From 3f20efba41916ee17ce82f0fdd02581ada2872b2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 27 Jan 2016 14:52:02 +0100 Subject: ipvs: handle ip_vs_fill_iph_skb_off failure ip_vs_fill_iph_skb_off() may not find an IP header, and gcc has determined that ip_vs_sip_fill_param() then incorrectly accesses the protocol fields: net/netfilter/ipvs/ip_vs_pe_sip.c: In function 'ip_vs_sip_fill_param': net/netfilter/ipvs/ip_vs_pe_sip.c:76:5: error: 'iph.protocol' may be used uninitialized in this function [-Werror=maybe-uninitialized] if (iph.protocol != IPPROTO_UDP) ^ net/netfilter/ipvs/ip_vs_pe_sip.c:81:10: error: 'iph.len' may be used uninitialized in this function [-Werror=maybe-uninitialized] dataoff = iph.len + sizeof(struct udphdr); ^ This adds a check for the ip_vs_fill_iph_skb_off() return code before looking at the ip header data returned from it. Signed-off-by: Arnd Bergmann Fixes: b0e010c527de ("ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off") Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_pe_sip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/netfilter/ipvs') diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c index 1b8d594e493a..c4e9ca016a88 100644 --- a/net/netfilter/ipvs/ip_vs_pe_sip.c +++ b/net/netfilter/ipvs/ip_vs_pe_sip.c @@ -70,10 +70,10 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb) const char *dptr; int retc; - ip_vs_fill_iph_skb(p->af, skb, false, &iph); + retc = ip_vs_fill_iph_skb(p->af, skb, false, &iph); /* Only useful with UDP */ - if (iph.protocol != IPPROTO_UDP) + if (!retc || iph.protocol != IPPROTO_UDP) return -EINVAL; /* todo: IPv6 fragments: * I think this only should be done for the first fragment. /HS -- cgit v1.2.1 From f719e3754ee2f7275437e61a6afd520181fdd43b Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Sat, 5 Mar 2016 15:03:22 +0200 Subject: ipvs: drop first packet to redirect conntrack Jiri Bohac is reporting for a problem where the attempt to reschedule existing connection to another real server needs proper redirect for the conntrack used by the IPVS connection. For example, when IPVS connection is created to NAT-ed real server we alter the reply direction of conntrack. If we later decide to select different real server we can not alter again the conntrack. And if we expire the old connection, the new connection is left without conntrack. So, the only way to redirect both the IPVS connection and the Netfilter's conntrack is to drop the SYN packet that hits existing connection, to wait for the next jiffie to expire the old connection and its conntrack and to rely on client's retransmission to create new connection as usually. Jiri Bohac provided a fix that drops all SYNs on rescheduling, I extended his patch to do such drops only for connections that use conntrack. Here is the original report from Jiri Bohac: Since commit dc7b3eb900aa ("ipvs: Fix reuse connection if real server is dead"), new connections to dead servers are redistributed immediately to new servers. The old connection is expired using ip_vs_conn_expire_now() which sets the connection timer to expire immediately. However, before the timer callback, ip_vs_conn_expire(), is run to clean the connection's conntrack entry, the new redistributed connection may already be established and its conntrack removed instead. Fix this by dropping the first packet of the new connection instead, like we do when the destination server is not available. The timer will have deleted the old conntrack entry long before the first packet of the new connection is retransmitted. Fixes: dc7b3eb900aa ("ipvs: Fix reuse connection if real server is dead") Signed-off-by: Jiri Bohac Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_core.