/*
* Set the tun MTU dynamically.
*/
void
frame_set_mtu_dynamic (struct frame *frame, int mtu, unsigned int flags)
{
#ifdef ENABLE_DEBUG
const int orig_mtu = mtu;
const int orig_link_mtu_dynamic = frame->link_mtu_dynamic;
#endif
ASSERT (mtu >= 0);
if (flags & SET_MTU_TUN)
mtu += TUN_LINK_DELTA (frame);
if (!(flags & SET_MTU_UPPER_BOUND) || mtu < frame->link_mtu_dynamic)
{
frame->link_mtu_dynamic = constrain_int (
mtu,
EXPANDED_SIZE_MIN (frame),
EXPANDED_SIZE (frame));
}
dmsg (D_MTU_DEBUG, "MTU DYNAMIC mtu=%d, flags=%u, %d -> %d",
orig_mtu,
flags,
orig_link_mtu_dynamic,
frame->link_mtu_dynamic);
}
void
comp_add_to_extra_buffer(struct frame *frame)
{
/* Leave room for compression buffer to expand in worst case scenario
where data is totally uncompressible */
frame_add_to_extra_buffer (frame, COMP_EXTRA_BUFFER (EXPANDED_SIZE(frame)));
}
void
check_send_occ_load_test_dowork (struct context *c)
{
if (CONNECTION_ESTABLISHED (c))
{
const struct mtu_load_test *entry;
if (!c->c2.occ_mtu_load_n_tries)
msg (M_INFO,
"NOTE: Beginning empirical MTU test -- results should be available in 3 to 4 minutes.");
entry = &mtu_load_test_sequence[c->c2.occ_mtu_load_n_tries++];
if (entry->op >= 0)
{
c->c2.occ_op = entry->op;
c->c2.occ_mtu_load_size =
EXPANDED_SIZE (&c->c2.frame) + entry->delta;
}
else
{
msg (M_INFO,
"NOTE: failed to empirically measure MTU (requires " PACKAGE_NAME " 1.5 or higher at other end of connection).");
event_timeout_clear (&c->c2.occ_mtu_load_test_interval);
c->c2.occ_mtu_load_n_tries = 0;
}
}
}
static void
lzo_decompress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
lzo_uint zlen = EXPANDED_SIZE(frame);
int err;
uint8_t c; /* flag indicating whether or not our peer compressed */
if (buf->len <= 0)
{
return;
}
ASSERT(buf_init(&work, FRAME_HEADROOM(frame)));
c = *BPTR(buf);
ASSERT(buf_advance(buf, 1));
if (c == LZO_COMPRESS_BYTE) /* packet was compressed */
{
ASSERT(buf_safe(&work, zlen));
err = LZO_DECOMPRESS(BPTR(buf), BLEN(buf), BPTR(&work), &zlen,
compctx->wu.lzo.wmem);
if (err != LZO_E_OK)
{
dmsg(D_COMP_ERRORS, "LZO decompression error: %d", err);
buf->len = 0;
return;
}
ASSERT(buf_safe(&work, zlen));
work.len = zlen;
dmsg(D_COMP, "LZO decompress %d -> %d", buf->len, work.len);
compctx->pre_decompress += buf->len;
compctx->post_decompress += work.len;
*buf = work;
}
else if (c == NO_COMPRESS_BYTE) /* packet was not compressed */
{
}
else
{
dmsg(D_COMP_ERRORS, "Bad LZO decompression header byte: %d", c);
buf->len = 0;
}
}
static void
lz4v2_decompress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
size_t zlen_max = EXPANDED_SIZE(frame);
uint8_t c; /* flag indicating whether or not our peer compressed */
if (buf->len <= 0)
{
return;
}
ASSERT(buf_init(&work, FRAME_HEADROOM(frame)));
/* do unframing/swap (assumes buf->len > 0) */
uint8_t *head = BPTR(buf);
c = *head;
/* Not compressed */
if (c != COMP_ALGV2_INDICATOR_BYTE)
{
return;
}
/* Packet to short to make sense */
if (buf->len <= 1)
{
buf->len = 0;
return;
}
c = head[1];
if (c == COMP_ALGV2_LZ4_BYTE) /* packet was compressed */
{
buf_advance(buf,2);
do_lz4_decompress(zlen_max, &work, buf, compctx);
