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TCPCT part 1a: add request_values parameter for sending SYNACK
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Add optional function parameters associated with sending SYNACK.
These parameters are not needed after sending SYNACK, and are not
used for retransmission.  Avoids extending struct tcp_request_sock,
and avoids allocating kernel memory.

Also affects DCCP as it uses common struct request_sock_ops,
but this parameter is currently reserved for future use.

Signed-off-by: [email protected]
Acked-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@was4 @davem330
was4 authored and davem330 committed Dec 3, 2009
1 parent e004840 commit e6b4d11
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Showing 10 changed files with 42 additions and 33 deletions.
8 changes: 7 additions & 1 deletion include/net/request_sock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,13 +27,19 @@ struct sk_buff;
struct dst_entry;
struct proto;

/* empty to "strongly type" an otherwise void parameter.
*/
struct request_values {
};

struct request_sock_ops {
int family;
int obj_size;
struct kmem_cache *slab;
char *slab_name;
int (*rtx_syn_ack)(struct sock *sk,
struct request_sock *req);
struct request_sock *req,
struct request_values *rvp);
void (*send_ack)(struct sock *sk, struct sk_buff *skb,
struct request_sock *req);
void (*send_reset)(struct sock *sk,
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3 changes: 2 additions & 1 deletion include/net/tcp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -440,7 +440,8 @@ extern int tcp_connect(struct sock *sk);

extern struct sk_buff * tcp_make_synack(struct sock *sk,
struct dst_entry *dst,
struct request_sock *req);
struct request_sock *req,
struct request_values *rvp);

extern int tcp_disconnect(struct sock *sk, int flags);

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5 changes: 3 additions & 2 deletions net/dccp/ipv4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -477,7 +477,8 @@ static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
return &rt->u.dst;
}

static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
struct request_values *rv_unused)
{
int err = -1;
struct sk_buff *skb;
Expand Down Expand Up @@ -626,7 +627,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
dreq->dreq_iss = dccp_v4_init_sequence(skb);
dreq->dreq_service = service;

if (dccp_v4_send_response(sk, req))
if (dccp_v4_send_response(sk, req, NULL))
goto drop_and_free;

inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
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5 changes: 3 additions & 2 deletions net/dccp/ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -241,7 +241,8 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
}


static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
struct request_values *rv_unused)
{
struct inet6_request_sock *ireq6 = inet6_rsk(req);
struct ipv6_pinfo *np = inet6_sk(sk);
Expand Down Expand Up @@ -468,7 +469,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
dreq->dreq_iss = dccp_v6_init_sequence(skb);
dreq->dreq_service = service;

if (dccp_v6_send_response(sk, req))
if (dccp_v6_send_response(sk, req, NULL))
goto drop_and_free;

inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
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2 changes: 1 addition & 1 deletion net/dccp/minisocks.c
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Original file line number Diff line number Diff line change
Expand Up @@ -184,7 +184,7 @@ struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
* counter (backoff, monitored by dccp_response_timer).
*/
req->retrans++;
req->rsk_ops->rtx_syn_ack(sk, req);
req->rsk_ops->rtx_syn_ack(sk, req, NULL);
}
/* Network Duplicate, discard packet */
return NULL;
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2 changes: 1 addition & 1 deletion net/ipv4/inet_connection_sock.c
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Original file line number Diff line number Diff line change
Expand Up @@ -531,7 +531,7 @@ void inet_csk_reqsk_queue_prune(struct sock *parent,
&expire, &resend);
if (!expire &&
(!resend ||
!req->rsk_ops->rtx_syn_ack(parent, req) ||
!req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||
inet_rsk(req)->acked)) {
unsigned long timeo;

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18 changes: 10 additions & 8 deletions net/ipv4/tcp_ipv4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -742,8 +742,9 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
* This still operates on a request_sock only, not on a big
* socket.
*/
static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
struct dst_entry *dst)
static int __tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
struct request_values *rvp)
{
const struct inet_request_sock *ireq = inet_rsk(req);
int err = -1;
Expand All @@ -753,7 +754,7 @@ static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
return -1;

skb = tcp_make_synack(sk, dst, req);
skb = tcp_make_synack(sk, dst, req, rvp);

if (skb) {
struct tcphdr *th = tcp_hdr(skb);
Expand All @@ -774,9 +775,10 @@ static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
return err;
}

static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req)
static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
struct request_values *rvp)
{
return __tcp_v4_send_synack(sk, req, NULL);
return __tcp_v4_send_synack(sk, NULL, req, rvp);
}

