[DCCP]: Fix checksum routines

Signed-off-by: Yoshifumi Nishida <nishida@csl.sony.co.jp>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yoshifumi Nishida 2005-08-09 20:15:35 -07:00 committed by David S. Miller
parent a019d6fe2b
commit 95b81ef794
3 changed files with 28 additions and 22 deletions

View file

@ -242,7 +242,8 @@ extern int dccp_setsockopt(struct sock *sk, int level, int optname,
char *optval, int optlen);
extern void dccp_shutdown(struct sock *sk, int how);
extern int dccp_v4_checksum(struct sk_buff *skb);
extern int dccp_v4_checksum(const struct sk_buff *skb,
const u32 saddr, const u32 daddr);
extern int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code);
extern void dccp_send_close(struct sock *sk);

View file

@ -802,9 +802,9 @@ static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
return sk;
}
int dccp_v4_checksum(struct sk_buff *skb)
int dccp_v4_checksum(const struct sk_buff *skb, const u32 saddr, const u32 daddr)
{
struct dccp_hdr* dh = dccp_hdr(skb);
const struct dccp_hdr* dh = dccp_hdr(skb);
int checksum_len;
u32 tmp;
@ -816,24 +816,24 @@ int dccp_v4_checksum(struct sk_buff *skb)
}
tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
return csum_fold(tmp);
return csum_tcpudp_magic(saddr, daddr, checksum_len, IPPROTO_DCCP, tmp);
}
static int dccp_v4_verify_checksum(struct sk_buff *skb)
static int dccp_v4_verify_checksum(struct sk_buff *skb,
const u32 saddr, const u32 daddr)
{
struct dccp_hdr *th = dccp_hdr(skb);
const u16 remote_checksum = th->dccph_checksum;
u16 local_checksum;
struct dccp_hdr *dh = dccp_hdr(skb);
int checksum_len;
u32 tmp;
/* FIXME: don't mess with skb payload */
th->dccph_checksum = 0; /* zero it for computation */
local_checksum = dccp_v4_checksum(skb);
/* FIXME: don't mess with skb payload */
th->dccph_checksum = remote_checksum; /* put it back */
return remote_checksum == local_checksum ? 0 : -1;
if (dh->dccph_cscov == 0)
checksum_len = skb->len;
else {
checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
checksum_len = checksum_len < skb->len ? checksum_len : skb->len;
}
tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
return csum_tcpudp_magic(saddr, daddr, checksum_len, IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
}
static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
@ -902,7 +902,8 @@ void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
dh->dccph_checksum = dccp_v4_checksum(skb);
dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
rxskb->nh.iph->daddr);
bh_lock_sock(dccp_ctl_socket->sk);
err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk,
@ -1024,7 +1025,8 @@ static inline int dccp_invalid_packet(struct sk_buff *skb)
}
/* If the header checksum is incorrect, drop packet and return */
if (dccp_v4_verify_checksum(skb) < 0) {
if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
skb->nh.iph->daddr) < 0) {
dccp_pr_debug("header checksum is incorrect\n");
return 1;
}

View file

@ -93,7 +93,8 @@ int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
break;
}
dh->dccph_checksum = dccp_v4_checksum(skb);
dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr,
inet->daddr);
if (dcb->dccpd_type == DCCP_PKT_ACK ||
dcb->dccpd_type == DCCP_PKT_DATAACK)
@ -193,7 +194,8 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
dccp_hdr_set_seq(dh, dccp_rsk(req)->dreq_iss);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dccp_rsk(req)->dreq_isr);
dh->dccph_checksum = dccp_v4_checksum(skb);
dh->dccph_checksum = dccp_v4_checksum(skb, inet_rsk(req)->loc_addr,
inet_rsk(req)->rmt_addr);
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
return skb;
@ -242,7 +244,8 @@ struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
dccp_hdr_reset(skb)->dccph_reset_code = code;
dh->dccph_checksum = dccp_v4_checksum(skb);
dh->dccph_checksum = dccp_v4_checksum(skb, inet_sk(sk)->saddr,
inet_sk(sk)->daddr);
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
return skb;