/* $NetBSD: bufferevent_sock.c,v 1.1.1.3 2017/01/31 21:14:52 christos Exp $ */ /* * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson * Copyright (c) 2002-2006 Niels Provos * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "event2/event-config.h" #include __RCSID("$NetBSD: bufferevent_sock.c,v 1.1.1.3 2017/01/31 21:14:52 christos Exp $"); #include "evconfig-private.h" #include #ifdef EVENT__HAVE_SYS_TIME_H #include #endif #include #include #include #include #ifdef EVENT__HAVE_STDARG_H #include #endif #ifdef EVENT__HAVE_UNISTD_H #include #endif #ifdef _WIN32 #include #include #endif #ifdef EVENT__HAVE_SYS_SOCKET_H #include #endif #ifdef EVENT__HAVE_NETINET_IN_H #include #endif #ifdef EVENT__HAVE_NETINET_IN6_H #include #endif #include "event2/util.h" #include "event2/bufferevent.h" #include "event2/buffer.h" #include "event2/bufferevent_struct.h" #include "event2/bufferevent_compat.h" #include "event2/event.h" #include "log-internal.h" #include "mm-internal.h" #include "bufferevent-internal.h" #include "util-internal.h" #ifdef _WIN32 #include "iocp-internal.h" #endif /* prototypes */ static int be_socket_enable(struct bufferevent *, short); static int be_socket_disable(struct bufferevent *, short); static void be_socket_destruct(struct bufferevent *); static int be_socket_flush(struct bufferevent *, short, enum bufferevent_flush_mode); static int be_socket_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *); static void be_socket_setfd(struct bufferevent *, evutil_socket_t); const struct bufferevent_ops bufferevent_ops_socket = { "socket", evutil_offsetof(struct bufferevent_private, bev), be_socket_enable, be_socket_disable, NULL, /* unlink */ be_socket_destruct, bufferevent_generic_adj_existing_timeouts_, be_socket_flush, be_socket_ctrl, }; const struct sockaddr* bufferevent_socket_get_conn_address_(struct bufferevent *bev) { struct bufferevent_private *bev_p = EVUTIL_UPCAST(bev, struct bufferevent_private, bev); return (struct sockaddr *)&bev_p->conn_address; } static void bufferevent_socket_set_conn_address_fd(struct bufferevent_private *bev_p, int fd) { socklen_t len = sizeof(bev_p->conn_address); struct sockaddr *addr = (struct sockaddr *)&bev_p->conn_address; if (addr->sa_family != AF_UNSPEC) getpeername(fd, addr, &len); } static void bufferevent_socket_set_conn_address(struct bufferevent_private *bev_p, struct sockaddr *addr, size_t addrlen) { EVUTIL_ASSERT(addrlen <= sizeof(bev_p->conn_address)); memcpy(&bev_p->conn_address, addr, addrlen); } static void bufferevent_socket_outbuf_cb(struct evbuffer *buf, const struct evbuffer_cb_info *cbinfo, void *arg) { struct bufferevent *bufev = arg; struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); if (cbinfo->n_added && (bufev->enabled & EV_WRITE) && !event_pending(&bufev->ev_write, EV_WRITE, NULL) && !bufev_p->write_suspended) { /* Somebody added data to the buffer, and we would like to * write, and we were not writing. So, start writing. */ if (bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1) { /* Should we log this? */ } } } static void bufferevent_readcb(evutil_socket_t fd, short event, void *arg) { struct bufferevent *bufev = arg; struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); struct evbuffer *input; int res = 0; short what = BEV_EVENT_READING; ev_ssize_t howmuch = -1, readmax=-1; bufferevent_incref_and_lock_(bufev); if (event == EV_TIMEOUT) { /* Note that we only check for event==EV_TIMEOUT. If * event==EV_TIMEOUT|EV_READ, we can safely ignore the * timeout, since a read has occurred */ what |= BEV_EVENT_TIMEOUT; goto error; } input = bufev->input; /* * If we have a high watermark configured then we don't want to * read more data than would make us reach the watermark. */ if (bufev->wm_read.high != 0) { howmuch = bufev->wm_read.high - evbuffer_get_length(input); /* we somehow lowered the watermark, stop reading */ if (howmuch <= 0) { bufferevent_wm_suspend_read(bufev); goto done; } } readmax = bufferevent_get_read_max_(bufev_p); if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited" * uglifies