1 files changed, 33 insertions, 131 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f2926ae1de57..9088d709725e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -93,8 +93,13 @@ 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,
-                                   unsigned int tcplen);
+                                   struct tcphdr *th, unsigned int tcplen);
+#else
+static inline
+struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
+{
+        return NULL;
+}
 #endif
 
 struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
@@ -584,8 +589,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
                                         key,
                                         ip_hdr(skb)->daddr,
                                         ip_hdr(skb)->saddr,
-                                        &rep.th, IPPROTO_TCP,
-                                        arg.iov[0].iov_len);
+                                        &rep.th, arg.iov[0].iov_len);
         }
 #endif
         arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
@@ -604,9 +608,9 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
    outside socket context is ugly, certainly. What can I do?
  */
 
-static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
-                            struct sk_buff *skb, u32 seq, u32 ack,
-                            u32 win, u32 ts)
+static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
+                            u32 win, u32 ts, int oif,
+                            struct tcp_md5sig_key *key)
 {
         struct tcphdr *th = tcp_hdr(skb);
         struct {
@@ -618,10 +622,6 @@ static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
                         ];
         } 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));
@@ -647,23 +647,6 @@ static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
         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, ip_hdr(skb)->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;
 
@@ -678,16 +661,15 @@ static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
                                         key,
                                         ip_hdr(skb)->daddr,
                                         ip_hdr(skb)->saddr,
-                                        &rep.th, IPPROTO_TCP,
-                                        arg.iov[0].iov_len);
+                                        &rep.th, arg.iov[0].iov_len);
         }
 #endif
         arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
                                       ip_hdr(skb)->saddr, /* XXX */
                                       arg.iov[0].iov_len, IPPROTO_TCP, 0);
         arg.csumoffset = offsetof(struct tcphdr, check) / 2;
-        if (twsk)
-                arg.bound_dev_if = twsk->tw_sk.tw_bound_dev_if;
+        if (oif)
+                arg.bound_dev_if = oif;
 
         ip_send_reply(dev_net(skb->dev)->ipv4.tcp_sock, skb,
                       &arg, arg.iov[0].iov_len);
@@ -700,9 +682,12 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
         struct inet_timewait_sock *tw = inet_twsk(sk);
         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 
-        tcp_v4_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+        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);
+                        tcptw->tw_ts_recent,
+                        tw->tw_bound_dev_if,
+                        tcp_twsk_md5_key(tcptw)
+                        );
 
         inet_twsk_put(tw);
 }
@@ -710,9 +695,11 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 static void tcp_v4_reqsk_send_ack(struct sk_buff *skb,
                                   struct request_sock *req)
 {
-        tcp_v4_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1,
+        tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
                         tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
-                        req->ts_recent);
+                        req->ts_recent,
+                        0,
+                        tcp_v4_md5_do_lookup(skb->sk, ip_hdr(skb)->daddr));
 }
 
 /*
@@ -1004,18 +991,12 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
 
 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,
+                                   struct tcphdr *th,
                                    unsigned 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,
@@ -1027,63 +1008,25 @@ static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
                 goto clear_hash_noput;
 
         bp = &hp->md5_blk.ip4;
-        desc = &hp->md5_desc;
 
         /*
-         * 1. the TCP pseudo-header (in the order: source IP address,
+         * 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->protocol = IPPROTO_TCP;
         bp->len = htons(tcplen);
 
-        sg_init_table(sg, 4);
-
-        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;
-
-        sg_mark_end(&sg[block - 1]);
-
-        /* 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);
+        err = tcp_calc_md5_hash(md5_hash, key, sizeof(*bp),
+                                th, tcplen, hp);
         if (err)
                 goto clear_hash;
 
-        /* Reset header, and free up the crypto */
+        /* Free up the crypto pool */
         tcp_put_md5sig_pool();
-        th->check = old_checksum;
-
 out:
         return 0;
 clear_hash:
@@ -1097,7 +1040,7 @@ 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,
+                         struct tcphdr *th,
                          unsigned int tcplen)
 {
         __be32 saddr, daddr;
@@ -1113,7 +1056,7 @@ int tcp_v4_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
         }
         return tcp_v4_do_calc_md5_hash(md5_hash, key,
                                        saddr, daddr,
-                                       th, protocol, tcplen);
+                                       th, tcplen);
 }
 
 EXPORT_SYMBOL(tcp_v4_calc_md5_hash);
@@ -1132,52 +1075,12 @@ static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
         struct tcp_md5sig_key *hash_expected;
         const struct iphdr *iph = ip_hdr(skb);
         struct tcphdr *th = tcp_hdr(skb);
-        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);
+        hash_location = tcp_parse_md5sig_option(th);
 
-        /*
-         * 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;
@@ -1204,8 +1107,7 @@ done_opts:
         genhash = tcp_v4_do_calc_md5_hash(newhash,
                                           hash_expected,
                                           iph->saddr, iph->daddr,
-                                          th, sk->sk_protocol,
-                                          skb->len);
+                                          th, skb->len);
 
         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
                 if (net_ratelimit()) {