ipv6: Refactor update of IPv6 flowi destination address for srcrt (RH) option

There are more than a dozen occurrences of following code in the
IPv6 stack:

    if (opt && opt->srcrt) {
            struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
            ipv6_addr_copy(&final, &fl.fl6_dst);
            ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
            final_p = &final;
    }

Replace those with a helper. Note that the helper overrides final_p
in all cases. This is ok as final_p was previously initialized to
NULL when declared.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 2600b69..f5808d5 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -551,6 +551,10 @@ extern int                         ipv6_ext_hdr(u8 nexthdr);
 
 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 
+extern struct in6_addr *fl6_update_dst(struct flowi *fl,
+                                      const struct ipv6_txoptions *opt,
+                                      struct in6_addr *orig);
+
 /*
  *     socket options (ipv6_sockglue.c)
  */

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 0916988..6e3f325 100644 (file)
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -248,7 +248,7 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct sk_buff *skb;
        struct ipv6_txoptions *opt = NULL;
-       struct in6_addr *final_p = NULL, final;
+       struct in6_addr *final_p, final;
        struct flowi fl;
        int err = -1;
        struct dst_entry *dst;
@@ -265,13 +265,7 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
 
        opt = np->opt;
 
-       if (opt != NULL && opt->srcrt != NULL) {
-               const struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;
-
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, opt, &final);
 
        err = ip6_dst_lookup(sk, &dst, &fl);
        if (err)
@@ -545,19 +539,13 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
                goto out_overflow;
 
        if (dst == NULL) {
-               struct in6_addr *final_p = NULL, final;
+               struct in6_addr *final_p, final;
                struct flowi fl;
 
                memset(&fl, 0, sizeof(fl));
                fl.proto = IPPROTO_DCCP;
                ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
-               if (opt != NULL && opt->srcrt != NULL) {
-                       const struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;
-
-                       ipv6_addr_copy(&final, &fl.fl6_dst);
-                       ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                       final_p = &final;
-               }
+               final_p = fl6_update_dst(&fl, opt, &final);
                ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
                fl.oif = sk->sk_bound_dev_if;
                fl.fl_ip_dport = inet_rsk(req)->rmt_port;
@@ -885,7 +873,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct dccp_sock *dp = dccp_sk(sk);
-       struct in6_addr *saddr = NULL, *final_p = NULL, final;
+       struct in6_addr *saddr = NULL, *final_p, final;
        struct flowi fl;
        struct dst_entry *dst;
        int addr_type;
@@ -988,13 +976,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
        fl.fl_ip_sport = inet->inet_sport;
        security_sk_classify_flow(sk, &fl);
 
-       if (np->opt != NULL && np->opt->srcrt != NULL) {
-               const struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
-
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, np->opt, &final);
 
        err = ip6_dst_lookup(sk, &dst, &fl);
        if (err)

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index e733942..94b1b9c 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -651,7 +651,7 @@ int inet6_sk_rebuild_header(struct sock *sk)
 
        if (dst == NULL) {
                struct inet_sock *inet = inet_sk(sk);
-               struct in6_addr *final_p = NULL, final;
+               struct in6_addr *final_p, final;
                struct flowi fl;
 
                memset(&fl, 0, sizeof(fl));
@@ -665,12 +665,7 @@ int inet6_sk_rebuild_header(struct sock *sk)
                fl.fl_ip_sport = inet->inet_sport;
                security_sk_classify_flow(sk, &fl);
 
-               if (np->opt && np->opt->srcrt) {
-                       struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
-                       ipv6_addr_copy(&final, &fl.fl6_dst);
-                       ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                       final_p = &final;
-               }
+               final_p = fl6_update_dst(&fl, np->opt, &final);
 
                err = ip6_dst_lookup(sk, &dst, &fl);
                if (err) {

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 7126846..7d929a2 100644 (file)
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -38,10 +38,11 @@ int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
        struct inet_sock        *inet = inet_sk(sk);
        struct ipv6_pinfo       *np = inet6_sk(sk);
-       struct in6_addr         *daddr, *final_p = NULL, final;
+       struct in6_addr         *daddr, *final_p, final;
        struct dst_entry        *dst;
        struct flowi            fl;
        struct ip6_flowlabel    *flowlabel = NULL;
+       struct ipv6_txoptions   *opt;
        int                     addr_type;
        int                     err;
 
@@ -155,19 +156,8 @@ ipv4_connected:
 
        security_sk_classify_flow(sk, &fl);
 
-       if (flowlabel) {
-               if (flowlabel->opt && flowlabel->opt->srcrt) {
-                       struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
-                       ipv6_addr_copy(&final, &fl.fl6_dst);
-                       ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                       final_p = &final;
-               }
-       } else if (np->opt && np->opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       opt = flowlabel ? flowlabel->opt : np->opt;
+       final_p = fl6_update_dst(&fl, opt, &final);
 
        err = ip6_dst_lookup(sk, &dst, &fl);
        if (err)

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 8a659f9..853a633 100644 (file)
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -874,3 +874,27 @@ struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
        return opt;
 }
 
