1 files changed, 647 insertions, 66 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 22ef8bd26620..a1222d6968c4 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -78,6 +78,9 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+
 int sysctl_tcp_tw_reuse __read_mostly;
 int sysctl_tcp_low_latency __read_mostly;
 
@@ -89,10 +92,19 @@ static struct socket *tcp_socket;
 
 void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
 
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
+                                                   __be32 addr);
+static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
+                                   __be32 saddr, __be32 daddr,
+                                   struct tcphdr *th, int protocol,
+                                   int tcplen);
+#endif
+
 struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
-        .lhash_lock     = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
-        .lhash_users    = ATOMIC_INIT(0),
-        .lhash_wait     = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
+        .lhash_lock  = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
+        .lhash_users = ATOMIC_INIT(0),
+        .lhash_wait  = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
 };
 
 static int tcp_v4_get_port(struct sock *sk, unsigned short snum)
@@ -111,7 +123,7 @@ void tcp_unhash(struct sock *sk)
         inet_unhash(&tcp_hashinfo, sk);
 }
 
-static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
+static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
 {
         return secure_tcp_sequence_number(skb->nh.iph->daddr,
                                           skb->nh.iph->saddr,
@@ -205,13 +217,14 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         if (tcp_death_row.sysctl_tw_recycle &&
             !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
                 struct inet_peer *peer = rt_get_peer(rt);
-
-                /* VJ's idea. We save last timestamp seen from
-                 * the destination in peer table, when entering state TIME-WAIT
-                 * and initialize rx_opt.ts_recent from it, when trying new connection.
+                /*
+                 * VJ's idea. We save last timestamp seen from
+                 * the destination in peer table, when entering state
+                 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
+                 * when trying new connection.
                  */
-
-                if (peer && peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) {
+                if (peer != NULL &&
+                    peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) {
                         tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
                         tp->rx_opt.ts_recent = peer->tcp_ts;
                 }
@@ -236,7 +249,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         if (err)
                 goto failure;
 
-        err = ip_route_newports(&rt, IPPROTO_TCP, inet->sport, inet->dport, sk);
+        err = ip_route_newports(&rt, IPPROTO_TCP,
+                                inet->sport, inet->dport, sk);
         if (err)
                 goto failure;
 
@@ -260,7 +274,10 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         return 0;
 
 failure:
-        /* This unhashes the socket and releases the local port, if necessary. */
+        /*
+         * This unhashes the socket and releases the local port,
+         * if necessary.
+         */
         tcp_set_state(sk, TCP_CLOSE);
         ip_rt_put(rt);
         sk->sk_route_caps = 0;
@@ -485,8 +502,9 @@ void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
         struct tcphdr *th = skb->h.th;
 
         if (skb->ip_summed == CHECKSUM_PARTIAL) {
-                th->check = ~tcp_v4_check(th, len, inet->saddr, inet->daddr, 0);
-                skb->csum = offsetof(struct tcphdr, check);
+                th->check = ~tcp_v4_check(th, len,
+                                          inet->saddr, inet->daddr, 0);
+                skb->csum_offset = offsetof(struct tcphdr, check);
         } else {
                 th->check = tcp_v4_check(th, len, inet->saddr, inet->daddr,
                                          csum_partial((char *)th,
@@ -508,7 +526,7 @@ int tcp_v4_gso_send_check(struct sk_buff *skb)
 
         th->check = 0;
         th->check = ~tcp_v4_check(th, skb->len, iph->saddr, iph->daddr, 0);
-        skb->csum = offsetof(struct tcphdr, check);
+        skb->csum_offset = offsetof(struct tcphdr, check);
         skb->ip_summed = CHECKSUM_PARTIAL;
         return 0;
 }
@@ -526,11 +544,19 @@ int tcp_v4_gso_send_check(struct sk_buff *skb)
  *      Exception: precedence violation. We do not implement it in any case.
  */
 
