From 7d59d7a37780379174f868278e184a6856bf4e44 Mon Sep 17 00:00:00 2001 From: Kristen Carlson Accardi Date: Thu, 29 Apr 2010 12:18:29 -0700 Subject: [PATCH] ppp: silently drop invalid packets --- gatchat/gatppp.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) diff --git a/gatchat/gatppp.c b/gatchat/gatppp.c index 3450ce3..f200ae7 100644 --- a/gatchat/gatppp.c +++ b/gatchat/gatppp.c @@ -71,24 +71,44 @@ void ppp_debug(GAtPPP *ppp, const char *str) ppp->debugf(str, ppp->debug_data); } +/* + * Silently discard packets which are received when they shouldn't be + */ +static inline gboolean ppp_drop_packet(GAtPPP *ppp, guint16 protocol) +{ + switch (ppp->phase) { + case PPP_PHASE_ESTABLISHMENT: + case PPP_PHASE_TERMINATION: + if (protocol != LCP_PROTOCOL) + return TRUE; + break; + case PPP_PHASE_AUTHENTICATION: + if (protocol != LCP_PROTOCOL && protocol != CHAP_PROTOCOL) + return TRUE; + break; + case PPP_PHASE_DEAD: + return TRUE; + case PPP_PHASE_NETWORK: + if (ppp->net == NULL) + return TRUE; + break; + } + + return FALSE; +} + static void ppp_receive(const unsigned char *buf, gsize len, void *data) { GAtPPP *ppp = data; guint16 protocol = ppp_proto(buf); const guint8 *packet = ppp_info(buf); - /* - * Any non-LCP packets received during Link Establishment - * phase must be silently discarded. - */ - if (ppp->phase == PPP_PHASE_ESTABLISHMENT && protocol != LCP_PROTOCOL) + if (ppp_drop_packet(ppp, protocol)) return; switch (protocol) { case PPP_IP_PROTO: - /* If network is up & open, process the packet, if not, drop */ - if (ppp->net) - ppp_net_process_packet(ppp->net, packet); + ppp_net_process_packet(ppp->net, packet); break; case LCP_PROTOCOL: pppcp_process_packet(ppp->lcp, packet); -- 2.7.4