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transmission/libtransmission/peer-io.c

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/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2 (b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <event2/event.h>
#include <event2/buffer.h>
#include <event2/bufferevent.h>
#include <libutp/utp.h>
#include "transmission.h"
#include "session.h"
#include "bandwidth.h"
#include "crypto.h"
#include "log.h"
#include "net.h"
#include "peer-common.h" /* MAX_BLOCK_SIZE */
#include "peer-io.h"
#include "trevent.h" /* tr_runInEventThread () */
#include "tr-utp.h"
#include "utils.h"
#ifdef WIN32
#define EAGAIN WSAEWOULDBLOCK
#define EINTR WSAEINTR
#define EINPROGRESS WSAEINPROGRESS
#define EPIPE WSAECONNRESET
#endif
/* The amount of read bufferring that we allow for uTP sockets. */
#define UTP_READ_BUFFER_SIZE (256 * 1024)
static size_t
guessPacketOverhead (size_t d)
{
/**
* http://sd.wareonearth.com/~phil/net/overhead/
*
* TCP over Ethernet:
* Assuming no header compression (e.g. not PPP)
* Add 20 IPv4 header or 40 IPv6 header (no options)
* Add 20 TCP header
* Add 12 bytes optional TCP timestamps
* Max TCP Payload data rates over ethernet are thus:
* (1500-40)/ (38+1500) = 94.9285 % IPv4, minimal headers
* (1500-52)/ (38+1500) = 94.1482 % IPv4, TCP timestamps
* (1500-52)/ (42+1500) = 93.9040 % 802.1q, IPv4, TCP timestamps
* (1500-60)/ (38+1500) = 93.6281 % IPv6, minimal headers
* (1500-72)/ (38+1500) = 92.8479 % IPv6, TCP timestamps
* (1500-72)/ (42+1500) = 92.6070 % 802.1q, IPv6, ICP timestamps
*/
const double assumed_payload_data_rate = 94.0;
return (unsigned int)(d * (100.0 / assumed_payload_data_rate) - d);
}
/**
***
**/
#define dbgmsg(io, ...) \
do \
{ \
if (tr_logGetDeepEnabled ()) \
tr_logAddDeep (__FILE__, __LINE__, tr_peerIoGetAddrStr (io), __VA_ARGS__); \
} \
while (0)
/**
***
**/
struct tr_datatype
{
struct tr_datatype * next;
size_t length;
bool isPieceData;
};
static struct tr_datatype * datatype_pool = NULL;
static const struct tr_datatype TR_DATATYPE_INIT = { NULL, 0, false };
static struct tr_datatype *
datatype_new (void)
{
struct tr_datatype * ret;
if (datatype_pool == NULL)
ret = tr_new (struct tr_datatype, 1);
else {
ret = datatype_pool;
datatype_pool = datatype_pool->next;
}
*ret = TR_DATATYPE_INIT;
return ret;
}
static void
datatype_free (struct tr_datatype * datatype)
{
datatype->next = datatype_pool;
datatype_pool = datatype;
}
static void
peer_io_pull_datatype (tr_peerIo * io)
{
struct tr_datatype * tmp;
if ((tmp = io->outbuf_datatypes))
{
io->outbuf_datatypes = tmp->next;
datatype_free (tmp);
}
}
static void
peer_io_push_datatype (tr_peerIo * io, struct tr_datatype * datatype)
{
struct tr_datatype * tmp;
if ((tmp = io->outbuf_datatypes)) {
while (tmp->next != NULL)
tmp = tmp->next;
tmp->next = datatype;
} else {
io->outbuf_datatypes = datatype;
}
}
/***
****
***/
static void
didWriteWrapper (tr_peerIo * io, unsigned int bytes_transferred)
{
while (bytes_transferred && tr_isPeerIo (io))
{
struct tr_datatype * next = io->outbuf_datatypes;
const unsigned int payload = MIN (next->length, bytes_transferred);
/* For uTP sockets, the overhead is computed in utp_on_overhead. */
const unsigned int overhead =
io->socket ? guessPacketOverhead (payload) : 0;
const uint64_t now = tr_time_msec ();
tr_bandwidthUsed (&io->bandwidth, TR_UP, payload, next->isPieceData, now);
if (overhead > 0)
tr_bandwidthUsed (&io->bandwidth, TR_UP, overhead, false, now);
if (io->didWrite)
io->didWrite (io, payload, next->isPieceData, io->userData);
