hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

[NETFILTER]: Get rid of HW checksum invalidation 

Update hardware checksums incrementally to avoid breaking GSO.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2006-08-05 00:58:33 -07:00 committed by David S. Miller
parent 84fa7933a3
commit 4cf411de49
14 changed files with 138 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/netfilter.h
View File

@ -282,6 +282,12 @@ extern void nf_invalidate_cache(int pf);
Returns true or false. */ Returns true or false. */
extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len); extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
extern u_int16_t nf_csum_update(u_int32_t oldval, u_int32_t newval,
u_int32_t csum);
extern u_int16_t nf_proto_csum_update(struct sk_buff *skb,
u_int32_t oldval, u_int32_t newval,
u_int16_t csum, int pseudohdr);
struct nf_afinfo { struct nf_afinfo {
unsigned short family; unsigned short family;
unsigned int (*checksum)(struct sk_buff *skb, unsigned int hook, unsigned int (*checksum)(struct sk_buff *skb, unsigned int hook,

4
include/linux/netfilter_ipv4/ip_nat.h
View File

@ -72,10 +72,6 @@ extern unsigned int ip_nat_setup_info(struct ip_conntrack *conntrack,
extern int ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple, extern int ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple,
const struct ip_conntrack *ignored_conntrack); const struct ip_conntrack *ignored_conntrack);
/* Calculate relative checksum. */
extern u_int16_t ip_nat_cheat_check(u_int32_t oldvalinv,
u_int32_t newval,
u_int16_t oldcheck);
#else /* !__KERNEL__: iptables wants this to compile. */ #else /* !__KERNEL__: iptables wants this to compile. */
#define ip_nat_multi_range ip_nat_multi_range_compat #define ip_nat_multi_range ip_nat_multi_range_compat
#endif /*__KERNEL__*/ #endif /*__KERNEL__*/

8
include/linux/netfilter_ipv4/ip_nat_core.h
View File

@ -11,8 +11,8 @@ extern unsigned int ip_nat_packet(struct ip_conntrack *ct,
unsigned int hooknum, unsigned int hooknum,
struct sk_buff **pskb); struct sk_buff **pskb);
extern int ip_nat_icmp_reply_translation(struct sk_buff **pskb, extern int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
enum ip_nat_manip_type manip, unsigned int hooknum,
enum ip_conntrack_dir dir); struct sk_buff **pskb);
#endif /* _IP_NAT_CORE_H */ #endif /* _IP_NAT_CORE_H */