-static void tcp_v4_send_reset(struct sk_buff *skb)
+static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
 {
         struct tcphdr *th = skb->h.th;
-        struct tcphdr rth;
+        struct {
+                struct tcphdr th;
+#ifdef CONFIG_TCP_MD5SIG
+                __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
+#endif
+        } rep;
         struct ip_reply_arg arg;
+#ifdef CONFIG_TCP_MD5SIG
+        struct tcp_md5sig_key *key;
+#endif
 
         /* Never send a reset in response to a reset. */
         if (th->rst)
@@ -540,29 +566,49 @@ static void tcp_v4_send_reset(struct sk_buff *skb)
                 return;
 
         /* Swap the send and the receive. */
-        memset(&rth, 0, sizeof(struct tcphdr));
-        rth.dest   = th->source;
-        rth.source = th->dest;
-        rth.doff   = sizeof(struct tcphdr) / 4;
-        rth.rst    = 1;
+        memset(&rep, 0, sizeof(rep));
+        rep.th.dest   = th->source;
+        rep.th.source = th->dest;
+        rep.th.doff   = sizeof(struct tcphdr) / 4;
+        rep.th.rst    = 1;
 
         if (th->ack) {
-                rth.seq = th->ack_seq;
+                rep.th.seq = th->ack_seq;
         } else {
-                rth.ack = 1;
-                rth.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
-                                    skb->len - (th->doff << 2));
+                rep.th.ack = 1;
+                rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
+                                       skb->len - (th->doff << 2));
         }
 
-        memset(&arg, 0, sizeof arg);
-        arg.iov[0].iov_base = (unsigned char *)&rth;
-        arg.iov[0].iov_len  = sizeof rth;
+        memset(&arg, 0, sizeof(arg));
+        arg.iov[0].iov_base = (unsigned char *)&rep;
+        arg.iov[0].iov_len  = sizeof(rep.th);
+
+#ifdef CONFIG_TCP_MD5SIG
+        key = sk ? tcp_v4_md5_do_lookup(sk, skb->nh.iph->daddr) : NULL;
+        if (key) {
+                rep.opt[0] = htonl((TCPOPT_NOP << 24) |
+                                   (TCPOPT_NOP << 16) |
+                                   (TCPOPT_MD5SIG << 8) |
+                                   TCPOLEN_MD5SIG);
+                /* Update length and the length the header thinks exists */
+                arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
+                rep.th.doff = arg.iov[0].iov_len / 4;
+
+                tcp_v4_do_calc_md5_hash((__u8 *)&rep.opt[1],
+                                        key,
+                                        skb->nh.iph->daddr,
+                                        skb->nh.iph->saddr,
+                                        &rep.th, IPPROTO_TCP,
+                                        arg.iov[0].iov_len);
+        }
+#endif
         arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr,
-                                      skb->nh.iph->saddr, /*XXX*/
+                                      skb->nh.iph->saddr, /* XXX */
                                       sizeof(struct tcphdr), IPPROTO_TCP, 0);
         arg.csumoffset = offsetof(struct tcphdr, check) / 2;
 
-        ip_send_reply(tcp_socket->sk, skb, &arg, sizeof rth);
+        ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
 
         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
@@ -572,28 +618,37 @@ static void tcp_v4_send_reset(struct sk_buff *skb)
    outside socket context is ugly, certainly. What can I do?
  */
 
-static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
+static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
+                            struct sk_buff *skb, u32 seq, u32 ack,
                             u32 win, u32 ts)
 {
         struct tcphdr *th = skb->h.th;
         struct {
                 struct tcphdr th;
-                u32 tsopt[TCPOLEN_TSTAMP_ALIGNED >> 2];
+                __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
+#ifdef CONFIG_TCP_MD5SIG
+                           + (TCPOLEN_MD5SIG_ALIGNED >> 2)
+#endif
+                        ];
         } rep;
         struct ip_reply_arg arg;
+#ifdef CONFIG_TCP_MD5SIG
+        struct tcp_md5sig_key *key;
+        struct tcp_md5sig_key tw_key;
+#endif
 
         memset(&rep.th, 0, sizeof(struct tcphdr));
-        memset(&arg, 0, sizeof arg);
+        memset(&arg, 0, sizeof(arg));
 
