/**
* tipc_msg_reverse(): swap source and destination addresses and add error code
* @buf: buffer containing message to be reversed
* @dnode: return value: node where to send message after reversal
* @err: error code to be set in message
* Consumes buffer if failure
* Returns true if success, otherwise false
*/
bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err)
{
struct tipc_msg *msg = buf_msg(buf);
uint imp = msg_importance(msg);
struct tipc_msg ohdr;
uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE);
if (skb_linearize(buf))
goto exit;
if (msg_dest_droppable(msg))
goto exit;
if (msg_errcode(msg))
goto exit;
memcpy(&ohdr, msg, msg_hdr_sz(msg));
imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE);
if (msg_isdata(msg))
msg_set_importance(msg, imp);
msg_set_errcode(msg, err);
msg_set_origport(msg, msg_destport(&ohdr));
msg_set_destport(msg, msg_origport(&ohdr));
msg_set_prevnode(msg, tipc_own_addr);
if (!msg_short(msg)) {
msg_set_orignode(msg, msg_destnode(&ohdr));
msg_set_destnode(msg, msg_orignode(&ohdr));
}
msg_set_size(msg, msg_hdr_sz(msg) + rdsz);
skb_trim(buf, msg_size(msg));
skb_orphan(buf);
*dnode = msg_orignode(&ohdr);
return true;
exit:
kfree_skb(buf);
return false;
}
/**
* tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
* @list: the buffer chain of the existing buffer ("bundle")
* @skb: buffer to be appended
* @mtu: max allowable size for the bundle buffer
* Consumes buffer if successful
* Returns true if bundling could be performed, otherwise false
*/
bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu)
{
struct sk_buff *bskb = skb_peek_tail(list);
struct tipc_msg *bmsg = buf_msg(bskb);
struct tipc_msg *msg = buf_msg(skb);
unsigned int bsz = msg_size(bmsg);
unsigned int msz = msg_size(msg);
u32 start = align(bsz);
u32 max = mtu - INT_H_SIZE;
u32 pad = start - bsz;
if (likely(msg_user(msg) == MSG_FRAGMENTER))
return false;
if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
return false;
if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
return false;
if (likely(msg_user(bmsg) != MSG_BUNDLER))
return false;
if (likely(!TIPC_SKB_CB(bskb)->bundling))
return false;
if (unlikely(skb_tailroom(bskb) < (pad + msz)))
return false;
if (unlikely(max < (start + msz)))
return false;
skb_put(bskb, pad + msz);
skb_copy_to_linear_data_offset(bskb, start, skb->data, msz);
msg_set_size(bmsg, start + msz);
msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
kfree_skb(skb);
return true;
}
/**
* tipc_msg_build - create message using specified header and data
*
* Note: Caller must not hold any locks in case copy_from_user() is interrupted!
*
* Returns message data size or errno
*/
int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
unsigned int len, int max_size, struct sk_buff **buf)
{
int dsz, sz, hsz;
unsigned char *to;
dsz = len;
hsz = msg_hdr_sz(hdr);
sz = hsz + dsz;
msg_set_size(hdr, sz);
if (unlikely(sz > max_size)) {
*buf = NULL;
return dsz;
}
*buf = tipc_buf_acquire(sz);
if (!(*buf))
return -ENOMEM;
skb_copy_to_linear_data(*buf, hdr, hsz);
to = (*buf)->data + hsz;
if (len && memcpy_fromiovecend(to, msg_sect, 0, dsz)) {
kfree_skb(*buf);
*buf = NULL;
return -EFAULT;
}
return dsz;
}
void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type,
u32 hsize, u32 destnode)
{
memset(m, 0, hsize);
msg_set_version(m);
msg_set_user(m, user);
msg_set_hdr_sz(m, hsize);
msg_set_size(m, hsize);
msg_set_prevnode(m, tipc_own_addr);
msg_set_type(m, type);
msg_set_orignode(m, tipc_own_addr);
msg_set_destnode(m, destnode);
}
int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
u32 num_sect, unsigned int total_len,