if (tr_isPeerIo (io))
{
bytes_transferred -= payload;
next->length -= payload;
if (!next->length)
peer_io_pull_datatype (io);
}
}
}
static void
canReadWrapper (tr_peerIo * io)
{
bool err = 0;
bool done = 0;
tr_session * session;
dbgmsg (io, "canRead");
tr_peerIoRef (io);
session = io->session;
/* try to consume the input buffer */
if (io->canRead)
{
const uint64_t now = tr_time_msec ();
tr_sessionLock (session);
while (!done && !err)
{
size_t piece = 0;
const size_t oldLen = evbuffer_get_length (io->inbuf);
const int ret = io->canRead (io, io->userData, &piece);
const size_t used = oldLen - evbuffer_get_length (io->inbuf);
const unsigned int overhead = guessPacketOverhead (used);
if (piece || (piece!=used))
{
if (piece)
tr_bandwidthUsed (&io->bandwidth, TR_DOWN, piece, true, now);
if (used != piece)
tr_bandwidthUsed (&io->bandwidth, TR_DOWN, used - piece, false, now);
}
if (overhead > 0)
tr_bandwidthUsed (&io->bandwidth, TR_UP, overhead, false, now);
switch (ret)
{
case READ_NOW:
if (evbuffer_get_length (io->inbuf))
continue;
done = 1;
break;
case READ_LATER:
done = 1;
break;
case READ_ERR:
err = 1;
break;
}
assert (tr_isPeerIo (io));
}
tr_sessionUnlock (session);
}
tr_peerIoUnref (io);
}
static void
event_read_cb (int fd, short event UNUSED, void * vio)
{
int res;
int e;
tr_peerIo * io = vio;
/* Limit the input buffer to 256K, so it doesn't grow too large */
unsigned int howmuch;
unsigned int curlen;
const tr_direction dir = TR_DOWN;
const unsigned int max = 256 * 1024;
assert (tr_isPeerIo (io));
assert (io->socket >= 0);
io->pendingEvents &= ~EV_READ;
curlen = evbuffer_get_length (io->inbuf);
howmuch = curlen >= max ? 0 : max - curlen;
howmuch = tr_bandwidthClamp (&io->bandwidth, TR_DOWN, howmuch);
dbgmsg (io, "libevent says this peer is ready to read");
/* if we don't have any bandwidth left, stop reading */
if (howmuch < 1) {
tr_peerIoSetEnabled (io, dir, false);
return;
}
EVUTIL_SET_SOCKET_ERROR (0);
res = evbuffer_read (io->inbuf, fd, (int)howmuch);
e = EVUTIL_SOCKET_ERROR ();
if (res > 0)
{
tr_peerIoSetEnabled (io, dir, true);
/* Invoke the user callback - must always be called last */
canReadWrapper (io);
}
else
{
char errstr[512];
short what = BEV_EVENT_READING;
if (res == 0) /* EOF */
what |= BEV_EVENT_EOF;
else if (res == -1) {
if (e == EAGAIN || e == EINTR) {
tr_peerIoSetEnabled (io, dir, true);
return;
}
what |= BEV_EVENT_ERROR;
}
dbgmsg (io, "event_read_cb got an error. res is %d, what is %hd, errno is %d (%s)",
res, what, e, tr_net_strerror (errstr, sizeof (errstr), e));
if (io->gotError != NULL)
io->gotError (io, what, io->userData);
}
}
static int
tr_evbuffer_write (tr_peerIo * io, int fd, size_t howmuch)
{
int e;
int n;
char errstr[256];
EVUTIL_SET_SOCKET_ERROR (0);
n = evbuffer_write_atmost (io->outbuf, fd, howmuch);
e = EVUTIL_SOCKET_ERROR ();
dbgmsg (io, "wrote %d to peer (%s)", n, (n==-1?tr_net_strerror (errstr,sizeof (errstr),e):""));
return n;
}
static void
event_write_cb (int fd, short event UNUSED, void * vio)
{
int res = 0;
int e;
short what = BEV_EVENT_WRITING;
tr_peerIo * io = vio;
size_t howmuch;
const tr_direction dir = TR_UP;
char errstr[1024];
assert (tr_isPeerIo (io));
assert (io->socket >= 0);
io->pendingEvents &= ~EV_WRITE;
dbgmsg (io, "libevent says this peer is ready to write");
/* Write as much as possible, since the socket is non-blocking, write () will
* return if it can't write any more data without blocking */
howmuch = tr_bandwidthClamp (&io->bandwidth, dir, evbuffer_get_length (io->outbuf));
