Use a ringbuffer in shared memory to transfer packets from the tapreader thread to the main thread.

It's a wonder it ever worked before. The socket that is created is not of a
datagram type, therefore packet boundaries were not preserved, which becomes
a problem as soon as the TAP-Win32 device receives packets in fast succession.
This commit is contained in:
Guus Sliepen 2007-01-03 18:18:54 +00:00
parent 52787a73b0
commit 03f3fc01e8

View file

@ -45,16 +45,23 @@ static int device_total_out = 0;
extern char *myport;
static struct packetbuf {
uint8_t data[MTU];
length_t len;
} *bufs;
static int nbufs = 64;
DWORD WINAPI tapreader(void *bla) {
int sock, err, status;
struct addrinfo *ai;
struct addrinfo hint = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_DGRAM,
.ai_protocol = IPPROTO_UDP,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP,
.ai_flags = 0,
};
char buf[MTU];
unsigned char bufno = 0;
long len;
OVERLAPPED overlapped;
@ -67,7 +74,7 @@ DWORD WINAPI tapreader(void *bla) {
return -1;
}
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
freeaddrinfo(ai);
@ -92,7 +99,7 @@ DWORD WINAPI tapreader(void *bla) {
overlapped.OffsetHigh = 0;
ResetEvent(overlapped.hEvent);
status = ReadFile(device_handle, buf, sizeof(buf), &len, &overlapped);
status = ReadFile(device_handle, bufs[bufno].data, MTU, &len, &overlapped);
if(!status) {
if(GetLastError() == ERROR_IO_PENDING) {
@ -106,8 +113,11 @@ DWORD WINAPI tapreader(void *bla) {
}
}
if(send(sock, buf, len, 0) <= 0)
bufs[bufno].len = len;
if(send(sock, &bufno, 1, 0) <= 0)
return -1;
if(++bufno >= nbufs)
bufno = 0;
}
}
@ -131,9 +141,9 @@ bool setup_device(void)
struct addrinfo *ai;
struct addrinfo hint = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_DGRAM,
.ai_protocol = IPPROTO_UDP,
.ai_flags = 0,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP,
.ai_flags = AI_PASSIVE,
};
cp();
@ -228,6 +238,16 @@ bool setup_device(void)
overwrite_mac = 1;
}
/* Set up ringbuffer */
get_config_int(lookup_config(config_tree, "RingBufferSize"), &nbufs);
if(nbufs <= 1)
nbufs = 1;
else if(nbufs > 256)
nbufs = 256;
bufs = xmalloc_and_zero(nbufs * sizeof *bufs);
/* Create a listening socket */
err = getaddrinfo(NULL, myport, &hint, &ai);
@ -237,7 +257,7 @@ bool setup_device(void)
return false;
}
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
if(sock < 0) {
logger(LOG_ERR, _("System call `%s' failed: %s"), "socket", strerror(errno));
@ -295,17 +315,18 @@ void close_device(void)
bool read_packet(vpn_packet_t *packet)
{
int lenin;
unsigned char bufno;
cp();
if((lenin = recv(device_fd, packet->data, MTU, 0)) <= 0) {
if((recv(device_fd, &bufno, 1, 0)) <= 0) {
logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
packet->len = lenin;
packet->len = bufs[bufno].len;
memcpy(packet->data, bufs[bufno].data, bufs[bufno].len);
device_total_in += packet->len;