From 58612741680994928e67a0e981c91bbffb7a2d20 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Wed, 23 Oct 2024 16:20:30 +0200 Subject: [PATCH] io_work: pass event_arg object to event handler in case of socket event In order to allow the code to work with multiple listening sockets it is essential to allow the generic multi_io event handler to distinguish between the various socket objects. This can be achieved by passing an event_arg object that contains a pointer to the link_socket. This code path is used on clients as well as UDP servers. Change-Id: I7ebf0d4fb2a23278e16003b2e35598178155d658 Signed-off-by: Antonio Quartulli Signed-off-by: Gianmarco De Gregori Message-Id: <20241023142030.731-1-gert@greenie.muc.de> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29625.html Signed-off-by: Gert Doering --- src/openvpn/event.h | 6 ++++++ src/openvpn/forward.c | 25 +++++++++++++++++++++++-- src/openvpn/mtcp.c | 10 ++++++++-- 3 files changed, 37 insertions(+), 4 deletions(-) diff --git a/src/openvpn/event.h b/src/openvpn/event.h index b3ba183bd5e..c212e0705d7 100644 --- a/src/openvpn/event.h +++ b/src/openvpn/event.h @@ -82,6 +82,12 @@ #define EVENT_METHOD_US_TIMEOUT (1<<0) #define EVENT_METHOD_FAST (1<<1) +/* + * The following constant is used as boundary between integer value + * and real addresses when passing arguments to event handlers as (void *) + */ +#define MULTI_N ((void *)16) /* upper bound on MTCP_x */ + #ifdef _WIN32 typedef const struct rw_handle *event_t; diff --git a/src/openvpn/forward.c b/src/openvpn/forward.c index 66e5be1b3fc..d50b24c65b5 100644 --- a/src/openvpn/forward.c +++ b/src/openvpn/forward.c @@ -2183,7 +2183,8 @@ io_wait_dowork(struct context *c, const unsigned int flags) /* * Configure event wait based on socket, tuntap flags. */ - socket_set(c->c2.link_socket, c->c2.event_set, socket, (void *)socket_shift, NULL); + socket_set(c->c2.link_socket, c->c2.event_set, socket, + &c->c2.link_socket->ev_arg, NULL); tun_set(c->c1.tuntap, c->c2.event_set, tuntap, (void *)tun_shift, NULL); #if defined(TARGET_LINUX) || defined(TARGET_FREEBSD) if (socket & EVENT_READ && c->c2.did_open_tun) @@ -2246,7 +2247,27 @@ io_wait_dowork(struct context *c, const unsigned int flags) for (i = 0; i < status; ++i) { const struct event_set_return *e = &esr[i]; - c->c2.event_set_status |= ((e->rwflags & 3) << (uintptr_t)e->arg); + uintptr_t shift; + + if (e->arg >= MULTI_N) + { + struct event_arg *ev_arg = (struct event_arg *)e->arg; + if (ev_arg->type != EVENT_ARG_LINK_SOCKET) + { + c->c2.event_set_status = ES_ERROR; + msg(D_LINK_ERRORS, + "io_work: non socket event delivered"); + return; + } + + shift = socket_shift; + } + else + { + shift = (uintptr_t)e->arg; + } + + c->c2.event_set_status |= ((e->rwflags & 3) << shift); } } else if (status == 0) diff --git a/src/openvpn/mtcp.c b/src/openvpn/mtcp.c index 28f6e8ef626..a2841f0da33 100644 --- a/src/openvpn/mtcp.c +++ b/src/openvpn/mtcp.c @@ -60,7 +60,13 @@ #define MTCP_FILE_CLOSE_WRITE ((void *)5) #define MTCP_DCO ((void *)6) -#define MTCP_N ((void *)16) /* upper bound on MTCP_x */ +struct ta_iow_flags +{ + unsigned int flags; + unsigned int ret; + unsigned int tun; + unsigned int sock; +}; #ifdef ENABLE_DEBUG static const char * @@ -686,7 +692,7 @@ multi_tcp_process_io(struct multi_context *m) struct event_set_return *e = &mtcp->esr[i]; /* incoming data for instance or listening socket? */ - if (e->arg >= MTCP_N) + if (e->arg >= MULTI_N) { struct event_arg *ev_arg = (struct event_arg *)e->arg; switch (ev_arg->type)