52
net/ipv4/netfilter/ip_nat_core.c
View File

@ -101,18 +101,6 @@ static void ip_nat_cleanup_conntrack(struct ip_conntrack *conn)
write_unlock_bh(&ip_nat_lock); write_unlock_bh(&ip_nat_lock);
} }
/* We do checksum mangling, so if they were wrong before they're still
* wrong. Also works for incomplete packets (eg. ICMP dest
* unreachables.) */
u_int16_t
ip_nat_cheat_check(u_int32_t oldvalinv, u_int32_t newval, u_int16_t oldcheck)
{
u_int32_t diffs[] = { oldvalinv, newval };
return csum_fold(csum_partial((char *)diffs, sizeof(diffs),
oldcheck^0xFFFF));
}
EXPORT_SYMBOL(ip_nat_cheat_check);
/* Is this tuple already taken? (not by us) */ /* Is this tuple already taken? (not by us) */
int int
ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple, ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple,
@ -378,12 +366,12 @@ manip_pkt(u_int16_t proto,
iph = (void *)(*pskb)->data + iphdroff; iph = (void *)(*pskb)->data + iphdroff;
if (maniptype == IP_NAT_MANIP_SRC) { if (maniptype == IP_NAT_MANIP_SRC) {
iph->check = ip_nat_cheat_check(~iph->saddr, target->src.ip, iph->check = nf_csum_update(~iph->saddr, target->src.ip,
iph->check); iph->check);
iph->saddr = target->src.ip; iph->saddr = target->src.ip;
} else { } else {
iph->check = ip_nat_cheat_check(~iph->daddr, target->dst.ip, iph->check = nf_csum_update(~iph->daddr, target->dst.ip,
iph->check); iph->check);
iph->daddr = target->dst.ip; iph->daddr = target->dst.ip;
} }
return 1; return 1;
@ -423,10 +411,10 @@ unsigned int ip_nat_packet(struct ip_conntrack *ct,
EXPORT_SYMBOL_GPL(ip_nat_packet); EXPORT_SYMBOL_GPL(ip_nat_packet);
/* Dir is direction ICMP is coming from (opposite to packet it contains) */ /* Dir is direction ICMP is coming from (opposite to packet it contains) */
int ip_nat_icmp_reply_translation(struct sk_buff **pskb, int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
enum ip_nat_manip_type manip, unsigned int hooknum,
enum ip_conntrack_dir dir) struct sk_buff **pskb)
{ {
struct { struct {
struct icmphdr icmp; struct icmphdr icmp;
@ -434,7 +422,9 @@ int ip_nat_icmp_reply_translation(struct sk_buff **pskb,
} *inside; } *inside;
struct ip_conntrack_tuple inner, target; struct ip_conntrack_tuple inner, target;
int hdrlen = (*pskb)->nh.iph->ihl * 4; int hdrlen = (*pskb)->nh.iph->ihl * 4;
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
unsigned long statusbit; unsigned long statusbit;
enum ip_nat_manip_type manip = HOOK2MANIP(hooknum);
if (!skb_make_writable(pskb, hdrlen + sizeof(*inside))) if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
return 0; return 0;
@ -443,12 +433,8 @@ int ip_nat_icmp_reply_translation(struct sk_buff **pskb,
/* We're actually going to mangle it beyond trivial checksum /* We're actually going to mangle it beyond trivial checksum
adjustment, so make sure the current checksum is correct. */ adjustment, so make sure the current checksum is correct. */
if ((*pskb)->ip_summed != CHECKSUM_UNNECESSARY) { if (nf_ip_checksum(*pskb, hooknum, hdrlen, 0))
hdrlen = (*pskb)->nh.iph->ihl * 4; return 0;
if ((u16)csum_fold(skb_checksum(*pskb, hdrlen,
(*pskb)->len - hdrlen, 0)))
return 0;
}
/* Must be RELATED */ /* Must be RELATED */
IP_NF_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED || IP_NF_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED ||
@ -487,12 +473,14 @@ int ip_nat_icmp_reply_translation(struct sk_buff **pskb,
!manip)) !manip))
return 0; return 0;
/* Reloading "inside" here since manip_pkt inner. */ if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4; /* Reloading "inside" here since manip_pkt inner. */
inside->icmp.checksum = 0; inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
inside->icmp.checksum = csum_fold(skb_checksum(*pskb, hdrlen, inside->icmp.checksum = 0;
(*pskb)->len - hdrlen, inside->icmp.checksum = csum_fold(skb_checksum(*pskb, hdrlen,
0)); (*pskb)->len - hdrlen,
0));
}
/* Change outer to look the reply to an incoming packet /* Change outer to look the reply to an incoming packet
* (proto 0 means don't invert per-proto part). */ * (proto 0 means don't invert per-proto part). */