/* if we don't have any bandwidth left, stop writing */
if (howmuch < 1) {
tr_peerIoSetEnabled (io, dir, false);
return;
}
EVUTIL_SET_SOCKET_ERROR (0);
res = tr_evbuffer_write (io, fd, howmuch);
e = EVUTIL_SOCKET_ERROR ();
if (res == -1) {
if (!e || e == EAGAIN || e == EINTR || e == EINPROGRESS)
goto reschedule;
/* error case */
what |= BEV_EVENT_ERROR;
} else if (res == 0) {
/* eof case */
what |= BEV_EVENT_EOF;
}
if (res <= 0)
goto error;
if (evbuffer_get_length (io->outbuf))
tr_peerIoSetEnabled (io, dir, true);
didWriteWrapper (io, res);
return;
reschedule:
if (evbuffer_get_length (io->outbuf))
tr_peerIoSetEnabled (io, dir, true);
return;
error:
tr_net_strerror (errstr, sizeof (errstr), e);
dbgmsg (io, "event_write_cb got an error. res is %d, what is %hd, errno is %d (%s)", res, what, e, errstr);
if (io->gotError != NULL)
io->gotError (io, what, io->userData);
}
/**
***
**/
static void
maybeSetCongestionAlgorithm (int socket, const char * algorithm)
{
if (algorithm && *algorithm)
{
const int rc = tr_netSetCongestionControl (socket, algorithm);
if (rc < 0)
tr_logAddNamedInfo ("Net", "Can't set congestion control algorithm '%s': %s",
algorithm, tr_strerror (errno));
}
}
#ifdef WITH_UTP
/* UTP callbacks */
static void
utp_on_read (void *closure, const unsigned char *buf, size_t buflen)
{
int rc;
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
rc = evbuffer_add (io->inbuf, buf, buflen);
dbgmsg (io, "utp_on_read got %zu bytes", buflen);
if (rc < 0) {
tr_logAddNamedError ("UTP", "On read evbuffer_add");
return;
}
tr_peerIoSetEnabled (io, TR_DOWN, true);
canReadWrapper (io);
}
static void
utp_on_write (void *closure, unsigned char *buf, size_t buflen)
{
int rc;
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
rc = evbuffer_remove (io->outbuf, buf, buflen);
dbgmsg (io, "utp_on_write sending %zu bytes... evbuffer_remove returned %d", buflen, rc);
assert (rc == (int)buflen); /* if this fails, we've corrupted our bookkeeping somewhere */
if (rc < (long)buflen) {
tr_logAddNamedError ("UTP", "Short write: %d < %ld", rc, (long)buflen);
}
didWriteWrapper (io, buflen);
}
static size_t
utp_get_rb_size (void *closure)
{
size_t bytes;
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
bytes = tr_bandwidthClamp (&io->bandwidth, TR_DOWN, UTP_READ_BUFFER_SIZE);
dbgmsg (io, "utp_get_rb_size is saying it's ready to read %zu bytes", bytes);
return UTP_READ_BUFFER_SIZE - bytes;
}
static int tr_peerIoTryWrite (tr_peerIo * io, size_t howmuch);
static void
utp_on_writable (tr_peerIo *io)
{
int n;
dbgmsg (io, "libutp says this peer is ready to write");
n = tr_peerIoTryWrite (io, SIZE_MAX);
tr_peerIoSetEnabled (io, TR_UP, n && evbuffer_get_length (io->outbuf));
}
static void
utp_on_state_change (void *closure, int state)
{
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
if (state == UTP_STATE_CONNECT) {
dbgmsg (io, "utp_on_state_change -- changed to connected");
io->utpSupported = true;
} else if (state == UTP_STATE_WRITABLE) {
dbgmsg (io, "utp_on_state_change -- changed to writable");
if (io->pendingEvents & EV_WRITE)
utp_on_writable (io);
} else if (state == UTP_STATE_EOF) {
if (io->gotError)
io->gotError (io, BEV_EVENT_EOF, io->userData);
} else if (state == UTP_STATE_DESTROYING) {
tr_logAddNamedError ("UTP", "Impossible state UTP_STATE_DESTROYING");
return;
} else {
tr_logAddNamedError ("UTP", "Unknown state %d", state);
}
}
static void
utp_on_error (void *closure, int errcode)
{
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
dbgmsg (io, "utp_on_error -- errcode is %d", errcode);
