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IPVS: Extend protocol DNAT/SNAT and state handlers
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Extend protocol DNAT/SNAT and state handlers to work with IPv6. Also
change/introduce new checksumming helper functions for this.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
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Julius Volz authored and Simon Horman committed Sep 5, 2008
1 parent 3b047d9 commit 0bbdd42
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Showing 3 changed files with 142 additions and 36 deletions.
11 changes: 11 additions & 0 deletions include/net/ip_vs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -904,6 +904,17 @@ static inline __wsum ip_vs_check_diff4(__be32 old, __be32 new, __wsum oldsum)
return csum_partial((char *) diff, sizeof(diff), oldsum);
}

#ifdef CONFIG_IP_VS_IPV6
static inline __wsum ip_vs_check_diff16(const __be32 *old, const __be32 *new,
__wsum oldsum)
{
__be32 diff[8] = { ~old[3], ~old[2], ~old[1], ~old[0],
new[3], new[2], new[1], new[0] };

return csum_partial((char *) diff, sizeof(diff), oldsum);
}
#endif

static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum)
{
__be16 diff[2] = { ~old, new };
Expand Down
85 changes: 68 additions & 17 deletions net/ipv4/ipvs/ip_vs_proto_tcp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,11 +114,21 @@ tcp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,


static inline void
tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip,
tcp_fast_csum_update(int af, struct tcphdr *tcph,
const union nf_inet_addr *oldip,
const union nf_inet_addr *newip,
__be16 oldport, __be16 newport)
{
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
tcph->check =
csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
ip_vs_check_diff2(oldport, newport,
~csum_unfold(tcph->check))));
else
#endif
tcph->check =
csum_fold(ip_vs_check_diff4(oldip, newip,
csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
ip_vs_check_diff2(oldport, newport,
~csum_unfold(tcph->check))));
}
Expand All @@ -129,39 +139,57 @@ tcp_snat_handler(struct sk_buff *skb,
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
struct tcphdr *tcph;
const unsigned int tcphoff = ip_hdrlen(skb);
unsigned int tcphoff;

#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
tcphoff = sizeof(struct ipv6hdr);
else
#endif
tcphoff = ip_hdrlen(skb);

/* csum_check requires unshared skb */
if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
return 0;

if (unlikely(cp->app != NULL)) {
/* Some checks before mangling */
if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
return 0;

/* Call application helper if needed */
if (!ip_vs_app_pkt_out(cp, skb))
return 0;
}

tcph = (void *)ip_hdr(skb) + tcphoff;
tcph = (void *)skb_network_header(skb) + tcphoff;
tcph->source = cp->vport;

/* Adjust TCP checksums */
if (!cp->app) {
/* Only port and addr are changed, do fast csum update */
tcp_fast_csum_update(tcph, cp->daddr.ip, cp->vaddr.ip,
tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
cp->dport, cp->vport);
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
} else {
/* full checksum calculation */
tcph->check = 0;
skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
tcph->check = csum_tcpudp_magic(cp->vaddr.ip, cp->caddr.ip,
skb->len - tcphoff,
cp->protocol, skb->csum);
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
tcph->check = csum_ipv6_magic(&cp->vaddr.in6,
&cp->caddr.in6,
skb->len - tcphoff,
cp->protocol, skb->csum);
else
#endif
tcph->check = csum_tcpudp_magic(cp->vaddr.ip,
cp->caddr.ip,
skb->len - tcphoff,
cp->protocol,
skb->csum);

IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
pp->name, tcph->check,
(char*)&(tcph->check) - (char*)tcph);
Expand All @@ -175,15 +203,22 @@ tcp_dnat_handler(struct sk_buff *skb,
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
struct tcphdr *tcph;
const unsigned int tcphoff = ip_hdrlen(skb);
unsigned int tcphoff;

#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
tcphoff = sizeof(struct ipv6hdr);
else
#endif
tcphoff = ip_hdrlen(skb);

/* csum_check requires unshared skb */
if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
return 0;

if (unlikely(cp->app != NULL)) {
/* Some checks before mangling */
if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
return 0;

/*
Expand All @@ -194,25 +229,35 @@ tcp_dnat_handler(struct sk_buff *skb,
return 0;
}

tcph = (void *)ip_hdr(skb) + tcphoff;
tcph = (void *)skb_network_header(skb) + tcphoff;
tcph->dest = cp->dport;

