tcp md5sig: Share MD5 Signature option parser between IPv4 and IPv6.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 633147c..b1c4b78 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -399,6 +399,8 @@ extern void                 tcp_parse_options(struct sk_buff *skb,
                                                  struct tcp_options_received *opt_rx,
                                                  int estab);
 
+extern u8                      *tcp_parse_md5sig_option(struct tcphdr *th);
+
 /*
  *     TCP v4 functions exported for the inet6 API
  */

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index eba873e..f331e67 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3450,6 +3450,43 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
        return 1;
 }
 
+#ifdef CONFIG_TCP_MD5SIG
+/*
+ * Parse MD5 Signature option
+ */
+u8 *tcp_parse_md5sig_option(struct tcphdr *th)
+{
+       int length = (th->doff << 2) - sizeof (*th);
+       u8 *ptr = (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 ptr;
+               }
+               ptr += opsize - 2;
+               length -= opsize;
+       }
+       return NULL;
+}
+#endif
+
 static inline void tcp_store_ts_recent(struct tcp_sock *tp)
 {
        tp->rx_opt.ts_recent = tp->rx_opt.rcv_tsval;
@@ -5467,6 +5504,9 @@ EXPORT_SYMBOL(sysctl_tcp_ecn);
 EXPORT_SYMBOL(sysctl_tcp_reordering);
 EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
 EXPORT_SYMBOL(tcp_parse_options);
+#ifdef CONFIG_TCP_MD5SIG
+EXPORT_SYMBOL(tcp_parse_md5sig_option);
+#endif
 EXPORT_SYMBOL(tcp_rcv_established);
 EXPORT_SYMBOL(tcp_rcv_state_process);
 EXPORT_SYMBOL(tcp_initialize_rcv_mss);

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index cd601a8..56f5509 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1134,52 +1134,12 @@ 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;

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 715965f..dd4ddb3 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -844,43 +844,12 @@ static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
        struct tcp_md5sig_key *hash_expected;
        struct ipv6hdr *ip6h = ipv6_hdr(skb);
        struct tcphdr *th = tcp_hdr(skb);
-       int length = (th->doff << 2) - sizeof (*th);
        int genhash;
-       u8 *ptr;
        u8 newhash[16];
 
        hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
+       hash_location = tcp_parse_md5sig_option(th);
 
-       /* If the TCP option is too short, we can short cut */
-       if (length < TCPOLEN_MD5SIG)
-               return hash_expected ? 1 : 0;
-
-       /* parse options */
-       ptr = (u8*)(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 || opsize > length)
-                               goto done_opts;
-                       if (opcode == TCPOPT_MD5SIG) {
-                               hash_location = ptr;
-                               goto done_opts;
-                       }
-               }
-               ptr += opsize - 2;
-               length -= opsize;
-       }
-
-done_opts:
        /* do we have a hash as expected? */
        if (!hash_expected) {
                if (!hash_location)