if (io->gotError) {
errno = errcode;
io->gotError (io, BEV_EVENT_ERROR, io->userData);
}
}
static void
utp_on_overhead (void *closure, uint8_t send, size_t count, int type UNUSED)
{
tr_peerIo *io = closure;
assert (tr_isPeerIo (io));
dbgmsg (io, "utp_on_overhead -- count is %zu", count);
tr_bandwidthUsed (&io->bandwidth, send ? TR_UP : TR_DOWN,
count, false, tr_time_msec ());
}
static struct UTPFunctionTable utp_function_table = {
.on_read = utp_on_read,
.on_write = utp_on_write,
.get_rb_size = utp_get_rb_size,
.on_state = utp_on_state_change,
.on_error = utp_on_error,
.on_overhead = utp_on_overhead
};
/* Dummy UTP callbacks. */
/* We switch a UTP socket to use these after the associated peerIo has been
destroyed -- see io_dtor. */
static void
dummy_read (void * closure UNUSED, const unsigned char *buf UNUSED, size_t buflen UNUSED)
{
/* This cannot happen, as far as I'm aware. */
tr_logAddNamedError ("UTP", "On_read called on closed socket");
}
static void
dummy_write (void * closure UNUSED, unsigned char *buf, size_t buflen)
{
/* This can very well happen if we've shut down a peer connection that
had unflushed buffers. Complain and send zeroes. */
tr_logAddNamedDbg ("UTP", "On_write called on closed socket");
memset (buf, 0, buflen);
}
static size_t
dummy_get_rb_size (void * closure UNUSED)
{
return 0;
}
static void
dummy_on_state_change (void * closure UNUSED, int state UNUSED)
{
return;
}
static void
dummy_on_error (void * closure UNUSED, int errcode UNUSED)
{
return;
}
static void
dummy_on_overhead (void *closure UNUSED, uint8_t send UNUSED, size_t count UNUSED, int type UNUSED)
{
return;
}
static struct UTPFunctionTable dummy_utp_function_table = {
.on_read = dummy_read,
.on_write = dummy_write,
.get_rb_size = dummy_get_rb_size,
.on_state = dummy_on_state_change,
.on_error = dummy_on_error,
.on_overhead = dummy_on_overhead
};
#endif /* #ifdef WITH_UTP */
static tr_peerIo*
tr_peerIoNew (tr_session * session,
tr_bandwidth * parent,
const tr_address * addr,
tr_port port,
const uint8_t * torrentHash,
bool isIncoming,
bool isSeed,
int socket,
struct UTPSocket * utp_socket)
{
tr_peerIo * io;
assert (session != NULL);
assert (session->events != NULL);
assert (tr_isBool (isIncoming));
assert (tr_isBool (isSeed));
assert (tr_amInEventThread (session));
assert ((socket < 0) == (utp_socket != NULL));
#ifndef WITH_UTP
assert (socket >= 0);
#endif
if (socket >= 0) {
tr_netSetTOS (socket, session->peerSocketTOS);
maybeSetCongestionAlgorithm (socket, session->peer_congestion_algorithm);
}
io = tr_new0 (tr_peerIo, 1);
io->magicNumber = PEER_IO_MAGIC_NUMBER;
io->refCount = 1;
tr_cryptoConstruct (&io->crypto, torrentHash, isIncoming);
io->session = session;
io->addr = *addr;
io->isSeed = isSeed;
io->port = port;
io->socket = socket;
io->utp_socket = utp_socket;
io->isIncoming = isIncoming != 0;
io->timeCreated = tr_time ();
io->inbuf = evbuffer_new ();
io->outbuf = evbuffer_new ();
tr_bandwidthConstruct (&io->bandwidth, session, parent);
tr_bandwidthSetPeer (&io->bandwidth, io);
dbgmsg (io, "bandwidth is %p; its parent is %p", &io->bandwidth, parent);
dbgmsg (io, "socket is %d, utp_socket is %p", socket, utp_socket);
if (io->socket >= 0) {
io->event_read = event_new (session->event_base,
io->socket, EV_READ, event_read_cb, io);
io->event_write = event_new (session->event_base,
io->socket, EV_WRITE, event_write_cb, io);
}
#ifdef WITH_UTP
else {
UTP_SetSockopt (utp_socket, SO_RCVBUF, UTP_READ_BUFFER_SIZE);
dbgmsg (io, "%s", "calling UTP_SetCallbacks &utp_function_table");
