external/uhub
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fix: Rework SSL poll event handling to avoid infinite loops

Browse Source 
The downstream connection callback must only be invoked when the event
that SSL requests for the connection to make progress has actually
occured. Otherwise, the downstream callback might do nothing but
re-queue an unrelated event (e.g. in user_net_io_want_write), and the
event loop comes around instantly while making no progress. Track the
SSL-requested events separately and deliver the required downstream
event when they fire.

Sample strace:

epoll_wait(0, {{EPOLLIN, {u32=96, u64=96}}}, 91, 10000) = 1
: net_ssl_callback in state tls_st_need_write calls cb NET_EVENT_WRITE
: User writes data, OpenSSL tries to write data
write(96, <snip>..., 170) = -1 EAGAIN (Resource temporarily unavailable)
: handle_openssl_error requests NET_EVENT_WRITE
epoll_ctl(0, EPOLL_CTL_MOD, 96, {EPOLLOUT, {u32=96, u64=96}}) = 0
: User callback then requests NET_EVENT_READ|NET_EVENT_WRITE
epoll_ctl(0, EPOLL_CTL_MOD, 96, {EPOLLIN|EPOLLOUT, {u32=96, u64=96}}) =
: Data available for *reading*
epoll_wait(0, {{EPOLLIN, {u32=96, u64=96}}}, 91, 10000) = 1
: net_ssl_callback in state tls_st_need_write calls cb NET_EVENT_WRITE
: again...
This commit is contained in:
Hector Martin
2014-04-03 21:24:41 +01:00
committed by Jan Vidar Krey
parent 9f78a2e85f
commit 0426cb523a
5 changed files with 74 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
src/network/connection.c
View File

@@ -19,6 +19,7 @@
#include "uhub.h"
#include "network/common.h"
#include "network/backend.h"
static int is_blocked_or_interrupted()
{
@@ -116,6 +117,23 @@ void* net_con_get_ptr(struct net_connection* con)
return con->ptr;
}
void net_con_update(struct net_connection* con, int events)
{
#ifdef SSL_SUPPORT
if (con->ssl)
net_ssl_update(con, events);
else
#endif
net_backend_update(con, events);
}
void net_con_reinitialize(struct net_connection* con, net_connection_cb callback, const void* ptr, int events)
{
con->callback = callback;
con->ptr = (void*) ptr;
net_con_update(con, events);
}
void net_con_destroy(struct net_connection* con)
{
#ifdef SSL_SUPPORT