}
else if (c == COMP_ALGV2_UNCOMPRESSED_BYTE)
{
buf_advance(buf,2);
}
else
{
dmsg(D_COMP_ERRORS, "Bad LZ4v2 decompression header byte: %d", c);
buf->len = 0;
}
}
static void
lz4_decompress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
size_t zlen_max = EXPANDED_SIZE(frame);
uint8_t c; /* flag indicating whether or not our peer compressed */
if (buf->len <= 0)
{
return;
}
ASSERT(buf_init(&work, FRAME_HEADROOM(frame)));
/* do unframing/swap (assumes buf->len > 0) */
{
uint8_t *head = BPTR(buf);
c = *head;
--buf->len;
*head = *BEND(buf);
}
if (c == LZ4_COMPRESS_BYTE) /* packet was compressed */
{
do_lz4_decompress(zlen_max, &work, buf, compctx);
}
else if (c == NO_COMPRESS_BYTE_SWAP) /* packet was not compressed */
{
}
else
{
dmsg(D_COMP_ERRORS, "Bad LZ4 decompression header byte: %d", c);
buf->len = 0;
}
}
void
process_outgoing_link (struct context *c)
{
struct gc_arena gc = gc_new ();
perf_push (PERF_PROC_OUT_LINK);
if (c->c2.to_link.len > 0 && c->c2.to_link.len <= EXPANDED_SIZE (&c->c2.frame))
{
/*
* Setup for call to send/sendto which will send
* packet to remote over the TCP/UDP port.
*/
int size = 0;
ASSERT (link_socket_actual_defined (c->c2.to_link_addr));
#ifdef ENABLE_DEBUG
/* In gremlin-test mode, we may choose to drop this packet */
if (!c->options.gremlin || ask_gremlin (c->options.gremlin))
#endif
{
/*
* Let the traffic shaper know how many bytes
* we wrote.
*/
#ifdef ENABLE_FEATURE_SHAPER
if (c->options.shaper)
shaper_wrote_bytes (&c->c2.shaper, BLEN (&c->c2.to_link)
+ datagram_overhead (c->options.ce.proto));
#endif
/*
* Let the pinger know that we sent a packet.
*/
if (c->options.ping_send_timeout)
event_timeout_reset (&c->c2.ping_send_interval);
#if PASSTOS_CAPABILITY
/* Set TOS */
link_socket_set_tos (c->c2.link_socket);
#endif
/* Log packet send */
#ifdef LOG_RW
if (c->c2.log_rw)
fprintf (stderr, "W");
#endif
msg (D_LINK_RW, "%s WRITE [%d] to %s: %s",
proto2ascii (c->c2.link_socket->info.proto, true),
BLEN (&c->c2.to_link),
print_link_socket_actual (c->c2.to_link_addr, &gc),
PROTO_DUMP (&c->c2.to_link, &gc));
/* Packet send complexified by possible Socks5 usage */
{
struct link_socket_actual *to_addr = c->c2.to_link_addr;
#ifdef ENABLE_SOCKS
int size_delta = 0;
#endif
#ifdef ENABLE_SOCKS
/* If Socks5 over UDP, prepend header */
socks_preprocess_outgoing_link (c, &to_addr, &size_delta);
#endif
/* Send packet */
size = link_socket_write (c->c2.link_socket,
&c->c2.to_link,
to_addr);
#ifdef ENABLE_SOCKS
/* Undo effect of prepend */
link_socket_write_post_size_adjust (&size, size_delta, &c->c2.to_link);
#endif
}
if (size > 0)
{
c->c2.max_send_size_local = max_int (size, c->c2.max_send_size_local);
c->c2.link_write_bytes += size;
link_write_bytes_global += size;
#ifdef ENABLE_MEMSTATS
if (mmap_stats)
mmap_stats->link_write_bytes = link_write_bytes_global;
#endif
#ifdef ENABLE_MANAGEMENT
if (management)
{
management_bytes_out (management, size);
#ifdef MANAGEMENT_DEF_AUTH
management_bytes_server (management, &c->c2.link_read_bytes, &c->c2.link_write_bytes, &c->c2.mda_context);
#endif
}
#endif
}
}
/* Check return status */
