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path: root/net/ipv4/tcp_ipv4.c
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Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c322
1 files changed, 164 insertions, 158 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 94d683a61cba..3a25cf743f8b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -50,6 +50,7 @@
* a single port at the same time.
*/
+#define pr_fmt(fmt) "TCP: " fmt
#include <linux/bottom_half.h>
#include <linux/types.h>
@@ -90,16 +91,8 @@ EXPORT_SYMBOL(sysctl_tcp_low_latency);
#ifdef CONFIG_TCP_MD5SIG
-static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
- __be32 addr);
-static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
+static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th);
-#else
-static inline
-struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
-{
- return NULL;
-}
#endif
struct inet_hashinfo tcp_hashinfo;
@@ -601,6 +594,10 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
struct ip_reply_arg arg;
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *key;
+ const __u8 *hash_location = NULL;
+ unsigned char newhash[16];
+ int genhash;
+ struct sock *sk1 = NULL;
#endif
struct net *net;
@@ -631,7 +628,36 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
arg.iov[0].iov_len = sizeof(rep.th);
#ifdef CONFIG_TCP_MD5SIG
- key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->saddr) : NULL;
+ hash_location = tcp_parse_md5sig_option(th);
+ if (!sk && hash_location) {
+ /*
+ * active side is lost. Try to find listening socket through
+ * source port, and then find md5 key through listening socket.
+ * we are not loose security here:
+ * Incoming packet is checked with md5 hash with finding key,
+ * no RST generated if md5 hash doesn't match.
+ */
+ sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
+ &tcp_hashinfo, ip_hdr(skb)->daddr,
+ ntohs(th->source), inet_iif(skb));
+ /* don't send rst if it can't find key */
+ if (!sk1)
+ return;
+ rcu_read_lock();
+ key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *)
+ &ip_hdr(skb)->saddr, AF_INET);
+ if (!key)
+ goto release_sk1;
+
+ genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb);
+ if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ goto release_sk1;
+ } else {
+ key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *)
+ &ip_hdr(skb)->saddr,
+ AF_INET) : NULL;
+ }
+
if (key) {
rep.opt[0] = htonl((TCPOPT_NOP << 24) |
(TCPOPT_NOP << 16) |
@@ -664,6 +690,14 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
+
+#ifdef CONFIG_TCP_MD5SIG
+release_sk1:
+ if (sk1) {
+ rcu_read_unlock();
+ sock_put(sk1);
+ }
+#endif
}
/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
@@ -764,7 +798,8 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
req->ts_recent,
0,
- tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
+ tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr,
+ AF_INET),
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos);
}
@@ -842,8 +877,7 @@ int tcp_syn_flood_action(struct sock *sk,
lopt = inet_csk(sk)->icsk_accept_queue.listen_opt;
if (!lopt->synflood_warned) {
lopt->synflood_warned = 1;
- pr_info("%s: Possible SYN flooding on port %d. %s. "
- " Check SNMP counters.\n",
+ pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
proto, ntohs(tcp_hdr(skb)->dest), msg);
}
return want_cookie;
@@ -881,153 +915,138 @@ static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
*/
/* Find the Key structure for an address. */
-static struct tcp_md5sig_key *
- tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
+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);
- int i;
-
- if (!tp->md5sig_info || !tp->md5sig_info->entries4)
+ struct tcp_md5sig_key *key;
+ struct hlist_node *pos;
+ unsigned int size = sizeof(struct in_addr);
+ struct tcp_md5sig_info *md5sig;
+
+ /* caller either holds rcu_read_lock() or socket lock */
+ md5sig = rcu_dereference_check(tp->md5sig_info,
+ sock_owned_by_user(sk) ||
+ lockdep_is_held(&sk->sk_lock.slock));
+ if (!md5sig)
return NULL;
- for (i = 0; i < tp->md5sig_info->entries4; i++) {
- if (tp->md5sig_info->keys4[i].addr == addr)
- return &tp->md5sig_info->keys4[i].base;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (family == AF_INET6)
+ size = sizeof(struct in6_addr);
+#endif
+ hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) {
+ if (key->family != family)
+ continue;
+ if (!memcmp(&key->addr, addr, size))
+ return key;
}
return NULL;
}
+EXPORT_SYMBOL(tcp_md5_do_lookup);
struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
struct sock *addr_sk)
{
- return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->inet_daddr);
