Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszere...

[karo-tx-linux.git] / net / ipv4 / ip_output.c

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 8d91b922fcfe74ea6c46d251928f02c350feedf2..6bf89a6312bc1c71da41ad0a1ebdbf819504367d 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -84,6 +84,7 @@ int sysctl_ip_default_ttl __read_mostly = IPDEFTTL;
 EXPORT_SYMBOL(sysctl_ip_default_ttl);
 
 static int ip_fragment(struct sock *sk, struct sk_buff *skb,
+                      unsigned int mtu,
                       int (*output)(struct sock *, struct sk_buff *));
 
 /* Generate a checksum for an outgoing IP datagram. */
@@ -171,7 +172,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
 }
 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt);
 
-static inline int ip_finish_output2(struct sock *sk, struct sk_buff *skb)
+static int ip_finish_output2(struct sock *sk, struct sk_buff *skb)
 {
        struct dst_entry *dst = skb_dst(skb);
        struct rtable *rt = (struct rtable *)dst;
@@ -219,7 +220,8 @@ static inline int ip_finish_output2(struct sock *sk, struct sk_buff *skb)
        return -EINVAL;
 }
 
-static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb)
+static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb,
+                               unsigned int mtu)
 {
        netdev_features_t features;
        struct sk_buff *segs;
@@ -227,7 +229,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb)
 
        /* common case: locally created skb or seglen is <= mtu */
        if (((IPCB(skb)->flags & IPSKB_FORWARDED) == 0) ||
-             skb_gso_network_seglen(skb) <= ip_skb_dst_mtu(skb))
+             skb_gso_network_seglen(skb) <= mtu)
                return ip_finish_output2(sk, skb);
 
        /* Slowpath -  GSO segment length is exceeding the dst MTU.
@@ -251,7 +253,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb)
                int err;
 
                segs->next = NULL;
-               err = ip_fragment(sk, segs, ip_finish_output2);
+               err = ip_fragment(sk, segs, mtu, ip_finish_output2);
 
                if (err && ret == 0)
                        ret = err;
@@ -263,6 +265,8 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb)
 
 static int ip_finish_output(struct sock *sk, struct sk_buff *skb)
 {
+       unsigned int mtu;
+
 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
        /* Policy lookup after SNAT yielded a new policy */
        if (skb_dst(skb)->xfrm) {
@@ -270,11 +274,12 @@ static int ip_finish_output(struct sock *sk, struct sk_buff *skb)
                return dst_output_sk(sk, skb);
        }
 #endif
+       mtu = ip_skb_dst_mtu(skb);
        if (skb_is_gso(skb))
-               return ip_finish_output_gso(sk, skb);
+               return ip_finish_output_gso(sk, skb, mtu);
 
-       if (skb->len > ip_skb_dst_mtu(skb))
-               return ip_fragment(sk, skb, ip_finish_output2);
+       if (skb->len > mtu || (IPCB(skb)->flags & IPSKB_FRAG_PMTU))
+               return ip_fragment(sk, skb, mtu, ip_finish_output2);
 
        return ip_finish_output2(sk, skb);
 }
@@ -482,12 +487,15 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 }
 
 static int ip_fragment(struct sock *sk, struct sk_buff *skb,
+                      unsigned int mtu,
                       int (*output)(struct sock *, struct sk_buff *))
 {
        struct iphdr *iph = ip_hdr(skb);
-       unsigned int mtu = ip_skb_dst_mtu(skb);
 
-       if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
+       if ((iph->frag_off & htons(IP_DF)) == 0)
+               return ip_do_fragment(sk, skb, output);
+
+       if (unlikely(!skb->ignore_df ||
                     (IPCB(skb)->frag_max_size &&
                      IPCB(skb)->frag_max_size > mtu))) {
                struct rtable *rt = skb_rtable(skb);
@@ -532,6 +540,8 @@ int ip_do_fragment(struct sock *sk, struct sk_buff *skb,
        iph = ip_hdr(skb);
 
        mtu = ip_skb_dst_mtu(skb);
+       if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu)
+               mtu = IPCB(skb)->frag_max_size;
 
        /*
         *      Setup starting values.
@@ -539,10 +549,6 @@ int ip_do_fragment(struct sock *sk, struct sk_buff *skb,
 
        hlen = iph->ihl * 4;
        mtu = mtu - hlen;       /* Size of data space */
-#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-       if (skb->nf_bridge)
-               mtu -= nf_bridge_mtu_reduction(skb);
-#endif
        IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE;
 
        /* When frag_list is given, use it. First, check its validity:
@@ -727,6 +733,9 @@ slow_path:
                iph = ip_hdr(skb2);
                iph->frag_off = htons((offset >> 3));
 
+               if (IPCB(skb)->flags & IPSKB_FRAG_PMTU)
+                       iph->frag_off |= htons(IP_DF);
+
                /* ANK: dirty, but effective trick. Upgrade options only if
                 * the segment to be fragmented was THE FIRST (otherwise,
                 * options are already fixed) and make it ONCE
@@ -1233,11 +1242,9 @@ ssize_t  ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
        }
 
        while (size > 0) {
-               int i;
-
-               if (skb_is_gso(skb))
+               if (skb_is_gso(skb)) {
                        len = size;
-               else {
+               } else {
 
                        /* Check if the remaining data fits into current packet. */
                        len = mtu - skb->len;
@@ -1289,15 +1296,10 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
                        continue;
                }
 
-               i = skb_shinfo(skb)->nr_frags;
                if (len > size)
                        len = size;
-               if (skb_can_coalesce(skb, i, page, offset)) {
-                       skb_frag_size_add(&skb_shinfo(skb)->frags[i-1], len);
-               } else if (i < MAX_SKB_FRAGS) {
-                       get_page(page);
-                       skb_fill_page_desc(skb, i, page, offset, len);
-               } else {
+
+               if (skb_append_pagefrags(skb, page, offset, len)) {
                        err = -EMSGSIZE;
                        goto error;
                }