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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 08:40:34 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 08:40:34 (GMT)
commit42a2d923cc349583ebf6fdd52a7d35e1c2f7e6bd (patch)
tree2b2b0c03b5389c1301800119333967efafd994ca /net/ipv6/syncookies.c
parent5cbb3d216e2041700231bcfc383ee5f8b7fc8b74 (diff)
parent75ecab1df14d90e86cebef9ec5c76befde46e65f (diff)
downloadlinux-42a2d923cc349583ebf6fdd52a7d35e1c2f7e6bd.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: 1) The addition of nftables. No longer will we need protocol aware firewall filtering modules, it can all live in userspace. At the core of nftables is a, for lack of a better term, virtual machine that executes byte codes to inspect packet or metadata (arriving interface index, etc.) and make verdict decisions. Besides support for loading packet contents and comparing them, the interpreter supports lookups in various datastructures as fundamental operations. For example sets are supports, and therefore one could create a set of whitelist IP address entries which have ACCEPT verdicts attached to them, and use the appropriate byte codes to do such lookups. Since the interpreted code is composed in userspace, userspace can do things like optimize things before giving it to the kernel. Another major improvement is the capability of atomically updating portions of the ruleset. In the existing netfilter implementation, one has to update the entire rule set in order to make a change and this is very expensive. Userspace tools exist to create nftables rules using existing netfilter rule sets, but both kernel implementations will need to co-exist for quite some time as we transition from the old to the new stuff. Kudos to Patrick McHardy, Pablo Neira Ayuso, and others who have worked so hard on this. 2) Daniel Borkmann and Hannes Frederic Sowa made several improvements to our pseudo-random number generator, mostly used for things like UDP port randomization and netfitler, amongst other things. In particular the taus88 generater is updated to taus113, and test cases are added. 3) Support 64-bit rates in HTB and TBF schedulers, from Eric Dumazet and Yang Yingliang. 4) Add support for new 577xx tigon3 chips to tg3 driver, from Nithin Sujir. 5) Fix two fatal flaws in TCP dynamic right sizing, from Eric Dumazet, Neal Cardwell, and Yuchung Cheng. 6) Allow IP_TOS and IP_TTL to be specified in sendmsg() ancillary control message data, much like other socket option attributes. From Francesco Fusco. 7) Allow applications to specify a cap on the rate computed automatically by the kernel for pacing flows, via a new SO_MAX_PACING_RATE socket option. From Eric Dumazet. 8) Make the initial autotuned send buffer sizing in TCP more closely reflect actual needs, from Eric Dumazet. 9) Currently early socket demux only happens for TCP sockets, but we can do it for connected UDP sockets too. Implementation from Shawn Bohrer. 10) Refactor inet socket demux with the goal of improving hash demux performance for listening sockets. With the main goals being able to use RCU lookups on even request sockets, and eliminating the listening lock contention. From Eric Dumazet. 11) The bonding layer has many demuxes in it's fast path, and an RCU conversion was started back in 3.11, several changes here extend the RCU usage to even more locations. From Ding Tianhong and Wang Yufen, based upon suggestions by Nikolay Aleksandrov and Veaceslav Falico. 12) Allow stackability of segmentation offloads to, in particular, allow segmentation offloading over tunnels. From Eric Dumazet. 13) Significantly improve the handling of secret keys we input into the various hash functions in the inet hashtables, TCP fast open, as well as syncookies. From Hannes Frederic Sowa. The key fundamental operation is "net_get_random_once()" which uses static keys. Hannes even extended this to ipv4/ipv6 fragmentation handling and our generic flow dissector. 