ipv4: Pass flow keys down into datagram packet building engine.

This way ip_output.c no longer needs rt->rt_{src,dst}.

We already have these keys sitting, ready and waiting, on the stack or
in a socket structure.

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 91 insertions, 93 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index acf8b7814c4e..a4253795c5c5 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -117,12 +117,14 @@ extern int		ip_generic_getfrag(void *from, char *to, int offset, int len, int od
 extern ssize_t          ip_append_page(struct sock *sk, struct page *page,
                                 int offset, size_t size, int flags);
 extern struct sk_buff  *__ip_make_skb(struct sock *sk,
+                                      struct flowi4 *fl4,
                                       struct sk_buff_head *queue,
                                       struct inet_cork *cork);
 extern int              ip_send_skb(struct sk_buff *skb);
-extern int              ip_push_pending_frames(struct sock *sk);
+extern int              ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 extern void             ip_flush_pending_frames(struct sock *sk);
 extern struct sk_buff  *ip_make_skb(struct sock *sk,
+                                    struct flowi4 *fl4,
                                     int getfrag(void *from, char *to, int offset, int len,
                                                 int odd, struct sk_buff *skb),
                                     void *from, int length, int transhdrlen,
@@ -130,9 +132,9 @@ extern struct sk_buff  *ip_make_skb(struct sock *sk,
                                     struct rtable **rtp,
                                     unsigned int flags);
 
-static inline struct sk_buff *ip_finish_skb(struct sock *sk)
+static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 {
-        return __ip_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
+        return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 }
 
 /* datagram.c */
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index cfeca3c2152d..be5cc8d04c00 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -290,6 +290,7 @@ static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
 }
 
 static void icmp_push_reply(struct icmp_bxm *icmp_param,
+                            struct flowi4 *fl4,
                             struct ipcm_cookie *ipc, struct rtable **rt)
 {
         struct sock *sk;
@@ -315,7 +316,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
                                                  icmp_param->head_len, csum);
                 icmph->checksum = csum_fold(csum);
                 skb->ip_summed = CHECKSUM_NONE;
-                ip_push_pending_frames(sk);
+                ip_push_pending_frames(sk, fl4);
         }
 }
 
@@ -328,6 +329,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
         struct ipcm_cookie ipc;
         struct rtable *rt = skb_rtable(skb);
         struct net *net = dev_net(rt->dst.dev);
+        struct flowi4 fl4;
         struct sock *sk;
         struct inet_sock *inet;
         __be32 daddr;
@@ -351,57 +353,52 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
                 if (ipc.opt->opt.srr)
                         daddr = icmp_param->replyopts.opt.opt.faddr;
         }
-        {
-                struct flowi4 fl4 = {
-                        .daddr = daddr,
-                        .saddr = rt->rt_spec_dst,
-                        .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
-                        .flowi4_proto = IPPROTO_ICMP,
-                };
-                security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
-                rt = ip_route_output_key(net, &fl4);
-                if (IS_ERR(rt))
-                        goto out_unlock;
-        }
+        memset(&fl4, 0, sizeof(fl4));
+        fl4.daddr = daddr;
+        fl4.saddr = rt->rt_spec_dst;
+        fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
+        fl4.flowi4_proto = IPPROTO_ICMP;
+        security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
+        rt = ip_route_output_key(net, &fl4);
+        if (IS_ERR(rt))
+                goto out_unlock;
         if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type,
                                icmp_param->data.icmph.code))
-                icmp_push_reply(icmp_param, &ipc, &rt);
+                icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
         ip_rt_put(rt);
 out_unlock:
         icmp_xmit_unlock(sk);
 }
 
-static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
+static struct rtable *icmp_route_lookup(struct net *net,
+                                        struct flowi4 *fl4,
+                                        struct sk_buff *skb_in,
                                         const struct iphdr *iph,
                                         __be32 saddr, u8 tos,
                                         int type, int code,
                                         struct icmp_bxm *param)
 {
-        struct flowi4 fl4 = {
-                .daddr = (param->replyopts.opt.opt.srr ?
-                          param->replyopts.opt.opt.faddr : iph->saddr),
-                .saddr = saddr,
-                .flowi4_tos = RT_TOS(tos),
-                .flowi4_proto = IPPROTO_ICMP,
-                .fl4_icmp_type = type,
-                .fl4_icmp_code = code,
-        };
         struct rtable *rt, *rt2;
         int err;
 