         arg.iov[0].iov_base = (unsigned char *)&rep;
         arg.iov[0].iov_len  = sizeof(rep.th);
         if (ts) {
-                rep.tsopt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
-                                     (TCPOPT_TIMESTAMP << 8) |
-                                     TCPOLEN_TIMESTAMP);
-                rep.tsopt[1] = htonl(tcp_time_stamp);
-                rep.tsopt[2] = htonl(ts);
-                arg.iov[0].iov_len = sizeof(rep);
+                rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+                                   (TCPOPT_TIMESTAMP << 8) |
+                                   TCPOLEN_TIMESTAMP);
+                rep.opt[1] = htonl(tcp_time_stamp);
+                rep.opt[2] = htonl(ts);
+                arg.iov[0].iov_len = TCPOLEN_TSTAMP_ALIGNED;
         }
 
         /* Swap the send and the receive. */
@@ -605,8 +660,44 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
         rep.th.ack     = 1;
         rep.th.window  = htons(win);
 
+#ifdef CONFIG_TCP_MD5SIG
+        /*
+         * The SKB holds an imcoming packet, but may not have a valid ->sk
+         * pointer. This is especially the case when we're dealing with a
+         * TIME_WAIT ack, because the sk structure is long gone, and only
+         * the tcp_timewait_sock remains. So the md5 key is stashed in that
+         * structure, and we use it in preference.  I believe that (twsk ||
+         * skb->sk) holds true, but we program defensively.
+         */
+        if (!twsk && skb->sk) {
+                key = tcp_v4_md5_do_lookup(skb->sk, skb->nh.iph->daddr);
+        } else if (twsk && twsk->tw_md5_keylen) {
+                tw_key.key = twsk->tw_md5_key;
+                tw_key.keylen = twsk->tw_md5_keylen;
+                key = &tw_key;
+        } else
+                key = NULL;
+
+        if (key) {
+                int offset = (ts) ? 3 : 0;
+
+                rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
+                                          (TCPOPT_NOP << 16) |
+                                          (TCPOPT_MD5SIG << 8) |
+                                          TCPOLEN_MD5SIG);
+                arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
+                rep.th.doff = arg.iov[0].iov_len/4;
+
+                tcp_v4_do_calc_md5_hash((__u8 *)&rep.opt[offset],
+                                        key,
+                                        skb->nh.iph->daddr,
+                                        skb->nh.iph->saddr,
+                                        &rep.th, IPPROTO_TCP,
+                                        arg.iov[0].iov_len);
+        }
+#endif
         arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr,
-                                      skb->nh.iph->saddr, /*XXX*/
+                                      skb->nh.iph->saddr, /* XXX */
                                       arg.iov[0].iov_len, IPPROTO_TCP, 0);
         arg.csumoffset = offsetof(struct tcphdr, check) / 2;
 
@@ -618,17 +709,20 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
 static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 {
         struct inet_timewait_sock *tw = inet_twsk(sk);
-        const struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+        struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 
-        tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
-                        tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcptw->tw_ts_recent);
+        tcp_v4_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+                        tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
+                        tcptw->tw_ts_recent);
 
         inet_twsk_put(tw);
 }
 
-static void tcp_v4_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
+static void tcp_v4_reqsk_send_ack(struct sk_buff *skb,
+                                  struct request_sock *req)
 {
-        tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
+        tcp_v4_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1,
+                        tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
                         req->ts_recent);
 }
 
@@ -662,8 +756,7 @@ static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
                 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
                                             ireq->rmt_addr,
                                             ireq->opt);
-                if (err == NET_XMIT_CN)
-                        err = 0;
+                err = net_xmit_eval(err);
         }
 
 out:
@@ -715,7 +808,423 @@ static struct ip_options *tcp_v4_save_options(struct sock *sk,
         return dopt;
 }
 