UTP_SetCallbacks (utp_socket,
&utp_function_table,
io);
if (!isIncoming) {
dbgmsg (io, "%s", "calling UTP_Connect");
UTP_Connect (utp_socket);
}
}
#endif
return io;
}
tr_peerIo*
tr_peerIoNewIncoming (tr_session * session,
tr_bandwidth * parent,
const tr_address * addr,
tr_port port,
int fd,
struct UTPSocket * utp_socket)
{
assert (session);
assert (tr_address_is_valid (addr));
return tr_peerIoNew (session, parent, addr, port, NULL, true, false,
fd, utp_socket);
}
tr_peerIo*
tr_peerIoNewOutgoing (tr_session * session,
tr_bandwidth * parent,
const tr_address * addr,
tr_port port,
const uint8_t * torrentHash,
bool isSeed,
bool utp)
{
int fd = -1;
struct UTPSocket * utp_socket = NULL;
assert (session);
assert (tr_address_is_valid (addr));
assert (torrentHash);
if (utp)
utp_socket = tr_netOpenPeerUTPSocket (session, addr, port, isSeed);
if (!utp_socket) {
fd = tr_netOpenPeerSocket (session, addr, port, isSeed);
dbgmsg (NULL, "tr_netOpenPeerSocket returned fd %d", fd);
}
if (fd < 0 && utp_socket == NULL)
return NULL;
return tr_peerIoNew (session, parent, addr, port,
torrentHash, false, isSeed, fd, utp_socket);
}
/***
****
***/
static void
event_enable (tr_peerIo * io, short event)
{
assert (tr_amInEventThread (io->session));
assert (io->session != NULL);
assert (io->session->events != NULL);
if (io->socket >= 0)
{
assert (event_initialized (io->event_read));
assert (event_initialized (io->event_write));
}
if ((event & EV_READ) && ! (io->pendingEvents & EV_READ))
{
dbgmsg (io, "enabling ready-to-read polling");
if (io->socket >= 0)
event_add (io->event_read, NULL);
io->pendingEvents |= EV_READ;
}
if ((event & EV_WRITE) && ! (io->pendingEvents & EV_WRITE))
{
dbgmsg (io, "enabling ready-to-write polling");
if (io->socket >= 0)
event_add (io->event_write, NULL);
io->pendingEvents |= EV_WRITE;
}
}
static void
event_disable (struct tr_peerIo * io, short event)
{
assert (tr_amInEventThread (io->session));
assert (io->session != NULL);
assert (io->session->events != NULL);
if (io->socket >= 0)
{
assert (event_initialized (io->event_read));
assert (event_initialized (io->event_write));
}
if ((event & EV_READ) && (io->pendingEvents & EV_READ))
{
dbgmsg (io, "disabling ready-to-read polling");
if (io->socket >= 0)
event_del (io->event_read);
io->pendingEvents &= ~EV_READ;
}
if ((event & EV_WRITE) && (io->pendingEvents & EV_WRITE))
{
dbgmsg (io, "disabling ready-to-write polling");
if (io->socket >= 0)
event_del (io->event_write);
io->pendingEvents &= ~EV_WRITE;
}
}
void
tr_peerIoSetEnabled (tr_peerIo * io,
tr_direction dir,
bool isEnabled)
{
const short event = dir == TR_UP ? EV_WRITE : EV_READ;
assert (tr_isPeerIo (io));
assert (tr_isDirection (dir));
assert (tr_amInEventThread (io->session));
assert (io->session->events != NULL);
if (isEnabled)
event_enable (io, event);
else
event_disable (io, event);
}
/***
****
***/
static void
io_close_socket (tr_peerIo * io)
{
if (io->socket >= 0) {
tr_netClose (io->session, io->socket);
io->socket = -1;
}
if (io->event_read != NULL) {
event_free (io->event_read);
io->event_read = NULL;
}
if (io->event_write != NULL) {
event_free (io->event_write);
io->event_write = NULL;
}
#ifdef WITH_UTP
if (io->utp_socket) {
UTP_SetCallbacks (io->utp_socket,
&dummy_utp_function_table,
NULL);
UTP_Close (io->utp_socket);
io->utp_socket = NULL;
}
#endif
}
static void
io_dtor (void * vio)
{
tr_peerIo * io = vio;
assert (tr_isPeerIo (io));
assert (tr_amInEventThread (io->session));
assert (io->session->events != NULL);
dbgmsg (io, "in tr_peerIo destructor");
