[PATCH net-next 09/20] ipvs: support ipv4 in ipv6 and ipv6 in ipv4 tunnel forwarding
From: Alex Gartrell <hidden>
Date: 2014-09-09 23:40:28
Also in:
lvs-devel
Subsystem:
ipvs, netfilter, networking [general], the rest · Maintainers:
Simon Horman, Julian Anastasov, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Pull the common logic for preparing an skb to prepend the header into a single function and then set fields such that they can be used in either case (generalize tos and tclass to dscp, hop_limit and ttl to ttl, etc) Signed-off-by: Alex Gartrell <redacted> --- net/netfilter/ipvs/ip_vs_conn.c | 12 +++- net/netfilter/ipvs/ip_vs_xmit.c | 148 +++++++++++++++++++++++++++++----------- 2 files changed, 117 insertions(+), 43 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index fdb4880..13e9cee 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c@@ -488,7 +488,12 @@ static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp) break; case IP_VS_CONN_F_TUNNEL: - cp->packet_xmit = ip_vs_tunnel_xmit; +#ifdef CONFIG_IP_VS_IPV6 + if (cp->daf == AF_INET6) + cp->packet_xmit = ip_vs_tunnel_xmit_v6; + else +#endif + cp->packet_xmit = ip_vs_tunnel_xmit; break; case IP_VS_CONN_F_DROUTE:
@@ -514,7 +519,10 @@ static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp) break; case IP_VS_CONN_F_TUNNEL: - cp->packet_xmit = ip_vs_tunnel_xmit_v6; + if (cp->daf == AF_INET6) + cp->packet_xmit = ip_vs_tunnel_xmit_v6; + else + cp->packet_xmit = ip_vs_tunnel_xmit; break; case IP_VS_CONN_F_DROUTE:
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index fa2fdd7..91f17c1 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c@@ -824,6 +824,81 @@ tx_error: } #endif +/* When forwarding a packet, we must ensure that we've got enough headroom + * for the encapsulation packet in the skb. This also gives us an + * opportunity to figure out what the payload_len, dsfield, ttl, and df + * values should be, so that we won't need to look at the old ip header + * again + */ +static struct sk_buff * +ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af, + unsigned int max_headroom, __u8 *next_protocol, + __u32 *payload_len, __u8 *dsfield, __u8 *ttl, + __be16 *df) +{ + struct sk_buff *new_skb = NULL; + struct iphdr *old_iph = NULL; +#ifdef CONFIG_IP_VS_IPV6 + struct ipv6hdr *old_ipv6h = NULL; +#endif + + if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) { + new_skb = skb_realloc_headroom(skb, max_headroom); + if (!new_skb) + goto error; + consume_skb(skb); + skb = new_skb; + } + +#ifdef CONFIG_IP_VS_IPV6 + if (skb_af == AF_INET6) { + old_ipv6h = ipv6_hdr(skb); + *next_protocol = IPPROTO_IPV6; + if (payload_len) + *payload_len = + ntohs(old_ipv6h->payload_len) + + sizeof(*old_ipv6h); + *dsfield = ipv6_get_dsfield(old_ipv6h); + *ttl = old_ipv6h->hop_limit; + if (df) + *df = 0; + } else +#endif + { + old_iph = ip_hdr(skb); + /* Copy DF, reset fragment offset and MF */ + if (df) + *df = (old_iph->frag_off & htons(IP_DF)); + *next_protocol = IPPROTO_IPIP; + + /* fix old IP header checksum */ + ip_send_check(old_iph); + *dsfield = ipv4_get_dsfield(old_iph); + *ttl = old_iph->ttl; + if (payload_len) + *payload_len = ntohs(old_iph->tot_len); + } + + return skb; +error: + kfree_skb(skb); + return ERR_PTR(-ENOMEM); +} + +static inline int __tun_gso_type_mask(int encaps_af, int orig_af) +{ + if (encaps_af == AF_INET) { + if (orig_af == AF_INET) + return SKB_GSO_IPIP; + + return SKB_GSO_SIT; + } + + /* GSO: we need to provide proper SKB_GSO_ value for IPv6: + * SKB_GSO_SIT/IPV6 + */ + return 0; +} /* * IP Tunneling transmitter
