inet: add RCU protection to inet->opt

[cascardo/linux.git] / net / ipv4 / ip_output.c

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 67f241b..362e66f 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -140,14 +140,14 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
  *
  */
 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
-                         __be32 saddr, __be32 daddr, struct ip_options *opt)
+                         __be32 saddr, __be32 daddr, struct ip_options_rcu *opt)
 {
        struct inet_sock *inet = inet_sk(sk);
        struct rtable *rt = skb_rtable(skb);
        struct iphdr *iph;
 
        /* Build the IP header. */
-       skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+       skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0));
        skb_reset_network_header(skb);
        iph = ip_hdr(skb);
        iph->version  = 4;
@@ -163,9 +163,9 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
        iph->protocol = sk->sk_protocol;
        ip_select_ident(iph, &rt->dst, sk);
 
-       if (opt && opt->optlen) {
-               iph->ihl += opt->optlen>>2;
-               ip_options_build(skb, opt, daddr, rt, 0);
+       if (opt && opt->opt.optlen) {
+               iph->ihl += opt->opt.optlen>>2;
+               ip_options_build(skb, &opt->opt, daddr, rt, 0);
        }
 
        skb->priority = sk->sk_priority;
@@ -316,7 +316,7 @@ int ip_queue_xmit(struct sk_buff *skb)
 {
        struct sock *sk = skb->sk;
        struct inet_sock *inet = inet_sk(sk);
-       struct ip_options *opt = inet->opt;
+       struct ip_options_rcu *inet_opt;
        struct rtable *rt;
        struct iphdr *iph;
        int res;
@@ -325,6 +325,7 @@ int ip_queue_xmit(struct sk_buff *skb)
         * f.e. by something like SCTP.
         */
        rcu_read_lock();
+       inet_opt = rcu_dereference(inet->inet_opt);
        rt = skb_rtable(skb);
        if (rt != NULL)
                goto packet_routed;
@@ -336,8 +337,8 @@ int ip_queue_xmit(struct sk_buff *skb)
 
                /* Use correct destination address if we have options. */
                daddr = inet->inet_daddr;
-               if(opt && opt->srr)
-                       daddr = opt->faddr;
+               if (inet_opt && inet_opt->opt.srr)
+                       daddr = inet_opt->opt.faddr;
 
                /* If this fails, retransmit mechanism of transport layer will
                 * keep trying until route appears or the connection times
@@ -357,11 +358,11 @@ int ip_queue_xmit(struct sk_buff *skb)
        skb_dst_set_noref(skb, &rt->dst);
 
 packet_routed:
-       if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+       if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway)
                goto no_route;
 
        /* OK, we know where to send it, allocate and build IP header. */
-       skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+       skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0));
        skb_reset_network_header(skb);
        iph = ip_hdr(skb);
        *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
@@ -375,9 +376,9 @@ packet_routed:
        iph->daddr    = rt->rt_dst;
        /* Transport layer set skb->h.foo itself. */
 
-       if (opt && opt->optlen) {
-               iph->ihl += opt->optlen >> 2;
-               ip_options_build(skb, opt, inet->inet_daddr, rt, 0);
+       if (inet_opt && inet_opt->opt.optlen) {
+               iph->ihl += inet_opt->opt.optlen >> 2;
+               ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
        }
 
        ip_select_ident_more(iph, &rt->dst, sk,
@@ -603,7 +604,7 @@ slow_path:
                /* IF: it doesn't fit, use 'mtu' - the data space left */
                if (len > mtu)
                        len = mtu;
-               /* IF: we are not sending upto and including the packet end
+               /* IF: we are not sending up to and including the packet end
                   then align the next start on an eight byte boundary */
                if (len < left) {
                        len &= ~7;
@@ -1033,7 +1034,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
                         struct ipcm_cookie *ipc, struct rtable **rtp)
 {
        struct inet_sock *inet = inet_sk(sk);
-       struct ip_options *opt;
+       struct ip_options_rcu *opt;
        struct rtable *rt;
 
        /*
@@ -1047,7 +1048,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
                        if (unlikely(cork->opt == NULL))
                                return -ENOBUFS;
                }
-               memcpy(cork->opt, opt, sizeof(struct ip_options) + opt->optlen);
+               memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen);
                cork->flags |= IPCORK_OPT;
                cork->addr = ipc->addr;
        }
@@ -1451,39 +1452,34 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
                   unsigned int len)
 {
        struct inet_sock *inet = inet_sk(sk);
-       struct {
-               struct ip_options       opt;
-               char                    data[40];
-       } replyopts;
+       struct ip_options_data replyopts;
        struct ipcm_cookie ipc;
        __be32 daddr;
        struct rtable *rt = skb_rtable(skb);
 
-       if (ip_options_echo(&replyopts.opt, skb))
+       if (ip_options_echo(&replyopts.opt.opt, skb))
                return;
 
        daddr = ipc.addr = rt->rt_src;
        ipc.opt = NULL;
        ipc.tx_flags = 0;
 
-       if (replyopts.opt.optlen) {
+       if (replyopts.opt.opt.optlen) {
                ipc.opt = &replyopts.opt;
 
-               if (ipc.opt->srr)
-                       daddr = replyopts.opt.faddr;
+               if (replyopts.opt.opt.srr)
+                       daddr = replyopts.opt.opt.faddr;
        }
 
        {
-               struct flowi4 fl4 = {
-                       .flowi4_oif = arg->bound_dev_if,
-                       .daddr = daddr,
-                       .saddr = rt->rt_spec_dst,
-                       .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
-                       .fl4_sport = tcp_hdr(skb)->dest,
-                       .fl4_dport = tcp_hdr(skb)->source,
-                       .flowi4_proto = sk->sk_protocol,
-                       .flowi4_flags = ip_reply_arg_flowi_flags(arg),
-               };
+               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))