mirror/openvpn
0
0
Fork 0
mirror of https://github.com/OpenVPN/openvpn.git synced 2024-09-20 12:02:28 +02:00
Code

Don't limit max incoming message size based on c2->frame

Browse Source 
"Be conservative in what you send, be liberal in what you accept"

When receiving packets, the real limitation of how much data we can accept
is the size of our internal buffers, not the maximum size we expect
incoming packets to have.

I ran into this while working on cipher negotiation, which will need
separate bookkeeping for the required internal buffer size, and the
link/tun MTU.  Basing this code on the buffer size instead of c2->frame
makes that easier.  A nice side-effect of this change is that it
simplifies the code.

This should also reduce the impact of using asymmetric tun/link MTU's,
such as in trac ticket #647.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1465388443-15484-2-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/11850
Signed-off-by: Gert Doering <gert@greenie.muc.de>
This commit is contained in:
Steffan Karger 2016-06-08 14:20:39 +02:00 committed by Gert Doering
parent 63b3e000c9
commit 3c1b19e047
3 changed files with 4 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/openvpn/forward.c
View File

@ -669,7 +669,6 @@ read_incoming_link (struct context *c)
status = link_socket_read (c->c2.link_socket,
&c->c2.buf,
MAX_RW_SIZE_LINK (&c->c2.frame),
&c->c2.from);
if (socket_connection_reset (c->c2.link_socket, status))

9
src/openvpn/socket.c
View File

@ -2886,7 +2886,6 @@ union openvpn_pktinfo {
static socklen_t
link_socket_read_udp_posix_recvmsg (struct link_socket *sock,
struct buffer *buf,
int maxsize,
struct link_socket_actual *from)
{
struct iovec iov;
@ -2895,7 +2894,7 @@ link_socket_read_udp_posix_recvmsg (struct link_socket *sock,
socklen_t fromlen = sizeof (from->dest.addr);
iov.iov_base = BPTR (buf);
iov.iov_len = maxsize;
iov.iov_len = buf_forward_capacity_total (buf);
mesg.msg_iov = &iov;
mesg.msg_iovlen = 1;
mesg.msg_name = &from->dest.addr;
@ -2954,20 +2953,18 @@ link_socket_read_udp_posix_recvmsg (struct link_socket *sock,
int
link_socket_read_udp_posix (struct link_socket *sock,
struct buffer *buf,
int maxsize,
struct link_socket_actual *from)
{
socklen_t fromlen = sizeof (from->dest.addr);
socklen_t expectedlen = af_addr_size(sock->info.af);
addr_zero_host(&from->dest);
ASSERT (buf_safe (buf, maxsize));
#if ENABLE_IP_PKTINFO
/* Both PROTO_UDPv4 and PROTO_UDPv6 */
if (sock->info.proto == PROTO_UDP && sock->sockflags & SF_USE_IP_PKTINFO)
fromlen = link_socket_read_udp_posix_recvmsg (sock, buf, maxsize, from);
fromlen = link_socket_read_udp_posix_recvmsg (sock, buf, from);
else
#endif
buf->len = recvfrom (sock->sd, BPTR (buf), maxsize, 0,
buf->len = recvfrom (sock->sd, BPTR (buf), buf_forward_capacity(buf), 0,
&from->dest.addr.sa, &fromlen);
/* FIXME: won't do anything when sock->info.af == AF_UNSPEC */
if (buf->len >= 0 && expectedlen && fromlen != expectedlen)

4
src/openvpn/socket.h
View File

@ -961,7 +961,6 @@ link_socket_read_udp_win32 (struct link_socket *sock,
int link_socket_read_udp_posix (struct link_socket *sock,
struct buffer *buf,
int maxsize,
struct link_socket_actual *from);
#endif
@ -970,7 +969,6 @@ int link_socket_read_udp_posix (struct link_socket *sock,
static inline int
link_socket_read (struct link_socket *sock,
struct buffer *buf,
int maxsize,
struct link_socket_actual *from)
{
if (proto_is_udp(sock->info.proto)) /* unified UDPv4 and UDPv6 */
@ -980,7 +978,7 @@ link_socket_read (struct link_socket *sock,
#ifdef WIN32
res = link_socket_read_udp_win32 (sock, buf, from);
#else
res = link_socket_read_udp_posix (sock, buf, maxsize, from);
res = link_socket_read_udp_posix (sock, buf, from);
#endif
return res;
}