+/**
+ * fl6_update_dst - update flowi destination address with info given
+ *                  by srcrt option, if any.
+ *
+ * @fl: flowi for which fl6_dst is to be updated
+ * @opt: struct ipv6_txoptions in which to look for srcrt opt
+ * @orig: copy of original fl6_dst address if modified
+ *
+ * Returns NULL if no txoptions or no srcrt, otherwise returns orig
+ * and initial value of fl->fl6_dst set in orig
+ */
+struct in6_addr *fl6_update_dst(struct flowi *fl,
+                               const struct ipv6_txoptions *opt,
+                               struct in6_addr *orig)
+{
+       if (!opt || !opt->srcrt)
+               return NULL;
+
+       ipv6_addr_copy(orig, &fl->fl6_dst);
+       ipv6_addr_copy(&fl->fl6_dst, ((struct rt0_hdr *)opt->srcrt)->addr);
+       return orig;
+}
+
+EXPORT_SYMBOL_GPL(fl6_update_dst);

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 0c5e3c3..8a16280 100644 (file)
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -185,7 +185,7 @@ int inet6_csk_xmit(struct sk_buff *skb)
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct flowi fl;
        struct dst_entry *dst;
-       struct in6_addr *final_p = NULL, final;
+       struct in6_addr *final_p, final;
 
        memset(&fl, 0, sizeof(fl));
        fl.proto = sk->sk_protocol;
@@ -199,12 +199,7 @@ int inet6_csk_xmit(struct sk_buff *skb)
        fl.fl_ip_dport = inet->inet_dport;
        security_sk_classify_flow(sk, &fl);
 
-       if (np->opt && np->opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, np->opt, &final);
 
        dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 4a4dcbe..864eb8e 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -725,7 +725,7 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
 {
        struct ipv6_txoptions opt_space;
        struct sockaddr_in6 * sin6 = (struct sockaddr_in6 *) msg->msg_name;
-       struct in6_addr *daddr, *final_p = NULL, final;
+       struct in6_addr *daddr, *final_p, final;
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct raw6_sock *rp = raw6_sk(sk);
@@ -847,13 +847,7 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
        if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
                ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 
-       /* merge ip6_build_xmit from ip6_output */
-       if (opt && opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, opt, &final);
 
        if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
                fl.oif = np->mcast_oif;

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 34d1f06..1238370 100644 (file)
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -240,17 +240,12 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         * me if there is a preferred way.
         */
        {
-               struct in6_addr *final_p = NULL, final;
+               struct in6_addr *final_p, final;
                struct flowi fl;
                memset(&fl, 0, sizeof(fl));
                fl.proto = IPPROTO_TCP;
                ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
-               if (np->opt && np->opt->srcrt) {
-                       struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
-                       ipv6_addr_copy(&final, &fl.fl6_dst);
-                       ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                       final_p = &final;
-               }
+               final_p = fl6_update_dst(&fl, np->opt, &final);
                ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
                fl.oif = sk->sk_bound_dev_if;
                fl.mark = sk->sk_mark;

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2b7c3a1..e487080 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -129,7 +129,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
        struct inet_connection_sock *icsk = inet_csk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct tcp_sock *tp = tcp_sk(sk);
-       struct in6_addr *saddr = NULL, *final_p = NULL, final;
+       struct in6_addr *saddr = NULL, *final_p, final;
        struct flowi fl;
        struct dst_entry *dst;
        int addr_type;
@@ -250,12 +250,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
        fl.fl_ip_dport = usin->sin6_port;
        fl.fl_ip_sport = inet->inet_sport;
 
-       if (np->opt && np->opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, np->opt, &final);
 
        security_sk_classify_flow(sk, &fl);
 
@@ -477,7 +472,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct sk_buff * skb;
        struct ipv6_txoptions *opt = NULL;
-       struct in6_addr * final_p = NULL, final;
+       struct in6_addr * final_p, final;
        struct flowi fl;
        struct dst_entry *dst;
        int err = -1;
@@ -494,12 +489,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
        security_req_classify_flow(req, &fl);
 
        opt = np->opt;
-       if (opt && opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
-       }
+       final_p = fl6_update_dst(&fl, opt, &final);
 
        err = ip6_dst_lookup(sk, &dst, &fl);
        if (err)
@@ -1392,18 +1382,13 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                goto out_overflow;
 
        if (dst == NULL) {
-               struct in6_addr *final_p = NULL, final;
+               struct in6_addr *final_p, final;
                struct flowi fl;
 
                memset(&fl, 0, sizeof(fl));
                fl.proto = IPPROTO_TCP;
                ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
-               if (opt && opt->srcrt) {
-                       struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
-                       ipv6_addr_copy(&final, &fl.fl6_dst);
-                       ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                       final_p = &final;
-               }
+               final_p = fl6_update_dst(&fl, opt, &final);
                ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
                fl.oif = sk->sk_bound_dev_if;
                fl.mark = sk->sk_mark;

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 3048f90..4aea57d 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -929,7 +929,7 @@ int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
-       struct in6_addr *daddr, *final_p = NULL, final;
+       struct in6_addr *daddr, *final_p, final;
        struct ipv6_txoptions *opt = NULL;
        struct ip6_flowlabel *flowlabel = NULL;
        struct flowi fl;
@@ -1099,14 +1099,9 @@ do_udp_sendmsg:
                ipv6_addr_copy(&fl.fl6_src, &np->saddr);
        fl.fl_ip_sport = inet->inet_sport;
 
-       /* merge ip6_build_xmit from ip6_output */
-       if (opt && opt->srcrt) {
-               struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
-               ipv6_addr_copy(&final, &fl.fl6_dst);
-               ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-               final_p = &final;
+       final_p = fl6_update_dst(&fl, opt, &final);
+       if (final_p)
                connected = 0;
-       }
 
        if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
                fl.oif = np->mcast_oif;