event_disable (io, EV_READ | EV_WRITE);
tr_bandwidthDestruct (&io->bandwidth);
evbuffer_free (io->outbuf);
evbuffer_free (io->inbuf);
io_close_socket (io);
tr_cryptoDestruct (&io->crypto);
while (io->outbuf_datatypes != NULL)
peer_io_pull_datatype (io);
memset (io, ~0, sizeof (tr_peerIo));
tr_free (io);
}
static void
tr_peerIoFree (tr_peerIo * io)
{
if (io)
{
dbgmsg (io, "in tr_peerIoFree");
io->canRead = NULL;
io->didWrite = NULL;
io->gotError = NULL;
tr_runInEventThread (io->session, io_dtor, io);
}
}
void
tr_peerIoRefImpl (const char * file, int line, tr_peerIo * io)
{
assert (tr_isPeerIo (io));
dbgmsg (io, "%s:%d is incrementing the IO's refcount from %d to %d",
file, line, io->refCount, io->refCount+1);
++io->refCount;
}
void
tr_peerIoUnrefImpl (const char * file, int line, tr_peerIo * io)
{
assert (tr_isPeerIo (io));
dbgmsg (io, "%s:%d is decrementing the IO's refcount from %d to %d",
file, line, io->refCount, io->refCount-1);
if (!--io->refCount)
tr_peerIoFree (io);
}
const tr_address*
tr_peerIoGetAddress (const tr_peerIo * io, tr_port * port)
{
assert (tr_isPeerIo (io));
if (port)
*port = io->port;
return &io->addr;
}
const char*
tr_peerIoAddrStr (const tr_address * addr, tr_port port)
{
static char buf[512];
tr_snprintf (buf, sizeof (buf), "[%s]:%u", tr_address_to_string (addr), ntohs (port));
return buf;
}
const char* tr_peerIoGetAddrStr (const tr_peerIo * io)
{
return tr_isPeerIo (io) ? tr_peerIoAddrStr (&io->addr, io->port) : "error";
}
void
tr_peerIoSetIOFuncs (tr_peerIo * io,
tr_can_read_cb readcb,
tr_did_write_cb writecb,
tr_net_error_cb errcb,
void * userData)
{
io->canRead = readcb;
io->didWrite = writecb;
io->gotError = errcb;
io->userData = userData;
}
void
tr_peerIoClear (tr_peerIo * io)
{
tr_peerIoSetIOFuncs (io, NULL, NULL, NULL, NULL);
tr_peerIoSetEnabled (io, TR_UP, false);
tr_peerIoSetEnabled (io, TR_DOWN, false);
}
int
tr_peerIoReconnect (tr_peerIo * io)
{
short int pendingEvents;
tr_session * session;
assert (tr_isPeerIo (io));
assert (!tr_peerIoIsIncoming (io));
session = tr_peerIoGetSession (io);
pendingEvents = io->pendingEvents;
event_disable (io, EV_READ | EV_WRITE);
io_close_socket (io);
io->socket = tr_netOpenPeerSocket (session, &io->addr, io->port, io->isSeed);
io->event_read = event_new (session->event_base, io->socket, EV_READ, event_read_cb, io);
io->event_write = event_new (session->event_base, io->socket, EV_WRITE, event_write_cb, io);
if (io->socket >= 0)
{
event_enable (io, pendingEvents);
tr_netSetTOS (io->socket, session->peerSocketTOS);
maybeSetCongestionAlgorithm (io->socket, session->peer_congestion_algorithm);
return 0;
}
return -1;
}
/**
***
**/
void
tr_peerIoSetTorrentHash (tr_peerIo * io,
const uint8_t * hash)
{
assert (tr_isPeerIo (io));
tr_cryptoSetTorrentHash (&io->crypto, hash);
}
const uint8_t*
tr_peerIoGetTorrentHash (tr_peerIo * io)
{
assert (tr_isPeerIo (io));
return tr_cryptoGetTorrentHash (&io->crypto);
}
int
tr_peerIoHasTorrentHash (const tr_peerIo * io)
{
assert (tr_isPeerIo (io));
return tr_cryptoHasTorrentHash (&io->crypto);
}
/**
***
**/
void
tr_peerIoSetPeersId (tr_peerIo * io, const uint8_t * peer_id)
{
assert (tr_isPeerIo (io));
if ((io->peerIdIsSet = peer_id != NULL))
memcpy (io->peerId, peer_id, 20);
else
memset (io->peerId, 0, 20);
}
/**
***
**/
static unsigned int
getDesiredOutputBufferSize (const tr_peerIo * io, uint64_t now)
{
/* this is all kind of arbitrary, but what seems to work well is
* being large enough to hold the next 20 seconds' worth of input,
* or a few blocks, whichever is bigger.