14) The generic driver layer takes care now to set the driver data to NULL on device removal, so it's no longer necessary for drivers to explicitly set it to NULL any more. Many drivers have been cleaned up in this way, from Jingoo Han. 15) Add a BPF based packet scheduler classifier, from Daniel Borkmann. 16) Improve CRC32 interfaces and generic SKB checksum iterators so that SCTP's checksumming can more cleanly be handled. Also from Daniel Borkmann. 17) Add a new PMTU discovery mode, IP_PMTUDISC_INTERFACE, which forces using the interface MTU value. This helps avoid PMTU attacks, particularly on DNS servers. From Hannes Frederic Sowa. 18) Use generic XPS for transmit queue steering rather than internal (re-)implementation in virtio-net. From Jason Wang. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits) random32: add test cases for taus113 implementation random32: upgrade taus88 generator to taus113 from errata paper random32: move rnd_state to linux/random.h random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized random32: add periodic reseeding random32: fix off-by-one in seeding requirement PHY: Add RTL8201CP phy_driver to realtek xtsonic: add missing platform_set_drvdata() in xtsonic_probe() macmace: add missing platform_set_drvdata() in mace_probe() ethernet/arc/arc_emac: add missing platform_set_drvdata() in arc_emac_probe() ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh vlan: Implement vlan_dev_get_egress_qos_mask as an inline. ixgbe: add warning when max_vfs is out of range. igb: Update link modes display in ethtool netfilter: push reasm skb through instead of original frag skbs ip6_output: fragment outgoing reassembled skb properly MAINTAINERS: mv643xx_eth: take over maintainership from Lennart net_sched: tbf: support of 64bit rates ixgbe: deleting dfwd stations out of order can cause null ptr deref ixgbe: fix build err, num_rx_queues is only available with CONFIG_RPS ...
Diffstat (limited to 'net/ipv6/syncookies.c')
-rw-r--r--net/ipv6/syncookies.c75
1 files changed, 36 insertions, 39 deletions
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index bf63ac8..535a3ad 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -24,26 +24,23 @@
#define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
-/* Table must be sorted. */
+static u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS];
+
+/* RFC 2460, Section 8.3:
+ * [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..]
+ *
+ * Due to IPV6_MIN_MTU=1280 the lowest possible MSS is 1220, which allows
+ * using higher values than ipv4 tcp syncookies.
+ * The other values are chosen based on ethernet (1500 and 9k MTU), plus
+ * one that accounts for common encap (PPPoe) overhead. Table must be sorted.
+ */
static __u16 const msstab[] = {
- 64,
- 512,
- 536,
- 1280 - 60,
+ 1280 - 60, /* IPV6_MIN_MTU - 60 */
1480 - 60,
1500 - 60,
- 4460 - 60,
9000 - 60,
};
-/*
- * This (misnamed) value is the age of syncookie which is permitted.
- * Its ideal value should be dependent on TCP_TIMEOUT_INIT and
- * sysctl_tcp_retries1. It's a rather complicated formula (exponential
- * backoff) to compute at runtime so it's currently hardcoded here.
- */
-#define COUNTER_TRIES 4
-
static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
struct request_sock *req,
struct dst_entry *dst)
@@ -66,14 +63,18 @@ static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS],
static u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *daddr,
__be16 sport, __be16 dport, u32 count, int c)
{
- __u32 *tmp = __get_cpu_var(ipv6_cookie_scratch);
+ __u32 *tmp;
+
+ net_get_random_once(syncookie6_secret, sizeof(syncookie6_secret));
+
+ tmp = __get_cpu_var(ipv6_cookie_scratch);
/*
* we have 320 bits of information to hash, copy in the remaining
- * 192 bits required for sha_transform, from the syncookie_secret
+ * 192 bits required for sha_transform, from the syncookie6_secret