check_status (size, "write", c->c2.link_socket, NULL);
if (size > 0)
{
/* Did we write a different size packet than we intended? */
if (size != BLEN (&c->c2.to_link))
msg (D_LINK_ERRORS,
"TCP/UDP packet was truncated/expanded on write to %s (tried=%d,actual=%d)",
print_link_socket_actual (c->c2.to_link_addr, &gc),
BLEN (&c->c2.to_link),
size);
}
/* if not a ping/control message, indicate activity regarding --inactive parameter */
if (c->c2.buf.len > 0 )
register_activity (c, size);
}
else
{
if (c->c2.to_link.len > 0)
msg (D_LINK_ERRORS, "TCP/UDP packet too large on write to %s (tried=%d,max=%d)",
print_link_socket_actual (c->c2.to_link_addr, &gc),
c->c2.to_link.len,
EXPANDED_SIZE (&c->c2.frame));
}
buf_reset (&c->c2.to_link);
perf_pop ();
gc_free (&gc);
}
void
check_send_occ_msg_dowork (struct context *c)
{
bool doit = false;
c->c2.buf = c->c2.buffers->aux_buf;
ASSERT (buf_init (&c->c2.buf, FRAME_HEADROOM (&c->c2.frame)));
ASSERT (buf_safe (&c->c2.buf, MAX_RW_SIZE_TUN (&c->c2.frame)));
ASSERT (buf_write (&c->c2.buf, occ_magic, OCC_STRING_SIZE));
switch (c->c2.occ_op)
{
case OCC_REQUEST:
if (!buf_write_u8 (&c->c2.buf, OCC_REQUEST))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_REQUEST");
doit = true;
break;
case OCC_REPLY:
if (!c->c2.options_string_local)
break;
if (!buf_write_u8 (&c->c2.buf, OCC_REPLY))
break;
if (!buf_write (&c->c2.buf, c->c2.options_string_local,
strlen (c->c2.options_string_local) + 1))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_REPLY");
doit = true;
break;
case OCC_MTU_REQUEST:
if (!buf_write_u8 (&c->c2.buf, OCC_MTU_REQUEST))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_REQUEST");
doit = true;
break;
case OCC_MTU_REPLY:
if (!buf_write_u8 (&c->c2.buf, OCC_MTU_REPLY))
break;
if (!buf_write_u16 (&c->c2.buf, c->c2.max_recv_size_local))
break;
if (!buf_write_u16 (&c->c2.buf, c->c2.max_send_size_local))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_REPLY");
doit = true;
break;
case OCC_MTU_LOAD_REQUEST:
if (!buf_write_u8 (&c->c2.buf, OCC_MTU_LOAD_REQUEST))
break;
if (!buf_write_u16 (&c->c2.buf, c->c2.occ_mtu_load_size))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_LOAD_REQUEST");
doit = true;
break;
case OCC_MTU_LOAD:
{
int need_to_add;
if (!buf_write_u8 (&c->c2.buf, OCC_MTU_LOAD))
break;
need_to_add = min_int (c->c2.occ_mtu_load_size, EXPANDED_SIZE (&c->c2.frame))
- OCC_STRING_SIZE
- sizeof (uint8_t)
- EXTRA_FRAME (&c->c2.frame);
while (need_to_add > 0)
{
/*
* Fill the load test packet with pseudo-random bytes.
*/
if (!buf_write_u8 (&c->c2.buf, get_random () & 0xFF))
break;
--need_to_add;
}
dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_LOAD min_int(%d-%d-%d-%d,%d) size=%d",
c->c2.occ_mtu_load_size,
OCC_STRING_SIZE,
(int) sizeof (uint8_t),
EXTRA_FRAME (&c->c2.frame),
MAX_RW_SIZE_TUN (&c->c2.frame),
BLEN (&c->c2.buf));
doit = true;
}
break;
case OCC_EXIT:
if (!buf_write_u8 (&c->c2.buf, OCC_EXIT))
break;
dmsg (D_PACKET_CONTENT, "SENT OCC_EXIT");
doit = true;
break;
}
if (doit)
{
/*
* We will treat the packet like any other outgoing packet,
* compress, encrypt, sign, etc.
*/
encrypt_sign (c, true);
}
c->c2.occ_op = -1;
}