this code. XXXX */ howmuch = readmax; if (bufev_p->read_suspended) goto done; evbuffer_unfreeze(input, 0); res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */ evbuffer_freeze(input, 0); if (res == -1) { int err = evutil_socket_geterror(fd); if (EVUTIL_ERR_RW_RETRIABLE(err)) goto reschedule; if (EVUTIL_ERR_CONNECT_REFUSED(err)) { bufev_p->connection_refused = 1; goto done; } /* error case */ what |= BEV_EVENT_ERROR; } else if (res == 0) { /* eof case */ what |= BEV_EVENT_EOF; } if (res <= 0) goto error; bufferevent_decrement_read_buckets_(bufev_p, res); /* Invoke the user callback - must always be called last */ bufferevent_trigger_nolock_(bufev, EV_READ, 0); goto done; reschedule: goto done; error: bufferevent_disable(bufev, EV_READ); bufferevent_run_eventcb_(bufev, what, 0); done: bufferevent_decref_and_unlock_(bufev); } static void bufferevent_writecb(evutil_socket_t fd, short event, void *arg) { struct bufferevent *bufev = arg; struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); int res = 0; short what = BEV_EVENT_WRITING; int connected = 0; ev_ssize_t atmost = -1; bufferevent_incref_and_lock_(bufev); if (event == EV_TIMEOUT) { /* Note that we only check for event==EV_TIMEOUT. If * event==EV_TIMEOUT|EV_WRITE, we can safely ignore the * timeout, since a read has occurred */ what |= BEV_EVENT_TIMEOUT; goto error; } if (bufev_p->connecting) { int c = evutil_socket_finished_connecting_(fd); /* we need to fake the error if the connection was refused * immediately - usually connection to localhost on BSD */ if (bufev_p->connection_refused) { bufev_p->connection_refused = 0; c = -1; } if (c == 0) goto done; bufev_p->connecting = 0; if (c < 0) { event_del(&bufev->ev_write); event_del(&bufev->ev_read); bufferevent_run_eventcb_(bufev, BEV_EVENT_ERROR, 0); goto done; } else { connected = 1; bufferevent_socket_set_conn_address_fd(bufev_p, fd); #ifdef _WIN32 if (BEV_IS_ASYNC(bufev)) { event_del(&bufev->ev_write); bufferevent_async_set_connected_(bufev); bufferevent_run_eventcb_(bufev, BEV_EVENT_CONNECTED, 0); goto done; } #endif bufferevent_run_eventcb_(bufev, BEV_EVENT_CONNECTED, 0); if (!(bufev->enabled & EV_WRITE) || bufev_p->write_suspended) { event_del(&bufev->ev_write); goto done; } } } atmost = bufferevent_get_write_max_(bufev_p); if (bufev_p->write_suspended) goto done; if (evbuffer_get_length(bufev->output)) { evbuffer_unfreeze(bufev->output, 1); res = evbuffer_write_atmost(bufev->output, fd, atmost); evbuffer_freeze(bufev->output, 1); if (res == -1) { int err = evutil_socket_geterror(fd); if (EVUTIL_ERR_RW_RETRIABLE(err)) goto reschedule; what |= BEV_EVENT_ERROR; } else if (res == 0) { /* eof case XXXX Actually, a 0 on write doesn't indicate an EOF. An ECONNRESET might be more typical. */ what |= BEV_EVENT_EOF; } if (res <= 0) goto error; bufferevent_decrement_write_buckets_(bufev_p, res); } if (evbuffer_get_length(bufev->output) == 0) { event_del(&bufev->ev_write); } /* * Invoke the user callback if our buffer is drained or below the * low watermark. */ if (res || !connected) { bufferevent_trigger_nolock_(bufev, EV_WRITE, 0); } goto done; reschedule: if (evbuffer_get_length(bufev->output) == 0) { event_del(&bufev->ev_write); } goto done; error: bufferevent_disable(bufev, EV_WRITE); bufferevent_run_eventcb_(bufev, what, 0); done: bufferevent_decref_and_unlock_(bufev); } struct bufferevent * bufferevent_socket_new(struct event_base *base, evutil_socket_t fd, int options) { struct bufferevent_private *bufev_p; struct bufferevent *bufev; #ifdef _WIN32 if (base && event_base_get_iocp_(base)) return bufferevent_async_new_(base, fd, options); #endif if ((bufev_p = mm_calloc(1, sizeof(struct bufferevent_private)))== NULL) return NULL; if (bufferevent_init_common_(bufev_p, base, &bufferevent_ops_socket, options) < 0) { mm_free(bufev_p); return NULL; } bufev = &bufev_p->bev; evbuffer_set_flags(bufev->output, EVBUFFER_FLAG_DRAINS_TO_FD); event_assign(&bufev->ev_read, bufev->ev_base, fd, EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev); event_assign(&bufev->ev_write, bufev->ev_base, fd, EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev); evbuffer_add_cb(bufev->output, bufferevent_socket_outbuf_cb, bufev); evbuffer_freeze(bufev->input, 0); evbuffer_freeze(bufev->output, 1); return bufev; } int bufferevent_socket_connect(struct bufferevent *bev, const struct sockaddr *sa, int socklen) { struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bev, struct bufferevent_private, bev); evutil_socket_t fd; int r = 0; int result=-1; int ownfd = 0; bufferevent_incref_and_lock_(bev); if (!bufev_p) goto done; fd = bufferevent_getfd(bev); if (fd < 0) { if (!sa) goto done; fd = evutil_socket_(sa->sa_family, SOCK_STREAM|EVUTIL_SOCK_NONBLOCK, 0); if (fd < 0) goto done; ownfd = 1; } if (sa) { #ifdef _WIN32 if (bufferevent_async_can_connect_(bev)) { bufferevent_setfd(bev, fd); r = bufferevent_async_connect_(bev, fd, sa, socklen); if (r < 0) goto freesock; bufev_p->connecting = 1; result = 0; goto done; } else #endif r = evutil_socket_connect_(&fd, sa, socklen); if (r < 0) goto freesock; } #ifdef _WIN32 /* ConnectEx() isn't always around, even when IOCP is enabled. * Here, we borrow the socket object's write handler to fall back * on a non-blocking connect() when ConnectEx() is unavailable. */ if (BEV_IS_ASYNC(bev)) { event_assign(&bev->ev_write, bev->ev_base, fd, EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bev); } #endif bufferevent_setfd(bev, fd); if (r == 0) { if (! be_socket_enable(bev, EV_WRITE)) { bufev_p->connecting = 1; result = 0; goto done; } } else if (r == 1) { /* The connect succeeded already. How very BSD of it. */ result = 0; bufev_p->connecting = 1; bufferevent_trigger_nolock_(bev, EV_WRITE, BEV_OPT_DEFER_CALLBACKS); } else { /* The connect failed already. How very BSD of it. */ result = 0; bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, BEV_OPT_DEFER_CALLBACKS); bufferevent_disable(bev, EV_WRITE|EV_READ); } goto done; freesock: bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0); if (ownfd) evutil_closesocket(fd); /* do something about the error? */ done: bufferevent_decref_and_unlock_(bev); return result; } static void bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai, void *arg) { struct bufferevent *bev = arg; struct bufferevent_private *bev_p = EVUTIL_UPCAST(bev, struct bufferevent_private, bev); int r; BEV_LOCK(bev); bufferevent_unsuspend_write_(bev, BEV_SUSPEND_LOOKUP); bufferevent_unsuspend_read_(bev, BEV_SUSPEND_LOOKUP); bev_p->dns_request = NULL; if (result == EVUTIL_EAI_CANCEL) { bev_p->dns_error = result; bufferevent_decref_and_unlock_(bev); return; } if (result != 0) { bev_p->dns_error = result; bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0); bufferevent_decref_and_unlock_(bev); if (ai) evutil_freeaddrinfo(ai); return; } /* XXX use the other addrinfos? */ /* XXX use this return value */ bufferevent_socket_set_conn_address(bev_p, ai->ai_addr, (int)ai->ai_addrlen); r = bufferevent_socket_connect(bev, ai->ai_addr, (int)ai->ai_addrlen); (void)r; bufferevent_decref_and_unlock_(bev); evutil_freeaddrinfo(ai); } int bufferevent_socket_connect_hostname(struct bufferevent *bev, struct evdns_base *evdns_base, int family, const char *hostname, int port) { char portbuf[10]; struct evutil_addrinfo hint; struct bufferevent_private *bev_p = EVUTIL_UPCAST(bev, struct bufferevent_private, bev); if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC) return -1; if (port < 1 || port > 65535) return -1; memset(&hint, 0, sizeof(hint)); hint.ai_family = family; hint.ai_protocol = IPPROTO_TCP; hint.ai_socktype = SOCK_STREAM; evutil_snprintf(portbuf, sizeof(portbuf), "%d", port); BEV_LOCK(bev); bev_p->dns_error = 0; bufferevent_suspend_write_(bev, BEV_SUSPEND_LOOKUP); bufferevent_suspend_read_(bev, BEV_SUSPEND_LOOKUP); bufferevent_incref_(bev); bev_p->dns_request = evutil_getaddrinfo_async_(evdns_base, hostname, portbuf, &hint, bufferevent_connect_getaddrinfo_cb, bev); BEV_UNLOCK(bev); return 0; } int bufferevent_socket_get_dns_error(struct