* and overwrite the digest with the secret
*/
- memcpy(tmp + 10, syncookie_secret[c], 44);
+ memcpy(tmp + 10, syncookie6_secret[c], 44);
memcpy(tmp, saddr, 16);
memcpy(tmp + 4, daddr, 16);
tmp[8] = ((__force u32)sport << 16) + (__force u32)dport;
@@ -86,8 +87,9 @@ static u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *dadd
static __u32 secure_tcp_syn_cookie(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__be16 sport, __be16 dport, __u32 sseq,
- __u32 count, __u32 data)
+ __u32 data)
{
+ u32 count = tcp_cookie_time();
return (cookie_hash(saddr, daddr, sport, dport, 0, 0) +
sseq + (count << COOKIEBITS) +
((cookie_hash(saddr, daddr, sport, dport, count, 1) + data)
@@ -96,15 +98,14 @@ static __u32 secure_tcp_syn_cookie(const struct in6_addr *saddr,
static __u32 check_tcp_syn_cookie(__u32 cookie, const struct in6_addr *saddr,
const struct in6_addr *daddr, __be16 sport,
- __be16 dport, __u32 sseq, __u32 count,
- __u32 maxdiff)
+ __be16 dport, __u32 sseq)
{
- __u32 diff;
+ __u32 diff, count = tcp_cookie_time();
cookie -= cookie_hash(saddr, daddr, sport, dport, 0, 0) + sseq;
diff = (count - (cookie >> COOKIEBITS)) & ((__u32) -1 >> COOKIEBITS);
- if (diff >= maxdiff)
+ if (diff >= MAX_SYNCOOKIE_AGE)
return (__u32)-1;
return (cookie -
@@ -125,8 +126,7 @@ u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph,
*mssp = msstab[mssind];
return secure_tcp_syn_cookie(&iph->saddr, &iph->daddr, th->source,
- th->dest, ntohl(th->seq),
- jiffies / (HZ * 60), mssind);
+ th->dest, ntohl(th->seq), mssind);
}
EXPORT_SYMBOL_GPL(__cookie_v6_init_sequence);
@@ -146,8 +146,7 @@ int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th,
{
__u32 seq = ntohl(th->seq) - 1;
__u32 mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr,
- th->source, th->dest, seq,
- jiffies / (HZ * 60), COUNTER_TRIES);
+ th->source, th->dest, seq);
return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0;
}
@@ -157,7 +156,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
{
struct tcp_options_received tcp_opt;
struct inet_request_sock *ireq;
- struct inet6_request_sock *ireq6;
struct tcp_request_sock *treq;
struct ipv6_pinfo *np = inet6_sk(sk);
struct tcp_sock *tp = tcp_sk(sk);
@@ -194,7 +192,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
goto out;
ireq = inet_rsk(req);
- ireq6 = inet6_rsk(req);
treq = tcp_rsk(req);
treq->listener = NULL;
@@ -202,22 +199,22 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
goto out_free;
req->mss = mss;
- ireq->rmt_port = th->source;
- ireq->loc_port = th->dest;
- ireq6->rmt_addr = ipv6_hdr(skb)->saddr;
- ireq6->loc_addr = ipv6_hdr(skb)->daddr;
+ ireq->ir_rmt_port = th->source;
+ ireq->ir_num = ntohs(th->dest);
+ ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
+ ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
if (ipv6_opt_accepted(sk, skb) ||
np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
atomic_inc(&skb->users);
- ireq6->pktopts = skb;
+ ireq->pktopts = skb;
}
- ireq6->iif = sk->sk_bound_dev_if;
+ ireq->ir_iif = sk->sk_bound_dev_if;
/* So that link locals have meaning */
if (!sk->sk_bound_dev_if &&
- ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
- ireq6->iif = inet6_iif(skb);
+ ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
+ ireq->ir_iif = inet6_iif(skb);
req->expires = 0UL;
req->num_retrans = 0;
@@ -241,12 +238,12 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
struct flowi6 fl6;
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_proto = IPPROTO_TCP;
- fl6.daddr = ireq6->rmt_addr;
+ fl6.daddr = ireq->ir_v6_rmt_addr;
final_p = fl6_update_dst(&fl6, np->opt, &final);
- fl6.saddr = ireq6->loc_addr;
+ fl6.saddr = ireq->ir_v6_loc_addr;
fl6.flowi6_oif = sk->sk_bound_dev_if;
fl6.flowi6_mark = sk->sk_mark;
- fl6.fl6_dport = inet_rsk(req)->rmt_port;
+ fl6.fl6_dport = ireq->ir_rmt_port;
fl6.fl6_sport = inet_sk(sk)->inet_sport;
security_req_classify_flow(req, flowi6_to_flowi(&fl6));