59
net/ipv4/netfilter/ip_nat_helper.c
View File

@ -165,7 +165,7 @@ ip_nat_mangle_tcp_packet(struct sk_buff **pskb,
{ {
struct iphdr *iph; struct iphdr *iph;
struct tcphdr *tcph; struct tcphdr *tcph;
int datalen; int oldlen, datalen;
if (!skb_make_writable(pskb, (*pskb)->len)) if (!skb_make_writable(pskb, (*pskb)->len))
return 0; return 0;
@ -180,13 +180,22 @@ ip_nat_mangle_tcp_packet(struct sk_buff **pskb,
iph = (*pskb)->nh.iph; iph = (*pskb)->nh.iph;
tcph = (void *)iph + iph->ihl*4; tcph = (void *)iph + iph->ihl*4;
oldlen = (*pskb)->len - iph->ihl*4;
mangle_contents(*pskb, iph->ihl*4 + tcph->doff*4, mangle_contents(*pskb, iph->ihl*4 + tcph->doff*4,
match_offset, match_len, rep_buffer, rep_len); match_offset, match_len, rep_buffer, rep_len);
datalen = (*pskb)->len - iph->ihl*4; datalen = (*pskb)->len - iph->ihl*4;
tcph->check = 0; if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
tcph->check = tcp_v4_check(tcph, datalen, iph->saddr, iph->daddr, tcph->check = 0;
csum_partial((char *)tcph, datalen, 0)); tcph->check = tcp_v4_check(tcph, datalen,
iph->saddr, iph->daddr,
csum_partial((char *)tcph,
datalen, 0));
} else
tcph->check = nf_proto_csum_update(*pskb,
htons(oldlen) ^ 0xFFFF,
htons(datalen),
tcph->check, 1);
if (rep_len != match_len) { if (rep_len != match_len) {
set_bit(IPS_SEQ_ADJUST_BIT, &ct->status); set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
@ -221,6 +230,7 @@ ip_nat_mangle_udp_packet(struct sk_buff **pskb,
{ {
struct iphdr *iph; struct iphdr *iph;
struct udphdr *udph; struct udphdr *udph;
int datalen, oldlen;
/* UDP helpers might accidentally mangle the wrong packet */ /* UDP helpers might accidentally mangle the wrong packet */
iph = (*pskb)->nh.iph; iph = (*pskb)->nh.iph;
@ -238,22 +248,32 @@ ip_nat_mangle_udp_packet(struct sk_buff **pskb,
iph = (*pskb)->nh.iph; iph = (*pskb)->nh.iph;
udph = (void *)iph + iph->ihl*4; udph = (void *)iph + iph->ihl*4;
oldlen = (*pskb)->len - iph->ihl*4;
mangle_contents(*pskb, iph->ihl*4 + sizeof(*udph), mangle_contents(*pskb, iph->ihl*4 + sizeof(*udph),
match_offset, match_len, rep_buffer, rep_len); match_offset, match_len, rep_buffer, rep_len);
/* update the length of the UDP packet */ /* update the length of the UDP packet */
udph->len = htons((*pskb)->len - iph->ihl*4); datalen = (*pskb)->len - iph->ihl*4;
udph->len = htons(datalen);
/* fix udp checksum if udp checksum was previously calculated */ /* fix udp checksum if udp checksum was previously calculated */
if (udph->check) { if (!udph->check && (*pskb)->ip_summed != CHECKSUM_PARTIAL)
int datalen = (*pskb)->len - iph->ihl * 4; return 1;
if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
udph->check = 0; udph->check = 0;
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
datalen, IPPROTO_UDP, datalen, IPPROTO_UDP,
csum_partial((char *)udph, csum_partial((char *)udph,
datalen, 0)); datalen, 0));
} if (!udph->check)
udph->check = -1;
} else
udph->check = nf_proto_csum_update(*pskb,
htons(oldlen) ^ 0xFFFF,
htons(datalen),
udph->check, 1);
return 1; return 1;
} }
EXPORT_SYMBOL(ip_nat_mangle_udp_packet); EXPORT_SYMBOL(ip_nat_mangle_udp_packet);
@ -293,11 +313,14 @@ sack_adjust(struct sk_buff *skb,
ntohl(sack->start_seq), new_start_seq, ntohl(sack->start_seq), new_start_seq,
ntohl(sack->end_seq), new_end_seq); ntohl(sack->end_seq), new_end_seq);
tcph->check = tcph->check = nf_proto_csum_update(skb,
ip_nat_cheat_check(~sack->start_seq, new_start_seq, ~sack->start_seq,
ip_nat_cheat_check(~sack->end_seq, new_start_seq,
new_end_seq, tcph->check, 0);
tcph->check)); tcph->check = nf_proto_csum_update(skb,
~sack->end_seq,
new_end_seq,
tcph->check, 0);
sack->start_seq = new_start_seq; sack->start_seq = new_start_seq;
sack->end_seq = new_end_seq; sack->end_seq = new_end_seq;
sackoff += sizeof(*sack); sackoff += sizeof(*sack);
@ -381,10 +404,10 @@ ip_nat_seq_adjust(struct sk_buff **pskb,
newack = ntohl(tcph->ack_seq) - other_way->offset_before; newack = ntohl(tcph->ack_seq) - other_way->offset_before;
newack = htonl(newack); newack = htonl(newack);
tcph->check = ip_nat_cheat_check(~tcph->seq, newseq, tcph->check = nf_proto_csum_update(*pskb, ~tcph->seq, newseq,
ip_nat_cheat_check(~tcph->ack_seq, tcph->check, 0);
newack, tcph->check = nf_proto_csum_update(*pskb, ~tcph->ack_seq, newack,
tcph->check)); tcph->check, 0);
DEBUGP("Adjusting sequence number from %u->%u, ack from %u->%u\n", DEBUGP("Adjusting sequence number from %u->%u, ack from %u->%u\n",
ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq), ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),

