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-rw-r--r--net/tipc/msg.c55
1 files changed, 54 insertions, 1 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index e525f8ce1dee..8be6e94a1ca9 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -1,7 +1,7 @@
/*
* net/tipc/msg.c: TIPC message header routines
*
- * Copyright (c) 2000-2006, Ericsson AB
+ * Copyright (c) 2000-2006, 2014, Ericsson AB
* Copyright (c) 2005, 2010-2011, Wind River Systems
* All rights reserved.
*
@@ -99,3 +99,56 @@ int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
}
return dsz;
}
+
+/* tipc_buf_append(): Append a buffer to the fragment list of another buffer
+ * Let first buffer become head buffer
+ * Returns 1 and sets *buf to headbuf if chain is complete, otherwise 0
+ * Leaves headbuf pointer at NULL if failure
+ */
+int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
+{
+ struct sk_buff *head = *headbuf;
+ struct sk_buff *frag = *buf;
+ struct sk_buff *tail;
+ struct tipc_msg *msg = buf_msg(frag);
+ u32 fragid = msg_type(msg);
+ bool headstolen;
+ int delta;
+
+ skb_pull(frag, msg_hdr_sz(msg));
+
+ if (fragid == FIRST_FRAGMENT) {
+ if (head || skb_unclone(frag, GFP_ATOMIC))
+ goto out_free;
+ head = *headbuf = frag;
+ skb_frag_list_init(head);
+ return 0;
+ }
+ if (!head)
+ goto out_free;
+ tail = TIPC_SKB_CB(head)->tail;
+ if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
+ kfree_skb_partial(frag, headstolen);
+ } else {
+ if (!skb_has_frag_list(head))
+ skb_shinfo(head)->frag_list = frag;
+ else
+ tail->next = frag;
+ head->truesize += frag->truesize;
+ head->data_len += frag->len;
+ head->len += frag->len;
+ TIPC_SKB_CB(head)->tail = frag;
+ }
+ if (fragid == LAST_FRAGMENT) {
+ *buf = head;
+ TIPC_SKB_CB(head)->tail = NULL;
+ *headbuf = NULL;
+ return 1;
+ }
+ *buf = NULL;
+ return 0;
+out_free:
+ pr_warn_ratelimited("Unable to build fragment list\n");
+ kfree_skb(*buf);
+ return 0;
+}