* It's okay to tweak this as needed */
const unsigned int currentSpeed_Bps = tr_bandwidthGetPieceSpeed_Bps (&io->bandwidth, now, TR_UP);
const unsigned int period = 15u; /* arbitrary */
/* the 3 is arbitrary; the .5 is to leave room for messages */
static const unsigned int ceiling = (unsigned int)(MAX_BLOCK_SIZE * 3.5);
return MAX (ceiling, currentSpeed_Bps*period);
}
size_t
tr_peerIoGetWriteBufferSpace (const tr_peerIo * io, uint64_t now)
{
const size_t desiredLen = getDesiredOutputBufferSize (io, now);
const size_t currentLen = evbuffer_get_length (io->outbuf);
size_t freeSpace = 0;
if (desiredLen > currentLen)
freeSpace = desiredLen - currentLen;
return freeSpace;
}
/**
***
**/
void
tr_peerIoSetEncryption (tr_peerIo * io, tr_encryption_type encryption_type)
{
assert (tr_isPeerIo (io));
assert (encryption_type == PEER_ENCRYPTION_NONE
|| encryption_type == PEER_ENCRYPTION_RC4);
io->encryption_type = encryption_type;
}
/**
***
**/
static void
addDatatype (tr_peerIo * io, size_t byteCount, bool isPieceData)
{
struct tr_datatype * d;
d = datatype_new ();
d->isPieceData = isPieceData != 0;
d->length = byteCount;
peer_io_push_datatype (io, d);
}
static void
maybeEncryptBuffer (tr_peerIo * io, struct evbuffer * buf)
{
if (io->encryption_type == PEER_ENCRYPTION_RC4)
{
struct evbuffer_ptr pos;
struct evbuffer_iovec iovec;
evbuffer_ptr_set (buf, &pos, 0, EVBUFFER_PTR_SET);
do {
evbuffer_peek (buf, -1, &pos, &iovec, 1);
tr_cryptoEncrypt (&io->crypto, iovec.iov_len, iovec.iov_base, iovec.iov_base);
} while (!evbuffer_ptr_set (buf, &pos, iovec.iov_len, EVBUFFER_PTR_ADD));
}
}
void
tr_peerIoWriteBuf (tr_peerIo * io, struct evbuffer * buf, bool isPieceData)
{
const size_t byteCount = evbuffer_get_length (buf);
maybeEncryptBuffer (io, buf);
evbuffer_add_buffer (io->outbuf, buf);
addDatatype (io, byteCount, isPieceData);
}
void
tr_peerIoWriteBytes (tr_peerIo * io, const void * bytes, size_t byteCount, bool isPieceData)
{
struct evbuffer_iovec iovec;
evbuffer_reserve_space (io->outbuf, byteCount, &iovec, 1);
iovec.iov_len = byteCount;
if (io->encryption_type == PEER_ENCRYPTION_RC4)
tr_cryptoEncrypt (&io->crypto, iovec.iov_len, bytes, iovec.iov_base);
else
memcpy (iovec.iov_base, bytes, iovec.iov_len);
evbuffer_commit_space (io->outbuf, &iovec, 1);
addDatatype (io, byteCount, isPieceData);
}
/***
****
***/
void
evbuffer_add_uint8 (struct evbuffer * outbuf, uint8_t byte)
{
evbuffer_add (outbuf, &byte, 1);
}
void
evbuffer_add_uint16 (struct evbuffer * outbuf, uint16_t addme_hs)
{
const uint16_t ns = htons (addme_hs);
evbuffer_add (outbuf, &ns, sizeof (ns));
}
void
evbuffer_add_uint32 (struct evbuffer * outbuf, uint32_t addme_hl)
{
const uint32_t nl = htonl (addme_hl);
evbuffer_add (outbuf, &nl, sizeof (nl));
}
void
evbuffer_add_uint64 (struct evbuffer * outbuf, uint64_t addme_hll)
{
const uint64_t nll = tr_htonll (addme_hll);
evbuffer_add (outbuf, &nll, sizeof (nll));
}
/***
****
***/
void
tr_peerIoReadBytesToBuf (tr_peerIo * io, struct evbuffer * inbuf, struct evbuffer * outbuf, size_t byteCount)
{
struct evbuffer * tmp;
const size_t old_length = evbuffer_get_length (outbuf);
assert (tr_isPeerIo (io));
assert (evbuffer_get_length (inbuf) >= byteCount);
/* append it to outbuf */
tmp = evbuffer_new ();
evbuffer_remove_buffer (inbuf, tmp, byteCount);
evbuffer_add_buffer (outbuf, tmp);
evbuffer_free (tmp);
/* decrypt if needed */
if (io->encryption_type == PEER_ENCRYPTION_RC4) {
struct evbuffer_ptr pos;
struct evbuffer_iovec iovec;
evbuffer_ptr_set (outbuf, &pos, old_length, EVBUFFER_PTR_SET);
do {
evbuffer_peek (outbuf, byteCount, &pos, &iovec, 1);
tr_cryptoDecrypt (&io->crypto, iovec.iov_len, iovec.iov_base, iovec.iov_base);
byteCount -= iovec.iov_len;
} while (!evbuffer_ptr_set (outbuf, &pos, iovec.iov_len, EVBUFFER_PTR_ADD));
}
}
void
tr_peerIoReadBytes (tr_peerIo * io, struct evbuffer * inbuf, void * bytes, size_t byteCount)
{
assert (tr_isPeerIo (io));
assert (evbuffer_get_length (inbuf) >= byteCount);
switch (io->encryption_type)
{
case PEER_ENCRYPTION_NONE:
evbuffer_remove (inbuf, bytes, byteCount);
break;
case PEER_ENCRYPTION_RC4:
evbuffer_remove (inbuf, bytes, byteCount);
tr_cryptoDecrypt (&io->crypto, byteCount, bytes, bytes);
break;
default:
assert (0);
}
}
void
tr_peerIoReadUint16 (tr_peerIo * io,
struct evbuffer * inbuf,
uint16_t * setme)
{
uint16_t tmp;
tr_peerIoReadBytes (io, inbuf, &tmp, sizeof (uint16_t));
*setme = ntohs (tmp);
}
void tr_peerIoReadUint32 (tr_peerIo * io,
struct evbuffer * inbuf,
uint32_t * setme)
{
uint32_t tmp;
tr_peerIoReadBytes (io, inbuf, &tmp, sizeof (uint32_t));
*setme = ntohl (tmp);
}
void
tr_peerIoDrain (tr_peerIo * io,
struct evbuffer * inbuf,
size_t byteCount)
{
char buf[4096];
const size_t buflen = sizeof (buf);
while (byteCount > 0)
{
const size_t thisPass = MIN (byteCount, buflen);
tr_peerIoReadBytes (io, inbuf, buf, thisPass);
byteCount -= thisPass;
}
}
/***
****
***/
static int
tr_peerIoTryRead (tr_peerIo * io, size_t howmuch)
{
int res = 0;
if ((howmuch = tr_bandwidthClamp (&io->bandwidth, TR_DOWN, howmuch)))
{
if (io->utp_socket != NULL) /* utp peer connection */
{
/* UTP_RBDrained notifies libutp that your read buffer is emtpy.