-        security_skb_classify_flow(skb_in, flowi4_to_flowi(&fl4));
-        rt = __ip_route_output_key(net, &fl4);
+        memset(fl4, 0, sizeof(*fl4));
+        fl4->daddr = (param->replyopts.opt.opt.srr ?
+                      param->replyopts.opt.opt.faddr : iph->saddr);
+        fl4->saddr = saddr;
+        fl4->flowi4_tos = RT_TOS(tos);
+        fl4->flowi4_proto = IPPROTO_ICMP;
+        fl4->fl4_icmp_type = type;
+        fl4->fl4_icmp_code = code;
+        security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
+        rt = __ip_route_output_key(net, fl4);
         if (IS_ERR(rt))
                 return rt;
 
         /* No need to clone since we're just using its address. */
         rt2 = rt;
 
-        if (!fl4.saddr)
-                fl4.saddr = rt->rt_src;
-
         rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
-                                           flowi4_to_flowi(&fl4), NULL, 0);
+                                           flowi4_to_flowi(fl4), NULL, 0);
         if (!IS_ERR(rt)) {
                 if (rt != rt2)
                         return rt;
@@ -410,19 +407,19 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
         } else
                 return rt;
 
-        err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4), AF_INET);
+        err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(fl4), AF_INET);
         if (err)
                 goto relookup_failed;
 
-        if (inet_addr_type(net, fl4.saddr) == RTN_LOCAL) {
-                rt2 = __ip_route_output_key(net, &fl4);
+        if (inet_addr_type(net, fl4->saddr) == RTN_LOCAL) {
+                rt2 = __ip_route_output_key(net, fl4);
                 if (IS_ERR(rt2))
                         err = PTR_ERR(rt2);
         } else {
                 struct flowi4 fl4_2 = {};
                 unsigned long orefdst;
 
-                fl4_2.daddr = fl4.saddr;
+                fl4_2.daddr = fl4->saddr;
                 rt2 = ip_route_output_key(net, &fl4_2);
                 if (IS_ERR(rt2)) {
                         err = PTR_ERR(rt2);
@@ -430,7 +427,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
                 }
                 /* Ugh! */
                 orefdst = skb_in->_skb_refdst; /* save old refdst */
-                err = ip_route_input(skb_in, fl4.daddr, fl4.saddr,
+                err = ip_route_input(skb_in, fl4->daddr, fl4->saddr,
                                      RT_TOS(tos), rt2->dst.dev);
 
                 dst_release(&rt2->dst);
@@ -442,7 +439,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
                 goto relookup_failed;
 
         rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
-                                            flowi4_to_flowi(&fl4), NULL,
+                                            flowi4_to_flowi(fl4), NULL,
                                             XFRM_LOOKUP_ICMP);
         if (!IS_ERR(rt2)) {
                 dst_release(&rt->dst);
@@ -481,6 +478,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
         struct icmp_bxm icmp_param;
         struct rtable *rt = skb_rtable(skb_in);
         struct ipcm_cookie ipc;
+        struct flowi4 fl4;
         __be32 saddr;
         u8  tos;
         struct net *net;
@@ -599,7 +597,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
         ipc.opt = &icmp_param.replyopts.opt;
         ipc.tx_flags = 0;
 
-        rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
+        rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos,
                                type, code, &icmp_param);
         if (IS_ERR(rt))
                 goto out_unlock;
@@ -620,7 +618,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
                 icmp_param.data_len = room;
         icmp_param.head_len = sizeof(struct icmphdr);
 