+ union tcp_md5_addr *addr;
+
+ addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_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)
{
- return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
+ union tcp_md5_addr *addr;
+
+ addr = (union tcp_md5_addr *)&inet_rsk(req)->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_v4_md5_do_add(struct sock *sk, __be32 addr,
- u8 *newkey, u8 newkeylen)
+int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
+ int family, const u8 *newkey, u8 newkeylen, gfp_t gfp)
{
/* Add Key to the list */
struct tcp_md5sig_key *key;
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp4_md5sig_key *keys;
+ struct tcp_md5sig_info *md5sig;
- key = tcp_v4_md5_do_lookup(sk, addr);
+ key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
if (key) {
/* Pre-existing entry - just update that one. */
- kfree(key->key);
- key->key = newkey;
+ memcpy(key->key, newkey, newkeylen);
key->keylen = newkeylen;
- } else {
- struct tcp_md5sig_info *md5sig;
-
- if (!tp->md5sig_info) {
- tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
- GFP_ATOMIC);
- if (!tp->md5sig_info) {
- kfree(newkey);
- return -ENOMEM;
- }
- sk_nocaps_add(sk, NETIF_F_GSO_MASK);
- }
+ return 0;
+ }
- md5sig = tp->md5sig_info;
- if (md5sig->entries4 == 0 &&
- tcp_alloc_md5sig_pool(sk) == NULL) {
- kfree(newkey);
+ md5sig = rcu_dereference_protected(tp->md5sig_info,
+ sock_owned_by_user(sk));
+ if (!md5sig) {
+ md5sig = kmalloc(sizeof(*md5sig), gfp);
+ if (!md5sig)
return -ENOMEM;
- }
- if (md5sig->alloced4 == md5sig->entries4) {
- keys = kmalloc((sizeof(*keys) *
- (md5sig->entries4 + 1)), GFP_ATOMIC);
- if (!keys) {
- kfree(newkey);
- if (md5sig->entries4 == 0)
- tcp_free_md5sig_pool();
- return -ENOMEM;
- }
-
- if (md5sig->entries4)
- memcpy(keys, md5sig->keys4,
- sizeof(*keys) * md5sig->entries4);
+ sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+ INIT_HLIST_HEAD(&md5sig->head);
+ rcu_assign_pointer(tp->md5sig_info, md5sig);
+ }
- /* Free old key list, and reference new one */
- kfree(md5sig->keys4);
- md5sig->keys4 = keys;
- md5sig->alloced4++;
- }
- md5sig->entries4++;
- md5sig->keys4[md5sig->entries4 - 1].addr = addr;
- md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
- md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
+ key = sock_kmalloc(sk, sizeof(*key), gfp);
+ if (!key)
+ return -ENOMEM;
+ if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) {
+ sock_kfree_s(sk, key, sizeof(*key));
+ return -ENOMEM;
}
- return 0;
-}
-EXPORT_SYMBOL(tcp_v4_md5_do_add);
-static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
- u8 *newkey, u8 newkeylen)
-{
- return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->inet_daddr,
- newkey, newkeylen);
+ memcpy(key->key, newkey, newkeylen);
+ key->keylen = newkeylen;
+ key->family = family;
+ memcpy(&key->addr, addr,
+ (family == AF_INET6) ? sizeof(struct in6_addr) :
+ sizeof(struct in_addr));
+ hlist_add_head_rcu(&key->node, &md5sig->head);
+ return 0;
}
+EXPORT_SYMBOL(tcp_md5_do_add);
-int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
+int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family)
{
struct tcp_sock *tp = tcp_sk(sk);
- int i;
-
- for (i = 0; i < tp->md5sig_info->entries4; i++) {
- if (tp->md5sig_info->keys4[i].addr == addr) {
- /* Free the key */
- kfree(tp->md5sig_info->keys4[i].base.key);
- tp->md5sig_info->entries4--;
-
- if (tp->md5sig_info->entries4 == 0) {
- kfree(tp->md5sig_info->keys4);
- tp->md5sig_info->keys4 = NULL;
- tp->md5sig_info->alloced4 = 0;
- tcp_free_md5sig_pool();
- } else if (tp->md5sig_info->entries4 != i) {
- /* Need to do some manipulation */
- memmove(&tp->md5sig_info->keys4[i],
- &tp->md5sig_info->keys4[i+1],
- (tp->md5sig_info->entries4 - i) *
- sizeof(struct tcp4_md5sig_key));
- }
- return 0;
- }
- }
- return -ENOENT;
+ struct tcp_md5sig_key *key;
+ struct tcp_md5sig_info *md5sig;
+
+ key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
+ if (!key)
+ return -ENOENT;
+ hlist_del_rcu(&key->node);
+ atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
+ kfree_rcu(key, rcu);
+ md5sig = rcu_dereference_protected(tp->md5sig_info,
+ sock_owned_by_user(sk));
+ if (hlist_empty(&md5sig->head))
+ tcp_free_md5sig_pool();
+ return 0;
}
-EXPORT_SYMBOL(tcp_v4_md5_do_del);
+EXPORT_SYMBOL(tcp_md5_do_del);
-static void tcp_v4_clear_md5_list(struct sock *sk)
+void tcp_clear_md5_list(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_key *key;
+ struct hlist_node *pos, *n;
+ struct tcp_md5sig_info *md5sig;
- /* Free each key, then the set of key keys,
- * the crypto element, and then decrement our
- * hold on the last resort crypto.