5
net/ipv4/netfilter/ip_nat_proto_gre.c
View File

@ -130,9 +130,10 @@ gre_manip_pkt(struct sk_buff **pskb,
if (greh->csum) { if (greh->csum) {
/* FIXME: Never tested this code... */ /* FIXME: Never tested this code... */
*(gre_csum(greh)) = *(gre_csum(greh)) =
ip_nat_cheat_check(~*(gre_key(greh)), nf_proto_csum_update(*pskb,
~*(gre_key(greh)),
tuple->dst.u.gre.key, tuple->dst.u.gre.key,
*(gre_csum(greh))); *(gre_csum(greh)), 0);
} }
*(gre_key(greh)) = tuple->dst.u.gre.key; *(gre_key(greh)) = tuple->dst.u.gre.key;
break; break;

8
net/ipv4/netfilter/ip_nat_proto_icmp.c
View File

@ -66,10 +66,10 @@ icmp_manip_pkt(struct sk_buff **pskb,
return 0; return 0;
hdr = (struct icmphdr *)((*pskb)->data + hdroff); hdr = (struct icmphdr *)((*pskb)->data + hdroff);
hdr->checksum = nf_proto_csum_update(*pskb,
hdr->checksum = ip_nat_cheat_check(hdr->un.echo.id ^ 0xFFFF, hdr->un.echo.id ^ 0xFFFF,
tuple->src.u.icmp.id, tuple->src.u.icmp.id,
hdr->checksum); hdr->checksum, 0);
hdr->un.echo.id = tuple->src.u.icmp.id; hdr->un.echo.id = tuple->src.u.icmp.id;
return 1; return 1;
} }

7
net/ipv4/netfilter/ip_nat_proto_tcp.c
View File

@ -129,10 +129,9 @@ tcp_manip_pkt(struct sk_buff **pskb,
if (hdrsize < sizeof(*hdr)) if (hdrsize < sizeof(*hdr))
return 1; return 1;
hdr->check = ip_nat_cheat_check(~oldip, newip, hdr->check = nf_proto_csum_update(*pskb, ~oldip, newip, hdr->check, 1);
ip_nat_cheat_check(oldport ^ 0xFFFF, hdr->check = nf_proto_csum_update(*pskb, oldport ^ 0xFFFF, newport,
newport, hdr->check, 0);
hdr->check));
return 1; return 1;
} }

15
net/ipv4/netfilter/ip_nat_proto_udp.c
View File

@ -113,11 +113,16 @@ udp_manip_pkt(struct sk_buff **pskb,
newport = tuple->dst.u.udp.port; newport = tuple->dst.u.udp.port;
portptr = &hdr->dest; portptr = &hdr->dest;
} }
if (hdr->check) /* 0 is a special case meaning no checksum */
hdr->check = ip_nat_cheat_check(~oldip, newip, if (hdr->check || (*pskb)->ip_summed == CHECKSUM_PARTIAL) {
ip_nat_cheat_check(*portptr ^ 0xFFFF, hdr->check = nf_proto_csum_update(*pskb, ~oldip, newip,
newport, hdr->check, 1);
hdr->check)); hdr->check = nf_proto_csum_update(*pskb,
*portptr ^ 0xFFFF, newport,
hdr->check, 0);
if (!hdr->check)
hdr->check = -1;
}
*portptr = newport; *portptr = newport;
return 1; return 1;
} }

