+#include <linux/inet_diag.h>
+#include <linux/inetdevice.h>
+#include <linux/tcp.h>
+#include <linux/tcp_md5.h>
+
+#include <crypto/hash.h>
+
+#include <net/inet6_hashtables.h>
+
+static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
+static DEFINE_MUTEX(tcp_md5sig_mutex);
+static bool tcp_md5sig_pool_populated;
+
+#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key)
+
+static void __tcp_alloc_md5sig_pool(void)
+{
+ struct crypto_ahash *hash;
+ int cpu;
+
+ hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hash))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
+ struct ahash_request *req;
+
+ if (!scratch) {
+ scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
+ sizeof(struct tcphdr),
+ GFP_KERNEL,
+ cpu_to_node(cpu));
+ if (!scratch)
+ return;
+ per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
+ }
+ if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
+ continue;
+
+ req = ahash_request_alloc(hash, GFP_KERNEL);
+ if (!req)
+ return;
+
+ ahash_request_set_callback(req, 0, NULL, NULL);
+
+ per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
+ }
+ /* before setting tcp_md5sig_pool_populated, we must commit all writes
+ * to memory. See smp_rmb() in tcp_get_md5sig_pool()
+ */
+ smp_wmb();
+ tcp_md5sig_pool_populated = true;
+}
+
+static bool tcp_alloc_md5sig_pool(void)
+{
+ if (unlikely(!tcp_md5sig_pool_populated)) {
+ mutex_lock(&tcp_md5sig_mutex);
+
+ if (!tcp_md5sig_pool_populated)
+ __tcp_alloc_md5sig_pool();
+
+ mutex_unlock(&tcp_md5sig_mutex);
+ }
+ return tcp_md5sig_pool_populated;
+}
+
+static void tcp_put_md5sig_pool(void)
+{
+ local_bh_enable();
+}
+
+/**
+ * tcp_get_md5sig_pool - get md5sig_pool for this user
+ *
+ * We use percpu structure, so if we succeed, we exit with preemption
+ * and BH disabled, to make sure another thread or softirq handling
+ * wont try to get same context.
+ */
+static struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
+{
+ local_bh_disable();
+
+ if (tcp_md5sig_pool_populated) {
+ /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
+ smp_rmb();
+ return this_cpu_ptr(&tcp_md5sig_pool);
+ }
+ local_bh_enable();
+ return NULL;
+}
+
+static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk,
+ const union tcp_md5_addr
*addr,
+ int family, u8 prefixlen)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_key *key;
+ unsigned int size = sizeof(struct in_addr);
+ const struct tcp_md5sig_info *md5sig;
+
+ /* caller either holds rcu_read_lock() or socket lock */
+ md5sig = rcu_dereference_check(tp->md5sig_info,
+ lockdep_sock_is_held(sk));
+ if (!md5sig)
+ return NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (family == AF_INET6)
+ size = sizeof(struct in6_addr);
+#endif
+ hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+ if (key->family != family)
+ continue;
+ if (!memcmp(&key->addr, addr, size) &&
+ key->prefixlen == prefixlen)
+ return key;
+ }
+ return NULL;
+}
+
+/* This can be called on a newly created socket, from other files */
+static int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
+ int family, u8 prefixlen, 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 tcp_md5sig_info *md5sig;
+
+ key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen);
+ if (key) {
+ /* Pre-existing entry - just update that one. */
+ memcpy(key->key, newkey, newkeylen);
+ key->keylen = newkeylen;
+ return 0;
+ }
+
+ md5sig = rcu_dereference_protected(tp->md5sig_info,
+ lockdep_sock_is_held(sk));
+ if (!md5sig) {
+ md5sig = kmalloc(sizeof(*md5sig), gfp);
+ if (!md5sig)
+ return -ENOMEM;
+
+ sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+ INIT_HLIST_HEAD(&md5sig->head);
+ rcu_assign_pointer(tp->md5sig_info, md5sig);
+ }
+
+ key = sock_kmalloc(sk, sizeof(*key), gfp);
+ if (!key)
+ return -ENOMEM;
+ if (!tcp_alloc_md5sig_pool()) {