@@ -852,9 +927,11 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, struct rtable *rt; /* Route to the other host */ __be32 saddr; /* Source for tunnel */ struct net_device *tdev; /* Device to other host */ - struct iphdr *old_iph = ip_hdr(skb); - u8 tos = old_iph->tos; - __be16 df; + __u8 next_protocol = 0; + __u8 dsfield = 0; + __u8 ttl = 0; + __be16 df = 0; + __be16 *dfp = NULL; struct iphdr *iph; /* Our new IP header */ unsigned int max_headroom; /* The extra header space needed */ int ret, local;
@@ -877,29 +954,21 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, rt = skb_rtable(skb); tdev = rt->dst.dev; - /* Copy DF, reset fragment offset and MF */ - df = sysctl_pmtu_disc(ipvs) ? old_iph->frag_off & htons(IP_DF) : 0; - /* * Okay, now see if we can stuff it in the buffer as-is. */ max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr); - if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) { - struct sk_buff *new_skb = - skb_realloc_headroom(skb, max_headroom); - - if (!new_skb) - goto tx_error; - consume_skb(skb); - skb = new_skb; - old_iph = ip_hdr(skb); - } - - /* fix old IP header checksum */ - ip_send_check(old_iph); + /* We only care about the df field if sysctl_pmtu_disc(ipvs) is set */ + dfp = sysctl_pmtu_disc(ipvs) ? &df : NULL; + skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom, + &next_protocol, NULL, &dsfield, + &ttl, dfp); + if (IS_ERR(skb)) + goto tx_error; - skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); + skb = iptunnel_handle_offloads( + skb, false, __tun_gso_type_mask(AF_INET, cp->af)); if (IS_ERR(skb)) goto tx_error;
@@ -916,11 +985,11 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, iph->version = 4; iph->ihl = sizeof(struct iphdr)>>2; iph->frag_off = df; - iph->protocol = IPPROTO_IPIP; - iph->tos = tos; + iph->protocol = next_protocol; + iph->tos = dsfield; iph->daddr = cp->daddr.ip; iph->saddr = saddr; - iph->ttl = old_iph->ttl; + iph->ttl = ttl; ip_select_ident(skb, NULL); /* Another hack: avoid icmp_send in ip_fragment */
@@ -953,7 +1022,10 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, struct rt6_info *rt; /* Route to the other host */ struct in6_addr saddr; /* Source for tunnel */ struct net_device *tdev; /* Device to other host */ - struct ipv6hdr *old_iph = ipv6_hdr(skb); + __u8 next_protocol = 0; + __u32 payload_len = 0; + __u8 dsfield = 0; + __u8 ttl = 0; struct ipv6hdr *iph; /* Our new IP header */ unsigned int max_headroom; /* The extra header space needed */ int ret, local;
@@ -981,19 +1053,14 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, */ max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr); - if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) { - struct sk_buff *new_skb = - skb_realloc_headroom(skb, max_headroom); - - if (!new_skb) - goto tx_error; - consume_skb(skb); - skb = new_skb; - old_iph = ipv6_hdr(skb); - } + skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom, + &next_protocol, &payload_len, + &dsfield, &ttl, NULL); + if (IS_ERR(skb)) + goto tx_error; - /* GSO: we need to provide proper SKB_GSO_ value for IPv6 */ - skb = iptunnel_handle_offloads(skb, false, 0); /* SKB_GSO_SIT/IPV6 */ + skb = iptunnel_handle_offloads( + skb, false, __tun_gso_type_mask(AF_INET6, cp->af)); if (IS_ERR(skb)) goto tx_error;
@@ -1008,14 +1075,13 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, */ iph = ipv6_hdr(skb); iph->version = 6; - iph->nexthdr = IPPROTO_IPV6; - iph->payload_len = old_iph->payload_len; - be16_add_cpu(&iph->payload_len, sizeof(*old_iph)); + iph->nexthdr = next_protocol; + iph->payload_len = htons(payload_len); memset(&iph->flow_lbl, 0, sizeof(iph->flow_lbl)); - ipv6_change_dsfield(iph, 0, ipv6_get_dsfield(old_iph)); + ipv6_change_dsfield(iph, 0, dsfield); iph->daddr = cp->daddr.in6; iph->saddr = saddr; - iph->hop_limit = old_iph->hop_limit; + iph->hop_limit = ttl; /* Another hack: avoid icmp_send in ip_fragment */ skb->ignore_df = 1;
--
1.8.1