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wfb-tun code cleanup
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@svpcom
svpcom committed Oct 9, 2024
1 parent d7b3737 commit 3a05304
Showing 1 changed file with 43 additions and 39 deletions.
82 changes: 43 additions & 39 deletions src/wfb_tun.c
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Original file line number Diff line number Diff line change
Expand Up @@ -53,11 +53,16 @@ static unsigned int agg_timeout_ms = 5;
typedef struct
{
char data[MTU * 2];
size_t data_size;
size_t batch_size;
size_t offset;
} packet_buffer_t;
size_t data_size; // size of packet buffer
size_t batch_size; // size of current ready-to-send batch <= MTU
} in_packet_buffer_t;

typedef struct
{
char data[MTU];
size_t data_size; // size of packet buffer
size_t offset; // offset of current packet for injection into tun
} out_packet_buffer_t;

// TUN packet header
typedef struct {
Expand All @@ -71,7 +76,7 @@ typedef struct {
#define dbg_log(...) ((void)0)
#endif

void event_sig_cb (evutil_socket_t sig, short flags, void *cls)
void event_sig_cb(evutil_socket_t sig, short flags, void *arg)
{
switch (sig)
{
Expand All @@ -87,7 +92,7 @@ void event_sig_cb (evutil_socket_t sig, short flags, void *cls)
event_base_loopexit (ev_base, NULL);
}

void ev_ping_cb (evutil_socket_t fd, short flags, void *arg)
void ev_ping_cb(evutil_socket_t fd, short flags, void *arg)
{
assert(fd >= 0);
assert((EV_TIMEOUT & flags) != 0);
Expand All @@ -101,25 +106,26 @@ void ev_ping_cb (evutil_socket_t fd, short flags, void *arg)
if(pkt_sem > 0) pkt_sem--;
}

void ev_tun_read_cb (evutil_socket_t fd, short flags, void *cls)
void ev_tun_read_cb(evutil_socket_t fd, short flags, void *arg)
{
packet_buffer_t *buf = cls;
in_packet_buffer_t *buf = arg;

assert(buf != NULL);
assert((EV_TIMEOUT & flags) == 0);
assert((EV_READ & flags) != 0);
assert(ev_tun_read != NULL);
assert(ev_socket_write != NULL);
assert(buf->data_size < MTU);

bool is_new_buffer = (buf->offset == 0);
bool is_new_buffer = (buf->data_size == 0);
int nread = read(fd,
buf->data + buf->offset + sizeof(tun_packet_hdr_t),
buf->data + buf->data_size + sizeof(tun_packet_hdr_t),
MTU - sizeof(tun_packet_hdr_t));

assert(nread > 0);
assert(nread <= MTU - sizeof(tun_packet_hdr_t));

((tun_packet_hdr_t*)(buf->data + buf->offset))->packet_size = htons(nread);
((tun_packet_hdr_t*)(buf->data + buf->data_size))->packet_size = htons(nread);

buf->data_size += (sizeof(tun_packet_hdr_t) + nread);

Expand All @@ -128,9 +134,7 @@ void ev_tun_read_cb (evutil_socket_t fd, short flags, void *cls)
buf->batch_size = buf->data_size;
}

dbg_log("tun_read: off=%zu, packet_size=%d, batch_size=%zu, data_size=%zu\n", buf->offset, nread, buf->batch_size, buf->data_size);

buf->offset += (sizeof(tun_packet_hdr_t) + nread);
dbg_log("tun_read: packet_size=%d, batch_size=%zu, data_size=%zu\n", nread, buf->batch_size, buf->data_size);

if(buf->data_size >= MTU || agg_timeout_ms == 0)
{
Expand All @@ -153,12 +157,13 @@ void ev_tun_read_cb (evutil_socket_t fd, short flags, void *cls)
}
}

void ev_socket_write_cb (evutil_socket_t fd, short flags, void *cls)
void ev_socket_write_cb(evutil_socket_t fd, short flags, void *arg)
{
packet_buffer_t *buf = cls;
in_packet_buffer_t *buf = arg;

assert(buf != NULL);
assert(ev_tun_read != NULL);
assert(ev_socket_write != NULL);