+ sock_kfree_s(sk, key, sizeof(*key));
+ return -ENOMEM;
+ }
+
+ memcpy(key->key, newkey, newkeylen);
+ key->keylen = newkeylen;
+ key->family = family;
+ key->prefixlen = prefixlen;
+ 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;
+}
+
+static void tcp_clear_md5_list(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_key *key;
+ struct hlist_node *n;
+ struct tcp_md5sig_info *md5sig;
+
+ md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
+
+ hlist_for_each_entry_safe(key, n, &md5sig->head, node) {
+ hlist_del_rcu(&key->node);
+ atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
+ kfree_rcu(key, rcu);
+ }
+}
+
+static int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr,
+ int family, u8 prefixlen)
+{
+ struct tcp_md5sig_key *key;
+
+ key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen);
+ if (!key)
+ return -ENOENT;
+ hlist_del_rcu(&key->node);
+ atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
+ kfree_rcu(key, rcu);
+ return 0;
+}
+
+static int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
+ const struct tcp_md5sig_key *key)
+{
+ struct scatterlist sg;
+
+ sg_init_one(&sg, key->key, key->keylen);
+ ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
+ return crypto_ahash_update(hp->md5_req);
+}
+
+static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
+ char __user *optval, int optlen)
+{
+ struct tcp_md5sig cmd;
+ struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
+ u8 prefixlen = 32;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ if (copy_from_user(&cmd, optval, sizeof(cmd)))
+ return -EFAULT;
+
+ if (sin->sin_family != AF_INET)
+ return -EINVAL;
+
+ if (optname == TCP_MD5SIG_EXT &&
+ cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
+ prefixlen = cmd.tcpm_prefixlen;
+ if (prefixlen > 32)
+ return -EINVAL;
+ }
+
+ if (!cmd.tcpm_keylen)
+ return tcp_md5_do_del(sk, (union tcp_md5_addr
*)&sin->sin_addr.s_addr,
+ AF_INET, prefixlen);
+
+ if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
+ return -EINVAL;
+
+ return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
+ AF_INET, prefixlen, cmd.tcpm_key, cmd.tcpm_keylen,
+ GFP_KERNEL);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
+ char __user *optval, int optlen)
+{
+ struct tcp_md5sig cmd;
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
+ u8 prefixlen;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ if (copy_from_user(&cmd, optval, sizeof(cmd)))
+ return -EFAULT;
+
+ if (sin6->sin6_family != AF_INET6)
+ return -EINVAL;
+
+ if (optname == TCP_MD5SIG_EXT &&
+ cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
+ prefixlen = cmd.tcpm_prefixlen;
+ if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
+ prefixlen > 32))
+ return -EINVAL;
+ } else {
+ prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
+ }
+
+ if (!cmd.tcpm_keylen) {
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ return tcp_md5_do_del(sk, (union tcp_md5_addr
*)&sin6->sin6_addr.s6_addr32[3],
+ AF_INET, prefixlen);
+ return tcp_md5_do_del(sk, (union tcp_md5_addr
*)&sin6->sin6_addr,
+ AF_INET6, prefixlen);
+ }
+
+ if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
+ return -EINVAL;
+
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ return tcp_md5_do_add(sk, (union tcp_md5_addr
*)&sin6->sin6_addr.s6_addr32[3],
+ AF_INET, prefixlen, cmd.tcpm_key,
+ cmd.tcpm_keylen, GFP_KERNEL);
+
+ return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
+ AF_INET6, prefixlen, cmd.tcpm_key,
+ cmd.tcpm_keylen, GFP_KERNEL);
+}
+#endif
+
+static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
+ __be32 daddr, __be32 saddr,
+ const struct tcphdr *th, int nbytes)
+{
+ struct tcp4_pseudohdr *bp;
+ struct scatterlist sg;
+ struct tcphdr *_th;
+
+ bp = hp->scratch;
+ bp->saddr = saddr;
+ bp->daddr = daddr;