-struct request_sock_ops tcp_request_sock_ops = {
+#ifdef CONFIG_TCP_MD5SIG
+/*
+ * 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_v4_md5_do_lookup(struct sock *sk, __be32 addr)
+{
+        struct tcp_sock *tp = tcp_sk(sk);
+        int i;
+
+        if (!tp->md5sig_info || !tp->md5sig_info->entries4)
+                return NULL;
+        for (i = 0; i < tp->md5sig_info->entries4; i++) {
+                if (tp->md5sig_info->keys4[i].addr == addr)
+                        return (struct tcp_md5sig_key *)
+                                                &tp->md5sig_info->keys4[i];
+        }
+        return NULL;
+}
+
+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)->daddr);
+}
+
+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);
+}
+
+/* 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)
+{
+        /* Add Key to the list */
+        struct tcp4_md5sig_key *key;
+        struct tcp_sock *tp = tcp_sk(sk);
+        struct tcp4_md5sig_key *keys;
+
+        key = (struct tcp4_md5sig_key *)tcp_v4_md5_do_lookup(sk, addr);
+        if (key) {
+                /* Pre-existing entry - just update that one. */
+                kfree(key->key);
+                key->key = newkey;
+                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;
+                        }
+                }
+                if (tcp_alloc_md5sig_pool() == NULL) {
+                        kfree(newkey);
+                        return -ENOMEM;
+                }
+                md5sig = tp->md5sig_info;
+
+                if (md5sig->alloced4 == md5sig->entries4) {
+                        keys = kmalloc((sizeof(*keys) *
+                                        (md5sig->entries4 + 1)), GFP_ATOMIC);
+                        if (!keys) {
+                                kfree(newkey);
+                                tcp_free_md5sig_pool();
+                                return -ENOMEM;
+                        }
+
+                        if (md5sig->entries4)
+                                memcpy(keys, md5sig->keys4,
+                                       sizeof(*keys) * md5sig->entries4);
+
+                        /* Free old key list, and reference new one */
+                        if (md5sig->keys4)
+                                kfree(md5sig->keys4);
+                        md5sig->keys4 = keys;
+                        md5sig->alloced4++;
+                }
+                md5sig->entries4++;
+                md5sig->keys4[md5sig->entries4 - 1].addr   = addr;
+                md5sig->keys4[md5sig->entries4 - 1].key    = newkey;
+                md5sig->keys4[md5sig->entries4 - 1].keylen = newkeylen;
+        }
+        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)->daddr,
+                                 newkey, newkeylen);
+}
+
+int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
+{
+        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].key);
+                        tp->md5sig_info->entries4--;
+
+                        if (tp->md5sig_info->entries4 == 0) {
+                                kfree(tp->md5sig_info->keys4);
+                                tp->md5sig_info->keys4 = NULL;
+                        } else if (tp->md5sig_info->entries4 != i) {
+                                /* Need to do some manipulation */
+                                memcpy(&tp->md5sig_info->keys4[i],
+                                       &tp->md5sig_info->keys4[i+1],
+                                       (tp->md5sig_info->entries4 - i) *
+                                        sizeof(struct tcp4_md5sig_key));
+                        }
+                        tcp_free_md5sig_pool();
+                        return 0;
+                }
+        }
+        return -ENOENT;
+}
+
+EXPORT_SYMBOL(tcp_v4_md5_do_del);
+
+static void tcp_v4_clear_md5_list(struct sock *sk)
+{
+        struct tcp_sock *tp = tcp_sk(sk);
+
+        /* 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].key);
+                tp->md5sig_info->entries4 = 0;
+                tcp_free_md5sig_pool();
+        }
+        if (tp->md5sig_info->keys4) {
+                kfree(tp->md5sig_info->keys4);
+                tp->md5sig_info->keys4 = NULL;
+                tp->md5sig_info->alloced4  = 0;
+        }
+}
+