10
net/ipv4/netfilter/ip_nat_standalone.c
View File

@ -110,12 +110,6 @@ ip_nat_fn(unsigned int hooknum,
IP_NF_ASSERT(!((*pskb)->nh.iph->frag_off IP_NF_ASSERT(!((*pskb)->nh.iph->frag_off
& htons(IP_MF|IP_OFFSET))); & htons(IP_MF|IP_OFFSET)));
/* If we had a hardware checksum before, it's now invalid */
if ((*pskb)->ip_summed == CHECKSUM_PARTIAL ||
(*pskb)->ip_summed == CHECKSUM_COMPLETE)
if (skb_checksum_help(*pskb))
return NF_DROP;
ct = ip_conntrack_get(*pskb, &ctinfo); ct = ip_conntrack_get(*pskb, &ctinfo);
/* Can't track? It's not due to stress, or conntrack would /* Can't track? It's not due to stress, or conntrack would
have dropped it. Hence it's the user's responsibilty to have dropped it. Hence it's the user's responsibilty to
@ -146,8 +140,8 @@ ip_nat_fn(unsigned int hooknum,
case IP_CT_RELATED: case IP_CT_RELATED:
case IP_CT_RELATED+IP_CT_IS_REPLY: case IP_CT_RELATED+IP_CT_IS_REPLY:
if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) { if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
if (!ip_nat_icmp_reply_translation(pskb, ct, maniptype, if (!ip_nat_icmp_reply_translation(ct, ctinfo,
CTINFO2DIR(ctinfo))) hooknum, pskb))
return NF_DROP; return NF_DROP;
else else
return NF_ACCEPT; return NF_ACCEPT;

19
net/ipv4/netfilter/ipt_ECN.c
View File

@ -52,7 +52,7 @@ static inline int
set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo) set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
{ {
struct tcphdr _tcph, *tcph; struct tcphdr _tcph, *tcph;
u_int16_t diffs[2]; u_int16_t oldval;
/* Not enought header? */ /* Not enought header? */
tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4, tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
@ -70,23 +70,16 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
return 0; return 0;
tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4; tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
if (((*pskb)->ip_summed == CHECKSUM_PARTIAL || oldval = ((u_int16_t *)tcph)[6];
(*pskb)->ip_summed == CHECKSUM_COMPLETE) &&
skb_checksum_help(*pskb))
return 0;
diffs[0] = ((u_int16_t *)tcph)[6];
if (einfo->operation & IPT_ECN_OP_SET_ECE) if (einfo->operation & IPT_ECN_OP_SET_ECE)
tcph->ece = einfo->proto.tcp.ece; tcph->ece = einfo->proto.tcp.ece;
if (einfo->operation & IPT_ECN_OP_SET_CWR) if (einfo->operation & IPT_ECN_OP_SET_CWR)
tcph->cwr = einfo->proto.tcp.cwr; tcph->cwr = einfo->proto.tcp.cwr;
diffs[1] = ((u_int16_t *)tcph)[6];
diffs[0] = diffs[0] ^ 0xFFFF;
if ((*pskb)->ip_summed != CHECKSUM_UNNECESSARY) tcph->check = nf_proto_csum_update((*pskb),
tcph->check = csum_fold(csum_partial((char *)diffs, oldval ^ 0xFFFF,
sizeof(diffs), ((u_int16_t *)tcph)[6],
tcph->check^0xFFFF)); tcph->check, 0);
return 1; return 1;
} }

1
net/ipv4/netfilter/ipt_REJECT.c
View File

@ -185,6 +185,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
tcph->urg_ptr = 0; tcph->urg_ptr = 0;
/* Adjust TCP checksum */ /* Adjust TCP checksum */
nskb->ip_summed = CHECKSUM_NONE;
tcph->check = 0; tcph->check = 0;
tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr), tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr),
nskb->nh.iph->saddr, nskb->nh.iph->saddr,