-        icmp_push_reply(&icmp_param, &ipc, &rt);
+        icmp_push_reply(&icmp_param, &fl4, &ipc, &rt);
 ende:
         ip_rt_put(rt);
 out_unlock:
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index b88ee5fdcbca..dca637b9d8ae 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1267,6 +1267,7 @@ static void ip_cork_release(struct inet_cork *cork)
  *      and push them out.
  */
 struct sk_buff *__ip_make_skb(struct sock *sk,
+                              struct flowi4 *fl4,
                               struct sk_buff_head *queue,
                               struct inet_cork *cork)
 {
@@ -1333,8 +1334,8 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
         ip_select_ident(iph, &rt->dst, sk);
         iph->ttl = ttl;
         iph->protocol = sk->sk_protocol;
-        iph->saddr = rt->rt_src;
-        iph->daddr = rt->rt_dst;
+        iph->saddr = fl4->saddr;
+        iph->daddr = fl4->daddr;
 
         skb->priority = sk->sk_priority;
         skb->mark = sk->sk_mark;
@@ -1370,11 +1371,11 @@ int ip_send_skb(struct sk_buff *skb)
         return err;
 }
 
-int ip_push_pending_frames(struct sock *sk)
+int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4)
 {
         struct sk_buff *skb;
 
-        skb = ip_finish_skb(sk);
+        skb = ip_finish_skb(sk, fl4);
         if (!skb)
                 return 0;
 
@@ -1403,6 +1404,7 @@ void ip_flush_pending_frames(struct sock *sk)
 }
 
 struct sk_buff *ip_make_skb(struct sock *sk,
+                            struct flowi4 *fl4,
                             int getfrag(void *from, char *to, int offset,
                                         int len, int odd, struct sk_buff *skb),
                             void *from, int length, int transhdrlen,
@@ -1432,7 +1434,7 @@ struct sk_buff *ip_make_skb(struct sock *sk,
                 return ERR_PTR(err);
         }
 
-        return __ip_make_skb(sk, &queue, &cork);
+        return __ip_make_skb(sk, fl4, &queue, &cork);
 }
 
 /*
@@ -1461,6 +1463,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
         struct inet_sock *inet = inet_sk(sk);
         struct ip_options_data replyopts;
         struct ipcm_cookie ipc;
+        struct flowi4 fl4;
         __be32 daddr;
         struct rtable *rt = skb_rtable(skb);
 
@@ -1478,20 +1481,16 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
                         daddr = replyopts.opt.opt.faddr;
         }
 
-        {
-                struct flowi4 fl4;
-
-                flowi4_init_output(&fl4, arg->bound_dev_if, 0,
-                                   RT_TOS(ip_hdr(skb)->tos),
-                                   RT_SCOPE_UNIVERSE, sk->sk_protocol,
-                                   ip_reply_arg_flowi_flags(arg),
-                                   daddr, rt->rt_spec_dst,
-                                   tcp_hdr(skb)->source, tcp_hdr(skb)->dest);
-                security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
-                rt = ip_route_output_key(sock_net(sk), &fl4);
-                if (IS_ERR(rt))
-                        return;
-        }
+        flowi4_init_output(&fl4, arg->bound_dev_if, 0,
+                           RT_TOS(ip_hdr(skb)->tos),
+                           RT_SCOPE_UNIVERSE, sk->sk_protocol,
+                           ip_reply_arg_flowi_flags(arg),
+                           daddr, rt->rt_spec_dst,
+                           tcp_hdr(skb)->source, tcp_hdr(skb)->dest);
+        security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
+        rt = ip_route_output_key(sock_net(sk), &fl4);
+        if (IS_ERR(rt))
+                return;
 
         /* And let IP do all the hard work.
 