+static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
+                                 int optlen)
+{
+        struct tcp_md5sig cmd;
+        struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
+        u8 *newkey;
+
+        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 (!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_keylen > TCP_MD5SIG_MAXKEYLEN)
+                return -EINVAL;
+
+        if (!tcp_sk(sk)->md5sig_info) {
+                struct tcp_sock *tp = tcp_sk(sk);
+                struct tcp_md5sig_info *p = kzalloc(sizeof(*p), GFP_KERNEL);
+
+                if (!p)
+                        return -EINVAL;
+
+                tp->md5sig_info = p;
+
+        }
+
+        newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
+        if (!newkey)
+                return -ENOMEM;
+        return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
+                                 newkey, cmd.tcpm_keylen);
+}
+
+static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
+                                   __be32 saddr, __be32 daddr,
+                                   struct tcphdr *th, int protocol,
+                                   int tcplen)
+{
+        struct scatterlist sg[4];
+        __u16 data_len;
+        int block = 0;
+        __sum16 old_checksum;
+        struct tcp_md5sig_pool *hp;
+        struct tcp4_pseudohdr *bp;
+        struct hash_desc *desc;
+        int err;
+        unsigned int nbytes = 0;
+
+        /*
+         * Okay, so RFC2385 is turned on for this connection,
+         * so we need to generate the MD5 hash for the packet now.
+         */
+
+        hp = tcp_get_md5sig_pool();
+        if (!hp)
+                goto clear_hash_noput;
+
+        bp = &hp->md5_blk.ip4;
+        desc = &hp->md5_desc;
+
+        /*
+         * 1. the TCP pseudo-header (in the order: source IP address,
+         * destination IP address, zero-padded protocol number, and
+         * segment length)
+         */
+        bp->saddr = saddr;
+        bp->daddr = daddr;
+        bp->pad = 0;
+        bp->protocol = protocol;
+        bp->len = htons(tcplen);
+        sg_set_buf(&sg[block++], bp, sizeof(*bp));
+        nbytes += sizeof(*bp);
+
+        /* 2. the TCP header, excluding options, and assuming a
+         * checksum of zero/
+         */
+        old_checksum = th->check;
+        th->check = 0;
+        sg_set_buf(&sg[block++], th, sizeof(struct tcphdr));
+        nbytes += sizeof(struct tcphdr);
+
+        /* 3. the TCP segment data (if any) */
+        data_len = tcplen - (th->doff << 2);
+        if (data_len > 0) {
+                unsigned char *data = (unsigned char *)th + (th->doff << 2);
+                sg_set_buf(&sg[block++], data, data_len);
+                nbytes += data_len;
+        }
+
+        /* 4. an independently-specified key or password, known to both
+         * TCPs and presumably connection-specific
+         */
+        sg_set_buf(&sg[block++], key->key, key->keylen);
+        nbytes += key->keylen;
+
+        /* Now store the Hash into the packet */
+        err = crypto_hash_init(desc);
+        if (err)
+                goto clear_hash;
+        err = crypto_hash_update(desc, sg, nbytes);
+        if (err)
+                goto clear_hash;
+        err = crypto_hash_final(desc, md5_hash);
+        if (err)
+                goto clear_hash;
+
+        /* Reset header, and free up the crypto */
+        tcp_put_md5sig_pool();
+        th->check = old_checksum;
+
+out:
+        return 0;
+clear_hash:
+        tcp_put_md5sig_pool();
+clear_hash_noput:
+        memset(md5_hash, 0, 16);
+        goto out;
+}
+
+int tcp_v4_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
+                         struct sock *sk,
+                         struct dst_entry *dst,
+                         struct request_sock *req,
+                         struct tcphdr *th, int protocol,
+                         int tcplen)
+{
+        __be32 saddr, daddr;
+
+        if (sk) {
+                saddr = inet_sk(sk)->saddr;
+                daddr = inet_sk(sk)->daddr;
+        } else {
+                struct rtable *rt = (struct rtable *)dst;
+                BUG_ON(!rt);
+                saddr = rt->rt_src;
+                daddr = rt->rt_dst;
+        }