/*
* Adjust TCP checksums
*/
if (!cp->app) {
/* Only port and addr are changed, do fast csum update */
tcp_fast_csum_update(tcph, cp->vaddr.ip, cp->daddr.ip,
tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
cp->vport, cp->dport);
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
} else {
/* full checksum calculation */
tcph->check = 0;
skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
tcph->check = csum_tcpudp_magic(cp->caddr.ip, cp->daddr.ip,
skb->len - tcphoff,
cp->protocol, skb->csum);
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
tcph->check = csum_ipv6_magic(&cp->caddr.in6,
&cp->daddr.in6,
skb->len - tcphoff,
cp->protocol, skb->csum);
else
#endif
tcph->check = csum_tcpudp_magic(cp->caddr.ip,
cp->daddr.ip,
skb->len - tcphoff,
cp->protocol,
skb->csum);
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
return 1;
Expand Down Expand Up @@ -487,7 +532,13 @@ tcp_state_transition(struct ip_vs_conn *cp, int direction,
{
struct tcphdr _tcph, *th;

th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
#ifdef CONFIG_IP_VS_IPV6
int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
#else
int ihl = ip_hdrlen(skb);
#endif

th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph);
if (th == NULL)
return 0;

Expand Down
82 changes: 63 additions & 19 deletions net/ipv4/ipvs/ip_vs_proto_udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -120,13 +120,23 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,


static inline void
udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip,
udp_fast_csum_update(int af, struct udphdr *uhdr,
const union nf_inet_addr *oldip,
const union nf_inet_addr *newip,
__be16 oldport, __be16 newport)
{
uhdr->check =
csum_fold(ip_vs_check_diff4(oldip, newip,
ip_vs_check_diff2(oldport, newport,
~csum_unfold(uhdr->check))));
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
uhdr->check =
csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
ip_vs_check_diff2(oldport, newport,
~csum_unfold(uhdr->check))));
else
#endif
uhdr->check =
csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
ip_vs_check_diff2(oldport, newport,
~csum_unfold(uhdr->check))));
if (!uhdr->check)
uhdr->check = CSUM_MANGLED_0;
}
Expand All @@ -136,15 +146,22 @@ udp_snat_handler(struct sk_buff *skb,
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
struct udphdr *udph;
const unsigned int udphoff = ip_hdrlen(skb);
unsigned int udphoff;

#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
udphoff = sizeof(struct ipv6hdr);
else
#endif
udphoff = ip_hdrlen(skb);

/* csum_check requires unshared skb */
if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
return 0;

if (unlikely(cp->app != NULL)) {
/* Some checks before mangling */
if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
return 0;

/*
Expand All @@ -154,25 +171,35 @@ udp_snat_handler(struct sk_buff *skb,
return 0;
}

udph = (void *)ip_hdr(skb) + udphoff;
udph = (void *)skb_network_header(skb) + udphoff;
udph->source = cp->vport;

/*
* Adjust UDP checksums
*/
if (!cp->app && (udph->check != 0)) {
/* Only port and addr are changed, do fast csum update */
udp_fast_csum_update(udph, cp->daddr.ip, cp->vaddr.ip,
udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
cp->dport, cp->vport);
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
} else {
/* full checksum calculation */
udph->check = 0;
skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
udph->check = csum_tcpudp_magic(cp->vaddr.ip, cp->caddr.ip,
skb->len - udphoff,
cp->protocol, skb->csum);
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
udph->check = csum_ipv6_magic(&cp->vaddr.in6,
&cp->caddr.in6,
skb->len - udphoff,
cp->protocol, skb->csum);
else
#endif
udph->check = csum_tcpudp_magic(cp->vaddr.ip,
cp->caddr.ip,
skb->len - udphoff,
cp->protocol,
skb->csum);
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
Expand All @@ -188,15 +215,22 @@ udp_dnat_handler(struct sk_buff *skb,
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
struct udphdr *udph;
unsigned int udphoff = ip_hdrlen(skb);
unsigned int udphoff;

#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
udphoff = sizeof(struct ipv6hdr);
else
#endif
udphoff = ip_hdrlen(skb);

/* csum_check requires unshared skb */
if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
return 0;

if (unlikely(cp->app != NULL)) {
/* Some checks before mangling */
if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
return 0;

/*
Expand All @@ -207,25 +241,35 @@ udp_dnat_handler(struct sk_buff *skb,
return 0;
}

udph = (void *)ip_hdr(skb) + udphoff;
udph = (void *)skb_network_header(skb) + udphoff;
udph->dest = cp->dport;

/*
* Adjust UDP checksums
*/
if (!cp->app && (udph->check != 0)) {
/* Only port and addr are changed, do fast csum update */
udp_fast_csum_update(udph, cp->vaddr.ip, cp->daddr.ip,
udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
cp->vport, cp->dport);
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
} else {
/* full checksum calculation */
udph->check = 0;
skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
udph->check = csum_tcpudp_magic(cp->caddr.ip, cp->daddr.ip,
skb->len - udphoff,
cp->protocol, skb->csum);
#ifdef CONFIG_IP_VS_IPV6
if (cp->af == AF_INET6)
udph->check = csum_ipv6_magic(&cp->caddr.in6,
&cp->daddr.in6,
skb->len - udphoff,
cp->protocol, skb->csum);
else
#endif
udph->check = csum_tcpudp_magic(cp->caddr.ip,
cp->daddr.ip,
skb->len - udphoff,
cp->protocol,
skb->csum);
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_UNNECESSARY;
Expand Down

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