*
* The `hlen` as calculated by skb_zerocopy_headlen() specifies the
* headroom in the `to` buffer.
+ *
+ * Return value:
+ * 0: everything is OK
+ * -ENOMEM: couldn't orphan frags of @from due to lack of memory
+ * -EFAULT: skb_copy_bits() found some problem with skb geometry
*/
-void
-skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
+int
+skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{
int i, j = 0;
int plen = 0; /* length of skb->head fragment */
+ int ret;
struct page *page;
unsigned int offset;
BUG_ON(!from->head_frag && !hlen);
/* dont bother with small payloads */
- if (len <= skb_tailroom(to)) {
- skb_copy_bits(from, 0, skb_put(to, len), len);
- return;
- }
+ if (len <= skb_tailroom(to))
+ return skb_copy_bits(from, 0, skb_put(to, len), len);
if (hlen) {
- skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+ ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+ if (unlikely(ret))
+ return ret;
len -= hlen;
} else {
plen = min_t(int, skb_headlen(from), len);
to->len += len + plen;
to->data_len += len + plen;
+ if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
+ skb_tx_error(from);
+ return -ENOMEM;
+ }
+
for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
if (!len)
break;
j++;
}
skb_shinfo(to)->nr_frags = j;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(skb_zerocopy);
int err = -ENOMEM;
int i = 0;
int pos;
+ int dummy;
- proto = skb_network_protocol(head_skb);
+ proto = skb_network_protocol(head_skb, &dummy);
if (unlikely(!proto))
return ERR_PTR(-EINVAL);
return elt;
}
+/* As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given
+ * sglist without mark the sg which contain last skb data as the end.
+ * So the caller can mannipulate sg list as will when padding new data after
+ * the first call without calling sg_unmark_end to expend sg list.
+ *
+ * Scenario to use skb_to_sgvec_nomark:
+ * 1. sg_init_table
+ * 2. skb_to_sgvec_nomark(payload1)
+ * 3. skb_to_sgvec_nomark(payload2)
+ *
+ * This is equivalent to:
+ * 1. sg_init_table
+ * 2. skb_to_sgvec(payload1)
+ * 3. sg_unmark_end
+ * 4. skb_to_sgvec(payload2)
+ *
+ * When mapping mutilple payload conditionally, skb_to_sgvec_nomark
+ * is more preferable.
+ */
+int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
+ int offset, int len)
+{
+ return __skb_to_sgvec(skb, sg, offset, len);
+}
+EXPORT_SYMBOL_GPL(skb_to_sgvec_nomark);
+
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
{
int nsg = __skb_to_sgvec(skb, sg, offset, len);
return 0;
}
+#define MAX_TCP_HDR_LEN (15 * 4)
+
+static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb,
+ typeof(IPPROTO_IP) proto,
+ unsigned int off)
+{
+ switch (proto) {
+ int err;
+
+ case IPPROTO_TCP:
+ err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr),
+ off + MAX_TCP_HDR_LEN);
+ if (!err && !skb_partial_csum_set(skb, off,
+ offsetof(struct tcphdr,
+ check)))
+ err = -EPROTO;
+ return err ? ERR_PTR(err) : &tcp_hdr(skb)->check;
+
+ case IPPROTO_UDP:
+ err = skb_maybe_pull_tail(skb, off + sizeof(struct udphdr),
+ off + sizeof(struct udphdr));
+ if (!err && !skb_partial_csum_set(skb, off,
+ offsetof(struct udphdr,
+ check)))
+ err = -EPROTO;
+ return err ? ERR_PTR(err) : &udp_hdr(skb)->check;
+ }
+
+ return ERR_PTR(-EPROTO);
+}
+
/* This value should be large enough to cover a tagged ethernet header plus
* maximally sized IP and TCP or UDP headers.
*/
#define MAX_IP_HDR_LEN 128
-static int skb_checksum_setup_ip(struct sk_buff *skb, bool recalculate)
+static int skb_checksum_setup_ipv4(struct sk_buff *skb, bool recalculate)
{
unsigned int off;
bool fragment;
+ __sum16 *csum;
int err;
fragment = false;
if (fragment)
goto out;
- switch (ip_hdr(skb)->protocol) {
- case IPPROTO_TCP:
- err = skb_maybe_pull_tail(skb,
- off + sizeof(struct tcphdr),
- MAX_IP_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct tcphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate)
- tcp_hdr(skb)->check =
- ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_TCP, 0);
- break;
- case IPPROTO_UDP:
- err = skb_maybe_pull_tail(skb,
- off + sizeof(struct udphdr),
- MAX_IP_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct udphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate)
- udp_hdr(skb)->check =
- ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_UDP, 0);
- break;
- default:
- goto out;
- }
+ csum = skb_checksum_setup_ip(skb, ip_hdr(skb)->protocol, off);
+ if (IS_ERR(csum))
+ return PTR_ERR(csum);
+ if (recalculate)
+ *csum = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
+ ip_hdr(skb)->daddr,
+ skb->len - off,
+ ip_hdr(skb)->protocol, 0);
err = 0;
out:
unsigned int len;
bool fragment;
bool done;
+ __sum16 *csum;
fragment = false;
done = false;
if (!done || fragment)
goto out;
- switch (nexthdr) {
- case IPPROTO_TCP:
- err = skb_maybe_pull_tail(skb,
- off + sizeof(struct tcphdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct tcphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate)
- tcp_hdr(skb)->check =
- ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_TCP, 0);
- break;
- case IPPROTO_UDP:
- err = skb_maybe_pull_tail(skb,
- off + sizeof(struct udphdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct udphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate)
- udp_hdr(skb)->check =
- ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_UDP, 0);
- break;
- default:
- goto out;
- }
+ csum = skb_checksum_setup_ip(skb, nexthdr, off);
+ if (IS_ERR(csum))
+ return PTR_ERR(csum);
+ if (recalculate)
+ *csum = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr,
+ skb->len - off, nexthdr, 0);
err = 0;
out:
switch (skb->protocol) {
case htons(ETH_P_IP):
- err = skb_checksum_setup_ip(skb, recalculate);
+ err = skb_checksum_setup_ipv4(skb, recalculate);
break;
case htons(ETH_P_IPV6):
unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
{
const struct skb_shared_info *shinfo = skb_shinfo(skb);
- unsigned int hdr_len;
if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
- hdr_len = tcp_hdrlen(skb);
- else
- hdr_len = sizeof(struct udphdr);
- return hdr_len + shinfo->gso_size;
+ return tcp_hdrlen(skb) + shinfo->gso_size;
+
+ /* UFO sets gso_size to the size of the fragmentation
+ * payload, i.e. the size of the L4 (UDP) header is already
+ * accounted for.
+ */
+ return shinfo->gso_size;
}
EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
projects / firefly-linux-kernel-4.4.55.git / blobdiff