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Merge branch 'listener_refactor_16'
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Eric Dumazet says:

====================
tcp: listener refactor part 16

A CONFIG_PROVE_RCU=y build revealed an RCU splat I had to fix.

I added const qualifiers to various md5 methods, as I expect
to call them on behalf of request sock traffic even if
the listener socket is not locked. This seems ok, but adding
const makes the contract clearer. Note a good reduction
of code size thanks to request/establish sockets convergence.
====================

Signed-off-by: David S. Miller <[email protected]>
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@davem330
davem330 committed Mar 25, 2015
2 parents 9ead352 + fd3a154 commit b1275eb
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Showing 5 changed files with 72 additions and 117 deletions.
37 changes: 17 additions & 20 deletions include/net/tcp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1296,15 +1296,14 @@ struct tcp_md5sig_pool {
};

/* - functions */
int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
const struct sock *sk, const struct request_sock *req,
const struct sk_buff *skb);
int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk, const struct sk_buff *skb);
int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
int family, const u8 *newkey, u8 newkeylen, gfp_t gfp);
int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr,
int family);
struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
struct sock *addr_sk);
const struct sock *addr_sk);

#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
Expand Down Expand Up @@ -1615,28 +1614,26 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct tcp_sock_af_ops {
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
struct sock *addr_sk);
int (*calc_md5_hash) (char *location,
struct tcp_md5sig_key *md5,
const struct sock *sk,
const struct request_sock *req,
const struct sk_buff *skb);
int (*md5_parse) (struct sock *sk,
char __user *optval,
int optlen);
const struct sock *addr_sk);
int (*calc_md5_hash)(char *location,
const struct tcp_md5sig_key *md5,
const struct sock *sk,
const struct sk_buff *skb);
int (*md5_parse)(struct sock *sk,
char __user *optval,
int optlen);
#endif
};

struct tcp_request_sock_ops {
u16 mss_clamp;
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
struct request_sock *req);
int (*calc_md5_hash) (char *location,
struct tcp_md5sig_key *md5,
const struct sock *sk,
const struct request_sock *req,
const struct sk_buff *skb);
struct tcp_md5sig_key *(*req_md5_lookup)(struct sock *sk,
const struct sock *addr_sk);
int (*calc_md5_hash) (char *location,
const struct tcp_md5sig_key *md5,
const struct sock *sk,
const struct sk_buff *skb);
#endif
void (*init_req)(struct request_sock *req, struct sock *sk,
struct sk_buff *skb);
Expand Down
25 changes: 13 additions & 12 deletions net/ipv4/tcp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1913,18 +1913,19 @@ EXPORT_SYMBOL_GPL(tcp_set_state);

static const unsigned char new_state[16] = {
/* current state: new state: action: */
/* (Invalid) */ TCP_CLOSE,
/* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
/* TCP_SYN_SENT */ TCP_CLOSE,
/* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
/* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
/* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
/* TCP_TIME_WAIT */ TCP_CLOSE,
/* TCP_CLOSE */ TCP_CLOSE,
/* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
/* TCP_LAST_ACK */ TCP_LAST_ACK,
/* TCP_LISTEN */ TCP_CLOSE,
/* TCP_CLOSING */ TCP_CLOSING,
[0 /* (Invalid) */] = TCP_CLOSE,
[TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
[TCP_SYN_SENT] = TCP_CLOSE,
[TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
[TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
[TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
[TCP_TIME_WAIT] = TCP_CLOSE,
[TCP_CLOSE] = TCP_CLOSE,
[TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
[TCP_LAST_ACK] = TCP_LAST_ACK,
[TCP_LISTEN] = TCP_CLOSE,
[TCP_CLOSING] = TCP_CLOSING,
[TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
};

static int tcp_close_state(struct sock *sk)
Expand Down
53 changes: 15 additions & 38 deletions net/ipv4/tcp_ipv4.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -648,7 +648,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
if (!key)
goto release_sk1;

genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb);
genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
if (genhash || memcmp(hash_location, newhash, 16) != 0)
goto release_sk1;
} else {
Expand Down Expand Up @@ -898,10 +898,10 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
const union tcp_md5_addr *addr,
int family)
{
struct tcp_sock *tp = tcp_sk(sk);
const struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *key;
unsigned int size = sizeof(struct in_addr);
struct tcp_md5sig_info *md5sig;
const struct tcp_md5sig_info *md5sig;

/* caller either holds rcu_read_lock() or socket lock */
md5sig = rcu_dereference_check(tp->md5sig_info,
Expand All @@ -924,24 +924,15 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
EXPORT_SYMBOL(tcp_md5_do_lookup);

struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
struct sock *addr_sk)
const struct sock *addr_sk)
{
union tcp_md5_addr *addr;

addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_daddr;
addr = (union tcp_md5_addr *)&sk->sk_daddr;
return tcp_md5_do_lookup(sk, addr, AF_INET);
}
EXPORT_SYMBOL(tcp_v4_md5_lookup);

static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
struct request_sock *req)
{
union tcp_md5_addr *addr;

addr = (union tcp_md5_addr *)&inet_rsk(req)->ir_rmt_addr;
return tcp_md5_do_lookup(sk, addr, AF_INET);
}