+ bp->pad = 0;
+ bp->protocol = IPPROTO_TCP;
+ bp->len = cpu_to_be16(nbytes);
+
+ _th = (struct tcphdr *)(bp + 1);
+ memcpy(_th, th, sizeof(*th));
+ _th->check = 0;
+
+ sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
+ ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ sizeof(*bp) + sizeof(*th));
+ return crypto_ahash_update(hp->md5_req);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr,
+ const struct tcphdr *th, int nbytes)
+{
+ struct tcp6_pseudohdr *bp;
+ struct scatterlist sg;
+ struct tcphdr *_th;
+
+ bp = hp->scratch;
+ /* 1. TCP pseudo-header (RFC2460) */
+ bp->saddr = *saddr;
+ bp->daddr = *daddr;
+ bp->protocol = cpu_to_be32(IPPROTO_TCP);
+ bp->len = cpu_to_be32(nbytes);
+
+ _th = (struct tcphdr *)(bp + 1);
+ memcpy(_th, th, sizeof(*th));
+ _th->check = 0;
+
+ sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
+ ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ sizeof(*bp) + sizeof(*th));
+ return crypto_ahash_update(hp->md5_req);
+}
+#endif
+
+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;
+ struct ahash_request *req;
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+ if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key
*key,
+ const struct in6_addr *daddr,
+ struct in6_addr *saddr, const struct tcphdr *th)
+{
+ struct tcp_md5sig_pool *hp;
+ struct ahash_request *req;
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+ if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+#endif
+
+/* RFC2385 MD5 checksumming requires a mapping of
+ * IP address->MD5 Key.
+ * We need to maintain these in the sk structure.
+ */
+
+/* Find the Key structure for an address. */
+static struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
+ const union tcp_md5_addr *addr,
+ int family)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_key *key;
+ const struct tcp_md5sig_info *md5sig;
+ __be32 mask;
+ struct tcp_md5sig_key *best_match = NULL;
+ bool match;
+
+ /* caller either holds rcu_read_lock() or socket lock */
+ md5sig = rcu_dereference_check(tp->md5sig_info,
+ lockdep_sock_is_held(sk));
+ if (!md5sig)
+ return NULL;
+
+ hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+ if (key->family != family)
+ continue;
+
+ if (family == AF_INET) {
+ mask = inet_make_mask(key->prefixlen);
+ match = (key->addr.a4.s_addr & mask) ==
+ (addr->a4.s_addr & mask);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (family == AF_INET6) {
+ match = ipv6_prefix_equal(&key->addr.a6, &addr->a6,
+ key->prefixlen);
+#endif
+ } else {
+ match = false;
+ }
+
+ if (match && (!best_match ||
+ key->prefixlen > best_match->prefixlen))
+ best_match = key;
+ }
+ return best_match;
+}
+
+/* Parse MD5 Signature option */
+static const u8 *tcp_parse_md5sig_option(const struct tcphdr *th)
+{
+ int length = (th->doff << 2) - sizeof(*th);
+ const u8 *ptr = (const u8 *)(th + 1);
+
+ /* If the TCP option is too short, we can short cut */
+ if (length < TCPOLEN_MD5SIG)
+ return NULL;
+
+ while (length > 0) {
+ int opcode = *ptr++;
+ int opsize;
+
+ switch (opcode) {
+ case TCPOPT_EOL:
+ return NULL;
+ case TCPOPT_NOP:
+ length--;
+ continue;
+ default:
+ opsize = *ptr++;
+ if (opsize < 2 || opsize > length)
+ return NULL;
+ if (opcode == TCPOPT_MD5SIG)
+ return opsize == TCPOLEN_MD5SIG ? ptr : NULL;
+ }
+ ptr += opsize - 2;
+ length -= opsize;
+ }
+ return NULL;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr)
+{
+ return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
+}
+#endif
+
+static int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
+ const struct sk_buff *skb,
+ unsigned int header_len)
+{
+ struct scatterlist sg;
+ const struct tcphdr *tp = tcp_hdr(skb);
+ struct ahash_request *req = hp->md5_req;
+ unsigned int i;
+ const unsigned int head_data_len = skb_headlen(skb) > header_len ?