* It opens up the congestion window by sending an ACK (soonish)
* if one was not going to be sent. */
if (evbuffer_get_length (io->inbuf) == 0)
UTP_RBDrained (io->utp_socket);
}
else /* tcp peer connection */
{
int e;
EVUTIL_SET_SOCKET_ERROR (0);
res = evbuffer_read (io->inbuf, io->socket, (int)howmuch);
e = EVUTIL_SOCKET_ERROR ();
dbgmsg (io, "read %d from peer (%s)", res, (res==-1?tr_strerror (e):""));
if (evbuffer_get_length (io->inbuf))
canReadWrapper (io);
if ((res <= 0) && (io->gotError) && (e != EAGAIN) && (e != EINTR) && (e != EINPROGRESS))
{
char errstr[512];
short what = BEV_EVENT_READING | BEV_EVENT_ERROR;
if (res == 0)
what |= BEV_EVENT_EOF;
dbgmsg (io, "tr_peerIoTryRead got an error. res is %d, what is %hd, errno is %d (%s)",
res, what, e, tr_net_strerror (errstr, sizeof (errstr), e));
io->gotError (io, what, io->userData);
}
}
}
return res;
}
static int
tr_peerIoTryWrite (tr_peerIo * io, size_t howmuch)
{
int n = 0;
const size_t old_len = evbuffer_get_length (io->outbuf);
dbgmsg (io, "in tr_peerIoTryWrite %zu", howmuch);
if (howmuch > old_len)
howmuch = old_len;
if ((howmuch = tr_bandwidthClamp (&io->bandwidth, TR_UP, howmuch)))
{
if (io->utp_socket != NULL) /* utp peer connection */
{
UTP_Write (io->utp_socket, howmuch);
n = old_len - evbuffer_get_length (io->outbuf);
}
else
{
int e;
EVUTIL_SET_SOCKET_ERROR (0);
n = tr_evbuffer_write (io, io->socket, howmuch);
e = EVUTIL_SOCKET_ERROR ();
if (n > 0)
didWriteWrapper (io, n);
if ((n < 0) && (io->gotError) && e && (e != EPIPE) && (e != EAGAIN) && (e != EINTR) && (e != EINPROGRESS))
{
char errstr[512];
const short what = BEV_EVENT_WRITING | BEV_EVENT_ERROR;
dbgmsg (io, "tr_peerIoTryWrite got an error. res is %d, what is %hd, errno is %d (%s)",
n, what, e, tr_net_strerror (errstr, sizeof (errstr), e));
if (io->gotError != NULL)
io->gotError (io, what, io->userData);
}
}
}
return n;
}
int
tr_peerIoFlush (tr_peerIo * io, tr_direction dir, size_t limit)
{
int bytesUsed = 0;
assert (tr_isPeerIo (io));
assert (tr_isDirection (dir));
if (dir == TR_DOWN)
bytesUsed = tr_peerIoTryRead (io, limit);
else
bytesUsed = tr_peerIoTryWrite (io, limit);
dbgmsg (io, "flushing peer-io, direction %d, limit %zu, bytesUsed %d", (int)dir, limit, bytesUsed);
return bytesUsed;
}
int
tr_peerIoFlushOutgoingProtocolMsgs (tr_peerIo * io)
{
size_t byteCount = 0;
const struct tr_datatype * it;
/* count up how many bytes are used by non-piece-data messages
at the front of our outbound queue */
for (it=io->outbuf_datatypes; it!=NULL; it=it->next)
if (it->isPieceData)
break;
else
byteCount += it->length;
return tr_peerIoFlush (io, TR_UP, byteCount);
}
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