39
net/ipv4/netfilter/ipt_TCPMSS.c
View File

@ -27,14 +27,6 @@ MODULE_DESCRIPTION("iptables TCP MSS modification module");
#define DEBUGP(format, args...) #define DEBUGP(format, args...)
#endif #endif
static u_int16_t
cheat_check(u_int32_t oldvalinv, u_int32_t newval, u_int16_t oldcheck)
{
u_int32_t diffs[] = { oldvalinv, newval };
return csum_fold(csum_partial((char *)diffs, sizeof(diffs),
oldcheck^0xFFFF));
}
static inline unsigned int static inline unsigned int
optlen(const u_int8_t *opt, unsigned int offset) optlen(const u_int8_t *opt, unsigned int offset)
{ {
@ -62,11 +54,6 @@ ipt_tcpmss_target(struct sk_buff **pskb,
if (!skb_make_writable(pskb, (*pskb)->len)) if (!skb_make_writable(pskb, (*pskb)->len))
return NF_DROP; return NF_DROP;
if (((*pskb)->ip_summed == CHECKSUM_PARTIAL ||
(*pskb)->ip_summed == CHECKSUM_COMPLETE) &&
skb_checksum_help(*pskb))
return NF_DROP;
iph = (*pskb)->nh.iph; iph = (*pskb)->nh.iph;
tcplen = (*pskb)->len - iph->ihl*4; tcplen = (*pskb)->len - iph->ihl*4;
@ -120,9 +107,10 @@ ipt_tcpmss_target(struct sk_buff **pskb,
opt[i+2] = (newmss & 0xff00) >> 8; opt[i+2] = (newmss & 0xff00) >> 8;
opt[i+3] = (newmss & 0x00ff); opt[i+3] = (newmss & 0x00ff);
tcph->check = cheat_check(htons(oldmss)^0xFFFF, tcph->check = nf_proto_csum_update(*pskb,
htons(newmss), htons(oldmss)^0xFFFF,
tcph->check); htons(newmss),
tcph->check, 0);
DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu" DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu"
"->%u.%u.%u.%u:%hu changed TCP MSS option" "->%u.%u.%u.%u:%hu changed TCP MSS option"
@ -162,8 +150,10 @@ ipt_tcpmss_target(struct sk_buff **pskb,
opt = (u_int8_t *)tcph + sizeof(struct tcphdr); opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr)); memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));
tcph->check = cheat_check(htons(tcplen) ^ 0xFFFF, tcph->check = nf_proto_csum_update(*pskb,
htons(tcplen + TCPOLEN_MSS), tcph->check); htons(tcplen) ^ 0xFFFF,
htons(tcplen + TCPOLEN_MSS),
tcph->check, 1);
tcplen += TCPOLEN_MSS; tcplen += TCPOLEN_MSS;
opt[0] = TCPOPT_MSS; opt[0] = TCPOPT_MSS;
@ -171,16 +161,19 @@ ipt_tcpmss_target(struct sk_buff **pskb,
opt[2] = (newmss & 0xff00) >> 8; opt[2] = (newmss & 0xff00) >> 8;
opt[3] = (newmss & 0x00ff); opt[3] = (newmss & 0x00ff);
tcph->check = cheat_check(~0, *((u_int32_t *)opt), tcph->check); tcph->check = nf_proto_csum_update(*pskb, ~0, *((u_int32_t *)opt),
tcph->check, 0);
oldval = ((u_int16_t *)tcph)[6]; oldval = ((u_int16_t *)tcph)[6];
tcph->doff += TCPOLEN_MSS/4; tcph->doff += TCPOLEN_MSS/4;
tcph->check = cheat_check(oldval ^ 0xFFFF, tcph->check = nf_proto_csum_update(*pskb,
((u_int16_t *)tcph)[6], tcph->check); oldval ^ 0xFFFF,
((u_int16_t *)tcph)[6],
tcph->check, 0);
newtotlen = htons(ntohs(iph->tot_len) + TCPOLEN_MSS); newtotlen = htons(ntohs(iph->tot_len) + TCPOLEN_MSS);
iph->check = cheat_check(iph->tot_len ^ 0xFFFF, iph->check = nf_csum_update(iph->tot_len ^ 0xFFFF,
newtotlen, iph->check); newtotlen, iph->check);
iph->tot_len = newtotlen; iph->tot_len = newtotlen;
DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu" DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu"

22
net/netfilter/core.c
View File

@ -222,6 +222,28 @@ copy_skb:
} }
EXPORT_SYMBOL(skb_make_writable); EXPORT_SYMBOL(skb_make_writable);
u_int16_t nf_csum_update(u_int32_t oldval, u_int32_t newval, u_int32_t csum)
{
u_int32_t diff[] = { oldval, newval };
return csum_fold(csum_partial((char *)diff, sizeof(diff), ~csum));
}
EXPORT_SYMBOL(nf_csum_update);
u_int16_t nf_proto_csum_update(struct sk_buff *skb,
u_int32_t oldval, u_int32_t newval,
u_int16_t csum, int pseudohdr)
{
if (skb->ip_summed != CHECKSUM_PARTIAL) {
csum = nf_csum_update(oldval, newval, csum);
if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
skb->csum = nf_csum_update(oldval, newval, skb->csum);
} else if (pseudohdr)
csum = ~nf_csum_update(oldval, newval, ~csum);
return csum;
}
EXPORT_SYMBOL(nf_proto_csum_update);
/* This does not belong here, but locally generated errors need it if connection /* This does not belong here, but locally generated errors need it if connection
tracking in use: without this, connection may not be in hash table, and hence tracking in use: without this, connection may not be in hash table, and hence