+ skb_headlen(skb) - header_len : 0;
+ const struct skb_shared_info *shi = skb_shinfo(skb);
+ struct sk_buff *frag_iter;
+
+ sg_init_table(&sg, 1);
+
+ sg_set_buf(&sg, ((u8 *)tp) + header_len, head_data_len);
+ ahash_request_set_crypt(req, &sg, NULL, head_data_len);
+ if (crypto_ahash_update(req))
+ return 1;
+
+ for (i = 0; i < shi->nr_frags; ++i) {
+ const struct skb_frag_struct *f = &shi->frags[i];
+ unsigned int offset = f->page_offset;
+ struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
+
+ sg_set_page(&sg, page, skb_frag_size(f),
+ offset_in_page(offset));
+ ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
+ if (crypto_ahash_update(req))
+ return 1;
+ }
+
+ skb_walk_frags(skb, frag_iter)
+ if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
+ return 1;
+
+ return 0;
+}
+
+int tcp_v4_md5_send_response_prepare(struct sk_buff *skb, u8 flags,
+ unsigned int remaining,
+ struct tcp_out_options *opts,
+ const struct sock *sk)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ const struct iphdr *iph = ip_hdr(skb);
+ const __u8 *hash_location = NULL;
+
+ rcu_read_lock();
+ hash_location = tcp_parse_md5sig_option(th);
+ if (sk && sk_fullsock(sk)) {
+ opts->md5 = tcp_md5_do_lookup(sk,
+ (union tcp_md5_addr *)&iph->saddr,
+ AF_INET);
+ } else if (sk && sk->sk_state == TCP_TIME_WAIT) {
+ struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+
+ opts->md5 = tcp_twsk_md5_key(tcptw);
+ } else if (sk && sk->sk_state == TCP_NEW_SYN_RECV) {
+ opts->md5 = tcp_md5_do_lookup(sk,
+ (union tcp_md5_addr *)&iph->saddr,
+ AF_INET);
+ } else if (hash_location) {
+ unsigned char newhash[16];
+ struct sock *sk1;
+ int genhash;
+
+ /* 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, NULL, 0,
+ iph->saddr,
+ th->source, iph->daddr,
+ ntohs(th->source), inet_iif(skb),
+ tcp_v4_sdif(skb));
+ /* don't send rst if it can't find key */
+ if (!sk1)
+ goto out_err;
+
+ opts->md5 = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *)
+ &iph->saddr, AF_INET);
+ if (!opts->md5)
+ goto out_err;
+
+ genhash = tcp_v4_md5_hash_skb(newhash, opts->md5, NULL, skb);
+ if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ goto out_err;
+ }
+
+ if (opts->md5)
+ return TCPOLEN_MD5SIG_ALIGNED;
+
+ rcu_read_unlock();
+ return 0;
+
+out_err:
+ rcu_read_unlock();
+ return -1;
+}
+
+void tcp_v4_md5_send_response_write(__be32 *topt, struct sk_buff *skb,
+ struct tcphdr *t1,
+ struct tcp_out_options *opts,
+ const struct sock *sk)
+{
+ if (opts->md5) {
+ *topt++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) |
+ TCPOLEN_MD5SIG);
+
+ tcp_v4_md5_hash_hdr((__u8 *)topt, opts->md5,
+ ip_hdr(skb)->saddr,
+ ip_hdr(skb)->daddr, t1);
+ rcu_read_unlock();
+ }
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+int tcp_v6_md5_send_response_prepare(struct sk_buff *skb, u8 flags,
+ unsigned int remaining,
+ struct tcp_out_options *opts,
+ const struct sock *sk)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ const __u8 *hash_location = NULL;
+
+ rcu_read_lock();
+ hash_location = tcp_parse_md5sig_option(th);
+ if (sk && sk_fullsock(sk)) {
+ opts->md5 = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
+ } else if (sk && sk->sk_state == TCP_TIME_WAIT) {
+ struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+
+ opts->md5 = tcp_twsk_md5_key(tcptw);
+ } else if (sk && sk->sk_state == TCP_NEW_SYN_RECV) {
+ opts->md5 = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
+ } else if (hash_location) {
+ unsigned char newhash[16];
+ struct sock *sk1;
+ int genhash;
+
+ /* 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 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
+ &tcp_hashinfo, NULL, 0,
+ &ipv6h->saddr,
+ th->source, &ipv6h->daddr,
+ ntohs(th->source), tcp_v6_iif(skb),
+ tcp_v6_sdif(skb));
+ if (!sk1)
+ goto out_err;
+
+ opts->md5 = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
+ if (!opts->md5)
+ goto out_err;
+
+ genhash = tcp_v6_md5_hash_skb(newhash, opts->md5, NULL, skb);
+ if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ goto out_err;
+ }
+
+ if (opts->md5)
+ return TCPOLEN_MD5SIG_ALIGNED;
+
+ rcu_read_unlock();
+ return 0;
+
+out_err:
+ rcu_read_unlock();
+ return -1;
+}
+EXPORT_SYMBOL_GPL(tcp_v6_md5_send_response_prepare);
+
+void tcp_v6_md5_send_response_write(__be32 *topt, struct sk_buff *skb,
+ struct tcphdr *t1,
+ struct tcp_out_options *opts,
+ const struct sock *sk)
+{
+ if (opts->md5) {
+ *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
+ tcp_v6_md5_hash_hdr((__u8 *)topt, opts->md5,
+ &ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr, t1);
+
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL_GPL(tcp_v6_md5_send_response_write);
+#endif
+
+struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
+ const struct sock *addr_sk)
+{
+ const union tcp_md5_addr *addr;
+
+ addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr;
+ return tcp_md5_do_lookup(sk, addr, AF_INET);
+}
+EXPORT_SYMBOL(tcp_v4_md5_lookup);
+
+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 ahash_request *req;
+ const struct tcphdr *th = tcp_hdr(skb);
+ __be32 saddr, daddr;
+
+ 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;
+ daddr = iph->daddr;
+ }
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+
+ if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ goto clear_hash;
+ if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
+
+#if IS_ENABLED(CONFIG_IPV6)
+int tcp_v6_md5_hash_skb(char *md5_hash,
+ const struct tcp_md5sig_key *key,
+ const struct sock *sk,
+ const struct sk_buff *skb)
+{
+ const struct in6_addr *saddr, *daddr;
+ struct tcp_md5sig_pool *hp;
+ struct ahash_request *req;
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ if (sk) { /* valid for establish/request sockets */
+ saddr = &sk->sk_v6_rcv_saddr;
+ daddr = &sk->sk_v6_daddr;
+ } else {
+ const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+
+ saddr = &ip6h->saddr;
+ daddr = &ip6h->daddr;
+ }
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+
+ if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ goto clear_hash;
+ if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(tcp_v6_md5_hash_skb);
+#endif
+
+/* Called with rcu_read_lock() */
+bool tcp_v4_inbound_md5_hash(const struct sock *sk,
+ const struct sk_buff *skb)
+{
+ /* This gets called for each TCP segment that arrives
+ * so we want to be efficient.
+ * We have 3 drop cases:
+ * o No MD5 hash and one expected.
+ * o MD5 hash and we're not expecting one.