// reset ping semaphore
pkt_sem = 1;
Expand All @@ -184,12 +189,11 @@ void ev_socket_write_cb (evutil_socket_t fd, short flags, void *cls)
{
memmove(buf->data, buf->data + buf->batch_size, buf->data_size - buf->batch_size);
buf->data_size -= buf->batch_size;
buf->offset = buf->data_size;
buf->batch_size = buf->data_size;
}
else
{
memset(buf, 0, sizeof(packet_buffer_t));
memset(buf, 0, sizeof(in_packet_buffer_t));
}

assert(buf->data_size <= MTU);
Expand All @@ -202,7 +206,7 @@ void ev_socket_write_cb (evutil_socket_t fd, short flags, void *cls)
{
event_add(ev_tun_read, NULL);

if(buf->offset > 0 && agg_timeout_ms > 0)
if(buf->data_size > 0 && agg_timeout_ms > 0)
{
// Set aggregation timeout for non-empty buffer
struct timeval tv = { .tv_sec = agg_timeout_ms / 1000,
Expand All @@ -214,57 +218,58 @@ void ev_socket_write_cb (evutil_socket_t fd, short flags, void *cls)
}


void ev_tun_write_cb (evutil_socket_t fd, short flags, void *cls)
void ev_tun_write_cb(evutil_socket_t fd, short flags, void *arg)
{
packet_buffer_t *buf = cls;
out_packet_buffer_t *buf = arg;
int nwrote;

assert(buf != NULL);
assert((EV_TIMEOUT & flags) == 0);
assert((EV_WRITE & flags) != 0);
assert(ev_tun_write != NULL);
assert(ev_socket_read != NULL);
assert(buf->data_size == buf->batch_size);

assert(buf->offset + sizeof(tun_packet_hdr_t) <= buf->batch_size);
assert(buf->offset + sizeof(tun_packet_hdr_t) <= buf->data_size);
uint16_t packet_size = ntohs(((tun_packet_hdr_t*)(buf->data + buf->offset))->packet_size);

dbg_log("tun_write: off=%zu, psize=%zu + %d, batch_size=%zu, data_size=%zu\n", buf->offset, sizeof(tun_packet_hdr_t), packet_size, buf->batch_size, buf->data_size);
assert(buf->offset + sizeof(tun_packet_hdr_t) + packet_size <= buf->batch_size);
dbg_log("tun_write: off=%zu, psize=%zu + %d, data_size=%zu\n", buf->offset, sizeof(tun_packet_hdr_t), packet_size, buf->data_size);
assert(buf->offset + sizeof(tun_packet_hdr_t) + packet_size <= buf->data_size);

nwrote = write(fd, buf->data + buf->offset + sizeof(tun_packet_hdr_t), packet_size);
assert(nwrote == packet_size);

buf->offset += (sizeof(tun_packet_hdr_t) + packet_size);

if (buf->offset < buf->batch_size)
if (buf->offset < buf->data_size)
{
event_add(ev_tun_write, NULL);
}
else
{
memset(buf, 0, sizeof(packet_buffer_t));
memset(buf, 0, sizeof(out_packet_buffer_t));
event_add(ev_socket_read, NULL);
}
}


void ev_socket_read_cb (evutil_socket_t fd, short flags, void *cls)
void ev_socket_read_cb(evutil_socket_t fd, short flags, void *arg)
{
packet_buffer_t *buf = cls;
out_packet_buffer_t *buf = arg;
int nread;

assert (buf != NULL);
assert ((EV_TIMEOUT & flags) == 0);
assert ((EV_READ & flags) != 0);
assert (ev_tun_write != NULL);
assert(buf != NULL);
assert((EV_TIMEOUT & flags) == 0);
assert((EV_READ & flags) != 0);
assert(ev_socket_read != NULL);
assert(ev_tun_write != NULL);

nread = recv(fd,
buf->data,
MTU,
MSG_DONTWAIT);

assert (nread >= 0);
assert (nread <= MTU);
assert(nread >= 0);
assert(nread <= MTU);

if(nread == 0)
{
Expand All @@ -276,9 +281,8 @@ void ev_socket_read_cb (evutil_socket_t fd, short flags, void *cls)

buf->offset = 0;
buf->data_size = nread;
buf->batch_size = nread;

dbg_log("socket_read: off=%zu, batch_size=%zu, data_size=%zu\n", buf->offset, buf->batch_size, buf->data_size);
dbg_log("socket_read: off=%zu, data_size=%zu\n", buf->offset, buf->data_size);

event_add(ev_tun_write, NULL);
}
Expand Down Expand Up @@ -385,10 +389,10 @@ int main (int argc, char *argv[])
int sock_fd = -1;

// buffer TUN -> socket
packet_buffer_t in_buf;
in_packet_buffer_t in_buf;

// buffer socket -> TUN
packet_buffer_t out_buf;
out_packet_buffer_t out_buf;

uint16_t bind_port = 5800;
char *tun_name = "wfb-tun";
Expand Down

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