks[0]; - socks_out->write_fd = socks[1]; - socks_out->alert_fn = sock_alert; - socks_out->drain_fn = sock_drain; - return 0; - } - return -1; -} - -/** Close the sockets in <b>socks</b>. */ -void -alert_sockets_close(alert_sockets_t *socks) -{ - if (socks->alert_fn == sock_alert) { - /* they are sockets. */ - tor_close_socket(socks->read_fd); - tor_close_socket(socks->write_fd); - } else { - close(socks->read_fd); - if (socks->write_fd != socks->read_fd) - close(socks->write_fd); - } - socks->read_fd = socks->write_fd = -1; -} - #ifndef HAVE_STDATOMIC_H /** Initialize a new atomic counter with the value 0 */ void diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h index d1fdfc96c..69350421b 100644 --- a/src/common/compat_threads.h +++ b/src/common/compat_threads.h @@ -52,32 +52,6 @@ int tor_cond_wait(tor_cond_t *cond, tor_mutex_t *mutex, void tor_cond_signal_one(tor_cond_t *cond); void tor_cond_signal_all(tor_cond_t *cond);

-/** Helper type used to manage waking up the main thread while it's in - * the libevent main loop. Used by the work queue code. */ -typedef struct alert_sockets_s { - /* XXXX This structure needs a better name. */ - /** Socket that the main thread should listen for EV_READ events on. - * Note that this socket may be a regular fd on a non-Windows platform. - */ - tor_socket_t read_fd; - /** Socket to use when alerting the main thread. */ - tor_socket_t write_fd; - /** Function to alert the main thread */ - int (*alert_fn)(tor_socket_t write_fd); - /** Function to make the main thread no longer alerted. */ - int (*drain_fn)(tor_socket_t read_fd); -} alert_sockets_t; - -/* Flags to disable one or more alert_sockets backends. */ -#define ASOCKS_NOEVENTFD2 (1u<<0) -#define ASOCKS_NOEVENTFD (1u<<1) -#define ASOCKS_NOPIPE2 (1u<<2) -#define ASOCKS_NOPIPE (1u<<3) -#define ASOCKS_NOSOCKETPAIR (1u<<4) - -int alert_sockets_create(alert_sockets_t *socks_out, uint32_t flags); -void alert_sockets_close(alert_sockets_t *socks); - typedef struct tor_threadlocal_s { #ifdef _WIN32 DWORD index; diff --git a/src/common/workqueue.c b/src/common/workqueue.c index 84945882d..fd31ccd7f 100644 --- a/src/common/workqueue.c +++ b/src/common/workqueue.c @@ -31,6 +31,7 @@ #include "common/util.h" #include "common/workqueue.h" #include "tor_queue.h" +#include "lib/net/alertsock.h" #include "lib/log/torlog.h"

#include <event2/event.h> @@ -675,4 +676,3 @@ replyqueue_process(replyqueue_t *queue)