+ * o MD5 hash and its wrong.
+ */
+ const __u8 *hash_location = NULL;
+ struct tcp_md5sig_key *hash_expected;
+ const struct iphdr *iph = ip_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+ int genhash;
+ unsigned char newhash[16];
+
+ 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? */
+ if (!hash_expected && !hash_location)
+ return false;
+
+ if (hash_expected && !hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ return true;
+ }
+
+ if (!hash_expected && hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+ return true;
+ }
+
+ /* Okay, so this is hash_expected and hash_location -
+ * so we need to calculate the checksum.
+ */
+ genhash = tcp_v4_md5_hash_skb(newhash,
+ hash_expected,
+ NULL, skb);
+
+ if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
+ net_info_ratelimited("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 true;
+ }
+ return false;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+bool tcp_v6_inbound_md5_hash(const struct sock *sk,
+ const struct sk_buff *skb)
+{
+ const __u8 *hash_location = NULL;
+ struct tcp_md5sig_key *hash_expected;
+ const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+ int genhash;
+ u8 newhash[16];
+
+ hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
+ hash_location = tcp_parse_md5sig_option(th);
+
+ /* We've parsed the options - do we have a hash? */
+ if (!hash_expected && !hash_location)
+ return false;
+
+ if (hash_expected && !hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ return true;
+ }
+
+ if (!hash_expected && hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+ return true;
+ }
+
+ /* check the signature */
+ genhash = tcp_v6_md5_hash_skb(newhash,
+ hash_expected,
+ NULL, skb);
+
+ if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
+ net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
+ genhash ? "failed" : "mismatch",
+ &ip6h->saddr, ntohs(th->source),
+ &ip6h->daddr, ntohs(th->dest));
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(tcp_v6_inbound_md5_hash);
+#endif
+
+void tcp_v4_md5_destroy_sock(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ /* Clean up the MD5 key list, if any */
+ if (tp->md5sig_info) {
+ tcp_clear_md5_list(sk);
+ kfree_rcu(tp->md5sig_info, rcu);
+ tp->md5sig_info = NULL;
+ }
+}
+
+void tcp_v4_md5_syn_recv_sock(const struct sock *listener, struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct tcp_md5sig_key *key;
+
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_md5_do_lookup(listener, (union tcp_md5_addr
*)&inet->inet_daddr,
+ AF_INET);
+ if (key) {
+ /* We're using one, so create a matching key
+ * on the sk structure. If we fail to get
+ * memory, then we end up not copying the key
+ * across. Shucks.
+ */
+ tcp_md5_do_add(sk, (union tcp_md5_addr *)&inet->inet_daddr,
+ AF_INET, 32, key->key, key->keylen, GFP_ATOMIC);
+ sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+ }
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+void tcp_v6_md5_syn_recv_sock(const struct sock *listener, struct sock *sk)
+{
+ struct tcp_md5sig_key *key;
+
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_v6_md5_do_lookup(listener, &sk->sk_v6_daddr);
+ if (key) {
+ /* We're using one, so create a matching key
+ * on the newsk structure. If we fail to get
+ * memory, then we end up not copying the key
+ * across. Shucks.
+ */
+ tcp_md5_do_add(sk, (union tcp_md5_addr *)&sk->sk_v6_daddr,
+ AF_INET6, 128, key->key, key->keylen,
+ sk_gfp_mask(sk, GFP_ATOMIC));
+ }
+}
+EXPORT_SYMBOL_GPL(tcp_v6_md5_syn_recv_sock);
+
+struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
+ const struct sock *addr_sk)
+{
+ return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
+}
+EXPORT_SYMBOL_GPL(tcp_v6_md5_lookup);
+#endif
+
+void tcp_md5_time_wait(struct sock *sk, struct inet_timewait_sock *tw)
+{
+ struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_md5sig_key *key;
+
+ /* The timewait bucket does not have the key DB from the
+ * sock structure. We just make a quick copy of the
+ * md5 key being used (if indeed we are using one)
+ * so the timewait ack generating code has the key.
