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Fixed lwIP driver thread model violation (tcp_close() was being called by application thread)

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This commit is contained in:
Joseph Henry
2017-09-19 10:52:59 -07:00
parent 91eb869e02
commit 5e320fb950
8 changed files with 1927 additions and 1856 deletions
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124
src/lwIP.cpp
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@@ -643,51 +643,53 @@ namespace ZeroTier
int lwIP::lwip_Close(VirtualSocket *vs)
{
// requests to close non-LISTEN PCBs are handled lwip_cb_poll()
int err = -1;
if (vs == NULL) {
DEBUG_ERROR("invalid vs");
handle_general_failure();
return -1;
}
DEBUG_EXTRA("fd=%d, vs=%p", vs->app_fd, vs);
int err = 0;
errno = 0;
if (vs->socket_type == SOCK_DGRAM) {
udp_remove((struct udp_pcb*)vs->pcb);
}
if (vs->socket_type == SOCK_STREAM) {
if (vs->pcb) {
struct tcp_pcb* tpcb = (struct tcp_pcb*)vs->pcb;
if (tpcb->state == CLOSED) {
DEBUG_EXTRA("pcb is in CLOSED state");
// calling tcp_close() here would be redundant
return 0;
}
if (tpcb->state == CLOSE_WAIT) {
DEBUG_EXTRA("pcb is in CLOSE_WAIT state");
// calling tcp_close() here would be redundant
}
if (tpcb->state > TIME_WAIT) {
DEBUG_ERROR("warning, pcb=%p is in an invalid state=%d", vs->pcb, tpcb->state);
handle_general_failure();
err = -1;
}
// unregister callbacks for this PCB
tcp_arg(tpcb, NULL);
if (tpcb->state == LISTEN) {
tcp_accept(tpcb, NULL);
}
else {
tcp_recv(tpcb, NULL);
tcp_sent(tpcb, NULL);
tcp_poll(tpcb, NULL, 0);
tcp_err(tpcb, NULL);
}
struct tcp_pcb *tpcb = (struct tcp_pcb*)(vs->pcb);
if (tpcb == NULL) {
DEBUG_ERROR("invalid pcb");
handle_general_failure();
return -1;
}
// should be safe to tcp_close() from application thread IF PCB is in LISTENING state (I think)
if (tpcb->state == LISTEN) {
DEBUG_EXTRA("PCB is in LISTEN, calling tcp_close() from application thread.");
tcp_accept(tpcb, NULL);
if ((err = tcp_close(tpcb)) < 0) {
DEBUG_ERROR("error while calling tcp_close, fd=%d, vs=%p, pcb=%p", vs->app_fd, vs, vs->pcb);
errno = lwip_err_to_errno(err);
err = -1;
}
return ERR_OK;
}
// handle junk state values
if (tpcb->state > TIME_WAIT) {
DEBUG_EXTRA("invalid TCP pcb state, already closed, report ERR_OK");
return ERR_OK;
}
else {
// place a request for the stack to close this VirtualSocket's PCB
vs->set_state(VS_SHOULD_STOP);
// wait for indication of success, this will block if the PCB can't close
while (true) {
sleep(1);
nanosleep((const struct timespec[]) {{0, (ZT_API_CHECK_INTERVAL * 1000000)}}, NULL);
DEBUG_EXTRA("checking closure state... pcb->state=%d", tpcb->state);
if (vs->get_state() == VS_STOPPED || tpcb->state == CLOSED) {
return ERR_OK;
}
}
}
}
if (vs->socket_type == SOCK_DGRAM) {
// place a request for the stack to close this VirtualSocket's PCB
vs->set_state(VS_SHOULD_STOP);
}
return err;
}
@@ -740,6 +742,7 @@ namespace ZeroTier
struct pbuf* q = p;
if (p == NULL) {
DEBUG_INFO("p=0x0 for pcb=%p, vs->pcb=%p, this indicates a closure. No need to call tcp_close()", PCB, vs->pcb);
vs->set_state(VS_SHOULD_STOP);
return ERR_ABRT;
}
vs->tap->_tcpconns_m.lock();
@@ -876,7 +879,6 @@ namespace ZeroTier
// payload
memcpy(udp_msg_buf + sizeof(int32_t) + sizeof(struct sockaddr_storage), &udp_payload_buf, tot_len);
if ((w = write(vs->sdk_fd, udp_msg_buf, msg_tot_len)) < 0) {
perror("write");
DEBUG_ERROR("write(fd=%d)=%d, errno=%d", vs->sdk_fd, w, errno);
}
}
@@ -933,7 +935,7 @@ namespace ZeroTier
}
// add to unhandled connection set for zts_connect to pick up on
vs->tap->_tcpconns_m.lock();
vs->state = ZT_SOCK_STATE_UNHANDLED_CONNECTED;
vs->set_state(VS_STATE_UNHANDLED_CONNECTED);
vs->tap->_VirtualSockets.push_back(vs);
vs->tap->_tcpconns_m.unlock();
return ERR_OK;
@@ -950,6 +952,58 @@ namespace ZeroTier
if (vs->socket_type == SOCK_DGRAM) {
DEBUG_INFO("fd=%d, vs=%p, pcb=%p", vs->app_fd, vs, PCB, vs->pcb);
}
// Handle PCB closure requests (set in lwip_Close())
if (vs->get_state() == VS_SHOULD_STOP) {
DEBUG_EXTRA("closing pcb=%p, fd=%d, vs=%p", PCB, vs->app_fd, vs);
int err = 0;
errno = 0;
if (vs->socket_type == SOCK_DGRAM) {
udp_remove((struct udp_pcb*)vs->pcb);
}
if (vs->socket_type == SOCK_STREAM) {
if (vs->pcb) {
struct tcp_pcb* tpcb = (struct tcp_pcb*)vs->pcb;
if (tpcb->state == CLOSED) {
DEBUG_EXTRA("pcb is in CLOSED state");
// calling tcp_close() here would be redundant
return 0;
}
//if (tpcb->state == CLOSE_WAIT) {
// DEBUG_EXTRA("pcb is in CLOSE_WAIT state");
// // calling tcp_close() here would be redundant
//}
if (tpcb->state > TIME_WAIT) {
DEBUG_ERROR("warning, pcb=%p is in an invalid state=%d", vs->pcb, tpcb->state);
handle_general_failure();
err = -1;
}
// unregister callbacks for this PCB
tcp_arg(tpcb, NULL);
if (tpcb->state == LISTEN) {
tcp_accept(tpcb, NULL);
}
else {
tcp_recv(tpcb, NULL);
tcp_sent(tpcb, NULL);
tcp_poll(tpcb, NULL, 0);
tcp_err(tpcb, NULL);
}
if ((err = tcp_close(tpcb)) < 0) {
DEBUG_ERROR("error while calling tcp_close, fd=%d, vs=%p, pcb=%p", vs->app_fd, vs, vs->pcb);
errno = lwip_err_to_errno(err);
err = -1;
}
else {
vs->set_state(VS_STOPPED); // success
}
}
}
}
// Handle transmission and reception of data
if (vs->socket_type == SOCK_STREAM) {
DEBUG_INFO("fd=%d, vs=%p, PCB=%p, vs->pcb=%p, vs->pcb->state=%d", vs->app_fd, vs, PCB, (struct tcp_pcb*)(vs->pcb), ((struct tcp_pcb*)(vs->pcb))->state);
if (((struct tcp_pcb*)(vs->pcb))->state == CLOSE_WAIT) {