+        return tcp_v4_do_calc_md5_hash(md5_hash, key,
+                                       saddr, daddr,
+                                       th, protocol, tcplen);
+}
+
+EXPORT_SYMBOL(tcp_v4_calc_md5_hash);
+
+static int tcp_v4_inbound_md5_hash(struct sock *sk, 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.
+         */
+        __u8 *hash_location = NULL;
+        struct tcp_md5sig_key *hash_expected;
+        struct iphdr *iph = skb->nh.iph;
+        struct tcphdr *th = skb->h.th;
+        int length = (th->doff << 2) - sizeof(struct tcphdr);
+        int genhash;
+        unsigned char *ptr;
+        unsigned char newhash[16];
+
+        hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
+
+        /*
+         * If the TCP option length is less than the TCP_MD5SIG
+         * option length, then we can shortcut
+         */
+        if (length < TCPOLEN_MD5SIG) {
+                if (hash_expected)
+                        return 1;
+                else
+                        return 0;
+        }
+
+        /* Okay, we can't shortcut - we have to grub through the options */
+        ptr = (unsigned char *)(th + 1);
+        while (length > 0) {
+                int opcode = *ptr++;
+                int opsize;
+
+                switch (opcode) {
+                case TCPOPT_EOL:
+                        goto done_opts;
+                case TCPOPT_NOP:
+                        length--;
+                        continue;
+                default:
+                        opsize = *ptr++;
+                        if (opsize < 2)
+                                goto done_opts;
+                        if (opsize > length)
+                                goto done_opts;
+
+                        if (opcode == TCPOPT_MD5SIG) {
+                                hash_location = ptr;
+                                goto done_opts;
+                        }
+                }
+                ptr += opsize-2;
+                length -= opsize;
+        }
+done_opts:
+        /* We've parsed the options - do we have a hash? */
+        if (!hash_expected && !hash_location)
+                return 0;
+
+        if (hash_expected && !hash_location) {
+                LIMIT_NETDEBUG(KERN_INFO "MD5 Hash NOT expected but found "
+                               "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
+                               NIPQUAD(iph->saddr), ntohs(th->source),
+                               NIPQUAD(iph->daddr), ntohs(th->dest));
+                return 1;
+        }
+
+        if (!hash_expected && hash_location) {
+                LIMIT_NETDEBUG(KERN_INFO "MD5 Hash NOT expected but found "
+                               "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
+                               NIPQUAD(iph->saddr), ntohs(th->source),
+                               NIPQUAD(iph->daddr), ntohs(th->dest));
+                return 1;
+        }
+
+        /* Okay, so this is hash_expected and hash_location -
+         * so we need to calculate the checksum.
+         */
+        genhash = tcp_v4_do_calc_md5_hash(newhash,
+                                          hash_expected,
+                                          iph->saddr, iph->daddr,
+                                          th, sk->sk_protocol,
+                                          skb->len);
+
+        if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+                if (net_ratelimit()) {
+                        printk(KERN_INFO "MD5 Hash failed for "
+                               "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)%s\n",
+                               NIPQUAD(iph->saddr), ntohs(th->source),
+                               NIPQUAD(iph->daddr), ntohs(th->dest),
+                               genhash ? " tcp_v4_calc_md5_hash failed" : "");
+                }
+                return 1;
+        }
+        return 0;
+}
+
+#endif
+
+struct request_sock_ops tcp_request_sock_ops __read_mostly = {
         .family         =       PF_INET,
         .obj_size       =       sizeof(struct tcp_request_sock),
         .rtx_syn_ack    =       tcp_v4_send_synack,
@@ -724,9 +1233,16 @@ struct request_sock_ops tcp_request_sock_ops = {
         .send_reset     =       tcp_v4_send_reset,
 };
 
