diff options
Diffstat (limited to 'net/tipc/msg.c')
| -rw-r--r-- | net/tipc/msg.c | 55 |
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; +} |