: Factor out common code for generating Resets
PATCH 8/8 : Factor out common code for generating Resets
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 <[email protected]>
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
--- net/dccp/dccp.h | 2 ++ net/dccp/ipv4.c | 38 +++++--------------------------------- net/dccp/ipv6.c | 39 ++++++--------------------------------- net/dccp/output.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 65 insertions(+), 66 deletions(-)
net/dccp/dccp.h +2 -0
@@ -294,6 +294,8 @@ extern unsigned int dccp_poll(struct file *file, struct socket *sock,extern int dccp_v4_connect (struct sock *sk,struct sockaddr *uaddr,int addr_len); +extern struct sk_buff *dccp_ctl_make_reset (struct socket *ctl, +struct sk_buff *skb);extern int dccp_send_reset (struct sock *sk,enum dccp_reset_codes code);extern void dccp_send_close (struct sock *sk,const int active);extern int dccp_invalid_packet (struct sk_buff *skb);
net/dccp/ipv4.c +5 -32
@@ -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,
net/dccp/ipv6.c +6 -32
@@ -301,50 +301,23 @@ static void dccp_v6_reqsk_destructor(struct request_sock *req)static void dccp_v6_ctl_send_reset (struct sock *sk,struct sk_buff *rxskb) { -struct dccp_hdr *rxdh =dccp_hdr (rxskb), *dh;struct ipv6hdr *rxip6h; -const u32 dccp_hdr_reset_len =sizeof (struct dccp_hdr ) + -sizeof (struct dccp_hdr_ext ) + -sizeof (struct dccp_hdr_reset );struct sk_buff *skb;struct flowi fl; -u64 seqno =0 ; -if (rxdh->dccph_type =DCCP_PKT_RESET ) +if (dccp_hdr (rxskb)->dccph_type =DCCP_PKT_RESET )return ;if (!ipv6_unicast_destination (rxskb))return ; - skb =alloc_skb (dccp_v6_ctl_socket->sk->sk_prot->max_header, -GFP_ATOMIC ); + skb =dccp_ctl_make_reset (dccp_v6_ctl_socket, rxskb);if (skb =NULL )return ; -skb_reserve (skb, dccp_v6_ctl_socket->sk->sk_prot->max_header); - - dh =dccp_zeroed_hdr (skb, dccp_hdr_reset_len); - -/* Swap the send and the receive. */ - 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); rxip6h =ipv6_hdr (rxskb); - dh->dccph_checksum =dccp_v6_csum_finish (skb, &rxip6h->saddr, - &rxip6h->daddr); +dccp_hdr (skb)->dccph_checksum =dccp_v6_csum_finish (skb, &rxip6h->saddr, + &rxip6h->daddr);memset (&fl,0 ,sizeof (fl));ipv6_addr_copy (&fl.fl6_dst, &rxip6h->saddr);
@@ -352,8 +325,8 @@ static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb) fl.proto =IPPROTO_DCCP ; fl.oif =inet6_iif (rxskb); - fl.fl_ip_dport = dh->dccph_dport; - fl.fl_ip_sport = dh->dccph_sport; + fl.fl_ip_dport =dccp_hdr (skb)->dccph_dport; + fl.fl_ip_sport =dccp_hdr (skb)->dccph_sport;security_skb_classify_flow (rxskb, &fl);/* sk = NULL, but it is safe for now. RST socket required. */
net/dccp/output.c +52 -0
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Signature · 1 line
1.5.2.2