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
+        .md5_lookup     =       tcp_v4_reqsk_md5_lookup,
+};
+#endif
+
 static struct timewait_sock_ops tcp_timewait_sock_ops = {
         .twsk_obj_size  = sizeof(struct tcp_timewait_sock),
         .twsk_unique    = tcp_twsk_unique,
+        .twsk_destructor= tcp_twsk_destructor,
 };
 
 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
@@ -774,6 +1290,10 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         if (!req)
                 goto drop;
 
+#ifdef CONFIG_TCP_MD5SIG
+        tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
+#endif
+
         tcp_clear_options(&tmp_opt);
         tmp_opt.mss_clamp = 536;
         tmp_opt.user_mss  = tcp_sk(sk)->rx_opt.user_mss;
@@ -859,7 +1379,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
                         goto drop_and_free;
                 }
 
-                isn = tcp_v4_init_sequence(sk, skb);
+                isn = tcp_v4_init_sequence(skb);
         }
         tcp_rsk(req)->snt_isn = isn;
 
@@ -892,6 +1412,9 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
         struct inet_sock *newinet;
         struct tcp_sock *newtp;
         struct sock *newsk;
+#ifdef CONFIG_TCP_MD5SIG
+        struct tcp_md5sig_key *key;
+#endif
 
         if (sk_acceptq_is_full(sk))
                 goto exit_overflow;
@@ -926,6 +1449,22 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
         tcp_initialize_rcv_mss(newsk);
 
+#ifdef CONFIG_TCP_MD5SIG
+        /* Copy over the MD5 key from the original socket */
+        if ((key = tcp_v4_md5_do_lookup(sk, newinet->daddr)) != NULL) {
+                /*
+                 * 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.
+                 */
+                char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
+                if (newkey != NULL)
+                        tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
+                                          newkey, key->keylen);
+        }
+#endif
+
         __inet_hash(&tcp_hashinfo, newsk, 0);
         __inet_inherit_port(&tcp_hashinfo, sk, newsk);
 
@@ -971,7 +1510,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
         return sk;
 }
 
-static int tcp_v4_checksum_init(struct sk_buff *skb)
+static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
 {
         if (skb->ip_summed == CHECKSUM_COMPLETE) {
                 if (!tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr,
@@ -1001,10 +1540,24 @@ static int tcp_v4_checksum_init(struct sk_buff *skb)
  */
 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
+        struct sock *rsk;
+#ifdef CONFIG_TCP_MD5SIG
+        /*
+         * We really want to reject the packet as early as possible
+         * if:
+         *  o We're expecting an MD5'd packet and this is no MD5 tcp option
+         *  o There is an MD5 option and we're not expecting one
+         */
+        if (tcp_v4_inbound_md5_hash(sk, skb))
+                goto discard;
+#endif
+
         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
                 TCP_CHECK_TIMER(sk);
-                if (tcp_rcv_established(sk, skb, skb->h.th, skb->len))
+                if (tcp_rcv_established(sk, skb, skb->h.th, skb->len)) {
+                        rsk = sk;
                         goto reset;
+                }
                 TCP_CHECK_TIMER(sk);
                 return 0;
         }
@@ -1018,20 +1571,24 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
                         goto discard;
 
                 if (nsk != sk) {
-                        if (tcp_child_process(sk, nsk, skb))
+                        if (tcp_child_process(sk, nsk, skb)) {
+                                rsk = nsk;
                                 goto reset;
+                        }
                         return 0;
                 }
         }
 
         TCP_CHECK_TIMER(sk);
-        if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len))
+        if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len)) {
+                rsk = sk;
                 goto reset;
+        }
         TCP_CHECK_TIMER(sk);
         return 0;
 
 reset:
-        tcp_v4_send_reset(skb);
+        tcp_v4_send_reset(rsk, skb);
 discard:
         kfree_skb(skb);
         /* Be careful here. If this function gets more complicated and
@@ -1140,7 +1697,7 @@ no_tcp_socket:
 bad_packet:
                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
         } else {
-                tcp_v4_send_reset(skb);
+                tcp_v4_send_reset(NULL, skb);
         }
 
 discard_it:
@@ -1263,6 +1820,15 @@ struct inet_connection_sock_af_ops ipv4_specific = {
 #endif
 };
 
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
+        .md5_lookup             = tcp_v4_md5_lookup,
+        .calc_md5_hash          = tcp_v4_calc_md5_hash,
+        .md5_add                = tcp_v4_md5_add_func,
+        .md5_parse              = tcp_v4_parse_md5_keys,
+};
+#endif
+
 /* NOTE: A lot of things set to zero explicitly by call to
  *       sk_alloc() so need not be done here.
  */
@@ -1302,6 +1868,9 @@ static int tcp_v4_init_sock(struct sock *sk)
 
         icsk->icsk_af_ops = &ipv4_specific;
         icsk->icsk_sync_mss = tcp_sync_mss;
+#ifdef CONFIG_TCP_MD5SIG
+        tp->af_specific = &tcp_sock_ipv4_specific;
+#endif
 
         sk->sk_sndbuf = sysctl_tcp_wmem[1];
         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
@@ -1325,6 +1894,15 @@ int tcp_v4_destroy_sock(struct sock *sk)
         /* Cleans up our, hopefully empty, out_of_order_queue. */
         __skb_queue_purge(&tp->out_of_order_queue);
 