/*
Expand Down Expand Up @@ -1211,13 +1213,13 @@ static struct timewait_sock_ops tcp_timewait_sock_ops = {

int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
{
struct inet_request_sock *ireq;
struct tcp_options_received tmp_opt;
struct request_sock *req;
struct inet_request_sock *ireq;
struct dst_entry *dst = NULL;
__be32 saddr = ip_hdr(skb)->saddr;
__be32 daddr = ip_hdr(skb)->daddr;
__u32 isn = TCP_SKB_CB(skb)->when;
struct dst_entry *dst = NULL;
#ifdef CONFIG_SYN_COOKIES
int want_cookie = 0;
#else
Expand Down Expand Up @@ -1337,7 +1339,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
}
tcp_rsk(req)->snt_isn = isn;

if (__tcp_v4_send_synack(sk, req, dst) || want_cookie)
if (__tcp_v4_send_synack(sk, dst, req, NULL) || want_cookie)
goto drop_and_free;

inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
Expand Down
2 changes: 1 addition & 1 deletion net/ipv4/tcp_minisocks.c
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Original file line number Diff line number Diff line change
Expand Up @@ -531,7 +531,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
* Enforce "SYN-ACK" according to figure 8, figure 6
* of RFC793, fixed by RFC1122.
*/
req->rsk_ops->rtx_syn_ack(sk, req);
req->rsk_ops->rtx_syn_ack(sk, req, NULL);
return NULL;
}

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3 changes: 2 additions & 1 deletion net/ipv4/tcp_output.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2224,7 +2224,8 @@ int tcp_send_synack(struct sock *sk)

/* Prepare a SYN-ACK. */
struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req)
struct request_sock *req,
struct request_values *rvp)
{
struct inet_request_sock *ireq = inet_rsk(req);
struct tcp_sock *tp = tcp_sk(sk);
Expand Down
27 changes: 12 additions & 15 deletions net/ipv6/tcp_ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -461,7 +461,8 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
}


static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
struct request_values *rvp)
{
struct inet6_request_sock *treq = inet6_rsk(req);
struct ipv6_pinfo *np = inet6_sk(sk);
Expand Down Expand Up @@ -499,7 +500,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
goto done;

skb = tcp_make_synack(sk, dst, req);
skb = tcp_make_synack(sk, dst, req, rvp);
if (skb) {
struct tcphdr *th = tcp_hdr(skb);

Expand Down Expand Up @@ -1161,13 +1162,13 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
*/
static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
{
struct tcp_options_received tmp_opt;
struct request_sock *req;
struct inet6_request_sock *treq;
struct ipv6_pinfo *np = inet6_sk(sk);
struct tcp_options_received tmp_opt;
struct tcp_sock *tp = tcp_sk(sk);
struct request_sock *req = NULL;
__u32 isn = TCP_SKB_CB(skb)->when;
struct dst_entry *dst = __sk_dst_get(sk);
__u32 isn = TCP_SKB_CB(skb)->when;
#ifdef CONFIG_SYN_COOKIES
int want_cookie = 0;
#else
Expand Down Expand Up @@ -1239,23 +1240,19 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)

isn = tcp_v6_init_sequence(skb);
}

tcp_rsk(req)->snt_isn = isn;

security_inet_conn_request(sk, skb, req);

if (tcp_v6_send_synack(sk, req))
goto drop;
if (tcp_v6_send_synack(sk, req, NULL) || want_cookie)
goto drop_and_free;

if (!want_cookie) {
inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
return 0;
}
inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
return 0;

drop_and_free:
reqsk_free(req);
drop:
if (req)
reqsk_free(req);

return 0; /* don't send reset */
}

Expand Down

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