int max_size, int usrmem, struct sk_buff **buf)
{
int dsz, sz, hsz, pos, res, cnt;
dsz = total_len;
pos = hsz = msg_hdr_sz(hdr);
sz = hsz + dsz;
msg_set_size(hdr, sz);
if (unlikely(sz > max_size)) {
*buf = NULL;
return dsz;
}
*buf = tipc_buf_acquire(sz);
if (!(*buf))
return -ENOMEM;
skb_copy_to_linear_data(*buf, hdr, hsz);
for (res = 1, cnt = 0; res && (cnt < num_sect); cnt++) {
if (likely(usrmem))
res = !copy_from_user((*buf)->data + pos,
msg_sect[cnt].iov_base,
msg_sect[cnt].iov_len);
else
skb_copy_to_linear_data_offset(*buf, pos,
msg_sect[cnt].iov_base,
msg_sect[cnt].iov_len);
pos += msg_sect[cnt].iov_len;
}
if (likely(res))
return dsz;
buf_discard(*buf);
*buf = NULL;
return -EFAULT;
}
struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
uint data_sz, u32 dnode, u32 onode,
u32 dport, u32 oport, int errcode)
{
struct tipc_msg *msg;
struct sk_buff *buf;
buf = tipc_buf_acquire(hdr_sz + data_sz);
if (unlikely(!buf))
return NULL;
msg = buf_msg(buf);
tipc_msg_init(msg, user, type, hdr_sz, dnode);
msg_set_size(msg, hdr_sz + data_sz);
msg_set_prevnode(msg, onode);
msg_set_origport(msg, oport);
msg_set_destport(msg, dport);
msg_set_errcode(msg, errcode);
if (hdr_sz > SHORT_H_SIZE) {
msg_set_orignode(msg, onode);
msg_set_destnode(msg, dnode);
}
return buf;
}
/**
* tipc_msg_build - create buffer chain containing specified header and data
* @mhdr: Message header, to be prepended to data
* @m: User message
* @offset: Posision in iov to start copying from
* @dsz: Total length of user data
* @pktmax: Max packet size that can be used
* @list: Buffer or chain of buffers to be returned to caller
*
* Returns message data size or errno: -ENOMEM, -EFAULT
*/
int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
int dsz, int pktmax, struct sk_buff_head *list)
{
int mhsz = msg_hdr_sz(mhdr);
int msz = mhsz + dsz;
int pktno = 1;
int pktsz;
int pktrem = pktmax;
int drem = dsz;
struct tipc_msg pkthdr;
struct sk_buff *skb;
char *pktpos;
int rc;
msg_set_size(mhdr, msz);
/* No fragmentation needed? */
if (likely(msz <= pktmax)) {
skb = tipc_buf_acquire(msz);
if (unlikely(!skb))
return -ENOMEM;
__skb_queue_tail(list, skb);
skb_copy_to_linear_data(skb, mhdr, mhsz);
pktpos = skb->data + mhsz;
if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset,
dsz))
return dsz;
rc = -EFAULT;
goto error;
}
/* Prepare reusable fragment header */
tipc_msg_init(&pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
INT_H_SIZE, msg_destnode(mhdr));
msg_set_size(&pkthdr, pktmax);
msg_set_fragm_no(&pkthdr, pktno);
/* Prepare first fragment */
skb = tipc_buf_acquire(pktmax);
if (!skb)
return -ENOMEM;
__skb_queue_tail(list, skb);
pktpos = skb->data;
skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
pktpos += INT_H_SIZE;
pktrem -= INT_H_SIZE;
skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
pktpos += mhsz;
pktrem -= mhsz;
do {
if (drem < pktrem)
pktrem = drem;
if (memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset, pktrem)) {
rc = -EFAULT;
goto error;
}
drem -= pktrem;
offset += pktrem;
if (!drem)
break;
/* Prepare new fragment: */
if (drem < (pktmax - INT_H_SIZE))
pktsz = drem + INT_H_SIZE;
else
pktsz = pktmax;
skb = tipc_buf_acquire(pktsz);
if (!skb) {
rc = -ENOMEM;
goto error;
}
__skb_queue_tail(list, skb);
msg_set_type(&pkthdr, FRAGMENT);
msg_set_size(&pkthdr, pktsz);
msg_set_fragm_no(&pkthdr, ++pktno);
skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
pktpos = skb->data + INT_H_SIZE;
pktrem = pktsz - INT_H_SIZE;
} while (1);
msg_set_type(buf_msg(skb), LAST_FRAGMENT);
return dsz;
error:
__skb_queue_purge(list);
__skb_queue_head_init(list);
return rc;
}
