2 * net/tipc/msg.c: TIPC message header routines
4 * Copyright (c) 2000-2006, 2014, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
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21 * GNU General Public License ("GPL") version 2 as published by the Free
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40 static unsigned int align(unsigned int i)
45 void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
50 msg_set_user(m, user);
51 msg_set_hdr_sz(m, hsize);
52 msg_set_size(m, hsize);
53 msg_set_prevnode(m, tipc_own_addr);
54 msg_set_type(m, type);
55 msg_set_orignode(m, tipc_own_addr);
56 msg_set_destnode(m, destnode);
60 * tipc_msg_build - create message using specified header and data
62 * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
64 * Returns message data size or errno
66 int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
67 unsigned int len, int max_size, struct sk_buff **buf)
73 hsz = msg_hdr_sz(hdr);
75 msg_set_size(hdr, sz);
76 if (unlikely(sz > max_size)) {
81 *buf = tipc_buf_acquire(sz);
84 skb_copy_to_linear_data(*buf, hdr, hsz);
85 to = (*buf)->data + hsz;
86 if (len && memcpy_fromiovecend(to, msg_sect, 0, dsz)) {
94 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
95 * Let first buffer become head buffer
96 * Returns 1 and sets *buf to headbuf if chain is complete, otherwise 0
97 * Leaves headbuf pointer at NULL if failure
99 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
101 struct sk_buff *head = *headbuf;
102 struct sk_buff *frag = *buf;
103 struct sk_buff *tail;
104 struct tipc_msg *msg = buf_msg(frag);
105 u32 fragid = msg_type(msg);
109 skb_pull(frag, msg_hdr_sz(msg));
111 if (fragid == FIRST_FRAGMENT) {
112 if (head || skb_unclone(frag, GFP_ATOMIC))
114 head = *headbuf = frag;
115 skb_frag_list_init(head);
120 tail = TIPC_SKB_CB(head)->tail;
121 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
122 kfree_skb_partial(frag, headstolen);
124 if (!skb_has_frag_list(head))
125 skb_shinfo(head)->frag_list = frag;
128 head->truesize += frag->truesize;
129 head->data_len += frag->len;
130 head->len += frag->len;
131 TIPC_SKB_CB(head)->tail = frag;
133 if (fragid == LAST_FRAGMENT) {
135 TIPC_SKB_CB(head)->tail = NULL;
142 pr_warn_ratelimited("Unable to build fragment list\n");
148 * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
149 * @bbuf: the existing buffer ("bundle")
150 * @buf: buffer to be appended
151 * @mtu: max allowable size for the bundle buffer
152 * Consumes buffer if successful
153 * Returns true if bundling could be performed, otherwise false
155 bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
157 struct tipc_msg *bmsg = buf_msg(bbuf);
158 struct tipc_msg *msg = buf_msg(buf);
159 unsigned int bsz = msg_size(bmsg);
160 unsigned int msz = msg_size(msg);
161 u32 start = align(bsz);
162 u32 max = mtu - INT_H_SIZE;
163 u32 pad = start - bsz;
165 if (likely(msg_user(msg) == MSG_FRAGMENTER))
167 if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
169 if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
171 if (likely(msg_user(bmsg) != MSG_BUNDLER))
173 if (likely(msg_type(bmsg) != BUNDLE_OPEN))
175 if (unlikely(skb_tailroom(bbuf) < (pad + msz)))
177 if (unlikely(max < (start + msz)))
180 skb_put(bbuf, pad + msz);
181 skb_copy_to_linear_data_offset(bbuf, start, buf->data, msz);
182 msg_set_size(bmsg, start + msz);
183 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
184 bbuf->next = buf->next;
190 * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
191 * @buf: buffer to be appended and replaced
192 * @mtu: max allowable size for the bundle buffer, inclusive header
193 * @dnode: destination node for message. (Not always present in header)
194 * Replaces buffer if successful
195 * Returns true if sucess, otherwise false
197 bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
199 struct sk_buff *bbuf;
200 struct tipc_msg *bmsg;
201 struct tipc_msg *msg = buf_msg(*buf);
202 u32 msz = msg_size(msg);
203 u32 max = mtu - INT_H_SIZE;
205 if (msg_user(msg) == MSG_FRAGMENTER)
207 if (msg_user(msg) == CHANGEOVER_PROTOCOL)
209 if (msg_user(msg) == BCAST_PROTOCOL)
214 bbuf = tipc_buf_acquire(max);
218 skb_trim(bbuf, INT_H_SIZE);
219 bmsg = buf_msg(bbuf);
220 tipc_msg_init(bmsg, MSG_BUNDLER, BUNDLE_OPEN, INT_H_SIZE, dnode);
221 msg_set_seqno(bmsg, msg_seqno(msg));
222 msg_set_ack(bmsg, msg_ack(msg));
223 msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
224 bbuf->next = (*buf)->next;
225 tipc_msg_bundle(bbuf, *buf, mtu);