bufferevent *bev) { int rv; struct bufferevent_private *bev_p = EVUTIL_UPCAST(bev, struct bufferevent_private, bev); BEV_LOCK(bev); rv = bev_p->dns_error; BEV_UNLOCK(bev); return rv; } /* * Create a new buffered event object. * * The read callback is invoked whenever we read new data. * The write callback is invoked whenever the output buffer is drained. * The error callback is invoked on a write/read error or on EOF. * * Both read and write callbacks maybe NULL. The error callback is not * allowed to be NULL and have to be provided always. */ struct bufferevent * bufferevent_new(evutil_socket_t fd, bufferevent_data_cb readcb, bufferevent_data_cb writecb, bufferevent_event_cb eventcb, void *cbarg) { struct bufferevent *bufev; if (!(bufev = bufferevent_socket_new(NULL, fd, 0))) return NULL; bufferevent_setcb(bufev, readcb, writecb, eventcb, cbarg); return bufev; } static int be_socket_enable(struct bufferevent *bufev, short event) { if (event & EV_READ && bufferevent_add_event_(&bufev->ev_read, &bufev->timeout_read) == -1) return -1; if (event & EV_WRITE && bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1) return -1; return 0; } static int be_socket_disable(struct bufferevent *bufev, short event) { struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); if (event & EV_READ) { if (event_del(&bufev->ev_read) == -1) return -1; } /* Don't actually disable the write if we are trying to connect. */ if ((event & EV_WRITE) && ! bufev_p->connecting) { if (event_del(&bufev->ev_write) == -1) return -1; } return 0; } static void be_socket_destruct(struct bufferevent *bufev) { struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); evutil_socket_t fd; EVUTIL_ASSERT(bufev->be_ops == &bufferevent_ops_socket); fd = event_get_fd(&bufev->ev_read); if ((bufev_p->options & BEV_OPT_CLOSE_ON_FREE) && fd >= 0) EVUTIL_CLOSESOCKET(fd); evutil_getaddrinfo_cancel_async_(bufev_p->dns_request); } static int be_socket_flush(struct bufferevent *bev, short iotype, enum bufferevent_flush_mode mode) { return 0; } static void be_socket_setfd(struct bufferevent *bufev, evutil_socket_t fd) { struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); BEV_LOCK(bufev); EVUTIL_ASSERT(bufev->be_ops == &bufferevent_ops_socket); event_del(&bufev->ev_read); event_del(&bufev->ev_write); evbuffer_unfreeze(bufev->input, 0); evbuffer_unfreeze(bufev->output, 1); event_assign(&bufev->ev_read, bufev->ev_base, fd, EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev); event_assign(&bufev->ev_write, bufev->ev_base, fd, EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev); if (fd >= 0) bufferevent_enable(bufev, bufev->enabled); evutil_getaddrinfo_cancel_async_(bufev_p->dns_request); BEV_UNLOCK(bufev); } /* XXXX Should non-socket bufferevents support this? */ int bufferevent_priority_set(struct bufferevent *bufev, int priority) { int r = -1; struct bufferevent_private *bufev_p = EVUTIL_UPCAST(bufev, struct bufferevent_private, bev); BEV_LOCK(bufev); if (bufev->be_ops != &bufferevent_ops_socket) goto done; if (event_priority_set(&bufev->ev_read, priority) == -1) goto done; if (event_priority_set(&bufev->ev_write, priority) == -1) goto done; event_deferred_cb_set_priority_(&bufev_p->deferred, priority); r = 0; done: BEV_UNLOCK(bufev); return r; } /* XXXX Should non-socket bufferevents support this? */ int bufferevent_base_set(struct event_base *base, struct bufferevent *bufev) { int res = -1; BEV_LOCK(bufev); if (bufev->be_ops != &bufferevent_ops_socket) goto done; bufev->ev_base = base; res = event_base_set(base, &bufev->ev_read); if (res == -1) goto done; res = event_base_set(base, &bufev->ev_write); done: BEV_UNLOCK(bufev); return res; } static int be_socket_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op, union bufferevent_ctrl_data *data) { switch (op) { case BEV_CTRL_SET_FD: be_socket_setfd(bev, data->fd); return 0; case BEV_CTRL_GET_FD: data->fd = event_get_fd(&bev->ev_read); return 0; case BEV_CTRL_GET_UNDERLYING: case BEV_CTRL_CANCEL_ALL: default: return -1; } }