/* This can be called on a newly created socket, from other files */
int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
int family, const u8 *newkey, u8 newkeylen, gfp_t gfp)
Expand Down Expand Up @@ -1102,21 +1093,18 @@ static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
return 1;
}

int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
const struct sock *sk, const struct request_sock *req,
int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk,
const struct sk_buff *skb)
{
struct tcp_md5sig_pool *hp;
struct hash_desc *desc;
const struct tcphdr *th = tcp_hdr(skb);
__be32 saddr, daddr;

if (sk) {
saddr = inet_sk(sk)->inet_saddr;
daddr = inet_sk(sk)->inet_daddr;
} else if (req) {
saddr = inet_rsk(req)->ir_loc_addr;
daddr = inet_rsk(req)->ir_rmt_addr;
if (sk) { /* valid for establish/request sockets */
saddr = sk->sk_rcv_saddr;
daddr = sk->sk_daddr;
} else {
const struct iphdr *iph = ip_hdr(skb);
saddr = iph->saddr;
Expand Down Expand Up @@ -1153,8 +1141,9 @@ int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
}
EXPORT_SYMBOL(tcp_v4_md5_hash_skb);

static bool __tcp_v4_inbound_md5_hash(struct sock *sk,
const struct sk_buff *skb)
/* Called with rcu_read_lock() */
static bool tcp_v4_inbound_md5_hash(struct sock *sk,
const struct sk_buff *skb)
{
/*
* This gets called for each TCP segment that arrives
Expand Down Expand Up @@ -1194,7 +1183,7 @@ static bool __tcp_v4_inbound_md5_hash(struct sock *sk,
*/
genhash = tcp_v4_md5_hash_skb(newhash,
hash_expected,
NULL, NULL, skb);
NULL, skb);

if (genhash || memcmp(hash_location, newhash, 16) != 0) {
net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
Expand All @@ -1206,18 +1195,6 @@ static bool __tcp_v4_inbound_md5_hash(struct sock *sk,
}
return false;
}

static bool tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
{
bool ret;

rcu_read_lock();
ret = __tcp_v4_inbound_md5_hash(sk, skb);
rcu_read_unlock();

return ret;
}

#endif

static void tcp_v4_init_req(struct request_sock *req, struct sock *sk_listener,
Expand Down Expand Up @@ -1261,7 +1238,7 @@ struct request_sock_ops tcp_request_sock_ops __read_mostly = {
static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
.mss_clamp = TCP_MSS_DEFAULT,
#ifdef CONFIG_TCP_MD5SIG
.md5_lookup = tcp_v4_reqsk_md5_lookup,
.req_md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
#endif
.init_req = tcp_v4_init_req,
Expand Down
24 changes: 13 additions & 11 deletions net/ipv4/tcp_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -601,15 +601,14 @@ static unsigned int tcp_synack_options(struct sock *sk,
struct request_sock *req,
unsigned int mss, struct sk_buff *skb,
struct tcp_out_options *opts,
struct tcp_md5sig_key **md5,
const struct tcp_md5sig_key *md5,
struct tcp_fastopen_cookie *foc)
{
struct inet_request_sock *ireq = inet_rsk(req);
unsigned int remaining = MAX_TCP_OPTION_SPACE;

#ifdef CONFIG_TCP_MD5SIG
*md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
if (*md5) {
if (md5) {
opts->options |= OPTION_MD5;
remaining -= TCPOLEN_MD5SIG_ALIGNED;

Expand All @@ -620,8 +619,6 @@ static unsigned int tcp_synack_options(struct sock *sk,
*/
ireq->tstamp_ok &= !ireq->sack_ok;
}
#else
*md5 = NULL;
#endif

/* We always send an MSS option. */
Expand Down Expand Up @@ -989,7 +986,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
if (md5) {
sk_nocaps_add(sk, NETIF_F_GSO_MASK);
tp->af_specific->calc_md5_hash(opts.hash_location,
md5, sk, NULL, skb);
md5, sk, skb);
}
#endif

Expand Down Expand Up @@ -2913,7 +2910,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
struct tcp_sock *tp = tcp_sk(sk);
struct tcphdr *th;
struct sk_buff *skb;
struct tcp_md5sig_key *md5;
struct tcp_md5sig_key *md5 = NULL;
int tcp_header_size;
int mss;

Expand All @@ -2938,7 +2935,12 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
else
#endif
skb_mstamp_get(&skb->skb_mstamp);
tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, &md5,

#ifdef CONFIG_TCP_MD5SIG
rcu_read_lock();
md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req));
#endif
tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
foc) + sizeof(*th);

skb_push(skb, tcp_header_size);
Expand Down Expand Up @@ -2969,10 +2971,10 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,

#ifdef CONFIG_TCP_MD5SIG
/* Okay, we have all we need - do the md5 hash if needed */
if (md5) {
if (md5)
tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location,
md5, NULL, req, skb);
}
md5, req_to_sk(req), skb);
rcu_read_unlock();
#endif

return skb;
Expand Down
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