xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: add real socket cookies

Browse Source 
A long standing problem in netlink socket dumps is the use
of kernel socket addresses as cookies.

1) It is a security concern.

2) Sockets can be reused quite quickly, so there is
   no guarantee a cookie is used once and identify
   a flow.

3) request sock, establish sock, and timewait socks
   for a given flow have different cookies.

Part of our effort to bring better TCP statistics requires
to switch to a different allocator.

In this patch, I chose to use a per network namespace 64bit generator,
and to use it only in the case a socket needs to be dumped to netlink.
(This might be refined later if needed)

Note that I tried to carry cookies from request sock, to establish sock,
then timewait sockets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Salo <salo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2015-03-11 18:53:14 -07:00
committed by David S. Miller
parent 654eff4516
commit 33cf7c90fe
13 changed files with 55 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
net/ipv4/inet_connection_sock.c
View File

@@ -678,6 +678,8 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
newsk->sk_write_space = sk_stream_write_space;
newsk->sk_mark = inet_rsk(req)->ir_mark;
atomic64_set(&newsk->sk_cookie,
atomic64_read(&inet_rsk(req)->ir_cookie));
newicsk->icsk_retransmits = 0;
newicsk->icsk_backoff = 0;

14
net/ipv4/inet_diag.c
View File

@@ -221,12 +221,13 @@ static int inet_csk_diag_fill(struct sock *sk,
user_ns, portid, seq, nlmsg_flags, unlh);
}
static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
static int inet_twsk_diag_fill(struct sock *sk,
struct sk_buff *skb,
const struct inet_diag_req_v2 *req,
u32 portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
{
struct inet_timewait_sock *tw = inet_twsk(sk);
struct inet_diag_msg *r;
struct nlmsghdr *nlh;
s32 tmo;
@@ -247,7 +248,7 @@ static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
r->idiag_retrans = 0;
r->id.idiag_if = tw->tw_bound_dev_if;
sock_diag_save_cookie(tw, r->id.idiag_cookie);
sock_diag_save_cookie(sk, r->id.idiag_cookie);
r->id.idiag_sport = tw->tw_sport;
r->id.idiag_dport = tw->tw_dport;
@@ -283,7 +284,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
const struct nlmsghdr *unlh)
{
if (sk->sk_state == TCP_TIME_WAIT)
return inet_twsk_diag_fill(inet_twsk(sk), skb, r, portid, seq,
return inet_twsk_diag_fill(sk, skb, r, portid, seq,
nlmsg_flags, unlh);
return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
@@ -675,7 +676,7 @@ static int inet_twsk_diag_dump(struct sock *sk,
if (!inet_diag_bc_sk(bc, sk))
return 0;
return inet_twsk_diag_fill(inet_twsk(sk), skb, r,
return inet_twsk_diag_fill(sk, skb, r,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
}
@@ -734,7 +735,10 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
r->idiag_retrans = req->num_retrans;
r->id.idiag_if = sk->sk_bound_dev_if;
sock_diag_save_cookie(req, r->id.idiag_cookie);
BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
offsetof(struct sock, sk_cookie));
sock_diag_save_cookie((struct sock *)ireq, r->id.idiag_cookie);
tmo = req->expires - jiffies;
if (tmo < 0)

1
net/ipv4/inet_timewait_sock.c
View File

@@ -195,6 +195,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
tw->tw_ipv6only = 0;
tw->tw_transparent = inet->transparent;
tw->tw_prot = sk->sk_prot_creator;
atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie));
twsk_net_set(tw, hold_net(sock_net(sk)));
/*
* Because we use RCU lookups, we should not set tw_refcnt

1
net/ipv4/syncookies.c
View File

@@ -346,6 +346,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
treq->snt_synack = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsecr : 0;
treq->listener = NULL;
ireq->ireq_net = sock_net(sk);
/* We throwed the options of the initial SYN away, so we hope
* the ACK carries the same options again (see RFC1122 4.2.3.8)

2
net/ipv4/tcp_input.c
View File

@@ -5965,6 +5965,8 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
tcp_openreq_init(req, &tmp_opt, skb, sk);
inet_rsk(req)->ireq_net = sock_net(sk);
atomic64_set(&inet_rsk(req)->ir_cookie, 0);
af_ops->init_req(req, sk, skb);