+ */
+ tcptw->tw_md5_key = NULL;
+ key = tp->af_specific->md5_lookup(sk, sk);
+ if (key) {
+ tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC);
+ BUG_ON(tcptw->tw_md5_key && !tcp_alloc_md5sig_pool());
+ }
+}
+
+static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info,
+ const struct tcp_md5sig_key *key)
+{
+ info->tcpm_family = key->family;
+ info->tcpm_prefixlen = key->prefixlen;
+ info->tcpm_keylen = key->keylen;
+ memcpy(info->tcpm_key, key->key, key->keylen);
+
+ if (key->family == AF_INET)
+ info->tcpm_addr[0] = key->addr.a4.s_addr;
+ #if IS_ENABLED(CONFIG_IPV6)
+ else if (key->family == AF_INET6)
+ memcpy(&info->tcpm_addr, &key->addr.a6,
+ sizeof(info->tcpm_addr));
+ #endif
+}
+
+static int tcp_diag_put_md5sig(struct sk_buff *skb,
+ const struct tcp_md5sig_info *md5sig)
+{
+ const struct tcp_md5sig_key *key;
+ struct tcp_diag_md5sig *info;
+ struct nlattr *attr;
+ int md5sig_count = 0;
+
+ hlist_for_each_entry_rcu(key, &md5sig->head, node)
+ md5sig_count++;
+ if (md5sig_count == 0)
+ return 0;
+
+ attr = nla_reserve(skb, INET_DIAG_MD5SIG,
+ md5sig_count * sizeof(struct tcp_diag_md5sig));
+ if (!attr)
+ return -EMSGSIZE;
+
+ info = nla_data(attr);
+ memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig));
+ hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+ tcp_diag_md5sig_fill(info++, key);
+ if (--md5sig_count == 0)
+ break;
+ }
+
+ return 0;
+}
+
+int tcp_md5_diag_get_aux(struct sock *sk, bool net_admin, struct sk_buff *skb)
+{
+ if (net_admin) {
+ struct tcp_md5sig_info *md5sig;
+ int err = 0;
+
+ rcu_read_lock();
+ md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
+ if (md5sig)
+ err = tcp_diag_put_md5sig(skb, md5sig);
+ rcu_read_unlock();
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tcp_md5_diag_get_aux);
+
+int tcp_md5_diag_get_aux_size(struct sock *sk, bool net_admin)
+{
+ int size = 0;
+
+ if (net_admin && sk_fullsock(sk)) {
+ const struct tcp_md5sig_info *md5sig;
+ const struct tcp_md5sig_key *key;
+ size_t md5sig_count = 0;
+
+ rcu_read_lock();
+ md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
+ if (md5sig) {
+ hlist_for_each_entry_rcu(key, &md5sig->head, node)
+ md5sig_count++;
+ }
+ rcu_read_unlock();
+ size += nla_total_size(md5sig_count *
+ sizeof(struct tcp_diag_md5sig));
+ }
+
+ return size;
+}
+EXPORT_SYMBOL_GPL(tcp_md5_diag_get_aux_size);
+
+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_parse = tcp_v4_parse_md5_keys,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
+ .md5_lookup = tcp_v6_md5_lookup,
+ .calc_md5_hash = tcp_v6_md5_hash_skb,
+ .md5_parse = tcp_v6_parse_md5_keys,
+};
+EXPORT_SYMBOL_GPL(tcp_sock_ipv6_specific);
+
+const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
+ .md5_lookup = tcp_v4_md5_lookup,
+ .calc_md5_hash = tcp_v4_md5_hash_skb,
+ .md5_parse = tcp_v6_parse_md5_keys,
+};
+EXPORT_SYMBOL_GPL(tcp_sock_ipv6_mapped_specific);
+#endif