tor_mutex_release(&queue->lock); } - diff --git a/src/lib/net/alertsock.c b/src/lib/net/alertsock.c new file mode 100644 index 000000000..c6ea1551f --- /dev/null +++ b/src/lib/net/alertsock.c @@ -0,0 +1,284 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#include "orconfig.h" +#include "lib/net/alertsock.h" +#include "lib/net/socket.h" +#include "lib/log/util_bug.h" + +#ifdef HAVE_SYS_EVENTFD_H +#include <sys/eventfd.h> +#endif +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef HAVE_SYS_SOCKET_H +#include <sys/socket.h> +#endif +#ifdef _WIN32 +#include <winsock2.h> +#endif + +#if defined(HAVE_EVENTFD) || defined(HAVE_PIPE) +/* As write(), but retry on EINTR, and return the negative error code on + * error. */ +static int +write_ni(int fd, const void *buf, size_t n) +{ + int r; + again: + r = (int) write(fd, buf, n); + if (r < 0) { + if (errno == EINTR) + goto again; + else + return -errno; + } + return r; +} +/* As read(), but retry on EINTR, and return the negative error code on error. + */ +static int +read_ni(int fd, void *buf, size_t n) +{ + int r; + again: + r = (int) read(fd, buf, n); + if (r < 0) { + if (errno == EINTR) + goto again; + else + return -errno; + } + return r; +} +#endif /* defined(HAVE_EVENTFD) || defined(HAVE_PIPE) */ + +/** As send(), but retry on EINTR, and return the negative error code on + * error. */ +static int +send_ni(int fd, const void *buf, size_t n, int flags) +{ + int r; + again: + r = (int) send(fd, buf, n, flags); + if (r < 0) { + int error = tor_socket_errno(fd); + if (ERRNO_IS_EINTR(error)) + goto again; + else + return -error; + } + return r; +} + +/** As recv(), but retry on EINTR, and return the negative error code on + * error. */ +static int +recv_ni(int fd, void *buf, size_t n, int flags) +{ + int r; + again: + r = (int) recv(fd, buf, n, flags); + if (r < 0) { + int error = tor_socket_errno(fd); + if (ERRNO_IS_EINTR(error)) + goto again; + else + return -error; + } + return r; +} + +#ifdef HAVE_EVENTFD +/* Increment the event count on an eventfd <b>fd</b> */ +static int +eventfd_alert(int fd) +{ + uint64_t u = 1; + int r = write_ni(fd, (void*)&u, sizeof(u)); + if (r < 0 && -r != EAGAIN) + return -1; + return 0; +} + +/* Drain all events from an eventfd <b>fd</b>. */ +static int +eventfd_drain(int fd) +{ + uint64_t u = 0; + int r = read_ni(fd, (void*)&u, sizeof(u)); + if (r < 0 && -r != EAGAIN) + return r; + return 0; +} +#endif /* defined(HAVE_EVENTFD) */ + +#ifdef HAVE_PIPE +/** Send a byte over a pipe. Return 0 on success or EAGAIN; -1 on error */ +static int +pipe_alert(int fd) +{ + ssize_t r = write_ni(fd, "x", 1); + if (r < 0 && -r != EAGAIN) + return (int)r; + return 0; +} + +/** Drain all input from a pipe <b>fd</b> and ignore it. Return 0 on + * success, -1 on error. */ +static int +pipe_drain(int fd) +{ + char buf[32]; + ssize_t r; + do { + r = read_ni(fd, buf, sizeof(buf)); + } while (r > 0); + if (r < 0 && errno != EAGAIN) + return -errno; + /* A value of r = 0 means EOF on the fd so successfully drained. */ + return 0; +} +#endif /* defined(HAVE_PIPE) */ + +/** Send a byte on socket <b>fd</b>t. Return 0 on success or EAGAIN, + * -1 on error. */ +static int +sock_alert(tor_socket_t fd) +{ + ssize_t r = send_ni(fd, "x", 1, 0); + if (r < 0 && !ERRNO_IS_EAGAIN(-r)) + return (int)r; + return 0; +} + +/** Drain all the input from a socket <b>fd</b>, and ignore it. Return 0 on + * success, -errno on error. */ +static int +sock_drain(tor_socket_t fd) +{ + char buf[32]; + ssize_t r; + do { + r = recv_ni(fd, buf, sizeof(buf), 0); + } while (r > 0); + if (r < 0 && !ERRNO_IS_EAGAIN(-r)) + return (int)r; + /* A value of r = 0 means EOF on the fd so successfully drained. */ + return 0; +} + +/** Allocate a new set of alert sockets, and set the appropriate function + * pointers, in <b>socks_out</b>. */ +int +alert_sockets_create(alert_sockets_t *socks_out, uint32_t flags) +{ + tor_socket_t socks[2] = { TOR_INVALID_SOCKET, TOR_INVALID_SOCKET }; + +#ifdef HAVE_EVENTFD + /* First, we try the Linux eventfd() syscall. This gives a 64-bit counter + * associated with a single file descriptor. */ +#if defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK) + if (!(flags & ASOCKS_NOEVENTFD2)) + socks[0] = eventfd(0, EFD_CLOEXEC|EFD_NONBLOCK); +#endif + if (socks[0] < 0 && !(flags & ASOCKS_NOEVENTFD)) { + socks[0] = eventfd(0,0); + if (socks[0] >= 0) { + if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 || + set_socket_nonblocking(socks[0]) < 0) { + // LCOV_EXCL_START -- if eventfd succeeds, fcntl will. + tor_assert_nonfatal_unreached(); + close(socks[0]); + return -1; + // LCOV_EXCL_STOP + } + } + } + if (socks[0] >= 0) { + socks_out->read_fd = socks_out->write_fd = socks[0]; + socks_out->alert_fn = eventfd_alert; + socks_out->drain_fn = eventfd_drain; + return 0; + } +#endif /* defined(HAVE_EVENTFD) */ + +#ifdef HAVE_PIPE2 + /* Now we're going to try pipes. First type the pipe2() syscall, if we + * have it, so we can save some calls... */ + if (!