+#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);
+                tp->md5sig_info = NULL;
+        }
+#endif
+
 #ifdef CONFIG_NET_DMA
         /* Cleans up our sk_async_wait_queue */
         __skb_queue_purge(&sk->sk_async_wait_queue);
@@ -1385,7 +1963,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
         if (st->state == TCP_SEQ_STATE_OPENREQ) {
                 struct request_sock *req = cur;
 
-                icsk = inet_csk(st->syn_wait_sk);
+                icsk = inet_csk(st->syn_wait_sk);
                 req = req->dl_next;
                 while (1) {
                         while (req) {
@@ -1395,7 +1973,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
                                 }
                                 req = req->dl_next;
                         }
-                        if (++st->sbucket >= TCP_SYNQ_HSIZE)
+                        if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
                                 break;
 get_req:
                         req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
@@ -1543,7 +2121,7 @@ static void *established_get_idx(struct seq_file *seq, loff_t pos)
         while (rc && pos) {
                 rc = established_get_next(seq, rc);
                 --pos;
-        }               
+        }
         return rc;
 }
 
@@ -1672,7 +2250,7 @@ int tcp_proc_register(struct tcp_seq_afinfo *afinfo)
         afinfo->seq_fops->read          = seq_read;
         afinfo->seq_fops->llseek        = seq_lseek;
         afinfo->seq_fops->release       = seq_release_private;
-        
+
         p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
         if (p)
                 p->data = afinfo;
@@ -1686,7 +2264,7 @@ void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo)
         if (!afinfo)
                 return;
         proc_net_remove(afinfo->name);
-        memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); 
+        memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
 }
 
 static void get_openreq4(struct sock *sk, struct request_sock *req,
@@ -1721,8 +2299,8 @@ static void get_tcp4_sock(struct sock *sp, char *tmpbuf, int i)
         struct tcp_sock *tp = tcp_sk(sp);
         const struct inet_connection_sock *icsk = inet_csk(sp);
         struct inet_sock *inet = inet_sk(sp);
-        unsigned int dest = inet->daddr;
-        unsigned int src = inet->rcv_saddr;
+        __be32 dest = inet->daddr;
+        __be32 src = inet->rcv_saddr;
         __u16 destp = ntohs(inet->dport);
         __u16 srcp = ntohs(inet->sport);
 
@@ -1744,7 +2322,8 @@ static void get_tcp4_sock(struct sock *sp, char *tmpbuf, int i)
                         "%08X %5d %8d %lu %d %p %u %u %u %u %d",
                 i, src, srcp, dest, destp, sp->sk_state,
                 tp->write_seq - tp->snd_una,
-                (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
+                sp->sk_state == TCP_LISTEN ? sp->sk_ack_backlog :
+                                             (tp->rcv_nxt - tp->copied_seq),
                 timer_active,
                 jiffies_to_clock_t(timer_expires - jiffies),
                 icsk->icsk_retransmits,
@@ -1759,7 +2338,8 @@ static void get_tcp4_sock(struct sock *sp, char *tmpbuf, int i)
                 tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh);
 }
 
-static void get_timewait4_sock(struct inet_timewait_sock *tw, char *tmpbuf, int i)
+static void get_timewait4_sock(struct inet_timewait_sock *tw,
+                               char *tmpbuf, int i)
 {
         __be32 dest, src;
         __u16 destp, srcp;
@@ -1872,7 +2452,8 @@ struct proto tcp_prot = {
 
 void __init tcp_v4_init(struct net_proto_family *ops)
 {
-        if (inet_csk_ctl_sock_create(&tcp_socket, PF_INET, SOCK_RAW, IPPROTO_TCP) < 0)
+        if (inet_csk_ctl_sock_create(&tcp_socket, PF_INET, SOCK_RAW,
+                                     IPPROTO_TCP) < 0)
                 panic("Failed to create the TCP control socket.\n");
 }