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ipvs-toa.patch
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ipvs-toa.patch
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diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 5d08c19..27df4d8 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -348,6 +348,22 @@ enum ip_vs_sctp_states {
IP_VS_SCTP_S_LAST
};
+#define TCPOPT_ADDR 254
+#define TCPOLEN_ADDR 8 /* |opcode|size|ip+port| = 1 + 1 + 6 */
+
+/*
+ * insert client ip in tcp option, now only support IPV4,
+ * must be 4 bytes alignment.
+ */
+struct ip_vs_tcpo_addr {
+ __u8 opcode;
+ __u8 opsize;
+ __u16 port;
+ __u32 addr;
+};
+
+extern int sysctl_ip_vs_toa_entry;
+
/* Delta sequence info structure
* Each ip_vs_conn has 2 (output AND input seq. changes).
* Only used in the VS/NAT.
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index e8f1556..3a5bbdd 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -66,6 +66,8 @@ int ip_vs_get_debug_level(void)
}
#endif
+int sysctl_ip_vs_toa_entry = 1;
+
/* Protos */
static void __ip_vs_del_service(struct ip_vs_service *svc, bool cleanup);
@@ -1637,6 +1639,7 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs)
#ifdef CONFIG_SYSCTL
static int zero;
+static int one = 1;
static int three = 3;
static int
@@ -1884,6 +1887,15 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs)
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "nat_toa_entry",
+ .data = &sysctl_ip_vs_toa_entry,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
#ifdef CONFIG_IP_VS_DEBUG
{
.procname = "debug_level",
diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c
index 121a321..cfa842c 100644
--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -142,6 +142,110 @@
csum_unfold(tcph->check))));
}
+/*
+ * add client (ip and port) in tcp option
+ * return 0 if success
+ */
+static int tcp_opt_add_toa(struct ip_vs_conn *cp,
+ struct sk_buff *skb,
+ struct tcphdr **tcph)
+{
+ __u32 mtu;
+ struct ip_vs_tcpo_addr *toa;
+ unsigned int tcphoff;
+ struct tcphdr *th;
+ __u8 *p, *q;
+
+ /* now only process IPV4 */
+ if (cp->af != AF_INET) {
+ return 1;
+ }
+
+ /* skb length and tcp option length checking */
+ if (skb_dst(skb))
+ mtu = dst_mtu(skb_dst(skb));
+ else /* fast_xmit can reach here */
+ mtu = sizeof(struct ip_vs_tcpo_addr);
+
+ if (skb->len > (mtu - sizeof(struct ip_vs_tcpo_addr))) {
+ return 1;
+ }
+
+ /* the maximum length of TCP head is 60 bytes, so only 40 bytes for options */
+ if ((60 - ((*tcph)->doff << 2)) < sizeof(struct ip_vs_tcpo_addr)) {
+ return 1;
+ }
+
+ /* expand skb if needed */
+ if ((sizeof(struct ip_vs_tcpo_addr) > skb_tailroom(skb)) &&
+ pskb_expand_head(skb, 0,
+ sizeof(struct ip_vs_tcpo_addr), GFP_ATOMIC)){
+ return 1;
+ }
+
+ /*
+ * add client ip
+ */
+ tcphoff = ip_hdrlen(skb);
+ /* get new tcp header */
+ *tcph = th =
+ (struct tcphdr *)((void *)skb_network_header(skb) + tcphoff);
+
+ /* ptr to old opts */
+ p = skb_tail_pointer(skb) - 1;
+ q = p + sizeof(struct ip_vs_tcpo_addr);
+
+ /* move data down, offset is sizeof(struct ip_vs_tcpo_addr) */
+ while (p >= ((__u8 *) th + sizeof(struct tcphdr))) {
+ *q = *p;
+ p--;
+ q--;
+ }
+
+ /* move tail to new postion */
+ skb->tail += sizeof(struct ip_vs_tcpo_addr);
+
+ /* put client ip opt , ptr point to opts */
+ toa = (struct ip_vs_tcpo_addr *)(th + 1);
+ toa->opcode = TCPOPT_ADDR;
+ toa->opsize = TCPOLEN_ADDR;
+ toa->port = cp->cport;
+ toa->addr = cp->caddr.ip;
+
+ /* reset tcp header length */
+ th->doff += sizeof(struct ip_vs_tcpo_addr) / 4;
+ /* reset ip header totoal length */
+ ip_hdr(skb)->tot_len =
+ htons(ntohs(ip_hdr(skb)->tot_len) +
+ sizeof(struct ip_vs_tcpo_addr));
+ /* reset skb length */
+ skb->len += sizeof(struct ip_vs_tcpo_addr);
+
+ /* re-calculate tcp csum, if no csum_offload */
+ bool sysctl_ip_vs_csum_offload = false;
+ if (!sysctl_ip_vs_csum_offload) {
+ th->check = 0;
+ skb->csum = skb_checksum(skb, tcphoff,
+ skb->len - tcphoff, 0);
+ th->check = csum_tcpudp_magic(cp->caddr.ip,
+ cp->vaddr.ip,
+ skb->len - tcphoff,
+ cp->protocol, skb->csum);
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ skb->ip_summed = CHECKSUM_COMPLETE;
+ skb_shinfo(skb)->gso_size = 0;
+ }
+ }
+
+ /* re-calculate ip head csum, tot_len has been adjusted */
+ ip_send_check(ip_hdr(skb));
+
+ return 0;
+}
+
+
+
static int
tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
@@ -225,6 +329,7 @@
tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
{
+
struct tcphdr *tcph;
unsigned int tcphoff = iph->len;
int oldlen;
@@ -261,6 +366,24 @@
}
tcph = (void *)skb_network_header(skb) + tcphoff;
+
+
+ /*
+ * for syn packet
+ * add toa
+ */
+ if (tcph->syn & !tcph->ack) {
+ tcp_opt_add_toa(cp, skb, &tcph);
+ }
+
+ /* TOA: add client ip */
+ if ((sysctl_ip_vs_toa_entry == 1)
+ // && (ntohl(tcph->ack_seq) == cp->in_seq.init_seq)
+ && !tcph->syn && !tcph->rst && !tcph->fin) {
+ tcp_opt_add_toa(cp, skb, &tcph);
+ }
+
+
tcph->dest = cp->dport;
/*
@@ -299,7 +422,6 @@
return 1;
}
-
static int
tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
{