(flags & ASOCKS_NOPIPE2) && + pipe2(socks, O_NONBLOCK|O_CLOEXEC) == 0) { + socks_out->read_fd = socks[0]; + socks_out->write_fd = socks[1]; + socks_out->alert_fn = pipe_alert; + socks_out->drain_fn = pipe_drain; + return 0; + } +#endif /* defined(HAVE_PIPE2) */ + +#ifdef HAVE_PIPE + /* Now try the regular pipe() syscall. Pipes have a bit lower overhead than + * socketpairs, fwict. */ + if (!(flags & ASOCKS_NOPIPE) && + pipe(socks) == 0) { + if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 || + fcntl(socks[1], F_SETFD, FD_CLOEXEC) < 0 || + set_socket_nonblocking(socks[0]) < 0 || + set_socket_nonblocking(socks[1]) < 0) { + // LCOV_EXCL_START -- if pipe succeeds, you can fcntl the output + tor_assert_nonfatal_unreached(); + close(socks[0]); + close(socks[1]); + return -1; + // LCOV_EXCL_STOP + } + socks_out->read_fd = socks[0]; + socks_out->write_fd = socks[1]; + socks_out->alert_fn = pipe_alert; + socks_out->drain_fn = pipe_drain; + return 0; + } +#endif /* defined(HAVE_PIPE) */ + + /* If nothing else worked, fall back on socketpair(). */ + if (!(flags & ASOCKS_NOSOCKETPAIR) && + tor_socketpair(AF_UNIX, SOCK_STREAM, 0, socks) == 0) { + if (set_socket_nonblocking(socks[0]) < 0 || + set_socket_nonblocking(socks[1])) { + // LCOV_EXCL_START -- if socketpair worked, you can make it nonblocking. + tor_assert_nonfatal_unreached(); + tor_close_socket(socks[0]); + tor_close_socket(socks[1]); + return -1; + // LCOV_EXCL_STOP + } + socks_out->read_fd = socks[0]; + socks_out->write_fd = socks[1]; + socks_out->alert_fn = sock_alert; + socks_out->drain_fn = sock_drain; + return 0; + } + return -1; +} + +/** Close the sockets in <b>socks</b>. */ +void +alert_sockets_close(alert_sockets_t *socks) +{ + if (socks->alert_fn == sock_alert) { + /* they are sockets. */ + tor_close_socket(socks->read_fd); + tor_close_socket(socks->write_fd); + } else { + close(socks->read_fd); + if (socks->write_fd != socks->read_fd) + close(socks->write_fd); + } + socks->read_fd = socks->write_fd = -1; +} diff --git a/src/lib/net/alertsock.h b/src/lib/net/alertsock.h new file mode 100644 index 000000000..026a15cad --- /dev/null +++ b/src/lib/net/alertsock.h @@ -0,0 +1,39 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#ifndef TOR_ALERTSOCK_H +#define TOR_ALERTSOCK_H + +#include "orconfig.h" +#include "lib/net/nettypes.h" +#include "lib/cc/torint.h" + +/** Helper type used to manage waking up the main thread while it's in + * the libevent main loop. Used by the work queue code. */ +typedef struct alert_sockets_t { + /* XXXX This structure needs a better name. */ + /** Socket that the main thread should listen for EV_READ events on. + * Note that this socket may be a regular fd on a non-Windows platform. + */ + tor_socket_t read_fd; + /** Socket to use when alerting the main thread. */ + tor_socket_t write_fd; + /** Function to alert the main thread */ + int (*alert_fn)(tor_socket_t write_fd); + /** Function to make the main thread no longer alerted. */ + int (*drain_fn)(tor_socket_t read_fd); +} alert_sockets_t; + +/* Flags to disable one or more alert_sockets backends. */ +#define ASOCKS_NOEVENTFD2 (1u<<0) +#define ASOCKS_NOEVENTFD (1u<<1) +#define ASOCKS_NOPIPE2 (1u<<2) +#define ASOCKS_NOPIPE (1u<<3) +#define ASOCKS_NOSOCKETPAIR (1u<<4) + +int alert_sockets_create(alert_sockets_t *socks_out, uint32_t flags); +void alert_sockets_close(alert_sockets_t *socks); + +#endif diff --git a/src/lib/net/include.am b/src/lib/net/include.am index 6bd829165..90049c95d 100644 --- a/src/lib/net/include.am +++ b/src/lib/net/include.am @@ -7,6 +7,7 @@ endif

src_lib_libtor_net_a_SOURCES = \ src/lib/net/address.c \ + src/lib/net/alertsock.c \ src/lib/net/ipv4.c \ src/lib/net/ipv6.c \ src/lib/net/resolve.c \ @@ -19,6 +20,7 @@ src_lib_libtor_net_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)

noinst_HEADERS += \ src/lib/net/address.h \ + src/lib/net/alertsock.h \ src/lib/net/ipv4.h \ src/lib/net/ipv6.h \ src/lib/net/nettypes.h \ diff --git a/src/test/test_workqueue.c b/src/test/test_workqueue.c index fe23c5319..7c525aa28 100644 --- a/src/test/test_workqueue.c +++ b/src/test/test_workqueue.c @@ -9,6 +9,7 @@ #include "common/workqueue.h" #include "lib/crypt_ops/crypto_curve25519.h" #include "lib/crypt_ops/crypto_rand.h" +#include "lib/net/alertsock.h" #include "common/compat_libevent.h"

#include <stdio.h> @@ -450,4 +451,3 @@ main(int argc, char **argv) return 0; } } -