@@ -1512,7 +1511,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
                           arg->csumoffset) = csum_fold(csum_add(skb->csum,
                                                                 arg->csum));
                 skb->ip_summed = CHECKSUM_NONE;
-                ip_push_pending_frames(sk);
+                ip_push_pending_frames(sk, &fl4);
         }
 
         bh_unlock_sock(sk);
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index a8659e0c4a6e..6fee91f656a9 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -314,9 +314,10 @@ int raw_rcv(struct sock *sk, struct sk_buff *skb)
         return 0;
 }
 
-static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
-                        struct rtable **rtp,
-                        unsigned int flags)
+static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
+                           void *from, size_t length,
+                           struct rtable **rtp,
+                           unsigned int flags)
 {
         struct inet_sock *inet = inet_sk(sk);
         struct net *net = sock_net(sk);
@@ -327,7 +328,7 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
         struct rtable *rt = *rtp;
 
         if (length > rt->dst.dev->mtu) {
-                ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->inet_dport,
+                ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,
                                rt->dst.dev->mtu);
                 return -EMSGSIZE;
         }
@@ -372,7 +373,7 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
 
         if (iphlen >= sizeof(*iph)) {
                 if (!iph->saddr)
-                        iph->saddr = rt->rt_src;
+                        iph->saddr = fl4->saddr;
                 iph->check   = 0;
                 iph->tot_len = htons(length);
                 if (!iph->id)
@@ -455,6 +456,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
         struct inet_sock *inet = inet_sk(sk);
         struct ipcm_cookie ipc;
         struct rtable *rt = NULL;
+        struct flowi4 fl4;
         int free = 0;
         __be32 daddr;
         __be32 saddr;
@@ -558,27 +560,23 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                         saddr = inet->mc_addr;
         }
 
-        {
-                struct flowi4 fl4;
+        flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
+                           RT_SCOPE_UNIVERSE,
+                           inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
+                           FLOWI_FLAG_CAN_SLEEP, daddr, saddr, 0, 0);
 
-                flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
-                                   RT_SCOPE_UNIVERSE,
-                                   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
-                                   FLOWI_FLAG_CAN_SLEEP, daddr, saddr, 0, 0);
-
-                if (!inet->hdrincl) {
-                        err = raw_probe_proto_opt(&fl4, msg);
-                        if (err)
-                                goto done;
-                }
-
-                security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
-                rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
-                if (IS_ERR(rt)) {
-                        err = PTR_ERR(rt);
-                        rt = NULL;
+        if (!inet->hdrincl) {
+                err = raw_probe_proto_opt(&fl4, msg);
+                if (err)
                         goto done;
-                }
+        }
+
+        security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
+        rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+        if (IS_ERR(rt)) {
+                err = PTR_ERR(rt);
+                rt = NULL;
+                goto done;
         }
 
         err = -EACCES;
@@ -590,19 +588,20 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 back_from_confirm:
 
         if (inet->hdrincl)
-                err = raw_send_hdrinc(sk, msg->msg_iov, len,
-                                        &rt, msg->msg_flags);
+                err = raw_send_hdrinc(sk, &fl4, msg->msg_iov, len,
+                                      &rt, msg->msg_flags);
 
          else {
                 if (!ipc.addr)
-                        ipc.addr = rt->rt_dst;
+                        ipc.addr = fl4.daddr;
                 lock_sock(sk);
-                err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, len, 0,
-                                        &ipc, &rt, msg->msg_flags);
+                err = ip_append_data(sk, ip_generic_getfrag,
+                                     msg->msg_iov, len, 0,
+                                     &ipc, &rt, msg->msg_flags);
                 if (err)
                         ip_flush_pending_frames(sk);
                 else if (!(msg->msg_flags & MSG_MORE)) {
-                        err = ip_push_pending_frames(sk);
+                        err = ip_push_pending_frames(sk, &fl4);
                         if (err == -ENOBUFS && !inet->recverr)
                                 err = 0;
                 }
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ba9f137f5aa7..006e2ccd6cc2 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -774,7 +774,7 @@ static int udp_push_pending_frames(struct sock *sk)
         struct sk_buff *skb;
         int err = 0;
 
-        skb = ip_finish_skb(sk);
+        skb = ip_finish_skb(sk, fl4);
         if (!skb)
                 goto out;
 
@@ -958,7 +958,7 @@ back_from_confirm:
 
         /* Lockless fast path for the non-corking case. */
         if (!corkreq) {
-                skb = ip_make_skb(sk, getfrag, msg->msg_iov, ulen,
+                skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
                                   sizeof(struct udphdr), &ipc, &rt,
                                   msg->msg_flags);
                 err = PTR_ERR(skb);