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[DCCP]: Factor out common code for generating Resets

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This factors code common to dccp_v{4,6}_ctl_send_reset into a separate function,
and adds support for filling in the Data 1 ... Data 3 fields from RFC 4340, 5.6.

It is useful to have this separate, since the following Reset codes will always
be generated from the control socket rather than via dccp_send_reset:
 * Code 3, "No Connection", cf. 8.3.1;
 * Code 4, "Packet Error" (identification for Data 1 added);
 * Code 5, "Option Error" (identification for Data 1..3 added, will be used later);
 * Code 6, "Mandatory Error" (same as Option Error);
 * Code 7, "Connection Refused" (what on Earth is the difference to "No Connection"?);
 * Code 8, "Bad Service Code";
 * Code 9, "Too Busy";
 * Code 10, "Bad Init Cookie" (not used).

Code 0 is not recommended by the RFC, the following codes would be used in
dccp_send_reset() instead, since they all relate to an established DCCP connection:
 * Code 1, "Closed";
 * Code 2, "Aborted";
 * Code 11, "Aggression Penalty" (12.3).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
This commit is contained in:
Gerrit Renker
2007-09-26 14:35:19 -03:00
committed by David S. Miller
parent 9bf55cda9b
commit e356d37a09
4 changed files with 65 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
net/dccp/ipv4.c
View File

@@ -510,17 +510,12 @@ out:
static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
{
int err;
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
const struct iphdr *rxiph;
const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
sizeof(struct dccp_hdr_ext) +
sizeof(struct dccp_hdr_reset);
struct sk_buff *skb;
struct dst_entry *dst;
u64 seqno = 0;
/* Never send a reset in response to a reset. */
if (rxdh->dccph_type == DCCP_PKT_RESET)
if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
return;
if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
@@ -530,37 +525,14 @@ static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
if (dst == NULL)
return;
skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header,
GFP_ATOMIC);
skb = dccp_ctl_make_reset(dccp_v4_ctl_socket, rxskb);
if (skb == NULL)
goto out;
/* Reserve space for headers. */
skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
skb->dst = dst_clone(dst);
dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
/* Build DCCP header and checksum it. */
dh->dccph_type = DCCP_PKT_RESET;
dh->dccph_sport = rxdh->dccph_dport;
dh->dccph_dport = rxdh->dccph_sport;
dh->dccph_doff = dccp_hdr_reset_len / 4;
dh->dccph_x = 1;
dccp_hdr_reset(skb)->dccph_reset_code =
DCCP_SKB_CB(rxskb)->dccpd_reset_code;
/* See "8.3.1. Abnormal Termination" in RFC 4340 */
if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
seqno = ADD48(DCCP_SKB_CB(rxskb)->dccpd_ack_seq, 1);
dccp_hdr_set_seq(dh, seqno);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
dccp_csum_outgoing(skb);
rxiph = ip_hdr(rxskb);
dh->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
rxiph->daddr);
dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
rxiph->daddr);
skb->dst = dst_clone(dst);
bh_lock_sock(dccp_v4_ctl_socket->sk);
err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,