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) (limited to 'net/netfilter/ipvs') diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index f57b4dcdb233..4da560005b0e 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1757,15 +1757,34 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int cp = pp->conn_in_get(ipvs, af, skb, &iph); conn_reuse_mode = sysctl_conn_reuse_mode(ipvs); - if (conn_reuse_mode && !iph.fragoffs && - is_new_conn(skb, &iph) && cp && - ((unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest && - unlikely(!atomic_read(&cp->dest->weight))) || - unlikely(is_new_conn_expected(cp, conn_reuse_mode)))) { - if (!atomic_read(&cp->n_control)) - ip_vs_conn_expire_now(cp); - __ip_vs_conn_put(cp); - cp = NULL; + if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) { + bool uses_ct = false, resched = false; + + if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest && + unlikely(!atomic_read(&cp->dest->weight))) { + resched = true; + uses_ct = ip_vs_conn_uses_conntrack(cp, skb); + } else if (is_new_conn_expected(cp, conn_reuse_mode)) { + uses_ct = ip_vs_conn_uses_conntrack(cp, skb); + if (!atomic_read(&cp->n_control)) { + resched = true; + } else { + /* Do not reschedule controlling connection + * that uses conntrack while it is still + * referenced by controlled connection(s). + */ + resched = !uses_ct; + } + } + + if (resched) { + if (!atomic_read(&cp->n_control)) + ip_vs_conn_expire_now(cp); + __ip_vs_conn_put(cp); + if (uses_ct) + return NF_DROP; + cp = NULL; + } } if (unlikely(!cp)) { -- cgit v1.2.1 From f911b675a06d05211da52cf8267db80c81b6aee4 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Sat, 5 Mar 2016 15:03:23 +0200 Subject: ipvs: allow rescheduling after RST "RFC 5961, 4.2. Mitigation" describes a mechanism to request client to confirm with RST the restart of TCP connection before resending its SYN. As result, IPVS can see SYNs for existing connection in CLOSE state. Add check to allow rescheduling in this state. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_core.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/netfilter/ipvs') diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 4da560005b0e..b9a4082afa3a 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1089,6 +1089,7 @@ static inline bool is_new_conn_expected(const struct ip_vs_conn *cp, switch (cp->protocol) { case IPPROTO_TCP: return (cp->state == IP_VS_TCP_S_TIME_WAIT) || + (cp->state == IP_VS_TCP_S_CLOSE) || ((conn_reuse_mode & 2) && (cp->state == IP_VS_TCP_S_FIN_WAIT) && (cp->flags & IP_VS_CONN_F_NOOUTPUT)); -- cgit v1.2.1 From 7617a24f83b5d67f4dab1844956be1cebc44aec8 Mon Sep 17 00:00:00 2001 From: Marco Angaroni Date: Sat, 5 Mar 2016 12:10:02 +0100 Subject: ipvs: correct initial offset of Call-ID header search in SIP persistence engine The IPVS SIP persistence engine is not able to parse the SIP header "Call-ID" when such header is inserted in the first positions of the SIP message. When IPVS is configured with "--pe sip" option, like for example: ipvsadm -A -u 1.2.3.4:5060 -s rr --pe sip -p 120 -o some particular messages (see below for details) do not create entries in the connection template table, which can be listed with: ipvsadm -Lcn --persistent-conn Problematic SIP messages are SIP responses having "Call-ID" header positioned just after message first line: SIP/2.0 200 OK [Call-ID header here] [rest of the headers] When "Call-ID" header is positioned down (after a few other headers) it is correctly recognized. This is due to the data offset used in get_callid function call inside ip_vs_pe_sip.c file: since dptr already points to the start of the SIP message, the value of dataoff should be initially 0. Otherwise the header is searched starting from some bytes after the first character of the SIP message. Fixes: 758ff0338722 ("IPVS: sip persistence engine") Signed-off-by: Marco Angaroni Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_pe_sip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/netfilter/ipvs') diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c index c4e9ca016a88..0a6eb5c0d9e9 100644 --- a/net/netfilter/ipvs/ip_vs_pe_sip.c +++ b/net/netfilter/ipvs/ip_vs_pe_sip.c @@ -88,7 +88,7 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb) dptr = skb->data + dataoff; datalen = skb->len - dataoff; - if (get_callid(dptr, dataoff, datalen, &matchoff, &matchlen)) + if (get_callid(dptr, 0, datalen, &matchoff, &matchlen)) return -EINVAL; /* N.B: pe_data is only set on success, -- cgit v1.2.1