- */
- if (tp->md5sig_info->entries4) {
- int i;
- for (i = 0; i < tp->md5sig_info->entries4; i++)
- kfree(tp->md5sig_info->keys4[i].base.key);
- tp->md5sig_info->entries4 = 0;
+ md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
+
+ if (!hlist_empty(&md5sig->head))
tcp_free_md5sig_pool();
- }
- if (tp->md5sig_info->keys4) {
- kfree(tp->md5sig_info->keys4);
- tp->md5sig_info->keys4 = NULL;
- tp->md5sig_info->alloced4 = 0;
+ hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) {
+ hlist_del_rcu(&key->node);
+ atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
+ kfree_rcu(key, rcu);
}
}
@@ -1036,7 +1055,6 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
{
struct tcp_md5sig cmd;
struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
- u8 *newkey;
if (optlen < sizeof(cmd))
return -EINVAL;
@@ -1047,32 +1065,16 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
if (sin->sin_family != AF_INET)
return -EINVAL;
- if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
- if (!tcp_sk(sk)->md5sig_info)
- return -ENOENT;
- return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
- }
+ if (!cmd.tcpm_key || !cmd.tcpm_keylen)
+ return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
+ AF_INET);
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
return -EINVAL;
- if (!tcp_sk(sk)->md5sig_info) {
- struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_md5sig_info *p;
-
- p = kzalloc(sizeof(*p), sk->sk_allocation);
- if (!p)
- return -EINVAL;
-
- tp->md5sig_info = p;
- sk_nocaps_add(sk, NETIF_F_GSO_MASK);
- }
-
- newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation);
- if (!newkey)
- return -ENOMEM;
- return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
- newkey, cmd.tcpm_keylen);
+ return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
+ AF_INET, cmd.tcpm_key, cmd.tcpm_keylen,
+ GFP_KERNEL);
}
static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
@@ -1098,7 +1100,7 @@ static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
}
-static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
+static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th)
{
struct tcp_md5sig_pool *hp;
@@ -1198,7 +1200,8 @@ static int tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
int genhash;
unsigned char newhash[16];
- hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
+ hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr,
+ AF_INET);
hash_location = tcp_parse_md5sig_option(th);
/* We've parsed the options - do we have a hash? */
@@ -1224,10 +1227,10 @@ static int tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
if (net_ratelimit()) {
- printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
- &iph->saddr, ntohs(th->source),
- &iph->daddr, ntohs(th->dest),
- genhash ? " tcp_v4_calc_md5_hash failed" : "");
+ pr_info("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
+ &iph->saddr, ntohs(th->source),
+ &iph->daddr, ntohs(th->dest),
+ genhash ? " tcp_v4_calc_md5_hash failed" : "");
}
return 1;
}
@@ -1396,7 +1399,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
* to destinations, already remembered
* to the moment of synflood.
*/
- LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n",
+ LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"),
&saddr, ntohs(tcp_hdr(skb)->source));
goto drop_and_release;
}
@@ -1461,14 +1464,19 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
ireq->opt = NULL;
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
+ newinet->rcv_tos = ip_hdr(skb)->tos;
inet_csk(newsk)->icsk_ext_hdr_len = 0;
if (inet_opt)
inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
newinet->inet_id = newtp->write_seq ^ jiffies;
- if (!dst && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
- goto put_and_exit;
-
+ if (!dst) {
+ dst = inet_csk_route_child_sock(sk, newsk, req);
+ if (!dst)
+ goto put_and_exit;
+ } else {
+ /* syncookie case : see end of cookie_v4_check() */
+ }
sk_setup_caps(newsk, dst);
tcp_mtup_init(newsk);
@@ -1486,7 +1494,8 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
#ifdef CONFIG_TCP_MD5SIG
/* Copy over the MD5 key from the original socket */
- key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr);
+ key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr,
+ AF_INET);
if (key != NULL) {
/*
* We're using one, so create a matching key
@@ -1494,10 +1503,8 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
* memory, then we end up not copying the key
* across. Shucks.
*/
- char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
- if (newkey != NULL)
- tcp_v4_md5_do_add(newsk, newinet->inet_daddr,
- newkey, key->keylen);
+ tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr,
+ AF_INET, key->key, key->keylen, GFP_ATOMIC);
sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
}
#endif
@@ -1858,7 +1865,6 @@ EXPORT_SYMBOL(ipv4_specific);
static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
.md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
- .md5_add = tcp_v4_md5_add_func,
.md5_parse = tcp_v4_parse_md5_keys,
};
#endif
@@ -1947,8 +1953,8 @@ void tcp_v4_destroy_sock(struct sock *sk)
#ifdef CONFIG_TCP_MD5SIG
/* Clean up the MD5 key list, if any */
if (tp->md5sig_info) {
- tcp_v4_clear_md5_list(sk);
- kfree(tp->md5sig_info);
+ tcp_clear_md5_list(sk);
+ kfree_rcu(tp->md5sig_info, rcu);
tp->md5sig_info = NULL;
}
#endif