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Diffstat (limited to 'net/ipv4/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c88
1 files changed, 53 insertions, 35 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index c65b93a7b711..6bf89a6312bc 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -83,6 +83,10 @@
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. */
void ip_send_check(struct iphdr *iph)
{
@@ -91,7 +95,7 @@ void ip_send_check(struct iphdr *iph)
}
EXPORT_SYMBOL(ip_send_check);
-int __ip_local_out_sk(struct sock *sk, struct sk_buff *skb)
+static int __ip_local_out_sk(struct sock *sk, struct sk_buff *skb)
{
struct iphdr *iph = ip_hdr(skb);
@@ -168,7 +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;
@@ -216,7 +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;
@@ -224,7 +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.
@@ -248,7 +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;
@@ -260,6 +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) {
@@ -267,11 +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);
}
@@ -478,6 +486,31 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
skb_copy_secmark(to, 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);
+
+ 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);
+ struct net_device *dev = rt->dst.dev;
+
+ IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(mtu));
+ kfree_skb(skb);
+ return -EMSGSIZE;
+ }
+
+ return ip_do_fragment(sk, skb, output);
+}
+
/*
* This IP datagram is too large to be sent in one piece. Break it up into
* smaller pieces (each of size equal to IP header plus
@@ -485,8 +518,8 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
* single device frame, and queue such a frame for sending.
*/
-int ip_fragment(struct sock *sk, struct sk_buff *skb,
- int (*output)(struct sock *, struct sk_buff *))
+int ip_do_fragment(struct sock *sk, struct sk_buff *skb,
+ int (*output)(struct sock *, struct sk_buff *))
{
struct iphdr *iph;
int ptr;
@@ -507,15 +540,8 @@ int ip_fragment(struct sock *sk, struct sk_buff *skb,
iph = ip_hdr(skb);
mtu = ip_skb_dst_mtu(skb);
- if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
- (IPCB(skb)->frag_max_size &&
- IPCB(skb)->frag_max_size > mtu))) {
- IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
- icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
- htonl(mtu));
- kfree_skb(skb);
- return -EMSGSIZE;
- }
+ if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu)
+ mtu = IPCB(skb)->frag_max_size;
/*
* Setup starting values.
@@ -523,10 +549,6 @@ int ip_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:
@@ -711,6 +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
@@ -751,7 +776,7 @@ fail:
IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
return err;
}
-EXPORT_SYMBOL(ip_fragment);
+EXPORT_SYMBOL(ip_do_fragment);
int
ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
@@ -1217,11 +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;
@@ -1273,15 +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;
}
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-25 03:04:39 +0000