skbuff: Function to send an skbuf on a socket
Add skb_send_sock to send an skbuff on a socket within the kernel.
Arguments include an offset so that an skbuf might be sent in mulitple
calls (e.g. send buffer limit is hit).
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c27da51..9c0e015 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1982,6 +1982,107 @@ int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
}
EXPORT_SYMBOL_GPL(skb_splice_bits);
+/* Send skb data on a socket. Socket must be locked. */
+int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
+ int len)
+{
+ unsigned int orig_len = len;
+ struct sk_buff *head = skb;
+ unsigned short fragidx;
+ int slen, ret;
+
+do_frag_list:
+
+ /* Deal with head data */
+ while (offset < skb_headlen(skb) && len) {
+ struct kvec kv;
+ struct msghdr msg;
+
+ slen = min_t(int, len, skb_headlen(skb) - offset);
+ kv.iov_base = skb->data + offset;
+ kv.iov_len = len;
+ memset(&msg, 0, sizeof(msg));
+
+ ret = kernel_sendmsg_locked(sk, &msg, &kv, 1, slen);
+ if (ret <= 0)
+ goto error;
+
+ offset += ret;
+ len -= ret;
+ }
+
+ /* All the data was skb head? */
+ if (!len)
+ goto out;
+
+ /* Make offset relative to start of frags */
+ offset -= skb_headlen(skb);
+
+ /* Find where we are in frag list */
+ for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx];
+
+ if (offset < frag->size)
+ break;
+
+ offset -= frag->size;
+ }
+
+ for (; len && fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx];
+
+ slen = min_t(size_t, len, frag->size - offset);
+
+ while (slen) {
+ ret = kernel_sendpage_locked(sk, frag->page.p,
+ frag->page_offset + offset,
+ slen, MSG_DONTWAIT);
+ if (ret <= 0)
+ goto error;
+
+ len -= ret;
+ offset += ret;
+ slen -= ret;
+ }
+
+ offset = 0;
+ }
+
+ if (len) {
+ /* Process any frag lists */
+
+ if (skb == head) {
+ if (skb_has_frag_list(skb)) {
+ skb = skb_shinfo(skb)->frag_list;
+ goto do_frag_list;
+ }
+ } else if (skb->next) {
+ skb = skb->next;
+ goto do_frag_list;
+ }
+ }
+
+out:
+ return orig_len - len;
+
+error:
+ return orig_len == len ? ret : orig_len - len;
+}
+EXPORT_SYMBOL_GPL(skb_send_sock_locked);
+
+/* Send skb data on a socket. */
+int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len)
+{
+ int ret = 0;
+
+ lock_sock(sk);
+ ret = skb_send_sock_locked(sk, skb, offset, len);
+ release_sock(sk);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(skb_send_sock);
+
/**
* skb_store_bits - store bits from kernel buffer to skb
* @skb: destination buffer